diff --git a/audio/common/all-versions/default/OWNERS b/audio/common/all-versions/default/OWNERS
index 6fdc97c..24071af 100644
--- a/audio/common/all-versions/default/OWNERS
+++ b/audio/common/all-versions/default/OWNERS
@@ -1,3 +1,2 @@
 elaurent@google.com
-krocard@google.com
 mnaganov@google.com
diff --git a/automotive/can/1.0/default/libnl++/Android.bp b/automotive/can/1.0/default/libnl++/Android.bp
index 790adcd..2ebd1b4 100644
--- a/automotive/can/1.0/default/libnl++/Android.bp
+++ b/automotive/can/1.0/default/libnl++/Android.bp
@@ -35,6 +35,7 @@
         "protocols/generic/Generic.cpp",
         "protocols/generic/GenericMessageBase.cpp",
         "protocols/generic/Unknown.cpp",
+        "protocols/generic/families/Mac80211hwsim.cpp",
         "protocols/generic/families/Nl80211.cpp",
         "protocols/route/Link.cpp",
         "protocols/route/Route.cpp",
@@ -42,6 +43,7 @@
         "protocols/MessageDefinition.cpp",
         "protocols/NetlinkProtocol.cpp",
         "protocols/all.cpp",
+        "protocols/structs.cpp",
         "Attributes.cpp",
         "MessageFactory.cpp",
         "MessageMutator.cpp",
diff --git a/automotive/can/1.0/default/libnl++/MessageMutator.cpp b/automotive/can/1.0/default/libnl++/MessageMutator.cpp
index 00b48a6..de2a2b1 100644
--- a/automotive/can/1.0/default/libnl++/MessageMutator.cpp
+++ b/automotive/can/1.0/default/libnl++/MessageMutator.cpp
@@ -19,7 +19,7 @@
 namespace android::nl {
 
 MessageMutator::MessageMutator(nlmsghdr* buffer, size_t totalLen)
-    : mConstBuffer(buffer, totalLen), mMutableBuffer(buffer) {
+    : mMutableBuffer(buffer), mTotalLen(totalLen) {
     CHECK(totalLen >= sizeof(nlmsghdr));
 }
 
@@ -27,8 +27,12 @@
     return mMutableBuffer;
 }
 
+Buffer<nlmsghdr> MessageMutator::constBuffer() const {
+    return {mMutableBuffer, mTotalLen};
+}
+
 MessageMutator::operator Buffer<nlmsghdr>() const {
-    return mConstBuffer;
+    return constBuffer();
 }
 
 uint64_t MessageMutator::read(Buffer<nlattr> attr) const {
@@ -37,7 +41,8 @@
 
 void MessageMutator::write(Buffer<nlattr> attr, uint64_t val) const {
     const auto attrData = attr.data<uint64_t>();
-    const auto offset = mConstBuffer.getOffset(attrData);
+    // TODO(b/177251183): deduplicate this code against fragment()
+    const auto offset = constBuffer().getOffset(attrData);
     CHECK(offset.has_value()) << "Trying to write attribute that's not a member of this message";
 
     const auto writeableBuffer = reinterpret_cast<uint8_t*>(mMutableBuffer) + *offset;
@@ -47,4 +52,40 @@
     memcpy(writeableBuffer, &val, std::min(sizeof(val), attrSize));
 }
 
+MessageMutator MessageMutator::fragment(Buffer<nlmsghdr> buf) const {
+    const auto offset = constBuffer().getOffset(buf);
+    CHECK(offset.has_value()) << "Trying to modify a fragment outside of buffer range";
+
+    const auto writeableBuffer = reinterpret_cast<nlmsghdr*>(uintptr_t(mMutableBuffer) + *offset);
+    const auto len = buf.getRaw().len();
+    CHECK(len <= mTotalLen - *offset);
+
+    return {writeableBuffer, len};
+}
+
+MessageMutator::iterator MessageMutator::begin() const {
+    return {*this, constBuffer().begin()};
+}
+
+MessageMutator::iterator MessageMutator::end() const {
+    return {*this, constBuffer().end()};
+}
+
+MessageMutator::iterator::iterator(const MessageMutator& container,
+                                   Buffer<nlmsghdr>::iterator current)
+    : mContainer(container), mCurrent(current) {}
+
+MessageMutator::iterator MessageMutator::iterator::operator++() {
+    ++mCurrent;
+    return *this;
+}
+
+bool MessageMutator::iterator::operator==(const iterator& other) const {
+    return other.mCurrent == mCurrent;
+}
+
+const MessageMutator MessageMutator::iterator::operator*() const {
+    return mContainer.fragment(*mCurrent);
+}
+
 }  // namespace android::nl
diff --git a/automotive/can/1.0/default/libnl++/include/libnl++/Buffer.h b/automotive/can/1.0/default/libnl++/include/libnl++/Buffer.h
index d759a0a..4cabb9a 100644
--- a/automotive/can/1.0/default/libnl++/include/libnl++/Buffer.h
+++ b/automotive/can/1.0/default/libnl++/include/libnl++/Buffer.h
@@ -138,7 +138,7 @@
     class raw_iterator : public iterator {
       public:
         iterator operator++() {
-            this->mCurrent.mData++;  // ignore alignment
+            ++this->mCurrent.mData;  // ignore alignment
             return *this;
         }
         const T& operator*() const { return *this->mCurrent.mData; }
diff --git a/automotive/can/1.0/default/libnl++/include/libnl++/Message.h b/automotive/can/1.0/default/libnl++/include/libnl++/Message.h
index 50b3c4b..29f397d 100644
--- a/automotive/can/1.0/default/libnl++/include/libnl++/Message.h
+++ b/automotive/can/1.0/default/libnl++/include/libnl++/Message.h
@@ -34,7 +34,7 @@
  * a single instance can only be used by a single thread - the one owning the underlying buffer).
  */
 template <typename T>
-class Message {
+class Message : public Buffer<nlmsghdr> {
   public:
     /**
      * Validate buffer contents as a message carrying T data and create instance of parsed message.
@@ -51,7 +51,7 @@
 
         const auto attributes = buf.data<nlattr>(sizeof(T));
 
-        return Message<T>(nlHeader, dataHeader, attributes);
+        return Message<T>(buf, nlHeader, dataHeader, attributes);
     }
 
     /**
@@ -94,8 +94,9 @@
     const T* operator->() const { return &data; }
 
   private:
-    Message(const nlmsghdr& nlHeader, const T& dataHeader, Attributes attributes)
-        : header(nlHeader), data(dataHeader), attributes(attributes) {}
+    Message(Buffer<nlmsghdr> buffer, const nlmsghdr& nlHeader, const T& dataHeader,
+            Attributes attributes)
+        : Buffer<nlmsghdr>(buffer), header(nlHeader), data(dataHeader), attributes(attributes) {}
 };
 
 }  // namespace android::nl
diff --git a/automotive/can/1.0/default/libnl++/include/libnl++/MessageMutator.h b/automotive/can/1.0/default/libnl++/include/libnl++/MessageMutator.h
index 7d495e9..baadc44 100644
--- a/automotive/can/1.0/default/libnl++/include/libnl++/MessageMutator.h
+++ b/automotive/can/1.0/default/libnl++/include/libnl++/MessageMutator.h
@@ -53,9 +53,27 @@
      */
     void write(Buffer<nlattr> attr, uint64_t val) const;
 
+    class iterator {
+      public:
+        iterator(const MessageMutator& container, Buffer<nlmsghdr>::iterator current);
+
+        iterator operator++();
+        bool operator==(const iterator& other) const;
+        const MessageMutator operator*() const;
+
+      protected:
+        const MessageMutator& mContainer;
+        Buffer<nlmsghdr>::iterator mCurrent;
+    };
+    iterator begin() const;
+    iterator end() const;
+
   private:
-    const Buffer<nlmsghdr> mConstBuffer;
     nlmsghdr* mMutableBuffer;
+    size_t mTotalLen;
+
+    Buffer<nlmsghdr> constBuffer() const;
+    MessageMutator fragment(Buffer<nlmsghdr> buf) const;
 };
 
 }  // namespace android::nl
diff --git a/automotive/can/1.0/default/libnl++/include/libnl++/generic/families/mac80211_hwsim.h b/automotive/can/1.0/default/libnl++/include/libnl++/generic/families/mac80211_hwsim.h
new file mode 100644
index 0000000..9b811f8
--- /dev/null
+++ b/automotive/can/1.0/default/libnl++/include/libnl++/generic/families/mac80211_hwsim.h
@@ -0,0 +1,73 @@
+/*
+ * Copyright (C) 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+// API definitions from kernel drivers/net/wireless/mac80211_hwsim.h
+
+#define BIT(n) (1 << (n))
+
+enum hwsim_tx_control_flags {
+    HWSIM_TX_CTL_REQ_TX_STATUS = BIT(0),
+    HWSIM_TX_CTL_NO_ACK = BIT(1),
+    HWSIM_TX_STAT_ACK = BIT(2),
+};
+
+enum {
+    HWSIM_CMD_UNSPEC,
+    HWSIM_CMD_REGISTER,
+    HWSIM_CMD_FRAME,
+    HWSIM_CMD_TX_INFO_FRAME,
+    HWSIM_CMD_NEW_RADIO,
+    HWSIM_CMD_DEL_RADIO,
+    HWSIM_CMD_GET_RADIO,
+    HWSIM_CMD_ADD_MAC_ADDR,
+    HWSIM_CMD_DEL_MAC_ADDR,
+};
+
+enum {
+    HWSIM_ATTR_UNSPEC,
+    HWSIM_ATTR_ADDR_RECEIVER,
+    HWSIM_ATTR_ADDR_TRANSMITTER,
+    HWSIM_ATTR_FRAME,
+    HWSIM_ATTR_FLAGS,
+    HWSIM_ATTR_RX_RATE,
+    HWSIM_ATTR_SIGNAL,
+    HWSIM_ATTR_TX_INFO,
+    HWSIM_ATTR_COOKIE,
+    HWSIM_ATTR_CHANNELS,
+    HWSIM_ATTR_RADIO_ID,
+    HWSIM_ATTR_REG_HINT_ALPHA2,
+    HWSIM_ATTR_REG_CUSTOM_REG,
+    HWSIM_ATTR_REG_STRICT_REG,
+    HWSIM_ATTR_SUPPORT_P2P_DEVICE,
+    HWSIM_ATTR_USE_CHANCTX,
+    HWSIM_ATTR_DESTROY_RADIO_ON_CLOSE,
+    HWSIM_ATTR_RADIO_NAME,
+    HWSIM_ATTR_NO_VIF,
+    HWSIM_ATTR_FREQ,
+    HWSIM_ATTR_PAD,
+    HWSIM_ATTR_TX_INFO_FLAGS,
+    HWSIM_ATTR_PERM_ADDR,
+    HWSIM_ATTR_IFTYPE_SUPPORT,
+    HWSIM_ATTR_CIPHER_SUPPORT,
+};
+
+struct hwsim_tx_rate {
+    int8_t idx;
+    uint8_t count;
+} __packed;
+static_assert(sizeof(hwsim_tx_rate) == 2);
+
+#undef BIT
diff --git a/automotive/can/1.0/default/libnl++/printer.cpp b/automotive/can/1.0/default/libnl++/printer.cpp
index f08897e..d540482 100644
--- a/automotive/can/1.0/default/libnl++/printer.cpp
+++ b/automotive/can/1.0/default/libnl++/printer.cpp
@@ -154,16 +154,19 @@
     }
 }
 
-std::string toString(const Buffer<nlmsghdr> hdr, int protocol, bool printPayload) {
-    if (!hdr.firstOk()) return "nlmsg{buffer overflow}";
+static void toStream(std::stringstream& ss, const Buffer<nlmsghdr> hdr, int protocol,
+                     bool printPayload) {
+    if (!hdr.firstOk()) {
+        ss << "nlmsg{buffer overflow}";
+        return;
+    }
 
-    std::stringstream ss;
     ss << std::setfill('0');
 
     auto protocolMaybe = protocols::get(protocol);
     if (!protocolMaybe.has_value()) {
         ss << "nlmsg{protocol=" << protocol << "}";
-        return ss.str();
+        return;
     }
     protocols::NetlinkProtocol& protocolDescr = *protocolMaybe;
 
@@ -187,7 +190,7 @@
     ss << ", crc=" << std::hex << std::setw(4) << crc16(hdr.data<uint8_t>()) << std::dec;
     ss << '}';
 
-    if (!printPayload) return ss.str();
+    if (!printPayload) return;
     ss << ' ';
 
     if (!msgDescMaybe.has_value()) {
@@ -210,6 +213,17 @@
     }
 
     ss << "}";
+}
+
+std::string toString(const Buffer<nlmsghdr> hdrs, int protocol, bool printPayload) {
+    std::stringstream ss;
+    bool first = true;
+    for (const auto hdr : hdrs) {
+        if (!first) ss << std::endl;
+        first = false;
+
+        toStream(ss, hdr, protocol, printPayload);
+    }
 
     return ss.str();
 }
diff --git a/automotive/can/1.0/default/libnl++/protocols/generic/Ctrl.cpp b/automotive/can/1.0/default/libnl++/protocols/generic/Ctrl.cpp
index 1e1ad12..478c383 100644
--- a/automotive/can/1.0/default/libnl++/protocols/generic/Ctrl.cpp
+++ b/automotive/can/1.0/default/libnl++/protocols/generic/Ctrl.cpp
@@ -16,6 +16,7 @@
 
 #include "Ctrl.h"
 
+#include "families/Mac80211hwsim.h"
 #include "families/Nl80211.h"
 
 #include <libnl++/Message.h>
@@ -68,12 +69,15 @@
     const auto familyId = msg.attributes.get<uint16_t>(CTRL_ATTR_FAMILY_ID);
     const auto familyName = msg.attributes.get<std::string>(CTRL_ATTR_FAMILY_NAME);
 
-    /* For now, we support just a single family. But if you add more, please define proper
+    /* For now, we support just two families. But if you add more, please define proper
      * abstraction and not hardcode every name and class here.
      */
     if (familyName == "nl80211") {
         mFamilyRegister[familyId] = std::make_shared<families::Nl80211>(familyId);
     }
+    if (familyName == "MAC80211_HWSIM") {
+        mFamilyRegister[familyId] = std::make_shared<families::Mac80211hwsim>(familyId);
+    }
 }
 
 }  // namespace android::nl::protocols::generic
diff --git a/automotive/can/1.0/default/libnl++/protocols/generic/GenericMessageBase.cpp b/automotive/can/1.0/default/libnl++/protocols/generic/GenericMessageBase.cpp
index b7b811b..f92d6c0 100644
--- a/automotive/can/1.0/default/libnl++/protocols/generic/GenericMessageBase.cpp
+++ b/automotive/can/1.0/default/libnl++/protocols/generic/GenericMessageBase.cpp
@@ -40,9 +40,9 @@
 
     ss << "genlmsghdr{";
     if (commandName.has_value()) {
-        ss << "cmd=" << unsigned(data.cmd);
-    } else {
         ss << "cmd=" << *commandName;
+    } else {
+        ss << "cmd=" << unsigned(data.cmd);
     }
     ss << ", version=" << unsigned(data.version);
     if (data.reserved != 0) ss << ", reserved=" << data.reserved;
diff --git a/automotive/can/1.0/default/libnl++/protocols/generic/families/Mac80211hwsim.cpp b/automotive/can/1.0/default/libnl++/protocols/generic/families/Mac80211hwsim.cpp
new file mode 100644
index 0000000..f85309e
--- /dev/null
+++ b/automotive/can/1.0/default/libnl++/protocols/generic/families/Mac80211hwsim.cpp
@@ -0,0 +1,91 @@
+/*
+ * Copyright (C) 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "Mac80211hwsim.h"
+
+#include "../../structs.h"
+#include "common.h"
+
+#include <libnl++/generic/families/mac80211_hwsim.h>
+
+namespace android::nl::protocols::generic::families {
+
+using DataType = AttributeDefinition::DataType;
+using Flags = AttributeDefinition::Flags;
+
+static void hwsim_tx_rateToStream(std::stringstream& ss, const Buffer<nlattr> attr);
+
+static const FlagsMap txControlFlags{
+        {HWSIM_TX_CTL_REQ_TX_STATUS, "REQ_TX"},
+        {HWSIM_TX_CTL_NO_ACK, "NO_ACK"},
+        {HWSIM_TX_STAT_ACK, "ACK"},
+};
+
+// clang-format off
+Mac80211hwsim::Mac80211hwsim(nlmsgtype_t familyId) : GenericMessageBase(familyId, "hwsim", {
+    {HWSIM_CMD_UNSPEC, "UNSPEC"},
+    {HWSIM_CMD_REGISTER, "REGISTER"},
+    {HWSIM_CMD_FRAME, "FRAME"},
+    {HWSIM_CMD_TX_INFO_FRAME, "TX_INFO_FRAME"},
+    {HWSIM_CMD_NEW_RADIO, "NEW_RADIO"},
+    {HWSIM_CMD_DEL_RADIO, "DEL_RADIO"},
+    {HWSIM_CMD_GET_RADIO, "GET_RADIO"},
+    {HWSIM_CMD_ADD_MAC_ADDR, "ADD_MAC_ADDR"},
+    {HWSIM_CMD_DEL_MAC_ADDR, "DEL_MAC_ADDR"},
+}, {
+    {HWSIM_ATTR_UNSPEC, {"UNSPEC"}},
+    {HWSIM_ATTR_ADDR_RECEIVER, {"ADDR_RECEIVER", DataType::Struct, hwaddrToStream}},
+    {HWSIM_ATTR_ADDR_TRANSMITTER, {"ADDR_TRANSMITTER", DataType::Struct, hwaddrToStream}},
+    {HWSIM_ATTR_FRAME, {"FRAME", DataType::Raw, AttributeMap{}, Flags::Verbose}},
+    {HWSIM_ATTR_FLAGS, {"FLAGS", DataType::Struct, flagsToStream(txControlFlags)}},
+    {HWSIM_ATTR_RX_RATE, {"RX_RATE", DataType::Uint}},
+    {HWSIM_ATTR_SIGNAL, {"SIGNAL", DataType::Uint}},
+    {HWSIM_ATTR_TX_INFO, {"TX_INFO", DataType::Struct, hwsim_tx_rateToStream}},
+    {HWSIM_ATTR_COOKIE, {"COOKIE", DataType::Uint}},
+    {HWSIM_ATTR_CHANNELS, {"CHANNELS", DataType::Uint}},
+    {HWSIM_ATTR_RADIO_ID, {"RADIO_ID", DataType::Uint}},
+    {HWSIM_ATTR_REG_HINT_ALPHA2, {"REG_HINT_ALPHA2", DataType::String}},
+    {HWSIM_ATTR_REG_CUSTOM_REG, {"REG_CUSTOM_REG", DataType::Uint}},
+    {HWSIM_ATTR_REG_STRICT_REG, {"REG_STRICT_REG", DataType::Flag}},
+    {HWSIM_ATTR_SUPPORT_P2P_DEVICE, {"SUPPORT_P2P_DEVICE", DataType::Flag}},
+    {HWSIM_ATTR_USE_CHANCTX, {"USE_CHANCTX", DataType::Flag}},
+    {HWSIM_ATTR_DESTROY_RADIO_ON_CLOSE, {"DESTROY_RADIO_ON_CLOSE", DataType::Flag}},
+    {HWSIM_ATTR_RADIO_NAME, {"RADIO_NAME", DataType::String}},
+    {HWSIM_ATTR_NO_VIF, {"NO_VIF", DataType::Flag}},
+    {HWSIM_ATTR_FREQ, {"FREQ", DataType::Uint}},
+    {HWSIM_ATTR_PAD, {"PAD", DataType::Uint}},
+    {HWSIM_ATTR_TX_INFO_FLAGS, {"TX_INFO_FLAGS"}},  // hwsim_tx_rate_flag
+    {HWSIM_ATTR_PERM_ADDR, {"PERM_ADDR"}},
+    {HWSIM_ATTR_IFTYPE_SUPPORT, {"IFTYPE_SUPPORT", DataType::Uint}},  // NL80211_IFTYPE_STATION etc
+    {HWSIM_ATTR_CIPHER_SUPPORT, {"CIPHER_SUPPORT", DataType::Struct, arrayToStream<int32_t>}},
+}) {}
+// clang-format on
+
+static void hwsim_tx_rateToStream(std::stringstream& ss, const Buffer<nlattr> attr) {
+    ss << '{';
+    bool first = true;
+    for (const auto rate : attr.data<hwsim_tx_rate>().getRaw()) {
+        if (rate.idx == -1) continue;
+
+        ss << (int)rate.idx << ": " << (unsigned)rate.count;
+
+        if (!first) ss << ", ";
+        first = false;
+    }
+    ss << '}';
+}
+
+}  // namespace android::nl::protocols::generic::families
diff --git a/automotive/can/1.0/default/libnl++/protocols/generic/families/Mac80211hwsim.h b/automotive/can/1.0/default/libnl++/protocols/generic/families/Mac80211hwsim.h
new file mode 100644
index 0000000..c01eb93
--- /dev/null
+++ b/automotive/can/1.0/default/libnl++/protocols/generic/families/Mac80211hwsim.h
@@ -0,0 +1,28 @@
+/*
+ * Copyright (C) 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#pragma once
+
+#include "../GenericMessageBase.h"
+
+namespace android::nl::protocols::generic::families {
+
+class Mac80211hwsim : public GenericMessageBase {
+  public:
+    Mac80211hwsim(nlmsgtype_t familyId);
+};
+
+}  // namespace android::nl::protocols::generic::families
diff --git a/automotive/can/1.0/default/libnl++/protocols/structs.cpp b/automotive/can/1.0/default/libnl++/protocols/structs.cpp
new file mode 100644
index 0000000..8ff71f0
--- /dev/null
+++ b/automotive/can/1.0/default/libnl++/protocols/structs.cpp
@@ -0,0 +1,57 @@
+/*
+ * Copyright (C) 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "structs.h"
+
+#include <iomanip>
+
+namespace android::nl::protocols {
+
+AttributeDefinition::ToStream flagsToStream(FlagsMap flags) {
+    return [flags](std::stringstream& ss, const Buffer<nlattr> attr) {
+        auto val = attr.data<uint64_t>().copyFirst();
+
+        bool first = true;
+        for (const auto& [flag, name] : flags) {
+            if ((val & flag) != flag) continue;
+            val &= ~flag;
+
+            if (!first) ss << '|';
+            first = false;
+
+            ss << name;
+        }
+
+        if (val == 0) return;
+
+        if (!first) ss << '|';
+        ss << std::hex << val << std::dec;
+    };
+}
+
+void hwaddrToStream(std::stringstream& ss, const Buffer<nlattr> attr) {
+    ss << std::hex;
+    bool first = true;
+    for (const auto byte : attr.data<uint8_t>().getRaw()) {
+        if (!first) ss << ':';
+        first = false;
+
+        ss << std::setw(2) << unsigned(byte);
+    }
+    ss << std::dec;
+}
+
+}  // namespace android::nl::protocols
diff --git a/automotive/can/1.0/default/libnl++/protocols/structs.h b/automotive/can/1.0/default/libnl++/protocols/structs.h
index 44c17b8..f3a8c44 100644
--- a/automotive/can/1.0/default/libnl++/protocols/structs.h
+++ b/automotive/can/1.0/default/libnl++/protocols/structs.h
@@ -16,6 +16,8 @@
 
 #pragma once
 
+#include "MessageDefinition.h"
+
 #include <sstream>
 
 namespace android::nl::protocols {
@@ -30,4 +32,9 @@
     ss << '}';
 }
 
+typedef std::map<uint64_t, std::string> FlagsMap;
+AttributeDefinition::ToStream flagsToStream(FlagsMap flags);
+
+void hwaddrToStream(std::stringstream& ss, const Buffer<nlattr> attr);
+
 }  // namespace android::nl::protocols
diff --git a/automotive/vehicle/2.0/default/impl/vhal_v2_0/DefaultConfig.h b/automotive/vehicle/2.0/default/impl/vhal_v2_0/DefaultConfig.h
index 5915a53..9d0b9ec 100644
--- a/automotive/vehicle/2.0/default/impl/vhal_v2_0/DefaultConfig.h
+++ b/automotive/vehicle/2.0/default/impl/vhal_v2_0/DefaultConfig.h
@@ -490,6 +490,14 @@
 
         {.config =
                  {
+                         .prop = toInt(VehicleProperty::PARKING_BRAKE_AUTO_APPLY),
+                         .access = VehiclePropertyAccess::READ,
+                         .changeMode = VehiclePropertyChangeMode::ON_CHANGE,
+                 },
+         .initialValue = {.int32Values = {1}}},
+
+        {.config =
+                 {
                          .prop = toInt(VehicleProperty::FUEL_LEVEL_LOW),
                          .access = VehiclePropertyAccess::READ,
                          .changeMode = VehiclePropertyChangeMode::ON_CHANGE,
@@ -1059,7 +1067,7 @@
         {.config =
                  {
                          .prop = toInt(VehicleProperty::SUPPORT_CUSTOMIZE_VENDOR_PERMISSION),
-                         .access = VehiclePropertyAccess::READ_WRITE,
+                         .access = VehiclePropertyAccess::READ,
                          .changeMode = VehiclePropertyChangeMode::ON_CHANGE,
                          .configArray =
                                  {kMixedTypePropertyForTest,
diff --git a/automotive/vehicle/2.0/types.hal b/automotive/vehicle/2.0/types.hal
index 94645a4..9ecb2d5 100644
--- a/automotive/vehicle/2.0/types.hal
+++ b/automotive/vehicle/2.0/types.hal
@@ -688,7 +688,7 @@
      * Parking brake state.
      *
      * @change_mode VehiclePropertyChangeMode:ON_CHANGE
-     * @access VehiclePropertyAccess:READ_WRITE
+     * @access VehiclePropertyAccess:READ
      */
     PARKING_BRAKE_ON = (
         0x0402
@@ -700,7 +700,7 @@
      * Auto-apply parking brake.
      *
      * @change_mode VehiclePropertyChangeMode:ON_CHANGE
-     * @access VehiclePropertyAccess:READ_WRITE
+     * @access VehiclePropertyAccess:READ
      */
     PARKING_BRAKE_AUTO_APPLY = (
         0x0403
diff --git a/compatibility_matrices/compatibility_matrix.current.xml b/compatibility_matrices/compatibility_matrix.current.xml
index 9e99c48..6800bbd 100644
--- a/compatibility_matrices/compatibility_matrix.current.xml
+++ b/compatibility_matrices/compatibility_matrix.current.xml
@@ -521,7 +521,7 @@
     </hal>
     <hal format="hidl" optional="true">
         <name>android.hardware.soundtrigger</name>
-        <version>2.3</version>
+        <version>2.3-4</version>
         <interface>
             <name>ISoundTriggerHw</name>
             <instance>default</instance>
diff --git a/drm/1.0/default/CryptoPlugin.cpp b/drm/1.0/default/CryptoPlugin.cpp
index e6d4e84..17a2f24 100644
--- a/drm/1.0/default/CryptoPlugin.cpp
+++ b/drm/1.0/default/CryptoPlugin.cpp
@@ -79,7 +79,7 @@
             }
         }
 
-        android::CryptoPlugin::Mode legacyMode;
+        android::CryptoPlugin::Mode legacyMode = android::CryptoPlugin::kMode_Unencrypted;
         switch(mode) {
         case Mode::UNENCRYPTED:
             legacyMode = android::CryptoPlugin::kMode_Unencrypted;
@@ -146,7 +146,10 @@
                 return Void();
             }
 
-            if (destBuffer.offset + destBuffer.size > destBase->getSize()) {
+            size_t totalSize = 0;
+            if (__builtin_add_overflow(destBuffer.offset, destBuffer.size, &totalSize) ||
+                totalSize > destBase->getSize()) {
+                android_errorWriteLog(0x534e4554, "176496353");
                 _hidl_cb(Status::ERROR_DRM_CANNOT_HANDLE, 0, "invalid buffer size");
                 return Void();
             }
@@ -157,7 +160,7 @@
             }
 
             base = static_cast<uint8_t *>(static_cast<void *>(destBase->getPointer()));
-            destPtr = static_cast<void *>(base + destination.nonsecureMemory.offset);
+            destPtr = static_cast<void*>(base + destination.nonsecureMemory.offset);
         } else if (destination.type == BufferType::NATIVE_HANDLE) {
             if (!secure) {
                 _hidl_cb(Status::BAD_VALUE, 0, "native handle destination must be secure");
diff --git a/drm/1.4/types.hal b/drm/1.4/types.hal
index a4490a5..8cb27cd 100644
--- a/drm/1.4/types.hal
+++ b/drm/1.4/types.hal
@@ -32,8 +32,16 @@
 /**
  * Returned by getLogMessages to report error diagnostics to the
  * app.
+ *
+ * The |message| field is for informational purposes only, and
+ * NOT meant to be parsed programmatically when handling errors.
+ * For programmatic error handling, please check the return |Status|
+ * of APIs instead.
  */
 struct LogMessage {
+  /**
+   * Epoch time in milliseconds.
+   */
   int64_t timeMs;
   LogPriority priority;
   string message;
diff --git a/graphics/composer/2.2/utils/vts/ReadbackVts.cpp b/graphics/composer/2.2/utils/vts/ReadbackVts.cpp
index 7bb9121..b179f35 100644
--- a/graphics/composer/2.2/utils/vts/ReadbackVts.cpp
+++ b/graphics/composer/2.2/utils/vts/ReadbackVts.cpp
@@ -268,7 +268,7 @@
     mLayerCount = 1;
     mFormat = format;
     mUsage = static_cast<uint64_t>(BufferUsage::CPU_READ_OFTEN | BufferUsage::CPU_WRITE_OFTEN |
-                                   BufferUsage::COMPOSER_OVERLAY);
+                                   BufferUsage::COMPOSER_OVERLAY | BufferUsage::GPU_TEXTURE);
 
     mAccessRegion.top = 0;
     mAccessRegion.left = 0;
diff --git a/neuralnetworks/1.0/types.t b/neuralnetworks/1.0/types.t
index d7b26aa..be1ee07 100644
--- a/neuralnetworks/1.0/types.t
+++ b/neuralnetworks/1.0/types.t
@@ -63,361 +63,25 @@
     RELU6 = 3,
 };
 
-/**
- * How an operand is used.
- */
-enum OperandLifeTime : int32_t {
-    /**
-     * The operand is internal to the model. It's created by an operation and
-     * consumed by other operations. It must be an output operand of
-     * exactly one operation.
-     */
-    TEMPORARY_VARIABLE,
+%insert OperandLifeTime
 
-    /**
-     * The operand is an input of the model. It must not be an output
-     * operand of any operation.
-     *
-     * An operand can't be both input and output of a model.
-     */
-    MODEL_INPUT,
+%insert DeviceStatus
 
-    /**
-     * The operand is an output of the model. It must be an output
-     * operand of exactly one operation.
-     *
-     * An operand can't be both input and output of a model.
-     */
-    MODEL_OUTPUT,
+%insert PerformanceInfo
 
-    /**
-     * The operand is a constant found in Model.operandValues. It must
-     * not be an output operand of any operation.
-     */
-    CONSTANT_COPY,
+%insert Capabilities
 
-    /**
-     * The operand is a constant that was specified via a Memory
-     * object. It must not be an output operand of any operation.
-     */
-    CONSTANT_REFERENCE,
+%insert DataLocation
 
-    /**
-     * The operand does not have a value. This is valid only for optional
-     * arguments of operations.
-     */
-    NO_VALUE,
-};
+%insert Operand
 
-/**
- * Status of a device.
- */
-enum DeviceStatus : int32_t {
-    AVAILABLE,
-    BUSY,
-    OFFLINE,
-    UNKNOWN,
-};
+%insert Operation
 
-/**
- * Performance information for the reference workload.
- *
- * Used by a driver to report its performance characteristics.
- */
-struct PerformanceInfo {
-    /**
-     * Ratio of the time taken by the driver to execute the
-     * workload compared to the time the CPU would take for the
-     * same workload. A lower number is better.
-     */
-    float execTime;
+%insert Model
 
-    /**
-     * Ratio of the energy used by the driver compared to what
-     * the CPU would use for doing the same workload. A lower number
-     * is better.
-     */
-    float powerUsage;
-};
+%insert RequestArgument
 
-/**
- * The capabilities of a driver.
- */
-struct Capabilities {
-    /**
-     * Driver performance when operating on float32 data.
-     */
-    PerformanceInfo float32Performance;
-
-    /**
-     * Driver performance when operating on asymmetric 8-bit quantized data.
-     */
-    PerformanceInfo quantized8Performance;
-};
-
-/**
- * Describes the location of a data object.
- */
-struct DataLocation {
-    /**
-     * The index of the memory pool where this location is found.
-     */
-    uint32_t poolIndex;
-
-    /**
-     * Offset in bytes from the start of the pool.
-     */
-    uint32_t offset;
-
-    /**
-     * The length of the data in bytes.
-     */
-    uint32_t length;
-};
-
-/**
- * Describes one operand of the model's graph.
- */
-struct Operand {
-    /**
-     * Data type of the operand.
-     */
-    OperandType type;
-
-    /**
-     * Dimensions of the operand.
-     *
-     * For a scalar operand, dimensions.size() must be 0.
-     *
-     * For a tensor operand, dimensions.size() must be at least 1;
-     * however, any of the dimensions may be unspecified.
-     *
-     * A tensor operand with all dimensions specified has "fully
-     * specified" dimensions. Whenever possible (i.e., whenever the
-     * dimensions are known at model construction time), a tensor
-     * operand should have (but is not required to have) fully
-     * specified dimensions, in order to enable the best possible
-     * performance.
-     *
-     * If a tensor operand's dimensions are not fully specified, the
-     * dimensions of the operand are deduced from the operand
-     * dimensions and values of the operation for which that operand
-     * is an output.
-     *
-     * In the following situations, a tensor operand's dimensions must
-     * be fully specified:
-     *
-     *     . The operand has lifetime CONSTANT_COPY or
-     *       CONSTANT_REFERENCE.
-     *
-     *     . The operand has lifetime MODEL_INPUT or MODEL_OUTPUT. Fully
-     *       specified dimensions must either be present in the
-     *       Operand or they must be provided in the corresponding
-     *       RequestArgument.
-     *       EXCEPTION: If the input or output is optional and omitted
-     *       (by setting the hasNoValue field of the corresponding
-     *       RequestArgument to true) then it need not have fully
-     *       specified dimensions.
-     *
-     * A tensor operand with some number of unspecified dimensions is
-     * represented by setting each unspecified dimension to 0.
-     */
-    vec<uint32_t> dimensions;
-
-    /**
-     * The number of times this operand appears as an operation input.
-     *
-     * (For example, if this operand appears once in one operation's
-     * input list, and three times in another operation's input list,
-     * then numberOfConsumers = 4.)
-     */
-    uint32_t numberOfConsumers;
-
-    /**
-     * Quantized scale of the operand.
-     *
-     * Only applicable if the operand is of type TENSOR_QUANT8_ASYMM or
-     * TENSOR_INT32.
-     */
-    float scale;
-
-    /**
-     * Quantized zero-point offset of the operand.
-     *
-     * Only applicable if the operand is of type TENSOR_QUANT8_ASYMM.
-     */
-    int32_t zeroPoint;
-
-    /**
-     * How the operand is used.
-     */
-    OperandLifeTime lifetime;
-
-    /**
-     * Where to find the data for this operand.
-     * If the lifetime is TEMPORARY_VARIABLE, MODEL_INPUT, MODEL_OUTPUT, or
-     * NO_VALUE:
-     * - All the fields must be 0.
-     * If the lifetime is CONSTANT_COPY:
-     * - location.poolIndex is 0.
-     * - location.offset is the offset in bytes into Model.operandValues.
-     * - location.length is set.
-     * If the lifetime is CONSTANT_REFERENCE:
-     * - location.poolIndex is set.
-     * - location.offset is the offset in bytes into the specified pool.
-     * - location.length is set.
-     */
-    DataLocation location;
-};
-
-/**
- * Describes one operation of the model's graph.
- */
-struct Operation {
-    /**
-     * The operation type.
-     */
-    OperationType type;
-
-    /**
-     * Describes the table that contains the indexes of the inputs of the
-     * operation. The offset is the index in the operandIndexes table.
-     */
-    vec<uint32_t> inputs;
-
-    /**
-     * Describes the table that contains the indexes of the outputs of the
-     * operation. The offset is the index in the operandIndexes table.
-     */
-    vec<uint32_t> outputs;
-};
-
-/**
- * A Neural Network Model.
- *
- * This includes not only the execution graph, but also constant data such as
- * weights or scalars added at construction time. The only information that
- * might not be known is the shape of the input tensors.
- */
-struct Model {
-    /**
-     * All operands included in the model.
-     */
-    vec<Operand> operands;
-
-    /**
-     * All operations included in the model.
-     *
-     * The operations are sorted into execution order. Every operand
-     * with lifetime MODEL_OUTPUT or TEMPORARY_VARIABLE must be
-     * written before it is read.
-     */
-    vec<Operation> operations;
-
-    /**
-     * Input indexes of the model. There must be at least one.
-     *
-     * Each value corresponds to the index of the operand in "operands".
-     */
-    vec<uint32_t> inputIndexes;
-
-    /**
-     * Output indexes of the model. There must be at least one.
-     *
-     * Each value corresponds to the index of the operand in "operands".
-     */
-    vec<uint32_t> outputIndexes;
-
-    /**
-     * A byte buffer containing operand data that were copied into the model.
-     *
-     * An operand's value must be located here if and only if Operand::lifetime
-     * equals OperandLifeTime::CONSTANT_COPY.
-     */
-    vec<uint8_t> operandValues;
-
-    /**
-     * A collection of shared memory pools containing operand values.
-     *
-     * An operand's value must be located here if and only if Operand::lifetime
-     * equals OperandLifeTime::CONSTANT_REFERENCE.
-     */
-    vec<memory> pools;
-};
-
-/**
- * Metadata information specifying the location of the input or output data and
- * any updates to the input or output operand.
- */
-struct RequestArgument {
-    /**
-     * If true, the argument does not have a value. This can be used for
-     * operations that take optional arguments. If true, the fields of location
-     * are set to 0 and the dimensions vector is left empty.
-     */
-    bool hasNoValue;
-
-    /**
-     * The location within one of the memory pools passed in the Request.
-     */
-    DataLocation location;
-
-    /**
-     * Updated dimension information.
-     *
-     * If dimensions.size() > 0, dimension information was provided
-     * along with the argument. This can be the case for models that
-     * accept inputs of varying size. This can't change the rank, just
-     * the value of the dimensions that were unspecified in the
-     * model. If dimensions.size() > 0, then all dimensions must be
-     * specified here; and any dimension that was specified in the
-     * model must have the same value here.
-     *
-     * If the dimensions in the model are not fully specified, then
-     * they must be fully specified here, unless hasNoValue is set to
-     * true. If the dimensions in the model are fully specified, then
-     * either dimensions.size() may be 0, or the dimensions in the
-     * model must be identical to the dimensions here.
-     */
-    vec<uint32_t> dimensions;
-};
-
-/**
- * Inputs to be sent to and outputs to be retrieved from a prepared model.
- *
- * A Request serves two primary tasks:
- * 1) Provides the input and output data to be used when executing the model.
- * 2) Specifies any updates to the input operand metadata that were left
- *    unspecified at model preparation time.
- *
- * An output must not overlap with any other output, with an input, or
- * with an operand of lifetime CONSTANT_REFERENCE.
- */
-struct Request {
-    /**
-     * Input data and information to be used in the execution of a prepared
-     * model.
-     *
-     * The index of the input corresponds to the index in Model.inputIndexes.
-     *   E.g., input[i] corresponds to Model.inputIndexes[i].
-     */
-    vec<RequestArgument> inputs;
-
-    /**
-     * Output data and information to be used in the execution of a prepared
-     * model.
-     *
-     * The index of the output corresponds to the index in Model.outputIndexes.
-     *   E.g., output[i] corresponds to Model.outputIndexes[i].
-     */
-    vec<RequestArgument> outputs;
-
-    /**
-     * A collection of shared memory pools containing operand data for both the
-     * inputs and the outputs to a model.
-     */
-    vec<memory> pools;
-};
+%insert Request
 
 /**
  * Return status of a function.
diff --git a/neuralnetworks/1.1/types.t b/neuralnetworks/1.1/types.t
index 75ac2e7..8c22b30 100644
--- a/neuralnetworks/1.1/types.t
+++ b/neuralnetworks/1.1/types.t
@@ -31,128 +31,10 @@
 %insert Operation_1.1
 };
 
-/**
- * The capabilities of a driver.
- */
-struct Capabilities {
-    /**
-     * Driver performance when operating on float32 data.
-     */
-    PerformanceInfo float32Performance;
+%insert Capabilities
 
-    /**
-     * Driver performance when operating on asymmetric 8-bit quantized data.
-     */
-    PerformanceInfo quantized8Performance;
+%insert Operation
 
-    /**
-     * Driver performance when operating on float32 data but performing
-     * calculations with range and/or precision as low as that of the IEEE
-     * 754 16-bit floating-point format.
-     */
-    PerformanceInfo relaxedFloat32toFloat16Performance;
-};
+%insert Model
 
-/**
- * Describes one operation of the model's graph.
- */
-struct Operation {
-    /**
-     * The operation type.
-     */
-    OperationType type;
-
-    /**
-     * Describes the table that contains the indexes of the inputs of the
-     * operation. The offset is the index in the operandIndexes table.
-     */
-    vec<uint32_t> inputs;
-
-    /**
-     * Describes the table that contains the indexes of the outputs of the
-     * operation. The offset is the index in the operandIndexes table.
-     */
-    vec<uint32_t> outputs;
-};
-
-/**
- * A Neural Network Model.
- *
- * This includes not only the execution graph, but also constant data such as
- * weights or scalars added at construction time. The only information that
- * may not be known is the shape of the input tensors.
- */
-struct Model {
-    /**
-     * All operands included in the model.
-     */
-    vec<Operand> operands;
-
-    /**
-     * All operations included in the model.
-     *
-     * The operations are sorted into execution order. Every operand
-     * with lifetime MODEL_OUTPUT or TEMPORARY_VARIABLE must be
-     * written before it is read.
-     */
-    vec<Operation> operations;
-
-    /**
-     * Input indexes of the model. There must be at least one.
-     *
-     * Each value corresponds to the index of the operand in "operands".
-     */
-    vec<uint32_t> inputIndexes;
-
-    /**
-     * Output indexes of the model. There must be at least one.
-     *
-     * Each value corresponds to the index of the operand in "operands".
-     */
-    vec<uint32_t> outputIndexes;
-
-    /**
-     * A byte buffer containing operand data that were copied into the model.
-     *
-     * An operand's value must be located here if and only if Operand::lifetime
-     * equals OperandLifeTime::CONSTANT_COPY.
-     */
-    vec<uint8_t> operandValues;
-
-    /**
-     * A collection of shared memory pools containing operand values.
-     *
-     * An operand's value must be located here if and only if Operand::lifetime
-     * equals OperandLifeTime::CONSTANT_REFERENCE.
-     */
-    vec<memory> pools;
-
-    /**
-     * 'true' indicates TENSOR_FLOAT32 may be calculated with range and/or
-     * precision as low as that of the IEEE 754 16-bit floating-point format.
-     * 'false' indicates TENSOR_FLOAT32 must be calculated using at least the
-     * range and precision of the IEEE 754 32-bit floating-point format.
-     */
-    bool relaxComputationFloat32toFloat16;
-};
-
-/**
- * Execution preferences.
- */
-enum ExecutionPreference : int32_t {
-    /**
-     * Prefer executing in a way that minimizes battery drain.
-     * This is desirable for compilations that will be executed often.
-     */
-    LOW_POWER = 0,
-    /**
-     * Prefer returning a single answer as fast as possible, even if this causes
-     * more power consumption.
-     */
-    FAST_SINGLE_ANSWER = 1,
-    /**
-     * Prefer maximizing the throughput of successive frames, for example when
-     * processing successive frames coming from the camera.
-     */
-    SUSTAINED_SPEED = 2,
-};
+%insert ExecutionPreference
diff --git a/neuralnetworks/1.2/types.t b/neuralnetworks/1.2/types.t
index 4c9fd02..b490f7f 100644
--- a/neuralnetworks/1.2/types.t
+++ b/neuralnetworks/1.2/types.t
@@ -97,379 +97,23 @@
     BASE_MAX        = 0xFFFF,
 };
 
-/**
- * Device types.
- *
- * The type of NNAPI device.
- */
-enum DeviceType : int32_t {
-    // Leaving 0 unused as it means unknown type in NDK NNAPI. There is no
-    // HAL equivalent of unknown type and a 1.2 HAL implementation must belong
-    // to one of the categories below.
-    /** The device does not fall into any category below. */
-    OTHER = 1,
-    /** The device runs NNAPI models on single or multi-core CPU. */
-    CPU = 2,
-    /** The device can run NNAPI models and also accelerate graphics APIs such
-     * as OpenGL ES and Vulkan. */
-    GPU = 3,
-    /** Dedicated accelerator for Machine Learning workloads. */
-    ACCELERATOR = 4,
-};
+%insert DeviceType
 
-/**
- * The capabilities of a driver.
- *
- * Performance of an operation comes from the type of its first operand.
- * This represents performance for non extension operand types.
- */
-struct Capabilities {
-    /**
-     * Driver performance when operating on float32 data but performing
-     * calculations with range and/or precision as low as that of the IEEE
-     * 754 16-bit floating-point format.
-     */
-    PerformanceInfo relaxedFloat32toFloat16PerformanceScalar;
-    PerformanceInfo relaxedFloat32toFloat16PerformanceTensor;
+%insert Capabilities
 
-    /**
-     * Driver performance when operating on a particular data type.
-     * In the case of float32 data, this is used when the calculations
-     * are not relaxed.
-     */
-    struct OperandPerformance {
-        OperandType type;
-        PerformanceInfo info;
-    };
+%insert Operation
 
-    /**
-     * Performance by operand type. Must be sorted by OperandType.
-     * If a particular OperandType is not present in operandPerformance,
-     * its performance is treated as { .execTime = FLT_MAX, .powerUsage = FLT_MAX }.
-     */
-    vec<OperandPerformance> operandPerformance;
-};
+%insert SymmPerChannelQuantParams
 
-/**
- * Describes one operation of the model's graph.
- */
-struct Operation {
-    /**
-     * The operation type.
-     *
-     * Besides the values listed in {@link OperationType}, any value above
-     * {@link OperationTypeRange::BASE_MAX} is possible and should be interpreted
-     * as an extension type according to {@link Model::extensionNameToPrefix}.
-     */
-    OperationType type;
+%insert Operand
 
-    /**
-     * Describes the table that contains the indexes of the inputs of the
-     * operation. The offset is the index in the operandIndexes table.
-     */
-    vec<uint32_t> inputs;
+%insert Model
 
-    /**
-     * Describes the table that contains the indexes of the outputs of the
-     * operation. The offset is the index in the operandIndexes table.
-     */
-    vec<uint32_t> outputs;
-};
+%insert OutputShape
 
-/**
- * Parameters for TENSOR_QUANT8_SYMM_PER_CHANNEL operand.
- */
-struct SymmPerChannelQuantParams {
-    /** Array of scaling values for each channel. Each value must be greater than zero. */
-    vec<float> scales;
-    /** Index of the channel dimension */
-    uint32_t channelDim;
-};
+%insert MeasureTiming
 
-/**
- * Describes one operand of the model's graph.
- */
-struct Operand {
-    /**
-     * The data type.
-     *
-     * Besides the values listed in {@link OperandType}, any value above
-     * {@link OperandTypeRange::BASE_MAX} is possible and should be interpreted
-     * as an extension type according to {@link Model::extensionNameToPrefix}.
-     */
-    OperandType type;
-
-    /**
-     * Dimensions of the operand.
-     *
-     * For a scalar operand, dimensions.size() must be 0.
-     *
-     * A tensor operand with all dimensions specified has "fully
-     * specified" dimensions. Whenever possible (i.e., whenever the
-     * dimensions are known at model construction time), a tensor
-     * operand should have (but is not required to have) fully
-     * specified dimensions, in order to enable the best possible
-     * performance.
-     *
-     * If a tensor operand's dimensions are not fully specified, the
-     * dimensions of the operand are deduced from the operand
-     * dimensions and values of the operation for which that operand
-     * is an output.
-     *
-     * In the following situations, a tensor operand's dimensions must
-     * be fully specified:
-     *
-     *     . The operand has lifetime CONSTANT_COPY or
-     *       CONSTANT_REFERENCE.
-     *
-     *     . The operand has lifetime MODEL_INPUT. Fully
-     *       specified dimensions must either be present in the
-     *       Operand or they must be provided in the corresponding
-     *       RequestArgument.
-     *       EXCEPTION: If the input is optional and omitted
-     *       (by setting the hasNoValue field of the corresponding
-     *       RequestArgument to true) then it need not have fully
-     *       specified dimensions.
-     *
-     * A tensor operand with some number of unspecified dimensions is
-     * represented by setting each unspecified dimension to 0.
-     *
-     * A tensor operand with unspecified rank is represented by providing
-     * an empty dimensions vector.
-     */
-    vec<uint32_t> dimensions;
-
-    /**
-     * The number of times this operand appears as an operation input.
-     *
-     * (For example, if this operand appears once in one operation's
-     * input list, and three times in another operation's input list,
-     * then numberOfConsumers = 4.)
-     */
-    uint32_t numberOfConsumers;
-
-    /**
-     * Quantized scale of the operand.
-     *
-     * Must be 0 when not applicable to an operand type.
-     *
-     * See {@link OperandType}.
-     */
-    float scale;
-
-    /**
-     * Quantized zero-point offset of the operand.
-     *
-     * Must be 0 when not applicable to an operand type.
-     *
-     * See {@link OperandType}.
-     */
-    int32_t zeroPoint;
-
-    /**
-     * How the operand is used.
-     */
-    OperandLifeTime lifetime;
-
-    /**
-     * Where to find the data for this operand.
-     * If the lifetime is TEMPORARY_VARIABLE, MODEL_INPUT, MODEL_OUTPUT, or
-     * NO_VALUE:
-     * - All the fields must be 0.
-     * If the lifetime is CONSTANT_COPY:
-     * - location.poolIndex is 0.
-     * - location.offset is the offset in bytes into Model.operandValues.
-     * - location.length is set.
-     * If the lifetime is CONSTANT_REFERENCE:
-     * - location.poolIndex is set.
-     * - location.offset is the offset in bytes into the specified pool.
-     * - location.length is set.
-     */
-    DataLocation location;
-
-    /**
-     * Additional parameters specific to a particular operand type.
-     */
-    safe_union ExtraParams {
-        /**
-         * No additional parameters.
-         */
-        Monostate none;
-
-        /**
-         * Symmetric per-channel quantization parameters.
-         *
-         * Only applicable to operands of type TENSOR_QUANT8_SYMM_PER_CHANNEL.
-         */
-        SymmPerChannelQuantParams channelQuant;
-
-        /**
-         * Extension operand parameters.
-         *
-         * The framework treats this as an opaque data blob.
-         * The format is up to individual extensions.
-         */
-        vec<uint8_t> extension;
-    } extraParams;
-};
-
-/**
- * A Neural Network Model.
- *
- * This includes not only the execution graph, but also constant data such as
- * weights or scalars added at construction time. The only information that
- * may not be known is the shape of the input tensors.
- */
-struct Model {
-    /**
-     * All operands included in the model.
-     */
-    vec<Operand> operands;
-
-    /**
-     * All operations included in the model.
-     *
-     * The operations are sorted into execution order. Every operand
-     * with lifetime MODEL_OUTPUT or TEMPORARY_VARIABLE must be
-     * written before it is read.
-     */
-    vec<Operation> operations;
-
-    /**
-     * Input indexes of the model. There must be at least one.
-     *
-     * Each value corresponds to the index of the operand in "operands".
-     */
-    vec<uint32_t> inputIndexes;
-
-    /**
-     * Output indexes of the model. There must be at least one.
-     *
-     * Each value corresponds to the index of the operand in "operands".
-     */
-    vec<uint32_t> outputIndexes;
-
-    /**
-     * A byte buffer containing operand data that were copied into the model.
-     *
-     * An operand's value must be located here if and only if Operand::lifetime
-     * equals OperandLifeTime::CONSTANT_COPY.
-     */
-    vec<uint8_t> operandValues;
-
-    /**
-     * A collection of shared memory pools containing operand values.
-     *
-     * An operand's value must be located here if and only if Operand::lifetime
-     * equals OperandLifeTime::CONSTANT_REFERENCE.
-     */
-    vec<memory> pools;
-
-    /**
-     * 'true' indicates TENSOR_FLOAT32 may be calculated with range and/or
-     * precision as low as that of the IEEE 754 16-bit floating-point format.
-     * 'false' indicates TENSOR_FLOAT32 must be calculated using at least the
-     * range and precision of the IEEE 754 32-bit floating-point format.
-     */
-    bool relaxComputationFloat32toFloat16;
-
-    /**
-     * The mapping between extension names and prefixes of operand and
-     * operation type values.
-     *
-     * An operand or operation whose numeric type value is above
-     * {@link OperandTypeRange::BASE_MAX} or
-     * {@link OperationTypeRange::BASE_MAX} respectively should be interpreted
-     * as an extension operand. The low
-     * {@link Model::ExtensionTypeEncoding::LOW_BITS_TYPE} bits of the value
-     * correspond to the type ID within the extension and the high
-     * {@link Model::ExtensionTypeEncoding::HIGH_BITS_PREFIX} bits encode
-     * the "prefix", which maps uniquely to the extension name.
-     *
-     * For example, if a model contains an operation whose value is
-     * 0xAAAABBBB and extensionNameToPrefix contains an entry with
-     * prefix=0xAAAA and name="vendor.test.test_extension", then
-     * the operation should be interpreted as the operation 0xBBBB
-     * of the extension named vendor.test.test_extension.
-     *
-     * This is a one-to-one correspondence. That is, there must be at most one
-     * prefix corresponding to each extension name and at most one extension
-     * name corresponding to each prefix.
-     */
-    vec<ExtensionNameAndPrefix> extensionNameToPrefix;
-
-    /**
-     * A correspondence between an extension name and a prefix of operand and
-     * operation type values.
-     */
-    struct ExtensionNameAndPrefix {
-        /**
-         * The extension name.
-         *
-         * See {@link Extension::name} for the format specification.
-         */
-        string name;
-
-        /**
-         * The unique extension identifier within the model.
-         *
-         * See {@link Model::extensionNameToPrefix}.
-         */
-        uint16_t prefix;
-    };
-
-    /**
-     * Numeric values of extension operand and operation types have the
-     * following structure:
-     * - 16 high bits represent the "prefix", which corresponds uniquely to the
-     *   extension name.
-     * - 16 low bits represent the type ID within the extension.
-     */
-    enum ExtensionTypeEncoding : uint8_t {
-        HIGH_BITS_PREFIX = 16,
-        LOW_BITS_TYPE = 16,
-    };
-};
-
-/**
- * Describes the shape information of an output operand after execution.
- */
-struct OutputShape {
-    /**
-     * Dimensions of the operand.
-     */
-    vec<uint32_t> dimensions;
-
-    /**
-     * Whether the provided buffer size is sufficient for the output.
-     */
-    bool isSufficient;
-};
-
-/**
- * Specifies whether or not to measure timing information during execution.
- */
-enum MeasureTiming : int32_t {
-    NO = 0,
-    YES = 1,
-};
-
-/**
-
- * Timing information measured during execution. Each time is a duration from
- * the beginning of some task to the end of that task, including time when that
- * task is not active (for example, preempted by some other task, or
- * waiting for some resource to become available).
- *
- * Times are measured in microseconds.
- * When a time is not available, it must be reported as UINT64_MAX.
- */
-struct Timing {
-    /** Execution time on device (not driver, which runs on host processor). */
-    uint64_t timeOnDevice;
-    /** Execution time in driver (including time on device). */
-    uint64_t timeInDriver;
-};
+%insert Timing
 
 /**
  * FmqRequestDatum is a single element of a serialized representation of an
@@ -683,46 +327,4 @@
     Timing executionTiming;
 };
 
-/**
- * Information about an extension.
- */
-struct Extension {
-    /**
-     * The extension name.
-     *
-     * The name must consist of lowercase latin letters, numbers, periods, and
-     * underscore signs. The name must contain at least one period.
-     *
-     * The name must start with the reverse domain name of the vendor.
-     *
-     * Example: com.google.test_extension
-     */
-    string name;
-
-    /**
-     * Information about an extension operand type.
-     */
-    struct OperandTypeInformation {
-        /**
-         * The extension operand type.
-         */
-        uint16_t type;
-
-        /**
-         * Indicates whether the extension operand type represents a tensor or
-         * a scalar.
-         */
-        bool isTensor;
-
-        /**
-         * The byte size of the operand (if scalar) or of a single element (if
-         * tensor).
-         */
-        uint32_t byteSize;
-    };
-
-    /**
-     * Information about operand types defined by the extension.
-     */
-    vec<OperandTypeInformation> operandTypes;
-};
+%insert Extension
diff --git a/neuralnetworks/1.2/utils/Android.bp b/neuralnetworks/1.2/utils/Android.bp
index 2921141..41281ee 100644
--- a/neuralnetworks/1.2/utils/Android.bp
+++ b/neuralnetworks/1.2/utils/Android.bp
@@ -27,7 +27,6 @@
     name: "neuralnetworks_utils_hal_1_2",
     defaults: ["neuralnetworks_utils_defaults"],
     srcs: ["src/*"],
-    exclude_srcs: ["src/ExecutionBurst*"],
     local_include_dirs: ["include/nnapi/hal/1.2/"],
     export_include_dirs: ["include"],
     cflags: ["-Wthread-safety"],
@@ -41,10 +40,16 @@
         "android.hardware.neuralnetworks@1.0",
         "android.hardware.neuralnetworks@1.1",
         "android.hardware.neuralnetworks@1.2",
+        "libfmq",
     ],
     export_static_lib_headers: [
         "neuralnetworks_utils_hal_common",
     ],
+    product_variables: {
+        debuggable: { // eng and userdebug builds
+            cflags: ["-DNN_DEBUGGABLE"],
+        },
+    },
 }
 
 cc_test {
diff --git a/neuralnetworks/1.2/utils/include/nnapi/hal/1.2/Conversions.h b/neuralnetworks/1.2/utils/include/nnapi/hal/1.2/Conversions.h
index 6fd1337..272cee7 100644
--- a/neuralnetworks/1.2/utils/include/nnapi/hal/1.2/Conversions.h
+++ b/neuralnetworks/1.2/utils/include/nnapi/hal/1.2/Conversions.h
@@ -52,6 +52,7 @@
 GeneralResult<Model> convert(const hal::V1_2::Model& model);
 GeneralResult<MeasureTiming> convert(const hal::V1_2::MeasureTiming& measureTiming);
 GeneralResult<Timing> convert(const hal::V1_2::Timing& timing);
+GeneralResult<SharedMemory> convert(const hardware::hidl_memory& memory);
 
 GeneralResult<std::vector<Extension>> convert(
         const hardware::hidl_vec<hal::V1_2::Extension>& extensions);
diff --git a/neuralnetworks/1.2/utils/include/nnapi/hal/1.2/ExecutionBurstController.h b/neuralnetworks/1.2/utils/include/nnapi/hal/1.2/ExecutionBurstController.h
index 5356a91..6b6fc71 100644
--- a/neuralnetworks/1.2/utils/include/nnapi/hal/1.2/ExecutionBurstController.h
+++ b/neuralnetworks/1.2/utils/include/nnapi/hal/1.2/ExecutionBurstController.h
@@ -14,23 +14,28 @@
  * limitations under the License.
  */
 
-#ifndef ANDROID_FRAMEWORKS_ML_NN_COMMON_EXECUTION_BURST_CONTROLLER_H
-#define ANDROID_FRAMEWORKS_ML_NN_COMMON_EXECUTION_BURST_CONTROLLER_H
+#ifndef ANDROID_HARDWARE_INTERFACES_NEURALNETWORKS_1_2_UTILS_EXECUTION_BURST_CONTROLLER_H
+#define ANDROID_HARDWARE_INTERFACES_NEURALNETWORKS_1_2_UTILS_EXECUTION_BURST_CONTROLLER_H
 
 #include "ExecutionBurstUtils.h"
 
-#include <android-base/macros.h>
+#include <android-base/thread_annotations.h>
 #include <android/hardware/neuralnetworks/1.0/types.h>
-#include <android/hardware/neuralnetworks/1.1/types.h>
 #include <android/hardware/neuralnetworks/1.2/IBurstCallback.h>
 #include <android/hardware/neuralnetworks/1.2/IBurstContext.h>
 #include <android/hardware/neuralnetworks/1.2/IPreparedModel.h>
 #include <android/hardware/neuralnetworks/1.2/types.h>
 #include <fmq/MessageQueue.h>
 #include <hidl/MQDescriptor.h>
+#include <nnapi/IBurst.h>
+#include <nnapi/IPreparedModel.h>
+#include <nnapi/Result.h>
+#include <nnapi/Types.h>
+#include <nnapi/hal/ProtectCallback.h>
 
 #include <atomic>
 #include <chrono>
+#include <functional>
 #include <map>
 #include <memory>
 #include <mutex>
@@ -39,147 +44,145 @@
 #include <utility>
 #include <vector>
 
-namespace android::nn {
+namespace android::hardware::neuralnetworks::V1_2::utils {
 
 /**
- * The ExecutionBurstController class manages both the serialization and
- * deserialization of data across FMQ, making it appear to the runtime as a
- * regular synchronous inference. Additionally, this class manages the burst's
- * memory cache.
+ * The ExecutionBurstController class manages both the serialization and deserialization of data
+ * across FMQ, making it appear to the runtime as a regular synchronous inference. Additionally,
+ * this class manages the burst's memory cache.
  */
-class ExecutionBurstController {
-    DISALLOW_IMPLICIT_CONSTRUCTORS(ExecutionBurstController);
+class ExecutionBurstController final : public nn::IBurst {
+    struct PrivateConstructorTag {};
 
   public:
+    using FallbackFunction =
+            std::function<nn::ExecutionResult<std::pair<std::vector<nn::OutputShape>, nn::Timing>>(
+                    const nn::Request&, nn::MeasureTiming)>;
+
     /**
-     * NN runtime burst callback object and memory cache.
+     * NN runtime memory cache.
      *
-     * ExecutionBurstCallback associates a hidl_memory object with a slot number
-     * to be passed across FMQ. The ExecutionBurstServer can use this callback
-     * to retrieve this hidl_memory corresponding to the slot via HIDL.
+     * MemoryCache associates a Memory object with a slot number to be passed across FMQ. The
+     * ExecutionBurstServer can use this callback to retrieve a hidl_memory corresponding to the
+     * slot via HIDL.
      *
-     * Whenever a hidl_memory object is copied, it will duplicate the underlying
-     * file descriptor. Because the NN runtime currently copies the hidl_memory
-     * on each execution, it is difficult to associate hidl_memory objects with
-     * previously cached hidl_memory objects. For this reason, callers of this
-     * class must pair each hidl_memory object with an associated key. For
-     * efficiency, if two hidl_memory objects represent the same underlying
-     * buffer, they must use the same key.
+     * Whenever a hidl_memory object is copied, it will duplicate the underlying file descriptor.
+     * Because the NN runtime currently copies the hidl_memory on each execution, it is difficult to
+     * associate hidl_memory objects with previously cached hidl_memory objects. For this reason,
+     * callers of this class must pair each hidl_memory object with an associated key. For
+     * efficiency, if two hidl_memory objects represent the same underlying buffer, they must use
+     * the same key.
+     *
+     * This class is thread-safe.
      */
-    class ExecutionBurstCallback : public hardware::neuralnetworks::V1_2::IBurstCallback {
-        DISALLOW_COPY_AND_ASSIGN(ExecutionBurstCallback);
+    class MemoryCache : public std::enable_shared_from_this<MemoryCache> {
+        struct PrivateConstructorTag {};
 
       public:
-        ExecutionBurstCallback() = default;
+        using Task = std::function<void()>;
+        using Cleanup = base::ScopeGuard<Task>;
+        using SharedCleanup = std::shared_ptr<const Cleanup>;
+        using WeakCleanup = std::weak_ptr<const Cleanup>;
 
-        hardware::Return<void> getMemories(const hardware::hidl_vec<int32_t>& slots,
-                                           getMemories_cb cb) override;
+        // Custom constructor to pre-allocate cache sizes.
+        MemoryCache();
 
         /**
-         * This function performs one of two different actions:
-         * 1) If a key corresponding to a memory resource is unrecognized by the
-         *    ExecutionBurstCallback object, the ExecutionBurstCallback object
-         *    will allocate a slot, bind the memory to the slot, and return the
-         *    slot identifier.
-         * 2) If a key corresponding to a memory resource is recognized by the
-         *    ExecutionBurstCallback object, the ExecutionBurstCallback object
-         *    will return the existing slot identifier.
+         * Add a burst context to the MemoryCache object.
          *
-         * @param memories Memory resources used in an inference.
-         * @param keys Unique identifiers where each element corresponds to a
-         *     memory resource element in "memories".
-         * @return Unique slot identifiers where each returned slot element
-         *     corresponds to a memory resource element in "memories".
+         * If this method is called, it must be called before the MemoryCache::cacheMemory or
+         * MemoryCache::getMemory is used.
+         *
+         * @param burstContext Burst context to be added to the MemoryCache object.
          */
-        std::vector<int32_t> getSlots(const hardware::hidl_vec<hardware::hidl_memory>& memories,
-                                      const std::vector<intptr_t>& keys);
+        void setBurstContext(sp<IBurstContext> burstContext);
 
-        /*
-         * This function performs two different actions:
-         * 1) Removes an entry from the cache (if present), including the local
-         *    storage of the hidl_memory object. Note that this call does not
-         *    free any corresponding hidl_memory object in ExecutionBurstServer,
-         *    which is separately freed via IBurstContext::freeMemory.
-         * 2) Return whether a cache entry was removed and which slot was removed if
-         *    found. If the key did not to correspond to any entry in the cache, a
-         *    slot number of 0 is returned. The slot number and whether the entry
-         *    existed is useful so the same slot can be freed in the
-         *    ExecutionBurstServer's cache via IBurstContext::freeMemory.
+        /**
+         * Cache a memory object in the MemoryCache object.
+         *
+         * @param memory Memory object to be cached while the returned `SharedCleanup` is alive.
+         * @return A pair of (1) a unique identifier for the cache entry and (2) a ref-counted
+         *     "hold" object which preserves the cache as long as the hold object is alive.
          */
-        std::pair<bool, int32_t> freeMemory(intptr_t key);
+        std::pair<int32_t, SharedCleanup> cacheMemory(const nn::SharedMemory& memory);
+
+        /**
+         * Get the memory object corresponding to a slot identifier.
+         *
+         * @param slot Slot which identifies the memory object to retrieve.
+         * @return The memory object corresponding to slot, otherwise GeneralError.
+         */
+        nn::GeneralResult<nn::SharedMemory> getMemory(int32_t slot);
 
       private:
-        int32_t getSlotLocked(const hardware::hidl_memory& memory, intptr_t key);
-        int32_t allocateSlotLocked();
+        void freeMemory(const nn::SharedMemory& memory);
+        int32_t allocateSlotLocked() REQUIRES(mMutex);
 
         std::mutex mMutex;
-        std::stack<int32_t, std::vector<int32_t>> mFreeSlots;
-        std::map<intptr_t, int32_t> mMemoryIdToSlot;
-        std::vector<hardware::hidl_memory> mMemoryCache;
+        std::condition_variable mCond;
+        sp<IBurstContext> mBurstContext GUARDED_BY(mMutex);
+        std::stack<int32_t, std::vector<int32_t>> mFreeSlots GUARDED_BY(mMutex);
+        std::map<nn::SharedMemory, int32_t> mMemoryIdToSlot GUARDED_BY(mMutex);
+        std::vector<nn::SharedMemory> mMemoryCache GUARDED_BY(mMutex);
+        std::vector<WeakCleanup> mCacheCleaner GUARDED_BY(mMutex);
+    };
+
+    /**
+     * HIDL Callback class to pass memory objects to the Burst server when given corresponding
+     * slots.
+     */
+    class ExecutionBurstCallback : public IBurstCallback {
+      public:
+        // Precondition: memoryCache must be non-null.
+        explicit ExecutionBurstCallback(const std::shared_ptr<MemoryCache>& memoryCache);
+
+        // See IBurstCallback::getMemories for information on this method.
+        Return<void> getMemories(const hidl_vec<int32_t>& slots, getMemories_cb cb) override;
+
+      private:
+        const std::weak_ptr<MemoryCache> kMemoryCache;
     };
 
     /**
      * Creates a burst controller on a prepared model.
      *
-     * Prefer this over ExecutionBurstController's constructor.
-     *
      * @param preparedModel Model prepared for execution to execute on.
-     * @param pollingTimeWindow How much time (in microseconds) the
-     *     ExecutionBurstController is allowed to poll the FMQ before waiting on
-     *     the blocking futex. Polling may result in lower latencies at the
-     *     potential cost of more power usage.
+     * @param pollingTimeWindow How much time (in microseconds) the ExecutionBurstController is
+     *     allowed to poll the FMQ before waiting on the blocking futex. Polling may result in lower
+     *     latencies at the potential cost of more power usage.
      * @return ExecutionBurstController Execution burst controller object.
      */
-    static std::unique_ptr<ExecutionBurstController> create(
-            const sp<hardware::neuralnetworks::V1_2::IPreparedModel>& preparedModel,
+    static nn::GeneralResult<std::shared_ptr<const ExecutionBurstController>> create(
+            const sp<IPreparedModel>& preparedModel, FallbackFunction fallback,
             std::chrono::microseconds pollingTimeWindow);
 
-    // prefer calling ExecutionBurstController::create
-    ExecutionBurstController(const std::shared_ptr<RequestChannelSender>& requestChannelSender,
-                             const std::shared_ptr<ResultChannelReceiver>& resultChannelReceiver,
-                             const sp<hardware::neuralnetworks::V1_2::IBurstContext>& burstContext,
-                             const sp<ExecutionBurstCallback>& callback,
-                             const sp<hardware::hidl_death_recipient>& deathHandler = nullptr);
+    ExecutionBurstController(PrivateConstructorTag tag, FallbackFunction fallback,
+                             std::unique_ptr<RequestChannelSender> requestChannelSender,
+                             std::unique_ptr<ResultChannelReceiver> resultChannelReceiver,
+                             sp<ExecutionBurstCallback> callback, sp<IBurstContext> burstContext,
+                             std::shared_ptr<MemoryCache> memoryCache,
+                             neuralnetworks::utils::DeathHandler deathHandler);
 
-    // explicit destructor to unregister the death recipient
-    ~ExecutionBurstController();
+    // See IBurst::cacheMemory for information on this method.
+    OptionalCacheHold cacheMemory(const nn::SharedMemory& memory) const override;
 
-    /**
-     * Execute a request on a model.
-     *
-     * @param request Arguments to be executed on a model.
-     * @param measure Whether to collect timing measurements, either YES or NO
-     * @param memoryIds Identifiers corresponding to each memory object in the
-     *     request's pools.
-     * @return A tuple of:
-     *     - result code of the execution
-     *     - dynamic output shapes from the execution
-     *     - any execution time measurements of the execution
-     *     - whether or not a failed burst execution should be re-run using a
-     *       different path (e.g., IPreparedModel::executeSynchronously)
-     */
-    std::tuple<int, std::vector<hardware::neuralnetworks::V1_2::OutputShape>,
-               hardware::neuralnetworks::V1_2::Timing, bool>
-    compute(const hardware::neuralnetworks::V1_0::Request& request,
-            hardware::neuralnetworks::V1_2::MeasureTiming measure,
-            const std::vector<intptr_t>& memoryIds);
-
-    /**
-     * Propagate a user's freeing of memory to the service.
-     *
-     * @param key Key corresponding to the memory object.
-     */
-    void freeMemory(intptr_t key);
+    // See IBurst::execute for information on this method.
+    nn::ExecutionResult<std::pair<std::vector<nn::OutputShape>, nn::Timing>> execute(
+            const nn::Request& request, nn::MeasureTiming measure) const override;
 
   private:
-    std::mutex mMutex;
-    const std::shared_ptr<RequestChannelSender> mRequestChannelSender;
-    const std::shared_ptr<ResultChannelReceiver> mResultChannelReceiver;
-    const sp<hardware::neuralnetworks::V1_2::IBurstContext> mBurstContext;
-    const sp<ExecutionBurstCallback> mMemoryCache;
-    const sp<hardware::hidl_death_recipient> mDeathHandler;
+    mutable std::atomic_flag mExecutionInFlight = ATOMIC_FLAG_INIT;
+    const FallbackFunction kFallback;
+    const std::unique_ptr<RequestChannelSender> mRequestChannelSender;
+    const std::unique_ptr<ResultChannelReceiver> mResultChannelReceiver;
+    const sp<ExecutionBurstCallback> mBurstCallback;
+    const sp<IBurstContext> mBurstContext;
+    const std::shared_ptr<MemoryCache> mMemoryCache;
+    // `kDeathHandler` must come after `mRequestChannelSender` and `mResultChannelReceiver` because
+    // it holds references to both objects.
+    const neuralnetworks::utils::DeathHandler kDeathHandler;
 };
 
-}  // namespace android::nn
+}  // namespace android::hardware::neuralnetworks::V1_2::utils
 
-#endif  // ANDROID_FRAMEWORKS_ML_NN_COMMON_EXECUTION_BURST_CONTROLLER_H
+#endif  // ANDROID_HARDWARE_INTERFACES_NEURALNETWORKS_1_2_UTILS_EXECUTION_BURST_CONTROLLER_H
diff --git a/neuralnetworks/1.2/utils/include/nnapi/hal/1.2/ExecutionBurstServer.h b/neuralnetworks/1.2/utils/include/nnapi/hal/1.2/ExecutionBurstServer.h
index 2e109b2..f7926f5 100644
--- a/neuralnetworks/1.2/utils/include/nnapi/hal/1.2/ExecutionBurstServer.h
+++ b/neuralnetworks/1.2/utils/include/nnapi/hal/1.2/ExecutionBurstServer.h
@@ -14,19 +14,22 @@
  * limitations under the License.
  */
 
-#ifndef ANDROID_FRAMEWORKS_ML_NN_COMMON_EXECUTION_BURST_SERVER_H
-#define ANDROID_FRAMEWORKS_ML_NN_COMMON_EXECUTION_BURST_SERVER_H
+#ifndef ANDROID_HARDWARE_INTERFACES_NEURALNETWORKS_1_2_UTILS_EXECUTION_BURST_SERVER_H
+#define ANDROID_HARDWARE_INTERFACES_NEURALNETWORKS_1_2_UTILS_EXECUTION_BURST_SERVER_H
 
 #include "ExecutionBurstUtils.h"
 
-#include <android-base/macros.h>
+#include <android-base/thread_annotations.h>
 #include <android/hardware/neuralnetworks/1.0/types.h>
-#include <android/hardware/neuralnetworks/1.1/types.h>
 #include <android/hardware/neuralnetworks/1.2/IBurstCallback.h>
 #include <android/hardware/neuralnetworks/1.2/IPreparedModel.h>
 #include <android/hardware/neuralnetworks/1.2/types.h>
 #include <fmq/MessageQueue.h>
 #include <hidl/MQDescriptor.h>
+#include <nnapi/IBurst.h>
+#include <nnapi/Result.h>
+#include <nnapi/Types.h>
+#include <nnapi/hal/ProtectCallback.h>
 
 #include <atomic>
 #include <chrono>
@@ -36,84 +39,61 @@
 #include <tuple>
 #include <vector>
 
-namespace android::nn {
+namespace android::hardware::neuralnetworks::V1_2::utils {
 
 /**
- * The ExecutionBurstServer class is responsible for waiting for and
- * deserializing a request object from a FMQ, performing the inference, and
- * serializing the result back across another FMQ.
+ * The ExecutionBurstServer class is responsible for waiting for and deserializing a request object
+ * from a FMQ, performing the inference, and serializing the result back across another FMQ.
  */
-class ExecutionBurstServer : public hardware::neuralnetworks::V1_2::IBurstContext {
-    DISALLOW_IMPLICIT_CONSTRUCTORS(ExecutionBurstServer);
+class ExecutionBurstServer : public IBurstContext {
+    struct PrivateConstructorTag {};
 
   public:
     /**
-     * IBurstExecutorWithCache is a callback object passed to
-     * ExecutionBurstServer's factory function that is used to perform an
-     * execution. Because some memory resources are needed across multiple
-     * executions, this object also contains a local cache that can directly be
-     * used in the execution.
+     * Class to cache the memory objects for a burst object.
      *
-     * ExecutionBurstServer will never access its IBurstExecutorWithCache object
-     * with concurrent calls.
+     * This class is thread-safe.
      */
-    class IBurstExecutorWithCache {
-        DISALLOW_COPY_AND_ASSIGN(IBurstExecutorWithCache);
-
+    class MemoryCache {
       public:
-        IBurstExecutorWithCache() = default;
-        virtual ~IBurstExecutorWithCache() = default;
+        // Precondition: burstExecutor != nullptr
+        // Precondition: burstCallback != nullptr
+        MemoryCache(nn::SharedBurst burstExecutor, sp<IBurstCallback> burstCallback);
 
         /**
-         * Checks if a cache entry specified by a slot is present in the cache.
+         * Get the cached memory objects corresponding to provided slot identifiers.
          *
-         * @param slot Identifier of the cache entry.
-         * @return 'true' if the cache entry is present in the cache, 'false'
-         *     otherwise.
+         * If the slot entry is not present in the cache, this class will use IBurstCallback to
+         * retrieve those entries that are not present in the cache, then cache them.
+         *
+         * @param slots Identifiers of memory objects to be retrieved.
+         * @return A vector where each element is the memory object and a ref-counted cache "hold"
+         *     object to preserve the cache entry of the IBurst object as long as the "hold" object
+         *     is alive, otherwise GeneralError. Each element of the vector corresponds to the
+         *     element of slot.
          */
-        virtual bool isCacheEntryPresent(int32_t slot) const = 0;
+        nn::GeneralResult<std::vector<std::pair<nn::SharedMemory, nn::IBurst::OptionalCacheHold>>>
+        getCacheEntries(const std::vector<int32_t>& slots);
 
         /**
-         * Adds an entry specified by a slot to the cache.
+         * Remove an entry from the cache.
          *
-         * The caller of this function must ensure that the cache entry that is
-         * being added is not already present in the cache. This can be checked
-         * via isCacheEntryPresent.
-         *
-         * @param memory Memory resource to be cached.
-         * @param slot Slot identifier corresponding to the memory resource.
+         * @param slot Identifier of the memory object to be removed from the cache.
          */
-        virtual void addCacheEntry(const hardware::hidl_memory& memory, int32_t slot) = 0;
+        void removeCacheEntry(int32_t slot);
 
-        /**
-         * Removes an entry specified by a slot from the cache.
-         *
-         * If the cache entry corresponding to the slot number does not exist,
-         * the call does nothing.
-         *
-         * @param slot Slot identifier corresponding to the memory resource.
-         */
-        virtual void removeCacheEntry(int32_t slot) = 0;
+      private:
+        nn::GeneralResult<void> ensureCacheEntriesArePresentLocked(
+                const std::vector<int32_t>& slots) REQUIRES(mMutex);
+        nn::GeneralResult<std::pair<nn::SharedMemory, nn::IBurst::OptionalCacheHold>>
+        getCacheEntryLocked(int32_t slot) REQUIRES(mMutex);
+        void addCacheEntryLocked(int32_t slot, nn::SharedMemory memory) REQUIRES(mMutex);
 
-        /**
-         * Perform an execution.
-         *
-         * @param request Request object with inputs and outputs specified.
-         *     Request::pools is empty, and DataLocation::poolIndex instead
-         *     refers to the 'slots' argument as if it were Request::pools.
-         * @param slots Slots corresponding to the cached memory entries to be
-         *     used.
-         * @param measure Whether timing information is requested for the
-         *     execution.
-         * @return Result of the execution, including the status of the
-         *     execution, dynamic output shapes, and any timing information.
-         */
-        virtual std::tuple<hardware::neuralnetworks::V1_0::ErrorStatus,
-                           hardware::hidl_vec<hardware::neuralnetworks::V1_2::OutputShape>,
-                           hardware::neuralnetworks::V1_2::Timing>
-        execute(const hardware::neuralnetworks::V1_0::Request& request,
-                const std::vector<int32_t>& slots,
-                hardware::neuralnetworks::V1_2::MeasureTiming measure) = 0;
+        std::mutex mMutex;
+        std::map<int32_t, std::pair<nn::SharedMemory, nn::IBurst::OptionalCacheHold>> mCache
+                GUARDED_BY(mMutex);
+        nn::SharedBurst kBurstExecutor;
+        const sp<IBurstCallback> kBurstCallback;
     };
 
     /**
@@ -124,85 +104,52 @@
      * 2) Execute a model with the given information
      * 3) Send the result to the created FMQ
      *
-     * @param callback Callback used to retrieve memories corresponding to
-     *     unrecognized slots.
-     * @param requestChannel Input FMQ channel through which the client passes the
-     *     request to the service.
-     * @param resultChannel Output FMQ channel from which the client can retrieve
-     *     the result of the execution.
-     * @param executorWithCache Object which maintains a local cache of the
-     *     memory pools and executes using the cached memory pools.
-     * @param pollingTimeWindow How much time (in microseconds) the
-     *     ExecutionBurstServer is allowed to poll the FMQ before waiting on
-     *     the blocking futex. Polling may result in lower latencies at the
-     *     potential cost of more power usage.
-     * @result IBurstContext Handle to the burst context.
-     */
-    static sp<ExecutionBurstServer> create(
-            const sp<hardware::neuralnetworks::V1_2::IBurstCallback>& callback,
-            const FmqRequestDescriptor& requestChannel, const FmqResultDescriptor& resultChannel,
-            std::shared_ptr<IBurstExecutorWithCache> executorWithCache,
-            std::chrono::microseconds pollingTimeWindow = std::chrono::microseconds{0});
-
-    /**
-     * Create automated context to manage FMQ-based executions.
-     *
-     * This function is intended to be used by a service to automatically:
-     * 1) Receive data from a provided FMQ
-     * 2) Execute a model with the given information
-     * 3) Send the result to the created FMQ
-     *
-     * @param callback Callback used to retrieve memories corresponding to
-     *     unrecognized slots.
-     * @param requestChannel Input FMQ channel through which the client passes the
-     *     request to the service.
-     * @param resultChannel Output FMQ channel from which the client can retrieve
-     *     the result of the execution.
-     * @param preparedModel PreparedModel that the burst object was created from.
-     *     IPreparedModel::executeSynchronously will be used to perform the
+     * @param callback Callback used to retrieve memories corresponding to unrecognized slots.
+     * @param requestChannel Input FMQ channel through which the client passes the request to the
+     *     service.
+     * @param resultChannel Output FMQ channel from which the client can retrieve the result of the
      *     execution.
-     * @param pollingTimeWindow How much time (in microseconds) the
-     *     ExecutionBurstServer is allowed to poll the FMQ before waiting on
-     *     the blocking futex. Polling may result in lower latencies at the
-     *     potential cost of more power usage.
-     * @result IBurstContext Handle to the burst context.
+     * @param burstExecutor Object which maintains a local cache of the memory pools and executes
+     *     using the cached memory pools.
+     * @param pollingTimeWindow How much time (in microseconds) the ExecutionBurstServer is allowed
+     *     to poll the FMQ before waiting on the blocking futex. Polling may result in lower
+     *     latencies at the potential cost of more power usage.
+     * @return IBurstContext Handle to the burst context.
      */
-    static sp<ExecutionBurstServer> create(
-            const sp<hardware::neuralnetworks::V1_2::IBurstCallback>& callback,
-            const FmqRequestDescriptor& requestChannel, const FmqResultDescriptor& resultChannel,
-            hardware::neuralnetworks::V1_2::IPreparedModel* preparedModel,
+    static nn::GeneralResult<sp<ExecutionBurstServer>> create(
+            const sp<IBurstCallback>& callback,
+            const MQDescriptorSync<FmqRequestDatum>& requestChannel,
+            const MQDescriptorSync<FmqResultDatum>& resultChannel, nn::SharedBurst burstExecutor,
             std::chrono::microseconds pollingTimeWindow = std::chrono::microseconds{0});
 
-    ExecutionBurstServer(const sp<hardware::neuralnetworks::V1_2::IBurstCallback>& callback,
+    ExecutionBurstServer(PrivateConstructorTag tag, const sp<IBurstCallback>& callback,
                          std::unique_ptr<RequestChannelReceiver> requestChannel,
                          std::unique_ptr<ResultChannelSender> resultChannel,
-                         std::shared_ptr<IBurstExecutorWithCache> cachedExecutor);
+                         nn::SharedBurst burstExecutor);
     ~ExecutionBurstServer();
 
-    // Used by the NN runtime to preemptively remove any stored memory.
-    hardware::Return<void> freeMemory(int32_t slot) override;
+    // Used by the NN runtime to preemptively remove any stored memory. See
+    // IBurstContext::freeMemory for more information.
+    Return<void> freeMemory(int32_t slot) override;
 
   private:
-    // Ensures all cache entries contained in mExecutorWithCache are present in
-    // the cache. If they are not present, they are retrieved (via
-    // IBurstCallback::getMemories) and added to mExecutorWithCache.
-    //
-    // This method is locked via mMutex when it is called.
-    void ensureCacheEntriesArePresentLocked(const std::vector<int32_t>& slots);
-
-    // Work loop that will continue processing execution requests until the
-    // ExecutionBurstServer object is freed.
+    // Work loop that will continue processing execution requests until the ExecutionBurstServer
+    // object is freed.
     void task();
 
+    nn::ExecutionResult<std::pair<hidl_vec<OutputShape>, Timing>> execute(
+            const V1_0::Request& requestWithoutPools, const std::vector<int32_t>& slotsOfPools,
+            MeasureTiming measure);
+
     std::thread mWorker;
-    std::mutex mMutex;
     std::atomic<bool> mTeardown{false};
-    const sp<hardware::neuralnetworks::V1_2::IBurstCallback> mCallback;
+    const sp<IBurstCallback> mCallback;
     const std::unique_ptr<RequestChannelReceiver> mRequestChannelReceiver;
     const std::unique_ptr<ResultChannelSender> mResultChannelSender;
-    const std::shared_ptr<IBurstExecutorWithCache> mExecutorWithCache;
+    const nn::SharedBurst mBurstExecutor;
+    MemoryCache mMemoryCache;
 };
 
-}  // namespace android::nn
+}  // namespace android::hardware::neuralnetworks::V1_2::utils
 
-#endif  // ANDROID_FRAMEWORKS_ML_NN_COMMON_EXECUTION_BURST_SERVER_H
+#endif  // ANDROID_HARDWARE_INTERFACES_NEURALNETWORKS_1_2_UTILS_EXECUTION_BURST_SERVER_H
diff --git a/neuralnetworks/1.2/utils/include/nnapi/hal/1.2/ExecutionBurstUtils.h b/neuralnetworks/1.2/utils/include/nnapi/hal/1.2/ExecutionBurstUtils.h
index 8a41591..c662bc3 100644
--- a/neuralnetworks/1.2/utils/include/nnapi/hal/1.2/ExecutionBurstUtils.h
+++ b/neuralnetworks/1.2/utils/include/nnapi/hal/1.2/ExecutionBurstUtils.h
@@ -18,15 +18,16 @@
 #define ANDROID_HARDWARE_INTERFACES_NEURALNETWORKS_1_2_UTILS_EXECUTION_BURST_UTILS_H
 
 #include <android/hardware/neuralnetworks/1.0/types.h>
-#include <android/hardware/neuralnetworks/1.1/types.h>
 #include <android/hardware/neuralnetworks/1.2/types.h>
 #include <fmq/MessageQueue.h>
 #include <hidl/MQDescriptor.h>
+#include <nnapi/Result.h>
+#include <nnapi/Types.h>
+#include <nnapi/hal/ProtectCallback.h>
 
 #include <atomic>
 #include <chrono>
 #include <memory>
-#include <optional>
 #include <tuple>
 #include <utility>
 #include <vector>
@@ -38,159 +39,139 @@
  */
 constexpr const size_t kExecutionBurstChannelLength = 1024;
 
-using FmqRequestDescriptor = MQDescriptorSync<FmqRequestDatum>;
-using FmqResultDescriptor = MQDescriptorSync<FmqResultDatum>;
+/**
+ * Get how long the burst controller should poll while waiting for results to be returned.
+ *
+ * This time can be affected by the property "debug.nn.burst-controller-polling-window".
+ *
+ * @return Polling time in microseconds.
+ */
+std::chrono::microseconds getBurstControllerPollingTimeWindow();
+
+/**
+ * Get how long the burst server should poll while waiting for a request to be received.
+ *
+ * This time can be affected by the property "debug.nn.burst-server-polling-window".
+ *
+ * @return Polling time in microseconds.
+ */
+std::chrono::microseconds getBurstServerPollingTimeWindow();
 
 /**
  * Function to serialize a request.
  *
- * Prefer calling RequestChannelSender::send.
- *
  * @param request Request object without the pool information.
  * @param measure Whether to collect timing information for the execution.
- * @param memoryIds Slot identifiers corresponding to memory resources for the
- *     request.
+ * @param memoryIds Slot identifiers corresponding to memory resources for the request.
  * @return Serialized FMQ request data.
  */
-std::vector<hardware::neuralnetworks::V1_2::FmqRequestDatum> serialize(
-        const hardware::neuralnetworks::V1_0::Request& request,
-        hardware::neuralnetworks::V1_2::MeasureTiming measure, const std::vector<int32_t>& slots);
+std::vector<FmqRequestDatum> serialize(const V1_0::Request& request, MeasureTiming measure,
+                                       const std::vector<int32_t>& slots);
 
 /**
  * Deserialize the FMQ request data.
  *
- * The three resulting fields are the Request object (where Request::pools is
- * empty), slot identifiers (which are stand-ins for Request::pools), and
- * whether timing information must be collected for the run.
+ * The three resulting fields are the Request object (where Request::pools is empty), slot
+ * identifiers (which are stand-ins for Request::pools), and whether timing information must be
+ * collected for the run.
  *
  * @param data Serialized FMQ request data.
- * @return Request object if successfully deserialized, std::nullopt otherwise.
+ * @return Request object if successfully deserialized, otherwise an error message.
  */
-std::optional<std::tuple<hardware::neuralnetworks::V1_0::Request, std::vector<int32_t>,
-                         hardware::neuralnetworks::V1_2::MeasureTiming>>
-deserialize(const std::vector<hardware::neuralnetworks::V1_2::FmqRequestDatum>& data);
+nn::Result<std::tuple<V1_0::Request, std::vector<int32_t>, MeasureTiming>> deserialize(
+        const std::vector<FmqRequestDatum>& data);
 
 /**
  * Function to serialize results.
  *
- * Prefer calling ResultChannelSender::send.
- *
  * @param errorStatus Status of the execution.
  * @param outputShapes Dynamic shapes of the output tensors.
  * @param timing Timing information of the execution.
  * @return Serialized FMQ result data.
  */
-std::vector<hardware::neuralnetworks::V1_2::FmqResultDatum> serialize(
-        hardware::neuralnetworks::V1_0::ErrorStatus errorStatus,
-        const std::vector<hardware::neuralnetworks::V1_2::OutputShape>& outputShapes,
-        hardware::neuralnetworks::V1_2::Timing timing);
+std::vector<FmqResultDatum> serialize(V1_0::ErrorStatus errorStatus,
+                                      const std::vector<OutputShape>& outputShapes, Timing timing);
 
 /**
  * Deserialize the FMQ result data.
  *
- * The three resulting fields are the status of the execution, the dynamic
- * shapes of the output tensors, and the timing information of the execution.
+ * The three resulting fields are the status of the execution, the dynamic shapes of the output
+ * tensors, and the timing information of the execution.
  *
  * @param data Serialized FMQ result data.
- * @return Result object if successfully deserialized, std::nullopt otherwise.
+ * @return Result object if successfully deserialized, otherwise an error message.
  */
-std::optional<std::tuple<hardware::neuralnetworks::V1_0::ErrorStatus,
-                         std::vector<hardware::neuralnetworks::V1_2::OutputShape>,
-                         hardware::neuralnetworks::V1_2::Timing>>
-deserialize(const std::vector<hardware::neuralnetworks::V1_2::FmqResultDatum>& data);
+nn::Result<std::tuple<V1_0::ErrorStatus, std::vector<OutputShape>, Timing>> deserialize(
+        const std::vector<FmqResultDatum>& data);
 
 /**
- * Convert result code to error status.
- *
- * @param resultCode Result code to be converted.
- * @return ErrorStatus Resultant error status.
+ * RequestChannelSender is responsible for serializing the result packet of information, sending it
+ * on the result channel, and signaling that the data is available.
  */
-hardware::neuralnetworks::V1_0::ErrorStatus legacyConvertResultCodeToErrorStatus(int resultCode);
-
-/**
- * RequestChannelSender is responsible for serializing the result packet of
- * information, sending it on the result channel, and signaling that the data is
- * available.
- */
-class RequestChannelSender {
-    using FmqRequestDescriptor =
-            hardware::MQDescriptorSync<hardware::neuralnetworks::V1_2::FmqRequestDatum>;
-    using FmqRequestChannel =
-            hardware::MessageQueue<hardware::neuralnetworks::V1_2::FmqRequestDatum,
-                                   hardware::kSynchronizedReadWrite>;
+class RequestChannelSender final : public neuralnetworks::utils::IProtectedCallback {
+    struct PrivateConstructorTag {};
 
   public:
     /**
      * Create the sending end of a request channel.
      *
-     * Prefer this call over the constructor.
-     *
      * @param channelLength Number of elements in the FMQ.
-     * @return A pair of ResultChannelReceiver and the FMQ descriptor on
-     *     successful creation, both nullptr otherwise.
+     * @return A pair of ResultChannelReceiver and the FMQ descriptor on successful creation,
+     *     GeneralError otherwise.
      */
-    static std::pair<std::unique_ptr<RequestChannelSender>, const FmqRequestDescriptor*> create(
-            size_t channelLength);
+    static nn::GeneralResult<std::pair<std::unique_ptr<RequestChannelSender>,
+                                       const MQDescriptorSync<FmqRequestDatum>*>>
+    create(size_t channelLength);
 
     /**
      * Send the request to the channel.
      *
      * @param request Request object without the pool information.
      * @param measure Whether to collect timing information for the execution.
-     * @param memoryIds Slot identifiers corresponding to memory resources for
-     *     the request.
-     * @return 'true' on successful send, 'false' otherwise.
+     * @param slots Slot identifiers corresponding to memory resources for the request.
+     * @return An empty `Result` on successful send, otherwise an error message.
      */
-    bool send(const hardware::neuralnetworks::V1_0::Request& request,
-              hardware::neuralnetworks::V1_2::MeasureTiming measure,
-              const std::vector<int32_t>& slots);
+    nn::Result<void> send(const V1_0::Request& request, MeasureTiming measure,
+                          const std::vector<int32_t>& slots);
 
     /**
-     * Method to mark the channel as invalid, causing all future calls to
-     * RequestChannelSender::send to immediately return false without attempting
-     * to send a message across the FMQ.
+     * Method to mark the channel as invalid, causing all future calls to RequestChannelSender::send
+     * to immediately return false without attempting to send a message across the FMQ.
      */
-    void invalidate();
+    void notifyAsDeadObject() override;
 
     // prefer calling RequestChannelSender::send
-    bool sendPacket(const std::vector<hardware::neuralnetworks::V1_2::FmqRequestDatum>& packet);
+    nn::Result<void> sendPacket(const std::vector<FmqRequestDatum>& packet);
 
-    RequestChannelSender(std::unique_ptr<FmqRequestChannel> fmqRequestChannel);
+    RequestChannelSender(PrivateConstructorTag tag, size_t channelLength);
 
   private:
-    const std::unique_ptr<FmqRequestChannel> mFmqRequestChannel;
+    MessageQueue<FmqRequestDatum, kSynchronizedReadWrite> mFmqRequestChannel;
     std::atomic<bool> mValid{true};
 };
 
 /**
- * RequestChannelReceiver is responsible for waiting on the channel until the
- * packet is available, extracting the packet from the channel, and
- * deserializing the packet.
+ * RequestChannelReceiver is responsible for waiting on the channel until the packet is available,
+ * extracting the packet from the channel, and deserializing the packet.
  *
- * Because the receiver can wait on a packet that may never come (e.g., because
- * the sending side of the packet has been closed), this object can be
- * invalidated, unblocking the receiver.
+ * Because the receiver can wait on a packet that may never come (e.g., because the sending side of
+ * the packet has been closed), this object can be invalidated, unblocking the receiver.
  */
-class RequestChannelReceiver {
-    using FmqRequestChannel =
-            hardware::MessageQueue<hardware::neuralnetworks::V1_2::FmqRequestDatum,
-                                   hardware::kSynchronizedReadWrite>;
+class RequestChannelReceiver final {
+    struct PrivateConstructorTag {};
 
   public:
     /**
      * Create the receiving end of a request channel.
      *
-     * Prefer this call over the constructor.
-     *
      * @param requestChannel Descriptor for the request channel.
-     * @param pollingTimeWindow How much time (in microseconds) the
-     *     RequestChannelReceiver is allowed to poll the FMQ before waiting on
-     *     the blocking futex. Polling may result in lower latencies at the
-     *     potential cost of more power usage.
+     * @param pollingTimeWindow How much time (in microseconds) the RequestChannelReceiver is
+     *     allowed to poll the FMQ before waiting on the blocking futex. Polling may result in lower
+     *     latencies at the potential cost of more power usage.
      * @return RequestChannelReceiver on successful creation, nullptr otherwise.
      */
-    static std::unique_ptr<RequestChannelReceiver> create(
-            const FmqRequestDescriptor& requestChannel,
+    static nn::GeneralResult<std::unique_ptr<RequestChannelReceiver>> create(
+            const MQDescriptorSync<FmqRequestDatum>& requestChannel,
             std::chrono::microseconds pollingTimeWindow);
 
     /**
@@ -200,49 +181,45 @@
      * 1) The packet has been retrieved, or
      * 2) The receiver has been invalidated
      *
-     * @return Request object if successfully received, std::nullopt if error or
-     *     if the receiver object was invalidated.
+     * @return Request object if successfully received, an appropriate message if error or if the
+     *     receiver object was invalidated.
      */
-    std::optional<std::tuple<hardware::neuralnetworks::V1_0::Request, std::vector<int32_t>,
-                             hardware::neuralnetworks::V1_2::MeasureTiming>>
-    getBlocking();
+    nn::Result<std::tuple<V1_0::Request, std::vector<int32_t>, MeasureTiming>> getBlocking();
 
     /**
-     * Method to mark the channel as invalid, unblocking any current or future
-     * calls to RequestChannelReceiver::getBlocking.
+     * Method to mark the channel as invalid, unblocking any current or future calls to
+     * RequestChannelReceiver::getBlocking.
      */
     void invalidate();
 
-    RequestChannelReceiver(std::unique_ptr<FmqRequestChannel> fmqRequestChannel,
+    RequestChannelReceiver(PrivateConstructorTag tag,
+                           const MQDescriptorSync<FmqRequestDatum>& requestChannel,
                            std::chrono::microseconds pollingTimeWindow);
 
   private:
-    std::optional<std::vector<hardware::neuralnetworks::V1_2::FmqRequestDatum>> getPacketBlocking();
+    nn::Result<std::vector<FmqRequestDatum>> getPacketBlocking();
 
-    const std::unique_ptr<FmqRequestChannel> mFmqRequestChannel;
+    MessageQueue<FmqRequestDatum, kSynchronizedReadWrite> mFmqRequestChannel;
     std::atomic<bool> mTeardown{false};
     const std::chrono::microseconds kPollingTimeWindow;
 };
 
 /**
- * ResultChannelSender is responsible for serializing the result packet of
- * information, sending it on the result channel, and signaling that the data is
- * available.
+ * ResultChannelSender is responsible for serializing the result packet of information, sending it
+ * on the result channel, and signaling that the data is available.
  */
-class ResultChannelSender {
-    using FmqResultChannel = hardware::MessageQueue<hardware::neuralnetworks::V1_2::FmqResultDatum,
-                                                    hardware::kSynchronizedReadWrite>;
+class ResultChannelSender final {
+    struct PrivateConstructorTag {};
 
   public:
     /**
      * Create the sending end of a result channel.
      *
-     * Prefer this call over the constructor.
-     *
      * @param resultChannel Descriptor for the result channel.
      * @return ResultChannelSender on successful creation, nullptr otherwise.
      */
-    static std::unique_ptr<ResultChannelSender> create(const FmqResultDescriptor& resultChannel);
+    static nn::GeneralResult<std::unique_ptr<ResultChannelSender>> create(
+            const MQDescriptorSync<FmqResultDatum>& resultChannel);
 
     /**
      * Send the result to the channel.
@@ -250,52 +227,44 @@
      * @param errorStatus Status of the execution.
      * @param outputShapes Dynamic shapes of the output tensors.
      * @param timing Timing information of the execution.
-     * @return 'true' on successful send, 'false' otherwise.
      */
-    bool send(hardware::neuralnetworks::V1_0::ErrorStatus errorStatus,
-              const std::vector<hardware::neuralnetworks::V1_2::OutputShape>& outputShapes,
-              hardware::neuralnetworks::V1_2::Timing timing);
+    void send(V1_0::ErrorStatus errorStatus, const std::vector<OutputShape>& outputShapes,
+              Timing timing);
 
     // prefer calling ResultChannelSender::send
-    bool sendPacket(const std::vector<hardware::neuralnetworks::V1_2::FmqResultDatum>& packet);
+    void sendPacket(const std::vector<FmqResultDatum>& packet);
 
-    ResultChannelSender(std::unique_ptr<FmqResultChannel> fmqResultChannel);
+    ResultChannelSender(PrivateConstructorTag tag,
+                        const MQDescriptorSync<FmqResultDatum>& resultChannel);
 
   private:
-    const std::unique_ptr<FmqResultChannel> mFmqResultChannel;
+    MessageQueue<FmqResultDatum, kSynchronizedReadWrite> mFmqResultChannel;
 };
 
 /**
- * ResultChannelReceiver is responsible for waiting on the channel until the
- * packet is available, extracting the packet from the channel, and
- * deserializing the packet.
+ * ResultChannelReceiver is responsible for waiting on the channel until the packet is available,
+ * extracting the packet from the channel, and deserializing the packet.
  *
- * Because the receiver can wait on a packet that may never come (e.g., because
- * the sending side of the packet has been closed), this object can be
- * invalidated, unblocking the receiver.
+ * Because the receiver can wait on a packet that may never come (e.g., because the sending side of
+ * the packet has been closed), this object can be invalidated, unblocking the receiver.
  */
-class ResultChannelReceiver {
-    using FmqResultDescriptor =
-            hardware::MQDescriptorSync<hardware::neuralnetworks::V1_2::FmqResultDatum>;
-    using FmqResultChannel = hardware::MessageQueue<hardware::neuralnetworks::V1_2::FmqResultDatum,
-                                                    hardware::kSynchronizedReadWrite>;
+class ResultChannelReceiver final : public neuralnetworks::utils::IProtectedCallback {
+    struct PrivateConstructorTag {};
 
   public:
     /**
      * Create the receiving end of a result channel.
      *
-     * Prefer this call over the constructor.
-     *
      * @param channelLength Number of elements in the FMQ.
-     * @param pollingTimeWindow How much time (in microseconds) the
-     *     ResultChannelReceiver is allowed to poll the FMQ before waiting on
-     *     the blocking futex. Polling may result in lower latencies at the
-     *     potential cost of more power usage.
-     * @return A pair of ResultChannelReceiver and the FMQ descriptor on
-     *     successful creation, both nullptr otherwise.
+     * @param pollingTimeWindow How much time (in microseconds) the ResultChannelReceiver is allowed
+     *     to poll the FMQ before waiting on the blocking futex. Polling may result in lower
+     *     latencies at the potential cost of more power usage.
+     * @return A pair of ResultChannelReceiver and the FMQ descriptor on successful creation, or
+     *     GeneralError otherwise.
      */
-    static std::pair<std::unique_ptr<ResultChannelReceiver>, const FmqResultDescriptor*> create(
-            size_t channelLength, std::chrono::microseconds pollingTimeWindow);
+    static nn::GeneralResult<std::pair<std::unique_ptr<ResultChannelReceiver>,
+                                       const MQDescriptorSync<FmqResultDatum>*>>
+    create(size_t channelLength, std::chrono::microseconds pollingTimeWindow);
 
     /**
      * Get the result from the channel.
@@ -304,28 +273,25 @@
      * 1) The packet has been retrieved, or
      * 2) The receiver has been invalidated
      *
-     * @return Result object if successfully received, std::nullopt if error or
+     * @return Result object if successfully received, otherwise an appropriate message if error or
      *     if the receiver object was invalidated.
      */
-    std::optional<std::tuple<hardware::neuralnetworks::V1_0::ErrorStatus,
-                             std::vector<hardware::neuralnetworks::V1_2::OutputShape>,
-                             hardware::neuralnetworks::V1_2::Timing>>
-    getBlocking();
+    nn::Result<std::tuple<V1_0::ErrorStatus, std::vector<OutputShape>, Timing>> getBlocking();
 
     /**
-     * Method to mark the channel as invalid, unblocking any current or future
-     * calls to ResultChannelReceiver::getBlocking.
+     * Method to mark the channel as invalid, unblocking any current or future calls to
+     * ResultChannelReceiver::getBlocking.
      */
-    void invalidate();
+    void notifyAsDeadObject() override;
 
     // prefer calling ResultChannelReceiver::getBlocking
-    std::optional<std::vector<hardware::neuralnetworks::V1_2::FmqResultDatum>> getPacketBlocking();
+    nn::Result<std::vector<FmqResultDatum>> getPacketBlocking();
 
-    ResultChannelReceiver(std::unique_ptr<FmqResultChannel> fmqResultChannel,
+    ResultChannelReceiver(PrivateConstructorTag tag, size_t channelLength,
                           std::chrono::microseconds pollingTimeWindow);
 
   private:
-    const std::unique_ptr<FmqResultChannel> mFmqResultChannel;
+    MessageQueue<FmqResultDatum, kSynchronizedReadWrite> mFmqResultChannel;
     std::atomic<bool> mValid{true};
     const std::chrono::microseconds kPollingTimeWindow;
 };
diff --git a/neuralnetworks/1.2/utils/src/Conversions.cpp b/neuralnetworks/1.2/utils/src/Conversions.cpp
index 86a417a..2c45583 100644
--- a/neuralnetworks/1.2/utils/src/Conversions.cpp
+++ b/neuralnetworks/1.2/utils/src/Conversions.cpp
@@ -331,6 +331,10 @@
     return validatedConvert(timing);
 }
 
+GeneralResult<SharedMemory> convert(const hardware::hidl_memory& memory) {
+    return validatedConvert(memory);
+}
+
 GeneralResult<std::vector<Extension>> convert(const hidl_vec<hal::V1_2::Extension>& extensions) {
     return validatedConvert(extensions);
 }
diff --git a/neuralnetworks/1.2/utils/src/ExecutionBurstController.cpp b/neuralnetworks/1.2/utils/src/ExecutionBurstController.cpp
index 2265861..eedf591 100644
--- a/neuralnetworks/1.2/utils/src/ExecutionBurstController.cpp
+++ b/neuralnetworks/1.2/utils/src/ExecutionBurstController.cpp
@@ -17,283 +17,321 @@
 #define LOG_TAG "ExecutionBurstController"
 
 #include "ExecutionBurstController.h"
+#include "ExecutionBurstUtils.h"
 
 #include <android-base/logging.h>
+#include <android-base/thread_annotations.h>
+#include <nnapi/IBurst.h>
+#include <nnapi/IPreparedModel.h>
+#include <nnapi/Result.h>
+#include <nnapi/TypeUtils.h>
+#include <nnapi/Types.h>
+#include <nnapi/Validation.h>
+#include <nnapi/hal/1.0/Conversions.h>
+#include <nnapi/hal/HandleError.h>
+#include <nnapi/hal/ProtectCallback.h>
+#include <nnapi/hal/TransferValue.h>
 
 #include <algorithm>
 #include <cstring>
 #include <limits>
 #include <memory>
 #include <string>
+#include <thread>
 #include <tuple>
 #include <utility>
 #include <vector>
 
-#include "ExecutionBurstUtils.h"
-#include "HalInterfaces.h"
+#include "Callbacks.h"
+#include "Conversions.h"
 #include "Tracing.h"
 #include "Utils.h"
 
-namespace android::nn {
+namespace android::hardware::neuralnetworks::V1_2::utils {
 namespace {
 
-class BurstContextDeathHandler : public hardware::hidl_death_recipient {
-  public:
-    using Callback = std::function<void()>;
-
-    BurstContextDeathHandler(const Callback& onDeathCallback) : mOnDeathCallback(onDeathCallback) {
-        CHECK(onDeathCallback != nullptr);
+nn::GeneralResult<sp<IBurstContext>> executionBurstResultCallback(
+        V1_0::ErrorStatus status, const sp<IBurstContext>& burstContext) {
+    HANDLE_HAL_STATUS(status) << "IPreparedModel::configureExecutionBurst failed with status "
+                              << toString(status);
+    if (burstContext == nullptr) {
+        return NN_ERROR(nn::ErrorStatus::GENERAL_FAILURE)
+               << "IPreparedModel::configureExecutionBurst returned nullptr for burst";
     }
-
-    void serviceDied(uint64_t /*cookie*/, const wp<hidl::base::V1_0::IBase>& /*who*/) override {
-        LOG(ERROR) << "BurstContextDeathHandler::serviceDied -- service unexpectedly died!";
-        mOnDeathCallback();
-    }
-
-  private:
-    const Callback mOnDeathCallback;
-};
-
-}  // anonymous namespace
-
-hardware::Return<void> ExecutionBurstController::ExecutionBurstCallback::getMemories(
-        const hardware::hidl_vec<int32_t>& slots, getMemories_cb cb) {
-    std::lock_guard<std::mutex> guard(mMutex);
-
-    // get all memories
-    hardware::hidl_vec<hardware::hidl_memory> memories(slots.size());
-    std::transform(slots.begin(), slots.end(), memories.begin(), [this](int32_t slot) {
-        return slot < mMemoryCache.size() ? mMemoryCache[slot] : hardware::hidl_memory{};
-    });
-
-    // ensure all memories are valid
-    if (!std::all_of(memories.begin(), memories.end(),
-                     [](const hardware::hidl_memory& memory) { return memory.valid(); })) {
-        cb(V1_0::ErrorStatus::INVALID_ARGUMENT, {});
-        return hardware::Void();
-    }
-
-    // return successful
-    cb(V1_0::ErrorStatus::NONE, std::move(memories));
-    return hardware::Void();
+    return burstContext;
 }
 
-std::vector<int32_t> ExecutionBurstController::ExecutionBurstCallback::getSlots(
-        const hardware::hidl_vec<hardware::hidl_memory>& memories,
-        const std::vector<intptr_t>& keys) {
-    std::lock_guard<std::mutex> guard(mMutex);
-
-    // retrieve (or bind) all slots corresponding to memories
-    std::vector<int32_t> slots;
-    slots.reserve(memories.size());
-    for (size_t i = 0; i < memories.size(); ++i) {
-        slots.push_back(getSlotLocked(memories[i], keys[i]));
+nn::GeneralResult<hidl_vec<hidl_memory>> getMemoriesHelper(
+        const hidl_vec<int32_t>& slots,
+        const std::shared_ptr<ExecutionBurstController::MemoryCache>& memoryCache) {
+    hidl_vec<hidl_memory> memories(slots.size());
+    for (size_t i = 0; i < slots.size(); ++i) {
+        const int32_t slot = slots[i];
+        const auto memory = NN_TRY(memoryCache->getMemory(slot));
+        memories[i] = NN_TRY(V1_0::utils::unvalidatedConvert(memory));
+        if (!memories[i].valid()) {
+            return NN_ERROR() << "memory at slot " << slot << " is invalid";
+        }
     }
-    return slots;
+    return memories;
 }
 
-std::pair<bool, int32_t> ExecutionBurstController::ExecutionBurstCallback::freeMemory(
-        intptr_t key) {
-    std::lock_guard<std::mutex> guard(mMutex);
+}  // namespace
 
-    auto iter = mMemoryIdToSlot.find(key);
-    if (iter == mMemoryIdToSlot.end()) {
-        return {false, 0};
-    }
-    const int32_t slot = iter->second;
-    mMemoryIdToSlot.erase(key);
-    mMemoryCache[slot] = {};
-    mFreeSlots.push(slot);
-    return {true, slot};
+// MemoryCache methods
+
+ExecutionBurstController::MemoryCache::MemoryCache() {
+    constexpr size_t kPreallocatedCount = 1024;
+    std::vector<int32_t> freeSlotsSpace;
+    freeSlotsSpace.reserve(kPreallocatedCount);
+    mFreeSlots = std::stack<int32_t, std::vector<int32_t>>(std::move(freeSlotsSpace));
+    mMemoryCache.reserve(kPreallocatedCount);
+    mCacheCleaner.reserve(kPreallocatedCount);
 }
 
-int32_t ExecutionBurstController::ExecutionBurstCallback::getSlotLocked(
-        const hardware::hidl_memory& memory, intptr_t key) {
-    auto iter = mMemoryIdToSlot.find(key);
-    if (iter == mMemoryIdToSlot.end()) {
-        const int32_t slot = allocateSlotLocked();
-        mMemoryIdToSlot[key] = slot;
-        mMemoryCache[slot] = memory;
-        return slot;
-    } else {
+void ExecutionBurstController::MemoryCache::setBurstContext(sp<IBurstContext> burstContext) {
+    std::lock_guard guard(mMutex);
+    mBurstContext = std::move(burstContext);
+}
+
+std::pair<int32_t, ExecutionBurstController::MemoryCache::SharedCleanup>
+ExecutionBurstController::MemoryCache::cacheMemory(const nn::SharedMemory& memory) {
+    std::unique_lock lock(mMutex);
+    base::ScopedLockAssertion lockAssert(mMutex);
+
+    // Use existing cache entry if (1) the Memory object is in the cache and (2) the cache entry is
+    // not currently being freed.
+    auto iter = mMemoryIdToSlot.find(memory);
+    while (iter != mMemoryIdToSlot.end()) {
         const int32_t slot = iter->second;
-        return slot;
+        if (auto cleaner = mCacheCleaner.at(slot).lock()) {
+            return std::make_pair(slot, std::move(cleaner));
+        }
+
+        // If the code reaches this point, the Memory object was in the cache, but is currently
+        // being destroyed. This code waits until the cache entry has been freed, then loops to
+        // ensure the cache entry has been freed or has been made present by another thread.
+        mCond.wait(lock);
+        iter = mMemoryIdToSlot.find(memory);
     }
+
+    // Allocate a new cache entry.
+    const int32_t slot = allocateSlotLocked();
+    mMemoryIdToSlot[memory] = slot;
+    mMemoryCache[slot] = memory;
+
+    // Create reference-counted self-cleaning cache object.
+    auto self = weak_from_this();
+    Task cleanup = [memory, memoryCache = std::move(self)] {
+        if (const auto lock = memoryCache.lock()) {
+            lock->freeMemory(memory);
+        }
+    };
+    auto cleaner = std::make_shared<const Cleanup>(std::move(cleanup));
+    mCacheCleaner[slot] = cleaner;
+
+    return std::make_pair(slot, std::move(cleaner));
 }
 
-int32_t ExecutionBurstController::ExecutionBurstCallback::allocateSlotLocked() {
+nn::GeneralResult<nn::SharedMemory> ExecutionBurstController::MemoryCache::getMemory(int32_t slot) {
+    std::lock_guard guard(mMutex);
+    if (slot < 0 || static_cast<size_t>(slot) >= mMemoryCache.size()) {
+        return NN_ERROR() << "Invalid slot: " << slot << " vs " << mMemoryCache.size();
+    }
+    return mMemoryCache[slot];
+}
+
+void ExecutionBurstController::MemoryCache::freeMemory(const nn::SharedMemory& memory) {
+    {
+        std::lock_guard guard(mMutex);
+        const int32_t slot = mMemoryIdToSlot.at(memory);
+        if (mBurstContext) {
+            mBurstContext->freeMemory(slot);
+        }
+        mMemoryIdToSlot.erase(memory);
+        mMemoryCache[slot] = {};
+        mCacheCleaner[slot].reset();
+        mFreeSlots.push(slot);
+    }
+    mCond.notify_all();
+}
+
+int32_t ExecutionBurstController::MemoryCache::allocateSlotLocked() {
     constexpr size_t kMaxNumberOfSlots = std::numeric_limits<int32_t>::max();
 
-    // if there is a free slot, use it
-    if (mFreeSlots.size() > 0) {
+    // If there is a free slot, use it.
+    if (!mFreeSlots.empty()) {
         const int32_t slot = mFreeSlots.top();
         mFreeSlots.pop();
         return slot;
     }
 
-    // otherwise use a slot for the first time
-    CHECK(mMemoryCache.size() < kMaxNumberOfSlots) << "Exceeded maximum number of slots!";
+    // Use a slot for the first time.
+    CHECK_LT(mMemoryCache.size(), kMaxNumberOfSlots) << "Exceeded maximum number of slots!";
     const int32_t slot = static_cast<int32_t>(mMemoryCache.size());
     mMemoryCache.emplace_back();
+    mCacheCleaner.emplace_back();
 
     return slot;
 }
 
-std::unique_ptr<ExecutionBurstController> ExecutionBurstController::create(
-        const sp<V1_2::IPreparedModel>& preparedModel,
+// ExecutionBurstCallback methods
+
+ExecutionBurstController::ExecutionBurstCallback::ExecutionBurstCallback(
+        const std::shared_ptr<MemoryCache>& memoryCache)
+    : kMemoryCache(memoryCache) {
+    CHECK(memoryCache != nullptr);
+}
+
+Return<void> ExecutionBurstController::ExecutionBurstCallback::getMemories(
+        const hidl_vec<int32_t>& slots, getMemories_cb cb) {
+    const auto memoryCache = kMemoryCache.lock();
+    if (memoryCache == nullptr) {
+        LOG(ERROR) << "ExecutionBurstController::ExecutionBurstCallback::getMemories called after "
+                      "the MemoryCache has been freed";
+        cb(V1_0::ErrorStatus::GENERAL_FAILURE, {});
+        return Void();
+    }
+
+    const auto maybeMemories = getMemoriesHelper(slots, memoryCache);
+    if (!maybeMemories.has_value()) {
+        const auto& [message, code] = maybeMemories.error();
+        LOG(ERROR) << "ExecutionBurstController::ExecutionBurstCallback::getMemories failed with "
+                   << code << ": " << message;
+        cb(V1_0::ErrorStatus::INVALID_ARGUMENT, {});
+        return Void();
+    }
+
+    cb(V1_0::ErrorStatus::NONE, maybeMemories.value());
+    return Void();
+}
+
+// ExecutionBurstController methods
+
+nn::GeneralResult<std::shared_ptr<const ExecutionBurstController>> ExecutionBurstController::create(
+        const sp<V1_2::IPreparedModel>& preparedModel, FallbackFunction fallback,
         std::chrono::microseconds pollingTimeWindow) {
     // check inputs
     if (preparedModel == nullptr) {
-        LOG(ERROR) << "ExecutionBurstController::create passed a nullptr";
-        return nullptr;
+        return NN_ERROR() << "ExecutionBurstController::create passed a nullptr";
     }
 
-    // create callback object
-    sp<ExecutionBurstCallback> callback = new ExecutionBurstCallback();
-
     // create FMQ objects
-    auto [requestChannelSenderTemp, requestChannelDescriptor] =
-            RequestChannelSender::create(kExecutionBurstChannelLength);
-    auto [resultChannelReceiverTemp, resultChannelDescriptor] =
-            ResultChannelReceiver::create(kExecutionBurstChannelLength, pollingTimeWindow);
-    std::shared_ptr<RequestChannelSender> requestChannelSender =
-            std::move(requestChannelSenderTemp);
-    std::shared_ptr<ResultChannelReceiver> resultChannelReceiver =
-            std::move(resultChannelReceiverTemp);
+    auto [requestChannelSender, requestChannelDescriptor] =
+            NN_TRY(RequestChannelSender::create(kExecutionBurstChannelLength));
+    auto [resultChannelReceiver, resultChannelDescriptor] =
+            NN_TRY(ResultChannelReceiver::create(kExecutionBurstChannelLength, pollingTimeWindow));
 
     // check FMQ objects
-    if (!requestChannelSender || !resultChannelReceiver || !requestChannelDescriptor ||
-        !resultChannelDescriptor) {
-        LOG(ERROR) << "ExecutionBurstController::create failed to create FastMessageQueue";
-        return nullptr;
-    }
+    CHECK(requestChannelSender != nullptr);
+    CHECK(requestChannelDescriptor != nullptr);
+    CHECK(resultChannelReceiver != nullptr);
+    CHECK(resultChannelDescriptor != nullptr);
+
+    // create memory cache
+    auto memoryCache = std::make_shared<MemoryCache>();
+
+    // create callback object
+    auto burstCallback = sp<ExecutionBurstCallback>::make(memoryCache);
+    auto cb = hal::utils::CallbackValue(executionBurstResultCallback);
 
     // configure burst
-    V1_0::ErrorStatus errorStatus;
-    sp<IBurstContext> burstContext;
-    const hardware::Return<void> ret = preparedModel->configureExecutionBurst(
-            callback, *requestChannelDescriptor, *resultChannelDescriptor,
-            [&errorStatus, &burstContext](V1_0::ErrorStatus status,
-                                          const sp<IBurstContext>& context) {
-                errorStatus = status;
-                burstContext = context;
-            });
+    const Return<void> ret = preparedModel->configureExecutionBurst(
+            burstCallback, *requestChannelDescriptor, *resultChannelDescriptor, cb);
+    HANDLE_TRANSPORT_FAILURE(ret);
 
-    // check burst
-    if (!ret.isOk()) {
-        LOG(ERROR) << "IPreparedModel::configureExecutionBurst failed with description "
-                   << ret.description();
-        return nullptr;
-    }
-    if (errorStatus != V1_0::ErrorStatus::NONE) {
-        LOG(ERROR) << "IPreparedModel::configureExecutionBurst failed with status "
-                   << toString(errorStatus);
-        return nullptr;
-    }
-    if (burstContext == nullptr) {
-        LOG(ERROR) << "IPreparedModel::configureExecutionBurst returned nullptr for burst";
-        return nullptr;
-    }
+    auto burstContext = NN_TRY(cb.take());
+    memoryCache->setBurstContext(burstContext);
 
     // create death handler object
-    BurstContextDeathHandler::Callback onDeathCallback = [requestChannelSender,
-                                                          resultChannelReceiver] {
-        requestChannelSender->invalidate();
-        resultChannelReceiver->invalidate();
-    };
-    const sp<BurstContextDeathHandler> deathHandler = new BurstContextDeathHandler(onDeathCallback);
-
-    // linkToDeath registers a callback that will be invoked on service death to
-    // proactively handle service crashes. If the linkToDeath call fails,
-    // asynchronous calls are susceptible to hangs if the service crashes before
-    // providing the response.
-    const hardware::Return<bool> deathHandlerRet = burstContext->linkToDeath(deathHandler, 0);
-    if (!deathHandlerRet.isOk() || deathHandlerRet != true) {
-        LOG(ERROR) << "ExecutionBurstController::create -- Failed to register a death recipient "
-                      "for the IBurstContext object.";
-        return nullptr;
-    }
+    auto deathHandler = NN_TRY(neuralnetworks::utils::DeathHandler::create(burstContext));
+    deathHandler.protectCallbackForLifetimeOfDeathHandler(requestChannelSender.get());
+    deathHandler.protectCallbackForLifetimeOfDeathHandler(resultChannelReceiver.get());
 
     // make and return controller
-    return std::make_unique<ExecutionBurstController>(requestChannelSender, resultChannelReceiver,
-                                                      burstContext, callback, deathHandler);
+    return std::make_shared<const ExecutionBurstController>(
+            PrivateConstructorTag{}, std::move(fallback), std::move(requestChannelSender),
+            std::move(resultChannelReceiver), std::move(burstCallback), std::move(burstContext),
+            std::move(memoryCache), std::move(deathHandler));
 }
 
 ExecutionBurstController::ExecutionBurstController(
-        const std::shared_ptr<RequestChannelSender>& requestChannelSender,
-        const std::shared_ptr<ResultChannelReceiver>& resultChannelReceiver,
-        const sp<IBurstContext>& burstContext, const sp<ExecutionBurstCallback>& callback,
-        const sp<hardware::hidl_death_recipient>& deathHandler)
-    : mRequestChannelSender(requestChannelSender),
-      mResultChannelReceiver(resultChannelReceiver),
-      mBurstContext(burstContext),
-      mMemoryCache(callback),
-      mDeathHandler(deathHandler) {}
+        PrivateConstructorTag /*tag*/, FallbackFunction fallback,
+        std::unique_ptr<RequestChannelSender> requestChannelSender,
+        std::unique_ptr<ResultChannelReceiver> resultChannelReceiver,
+        sp<ExecutionBurstCallback> callback, sp<IBurstContext> burstContext,
+        std::shared_ptr<MemoryCache> memoryCache, neuralnetworks::utils::DeathHandler deathHandler)
+    : kFallback(std::move(fallback)),
+      mRequestChannelSender(std::move(requestChannelSender)),
+      mResultChannelReceiver(std::move(resultChannelReceiver)),
+      mBurstCallback(std::move(callback)),
+      mBurstContext(std::move(burstContext)),
+      mMemoryCache(std::move(memoryCache)),
+      kDeathHandler(std::move(deathHandler)) {}
 
-ExecutionBurstController::~ExecutionBurstController() {
-    // It is safe to ignore any errors resulting from this unlinkToDeath call
-    // because the ExecutionBurstController object is already being destroyed
-    // and its underlying IBurstContext object is no longer being used by the NN
-    // runtime.
-    if (mDeathHandler) {
-        mBurstContext->unlinkToDeath(mDeathHandler).isOk();
+ExecutionBurstController::OptionalCacheHold ExecutionBurstController::cacheMemory(
+        const nn::SharedMemory& memory) const {
+    auto [slot, hold] = mMemoryCache->cacheMemory(memory);
+    return hold;
+}
+
+nn::ExecutionResult<std::pair<std::vector<nn::OutputShape>, nn::Timing>>
+ExecutionBurstController::execute(const nn::Request& request, nn::MeasureTiming measure) const {
+    // This is the first point when we know an execution is occurring, so begin to collect
+    // systraces. Note that the first point we can begin collecting systraces in
+    // ExecutionBurstServer is when the RequestChannelReceiver realizes there is data in the FMQ, so
+    // ExecutionBurstServer collects systraces at different points in the code.
+    NNTRACE_FULL(NNTRACE_LAYER_IPC, NNTRACE_PHASE_EXECUTION, "ExecutionBurstController::execute");
+
+    // if the request is valid but of a higher version than what's supported in burst execution,
+    // fall back to another execution path
+    if (const auto version = NN_TRY(hal::utils::makeExecutionFailure(nn::validate(request)));
+        version > nn::Version::ANDROID_Q) {
+        // fallback to another execution path if the packet could not be sent
+        if (kFallback) {
+            return kFallback(request, measure);
+        }
+        return NN_ERROR() << "Request object has features not supported by IBurst::execute";
     }
-}
 
-static std::tuple<int, std::vector<V1_2::OutputShape>, V1_2::Timing, bool> getExecutionResult(
-        V1_0::ErrorStatus status, std::vector<V1_2::OutputShape> outputShapes, V1_2::Timing timing,
-        bool fallback) {
-    auto [n, checkedOutputShapes, checkedTiming] =
-            getExecutionResult(convertToV1_3(status), std::move(outputShapes), timing);
-    return {n, convertToV1_2(checkedOutputShapes), convertToV1_2(checkedTiming), fallback};
-}
+    // clear pools field of request, as they will be provided via slots
+    const auto requestWithoutPools =
+            nn::Request{.inputs = request.inputs, .outputs = request.outputs, .pools = {}};
+    auto hidlRequest = NN_TRY(
+            hal::utils::makeExecutionFailure(V1_0::utils::unvalidatedConvert(requestWithoutPools)));
+    const auto hidlMeasure = NN_TRY(hal::utils::makeExecutionFailure(convert(measure)));
 
-std::tuple<int, std::vector<V1_2::OutputShape>, V1_2::Timing, bool>
-ExecutionBurstController::compute(const V1_0::Request& request, V1_2::MeasureTiming measure,
-                                  const std::vector<intptr_t>& memoryIds) {
-    // This is the first point when we know an execution is occurring, so begin
-    // to collect systraces. Note that the first point we can begin collecting
-    // systraces in ExecutionBurstServer is when the RequestChannelReceiver
-    // realizes there is data in the FMQ, so ExecutionBurstServer collects
-    // systraces at different points in the code.
-    NNTRACE_FULL(NNTRACE_LAYER_IPC, NNTRACE_PHASE_EXECUTION, "ExecutionBurstController::compute");
+    // Ensure that at most one execution is in flight at any given time.
+    const bool alreadyInFlight = mExecutionInFlight.test_and_set();
+    if (alreadyInFlight) {
+        return NN_ERROR() << "IBurst already has an execution in flight";
+    }
+    const auto guard = base::make_scope_guard([this] { mExecutionInFlight.clear(); });
 
-    std::lock_guard<std::mutex> guard(mMutex);
+    std::vector<int32_t> slots;
+    std::vector<OptionalCacheHold> holds;
+    slots.reserve(request.pools.size());
+    holds.reserve(request.pools.size());
+    for (const auto& memoryPool : request.pools) {
+        auto [slot, hold] = mMemoryCache->cacheMemory(std::get<nn::SharedMemory>(memoryPool));
+        slots.push_back(slot);
+        holds.push_back(std::move(hold));
+    }
 
     // send request packet
-    const std::vector<int32_t> slots = mMemoryCache->getSlots(request.pools, memoryIds);
-    const bool success = mRequestChannelSender->send(request, measure, slots);
-    if (!success) {
-        LOG(ERROR) << "Error sending FMQ packet";
-        // only use fallback execution path if the packet could not be sent
-        return getExecutionResult(V1_0::ErrorStatus::GENERAL_FAILURE, {}, kNoTiming12,
-                                  /*fallback=*/true);
+    const auto sendStatus = mRequestChannelSender->send(hidlRequest, hidlMeasure, slots);
+    if (!sendStatus.ok()) {
+        // fallback to another execution path if the packet could not be sent
+        if (kFallback) {
+            return kFallback(request, measure);
+        }
+        return NN_ERROR() << "Error sending FMQ packet: " << sendStatus.error();
     }
 
     // get result packet
-    const auto result = mResultChannelReceiver->getBlocking();
-    if (!result) {
-        LOG(ERROR) << "Error retrieving FMQ packet";
-        // only use fallback execution path if the packet could not be sent
-        return getExecutionResult(V1_0::ErrorStatus::GENERAL_FAILURE, {}, kNoTiming12,
-                                  /*fallback=*/false);
-    }
-
-    // unpack results and return (only use fallback execution path if the
-    // packet could not be sent)
-    auto [status, outputShapes, timing] = std::move(*result);
-    return getExecutionResult(status, std::move(outputShapes), timing, /*fallback=*/false);
+    const auto [status, outputShapes, timing] =
+            NN_TRY(hal::utils::makeExecutionFailure(mResultChannelReceiver->getBlocking()));
+    return executionCallback(status, outputShapes, timing);
 }
 
-void ExecutionBurstController::freeMemory(intptr_t key) {
-    std::lock_guard<std::mutex> guard(mMutex);
-
-    bool valid;
-    int32_t slot;
-    std::tie(valid, slot) = mMemoryCache->freeMemory(key);
-    if (valid) {
-        mBurstContext->freeMemory(slot).isOk();
-    }
-}
-
-}  // namespace android::nn
+}  // namespace android::hardware::neuralnetworks::V1_2::utils
diff --git a/neuralnetworks/1.2/utils/src/ExecutionBurstServer.cpp b/neuralnetworks/1.2/utils/src/ExecutionBurstServer.cpp
index 022548d..50af881 100644
--- a/neuralnetworks/1.2/utils/src/ExecutionBurstServer.cpp
+++ b/neuralnetworks/1.2/utils/src/ExecutionBurstServer.cpp
@@ -17,8 +17,19 @@
 #define LOG_TAG "ExecutionBurstServer"
 
 #include "ExecutionBurstServer.h"
+#include "Conversions.h"
+#include "ExecutionBurstUtils.h"
 
 #include <android-base/logging.h>
+#include <nnapi/IBurst.h>
+#include <nnapi/Result.h>
+#include <nnapi/TypeUtils.h>
+#include <nnapi/Types.h>
+#include <nnapi/Validation.h>
+#include <nnapi/hal/1.0/Conversions.h>
+#include <nnapi/hal/HandleError.h>
+#include <nnapi/hal/ProtectCallback.h>
+#include <nnapi/hal/TransferValue.h>
 
 #include <algorithm>
 #include <cstring>
@@ -29,134 +40,146 @@
 #include <utility>
 #include <vector>
 
-#include "ExecutionBurstUtils.h"
-#include "HalInterfaces.h"
 #include "Tracing.h"
 
-namespace android::nn {
+namespace android::hardware::neuralnetworks::V1_2::utils {
 namespace {
 
-// DefaultBurstExecutorWithCache adapts an IPreparedModel so that it can be
-// used as an IBurstExecutorWithCache. Specifically, the cache simply stores the
-// hidl_memory object, and the execution forwards calls to the provided
-// IPreparedModel's "executeSynchronously" method. With this class, hidl_memory
-// must be mapped and unmapped for each execution.
-class DefaultBurstExecutorWithCache : public ExecutionBurstServer::IBurstExecutorWithCache {
-  public:
-    DefaultBurstExecutorWithCache(V1_2::IPreparedModel* preparedModel)
-        : mpPreparedModel(preparedModel) {}
+using neuralnetworks::utils::makeExecutionFailure;
 
-    bool isCacheEntryPresent(int32_t slot) const override {
-        const auto it = mMemoryCache.find(slot);
-        return (it != mMemoryCache.end()) && it->second.valid();
+constexpr V1_2::Timing kNoTiming = {std::numeric_limits<uint64_t>::max(),
+                                    std::numeric_limits<uint64_t>::max()};
+
+nn::GeneralResult<std::vector<nn::SharedMemory>> getMemoriesCallback(
+        V1_0::ErrorStatus status, const hidl_vec<hidl_memory>& memories) {
+    HANDLE_HAL_STATUS(status) << "getting burst memories failed with " << toString(status);
+    std::vector<nn::SharedMemory> canonicalMemories;
+    canonicalMemories.reserve(memories.size());
+    for (const auto& memory : memories) {
+        canonicalMemories.push_back(NN_TRY(nn::convert(memory)));
     }
-
-    void addCacheEntry(const hardware::hidl_memory& memory, int32_t slot) override {
-        mMemoryCache[slot] = memory;
-    }
-
-    void removeCacheEntry(int32_t slot) override { mMemoryCache.erase(slot); }
-
-    std::tuple<V1_0::ErrorStatus, hardware::hidl_vec<V1_2::OutputShape>, V1_2::Timing> execute(
-            const V1_0::Request& request, const std::vector<int32_t>& slots,
-            V1_2::MeasureTiming measure) override {
-        // convert slots to pools
-        hardware::hidl_vec<hardware::hidl_memory> pools(slots.size());
-        std::transform(slots.begin(), slots.end(), pools.begin(),
-                       [this](int32_t slot) { return mMemoryCache[slot]; });
-
-        // create full request
-        V1_0::Request fullRequest = request;
-        fullRequest.pools = std::move(pools);
-
-        // setup execution
-        V1_0::ErrorStatus returnedStatus = V1_0::ErrorStatus::GENERAL_FAILURE;
-        hardware::hidl_vec<V1_2::OutputShape> returnedOutputShapes;
-        V1_2::Timing returnedTiming;
-        auto cb = [&returnedStatus, &returnedOutputShapes, &returnedTiming](
-                          V1_0::ErrorStatus status,
-                          const hardware::hidl_vec<V1_2::OutputShape>& outputShapes,
-                          const V1_2::Timing& timing) {
-            returnedStatus = status;
-            returnedOutputShapes = outputShapes;
-            returnedTiming = timing;
-        };
-
-        // execute
-        const hardware::Return<void> ret =
-                mpPreparedModel->executeSynchronously(fullRequest, measure, cb);
-        if (!ret.isOk() || returnedStatus != V1_0::ErrorStatus::NONE) {
-            LOG(ERROR) << "IPreparedModelAdapter::execute -- Error executing";
-            return {returnedStatus, std::move(returnedOutputShapes), kNoTiming};
-        }
-
-        return std::make_tuple(returnedStatus, std::move(returnedOutputShapes), returnedTiming);
-    }
-
-  private:
-    V1_2::IPreparedModel* const mpPreparedModel;
-    std::map<int32_t, hardware::hidl_memory> mMemoryCache;
-};
+    return canonicalMemories;
+}
 
 }  // anonymous namespace
 
+ExecutionBurstServer::MemoryCache::MemoryCache(nn::SharedBurst burstExecutor,
+                                               sp<IBurstCallback> burstCallback)
+    : kBurstExecutor(std::move(burstExecutor)), kBurstCallback(std::move(burstCallback)) {
+    CHECK(kBurstExecutor != nullptr);
+    CHECK(kBurstCallback != nullptr);
+}
+
+nn::GeneralResult<std::vector<std::pair<nn::SharedMemory, nn::IBurst::OptionalCacheHold>>>
+ExecutionBurstServer::MemoryCache::getCacheEntries(const std::vector<int32_t>& slots) {
+    std::lock_guard guard(mMutex);
+    NN_TRY(ensureCacheEntriesArePresentLocked(slots));
+
+    std::vector<std::pair<nn::SharedMemory, nn::IBurst::OptionalCacheHold>> results;
+    results.reserve(slots.size());
+    for (int32_t slot : slots) {
+        results.push_back(NN_TRY(getCacheEntryLocked(slot)));
+    }
+
+    return results;
+}
+
+nn::GeneralResult<void> ExecutionBurstServer::MemoryCache::ensureCacheEntriesArePresentLocked(
+        const std::vector<int32_t>& slots) {
+    const auto slotIsKnown = [this](int32_t slot)
+                                     REQUIRES(mMutex) { return mCache.count(slot) > 0; };
+
+    // find unique unknown slots
+    std::vector<int32_t> unknownSlots = slots;
+    std::sort(unknownSlots.begin(), unknownSlots.end());
+    auto unknownSlotsEnd = std::unique(unknownSlots.begin(), unknownSlots.end());
+    unknownSlotsEnd = std::remove_if(unknownSlots.begin(), unknownSlotsEnd, slotIsKnown);
+    unknownSlots.erase(unknownSlotsEnd, unknownSlots.end());
+
+    // quick-exit if all slots are known
+    if (unknownSlots.empty()) {
+        return {};
+    }
+
+    auto cb = neuralnetworks::utils::CallbackValue(getMemoriesCallback);
+
+    const auto ret = kBurstCallback->getMemories(unknownSlots, cb);
+    HANDLE_TRANSPORT_FAILURE(ret);
+
+    auto returnedMemories = NN_TRY(cb.take());
+
+    if (returnedMemories.size() != unknownSlots.size()) {
+        return NN_ERROR()
+               << "ExecutionBurstServer::MemoryCache::ensureCacheEntriesArePresentLocked: Error "
+                  "retrieving memories -- count mismatch between requested memories ("
+               << unknownSlots.size() << ") and returned memories (" << returnedMemories.size()
+               << ")";
+    }
+
+    // add memories to unknown slots
+    for (size_t i = 0; i < unknownSlots.size(); ++i) {
+        addCacheEntryLocked(unknownSlots[i], std::move(returnedMemories[i]));
+    }
+
+    return {};
+}
+
+nn::GeneralResult<std::pair<nn::SharedMemory, nn::IBurst::OptionalCacheHold>>
+ExecutionBurstServer::MemoryCache::getCacheEntryLocked(int32_t slot) {
+    if (const auto iter = mCache.find(slot); iter != mCache.end()) {
+        return iter->second;
+    }
+    return NN_ERROR()
+           << "ExecutionBurstServer::MemoryCache::getCacheEntryLocked failed because slot " << slot
+           << " is not present in the cache";
+}
+
+void ExecutionBurstServer::MemoryCache::addCacheEntryLocked(int32_t slot, nn::SharedMemory memory) {
+    auto hold = kBurstExecutor->cacheMemory(memory);
+    mCache.emplace(slot, std::make_pair(std::move(memory), std::move(hold)));
+}
+
+void ExecutionBurstServer::MemoryCache::removeCacheEntry(int32_t slot) {
+    std::lock_guard guard(mMutex);
+    mCache.erase(slot);
+}
+
 // ExecutionBurstServer methods
 
-sp<ExecutionBurstServer> ExecutionBurstServer::create(
+nn::GeneralResult<sp<ExecutionBurstServer>> ExecutionBurstServer::create(
         const sp<IBurstCallback>& callback, const MQDescriptorSync<FmqRequestDatum>& requestChannel,
-        const MQDescriptorSync<FmqResultDatum>& resultChannel,
-        std::shared_ptr<IBurstExecutorWithCache> executorWithCache,
+        const MQDescriptorSync<FmqResultDatum>& resultChannel, nn::SharedBurst burstExecutor,
         std::chrono::microseconds pollingTimeWindow) {
     // check inputs
-    if (callback == nullptr || executorWithCache == nullptr) {
-        LOG(ERROR) << "ExecutionBurstServer::create passed a nullptr";
-        return nullptr;
+    if (callback == nullptr || burstExecutor == nullptr) {
+        return NN_ERROR() << "ExecutionBurstServer::create passed a nullptr";
     }
 
     // create FMQ objects
-    std::unique_ptr<RequestChannelReceiver> requestChannelReceiver =
-            RequestChannelReceiver::create(requestChannel, pollingTimeWindow);
-    std::unique_ptr<ResultChannelSender> resultChannelSender =
-            ResultChannelSender::create(resultChannel);
+    auto requestChannelReceiver =
+            NN_TRY(RequestChannelReceiver::create(requestChannel, pollingTimeWindow));
+    auto resultChannelSender = NN_TRY(ResultChannelSender::create(resultChannel));
 
     // check FMQ objects
-    if (!requestChannelReceiver || !resultChannelSender) {
-        LOG(ERROR) << "ExecutionBurstServer::create failed to create FastMessageQueue";
-        return nullptr;
-    }
+    CHECK(requestChannelReceiver != nullptr);
+    CHECK(resultChannelSender != nullptr);
 
     // make and return context
-    return new ExecutionBurstServer(callback, std::move(requestChannelReceiver),
-                                    std::move(resultChannelSender), std::move(executorWithCache));
+    return sp<ExecutionBurstServer>::make(PrivateConstructorTag{}, callback,
+                                          std::move(requestChannelReceiver),
+                                          std::move(resultChannelSender), std::move(burstExecutor));
 }
 
-sp<ExecutionBurstServer> ExecutionBurstServer::create(
-        const sp<IBurstCallback>& callback, const MQDescriptorSync<FmqRequestDatum>& requestChannel,
-        const MQDescriptorSync<FmqResultDatum>& resultChannel, V1_2::IPreparedModel* preparedModel,
-        std::chrono::microseconds pollingTimeWindow) {
-    // check relevant input
-    if (preparedModel == nullptr) {
-        LOG(ERROR) << "ExecutionBurstServer::create passed a nullptr";
-        return nullptr;
-    }
-
-    // adapt IPreparedModel to have caching
-    const std::shared_ptr<DefaultBurstExecutorWithCache> preparedModelAdapter =
-            std::make_shared<DefaultBurstExecutorWithCache>(preparedModel);
-
-    // make and return context
-    return ExecutionBurstServer::create(callback, requestChannel, resultChannel,
-                                        preparedModelAdapter, pollingTimeWindow);
-}
-
-ExecutionBurstServer::ExecutionBurstServer(
-        const sp<IBurstCallback>& callback, std::unique_ptr<RequestChannelReceiver> requestChannel,
-        std::unique_ptr<ResultChannelSender> resultChannel,
-        std::shared_ptr<IBurstExecutorWithCache> executorWithCache)
+ExecutionBurstServer::ExecutionBurstServer(PrivateConstructorTag /*tag*/,
+                                           const sp<IBurstCallback>& callback,
+                                           std::unique_ptr<RequestChannelReceiver> requestChannel,
+                                           std::unique_ptr<ResultChannelSender> resultChannel,
+                                           nn::SharedBurst burstExecutor)
     : mCallback(callback),
       mRequestChannelReceiver(std::move(requestChannel)),
       mResultChannelSender(std::move(resultChannel)),
-      mExecutorWithCache(std::move(executorWithCache)) {
+      mBurstExecutor(std::move(burstExecutor)),
+      mMemoryCache(mBurstExecutor, mCallback) {
     // TODO: highly document the threading behavior of this class
     mWorker = std::thread([this] { task(); });
 }
@@ -170,51 +193,9 @@
     mWorker.join();
 }
 
-hardware::Return<void> ExecutionBurstServer::freeMemory(int32_t slot) {
-    std::lock_guard<std::mutex> hold(mMutex);
-    mExecutorWithCache->removeCacheEntry(slot);
-    return hardware::Void();
-}
-
-void ExecutionBurstServer::ensureCacheEntriesArePresentLocked(const std::vector<int32_t>& slots) {
-    const auto slotIsKnown = [this](int32_t slot) {
-        return mExecutorWithCache->isCacheEntryPresent(slot);
-    };
-
-    // find unique unknown slots
-    std::vector<int32_t> unknownSlots = slots;
-    auto unknownSlotsEnd = unknownSlots.end();
-    std::sort(unknownSlots.begin(), unknownSlotsEnd);
-    unknownSlotsEnd = std::unique(unknownSlots.begin(), unknownSlotsEnd);
-    unknownSlotsEnd = std::remove_if(unknownSlots.begin(), unknownSlotsEnd, slotIsKnown);
-    unknownSlots.erase(unknownSlotsEnd, unknownSlots.end());
-
-    // quick-exit if all slots are known
-    if (unknownSlots.empty()) {
-        return;
-    }
-
-    V1_0::ErrorStatus errorStatus = V1_0::ErrorStatus::GENERAL_FAILURE;
-    std::vector<hardware::hidl_memory> returnedMemories;
-    auto cb = [&errorStatus, &returnedMemories](
-                      V1_0::ErrorStatus status,
-                      const hardware::hidl_vec<hardware::hidl_memory>& memories) {
-        errorStatus = status;
-        returnedMemories = memories;
-    };
-
-    const hardware::Return<void> ret = mCallback->getMemories(unknownSlots, cb);
-
-    if (!ret.isOk() || errorStatus != V1_0::ErrorStatus::NONE ||
-        returnedMemories.size() != unknownSlots.size()) {
-        LOG(ERROR) << "Error retrieving memories";
-        return;
-    }
-
-    // add memories to unknown slots
-    for (size_t i = 0; i < unknownSlots.size(); ++i) {
-        mExecutorWithCache->addCacheEntry(returnedMemories[i], unknownSlots[i]);
-    }
+Return<void> ExecutionBurstServer::freeMemory(int32_t slot) {
+    mMemoryCache.removeCacheEntry(slot);
+    return Void();
 }
 
 void ExecutionBurstServer::task() {
@@ -223,38 +204,65 @@
         // receive request
         auto arguments = mRequestChannelReceiver->getBlocking();
 
-        // if the request packet was not properly received, return a generic
-        // error and skip the execution
+        // if the request packet was not properly received, return a generic error and skip the
+        // execution
         //
-        // if the burst is being torn down, skip the execution so the "task"
-        // function can end
-        if (!arguments) {
+        // if the burst is being torn down, skip the execution so the "task" function can end
+        if (!arguments.has_value()) {
             if (!mTeardown) {
                 mResultChannelSender->send(V1_0::ErrorStatus::GENERAL_FAILURE, {}, kNoTiming);
             }
             continue;
         }
 
-        // otherwise begin tracing execution
-        NNTRACE_FULL(NNTRACE_LAYER_IPC, NNTRACE_PHASE_EXECUTION,
-                     "ExecutionBurstServer getting memory, executing, and returning results");
+        // unpack the arguments; types are Request, std::vector<int32_t>, and MeasureTiming,
+        // respectively
+        const auto [requestWithoutPools, slotsOfPools, measure] = std::move(arguments).value();
 
-        // unpack the arguments; types are Request, std::vector<int32_t>, and
-        // MeasureTiming, respectively
-        const auto [requestWithoutPools, slotsOfPools, measure] = std::move(*arguments);
-
-        // ensure executor with cache has required memory
-        std::lock_guard<std::mutex> hold(mMutex);
-        ensureCacheEntriesArePresentLocked(slotsOfPools);
-
-        // perform computation; types are ErrorStatus, hidl_vec<OutputShape>,
-        // and Timing, respectively
-        const auto [errorStatus, outputShapes, returnedTiming] =
-                mExecutorWithCache->execute(requestWithoutPools, slotsOfPools, measure);
+        auto result = execute(requestWithoutPools, slotsOfPools, measure);
 
         // return result
-        mResultChannelSender->send(errorStatus, outputShapes, returnedTiming);
+        if (result.has_value()) {
+            const auto& [outputShapes, timing] = result.value();
+            mResultChannelSender->send(V1_0::ErrorStatus::NONE, outputShapes, timing);
+        } else {
+            const auto& [message, code, outputShapes] = result.error();
+            LOG(ERROR) << "IBurst::execute failed with " << code << ": " << message;
+            mResultChannelSender->send(convert(code).value(), convert(outputShapes).value(),
+                                       kNoTiming);
+        }
     }
 }
 
-}  // namespace android::nn
+nn::ExecutionResult<std::pair<hidl_vec<OutputShape>, Timing>> ExecutionBurstServer::execute(
+        const V1_0::Request& requestWithoutPools, const std::vector<int32_t>& slotsOfPools,
+        MeasureTiming measure) {
+    NNTRACE_FULL(NNTRACE_LAYER_IPC, NNTRACE_PHASE_EXECUTION,
+                 "ExecutionBurstServer getting memory, executing, and returning results");
+
+    // ensure executor with cache has required memory
+    const auto cacheEntries =
+            NN_TRY(makeExecutionFailure(mMemoryCache.getCacheEntries(slotsOfPools)));
+
+    // convert request, populating its pools
+    // This code performs an unvalidated convert because the request object without its pools is
+    // invalid because it is incomplete. Instead, the validation is performed after the memory pools
+    // have been added to the request.
+    auto canonicalRequest =
+            NN_TRY(makeExecutionFailure(nn::unvalidatedConvert(requestWithoutPools)));
+    CHECK(canonicalRequest.pools.empty());
+    std::transform(cacheEntries.begin(), cacheEntries.end(),
+                   std::back_inserter(canonicalRequest.pools),
+                   [](const auto& cacheEntry) { return cacheEntry.first; });
+    NN_TRY(makeExecutionFailure(validate(canonicalRequest)));
+
+    nn::MeasureTiming canonicalMeasure = NN_TRY(makeExecutionFailure(nn::convert(measure)));
+
+    const auto [outputShapes, timing] =
+            NN_TRY(mBurstExecutor->execute(canonicalRequest, canonicalMeasure));
+
+    return std::make_pair(NN_TRY(makeExecutionFailure(convert(outputShapes))),
+                          NN_TRY(makeExecutionFailure(convert(timing))));
+}
+
+}  // namespace android::hardware::neuralnetworks::V1_2::utils
diff --git a/neuralnetworks/1.2/utils/src/ExecutionBurstUtils.cpp b/neuralnetworks/1.2/utils/src/ExecutionBurstUtils.cpp
index f0275f9..ca3a52c 100644
--- a/neuralnetworks/1.2/utils/src/ExecutionBurstUtils.cpp
+++ b/neuralnetworks/1.2/utils/src/ExecutionBurstUtils.cpp
@@ -19,11 +19,15 @@
 #include "ExecutionBurstUtils.h"
 
 #include <android-base/logging.h>
+#include <android-base/properties.h>
 #include <android/hardware/neuralnetworks/1.0/types.h>
 #include <android/hardware/neuralnetworks/1.1/types.h>
 #include <android/hardware/neuralnetworks/1.2/types.h>
 #include <fmq/MessageQueue.h>
 #include <hidl/MQDescriptor.h>
+#include <nnapi/Result.h>
+#include <nnapi/Types.h>
+#include <nnapi/hal/ProtectCallback.h>
 
 #include <atomic>
 #include <chrono>
@@ -39,84 +43,97 @@
 constexpr V1_2::Timing kNoTiming = {std::numeric_limits<uint64_t>::max(),
                                     std::numeric_limits<uint64_t>::max()};
 
+std::chrono::microseconds getPollingTimeWindow(const std::string& property) {
+    constexpr int32_t kDefaultPollingTimeWindow = 0;
+#ifdef NN_DEBUGGABLE
+    constexpr int32_t kMinPollingTimeWindow = 0;
+    const int32_t selectedPollingTimeWindow =
+            base::GetIntProperty(property, kDefaultPollingTimeWindow, kMinPollingTimeWindow);
+    return std::chrono::microseconds(selectedPollingTimeWindow);
+#else
+    (void)property;
+    return std::chrono::microseconds(kDefaultPollingTimeWindow);
+#endif  // NN_DEBUGGABLE
+}
+
+}  // namespace
+
+std::chrono::microseconds getBurstControllerPollingTimeWindow() {
+    return getPollingTimeWindow("debug.nn.burst-controller-polling-window");
+}
+
+std::chrono::microseconds getBurstServerPollingTimeWindow() {
+    return getPollingTimeWindow("debug.nn.burst-server-polling-window");
 }
 
 // serialize a request into a packet
 std::vector<FmqRequestDatum> serialize(const V1_0::Request& request, V1_2::MeasureTiming measure,
                                        const std::vector<int32_t>& slots) {
     // count how many elements need to be sent for a request
-    size_t count = 2 + request.inputs.size() + request.outputs.size() + request.pools.size();
+    size_t count = 2 + request.inputs.size() + request.outputs.size() + slots.size();
     for (const auto& input : request.inputs) {
         count += input.dimensions.size();
     }
     for (const auto& output : request.outputs) {
         count += output.dimensions.size();
     }
+    CHECK_LE(count, std::numeric_limits<uint32_t>::max());
 
     // create buffer to temporarily store elements
     std::vector<FmqRequestDatum> data;
     data.reserve(count);
 
     // package packetInfo
-    {
-        FmqRequestDatum datum;
-        datum.packetInformation(
-                {/*.packetSize=*/static_cast<uint32_t>(count),
-                 /*.numberOfInputOperands=*/static_cast<uint32_t>(request.inputs.size()),
-                 /*.numberOfOutputOperands=*/static_cast<uint32_t>(request.outputs.size()),
-                 /*.numberOfPools=*/static_cast<uint32_t>(request.pools.size())});
-        data.push_back(datum);
-    }
+    data.emplace_back();
+    data.back().packetInformation(
+            {.packetSize = static_cast<uint32_t>(count),
+             .numberOfInputOperands = static_cast<uint32_t>(request.inputs.size()),
+             .numberOfOutputOperands = static_cast<uint32_t>(request.outputs.size()),
+             .numberOfPools = static_cast<uint32_t>(slots.size())});
 
     // package input data
     for (const auto& input : request.inputs) {
         // package operand information
-        FmqRequestDatum datum;
-        datum.inputOperandInformation(
-                {/*.hasNoValue=*/input.hasNoValue,
-                 /*.location=*/input.location,
-                 /*.numberOfDimensions=*/static_cast<uint32_t>(input.dimensions.size())});
-        data.push_back(datum);
+        data.emplace_back();
+        data.back().inputOperandInformation(
+                {.hasNoValue = input.hasNoValue,
+                 .location = input.location,
+                 .numberOfDimensions = static_cast<uint32_t>(input.dimensions.size())});
 
         // package operand dimensions
         for (uint32_t dimension : input.dimensions) {
-            FmqRequestDatum datum;
-            datum.inputOperandDimensionValue(dimension);
-            data.push_back(datum);
+            data.emplace_back();
+            data.back().inputOperandDimensionValue(dimension);
         }
     }
 
     // package output data
     for (const auto& output : request.outputs) {
         // package operand information
-        FmqRequestDatum datum;
-        datum.outputOperandInformation(
-                {/*.hasNoValue=*/output.hasNoValue,
-                 /*.location=*/output.location,
-                 /*.numberOfDimensions=*/static_cast<uint32_t>(output.dimensions.size())});
-        data.push_back(datum);
+        data.emplace_back();
+        data.back().outputOperandInformation(
+                {.hasNoValue = output.hasNoValue,
+                 .location = output.location,
+                 .numberOfDimensions = static_cast<uint32_t>(output.dimensions.size())});
 
         // package operand dimensions
         for (uint32_t dimension : output.dimensions) {
-            FmqRequestDatum datum;
-            datum.outputOperandDimensionValue(dimension);
-            data.push_back(datum);
+            data.emplace_back();
+            data.back().outputOperandDimensionValue(dimension);
         }
     }
 
     // package pool identifier
     for (int32_t slot : slots) {
-        FmqRequestDatum datum;
-        datum.poolIdentifier(slot);
-        data.push_back(datum);
+        data.emplace_back();
+        data.back().poolIdentifier(slot);
     }
 
     // package measureTiming
-    {
-        FmqRequestDatum datum;
-        datum.measureTiming(measure);
-        data.push_back(datum);
-    }
+    data.emplace_back();
+    data.back().measureTiming(measure);
+
+    CHECK_EQ(data.size(), count);
 
     // return packet
     return data;
@@ -137,46 +154,38 @@
     data.reserve(count);
 
     // package packetInfo
-    {
-        FmqResultDatum datum;
-        datum.packetInformation({/*.packetSize=*/static_cast<uint32_t>(count),
-                                 /*.errorStatus=*/errorStatus,
-                                 /*.numberOfOperands=*/static_cast<uint32_t>(outputShapes.size())});
-        data.push_back(datum);
-    }
+    data.emplace_back();
+    data.back().packetInformation({.packetSize = static_cast<uint32_t>(count),
+                                   .errorStatus = errorStatus,
+                                   .numberOfOperands = static_cast<uint32_t>(outputShapes.size())});
 
     // package output shape data
     for (const auto& operand : outputShapes) {
         // package operand information
-        FmqResultDatum::OperandInformation info{};
-        info.isSufficient = operand.isSufficient;
-        info.numberOfDimensions = static_cast<uint32_t>(operand.dimensions.size());
-
-        FmqResultDatum datum;
-        datum.operandInformation(info);
-        data.push_back(datum);
+        data.emplace_back();
+        data.back().operandInformation(
+                {.isSufficient = operand.isSufficient,
+                 .numberOfDimensions = static_cast<uint32_t>(operand.dimensions.size())});
 
         // package operand dimensions
         for (uint32_t dimension : operand.dimensions) {
-            FmqResultDatum datum;
-            datum.operandDimensionValue(dimension);
-            data.push_back(datum);
+            data.emplace_back();
+            data.back().operandDimensionValue(dimension);
         }
     }
 
     // package executionTiming
-    {
-        FmqResultDatum datum;
-        datum.executionTiming(timing);
-        data.push_back(datum);
-    }
+    data.emplace_back();
+    data.back().executionTiming(timing);
+
+    CHECK_EQ(data.size(), count);
 
     // return result
     return data;
 }
 
 // deserialize request
-std::optional<std::tuple<V1_0::Request, std::vector<int32_t>, V1_2::MeasureTiming>> deserialize(
+nn::Result<std::tuple<V1_0::Request, std::vector<int32_t>, V1_2::MeasureTiming>> deserialize(
         const std::vector<FmqRequestDatum>& data) {
     using discriminator = FmqRequestDatum::hidl_discriminator;
 
@@ -184,8 +193,7 @@
 
     // validate packet information
     if (data.size() == 0 || data[index].getDiscriminator() != discriminator::packetInformation) {
-        LOG(ERROR) << "FMQ Request packet ill-formed";
-        return std::nullopt;
+        return NN_ERROR() << "FMQ Request packet ill-formed";
     }
 
     // unpackage packet information
@@ -198,8 +206,7 @@
 
     // verify packet size
     if (data.size() != packetSize) {
-        LOG(ERROR) << "FMQ Request packet ill-formed";
-        return std::nullopt;
+        return NN_ERROR() << "FMQ Request packet ill-formed";
     }
 
     // unpackage input operands
@@ -208,8 +215,7 @@
     for (size_t operand = 0; operand < numberOfInputOperands; ++operand) {
         // validate input operand information
         if (data[index].getDiscriminator() != discriminator::inputOperandInformation) {
-            LOG(ERROR) << "FMQ Request packet ill-formed";
-            return std::nullopt;
+            return NN_ERROR() << "FMQ Request packet ill-formed";
         }
 
         // unpackage operand information
@@ -226,8 +232,7 @@
         for (size_t i = 0; i < numberOfDimensions; ++i) {
             // validate dimension
             if (data[index].getDiscriminator() != discriminator::inputOperandDimensionValue) {
-                LOG(ERROR) << "FMQ Request packet ill-formed";
-                return std::nullopt;
+                return NN_ERROR() << "FMQ Request packet ill-formed";
             }
 
             // unpackage dimension
@@ -240,7 +245,7 @@
 
         // store result
         inputs.push_back(
-                {/*.hasNoValue=*/hasNoValue, /*.location=*/location, /*.dimensions=*/dimensions});
+                {.hasNoValue = hasNoValue, .location = location, .dimensions = dimensions});
     }
 
     // unpackage output operands
@@ -249,8 +254,7 @@
     for (size_t operand = 0; operand < numberOfOutputOperands; ++operand) {
         // validate output operand information
         if (data[index].getDiscriminator() != discriminator::outputOperandInformation) {
-            LOG(ERROR) << "FMQ Request packet ill-formed";
-            return std::nullopt;
+            return NN_ERROR() << "FMQ Request packet ill-formed";
         }
 
         // unpackage operand information
@@ -267,8 +271,7 @@
         for (size_t i = 0; i < numberOfDimensions; ++i) {
             // validate dimension
             if (data[index].getDiscriminator() != discriminator::outputOperandDimensionValue) {
-                LOG(ERROR) << "FMQ Request packet ill-formed";
-                return std::nullopt;
+                return NN_ERROR() << "FMQ Request packet ill-formed";
             }
 
             // unpackage dimension
@@ -281,7 +284,7 @@
 
         // store result
         outputs.push_back(
-                {/*.hasNoValue=*/hasNoValue, /*.location=*/location, /*.dimensions=*/dimensions});
+                {.hasNoValue = hasNoValue, .location = location, .dimensions = dimensions});
     }
 
     // unpackage pools
@@ -290,8 +293,7 @@
     for (size_t pool = 0; pool < numberOfPools; ++pool) {
         // validate input operand information
         if (data[index].getDiscriminator() != discriminator::poolIdentifier) {
-            LOG(ERROR) << "FMQ Request packet ill-formed";
-            return std::nullopt;
+            return NN_ERROR() << "FMQ Request packet ill-formed";
         }
 
         // unpackage operand information
@@ -304,8 +306,7 @@
 
     // validate measureTiming
     if (data[index].getDiscriminator() != discriminator::measureTiming) {
-        LOG(ERROR) << "FMQ Request packet ill-formed";
-        return std::nullopt;
+        return NN_ERROR() << "FMQ Request packet ill-formed";
     }
 
     // unpackage measureTiming
@@ -314,27 +315,23 @@
 
     // validate packet information
     if (index != packetSize) {
-        LOG(ERROR) << "FMQ Result packet ill-formed";
-        return std::nullopt;
+        return NN_ERROR() << "FMQ Result packet ill-formed";
     }
 
     // return request
-    V1_0::Request request = {/*.inputs=*/inputs, /*.outputs=*/outputs, /*.pools=*/{}};
+    V1_0::Request request = {.inputs = inputs, .outputs = outputs, .pools = {}};
     return std::make_tuple(std::move(request), std::move(slots), measure);
 }
 
 // deserialize a packet into the result
-std::optional<std::tuple<V1_0::ErrorStatus, std::vector<V1_2::OutputShape>, V1_2::Timing>>
-deserialize(const std::vector<FmqResultDatum>& data) {
+nn::Result<std::tuple<V1_0::ErrorStatus, std::vector<V1_2::OutputShape>, V1_2::Timing>> deserialize(
+        const std::vector<FmqResultDatum>& data) {
     using discriminator = FmqResultDatum::hidl_discriminator;
-
-    std::vector<V1_2::OutputShape> outputShapes;
     size_t index = 0;
 
     // validate packet information
     if (data.size() == 0 || data[index].getDiscriminator() != discriminator::packetInformation) {
-        LOG(ERROR) << "FMQ Result packet ill-formed";
-        return std::nullopt;
+        return NN_ERROR() << "FMQ Result packet ill-formed";
     }
 
     // unpackage packet information
@@ -346,16 +343,16 @@
 
     // verify packet size
     if (data.size() != packetSize) {
-        LOG(ERROR) << "FMQ Result packet ill-formed";
-        return std::nullopt;
+        return NN_ERROR() << "FMQ Result packet ill-formed";
     }
 
     // unpackage operands
+    std::vector<V1_2::OutputShape> outputShapes;
+    outputShapes.reserve(numberOfOperands);
     for (size_t operand = 0; operand < numberOfOperands; ++operand) {
         // validate operand information
         if (data[index].getDiscriminator() != discriminator::operandInformation) {
-            LOG(ERROR) << "FMQ Result packet ill-formed";
-            return std::nullopt;
+            return NN_ERROR() << "FMQ Result packet ill-formed";
         }
 
         // unpackage operand information
@@ -370,8 +367,7 @@
         for (size_t i = 0; i < numberOfDimensions; ++i) {
             // validate dimension
             if (data[index].getDiscriminator() != discriminator::operandDimensionValue) {
-                LOG(ERROR) << "FMQ Result packet ill-formed";
-                return std::nullopt;
+                return NN_ERROR() << "FMQ Result packet ill-formed";
             }
 
             // unpackage dimension
@@ -383,13 +379,12 @@
         }
 
         // store result
-        outputShapes.push_back({/*.dimensions=*/dimensions, /*.isSufficient=*/isSufficient});
+        outputShapes.push_back({.dimensions = dimensions, .isSufficient = isSufficient});
     }
 
     // validate execution timing
     if (data[index].getDiscriminator() != discriminator::executionTiming) {
-        LOG(ERROR) << "FMQ Result packet ill-formed";
-        return std::nullopt;
+        return NN_ERROR() << "FMQ Result packet ill-formed";
     }
 
     // unpackage execution timing
@@ -398,123 +393,113 @@
 
     // validate packet information
     if (index != packetSize) {
-        LOG(ERROR) << "FMQ Result packet ill-formed";
-        return std::nullopt;
+        return NN_ERROR() << "FMQ Result packet ill-formed";
     }
 
     // return result
     return std::make_tuple(errorStatus, std::move(outputShapes), timing);
 }
 
-V1_0::ErrorStatus legacyConvertResultCodeToErrorStatus(int resultCode) {
-    return convertToV1_0(convertResultCodeToErrorStatus(resultCode));
-}
-
 // RequestChannelSender methods
 
-std::pair<std::unique_ptr<RequestChannelSender>, const FmqRequestDescriptor*>
+nn::GeneralResult<
+        std::pair<std::unique_ptr<RequestChannelSender>, const MQDescriptorSync<FmqRequestDatum>*>>
 RequestChannelSender::create(size_t channelLength) {
-    std::unique_ptr<FmqRequestChannel> fmqRequestChannel =
-            std::make_unique<FmqRequestChannel>(channelLength, /*confEventFlag=*/true);
-    if (!fmqRequestChannel->isValid()) {
-        LOG(ERROR) << "Unable to create RequestChannelSender";
-        return {nullptr, nullptr};
+    auto requestChannelSender =
+            std::make_unique<RequestChannelSender>(PrivateConstructorTag{}, channelLength);
+    if (!requestChannelSender->mFmqRequestChannel.isValid()) {
+        return NN_ERROR() << "Unable to create RequestChannelSender";
     }
 
-    const FmqRequestDescriptor* descriptor = fmqRequestChannel->getDesc();
-    return std::make_pair(std::make_unique<RequestChannelSender>(std::move(fmqRequestChannel)),
-                          descriptor);
+    const MQDescriptorSync<FmqRequestDatum>* descriptor =
+            requestChannelSender->mFmqRequestChannel.getDesc();
+    return std::make_pair(std::move(requestChannelSender), descriptor);
 }
 
-RequestChannelSender::RequestChannelSender(std::unique_ptr<FmqRequestChannel> fmqRequestChannel)
-    : mFmqRequestChannel(std::move(fmqRequestChannel)) {}
+RequestChannelSender::RequestChannelSender(PrivateConstructorTag /*tag*/, size_t channelLength)
+    : mFmqRequestChannel(channelLength, /*configureEventFlagWord=*/true) {}
 
-bool RequestChannelSender::send(const V1_0::Request& request, V1_2::MeasureTiming measure,
-                                const std::vector<int32_t>& slots) {
+nn::Result<void> RequestChannelSender::send(const V1_0::Request& request,
+                                            V1_2::MeasureTiming measure,
+                                            const std::vector<int32_t>& slots) {
     const std::vector<FmqRequestDatum> serialized = serialize(request, measure, slots);
     return sendPacket(serialized);
 }
 
-bool RequestChannelSender::sendPacket(const std::vector<FmqRequestDatum>& packet) {
+nn::Result<void> RequestChannelSender::sendPacket(const std::vector<FmqRequestDatum>& packet) {
     if (!mValid) {
-        return false;
+        return NN_ERROR() << "FMQ object is invalid";
     }
 
-    if (packet.size() > mFmqRequestChannel->availableToWrite()) {
-        LOG(ERROR)
-                << "RequestChannelSender::sendPacket -- packet size exceeds size available in FMQ";
-        return false;
+    if (packet.size() > mFmqRequestChannel.availableToWrite()) {
+        return NN_ERROR()
+               << "RequestChannelSender::sendPacket -- packet size exceeds size available in FMQ";
     }
 
-    // Always send the packet with "blocking" because this signals the futex and
-    // unblocks the consumer if it is waiting on the futex.
-    return mFmqRequestChannel->writeBlocking(packet.data(), packet.size());
+    // Always send the packet with "blocking" because this signals the futex and unblocks the
+    // consumer if it is waiting on the futex.
+    const bool success = mFmqRequestChannel.writeBlocking(packet.data(), packet.size());
+    if (!success) {
+        return NN_ERROR()
+               << "RequestChannelSender::sendPacket -- FMQ's writeBlocking returned an error";
+    }
+
+    return {};
 }
 
-void RequestChannelSender::invalidate() {
+void RequestChannelSender::notifyAsDeadObject() {
     mValid = false;
 }
 
 // RequestChannelReceiver methods
 
-std::unique_ptr<RequestChannelReceiver> RequestChannelReceiver::create(
-        const FmqRequestDescriptor& requestChannel, std::chrono::microseconds pollingTimeWindow) {
-    std::unique_ptr<FmqRequestChannel> fmqRequestChannel =
-            std::make_unique<FmqRequestChannel>(requestChannel);
+nn::GeneralResult<std::unique_ptr<RequestChannelReceiver>> RequestChannelReceiver::create(
+        const MQDescriptorSync<FmqRequestDatum>& requestChannel,
+        std::chrono::microseconds pollingTimeWindow) {
+    auto requestChannelReceiver = std::make_unique<RequestChannelReceiver>(
+            PrivateConstructorTag{}, requestChannel, pollingTimeWindow);
 
-    if (!fmqRequestChannel->isValid()) {
-        LOG(ERROR) << "Unable to create RequestChannelReceiver";
-        return nullptr;
+    if (!requestChannelReceiver->mFmqRequestChannel.isValid()) {
+        return NN_ERROR() << "Unable to create RequestChannelReceiver";
     }
-    if (fmqRequestChannel->getEventFlagWord() == nullptr) {
-        LOG(ERROR)
-                << "RequestChannelReceiver::create was passed an MQDescriptor without an EventFlag";
-        return nullptr;
+    if (requestChannelReceiver->mFmqRequestChannel.getEventFlagWord() == nullptr) {
+        return NN_ERROR()
+               << "RequestChannelReceiver::create was passed an MQDescriptor without an EventFlag";
     }
 
-    return std::make_unique<RequestChannelReceiver>(std::move(fmqRequestChannel),
-                                                    pollingTimeWindow);
+    return requestChannelReceiver;
 }
 
-RequestChannelReceiver::RequestChannelReceiver(std::unique_ptr<FmqRequestChannel> fmqRequestChannel,
-                                               std::chrono::microseconds pollingTimeWindow)
-    : mFmqRequestChannel(std::move(fmqRequestChannel)), kPollingTimeWindow(pollingTimeWindow) {}
+RequestChannelReceiver::RequestChannelReceiver(
+        PrivateConstructorTag /*tag*/, const MQDescriptorSync<FmqRequestDatum>& requestChannel,
+        std::chrono::microseconds pollingTimeWindow)
+    : mFmqRequestChannel(requestChannel), kPollingTimeWindow(pollingTimeWindow) {}
 
-std::optional<std::tuple<V1_0::Request, std::vector<int32_t>, V1_2::MeasureTiming>>
+nn::Result<std::tuple<V1_0::Request, std::vector<int32_t>, V1_2::MeasureTiming>>
 RequestChannelReceiver::getBlocking() {
-    const auto packet = getPacketBlocking();
-    if (!packet) {
-        return std::nullopt;
-    }
-
-    return deserialize(*packet);
+    const auto packet = NN_TRY(getPacketBlocking());
+    return deserialize(packet);
 }
 
 void RequestChannelReceiver::invalidate() {
     mTeardown = true;
 
     // force unblock
-    // ExecutionBurstServer is by default waiting on a request packet. If the
-    // client process destroys its burst object, the server may still be waiting
-    // on the futex. This force unblock wakes up any thread waiting on the
-    // futex.
-    // TODO: look for a different/better way to signal/notify the futex to wake
-    // up any thread waiting on it
-    FmqRequestDatum datum;
-    datum.packetInformation({/*.packetSize=*/0, /*.numberOfInputOperands=*/0,
-                             /*.numberOfOutputOperands=*/0, /*.numberOfPools=*/0});
-    mFmqRequestChannel->writeBlocking(&datum, 1);
+    // ExecutionBurstServer is by default waiting on a request packet. If the client process
+    // destroys its burst object, the server may still be waiting on the futex. This force unblock
+    // wakes up any thread waiting on the futex.
+    const auto data = serialize(V1_0::Request{}, V1_2::MeasureTiming::NO, {});
+    mFmqRequestChannel.writeBlocking(data.data(), data.size());
 }
 
-std::optional<std::vector<FmqRequestDatum>> RequestChannelReceiver::getPacketBlocking() {
+nn::Result<std::vector<FmqRequestDatum>> RequestChannelReceiver::getPacketBlocking() {
     if (mTeardown) {
-        return std::nullopt;
+        return NN_ERROR() << "FMQ object is being torn down";
     }
 
-    // First spend time polling if results are available in FMQ instead of
-    // waiting on the futex. Polling is more responsive (yielding lower
-    // latencies), but can take up more power, so only poll for a limited period
-    // of time.
+    // First spend time polling if results are available in FMQ instead of waiting on the futex.
+    // Polling is more responsive (yielding lower latencies), but can take up more power, so only
+    // poll for a limited period of time.
 
     auto& getCurrentTime = std::chrono::high_resolution_clock::now;
     const auto timeToStopPolling = getCurrentTime() + kPollingTimeWindow;
@@ -522,173 +507,144 @@
     while (getCurrentTime() < timeToStopPolling) {
         // if class is being torn down, immediately return
         if (mTeardown.load(std::memory_order_relaxed)) {
-            return std::nullopt;
+            return NN_ERROR() << "FMQ object is being torn down";
         }
 
-        // Check if data is available. If it is, immediately retrieve it and
-        // return.
-        const size_t available = mFmqRequestChannel->availableToRead();
+        // Check if data is available. If it is, immediately retrieve it and return.
+        const size_t available = mFmqRequestChannel.availableToRead();
         if (available > 0) {
-            // This is the first point when we know an execution is occurring,
-            // so begin to collect systraces. Note that a similar systrace does
-            // not exist at the corresponding point in
-            // ResultChannelReceiver::getPacketBlocking because the execution is
-            // already in flight.
-            NNTRACE_FULL(NNTRACE_LAYER_IPC, NNTRACE_PHASE_EXECUTION,
-                         "ExecutionBurstServer getting packet");
             std::vector<FmqRequestDatum> packet(available);
-            const bool success = mFmqRequestChannel->read(packet.data(), available);
+            const bool success = mFmqRequestChannel.readBlocking(packet.data(), available);
             if (!success) {
-                LOG(ERROR) << "Error receiving packet";
-                return std::nullopt;
+                return NN_ERROR() << "Error receiving packet";
             }
-            return std::make_optional(std::move(packet));
+            return packet;
         }
     }
 
-    // If we get to this point, we either stopped polling because it was taking
-    // too long or polling was not allowed. Instead, perform a blocking call
-    // which uses a futex to save power.
+    // If we get to this point, we either stopped polling because it was taking too long or polling
+    // was not allowed. Instead, perform a blocking call which uses a futex to save power.
 
     // wait for request packet and read first element of request packet
     FmqRequestDatum datum;
-    bool success = mFmqRequestChannel->readBlocking(&datum, 1);
-
-    // This is the first point when we know an execution is occurring, so begin
-    // to collect systraces. Note that a similar systrace does not exist at the
-    // corresponding point in ResultChannelReceiver::getPacketBlocking because
-    // the execution is already in flight.
-    NNTRACE_FULL(NNTRACE_LAYER_IPC, NNTRACE_PHASE_EXECUTION, "ExecutionBurstServer getting packet");
+    bool success = mFmqRequestChannel.readBlocking(&datum, 1);
 
     // retrieve remaining elements
-    // NOTE: all of the data is already available at this point, so there's no
-    // need to do a blocking wait to wait for more data. This is known because
-    // in FMQ, all writes are published (made available) atomically. Currently,
-    // the producer always publishes the entire packet in one function call, so
-    // if the first element of the packet is available, the remaining elements
-    // are also available.
-    const size_t count = mFmqRequestChannel->availableToRead();
+    // NOTE: all of the data is already available at this point, so there's no need to do a blocking
+    // wait to wait for more data. This is known because in FMQ, all writes are published (made
+    // available) atomically. Currently, the producer always publishes the entire packet in one
+    // function call, so if the first element of the packet is available, the remaining elements are
+    // also available.
+    const size_t count = mFmqRequestChannel.availableToRead();
     std::vector<FmqRequestDatum> packet(count + 1);
     std::memcpy(&packet.front(), &datum, sizeof(datum));
-    success &= mFmqRequestChannel->read(packet.data() + 1, count);
+    success &= mFmqRequestChannel.read(packet.data() + 1, count);
 
     // terminate loop
     if (mTeardown) {
-        return std::nullopt;
+        return NN_ERROR() << "FMQ object is being torn down";
     }
 
     // ensure packet was successfully received
     if (!success) {
-        LOG(ERROR) << "Error receiving packet";
-        return std::nullopt;
+        return NN_ERROR() << "Error receiving packet";
     }
 
-    return std::make_optional(std::move(packet));
+    return packet;
 }
 
 // ResultChannelSender methods
 
-std::unique_ptr<ResultChannelSender> ResultChannelSender::create(
-        const FmqResultDescriptor& resultChannel) {
-    std::unique_ptr<FmqResultChannel> fmqResultChannel =
-            std::make_unique<FmqResultChannel>(resultChannel);
+nn::GeneralResult<std::unique_ptr<ResultChannelSender>> ResultChannelSender::create(
+        const MQDescriptorSync<FmqResultDatum>& resultChannel) {
+    auto resultChannelSender =
+            std::make_unique<ResultChannelSender>(PrivateConstructorTag{}, resultChannel);
 
-    if (!fmqResultChannel->isValid()) {
-        LOG(ERROR) << "Unable to create RequestChannelSender";
-        return nullptr;
+    if (!resultChannelSender->mFmqResultChannel.isValid()) {
+        return NN_ERROR() << "Unable to create RequestChannelSender";
     }
-    if (fmqResultChannel->getEventFlagWord() == nullptr) {
-        LOG(ERROR) << "ResultChannelSender::create was passed an MQDescriptor without an EventFlag";
-        return nullptr;
+    if (resultChannelSender->mFmqResultChannel.getEventFlagWord() == nullptr) {
+        return NN_ERROR()
+               << "ResultChannelSender::create was passed an MQDescriptor without an EventFlag";
     }
 
-    return std::make_unique<ResultChannelSender>(std::move(fmqResultChannel));
+    return resultChannelSender;
 }
 
-ResultChannelSender::ResultChannelSender(std::unique_ptr<FmqResultChannel> fmqResultChannel)
-    : mFmqResultChannel(std::move(fmqResultChannel)) {}
+ResultChannelSender::ResultChannelSender(PrivateConstructorTag /*tag*/,
+                                         const MQDescriptorSync<FmqResultDatum>& resultChannel)
+    : mFmqResultChannel(resultChannel) {}
 
-bool ResultChannelSender::send(V1_0::ErrorStatus errorStatus,
+void ResultChannelSender::send(V1_0::ErrorStatus errorStatus,
                                const std::vector<V1_2::OutputShape>& outputShapes,
                                V1_2::Timing timing) {
     const std::vector<FmqResultDatum> serialized = serialize(errorStatus, outputShapes, timing);
-    return sendPacket(serialized);
+    sendPacket(serialized);
 }
 
-bool ResultChannelSender::sendPacket(const std::vector<FmqResultDatum>& packet) {
-    if (packet.size() > mFmqResultChannel->availableToWrite()) {
+void ResultChannelSender::sendPacket(const std::vector<FmqResultDatum>& packet) {
+    if (packet.size() > mFmqResultChannel.availableToWrite()) {
         LOG(ERROR)
                 << "ResultChannelSender::sendPacket -- packet size exceeds size available in FMQ";
         const std::vector<FmqResultDatum> errorPacket =
                 serialize(V1_0::ErrorStatus::GENERAL_FAILURE, {}, kNoTiming);
 
-        // Always send the packet with "blocking" because this signals the futex
-        // and unblocks the consumer if it is waiting on the futex.
-        return mFmqResultChannel->writeBlocking(errorPacket.data(), errorPacket.size());
+        // Always send the packet with "blocking" because this signals the futex and unblocks the
+        // consumer if it is waiting on the futex.
+        mFmqResultChannel.writeBlocking(errorPacket.data(), errorPacket.size());
+    } else {
+        // Always send the packet with "blocking" because this signals the futex and unblocks the
+        // consumer if it is waiting on the futex.
+        mFmqResultChannel.writeBlocking(packet.data(), packet.size());
     }
-
-    // Always send the packet with "blocking" because this signals the futex and
-    // unblocks the consumer if it is waiting on the futex.
-    return mFmqResultChannel->writeBlocking(packet.data(), packet.size());
 }
 
 // ResultChannelReceiver methods
 
-std::pair<std::unique_ptr<ResultChannelReceiver>, const FmqResultDescriptor*>
+nn::GeneralResult<
+        std::pair<std::unique_ptr<ResultChannelReceiver>, const MQDescriptorSync<FmqResultDatum>*>>
 ResultChannelReceiver::create(size_t channelLength, std::chrono::microseconds pollingTimeWindow) {
-    std::unique_ptr<FmqResultChannel> fmqResultChannel =
-            std::make_unique<FmqResultChannel>(channelLength, /*confEventFlag=*/true);
-    if (!fmqResultChannel->isValid()) {
-        LOG(ERROR) << "Unable to create ResultChannelReceiver";
-        return {nullptr, nullptr};
+    auto resultChannelReceiver = std::make_unique<ResultChannelReceiver>(
+            PrivateConstructorTag{}, channelLength, pollingTimeWindow);
+    if (!resultChannelReceiver->mFmqResultChannel.isValid()) {
+        return NN_ERROR() << "Unable to create ResultChannelReceiver";
     }
 
-    const FmqResultDescriptor* descriptor = fmqResultChannel->getDesc();
-    return std::make_pair(
-            std::make_unique<ResultChannelReceiver>(std::move(fmqResultChannel), pollingTimeWindow),
-            descriptor);
+    const MQDescriptorSync<FmqResultDatum>* descriptor =
+            resultChannelReceiver->mFmqResultChannel.getDesc();
+    return std::make_pair(std::move(resultChannelReceiver), descriptor);
 }
 
-ResultChannelReceiver::ResultChannelReceiver(std::unique_ptr<FmqResultChannel> fmqResultChannel,
+ResultChannelReceiver::ResultChannelReceiver(PrivateConstructorTag /*tag*/, size_t channelLength,
                                              std::chrono::microseconds pollingTimeWindow)
-    : mFmqResultChannel(std::move(fmqResultChannel)), kPollingTimeWindow(pollingTimeWindow) {}
+    : mFmqResultChannel(channelLength, /*configureEventFlagWord=*/true),
+      kPollingTimeWindow(pollingTimeWindow) {}
 
-std::optional<std::tuple<V1_0::ErrorStatus, std::vector<V1_2::OutputShape>, V1_2::Timing>>
+nn::Result<std::tuple<V1_0::ErrorStatus, std::vector<V1_2::OutputShape>, V1_2::Timing>>
 ResultChannelReceiver::getBlocking() {
-    const auto packet = getPacketBlocking();
-    if (!packet) {
-        return std::nullopt;
-    }
-
-    return deserialize(*packet);
+    const auto packet = NN_TRY(getPacketBlocking());
+    return deserialize(packet);
 }
 
-void ResultChannelReceiver::invalidate() {
+void ResultChannelReceiver::notifyAsDeadObject() {
     mValid = false;
 
     // force unblock
-    // ExecutionBurstController waits on a result packet after sending a
-    // request. If the driver containing ExecutionBurstServer crashes, the
-    // controller may be waiting on the futex. This force unblock wakes up any
-    // thread waiting on the futex.
-    // TODO: look for a different/better way to signal/notify the futex to
-    // wake up any thread waiting on it
-    FmqResultDatum datum;
-    datum.packetInformation({/*.packetSize=*/0,
-                             /*.errorStatus=*/V1_0::ErrorStatus::GENERAL_FAILURE,
-                             /*.numberOfOperands=*/0});
-    mFmqResultChannel->writeBlocking(&datum, 1);
+    // ExecutionBurstController waits on a result packet after sending a request. If the driver
+    // containing ExecutionBurstServer crashes, the controller may be waiting on the futex. This
+    // force unblock wakes up any thread waiting on the futex.
+    const auto data = serialize(V1_0::ErrorStatus::GENERAL_FAILURE, {}, kNoTiming);
+    mFmqResultChannel.writeBlocking(data.data(), data.size());
 }
 
-std::optional<std::vector<FmqResultDatum>> ResultChannelReceiver::getPacketBlocking() {
+nn::Result<std::vector<FmqResultDatum>> ResultChannelReceiver::getPacketBlocking() {
     if (!mValid) {
-        return std::nullopt;
+        return NN_ERROR() << "FMQ object is invalid";
     }
 
-    // First spend time polling if results are available in FMQ instead of
-    // waiting on the futex. Polling is more responsive (yielding lower
-    // latencies), but can take up more power, so only poll for a limited period
-    // of time.
+    // First spend time polling if results are available in FMQ instead of waiting on the futex.
+    // Polling is more responsive (yielding lower latencies), but can take up more power, so only
+    // poll for a limited period of time.
 
     auto& getCurrentTime = std::chrono::high_resolution_clock::now;
     const auto timeToStopPolling = getCurrentTime() + kPollingTimeWindow;
@@ -696,54 +652,49 @@
     while (getCurrentTime() < timeToStopPolling) {
         // if class is being torn down, immediately return
         if (!mValid.load(std::memory_order_relaxed)) {
-            return std::nullopt;
+            return NN_ERROR() << "FMQ object is invalid";
         }
 
-        // Check if data is available. If it is, immediately retrieve it and
-        // return.
-        const size_t available = mFmqResultChannel->availableToRead();
+        // Check if data is available. If it is, immediately retrieve it and return.
+        const size_t available = mFmqResultChannel.availableToRead();
         if (available > 0) {
             std::vector<FmqResultDatum> packet(available);
-            const bool success = mFmqResultChannel->read(packet.data(), available);
+            const bool success = mFmqResultChannel.readBlocking(packet.data(), available);
             if (!success) {
-                LOG(ERROR) << "Error receiving packet";
-                return std::nullopt;
+                return NN_ERROR() << "Error receiving packet";
             }
-            return std::make_optional(std::move(packet));
+            return packet;
         }
     }
 
-    // If we get to this point, we either stopped polling because it was taking
-    // too long or polling was not allowed. Instead, perform a blocking call
-    // which uses a futex to save power.
+    // If we get to this point, we either stopped polling because it was taking too long or polling
+    // was not allowed. Instead, perform a blocking call which uses a futex to save power.
 
     // wait for result packet and read first element of result packet
     FmqResultDatum datum;
-    bool success = mFmqResultChannel->readBlocking(&datum, 1);
+    bool success = mFmqResultChannel.readBlocking(&datum, 1);
 
     // retrieve remaining elements
-    // NOTE: all of the data is already available at this point, so there's no
-    // need to do a blocking wait to wait for more data. This is known because
-    // in FMQ, all writes are published (made available) atomically. Currently,
-    // the producer always publishes the entire packet in one function call, so
-    // if the first element of the packet is available, the remaining elements
-    // are also available.
-    const size_t count = mFmqResultChannel->availableToRead();
+    // NOTE: all of the data is already available at this point, so there's no need to do a blocking
+    // wait to wait for more data. This is known because in FMQ, all writes are published (made
+    // available) atomically. Currently, the producer always publishes the entire packet in one
+    // function call, so if the first element of the packet is available, the remaining elements are
+    // also available.
+    const size_t count = mFmqResultChannel.availableToRead();
     std::vector<FmqResultDatum> packet(count + 1);
     std::memcpy(&packet.front(), &datum, sizeof(datum));
-    success &= mFmqResultChannel->read(packet.data() + 1, count);
+    success &= mFmqResultChannel.read(packet.data() + 1, count);
 
     if (!mValid) {
-        return std::nullopt;
+        return NN_ERROR() << "FMQ object is invalid";
     }
 
     // ensure packet was successfully received
     if (!success) {
-        LOG(ERROR) << "Error receiving packet";
-        return std::nullopt;
+        return NN_ERROR() << "Error receiving packet";
     }
 
-    return std::make_optional(std::move(packet));
+    return packet;
 }
 
 }  // namespace android::hardware::neuralnetworks::V1_2::utils
diff --git a/neuralnetworks/1.2/utils/src/PreparedModel.cpp b/neuralnetworks/1.2/utils/src/PreparedModel.cpp
index 6841c5e..71a4ea8 100644
--- a/neuralnetworks/1.2/utils/src/PreparedModel.cpp
+++ b/neuralnetworks/1.2/utils/src/PreparedModel.cpp
@@ -18,6 +18,8 @@
 
 #include "Callbacks.h"
 #include "Conversions.h"
+#include "ExecutionBurstController.h"
+#include "ExecutionBurstUtils.h"
 #include "Utils.h"
 
 #include <android/hardware/neuralnetworks/1.0/types.h>
@@ -27,12 +29,12 @@
 #include <nnapi/IPreparedModel.h>
 #include <nnapi/Result.h>
 #include <nnapi/Types.h>
-#include <nnapi/hal/1.0/Burst.h>
 #include <nnapi/hal/1.0/Conversions.h>
 #include <nnapi/hal/CommonUtils.h>
 #include <nnapi/hal/HandleError.h>
 #include <nnapi/hal/ProtectCallback.h>
 
+#include <chrono>
 #include <memory>
 #include <tuple>
 #include <utility>
@@ -119,7 +121,14 @@
 }
 
 nn::GeneralResult<nn::SharedBurst> PreparedModel::configureExecutionBurst() const {
-    return V1_0::utils::Burst::create(shared_from_this());
+    auto self = shared_from_this();
+    auto fallback = [preparedModel = std::move(self)](const nn::Request& request,
+                                                      nn::MeasureTiming measure)
+            -> nn::ExecutionResult<std::pair<std::vector<nn::OutputShape>, nn::Timing>> {
+        return preparedModel->execute(request, measure, {}, {});
+    };
+    const auto pollingTimeWindow = getBurstControllerPollingTimeWindow();
+    return ExecutionBurstController::create(kPreparedModel, std::move(fallback), pollingTimeWindow);
 }
 
 std::any PreparedModel::getUnderlyingResource() const {
diff --git a/neuralnetworks/1.2/utils/test/DeviceTest.cpp b/neuralnetworks/1.2/utils/test/DeviceTest.cpp
index 9c8adde..215d44c 100644
--- a/neuralnetworks/1.2/utils/test/DeviceTest.cpp
+++ b/neuralnetworks/1.2/utils/test/DeviceTest.cpp
@@ -772,7 +772,7 @@
     EXPECT_NE(result.value(), nullptr);
 }
 
-TEST(DeviceTest, prepareModelFromCacheError) {
+TEST(DeviceTest, prepareModelFromCacheLaunchError) {
     // setup call
     const auto mockDevice = createMockDevice();
     const auto device = Device::create(kName, mockDevice).value();
@@ -790,6 +790,23 @@
     EXPECT_EQ(result.error().code, nn::ErrorStatus::GENERAL_FAILURE);
 }
 
+TEST(DeviceTest, prepareModelFromCacheReturnError) {
+    // setup call
+    const auto mockDevice = createMockDevice();
+    const auto device = Device::create(kName, mockDevice).value();
+    EXPECT_CALL(*mockDevice, prepareModelFromCache(_, _, _, _))
+            .Times(1)
+            .WillOnce(Invoke(makePreparedModelFromCacheReturn(
+                    V1_0::ErrorStatus::NONE, V1_0::ErrorStatus::GENERAL_FAILURE, nullptr)));
+
+    // run test
+    const auto result = device->prepareModelFromCache({}, {}, {}, {});
+
+    // verify result
+    ASSERT_FALSE(result.has_value());
+    EXPECT_EQ(result.error().code, nn::ErrorStatus::GENERAL_FAILURE);
+}
+
 TEST(DeviceTest, prepareModelFromCacheNullptrError) {
     // setup call
     const auto mockDevice = createMockDevice();
diff --git a/neuralnetworks/1.3/types.t b/neuralnetworks/1.3/types.t
index 9f69c9e..96d1a1b 100644
--- a/neuralnetworks/1.3/types.t
+++ b/neuralnetworks/1.3/types.t
@@ -90,459 +90,25 @@
     BASE_MAX        = 0xFFFF,
 };
 
-/**
- * Priority given to a prepared model for execution.
- */
-enum Priority : int32_t {
-    LOW,
-    MEDIUM,
-    HIGH,
-};
+%insert Priority
 
-/**
- * The capabilities of a driver.
- *
- * This represents performance of non-extension operations.
- *
- * Performance of an operation other than {@link OperationType::IF} and
- * {@link OperationType::WHILE} comes from the type of its first operand.
- */
-struct Capabilities {
-    /**
-     * Driver performance when operating on float32 data but performing
-     * calculations with range and/or precision as low as that of the IEEE
-     * 754 16-bit floating-point format.
-     */
-    PerformanceInfo relaxedFloat32toFloat16PerformanceScalar;
-    PerformanceInfo relaxedFloat32toFloat16PerformanceTensor;
+%insert Capabilities
 
-    /**
-     * Driver performance when operating on a particular data type.
-     * In the case of float32 data, this is used when the calculations
-     * are not relaxed.
-     */
-    struct OperandPerformance {
-        OperandType type;
-        PerformanceInfo info;
-    };
+%insert Operation
 
-    /**
-     * Performance by operand type. Must be sorted by OperandType.
-     *
-     * If a particular {@link OperandType} is not present in operandPerformance,
-     * its performance is treated as
-     * { .execTime = FLT_MAX, .powerUsage = FLT_MAX }.
-     *
-     * Performance does not apply to {@link OperandType::SUBGRAPH}, and a driver
-     * must not report operand performance for {@link OperandType::SUBGRAPH}.
-     */
-    vec<OperandPerformance> operandPerformance;
+%insert OperandLifeTime
 
-    /**
-     * Performance of an {@link OperationType::IF} operation is the sum of
-     * {@link Capabilities::ifPerformance} and the mean of performance for the
-     * two branch subgraphs, where performance for a subgraph is the sum of the
-     * performance of all operations within the subgraph.
-     */
-    PerformanceInfo ifPerformance;
+%insert Operand
 
-    /**
-     * Performance of a {@link OperationType::WHILE} operation is the sum of
-     * {@link Capabilities::whilePerformance}, performance for the condition
-     * subgraph and performance for the body subgraph, where performance for a
-     * subgraph is the sum of the performance of all operations within the
-     * subgraph.
-     */
-    PerformanceInfo whilePerformance;
-};
+%insert Model
 
-/**
- * Describes one operation of the model's graph.
- */
-struct Operation {
-    /**
-     * The operation type.
-     *
-     * Besides the values listed in {@link OperationType}, any value above
-     * {@link OperationTypeRange::BASE_MAX} is possible and should be interpreted
-     * as an extension type according to {@link Model::extensionNameToPrefix}.
-     */
-    OperationType type;
+%insert Subgraph
 
-    /**
-     * Describes the table that contains the indexes of the inputs of the
-     * operation. The offset is the index in the operandIndexes table.
-     */
-    vec<uint32_t> inputs;
+%insert BufferDesc
 
-    /**
-     * Describes the table that contains the indexes of the outputs of the
-     * operation. The offset is the index in the operandIndexes table.
-     */
-    vec<uint32_t> outputs;
-};
+%insert BufferRole
 
-/**
- * How an operand is used.
- */
-enum OperandLifeTime : int32_t {
-    /**
-     * The operand is internal to the model. It's created by an operation and
-     * consumed by other operations. It must be an output operand of
-     * exactly one operation.
-     */
-    TEMPORARY_VARIABLE,
-
-    /**
-     * The operand is an input of a subgraph. It must not be an output
-     * operand of any operation.
-     *
-     * An operand can't be both input and output of a subgraph.
-     */
-    SUBGRAPH_INPUT,
-
-    /**
-     * The operand is an output of a subgraph. It must be an output
-     * operand of exactly one operation.
-     *
-     * An operand can't be both input and output of a subgraph.
-     */
-    SUBGRAPH_OUTPUT,
-
-    /**
-     * The operand is a constant found in Model.operandValues. It must
-     * not be an output operand of any operation.
-     */
-    CONSTANT_COPY,
-
-    /**
-     * The operand is a constant that was specified via a Memory
-     * object. It must not be an output operand of any operation.
-     */
-    CONSTANT_REFERENCE,
-
-    /**
-     * The operand does not have a value. This is valid only for optional
-     * arguments of operations.
-     */
-    NO_VALUE,
-
-    /**
-     * The operand is a reference to a subgraph. It must be an input to one
-     * or more {@link OperationType::IF} or {@link OperationType::WHILE}
-     * operations.
-     */
-    SUBGRAPH,
-};
-
-/**
- * Describes one operand of the model's graph.
- */
-struct Operand {
-    /**
-     * The data type.
-     *
-     * Besides the values listed in {@link OperandType}, any value above
-     * {@link OperandTypeRange::BASE_MAX} is possible and should be interpreted
-     * as an extension type according to {@link Model::extensionNameToPrefix}.
-     */
-    OperandType type;
-
-    /**
-     * Dimensions of the operand.
-     *
-     * For a scalar operand, dimensions.size() must be 0.
-     *
-     * A tensor operand with all dimensions specified has "fully
-     * specified" dimensions. Whenever possible (i.e., whenever the
-     * dimensions are known at model construction time), a tensor
-     * operand should have (but is not required to have) fully
-     * specified dimensions, in order to enable the best possible
-     * performance.
-     *
-     * If a tensor operand's dimensions are not fully specified, the
-     * dimensions of the operand are deduced from the operand
-     * dimensions and values of the operation for which that operand
-     * is an output or from the corresponding {@link OperationType::IF} or
-     * {@link OperationType::WHILE} operation input operand dimensions in the
-     * case of referenced subgraph input operands.
-     *
-     * In the following situations, a tensor operand's dimensions must
-     * be fully specified:
-     *
-     *     . The operand has lifetime CONSTANT_COPY or
-     *       CONSTANT_REFERENCE.
-     *
-     *     . The operand has lifetime SUBGRAPH_INPUT and belongs to the main
-     *       subgraph. Fully specified dimensions must either be present in the
-     *       Operand or they must be provided in the corresponding
-     *       RequestArgument.
-     *       EXCEPTION: If the input is optional and omitted
-     *       (by setting the hasNoValue field of the corresponding
-     *       RequestArgument to true) then it need not have fully
-     *       specified dimensions.
-     *
-     * A tensor operand with some number of unspecified dimensions is
-     * represented by setting each unspecified dimension to 0.
-     *
-     * A tensor operand with unspecified rank is represented by providing
-     * an empty dimensions vector.
-     */
-    vec<uint32_t> dimensions;
-
-    /**
-     * The number of times this operand appears as an operation input.
-     *
-     * (For example, if this operand appears once in one operation's
-     * input list, and three times in another operation's input list,
-     * then numberOfConsumers = 4.)
-     */
-    uint32_t numberOfConsumers;
-
-    /**
-     * Quantized scale of the operand.
-     *
-     * Must be 0 when not applicable to an operand type.
-     *
-     * See {@link OperandType}.
-     */
-    float scale;
-
-    /**
-     * Quantized zero-point offset of the operand.
-     *
-     * Must be 0 when not applicable to an operand type.
-     *
-     * See {@link OperandType}.
-     */
-    int32_t zeroPoint;
-
-    /**
-     * How the operand is used.
-     */
-    OperandLifeTime lifetime;
-
-    /**
-     * Where to find the data for this operand.
-     * If the lifetime is TEMPORARY_VARIABLE, SUBGRAPH_INPUT, SUBGRAPH_OUTPUT,
-     * or NO_VALUE:
-     * - All the fields must be 0.
-     * If the lifetime is CONSTANT_COPY:
-     * - location.poolIndex is 0.
-     * - location.offset is the offset in bytes into Model.operandValues.
-     * - location.length is set.
-     * If the lifetime is CONSTANT_REFERENCE:
-     * - location.poolIndex is set.
-     * - location.offset is the offset in bytes into the specified pool.
-     * - location.length is set.
-     * If the lifetime is SUBGRAPH:
-     * - location.poolIndex is 0.
-     * - location.offset is the index of the referenced subgraph in
-     *   {@link Model::referenced}.
-     * - location.length is 0.
-     */
-    DataLocation location;
-
-    /**
-     * Additional parameters specific to a particular operand type.
-     */
-    @1.2::Operand.ExtraParams extraParams;
-};
-
-/**
- * A Neural Network Model.
- *
- * This includes not only the execution graph, but also constant data such as
- * weights or scalars added at construction time. The only information that
- * may not be known is the shape of the input tensors.
- */
-struct Model {
-    /**
-     * The top-level subgraph.
-     */
-    Subgraph main;
-
-    /**
-     * Referenced subgraphs.
-     *
-     * Each subgraph is referenced by the main subgraph or at least one other
-     * referenced subgraph.
-     *
-     * There must be no reference cycles.
-     */
-    vec<Subgraph> referenced;
-
-    /**
-     * A byte buffer containing operand data that were copied into the model.
-     *
-     * An operand's value must be located here if and only if Operand::lifetime
-     * equals OperandLifeTime::CONSTANT_COPY.
-     */
-    vec<uint8_t> operandValues;
-
-    /**
-     * A collection of shared memory pools containing operand values.
-     *
-     * An operand's value must be located here if and only if Operand::lifetime
-     * equals OperandLifeTime::CONSTANT_REFERENCE.
-     */
-    vec<memory> pools;
-
-    /**
-     * 'true' indicates TENSOR_FLOAT32 may be calculated with range and/or
-     * precision as low as that of the IEEE 754 16-bit floating-point format.
-     * 'false' indicates TENSOR_FLOAT32 must be calculated using at least the
-     * range and precision of the IEEE 754 32-bit floating-point format.
-     */
-    bool relaxComputationFloat32toFloat16;
-
-    /**
-     * The mapping between extension names and prefixes of operand and
-     * operation type values.
-     *
-     * An operand or operation whose numeric type value is above
-     * {@link OperandTypeRange::BASE_MAX} or
-     * {@link OperationTypeRange::BASE_MAX} respectively should be interpreted
-     * as an extension operand. The low
-     * {@link @1.2::Model::ExtensionTypeEncoding::LOW_BITS_TYPE} bits of the
-     * value correspond to the type ID within the extension and the high
-     * {@link @1.2::Model::ExtensionTypeEncoding::HIGH_BITS_PREFIX} bits encode
-     * the "prefix", which maps uniquely to the extension name.
-     *
-     * For example, if a model contains an operation whose value is
-     * 0xAAAABBBB and extensionNameToPrefix contains an entry with
-     * prefix=0xAAAA and name="vendor.test.test_extension", then
-     * the operation should be interpreted as the operation 0xBBBB
-     * of the extension named vendor.test.test_extension.
-     *
-     * This is a one-to-one correspondence. That is, there must be at most one
-     * prefix corresponding to each extension name and at most one extension
-     * name corresponding to each prefix.
-     */
-    vec<@1.2::Model.ExtensionNameAndPrefix> extensionNameToPrefix;
-};
-
-/**
- * An excerpt of the execution graph.
- */
-struct Subgraph {
-    /**
-     * All operands included in the subgraph.
-     */
-    vec<Operand> operands;
-
-    /**
-     * All operations included in the subgraph.
-     *
-     * The operations are sorted into execution order. Every operand
-     * with lifetime SUBGRAPH_OUTPUT or TEMPORARY_VARIABLE must be
-     * written before it is read.
-     */
-    vec<Operation> operations;
-
-    /**
-     * Input indexes of the subgraph. There must be at least one.
-     *
-     * Each value corresponds to the index of the operand in "operands".
-     */
-    vec<uint32_t> inputIndexes;
-
-    /**
-     * Output indexes of the subgraph. There must be at least one.
-     *
-     * Each value corresponds to the index of the operand in "operands".
-     */
-    vec<uint32_t> outputIndexes;
-};
-
-/**
- * A buffer descriptor. Describes the properties of a buffer.
- */
-struct BufferDesc {
-    /**
-     * Dimensions of the buffer. May have unknown dimensions or rank. A buffer with some number
-     * of unspecified dimensions is represented by setting each unspecified dimension to 0. A
-     * buffer with unspecified rank is represented by providing an empty dimensions vector.
-     */
-    vec<uint32_t> dimensions;
-};
-
-/**
- * Describes a role of an input or output to a prepared model.
- */
-struct BufferRole {
-    /**
-     * The index of the IPreparedModel within the "preparedModel" argument passed in
-     * IDevice::allocate.
-     */
-    uint32_t modelIndex;
-
-    /**
-     * The index of the input or output operand.
-     */
-    uint32_t ioIndex;
-
-    /**
-     * A floating-point value within the range (0.0, 1.0]. Describes how likely the
-     * buffer is to be used in the specified role. This is provided as a hint to
-     * optimize the case when multiple roles prefer different buffer locations or data
-     * layouts.
-     */
-    float frequency;
-};
-
-/**
- * Inputs to be sent to and outputs to be retrieved from a prepared model.
- *
- * A Request serves two primary tasks:
- * 1) Provides the input and output data to be used when executing the model.
- * 2) Specifies any updates to the input operand metadata that were left
- *    unspecified at model preparation time.
- *
- * An output must not overlap with any other output, with an input, or
- * with an operand of lifetime CONSTANT_REFERENCE.
- */
-struct Request {
-    /**
-     * Input data and information to be used in the execution of a prepared
-     * model.
-     *
-     * The index of the input corresponds to the index in Model.main.inputIndexes.
-     *   E.g., input[i] corresponds to Model.main.inputIndexes[i].
-     */
-    vec<RequestArgument> inputs;
-
-    /**
-     * Output data and information to be used in the execution of a prepared
-     * model.
-     *
-     * The index of the output corresponds to the index in Model.main.outputIndexes.
-     *   E.g., output[i] corresponds to Model.main.outputIndexes[i].
-     */
-    vec<RequestArgument> outputs;
-
-    /**
-     * A memory pool.
-     */
-    safe_union MemoryPool {
-        /**
-         * Specifies a client-managed shared memory pool.
-         */
-        memory hidlMemory;
-
-        /**
-         * Specifies a driver-managed buffer. It is the token returned from IDevice::allocate,
-         * and is specific to the IDevice object.
-         */
-        uint32_t token;
-    };
-
-    /**
-     * A collection of memory pools containing operand data for both the
-     * inputs and the outputs to a model.
-     */
-    vec<MemoryPool> pools;
-};
+%insert Request
 
 /**
  * Optional time point of the steady clock (as from std::chrono::steady_clock)
diff --git a/neuralnetworks/1.3/utils/Android.bp b/neuralnetworks/1.3/utils/Android.bp
index 2b1dcc4..28c036a 100644
--- a/neuralnetworks/1.3/utils/Android.bp
+++ b/neuralnetworks/1.3/utils/Android.bp
@@ -42,6 +42,7 @@
         "android.hardware.neuralnetworks@1.1",
         "android.hardware.neuralnetworks@1.2",
         "android.hardware.neuralnetworks@1.3",
+        "libfmq",
     ],
     export_static_lib_headers: [
         "neuralnetworks_utils_hal_common",
diff --git a/neuralnetworks/1.3/utils/include/nnapi/hal/1.3/Conversions.h b/neuralnetworks/1.3/utils/include/nnapi/hal/1.3/Conversions.h
index 8e1cdb8..b677c62 100644
--- a/neuralnetworks/1.3/utils/include/nnapi/hal/1.3/Conversions.h
+++ b/neuralnetworks/1.3/utils/include/nnapi/hal/1.3/Conversions.h
@@ -59,7 +59,6 @@
 GeneralResult<ErrorStatus> convert(const hal::V1_3::ErrorStatus& errorStatus);
 
 GeneralResult<SharedHandle> convert(const hardware::hidl_handle& handle);
-GeneralResult<SharedMemory> convert(const hardware::hidl_memory& memory);
 GeneralResult<std::vector<BufferRole>> convert(
         const hardware::hidl_vec<hal::V1_3::BufferRole>& bufferRoles);
 
diff --git a/neuralnetworks/1.3/utils/src/Conversions.cpp b/neuralnetworks/1.3/utils/src/Conversions.cpp
index 320c74c..9788fe1 100644
--- a/neuralnetworks/1.3/utils/src/Conversions.cpp
+++ b/neuralnetworks/1.3/utils/src/Conversions.cpp
@@ -352,10 +352,6 @@
     return validatedConvert(handle);
 }
 
-GeneralResult<SharedMemory> convert(const hardware::hidl_memory& memory) {
-    return validatedConvert(memory);
-}
-
 GeneralResult<std::vector<BufferRole>> convert(
         const hardware::hidl_vec<hal::V1_3::BufferRole>& bufferRoles) {
     return validatedConvert(bufferRoles);
diff --git a/neuralnetworks/1.3/utils/src/PreparedModel.cpp b/neuralnetworks/1.3/utils/src/PreparedModel.cpp
index 725e4f5..64275a3 100644
--- a/neuralnetworks/1.3/utils/src/PreparedModel.cpp
+++ b/neuralnetworks/1.3/utils/src/PreparedModel.cpp
@@ -29,8 +29,9 @@
 #include <nnapi/Result.h>
 #include <nnapi/TypeUtils.h>
 #include <nnapi/Types.h>
-#include <nnapi/hal/1.0/Burst.h>
 #include <nnapi/hal/1.2/Conversions.h>
+#include <nnapi/hal/1.2/ExecutionBurstController.h>
+#include <nnapi/hal/1.2/ExecutionBurstUtils.h>
 #include <nnapi/hal/CommonUtils.h>
 #include <nnapi/hal/HandleError.h>
 #include <nnapi/hal/ProtectCallback.h>
@@ -199,7 +200,15 @@
 }
 
 nn::GeneralResult<nn::SharedBurst> PreparedModel::configureExecutionBurst() const {
-    return V1_0::utils::Burst::create(shared_from_this());
+    auto self = shared_from_this();
+    auto fallback = [preparedModel = std::move(self)](const nn::Request& request,
+                                                      nn::MeasureTiming measure)
+            -> nn::ExecutionResult<std::pair<std::vector<nn::OutputShape>, nn::Timing>> {
+        return preparedModel->execute(request, measure, {}, {});
+    };
+    const auto pollingTimeWindow = V1_2::utils::getBurstControllerPollingTimeWindow();
+    return V1_2::utils::ExecutionBurstController::create(kPreparedModel, std::move(fallback),
+                                                         pollingTimeWindow);
 }
 
 std::any PreparedModel::getUnderlyingResource() const {
diff --git a/neuralnetworks/1.3/utils/test/DeviceTest.cpp b/neuralnetworks/1.3/utils/test/DeviceTest.cpp
index f260990..2d1b2f2 100644
--- a/neuralnetworks/1.3/utils/test/DeviceTest.cpp
+++ b/neuralnetworks/1.3/utils/test/DeviceTest.cpp
@@ -794,7 +794,7 @@
     EXPECT_NE(result.value(), nullptr);
 }
 
-TEST(DeviceTest, prepareModelFromCacheError) {
+TEST(DeviceTest, prepareModelFromCacheLaunchError) {
     // setup call
     const auto mockDevice = createMockDevice();
     const auto device = Device::create(kName, mockDevice).value();
@@ -812,6 +812,23 @@
     EXPECT_EQ(result.error().code, nn::ErrorStatus::GENERAL_FAILURE);
 }
 
+TEST(DeviceTest, prepareModelFromCacheReturnError) {
+    // setup call
+    const auto mockDevice = createMockDevice();
+    const auto device = Device::create(kName, mockDevice).value();
+    EXPECT_CALL(*mockDevice, prepareModelFromCache_1_3(_, _, _, _, _))
+            .Times(1)
+            .WillOnce(Invoke(makePreparedModelFromCacheReturn(
+                    V1_3::ErrorStatus::NONE, V1_3::ErrorStatus::GENERAL_FAILURE, nullptr)));
+
+    // run test
+    const auto result = device->prepareModelFromCache({}, {}, {}, {});
+
+    // verify result
+    ASSERT_FALSE(result.has_value());
+    EXPECT_EQ(result.error().code, nn::ErrorStatus::GENERAL_FAILURE);
+}
+
 TEST(DeviceTest, prepareModelFromCacheNullptrError) {
     // setup call
     const auto mockDevice = createMockDevice();
diff --git a/neuralnetworks/TEST_MAPPING b/neuralnetworks/TEST_MAPPING
index 5d168d2..d296828 100644
--- a/neuralnetworks/TEST_MAPPING
+++ b/neuralnetworks/TEST_MAPPING
@@ -16,6 +16,9 @@
       "name": "neuralnetworks_utils_hal_1_3_test"
     },
     {
+      "name": "neuralnetworks_utils_hal_aidl_test"
+    },
+    {
       "name": "VtsHalNeuralnetworksV1_0TargetTest",
       "options": [
         {
diff --git a/neuralnetworks/aidl/android/hardware/neuralnetworks/DataLocation.aidl b/neuralnetworks/aidl/android/hardware/neuralnetworks/DataLocation.aidl
index 1b2378f..f656360 100644
--- a/neuralnetworks/aidl/android/hardware/neuralnetworks/DataLocation.aidl
+++ b/neuralnetworks/aidl/android/hardware/neuralnetworks/DataLocation.aidl
@@ -35,6 +35,11 @@
  * total size of the writable region of the output data, and padding specifies the extra bytes at
  * the end of the memory region that may be used by the device to access memory in chunks, for
  * efficiency, but must not be used to hold any output data.
+ *
+ * When used in RequestArgument, clients should prefer to align and pad the sub-region to
+ * 64 bytes when possible; this may allow the device to access the sub-region more efficiently.
+ * The sub-region is aligned to 64 bytes if the value of offset is a multiple of 64.
+ * The sub-region is padded to 64 bytes if the sum of length and padding is a multiple of 64.
  */
 @VintfStability
 parcelable DataLocation {
diff --git a/neuralnetworks/aidl/utils/Android.bp b/neuralnetworks/aidl/utils/Android.bp
index 2673cae..476dac9 100644
--- a/neuralnetworks/aidl/utils/Android.bp
+++ b/neuralnetworks/aidl/utils/Android.bp
@@ -29,10 +29,12 @@
     srcs: ["src/*"],
     local_include_dirs: ["include/nnapi/hal/aidl/"],
     export_include_dirs: ["include"],
+    cflags: ["-Wthread-safety"],
     static_libs: [
         "libarect",
         "neuralnetworks_types",
         "neuralnetworks_utils_hal_common",
+        "neuralnetworks_utils_hal_1_0",
     ],
     shared_libs: [
         "android.hardware.neuralnetworks-V1-ndk_platform",
@@ -41,3 +43,38 @@
         "libnativewindow",
     ],
 }
+
+cc_test {
+    name: "neuralnetworks_utils_hal_aidl_test",
+    defaults: ["neuralnetworks_utils_defaults"],
+    srcs: [
+        "test/*.cpp",
+    ],
+    static_libs: [
+        "android.hardware.common-V2-ndk_platform",
+        "android.hardware.neuralnetworks-V1-ndk_platform",
+        "libgmock",
+        "libneuralnetworks_common",
+        "neuralnetworks_types",
+        "neuralnetworks_utils_hal_aidl",
+        "neuralnetworks_utils_hal_common",
+    ],
+    shared_libs: [
+        "android.hidl.allocator@1.0",
+        "libbase",
+        "libbinder_ndk",
+        "libcutils",
+        "libhidlbase",
+        "libhidlmemory",
+        "liblog",
+        "libnativewindow",
+        "libutils",
+    ],
+    cflags: [
+        /* GMOCK defines functions for printing all MOCK_DEVICE arguments and
+         * MockDevice contains a string pointer which triggers a warning in the
+         * base logging library. */
+        "-Wno-user-defined-warnings",
+    ],
+    test_suites: ["general-tests"],
+}
diff --git a/neuralnetworks/aidl/utils/include/nnapi/hal/aidl/Buffer.h b/neuralnetworks/aidl/utils/include/nnapi/hal/aidl/Buffer.h
new file mode 100644
index 0000000..46190c4
--- /dev/null
+++ b/neuralnetworks/aidl/utils/include/nnapi/hal/aidl/Buffer.h
@@ -0,0 +1,56 @@
+/*
+ * Copyright (C) 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef ANDROID_HARDWARE_INTERFACES_NEURALNETWORKS_AIDL_UTILS_BUFFER_H
+#define ANDROID_HARDWARE_INTERFACES_NEURALNETWORKS_AIDL_UTILS_BUFFER_H
+
+#include <aidl/android/hardware/neuralnetworks/IBuffer.h>
+#include <nnapi/IBuffer.h>
+#include <nnapi/Result.h>
+#include <nnapi/Types.h>
+#include <nnapi/hal/CommonUtils.h>
+#include <memory>
+
+// See hardware/interfaces/neuralnetworks/utils/README.md for more information on AIDL interface
+// lifetimes across processes.
+
+namespace aidl::android::hardware::neuralnetworks::utils {
+
+// Class that adapts aidl_hal::IBuffer to  nn::IBuffer.
+class Buffer final : public nn::IBuffer {
+    struct PrivateConstructorTag {};
+
+  public:
+    static nn::GeneralResult<std::shared_ptr<const Buffer>> create(
+            std::shared_ptr<aidl_hal::IBuffer> buffer, nn::Request::MemoryDomainToken token);
+
+    Buffer(PrivateConstructorTag tag, std::shared_ptr<aidl_hal::IBuffer> buffer,
+           nn::Request::MemoryDomainToken token);
+
+    nn::Request::MemoryDomainToken getToken() const override;
+
+    nn::GeneralResult<void> copyTo(const nn::SharedMemory& dst) const override;
+    nn::GeneralResult<void> copyFrom(const nn::SharedMemory& src,
+                                     const nn::Dimensions& dimensions) const override;
+
+  private:
+    const std::shared_ptr<aidl_hal::IBuffer> kBuffer;
+    const nn::Request::MemoryDomainToken kToken;
+};
+
+}  // namespace aidl::android::hardware::neuralnetworks::utils
+
+#endif  // ANDROID_HARDWARE_INTERFACES_NEURALNETWORKS_AIDL_UTILS_BUFFER_H
diff --git a/neuralnetworks/aidl/utils/include/nnapi/hal/aidl/Callbacks.h b/neuralnetworks/aidl/utils/include/nnapi/hal/aidl/Callbacks.h
new file mode 100644
index 0000000..8651912
--- /dev/null
+++ b/neuralnetworks/aidl/utils/include/nnapi/hal/aidl/Callbacks.h
@@ -0,0 +1,53 @@
+/*
+ * Copyright (C) 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef ANDROID_HARDWARE_INTERFACES_NEURALNETWORKS_AIDL_UTILS_CALLBACKS_H
+#define ANDROID_HARDWARE_INTERFACES_NEURALNETWORKS_AIDL_UTILS_CALLBACKS_H
+
+#include <aidl/android/hardware/neuralnetworks/BnPreparedModelCallback.h>
+#include <aidl/android/hardware/neuralnetworks/IDevice.h>
+#include <nnapi/IPreparedModel.h>
+#include <nnapi/Result.h>
+#include <nnapi/Types.h>
+#include <nnapi/hal/CommonUtils.h>
+#include <nnapi/hal/TransferValue.h>
+#include <nnapi/hal/aidl/ProtectCallback.h>
+
+// See hardware/interfaces/neuralnetworks/utils/README.md for more information on AIDL interface
+// lifetimes across processes and for protecting asynchronous calls across AIDL.
+
+namespace aidl::android::hardware::neuralnetworks::utils {
+
+// An AIDL callback class to receive the results of IDevice::prepareModel* asynchronously.
+class PreparedModelCallback final : public BnPreparedModelCallback,
+                                    public hal::utils::IProtectedCallback {
+  public:
+    using Data = nn::GeneralResult<nn::SharedPreparedModel>;
+
+    ndk::ScopedAStatus notify(ErrorStatus status,
+                              const std::shared_ptr<IPreparedModel>& preparedModel) override;
+
+    void notifyAsDeadObject() override;
+
+    Data get();
+
+  private:
+    hal::utils::TransferValue<Data> mData;
+};
+
+}  // namespace aidl::android::hardware::neuralnetworks::utils
+
+#endif  // ANDROID_HARDWARE_INTERFACES_NEURALNETWORKS_AIDL_UTILS_CALLBACKS_H
diff --git a/neuralnetworks/aidl/utils/include/nnapi/hal/aidl/Conversions.h b/neuralnetworks/aidl/utils/include/nnapi/hal/aidl/Conversions.h
index 1b2f69c..4922a6e 100644
--- a/neuralnetworks/aidl/utils/include/nnapi/hal/aidl/Conversions.h
+++ b/neuralnetworks/aidl/utils/include/nnapi/hal/aidl/Conversions.h
@@ -46,6 +46,7 @@
 #include <aidl/android/hardware/neuralnetworks/SymmPerChannelQuantParams.h>
 #include <aidl/android/hardware/neuralnetworks/Timing.h>
 
+#include <android/binder_auto_utils.h>
 #include <nnapi/Result.h>
 #include <nnapi/Types.h>
 #include <nnapi/hal/CommonUtils.h>
@@ -96,7 +97,11 @@
         const aidl_hal::ExtensionOperandTypeInformation& operandTypeInformation);
 GeneralResult<SharedHandle> unvalidatedConvert(
         const ::aidl::android::hardware::common::NativeHandle& handle);
+GeneralResult<SyncFence> unvalidatedConvert(const ndk::ScopedFileDescriptor& syncFence);
 
+GeneralResult<Capabilities> convert(const aidl_hal::Capabilities& capabilities);
+GeneralResult<DeviceType> convert(const aidl_hal::DeviceType& deviceType);
+GeneralResult<ErrorStatus> convert(const aidl_hal::ErrorStatus& errorStatus);
 GeneralResult<ExecutionPreference> convert(
         const aidl_hal::ExecutionPreference& executionPreference);
 GeneralResult<SharedMemory> convert(const aidl_hal::Memory& memory);
@@ -106,9 +111,14 @@
 GeneralResult<Priority> convert(const aidl_hal::Priority& priority);
 GeneralResult<Request::MemoryPool> convert(const aidl_hal::RequestMemoryPool& memoryPool);
 GeneralResult<Request> convert(const aidl_hal::Request& request);
+GeneralResult<Timing> convert(const aidl_hal::Timing& timing);
+GeneralResult<SyncFence> convert(const ndk::ScopedFileDescriptor& syncFence);
 
+GeneralResult<std::vector<Extension>> convert(const std::vector<aidl_hal::Extension>& extension);
 GeneralResult<std::vector<Operation>> convert(const std::vector<aidl_hal::Operation>& outputShapes);
 GeneralResult<std::vector<SharedMemory>> convert(const std::vector<aidl_hal::Memory>& memories);
+GeneralResult<std::vector<OutputShape>> convert(
+        const std::vector<aidl_hal::OutputShape>& outputShapes);
 
 GeneralResult<std::vector<uint32_t>> toUnsigned(const std::vector<int32_t>& vec);
 
@@ -118,14 +128,62 @@
 
 namespace nn = ::android::nn;
 
+nn::GeneralResult<std::vector<uint8_t>> unvalidatedConvert(const nn::CacheToken& cacheToken);
+nn::GeneralResult<BufferDesc> unvalidatedConvert(const nn::BufferDesc& bufferDesc);
+nn::GeneralResult<BufferRole> unvalidatedConvert(const nn::BufferRole& bufferRole);
+nn::GeneralResult<bool> unvalidatedConvert(const nn::MeasureTiming& measureTiming);
 nn::GeneralResult<Memory> unvalidatedConvert(const nn::SharedMemory& memory);
 nn::GeneralResult<OutputShape> unvalidatedConvert(const nn::OutputShape& outputShape);
 nn::GeneralResult<ErrorStatus> unvalidatedConvert(const nn::ErrorStatus& errorStatus);
+nn::GeneralResult<ExecutionPreference> unvalidatedConvert(
+        const nn::ExecutionPreference& executionPreference);
+nn::GeneralResult<OperandType> unvalidatedConvert(const nn::OperandType& operandType);
+nn::GeneralResult<OperandLifeTime> unvalidatedConvert(const nn::Operand::LifeTime& operandLifeTime);
+nn::GeneralResult<DataLocation> unvalidatedConvert(const nn::DataLocation& location);
+nn::GeneralResult<std::optional<OperandExtraParams>> unvalidatedConvert(
+        const nn::Operand::ExtraParams& extraParams);
+nn::GeneralResult<Operand> unvalidatedConvert(const nn::Operand& operand);
+nn::GeneralResult<OperationType> unvalidatedConvert(const nn::OperationType& operationType);
+nn::GeneralResult<Operation> unvalidatedConvert(const nn::Operation& operation);
+nn::GeneralResult<Subgraph> unvalidatedConvert(const nn::Model::Subgraph& subgraph);
+nn::GeneralResult<std::vector<uint8_t>> unvalidatedConvert(
+        const nn::Model::OperandValues& operandValues);
+nn::GeneralResult<ExtensionNameAndPrefix> unvalidatedConvert(
+        const nn::Model::ExtensionNameAndPrefix& extensionNameToPrefix);
+nn::GeneralResult<Model> unvalidatedConvert(const nn::Model& model);
+nn::GeneralResult<Priority> unvalidatedConvert(const nn::Priority& priority);
+nn::GeneralResult<Request> unvalidatedConvert(const nn::Request& request);
+nn::GeneralResult<RequestArgument> unvalidatedConvert(const nn::Request::Argument& requestArgument);
+nn::GeneralResult<RequestMemoryPool> unvalidatedConvert(const nn::Request::MemoryPool& memoryPool);
+nn::GeneralResult<Timing> unvalidatedConvert(const nn::Timing& timing);
+nn::GeneralResult<int64_t> unvalidatedConvert(const nn::Duration& duration);
+nn::GeneralResult<int64_t> unvalidatedConvert(const nn::OptionalDuration& optionalDuration);
+nn::GeneralResult<int64_t> unvalidatedConvert(const nn::OptionalTimePoint& optionalTimePoint);
+nn::GeneralResult<ndk::ScopedFileDescriptor> unvalidatedConvert(const nn::SyncFence& syncFence);
+nn::GeneralResult<common::NativeHandle> unvalidatedConvert(const nn::SharedHandle& sharedHandle);
+nn::GeneralResult<ndk::ScopedFileDescriptor> unvalidatedConvertCache(
+        const nn::SharedHandle& handle);
 
+nn::GeneralResult<std::vector<uint8_t>> convert(const nn::CacheToken& cacheToken);
+nn::GeneralResult<BufferDesc> convert(const nn::BufferDesc& bufferDesc);
+nn::GeneralResult<bool> convert(const nn::MeasureTiming& measureTiming);
 nn::GeneralResult<Memory> convert(const nn::SharedMemory& memory);
 nn::GeneralResult<ErrorStatus> convert(const nn::ErrorStatus& errorStatus);
+nn::GeneralResult<ExecutionPreference> convert(const nn::ExecutionPreference& executionPreference);
+nn::GeneralResult<Model> convert(const nn::Model& model);
+nn::GeneralResult<Priority> convert(const nn::Priority& priority);
+nn::GeneralResult<Request> convert(const nn::Request& request);
+nn::GeneralResult<Timing> convert(const nn::Timing& timing);
+nn::GeneralResult<int64_t> convert(const nn::OptionalDuration& optionalDuration);
+nn::GeneralResult<int64_t> convert(const nn::OptionalTimePoint& optionalTimePoint);
+
+nn::GeneralResult<std::vector<BufferRole>> convert(const std::vector<nn::BufferRole>& bufferRoles);
 nn::GeneralResult<std::vector<OutputShape>> convert(
         const std::vector<nn::OutputShape>& outputShapes);
+nn::GeneralResult<std::vector<ndk::ScopedFileDescriptor>> convert(
+        const std::vector<nn::SharedHandle>& handles);
+nn::GeneralResult<std::vector<ndk::ScopedFileDescriptor>> convert(
+        const std::vector<nn::SyncFence>& syncFences);
 
 nn::GeneralResult<std::vector<int32_t>> toSigned(const std::vector<uint32_t>& vec);
 
diff --git a/neuralnetworks/aidl/utils/include/nnapi/hal/aidl/Device.h b/neuralnetworks/aidl/utils/include/nnapi/hal/aidl/Device.h
new file mode 100644
index 0000000..eb194e3
--- /dev/null
+++ b/neuralnetworks/aidl/utils/include/nnapi/hal/aidl/Device.h
@@ -0,0 +1,98 @@
+/*
+ * Copyright (C) 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef ANDROID_HARDWARE_INTERFACES_NEURALNETWORKS_AIDL_UTILS_DEVICE_H
+#define ANDROID_HARDWARE_INTERFACES_NEURALNETWORKS_AIDL_UTILS_DEVICE_H
+
+#include <aidl/android/hardware/neuralnetworks/IDevice.h>
+#include <nnapi/IBuffer.h>
+#include <nnapi/IDevice.h>
+#include <nnapi/OperandTypes.h>
+#include <nnapi/Result.h>
+#include <nnapi/Types.h>
+#include <nnapi/hal/CommonUtils.h>
+#include <nnapi/hal/aidl/ProtectCallback.h>
+
+#include <functional>
+#include <memory>
+#include <optional>
+#include <string>
+#include <vector>
+
+// See hardware/interfaces/neuralnetworks/utils/README.md for more information on AIDL interface
+// lifetimes across processes and for protecting asynchronous calls across AIDL.
+
+namespace aidl::android::hardware::neuralnetworks::utils {
+
+// Class that adapts aidl_hal::IDevice to nn::IDevice.
+class Device final : public nn::IDevice {
+    struct PrivateConstructorTag {};
+
+  public:
+    static nn::GeneralResult<std::shared_ptr<const Device>> create(
+            std::string name, std::shared_ptr<aidl_hal::IDevice> device);
+
+    Device(PrivateConstructorTag tag, std::string name, std::string versionString,
+           nn::DeviceType deviceType, std::vector<nn::Extension> extensions,
+           nn::Capabilities capabilities, std::pair<uint32_t, uint32_t> numberOfCacheFilesNeeded,
+           std::shared_ptr<aidl_hal::IDevice> device, DeathHandler deathHandler);
+
+    const std::string& getName() const override;
+    const std::string& getVersionString() const override;
+    nn::Version getFeatureLevel() const override;
+    nn::DeviceType getType() const override;
+    bool isUpdatable() const override;
+    const std::vector<nn::Extension>& getSupportedExtensions() const override;
+    const nn::Capabilities& getCapabilities() const override;
+    std::pair<uint32_t, uint32_t> getNumberOfCacheFilesNeeded() const override;
+
+    nn::GeneralResult<void> wait() const override;
+
+    nn::GeneralResult<std::vector<bool>> getSupportedOperations(
+            const nn::Model& model) const override;
+
+    nn::GeneralResult<nn::SharedPreparedModel> prepareModel(
+            const nn::Model& model, nn::ExecutionPreference preference, nn::Priority priority,
+            nn::OptionalTimePoint deadline, const std::vector<nn::SharedHandle>& modelCache,
+            const std::vector<nn::SharedHandle>& dataCache,
+            const nn::CacheToken& token) const override;
+
+    nn::GeneralResult<nn::SharedPreparedModel> prepareModelFromCache(
+            nn::OptionalTimePoint deadline, const std::vector<nn::SharedHandle>& modelCache,
+            const std::vector<nn::SharedHandle>& dataCache,
+            const nn::CacheToken& token) const override;
+
+    nn::GeneralResult<nn::SharedBuffer> allocate(
+            const nn::BufferDesc& desc, const std::vector<nn::SharedPreparedModel>& preparedModels,
+            const std::vector<nn::BufferRole>& inputRoles,
+            const std::vector<nn::BufferRole>& outputRoles) const override;
+
+    DeathMonitor* getDeathMonitor() const;
+
+  private:
+    const std::string kName;
+    const std::string kVersionString;
+    const nn::DeviceType kDeviceType;
+    const std::vector<nn::Extension> kExtensions;
+    const nn::Capabilities kCapabilities;
+    const std::pair<uint32_t, uint32_t> kNumberOfCacheFilesNeeded;
+    const std::shared_ptr<aidl_hal::IDevice> kDevice;
+    const DeathHandler kDeathHandler;
+};
+
+}  // namespace aidl::android::hardware::neuralnetworks::utils
+
+#endif  // ANDROID_HARDWARE_INTERFACES_NEURALNETWORKS_AIDL_UTILS_DEVICE_H
diff --git a/neuralnetworks/aidl/utils/include/nnapi/hal/aidl/PreparedModel.h b/neuralnetworks/aidl/utils/include/nnapi/hal/aidl/PreparedModel.h
new file mode 100644
index 0000000..9b28588
--- /dev/null
+++ b/neuralnetworks/aidl/utils/include/nnapi/hal/aidl/PreparedModel.h
@@ -0,0 +1,70 @@
+/*
+ * Copyright (C) 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef ANDROID_HARDWARE_INTERFACES_NEURALNETWORKS_AIDL_UTILS_PREPARED_MODEL_H
+#define ANDROID_HARDWARE_INTERFACES_NEURALNETWORKS_AIDL_UTILS_PREPARED_MODEL_H
+
+#include <aidl/android/hardware/neuralnetworks/IPreparedModel.h>
+#include <nnapi/IPreparedModel.h>
+#include <nnapi/Result.h>
+#include <nnapi/Types.h>
+#include <nnapi/hal/CommonUtils.h>
+#include <nnapi/hal/aidl/ProtectCallback.h>
+
+#include <memory>
+#include <tuple>
+#include <utility>
+#include <vector>
+
+// See hardware/interfaces/neuralnetworks/utils/README.md for more information on AIDL interface
+// lifetimes across processes and for protecting asynchronous calls across AIDL.
+
+namespace aidl::android::hardware::neuralnetworks::utils {
+
+// Class that adapts aidl_hal::IPreparedModel to nn::IPreparedModel.
+class PreparedModel final : public nn::IPreparedModel,
+                            public std::enable_shared_from_this<PreparedModel> {
+    struct PrivateConstructorTag {};
+
+  public:
+    static nn::GeneralResult<std::shared_ptr<const PreparedModel>> create(
+            std::shared_ptr<aidl_hal::IPreparedModel> preparedModel);
+
+    PreparedModel(PrivateConstructorTag tag,
+                  std::shared_ptr<aidl_hal::IPreparedModel> preparedModel);
+
+    nn::ExecutionResult<std::pair<std::vector<nn::OutputShape>, nn::Timing>> execute(
+            const nn::Request& request, nn::MeasureTiming measure,
+            const nn::OptionalTimePoint& deadline,
+            const nn::OptionalDuration& loopTimeoutDuration) const override;
+
+    nn::GeneralResult<std::pair<nn::SyncFence, nn::ExecuteFencedInfoCallback>> executeFenced(
+            const nn::Request& request, const std::vector<nn::SyncFence>& waitFor,
+            nn::MeasureTiming measure, const nn::OptionalTimePoint& deadline,
+            const nn::OptionalDuration& loopTimeoutDuration,
+            const nn::OptionalDuration& timeoutDurationAfterFence) const override;
+
+    nn::GeneralResult<nn::SharedBurst> configureExecutionBurst() const override;
+
+    std::any getUnderlyingResource() const override;
+
+  private:
+    const std::shared_ptr<aidl_hal::IPreparedModel> kPreparedModel;
+};
+
+}  // namespace aidl::android::hardware::neuralnetworks::utils
+
+#endif  // ANDROID_HARDWARE_INTERFACES_NEURALNETWORKS_AIDL_UTILS_PREPARED_MODEL_H
diff --git a/neuralnetworks/aidl/utils/include/nnapi/hal/aidl/ProtectCallback.h b/neuralnetworks/aidl/utils/include/nnapi/hal/aidl/ProtectCallback.h
new file mode 100644
index 0000000..ab1108c
--- /dev/null
+++ b/neuralnetworks/aidl/utils/include/nnapi/hal/aidl/ProtectCallback.h
@@ -0,0 +1,81 @@
+/*
+ * Copyright (C) 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef ANDROID_HARDWARE_INTERFACES_NEURALNETWORKS_AIDL_UTILS_PROTECT_CALLBACK_H
+#define ANDROID_HARDWARE_INTERFACES_NEURALNETWORKS_AIDL_UTILS_PROTECT_CALLBACK_H
+
+#include <android-base/scopeguard.h>
+#include <android-base/thread_annotations.h>
+#include <android/binder_interface_utils.h>
+#include <nnapi/Result.h>
+#include <nnapi/Types.h>
+#include <nnapi/hal/CommonUtils.h>
+#include <nnapi/hal/ProtectCallback.h>
+
+#include <functional>
+#include <mutex>
+#include <vector>
+
+// See hardware/interfaces/neuralnetworks/utils/README.md for more information on AIDL interface
+// lifetimes across processes and for protecting asynchronous calls across AIDL.
+
+namespace aidl::android::hardware::neuralnetworks::utils {
+
+// Thread safe class
+class DeathMonitor final {
+  public:
+    static void serviceDied(void* cookie);
+    void serviceDied();
+    // Precondition: `killable` must be non-null.
+    void add(hal::utils::IProtectedCallback* killable) const;
+    // Precondition: `killable` must be non-null.
+    void remove(hal::utils::IProtectedCallback* killable) const;
+
+  private:
+    mutable std::mutex mMutex;
+    mutable std::vector<hal::utils::IProtectedCallback*> mObjects GUARDED_BY(mMutex);
+};
+
+class DeathHandler final {
+  public:
+    static nn::GeneralResult<DeathHandler> create(std::shared_ptr<ndk::ICInterface> object);
+
+    DeathHandler(const DeathHandler&) = delete;
+    DeathHandler(DeathHandler&&) noexcept = default;
+    DeathHandler& operator=(const DeathHandler&) = delete;
+    DeathHandler& operator=(DeathHandler&&) noexcept = delete;
+    ~DeathHandler();
+
+    using Cleanup = std::function<void()>;
+    // Precondition: `killable` must be non-null.
+    [[nodiscard]] ::android::base::ScopeGuard<Cleanup> protectCallback(
+            hal::utils::IProtectedCallback* killable) const;
+
+    std::shared_ptr<DeathMonitor> getDeathMonitor() const { return kDeathMonitor; }
+
+  private:
+    DeathHandler(std::shared_ptr<ndk::ICInterface> object,
+                 ndk::ScopedAIBinder_DeathRecipient deathRecipient,
+                 std::shared_ptr<DeathMonitor> deathMonitor);
+
+    std::shared_ptr<ndk::ICInterface> kObject;
+    ndk::ScopedAIBinder_DeathRecipient kDeathRecipient;
+    std::shared_ptr<DeathMonitor> kDeathMonitor;
+};
+
+}  // namespace aidl::android::hardware::neuralnetworks::utils
+
+#endif  // ANDROID_HARDWARE_INTERFACES_NEURALNETWORKS_AIDL_UTILS_PROTECT_CALLBACK_H
diff --git a/neuralnetworks/aidl/utils/include/nnapi/hal/aidl/Service.h b/neuralnetworks/aidl/utils/include/nnapi/hal/aidl/Service.h
new file mode 100644
index 0000000..cb6ff4b
--- /dev/null
+++ b/neuralnetworks/aidl/utils/include/nnapi/hal/aidl/Service.h
@@ -0,0 +1,32 @@
+/*
+ * Copyright (C) 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef ANDROID_HARDWARE_INTERFACES_NEURALNETWORKS_AIDL_UTILS_SERVICE_H
+#define ANDROID_HARDWARE_INTERFACES_NEURALNETWORKS_AIDL_UTILS_SERVICE_H
+
+#include <nnapi/IDevice.h>
+#include <nnapi/Result.h>
+#include <nnapi/Types.h>
+
+#include <string>
+
+namespace aidl::android::hardware::neuralnetworks::utils {
+
+::android::nn::GeneralResult<::android::nn::SharedDevice> getDevice(const std::string& name);
+
+}  // namespace aidl::android::hardware::neuralnetworks::utils
+
+#endif  // ANDROID_HARDWARE_INTERFACES_NEURALNETWORKS_AIDL_UTILS_SERVICE_H
diff --git a/neuralnetworks/aidl/utils/include/nnapi/hal/aidl/Utils.h b/neuralnetworks/aidl/utils/include/nnapi/hal/aidl/Utils.h
index 79b511d..58dcfe3 100644
--- a/neuralnetworks/aidl/utils/include/nnapi/hal/aidl/Utils.h
+++ b/neuralnetworks/aidl/utils/include/nnapi/hal/aidl/Utils.h
@@ -23,6 +23,7 @@
 #include <nnapi/Result.h>
 #include <nnapi/Types.h>
 #include <nnapi/Validation.h>
+#include <nnapi/hal/HandleError.h>
 
 namespace aidl::android::hardware::neuralnetworks::utils {
 
@@ -52,6 +53,12 @@
 nn::GeneralResult<RequestMemoryPool> clone(const RequestMemoryPool& requestPool);
 nn::GeneralResult<Model> clone(const Model& model);
 
+nn::GeneralResult<void> handleTransportError(const ndk::ScopedAStatus& ret);
+
+#define HANDLE_ASTATUS(ret)                                            \
+    for (const auto status = handleTransportError(ret); !status.ok();) \
+    return NN_ERROR(status.error().code) << status.error().message << ": "
+
 }  // namespace aidl::android::hardware::neuralnetworks::utils
 
 #endif  // ANDROID_HARDWARE_INTERFACES_NEURALNETWORKS_AIDL_UTILS_H
diff --git a/neuralnetworks/aidl/utils/src/Buffer.cpp b/neuralnetworks/aidl/utils/src/Buffer.cpp
new file mode 100644
index 0000000..c729a68
--- /dev/null
+++ b/neuralnetworks/aidl/utils/src/Buffer.cpp
@@ -0,0 +1,78 @@
+/*
+ * Copyright (C) 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "Buffer.h"
+
+#include <nnapi/IPreparedModel.h>
+#include <nnapi/Result.h>
+#include <nnapi/Types.h>
+
+#include "Conversions.h"
+#include "Utils.h"
+#include "nnapi/hal/aidl/Conversions.h"
+
+#include <memory>
+#include <utility>
+
+// See hardware/interfaces/neuralnetworks/utils/README.md for more information on AIDL interface
+// lifetimes across processes.
+
+namespace aidl::android::hardware::neuralnetworks::utils {
+
+nn::GeneralResult<std::shared_ptr<const Buffer>> Buffer::create(
+        std::shared_ptr<aidl_hal::IBuffer> buffer, nn::Request::MemoryDomainToken token) {
+    if (buffer == nullptr) {
+        return NN_ERROR() << "aidl_hal::utils::Buffer::create must have non-null buffer";
+    }
+    if (token == static_cast<nn::Request::MemoryDomainToken>(0)) {
+        return NN_ERROR() << "aidl_hal::utils::Buffer::create must have non-zero token";
+    }
+
+    return std::make_shared<const Buffer>(PrivateConstructorTag{}, std::move(buffer), token);
+}
+
+Buffer::Buffer(PrivateConstructorTag /*tag*/, std::shared_ptr<aidl_hal::IBuffer> buffer,
+               nn::Request::MemoryDomainToken token)
+    : kBuffer(std::move(buffer)), kToken(token) {
+    CHECK(kBuffer != nullptr);
+    CHECK(kToken != static_cast<nn::Request::MemoryDomainToken>(0));
+}
+
+nn::Request::MemoryDomainToken Buffer::getToken() const {
+    return kToken;
+}
+
+nn::GeneralResult<void> Buffer::copyTo(const nn::SharedMemory& dst) const {
+    const auto aidlDst = NN_TRY(convert(dst));
+
+    const auto ret = kBuffer->copyTo(aidlDst);
+    HANDLE_ASTATUS(ret) << "IBuffer::copyTo failed";
+
+    return {};
+}
+
+nn::GeneralResult<void> Buffer::copyFrom(const nn::SharedMemory& src,
+                                         const nn::Dimensions& dimensions) const {
+    const auto aidlSrc = NN_TRY(convert(src));
+    const auto aidlDimensions = NN_TRY(toSigned(dimensions));
+
+    const auto ret = kBuffer->copyFrom(aidlSrc, aidlDimensions);
+    HANDLE_ASTATUS(ret) << "IBuffer::copyFrom failed";
+
+    return {};
+}
+
+}  // namespace aidl::android::hardware::neuralnetworks::utils
diff --git a/neuralnetworks/aidl/utils/src/Callbacks.cpp b/neuralnetworks/aidl/utils/src/Callbacks.cpp
new file mode 100644
index 0000000..8055665
--- /dev/null
+++ b/neuralnetworks/aidl/utils/src/Callbacks.cpp
@@ -0,0 +1,61 @@
+/*
+ * Copyright (C) 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "Callbacks.h"
+
+#include "Conversions.h"
+#include "PreparedModel.h"
+#include "ProtectCallback.h"
+#include "Utils.h"
+
+#include <nnapi/IPreparedModel.h>
+#include <nnapi/Result.h>
+#include <nnapi/Types.h>
+
+#include <utility>
+
+// See hardware/interfaces/neuralnetworks/utils/README.md for more information on AIDL interface
+// lifetimes across processes and for protecting asynchronous calls across AIDL.
+
+namespace aidl::android::hardware::neuralnetworks::utils {
+namespace {
+
+// Converts the results of IDevice::prepareModel* to the NN canonical format. On success, this
+// function returns with a non-null nn::SharedPreparedModel with a feature level of
+// nn::Version::ANDROID_S. On failure, this function returns with the appropriate nn::GeneralError.
+nn::GeneralResult<nn::SharedPreparedModel> prepareModelCallback(
+        ErrorStatus status, const std::shared_ptr<IPreparedModel>& preparedModel) {
+    HANDLE_HAL_STATUS(status) << "model preparation failed with " << toString(status);
+    return NN_TRY(PreparedModel::create(preparedModel));
+}
+
+}  // namespace
+
+ndk::ScopedAStatus PreparedModelCallback::notify(
+        ErrorStatus status, const std::shared_ptr<IPreparedModel>& preparedModel) {
+    mData.put(prepareModelCallback(status, preparedModel));
+    return ndk::ScopedAStatus::ok();
+}
+
+void PreparedModelCallback::notifyAsDeadObject() {
+    mData.put(NN_ERROR(nn::ErrorStatus::DEAD_OBJECT) << "Dead object");
+}
+
+PreparedModelCallback::Data PreparedModelCallback::get() {
+    return mData.take();
+}
+
+}  // namespace aidl::android::hardware::neuralnetworks::utils
diff --git a/neuralnetworks/aidl/utils/src/Conversions.cpp b/neuralnetworks/aidl/utils/src/Conversions.cpp
index 9a06d47..c47ba0e 100644
--- a/neuralnetworks/aidl/utils/src/Conversions.cpp
+++ b/neuralnetworks/aidl/utils/src/Conversions.cpp
@@ -18,6 +18,8 @@
 
 #include <aidl/android/hardware/common/NativeHandle.h>
 #include <android-base/logging.h>
+#include <android-base/unique_fd.h>
+#include <android/binder_auto_utils.h>
 #include <android/hardware_buffer.h>
 #include <cutils/native_handle.h>
 #include <nnapi/OperandTypes.h>
@@ -42,14 +44,17 @@
 #define VERIFY_NON_NEGATIVE(value) \
     while (UNLIKELY(value < 0)) return NN_ERROR()
 
-namespace {
+#define VERIFY_LE_INT32_MAX(value) \
+    while (UNLIKELY(value > std::numeric_limits<int32_t>::max())) return NN_ERROR()
 
+namespace {
 template <typename Type>
 constexpr std::underlying_type_t<Type> underlyingType(Type value) {
     return static_cast<std::underlying_type_t<Type>>(value);
 }
 
 constexpr auto kVersion = android::nn::Version::ANDROID_S;
+constexpr int64_t kNoTiming = -1;
 
 }  // namespace
 
@@ -134,13 +139,8 @@
     std::vector<base::unique_fd> fds;
     fds.reserve(aidlNativeHandle.fds.size());
     for (const auto& fd : aidlNativeHandle.fds) {
-        const int dupFd = dup(fd.get());
-        if (dupFd == -1) {
-            // TODO(b/120417090): is ANEURALNETWORKS_UNEXPECTED_NULL the correct error to return
-            // here?
-            return NN_ERROR() << "Failed to dup the fd";
-        }
-        fds.emplace_back(dupFd);
+        auto duplicatedFd = NN_TRY(dupFd(fd.get()));
+        fds.emplace_back(duplicatedFd.release());
     }
 
     return Handle{.fds = std::move(fds), .ints = aidlNativeHandle.ints};
@@ -157,16 +157,12 @@
 
 using UniqueNativeHandle = std::unique_ptr<native_handle_t, NativeHandleDeleter>;
 
-static nn::GeneralResult<UniqueNativeHandle> nativeHandleFromAidlHandle(
-        const NativeHandle& handle) {
+static GeneralResult<UniqueNativeHandle> nativeHandleFromAidlHandle(const NativeHandle& handle) {
     std::vector<base::unique_fd> fds;
     fds.reserve(handle.fds.size());
     for (const auto& fd : handle.fds) {
-        const int dupFd = dup(fd.get());
-        if (dupFd == -1) {
-            return NN_ERROR() << "Failed to dup the fd";
-        }
-        fds.emplace_back(dupFd);
+        auto duplicatedFd = NN_TRY(dupFd(fd.get()));
+        fds.emplace_back(duplicatedFd.release());
     }
 
     constexpr size_t kIntMax = std::numeric_limits<int>::max();
@@ -388,14 +384,14 @@
 
 GeneralResult<SharedMemory> unvalidatedConvert(const aidl_hal::Memory& memory) {
     VERIFY_NON_NEGATIVE(memory.size) << "Memory size must not be negative";
-    if (memory.size > std::numeric_limits<uint32_t>::max()) {
+    if (memory.size > std::numeric_limits<size_t>::max()) {
         return NN_ERROR() << "Memory: size must be <= std::numeric_limits<size_t>::max()";
     }
 
     if (memory.name != "hardware_buffer_blob") {
         return std::make_shared<const Memory>(Memory{
                 .handle = NN_TRY(unvalidatedConvertHelper(memory.handle)),
-                .size = static_cast<uint32_t>(memory.size),
+                .size = static_cast<size_t>(memory.size),
                 .name = memory.name,
         });
     }
@@ -440,11 +436,28 @@
 
     return std::make_shared<const Memory>(Memory{
             .handle = HardwareBufferHandle(hardwareBuffer, /*takeOwnership=*/true),
-            .size = static_cast<uint32_t>(memory.size),
+            .size = static_cast<size_t>(memory.size),
             .name = memory.name,
     });
 }
 
+GeneralResult<Timing> unvalidatedConvert(const aidl_hal::Timing& timing) {
+    if (timing.timeInDriver < -1) {
+        return NN_ERROR() << "Timing: timeInDriver must not be less than -1";
+    }
+    if (timing.timeOnDevice < -1) {
+        return NN_ERROR() << "Timing: timeOnDevice must not be less than -1";
+    }
+    constexpr auto convertTiming = [](int64_t halTiming) -> OptionalDuration {
+        if (halTiming == kNoTiming) {
+            return {};
+        }
+        return nn::Duration(static_cast<uint64_t>(halTiming));
+    };
+    return Timing{.timeOnDevice = convertTiming(timing.timeOnDevice),
+                  .timeInDriver = convertTiming(timing.timeInDriver)};
+}
+
 GeneralResult<Model::OperandValues> unvalidatedConvert(const std::vector<uint8_t>& operandValues) {
     return Model::OperandValues(operandValues.data(), operandValues.size());
 }
@@ -521,6 +534,23 @@
     return std::make_shared<const Handle>(NN_TRY(unvalidatedConvertHelper(aidlNativeHandle)));
 }
 
+GeneralResult<SyncFence> unvalidatedConvert(const ndk::ScopedFileDescriptor& syncFence) {
+    auto duplicatedFd = NN_TRY(dupFd(syncFence.get()));
+    return SyncFence::create(std::move(duplicatedFd));
+}
+
+GeneralResult<Capabilities> convert(const aidl_hal::Capabilities& capabilities) {
+    return validatedConvert(capabilities);
+}
+
+GeneralResult<DeviceType> convert(const aidl_hal::DeviceType& deviceType) {
+    return validatedConvert(deviceType);
+}
+
+GeneralResult<ErrorStatus> convert(const aidl_hal::ErrorStatus& errorStatus) {
+    return validatedConvert(errorStatus);
+}
+
 GeneralResult<ExecutionPreference> convert(
         const aidl_hal::ExecutionPreference& executionPreference) {
     return validatedConvert(executionPreference);
@@ -554,6 +584,18 @@
     return validatedConvert(request);
 }
 
+GeneralResult<Timing> convert(const aidl_hal::Timing& timing) {
+    return validatedConvert(timing);
+}
+
+GeneralResult<SyncFence> convert(const ndk::ScopedFileDescriptor& syncFence) {
+    return unvalidatedConvert(syncFence);
+}
+
+GeneralResult<std::vector<Extension>> convert(const std::vector<aidl_hal::Extension>& extension) {
+    return validatedConvert(extension);
+}
+
 GeneralResult<std::vector<Operation>> convert(const std::vector<aidl_hal::Operation>& operations) {
     return unvalidatedConvert(operations);
 }
@@ -562,6 +604,11 @@
     return validatedConvert(memories);
 }
 
+GeneralResult<std::vector<OutputShape>> convert(
+        const std::vector<aidl_hal::OutputShape>& outputShapes) {
+    return validatedConvert(outputShapes);
+}
+
 GeneralResult<std::vector<uint32_t>> toUnsigned(const std::vector<int32_t>& vec) {
     if (!std::all_of(vec.begin(), vec.end(), [](int32_t v) { return v >= 0; })) {
         return NN_ERROR() << "Negative value passed to conversion from signed to unsigned";
@@ -581,14 +628,21 @@
 template <typename Type>
 nn::GeneralResult<std::vector<UnvalidatedConvertOutput<Type>>> unvalidatedConvertVec(
         const std::vector<Type>& arguments) {
-    std::vector<UnvalidatedConvertOutput<Type>> halObject(arguments.size());
-    for (size_t i = 0; i < arguments.size(); ++i) {
-        halObject[i] = NN_TRY(unvalidatedConvert(arguments[i]));
+    std::vector<UnvalidatedConvertOutput<Type>> halObject;
+    halObject.reserve(arguments.size());
+    for (const auto& argument : arguments) {
+        halObject.push_back(NN_TRY(unvalidatedConvert(argument)));
     }
     return halObject;
 }
 
 template <typename Type>
+nn::GeneralResult<std::vector<UnvalidatedConvertOutput<Type>>> unvalidatedConvert(
+        const std::vector<Type>& arguments) {
+    return unvalidatedConvertVec(arguments);
+}
+
+template <typename Type>
 nn::GeneralResult<UnvalidatedConvertOutput<Type>> validatedConvert(const Type& canonical) {
     const auto maybeVersion = nn::validate(canonical);
     if (!maybeVersion.has_value()) {
@@ -615,29 +669,29 @@
     common::NativeHandle aidlNativeHandle;
     aidlNativeHandle.fds.reserve(handle.fds.size());
     for (const auto& fd : handle.fds) {
-        const int dupFd = dup(fd.get());
-        if (dupFd == -1) {
-            // TODO(b/120417090): is ANEURALNETWORKS_UNEXPECTED_NULL the correct error to return
-            // here?
-            return NN_ERROR() << "Failed to dup the fd";
-        }
-        aidlNativeHandle.fds.emplace_back(dupFd);
+        auto duplicatedFd = NN_TRY(nn::dupFd(fd.get()));
+        aidlNativeHandle.fds.emplace_back(duplicatedFd.release());
     }
     aidlNativeHandle.ints = handle.ints;
     return aidlNativeHandle;
 }
 
+// Helper template for std::visit
+template <class... Ts>
+struct overloaded : Ts... {
+    using Ts::operator()...;
+};
+template <class... Ts>
+overloaded(Ts...)->overloaded<Ts...>;
+
 static nn::GeneralResult<common::NativeHandle> aidlHandleFromNativeHandle(
         const native_handle_t& handle) {
     common::NativeHandle aidlNativeHandle;
 
     aidlNativeHandle.fds.reserve(handle.numFds);
     for (int i = 0; i < handle.numFds; ++i) {
-        const int dupFd = dup(handle.data[i]);
-        if (dupFd == -1) {
-            return NN_ERROR(nn::ErrorStatus::GENERAL_FAILURE) << "Failed to dup the fd";
-        }
-        aidlNativeHandle.fds.emplace_back(dupFd);
+        auto duplicatedFd = NN_TRY(nn::dupFd(handle.data[i]));
+        aidlNativeHandle.fds.emplace_back(duplicatedFd.release());
     }
 
     aidlNativeHandle.ints = std::vector<int>(&handle.data[handle.numFds],
@@ -648,6 +702,30 @@
 
 }  // namespace
 
+nn::GeneralResult<std::vector<uint8_t>> unvalidatedConvert(const nn::CacheToken& cacheToken) {
+    return std::vector<uint8_t>(cacheToken.begin(), cacheToken.end());
+}
+
+nn::GeneralResult<BufferDesc> unvalidatedConvert(const nn::BufferDesc& bufferDesc) {
+    return BufferDesc{.dimensions = NN_TRY(toSigned(bufferDesc.dimensions))};
+}
+
+nn::GeneralResult<BufferRole> unvalidatedConvert(const nn::BufferRole& bufferRole) {
+    VERIFY_LE_INT32_MAX(bufferRole.modelIndex)
+            << "BufferRole: modelIndex must be <= std::numeric_limits<int32_t>::max()";
+    VERIFY_LE_INT32_MAX(bufferRole.ioIndex)
+            << "BufferRole: ioIndex must be <= std::numeric_limits<int32_t>::max()";
+    return BufferRole{
+            .modelIndex = static_cast<int32_t>(bufferRole.modelIndex),
+            .ioIndex = static_cast<int32_t>(bufferRole.ioIndex),
+            .frequency = bufferRole.frequency,
+    };
+}
+
+nn::GeneralResult<bool> unvalidatedConvert(const nn::MeasureTiming& measureTiming) {
+    return measureTiming == nn::MeasureTiming::YES;
+}
+
 nn::GeneralResult<common::NativeHandle> unvalidatedConvert(const nn::SharedHandle& sharedHandle) {
     CHECK(sharedHandle != nullptr);
     return unvalidatedConvert(*sharedHandle);
@@ -713,6 +791,230 @@
                        .isSufficient = outputShape.isSufficient};
 }
 
+nn::GeneralResult<ExecutionPreference> unvalidatedConvert(
+        const nn::ExecutionPreference& executionPreference) {
+    return static_cast<ExecutionPreference>(executionPreference);
+}
+
+nn::GeneralResult<OperandType> unvalidatedConvert(const nn::OperandType& operandType) {
+    return static_cast<OperandType>(operandType);
+}
+
+nn::GeneralResult<OperandLifeTime> unvalidatedConvert(
+        const nn::Operand::LifeTime& operandLifeTime) {
+    return static_cast<OperandLifeTime>(operandLifeTime);
+}
+
+nn::GeneralResult<DataLocation> unvalidatedConvert(const nn::DataLocation& location) {
+    VERIFY_LE_INT32_MAX(location.poolIndex)
+            << "DataLocation: pool index must be <= std::numeric_limits<int32_t>::max()";
+    return DataLocation{
+            .poolIndex = static_cast<int32_t>(location.poolIndex),
+            .offset = static_cast<int64_t>(location.offset),
+            .length = static_cast<int64_t>(location.length),
+    };
+}
+
+nn::GeneralResult<std::optional<OperandExtraParams>> unvalidatedConvert(
+        const nn::Operand::ExtraParams& extraParams) {
+    return std::visit(
+            overloaded{
+                    [](const nn::Operand::NoParams&)
+                            -> nn::GeneralResult<std::optional<OperandExtraParams>> {
+                        return std::nullopt;
+                    },
+                    [](const nn::Operand::SymmPerChannelQuantParams& symmPerChannelQuantParams)
+                            -> nn::GeneralResult<std::optional<OperandExtraParams>> {
+                        if (symmPerChannelQuantParams.channelDim >
+                            std::numeric_limits<int32_t>::max()) {
+                            // Using explicit type conversion because std::optional in successful
+                            // result confuses the compiler.
+                            return (NN_ERROR() << "symmPerChannelQuantParams.channelDim must be <= "
+                                                  "std::numeric_limits<int32_t>::max(), received: "
+                                               << symmPerChannelQuantParams.channelDim)
+                                    .
+                                    operator nn::GeneralResult<std::optional<OperandExtraParams>>();
+                        }
+                        return OperandExtraParams::make<OperandExtraParams::Tag::channelQuant>(
+                                SymmPerChannelQuantParams{
+                                        .scales = symmPerChannelQuantParams.scales,
+                                        .channelDim = static_cast<int32_t>(
+                                                symmPerChannelQuantParams.channelDim),
+                                });
+                    },
+                    [](const nn::Operand::ExtensionParams& extensionParams)
+                            -> nn::GeneralResult<std::optional<OperandExtraParams>> {
+                        return OperandExtraParams::make<OperandExtraParams::Tag::extension>(
+                                extensionParams);
+                    },
+            },
+            extraParams);
+}
+
+nn::GeneralResult<Operand> unvalidatedConvert(const nn::Operand& operand) {
+    return Operand{
+            .type = NN_TRY(unvalidatedConvert(operand.type)),
+            .dimensions = NN_TRY(toSigned(operand.dimensions)),
+            .scale = operand.scale,
+            .zeroPoint = operand.zeroPoint,
+            .lifetime = NN_TRY(unvalidatedConvert(operand.lifetime)),
+            .location = NN_TRY(unvalidatedConvert(operand.location)),
+            .extraParams = NN_TRY(unvalidatedConvert(operand.extraParams)),
+    };
+}
+
+nn::GeneralResult<OperationType> unvalidatedConvert(const nn::OperationType& operationType) {
+    return static_cast<OperationType>(operationType);
+}
+
+nn::GeneralResult<Operation> unvalidatedConvert(const nn::Operation& operation) {
+    return Operation{
+            .type = NN_TRY(unvalidatedConvert(operation.type)),
+            .inputs = NN_TRY(toSigned(operation.inputs)),
+            .outputs = NN_TRY(toSigned(operation.outputs)),
+    };
+}
+
+nn::GeneralResult<Subgraph> unvalidatedConvert(const nn::Model::Subgraph& subgraph) {
+    return Subgraph{
+            .operands = NN_TRY(unvalidatedConvert(subgraph.operands)),
+            .operations = NN_TRY(unvalidatedConvert(subgraph.operations)),
+            .inputIndexes = NN_TRY(toSigned(subgraph.inputIndexes)),
+            .outputIndexes = NN_TRY(toSigned(subgraph.outputIndexes)),
+    };
+}
+
+nn::GeneralResult<std::vector<uint8_t>> unvalidatedConvert(
+        const nn::Model::OperandValues& operandValues) {
+    return std::vector<uint8_t>(operandValues.data(), operandValues.data() + operandValues.size());
+}
+
+nn::GeneralResult<ExtensionNameAndPrefix> unvalidatedConvert(
+        const nn::Model::ExtensionNameAndPrefix& extensionNameToPrefix) {
+    return ExtensionNameAndPrefix{
+            .name = extensionNameToPrefix.name,
+            .prefix = extensionNameToPrefix.prefix,
+    };
+}
+
+nn::GeneralResult<Model> unvalidatedConvert(const nn::Model& model) {
+    return Model{
+            .main = NN_TRY(unvalidatedConvert(model.main)),
+            .referenced = NN_TRY(unvalidatedConvert(model.referenced)),
+            .operandValues = NN_TRY(unvalidatedConvert(model.operandValues)),
+            .pools = NN_TRY(unvalidatedConvert(model.pools)),
+            .relaxComputationFloat32toFloat16 = model.relaxComputationFloat32toFloat16,
+            .extensionNameToPrefix = NN_TRY(unvalidatedConvert(model.extensionNameToPrefix)),
+    };
+}
+
+nn::GeneralResult<Priority> unvalidatedConvert(const nn::Priority& priority) {
+    return static_cast<Priority>(priority);
+}
+
+nn::GeneralResult<Request> unvalidatedConvert(const nn::Request& request) {
+    return Request{
+            .inputs = NN_TRY(unvalidatedConvert(request.inputs)),
+            .outputs = NN_TRY(unvalidatedConvert(request.outputs)),
+            .pools = NN_TRY(unvalidatedConvert(request.pools)),
+    };
+}
+
+nn::GeneralResult<RequestArgument> unvalidatedConvert(
+        const nn::Request::Argument& requestArgument) {
+    if (requestArgument.lifetime == nn::Request::Argument::LifeTime::POINTER) {
+        return NN_ERROR(nn::ErrorStatus::INVALID_ARGUMENT)
+               << "Request cannot be unvalidatedConverted because it contains pointer-based memory";
+    }
+    const bool hasNoValue = requestArgument.lifetime == nn::Request::Argument::LifeTime::NO_VALUE;
+    return RequestArgument{
+            .hasNoValue = hasNoValue,
+            .location = NN_TRY(unvalidatedConvert(requestArgument.location)),
+            .dimensions = NN_TRY(toSigned(requestArgument.dimensions)),
+    };
+}
+
+nn::GeneralResult<RequestMemoryPool> unvalidatedConvert(const nn::Request::MemoryPool& memoryPool) {
+    return std::visit(
+            overloaded{
+                    [](const nn::SharedMemory& memory) -> nn::GeneralResult<RequestMemoryPool> {
+                        return RequestMemoryPool::make<RequestMemoryPool::Tag::pool>(
+                                NN_TRY(unvalidatedConvert(memory)));
+                    },
+                    [](const nn::Request::MemoryDomainToken& token)
+                            -> nn::GeneralResult<RequestMemoryPool> {
+                        return RequestMemoryPool::make<RequestMemoryPool::Tag::token>(
+                                underlyingType(token));
+                    },
+                    [](const nn::SharedBuffer& /*buffer*/) {
+                        return (NN_ERROR(nn::ErrorStatus::GENERAL_FAILURE)
+                                << "Unable to make memory pool from IBuffer")
+                                .
+                                operator nn::GeneralResult<RequestMemoryPool>();
+                    },
+            },
+            memoryPool);
+}
+
+nn::GeneralResult<Timing> unvalidatedConvert(const nn::Timing& timing) {
+    return Timing{
+            .timeOnDevice = NN_TRY(unvalidatedConvert(timing.timeOnDevice)),
+            .timeInDriver = NN_TRY(unvalidatedConvert(timing.timeInDriver)),
+    };
+}
+
+nn::GeneralResult<int64_t> unvalidatedConvert(const nn::Duration& duration) {
+    const uint64_t nanoseconds = duration.count();
+    if (nanoseconds > std::numeric_limits<int64_t>::max()) {
+        return std::numeric_limits<int64_t>::max();
+    }
+    return static_cast<int64_t>(nanoseconds);
+}
+
+nn::GeneralResult<int64_t> unvalidatedConvert(const nn::OptionalDuration& optionalDuration) {
+    if (!optionalDuration.has_value()) {
+        return kNoTiming;
+    }
+    return unvalidatedConvert(optionalDuration.value());
+}
+
+nn::GeneralResult<int64_t> unvalidatedConvert(const nn::OptionalTimePoint& optionalTimePoint) {
+    if (!optionalTimePoint.has_value()) {
+        return kNoTiming;
+    }
+    return unvalidatedConvert(optionalTimePoint->time_since_epoch());
+}
+
+nn::GeneralResult<ndk::ScopedFileDescriptor> unvalidatedConvert(const nn::SyncFence& syncFence) {
+    auto duplicatedFd = NN_TRY(nn::dupFd(syncFence.getFd()));
+    return ndk::ScopedFileDescriptor(duplicatedFd.release());
+}
+
+nn::GeneralResult<ndk::ScopedFileDescriptor> unvalidatedConvertCache(
+        const nn::SharedHandle& handle) {
+    if (handle->ints.size() != 0) {
+        NN_ERROR() << "Cache handle must not contain ints";
+    }
+    if (handle->fds.size() != 1) {
+        NN_ERROR() << "Cache handle must contain exactly one fd but contains "
+                   << handle->fds.size();
+    }
+    auto duplicatedFd = NN_TRY(nn::dupFd(handle->fds.front().get()));
+    return ndk::ScopedFileDescriptor(duplicatedFd.release());
+}
+
+nn::GeneralResult<std::vector<uint8_t>> convert(const nn::CacheToken& cacheToken) {
+    return unvalidatedConvert(cacheToken);
+}
+
+nn::GeneralResult<BufferDesc> convert(const nn::BufferDesc& bufferDesc) {
+    return validatedConvert(bufferDesc);
+}
+
+nn::GeneralResult<bool> convert(const nn::MeasureTiming& measureTiming) {
+    return validatedConvert(measureTiming);
+}
+
 nn::GeneralResult<Memory> convert(const nn::SharedMemory& memory) {
     return validatedConvert(memory);
 }
@@ -721,11 +1023,62 @@
     return validatedConvert(errorStatus);
 }
 
+nn::GeneralResult<ExecutionPreference> convert(const nn::ExecutionPreference& executionPreference) {
+    return validatedConvert(executionPreference);
+}
+
+nn::GeneralResult<Model> convert(const nn::Model& model) {
+    return validatedConvert(model);
+}
+
+nn::GeneralResult<Priority> convert(const nn::Priority& priority) {
+    return validatedConvert(priority);
+}
+
+nn::GeneralResult<Request> convert(const nn::Request& request) {
+    return validatedConvert(request);
+}
+
+nn::GeneralResult<Timing> convert(const nn::Timing& timing) {
+    return validatedConvert(timing);
+}
+
+nn::GeneralResult<int64_t> convert(const nn::OptionalDuration& optionalDuration) {
+    return validatedConvert(optionalDuration);
+}
+
+nn::GeneralResult<int64_t> convert(const nn::OptionalTimePoint& outputShapes) {
+    return validatedConvert(outputShapes);
+}
+
+nn::GeneralResult<std::vector<BufferRole>> convert(const std::vector<nn::BufferRole>& bufferRoles) {
+    return validatedConvert(bufferRoles);
+}
+
 nn::GeneralResult<std::vector<OutputShape>> convert(
         const std::vector<nn::OutputShape>& outputShapes) {
     return validatedConvert(outputShapes);
 }
 
+nn::GeneralResult<std::vector<ndk::ScopedFileDescriptor>> convert(
+        const std::vector<nn::SharedHandle>& cacheHandles) {
+    const auto version = NN_TRY(hal::utils::makeGeneralFailure(nn::validate(cacheHandles)));
+    if (version > kVersion) {
+        return NN_ERROR() << "Insufficient version: " << version << " vs required " << kVersion;
+    }
+    std::vector<ndk::ScopedFileDescriptor> cacheFds;
+    cacheFds.reserve(cacheHandles.size());
+    for (const auto& cacheHandle : cacheHandles) {
+        cacheFds.push_back(NN_TRY(unvalidatedConvertCache(cacheHandle)));
+    }
+    return cacheFds;
+}
+
+nn::GeneralResult<std::vector<ndk::ScopedFileDescriptor>> convert(
+        const std::vector<nn::SyncFence>& syncFences) {
+    return unvalidatedConvert(syncFences);
+}
+
 nn::GeneralResult<std::vector<int32_t>> toSigned(const std::vector<uint32_t>& vec) {
     if (!std::all_of(vec.begin(), vec.end(),
                      [](uint32_t v) { return v <= std::numeric_limits<int32_t>::max(); })) {
diff --git a/neuralnetworks/aidl/utils/src/Device.cpp b/neuralnetworks/aidl/utils/src/Device.cpp
new file mode 100644
index 0000000..02ca861
--- /dev/null
+++ b/neuralnetworks/aidl/utils/src/Device.cpp
@@ -0,0 +1,294 @@
+/*
+ * Copyright (C) 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "Device.h"
+
+#include "Buffer.h"
+#include "Callbacks.h"
+#include "Conversions.h"
+#include "PreparedModel.h"
+#include "ProtectCallback.h"
+#include "Utils.h"
+
+#include <aidl/android/hardware/neuralnetworks/IDevice.h>
+#include <android/binder_auto_utils.h>
+#include <android/binder_interface_utils.h>
+#include <nnapi/IBuffer.h>
+#include <nnapi/IDevice.h>
+#include <nnapi/IPreparedModel.h>
+#include <nnapi/OperandTypes.h>
+#include <nnapi/Result.h>
+#include <nnapi/Types.h>
+#include <nnapi/hal/CommonUtils.h>
+
+#include <any>
+#include <functional>
+#include <memory>
+#include <optional>
+#include <string>
+#include <vector>
+
+// See hardware/interfaces/neuralnetworks/utils/README.md for more information on AIDL interface
+// lifetimes across processes and for protecting asynchronous calls across AIDL.
+
+namespace aidl::android::hardware::neuralnetworks::utils {
+
+namespace {
+
+nn::GeneralResult<std::vector<std::shared_ptr<IPreparedModel>>> convert(
+        const std::vector<nn::SharedPreparedModel>& preparedModels) {
+    std::vector<std::shared_ptr<IPreparedModel>> aidlPreparedModels(preparedModels.size());
+    for (size_t i = 0; i < preparedModels.size(); ++i) {
+        std::any underlyingResource = preparedModels[i]->getUnderlyingResource();
+        if (const auto* aidlPreparedModel =
+                    std::any_cast<std::shared_ptr<aidl_hal::IPreparedModel>>(&underlyingResource)) {
+            aidlPreparedModels[i] = *aidlPreparedModel;
+        } else {
+            return NN_ERROR(nn::ErrorStatus::INVALID_ARGUMENT)
+                   << "Unable to convert from nn::IPreparedModel to aidl_hal::IPreparedModel";
+        }
+    }
+    return aidlPreparedModels;
+}
+
+nn::GeneralResult<nn::Capabilities> getCapabilitiesFrom(IDevice* device) {
+    CHECK(device != nullptr);
+    Capabilities capabilities;
+    const auto ret = device->getCapabilities(&capabilities);
+    HANDLE_ASTATUS(ret) << "getCapabilities failed";
+    return nn::convert(capabilities);
+}
+
+nn::GeneralResult<std::string> getVersionStringFrom(aidl_hal::IDevice* device) {
+    CHECK(device != nullptr);
+    std::string version;
+    const auto ret = device->getVersionString(&version);
+    HANDLE_ASTATUS(ret) << "getVersionString failed";
+    return version;
+}
+
+nn::GeneralResult<nn::DeviceType> getDeviceTypeFrom(aidl_hal::IDevice* device) {
+    CHECK(device != nullptr);
+    DeviceType deviceType;
+    const auto ret = device->getType(&deviceType);
+    HANDLE_ASTATUS(ret) << "getDeviceType failed";
+    return nn::convert(deviceType);
+}
+
+nn::GeneralResult<std::vector<nn::Extension>> getSupportedExtensionsFrom(
+        aidl_hal::IDevice* device) {
+    CHECK(device != nullptr);
+    std::vector<Extension> supportedExtensions;
+    const auto ret = device->getSupportedExtensions(&supportedExtensions);
+    HANDLE_ASTATUS(ret) << "getExtensions failed";
+    return nn::convert(supportedExtensions);
+}
+
+nn::GeneralResult<std::pair<uint32_t, uint32_t>> getNumberOfCacheFilesNeededFrom(
+        aidl_hal::IDevice* device) {
+    CHECK(device != nullptr);
+    NumberOfCacheFiles numberOfCacheFiles;
+    const auto ret = device->getNumberOfCacheFilesNeeded(&numberOfCacheFiles);
+    HANDLE_ASTATUS(ret) << "getNumberOfCacheFilesNeeded failed";
+
+    if (numberOfCacheFiles.numDataCache < 0 || numberOfCacheFiles.numModelCache < 0) {
+        return NN_ERROR() << "Driver reported negative numer of cache files needed";
+    }
+    if (static_cast<uint32_t>(numberOfCacheFiles.numModelCache) > nn::kMaxNumberOfCacheFiles) {
+        return NN_ERROR() << "getNumberOfCacheFilesNeeded returned numModelCache files greater "
+                             "than allowed max ("
+                          << numberOfCacheFiles.numModelCache << " vs "
+                          << nn::kMaxNumberOfCacheFiles << ")";
+    }
+    if (static_cast<uint32_t>(numberOfCacheFiles.numDataCache) > nn::kMaxNumberOfCacheFiles) {
+        return NN_ERROR() << "getNumberOfCacheFilesNeeded returned numDataCache files greater "
+                             "than allowed max ("
+                          << numberOfCacheFiles.numDataCache << " vs " << nn::kMaxNumberOfCacheFiles
+                          << ")";
+    }
+    return std::make_pair(numberOfCacheFiles.numDataCache, numberOfCacheFiles.numModelCache);
+}
+
+}  // namespace
+
+nn::GeneralResult<std::shared_ptr<const Device>> Device::create(
+        std::string name, std::shared_ptr<aidl_hal::IDevice> device) {
+    if (name.empty()) {
+        return NN_ERROR(nn::ErrorStatus::INVALID_ARGUMENT)
+               << "aidl_hal::utils::Device::create must have non-empty name";
+    }
+    if (device == nullptr) {
+        return NN_ERROR(nn::ErrorStatus::INVALID_ARGUMENT)
+               << "aidl_hal::utils::Device::create must have non-null device";
+    }
+
+    auto versionString = NN_TRY(getVersionStringFrom(device.get()));
+    const auto deviceType = NN_TRY(getDeviceTypeFrom(device.get()));
+    auto extensions = NN_TRY(getSupportedExtensionsFrom(device.get()));
+    auto capabilities = NN_TRY(getCapabilitiesFrom(device.get()));
+    const auto numberOfCacheFilesNeeded = NN_TRY(getNumberOfCacheFilesNeededFrom(device.get()));
+
+    auto deathHandler = NN_TRY(DeathHandler::create(device));
+    return std::make_shared<const Device>(
+            PrivateConstructorTag{}, std::move(name), std::move(versionString), deviceType,
+            std::move(extensions), std::move(capabilities), numberOfCacheFilesNeeded,
+            std::move(device), std::move(deathHandler));
+}
+
+Device::Device(PrivateConstructorTag /*tag*/, std::string name, std::string versionString,
+               nn::DeviceType deviceType, std::vector<nn::Extension> extensions,
+               nn::Capabilities capabilities,
+               std::pair<uint32_t, uint32_t> numberOfCacheFilesNeeded,
+               std::shared_ptr<aidl_hal::IDevice> device, DeathHandler deathHandler)
+    : kName(std::move(name)),
+      kVersionString(std::move(versionString)),
+      kDeviceType(deviceType),
+      kExtensions(std::move(extensions)),
+      kCapabilities(std::move(capabilities)),
+      kNumberOfCacheFilesNeeded(numberOfCacheFilesNeeded),
+      kDevice(std::move(device)),
+      kDeathHandler(std::move(deathHandler)) {}
+
+const std::string& Device::getName() const {
+    return kName;
+}
+
+const std::string& Device::getVersionString() const {
+    return kVersionString;
+}
+
+nn::Version Device::getFeatureLevel() const {
+    return nn::Version::ANDROID_S;
+}
+
+nn::DeviceType Device::getType() const {
+    return kDeviceType;
+}
+
+bool Device::isUpdatable() const {
+    return false;
+}
+
+const std::vector<nn::Extension>& Device::getSupportedExtensions() const {
+    return kExtensions;
+}
+
+const nn::Capabilities& Device::getCapabilities() const {
+    return kCapabilities;
+}
+
+std::pair<uint32_t, uint32_t> Device::getNumberOfCacheFilesNeeded() const {
+    return kNumberOfCacheFilesNeeded;
+}
+
+nn::GeneralResult<void> Device::wait() const {
+    const auto ret = ndk::ScopedAStatus::fromStatus(AIBinder_ping(kDevice->asBinder().get()));
+    HANDLE_ASTATUS(ret) << "ping failed";
+    return {};
+}
+
+nn::GeneralResult<std::vector<bool>> Device::getSupportedOperations(const nn::Model& model) const {
+    // Ensure that model is ready for IPC.
+    std::optional<nn::Model> maybeModelInShared;
+    const nn::Model& modelInShared =
+            NN_TRY(hal::utils::flushDataFromPointerToShared(&model, &maybeModelInShared));
+
+    const auto aidlModel = NN_TRY(convert(modelInShared));
+
+    std::vector<bool> supportedOperations;
+    const auto ret = kDevice->getSupportedOperations(aidlModel, &supportedOperations);
+    HANDLE_ASTATUS(ret) << "getSupportedOperations failed";
+
+    return supportedOperations;
+}
+
+nn::GeneralResult<nn::SharedPreparedModel> Device::prepareModel(
+        const nn::Model& model, nn::ExecutionPreference preference, nn::Priority priority,
+        nn::OptionalTimePoint deadline, const std::vector<nn::SharedHandle>& modelCache,
+        const std::vector<nn::SharedHandle>& dataCache, const nn::CacheToken& token) const {
+    // Ensure that model is ready for IPC.
+    std::optional<nn::Model> maybeModelInShared;
+    const nn::Model& modelInShared =
+            NN_TRY(hal::utils::flushDataFromPointerToShared(&model, &maybeModelInShared));
+
+    const auto aidlModel = NN_TRY(convert(modelInShared));
+    const auto aidlPreference = NN_TRY(convert(preference));
+    const auto aidlPriority = NN_TRY(convert(priority));
+    const auto aidlDeadline = NN_TRY(convert(deadline));
+    const auto aidlModelCache = NN_TRY(convert(modelCache));
+    const auto aidlDataCache = NN_TRY(convert(dataCache));
+    const auto aidlToken = NN_TRY(convert(token));
+
+    const auto cb = ndk::SharedRefBase::make<PreparedModelCallback>();
+    const auto scoped = kDeathHandler.protectCallback(cb.get());
+
+    const auto ret = kDevice->prepareModel(aidlModel, aidlPreference, aidlPriority, aidlDeadline,
+                                           aidlModelCache, aidlDataCache, aidlToken, cb);
+    HANDLE_ASTATUS(ret) << "prepareModel failed";
+
+    return cb->get();
+}
+
+nn::GeneralResult<nn::SharedPreparedModel> Device::prepareModelFromCache(
+        nn::OptionalTimePoint deadline, const std::vector<nn::SharedHandle>& modelCache,
+        const std::vector<nn::SharedHandle>& dataCache, const nn::CacheToken& token) const {
+    const auto aidlDeadline = NN_TRY(convert(deadline));
+    const auto aidlModelCache = NN_TRY(convert(modelCache));
+    const auto aidlDataCache = NN_TRY(convert(dataCache));
+    const auto aidlToken = NN_TRY(convert(token));
+
+    const auto cb = ndk::SharedRefBase::make<PreparedModelCallback>();
+    const auto scoped = kDeathHandler.protectCallback(cb.get());
+
+    const auto ret = kDevice->prepareModelFromCache(aidlDeadline, aidlModelCache, aidlDataCache,
+                                                    aidlToken, cb);
+    HANDLE_ASTATUS(ret) << "prepareModelFromCache failed";
+
+    return cb->get();
+}
+
+nn::GeneralResult<nn::SharedBuffer> Device::allocate(
+        const nn::BufferDesc& desc, const std::vector<nn::SharedPreparedModel>& preparedModels,
+        const std::vector<nn::BufferRole>& inputRoles,
+        const std::vector<nn::BufferRole>& outputRoles) const {
+    const auto aidlDesc = NN_TRY(convert(desc));
+    const auto aidlPreparedModels = NN_TRY(convert(preparedModels));
+    const auto aidlInputRoles = NN_TRY(convert(inputRoles));
+    const auto aidlOutputRoles = NN_TRY(convert(outputRoles));
+
+    std::vector<IPreparedModelParcel> aidlPreparedModelParcels;
+    aidlPreparedModelParcels.reserve(aidlPreparedModels.size());
+    for (const auto& preparedModel : aidlPreparedModels) {
+        aidlPreparedModelParcels.push_back({.preparedModel = preparedModel});
+    }
+
+    DeviceBuffer buffer;
+    const auto ret = kDevice->allocate(aidlDesc, aidlPreparedModelParcels, aidlInputRoles,
+                                       aidlOutputRoles, &buffer);
+    HANDLE_ASTATUS(ret) << "IDevice::allocate failed";
+
+    if (buffer.token < 0) {
+        return NN_ERROR() << "IDevice::allocate returned negative token";
+    }
+
+    return Buffer::create(buffer.buffer, static_cast<nn::Request::MemoryDomainToken>(buffer.token));
+}
+
+DeathMonitor* Device::getDeathMonitor() const {
+    return kDeathHandler.getDeathMonitor().get();
+}
+
+}  // namespace aidl::android::hardware::neuralnetworks::utils
diff --git a/neuralnetworks/aidl/utils/src/PreparedModel.cpp b/neuralnetworks/aidl/utils/src/PreparedModel.cpp
new file mode 100644
index 0000000..aee4d90
--- /dev/null
+++ b/neuralnetworks/aidl/utils/src/PreparedModel.cpp
@@ -0,0 +1,172 @@
+/*
+ * Copyright (C) 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "PreparedModel.h"
+
+#include "Callbacks.h"
+#include "Conversions.h"
+#include "ProtectCallback.h"
+#include "Utils.h"
+
+#include <android/binder_auto_utils.h>
+#include <nnapi/IPreparedModel.h>
+#include <nnapi/Result.h>
+#include <nnapi/TypeUtils.h>
+#include <nnapi/Types.h>
+#include <nnapi/hal/1.0/Burst.h>
+#include <nnapi/hal/CommonUtils.h>
+#include <nnapi/hal/HandleError.h>
+
+#include <memory>
+#include <tuple>
+#include <utility>
+#include <vector>
+
+// See hardware/interfaces/neuralnetworks/utils/README.md for more information on AIDL interface
+// lifetimes across processes and for protecting asynchronous calls across AIDL.
+
+namespace aidl::android::hardware::neuralnetworks::utils {
+namespace {
+
+nn::GeneralResult<std::pair<std::vector<nn::OutputShape>, nn::Timing>> convertExecutionResults(
+        const std::vector<OutputShape>& outputShapes, const Timing& timing) {
+    return std::make_pair(NN_TRY(nn::convert(outputShapes)), NN_TRY(nn::convert(timing)));
+}
+
+nn::GeneralResult<std::pair<nn::Timing, nn::Timing>> convertFencedExecutionResults(
+        ErrorStatus status, const aidl_hal::Timing& timingLaunched,
+        const aidl_hal::Timing& timingFenced) {
+    HANDLE_HAL_STATUS(status) << "fenced execution callback info failed with " << toString(status);
+    return std::make_pair(NN_TRY(nn::convert(timingLaunched)), NN_TRY(nn::convert(timingFenced)));
+}
+
+}  // namespace
+
+nn::GeneralResult<std::shared_ptr<const PreparedModel>> PreparedModel::create(
+        std::shared_ptr<aidl_hal::IPreparedModel> preparedModel) {
+    if (preparedModel == nullptr) {
+        return NN_ERROR()
+               << "aidl_hal::utils::PreparedModel::create must have non-null preparedModel";
+    }
+
+    return std::make_shared<const PreparedModel>(PrivateConstructorTag{}, std::move(preparedModel));
+}
+
+PreparedModel::PreparedModel(PrivateConstructorTag /*tag*/,
+                             std::shared_ptr<aidl_hal::IPreparedModel> preparedModel)
+    : kPreparedModel(std::move(preparedModel)) {}
+
+nn::ExecutionResult<std::pair<std::vector<nn::OutputShape>, nn::Timing>> PreparedModel::execute(
+        const nn::Request& request, nn::MeasureTiming measure,
+        const nn::OptionalTimePoint& deadline,
+        const nn::OptionalDuration& loopTimeoutDuration) const {
+    // Ensure that request is ready for IPC.
+    std::optional<nn::Request> maybeRequestInShared;
+    const nn::Request& requestInShared = NN_TRY(hal::utils::makeExecutionFailure(
+            hal::utils::flushDataFromPointerToShared(&request, &maybeRequestInShared)));
+
+    const auto aidlRequest = NN_TRY(hal::utils::makeExecutionFailure(convert(requestInShared)));
+    const auto aidlMeasure = NN_TRY(hal::utils::makeExecutionFailure(convert(measure)));
+    const auto aidlDeadline = NN_TRY(hal::utils::makeExecutionFailure(convert(deadline)));
+    const auto aidlLoopTimeoutDuration =
+            NN_TRY(hal::utils::makeExecutionFailure(convert(loopTimeoutDuration)));
+
+    ExecutionResult executionResult;
+    const auto ret = kPreparedModel->executeSynchronously(
+            aidlRequest, aidlMeasure, aidlDeadline, aidlLoopTimeoutDuration, &executionResult);
+    HANDLE_ASTATUS(ret) << "executeSynchronously failed";
+    if (!executionResult.outputSufficientSize) {
+        auto canonicalOutputShapes =
+                nn::convert(executionResult.outputShapes).value_or(std::vector<nn::OutputShape>{});
+        return NN_ERROR(nn::ErrorStatus::OUTPUT_INSUFFICIENT_SIZE, std::move(canonicalOutputShapes))
+               << "execution failed with " << nn::ErrorStatus::OUTPUT_INSUFFICIENT_SIZE;
+    }
+    auto [outputShapes, timing] = NN_TRY(hal::utils::makeExecutionFailure(
+            convertExecutionResults(executionResult.outputShapes, executionResult.timing)));
+
+    NN_TRY(hal::utils::makeExecutionFailure(
+            hal::utils::unflushDataFromSharedToPointer(request, maybeRequestInShared)));
+
+    return std::make_pair(std::move(outputShapes), timing);
+}
+
+nn::GeneralResult<std::pair<nn::SyncFence, nn::ExecuteFencedInfoCallback>>
+PreparedModel::executeFenced(const nn::Request& request, const std::vector<nn::SyncFence>& waitFor,
+                             nn::MeasureTiming measure, const nn::OptionalTimePoint& deadline,
+                             const nn::OptionalDuration& loopTimeoutDuration,
+                             const nn::OptionalDuration& timeoutDurationAfterFence) const {
+    // Ensure that request is ready for IPC.
+    std::optional<nn::Request> maybeRequestInShared;
+    const nn::Request& requestInShared =
+            NN_TRY(hal::utils::flushDataFromPointerToShared(&request, &maybeRequestInShared));
+
+    const auto aidlRequest = NN_TRY(convert(requestInShared));
+    const auto aidlWaitFor = NN_TRY(convert(waitFor));
+    const auto aidlMeasure = NN_TRY(convert(measure));
+    const auto aidlDeadline = NN_TRY(convert(deadline));
+    const auto aidlLoopTimeoutDuration = NN_TRY(convert(loopTimeoutDuration));
+    const auto aidlTimeoutDurationAfterFence = NN_TRY(convert(timeoutDurationAfterFence));
+
+    FencedExecutionResult result;
+    const auto ret = kPreparedModel->executeFenced(aidlRequest, aidlWaitFor, aidlMeasure,
+                                                   aidlDeadline, aidlLoopTimeoutDuration,
+                                                   aidlTimeoutDurationAfterFence, &result);
+    HANDLE_ASTATUS(ret) << "executeFenced failed";
+
+    auto resultSyncFence = nn::SyncFence::createAsSignaled();
+    if (result.syncFence.get() != -1) {
+        resultSyncFence = NN_TRY(nn::convert(result.syncFence));
+    }
+
+    auto callback = result.callback;
+    if (callback == nullptr) {
+        return NN_ERROR(nn::ErrorStatus::GENERAL_FAILURE) << "callback is null";
+    }
+
+    // If executeFenced required the request memory to be moved into shared memory, block here until
+    // the fenced execution has completed and flush the memory back.
+    if (maybeRequestInShared.has_value()) {
+        const auto state = resultSyncFence.syncWait({});
+        if (state != nn::SyncFence::FenceState::SIGNALED) {
+            return NN_ERROR() << "syncWait failed with " << state;
+        }
+        NN_TRY(hal::utils::unflushDataFromSharedToPointer(request, maybeRequestInShared));
+    }
+
+    // Create callback which can be used to retrieve the execution error status and timings.
+    nn::ExecuteFencedInfoCallback resultCallback =
+            [callback]() -> nn::GeneralResult<std::pair<nn::Timing, nn::Timing>> {
+        ErrorStatus errorStatus;
+        Timing timingLaunched;
+        Timing timingFenced;
+        const auto ret = callback->getExecutionInfo(&timingLaunched, &timingFenced, &errorStatus);
+        HANDLE_ASTATUS(ret) << "fenced execution callback getExecutionInfo failed";
+        return convertFencedExecutionResults(errorStatus, timingLaunched, timingFenced);
+    };
+
+    return std::make_pair(std::move(resultSyncFence), std::move(resultCallback));
+}
+
+nn::GeneralResult<nn::SharedBurst> PreparedModel::configureExecutionBurst() const {
+    return hal::V1_0::utils::Burst::create(shared_from_this());
+}
+
+std::any PreparedModel::getUnderlyingResource() const {
+    std::shared_ptr<aidl_hal::IPreparedModel> resource = kPreparedModel;
+    return resource;
+}
+
+}  // namespace aidl::android::hardware::neuralnetworks::utils
diff --git a/neuralnetworks/aidl/utils/src/ProtectCallback.cpp b/neuralnetworks/aidl/utils/src/ProtectCallback.cpp
new file mode 100644
index 0000000..124641c
--- /dev/null
+++ b/neuralnetworks/aidl/utils/src/ProtectCallback.cpp
@@ -0,0 +1,112 @@
+/*
+ * Copyright (C) 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "ProtectCallback.h"
+
+#include <android-base/logging.h>
+#include <android-base/scopeguard.h>
+#include <android-base/thread_annotations.h>
+#include <android/binder_auto_utils.h>
+#include <android/binder_interface_utils.h>
+#include <nnapi/Result.h>
+#include <nnapi/hal/ProtectCallback.h>
+
+#include <algorithm>
+#include <functional>
+#include <memory>
+#include <mutex>
+#include <vector>
+
+#include "Utils.h"
+
+namespace aidl::android::hardware::neuralnetworks::utils {
+
+void DeathMonitor::serviceDied() {
+    std::lock_guard guard(mMutex);
+    std::for_each(mObjects.begin(), mObjects.end(),
+                  [](hal::utils::IProtectedCallback* killable) { killable->notifyAsDeadObject(); });
+}
+
+void DeathMonitor::serviceDied(void* cookie) {
+    auto deathMonitor = static_cast<DeathMonitor*>(cookie);
+    deathMonitor->serviceDied();
+}
+
+void DeathMonitor::add(hal::utils::IProtectedCallback* killable) const {
+    CHECK(killable != nullptr);
+    std::lock_guard guard(mMutex);
+    mObjects.push_back(killable);
+}
+
+void DeathMonitor::remove(hal::utils::IProtectedCallback* killable) const {
+    CHECK(killable != nullptr);
+    std::lock_guard guard(mMutex);
+    const auto removedIter = std::remove(mObjects.begin(), mObjects.end(), killable);
+    mObjects.erase(removedIter);
+}
+
+nn::GeneralResult<DeathHandler> DeathHandler::create(std::shared_ptr<ndk::ICInterface> object) {
+    if (object == nullptr) {
+        return NN_ERROR(nn::ErrorStatus::INVALID_ARGUMENT)
+               << "utils::DeathHandler::create must have non-null object";
+    }
+    auto deathMonitor = std::make_shared<DeathMonitor>();
+    auto deathRecipient = ndk::ScopedAIBinder_DeathRecipient(
+            AIBinder_DeathRecipient_new(DeathMonitor::serviceDied));
+
+    // If passed a local binder, AIBinder_linkToDeath will do nothing and return
+    // STATUS_INVALID_OPERATION. We ignore this case because we only use local binders in tests
+    // where this is not an error.
+    if (object->isRemote()) {
+        const auto ret = ndk::ScopedAStatus::fromStatus(AIBinder_linkToDeath(
+                object->asBinder().get(), deathRecipient.get(), deathMonitor.get()));
+        HANDLE_ASTATUS(ret) << "AIBinder_linkToDeath failed";
+    }
+
+    return DeathHandler(std::move(object), std::move(deathRecipient), std::move(deathMonitor));
+}
+
+DeathHandler::DeathHandler(std::shared_ptr<ndk::ICInterface> object,
+                           ndk::ScopedAIBinder_DeathRecipient deathRecipient,
+                           std::shared_ptr<DeathMonitor> deathMonitor)
+    : kObject(std::move(object)),
+      kDeathRecipient(std::move(deathRecipient)),
+      kDeathMonitor(std::move(deathMonitor)) {
+    CHECK(kObject != nullptr);
+    CHECK(kDeathRecipient.get() != nullptr);
+    CHECK(kDeathMonitor != nullptr);
+}
+
+DeathHandler::~DeathHandler() {
+    if (kObject != nullptr && kDeathRecipient.get() != nullptr && kDeathMonitor != nullptr) {
+        const auto ret = ndk::ScopedAStatus::fromStatus(AIBinder_unlinkToDeath(
+                kObject->asBinder().get(), kDeathRecipient.get(), kDeathMonitor.get()));
+        const auto maybeSuccess = handleTransportError(ret);
+        if (!maybeSuccess.ok()) {
+            LOG(ERROR) << maybeSuccess.error().message;
+        }
+    }
+}
+
+[[nodiscard]] ::android::base::ScopeGuard<DeathHandler::Cleanup> DeathHandler::protectCallback(
+        hal::utils::IProtectedCallback* killable) const {
+    CHECK(killable != nullptr);
+    kDeathMonitor->add(killable);
+    return ::android::base::make_scope_guard(
+            [deathMonitor = kDeathMonitor, killable] { deathMonitor->remove(killable); });
+}
+
+}  // namespace aidl::android::hardware::neuralnetworks::utils
diff --git a/neuralnetworks/aidl/utils/src/Service.cpp b/neuralnetworks/aidl/utils/src/Service.cpp
new file mode 100644
index 0000000..511de55
--- /dev/null
+++ b/neuralnetworks/aidl/utils/src/Service.cpp
@@ -0,0 +1,53 @@
+/*
+ * Copyright (C) 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "Service.h"
+
+#include <android/binder_auto_utils.h>
+#include <android/binder_manager.h>
+#include <android/binder_process.h>
+
+#include <nnapi/IDevice.h>
+#include <nnapi/Result.h>
+#include <nnapi/Types.h>
+#include <nnapi/hal/ResilientDevice.h>
+#include <string>
+
+#include "Device.h"
+
+namespace aidl::android::hardware::neuralnetworks::utils {
+
+nn::GeneralResult<nn::SharedDevice> getDevice(const std::string& instanceName) {
+    auto fullName = std::string(IDevice::descriptor) + "/" + instanceName;
+    hal::utils::ResilientDevice::Factory makeDevice =
+            [instanceName,
+             name = std::move(fullName)](bool blocking) -> nn::GeneralResult<nn::SharedDevice> {
+        const auto& getService =
+                blocking ? AServiceManager_getService : AServiceManager_checkService;
+        auto service = IDevice::fromBinder(ndk::SpAIBinder(getService(name.c_str())));
+        if (service == nullptr) {
+            return NN_ERROR() << (blocking ? "AServiceManager_getService"
+                                           : "AServiceManager_checkService")
+                              << " returned nullptr";
+        }
+        ABinderProcess_startThreadPool();
+        return Device::create(instanceName, std::move(service));
+    };
+
+    return hal::utils::ResilientDevice::create(std::move(makeDevice));
+}
+
+}  // namespace aidl::android::hardware::neuralnetworks::utils
diff --git a/neuralnetworks/aidl/utils/src/Utils.cpp b/neuralnetworks/aidl/utils/src/Utils.cpp
index 8d00e59..95516c8 100644
--- a/neuralnetworks/aidl/utils/src/Utils.cpp
+++ b/neuralnetworks/aidl/utils/src/Utils.cpp
@@ -16,13 +16,12 @@
 
 #include "Utils.h"
 
+#include <android/binder_status.h>
 #include <nnapi/Result.h>
 
 namespace aidl::android::hardware::neuralnetworks::utils {
 namespace {
 
-using ::android::nn::GeneralResult;
-
 template <typename Type>
 nn::GeneralResult<std::vector<Type>> cloneVec(const std::vector<Type>& arguments) {
     std::vector<Type> clonedObjects;
@@ -34,13 +33,13 @@
 }
 
 template <typename Type>
-GeneralResult<std::vector<Type>> clone(const std::vector<Type>& arguments) {
+nn::GeneralResult<std::vector<Type>> clone(const std::vector<Type>& arguments) {
     return cloneVec(arguments);
 }
 
 }  // namespace
 
-GeneralResult<Memory> clone(const Memory& memory) {
+nn::GeneralResult<Memory> clone(const Memory& memory) {
     common::NativeHandle nativeHandle;
     nativeHandle.ints = memory.handle.ints;
     nativeHandle.fds.reserve(memory.handle.fds.size());
@@ -58,7 +57,7 @@
     };
 }
 
-GeneralResult<RequestMemoryPool> clone(const RequestMemoryPool& requestPool) {
+nn::GeneralResult<RequestMemoryPool> clone(const RequestMemoryPool& requestPool) {
     using Tag = RequestMemoryPool::Tag;
     switch (requestPool.getTag()) {
         case Tag::pool:
@@ -70,10 +69,10 @@
     // compiler.
     return (NN_ERROR() << "Unrecognized request pool tag: " << requestPool.getTag())
             .
-            operator GeneralResult<RequestMemoryPool>();
+            operator nn::GeneralResult<RequestMemoryPool>();
 }
 
-GeneralResult<Request> clone(const Request& request) {
+nn::GeneralResult<Request> clone(const Request& request) {
     return Request{
             .inputs = request.inputs,
             .outputs = request.outputs,
@@ -81,7 +80,7 @@
     };
 }
 
-GeneralResult<Model> clone(const Model& model) {
+nn::GeneralResult<Model> clone(const Model& model) {
     return Model{
             .main = model.main,
             .referenced = model.referenced,
@@ -92,4 +91,20 @@
     };
 }
 
+nn::GeneralResult<void> handleTransportError(const ndk::ScopedAStatus& ret) {
+    if (ret.getStatus() == STATUS_DEAD_OBJECT) {
+        return nn::error(nn::ErrorStatus::DEAD_OBJECT)
+               << "Binder transaction returned STATUS_DEAD_OBJECT: " << ret.getDescription();
+    }
+    if (ret.isOk()) {
+        return {};
+    }
+    if (ret.getExceptionCode() != EX_SERVICE_SPECIFIC) {
+        return nn::error(nn::ErrorStatus::GENERAL_FAILURE)
+               << "Binder transaction returned exception: " << ret.getDescription();
+    }
+    return nn::error(static_cast<nn::ErrorStatus>(ret.getServiceSpecificError()))
+           << ret.getMessage();
+}
+
 }  // namespace aidl::android::hardware::neuralnetworks::utils
diff --git a/neuralnetworks/aidl/utils/test/BufferTest.cpp b/neuralnetworks/aidl/utils/test/BufferTest.cpp
new file mode 100644
index 0000000..9736160
--- /dev/null
+++ b/neuralnetworks/aidl/utils/test/BufferTest.cpp
@@ -0,0 +1,212 @@
+/*
+ * Copyright (C) 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "MockBuffer.h"
+
+#include <aidl/android/hardware/neuralnetworks/ErrorStatus.h>
+#include <aidl/android/hardware/neuralnetworks/IBuffer.h>
+#include <android/binder_auto_utils.h>
+#include <gmock/gmock.h>
+#include <gtest/gtest.h>
+#include <nnapi/IBuffer.h>
+#include <nnapi/SharedMemory.h>
+#include <nnapi/TypeUtils.h>
+#include <nnapi/Types.h>
+#include <nnapi/hal/aidl/Buffer.h>
+
+#include <functional>
+#include <memory>
+
+namespace aidl::android::hardware::neuralnetworks::utils {
+namespace {
+
+using ::testing::_;
+using ::testing::Invoke;
+using ::testing::InvokeWithoutArgs;
+using ::testing::Return;
+
+const auto kMemory = nn::createSharedMemory(4).value();
+const std::shared_ptr<IBuffer> kInvalidBuffer;
+constexpr auto kInvalidToken = nn::Request::MemoryDomainToken{0};
+constexpr auto kToken = nn::Request::MemoryDomainToken{1};
+
+constexpr auto makeStatusOk = [] { return ndk::ScopedAStatus::ok(); };
+
+constexpr auto makeGeneralFailure = [] {
+    return ndk::ScopedAStatus::fromServiceSpecificError(
+            static_cast<int32_t>(ErrorStatus::GENERAL_FAILURE));
+};
+constexpr auto makeGeneralTransportFailure = [] {
+    return ndk::ScopedAStatus::fromStatus(STATUS_NO_MEMORY);
+};
+constexpr auto makeDeadObjectFailure = [] {
+    return ndk::ScopedAStatus::fromStatus(STATUS_DEAD_OBJECT);
+};
+
+}  // namespace
+
+TEST(BufferTest, invalidBuffer) {
+    // run test
+    const auto result = Buffer::create(kInvalidBuffer, kToken);
+
+    // verify result
+    ASSERT_FALSE(result.has_value());
+    EXPECT_EQ(result.error().code, nn::ErrorStatus::GENERAL_FAILURE);
+}
+
+TEST(BufferTest, invalidToken) {
+    // setup call
+    const auto mockBuffer = MockBuffer::create();
+
+    // run test
+    const auto result = Buffer::create(mockBuffer, kInvalidToken);
+
+    // verify result
+    ASSERT_FALSE(result.has_value());
+    EXPECT_EQ(result.error().code, nn::ErrorStatus::GENERAL_FAILURE);
+}
+
+TEST(BufferTest, create) {
+    // setup call
+    const auto mockBuffer = MockBuffer::create();
+    const auto buffer = Buffer::create(mockBuffer, kToken).value();
+
+    // run test
+    const auto token = buffer->getToken();
+
+    // verify result
+    EXPECT_EQ(token, kToken);
+}
+
+TEST(BufferTest, copyTo) {
+    // setup call
+    const auto mockBuffer = MockBuffer::create();
+    const auto buffer = Buffer::create(mockBuffer, kToken).value();
+    EXPECT_CALL(*mockBuffer, copyTo(_)).Times(1).WillOnce(InvokeWithoutArgs(makeStatusOk));
+
+    // run test
+    const auto result = buffer->copyTo(kMemory);
+
+    // verify result
+    EXPECT_TRUE(result.has_value()) << result.error().message;
+}
+
+TEST(BufferTest, copyToError) {
+    // setup test
+    const auto mockBuffer = MockBuffer::create();
+    const auto buffer = Buffer::create(mockBuffer, kToken).value();
+    EXPECT_CALL(*mockBuffer, copyTo(_)).Times(1).WillOnce(InvokeWithoutArgs(makeGeneralFailure));
+
+    // run test
+    const auto result = buffer->copyTo(kMemory);
+
+    // verify result
+    ASSERT_FALSE(result.has_value());
+    EXPECT_EQ(result.error().code, nn::ErrorStatus::GENERAL_FAILURE);
+}
+
+TEST(BufferTest, copyToTransportFailure) {
+    // setup test
+    const auto mockBuffer = MockBuffer::create();
+    const auto buffer = Buffer::create(mockBuffer, kToken).value();
+    EXPECT_CALL(*mockBuffer, copyTo(_))
+            .Times(1)
+            .WillOnce(InvokeWithoutArgs(makeGeneralTransportFailure));
+
+    // run test
+    const auto result = buffer->copyTo(kMemory);
+
+    // verify result
+    ASSERT_FALSE(result.has_value());
+    EXPECT_EQ(result.error().code, nn::ErrorStatus::GENERAL_FAILURE);
+}
+
+TEST(BufferTest, copyToDeadObject) {
+    // setup test
+    const auto mockBuffer = MockBuffer::create();
+    const auto buffer = Buffer::create(mockBuffer, kToken).value();
+    EXPECT_CALL(*mockBuffer, copyTo(_)).Times(1).WillOnce(InvokeWithoutArgs(makeDeadObjectFailure));
+
+    // run test
+    const auto result = buffer->copyTo(kMemory);
+
+    // verify result
+    ASSERT_FALSE(result.has_value());
+    EXPECT_EQ(result.error().code, nn::ErrorStatus::DEAD_OBJECT);
+}
+
+TEST(BufferTest, copyFrom) {
+    // setup call
+    const auto mockBuffer = MockBuffer::create();
+    const auto buffer = Buffer::create(mockBuffer, kToken).value();
+    EXPECT_CALL(*mockBuffer, copyFrom(_, _)).Times(1).WillOnce(InvokeWithoutArgs(makeStatusOk));
+
+    // run test
+    const auto result = buffer->copyFrom(kMemory, {});
+
+    // verify result
+    EXPECT_TRUE(result.has_value());
+}
+
+TEST(BufferTest, copyFromError) {
+    // setup test
+    const auto mockBuffer = MockBuffer::create();
+    const auto buffer = Buffer::create(mockBuffer, kToken).value();
+    EXPECT_CALL(*mockBuffer, copyFrom(_, _))
+            .Times(1)
+            .WillOnce(InvokeWithoutArgs(makeGeneralFailure));
+
+    // run test
+    const auto result = buffer->copyFrom(kMemory, {});
+
+    // verify result
+    ASSERT_FALSE(result.has_value());
+    EXPECT_EQ(result.error().code, nn::ErrorStatus::GENERAL_FAILURE);
+}
+
+TEST(BufferTest, copyFromTransportFailure) {
+    // setup test
+    const auto mockBuffer = MockBuffer::create();
+    const auto buffer = Buffer::create(mockBuffer, kToken).value();
+    EXPECT_CALL(*mockBuffer, copyFrom(_, _))
+            .Times(1)
+            .WillOnce(InvokeWithoutArgs(makeGeneralTransportFailure));
+
+    // run test
+    const auto result = buffer->copyFrom(kMemory, {});
+
+    // verify result
+    ASSERT_FALSE(result.has_value());
+    EXPECT_EQ(result.error().code, nn::ErrorStatus::GENERAL_FAILURE);
+}
+
+TEST(BufferTest, copyFromDeadObject) {
+    // setup test
+    const auto mockBuffer = MockBuffer::create();
+    const auto buffer = Buffer::create(mockBuffer, kToken).value();
+    EXPECT_CALL(*mockBuffer, copyFrom(_, _))
+            .Times(1)
+            .WillOnce(InvokeWithoutArgs(makeDeadObjectFailure));
+
+    // run test
+    const auto result = buffer->copyFrom(kMemory, {});
+
+    // verify result
+    ASSERT_FALSE(result.has_value());
+    EXPECT_EQ(result.error().code, nn::ErrorStatus::DEAD_OBJECT);
+}
+
+}  // namespace aidl::android::hardware::neuralnetworks::utils
diff --git a/neuralnetworks/aidl/utils/test/DeviceTest.cpp b/neuralnetworks/aidl/utils/test/DeviceTest.cpp
new file mode 100644
index 0000000..e53b0a8
--- /dev/null
+++ b/neuralnetworks/aidl/utils/test/DeviceTest.cpp
@@ -0,0 +1,861 @@
+/*
+ * Copyright (C) 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "MockBuffer.h"
+#include "MockDevice.h"
+#include "MockPreparedModel.h"
+
+#include <aidl/android/hardware/neuralnetworks/BnDevice.h>
+#include <android/binder_auto_utils.h>
+#include <android/binder_status.h>
+#include <gmock/gmock.h>
+#include <gtest/gtest.h>
+#include <nnapi/IDevice.h>
+#include <nnapi/TypeUtils.h>
+#include <nnapi/Types.h>
+#include <nnapi/hal/aidl/Device.h>
+
+#include <functional>
+#include <memory>
+#include <string>
+
+namespace aidl::android::hardware::neuralnetworks::utils {
+namespace {
+
+namespace nn = ::android::nn;
+using ::testing::_;
+using ::testing::DoAll;
+using ::testing::Invoke;
+using ::testing::InvokeWithoutArgs;
+using ::testing::SetArgPointee;
+
+const nn::Model kSimpleModel = {
+        .main = {.operands = {{.type = nn::OperandType::TENSOR_FLOAT32,
+                               .dimensions = {1},
+                               .lifetime = nn::Operand::LifeTime::SUBGRAPH_INPUT},
+                              {.type = nn::OperandType::TENSOR_FLOAT32,
+                               .dimensions = {1},
+                               .lifetime = nn::Operand::LifeTime::SUBGRAPH_OUTPUT}},
+                 .operations = {{.type = nn::OperationType::RELU, .inputs = {0}, .outputs = {1}}},
+                 .inputIndexes = {0},
+                 .outputIndexes = {1}}};
+
+const std::string kName = "Google-MockV1";
+const std::string kInvalidName = "";
+const std::shared_ptr<BnDevice> kInvalidDevice;
+constexpr PerformanceInfo kNoPerformanceInfo = {.execTime = std::numeric_limits<float>::max(),
+                                                .powerUsage = std::numeric_limits<float>::max()};
+constexpr NumberOfCacheFiles kNumberOfCacheFiles = {.numModelCache = nn::kMaxNumberOfCacheFiles,
+                                                    .numDataCache = nn::kMaxNumberOfCacheFiles};
+
+constexpr auto makeStatusOk = [] { return ndk::ScopedAStatus::ok(); };
+
+std::shared_ptr<MockDevice> createMockDevice() {
+    const auto mockDevice = MockDevice::create();
+
+    // Setup default actions for each relevant call.
+    ON_CALL(*mockDevice, getVersionString(_))
+            .WillByDefault(DoAll(SetArgPointee<0>(kName), InvokeWithoutArgs(makeStatusOk)));
+    ON_CALL(*mockDevice, getType(_))
+            .WillByDefault(
+                    DoAll(SetArgPointee<0>(DeviceType::OTHER), InvokeWithoutArgs(makeStatusOk)));
+    ON_CALL(*mockDevice, getSupportedExtensions(_))
+            .WillByDefault(DoAll(SetArgPointee<0>(std::vector<Extension>{}),
+                                 InvokeWithoutArgs(makeStatusOk)));
+    ON_CALL(*mockDevice, getNumberOfCacheFilesNeeded(_))
+            .WillByDefault(
+                    DoAll(SetArgPointee<0>(kNumberOfCacheFiles), InvokeWithoutArgs(makeStatusOk)));
+    ON_CALL(*mockDevice, getCapabilities(_))
+            .WillByDefault(
+                    DoAll(SetArgPointee<0>(Capabilities{
+                                  .relaxedFloat32toFloat16PerformanceScalar = kNoPerformanceInfo,
+                                  .relaxedFloat32toFloat16PerformanceTensor = kNoPerformanceInfo,
+                                  .ifPerformance = kNoPerformanceInfo,
+                                  .whilePerformance = kNoPerformanceInfo,
+                          }),
+                          InvokeWithoutArgs(makeStatusOk)));
+
+    // These EXPECT_CALL(...).Times(testing::AnyNumber()) calls are to suppress warnings on the
+    // uninteresting methods calls.
+    EXPECT_CALL(*mockDevice, getVersionString(_)).Times(testing::AnyNumber());
+    EXPECT_CALL(*mockDevice, getType(_)).Times(testing::AnyNumber());
+    EXPECT_CALL(*mockDevice, getSupportedExtensions(_)).Times(testing::AnyNumber());
+    EXPECT_CALL(*mockDevice, getNumberOfCacheFilesNeeded(_)).Times(testing::AnyNumber());
+    EXPECT_CALL(*mockDevice, getCapabilities(_)).Times(testing::AnyNumber());
+
+    return mockDevice;
+}
+
+constexpr auto makePreparedModelReturnImpl =
+        [](ErrorStatus launchStatus, ErrorStatus returnStatus,
+           const std::shared_ptr<MockPreparedModel>& preparedModel,
+           const std::shared_ptr<IPreparedModelCallback>& cb) {
+            cb->notify(returnStatus, preparedModel);
+            if (launchStatus == ErrorStatus::NONE) {
+                return ndk::ScopedAStatus::ok();
+            }
+            return ndk::ScopedAStatus::fromServiceSpecificError(static_cast<int32_t>(launchStatus));
+        };
+
+auto makePreparedModelReturn(ErrorStatus launchStatus, ErrorStatus returnStatus,
+                             const std::shared_ptr<MockPreparedModel>& preparedModel) {
+    return [launchStatus, returnStatus, preparedModel](
+                   const Model& /*model*/, ExecutionPreference /*preference*/,
+                   Priority /*priority*/, const int64_t& /*deadline*/,
+                   const std::vector<ndk::ScopedFileDescriptor>& /*modelCache*/,
+                   const std::vector<ndk::ScopedFileDescriptor>& /*dataCache*/,
+                   const std::vector<uint8_t>& /*token*/,
+                   const std::shared_ptr<IPreparedModelCallback>& cb) -> ndk::ScopedAStatus {
+        return makePreparedModelReturnImpl(launchStatus, returnStatus, preparedModel, cb);
+    };
+}
+
+auto makePreparedModelFromCacheReturn(ErrorStatus launchStatus, ErrorStatus returnStatus,
+                                      const std::shared_ptr<MockPreparedModel>& preparedModel) {
+    return [launchStatus, returnStatus, preparedModel](
+                   const int64_t& /*deadline*/,
+                   const std::vector<ndk::ScopedFileDescriptor>& /*modelCache*/,
+                   const std::vector<ndk::ScopedFileDescriptor>& /*dataCache*/,
+                   const std::vector<uint8_t>& /*token*/,
+                   const std::shared_ptr<IPreparedModelCallback>& cb) {
+        return makePreparedModelReturnImpl(launchStatus, returnStatus, preparedModel, cb);
+    };
+}
+
+constexpr auto makeGeneralFailure = [] {
+    return ndk::ScopedAStatus::fromServiceSpecificError(
+            static_cast<int32_t>(ErrorStatus::GENERAL_FAILURE));
+};
+constexpr auto makeGeneralTransportFailure = [] {
+    return ndk::ScopedAStatus::fromStatus(STATUS_NO_MEMORY);
+};
+constexpr auto makeDeadObjectFailure = [] {
+    return ndk::ScopedAStatus::fromStatus(STATUS_DEAD_OBJECT);
+};
+
+}  // namespace
+
+TEST(DeviceTest, invalidName) {
+    // run test
+    const auto device = MockDevice::create();
+    const auto result = Device::create(kInvalidName, device);
+
+    // verify result
+    ASSERT_FALSE(result.has_value());
+    EXPECT_EQ(result.error().code, nn::ErrorStatus::INVALID_ARGUMENT);
+}
+
+TEST(DeviceTest, invalidDevice) {
+    // run test
+    const auto result = Device::create(kName, kInvalidDevice);
+
+    // verify result
+    ASSERT_FALSE(result.has_value());
+    EXPECT_EQ(result.error().code, nn::ErrorStatus::INVALID_ARGUMENT);
+}
+
+TEST(DeviceTest, getVersionStringError) {
+    // setup call
+    const auto mockDevice = createMockDevice();
+    EXPECT_CALL(*mockDevice, getVersionString(_))
+            .Times(1)
+            .WillOnce(InvokeWithoutArgs(makeGeneralFailure));
+
+    // run test
+    const auto result = Device::create(kName, mockDevice);
+
+    // verify result
+    ASSERT_FALSE(result.has_value());
+    EXPECT_EQ(result.error().code, nn::ErrorStatus::GENERAL_FAILURE);
+}
+
+TEST(DeviceTest, getVersionStringTransportFailure) {
+    // setup call
+    const auto mockDevice = createMockDevice();
+    EXPECT_CALL(*mockDevice, getVersionString(_))
+            .Times(1)
+            .WillOnce(InvokeWithoutArgs(makeGeneralTransportFailure));
+
+    // run test
+    const auto result = Device::create(kName, mockDevice);
+
+    // verify result
+    ASSERT_FALSE(result.has_value());
+    EXPECT_EQ(result.error().code, nn::ErrorStatus::GENERAL_FAILURE);
+}
+
+TEST(DeviceTest, getVersionStringDeadObject) {
+    // setup call
+    const auto mockDevice = createMockDevice();
+    EXPECT_CALL(*mockDevice, getVersionString(_))
+            .Times(1)
+            .WillOnce(InvokeWithoutArgs(makeDeadObjectFailure));
+
+    // run test
+    const auto result = Device::create(kName, mockDevice);
+
+    // verify result
+    ASSERT_FALSE(result.has_value());
+    EXPECT_EQ(result.error().code, nn::ErrorStatus::DEAD_OBJECT);
+}
+
+TEST(DeviceTest, getTypeError) {
+    // setup call
+    const auto mockDevice = createMockDevice();
+    EXPECT_CALL(*mockDevice, getType(_)).Times(1).WillOnce(InvokeWithoutArgs(makeGeneralFailure));
+
+    // run test
+    const auto result = Device::create(kName, mockDevice);
+
+    // verify result
+    ASSERT_FALSE(result.has_value());
+    EXPECT_EQ(result.error().code, nn::ErrorStatus::GENERAL_FAILURE);
+}
+
+TEST(DeviceTest, getTypeTransportFailure) {
+    // setup call
+    const auto mockDevice = createMockDevice();
+    EXPECT_CALL(*mockDevice, getType(_))
+            .Times(1)
+            .WillOnce(InvokeWithoutArgs(makeGeneralTransportFailure));
+
+    // run test
+    const auto result = Device::create(kName, mockDevice);
+
+    // verify result
+    ASSERT_FALSE(result.has_value());
+    EXPECT_EQ(result.error().code, nn::ErrorStatus::GENERAL_FAILURE);
+}
+
+TEST(DeviceTest, getTypeDeadObject) {
+    // setup call
+    const auto mockDevice = createMockDevice();
+    EXPECT_CALL(*mockDevice, getType(_))
+            .Times(1)
+            .WillOnce(InvokeWithoutArgs(makeDeadObjectFailure));
+
+    // run test
+    const auto result = Device::create(kName, mockDevice);
+
+    // verify result
+    ASSERT_FALSE(result.has_value());
+    EXPECT_EQ(result.error().code, nn::ErrorStatus::DEAD_OBJECT);
+}
+
+TEST(DeviceTest, getSupportedExtensionsError) {
+    // setup call
+    const auto mockDevice = createMockDevice();
+    EXPECT_CALL(*mockDevice, getSupportedExtensions(_))
+            .Times(1)
+            .WillOnce(InvokeWithoutArgs(makeGeneralFailure));
+
+    // run test
+    const auto result = Device::create(kName, mockDevice);
+
+    // verify result
+    ASSERT_FALSE(result.has_value());
+    EXPECT_EQ(result.error().code, nn::ErrorStatus::GENERAL_FAILURE);
+}
+
+TEST(DeviceTest, getSupportedExtensionsTransportFailure) {
+    // setup call
+    const auto mockDevice = createMockDevice();
+    EXPECT_CALL(*mockDevice, getSupportedExtensions(_))
+            .Times(1)
+            .WillOnce(InvokeWithoutArgs(makeGeneralTransportFailure));
+
+    // run test
+    const auto result = Device::create(kName, mockDevice);
+
+    // verify result
+    ASSERT_FALSE(result.has_value());
+    EXPECT_EQ(result.error().code, nn::ErrorStatus::GENERAL_FAILURE);
+}
+
+TEST(DeviceTest, getSupportedExtensionsDeadObject) {
+    // setup call
+    const auto mockDevice = createMockDevice();
+    EXPECT_CALL(*mockDevice, getSupportedExtensions(_))
+            .Times(1)
+            .WillOnce(InvokeWithoutArgs(makeDeadObjectFailure));
+
+    // run test
+    const auto result = Device::create(kName, mockDevice);
+
+    // verify result
+    ASSERT_FALSE(result.has_value());
+    EXPECT_EQ(result.error().code, nn::ErrorStatus::DEAD_OBJECT);
+}
+
+TEST(DeviceTest, getNumberOfCacheFilesNeededError) {
+    // setup call
+    const auto mockDevice = createMockDevice();
+    EXPECT_CALL(*mockDevice, getNumberOfCacheFilesNeeded(_))
+            .Times(1)
+            .WillOnce(InvokeWithoutArgs(makeGeneralFailure));
+
+    // run test
+    const auto result = Device::create(kName, mockDevice);
+
+    // verify result
+    ASSERT_FALSE(result.has_value());
+    EXPECT_EQ(result.error().code, nn::ErrorStatus::GENERAL_FAILURE);
+}
+
+TEST(DeviceTest, dataCacheFilesExceedsSpecifiedMax) {
+    // setup test
+    const auto mockDevice = createMockDevice();
+    EXPECT_CALL(*mockDevice, getNumberOfCacheFilesNeeded(_))
+            .Times(1)
+            .WillOnce(DoAll(SetArgPointee<0>(NumberOfCacheFiles{
+                                    .numModelCache = nn::kMaxNumberOfCacheFiles + 1,
+                                    .numDataCache = nn::kMaxNumberOfCacheFiles}),
+                            InvokeWithoutArgs(makeStatusOk)));
+
+    // run test
+    const auto result = Device::create(kName, mockDevice);
+
+    // verify result
+    ASSERT_FALSE(result.has_value());
+    EXPECT_EQ(result.error().code, nn::ErrorStatus::GENERAL_FAILURE);
+}
+
+TEST(DeviceTest, modelCacheFilesExceedsSpecifiedMax) {
+    // setup test
+    const auto mockDevice = createMockDevice();
+    EXPECT_CALL(*mockDevice, getNumberOfCacheFilesNeeded(_))
+            .Times(1)
+            .WillOnce(DoAll(SetArgPointee<0>(NumberOfCacheFiles{
+                                    .numModelCache = nn::kMaxNumberOfCacheFiles,
+                                    .numDataCache = nn::kMaxNumberOfCacheFiles + 1}),
+                            InvokeWithoutArgs(makeStatusOk)));
+
+    // run test
+    const auto result = Device::create(kName, mockDevice);
+
+    // verify result
+    ASSERT_FALSE(result.has_value());
+    EXPECT_EQ(result.error().code, nn::ErrorStatus::GENERAL_FAILURE);
+}
+
+TEST(DeviceTest, getNumberOfCacheFilesNeededTransportFailure) {
+    // setup call
+    const auto mockDevice = createMockDevice();
+    EXPECT_CALL(*mockDevice, getNumberOfCacheFilesNeeded(_))
+            .Times(1)
+            .WillOnce(InvokeWithoutArgs(makeGeneralTransportFailure));
+
+    // run test
+    const auto result = Device::create(kName, mockDevice);
+
+    // verify result
+    ASSERT_FALSE(result.has_value());
+    EXPECT_EQ(result.error().code, nn::ErrorStatus::GENERAL_FAILURE);
+}
+
+TEST(DeviceTest, getNumberOfCacheFilesNeededDeadObject) {
+    // setup call
+    const auto mockDevice = createMockDevice();
+    EXPECT_CALL(*mockDevice, getNumberOfCacheFilesNeeded(_))
+            .Times(1)
+            .WillOnce(InvokeWithoutArgs(makeDeadObjectFailure));
+
+    // run test
+    const auto result = Device::create(kName, mockDevice);
+
+    // verify result
+    ASSERT_FALSE(result.has_value());
+    EXPECT_EQ(result.error().code, nn::ErrorStatus::DEAD_OBJECT);
+}
+
+TEST(DeviceTest, getCapabilitiesError) {
+    // setup call
+    const auto mockDevice = createMockDevice();
+    EXPECT_CALL(*mockDevice, getCapabilities(_))
+            .Times(1)
+            .WillOnce(InvokeWithoutArgs(makeGeneralFailure));
+
+    // run test
+    const auto result = Device::create(kName, mockDevice);
+
+    // verify result
+    ASSERT_FALSE(result.has_value());
+    EXPECT_EQ(result.error().code, nn::ErrorStatus::GENERAL_FAILURE);
+}
+
+TEST(DeviceTest, getCapabilitiesTransportFailure) {
+    // setup call
+    const auto mockDevice = createMockDevice();
+    EXPECT_CALL(*mockDevice, getCapabilities(_))
+            .Times(1)
+            .WillOnce(InvokeWithoutArgs(makeGeneralTransportFailure));
+
+    // run test
+    const auto result = Device::create(kName, mockDevice);
+
+    // verify result
+    ASSERT_FALSE(result.has_value());
+    EXPECT_EQ(result.error().code, nn::ErrorStatus::GENERAL_FAILURE);
+}
+
+TEST(DeviceTest, getCapabilitiesDeadObject) {
+    // setup call
+    const auto mockDevice = createMockDevice();
+    EXPECT_CALL(*mockDevice, getCapabilities(_))
+            .Times(1)
+            .WillOnce(InvokeWithoutArgs(makeDeadObjectFailure));
+
+    // run test
+    const auto result = Device::create(kName, mockDevice);
+
+    // verify result
+    ASSERT_FALSE(result.has_value());
+    EXPECT_EQ(result.error().code, nn::ErrorStatus::DEAD_OBJECT);
+}
+
+TEST(DeviceTest, getName) {
+    // setup call
+    const auto mockDevice = createMockDevice();
+    const auto device = Device::create(kName, mockDevice).value();
+
+    // run test
+    const auto& name = device->getName();
+
+    // verify result
+    EXPECT_EQ(name, kName);
+}
+
+TEST(DeviceTest, getFeatureLevel) {
+    // setup call
+    const auto mockDevice = createMockDevice();
+    const auto device = Device::create(kName, mockDevice).value();
+
+    // run test
+    const auto featureLevel = device->getFeatureLevel();
+
+    // verify result
+    EXPECT_EQ(featureLevel, nn::Version::ANDROID_S);
+}
+
+TEST(DeviceTest, getCachedData) {
+    // setup call
+    const auto mockDevice = createMockDevice();
+    EXPECT_CALL(*mockDevice, getVersionString(_)).Times(1);
+    EXPECT_CALL(*mockDevice, getType(_)).Times(1);
+    EXPECT_CALL(*mockDevice, getSupportedExtensions(_)).Times(1);
+    EXPECT_CALL(*mockDevice, getNumberOfCacheFilesNeeded(_)).Times(1);
+    EXPECT_CALL(*mockDevice, getCapabilities(_)).Times(1);
+
+    const auto result = Device::create(kName, mockDevice);
+    ASSERT_TRUE(result.has_value())
+            << "Failed with " << result.error().code << ": " << result.error().message;
+    const auto& device = result.value();
+
+    // run test and verify results
+    EXPECT_EQ(device->getVersionString(), device->getVersionString());
+    EXPECT_EQ(device->getType(), device->getType());
+    EXPECT_EQ(device->getSupportedExtensions(), device->getSupportedExtensions());
+    EXPECT_EQ(device->getNumberOfCacheFilesNeeded(), device->getNumberOfCacheFilesNeeded());
+    EXPECT_EQ(device->getCapabilities(), device->getCapabilities());
+}
+
+TEST(DeviceTest, getSupportedOperations) {
+    // setup call
+    const auto mockDevice = createMockDevice();
+    const auto device = Device::create(kName, mockDevice).value();
+    EXPECT_CALL(*mockDevice, getSupportedOperations(_, _))
+            .Times(1)
+            .WillOnce(DoAll(
+                    SetArgPointee<1>(std::vector<bool>(kSimpleModel.main.operations.size(), true)),
+                    InvokeWithoutArgs(makeStatusOk)));
+
+    // run test
+    const auto result = device->getSupportedOperations(kSimpleModel);
+
+    // verify result
+    ASSERT_TRUE(result.has_value())
+            << "Failed with " << result.error().code << ": " << result.error().message;
+    const auto& supportedOperations = result.value();
+    EXPECT_EQ(supportedOperations.size(), kSimpleModel.main.operations.size());
+    EXPECT_THAT(supportedOperations, Each(testing::IsTrue()));
+}
+
+TEST(DeviceTest, getSupportedOperationsError) {
+    // setup call
+    const auto mockDevice = createMockDevice();
+    const auto device = Device::create(kName, mockDevice).value();
+    EXPECT_CALL(*mockDevice, getSupportedOperations(_, _))
+            .Times(1)
+            .WillOnce(InvokeWithoutArgs(makeGeneralFailure));
+
+    // run test
+    const auto result = device->getSupportedOperations(kSimpleModel);
+
+    // verify result
+    ASSERT_FALSE(result.has_value());
+    EXPECT_EQ(result.error().code, nn::ErrorStatus::GENERAL_FAILURE);
+}
+
+TEST(DeviceTest, getSupportedOperationsTransportFailure) {
+    // setup call
+    const auto mockDevice = createMockDevice();
+    const auto device = Device::create(kName, mockDevice).value();
+    EXPECT_CALL(*mockDevice, getSupportedOperations(_, _))
+            .Times(1)
+            .WillOnce(InvokeWithoutArgs(makeGeneralTransportFailure));
+
+    // run test
+    const auto result = device->getSupportedOperations(kSimpleModel);
+
+    // verify result
+    ASSERT_FALSE(result.has_value());
+    EXPECT_EQ(result.error().code, nn::ErrorStatus::GENERAL_FAILURE);
+}
+
+TEST(DeviceTest, getSupportedOperationsDeadObject) {
+    // setup call
+    const auto mockDevice = createMockDevice();
+    const auto device = Device::create(kName, mockDevice).value();
+    EXPECT_CALL(*mockDevice, getSupportedOperations(_, _))
+            .Times(1)
+            .WillOnce(InvokeWithoutArgs(makeDeadObjectFailure));
+
+    // run test
+    const auto result = device->getSupportedOperations(kSimpleModel);
+
+    // verify result
+    ASSERT_FALSE(result.has_value());
+    EXPECT_EQ(result.error().code, nn::ErrorStatus::DEAD_OBJECT);
+}
+
+TEST(DeviceTest, prepareModel) {
+    // setup call
+    const auto mockDevice = createMockDevice();
+    const auto device = Device::create(kName, mockDevice).value();
+    const auto mockPreparedModel = MockPreparedModel::create();
+    EXPECT_CALL(*mockDevice, prepareModel(_, _, _, _, _, _, _, _))
+            .Times(1)
+            .WillOnce(Invoke(makePreparedModelReturn(ErrorStatus::NONE, ErrorStatus::NONE,
+                                                     mockPreparedModel)));
+
+    // run test
+    const auto result = device->prepareModel(kSimpleModel, nn::ExecutionPreference::DEFAULT,
+                                             nn::Priority::DEFAULT, {}, {}, {}, {});
+
+    // verify result
+    ASSERT_TRUE(result.has_value())
+            << "Failed with " << result.error().code << ": " << result.error().message;
+    EXPECT_NE(result.value(), nullptr);
+}
+
+TEST(DeviceTest, prepareModelLaunchError) {
+    // setup call
+    const auto mockDevice = createMockDevice();
+    const auto device = Device::create(kName, mockDevice).value();
+    EXPECT_CALL(*mockDevice, prepareModel(_, _, _, _, _, _, _, _))
+            .Times(1)
+            .WillOnce(Invoke(makePreparedModelReturn(ErrorStatus::GENERAL_FAILURE,
+                                                     ErrorStatus::GENERAL_FAILURE, nullptr)));
+
+    // run test
+    const auto result = device->prepareModel(kSimpleModel, nn::ExecutionPreference::DEFAULT,
+                                             nn::Priority::DEFAULT, {}, {}, {}, {});
+
+    // verify result
+    ASSERT_FALSE(result.has_value());
+    EXPECT_EQ(result.error().code, nn::ErrorStatus::GENERAL_FAILURE);
+}
+
+TEST(DeviceTest, prepareModelReturnError) {
+    // setup call
+    const auto mockDevice = createMockDevice();
+    const auto device = Device::create(kName, mockDevice).value();
+    EXPECT_CALL(*mockDevice, prepareModel(_, _, _, _, _, _, _, _))
+            .Times(1)
+            .WillOnce(Invoke(makePreparedModelReturn(ErrorStatus::NONE,
+                                                     ErrorStatus::GENERAL_FAILURE, nullptr)));
+
+    // run test
+    const auto result = device->prepareModel(kSimpleModel, nn::ExecutionPreference::DEFAULT,
+                                             nn::Priority::DEFAULT, {}, {}, {}, {});
+
+    // verify result
+    ASSERT_FALSE(result.has_value());
+    EXPECT_EQ(result.error().code, nn::ErrorStatus::GENERAL_FAILURE);
+}
+
+TEST(DeviceTest, prepareModelNullptrError) {
+    // setup call
+    const auto mockDevice = createMockDevice();
+    const auto device = Device::create(kName, mockDevice).value();
+    EXPECT_CALL(*mockDevice, prepareModel(_, _, _, _, _, _, _, _))
+            .Times(1)
+            .WillOnce(
+                    Invoke(makePreparedModelReturn(ErrorStatus::NONE, ErrorStatus::NONE, nullptr)));
+
+    // run test
+    const auto result = device->prepareModel(kSimpleModel, nn::ExecutionPreference::DEFAULT,
+                                             nn::Priority::DEFAULT, {}, {}, {}, {});
+
+    // verify result
+    ASSERT_FALSE(result.has_value());
+    EXPECT_EQ(result.error().code, nn::ErrorStatus::GENERAL_FAILURE);
+}
+
+TEST(DeviceTest, prepareModelTransportFailure) {
+    // setup call
+    const auto mockDevice = createMockDevice();
+    const auto device = Device::create(kName, mockDevice).value();
+    EXPECT_CALL(*mockDevice, prepareModel(_, _, _, _, _, _, _, _))
+            .Times(1)
+            .WillOnce(InvokeWithoutArgs(makeGeneralTransportFailure));
+
+    // run test
+    const auto result = device->prepareModel(kSimpleModel, nn::ExecutionPreference::DEFAULT,
+                                             nn::Priority::DEFAULT, {}, {}, {}, {});
+
+    // verify result
+    ASSERT_FALSE(result.has_value());
+    EXPECT_EQ(result.error().code, nn::ErrorStatus::GENERAL_FAILURE);
+}
+
+TEST(DeviceTest, prepareModelDeadObject) {
+    // setup call
+    const auto mockDevice = createMockDevice();
+    const auto device = Device::create(kName, mockDevice).value();
+    EXPECT_CALL(*mockDevice, prepareModel(_, _, _, _, _, _, _, _))
+            .Times(1)
+            .WillOnce(InvokeWithoutArgs(makeDeadObjectFailure));
+
+    // run test
+    const auto result = device->prepareModel(kSimpleModel, nn::ExecutionPreference::DEFAULT,
+                                             nn::Priority::DEFAULT, {}, {}, {}, {});
+
+    // verify result
+    ASSERT_FALSE(result.has_value());
+    EXPECT_EQ(result.error().code, nn::ErrorStatus::DEAD_OBJECT);
+}
+
+TEST(DeviceTest, prepareModelAsyncCrash) {
+    // setup test
+    const auto mockDevice = createMockDevice();
+    const auto device = Device::create(kName, mockDevice).value();
+    const auto ret = [&device]() {
+        DeathMonitor::serviceDied(device->getDeathMonitor());
+        return ndk::ScopedAStatus::ok();
+    };
+    EXPECT_CALL(*mockDevice, prepareModel(_, _, _, _, _, _, _, _))
+            .Times(1)
+            .WillOnce(InvokeWithoutArgs(ret));
+
+    // run test
+    const auto result = device->prepareModel(kSimpleModel, nn::ExecutionPreference::DEFAULT,
+                                             nn::Priority::DEFAULT, {}, {}, {}, {});
+
+    // verify result
+    ASSERT_FALSE(result.has_value());
+    EXPECT_EQ(result.error().code, nn::ErrorStatus::DEAD_OBJECT);
+}
+
+TEST(DeviceTest, prepareModelFromCache) {
+    // setup call
+    const auto mockDevice = createMockDevice();
+    const auto device = Device::create(kName, mockDevice).value();
+    const auto mockPreparedModel = MockPreparedModel::create();
+    EXPECT_CALL(*mockDevice, prepareModelFromCache(_, _, _, _, _))
+            .Times(1)
+            .WillOnce(Invoke(makePreparedModelFromCacheReturn(ErrorStatus::NONE, ErrorStatus::NONE,
+                                                              mockPreparedModel)));
+
+    // run test
+    const auto result = device->prepareModelFromCache({}, {}, {}, {});
+
+    // verify result
+    ASSERT_TRUE(result.has_value())
+            << "Failed with " << result.error().code << ": " << result.error().message;
+    EXPECT_NE(result.value(), nullptr);
+}
+
+TEST(DeviceTest, prepareModelFromCacheLaunchError) {
+    // setup call
+    const auto mockDevice = createMockDevice();
+    const auto device = Device::create(kName, mockDevice).value();
+    EXPECT_CALL(*mockDevice, prepareModelFromCache(_, _, _, _, _))
+            .Times(1)
+            .WillOnce(Invoke(makePreparedModelFromCacheReturn(
+                    ErrorStatus::GENERAL_FAILURE, ErrorStatus::GENERAL_FAILURE, nullptr)));
+
+    // run test
+    const auto result = device->prepareModelFromCache({}, {}, {}, {});
+
+    // verify result
+    ASSERT_FALSE(result.has_value());
+    EXPECT_EQ(result.error().code, nn::ErrorStatus::GENERAL_FAILURE);
+}
+
+TEST(DeviceTest, prepareModelFromCacheReturnError) {
+    // setup call
+    const auto mockDevice = createMockDevice();
+    const auto device = Device::create(kName, mockDevice).value();
+    EXPECT_CALL(*mockDevice, prepareModelFromCache(_, _, _, _, _))
+            .Times(1)
+            .WillOnce(Invoke(makePreparedModelFromCacheReturn(
+                    ErrorStatus::NONE, ErrorStatus::GENERAL_FAILURE, nullptr)));
+
+    // run test
+    const auto result = device->prepareModelFromCache({}, {}, {}, {});
+
+    // verify result
+    ASSERT_FALSE(result.has_value());
+    EXPECT_EQ(result.error().code, nn::ErrorStatus::GENERAL_FAILURE);
+}
+
+TEST(DeviceTest, prepareModelFromCacheNullptrError) {
+    // setup call
+    const auto mockDevice = createMockDevice();
+    const auto device = Device::create(kName, mockDevice).value();
+    EXPECT_CALL(*mockDevice, prepareModelFromCache(_, _, _, _, _))
+            .Times(1)
+            .WillOnce(Invoke(makePreparedModelFromCacheReturn(ErrorStatus::NONE, ErrorStatus::NONE,
+                                                              nullptr)));
+
+    // run test
+    const auto result = device->prepareModelFromCache({}, {}, {}, {});
+
+    // verify result
+    ASSERT_FALSE(result.has_value());
+    EXPECT_EQ(result.error().code, nn::ErrorStatus::GENERAL_FAILURE);
+}
+
+TEST(DeviceTest, prepareModelFromCacheTransportFailure) {
+    // setup call
+    const auto mockDevice = createMockDevice();
+    const auto device = Device::create(kName, mockDevice).value();
+    EXPECT_CALL(*mockDevice, prepareModelFromCache(_, _, _, _, _))
+            .Times(1)
+            .WillOnce(InvokeWithoutArgs(makeGeneralTransportFailure));
+
+    // run test
+    const auto result = device->prepareModelFromCache({}, {}, {}, {});
+
+    // verify result
+    ASSERT_FALSE(result.has_value());
+    EXPECT_EQ(result.error().code, nn::ErrorStatus::GENERAL_FAILURE);
+}
+
+TEST(DeviceTest, prepareModelFromCacheDeadObject) {
+    // setup call
+    const auto mockDevice = createMockDevice();
+    const auto device = Device::create(kName, mockDevice).value();
+    EXPECT_CALL(*mockDevice, prepareModelFromCache(_, _, _, _, _))
+            .Times(1)
+            .WillOnce(InvokeWithoutArgs(makeDeadObjectFailure));
+
+    // run test
+    const auto result = device->prepareModelFromCache({}, {}, {}, {});
+
+    // verify result
+    ASSERT_FALSE(result.has_value());
+    EXPECT_EQ(result.error().code, nn::ErrorStatus::DEAD_OBJECT);
+}
+
+TEST(DeviceTest, prepareModelFromCacheAsyncCrash) {
+    // setup test
+    const auto mockDevice = createMockDevice();
+    const auto device = Device::create(kName, mockDevice).value();
+    const auto ret = [&device]() {
+        DeathMonitor::serviceDied(device->getDeathMonitor());
+        return ndk::ScopedAStatus::ok();
+    };
+    EXPECT_CALL(*mockDevice, prepareModelFromCache(_, _, _, _, _))
+            .Times(1)
+            .WillOnce(InvokeWithoutArgs(ret));
+
+    // run test
+    const auto result = device->prepareModelFromCache({}, {}, {}, {});
+
+    // verify result
+    ASSERT_FALSE(result.has_value());
+    EXPECT_EQ(result.error().code, nn::ErrorStatus::DEAD_OBJECT);
+}
+
+TEST(DeviceTest, allocate) {
+    // setup call
+    const auto mockDevice = createMockDevice();
+    const auto device = Device::create(kName, mockDevice).value();
+    const auto mockBuffer = DeviceBuffer{.buffer = MockBuffer::create(), .token = 1};
+    EXPECT_CALL(*mockDevice, allocate(_, _, _, _, _))
+            .Times(1)
+            .WillOnce(DoAll(SetArgPointee<4>(mockBuffer), InvokeWithoutArgs(makeStatusOk)));
+
+    // run test
+    const auto result = device->allocate({}, {}, {}, {});
+
+    // verify result
+    ASSERT_TRUE(result.has_value())
+            << "Failed with " << result.error().code << ": " << result.error().message;
+    EXPECT_NE(result.value(), nullptr);
+}
+
+TEST(DeviceTest, allocateError) {
+    // setup call
+    const auto mockDevice = createMockDevice();
+    const auto device = Device::create(kName, mockDevice).value();
+    EXPECT_CALL(*mockDevice, allocate(_, _, _, _, _))
+            .Times(1)
+            .WillOnce(InvokeWithoutArgs(makeGeneralFailure));
+
+    // run test
+    const auto result = device->allocate({}, {}, {}, {});
+
+    // verify result
+    ASSERT_FALSE(result.has_value());
+    EXPECT_EQ(result.error().code, nn::ErrorStatus::GENERAL_FAILURE);
+}
+
+TEST(DeviceTest, allocateTransportFailure) {
+    // setup call
+    const auto mockDevice = createMockDevice();
+    const auto device = Device::create(kName, mockDevice).value();
+    EXPECT_CALL(*mockDevice, allocate(_, _, _, _, _))
+            .Times(1)
+            .WillOnce(InvokeWithoutArgs(makeGeneralTransportFailure));
+
+    // run test
+    const auto result = device->allocate({}, {}, {}, {});
+
+    // verify result
+    ASSERT_FALSE(result.has_value());
+    EXPECT_EQ(result.error().code, nn::ErrorStatus::GENERAL_FAILURE);
+}
+
+TEST(DeviceTest, allocateDeadObject) {
+    // setup call
+    const auto mockDevice = createMockDevice();
+    const auto device = Device::create(kName, mockDevice).value();
+    EXPECT_CALL(*mockDevice, allocate(_, _, _, _, _))
+            .Times(1)
+            .WillOnce(InvokeWithoutArgs(makeDeadObjectFailure));
+
+    // run test
+    const auto result = device->allocate({}, {}, {}, {});
+
+    // verify result
+    ASSERT_FALSE(result.has_value());
+    EXPECT_EQ(result.error().code, nn::ErrorStatus::DEAD_OBJECT);
+}
+
+}  // namespace aidl::android::hardware::neuralnetworks::utils
diff --git a/neuralnetworks/aidl/utils/test/MockBuffer.h b/neuralnetworks/aidl/utils/test/MockBuffer.h
new file mode 100644
index 0000000..5746176
--- /dev/null
+++ b/neuralnetworks/aidl/utils/test/MockBuffer.h
@@ -0,0 +1,43 @@
+/*
+ * Copyright (C) 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef ANDROID_HARDWARE_INTERFACES_NEURALNETWORKS_AIDL_UTILS_TEST_MOCK_BUFFER
+#define ANDROID_HARDWARE_INTERFACES_NEURALNETWORKS_AIDL_UTILS_TEST_MOCK_BUFFER
+
+#include <aidl/android/hardware/neuralnetworks/BnBuffer.h>
+#include <android/binder_interface_utils.h>
+#include <gmock/gmock.h>
+#include <gtest/gtest.h>
+#include <hidl/Status.h>
+
+namespace aidl::android::hardware::neuralnetworks::utils {
+
+class MockBuffer final : public BnBuffer {
+  public:
+    static std::shared_ptr<MockBuffer> create();
+
+    MOCK_METHOD(ndk::ScopedAStatus, copyTo, (const Memory& dst), (override));
+    MOCK_METHOD(ndk::ScopedAStatus, copyFrom,
+                (const Memory& src, const std::vector<int32_t>& dimensions), (override));
+};
+
+inline std::shared_ptr<MockBuffer> MockBuffer::create() {
+    return ndk::SharedRefBase::make<MockBuffer>();
+}
+
+}  // namespace aidl::android::hardware::neuralnetworks::utils
+
+#endif  // ANDROID_HARDWARE_INTERFACES_NEURALNETWORKS_AIDL_UTILS_TEST_MOCK_BUFFER
diff --git a/neuralnetworks/aidl/utils/test/MockDevice.h b/neuralnetworks/aidl/utils/test/MockDevice.h
new file mode 100644
index 0000000..9b35bf8
--- /dev/null
+++ b/neuralnetworks/aidl/utils/test/MockDevice.h
@@ -0,0 +1,67 @@
+/*
+ * Copyright (C) 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef ANDROID_HARDWARE_INTERFACES_NEURALNETWORKS_AIDL_UTILS_TEST_MOCK_DEVICE
+#define ANDROID_HARDWARE_INTERFACES_NEURALNETWORKS_AIDL_UTILS_TEST_MOCK_DEVICE
+
+#include <aidl/android/hardware/neuralnetworks/BnDevice.h>
+#include <android/binder_auto_utils.h>
+#include <android/binder_interface_utils.h>
+#include <gmock/gmock.h>
+#include <gtest/gtest.h>
+
+namespace aidl::android::hardware::neuralnetworks::utils {
+
+class MockDevice final : public BnDevice {
+  public:
+    static std::shared_ptr<MockDevice> create();
+
+    MOCK_METHOD(ndk::ScopedAStatus, allocate,
+                (const BufferDesc& desc, const std::vector<IPreparedModelParcel>& preparedModels,
+                 const std::vector<BufferRole>& inputRoles,
+                 const std::vector<BufferRole>& outputRoles, DeviceBuffer* deviceBuffer),
+                (override));
+    MOCK_METHOD(ndk::ScopedAStatus, getCapabilities, (Capabilities * capabilities), (override));
+    MOCK_METHOD(ndk::ScopedAStatus, getNumberOfCacheFilesNeeded,
+                (NumberOfCacheFiles * numberOfCacheFiles), (override));
+    MOCK_METHOD(ndk::ScopedAStatus, getSupportedExtensions, (std::vector<Extension> * extensions),
+                (override));
+    MOCK_METHOD(ndk::ScopedAStatus, getSupportedOperations,
+                (const Model& model, std::vector<bool>* supportedOperations), (override));
+    MOCK_METHOD(ndk::ScopedAStatus, getType, (DeviceType * deviceType), (override));
+    MOCK_METHOD(ndk::ScopedAStatus, getVersionString, (std::string * version), (override));
+    MOCK_METHOD(ndk::ScopedAStatus, prepareModel,
+                (const Model& model, ExecutionPreference preference, Priority priority,
+                 int64_t deadline, const std::vector<ndk::ScopedFileDescriptor>& modelCache,
+                 const std::vector<ndk::ScopedFileDescriptor>& dataCache,
+                 const std::vector<uint8_t>& token,
+                 const std::shared_ptr<IPreparedModelCallback>& callback),
+                (override));
+    MOCK_METHOD(ndk::ScopedAStatus, prepareModelFromCache,
+                (int64_t deadline, const std::vector<ndk::ScopedFileDescriptor>& modelCache,
+                 const std::vector<ndk::ScopedFileDescriptor>& dataCache,
+                 const std::vector<uint8_t>& token,
+                 const std::shared_ptr<IPreparedModelCallback>& callback),
+                (override));
+};
+
+inline std::shared_ptr<MockDevice> MockDevice::create() {
+    return ndk::SharedRefBase::make<MockDevice>();
+}
+
+}  // namespace aidl::android::hardware::neuralnetworks::utils
+
+#endif  // ANDROID_HARDWARE_INTERFACES_NEURALNETWORKS_AIDL_UTILS_TEST_MOCK_DEVICE
diff --git a/neuralnetworks/aidl/utils/test/MockFencedExecutionCallback.h b/neuralnetworks/aidl/utils/test/MockFencedExecutionCallback.h
new file mode 100644
index 0000000..463e1c9
--- /dev/null
+++ b/neuralnetworks/aidl/utils/test/MockFencedExecutionCallback.h
@@ -0,0 +1,45 @@
+/*
+ * Copyright (C) 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef ANDROID_HARDWARE_INTERFACES_NEURALNETWORKS_AIDL_UTILS_TEST_MOCK_FENCED_EXECUTION_CALLBACK
+#define ANDROID_HARDWARE_INTERFACES_NEURALNETWORKS_AIDL_UTILS_TEST_MOCK_FENCED_EXECUTION_CALLBACK
+
+#include <aidl/android/hardware/neuralnetworks/BnFencedExecutionCallback.h>
+#include <android/binder_auto_utils.h>
+#include <android/binder_interface_utils.h>
+#include <gmock/gmock.h>
+#include <gtest/gtest.h>
+#include <hidl/Status.h>
+
+namespace aidl::android::hardware::neuralnetworks::utils {
+
+class MockFencedExecutionCallback final : public BnFencedExecutionCallback {
+  public:
+    static std::shared_ptr<MockFencedExecutionCallback> create();
+
+    // V1_3 methods below.
+    MOCK_METHOD(ndk::ScopedAStatus, getExecutionInfo,
+                (Timing * timingLaunched, Timing* timingFenced, ErrorStatus* errorStatus),
+                (override));
+};
+
+inline std::shared_ptr<MockFencedExecutionCallback> MockFencedExecutionCallback::create() {
+    return ndk::SharedRefBase::make<MockFencedExecutionCallback>();
+}
+
+}  // namespace aidl::android::hardware::neuralnetworks::utils
+
+#endif  // ANDROID_HARDWARE_INTERFACES_NEURALNETWORKS_AIDL_UTILS_TEST_MOCK_FENCED_EXECUTION_CALLBACK
diff --git a/neuralnetworks/aidl/utils/test/MockPreparedModel.h b/neuralnetworks/aidl/utils/test/MockPreparedModel.h
new file mode 100644
index 0000000..545b491
--- /dev/null
+++ b/neuralnetworks/aidl/utils/test/MockPreparedModel.h
@@ -0,0 +1,50 @@
+/*
+ * Copyright (C) 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef ANDROID_HARDWARE_INTERFACES_NEURALNETWORKS_AIDL_UTILS_TEST_MOCK_PREPARED_MODEL
+#define ANDROID_HARDWARE_INTERFACES_NEURALNETWORKS_AIDL_UTILS_TEST_MOCK_PREPARED_MODEL
+
+#include <aidl/android/hardware/neuralnetworks/BnPreparedModel.h>
+#include <android/binder_interface_utils.h>
+#include <gmock/gmock.h>
+#include <gtest/gtest.h>
+#include <hidl/HidlSupport.h>
+#include <hidl/Status.h>
+
+namespace aidl::android::hardware::neuralnetworks::utils {
+
+class MockPreparedModel final : public BnPreparedModel {
+  public:
+    static std::shared_ptr<MockPreparedModel> create();
+
+    MOCK_METHOD(ndk::ScopedAStatus, executeSynchronously,
+                (const Request& request, bool measureTiming, int64_t deadline,
+                 int64_t loopTimeoutDuration, ExecutionResult* executionResult),
+                (override));
+    MOCK_METHOD(ndk::ScopedAStatus, executeFenced,
+                (const Request& request, const std::vector<ndk::ScopedFileDescriptor>& waitFor,
+                 bool measureTiming, int64_t deadline, int64_t loopTimeoutDuration,
+                 int64_t duration, FencedExecutionResult* fencedExecutionResult),
+                (override));
+};
+
+inline std::shared_ptr<MockPreparedModel> MockPreparedModel::create() {
+    return ndk::SharedRefBase::make<MockPreparedModel>();
+}
+
+}  // namespace aidl::android::hardware::neuralnetworks::utils
+
+#endif  // ANDROID_HARDWARE_INTERFACES_NEURALNETWORKS_AIDL_UTILS_TEST_MOCK_PREPARED_MODEL
diff --git a/neuralnetworks/aidl/utils/test/PreparedModelTest.cpp b/neuralnetworks/aidl/utils/test/PreparedModelTest.cpp
new file mode 100644
index 0000000..7e28861
--- /dev/null
+++ b/neuralnetworks/aidl/utils/test/PreparedModelTest.cpp
@@ -0,0 +1,272 @@
+/*
+ * Copyright (C) 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "MockFencedExecutionCallback.h"
+#include "MockPreparedModel.h"
+
+#include <aidl/android/hardware/neuralnetworks/IFencedExecutionCallback.h>
+#include <gmock/gmock.h>
+#include <gtest/gtest.h>
+#include <nnapi/IPreparedModel.h>
+#include <nnapi/TypeUtils.h>
+#include <nnapi/Types.h>
+#include <nnapi/hal/aidl/PreparedModel.h>
+
+#include <functional>
+#include <memory>
+
+namespace aidl::android::hardware::neuralnetworks::utils {
+namespace {
+
+using ::testing::_;
+using ::testing::DoAll;
+using ::testing::Invoke;
+using ::testing::InvokeWithoutArgs;
+using ::testing::SetArgPointee;
+
+const std::shared_ptr<IPreparedModel> kInvalidPreparedModel;
+constexpr auto kNoTiming = Timing{.timeOnDevice = -1, .timeInDriver = -1};
+
+constexpr auto makeStatusOk = [] { return ndk::ScopedAStatus::ok(); };
+
+constexpr auto makeGeneralFailure = [] {
+    return ndk::ScopedAStatus::fromServiceSpecificError(
+            static_cast<int32_t>(ErrorStatus::GENERAL_FAILURE));
+};
+constexpr auto makeGeneralTransportFailure = [] {
+    return ndk::ScopedAStatus::fromStatus(STATUS_NO_MEMORY);
+};
+constexpr auto makeDeadObjectFailure = [] {
+    return ndk::ScopedAStatus::fromStatus(STATUS_DEAD_OBJECT);
+};
+
+auto makeFencedExecutionResult(const std::shared_ptr<MockFencedExecutionCallback>& callback) {
+    return [callback](const Request& /*request*/,
+                      const std::vector<ndk::ScopedFileDescriptor>& /*waitFor*/,
+                      bool /*measureTiming*/, int64_t /*deadline*/, int64_t /*loopTimeoutDuration*/,
+                      int64_t /*duration*/, FencedExecutionResult* fencedExecutionResult) {
+        *fencedExecutionResult = FencedExecutionResult{.callback = callback,
+                                                       .syncFence = ndk::ScopedFileDescriptor(-1)};
+        return ndk::ScopedAStatus::ok();
+    };
+}
+
+}  // namespace
+
+TEST(PreparedModelTest, invalidPreparedModel) {
+    // run test
+    const auto result = PreparedModel::create(kInvalidPreparedModel);
+
+    // verify result
+    ASSERT_FALSE(result.has_value());
+    EXPECT_EQ(result.error().code, nn::ErrorStatus::GENERAL_FAILURE);
+}
+
+TEST(PreparedModelTest, executeSync) {
+    // setup call
+    const auto mockPreparedModel = MockPreparedModel::create();
+    const auto preparedModel = PreparedModel::create(mockPreparedModel).value();
+    const auto mockExecutionResult = ExecutionResult{
+            .outputSufficientSize = true,
+            .outputShapes = {},
+            .timing = kNoTiming,
+    };
+    EXPECT_CALL(*mockPreparedModel, executeSynchronously(_, _, _, _, _))
+            .Times(1)
+            .WillOnce(
+                    DoAll(SetArgPointee<4>(mockExecutionResult), InvokeWithoutArgs(makeStatusOk)));
+
+    // run test
+    const auto result = preparedModel->execute({}, {}, {}, {});
+
+    // verify result
+    EXPECT_TRUE(result.has_value())
+            << "Failed with " << result.error().code << ": " << result.error().message;
+}
+
+TEST(PreparedModelTest, executeSyncError) {
+    // setup test
+    const auto mockPreparedModel = MockPreparedModel::create();
+    const auto preparedModel = PreparedModel::create(mockPreparedModel).value();
+    EXPECT_CALL(*mockPreparedModel, executeSynchronously(_, _, _, _, _))
+            .Times(1)
+            .WillOnce(Invoke(makeGeneralFailure));
+
+    // run test
+    const auto result = preparedModel->execute({}, {}, {}, {});
+
+    // verify result
+    ASSERT_FALSE(result.has_value());
+    EXPECT_EQ(result.error().code, nn::ErrorStatus::GENERAL_FAILURE);
+}
+
+TEST(PreparedModelTest, executeSyncTransportFailure) {
+    // setup test
+    const auto mockPreparedModel = MockPreparedModel::create();
+    const auto preparedModel = PreparedModel::create(mockPreparedModel).value();
+    EXPECT_CALL(*mockPreparedModel, executeSynchronously(_, _, _, _, _))
+            .Times(1)
+            .WillOnce(InvokeWithoutArgs(makeGeneralTransportFailure));
+
+    // run test
+    const auto result = preparedModel->execute({}, {}, {}, {});
+
+    // verify result
+    ASSERT_FALSE(result.has_value());
+    EXPECT_EQ(result.error().code, nn::ErrorStatus::GENERAL_FAILURE);
+}
+
+TEST(PreparedModelTest, executeSyncDeadObject) {
+    // setup test
+    const auto mockPreparedModel = MockPreparedModel::create();
+    const auto preparedModel = PreparedModel::create(mockPreparedModel).value();
+    EXPECT_CALL(*mockPreparedModel, executeSynchronously(_, _, _, _, _))
+            .Times(1)
+            .WillOnce(InvokeWithoutArgs(makeDeadObjectFailure));
+
+    // run test
+    const auto result = preparedModel->execute({}, {}, {}, {});
+
+    // verify result
+    ASSERT_FALSE(result.has_value());
+    EXPECT_EQ(result.error().code, nn::ErrorStatus::DEAD_OBJECT);
+}
+
+TEST(PreparedModelTest, executeFenced) {
+    // setup call
+    const auto mockPreparedModel = MockPreparedModel::create();
+    const auto preparedModel = PreparedModel::create(mockPreparedModel).value();
+    const auto mockCallback = MockFencedExecutionCallback::create();
+    EXPECT_CALL(*mockCallback, getExecutionInfo(_, _, _))
+            .Times(1)
+            .WillOnce(DoAll(SetArgPointee<0>(kNoTiming), SetArgPointee<1>(kNoTiming),
+                            SetArgPointee<2>(ErrorStatus::NONE), Invoke(makeStatusOk)));
+    EXPECT_CALL(*mockPreparedModel, executeFenced(_, _, _, _, _, _, _))
+            .Times(1)
+            .WillOnce(Invoke(makeFencedExecutionResult(mockCallback)));
+
+    // run test
+    const auto result = preparedModel->executeFenced({}, {}, {}, {}, {}, {});
+
+    // verify result
+    ASSERT_TRUE(result.has_value())
+            << "Failed with " << result.error().code << ": " << result.error().message;
+    const auto& [syncFence, callback] = result.value();
+    EXPECT_EQ(syncFence.syncWait({}), nn::SyncFence::FenceState::SIGNALED);
+    ASSERT_NE(callback, nullptr);
+
+    // get results from callback
+    const auto callbackResult = callback();
+    ASSERT_TRUE(callbackResult.has_value()) << "Failed with " << callbackResult.error().code << ": "
+                                            << callbackResult.error().message;
+}
+
+TEST(PreparedModelTest, executeFencedCallbackError) {
+    // setup call
+    const auto mockPreparedModel = MockPreparedModel::create();
+    const auto preparedModel = PreparedModel::create(mockPreparedModel).value();
+    const auto mockCallback = MockFencedExecutionCallback::create();
+    EXPECT_CALL(*mockCallback, getExecutionInfo(_, _, _))
+            .Times(1)
+            .WillOnce(Invoke(DoAll(SetArgPointee<0>(kNoTiming), SetArgPointee<1>(kNoTiming),
+                                   SetArgPointee<2>(ErrorStatus::GENERAL_FAILURE),
+                                   Invoke(makeStatusOk))));
+    EXPECT_CALL(*mockPreparedModel, executeFenced(_, _, _, _, _, _, _))
+            .Times(1)
+            .WillOnce(Invoke(makeFencedExecutionResult(mockCallback)));
+
+    // run test
+    const auto result = preparedModel->executeFenced({}, {}, {}, {}, {}, {});
+
+    // verify result
+    ASSERT_TRUE(result.has_value())
+            << "Failed with " << result.error().code << ": " << result.error().message;
+    const auto& [syncFence, callback] = result.value();
+    EXPECT_NE(syncFence.syncWait({}), nn::SyncFence::FenceState::ACTIVE);
+    ASSERT_NE(callback, nullptr);
+
+    // verify callback failure
+    const auto callbackResult = callback();
+    ASSERT_FALSE(callbackResult.has_value());
+    EXPECT_EQ(callbackResult.error().code, nn::ErrorStatus::GENERAL_FAILURE);
+}
+
+TEST(PreparedModelTest, executeFencedError) {
+    // setup test
+    const auto mockPreparedModel = MockPreparedModel::create();
+    const auto preparedModel = PreparedModel::create(mockPreparedModel).value();
+    EXPECT_CALL(*mockPreparedModel, executeFenced(_, _, _, _, _, _, _))
+            .Times(1)
+            .WillOnce(InvokeWithoutArgs(makeGeneralFailure));
+
+    // run test
+    const auto result = preparedModel->executeFenced({}, {}, {}, {}, {}, {});
+
+    // verify result
+    ASSERT_FALSE(result.has_value());
+    EXPECT_EQ(result.error().code, nn::ErrorStatus::GENERAL_FAILURE);
+}
+
+TEST(PreparedModelTest, executeFencedTransportFailure) {
+    // setup test
+    const auto mockPreparedModel = MockPreparedModel::create();
+    const auto preparedModel = PreparedModel::create(mockPreparedModel).value();
+    EXPECT_CALL(*mockPreparedModel, executeFenced(_, _, _, _, _, _, _))
+            .Times(1)
+            .WillOnce(InvokeWithoutArgs(makeGeneralTransportFailure));
+
+    // run test
+    const auto result = preparedModel->executeFenced({}, {}, {}, {}, {}, {});
+
+    // verify result
+    ASSERT_FALSE(result.has_value());
+    EXPECT_EQ(result.error().code, nn::ErrorStatus::GENERAL_FAILURE);
+}
+
+TEST(PreparedModelTest, executeFencedDeadObject) {
+    // setup test
+    const auto mockPreparedModel = MockPreparedModel::create();
+    const auto preparedModel = PreparedModel::create(mockPreparedModel).value();
+    EXPECT_CALL(*mockPreparedModel, executeFenced(_, _, _, _, _, _, _))
+            .Times(1)
+            .WillOnce(InvokeWithoutArgs(makeDeadObjectFailure));
+
+    // run test
+    const auto result = preparedModel->executeFenced({}, {}, {}, {}, {}, {});
+
+    // verify result
+    ASSERT_FALSE(result.has_value());
+    EXPECT_EQ(result.error().code, nn::ErrorStatus::DEAD_OBJECT);
+}
+
+// TODO: test burst execution if/when it is added to nn::IPreparedModel.
+
+TEST(PreparedModelTest, getUnderlyingResource) {
+    // setup test
+    const auto mockPreparedModel = MockPreparedModel::create();
+    const auto preparedModel = PreparedModel::create(mockPreparedModel).value();
+
+    // run test
+    const auto resource = preparedModel->getUnderlyingResource();
+
+    // verify resource
+    const std::shared_ptr<IPreparedModel>* maybeMock =
+            std::any_cast<std::shared_ptr<IPreparedModel>>(&resource);
+    ASSERT_NE(maybeMock, nullptr);
+    EXPECT_EQ(maybeMock->get(), mockPreparedModel.get());
+}
+
+}  // namespace aidl::android::hardware::neuralnetworks::utils
diff --git a/neuralnetworks/aidl/vts/functional/GeneratedTestHarness.cpp b/neuralnetworks/aidl/vts/functional/GeneratedTestHarness.cpp
index 4eb704b..7a042ed 100644
--- a/neuralnetworks/aidl/vts/functional/GeneratedTestHarness.cpp
+++ b/neuralnetworks/aidl/vts/functional/GeneratedTestHarness.cpp
@@ -299,9 +299,11 @@
 }
 
 static void makeOutputInsufficientSize(uint32_t outputIndex, Request* request) {
-    auto& length = request->outputs[outputIndex].location.length;
-    ASSERT_GT(length, 1u);
-    length -= 1u;
+    auto& loc = request->outputs[outputIndex].location;
+    ASSERT_GT(loc.length, 1u);
+    loc.length -= 1u;
+    // Test that the padding is not used for output data.
+    loc.padding += 1u;
 }
 
 static void makeOutputDimensionsUnspecified(Model* model) {
@@ -336,6 +338,12 @@
     std::vector<std::shared_ptr<IBuffer>> mBuffers;
 };
 
+// Returns the number of bytes needed to round up "size" to the nearest multiple of "multiple".
+static uint32_t roundUpBytesNeeded(uint32_t size, uint32_t multiple) {
+    CHECK(multiple != 0);
+    return ((size + multiple - 1) / multiple) * multiple - size;
+}
+
 std::optional<Request> ExecutionContext::createRequest(const TestModel& testModel,
                                                        MemoryType memoryType) {
     // Memory pools are organized as:
@@ -370,10 +378,13 @@
         }
 
         // Reserve shared memory for input.
+        inputSize += roundUpBytesNeeded(inputSize, nn::kDefaultRequestMemoryAlignment);
+        const auto padding = roundUpBytesNeeded(op.data.size(), nn::kDefaultRequestMemoryPadding);
         DataLocation loc = {.poolIndex = kInputPoolIndex,
                             .offset = static_cast<int64_t>(inputSize),
-                            .length = static_cast<int64_t>(op.data.size())};
-        inputSize += op.data.alignedSize();
+                            .length = static_cast<int64_t>(op.data.size()),
+                            .padding = static_cast<int64_t>(padding)};
+        inputSize += (op.data.size() + padding);
         inputs[i] = {.hasNoValue = false, .location = loc, .dimensions = {}};
     }
 
@@ -404,10 +415,13 @@
         size_t bufferSize = std::max<size_t>(op.data.size(), 1);
 
         // Reserve shared memory for output.
+        outputSize += roundUpBytesNeeded(outputSize, nn::kDefaultRequestMemoryAlignment);
+        const auto padding = roundUpBytesNeeded(bufferSize, nn::kDefaultRequestMemoryPadding);
         DataLocation loc = {.poolIndex = kOutputPoolIndex,
                             .offset = static_cast<int64_t>(outputSize),
-                            .length = static_cast<int64_t>(bufferSize)};
-        outputSize += op.data.size() == 0 ? TestBuffer::kAlignment : op.data.alignedSize();
+                            .length = static_cast<int64_t>(bufferSize),
+                            .padding = static_cast<int64_t>(padding)};
+        outputSize += (bufferSize + padding);
         outputs[i] = {.hasNoValue = false, .location = loc, .dimensions = {}};
     }
 
diff --git a/neuralnetworks/utils/README.md b/neuralnetworks/utils/README.md
index 45ca0b4..87b3f9f 100644
--- a/neuralnetworks/utils/README.md
+++ b/neuralnetworks/utils/README.md
@@ -49,7 +49,9 @@
 (i.e., not as a nested class) or used in a subsequent version of the NN HAL. Prefer using `convert`
 over `unvalidatedConvert`.
 
-# HIDL Interface Lifetimes across Processes
+# Interface Lifetimes across Processes
+
+## HIDL
 
 Some notes about HIDL interface objects and lifetimes across processes:
 
@@ -68,7 +70,20 @@
 If the process which created the HIDL interface object dies, any call on this object from another
 process will result in a HIDL transport error with the code `DEAD_OBJECT`.
 
-# Protecting Asynchronous Calls across HIDL
+## AIDL
+
+We use NDK backend for AIDL interfaces. Handling of lifetimes is generally the same with the
+following differences:
+* Interfaces inherit from `ndk::ICInterface`, which inherits from `ndk::SharedRefBase`. The latter
+  is an analog of `::android::RefBase` using `std::shared_ptr` for reference counting.
+* AIDL calls return `ndk::ScopedAStatus` which wraps fields of types `binder_status_t` and
+  `binder_exception_t`. In case the call is made on a dead object, the call will return
+  `ndk::ScopedAStatus` with exception `EX_TRANSACTION_FAILED` and binder status
+  `STATUS_DEAD_OBJECT`.
+
+# Protecting Asynchronous Calls
+
+## Across HIDL
 
 Some notes about asynchronous calls across HIDL:
 
@@ -95,3 +110,17 @@
 driver process has died, and `DeathHandler` will unblock any thread waiting on the results of an
 `IProtectedCallback` callback object that may otherwise not be signaled. In order for this to work,
 the `IProtectedCallback` object must have been registered via `DeathHandler::protectCallback()`.
+
+## Across AIDL
+
+We use NDK backend for AIDL interfaces. Handling of asynchronous calls is generally the same with
+the following differences:
+* AIDL calls return `ndk::ScopedAStatus` which wraps fields of types `binder_status_t` and
+  `binder_exception_t`. In case the call is made on a dead object, the call will return
+  `ndk::ScopedAStatus` with exception `EX_TRANSACTION_FAILED` and binder status
+  `STATUS_DEAD_OBJECT`.
+* AIDL interface doesn't contain asynchronous `IPreparedModel::execute`.
+* Service death is handled using `AIBinder_DeathRecipient` object which is linked to an interface
+  object using `AIBinder_linkToDeath`. nnapi/hal/aidl/ProtectCallback.h provides `DeathHandler`
+  object that is a direct analog of HIDL `DeathHandler`, only using libbinder_ndk objects for
+  implementation.
diff --git a/neuralnetworks/utils/common/Android.bp b/neuralnetworks/utils/common/Android.bp
index 6162fe8..2ed1e40 100644
--- a/neuralnetworks/utils/common/Android.bp
+++ b/neuralnetworks/utils/common/Android.bp
@@ -35,8 +35,10 @@
         "neuralnetworks_types",
     ],
     shared_libs: [
+        "android.hardware.neuralnetworks-V1-ndk_platform",
         "libhidlbase",
         "libnativewindow",
+        "libbinder_ndk",
     ],
 }
 
diff --git a/neuralnetworks/utils/common/include/nnapi/hal/CommonUtils.h b/neuralnetworks/utils/common/include/nnapi/hal/CommonUtils.h
index 2f6112a..8fe6b90 100644
--- a/neuralnetworks/utils/common/include/nnapi/hal/CommonUtils.h
+++ b/neuralnetworks/utils/common/include/nnapi/hal/CommonUtils.h
@@ -32,6 +32,8 @@
 // Shorthands
 namespace aidl::android::hardware::neuralnetworks {
 namespace aidl_hal = ::aidl::android::hardware::neuralnetworks;
+namespace hal = ::android::hardware::neuralnetworks;
+namespace nn = ::android::nn;
 }  // namespace aidl::android::hardware::neuralnetworks
 
 // Shorthands
diff --git a/neuralnetworks/utils/common/include/nnapi/hal/ProtectCallback.h b/neuralnetworks/utils/common/include/nnapi/hal/ProtectCallback.h
index c921885..05110bc 100644
--- a/neuralnetworks/utils/common/include/nnapi/hal/ProtectCallback.h
+++ b/neuralnetworks/utils/common/include/nnapi/hal/ProtectCallback.h
@@ -56,7 +56,7 @@
 // Thread safe class
 class DeathRecipient final : public hidl_death_recipient {
   public:
-    void serviceDied(uint64_t /*cookie*/, const wp<hidl::base::V1_0::IBase>& /*who*/) override;
+    void serviceDied(uint64_t cookie, const wp<hidl::base::V1_0::IBase>& who) override;
     // Precondition: `killable` must be non-null.
     void add(IProtectedCallback* killable) const;
     // Precondition: `killable` must be non-null.
@@ -64,6 +64,7 @@
 
   private:
     mutable std::mutex mMutex;
+    mutable bool mIsDeadObject GUARDED_BY(mMutex) = false;
     mutable std::vector<IProtectedCallback*> mObjects GUARDED_BY(mMutex);
 };
 
@@ -78,14 +79,21 @@
     ~DeathHandler();
 
     using Cleanup = std::function<void()>;
+    using Hold = base::ScopeGuard<Cleanup>;
+
     // Precondition: `killable` must be non-null.
-    [[nodiscard]] base::ScopeGuard<Cleanup> protectCallback(IProtectedCallback* killable) const;
+    // `killable` must outlive the return value `Hold`.
+    [[nodiscard]] Hold protectCallback(IProtectedCallback* killable) const;
+
+    // Precondition: `killable` must be non-null.
+    // `killable` must outlive the `DeathHandler`.
+    void protectCallbackForLifetimeOfDeathHandler(IProtectedCallback* killable) const;
 
   private:
     DeathHandler(sp<hidl::base::V1_0::IBase> object, sp<DeathRecipient> deathRecipient);
 
-    sp<hidl::base::V1_0::IBase> kObject;
-    sp<DeathRecipient> kDeathRecipient;
+    sp<hidl::base::V1_0::IBase> mObject;
+    sp<DeathRecipient> mDeathRecipient;
 };
 
 }  // namespace android::hardware::neuralnetworks::utils
diff --git a/neuralnetworks/utils/common/src/ProtectCallback.cpp b/neuralnetworks/utils/common/src/ProtectCallback.cpp
index abe4cb6..18e1f3b 100644
--- a/neuralnetworks/utils/common/src/ProtectCallback.cpp
+++ b/neuralnetworks/utils/common/src/ProtectCallback.cpp
@@ -35,19 +35,25 @@
     std::lock_guard guard(mMutex);
     std::for_each(mObjects.begin(), mObjects.end(),
                   [](IProtectedCallback* killable) { killable->notifyAsDeadObject(); });
+    mObjects.clear();
+    mIsDeadObject = true;
 }
 
 void DeathRecipient::add(IProtectedCallback* killable) const {
     CHECK(killable != nullptr);
     std::lock_guard guard(mMutex);
-    mObjects.push_back(killable);
+    if (mIsDeadObject) {
+        killable->notifyAsDeadObject();
+    } else {
+        mObjects.push_back(killable);
+    }
 }
 
 void DeathRecipient::remove(IProtectedCallback* killable) const {
     CHECK(killable != nullptr);
     std::lock_guard guard(mMutex);
-    const auto removedIter = std::remove(mObjects.begin(), mObjects.end(), killable);
-    mObjects.erase(removedIter);
+    const auto newEnd = std::remove(mObjects.begin(), mObjects.end(), killable);
+    mObjects.erase(newEnd, mObjects.end());
 }
 
 nn::GeneralResult<DeathHandler> DeathHandler::create(sp<hidl::base::V1_0::IBase> object) {
@@ -67,19 +73,16 @@
 }
 
 DeathHandler::DeathHandler(sp<hidl::base::V1_0::IBase> object, sp<DeathRecipient> deathRecipient)
-    : kObject(std::move(object)), kDeathRecipient(std::move(deathRecipient)) {
-    CHECK(kObject != nullptr);
-    CHECK(kDeathRecipient != nullptr);
+    : mObject(std::move(object)), mDeathRecipient(std::move(deathRecipient)) {
+    CHECK(mObject != nullptr);
+    CHECK(mDeathRecipient != nullptr);
 }
 
 DeathHandler::~DeathHandler() {
-    if (kObject != nullptr && kDeathRecipient != nullptr) {
-        const auto ret = kObject->unlinkToDeath(kDeathRecipient);
-        const auto maybeSuccess = handleTransportError(ret);
-        if (!maybeSuccess.has_value()) {
-            LOG(ERROR) << maybeSuccess.error().message;
-        } else if (!maybeSuccess.value()) {
-            LOG(ERROR) << "IBase::linkToDeath returned false";
+    if (mObject != nullptr && mDeathRecipient != nullptr) {
+        const auto successful = mObject->unlinkToDeath(mDeathRecipient).isOk();
+        if (!successful) {
+            LOG(ERROR) << "IBase::linkToDeath failed";
         }
     }
 }
@@ -87,9 +90,14 @@
 [[nodiscard]] base::ScopeGuard<DeathHandler::Cleanup> DeathHandler::protectCallback(
         IProtectedCallback* killable) const {
     CHECK(killable != nullptr);
-    kDeathRecipient->add(killable);
+    mDeathRecipient->add(killable);
     return base::make_scope_guard(
-            [deathRecipient = kDeathRecipient, killable] { deathRecipient->remove(killable); });
+            [deathRecipient = mDeathRecipient, killable] { deathRecipient->remove(killable); });
+}
+
+void DeathHandler::protectCallbackForLifetimeOfDeathHandler(IProtectedCallback* killable) const {
+    CHECK(killable != nullptr);
+    mDeathRecipient->add(killable);
 }
 
 }  // namespace android::hardware::neuralnetworks::utils
diff --git a/neuralnetworks/utils/service/Android.bp b/neuralnetworks/utils/service/Android.bp
index 9f8b9bb..5f36dff 100644
--- a/neuralnetworks/utils/service/Android.bp
+++ b/neuralnetworks/utils/service/Android.bp
@@ -35,12 +35,15 @@
         "neuralnetworks_utils_hal_1_1",
         "neuralnetworks_utils_hal_1_2",
         "neuralnetworks_utils_hal_1_3",
+        "neuralnetworks_utils_hal_aidl",
         "neuralnetworks_utils_hal_common",
     ],
     shared_libs: [
+        "android.hardware.neuralnetworks-V1-ndk_platform",
         "android.hardware.neuralnetworks@1.0",
         "android.hardware.neuralnetworks@1.1",
         "android.hardware.neuralnetworks@1.2",
         "android.hardware.neuralnetworks@1.3",
+        "libbinder_ndk",
     ],
 }
diff --git a/neuralnetworks/utils/service/src/Service.cpp b/neuralnetworks/utils/service/src/Service.cpp
index a59549d..c83bcc9 100644
--- a/neuralnetworks/utils/service/src/Service.cpp
+++ b/neuralnetworks/utils/service/src/Service.cpp
@@ -16,7 +16,9 @@
 
 #include "Service.h"
 
+#include <aidl/android/hardware/neuralnetworks/IDevice.h>
 #include <android-base/logging.h>
+#include <android/binder_manager.h>
 #include <android/hardware/neuralnetworks/1.0/IDevice.h>
 #include <android/hardware/neuralnetworks/1.1/IDevice.h>
 #include <android/hardware/neuralnetworks/1.2/IDevice.h>
@@ -31,6 +33,7 @@
 #include <nnapi/hal/1.1/Service.h>
 #include <nnapi/hal/1.2/Service.h>
 #include <nnapi/hal/1.3/Service.h>
+#include <nnapi/hal/aidl/Service.h>
 
 #include <functional>
 #include <memory>
@@ -42,11 +45,12 @@
 namespace android::hardware::neuralnetworks::service {
 namespace {
 
+namespace aidl_hal = ::aidl::android::hardware::neuralnetworks;
 using getDeviceFn = std::add_pointer_t<nn::GeneralResult<nn::SharedDevice>(const std::string&)>;
 
-void getDevicesForVersion(const std::string& descriptor, getDeviceFn getDevice,
-                          std::vector<nn::SharedDevice>* devices,
-                          std::unordered_set<std::string>* registeredDevices) {
+void getHidlDevicesForVersion(const std::string& descriptor, getDeviceFn getDevice,
+                              std::vector<nn::SharedDevice>* devices,
+                              std::unordered_set<std::string>* registeredDevices) {
     CHECK(devices != nullptr);
     CHECK(registeredDevices != nullptr);
 
@@ -66,18 +70,52 @@
     }
 }
 
+void getAidlDevices(std::vector<nn::SharedDevice>* devices,
+                    std::unordered_set<std::string>* registeredDevices) {
+    CHECK(devices != nullptr);
+    CHECK(registeredDevices != nullptr);
+
+    std::vector<std::string> names;
+    constexpr auto callback = [](const char* serviceName, void* names) {
+        static_cast<std::vector<std::string>*>(names)->emplace_back(serviceName);
+    };
+
+    // Devices with SDK level lower than 31 (Android S) don't have any AIDL drivers available, so
+    // there is no need for a workaround supported on lower levels.
+    if (__builtin_available(android __ANDROID_API_S__, *)) {
+        AServiceManager_forEachDeclaredInstance(aidl_hal::IDevice::descriptor,
+                                                static_cast<void*>(&names), callback);
+    }
+
+    for (const auto& name : names) {
+        if (const auto [it, unregistered] = registeredDevices->insert(name); unregistered) {
+            auto maybeDevice = aidl_hal::utils::getDevice(name);
+            if (maybeDevice.has_value()) {
+                auto device = std::move(maybeDevice).value();
+                CHECK(device != nullptr);
+                devices->push_back(std::move(device));
+            } else {
+                LOG(ERROR) << "getDevice(" << name << ") failed with " << maybeDevice.error().code
+                           << ": " << maybeDevice.error().message;
+            }
+        }
+    }
+}
+
 std::vector<nn::SharedDevice> getDevices() {
     std::vector<nn::SharedDevice> devices;
     std::unordered_set<std::string> registeredDevices;
 
-    getDevicesForVersion(V1_3::IDevice::descriptor, &V1_3::utils::getDevice, &devices,
-                         &registeredDevices);
-    getDevicesForVersion(V1_2::IDevice::descriptor, &V1_2::utils::getDevice, &devices,
-                         &registeredDevices);
-    getDevicesForVersion(V1_1::IDevice::descriptor, &V1_1::utils::getDevice, &devices,
-                         &registeredDevices);
-    getDevicesForVersion(V1_0::IDevice::descriptor, &V1_0::utils::getDevice, &devices,
-                         &registeredDevices);
+    getAidlDevices(&devices, &registeredDevices);
+
+    getHidlDevicesForVersion(V1_3::IDevice::descriptor, &V1_3::utils::getDevice, &devices,
+                             &registeredDevices);
+    getHidlDevicesForVersion(V1_2::IDevice::descriptor, &V1_2::utils::getDevice, &devices,
+                             &registeredDevices);
+    getHidlDevicesForVersion(V1_1::IDevice::descriptor, &V1_1::utils::getDevice, &devices,
+                             &registeredDevices);
+    getHidlDevicesForVersion(V1_0::IDevice::descriptor, &V1_0::utils::getDevice, &devices,
+                             &registeredDevices);
 
     return devices;
 }
diff --git a/power/1.0/default/Power.cpp b/power/1.0/default/Power.cpp
index 51f87f5..b91a6e8 100644
--- a/power/1.0/default/Power.cpp
+++ b/power/1.0/default/Power.cpp
@@ -35,7 +35,6 @@
 }
 
 Power::~Power() {
-    delete(mModule);
 }
 
 // Methods from ::android::hardware::power::V1_0::IPower follow.
diff --git a/radio/1.6/vts/functional/radio_response.cpp b/radio/1.6/vts/functional/radio_response.cpp
index 8034fd2..d0c2984 100644
--- a/radio/1.6/vts/functional/radio_response.cpp
+++ b/radio/1.6/vts/functional/radio_response.cpp
@@ -849,7 +849,9 @@
 
 /* 1.4 Apis */
 Return<void> RadioResponse_v1_6::emergencyDialResponse(
-        const ::android::hardware::radio::V1_0::RadioResponseInfo& /*info*/) {
+        const ::android::hardware::radio::V1_0::RadioResponseInfo& info) {
+    rspInfo_v1_0 = info;
+    parent_v1_6.notify(info.serial);
     return Void();
 }
 
diff --git a/scripts/list_hal_vts.py b/scripts/list_hal_vts.py
new file mode 100755
index 0000000..1fb51a5
--- /dev/null
+++ b/scripts/list_hal_vts.py
@@ -0,0 +1,143 @@
+#!/usr/bin/python3
+
+"""
+List VTS tests for each HAL by parsing module-info.json.
+
+Example usage:
+
+  # First, build modules-info.json
+  m -j "${ANDROID_PRODUCT_OUT#$ANDROID_BUILD_TOP/}/module-info.json"
+
+  # List with pretty-printed JSON. *IDL packages without a VTS module will show up
+  # as keys with empty lists.
+  ./list_hals_vts.py | python3 -m json.tool
+
+  # List with CSV. *IDL packages without a VTS module will show up as a line with
+  # empty value in the VTS module column.
+  ./list_hals_vts.py --csv
+"""
+
+import argparse
+import collections
+import csv
+import io
+import json
+import os
+import logging
+import pathlib
+import re
+import sys
+
+PATH_PACKAGE_PATTERN = re.compile(
+  r'^hardware/interfaces/(?P<path>(?:\w+/)*?)(?:aidl|(?P<version>\d+\.\d+))/.*')
+
+
+class CriticalHandler(logging.StreamHandler):
+  def emit(self, record):
+    super(CriticalHandler, self).emit(record)
+    if record.levelno >= logging.CRITICAL:
+      sys.exit(1)
+
+
+logger = logging.getLogger(__name__)
+logger.addHandler(CriticalHandler())
+
+
+def default_json():
+  out = os.environ.get('ANDROID_PRODUCT_OUT')
+  if not out: return None
+  return os.path.join(out, 'module-info.json')
+
+
+def infer_package(path):
+  """
+  Infer package from a relative path from build top where a VTS module lives.
+
+  :param path: a path like 'hardware/interfaces/vibrator/aidl/vts'
+  :return: The inferred *IDL package, e.g. 'android.hardware.vibrator'
+
+  >>> infer_package('hardware/interfaces/automotive/sv/1.0/vts/functional')
+  'android.hardware.automotive.sv@1.0'
+  >>> infer_package('hardware/interfaces/vibrator/aidl/vts')
+  'android.hardware.vibrator'
+  """
+  mo = re.match(PATH_PACKAGE_PATTERN, path)
+  if not mo: return None
+  package = 'android.hardware.' + ('.'.join(pathlib.Path(mo.group('path')).parts))
+  if mo.group('version'):
+    package += '@' + mo.group('version')
+  return package
+
+
+def load_modules_info(json_file):
+  """
+  :param json_file: The path to modules-info.json
+  :return: a dictionary, where the keys are inferred *IDL package names, and
+           values are a list of VTS modules with that inferred package name.
+  """
+  with open(json_file) as fp:
+    root = json.load(fp)
+    ret = collections.defaultdict(list)
+    for module_name, module_info in root.items():
+      if 'vts' not in module_info.get('compatibility_suites', []):
+        continue
+      for path in module_info.get('path', []):
+        inferred_package = infer_package(path)
+        if not inferred_package:
+          continue
+        ret[inferred_package].append(module_name)
+    return ret
+
+
+def add_missing_idl(vts_modules):
+  top = os.environ.get("ANDROID_BUILD_TOP")
+  interfaces = None
+  if top:
+    interfaces = os.path.join(top, "hardware", "interfaces")
+  else:
+    logger.warning("Missing ANDROID_BUILD_TOP")
+    interfaces = "hardware/interfaces"
+  if not os.path.isdir(interfaces):
+    logger.error("Not adding missing *IDL modules because missing hardware/interfaces dir")
+    return
+  assert not interfaces.endswith(os.path.sep)
+  for root, dirs, files in os.walk(interfaces):
+    for dir in dirs:
+      full_dir = os.path.join(root, dir)
+      assert full_dir.startswith(interfaces)
+      top_rel_dir = os.path.join('hardware', 'interfaces', full_dir[len(interfaces) + 1:])
+      inferred_package = infer_package(top_rel_dir)
+      if inferred_package is None:
+        continue
+      if inferred_package not in vts_modules:
+        vts_modules[inferred_package] = []
+
+
+def main():
+  parser = argparse.ArgumentParser(__doc__, formatter_class=argparse.RawDescriptionHelpFormatter)
+  parser.add_argument('json', metavar='module-info.json', default=default_json(), nargs='?')
+  parser.add_argument('--csv', action='store_true', help='Print CSV. If not specified print JSON.')
+  args = parser.parse_args()
+  if not args.json:
+    logger.critical('No module-info.json is specified or found.')
+  vts_modules = load_modules_info(args.json)
+  add_missing_idl(vts_modules)
+
+  if args.csv:
+    out = io.StringIO()
+    writer = csv.writer(out, )
+    writer.writerow(["package", "vts_module"])
+    for package, modules in vts_modules.items():
+      if not modules:
+        writer.writerow([package, ""])
+      for module in modules:
+        writer.writerow([package, module])
+    result = out.getvalue()
+  else:
+    result = json.dumps(vts_modules)
+
+  print(result)
+
+
+if __name__ == '__main__':
+  main()
diff --git a/security/keymint/aidl/aidl_api/android.hardware.security.keymint/current/android/hardware/security/keymint/Algorithm.aidl b/security/keymint/aidl/aidl_api/android.hardware.security.keymint/current/android/hardware/security/keymint/Algorithm.aidl
index 29ff8f8..5adbdc1 100644
--- a/security/keymint/aidl/aidl_api/android.hardware.security.keymint/current/android/hardware/security/keymint/Algorithm.aidl
+++ b/security/keymint/aidl/aidl_api/android.hardware.security.keymint/current/android/hardware/security/keymint/Algorithm.aidl
@@ -12,7 +12,8 @@
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
- *////////////////////////////////////////////////////////////////////////////////
+ */
+///////////////////////////////////////////////////////////////////////////////
 // THIS FILE IS IMMUTABLE. DO NOT EDIT IN ANY CASE.                          //
 ///////////////////////////////////////////////////////////////////////////////
 
diff --git a/security/keymint/aidl/aidl_api/android.hardware.security.keymint/current/android/hardware/security/keymint/AttestationKey.aidl b/security/keymint/aidl/aidl_api/android.hardware.security.keymint/current/android/hardware/security/keymint/AttestationKey.aidl
index 893b016..21721bf 100644
--- a/security/keymint/aidl/aidl_api/android.hardware.security.keymint/current/android/hardware/security/keymint/AttestationKey.aidl
+++ b/security/keymint/aidl/aidl_api/android.hardware.security.keymint/current/android/hardware/security/keymint/AttestationKey.aidl
@@ -12,7 +12,8 @@
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
- *////////////////////////////////////////////////////////////////////////////////
+ */
+///////////////////////////////////////////////////////////////////////////////
 // THIS FILE IS IMMUTABLE. DO NOT EDIT IN ANY CASE.                          //
 ///////////////////////////////////////////////////////////////////////////////
 
diff --git a/security/keymint/aidl/aidl_api/android.hardware.security.keymint/current/android/hardware/security/keymint/BeginResult.aidl b/security/keymint/aidl/aidl_api/android.hardware.security.keymint/current/android/hardware/security/keymint/BeginResult.aidl
index 4421619..d9d9c13 100644
--- a/security/keymint/aidl/aidl_api/android.hardware.security.keymint/current/android/hardware/security/keymint/BeginResult.aidl
+++ b/security/keymint/aidl/aidl_api/android.hardware.security.keymint/current/android/hardware/security/keymint/BeginResult.aidl
@@ -12,7 +12,8 @@
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
- *////////////////////////////////////////////////////////////////////////////////
+ */
+///////////////////////////////////////////////////////////////////////////////
 // THIS FILE IS IMMUTABLE. DO NOT EDIT IN ANY CASE.                          //
 ///////////////////////////////////////////////////////////////////////////////
 
diff --git a/security/keymint/aidl/aidl_api/android.hardware.security.keymint/current/android/hardware/security/keymint/BlockMode.aidl b/security/keymint/aidl/aidl_api/android.hardware.security.keymint/current/android/hardware/security/keymint/BlockMode.aidl
index e9652c3..feba9d0 100644
--- a/security/keymint/aidl/aidl_api/android.hardware.security.keymint/current/android/hardware/security/keymint/BlockMode.aidl
+++ b/security/keymint/aidl/aidl_api/android.hardware.security.keymint/current/android/hardware/security/keymint/BlockMode.aidl
@@ -12,7 +12,8 @@
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
- *////////////////////////////////////////////////////////////////////////////////
+ */
+///////////////////////////////////////////////////////////////////////////////
 // THIS FILE IS IMMUTABLE. DO NOT EDIT IN ANY CASE.                          //
 ///////////////////////////////////////////////////////////////////////////////
 
diff --git a/security/keymint/aidl/aidl_api/android.hardware.security.keymint/current/android/hardware/security/keymint/Certificate.aidl b/security/keymint/aidl/aidl_api/android.hardware.security.keymint/current/android/hardware/security/keymint/Certificate.aidl
index 5d1cc68..470d534 100644
--- a/security/keymint/aidl/aidl_api/android.hardware.security.keymint/current/android/hardware/security/keymint/Certificate.aidl
+++ b/security/keymint/aidl/aidl_api/android.hardware.security.keymint/current/android/hardware/security/keymint/Certificate.aidl
@@ -12,7 +12,8 @@
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
- *////////////////////////////////////////////////////////////////////////////////
+ */
+///////////////////////////////////////////////////////////////////////////////
 // THIS FILE IS IMMUTABLE. DO NOT EDIT IN ANY CASE.                          //
 ///////////////////////////////////////////////////////////////////////////////
 
diff --git a/security/keymint/aidl/aidl_api/android.hardware.security.keymint/current/android/hardware/security/keymint/Digest.aidl b/security/keymint/aidl/aidl_api/android.hardware.security.keymint/current/android/hardware/security/keymint/Digest.aidl
index 5055d75..5a15aad 100644
--- a/security/keymint/aidl/aidl_api/android.hardware.security.keymint/current/android/hardware/security/keymint/Digest.aidl
+++ b/security/keymint/aidl/aidl_api/android.hardware.security.keymint/current/android/hardware/security/keymint/Digest.aidl
@@ -12,7 +12,8 @@
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
- *////////////////////////////////////////////////////////////////////////////////
+ */
+///////////////////////////////////////////////////////////////////////////////
 // THIS FILE IS IMMUTABLE. DO NOT EDIT IN ANY CASE.                          //
 ///////////////////////////////////////////////////////////////////////////////
 
diff --git a/security/keymint/aidl/aidl_api/android.hardware.security.keymint/current/android/hardware/security/keymint/EcCurve.aidl b/security/keymint/aidl/aidl_api/android.hardware.security.keymint/current/android/hardware/security/keymint/EcCurve.aidl
index 1a7e9b5..d7ec006 100644
--- a/security/keymint/aidl/aidl_api/android.hardware.security.keymint/current/android/hardware/security/keymint/EcCurve.aidl
+++ b/security/keymint/aidl/aidl_api/android.hardware.security.keymint/current/android/hardware/security/keymint/EcCurve.aidl
@@ -12,7 +12,8 @@
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
- *////////////////////////////////////////////////////////////////////////////////
+ */
+///////////////////////////////////////////////////////////////////////////////
 // THIS FILE IS IMMUTABLE. DO NOT EDIT IN ANY CASE.                          //
 ///////////////////////////////////////////////////////////////////////////////
 
diff --git a/security/keymint/aidl/aidl_api/android.hardware.security.keymint/current/android/hardware/security/keymint/ErrorCode.aidl b/security/keymint/aidl/aidl_api/android.hardware.security.keymint/current/android/hardware/security/keymint/ErrorCode.aidl
index 2eb6e35..91e2899 100644
--- a/security/keymint/aidl/aidl_api/android.hardware.security.keymint/current/android/hardware/security/keymint/ErrorCode.aidl
+++ b/security/keymint/aidl/aidl_api/android.hardware.security.keymint/current/android/hardware/security/keymint/ErrorCode.aidl
@@ -12,7 +12,8 @@
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
- *////////////////////////////////////////////////////////////////////////////////
+ */
+///////////////////////////////////////////////////////////////////////////////
 // THIS FILE IS IMMUTABLE. DO NOT EDIT IN ANY CASE.                          //
 ///////////////////////////////////////////////////////////////////////////////
 
diff --git a/security/keymint/aidl/aidl_api/android.hardware.security.keymint/current/android/hardware/security/keymint/HardwareAuthToken.aidl b/security/keymint/aidl/aidl_api/android.hardware.security.keymint/current/android/hardware/security/keymint/HardwareAuthToken.aidl
index 30fe6dc..3205a46 100644
--- a/security/keymint/aidl/aidl_api/android.hardware.security.keymint/current/android/hardware/security/keymint/HardwareAuthToken.aidl
+++ b/security/keymint/aidl/aidl_api/android.hardware.security.keymint/current/android/hardware/security/keymint/HardwareAuthToken.aidl
@@ -12,7 +12,8 @@
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
- *////////////////////////////////////////////////////////////////////////////////
+ */
+///////////////////////////////////////////////////////////////////////////////
 // THIS FILE IS IMMUTABLE. DO NOT EDIT IN ANY CASE.                          //
 ///////////////////////////////////////////////////////////////////////////////
 
diff --git a/security/keymint/aidl/aidl_api/android.hardware.security.keymint/current/android/hardware/security/keymint/HardwareAuthenticatorType.aidl b/security/keymint/aidl/aidl_api/android.hardware.security.keymint/current/android/hardware/security/keymint/HardwareAuthenticatorType.aidl
index ae64110..926f2ec 100644
--- a/security/keymint/aidl/aidl_api/android.hardware.security.keymint/current/android/hardware/security/keymint/HardwareAuthenticatorType.aidl
+++ b/security/keymint/aidl/aidl_api/android.hardware.security.keymint/current/android/hardware/security/keymint/HardwareAuthenticatorType.aidl
@@ -12,7 +12,8 @@
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
- *////////////////////////////////////////////////////////////////////////////////
+ */
+///////////////////////////////////////////////////////////////////////////////
 // THIS FILE IS IMMUTABLE. DO NOT EDIT IN ANY CASE.                          //
 ///////////////////////////////////////////////////////////////////////////////
 
diff --git a/security/keymint/aidl/aidl_api/android.hardware.security.keymint/current/android/hardware/security/keymint/IKeyMintDevice.aidl b/security/keymint/aidl/aidl_api/android.hardware.security.keymint/current/android/hardware/security/keymint/IKeyMintDevice.aidl
index 7150c44..bb18669 100644
--- a/security/keymint/aidl/aidl_api/android.hardware.security.keymint/current/android/hardware/security/keymint/IKeyMintDevice.aidl
+++ b/security/keymint/aidl/aidl_api/android.hardware.security.keymint/current/android/hardware/security/keymint/IKeyMintDevice.aidl
@@ -12,7 +12,8 @@
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
- *////////////////////////////////////////////////////////////////////////////////
+ */
+///////////////////////////////////////////////////////////////////////////////
 // THIS FILE IS IMMUTABLE. DO NOT EDIT IN ANY CASE.                          //
 ///////////////////////////////////////////////////////////////////////////////
 
diff --git a/security/keymint/aidl/aidl_api/android.hardware.security.keymint/current/android/hardware/security/keymint/IKeyMintOperation.aidl b/security/keymint/aidl/aidl_api/android.hardware.security.keymint/current/android/hardware/security/keymint/IKeyMintOperation.aidl
index 80ed526..28a83da 100644
--- a/security/keymint/aidl/aidl_api/android.hardware.security.keymint/current/android/hardware/security/keymint/IKeyMintOperation.aidl
+++ b/security/keymint/aidl/aidl_api/android.hardware.security.keymint/current/android/hardware/security/keymint/IKeyMintOperation.aidl
@@ -12,7 +12,8 @@
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
- *////////////////////////////////////////////////////////////////////////////////
+ */
+///////////////////////////////////////////////////////////////////////////////
 // THIS FILE IS IMMUTABLE. DO NOT EDIT IN ANY CASE.                          //
 ///////////////////////////////////////////////////////////////////////////////
 
diff --git a/security/keymint/aidl/aidl_api/android.hardware.security.keymint/current/android/hardware/security/keymint/IRemotelyProvisionedComponent.aidl b/security/keymint/aidl/aidl_api/android.hardware.security.keymint/current/android/hardware/security/keymint/IRemotelyProvisionedComponent.aidl
index a864c3c..8387ecc 100644
--- a/security/keymint/aidl/aidl_api/android.hardware.security.keymint/current/android/hardware/security/keymint/IRemotelyProvisionedComponent.aidl
+++ b/security/keymint/aidl/aidl_api/android.hardware.security.keymint/current/android/hardware/security/keymint/IRemotelyProvisionedComponent.aidl
@@ -12,7 +12,8 @@
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
- *////////////////////////////////////////////////////////////////////////////////
+ */
+///////////////////////////////////////////////////////////////////////////////
 // THIS FILE IS IMMUTABLE. DO NOT EDIT IN ANY CASE.                          //
 ///////////////////////////////////////////////////////////////////////////////
 
diff --git a/security/keymint/aidl/aidl_api/android.hardware.security.keymint/current/android/hardware/security/keymint/KeyCharacteristics.aidl b/security/keymint/aidl/aidl_api/android.hardware.security.keymint/current/android/hardware/security/keymint/KeyCharacteristics.aidl
index 994bd4c..91ac7be 100644
--- a/security/keymint/aidl/aidl_api/android.hardware.security.keymint/current/android/hardware/security/keymint/KeyCharacteristics.aidl
+++ b/security/keymint/aidl/aidl_api/android.hardware.security.keymint/current/android/hardware/security/keymint/KeyCharacteristics.aidl
@@ -12,7 +12,8 @@
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
- *////////////////////////////////////////////////////////////////////////////////
+ */
+///////////////////////////////////////////////////////////////////////////////
 // THIS FILE IS IMMUTABLE. DO NOT EDIT IN ANY CASE.                          //
 ///////////////////////////////////////////////////////////////////////////////
 
diff --git a/security/keymint/aidl/aidl_api/android.hardware.security.keymint/current/android/hardware/security/keymint/KeyCreationResult.aidl b/security/keymint/aidl/aidl_api/android.hardware.security.keymint/current/android/hardware/security/keymint/KeyCreationResult.aidl
index 4139436..b85203f 100644
--- a/security/keymint/aidl/aidl_api/android.hardware.security.keymint/current/android/hardware/security/keymint/KeyCreationResult.aidl
+++ b/security/keymint/aidl/aidl_api/android.hardware.security.keymint/current/android/hardware/security/keymint/KeyCreationResult.aidl
@@ -12,7 +12,8 @@
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
- *////////////////////////////////////////////////////////////////////////////////
+ */
+///////////////////////////////////////////////////////////////////////////////
 // THIS FILE IS IMMUTABLE. DO NOT EDIT IN ANY CASE.                          //
 ///////////////////////////////////////////////////////////////////////////////
 
diff --git a/security/keymint/aidl/aidl_api/android.hardware.security.keymint/current/android/hardware/security/keymint/KeyFormat.aidl b/security/keymint/aidl/aidl_api/android.hardware.security.keymint/current/android/hardware/security/keymint/KeyFormat.aidl
index 1ad7c51..4500288 100644
--- a/security/keymint/aidl/aidl_api/android.hardware.security.keymint/current/android/hardware/security/keymint/KeyFormat.aidl
+++ b/security/keymint/aidl/aidl_api/android.hardware.security.keymint/current/android/hardware/security/keymint/KeyFormat.aidl
@@ -12,7 +12,8 @@
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
- *////////////////////////////////////////////////////////////////////////////////
+ */
+///////////////////////////////////////////////////////////////////////////////
 // THIS FILE IS IMMUTABLE. DO NOT EDIT IN ANY CASE.                          //
 ///////////////////////////////////////////////////////////////////////////////
 
diff --git a/security/keymint/aidl/aidl_api/android.hardware.security.keymint/current/android/hardware/security/keymint/KeyMintHardwareInfo.aidl b/security/keymint/aidl/aidl_api/android.hardware.security.keymint/current/android/hardware/security/keymint/KeyMintHardwareInfo.aidl
index 7747c59..d959ac4 100644
--- a/security/keymint/aidl/aidl_api/android.hardware.security.keymint/current/android/hardware/security/keymint/KeyMintHardwareInfo.aidl
+++ b/security/keymint/aidl/aidl_api/android.hardware.security.keymint/current/android/hardware/security/keymint/KeyMintHardwareInfo.aidl
@@ -12,7 +12,8 @@
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
- *////////////////////////////////////////////////////////////////////////////////
+ */
+///////////////////////////////////////////////////////////////////////////////
 // THIS FILE IS IMMUTABLE. DO NOT EDIT IN ANY CASE.                          //
 ///////////////////////////////////////////////////////////////////////////////
 
diff --git a/security/keymint/aidl/aidl_api/android.hardware.security.keymint/current/android/hardware/security/keymint/KeyOrigin.aidl b/security/keymint/aidl/aidl_api/android.hardware.security.keymint/current/android/hardware/security/keymint/KeyOrigin.aidl
index acaf60d..2b65567 100644
--- a/security/keymint/aidl/aidl_api/android.hardware.security.keymint/current/android/hardware/security/keymint/KeyOrigin.aidl
+++ b/security/keymint/aidl/aidl_api/android.hardware.security.keymint/current/android/hardware/security/keymint/KeyOrigin.aidl
@@ -12,7 +12,8 @@
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
- *////////////////////////////////////////////////////////////////////////////////
+ */
+///////////////////////////////////////////////////////////////////////////////
 // THIS FILE IS IMMUTABLE. DO NOT EDIT IN ANY CASE.                          //
 ///////////////////////////////////////////////////////////////////////////////
 
diff --git a/security/keymint/aidl/aidl_api/android.hardware.security.keymint/current/android/hardware/security/keymint/KeyParameter.aidl b/security/keymint/aidl/aidl_api/android.hardware.security.keymint/current/android/hardware/security/keymint/KeyParameter.aidl
index 21b083c..ee8abda 100644
--- a/security/keymint/aidl/aidl_api/android.hardware.security.keymint/current/android/hardware/security/keymint/KeyParameter.aidl
+++ b/security/keymint/aidl/aidl_api/android.hardware.security.keymint/current/android/hardware/security/keymint/KeyParameter.aidl
@@ -12,7 +12,8 @@
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
- *////////////////////////////////////////////////////////////////////////////////
+ */
+///////////////////////////////////////////////////////////////////////////////
 // THIS FILE IS IMMUTABLE. DO NOT EDIT IN ANY CASE.                          //
 ///////////////////////////////////////////////////////////////////////////////
 
diff --git a/security/keymint/aidl/aidl_api/android.hardware.security.keymint/current/android/hardware/security/keymint/KeyParameterValue.aidl b/security/keymint/aidl/aidl_api/android.hardware.security.keymint/current/android/hardware/security/keymint/KeyParameterValue.aidl
index c79614a..fc57cd2 100644
--- a/security/keymint/aidl/aidl_api/android.hardware.security.keymint/current/android/hardware/security/keymint/KeyParameterValue.aidl
+++ b/security/keymint/aidl/aidl_api/android.hardware.security.keymint/current/android/hardware/security/keymint/KeyParameterValue.aidl
@@ -12,7 +12,8 @@
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
- *////////////////////////////////////////////////////////////////////////////////
+ */
+///////////////////////////////////////////////////////////////////////////////
 // THIS FILE IS IMMUTABLE. DO NOT EDIT IN ANY CASE.                          //
 ///////////////////////////////////////////////////////////////////////////////
 
diff --git a/security/keymint/aidl/aidl_api/android.hardware.security.keymint/current/android/hardware/security/keymint/KeyPurpose.aidl b/security/keymint/aidl/aidl_api/android.hardware.security.keymint/current/android/hardware/security/keymint/KeyPurpose.aidl
index 61bb7e4..f891de6 100644
--- a/security/keymint/aidl/aidl_api/android.hardware.security.keymint/current/android/hardware/security/keymint/KeyPurpose.aidl
+++ b/security/keymint/aidl/aidl_api/android.hardware.security.keymint/current/android/hardware/security/keymint/KeyPurpose.aidl
@@ -12,7 +12,8 @@
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
- *////////////////////////////////////////////////////////////////////////////////
+ */
+///////////////////////////////////////////////////////////////////////////////
 // THIS FILE IS IMMUTABLE. DO NOT EDIT IN ANY CASE.                          //
 ///////////////////////////////////////////////////////////////////////////////
 
diff --git a/security/keymint/aidl/aidl_api/android.hardware.security.keymint/current/android/hardware/security/keymint/MacedPublicKey.aidl b/security/keymint/aidl/aidl_api/android.hardware.security.keymint/current/android/hardware/security/keymint/MacedPublicKey.aidl
index b4caeed..30b38e1 100644
--- a/security/keymint/aidl/aidl_api/android.hardware.security.keymint/current/android/hardware/security/keymint/MacedPublicKey.aidl
+++ b/security/keymint/aidl/aidl_api/android.hardware.security.keymint/current/android/hardware/security/keymint/MacedPublicKey.aidl
@@ -12,7 +12,8 @@
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
- *////////////////////////////////////////////////////////////////////////////////
+ */
+///////////////////////////////////////////////////////////////////////////////
 // THIS FILE IS IMMUTABLE. DO NOT EDIT IN ANY CASE.                          //
 ///////////////////////////////////////////////////////////////////////////////
 
diff --git a/security/keymint/aidl/aidl_api/android.hardware.security.keymint/current/android/hardware/security/keymint/PaddingMode.aidl b/security/keymint/aidl/aidl_api/android.hardware.security.keymint/current/android/hardware/security/keymint/PaddingMode.aidl
index 96b63e1..bfb6ea1 100644
--- a/security/keymint/aidl/aidl_api/android.hardware.security.keymint/current/android/hardware/security/keymint/PaddingMode.aidl
+++ b/security/keymint/aidl/aidl_api/android.hardware.security.keymint/current/android/hardware/security/keymint/PaddingMode.aidl
@@ -12,7 +12,8 @@
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
- *////////////////////////////////////////////////////////////////////////////////
+ */
+///////////////////////////////////////////////////////////////////////////////
 // THIS FILE IS IMMUTABLE. DO NOT EDIT IN ANY CASE.                          //
 ///////////////////////////////////////////////////////////////////////////////
 
diff --git a/security/keymint/aidl/aidl_api/android.hardware.security.keymint/current/android/hardware/security/keymint/ProtectedData.aidl b/security/keymint/aidl/aidl_api/android.hardware.security.keymint/current/android/hardware/security/keymint/ProtectedData.aidl
index 46f602f..64cce78 100644
--- a/security/keymint/aidl/aidl_api/android.hardware.security.keymint/current/android/hardware/security/keymint/ProtectedData.aidl
+++ b/security/keymint/aidl/aidl_api/android.hardware.security.keymint/current/android/hardware/security/keymint/ProtectedData.aidl
@@ -12,7 +12,8 @@
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
- *////////////////////////////////////////////////////////////////////////////////
+ */
+///////////////////////////////////////////////////////////////////////////////
 // THIS FILE IS IMMUTABLE. DO NOT EDIT IN ANY CASE.                          //
 ///////////////////////////////////////////////////////////////////////////////
 
diff --git a/security/keymint/aidl/aidl_api/android.hardware.security.keymint/current/android/hardware/security/keymint/SecurityLevel.aidl b/security/keymint/aidl/aidl_api/android.hardware.security.keymint/current/android/hardware/security/keymint/SecurityLevel.aidl
index c720d6d..628476d 100644
--- a/security/keymint/aidl/aidl_api/android.hardware.security.keymint/current/android/hardware/security/keymint/SecurityLevel.aidl
+++ b/security/keymint/aidl/aidl_api/android.hardware.security.keymint/current/android/hardware/security/keymint/SecurityLevel.aidl
@@ -12,7 +12,8 @@
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
- *////////////////////////////////////////////////////////////////////////////////
+ */
+///////////////////////////////////////////////////////////////////////////////
 // THIS FILE IS IMMUTABLE. DO NOT EDIT IN ANY CASE.                          //
 ///////////////////////////////////////////////////////////////////////////////
 
diff --git a/security/keymint/aidl/aidl_api/android.hardware.security.keymint/current/android/hardware/security/keymint/Tag.aidl b/security/keymint/aidl/aidl_api/android.hardware.security.keymint/current/android/hardware/security/keymint/Tag.aidl
index 2469d27..ccb0404 100644
--- a/security/keymint/aidl/aidl_api/android.hardware.security.keymint/current/android/hardware/security/keymint/Tag.aidl
+++ b/security/keymint/aidl/aidl_api/android.hardware.security.keymint/current/android/hardware/security/keymint/Tag.aidl
@@ -12,7 +12,8 @@
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
- *////////////////////////////////////////////////////////////////////////////////
+ */
+///////////////////////////////////////////////////////////////////////////////
 // THIS FILE IS IMMUTABLE. DO NOT EDIT IN ANY CASE.                          //
 ///////////////////////////////////////////////////////////////////////////////
 
diff --git a/security/keymint/aidl/aidl_api/android.hardware.security.keymint/current/android/hardware/security/keymint/TagType.aidl b/security/keymint/aidl/aidl_api/android.hardware.security.keymint/current/android/hardware/security/keymint/TagType.aidl
index 75a19a3..58f8bd3 100644
--- a/security/keymint/aidl/aidl_api/android.hardware.security.keymint/current/android/hardware/security/keymint/TagType.aidl
+++ b/security/keymint/aidl/aidl_api/android.hardware.security.keymint/current/android/hardware/security/keymint/TagType.aidl
@@ -12,7 +12,8 @@
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
- *////////////////////////////////////////////////////////////////////////////////
+ */
+///////////////////////////////////////////////////////////////////////////////
 // THIS FILE IS IMMUTABLE. DO NOT EDIT IN ANY CASE.                          //
 ///////////////////////////////////////////////////////////////////////////////
 
diff --git a/security/keymint/aidl/android/hardware/security/keymint/IRemotelyProvisionedComponent.aidl b/security/keymint/aidl/android/hardware/security/keymint/IRemotelyProvisionedComponent.aidl
index 1b09e9d..327e4a1 100644
--- a/security/keymint/aidl/android/hardware/security/keymint/IRemotelyProvisionedComponent.aidl
+++ b/security/keymint/aidl/android/hardware/security/keymint/IRemotelyProvisionedComponent.aidl
@@ -165,7 +165,7 @@
      *                protected: bstr .cbor {
      *                    1 : -8,                     // Algorithm : EdDSA
      *                },
-     *                unprotected: bstr .size 0
+     *                unprotected: { },
      *                payload: bstr .cbor SignatureKey,
      *                signature: bstr PureEd25519(.cbor SignatureKeySignatureInput)
      *            ]
@@ -190,7 +190,7 @@
      *                protected: bstr .cbor {
      *                    1 : -8,                     // Algorithm : EdDSA
      *                },
-     *                unprotected: bstr .size 0
+     *                unprotected: { },
      *                payload: bstr .cbor Eek,
      *                signature: bstr PureEd25519(.cbor EekSignatureInput)
      *            ]
@@ -239,7 +239,7 @@
      *                protected : bstr .cbor {
      *                    1 : 5,                           // Algorithm : HMAC-256
      *                },
-     *                unprotected : bstr .size 0,
+     *                unprotected : { },
      *                // Payload is PublicKeys from keysToSign argument, in provided order.
      *                payload: bstr .cbor [ * PublicKey ],
      *                tag: bstr
diff --git a/security/keymint/aidl/android/hardware/security/keymint/MacedPublicKey.aidl b/security/keymint/aidl/android/hardware/security/keymint/MacedPublicKey.aidl
index da85a50..cb5492d 100644
--- a/security/keymint/aidl/android/hardware/security/keymint/MacedPublicKey.aidl
+++ b/security/keymint/aidl/android/hardware/security/keymint/MacedPublicKey.aidl
@@ -29,7 +29,7 @@
      *
      *     MacedPublicKey = [                     // COSE_Mac0
      *         protected: bstr .cbor { 1 : 5},    // Algorithm : HMAC-256
-     *         unprotected: bstr .size 0,
+     *         unprotected: { },
      *         payload : bstr .cbor PublicKey,
      *         tag : bstr HMAC-256(K_mac, MAC_structure)
      *     ]
diff --git a/security/keymint/aidl/android/hardware/security/keymint/ProtectedData.aidl b/security/keymint/aidl/android/hardware/security/keymint/ProtectedData.aidl
index 1ec3bf0..438505e 100644
--- a/security/keymint/aidl/android/hardware/security/keymint/ProtectedData.aidl
+++ b/security/keymint/aidl/android/hardware/security/keymint/ProtectedData.aidl
@@ -80,7 +80,7 @@
      *         bstr .cbor {                    // Protected params
      *             1 : -8,                     // Algorithm : EdDSA
      *         },
-     *         bstr .size 0,                   // Unprotected params
+     *         { },                            // Unprotected params
      *         bstr .size 32,                  // MAC key
      *         bstr PureEd25519(DK_priv, .cbor SignedMac_structure)
      *     ]
@@ -127,7 +127,7 @@
      *         protected: bstr .cbor {
      *             1 : -8,                    // Algorithm : EdDSA
      *         },
-     *         unprotected: bstr .size 0,
+     *         unprotected: { },
      *         payload: bstr .cbor BccPayload,
      *         // First entry in the chain is signed by DK_pub, the others are each signed by their
      *         // immediate predecessor.  See RFC 8032 for signature representation.
diff --git a/security/keymint/aidl/default/RemotelyProvisionedComponent.cpp b/security/keymint/aidl/default/RemotelyProvisionedComponent.cpp
index 2373b26..749f0bc 100644
--- a/security/keymint/aidl/default/RemotelyProvisionedComponent.cpp
+++ b/security/keymint/aidl/default/RemotelyProvisionedComponent.cpp
@@ -156,7 +156,7 @@
         }
 
         auto protectedParms = macedKeyItem->asArray()->get(kCoseMac0ProtectedParams)->asBstr();
-        auto unprotectedParms = macedKeyItem->asArray()->get(kCoseMac0UnprotectedParams)->asBstr();
+        auto unprotectedParms = macedKeyItem->asArray()->get(kCoseMac0UnprotectedParams)->asMap();
         auto payload = macedKeyItem->asArray()->get(kCoseMac0Payload)->asBstr();
         auto tag = macedKeyItem->asArray()->get(kCoseMac0Tag)->asBstr();
         if (!protectedParms || !unprotectedParms || !payload || !tag) {
diff --git a/security/keymint/aidl/vts/functional/VtsRemotelyProvisionedComponentTests.cpp b/security/keymint/aidl/vts/functional/VtsRemotelyProvisionedComponentTests.cpp
index db53a8f..50e6cce 100644
--- a/security/keymint/aidl/vts/functional/VtsRemotelyProvisionedComponentTests.cpp
+++ b/security/keymint/aidl/vts/functional/VtsRemotelyProvisionedComponentTests.cpp
@@ -97,9 +97,9 @@
     ASSERT_NE(protParms, nullptr);
     ASSERT_EQ(cppbor::prettyPrint(protParms->value()), "{\n  1 : 5,\n}");
 
-    auto unprotParms = coseMac0->asArray()->get(kCoseMac0UnprotectedParams)->asBstr();
+    auto unprotParms = coseMac0->asArray()->get(kCoseMac0UnprotectedParams)->asMap();
     ASSERT_NE(unprotParms, nullptr);
-    ASSERT_EQ(unprotParms->value().size(), 0);
+    ASSERT_EQ(unprotParms->size(), 0);
 
     auto payload = coseMac0->asArray()->get(kCoseMac0Payload)->asBstr();
     ASSERT_NE(payload, nullptr);
@@ -150,9 +150,9 @@
     ASSERT_NE(protParms, nullptr);
     ASSERT_EQ(cppbor::prettyPrint(protParms->value()), "{\n  1 : 5,\n}");
 
-    auto unprotParms = coseMac0->asArray()->get(kCoseMac0UnprotectedParams)->asBstr();
+    auto unprotParms = coseMac0->asArray()->get(kCoseMac0UnprotectedParams)->asMap();
     ASSERT_NE(unprotParms, nullptr);
-    ASSERT_EQ(unprotParms->value().size(), 0);
+    ASSERT_EQ(unprotParms->size(), 0);
 
     auto payload = coseMac0->asArray()->get(kCoseMac0Payload)->asBstr();
     ASSERT_NE(payload, nullptr);
@@ -279,7 +279,7 @@
                                          .add(ALGORITHM, HMAC_256)
                                          .canonicalize()
                                          .encode())
-                            .add(cppbor::Bstr())             // unprotected
+                            .add(cppbor::Map())              // unprotected
                             .add(cppbor::Array().encode())   // payload (keysToSign)
                             .add(std::move(keysToSignMac));  // tag
 
@@ -364,7 +364,7 @@
                                          .add(ALGORITHM, HMAC_256)
                                          .canonicalize()
                                          .encode())
-                            .add(cppbor::Bstr())             // unprotected
+                            .add(cppbor::Map())              // unprotected
                             .add(cborKeysToSign_.encode())   // payload
                             .add(std::move(keysToSignMac));  // tag
 
diff --git a/security/keymint/support/cppcose.cpp b/security/keymint/support/cppcose.cpp
index c626ade..bafb2b6 100644
--- a/security/keymint/support/cppcose.cpp
+++ b/security/keymint/support/cppcose.cpp
@@ -85,7 +85,7 @@
 
     return cppbor::Array()
             .add(cppbor::Map().add(ALGORITHM, HMAC_256).canonicalize().encode())
-            .add(cppbor::Bstr() /* unprotected */)
+            .add(cppbor::Map() /* unprotected */)
             .add(payload)
             .add(tag.moveValue());
 }
@@ -97,7 +97,7 @@
     }
 
     auto protectedParms = mac->get(kCoseMac0ProtectedParams)->asBstr();
-    auto unprotectedParms = mac->get(kCoseMac0UnprotectedParams)->asBstr();
+    auto unprotectedParms = mac->get(kCoseMac0UnprotectedParams)->asMap();
     auto payload = mac->get(kCoseMac0Payload)->asBstr();
     auto tag = mac->get(kCoseMac0Tag)->asBstr();
     if (!protectedParms || !unprotectedParms || !payload || !tag) {
@@ -115,7 +115,7 @@
     }
 
     auto protectedParms = mac->get(kCoseMac0ProtectedParams)->asBstr();
-    auto unprotectedParms = mac->get(kCoseMac0UnprotectedParams)->asBstr();
+    auto unprotectedParms = mac->get(kCoseMac0UnprotectedParams)->asMap();
     auto payload = mac->get(kCoseMac0Payload)->asBstr();
     auto tag = mac->get(kCoseMac0Tag)->asBstr();
     if (!protectedParms || !unprotectedParms || !payload || !tag) {
@@ -168,7 +168,7 @@
 
     return cppbor::Array()
             .add(protParms)
-            .add(bytevec{} /* unprotected parameters */)
+            .add(cppbor::Map() /* unprotected parameters */)
             .add(payload)
             .add(*signature);
 }
@@ -185,7 +185,7 @@
     }
 
     const cppbor::Bstr* protectedParams = coseSign1->get(kCoseSign1ProtectedParams)->asBstr();
-    const cppbor::Bstr* unprotectedParams = coseSign1->get(kCoseSign1UnprotectedParams)->asBstr();
+    const cppbor::Map* unprotectedParams = coseSign1->get(kCoseSign1UnprotectedParams)->asMap();
     const cppbor::Bstr* payload = coseSign1->get(kCoseSign1Payload)->asBstr();
     const cppbor::Bstr* signature = coseSign1->get(kCoseSign1Signature)->asBstr();
 
diff --git a/security/keymint/support/remote_prov_utils.cpp b/security/keymint/support/remote_prov_utils.cpp
index 111cb30..3e4f3f7 100644
--- a/security/keymint/support/remote_prov_utils.cpp
+++ b/security/keymint/support/remote_prov_utils.cpp
@@ -83,7 +83,7 @@
     }
 
     const cppbor::Bstr* protectedParams = coseSign1->get(kCoseSign1ProtectedParams)->asBstr();
-    const cppbor::Bstr* unprotectedParams = coseSign1->get(kCoseSign1UnprotectedParams)->asBstr();
+    const cppbor::Map* unprotectedParams = coseSign1->get(kCoseSign1UnprotectedParams)->asMap();
     const cppbor::Bstr* payload = coseSign1->get(kCoseSign1Payload)->asBstr();
     const cppbor::Bstr* signature = coseSign1->get(kCoseSign1Signature)->asBstr();
 
diff --git a/soundtrigger/2.4/Android.bp b/soundtrigger/2.4/Android.bp
new file mode 100644
index 0000000..38c32df
--- /dev/null
+++ b/soundtrigger/2.4/Android.bp
@@ -0,0 +1,21 @@
+// This file is autogenerated by hidl-gen -Landroidbp.
+
+hidl_interface {
+    name: "android.hardware.soundtrigger@2.4",
+    root: "android.hardware",
+    srcs: [
+        "ISoundTriggerHw.hal",
+        "ISoundTriggerHwCallback.hal",
+        "ISoundTriggerHwGlobalCallback.hal",
+    ],
+    interfaces: [
+        "android.hardware.audio.common@2.0",
+        "android.hardware.soundtrigger@2.0",
+        "android.hardware.soundtrigger@2.1",
+        "android.hardware.soundtrigger@2.2",
+        "android.hardware.soundtrigger@2.3",
+        "android.hidl.base@1.0",
+        "android.hidl.safe_union@1.0",
+    ],
+    gen_java: true,
+}
diff --git a/soundtrigger/2.4/ISoundTriggerHw.hal b/soundtrigger/2.4/ISoundTriggerHw.hal
new file mode 100644
index 0000000..fd39303
--- /dev/null
+++ b/soundtrigger/2.4/ISoundTriggerHw.hal
@@ -0,0 +1,190 @@
+/*
+ * Copyright 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package android.hardware.soundtrigger@2.4;
+
+import @2.0::SoundModelHandle;
+import @2.1::ISoundTriggerHw.SoundModel;
+import @2.1::ISoundTriggerHw.PhraseSoundModel;
+import @2.3::ISoundTriggerHw;
+import @2.3::RecognitionConfig;
+import ISoundTriggerHwCallback;
+import ISoundTriggerHwGlobalCallback;
+
+/**
+ * SoundTrigger HAL interface. Used for hardware recognition of hotwords
+ * and other sounds.
+ *
+ * Important notes about the threading model:
+ * ==========================================
+ * Both this interface and the corresponding callback interface use a synchronized calling
+ * convention. This model comes with some advantages, but also with some risks of deadlocks if the
+ * implementation does not handle this correctly. Please consider the following:
+ * - After stopRecognition() returns no more recognition events for that model may be sent. This
+ *   implies that any queues holding such events must be flushed before the call returns and that
+ *   may imply that callback from the HAL to the client are done while stopRecognition() is blocked.
+ *   This is OK, and supported by the framework.
+ * - Similarly, the same relationship applies between unloadModel() and subsequent callbacks to
+ *   modelUnloaded().
+ * - Other than these two cases, calls into the HAL *MAY NOT* block on callbacks from the HAL, or
+ *   else deadlock conditions may result, which may be handled by rebooting of the HAL process and
+ *   cause service outages.
+ *
+ * Similarly, it is expected that a single call to startRecognition() generates at most one event
+ * (the model automatically becomes stopped when the event occurs, until explicitly started again)
+ * and that after a modelUnloaded() event no more events would be sent regarding the model.
+ * Note that a getModelState() call may generate a recognition event, but this event DOES NOT modify
+ * the model state - the model remains started.
+ *
+ * The HAL is expected to correctly handle a stopRecognition() call even after it sent an event
+ * indicating that recognition is stopped and an unloadModel() call even after it sent an event
+ * indicating that it has been unloaded. This is required in order to prevent race conditions
+ * between these calls. This also implies that model handles should generally not be reused until
+ * explicitly unloaded. To avoid the rare possibility of running out of handles, the framework will
+ * call unloadModel() on models that have been preemptively unloaded by the HAL.
+ *
+ * Due to the asynchronous nature of recognition events and preemptive model unloading, the HAL must
+ * correctly handle requests that would have been valid before an event has been delivered, but
+ * became moot as result of the event. Namely:
+ * - stopRecognition() may be called on a model that has already delivered an event and became
+ *   inactive as a result. The HAL must return a successful return code in this case.
+ * - Furthermore, if a model is preemptively unloaded after it triggers (typically, this would
+ *   happen when it is first aborted and immediately preemptively unloaded), stopRecognition() may
+ *   be called on it. The HAL must return a successful return code in this case.
+ * - startRecognition() may be called on a model that has been preemptively unloaded. In this case,
+ *   the HAL must return -EBUSY to indicate that the operation is temporarily unsuccessful.
+ * - unloadSoundModel() may be called on a model that has been preemptively unloaded. The HAL must
+ *   return a successful return code in this case.
+ *
+ * Important notes about resource constraints and concurrency
+ * =========================================================
+ * Up until this version, the framework would enforce concurrency constraints expressed by the
+ * Properties presented by the soundtrigger instance. These include constraints on the maximum
+ * amount of models that can be loaded at the same time and on running recognition while capturing
+ * from the microphone.
+ * This version changes the approach for how these constraints are modeled, both offering the HAL
+ * implementation more flexibility and simplifying the framework's job in enforcing these
+ * limitations. Note that there is no change for how the framework behaves with earlier versions,
+ * everything described below only applies to this version and onward.
+ * The way this is achieved is as following:
+ * - The framework will no longer enforce constraints on concurrent loading of models, as expressed
+ *   in the Properties.maxSoundModels field (this property is merely a hint at this point and may be
+ *   deprecated in the future.
+ * - The framework will no longer enforce constraints on concurrency of audio recording and
+ *   soundtrigger operation, as expressed in the Properties.concurrentCapture field (this property
+ *   is merely a hint at this point and may be deprecated in the future).
+ * - The framework will no longer enforce constraints on concurrent loading of models, as expressed
+ *   in the Properties (these properties are merely hints at this point and may be deprecated in the
+ *   future.
+ * - The HAL implementation is free to reject starting of any model at any time by having the
+ *   respective start*() method return -EBUSY.
+ * - The HAL implementation is free to reject loading of any model at any time by having the
+ *   respective load*() method return -EBUSY.
+ * - The HAL implementation is free to preemptively stop a previously started model at its own
+ *   discretion (for example, if a higher priority use-case which cannot coexist with detection
+ *   has been requested). The HAL must notify the framework of the preemption by sending a
+ *   recognition event with an `ABORT` status. The implementation must NOT attempt to restart the
+ *   recognition automatically when conditions change.
+ * - The HAL implementation is free to preemptively unload a previously loaded model at its own
+ *   discretion (for example, if a higher-priority model is being loaded and the two cannot
+ *   coexist). When doing so, it must first abort the detection if active (as per above) and then
+ *   notify the framework of the unload using the newly added modelUnloaded callback.
+ * - When conditions change, such that a model that couldn't previously load or start or that had
+ *   previously been preemptively stopped or unloaded, the HAL must notify the framework via the
+ *   newly added tryAgain() callback. This callback is not a guarantee that any operation would now
+ *   succeed, but merely a hint that retrying something that had previously failed, now MAY succeed.
+ *   Until this callback arrives, the framework may assume that any operation that had previously
+ *   failed or aborted would still fail if retried, so the implementation should not forget to
+ *   deliver it. There are no guarantees regarding how the framework may respond to this event and
+ *   the order in which it may choose to reload/restart its models. Typically, as result of this
+ *   event the framework will make a single attempt per model to bring this model to its desired
+ *   state (loaded, started).
+ */
+interface ISoundTriggerHw extends @2.3::ISoundTriggerHw {
+    /**
+     * This will get called at most once per every attachment to the service.
+     *
+     * All events not tied to a specific model should go through this callback.
+     */
+    registerGlobalCallback(ISoundTriggerHwGlobalCallback callback);
+
+    /**
+     * Load a sound model. Once loaded, recognition of this model can be
+     * started and stopped.
+     * The implementation returns a unique handle used by other functions
+     * (unloadSoundModel(), startRecognition*(), etc...
+     *
+     * Must have the exact same semantics as loadSoundModel from ISoundTriggerHw@2.3 except that the
+     * return values have changed and that there is no cookie provided (the implementation may pass
+     * any value to the callback, as it is ignored).
+     *
+     * @param soundModel A SoundModel structure describing the sound model
+     *     to load.
+     * @param callback The callback interface on which the soundModelCallback*()
+     *     method must be called upon completion and modelUnloaded() upon preempted unload.
+     * @return retval Operation completion status: 0 in case of success,
+     *     -EBUSY in case the operation is temporarily unavailable (but possible in general).
+     * @return modelHandle A unique handle assigned by the HAL for use by the
+     *     framework when controlling activity for this sound model.
+     */
+    loadSoundModel_2_4(SoundModel soundModel, ISoundTriggerHwCallback callback)
+            generates (int32_t retval, SoundModelHandle modelHandle);
+
+    /**
+     * Load a key phrase sound model. Once loaded, recognition of this model can
+     * be started and stopped. Only one active recognition per model at a time.
+     * The SoundTrigger service must handle concurrent recognition requests by
+     * different users/applications on the same model.
+     * The implementation returns a unique handle used by other functions
+     * (unloadSoundModel(), startRecognition*(), etc...
+     *
+     * Must have the exact same semantics as loadPhraseSoundModel from ISoundTriggerHw@2.3 except
+     * that the return values have changed and that there is no cookie provided (the implementation
+     * may pass any value to the callback, as it is ignored).
+     *
+     * @param soundModel A PhraseSoundModel structure describing the sound model
+     *     to load.
+     * @param callback The callback interface on which the soundModelCallback*()
+     *     method must be called upon completion and modelUnloaded() upon preempted unload.
+     * @return retval Operation completion status: 0 in case of success,
+     *     -EBUSY in case the operation is temporarily unavailable (but possible in general).
+     * @return modelHandle A unique handle assigned by the HAL for use by the
+     *     framework when controlling activity for this sound model.
+     */
+    loadPhraseSoundModel_2_4(PhraseSoundModel soundModel, ISoundTriggerHwCallback callback)
+            generates (int32_t retval, SoundModelHandle modelHandle);
+
+    /**
+     * Start recognition on a given model. Only one recognition active
+     * at a time per model. Once recognition succeeds or fails, the callback
+     * associated with the model handle is called.
+     *
+     * Must have the exact same semantics as startRecognition from ISoundTriggerHw@2.3 except that
+     * there are different expectations of the return value and that there is no cookie provided
+     * (the implementation may pass any value to the callback, as it is ignored).
+     *
+     * @param modelHandle the handle of the sound model to use for recognition
+     * @param config A RecognitionConfig structure containing attributes of the
+     *     recognition to perform
+     * @param callback The callback interface on which the recognitionCallback()
+     *     method must be called upon recognition.
+     * @return retval Operation completion status: 0 in case of success,
+     *     -EBUSY in case the operation is temporarily unavailable (but possible in general), or in
+     *            case model has been preemtively unloaded.
+     */
+    startRecognition_2_4(SoundModelHandle modelHandle, RecognitionConfig config)
+            generates (int32_t retval);
+};
diff --git a/soundtrigger/2.4/ISoundTriggerHwCallback.hal b/soundtrigger/2.4/ISoundTriggerHwCallback.hal
new file mode 100644
index 0000000..594deb0
--- /dev/null
+++ b/soundtrigger/2.4/ISoundTriggerHwCallback.hal
@@ -0,0 +1,34 @@
+/*
+ * Copyright 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package android.hardware.soundtrigger@2.4;
+
+import @2.0::SoundModelHandle;
+import @2.1::ISoundTriggerHwCallback;
+
+/**
+ * SoundTrigger HAL per-model Callback interface.
+ */
+interface ISoundTriggerHwCallback extends @2.1::ISoundTriggerHwCallback {
+    /**
+     * Callback method called by the HAL when a model has been unloaded at the HAL implementation's
+     * discretion. Only a stopped model may be unloaded.
+     * This event is NOT sent as part of an unload sequence initiated by the client.
+     *
+     * @param model The model handle.
+     */
+    modelUnloaded(SoundModelHandle model);
+};
diff --git a/soundtrigger/2.4/ISoundTriggerHwGlobalCallback.hal b/soundtrigger/2.4/ISoundTriggerHwGlobalCallback.hal
new file mode 100644
index 0000000..2f1a977
--- /dev/null
+++ b/soundtrigger/2.4/ISoundTriggerHwGlobalCallback.hal
@@ -0,0 +1,32 @@
+/*
+ * Copyright 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package android.hardware.soundtrigger@2.4;
+
+/**
+ * SoundTrigger HAL callback interface for events not associated with a particular model.
+ */
+interface ISoundTriggerHwGlobalCallback {
+    /**
+     * Callback method called by the HAL whenever internal conditions have been made available, such
+     * that a call that would previously have failed with an -EBUSY status may now succeed.
+     * There is no guarantee that any call would succeed following this event. It is merely a hint
+     * to the client that it may retry.
+     * Conversely, any call that have failed previously with -EBUSY is guaranteed to fail again if
+     * retried, until this callback is delivered.
+     */
+    onResourcesAvailable();
+};
diff --git a/soundtrigger/2.4/vts/functional/Android.bp b/soundtrigger/2.4/vts/functional/Android.bp
new file mode 100644
index 0000000..0e69bf4
--- /dev/null
+++ b/soundtrigger/2.4/vts/functional/Android.bp
@@ -0,0 +1,32 @@
+//
+// Copyright (C) 2021 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+
+cc_test {
+    name: "VtsHalSoundtriggerV2_4TargetTest",
+    defaults: ["VtsHalTargetTestDefaults"],
+    srcs: ["VtsHalSoundtriggerV2_4TargetTest.cpp"],
+    static_libs: [
+        "android.hardware.soundtrigger@2.0",
+        "android.hardware.soundtrigger@2.1",
+        "android.hardware.soundtrigger@2.2",
+        "android.hardware.soundtrigger@2.3",
+        "android.hardware.soundtrigger@2.4",
+    ],
+    test_suites: [
+        "general-tests",
+        "vts",
+    ],
+}
diff --git a/soundtrigger/2.4/vts/functional/VtsHalSoundtriggerV2_4TargetTest.cpp b/soundtrigger/2.4/vts/functional/VtsHalSoundtriggerV2_4TargetTest.cpp
new file mode 100644
index 0000000..13d7005
--- /dev/null
+++ b/soundtrigger/2.4/vts/functional/VtsHalSoundtriggerV2_4TargetTest.cpp
@@ -0,0 +1,84 @@
+/*
+ * Copyright (C) 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#define LOG_TAG "SoundTriggerHidlHalTest"
+
+#include <android-base/logging.h>
+#include <android/hardware/audio/common/2.0/types.h>
+#include <android/hardware/soundtrigger/2.4/ISoundTriggerHwGlobalCallback.h>
+#include <android/hardware/soundtrigger/2.4/ISoundTriggerHw.h>
+#include <gtest/gtest.h>
+#include <hidl/GtestPrinter.h>
+#include <hidl/ServiceManagement.h>
+
+using ::android::sp;
+using ::android::hardware::Return;
+using ::android::hardware::Status;
+using ::android::hardware::soundtrigger::V2_4::ISoundTriggerHw;
+using ::android::hardware::soundtrigger::V2_4::ISoundTriggerHwGlobalCallback;
+
+/**
+ * Test class holding the instance of the SoundTriggerHW service to test.
+ * The passed parameter is the registered name of the implementing service
+ * supplied by INSTANTIATE_TEST_SUITE_P() call.
+ */
+class SoundTriggerHidlTest : public testing::TestWithParam<std::string> {
+public:
+    void SetUp() override {
+        mSoundtrigger = ISoundTriggerHw::getService(GetParam());
+
+        ASSERT_NE(mSoundtrigger, nullptr);
+        LOG(INFO) << "Test is remote " << mSoundtrigger->isRemote();
+    }
+
+protected:
+    sp<ISoundTriggerHw> mSoundtrigger;
+};
+
+/**
+ * Empty test is in place to ensure service is initialized.
+ * Due to the nature of SoundTrigger HAL providing an interface for
+ * proprietary or vendor specific implementations, limited testing on
+ * individual APIs is possible.
+ */
+TEST_P(SoundTriggerHidlTest, ServiceIsInstantiated) {}
+
+class GlobalCallback : public ISoundTriggerHwGlobalCallback {
+    Return<void> onResourcesAvailable() override {
+        return Status::ok();
+    }
+};
+
+/**
+ * Test ISoundTriggerHw::registerGlobalCallback method
+ *
+ * Verifies that:
+ * - the implementation implements the method
+ * - the method returns no error
+ */
+TEST_P(SoundTriggerHidlTest, RegisterGlobalCallback) {
+    Return<void> hidlReturn;
+    sp<ISoundTriggerHwGlobalCallback> callback = new GlobalCallback();
+    hidlReturn = mSoundtrigger->registerGlobalCallback(callback);
+    EXPECT_TRUE(hidlReturn.isOk());
+}
+
+GTEST_ALLOW_UNINSTANTIATED_PARAMETERIZED_TEST(SoundTriggerHidlTest);
+
+INSTANTIATE_TEST_SUITE_P(
+        PerInstance, SoundTriggerHidlTest,
+        testing::ValuesIn(android::hardware::getAllHalInstanceNames(ISoundTriggerHw::descriptor)),
+        android::hardware::PrintInstanceNameToString);
diff --git a/soundtrigger/sthal_cli/Android.bp b/soundtrigger/sthal_cli/Android.bp
new file mode 100644
index 0000000..dafdfc3
--- /dev/null
+++ b/soundtrigger/sthal_cli/Android.bp
@@ -0,0 +1,8 @@
+java_binary {
+    name: "sthal_cli",
+    wrapper: "sthal_cli",
+    srcs: ["java/**/*.java"],
+    static_libs: [
+        "android.hardware.soundtrigger-V2.4-java",
+    ],
+}
diff --git a/soundtrigger/sthal_cli/OWNERS b/soundtrigger/sthal_cli/OWNERS
new file mode 100644
index 0000000..e21b66e
--- /dev/null
+++ b/soundtrigger/sthal_cli/OWNERS
@@ -0,0 +1 @@
+include /media/java/android/media/soundtrigger_middleware/OWNERS
diff --git a/soundtrigger/sthal_cli/java/android/hardware/soundtrigger/cli/SthalCli.java b/soundtrigger/sthal_cli/java/android/hardware/soundtrigger/cli/SthalCli.java
new file mode 100644
index 0000000..ebefd90
--- /dev/null
+++ b/soundtrigger/sthal_cli/java/android/hardware/soundtrigger/cli/SthalCli.java
@@ -0,0 +1,406 @@
+/*
+ * Copyright 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package android.hardware.soundtrigger.cli;
+
+import android.hardware.soundtrigger.V2_0.PhraseRecognitionExtra;
+import android.hardware.soundtrigger.V2_0.RecognitionMode;
+import android.hardware.soundtrigger.V2_0.SoundModelType;
+import android.hardware.soundtrigger.V2_3.OptionalModelParameterRange;
+import android.hardware.soundtrigger.V2_4.ISoundTriggerHw;
+import android.hardware.soundtrigger.V2_4.ISoundTriggerHwCallback;
+import android.hardware.soundtrigger.V2_4.ISoundTriggerHwGlobalCallback;
+import android.os.HidlMemoryUtil;
+import android.os.HwBinder;
+import android.os.RemoteException;
+import android.os.SystemProperties;
+import java.util.Scanner;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.ConcurrentMap;
+
+/**
+ * This is a quick-and-dirty sound trigger HAL console mock.
+ *
+ * It would only work on userdebug builds.
+ *
+ * When this app is started, it will initially:
+ * - Register a ISoundTriggerHw HAL with an instance name "mock".
+ * - Set a sysprop that tells SoundTriggerMiddlewareService to try to connect to the mock instance
+ * rather than the default one.
+ * - Reboot the real (default) HAL.
+ *
+ * In response to that, SoundTriggerMiddlewareService is going to connect to the mock HAL and resume
+ * normal operation.
+ *
+ * Our mock HAL will print to stdout every call it receives as well as expose a basic set of
+ * operations for sending event callbacks to the client. This allows us to simulate the frameworks
+ * behavior in response to different HAL behaviors.
+ */
+public class SthalCli {
+    private static SoundTriggerImpl mService;
+    private static final Scanner scanner = new Scanner(System.in);
+
+    public static void main(String[] args) {
+        try {
+            System.out.println("Registering mock STHAL");
+            HwBinder.setTrebleTestingOverride(true);
+            mService = new SoundTriggerImpl();
+            mService.registerAsService("mock");
+
+            System.out.println("Rebooting STHAL");
+            SystemProperties.set("debug.soundtrigger_middleware.use_mock_hal", "true");
+            SystemProperties.set("sys.audio.restart.hal", "1");
+
+            while (processCommand())
+                ;
+        } catch (Exception e) {
+            e.printStackTrace();
+        } finally {
+            cleanup();
+        }
+    }
+
+    private static void cleanup() {
+        System.out.println("Cleaning up.");
+        SystemProperties.set("debug.soundtrigger_middleware.use_mock_hal", "false");
+        HwBinder.setTrebleTestingOverride(false);
+    }
+
+    private static boolean processCommand() {
+        String line = scanner.nextLine();
+        String[] tokens = line.split("\\s+");
+        if (tokens.length < 1) {
+            return false;
+        }
+        switch (tokens[0]) {
+            case "q":
+                return false;
+
+            case "a":
+                mService.sendOnResourcesAvailable();
+                return true;
+
+            case "u":
+                mService.sendModelUnloaded(Integer.parseInt(tokens[1]));
+                return true;
+
+            case "r":
+                mService.sendRecognitionEvent(
+                        Integer.parseInt(tokens[1]), Integer.parseInt(tokens[2]));
+                return true;
+
+            case "p":
+                mService.sendPhraseRecognitionEvent(
+                        Integer.parseInt(tokens[1]), Integer.parseInt(tokens[2]));
+                return true;
+
+            case "d":
+                mService.dumpModels();
+                return true;
+
+            case "h":
+                System.out.print("Available commands:\n"
+                        + "h - help\n"
+                        + "q - quit\n"
+                        + "a - send onResourcesAvailable event\n"
+                        + "u <model> - send modelUnloaded event\n"
+                        + "r <model> <status> - send recognitionEvent\n"
+                        + "p <model> <status> - send phraseRecognitionEvent\n"
+                        + "d - dump models\n");
+
+            default:
+                return true;
+        }
+    }
+
+    private static class SoundTriggerImpl extends ISoundTriggerHw.Stub {
+        static class Model {
+            final ISoundTriggerHwCallback callback;
+            final SoundModel model;
+            final PhraseSoundModel phraseModel;
+            public android.hardware.soundtrigger.V2_3.RecognitionConfig config = null;
+
+            Model(ISoundTriggerHwCallback callback, SoundModel model) {
+                this.callback = callback;
+                this.model = model;
+                this.phraseModel = null;
+            }
+
+            Model(ISoundTriggerHwCallback callback, PhraseSoundModel model) {
+                this.callback = callback;
+                this.model = null;
+                this.phraseModel = model;
+            }
+        }
+
+        private ISoundTriggerHwGlobalCallback mGlobalCallback;
+        private final ConcurrentMap<Integer, Model> mLoadedModels = new ConcurrentHashMap<>();
+        private int mHandleCounter = 1;
+
+        public void dumpModels() {
+            mLoadedModels.forEach((handle, model) -> {
+                System.out.println("+++ Model " + handle);
+                System.out.println("    config = " + model.config);
+                android.hardware.soundtrigger.V2_3.RecognitionConfig recognitionConfig =
+                        model.config;
+                if (recognitionConfig != null) {
+                    System.out.println("    ACTIVE recognitionConfig = " + recognitionConfig);
+                } else {
+                    System.out.println("    INACTIVE");
+                }
+            });
+        }
+
+        public void sendOnResourcesAvailable() {
+            if (mGlobalCallback != null) {
+                try {
+                    mGlobalCallback.onResourcesAvailable();
+                } catch (RemoteException e) {
+                    e.printStackTrace();
+                }
+            }
+        }
+
+        public void sendRecognitionEvent(int modelHandle, int status) {
+            Model model = mLoadedModels.get(modelHandle);
+            if (model != null && model.config != null) {
+                android.hardware.soundtrigger.V2_1.ISoundTriggerHwCallback.RecognitionEvent event =
+                        new android.hardware.soundtrigger.V2_1.ISoundTriggerHwCallback
+                                .RecognitionEvent();
+                event.header.model = modelHandle;
+                event.header.type = SoundModelType.GENERIC;
+                event.header.status = status;
+                event.header.captureSession = model.config.base.header.captureHandle;
+                event.header.captureAvailable = true;
+                event.header.audioConfig.channelMask = 16;
+                event.header.audioConfig.format = 1;
+                event.header.audioConfig.sampleRateHz = 16000;
+                event.data = HidlMemoryUtil.byteArrayToHidlMemory(new byte[0]);
+                try {
+                    model.callback.recognitionCallback_2_1(event, 0);
+                } catch (RemoteException e) {
+                    e.printStackTrace();
+                }
+                model.config = null;
+            }
+        }
+
+        public void sendPhraseRecognitionEvent(int modelHandle, int status) {
+            Model model = mLoadedModels.get(modelHandle);
+            if (model != null && model.config != null) {
+                android.hardware.soundtrigger.V2_1.ISoundTriggerHwCallback
+                        .PhraseRecognitionEvent event =
+                        new android.hardware.soundtrigger.V2_1.ISoundTriggerHwCallback
+                                .PhraseRecognitionEvent();
+                event.common.header.model = modelHandle;
+                event.common.header.type = SoundModelType.KEYPHRASE;
+                event.common.header.status = status;
+                event.common.header.captureSession = model.config.base.header.captureHandle;
+                event.common.header.captureAvailable = true;
+                event.common.header.audioConfig.channelMask = 16;
+                event.common.header.audioConfig.format = 1;
+                event.common.header.audioConfig.sampleRateHz = 16000;
+                event.common.data = HidlMemoryUtil.byteArrayToHidlMemory(new byte[0]);
+                if (!model.phraseModel.phrases.isEmpty()) {
+                    PhraseRecognitionExtra extra = new PhraseRecognitionExtra();
+                    extra.id = model.phraseModel.phrases.get(0).id;
+                    extra.confidenceLevel = 100;
+                    extra.recognitionModes = model.phraseModel.phrases.get(0).recognitionModes;
+                    event.phraseExtras.add(extra);
+                }
+                try {
+                    model.callback.phraseRecognitionCallback_2_1(event, 0);
+                } catch (RemoteException e) {
+                    e.printStackTrace();
+                }
+                model.config = null;
+            }
+        }
+
+        public void sendModelUnloaded(int modelHandle) {
+            Model model = mLoadedModels.remove(modelHandle);
+            if (model != null) {
+                try {
+                    model.callback.modelUnloaded(modelHandle);
+                } catch (RemoteException e) {
+                    e.printStackTrace();
+                }
+            }
+        }
+
+        @Override
+        public void registerGlobalCallback(ISoundTriggerHwGlobalCallback callback) {
+            System.out.println("registerGlobalCallback()");
+            mGlobalCallback = callback;
+        }
+
+        @Override
+        public void loadSoundModel_2_4(SoundModel soundModel, ISoundTriggerHwCallback callback,
+                loadSoundModel_2_4Callback _hidl_cb) {
+            int handle = mHandleCounter++;
+            System.out.println(
+                    String.format("loadSoundModel_2_4(soundModel=%s) -> %d", soundModel, handle));
+            mLoadedModels.put(handle, new Model(callback, soundModel));
+            _hidl_cb.onValues(0, handle);
+        }
+
+        @Override
+        public void loadPhraseSoundModel_2_4(PhraseSoundModel soundModel,
+                ISoundTriggerHwCallback callback, loadPhraseSoundModel_2_4Callback _hidl_cb) {
+            int handle = mHandleCounter++;
+            System.out.println(String.format(
+                    "loadPhraseSoundModel_2_4(soundModel=%s) -> %d", soundModel, handle));
+            mLoadedModels.put(handle, new Model(callback, soundModel));
+            _hidl_cb.onValues(0, handle);
+        }
+
+        @Override
+        public int startRecognition_2_4(
+                int modelHandle, android.hardware.soundtrigger.V2_3.RecognitionConfig config) {
+            System.out.println(String.format("startRecognition_2_4(modelHandle=%d)", modelHandle));
+            Model model = mLoadedModels.get(modelHandle);
+            if (model != null) {
+                model.config = config;
+            }
+            return 0;
+        }
+
+        @Override
+        public void getProperties_2_3(getProperties_2_3Callback _hidl_cb) {
+            System.out.println("getProperties_2_3()");
+            android.hardware.soundtrigger.V2_3.Properties properties =
+                    new android.hardware.soundtrigger.V2_3.Properties();
+            properties.base.implementor = "Android";
+            properties.base.description = "Mock STHAL";
+            properties.base.maxSoundModels = 2;
+            properties.base.maxKeyPhrases = 1;
+            properties.base.recognitionModes =
+                    RecognitionMode.VOICE_TRIGGER | RecognitionMode.GENERIC_TRIGGER;
+            _hidl_cb.onValues(0, properties);
+        }
+
+        @Override
+        public void queryParameter(
+                int modelHandle, int modelParam, queryParameterCallback _hidl_cb) {
+            _hidl_cb.onValues(0, new OptionalModelParameterRange());
+        }
+
+        @Override
+        public int getModelState(int modelHandle) {
+            System.out.println(String.format("getModelState(modelHandle=%d)", modelHandle));
+            return 0;
+        }
+
+        @Override
+        public int unloadSoundModel(int modelHandle) {
+            System.out.println(String.format("unloadSoundModel(modelHandle=%d)", modelHandle));
+            return 0;
+        }
+
+        @Override
+        public int stopRecognition(int modelHandle) {
+            System.out.println(String.format("stopRecognition(modelHandle=%d)", modelHandle));
+            Model model = mLoadedModels.get(modelHandle);
+            if (model != null) {
+                model.config = null;
+            }
+            return 0;
+        }
+
+        @Override
+        public void debug(android.os.NativeHandle fd, java.util.ArrayList<String> options) {
+            if (!options.isEmpty()) {
+                switch (options.get(0)) {
+                    case "reboot":
+                        System.out.println("Received a reboot request. Exiting.");
+                        cleanup();
+                        System.exit(1);
+                }
+            }
+        }
+
+        ////////////////////////////////////////////////////////////////////////////////////////////
+        // Everything below is not implemented and not expected to be called.
+
+        @Override
+        public int startRecognition_2_3(
+                int modelHandle, android.hardware.soundtrigger.V2_3.RecognitionConfig config) {
+            throw new UnsupportedOperationException();
+        }
+
+        @Override
+        public int setParameter(int modelHandle, int modelParam, int value) {
+            throw new UnsupportedOperationException();
+        }
+
+        @Override
+        public void getParameter(int modelHandle, int modelParam, getParameterCallback _hidl_cb) {
+            throw new UnsupportedOperationException();
+        }
+
+        @Override
+        public void loadSoundModel_2_1(SoundModel soundModel,
+                android.hardware.soundtrigger.V2_1.ISoundTriggerHwCallback callback, int cookie,
+                loadSoundModel_2_1Callback _hidl_cb) {
+            throw new UnsupportedOperationException();
+        }
+
+        @Override
+        public void loadPhraseSoundModel_2_1(PhraseSoundModel soundModel,
+                android.hardware.soundtrigger.V2_1.ISoundTriggerHwCallback callback, int cookie,
+                loadPhraseSoundModel_2_1Callback _hidl_cb) {
+            throw new UnsupportedOperationException();
+        }
+
+        @Override
+        public int startRecognition_2_1(int modelHandle, RecognitionConfig config,
+                android.hardware.soundtrigger.V2_1.ISoundTriggerHwCallback callback, int cookie) {
+            throw new UnsupportedOperationException();
+        }
+
+        @Override
+        public void getProperties(getPropertiesCallback _hidl_cb) {
+            throw new UnsupportedOperationException();
+        }
+
+        @Override
+        public void loadSoundModel(
+                android.hardware.soundtrigger.V2_0.ISoundTriggerHw.SoundModel soundModel,
+                android.hardware.soundtrigger.V2_0.ISoundTriggerHwCallback callback, int cookie,
+                loadSoundModelCallback _hidl_cb) {
+            throw new UnsupportedOperationException();
+        }
+
+        @Override
+        public void loadPhraseSoundModel(
+                android.hardware.soundtrigger.V2_0.ISoundTriggerHw.PhraseSoundModel soundModel,
+                android.hardware.soundtrigger.V2_0.ISoundTriggerHwCallback callback, int cookie,
+                loadPhraseSoundModelCallback _hidl_cb) {
+            throw new UnsupportedOperationException();
+        }
+
+        @Override
+        public int startRecognition(int modelHandle,
+                android.hardware.soundtrigger.V2_0.ISoundTriggerHw.RecognitionConfig config,
+                android.hardware.soundtrigger.V2_0.ISoundTriggerHwCallback callback, int cookie) {
+            throw new UnsupportedOperationException();
+        }
+
+        @Override
+        public int stopAllRecognitions() {
+            throw new UnsupportedOperationException();
+        }
+    }
+}
\ No newline at end of file
diff --git a/soundtrigger/sthal_cli/sthal_cli b/soundtrigger/sthal_cli/sthal_cli
new file mode 100644
index 0000000..9fc6779
--- /dev/null
+++ b/soundtrigger/sthal_cli/sthal_cli
@@ -0,0 +1,7 @@
+#!/system/bin/sh
+# Script to start "sthal_cli" on the device
+#
+base=/system
+export CLASSPATH=$base/framework/sthal_cli.jar
+exec app_process $base/bin android.hardware.soundtrigger.cli.SthalCli "$@"
+
diff --git a/wifi/hostapd/1.3/IHostapdCallback.hal b/wifi/hostapd/1.3/IHostapdCallback.hal
index a098d87..3208366 100644
--- a/wifi/hostapd/1.3/IHostapdCallback.hal
+++ b/wifi/hostapd/1.3/IHostapdCallback.hal
@@ -35,12 +35,12 @@
      * The apIfaceInstance can be used to identify which instance the callback
      * is from.
      * Note: The apIfaceInstance must be same as ifaceName in single AP mode.
-     * @param freq The operational frequency of the AP.
+     * @param freqMhz The operational frequency of the AP in Mhz.
      * @param bandwidth The operational bandwidth of the AP.
      * @param generation The operational mode of the AP (e.g. 11ac, 11ax).
      * @param apIfaceInstanceMacAddress MAC Address of the apIfaceInstance.
      */
-    oneway onApInstanceInfoChanged(string ifaceName, string apIfaceInstance, uint32_t freq,
+    oneway onApInstanceInfoChanged(string ifaceName, string apIfaceInstance, uint32_t freqMhz,
         Bandwidth bandwidth, Generation generation, MacAddress apIfaceInstanceMacAddress);
 
     /**