Merge "wifi: Add WFD R2 HAL API" into sc-dev am: d7fcfd7795

Original change: https://googleplex-android-review.googlesource.com/c/platform/hardware/interfaces/+/13774520

MUST ONLY BE SUBMITTED BY AUTOMERGER

Change-Id: Ic829bf9eea4d8a68c3bfa91f4a99f9957c59393d
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/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/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/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/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..b4587ac
--- /dev/null
+++ b/neuralnetworks/aidl/utils/include/nnapi/hal/aidl/Service.h
@@ -0,0 +1,33 @@
+/*
+ * 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 <nnapi/hal/CommonUtils.h>
+
+#include <string>
+
+namespace aidl::android::hardware::neuralnetworks::utils {
+
+nn::GeneralResult<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 db3504b..5d9c55b 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();
@@ -382,14 +378,14 @@
 
 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,
         });
     }
@@ -434,11 +430,28 @@
 
     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());
 }
@@ -515,6 +528,23 @@
     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);
@@ -548,6 +578,18 @@
     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);
 }
@@ -556,6 +598,11 @@
     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";
@@ -575,14 +622,21 @@
 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()) {
@@ -609,29 +663,29 @@
     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],
@@ -642,6 +696,30 @@
 
 }  // 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);
@@ -707,6 +785,230 @@
                        .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);
 }
@@ -715,11 +1017,62 @@
     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..5ec6ded
--- /dev/null
+++ b/neuralnetworks/aidl/utils/src/Service.cpp
@@ -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.
+ */
+
+#include "Service.h"
+
+#include <android/binder_auto_utils.h>
+#include <android/binder_manager.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& name) {
+    hal::utils::ResilientDevice::Factory makeDevice =
+            [name](bool blocking) -> nn::GeneralResult<nn::SharedDevice> {
+        auto service = blocking ? IDevice::fromBinder(
+                                          ndk::SpAIBinder(AServiceManager_getService(name.c_str())))
+                                : IDevice::fromBinder(ndk::SpAIBinder(
+                                          AServiceManager_checkService(name.c_str())));
+        if (service == nullptr) {
+            return NN_ERROR() << (blocking ? "AServiceManager_getService"
+                                           : "AServiceManager_checkService")
+                              << " returned nullptr";
+        }
+        return Device::create(name, 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/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/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);