diff --git a/base/include/android-base/strings.h b/base/include/android-base/strings.h
index b1c22c9..14d534a 100644
--- a/base/include/android-base/strings.h
+++ b/base/include/android-base/strings.h
@@ -85,5 +85,10 @@
   return true;
 }
 
+// Replaces `from` with `to` in `s`, once if `all == false`, or as many times as
+// there are matches if `all == true`.
+[[nodiscard]] std::string StringReplace(std::string_view s, std::string_view from,
+                                        std::string_view to, bool all);
+
 }  // namespace base
 }  // namespace android
diff --git a/base/strings.cpp b/base/strings.cpp
index bb3167e..40b2bf2 100644
--- a/base/strings.cpp
+++ b/base/strings.cpp
@@ -116,5 +116,24 @@
   return lhs.size() == rhs.size() && strncasecmp(lhs.data(), rhs.data(), lhs.size()) == 0;
 }
 
+std::string StringReplace(std::string_view s, std::string_view from, std::string_view to,
+                          bool all) {
+  if (from.empty()) return std::string(s);
+
+  std::string result;
+  std::string_view::size_type start_pos = 0;
+  do {
+    std::string_view::size_type pos = s.find(from, start_pos);
+    if (pos == std::string_view::npos) break;
+
+    result.append(s.data() + start_pos, pos - start_pos);
+    result.append(to.data(), to.size());
+
+    start_pos = pos + from.size();
+  } while (all);
+  result.append(s.data() + start_pos, s.size() - start_pos);
+  return result;
+}
+
 }  // namespace base
 }  // namespace android
diff --git a/base/strings_test.cpp b/base/strings_test.cpp
index ca3c0b8..5ae3094 100644
--- a/base/strings_test.cpp
+++ b/base/strings_test.cpp
@@ -311,3 +311,46 @@
   ASSERT_TRUE(android::base::ConsumeSuffix(&s, ".bar"));
   ASSERT_EQ("foo", s);
 }
+
+TEST(strings, StringReplace_false) {
+  // No change.
+  ASSERT_EQ("abcabc", android::base::StringReplace("abcabc", "z", "Z", false));
+  ASSERT_EQ("", android::base::StringReplace("", "z", "Z", false));
+  ASSERT_EQ("abcabc", android::base::StringReplace("abcabc", "", "Z", false));
+
+  // Equal lengths.
+  ASSERT_EQ("Abcabc", android::base::StringReplace("abcabc", "a", "A", false));
+  ASSERT_EQ("aBcabc", android::base::StringReplace("abcabc", "b", "B", false));
+  ASSERT_EQ("abCabc", android::base::StringReplace("abcabc", "c", "C", false));
+
+  // Longer replacement.
+  ASSERT_EQ("foobcabc", android::base::StringReplace("abcabc", "a", "foo", false));
+  ASSERT_EQ("afoocabc", android::base::StringReplace("abcabc", "b", "foo", false));
+  ASSERT_EQ("abfooabc", android::base::StringReplace("abcabc", "c", "foo", false));
+
+  // Shorter replacement.
+  ASSERT_EQ("xxyz", android::base::StringReplace("abcxyz", "abc", "x", false));
+  ASSERT_EQ("axyz", android::base::StringReplace("abcxyz", "bcx", "x", false));
+  ASSERT_EQ("abcx", android::base::StringReplace("abcxyz", "xyz", "x", false));
+}
+
+TEST(strings, StringReplace_true) {
+  // No change.
+  ASSERT_EQ("abcabc", android::base::StringReplace("abcabc", "z", "Z", true));
+  ASSERT_EQ("", android::base::StringReplace("", "z", "Z", true));
+  ASSERT_EQ("abcabc", android::base::StringReplace("abcabc", "", "Z", true));
+
+  // Equal lengths.
+  ASSERT_EQ("AbcAbc", android::base::StringReplace("abcabc", "a", "A", true));
+  ASSERT_EQ("aBcaBc", android::base::StringReplace("abcabc", "b", "B", true));
+  ASSERT_EQ("abCabC", android::base::StringReplace("abcabc", "c", "C", true));
+
+  // Longer replacement.
+  ASSERT_EQ("foobcfoobc", android::base::StringReplace("abcabc", "a", "foo", true));
+  ASSERT_EQ("afoocafooc", android::base::StringReplace("abcabc", "b", "foo", true));
+  ASSERT_EQ("abfooabfoo", android::base::StringReplace("abcabc", "c", "foo", true));
+
+  // Shorter replacement.
+  ASSERT_EQ("xxyzx", android::base::StringReplace("abcxyzabc", "abc", "x", true));
+  ASSERT_EQ("<xx>", android::base::StringReplace("<abcabc>", "abc", "x", true));
+}
diff --git a/debuggerd/libdebuggerd/include/libdebuggerd/utility.h b/debuggerd/libdebuggerd/include/libdebuggerd/utility.h
index f189c45..75bac87 100644
--- a/debuggerd/libdebuggerd/include/libdebuggerd/utility.h
+++ b/debuggerd/libdebuggerd/include/libdebuggerd/utility.h
@@ -20,6 +20,7 @@
 
 #include <inttypes.h>
 #include <signal.h>
+#include <stdarg.h>
 #include <stdbool.h>
 #include <sys/types.h>
 
@@ -71,6 +72,7 @@
 
 // Log information onto the tombstone.
 void _LOG(log_t* log, logtype ltype, const char* fmt, ...) __attribute__((format(printf, 3, 4)));
+void _VLOG(log_t* log, logtype ltype, const char* fmt, va_list ap);
 
 namespace unwindstack {
 class Unwinder;
diff --git a/debuggerd/libdebuggerd/tombstone.cpp b/debuggerd/libdebuggerd/tombstone.cpp
index 1993840..236fcf7 100644
--- a/debuggerd/libdebuggerd/tombstone.cpp
+++ b/debuggerd/libdebuggerd/tombstone.cpp
@@ -428,7 +428,7 @@
   std::vector<std::pair<std::string, uint64_t>> special_row;
 
 #if defined(__arm__) || defined(__aarch64__)
-  static constexpr const char* special_registers[] = {"ip", "lr", "sp", "pc"};
+  static constexpr const char* special_registers[] = {"ip", "lr", "sp", "pc", "pst"};
 #elif defined(__i386__)
   static constexpr const char* special_registers[] = {"ebp", "esp", "eip"};
 #elif defined(__x86_64__)
diff --git a/debuggerd/libdebuggerd/utility.cpp b/debuggerd/libdebuggerd/utility.cpp
index 9b2779a..5ce26fc 100644
--- a/debuggerd/libdebuggerd/utility.cpp
+++ b/debuggerd/libdebuggerd/utility.cpp
@@ -67,6 +67,14 @@
 
 __attribute__((__weak__, visibility("default")))
 void _LOG(log_t* log, enum logtype ltype, const char* fmt, ...) {
+  va_list ap;
+  va_start(ap, fmt);
+  _VLOG(log, ltype, fmt, ap);
+  va_end(ap);
+}
+
+__attribute__((__weak__, visibility("default")))
+void _VLOG(log_t* log, enum logtype ltype, const char* fmt, va_list ap) {
   bool write_to_tombstone = (log->tfd != -1);
   bool write_to_logcat = is_allowed_in_logcat(ltype)
                       && log->crashed_tid != -1
@@ -75,10 +83,7 @@
   static bool write_to_kmsg = should_write_to_kmsg();
 
   std::string msg;
-  va_list ap;
-  va_start(ap, fmt);
   android::base::StringAppendV(&msg, fmt, ap);
-  va_end(ap);
 
   if (msg.empty()) return;
 
diff --git a/fastboot/Android.bp b/fastboot/Android.bp
index 02a887e..a757d56 100644
--- a/fastboot/Android.bp
+++ b/fastboot/Android.bp
@@ -137,12 +137,14 @@
         "libhidlbase",
         "liblog",
         "liblp",
+        "libprotobuf-cpp-lite",
         "libsparse",
         "libutils",
     ],
 
     static_libs: [
         "libhealthhalutils",
+        "libsnapshot_nobinder",
     ],
 
     header_libs: [
diff --git a/fastboot/device/commands.cpp b/fastboot/device/commands.cpp
index a2c95d6..1a745ab 100644
--- a/fastboot/device/commands.cpp
+++ b/fastboot/device/commands.cpp
@@ -19,6 +19,8 @@
 #include <sys/socket.h>
 #include <sys/un.h>
 
+#include <unordered_set>
+
 #include <android-base/logging.h>
 #include <android-base/parseint.h>
 #include <android-base/properties.h>
@@ -33,6 +35,7 @@
 #include <libgsi/libgsi.h>
 #include <liblp/builder.h>
 #include <liblp/liblp.h>
+#include <libsnapshot/snapshot.h>
 #include <uuid/uuid.h>
 
 #include "constants.h"
@@ -48,6 +51,7 @@
 using ::android::hardware::boot::V1_1::MergeStatus;
 using ::android::hardware::fastboot::V1_0::Result;
 using ::android::hardware::fastboot::V1_0::Status;
+using android::snapshot::SnapshotManager;
 using IBootControl1_1 = ::android::hardware::boot::V1_1::IBootControl;
 
 struct VariableHandlers {
@@ -57,6 +61,24 @@
     std::function<std::vector<std::vector<std::string>>(FastbootDevice*)> get_all_args;
 };
 
+static bool IsSnapshotUpdateInProgress(FastbootDevice* device) {
+    auto hal = device->boot1_1();
+    if (!hal) {
+        return false;
+    }
+    auto merge_status = hal->getSnapshotMergeStatus();
+    return merge_status == MergeStatus::SNAPSHOTTED || merge_status == MergeStatus::MERGING;
+}
+
+static bool IsProtectedPartitionDuringMerge(FastbootDevice* device, const std::string& name) {
+    static const std::unordered_set<std::string> ProtectedPartitionsDuringMerge = {
+            "userdata", "metadata", "misc"};
+    if (ProtectedPartitionsDuringMerge.count(name) == 0) {
+        return false;
+    }
+    return IsSnapshotUpdateInProgress(device);
+}
+
 static void GetAllVars(FastbootDevice* device, const std::string& name,
                        const VariableHandlers& handlers) {
     if (!handlers.get_all_args) {
@@ -143,8 +165,14 @@
         return device->WriteStatus(FastbootResult::FAIL, "Erase is not allowed on locked devices");
     }
 
+    const auto& partition_name = args[1];
+    if (IsProtectedPartitionDuringMerge(device, partition_name)) {
+        auto message = "Cannot erase " + partition_name + " while a snapshot update is in progress";
+        return device->WriteFail(message);
+    }
+
     PartitionHandle handle;
-    if (!OpenPartition(device, args[1], &handle)) {
+    if (!OpenPartition(device, partition_name, &handle)) {
         return device->WriteStatus(FastbootResult::FAIL, "Partition doesn't exist");
     }
     if (wipe_block_device(handle.fd(), get_block_device_size(handle.fd())) == 0) {
@@ -209,9 +237,9 @@
                                    "set_active command is not allowed on locked devices");
     }
 
-    // Slot suffix needs to be between 'a' and 'z'.
     Slot slot;
     if (!GetSlotNumber(args[1], &slot)) {
+        // Slot suffix needs to be between 'a' and 'z'.
         return device->WriteStatus(FastbootResult::FAIL, "Bad slot suffix");
     }
 
@@ -224,6 +252,32 @@
     if (slot >= boot_control_hal->getNumberSlots()) {
         return device->WriteStatus(FastbootResult::FAIL, "Slot out of range");
     }
+
+    // If the slot is not changing, do nothing.
+    if (slot == boot_control_hal->getCurrentSlot()) {
+        return device->WriteOkay("");
+    }
+
+    // Check how to handle the current snapshot state.
+    if (auto hal11 = device->boot1_1()) {
+        auto merge_status = hal11->getSnapshotMergeStatus();
+        if (merge_status == MergeStatus::MERGING) {
+            return device->WriteFail("Cannot change slots while a snapshot update is in progress");
+        }
+        // Note: we allow the slot change if the state is SNAPSHOTTED. First-
+        // stage init does not have access to the HAL, and uses the slot number
+        // and /metadata OTA state to determine whether a slot change occurred.
+        // Booting into the old slot would erase the OTA, and switching A->B->A
+        // would simply resume it if no boots occur in between. Re-flashing
+        // partitions implicitly cancels the OTA, so leaving the state as-is is
+        // safe.
+        if (merge_status == MergeStatus::SNAPSHOTTED) {
+            device->WriteInfo(
+                    "Changing the active slot with a snapshot applied may cancel the"
+                    " update.");
+        }
+    }
+
     CommandResult ret;
     auto cb = [&ret](CommandResult result) { ret = result; };
     auto result = boot_control_hal->setActiveBootSlot(slot, cb);
@@ -467,6 +521,11 @@
     }
 
     const auto& partition_name = args[1];
+    if (IsProtectedPartitionDuringMerge(device, partition_name)) {
+        auto message = "Cannot flash " + partition_name + " while a snapshot update is in progress";
+        return device->WriteFail(message);
+    }
+
     if (LogicalPartitionExists(device, partition_name)) {
         CancelPartitionSnapshot(device, partition_name);
     }
@@ -556,12 +615,9 @@
 bool SnapshotUpdateHandler(FastbootDevice* device, const std::vector<std::string>& args) {
     // Note that we use the HAL rather than mounting /metadata, since we want
     // our results to match the bootloader.
-    auto hal = device->boot_control_hal();
+    auto hal = device->boot1_1();
     if (!hal) return device->WriteFail("Not supported");
 
-    android::sp<IBootControl1_1> hal11 = IBootControl1_1::castFrom(hal);
-    if (!hal11) return device->WriteFail("Not supported");
-
     // If no arguments, return the same thing as a getvar. Note that we get the
     // HAL first so we can return "not supported" before we return the less
     // specific error message below.
@@ -574,18 +630,34 @@
         return device->WriteOkay("");
     }
 
-    if (args.size() != 2 || args[1] != "cancel") {
+    MergeStatus status = hal->getSnapshotMergeStatus();
+
+    if (args.size() != 2) {
         return device->WriteFail("Invalid arguments");
     }
+    if (args[1] == "cancel") {
+        switch (status) {
+            case MergeStatus::SNAPSHOTTED:
+            case MergeStatus::MERGING:
+                hal->setSnapshotMergeStatus(MergeStatus::CANCELLED);
+                break;
+            default:
+                break;
+        }
+    } else if (args[1] == "merge") {
+        if (status != MergeStatus::MERGING) {
+            return device->WriteFail("No snapshot merge is in progress");
+        }
 
-    MergeStatus status = hal11->getSnapshotMergeStatus();
-    switch (status) {
-        case MergeStatus::SNAPSHOTTED:
-        case MergeStatus::MERGING:
-            hal11->setSnapshotMergeStatus(MergeStatus::CANCELLED);
-            break;
-        default:
-            break;
+        auto sm = SnapshotManager::NewForFirstStageMount();
+        if (!sm) {
+            return device->WriteFail("Unable to create SnapshotManager");
+        }
+        if (!sm->HandleImminentDataWipe()) {
+            return device->WriteFail("Unable to finish snapshot merge");
+        }
+    } else {
+        return device->WriteFail("Invalid parameter to snapshot-update");
     }
     return device->WriteStatus(FastbootResult::OKAY, "Success");
 }
diff --git a/fastboot/device/fastboot_device.cpp b/fastboot/device/fastboot_device.cpp
index d3c2bda..31fc359 100644
--- a/fastboot/device/fastboot_device.cpp
+++ b/fastboot/device/fastboot_device.cpp
@@ -60,7 +60,11 @@
       boot_control_hal_(IBootControl::getService()),
       health_hal_(get_health_service()),
       fastboot_hal_(IFastboot::getService()),
-      active_slot_("") {}
+      active_slot_("") {
+    if (boot_control_hal_) {
+        boot1_1_ = android::hardware::boot::V1_1::IBootControl::castFrom(boot_control_hal_);
+    }
+}
 
 FastbootDevice::~FastbootDevice() {
     CloseDevice();
diff --git a/fastboot/device/fastboot_device.h b/fastboot/device/fastboot_device.h
index 091aadf..bbe8172 100644
--- a/fastboot/device/fastboot_device.h
+++ b/fastboot/device/fastboot_device.h
@@ -23,6 +23,7 @@
 #include <vector>
 
 #include <android/hardware/boot/1.0/IBootControl.h>
+#include <android/hardware/boot/1.1/IBootControl.h>
 #include <android/hardware/fastboot/1.0/IFastboot.h>
 #include <android/hardware/health/2.0/IHealth.h>
 
@@ -51,6 +52,7 @@
     android::sp<android::hardware::boot::V1_0::IBootControl> boot_control_hal() {
         return boot_control_hal_;
     }
+    android::sp<android::hardware::boot::V1_1::IBootControl> boot1_1() { return boot1_1_; }
     android::sp<android::hardware::fastboot::V1_0::IFastboot> fastboot_hal() {
         return fastboot_hal_;
     }
@@ -63,6 +65,7 @@
 
     std::unique_ptr<Transport> transport_;
     android::sp<android::hardware::boot::V1_0::IBootControl> boot_control_hal_;
+    android::sp<android::hardware::boot::V1_1::IBootControl> boot1_1_;
     android::sp<android::hardware::health::V2_0::IHealth> health_hal_;
     android::sp<android::hardware::fastboot::V1_0::IFastboot> fastboot_hal_;
     std::vector<char> download_data_;
diff --git a/fastboot/device/variables.cpp b/fastboot/device/variables.cpp
index 717db06..10eac01 100644
--- a/fastboot/device/variables.cpp
+++ b/fastboot/device/variables.cpp
@@ -432,19 +432,13 @@
                              std::string* message) {
     // Note that we use the HAL rather than mounting /metadata, since we want
     // our results to match the bootloader.
-    auto hal = device->boot_control_hal();
+    auto hal = device->boot1_1();
     if (!hal) {
         *message = "not supported";
         return false;
     }
 
-    android::sp<IBootControl1_1> hal11 = IBootControl1_1::castFrom(hal);
-    if (!hal11) {
-        *message = "not supported";
-        return false;
-    }
-
-    MergeStatus status = hal11->getSnapshotMergeStatus();
+    MergeStatus status = hal->getSnapshotMergeStatus();
     switch (status) {
         case MergeStatus::SNAPSHOTTED:
             *message = "snapshotted";
diff --git a/fastboot/fastboot.cpp b/fastboot/fastboot.cpp
index 7ce7c7c..cbd42b1 100644
--- a/fastboot/fastboot.cpp
+++ b/fastboot/fastboot.cpp
@@ -399,6 +399,9 @@
             " snapshot-update cancel     On devices that support snapshot-based updates, cancel\n"
             "                            an in-progress update. This may make the device\n"
             "                            unbootable until it is reflashed.\n"
+            " snapshot-update merge      On devices that support snapshot-based updates, finish\n"
+            "                            an in-progress update if it is in the \"merging\"\n"
+            "                            phase.\n"
             "\n"
             "boot image:\n"
             " boot KERNEL [RAMDISK [SECOND]]\n"
@@ -2089,8 +2092,8 @@
             if (!args.empty()) {
                 arg = next_arg(&args);
             }
-            if (!arg.empty() && arg != "cancel") {
-                syntax_error("expected: snapshot-update [cancel]");
+            if (!arg.empty() && (arg != "cancel" && arg != "merge")) {
+                syntax_error("expected: snapshot-update [cancel|merge]");
             }
             fb->SnapshotUpdateCommand(arg);
         } else {
diff --git a/fastboot/fastboot_driver.cpp b/fastboot/fastboot_driver.cpp
index 6a5ad20..8d534ea 100644
--- a/fastboot/fastboot_driver.cpp
+++ b/fastboot/fastboot_driver.cpp
@@ -124,8 +124,11 @@
 
 RetCode FastBootDriver::SnapshotUpdateCommand(const std::string& command, std::string* response,
                                               std::vector<std::string>* info) {
+    prolog_(StringPrintf("Snapshot %s", command.c_str()));
     std::string raw = FB_CMD_SNAPSHOT_UPDATE ":" + command;
-    return RawCommand(raw, response, info);
+    auto result = RawCommand(raw, response, info);
+    epilog_(result);
+    return result;
 }
 
 RetCode FastBootDriver::FlashPartition(const std::string& partition,
diff --git a/fs_mgr/libsnapshot/include/libsnapshot/snapshot.h b/fs_mgr/libsnapshot/include/libsnapshot/snapshot.h
index 8f24709..7411e5a 100644
--- a/fs_mgr/libsnapshot/include/libsnapshot/snapshot.h
+++ b/fs_mgr/libsnapshot/include/libsnapshot/snapshot.h
@@ -224,7 +224,8 @@
     bool CreateLogicalAndSnapshotPartitions(const std::string& super_device);
 
     // This method should be called preceding any wipe or flash of metadata or
-    // userdata. It is only valid in recovery.
+    // userdata. It is only valid in recovery or fastbootd, and it ensures that
+    // a merge has been completed.
     //
     // When userdata will be wiped or flashed, it is necessary to clean up any
     // snapshot state. If a merge is in progress, the merge must be finished.
diff --git a/fs_mgr/libsnapshot/snapshot.cpp b/fs_mgr/libsnapshot/snapshot.cpp
index 1de7008..008ece7 100644
--- a/fs_mgr/libsnapshot/snapshot.cpp
+++ b/fs_mgr/libsnapshot/snapshot.cpp
@@ -2185,6 +2185,15 @@
         return true;
     }
 
+    // Check this early, so we don't accidentally start trying to populate
+    // the state file in recovery. Note we don't call GetUpdateState since
+    // we want errors in acquiring the lock to be propagated, instead of
+    // returning UpdateState::None.
+    auto state_file = GetStateFilePath();
+    if (access(state_file.c_str(), F_OK) != 0 && errno == ENOENT) {
+        return true;
+    }
+
     auto slot_number = SlotNumberForSlotSuffix(device_->GetSlotSuffix());
     auto super_path = device_->GetSuperDevice(slot_number);
     if (!CreateLogicalAndSnapshotPartitions(super_path)) {
diff --git a/init/Android.bp b/init/Android.bp
index c7021c3..9529617 100644
--- a/init/Android.bp
+++ b/init/Android.bp
@@ -152,6 +152,7 @@
     whole_static_libs: [
         "libcap",
         "com.android.sysprop.apex",
+        "com.android.sysprop.init",
     ],
     header_libs: ["bootimg_headers"],
     proto: {
diff --git a/init/builtins.cpp b/init/builtins.cpp
index 8f58145..485806b 100644
--- a/init/builtins.cpp
+++ b/init/builtins.cpp
@@ -45,6 +45,7 @@
 #include <memory>
 
 #include <ApexProperties.sysprop.h>
+#include <InitProperties.sysprop.h>
 #include <android-base/chrono_utils.h>
 #include <android-base/file.h>
 #include <android-base/logging.h>
@@ -1222,7 +1223,9 @@
     boot_clock::time_point now = boot_clock::now();
     property_set("sys.init.userspace_reboot.last_finished",
                  std::to_string(now.time_since_epoch().count()));
-    property_set(kUserspaceRebootInProgress, "0");
+    if (!android::sysprop::InitProperties::userspace_reboot_in_progress(false)) {
+        return Error() << "Failed to set sys.init.userspace_reboot.in_progress property";
+    }
     return {};
 }
 
diff --git a/init/reboot.cpp b/init/reboot.cpp
index 7167672..13cebcc 100644
--- a/init/reboot.cpp
+++ b/init/reboot.cpp
@@ -38,6 +38,7 @@
 #include <thread>
 #include <vector>
 
+#include <InitProperties.sysprop.h>
 #include <android-base/chrono_utils.h>
 #include <android-base/file.h>
 #include <android-base/logging.h>
@@ -743,8 +744,8 @@
     // actions. We should make sure, that all of them are propagated before
     // proceeding with userspace reboot. Synchronously setting kUserspaceRebootInProgress property
     // is not perfect, but it should do the trick.
-    if (property_set(kUserspaceRebootInProgress, "1") != 0) {
-        return Error() << "Failed to set property " << kUserspaceRebootInProgress;
+    if (!android::sysprop::InitProperties::userspace_reboot_in_progress(true)) {
+        return Error() << "Failed to set sys.init.userspace_reboot.in_progress property";
     }
     EnterShutdown();
     std::vector<Service*> stop_first;
diff --git a/init/reboot.h b/init/reboot.h
index cdfa024..81c3edc 100644
--- a/init/reboot.h
+++ b/init/reboot.h
@@ -22,8 +22,6 @@
 namespace android {
 namespace init {
 
-static const constexpr char* kUserspaceRebootInProgress = "sys.init.userspace_reboot.in_progress";
-
 // Parses and handles a setprop sys.powerctl message.
 void HandlePowerctlMessage(const std::string& command);
 
diff --git a/init/sysprop/Android.bp b/init/sysprop/Android.bp
new file mode 100644
index 0000000..7582875
--- /dev/null
+++ b/init/sysprop/Android.bp
@@ -0,0 +1,7 @@
+sysprop_library {
+  name: "com.android.sysprop.init",
+  srcs: ["InitProperties.sysprop"],
+  property_owner: "Platform",
+  api_packages: ["android.sysprop"],
+  recovery_available: true,
+}
diff --git a/init/sysprop/InitProperties.sysprop b/init/sysprop/InitProperties.sysprop
new file mode 100644
index 0000000..d6a1ab6
--- /dev/null
+++ b/init/sysprop/InitProperties.sysprop
@@ -0,0 +1,27 @@
+# Copyright (C) 2019 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.
+
+owner: Platform
+module: "android.sysprop.InitProperties"
+
+# Serves as a signal to all processes that userspace reboot is happening.
+prop {
+    api_name: "userspace_reboot_in_progress"
+    type: Boolean
+    scope: Public
+    access: ReadWrite
+    prop_name: "sys.init.userspace_reboot.in_progress"
+    integer_as_bool: true
+}
+
diff --git a/init/sysprop/api/com.android.sysprop.init-current.txt b/init/sysprop/api/com.android.sysprop.init-current.txt
new file mode 100644
index 0000000..8da50e0
--- /dev/null
+++ b/init/sysprop/api/com.android.sysprop.init-current.txt
@@ -0,0 +1,9 @@
+props {
+  module: "android.sysprop.InitProperties"
+  prop {
+    api_name: "userspace_reboot_in_progress"
+    access: ReadWrite
+    prop_name: "sys.init.userspace_reboot.in_progress"
+    integer_as_bool: true
+  }
+}
diff --git a/init/sysprop/api/com.android.sysprop.init-latest.txt b/init/sysprop/api/com.android.sysprop.init-latest.txt
new file mode 100644
index 0000000..c835b95
--- /dev/null
+++ b/init/sysprop/api/com.android.sysprop.init-latest.txt
@@ -0,0 +1,9 @@
+props {
+  module: "android.sysprop.InitProperties"
+  prop {
+    api_name: "userspace_reboot_in_progress"
+    scope: Public
+    prop_name: "sys.init.userspace_reboot.in_progress"
+    integer_as_bool: true
+  }
+}
diff --git a/liblog/logger.h b/liblog/logger.h
index d2251e5..f0a4a92 100644
--- a/liblog/logger.h
+++ b/liblog/logger.h
@@ -85,9 +85,9 @@
 // bits 0-2: the decimal value of the log buffer.
 // Other bits are unused.
 
-#define LOGGER_LOGD (1 << 31)
-#define LOGGER_PMSG (1 << 30)
-#define LOGGER_LOG_ID_MASK ((1 << 3) - 1)
+#define LOGGER_LOGD (1U << 31)
+#define LOGGER_PMSG (1U << 30)
+#define LOGGER_LOG_ID_MASK ((1U << 3) - 1)
 
 inline bool android_logger_is_logd(struct logger* logger) {
   return reinterpret_cast<uintptr_t>(logger) & LOGGER_LOGD;
diff --git a/libunwindstack/RegsArm64.cpp b/libunwindstack/RegsArm64.cpp
index e9787aa..2e8af20 100644
--- a/libunwindstack/RegsArm64.cpp
+++ b/libunwindstack/RegsArm64.cpp
@@ -103,6 +103,7 @@
   fn("sp", regs_[ARM64_REG_SP]);
   fn("lr", regs_[ARM64_REG_LR]);
   fn("pc", regs_[ARM64_REG_PC]);
+  fn("pst", regs_[ARM64_REG_PSTATE]);
 }
 
 Regs* RegsArm64::Read(void* remote_data) {
@@ -113,6 +114,7 @@
   uint64_t* reg_data = reinterpret_cast<uint64_t*>(regs->RawData());
   reg_data[ARM64_REG_PC] = user->pc;
   reg_data[ARM64_REG_SP] = user->sp;
+  reg_data[ARM64_REG_PSTATE] = user->pstate;
   return regs;
 }
 
diff --git a/libunwindstack/include/unwindstack/MachineArm64.h b/libunwindstack/include/unwindstack/MachineArm64.h
index e8b778b..e953335 100644
--- a/libunwindstack/include/unwindstack/MachineArm64.h
+++ b/libunwindstack/include/unwindstack/MachineArm64.h
@@ -55,6 +55,7 @@
   ARM64_REG_R30,
   ARM64_REG_R31,
   ARM64_REG_PC,
+  ARM64_REG_PSTATE,
   ARM64_REG_LAST,
 
   ARM64_REG_SP = ARM64_REG_R31,
diff --git a/libunwindstack/tests/RegsIterateTest.cpp b/libunwindstack/tests/RegsIterateTest.cpp
index 7e36953..bc95851 100644
--- a/libunwindstack/tests/RegsIterateTest.cpp
+++ b/libunwindstack/tests/RegsIterateTest.cpp
@@ -114,6 +114,7 @@
   result.push_back({"sp", ARM64_REG_SP});
   result.push_back({"lr", ARM64_REG_LR});
   result.push_back({"pc", ARM64_REG_PC});
+  result.push_back({"pst", ARM64_REG_PSTATE});
   return result;
 }
 
diff --git a/libutils/Android.bp b/libutils/Android.bp
index 98921be..efa4c41 100644
--- a/libutils/Android.bp
+++ b/libutils/Android.bp
@@ -125,6 +125,7 @@
     native_bridge_supported: true,
 
     srcs: [
+        "Errors.cpp",
         "FileMap.cpp",
         "JenkinsHash.cpp",
         "NativeHandle.cpp",
diff --git a/libutils/Errors.cpp b/libutils/Errors.cpp
new file mode 100644
index 0000000..2dfd138
--- /dev/null
+++ b/libutils/Errors.cpp
@@ -0,0 +1,51 @@
+/*
+ * Copyright (C) 2019 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 <utils/Errors.h>
+
+namespace android {
+
+std::string statusToString(status_t s) {
+#define STATUS_CASE(STATUS) \
+    case STATUS:            \
+        return #STATUS
+
+    switch (s) {
+        STATUS_CASE(OK);
+        STATUS_CASE(UNKNOWN_ERROR);
+        STATUS_CASE(NO_MEMORY);
+        STATUS_CASE(INVALID_OPERATION);
+        STATUS_CASE(BAD_VALUE);
+        STATUS_CASE(BAD_TYPE);
+        STATUS_CASE(NAME_NOT_FOUND);
+        STATUS_CASE(PERMISSION_DENIED);
+        STATUS_CASE(NO_INIT);
+        STATUS_CASE(ALREADY_EXISTS);
+        STATUS_CASE(DEAD_OBJECT);
+        STATUS_CASE(FAILED_TRANSACTION);
+        STATUS_CASE(BAD_INDEX);
+        STATUS_CASE(NOT_ENOUGH_DATA);
+        STATUS_CASE(WOULD_BLOCK);
+        STATUS_CASE(TIMED_OUT);
+        STATUS_CASE(UNKNOWN_TRANSACTION);
+        STATUS_CASE(FDS_NOT_ALLOWED);
+        STATUS_CASE(UNEXPECTED_NULL);
+#undef STATUS_CASE
+    }
+
+    return std::to_string(s) + ' ' + strerror(-s);
+}
+
+}  // namespace android
diff --git a/libutils/include/utils/Errors.h b/libutils/include/utils/Errors.h
index 1e03677..d14d223 100644
--- a/libutils/include/utils/Errors.h
+++ b/libutils/include/utils/Errors.h
@@ -19,6 +19,7 @@
 #include <errno.h>
 #include <stdint.h>
 #include <sys/types.h>
+#include <string>
 
 namespace android {
 
@@ -72,6 +73,9 @@
     UNEXPECTED_NULL     = (UNKNOWN_ERROR + 8),
 };
 
+// Human readable name of error
+std::string statusToString(status_t status);
+
 // Restore define; enumeration is in "android" namespace, so the value defined
 // there won't work for Win32 code in a different namespace.
 #ifdef _WIN32
diff --git a/property_service/libpropertyinfoserializer/property_info_serializer_test.cpp b/property_service/libpropertyinfoserializer/property_info_serializer_test.cpp
index 33da1f1..f4a846f 100644
--- a/property_service/libpropertyinfoserializer/property_info_serializer_test.cpp
+++ b/property_service/libpropertyinfoserializer/property_info_serializer_test.cpp
@@ -375,9 +375,11 @@
       {"audio_hal.period_size", "u:object_r:default_prop:s0"},
       {"bluetooth.enable_timeout_ms", "u:object_r:bluetooth_prop:s0"},
       {"dalvik.vm.appimageformat", "u:object_r:dalvik_prop:s0"},
+      {"dalvik.vm.boot-dex2oat-cpu-set", "u:object_r:dalvik_prop:s0"},
       {"dalvik.vm.boot-dex2oat-threads", "u:object_r:dalvik_prop:s0"},
       {"dalvik.vm.dex2oat-Xms", "u:object_r:dalvik_prop:s0"},
       {"dalvik.vm.dex2oat-Xmx", "u:object_r:dalvik_prop:s0"},
+      {"dalvik.vm.dex2oat-cpu-set", "u:object_r:dalvik_prop:s0"},
       {"dalvik.vm.dex2oat-threads", "u:object_r:dalvik_prop:s0"},
       {"dalvik.vm.dexopt.secondary", "u:object_r:dalvik_prop:s0"},
       {"dalvik.vm.heapgrowthlimit", "u:object_r:dalvik_prop:s0"},
@@ -388,6 +390,7 @@
       {"dalvik.vm.heaptargetutilization", "u:object_r:dalvik_prop:s0"},
       {"dalvik.vm.image-dex2oat-Xms", "u:object_r:dalvik_prop:s0"},
       {"dalvik.vm.image-dex2oat-Xmx", "u:object_r:dalvik_prop:s0"},
+      {"dalvik.vm.image-dex2oat-cpu-set", "u:object_r:dalvik_prop:s0"},
       {"dalvik.vm.image-dex2oat-threads", "u:object_r:dalvik_prop:s0"},
       {"dalvik.vm.isa.arm.features", "u:object_r:dalvik_prop:s0"},
       {"dalvik.vm.isa.arm.variant", "u:object_r:dalvik_prop:s0"},