diff --git a/adb/Android.bp b/adb/Android.bp
index 07f052f..906c5e3 100644
--- a/adb/Android.bp
+++ b/adb/Android.bp
@@ -277,26 +277,113 @@
     },
 }
 
+// libadbd_core contains the common sources to build libadbd and libadbd_services.
 cc_library_static {
+    name: "libadbd_core",
+    defaults: ["adb_defaults"],
+    recovery_available: true,
+
+    // libminadbd wants both, as it's used to build native tests.
+    compile_multilib: "both",
+
+    srcs: libadb_srcs + libadb_posix_srcs + [
+        "daemon/auth.cpp",
+        "daemon/jdwp_service.cpp",
+        "daemon/usb.cpp",
+    ],
+
+    local_include_dirs: [
+        "daemon/include",
+    ],
+
+    static_libs: [
+        "libdiagnose_usb",
+        "libqemu_pipe",
+    ],
+
+    shared_libs: [
+        "libasyncio",
+        "libbase",
+        "libcrypto",
+        "libcrypto_utils",
+        "libcutils",
+        "liblog",
+    ],
+}
+
+cc_library {
+    name: "libadbd_services",
+    defaults: ["adb_defaults"],
+    recovery_available: true,
+    compile_multilib: "both",
+
+    srcs: [
+        "daemon/file_sync_service.cpp",
+        "daemon/framebuffer_service.cpp",
+        "daemon/mdns.cpp",
+        "daemon/remount_service.cpp",
+        "daemon/services.cpp",
+        "daemon/set_verity_enable_state_service.cpp",
+        "daemon/shell_service.cpp",
+        "shell_service_protocol.cpp",
+    ],
+
+    cflags: [
+        "-D_GNU_SOURCE",
+        "-Wno-deprecated-declarations",
+    ],
+
+    static_libs: [
+        "libadbd_core",
+        "libavb_user",
+        "libdiagnose_usb",
+        "libqemu_pipe",
+
+        // `daemon/shell_service.cpp` uses selinux_android_setcon(), which is not exposed by
+        // libselinux.
+        "libselinux",
+    ],
+
+    shared_libs: [
+        "libasyncio",
+        "libbase",
+        "libbootloader_message",
+        "libcrypto",
+        "libcrypto_utils",
+        "libcutils",
+        "libext4_utils",
+        "libfec",
+        "libfec_rs",
+        "libfs_mgr",
+        "liblog",
+        "libmdnssd",
+    ],
+}
+
+cc_library {
     name: "libadbd",
     defaults: ["adb_defaults"],
     recovery_available: true,
 
-    // libminadbd wants both, for some reason.
+    // Avoid getting duplicate symbol of android::build::GetBuildNumber().
+    use_version_lib: false,
+
+    // libminadbd wants both, as it's used to build native tests.
     compile_multilib: "both",
-    srcs: libadb_srcs + libadb_posix_srcs + [
-        "daemon/auth.cpp",
-        "daemon/usb.cpp",
-        "daemon/jdwp_service.cpp",
+
+    // libadbd doesn't build any additional source, but to expose libadbd_core as a shared library.
+    whole_static_libs: [
+        "libadbd_core",
     ],
 
-    static_libs: [
+    shared_libs: [
+        "libadbd_services",
         "libasyncio",
-        "libcrypto_utils",
-        "libcrypto",
-        "libdiagnose_usb",
-        "libqemu_pipe",
         "libbase",
+        "libcrypto",
+        "libcrypto_utils",
+        "libcutils",
+        "liblog",
     ],
 
     export_include_dirs: [
@@ -307,19 +394,10 @@
 cc_binary {
     name: "adbd",
     defaults: ["adb_defaults"],
-
     recovery_available: true,
 
     srcs: [
         "daemon/main.cpp",
-        "daemon/mdns.cpp",
-        "daemon/file_sync_service.cpp",
-        "daemon/framebuffer_service.cpp",
-        "daemon/remount_service.cpp",
-        "daemon/set_verity_enable_state_service.cpp",
-        "daemon/services.cpp",
-        "daemon/shell_service.cpp",
-        "shell_service_protocol.cpp",
     ],
 
     cflags: [
@@ -331,27 +409,16 @@
         keep_symbols: true,
     },
 
-    static_libs: [
+    shared_libs: [
         "libadbd",
-        "libasyncio",
-        "libavb_user",
-        "libbootloader_message",
-        "libcrypto_utils",
+        "libadbd_services",
+        "libbase",
+        "libcap",
         "libcrypto",
-        "libdiagnose_usb",
-        "libfec",
-        "libfec_rs",
-        "libfs_mgr",
+        "libcutils",
         "liblog",
-        "libext4_utils",
-        "libmdnssd",
         "libminijail",
         "libselinux",
-        "libsquashfs_utils",
-        "libqemu_pipe",
-
-        "libbase",
-        "libcutils",
     ],
 }
 
diff --git a/adb/client/commandline.cpp b/adb/client/commandline.cpp
index 3fb14f3..da273fd 100644
--- a/adb/client/commandline.cpp
+++ b/adb/client/commandline.cpp
@@ -1925,7 +1925,8 @@
     for (int i = argc - 1; i >= 0; i--) {
         const char* file = argv[i];
 
-        if (android::base::EndsWithIgnoreCase(file, ".apk")) {
+        if (android::base::EndsWithIgnoreCase(file, ".apk") ||
+            android::base::EndsWithIgnoreCase(file, ".dm")) {
             struct stat sb;
             if (stat(file, &sb) != -1) total_size += sb.st_size;
             first_apk = i;
@@ -1986,9 +1987,8 @@
         }
 
         std::string cmd = android::base::StringPrintf(
-                "%s install-write -S %" PRIu64 " %d %d_%s -",
-                install_cmd.c_str(), static_cast<uint64_t>(sb.st_size), session_id, i,
-                android::base::Basename(file).c_str());
+            "%s install-write -S %" PRIu64 " %d %s -", install_cmd.c_str(),
+            static_cast<uint64_t>(sb.st_size), session_id, android::base::Basename(file).c_str());
 
         int localFd = adb_open(file, O_RDONLY);
         if (localFd < 0) {
diff --git a/adb/daemon/services.cpp b/adb/daemon/services.cpp
index 1f59d64..dfcc52d 100644
--- a/adb/daemon/services.cpp
+++ b/adb/daemon/services.cpp
@@ -94,7 +94,7 @@
     WriteFdExactly(fd.get(), "restarting in USB mode\n");
 }
 
-bool reboot_service_impl(unique_fd fd, const std::string& arg) {
+void reboot_service(unique_fd fd, const std::string& arg) {
     std::string reboot_arg = arg;
     bool auto_reboot = false;
 
@@ -108,7 +108,7 @@
     if (reboot_arg == "sideload") {
         if (getuid() != 0) {
             WriteFdExactly(fd.get(), "'adb root' is required for 'adb reboot sideload'.\n");
-            return false;
+            return;
         }
 
         const std::vector<std::string> options = {auto_reboot ? "--sideload_auto_reboot"
@@ -116,7 +116,7 @@
         std::string err;
         if (!write_bootloader_message(options, &err)) {
             D("Failed to set bootloader message: %s", err.c_str());
-            return false;
+            return;
         }
 
         reboot_arg = "recovery";
@@ -128,16 +128,9 @@
     std::string reboot_string = android::base::StringPrintf("reboot,%s", reboot_arg.c_str());
     if (!android::base::SetProperty(ANDROID_RB_PROPERTY, reboot_string)) {
         WriteFdFmt(fd.get(), "reboot (%s) failed\n", reboot_string.c_str());
-        return false;
-    }
-
-    return true;
-}
-
-void reboot_service(unique_fd fd, const std::string& arg) {
-    if (!reboot_service_impl(std::move(fd), arg)) {
         return;
     }
+
     // Don't return early. Give the reboot command time to take effect
     // to avoid messing up scripts which do "adb reboot && adb wait-for-device"
     while (true) {
diff --git a/adb/transport.cpp b/adb/transport.cpp
index 9222008..3c74c75 100644
--- a/adb/transport.cpp
+++ b/adb/transport.cpp
@@ -1190,17 +1190,11 @@
 }
 #endif  // ADB_HOST
 
-int register_socket_transport(unique_fd s, const char* serial, int port, int local,
+int register_socket_transport(unique_fd s, std::string serial, int port, int local,
                               atransport::ReconnectCallback reconnect) {
     atransport* t = new atransport(std::move(reconnect), kCsOffline);
 
-    if (!serial) {
-        char buf[32];
-        snprintf(buf, sizeof(buf), "T-%p", t);
-        serial = buf;
-    }
-
-    D("transport: %s init'ing for socket %d, on port %d", serial, s.get(), port);
+    D("transport: %s init'ing for socket %d, on port %d", serial.c_str(), s.get(), port);
     if (init_socket_transport(t, std::move(s), port, local) < 0) {
         delete t;
         return -1;
@@ -1208,7 +1202,7 @@
 
     std::unique_lock<std::recursive_mutex> lock(transport_lock);
     for (const auto& transport : pending_list) {
-        if (strcmp(serial, transport->serial.c_str()) == 0) {
+        if (serial == transport->serial) {
             VLOG(TRANSPORT) << "socket transport " << transport->serial
                             << " is already in pending_list and fails to register";
             delete t;
@@ -1217,7 +1211,7 @@
     }
 
     for (const auto& transport : transport_list) {
-        if (strcmp(serial, transport->serial.c_str()) == 0) {
+        if (serial == transport->serial) {
             VLOG(TRANSPORT) << "socket transport " << transport->serial
                             << " is already in transport_list and fails to register";
             delete t;
@@ -1225,8 +1219,8 @@
         }
     }
 
+    t->serial = std::move(serial);
     pending_list.push_front(t);
-    t->serial = serial;
 
     lock.unlock();
 
diff --git a/adb/transport.h b/adb/transport.h
index 1844ae8..4bfc2ce 100644
--- a/adb/transport.h
+++ b/adb/transport.h
@@ -364,7 +364,7 @@
 void connect_device(const std::string& address, std::string* response);
 
 /* cause new transports to be init'd and added to the list */
-int register_socket_transport(unique_fd s, const char* serial, int port, int local,
+int register_socket_transport(unique_fd s, std::string serial, int port, int local,
                               atransport::ReconnectCallback reconnect);
 
 // This should only be used for transports with connection_state == kCsNoPerm.
diff --git a/adb/transport_local.cpp b/adb/transport_local.cpp
index 9398ceb..b20dee9 100644
--- a/adb/transport_local.cpp
+++ b/adb/transport_local.cpp
@@ -125,8 +125,7 @@
         return init_socket_transport(t, std::move(fd), port, 0) >= 0;
     };
 
-    int ret =
-            register_socket_transport(std::move(fd), serial.c_str(), port, 0, std::move(reconnect));
+    int ret = register_socket_transport(std::move(fd), serial, port, 0, std::move(reconnect));
     if (ret < 0) {
         if (ret == -EALREADY) {
             *response = android::base::StringPrintf("already connected to %s", serial.c_str());
@@ -162,7 +161,7 @@
         close_on_exec(fd.get());
         disable_tcp_nagle(fd.get());
         std::string serial = getEmulatorSerialString(console_port);
-        if (register_socket_transport(std::move(fd), serial.c_str(), adb_port, 1,
+        if (register_socket_transport(std::move(fd), std::move(serial), adb_port, 1,
                                       [](atransport*) { return false; }) == 0) {
             return 0;
         }
@@ -265,7 +264,7 @@
             close_on_exec(fd.get());
             disable_tcp_nagle(fd.get());
             std::string serial = android::base::StringPrintf("host-%d", fd.get());
-            register_socket_transport(std::move(fd), serial.c_str(), port, 1,
+            register_socket_transport(std::move(fd), std::move(serial), port, 1,
                                       [](atransport*) { return false; });
         }
     }
@@ -362,7 +361,7 @@
                  * exchange. */
                 std::string serial = android::base::StringPrintf("host-%d", fd.get());
                 WriteFdExactly(fd.get(), _start_req, strlen(_start_req));
-                register_socket_transport(std::move(fd), serial.c_str(), port, 1,
+                register_socket_transport(std::move(fd), std::move(serial), port, 1,
                                           [](atransport*) { return false; });
             }
 
@@ -454,10 +453,6 @@
     return it->second;
 }
 
-std::string getEmulatorSerialString(int console_port) {
-    return android::base::StringPrintf("emulator-%d", console_port);
-}
-
 atransport* find_emulator_transport_by_adb_port(int adb_port) {
     std::lock_guard<std::mutex> lock(local_transports_lock);
     return find_emulator_transport_by_adb_port_locked(adb_port);
@@ -468,6 +463,10 @@
 }
 #endif
 
+std::string getEmulatorSerialString(int console_port) {
+    return android::base::StringPrintf("emulator-%d", console_port);
+}
+
 int init_socket_transport(atransport* t, unique_fd fd, int adb_port, int local) {
     int fail = 0;
 
diff --git a/fastboot/Android.bp b/fastboot/Android.bp
index 2b4a954..51cc62a 100644
--- a/fastboot/Android.bp
+++ b/fastboot/Android.bp
@@ -1,3 +1,17 @@
+// Copyright (C) 2018 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_library_host_static {
     name: "libfastboot2",
 
@@ -54,3 +68,54 @@
     export_include_dirs: ["."],
 
 }
+
+cc_defaults {
+    name: "fastboot_defaults",
+
+    cflags: [
+        "-Wall",
+        "-Wextra",
+        "-Werror",
+        "-Wvla",
+    ],
+    rtti: true,
+
+    clang_cflags: [
+        "-Wthread-safety",
+    ],
+}
+
+cc_binary {
+    name: "fastbootd",
+    defaults: ["fastboot_defaults"],
+
+    recovery: true,
+
+    srcs: [
+        "device/commands.cpp",
+        "device/fastboot_device.cpp",
+        "device/main.cpp",
+        "device/usb_client.cpp",
+    ],
+
+    shared_libs: [
+        "libasyncio",
+        "libext4_utils",
+        "libsparse",
+        "liblog",
+        "libbootloader_message",
+        "libhidltransport",
+        "libhidlbase",
+        "libhwbinder",
+        "libbase",
+        "libutils",
+        "libcutils",
+        "libfs_mgr",
+    ],
+
+    static_libs: [
+        "libadbd",
+    ],
+
+    cpp_std: "c++17",
+}
diff --git a/fastboot/constants.h b/fastboot/constants.h
index 5e7e955..7caca3d 100644
--- a/fastboot/constants.h
+++ b/fastboot/constants.h
@@ -27,6 +27,8 @@
 #define FB_CMD_REBOOT "reboot"
 #define FB_CMD_SHUTDOWN "shutdown"
 #define FB_CMD_REBOOT_BOOTLOADER "reboot-bootloader"
+#define FB_CMD_REBOOT_RECOVERY "reboot-recovery"
+#define FB_CMD_REBOOT_FASTBOOT "reboot-fastboot"
 #define FB_CMD_POWERDOWN "powerdown"
 
 #define RESPONSE_OKAY "OKAY"
diff --git a/fastboot/device/commands.cpp b/fastboot/device/commands.cpp
new file mode 100644
index 0000000..a3cbf96
--- /dev/null
+++ b/fastboot/device/commands.cpp
@@ -0,0 +1,126 @@
+/*
+ * Copyright (C) 2018 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 "commands.h"
+
+#include <sys/socket.h>
+#include <sys/un.h>
+
+#include <android-base/logging.h>
+#include <android-base/parseint.h>
+#include <android-base/properties.h>
+#include <android-base/stringprintf.h>
+#include <android-base/strings.h>
+#include <android-base/unique_fd.h>
+#include <cutils/android_reboot.h>
+
+#include "fastboot_device.h"
+
+bool DownloadHandler(FastbootDevice* device, const std::vector<std::string>& args) {
+    if (args.size() < 2) {
+        return device->WriteStatus(FastbootResult::FAIL, "size argument unspecified");
+    }
+    // arg[0] is the command name, arg[1] contains size of data to be downloaded
+    unsigned int size;
+    if (!android::base::ParseUint("0x" + args[1], &size, UINT_MAX)) {
+        return device->WriteStatus(FastbootResult::FAIL, "Invalid size");
+    }
+    device->get_download_data().resize(size);
+    if (!device->WriteStatus(FastbootResult::DATA, android::base::StringPrintf("%08x", size))) {
+        return false;
+    }
+
+    if (device->HandleData(true, &device->get_download_data())) {
+        return device->WriteStatus(FastbootResult::OKAY, "");
+    }
+
+    PLOG(ERROR) << "Couldn't download data";
+    return device->WriteStatus(FastbootResult::FAIL, "Couldn't download data");
+}
+
+bool SetActiveHandler(FastbootDevice* device, const std::vector<std::string>& /* args */) {
+    return device->WriteStatus(FastbootResult::OKAY, "");
+}
+
+bool ShutDownHandler(FastbootDevice* device, const std::vector<std::string>& /* args */) {
+    auto result = device->WriteStatus(FastbootResult::OKAY, "Shutting down");
+    android::base::SetProperty(ANDROID_RB_PROPERTY, "shutdown,fastboot");
+    device->CloseDevice();
+    TEMP_FAILURE_RETRY(pause());
+    return result;
+}
+
+bool RebootHandler(FastbootDevice* device, const std::vector<std::string>& /* args */) {
+    auto result = device->WriteStatus(FastbootResult::OKAY, "Rebooting");
+    android::base::SetProperty(ANDROID_RB_PROPERTY, "reboot,from_fastboot");
+    device->CloseDevice();
+    TEMP_FAILURE_RETRY(pause());
+    return result;
+}
+
+bool RebootBootloaderHandler(FastbootDevice* device, const std::vector<std::string>& /* args */) {
+    auto result = device->WriteStatus(FastbootResult::OKAY, "Rebooting bootloader");
+    android::base::SetProperty(ANDROID_RB_PROPERTY, "reboot,bootloader");
+    device->CloseDevice();
+    TEMP_FAILURE_RETRY(pause());
+    return result;
+}
+
+bool RebootFastbootHandler(FastbootDevice* device, const std::vector<std::string>& /* args */) {
+    auto result = device->WriteStatus(FastbootResult::OKAY, "Rebooting fastboot");
+    android::base::SetProperty(ANDROID_RB_PROPERTY, "reboot,fastboot");
+    device->CloseDevice();
+    TEMP_FAILURE_RETRY(pause());
+    return result;
+}
+
+static bool EnterRecovery() {
+    const char msg_switch_to_recovery = 'r';
+
+    android::base::unique_fd sock(socket(AF_UNIX, SOCK_STREAM, 0));
+    if (sock < 0) {
+        PLOG(ERROR) << "Couldn't create sock";
+        return false;
+    }
+
+    struct sockaddr_un addr = {.sun_family = AF_UNIX};
+    strncpy(addr.sun_path, "/dev/socket/recovery", sizeof(addr.sun_path) - 1);
+    if (connect(sock, (struct sockaddr*)&addr, sizeof(addr)) < 0) {
+        PLOG(ERROR) << "Couldn't connect to recovery";
+        return false;
+    }
+    // Switch to recovery will not update the boot reason since it does not
+    // require a reboot.
+    auto ret = write(sock, &msg_switch_to_recovery, sizeof(msg_switch_to_recovery));
+    if (ret != sizeof(msg_switch_to_recovery)) {
+        PLOG(ERROR) << "Couldn't write message to switch to recovery";
+        return false;
+    }
+
+    return true;
+}
+
+bool RebootRecoveryHandler(FastbootDevice* device, const std::vector<std::string>& /* args */) {
+    auto status = true;
+    if (EnterRecovery()) {
+        status = device->WriteStatus(FastbootResult::OKAY, "Rebooting to recovery");
+    } else {
+        status = device->WriteStatus(FastbootResult::FAIL, "Unable to reboot to recovery");
+    }
+    device->CloseDevice();
+    TEMP_FAILURE_RETRY(pause());
+    return status;
+}
diff --git a/fastboot/device/commands.h b/fastboot/device/commands.h
new file mode 100644
index 0000000..cd984c8
--- /dev/null
+++ b/fastboot/device/commands.h
@@ -0,0 +1,40 @@
+/*
+ * Copyright (C) 2018 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 <functional>
+#include <string>
+#include <vector>
+
+class FastbootDevice;
+
+enum class FastbootResult {
+    OKAY,
+    FAIL,
+    INFO,
+    DATA,
+};
+
+// Execute a command with the given arguments (possibly empty).
+using CommandHandler = std::function<bool(FastbootDevice*, const std::vector<std::string>&)>;
+
+bool DownloadHandler(FastbootDevice* device, const std::vector<std::string>& args);
+bool SetActiveHandler(FastbootDevice* device, const std::vector<std::string>& args);
+bool ShutDownHandler(FastbootDevice* device, const std::vector<std::string>& args);
+bool RebootHandler(FastbootDevice* device, const std::vector<std::string>& args);
+bool RebootBootloaderHandler(FastbootDevice* device, const std::vector<std::string>& args);
+bool RebootFastbootHandler(FastbootDevice* device, const std::vector<std::string>& args);
+bool RebootRecoveryHandler(FastbootDevice* device, const std::vector<std::string>& args);
diff --git a/fastboot/device/fastboot_device.cpp b/fastboot/device/fastboot_device.cpp
new file mode 100644
index 0000000..4c3d23f
--- /dev/null
+++ b/fastboot/device/fastboot_device.cpp
@@ -0,0 +1,104 @@
+/*
+ * Copyright (C) 2018 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 "fastboot_device.h"
+
+#include <android-base/logging.h>
+#include <android-base/strings.h>
+
+#include <algorithm>
+
+#include "constants.h"
+#include "usb_client.h"
+
+FastbootDevice::FastbootDevice()
+    : kCommandMap({
+              {FB_CMD_SET_ACTIVE, SetActiveHandler},
+              {FB_CMD_DOWNLOAD, DownloadHandler},
+              {FB_CMD_SHUTDOWN, ShutDownHandler},
+              {FB_CMD_REBOOT, RebootHandler},
+              {FB_CMD_REBOOT_BOOTLOADER, RebootBootloaderHandler},
+              {FB_CMD_REBOOT_FASTBOOT, RebootFastbootHandler},
+              {FB_CMD_REBOOT_RECOVERY, RebootRecoveryHandler},
+      }),
+      transport_(std::make_unique<ClientUsbTransport>()) {}
+
+FastbootDevice::~FastbootDevice() {
+    CloseDevice();
+}
+
+void FastbootDevice::CloseDevice() {
+    transport_->Close();
+}
+
+bool FastbootDevice::WriteStatus(FastbootResult result, const std::string& message) {
+    constexpr size_t kResponseReasonSize = 4;
+    constexpr size_t kNumResponseTypes = 4;  // "FAIL", "OKAY", "INFO", "DATA"
+    char buf[FB_RESPONSE_SZ];
+    constexpr size_t kMaxMessageSize = sizeof(buf) - kResponseReasonSize;
+    size_t msg_len = std::min(kMaxMessageSize, message.size());
+
+    constexpr const char* kResultStrings[kNumResponseTypes] = {RESPONSE_OKAY, RESPONSE_FAIL,
+                                                               RESPONSE_INFO, RESPONSE_DATA};
+
+    if (static_cast<size_t>(result) >= kNumResponseTypes) {
+        return false;
+    }
+
+    memcpy(buf, kResultStrings[static_cast<size_t>(result)], kResponseReasonSize);
+    memcpy(buf + kResponseReasonSize, message.c_str(), msg_len);
+
+    size_t response_len = kResponseReasonSize + msg_len;
+    auto write_ret = this->get_transport()->Write(buf, response_len);
+    if (write_ret != static_cast<ssize_t>(response_len)) {
+        PLOG(ERROR) << "Failed to write " << message;
+        return false;
+    }
+
+    return true;
+}
+
+bool FastbootDevice::HandleData(bool read, std::vector<char>* data) {
+    auto read_write_data_size = read ? this->get_transport()->Read(data->data(), data->size())
+                                     : this->get_transport()->Write(data->data(), data->size());
+    if (read_write_data_size == -1 || static_cast<size_t>(read_write_data_size) != data->size()) {
+        return false;
+    }
+    return true;
+}
+
+void FastbootDevice::ExecuteCommands() {
+    char command[FB_RESPONSE_SZ + 1];
+    for (;;) {
+        auto bytes_read = transport_->Read(command, FB_RESPONSE_SZ);
+        if (bytes_read == -1) {
+            PLOG(ERROR) << "Couldn't read command";
+            return;
+        }
+        command[bytes_read] = '\0';
+
+        LOG(INFO) << "Fastboot command: " << command;
+        auto args = android::base::Split(command, ":");
+        auto found_command = kCommandMap.find(args[0]);
+        if (found_command == kCommandMap.end()) {
+            WriteStatus(FastbootResult::FAIL, "Unrecognized command");
+            continue;
+        }
+        if (!found_command->second(this, args)) {
+            return;
+        }
+    }
+}
diff --git a/fastboot/device/fastboot_device.h b/fastboot/device/fastboot_device.h
new file mode 100644
index 0000000..fec42a7
--- /dev/null
+++ b/fastboot/device/fastboot_device.h
@@ -0,0 +1,52 @@
+/*
+ * Copyright (C) 2018 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 <memory>
+#include <string>
+#include <unordered_map>
+#include <utility>
+#include <vector>
+
+#include "commands.h"
+#include "transport.h"
+
+class FastbootDevice;
+
+class FastbootDevice {
+  public:
+    FastbootDevice();
+    ~FastbootDevice();
+
+    void CloseDevice();
+    void ExecuteCommands();
+    bool WriteStatus(FastbootResult result, const std::string& message);
+    bool HandleData(bool read, std::vector<char>* data);
+
+    std::vector<char>& get_download_data() { return download_data_; }
+    void set_upload_data(const std::vector<char>& data) { upload_data_ = data; }
+    void set_upload_data(std::vector<char>&& data) { upload_data_ = std::move(data); }
+    Transport* get_transport() { return transport_.get(); }
+
+  private:
+    const std::unordered_map<std::string, CommandHandler> kCommandMap;
+
+    std::unique_ptr<Transport> transport_;
+
+    std::vector<char> download_data_;
+    std::vector<char> upload_data_;
+};
diff --git a/init/watchdogd.h b/fastboot/device/main.cpp
similarity index 63%
copy from init/watchdogd.h
copy to fastboot/device/main.cpp
index 73f77d5..df9c900 100644
--- a/init/watchdogd.h
+++ b/fastboot/device/main.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2012 The Android Open Source Project
+ * Copyright (C) 2018 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.
@@ -14,15 +14,15 @@
  * limitations under the License.
  */
 
-#ifndef _INIT_WATCHDOGD_H_
-#define _INIT_WATCHDOGD_H_
+#include <android-base/logging.h>
 
-namespace android {
-namespace init {
+#include "fastboot_device.h"
 
-int watchdogd_main(int argc, char **argv);
+int main(int /*argc*/, char* argv[]) {
+    android::base::InitLogging(argv, &android::base::KernelLogger);
 
-}  // namespace init
-}  // namespace android
-
-#endif
+    while (true) {
+        FastbootDevice device;
+        device.ExecuteCommands();
+    }
+}
diff --git a/fastboot/device/usb_client.cpp b/fastboot/device/usb_client.cpp
new file mode 100644
index 0000000..215f99a
--- /dev/null
+++ b/fastboot/device/usb_client.cpp
@@ -0,0 +1,307 @@
+/*
+ * Copyright (C) 2018 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 "usb_client.h"
+
+#include <endian.h>
+#include <fcntl.h>
+#include <linux/usb/ch9.h>
+#include <linux/usb/functionfs.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+
+#include <android-base/logging.h>
+#include <android-base/properties.h>
+
+constexpr int kMaxPacketSizeFs = 64;
+constexpr int kMaxPacketSizeHs = 512;
+constexpr int kMaxPacketsizeSs = 1024;
+
+constexpr size_t kFbFfsNumBufs = 16;
+constexpr size_t kFbFfsBufSize = 32768;
+
+constexpr const char* kUsbFfsFastbootEp0 = "/dev/usb-ffs/fastboot/ep0";
+constexpr const char* kUsbFfsFastbootOut = "/dev/usb-ffs/fastboot/ep1";
+constexpr const char* kUsbFfsFastbootIn = "/dev/usb-ffs/fastboot/ep2";
+
+struct FuncDesc {
+    struct usb_interface_descriptor intf;
+    struct usb_endpoint_descriptor_no_audio source;
+    struct usb_endpoint_descriptor_no_audio sink;
+} __attribute__((packed));
+
+struct SsFuncDesc {
+    struct usb_interface_descriptor intf;
+    struct usb_endpoint_descriptor_no_audio source;
+    struct usb_ss_ep_comp_descriptor source_comp;
+    struct usb_endpoint_descriptor_no_audio sink;
+    struct usb_ss_ep_comp_descriptor sink_comp;
+} __attribute__((packed));
+
+struct DescV2 {
+    struct usb_functionfs_descs_head_v2 header;
+    // The rest of the structure depends on the flags in the header.
+    __le32 fs_count;
+    __le32 hs_count;
+    __le32 ss_count;
+    struct FuncDesc fs_descs, hs_descs;
+    struct SsFuncDesc ss_descs;
+} __attribute__((packed));
+
+struct usb_interface_descriptor fastboot_interface = {
+        .bLength = USB_DT_INTERFACE_SIZE,
+        .bDescriptorType = USB_DT_INTERFACE,
+        .bInterfaceNumber = 0,
+        .bNumEndpoints = 2,
+        .bInterfaceClass = USB_CLASS_VENDOR_SPEC,
+        .bInterfaceSubClass = 66,
+        .bInterfaceProtocol = 3,
+        .iInterface = 1, /* first string from the provided table */
+};
+
+static struct FuncDesc fs_descriptors = {
+        .intf = fastboot_interface,
+        .source =
+                {
+                        .bLength = sizeof(fs_descriptors.source),
+                        .bDescriptorType = USB_DT_ENDPOINT,
+                        .bEndpointAddress = 1 | USB_DIR_OUT,
+                        .bmAttributes = USB_ENDPOINT_XFER_BULK,
+                        .wMaxPacketSize = kMaxPacketSizeFs,
+                },
+        .sink =
+                {
+                        .bLength = sizeof(fs_descriptors.sink),
+                        .bDescriptorType = USB_DT_ENDPOINT,
+                        .bEndpointAddress = 1 | USB_DIR_IN,
+                        .bmAttributes = USB_ENDPOINT_XFER_BULK,
+                        .wMaxPacketSize = kMaxPacketSizeFs,
+                },
+};
+
+static struct FuncDesc hs_descriptors = {
+        .intf = fastboot_interface,
+        .source =
+                {
+                        .bLength = sizeof(hs_descriptors.source),
+                        .bDescriptorType = USB_DT_ENDPOINT,
+                        .bEndpointAddress = 1 | USB_DIR_OUT,
+                        .bmAttributes = USB_ENDPOINT_XFER_BULK,
+                        .wMaxPacketSize = kMaxPacketSizeHs,
+                },
+        .sink =
+                {
+                        .bLength = sizeof(hs_descriptors.sink),
+                        .bDescriptorType = USB_DT_ENDPOINT,
+                        .bEndpointAddress = 1 | USB_DIR_IN,
+                        .bmAttributes = USB_ENDPOINT_XFER_BULK,
+                        .wMaxPacketSize = kMaxPacketSizeHs,
+                },
+};
+
+static struct SsFuncDesc ss_descriptors = {
+        .intf = fastboot_interface,
+        .source =
+                {
+                        .bLength = sizeof(ss_descriptors.source),
+                        .bDescriptorType = USB_DT_ENDPOINT,
+                        .bEndpointAddress = 1 | USB_DIR_OUT,
+                        .bmAttributes = USB_ENDPOINT_XFER_BULK,
+                        .wMaxPacketSize = kMaxPacketsizeSs,
+                },
+        .source_comp =
+                {
+                        .bLength = sizeof(ss_descriptors.source_comp),
+                        .bDescriptorType = USB_DT_SS_ENDPOINT_COMP,
+                        .bMaxBurst = 15,
+                },
+        .sink =
+                {
+                        .bLength = sizeof(ss_descriptors.sink),
+                        .bDescriptorType = USB_DT_ENDPOINT,
+                        .bEndpointAddress = 1 | USB_DIR_IN,
+                        .bmAttributes = USB_ENDPOINT_XFER_BULK,
+                        .wMaxPacketSize = kMaxPacketsizeSs,
+                },
+        .sink_comp =
+                {
+                        .bLength = sizeof(ss_descriptors.sink_comp),
+                        .bDescriptorType = USB_DT_SS_ENDPOINT_COMP,
+                        .bMaxBurst = 15,
+                },
+};
+
+#define STR_INTERFACE_ "fastboot"
+
+static const struct {
+    struct usb_functionfs_strings_head header;
+    struct {
+        __le16 code;
+        const char str1[sizeof(STR_INTERFACE_)];
+    } __attribute__((packed)) lang0;
+} __attribute__((packed)) strings = {
+        .header =
+                {
+                        .magic = htole32(FUNCTIONFS_STRINGS_MAGIC),
+                        .length = htole32(sizeof(strings)),
+                        .str_count = htole32(1),
+                        .lang_count = htole32(1),
+                },
+        .lang0 =
+                {
+                        htole16(0x0409), /* en-us */
+                        STR_INTERFACE_,
+                },
+};
+
+static struct DescV2 v2_descriptor = {
+        .header =
+                {
+                        .magic = htole32(FUNCTIONFS_DESCRIPTORS_MAGIC_V2),
+                        .length = htole32(sizeof(v2_descriptor)),
+                        .flags = FUNCTIONFS_HAS_FS_DESC | FUNCTIONFS_HAS_HS_DESC |
+                                 FUNCTIONFS_HAS_SS_DESC,
+                },
+        .fs_count = 3,
+        .hs_count = 3,
+        .ss_count = 5,
+        .fs_descs = fs_descriptors,
+        .hs_descs = hs_descriptors,
+        .ss_descs = ss_descriptors,
+};
+
+// Reimplementing since usb_ffs_close() does not close the control FD.
+static void CloseFunctionFs(usb_handle* h) {
+    if (h->bulk_in > 0) {
+        close(h->bulk_in);
+        h->bulk_in = -1;
+    }
+    if (h->bulk_out > 0) {
+        close(h->bulk_out);
+        h->bulk_out = -1;
+    }
+    if (h->control > 0) {
+        close(h->control);
+        h->control = -1;
+    }
+}
+
+static bool InitFunctionFs(usb_handle* h) {
+    LOG(INFO) << "initializing functionfs";
+
+    if (h->control < 0) {  // might have already done this before
+        LOG(INFO) << "opening control endpoint " << kUsbFfsFastbootEp0;
+        h->control = open(kUsbFfsFastbootEp0, O_RDWR);
+        if (h->control < 0) {
+            PLOG(ERROR) << "cannot open control endpoint " << kUsbFfsFastbootEp0;
+            goto err;
+        }
+
+        auto ret = write(h->control, &v2_descriptor, sizeof(v2_descriptor));
+        if (ret < 0) {
+            PLOG(ERROR) << "cannot write descriptors " << kUsbFfsFastbootEp0;
+            goto err;
+        }
+
+        ret = write(h->control, &strings, sizeof(strings));
+        if (ret < 0) {
+            PLOG(ERROR) << "cannot write strings " << kUsbFfsFastbootEp0;
+            goto err;
+        }
+        // Signal only when writing the descriptors to ffs
+        android::base::SetProperty("sys.usb.ffs.ready", "1");
+    }
+
+    h->bulk_out = open(kUsbFfsFastbootOut, O_RDONLY);
+    if (h->bulk_out < 0) {
+        PLOG(ERROR) << "cannot open bulk-out endpoint " << kUsbFfsFastbootOut;
+        goto err;
+    }
+
+    h->bulk_in = open(kUsbFfsFastbootIn, O_WRONLY);
+    if (h->bulk_in < 0) {
+        PLOG(ERROR) << "cannot open bulk-in endpoint " << kUsbFfsFastbootIn;
+        goto err;
+    }
+
+    h->read_aiob.fd = h->bulk_out;
+    h->write_aiob.fd = h->bulk_in;
+    h->reads_zero_packets = false;
+    return true;
+
+err:
+    CloseFunctionFs(h);
+    return false;
+}
+
+ClientUsbTransport::ClientUsbTransport()
+    : handle_(std::unique_ptr<usb_handle>(create_usb_handle(kFbFfsNumBufs, kFbFfsBufSize))) {
+    if (!InitFunctionFs(handle_.get())) {
+        handle_.reset(nullptr);
+    }
+}
+
+ssize_t ClientUsbTransport::Read(void* data, size_t len) {
+    if (handle_ == nullptr || len > SSIZE_MAX) {
+        return -1;
+    }
+    char* char_data = static_cast<char*>(data);
+    size_t bytes_read_total = 0;
+    while (bytes_read_total < len) {
+        auto bytes_to_read = std::min(len - bytes_read_total, kFbFfsNumBufs * kFbFfsBufSize);
+        auto bytes_read_now = handle_->read(handle_.get(), char_data, bytes_to_read);
+        if (bytes_read_now < 0) {
+            return bytes_read_total;
+        }
+        bytes_read_total += bytes_read_now;
+        char_data += bytes_read_now;
+        if (static_cast<size_t>(bytes_read_now) < bytes_to_read) {
+            break;
+        }
+    }
+    return bytes_read_total;
+}
+
+ssize_t ClientUsbTransport::Write(const void* data, size_t len) {
+    if (handle_ == nullptr || len > SSIZE_MAX) {
+        return -1;
+    }
+    const char* char_data = reinterpret_cast<const char*>(data);
+    size_t bytes_written_total = 0;
+    while (bytes_written_total < len) {
+        auto bytes_to_write = std::min(len - bytes_written_total, kFbFfsNumBufs * kFbFfsBufSize);
+        auto bytes_written_now = handle_->write(handle_.get(), data, bytes_to_write);
+        if (bytes_written_now < 0) {
+            return bytes_written_total;
+        }
+        bytes_written_total += bytes_written_now;
+        char_data += bytes_written_now;
+        if (static_cast<size_t>(bytes_written_now) < bytes_to_write) {
+            break;
+        }
+    }
+    return bytes_written_total;
+}
+
+int ClientUsbTransport::Close() {
+    if (handle_ == nullptr) {
+        return -1;
+    }
+    CloseFunctionFs(handle_.get());
+    return 0;
+}
diff --git a/fastboot/device/usb_client.h b/fastboot/device/usb_client.h
new file mode 100644
index 0000000..3694f9a
--- /dev/null
+++ b/fastboot/device/usb_client.h
@@ -0,0 +1,37 @@
+/*
+ * Copyright (C) 2018 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 <memory>
+
+#include <adbd/usb.h>
+
+#include "transport.h"
+
+class ClientUsbTransport : public Transport {
+  public:
+    ClientUsbTransport();
+    ~ClientUsbTransport() override = default;
+
+    ssize_t Read(void* data, size_t len) override;
+    ssize_t Write(const void* data, size_t len) override;
+    int Close() override;
+
+  private:
+    std::unique_ptr<usb_handle> handle_;
+
+    DISALLOW_COPY_AND_ASSIGN(ClientUsbTransport);
+};
diff --git a/fastboot/fastboot.cpp b/fastboot/fastboot.cpp
index 321e6ba..d787d09 100644
--- a/fastboot/fastboot.cpp
+++ b/fastboot/fastboot.cpp
@@ -111,12 +111,13 @@
     const char* img_name;
     const char* sig_name;
     const char* part_name;
-    bool is_optional;
-    bool is_secondary;
+    bool optional_if_no_image;
+    bool optional_if_no_partition;
+    bool IsSecondary() const { return nickname == nullptr; }
 } images[] = {
         // clang-format off
     { "boot",     "boot.img",         "boot.sig",     "boot",     false, false },
-    { nullptr,    "boot_other.img",   "boot.sig",     "boot",     true,  true  },
+    { nullptr,    "boot_other.img",   "boot.sig",     "boot",     true,  false },
     { "dtbo",     "dtbo.img",         "dtbo.sig",     "dtbo",     true,  false },
     { "dts",      "dt.img",           "dt.sig",       "dts",      true,  false },
     { "odm",      "odm.img",          "odm.sig",      "odm",      true,  false },
@@ -125,14 +126,14 @@
                   "product-services.img",
                                       "product-services.sig",
                                                       "product-services",
-                                                                  true,  false },
+                                                                  true,  true  },
     { "recovery", "recovery.img",     "recovery.sig", "recovery", true,  false },
-    { "super",    "super.img",        "super.sig",    "super",    true,  false },
-    { "system",   "system.img",       "system.sig",   "system",   false, false },
-    { nullptr,    "system_other.img", "system.sig",   "system",   true,  true  },
+    { "super",    "super.img",        "super.sig",    "super",    true,  true  },
+    { "system",   "system.img",       "system.sig",   "system",   false, true  },
+    { nullptr,    "system_other.img", "system.sig",   "system",   true,  false },
     { "vbmeta",   "vbmeta.img",       "vbmeta.sig",   "vbmeta",   true,  false },
-    { "vendor",   "vendor.img",       "vendor.sig",   "vendor",   true,  false },
-    { nullptr,    "vendor_other.img", "vendor.sig",   "vendor",   true,  true  },
+    { "vendor",   "vendor.img",       "vendor.sig",   "vendor",   true,  true  },
+    { nullptr,    "vendor_other.img", "vendor.sig",   "vendor",   true,  false },
         // clang-format on
 };
 
@@ -637,7 +638,8 @@
     // "require partition-exists=x" is a special case, added because of the trouble we had when
     // Pixel 2 shipped with new partitions and users used old versions of fastboot to flash them,
     // missing out new partitions. A device with new partitions can use "partition-exists" to
-    // override the `is_optional` field in the `images` array.
+    // override the fields `optional_if_no_image` and 'optional_if_no_partition' in the `images`
+    // array.
     if (!strcmp(name, "partition-exists")) {
         const char* partition_name = val[0];
         std::string has_slot;
@@ -648,7 +650,8 @@
         bool known_partition = false;
         for (size_t i = 0; i < arraysize(images); ++i) {
             if (images[i].nickname && !strcmp(images[i].nickname, partition_name)) {
-                images[i].is_optional = false;
+                images[i].optional_if_no_image = false;
+                images[i].optional_if_no_partition = false;
                 known_partition = true;
             }
         }
@@ -1041,6 +1044,25 @@
     }
 }
 
+static bool if_partition_exists(const std::string& partition, const std::string& slot) {
+    std::string has_slot;
+    std::string partition_name = partition;
+
+    if (fb_getvar("has-slot:" + partition, &has_slot) && has_slot == "yes") {
+        if (slot == "") {
+            std::string current_slot = get_current_slot();
+            if (current_slot == "") {
+                die("Failed to identify current slot");
+            }
+            partition_name += "_" + current_slot;
+        } else {
+            partition_name += "_" + slot;
+        }
+    }
+    std::string partition_size;
+    return fb_getvar("partition-size:" + partition_name, &partition_size);
+}
+
 static void do_update(const char* filename, const std::string& slot_override, bool skip_secondary) {
     queue_info_dump();
 
@@ -1076,7 +1098,7 @@
     }
     for (size_t i = 0; i < arraysize(images); ++i) {
         const char* slot = slot_override.c_str();
-        if (images[i].is_secondary) {
+        if (images[i].IsSecondary()) {
             if (!skip_secondary) {
                 slot = secondary.c_str();
             } else {
@@ -1086,12 +1108,17 @@
 
         int fd = unzip_to_file(zip, images[i].img_name);
         if (fd == -1) {
-            if (images[i].is_optional) {
+            if (images[i].optional_if_no_image) {
                 continue; // An optional file is missing, so ignore it.
             }
             die("non-optional file %s missing", images[i].img_name);
         }
 
+        if (images[i].optional_if_no_partition &&
+            !if_partition_exists(images[i].part_name, slot)) {
+            continue;
+        }
+
         fastboot_buffer buf;
         if (!load_buf_fd(fd, &buf)) {
             die("cannot load %s from flash: %s", images[i].img_name, strerror(errno));
@@ -1163,7 +1190,7 @@
 
     for (size_t i = 0; i < arraysize(images); i++) {
         const char* slot = NULL;
-        if (images[i].is_secondary) {
+        if (images[i].IsSecondary()) {
             if (!skip_secondary) slot = secondary.c_str();
         } else {
             slot = slot_override.c_str();
@@ -1172,10 +1199,13 @@
         fname = find_item_given_name(images[i].img_name);
         fastboot_buffer buf;
         if (!load_buf(fname.c_str(), &buf)) {
-            if (images[i].is_optional) continue;
+            if (images[i].optional_if_no_image) continue;
             die("could not load '%s': %s", images[i].img_name, strerror(errno));
         }
-
+        if (images[i].optional_if_no_partition &&
+            !if_partition_exists(images[i].part_name, slot)) {
+            continue;
+        }
         auto flashall = [&](const std::string &partition) {
             do_send_signature(fname.c_str());
             flash_buf(partition.c_str(), &buf);
@@ -1333,6 +1363,8 @@
     bool wants_wipe = false;
     bool wants_reboot = false;
     bool wants_reboot_bootloader = false;
+    bool wants_reboot_recovery = false;
+    bool wants_reboot_fastboot = false;
     bool skip_reboot = false;
     bool wants_set_active = false;
     bool skip_secondary = false;
@@ -1555,6 +1587,12 @@
                 if (what == "bootloader") {
                     wants_reboot = false;
                     wants_reboot_bootloader = true;
+                } else if (what == "recovery") {
+                    wants_reboot = false;
+                    wants_reboot_recovery = true;
+                } else if (what == "fastboot") {
+                    wants_reboot = false;
+                    wants_reboot_fastboot = true;
                 } else {
                     syntax_error("unknown reboot target %s", what.c_str());
                 }
@@ -1563,6 +1601,10 @@
             if (!args.empty()) syntax_error("junk after reboot command");
         } else if (command == "reboot-bootloader") {
             wants_reboot_bootloader = true;
+        } else if (command == "reboot-recovery") {
+            wants_reboot_recovery = true;
+        } else if (command == "reboot-fastboot") {
+            wants_reboot_fastboot = true;
         } else if (command == "continue") {
             fb_queue_command("continue", "resuming boot");
         } else if (command == "boot") {
@@ -1680,6 +1722,12 @@
     } else if (wants_reboot_bootloader) {
         fb_queue_command("reboot-bootloader", "rebooting into bootloader");
         fb_queue_wait_for_disconnect();
+    } else if (wants_reboot_recovery) {
+        fb_queue_command("reboot-recovery", "rebooting into recovery");
+        fb_queue_wait_for_disconnect();
+    } else if (wants_reboot_fastboot) {
+        fb_queue_command("reboot-fastboot", "rebooting into fastboot");
+        fb_queue_wait_for_disconnect();
     }
 
     int status = fb_execute_queue() ? EXIT_FAILURE : EXIT_SUCCESS;
diff --git a/fastboot/fastboot_driver.cpp b/fastboot/fastboot_driver.cpp
index aabc620..55ca65d 100644
--- a/fastboot/fastboot_driver.cpp
+++ b/fastboot/fastboot_driver.cpp
@@ -134,7 +134,7 @@
         return ret;
     }
 
-    std::regex reg("partition-size[[:s:]]*:[[:s:]]*([[:w:]]+)[[:s:]]*:[[:s:]]*0x([[:d:]]+)");
+    std::regex reg("partition-size[[:s:]]*:[[:s:]]*([[:w:]]+)[[:s:]]*:[[:s:]]*0x([[:xdigit:]]+)");
     std::smatch sm;
 
     for (auto& s : all) {
@@ -264,11 +264,16 @@
                                std::vector<std::string>* info) {
     RetCode ret;
     int dsize;
-    if ((ret = RawCommand(Commands::UPLOAD, response, info, &dsize)) || dsize == 0) {
-        error_ = "Upload request failed";
+    if ((ret = RawCommand(Commands::UPLOAD, response, info, &dsize))) {
+        error_ = "Upload request failed: " + error_;
         return ret;
     }
 
+    if (!dsize) {
+        error_ = "Upload request failed, device reports 0 bytes available";
+        return BAD_DEV_RESP;
+    }
+
     std::vector<char> data;
     data.resize(dsize);
 
@@ -462,10 +467,10 @@
 }
 
 RetCode FastBootDriver::SendBuffer(const void* buf, size_t size) {
+    // ioctl on 0-length buffer causes freezing
     if (!size) {
-        return SUCCESS;
+        return BAD_ARG;
     }
-
     // Write the buffer
     ssize_t tmp = transport->Write(buf, size);
 
@@ -521,7 +526,7 @@
     // Now we need to send a multiple of chunk size
     size_t nchunks = (len - total) / TRANSPORT_CHUNK_SIZE;
     size_t nbytes = TRANSPORT_CHUNK_SIZE * nchunks;
-    if (SendBuffer(data + total, nbytes)) {
+    if (nbytes && SendBuffer(data + total, nbytes)) {  // Don't send a ZLP
         error_ = ErrnoStr("Send failed in SparseWriteCallback()");
         return -1;
     }
diff --git a/fastboot/fastboot_driver.h b/fastboot/fastboot_driver.h
index 9fdd317..e8711cb 100644
--- a/fastboot/fastboot_driver.h
+++ b/fastboot/fastboot_driver.h
@@ -103,7 +103,7 @@
 
     /* HELPERS */
     void SetInfoCallback(std::function<void(std::string&)> info);
-    const std::string RCString(RetCode rc);
+    static const std::string RCString(RetCode rc);
     std::string Error();
     RetCode WaitForDisconnect();
 
diff --git a/fs_mgr/fs_mgr_dm_linear.cpp b/fs_mgr/fs_mgr_dm_linear.cpp
index 05e03e1..a91e92e 100644
--- a/fs_mgr/fs_mgr_dm_linear.cpp
+++ b/fs_mgr/fs_mgr_dm_linear.cpp
@@ -80,13 +80,17 @@
 }
 
 static bool CreateLogicalPartition(const std::string& block_device, const LpMetadata& metadata,
-                                   const LpMetadataPartition& partition, std::string* path) {
+                                   const LpMetadataPartition& partition, bool force_writable,
+                                   std::string* path) {
     DeviceMapper& dm = DeviceMapper::Instance();
 
     DmTable table;
     if (!CreateDmTable(block_device, metadata, partition, &table)) {
         return false;
     }
+    if (force_writable) {
+        table.set_readonly(false);
+    }
     std::string name = GetPartitionName(partition);
     if (!dm.CreateDevice(name, table)) {
         return false;
@@ -106,8 +110,12 @@
         return true;
     }
     for (const auto& partition : metadata->partitions) {
+        if (!partition.num_extents) {
+            LINFO << "Skipping zero-length logical partition: " << GetPartitionName(partition);
+            continue;
+        }
         std::string path;
-        if (!CreateLogicalPartition(block_device, *metadata.get(), partition, &path)) {
+        if (!CreateLogicalPartition(block_device, *metadata.get(), partition, false, &path)) {
             LERROR << "Could not create logical partition: " << GetPartitionName(partition);
             return false;
         }
@@ -116,7 +124,8 @@
 }
 
 bool CreateLogicalPartition(const std::string& block_device, uint32_t metadata_slot,
-                            const std::string& partition_name, std::string* path) {
+                            const std::string& partition_name, bool force_writable,
+                            std::string* path) {
     auto metadata = ReadMetadata(block_device.c_str(), metadata_slot);
     if (!metadata) {
         LOG(ERROR) << "Could not read partition table.";
@@ -124,7 +133,8 @@
     }
     for (const auto& partition : metadata->partitions) {
         if (GetPartitionName(partition) == partition_name) {
-            return CreateLogicalPartition(block_device, *metadata.get(), partition, path);
+            return CreateLogicalPartition(block_device, *metadata.get(), partition, force_writable,
+                                          path);
         }
     }
     LERROR << "Could not find any partition with name: " << partition_name;
@@ -133,7 +143,11 @@
 
 bool DestroyLogicalPartition(const std::string& name) {
     DeviceMapper& dm = DeviceMapper::Instance();
-    return dm.DeleteDevice(name);
+    if (!dm.DeleteDevice(name)) {
+        return false;
+    }
+    LINFO << "Unmapped logical partition " << name;
+    return true;
 }
 
 }  // namespace fs_mgr
diff --git a/fs_mgr/include/fs_mgr_dm_linear.h b/fs_mgr/include/fs_mgr_dm_linear.h
index cac475c..f15c450 100644
--- a/fs_mgr/include/fs_mgr_dm_linear.h
+++ b/fs_mgr/include/fs_mgr_dm_linear.h
@@ -41,9 +41,11 @@
 
 // Create a block device for a single logical partition, given metadata and
 // the partition name. On success, a path to the partition's block device is
-// returned.
+// returned. If |force_writable| is true, the "readonly" flag will be ignored
+// so the partition can be flashed.
 bool CreateLogicalPartition(const std::string& block_device, uint32_t metadata_slot,
-                            const std::string& partition_name, std::string* path);
+                            const std::string& partition_name, bool force_writable,
+                            std::string* path);
 
 // Destroy the block device for a logical partition, by name.
 bool DestroyLogicalPartition(const std::string& name);
diff --git a/fs_mgr/liblp/builder.cpp b/fs_mgr/liblp/builder.cpp
index d6eee6b..2015e4d 100644
--- a/fs_mgr/liblp/builder.cpp
+++ b/fs_mgr/liblp/builder.cpp
@@ -48,10 +48,20 @@
         PERROR << __PRETTY_FUNCTION__ << "BLKIOMIN failed";
         return false;
     }
-    if (ioctl(fd, BLKALIGNOFF, &device_info->alignment_offset) < 0) {
+
+    int alignment_offset;
+    if (ioctl(fd, BLKALIGNOFF, &alignment_offset) < 0) {
         PERROR << __PRETTY_FUNCTION__ << "BLKIOMIN failed";
         return false;
     }
+    int logical_block_size;
+    if (ioctl(fd, BLKSSZGET, &logical_block_size) < 0) {
+        PERROR << __PRETTY_FUNCTION__ << "BLKSSZGET failed";
+        return false;
+    }
+
+    device_info->alignment_offset = static_cast<uint32_t>(alignment_offset);
+    device_info->logical_block_size = static_cast<uint32_t>(logical_block_size);
     return true;
 #else
     (void)block_device;
@@ -74,6 +84,19 @@
 
 void Partition::AddExtent(std::unique_ptr<Extent>&& extent) {
     size_ += extent->num_sectors() * LP_SECTOR_SIZE;
+
+    if (LinearExtent* new_extent = extent->AsLinearExtent()) {
+        if (!extents_.empty() && extents_.back()->AsLinearExtent() &&
+            extents_.back()->AsLinearExtent()->end_sector() == new_extent->physical_sector()) {
+            // If the previous extent can be merged into this new one, do so
+            // to avoid creating unnecessary extents.
+            LinearExtent* prev_extent = extents_.back()->AsLinearExtent();
+            extent = std::make_unique<LinearExtent>(
+                    prev_extent->num_sectors() + new_extent->num_sectors(),
+                    prev_extent->physical_sector());
+            extents_.pop_back();
+        }
+    }
     extents_.push_back(std::move(extent));
 }
 
@@ -178,6 +201,7 @@
 
     device_info_.alignment = geometry_.alignment;
     device_info_.alignment_offset = geometry_.alignment_offset;
+    device_info_.logical_block_size = geometry_.logical_block_size;
     return true;
 }
 
@@ -201,6 +225,10 @@
         LERROR << "Block device size must be a multiple of 512.";
         return false;
     }
+    if (device_info_.logical_block_size % LP_SECTOR_SIZE != 0) {
+        LERROR << "Logical block size must be a multiple of 512.";
+        return false;
+    }
     if (device_info_.alignment_offset % LP_SECTOR_SIZE != 0) {
         LERROR << "Alignment offset is not sector-aligned.";
         return false;
@@ -244,6 +272,18 @@
         return false;
     }
 
+    // Finally, the size of the allocatable space must be a multiple of the
+    // logical block size. If we have no more free space after this
+    // computation, then we abort. Note that the last sector is inclusive,
+    // so we have to account for that.
+    uint64_t num_free_sectors = last_sector - first_sector + 1;
+    uint64_t sectors_per_block = device_info_.logical_block_size / LP_SECTOR_SIZE;
+    if (num_free_sectors < sectors_per_block) {
+        LERROR << "Not enough space to allocate any partition tables.";
+        return false;
+    }
+    last_sector = first_sector + (num_free_sectors / sectors_per_block) * sectors_per_block - 1;
+
     geometry_.first_logical_sector = first_sector;
     geometry_.last_logical_sector = last_sector;
     geometry_.metadata_max_size = metadata_max_size;
@@ -251,6 +291,7 @@
     geometry_.alignment = device_info_.alignment;
     geometry_.alignment_offset = device_info_.alignment_offset;
     geometry_.block_device_size = device_info_.size;
+    geometry_.logical_block_size = device_info.logical_block_size;
     return true;
 }
 
@@ -297,87 +338,93 @@
         uint64_t end;
 
         Interval(uint64_t start, uint64_t end) : start(start), end(end) {}
+        uint64_t length() const { return end - start; }
         bool operator<(const Interval& other) const { return start < other.start; }
     };
-    std::vector<Interval> intervals;
 
-    // Collect all extents in the partition table.
+    // Collect all extents in the partition table, then sort them by starting
+    // sector.
+    std::vector<Interval> extents;
     for (const auto& partition : partitions_) {
         for (const auto& extent : partition->extents()) {
             LinearExtent* linear = extent->AsLinearExtent();
             if (!linear) {
                 continue;
             }
-            intervals.emplace_back(linear->physical_sector(),
-                                   linear->physical_sector() + extent->num_sectors());
+            extents.emplace_back(linear->physical_sector(),
+                                 linear->physical_sector() + extent->num_sectors());
         }
     }
+    std::sort(extents.begin(), extents.end());
 
-    // Sort extents by starting sector.
-    std::sort(intervals.begin(), intervals.end());
+    // Convert the extent list into a list of gaps between the extents; i.e.,
+    // the list of ranges that are free on the disk.
+    std::vector<Interval> free_regions;
+    for (size_t i = 1; i < extents.size(); i++) {
+        const Interval& previous = extents[i - 1];
+        const Interval& current = extents[i];
+
+        uint64_t aligned = AlignSector(previous.end);
+        if (aligned >= current.start) {
+            // There is no gap between these two extents, try the next one.
+            // Note that we check with >= instead of >, since alignment may
+            // bump the ending sector past the beginning of the next extent.
+            continue;
+        }
+
+        // The new interval represents the free space starting at the end of
+        // the previous interval, and ending at the start of the next interval.
+        free_regions.emplace_back(aligned, current.start);
+    }
+
+    // Add a final interval representing the remainder of the free space.
+    uint64_t last_free_extent_start =
+            extents.empty() ? geometry_.first_logical_sector : extents.back().end;
+    last_free_extent_start = AlignSector(last_free_extent_start);
+    if (last_free_extent_start <= geometry_.last_logical_sector) {
+        free_regions.emplace_back(last_free_extent_start, geometry_.last_logical_sector + 1);
+    }
+
+    const uint64_t sectors_per_block = device_info_.logical_block_size / LP_SECTOR_SIZE;
+    CHECK(sectors_needed % sectors_per_block == 0);
 
     // Find gaps that we can use for new extents. Note we store new extents in a
     // temporary vector, and only commit them if we are guaranteed enough free
     // space.
     std::vector<std::unique_ptr<LinearExtent>> new_extents;
-    for (size_t i = 1; i < intervals.size(); i++) {
-        const Interval& previous = intervals[i - 1];
-        const Interval& current = intervals[i];
+    for (auto& region : free_regions) {
+        if (region.length() % sectors_per_block != 0) {
+            // This should never happen, because it would imply that we
+            // once allocated an extent that was not a multiple of the
+            // block size. That extent would be rejected by DM_TABLE_LOAD.
+            LERROR << "Region " << region.start << ".." << region.end
+                   << " is not a multiple of the block size, " << sectors_per_block;
 
-        if (previous.end >= current.start) {
-            // There is no gap between these two extents, try the next one. Note that
-            // extents may never overlap, but just for safety, we ignore them if they
-            // do.
-            DCHECK(previous.end == current.start);
-            continue;
+            // If for some reason the final region is mis-sized we still want
+            // to be able to grow partitions. So just to be safe, round the
+            // region down to the nearest block.
+            region.end = region.start + (region.length() / sectors_per_block) * sectors_per_block;
+            if (!region.length()) {
+                continue;
+            }
         }
 
-        uint64_t aligned = AlignSector(previous.end);
-        if (aligned >= current.start) {
-            // After alignment, this extent is not usable.
-            continue;
-        }
+        uint64_t sectors = std::min(sectors_needed, region.length());
+        CHECK(sectors % sectors_per_block == 0);
 
-        // This gap is enough to hold the remainder of the space requested, so we
-        // can allocate what we need and return.
-        if (current.start - aligned >= sectors_needed) {
-            auto extent = std::make_unique<LinearExtent>(sectors_needed, aligned);
-            sectors_needed -= extent->num_sectors();
-            new_extents.push_back(std::move(extent));
+        auto extent = std::make_unique<LinearExtent>(sectors, region.start);
+        new_extents.push_back(std::move(extent));
+        sectors_needed -= sectors;
+        if (!sectors_needed) {
             break;
         }
-
-        // This gap is not big enough to fit the remainder of the space requested,
-        // so consume the whole thing and keep looking for more.
-        auto extent = std::make_unique<LinearExtent>(current.start - aligned, aligned);
-        sectors_needed -= extent->num_sectors();
-        new_extents.push_back(std::move(extent));
     }
-
-    // If we still have more to allocate, take it from the remaining free space
-    // in the allocatable region.
     if (sectors_needed) {
-        uint64_t first_sector;
-        if (intervals.empty()) {
-            first_sector = geometry_.first_logical_sector;
-        } else {
-            first_sector = intervals.back().end;
-        }
-        DCHECK(first_sector <= geometry_.last_logical_sector);
-
-        // Note: After alignment, |first_sector| may be > the last usable sector.
-        first_sector = AlignSector(first_sector);
-
-        // Note: the last usable sector is inclusive.
-        if (first_sector > geometry_.last_logical_sector ||
-            geometry_.last_logical_sector + 1 - first_sector < sectors_needed) {
-            LERROR << "Not enough free space to expand partition: " << partition->name();
-            return false;
-        }
-        auto extent = std::make_unique<LinearExtent>(sectors_needed, first_sector);
-        new_extents.push_back(std::move(extent));
+        LERROR << "Not enough free space to expand partition: " << partition->name();
+        return false;
     }
 
+    // Everything succeeded, so commit the new extents.
     for (auto& extent : new_extents) {
         partition->AddExtent(std::move(extent));
     }
@@ -445,6 +492,12 @@
 void MetadataBuilder::set_block_device_info(const BlockDeviceInfo& device_info) {
     device_info_.size = device_info.size;
 
+    // Note that if the logical block size changes, we're probably in trouble:
+    // we could have already built extents that will only work on the previous
+    // size.
+    DCHECK(partitions_.empty() ||
+           device_info_.logical_block_size == device_info.logical_block_size);
+
     // The kernel does not guarantee these values are present, so we only
     // replace existing values if the new values are non-zero.
     if (device_info.alignment) {
@@ -457,14 +510,19 @@
 
 bool MetadataBuilder::ResizePartition(Partition* partition, uint64_t requested_size) {
     // Align the space needed up to the nearest sector.
-    uint64_t aligned_size = AlignTo(requested_size, LP_SECTOR_SIZE);
+    uint64_t aligned_size = AlignTo(requested_size, device_info_.logical_block_size);
+    uint64_t old_size = partition->size();
 
-    if (aligned_size > partition->size()) {
-        return GrowPartition(partition, aligned_size);
-    }
-    if (aligned_size < partition->size()) {
+    if (aligned_size > old_size) {
+        if (!GrowPartition(partition, aligned_size)) {
+            return false;
+        }
+    } else if (aligned_size < partition->size()) {
         ShrinkPartition(partition, aligned_size);
     }
+
+    LINFO << "Partition " << partition->name() << " will resize from " << old_size << " bytes to "
+          << aligned_size << " bytes";
     return true;
 }
 
diff --git a/fs_mgr/liblp/builder_test.cpp b/fs_mgr/liblp/builder_test.cpp
index 4334d51..da9c8f3 100644
--- a/fs_mgr/liblp/builder_test.cpp
+++ b/fs_mgr/liblp/builder_test.cpp
@@ -69,6 +69,11 @@
     EXPECT_EQ(system->size(), 131072);
     EXPECT_EQ(system->extents().size(), 1);
     EXPECT_EQ(system->extents()[0]->num_sectors(), 131072 / LP_SECTOR_SIZE);
+    // Test resizing again, that the extents are merged together.
+    builder->ResizePartition(system, 1024 * 256);
+    EXPECT_EQ(system->size(), 1024 * 256);
+    EXPECT_EQ(system->extents().size(), 1);
+    EXPECT_EQ(system->extents()[0]->num_sectors(), (1024 * 256) / LP_SECTOR_SIZE);
 
     // Test shrinking within the same extent.
     builder->ResizePartition(system, 32768);
@@ -92,11 +97,11 @@
     Partition* system = builder->AddPartition("system", TEST_GUID, LP_PARTITION_ATTR_READONLY);
     ASSERT_NE(system, nullptr);
     EXPECT_EQ(builder->ResizePartition(system, 10000), true);
-    EXPECT_EQ(system->size(), 10240);
+    EXPECT_EQ(system->size(), 12288);
     EXPECT_EQ(system->extents().size(), 1);
 
-    builder->ResizePartition(system, 9000);
-    EXPECT_EQ(system->size(), 9216);
+    builder->ResizePartition(system, 7000);
+    EXPECT_EQ(system->size(), 8192);
     EXPECT_EQ(system->extents().size(), 1);
 }
 
@@ -120,13 +125,13 @@
 
 TEST(liblp, InternalAlignment) {
     // Test the metadata fitting within alignment.
-    BlockDeviceInfo device_info(1024 * 1024, 768 * 1024, 0);
+    BlockDeviceInfo device_info(1024 * 1024, 768 * 1024, 0, 4096);
     unique_ptr<MetadataBuilder> builder = MetadataBuilder::New(device_info, 1024, 2);
     ASSERT_NE(builder, nullptr);
     unique_ptr<LpMetadata> exported = builder->Export();
     ASSERT_NE(exported, nullptr);
     EXPECT_EQ(exported->geometry.first_logical_sector, 1536);
-    EXPECT_EQ(exported->geometry.last_logical_sector, 2035);
+    EXPECT_EQ(exported->geometry.last_logical_sector, 2031);
 
     // Test a large alignment offset thrown in.
     device_info.alignment_offset = 753664;
@@ -135,7 +140,7 @@
     exported = builder->Export();
     ASSERT_NE(exported, nullptr);
     EXPECT_EQ(exported->geometry.first_logical_sector, 1472);
-    EXPECT_EQ(exported->geometry.last_logical_sector, 2035);
+    EXPECT_EQ(exported->geometry.last_logical_sector, 2031);
 
     // Alignment offset without alignment doesn't mean anything.
     device_info.alignment = 0;
@@ -150,7 +155,7 @@
     exported = builder->Export();
     ASSERT_NE(exported, nullptr);
     EXPECT_EQ(exported->geometry.first_logical_sector, 78);
-    EXPECT_EQ(exported->geometry.last_logical_sector, 1975);
+    EXPECT_EQ(exported->geometry.last_logical_sector, 1973);
 
     // Test a small alignment with no alignment offset.
     device_info.alignment = 11 * 1024;
@@ -163,7 +168,7 @@
 }
 
 TEST(liblp, InternalPartitionAlignment) {
-    BlockDeviceInfo device_info(512 * 1024 * 1024, 768 * 1024, 753664);
+    BlockDeviceInfo device_info(512 * 1024 * 1024, 768 * 1024, 753664, 4096);
     unique_ptr<MetadataBuilder> builder = MetadataBuilder::New(device_info, 32 * 1024, 2);
 
     Partition* a = builder->AddPartition("a", TEST_GUID, 0);
@@ -381,7 +386,7 @@
     static const size_t kMetadataSize = 64 * 1024;
 
     // No space to store metadata + geometry.
-    BlockDeviceInfo device_info(kDiskSize, 0, 0);
+    BlockDeviceInfo device_info(kDiskSize, 0, 0, 4096);
     unique_ptr<MetadataBuilder> builder = MetadataBuilder::New(device_info, kMetadataSize, 1);
     EXPECT_EQ(builder, nullptr);
 
@@ -390,8 +395,8 @@
     builder = MetadataBuilder::New(device_info, kMetadataSize, 1);
     EXPECT_EQ(builder, nullptr);
 
-    // Space for metadata + geometry + one free sector.
-    device_info.size += LP_SECTOR_SIZE;
+    // Space for metadata + geometry + one free block.
+    device_info.size += device_info.logical_block_size;
     builder = MetadataBuilder::New(device_info, kMetadataSize, 1);
     EXPECT_NE(builder, nullptr);
 
@@ -424,19 +429,21 @@
     ASSERT_EQ(device_info.alignment % LP_SECTOR_SIZE, 0);
     ASSERT_EQ(device_info.alignment_offset % LP_SECTOR_SIZE, 0);
     ASSERT_LE(device_info.alignment_offset, INT_MAX);
+    ASSERT_EQ(device_info.logical_block_size % LP_SECTOR_SIZE, 0);
 
     // Having an alignment offset > alignment doesn't really make sense.
     ASSERT_LT(device_info.alignment_offset, device_info.alignment);
 }
 
 TEST(liblp, UpdateBlockDeviceInfo) {
-    BlockDeviceInfo device_info(1024 * 1024, 4096, 1024);
+    BlockDeviceInfo device_info(1024 * 1024, 4096, 1024, 4096);
     unique_ptr<MetadataBuilder> builder = MetadataBuilder::New(device_info, 1024, 1);
     ASSERT_NE(builder, nullptr);
 
     EXPECT_EQ(builder->block_device_info().size, device_info.size);
     EXPECT_EQ(builder->block_device_info().alignment, device_info.alignment);
     EXPECT_EQ(builder->block_device_info().alignment_offset, device_info.alignment_offset);
+    EXPECT_EQ(builder->block_device_info().logical_block_size, device_info.logical_block_size);
 
     device_info.alignment = 0;
     device_info.alignment_offset = 2048;
@@ -450,3 +457,27 @@
     EXPECT_EQ(builder->block_device_info().alignment, 8192);
     EXPECT_EQ(builder->block_device_info().alignment_offset, 2048);
 }
+
+TEST(liblp, InvalidBlockSize) {
+    BlockDeviceInfo device_info(1024 * 1024, 0, 0, 513);
+    unique_ptr<MetadataBuilder> builder = MetadataBuilder::New(device_info, 1024, 1);
+    EXPECT_EQ(builder, nullptr);
+}
+
+TEST(liblp, AlignedExtentSize) {
+    BlockDeviceInfo device_info(1024 * 1024, 0, 0, 4096);
+    unique_ptr<MetadataBuilder> builder = MetadataBuilder::New(device_info, 1024, 1);
+    ASSERT_NE(builder, nullptr);
+
+    Partition* partition = builder->AddPartition("system", TEST_GUID, 0);
+    ASSERT_NE(partition, nullptr);
+    ASSERT_TRUE(builder->ResizePartition(partition, 512));
+    EXPECT_EQ(partition->size(), 4096);
+}
+
+TEST(liblp, AlignedFreeSpace) {
+    // Only one sector free - at least one block is required.
+    BlockDeviceInfo device_info(10240, 0, 0, 4096);
+    unique_ptr<MetadataBuilder> builder = MetadataBuilder::New(device_info, 512, 1);
+    ASSERT_EQ(builder, nullptr);
+}
diff --git a/fs_mgr/liblp/include/liblp/builder.h b/fs_mgr/liblp/include/liblp/builder.h
index 0f96e3a..a35cf8e 100644
--- a/fs_mgr/liblp/include/liblp/builder.h
+++ b/fs_mgr/liblp/include/liblp/builder.h
@@ -32,11 +32,16 @@
 
 // By default, partitions are aligned on a 1MiB boundary.
 static const uint32_t kDefaultPartitionAlignment = 1024 * 1024;
+static const uint32_t kDefaultBlockSize = 4096;
 
 struct BlockDeviceInfo {
-    BlockDeviceInfo() : size(0), alignment(0), alignment_offset(0) {}
-    BlockDeviceInfo(uint64_t size, uint32_t alignment, uint32_t alignment_offset)
-        : size(size), alignment(alignment), alignment_offset(alignment_offset) {}
+    BlockDeviceInfo() : size(0), alignment(0), alignment_offset(0), logical_block_size(0) {}
+    BlockDeviceInfo(uint64_t size, uint32_t alignment, uint32_t alignment_offset,
+                    uint32_t logical_block_size)
+        : size(size),
+          alignment(alignment),
+          alignment_offset(alignment_offset),
+          logical_block_size(logical_block_size) {}
     // Size of the block device, in bytes.
     uint64_t size;
     // Optimal target alignment, in bytes. Partition extents will be aligned to
@@ -46,6 +51,8 @@
     // |alignment_offset| on the target device is correctly aligned on its
     // parent device. This value must be 0 or a multiple of 512.
     uint32_t alignment_offset;
+    // Block size, for aligning extent sizes and partition sizes.
+    uint32_t logical_block_size;
 };
 
 // Abstraction around dm-targets that can be encoded into logical partition tables.
@@ -74,6 +81,7 @@
     LinearExtent* AsLinearExtent() override { return this; }
 
     uint64_t physical_sector() const { return physical_sector_; }
+    uint64_t end_sector() const { return physical_sector_ + num_sectors_; }
 
   private:
     uint64_t physical_sector_;
@@ -88,6 +96,8 @@
 };
 
 class Partition final {
+    friend class MetadataBuilder;
+
   public:
     Partition(const std::string& name, const std::string& guid, uint32_t attributes);
 
@@ -97,10 +107,6 @@
     // Remove all extents from this partition.
     void RemoveExtents();
 
-    // Remove and/or shrink extents until the partition is the requested size.
-    // See MetadataBuilder::ShrinkPartition for more information.
-    void ShrinkTo(uint64_t requested_size);
-
     const std::string& name() const { return name_; }
     uint32_t attributes() const { return attributes_; }
     const std::string& guid() const { return guid_; }
@@ -108,6 +114,8 @@
     uint64_t size() const { return size_; }
 
   private:
+    void ShrinkTo(uint64_t aligned_size);
+
     std::string name_;
     std::string guid_;
     std::vector<std::unique_ptr<Extent>> extents_;
@@ -144,7 +152,7 @@
     // size. This is a convenience method for tests.
     static std::unique_ptr<MetadataBuilder> New(uint64_t blockdev_size, uint32_t metadata_max_size,
                                                 uint32_t metadata_slot_count) {
-        BlockDeviceInfo device_info(blockdev_size, 0, 0);
+        BlockDeviceInfo device_info(blockdev_size, 0, 0, kDefaultBlockSize);
         return New(device_info, metadata_max_size, metadata_slot_count);
     }
 
diff --git a/fs_mgr/liblp/include/liblp/metadata_format.h b/fs_mgr/liblp/include/liblp/metadata_format.h
index e1323e1..52c80f7 100644
--- a/fs_mgr/liblp/include/liblp/metadata_format.h
+++ b/fs_mgr/liblp/include/liblp/metadata_format.h
@@ -136,6 +136,12 @@
      * can be used to verify the geometry against a target device.
      */
     uint64_t block_device_size;
+
+    /* 76: Logical block size of the super partition block device. This is the
+     * minimal alignment for partition and extent sizes, and it must be a
+     * multiple of LP_SECTOR_SIZE.
+     */
+    uint32_t logical_block_size;
 } __attribute__((packed)) LpMetadataGeometry;
 
 /* The logical partition metadata has a number of tables; they are described
diff --git a/fs_mgr/liblp/utility.h b/fs_mgr/liblp/utility.h
index 4522275..6ef5124 100644
--- a/fs_mgr/liblp/utility.h
+++ b/fs_mgr/liblp/utility.h
@@ -26,6 +26,8 @@
 #include "liblp/metadata_format.h"
 
 #define LP_TAG "[liblp]"
+#define LWARN LOG(WARNING) << LP_TAG
+#define LINFO LOG(INFO) << LP_TAG
 #define LERROR LOG(ERROR) << LP_TAG
 #define PERROR PLOG(ERROR) << LP_TAG
 
diff --git a/fs_mgr/liblp/utility_test.cpp b/fs_mgr/liblp/utility_test.cpp
index 092dbf1..7bf42ae 100644
--- a/fs_mgr/liblp/utility_test.cpp
+++ b/fs_mgr/liblp/utility_test.cpp
@@ -40,7 +40,8 @@
                                    80000,
                                    0,
                                    0,
-                                   1024 * 1024};
+                                   1024 * 1024,
+                                   4096};
     EXPECT_EQ(GetPrimaryMetadataOffset(geometry, 0), 4096);
     EXPECT_EQ(GetPrimaryMetadataOffset(geometry, 1), 4096 + 16384);
     EXPECT_EQ(GetPrimaryMetadataOffset(geometry, 2), 4096 + 16384 * 2);
diff --git a/fs_mgr/liblp/writer.cpp b/fs_mgr/liblp/writer.cpp
index 156319b..fc9d83f 100644
--- a/fs_mgr/liblp/writer.cpp
+++ b/fs_mgr/liblp/writer.cpp
@@ -304,7 +304,11 @@
         PERROR << __PRETTY_FUNCTION__ << "open failed: " << block_device;
         return false;
     }
-    return FlashPartitionTable(fd, metadata, slot_number);
+    if (!FlashPartitionTable(fd, metadata, slot_number)) {
+        return false;
+    }
+    LWARN << "Flashed new logical partition geometry to " << block_device;
+    return true;
 }
 
 bool UpdatePartitionTable(const std::string& block_device, const LpMetadata& metadata,
@@ -314,7 +318,12 @@
         PERROR << __PRETTY_FUNCTION__ << "open failed: " << block_device;
         return false;
     }
-    return UpdatePartitionTable(fd, metadata, slot_number);
+    if (!UpdatePartitionTable(fd, metadata, slot_number)) {
+        return false;
+    }
+    LINFO << "Updated logical partition table at slot " << slot_number << " on device "
+          << block_device;
+    return true;
 }
 
 bool UpdatePartitionTable(int fd, const LpMetadata& metadata, uint32_t slot_number) {
diff --git a/init/Android.bp b/init/Android.bp
index 660d586..d42ab8a 100644
--- a/init/Android.bp
+++ b/init/Android.bp
@@ -107,6 +107,7 @@
         "first_stage_mount.cpp",
         "import_parser.cpp",
         "init.cpp",
+        "init_first_stage.cpp",
         "keychords.cpp",
         "modalias_handler.cpp",
         "parser.cpp",
@@ -115,6 +116,7 @@
         "property_service.cpp",
         "property_type.cpp",
         "reboot.cpp",
+        "reboot_utils.cpp",
         "security.cpp",
         "selinux.cpp",
         "service.cpp",
@@ -127,7 +129,6 @@
         "ueventd.cpp",
         "ueventd_parser.cpp",
         "util.cpp",
-        "watchdogd.cpp",
     ],
     whole_static_libs: ["libcap"],
     header_libs: ["bootimg_headers"],
@@ -157,7 +158,6 @@
     srcs: ["main.cpp"],
     symlinks: [
         "sbin/ueventd",
-        "sbin/watchdogd",
     ],
 }
 */
diff --git a/init/Android.mk b/init/Android.mk
index d0cb820..9d9d368 100644
--- a/init/Android.mk
+++ b/init/Android.mk
@@ -98,7 +98,6 @@
 # Create symlinks.
 LOCAL_POST_INSTALL_CMD := $(hide) mkdir -p $(TARGET_ROOT_OUT)/sbin; \
     ln -sf ../init $(TARGET_ROOT_OUT)/sbin/ueventd; \
-    ln -sf ../init $(TARGET_ROOT_OUT)/sbin/watchdogd
 
 LOCAL_SANITIZE := signed-integer-overflow
 include $(BUILD_EXECUTABLE)
diff --git a/init/devices.cpp b/init/devices.cpp
index ed4a739..58c8b2e 100644
--- a/init/devices.cpp
+++ b/init/devices.cpp
@@ -34,7 +34,7 @@
 #include "util.h"
 
 #ifdef _INIT_INIT_H
-#error "Do not include init.h in files used by ueventd or watchdogd; it will expose init's globals"
+#error "Do not include init.h in files used by ueventd; it will expose init's globals"
 #endif
 
 using android::base::Basename;
@@ -372,7 +372,7 @@
     }
 }
 
-void DeviceHandler::HandleDeviceEvent(const Uevent& uevent) {
+void DeviceHandler::HandleUevent(const Uevent& uevent) {
     if (uevent.action == "add" || uevent.action == "change" || uevent.action == "online") {
         FixupSysPermissions(uevent.path, uevent.subsystem);
     }
@@ -418,6 +418,10 @@
     HandleDevice(uevent.action, devpath, block, uevent.major, uevent.minor, links);
 }
 
+void DeviceHandler::ColdbootDone() {
+    skip_restorecon_ = true;
+}
+
 DeviceHandler::DeviceHandler(std::vector<Permissions> dev_permissions,
                              std::vector<SysfsPermissions> sysfs_permissions,
                              std::vector<Subsystem> subsystems, std::set<std::string> boot_devices,
diff --git a/init/devices.h b/init/devices.h
index 0be660f..9d39eaa 100644
--- a/init/devices.h
+++ b/init/devices.h
@@ -29,6 +29,7 @@
 #include <selinux/label.h>
 
 #include "uevent.h"
+#include "uevent_handler.h"
 
 namespace android {
 namespace init {
@@ -105,7 +106,7 @@
     std::string dir_name_ = "/dev";
 };
 
-class DeviceHandler {
+class DeviceHandler : public UeventHandler {
   public:
     friend class DeviceHandlerTester;
 
@@ -113,11 +114,12 @@
     DeviceHandler(std::vector<Permissions> dev_permissions,
                   std::vector<SysfsPermissions> sysfs_permissions, std::vector<Subsystem> subsystems,
                   std::set<std::string> boot_devices, bool skip_restorecon);
+    virtual ~DeviceHandler() = default;
 
-    void HandleDeviceEvent(const Uevent& uevent);
+    void HandleUevent(const Uevent& uevent) override;
+    void ColdbootDone() override;
 
     std::vector<std::string> GetBlockDeviceSymlinks(const Uevent& uevent) const;
-    void set_skip_restorecon(bool value) { skip_restorecon_ = value; }
 
   private:
     bool FindPlatformDevice(std::string path, std::string* platform_device_path) const;
diff --git a/init/firmware_handler.cpp b/init/firmware_handler.cpp
index 28bda34..740e82c 100644
--- a/init/firmware_handler.cpp
+++ b/init/firmware_handler.cpp
@@ -35,8 +35,6 @@
 namespace android {
 namespace init {
 
-std::vector<std::string> firmware_directories;
-
 static void LoadFirmware(const Uevent& uevent, const std::string& root, int fw_fd, size_t fw_size,
                          int loading_fd, int data_fd) {
     // Start transfer.
@@ -58,7 +56,10 @@
     return access("/dev/.booting", F_OK) == 0;
 }
 
-static void ProcessFirmwareEvent(const Uevent& uevent) {
+FirmwareHandler::FirmwareHandler(std::vector<std::string> firmware_directories)
+    : firmware_directories_(std::move(firmware_directories)) {}
+
+void FirmwareHandler::ProcessFirmwareEvent(const Uevent& uevent) {
     int booting = IsBooting();
 
     LOG(INFO) << "firmware: loading '" << uevent.firmware << "' for '" << uevent.path << "'";
@@ -80,7 +81,7 @@
     }
 
 try_loading_again:
-    for (const auto& firmware_directory : firmware_directories) {
+    for (const auto& firmware_directory : firmware_directories_) {
         std::string file = firmware_directory + uevent.firmware;
         unique_fd fw_fd(open(file.c_str(), O_RDONLY | O_CLOEXEC));
         struct stat sb;
@@ -104,7 +105,7 @@
     write(loading_fd, "-1", 2);
 }
 
-void HandleFirmwareEvent(const Uevent& uevent) {
+void FirmwareHandler::HandleUevent(const Uevent& uevent) {
     if (uevent.subsystem != "firmware" || uevent.action != "add") return;
 
     // Loading the firmware in a child means we can do that in parallel...
diff --git a/init/firmware_handler.h b/init/firmware_handler.h
index 6081511..3996096 100644
--- a/init/firmware_handler.h
+++ b/init/firmware_handler.h
@@ -21,13 +21,23 @@
 #include <vector>
 
 #include "uevent.h"
+#include "uevent_handler.h"
 
 namespace android {
 namespace init {
 
-extern std::vector<std::string> firmware_directories;
+class FirmwareHandler : public UeventHandler {
+  public:
+    explicit FirmwareHandler(std::vector<std::string> firmware_directories);
+    virtual ~FirmwareHandler() = default;
 
-void HandleFirmwareEvent(const Uevent& uevent);
+    void HandleUevent(const Uevent& uevent) override;
+
+  private:
+    void ProcessFirmwareEvent(const Uevent& uevent);
+
+    std::vector<std::string> firmware_directories_;
+};
 
 }  // namespace init
 }  // namespace android
diff --git a/init/first_stage_mount.cpp b/init/first_stage_mount.cpp
index 43075b2..41e8fff 100644
--- a/init/first_stage_mount.cpp
+++ b/init/first_stage_mount.cpp
@@ -206,7 +206,7 @@
         bool found = false;
         auto dm_callback = [this, &dm_path, &found](const Uevent& uevent) {
             if (uevent.path == dm_path) {
-                device_handler_->HandleDeviceEvent(uevent);
+                device_handler_->HandleUevent(uevent);
                 found = true;
                 return ListenerAction::kStop;
             }
@@ -273,7 +273,7 @@
             lp_metadata_partition_ = links[0];
         }
         required_devices_partition_names_.erase(iter);
-        device_handler_->HandleDeviceEvent(uevent);
+        device_handler_->HandleUevent(uevent);
         if (required_devices_partition_names_.empty()) {
             return ListenerAction::kStop;
         } else {
@@ -310,7 +310,7 @@
     auto verity_callback = [&device_name, &dm_device, this, &found](const Uevent& uevent) {
         if (uevent.device_name == device_name) {
             LOG(VERBOSE) << "Creating device-mapper device : " << dm_device;
-            device_handler_->HandleDeviceEvent(uevent);
+            device_handler_->HandleUevent(uevent);
             found = true;
             return ListenerAction::kStop;
         }
diff --git a/init/host_init_stubs.cpp b/init/host_init_stubs.cpp
index 2352fc7..8866bdc 100644
--- a/init/host_init_stubs.cpp
+++ b/init/host_init_stubs.cpp
@@ -41,10 +41,9 @@
 }
 
 // selinux.h
-bool SelinuxHasVendorInit() {
-    return true;
+int SelinuxGetVendorAndroidVersion() {
+    return 10000;
 }
-
 void SelabelInitialize() {}
 
 bool SelabelLookupFileContext(const std::string& key, int type, std::string* result) {
diff --git a/init/host_init_stubs.h b/init/host_init_stubs.h
index f0e1f07..0af11f6 100644
--- a/init/host_init_stubs.h
+++ b/init/host_init_stubs.h
@@ -23,6 +23,9 @@
 
 #include <string>
 
+// android/api-level.h
+#define __ANDROID_API_P__ 28
+
 // sys/system_properties.h
 #define PROP_VALUE_MAX 92
 
@@ -41,7 +44,7 @@
                            const std::string& source_context, const ucred& cr, std::string* error);
 
 // selinux.h
-bool SelinuxHasVendorInit();
+int SelinuxGetVendorAndroidVersion();
 void SelabelInitialize();
 bool SelabelLookupFileContext(const std::string& key, int type, std::string* result);
 
diff --git a/init/init.cpp b/init/init.cpp
index 7ad9ec3..ad80c98 100644
--- a/init/init.cpp
+++ b/init/init.cpp
@@ -18,15 +18,12 @@
 
 #include <dirent.h>
 #include <fcntl.h>
-#include <paths.h>
 #include <pthread.h>
-#include <seccomp_policy.h>
 #include <signal.h>
 #include <stdlib.h>
 #include <string.h>
 #include <sys/mount.h>
 #include <sys/signalfd.h>
-#include <sys/sysmacros.h>
 #include <sys/types.h>
 #include <unistd.h>
 
@@ -43,8 +40,6 @@
 #include <cutils/android_reboot.h>
 #include <keyutils.h>
 #include <libavb/libavb.h>
-#include <private/android_filesystem_config.h>
-#include <selinux/android.h>
 
 #include "action_parser.h"
 #include "epoll.h"
@@ -53,12 +48,12 @@
 #include "keychords.h"
 #include "property_service.h"
 #include "reboot.h"
+#include "reboot_utils.h"
 #include "security.h"
 #include "selinux.h"
 #include "sigchld_handler.h"
 #include "ueventd.h"
 #include "util.h"
-#include "watchdogd.h"
 
 using namespace std::chrono_literals;
 using namespace std::string_literals;
@@ -418,14 +413,6 @@
     return Success();
 }
 
-static void global_seccomp() {
-    import_kernel_cmdline(false, [](const std::string& key, const std::string& value, bool in_qemu) {
-        if (key == "androidboot.seccomp" && value == "global" && !set_global_seccomp_filter()) {
-            LOG(FATAL) << "Failed to globally enable seccomp!";
-        }
-    });
-}
-
 // Set the UDC controller for the ConfigFS USB Gadgets.
 // Read the UDC controller in use from "/sys/class/udc".
 // In case of multiple UDC controllers select the first one.
@@ -442,40 +429,6 @@
     }
 }
 
-static void InstallRebootSignalHandlers() {
-    // Instead of panic'ing the kernel as is the default behavior when init crashes,
-    // we prefer to reboot to bootloader on development builds, as this will prevent
-    // boot looping bad configurations and allow both developers and test farms to easily
-    // recover.
-    struct sigaction action;
-    memset(&action, 0, sizeof(action));
-    sigfillset(&action.sa_mask);
-    action.sa_handler = [](int signal) {
-        // These signal handlers are also caught for processes forked from init, however we do not
-        // want them to trigger reboot, so we directly call _exit() for children processes here.
-        if (getpid() != 1) {
-            _exit(signal);
-        }
-
-        // Calling DoReboot() or LOG(FATAL) is not a good option as this is a signal handler.
-        // RebootSystem uses syscall() which isn't actually async-signal-safe, but our only option
-        // and probably good enough given this is already an error case and only enabled for
-        // development builds.
-        RebootSystem(ANDROID_RB_RESTART2, "bootloader");
-    };
-    action.sa_flags = SA_RESTART;
-    sigaction(SIGABRT, &action, nullptr);
-    sigaction(SIGBUS, &action, nullptr);
-    sigaction(SIGFPE, &action, nullptr);
-    sigaction(SIGILL, &action, nullptr);
-    sigaction(SIGSEGV, &action, nullptr);
-#if defined(SIGSTKFLT)
-    sigaction(SIGSTKFLT, &action, nullptr);
-#endif
-    sigaction(SIGSYS, &action, nullptr);
-    sigaction(SIGTRAP, &action, nullptr);
-}
-
 static void HandleSigtermSignal(const signalfd_siginfo& siginfo) {
     if (siginfo.ssi_pid != 0) {
         // Drop any userspace SIGTERM requests.
@@ -612,129 +565,27 @@
     android::base::InitLogging(argv, &android::base::KernelLogger, InitAborter);
 }
 
+int first_stage_main(int argc, char** argv);
+
 int main(int argc, char** argv) {
     if (!strcmp(basename(argv[0]), "ueventd")) {
         return ueventd_main(argc, argv);
     }
 
-    if (!strcmp(basename(argv[0]), "watchdogd")) {
-        return watchdogd_main(argc, argv);
-    }
-
     if (argc > 1 && !strcmp(argv[1], "subcontext")) {
         android::base::InitLogging(argv, &android::base::KernelLogger);
         const BuiltinFunctionMap function_map;
         return SubcontextMain(argc, argv, &function_map);
     }
 
+    if (getenv("INIT_SECOND_STAGE") == nullptr) {
+        return first_stage_main(argc, argv);
+    }
+
     if (REBOOT_BOOTLOADER_ON_PANIC) {
         InstallRebootSignalHandlers();
     }
 
-    bool is_first_stage = (getenv("INIT_SECOND_STAGE") == nullptr);
-
-    if (is_first_stage) {
-        boot_clock::time_point start_time = boot_clock::now();
-
-        std::vector<std::pair<std::string, int>> errors;
-#define CHECKCALL(x) \
-    if (x != 0) errors.emplace_back(#x " failed", errno);
-
-        // Clear the umask.
-        umask(0);
-
-        CHECKCALL(clearenv());
-        CHECKCALL(setenv("PATH", _PATH_DEFPATH, 1));
-        // Get the basic filesystem setup we need put together in the initramdisk
-        // on / and then we'll let the rc file figure out the rest.
-        CHECKCALL(mount("tmpfs", "/dev", "tmpfs", MS_NOSUID, "mode=0755"));
-        CHECKCALL(mkdir("/dev/pts", 0755));
-        CHECKCALL(mkdir("/dev/socket", 0755));
-        CHECKCALL(mount("devpts", "/dev/pts", "devpts", 0, NULL));
-#define MAKE_STR(x) __STRING(x)
-        CHECKCALL(mount("proc", "/proc", "proc", 0, "hidepid=2,gid=" MAKE_STR(AID_READPROC)));
-#undef MAKE_STR
-        // Don't expose the raw commandline to unprivileged processes.
-        CHECKCALL(chmod("/proc/cmdline", 0440));
-        gid_t groups[] = { AID_READPROC };
-        CHECKCALL(setgroups(arraysize(groups), groups));
-        CHECKCALL(mount("sysfs", "/sys", "sysfs", 0, NULL));
-        CHECKCALL(mount("selinuxfs", "/sys/fs/selinux", "selinuxfs", 0, NULL));
-
-        CHECKCALL(mknod("/dev/kmsg", S_IFCHR | 0600, makedev(1, 11)));
-
-        if constexpr (WORLD_WRITABLE_KMSG) {
-            CHECKCALL(mknod("/dev/kmsg_debug", S_IFCHR | 0622, makedev(1, 11)));
-        }
-
-        CHECKCALL(mknod("/dev/random", S_IFCHR | 0666, makedev(1, 8)));
-        CHECKCALL(mknod("/dev/urandom", S_IFCHR | 0666, makedev(1, 9)));
-
-        // This is needed for log wrapper, which gets called before ueventd runs.
-        CHECKCALL(mknod("/dev/ptmx", S_IFCHR | 0666, makedev(5, 2)));
-        CHECKCALL(mknod("/dev/null", S_IFCHR | 0666, makedev(1, 3)));
-
-        // Mount staging areas for devices managed by vold
-        // See storage config details at http://source.android.com/devices/storage/
-        CHECKCALL(mount("tmpfs", "/mnt", "tmpfs", MS_NOEXEC | MS_NOSUID | MS_NODEV,
-                        "mode=0755,uid=0,gid=1000"));
-        // /mnt/vendor is used to mount vendor-specific partitions that can not be
-        // part of the vendor partition, e.g. because they are mounted read-write.
-        CHECKCALL(mkdir("/mnt/vendor", 0755));
-        // /mnt/product is used to mount product-specific partitions that can not be
-        // part of the product partition, e.g. because they are mounted read-write.
-        CHECKCALL(mkdir("/mnt/product", 0755));
-
-#undef CHECKCALL
-
-        // Now that tmpfs is mounted on /dev and we have /dev/kmsg, we can actually
-        // talk to the outside world...
-        InitKernelLogging(argv);
-
-        if (!errors.empty()) {
-            for (const auto& [error_string, error_errno] : errors) {
-                LOG(ERROR) << error_string << " " << strerror(error_errno);
-            }
-            LOG(FATAL) << "Init encountered errors starting first stage, aborting";
-        }
-
-        LOG(INFO) << "init first stage started!";
-
-        if (!DoFirstStageMount()) {
-            LOG(FATAL) << "Failed to mount required partitions early ...";
-        }
-
-        SetInitAvbVersionInRecovery();
-
-        // Enable seccomp if global boot option was passed (otherwise it is enabled in zygote).
-        global_seccomp();
-
-        // Set up SELinux, loading the SELinux policy.
-        SelinuxSetupKernelLogging();
-        SelinuxInitialize();
-
-        // We're in the kernel domain, so re-exec init to transition to the init domain now
-        // that the SELinux policy has been loaded.
-        if (selinux_android_restorecon("/init", 0) == -1) {
-            PLOG(FATAL) << "restorecon failed of /init failed";
-        }
-
-        setenv("INIT_SECOND_STAGE", "true", 1);
-
-        static constexpr uint32_t kNanosecondsPerMillisecond = 1e6;
-        uint64_t start_ms = start_time.time_since_epoch().count() / kNanosecondsPerMillisecond;
-        setenv("INIT_STARTED_AT", std::to_string(start_ms).c_str(), 1);
-
-        char* path = argv[0];
-        char* args[] = { path, nullptr };
-        execv(path, args);
-
-        // execv() only returns if an error happened, in which case we
-        // panic and never fall through this conditional.
-        PLOG(FATAL) << "execv(\"" << path << "\") failed";
-    }
-
-    // At this point we're in the second stage of init.
     InitKernelLogging(argv);
     LOG(INFO) << "init second stage started!";
 
diff --git a/init/init.h b/init/init.h
index 6c82fa1..f244ad7 100644
--- a/init/init.h
+++ b/init/init.h
@@ -31,8 +31,8 @@
 namespace android {
 namespace init {
 
-// Note: These globals are *only* valid in init, so they should not be used in ueventd,
-// watchdogd, or any files that may be included in those, such as devices.cpp and util.cpp.
+// Note: These globals are *only* valid in init, so they should not be used in ueventd
+// or any files that may be included in ueventd, such as devices.cpp and util.cpp.
 // TODO: Have an Init class and remove all globals.
 extern std::string default_console;
 extern std::vector<std::string> late_import_paths;
diff --git a/init/init_first_stage.cpp b/init/init_first_stage.cpp
new file mode 100644
index 0000000..ef9ce81
--- /dev/null
+++ b/init/init_first_stage.cpp
@@ -0,0 +1,166 @@
+/*
+ * Copyright (C) 2018 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 <paths.h>
+#include <seccomp_policy.h>
+#include <stdlib.h>
+#include <sys/mount.h>
+#include <sys/stat.h>
+#include <sys/sysmacros.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#include <string>
+#include <vector>
+
+#include <android-base/chrono_utils.h>
+#include <android-base/logging.h>
+#include <cutils/android_reboot.h>
+#include <private/android_filesystem_config.h>
+#include <selinux/android.h>
+
+#include "first_stage_mount.h"
+#include "reboot_utils.h"
+#include "selinux.h"
+#include "util.h"
+
+using android::base::boot_clock;
+
+namespace android {
+namespace init {
+
+static void GlobalSeccomp() {
+    import_kernel_cmdline(false, [](const std::string& key, const std::string& value,
+                                    bool in_qemu) {
+        if (key == "androidboot.seccomp" && value == "global" && !set_global_seccomp_filter()) {
+            LOG(FATAL) << "Failed to globally enable seccomp!";
+        }
+    });
+}
+
+int first_stage_main(int argc, char** argv) {
+    if (REBOOT_BOOTLOADER_ON_PANIC) {
+        InstallRebootSignalHandlers();
+    }
+
+    boot_clock::time_point start_time = boot_clock::now();
+
+    std::vector<std::pair<std::string, int>> errors;
+#define CHECKCALL(x) \
+    if (x != 0) errors.emplace_back(#x " failed", errno);
+
+    // Clear the umask.
+    umask(0);
+
+    CHECKCALL(clearenv());
+    CHECKCALL(setenv("PATH", _PATH_DEFPATH, 1));
+    // Get the basic filesystem setup we need put together in the initramdisk
+    // on / and then we'll let the rc file figure out the rest.
+    CHECKCALL(mount("tmpfs", "/dev", "tmpfs", MS_NOSUID, "mode=0755"));
+    CHECKCALL(mkdir("/dev/pts", 0755));
+    CHECKCALL(mkdir("/dev/socket", 0755));
+    CHECKCALL(mount("devpts", "/dev/pts", "devpts", 0, NULL));
+#define MAKE_STR(x) __STRING(x)
+    CHECKCALL(mount("proc", "/proc", "proc", 0, "hidepid=2,gid=" MAKE_STR(AID_READPROC)));
+#undef MAKE_STR
+    // Don't expose the raw commandline to unprivileged processes.
+    CHECKCALL(chmod("/proc/cmdline", 0440));
+    gid_t groups[] = {AID_READPROC};
+    CHECKCALL(setgroups(arraysize(groups), groups));
+    CHECKCALL(mount("sysfs", "/sys", "sysfs", 0, NULL));
+    CHECKCALL(mount("selinuxfs", "/sys/fs/selinux", "selinuxfs", 0, NULL));
+
+    CHECKCALL(mknod("/dev/kmsg", S_IFCHR | 0600, makedev(1, 11)));
+
+    if constexpr (WORLD_WRITABLE_KMSG) {
+        CHECKCALL(mknod("/dev/kmsg_debug", S_IFCHR | 0622, makedev(1, 11)));
+    }
+
+    CHECKCALL(mknod("/dev/random", S_IFCHR | 0666, makedev(1, 8)));
+    CHECKCALL(mknod("/dev/urandom", S_IFCHR | 0666, makedev(1, 9)));
+
+    // This is needed for log wrapper, which gets called before ueventd runs.
+    CHECKCALL(mknod("/dev/ptmx", S_IFCHR | 0666, makedev(5, 2)));
+    CHECKCALL(mknod("/dev/null", S_IFCHR | 0666, makedev(1, 3)));
+
+    // Mount staging areas for devices managed by vold
+    // See storage config details at http://source.android.com/devices/storage/
+    CHECKCALL(mount("tmpfs", "/mnt", "tmpfs", MS_NOEXEC | MS_NOSUID | MS_NODEV,
+                    "mode=0755,uid=0,gid=1000"));
+    // /mnt/vendor is used to mount vendor-specific partitions that can not be
+    // part of the vendor partition, e.g. because they are mounted read-write.
+    CHECKCALL(mkdir("/mnt/vendor", 0755));
+    // /mnt/product is used to mount product-specific partitions that can not be
+    // part of the product partition, e.g. because they are mounted read-write.
+    CHECKCALL(mkdir("/mnt/product", 0755));
+
+#undef CHECKCALL
+
+    // Now that tmpfs is mounted on /dev and we have /dev/kmsg, we can actually
+    // talk to the outside world...
+    android::base::InitLogging(argv, &android::base::KernelLogger, [](const char*) {
+        RebootSystem(ANDROID_RB_RESTART2, "bootloader");
+    });
+
+    if (!errors.empty()) {
+        for (const auto& [error_string, error_errno] : errors) {
+            LOG(ERROR) << error_string << " " << strerror(error_errno);
+        }
+        LOG(FATAL) << "Init encountered errors starting first stage, aborting";
+    }
+
+    LOG(INFO) << "init first stage started!";
+
+    if (!DoFirstStageMount()) {
+        LOG(FATAL) << "Failed to mount required partitions early ...";
+    }
+
+    SetInitAvbVersionInRecovery();
+
+    // Does this need to be done in first stage init or can it be done later?
+    // Enable seccomp if global boot option was passed (otherwise it is enabled in zygote).
+    GlobalSeccomp();
+
+    // Set up SELinux, loading the SELinux policy.
+    SelinuxSetupKernelLogging();
+    SelinuxInitialize();
+
+    // Unneeded?  It's an ext4 file system so shouldn't it have the right domain already?
+    // We're in the kernel domain, so re-exec init to transition to the init domain now
+    // that the SELinux policy has been loaded.
+    if (selinux_android_restorecon("/init", 0) == -1) {
+        PLOG(FATAL) << "restorecon failed of /init failed";
+    }
+
+    setenv("INIT_SECOND_STAGE", "true", 1);
+
+    static constexpr uint32_t kNanosecondsPerMillisecond = 1e6;
+    uint64_t start_ms = start_time.time_since_epoch().count() / kNanosecondsPerMillisecond;
+    setenv("INIT_STARTED_AT", std::to_string(start_ms).c_str(), 1);
+
+    const char* path = argv[0];
+    const char* args[] = {path, nullptr};
+    execv(path, const_cast<char**>(args));
+
+    // execv() only returns if an error happened, in which case we
+    // panic and never fall through this conditional.
+    PLOG(FATAL) << "execv(\"" << path << "\") failed";
+
+    return 1;
+}
+
+}  // namespace init
+}  // namespace android
diff --git a/init/modalias_handler.cpp b/init/modalias_handler.cpp
index 1734a7e..1e0db57 100644
--- a/init/modalias_handler.cpp
+++ b/init/modalias_handler.cpp
@@ -139,7 +139,7 @@
     return Insmod(dependencies[0], args);
 }
 
-void ModaliasHandler::HandleModaliasEvent(const Uevent& uevent) {
+void ModaliasHandler::HandleUevent(const Uevent& uevent) {
     if (uevent.modalias.empty()) return;
 
     for (const auto& [alias, module] : module_aliases_) {
diff --git a/init/modalias_handler.h b/init/modalias_handler.h
index e79da32..3247c86 100644
--- a/init/modalias_handler.h
+++ b/init/modalias_handler.h
@@ -16,22 +16,23 @@
 
 #pragma once
 
-#include "result.h"
-#include "uevent.h"
-
 #include <string>
 #include <unordered_map>
 #include <vector>
 
+#include "result.h"
+#include "uevent.h"
+#include "uevent_handler.h"
+
 namespace android {
 namespace init {
 
-class ModaliasHandler {
+class ModaliasHandler : public UeventHandler {
   public:
     ModaliasHandler();
-    ~ModaliasHandler(){};
+    virtual ~ModaliasHandler() = default;
 
-    void HandleModaliasEvent(const Uevent& uevent);
+    void HandleUevent(const Uevent& uevent) override;
 
   private:
     Result<Success> InsmodWithDeps(const std::string& module_name, const std::string& args);
diff --git a/init/property_service.cpp b/init/property_service.cpp
index c0d811f..cd2f630 100644
--- a/init/property_service.cpp
+++ b/init/property_service.cpp
@@ -16,6 +16,7 @@
 
 #include "property_service.h"
 
+#include <android/api-level.h>
 #include <ctype.h>
 #include <errno.h>
 #include <fcntl.h>
@@ -576,7 +577,7 @@
     size_t flen = 0;
 
     const char* context = kInitContext.c_str();
-    if (SelinuxHasVendorInit()) {
+    if (SelinuxGetVendorAndroidVersion() >= __ANDROID_API_P__) {
         for (const auto& [path_prefix, secontext] : paths_and_secontexts) {
             if (StartsWith(filename, path_prefix)) {
                 context = secontext;
diff --git a/init/reboot.cpp b/init/reboot.cpp
index 11507f4..7401857 100644
--- a/init/reboot.cpp
+++ b/init/reboot.cpp
@@ -20,11 +20,9 @@
 #include <fcntl.h>
 #include <linux/fs.h>
 #include <mntent.h>
-#include <sys/capability.h>
 #include <sys/cdefs.h>
 #include <sys/ioctl.h>
 #include <sys/mount.h>
-#include <sys/reboot.h>
 #include <sys/stat.h>
 #include <sys/syscall.h>
 #include <sys/types.h>
@@ -51,9 +49,9 @@
 #include <selinux/selinux.h>
 
 #include "action_manager.h"
-#include "capabilities.h"
 #include "init.h"
 #include "property_service.h"
+#include "reboot_utils.h"
 #include "service.h"
 #include "sigchld_handler.h"
 
@@ -159,54 +157,6 @@
                  << stat;
 }
 
-bool IsRebootCapable() {
-    if (!CAP_IS_SUPPORTED(CAP_SYS_BOOT)) {
-        PLOG(WARNING) << "CAP_SYS_BOOT is not supported";
-        return true;
-    }
-
-    ScopedCaps caps(cap_get_proc());
-    if (!caps) {
-        PLOG(WARNING) << "cap_get_proc() failed";
-        return true;
-    }
-
-    cap_flag_value_t value = CAP_SET;
-    if (cap_get_flag(caps.get(), CAP_SYS_BOOT, CAP_EFFECTIVE, &value) != 0) {
-        PLOG(WARNING) << "cap_get_flag(CAP_SYS_BOOT, EFFECTIVE) failed";
-        return true;
-    }
-    return value == CAP_SET;
-}
-
-void __attribute__((noreturn)) RebootSystem(unsigned int cmd, const std::string& rebootTarget) {
-    LOG(INFO) << "Reboot ending, jumping to kernel";
-
-    if (!IsRebootCapable()) {
-        // On systems where init does not have the capability of rebooting the
-        // device, just exit cleanly.
-        exit(0);
-    }
-
-    switch (cmd) {
-        case ANDROID_RB_POWEROFF:
-            reboot(RB_POWER_OFF);
-            break;
-
-        case ANDROID_RB_RESTART2:
-            syscall(__NR_reboot, LINUX_REBOOT_MAGIC1, LINUX_REBOOT_MAGIC2,
-                    LINUX_REBOOT_CMD_RESTART2, rebootTarget.c_str());
-            break;
-
-        case ANDROID_RB_THERMOFF:
-            reboot(RB_POWER_OFF);
-            break;
-    }
-    // In normal case, reboot should not return.
-    PLOG(ERROR) << "reboot call returned";
-    abort();
-}
-
 /* Find all read+write block devices and emulated devices in /proc/mounts
  * and add them to correpsponding list.
  */
@@ -329,8 +279,15 @@
     return stat;
 }
 
-void DoReboot(unsigned int cmd, const std::string& reason, const std::string& rebootTarget,
-              bool runFsck) {
+//* Reboot / shutdown the system.
+// cmd ANDROID_RB_* as defined in android_reboot.h
+// reason Reason string like "reboot", "shutdown,userrequested"
+// rebootTarget Reboot target string like "bootloader". Otherwise, it should be an
+//              empty string.
+// runFsck Whether to run fsck after umount is done.
+//
+static void DoReboot(unsigned int cmd, const std::string& reason, const std::string& rebootTarget,
+                     bool runFsck) {
     Timer t;
     LOG(INFO) << "Reboot start, reason: " << reason << ", rebootTarget: " << rebootTarget;
 
diff --git a/init/reboot.h b/init/reboot.h
index 1c58bd1..07dcb6e 100644
--- a/init/reboot.h
+++ b/init/reboot.h
@@ -22,26 +22,9 @@
 namespace android {
 namespace init {
 
-// This is a wrapper around the actual reboot calls.  DoReboot() should be preferred in most cases.
-void __attribute__((noreturn)) RebootSystem(unsigned int cmd, const std::string& rebootTarget);
-
-/* Reboot / shutdown the system.
- * cmd ANDROID_RB_* as defined in android_reboot.h
- * reason Reason string like "reboot", "shutdown,userrequested"
- * rebootTarget Reboot target string like "bootloader". Otherwise, it should be an
- *              empty string.
- * runFsck Whether to run fsck after umount is done.
- */
-void DoReboot(unsigned int cmd, const std::string& reason, const std::string& rebootTarget,
-              bool runFsck) __attribute__((__noreturn__));
-
 // Parses and handles a setprop sys.powerctl message.
 bool HandlePowerctlMessage(const std::string& command);
 
-// Determines whether the system is capable of rebooting. This is conservative,
-// so if any of the attempts to determine this fail, it will still return true.
-bool IsRebootCapable();
-
 }  // namespace init
 }  // namespace android
 
diff --git a/init/reboot_utils.cpp b/init/reboot_utils.cpp
new file mode 100644
index 0000000..9610304
--- /dev/null
+++ b/init/reboot_utils.cpp
@@ -0,0 +1,113 @@
+/*
+ * Copyright (C) 2018 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 <sys/capability.h>
+#include <sys/reboot.h>
+#include <sys/syscall.h>
+#include <unistd.h>
+
+#include <android-base/logging.h>
+#include <cutils/android_reboot.h>
+
+#include "capabilities.h"
+
+namespace android {
+namespace init {
+
+bool IsRebootCapable() {
+    if (!CAP_IS_SUPPORTED(CAP_SYS_BOOT)) {
+        PLOG(WARNING) << "CAP_SYS_BOOT is not supported";
+        return true;
+    }
+
+    ScopedCaps caps(cap_get_proc());
+    if (!caps) {
+        PLOG(WARNING) << "cap_get_proc() failed";
+        return true;
+    }
+
+    cap_flag_value_t value = CAP_SET;
+    if (cap_get_flag(caps.get(), CAP_SYS_BOOT, CAP_EFFECTIVE, &value) != 0) {
+        PLOG(WARNING) << "cap_get_flag(CAP_SYS_BOOT, EFFECTIVE) failed";
+        return true;
+    }
+    return value == CAP_SET;
+}
+
+void __attribute__((noreturn)) RebootSystem(unsigned int cmd, const std::string& rebootTarget) {
+    LOG(INFO) << "Reboot ending, jumping to kernel";
+
+    if (!IsRebootCapable()) {
+        // On systems where init does not have the capability of rebooting the
+        // device, just exit cleanly.
+        exit(0);
+    }
+
+    switch (cmd) {
+        case ANDROID_RB_POWEROFF:
+            reboot(RB_POWER_OFF);
+            break;
+
+        case ANDROID_RB_RESTART2:
+            syscall(__NR_reboot, LINUX_REBOOT_MAGIC1, LINUX_REBOOT_MAGIC2,
+                    LINUX_REBOOT_CMD_RESTART2, rebootTarget.c_str());
+            break;
+
+        case ANDROID_RB_THERMOFF:
+            reboot(RB_POWER_OFF);
+            break;
+    }
+    // In normal case, reboot should not return.
+    PLOG(ERROR) << "reboot call returned";
+    abort();
+}
+
+void InstallRebootSignalHandlers() {
+    // Instead of panic'ing the kernel as is the default behavior when init crashes,
+    // we prefer to reboot to bootloader on development builds, as this will prevent
+    // boot looping bad configurations and allow both developers and test farms to easily
+    // recover.
+    struct sigaction action;
+    memset(&action, 0, sizeof(action));
+    sigfillset(&action.sa_mask);
+    action.sa_handler = [](int signal) {
+        // These signal handlers are also caught for processes forked from init, however we do not
+        // want them to trigger reboot, so we directly call _exit() for children processes here.
+        if (getpid() != 1) {
+            _exit(signal);
+        }
+
+        // Calling DoReboot() or LOG(FATAL) is not a good option as this is a signal handler.
+        // RebootSystem uses syscall() which isn't actually async-signal-safe, but our only option
+        // and probably good enough given this is already an error case and only enabled for
+        // development builds.
+        RebootSystem(ANDROID_RB_RESTART2, "bootloader");
+    };
+    action.sa_flags = SA_RESTART;
+    sigaction(SIGABRT, &action, nullptr);
+    sigaction(SIGBUS, &action, nullptr);
+    sigaction(SIGFPE, &action, nullptr);
+    sigaction(SIGILL, &action, nullptr);
+    sigaction(SIGSEGV, &action, nullptr);
+#if defined(SIGSTKFLT)
+    sigaction(SIGSTKFLT, &action, nullptr);
+#endif
+    sigaction(SIGSYS, &action, nullptr);
+    sigaction(SIGTRAP, &action, nullptr);
+}
+
+}  // namespace init
+}  // namespace android
diff --git a/init/reboot_utils.h b/init/reboot_utils.h
new file mode 100644
index 0000000..073a16a
--- /dev/null
+++ b/init/reboot_utils.h
@@ -0,0 +1,32 @@
+/*
+ * Copyright (C) 2010 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 <string>
+
+namespace android {
+namespace init {
+
+// Determines whether the system is capable of rebooting. This is conservative,
+// so if any of the attempts to determine this fail, it will still return true.
+bool IsRebootCapable();
+// This is a wrapper around the actual reboot calls.
+void __attribute__((noreturn)) RebootSystem(unsigned int cmd, const std::string& reboot_target);
+void InstallRebootSignalHandlers();
+
+}  // namespace init
+}  // namespace android
diff --git a/init/selinux.cpp b/init/selinux.cpp
index b788be9..fd7e86f 100644
--- a/init/selinux.cpp
+++ b/init/selinux.cpp
@@ -47,6 +47,7 @@
 
 #include "selinux.h"
 
+#include <android/api-level.h>
 #include <fcntl.h>
 #include <stdlib.h>
 #include <sys/wait.h>
@@ -472,29 +473,27 @@
     selinux_set_callback(SELINUX_CB_LOG, cb);
 }
 
-// This function checks whether the sepolicy supports vendor init.
-bool SelinuxHasVendorInit() {
+// This function returns the Android version with which the vendor SEPolicy was compiled.
+// It is used for version checks such as whether or not vendor_init should be used
+int SelinuxGetVendorAndroidVersion() {
     if (!IsSplitPolicyDevice()) {
-        // If this device does not split sepolicy files, vendor_init will be available in the latest
-        // monolithic sepolicy file.
-        return true;
+        // If this device does not split sepolicy files, it's not a Treble device and therefore,
+        // we assume it's always on the latest platform.
+        return __ANDROID_API_FUTURE__;
     }
 
     std::string version;
     if (!GetVendorMappingVersion(&version)) {
-        // Return true as the default if we failed to load the vendor sepolicy version.
-        return true;
+        LOG(FATAL) << "Could not read vendor SELinux version";
     }
 
     int major_version;
     std::string major_version_str(version, 0, version.find('.'));
     if (!ParseInt(major_version_str, &major_version)) {
-        PLOG(ERROR) << "Failed to parse the vendor sepolicy major version " << major_version_str;
-        // Return true as the default if we failed to parse the major version.
-        return true;
+        PLOG(FATAL) << "Failed to parse the vendor sepolicy major version " << major_version_str;
     }
 
-    return major_version >= 28;
+    return major_version;
 }
 
 // selinux_android_file_context_handle() takes on the order of 10+ms to run, so we want to cache
diff --git a/init/selinux.h b/init/selinux.h
index 30069b5..c41d7f0 100644
--- a/init/selinux.h
+++ b/init/selinux.h
@@ -27,7 +27,7 @@
 void SelinuxRestoreContext();
 
 void SelinuxSetupKernelLogging();
-bool SelinuxHasVendorInit();
+int SelinuxGetVendorAndroidVersion();
 
 void SelabelInitialize();
 bool SelabelLookupFileContext(const std::string& key, int type, std::string* result);
diff --git a/init/service.cpp b/init/service.cpp
index 4c2747e..d20e90a 100644
--- a/init/service.cpp
+++ b/init/service.cpp
@@ -46,10 +46,12 @@
 #include "util.h"
 
 #if defined(__ANDROID__)
+#include <android/api-level.h>
 #include <sys/system_properties.h>
 
 #include "init.h"
 #include "property_service.h"
+#include "selinux.h"
 #else
 #include "host_init_stubs.h"
 #endif
@@ -1211,6 +1213,13 @@
     }
 
     std::vector<std::string> str_args(args.begin() + 2, args.end());
+
+    if (SelinuxGetVendorAndroidVersion() <= __ANDROID_API_P__) {
+        if (str_args[0] == "/sbin/watchdogd") {
+            str_args[0] = "/system/bin/watchdogd";
+        }
+    }
+
     service_ = std::make_unique<Service>(name, restart_action_subcontext, str_args);
     return Success();
 }
diff --git a/init/subcontext.cpp b/init/subcontext.cpp
index ee72513..c2a21d4 100644
--- a/init/subcontext.cpp
+++ b/init/subcontext.cpp
@@ -30,6 +30,7 @@
 #include "util.h"
 
 #if defined(__ANDROID__)
+#include <android/api-level.h>
 #include "property_service.h"
 #include "selinux.h"
 #else
@@ -355,7 +356,7 @@
 static bool shutting_down;
 
 std::vector<Subcontext>* InitializeSubcontexts() {
-    if (SelinuxHasVendorInit()) {
+    if (SelinuxGetVendorAndroidVersion() >= __ANDROID_API_P__) {
         for (const auto& [path_prefix, secontext] : paths_and_secontexts) {
             subcontexts.emplace_back(path_prefix, secontext);
         }
diff --git a/init/watchdogd.h b/init/uevent_handler.h
similarity index 71%
rename from init/watchdogd.h
rename to init/uevent_handler.h
index 73f77d5..75d1990 100644
--- a/init/watchdogd.h
+++ b/init/uevent_handler.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2012 The Android Open Source Project
+ * Copyright (C) 2018 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.
@@ -14,15 +14,21 @@
  * limitations under the License.
  */
 
-#ifndef _INIT_WATCHDOGD_H_
-#define _INIT_WATCHDOGD_H_
+#pragma once
+
+#include "uevent.h"
 
 namespace android {
 namespace init {
 
-int watchdogd_main(int argc, char **argv);
+class UeventHandler {
+  public:
+    virtual ~UeventHandler() = default;
+
+    virtual void HandleUevent(const Uevent& uevent) = 0;
+
+    virtual void ColdbootDone() {}
+};
 
 }  // namespace init
 }  // namespace android
-
-#endif
diff --git a/init/ueventd.cpp b/init/ueventd.cpp
index e9d829b..95be6af 100644
--- a/init/ueventd.cpp
+++ b/init/ueventd.cpp
@@ -38,6 +38,7 @@
 #include "firmware_handler.h"
 #include "modalias_handler.h"
 #include "selinux.h"
+#include "uevent_handler.h"
 #include "uevent_listener.h"
 #include "ueventd_parser.h"
 #include "util.h"
@@ -107,11 +108,10 @@
 
 class ColdBoot {
   public:
-    ColdBoot(UeventListener& uevent_listener, DeviceHandler& device_handler,
-             ModaliasHandler& modalias_handler)
+    ColdBoot(UeventListener& uevent_listener,
+             std::vector<std::unique_ptr<UeventHandler>>& uevent_handlers)
         : uevent_listener_(uevent_listener),
-          device_handler_(device_handler),
-          modalias_handler_(modalias_handler),
+          uevent_handlers_(uevent_handlers),
           num_handler_subprocesses_(std::thread::hardware_concurrency() ?: 4) {}
 
     void Run();
@@ -124,8 +124,7 @@
     void WaitForSubProcesses();
 
     UeventListener& uevent_listener_;
-    DeviceHandler& device_handler_;
-    ModaliasHandler& modalias_handler_;
+    std::vector<std::unique_ptr<UeventHandler>>& uevent_handlers_;
 
     unsigned int num_handler_subprocesses_;
     std::vector<Uevent> uevent_queue_;
@@ -136,16 +135,16 @@
 void ColdBoot::UeventHandlerMain(unsigned int process_num, unsigned int total_processes) {
     for (unsigned int i = process_num; i < uevent_queue_.size(); i += total_processes) {
         auto& uevent = uevent_queue_[i];
-        device_handler_.HandleDeviceEvent(uevent);
-        modalias_handler_.HandleModaliasEvent(uevent);
+
+        for (auto& uevent_handler : uevent_handlers_) {
+            uevent_handler->HandleUevent(uevent);
+        }
     }
     _exit(EXIT_SUCCESS);
 }
 
 void ColdBoot::RegenerateUevents() {
     uevent_listener_.RegenerateUevents([this](const Uevent& uevent) {
-        HandleFirmwareEvent(uevent);
-
         uevent_queue_.emplace_back(std::move(uevent));
         return ListenerAction::kContinue;
     });
@@ -168,7 +167,6 @@
 
 void ColdBoot::DoRestoreCon() {
     selinux_android_restorecon("/sys", SELINUX_ANDROID_RESTORECON_RECURSE);
-    device_handler_.set_skip_restorecon(false);
 }
 
 void ColdBoot::WaitForSubProcesses() {
@@ -234,8 +232,7 @@
     SelinuxSetupKernelLogging();
     SelabelInitialize();
 
-    DeviceHandler device_handler;
-    ModaliasHandler modalias_handler;
+    std::vector<std::unique_ptr<UeventHandler>> uevent_handlers;
     UeventListener uevent_listener;
 
     {
@@ -248,19 +245,27 @@
                 ParseConfig({"/ueventd.rc", "/vendor/ueventd.rc", "/odm/ueventd.rc",
                              "/ueventd." + hardware + ".rc"});
 
-        device_handler = DeviceHandler{std::move(ueventd_configuration.dev_permissions),
-                                       std::move(ueventd_configuration.sysfs_permissions),
-                                       std::move(ueventd_configuration.subsystems),
-                                       fs_mgr_get_boot_devices(), true};
+        uevent_handlers.emplace_back(std::make_unique<DeviceHandler>(
+                std::move(ueventd_configuration.dev_permissions),
+                std::move(ueventd_configuration.sysfs_permissions),
+                std::move(ueventd_configuration.subsystems), fs_mgr_get_boot_devices(), true));
+        uevent_handlers.emplace_back(std::make_unique<FirmwareHandler>(
+                std::move(ueventd_configuration.firmware_directories)));
 
-        firmware_directories = ueventd_configuration.firmware_directories;
+        if (ueventd_configuration.enable_modalias_handling) {
+            uevent_handlers.emplace_back(std::make_unique<ModaliasHandler>());
+        }
     }
 
     if (access(COLDBOOT_DONE, F_OK) != 0) {
-        ColdBoot cold_boot(uevent_listener, device_handler, modalias_handler);
+        ColdBoot cold_boot(uevent_listener, uevent_handlers);
         cold_boot.Run();
     }
 
+    for (auto& uevent_handler : uevent_handlers) {
+        uevent_handler->ColdbootDone();
+    }
+
     // We use waitpid() in ColdBoot, so we can't ignore SIGCHLD until now.
     signal(SIGCHLD, SIG_IGN);
     // Reap and pending children that exited between the last call to waitpid() and setting SIG_IGN
@@ -268,10 +273,10 @@
     while (waitpid(-1, nullptr, WNOHANG) > 0) {
     }
 
-    uevent_listener.Poll([&device_handler, &modalias_handler](const Uevent& uevent) {
-        HandleFirmwareEvent(uevent);
-        modalias_handler.HandleModaliasEvent(uevent);
-        device_handler.HandleDeviceEvent(uevent);
+    uevent_listener.Poll([&uevent_handlers](const Uevent& uevent) {
+        for (auto& uevent_handler : uevent_handlers) {
+            uevent_handler->HandleUevent(uevent);
+        }
         return ListenerAction::kContinue;
     });
 
diff --git a/init/ueventd_parser.cpp b/init/ueventd_parser.cpp
index 54b0d16..677938e 100644
--- a/init/ueventd_parser.cpp
+++ b/init/ueventd_parser.cpp
@@ -84,6 +84,23 @@
     return Success();
 }
 
+Result<Success> ParseModaliasHandlingLine(std::vector<std::string>&& args,
+                                          bool* enable_modalias_handling) {
+    if (args.size() != 2) {
+        return Error() << "modalias_handling lines take exactly one parameter";
+    }
+
+    if (args[1] == "enabled") {
+        *enable_modalias_handling = true;
+    } else if (args[1] == "disabled") {
+        *enable_modalias_handling = false;
+    } else {
+        return Error() << "modalias_handling takes either 'enabled' or 'disabled' as a parameter";
+    }
+
+    return Success();
+}
+
 class SubsystemParser : public SectionParser {
   public:
     SubsystemParser(std::vector<Subsystem>* subsystems) : subsystems_(subsystems) {}
@@ -182,6 +199,9 @@
     parser.AddSingleLineParser("firmware_directories",
                                std::bind(ParseFirmwareDirectoriesLine, _1,
                                          &ueventd_configuration.firmware_directories));
+    parser.AddSingleLineParser("modalias_handling",
+                               std::bind(ParseModaliasHandlingLine, _1,
+                                         &ueventd_configuration.enable_modalias_handling));
 
     for (const auto& config : configs) {
         parser.ParseConfig(config);
diff --git a/init/ueventd_parser.h b/init/ueventd_parser.h
index 343d58b..7d30edf 100644
--- a/init/ueventd_parser.h
+++ b/init/ueventd_parser.h
@@ -30,6 +30,7 @@
     std::vector<SysfsPermissions> sysfs_permissions;
     std::vector<Permissions> dev_permissions;
     std::vector<std::string> firmware_directories;
+    bool enable_modalias_handling = false;
 };
 
 UeventdConfiguration ParseConfig(const std::vector<std::string>& configs);
diff --git a/init/util.cpp b/init/util.cpp
index 7735717..105ac87 100644
--- a/init/util.cpp
+++ b/init/util.cpp
@@ -47,7 +47,7 @@
 #endif
 
 #ifdef _INIT_INIT_H
-#error "Do not include init.h in files used by ueventd or watchdogd; it will expose init's globals"
+#error "Do not include init.h in files used by ueventd; it will expose init's globals"
 #endif
 
 using android::base::boot_clock;
diff --git a/libpixelflinger/fixed.cpp b/libpixelflinger/fixed.cpp
index 5094537..de6b479 100644
--- a/libpixelflinger/fixed.cpp
+++ b/libpixelflinger/fixed.cpp
@@ -70,17 +70,6 @@
 
 // ------------------------------------------------------------------------
 
-GGLfixed gglFastDivx(GGLfixed n, GGLfixed d)
-{
-    if ((d>>24) && ((d>>24)+1)) {
-        n >>= 8;
-        d >>= 8;
-    }
-    return gglMulx(n, gglRecip(d));
-}
-
-// ------------------------------------------------------------------------
-
 static const GGLfixed ggl_sqrt_reciproc_approx_tab[8] = {
     // 1/sqrt(x) with x = 1-N/16, N=[8...1]
     0x16A09, 0x15555, 0x143D1, 0x134BF, 0x1279A, 0x11C01, 0x111AC, 0x10865
diff --git a/libpixelflinger/include/private/pixelflinger/ggl_fixed.h b/libpixelflinger/include/private/pixelflinger/ggl_fixed.h
index 51e9e26..7f39e9b 100644
--- a/libpixelflinger/include/private/pixelflinger/ggl_fixed.h
+++ b/libpixelflinger/include/private/pixelflinger/ggl_fixed.h
@@ -86,7 +86,6 @@
 GGLfixed gglPowx(GGLfixed x, GGLfixed y) CONST;
 GGLfixed gglSqrtx(GGLfixed a) CONST;
 GGLfixed gglSqrtRecipx(GGLfixed x) CONST;
-GGLfixed gglFastDivx(GGLfixed n, GGLfixed d) CONST;
 int32_t gglMulDivi(int32_t a, int32_t b, int32_t c);
 
 int32_t gglRecipQNormalized(int32_t x, int* exponent);
diff --git a/libunwindstack/Android.bp b/libunwindstack/Android.bp
index df5da65..be2145d 100644
--- a/libunwindstack/Android.bp
+++ b/libunwindstack/Android.bp
@@ -190,6 +190,7 @@
         "tests/MemoryRangeTest.cpp",
         "tests/MemoryRemoteTest.cpp",
         "tests/MemoryTest.cpp",
+        "tests/RegsInfoTest.cpp",
         "tests/RegsIterateTest.cpp",
         "tests/RegsStepIfSignalHandlerTest.cpp",
         "tests/RegsTest.cpp",
diff --git a/libunwindstack/ElfInterface.cpp b/libunwindstack/ElfInterface.cpp
index 2c00456..f59a472 100644
--- a/libunwindstack/ElfInterface.cpp
+++ b/libunwindstack/ElfInterface.cpp
@@ -167,15 +167,10 @@
     return false;
   }
 
-  if (!ReadProgramHeaders<EhdrType, PhdrType>(ehdr, load_bias)) {
-    return false;
-  }
-
-  // We could still potentially unwind without the section header
-  // information, so ignore any errors.
-  if (!ReadSectionHeaders<EhdrType, ShdrType>(ehdr)) {
-    log(0, "Malformed section header found, ignoring...");
-  }
+  // If we have enough information that this is an elf file, then allow
+  // malformed program and section headers.
+  ReadProgramHeaders<EhdrType, PhdrType>(ehdr, load_bias);
+  ReadSectionHeaders<EhdrType, ShdrType>(ehdr);
   return true;
 }
 
@@ -200,14 +195,12 @@
 }
 
 template <typename EhdrType, typename PhdrType>
-bool ElfInterface::ReadProgramHeaders(const EhdrType& ehdr, uint64_t* load_bias) {
+void ElfInterface::ReadProgramHeaders(const EhdrType& ehdr, uint64_t* load_bias) {
   uint64_t offset = ehdr.e_phoff;
   for (size_t i = 0; i < ehdr.e_phnum; i++, offset += ehdr.e_phentsize) {
     PhdrType phdr;
     if (!memory_->ReadFully(offset, &phdr, sizeof(phdr))) {
-      last_error_.code = ERROR_MEMORY_INVALID;
-      last_error_.address = offset;
-      return false;
+      return;
     }
 
     switch (phdr.p_type) {
@@ -242,11 +235,10 @@
       break;
     }
   }
-  return true;
 }
 
 template <typename EhdrType, typename ShdrType>
-bool ElfInterface::ReadSectionHeaders(const EhdrType& ehdr) {
+void ElfInterface::ReadSectionHeaders(const EhdrType& ehdr) {
   uint64_t offset = ehdr.e_shoff;
   uint64_t sec_offset = 0;
   uint64_t sec_size = 0;
@@ -267,9 +259,7 @@
   offset += ehdr.e_shentsize;
   for (size_t i = 1; i < ehdr.e_shnum; i++, offset += ehdr.e_shentsize) {
     if (!memory_->Read(offset, &shdr, sizeof(shdr))) {
-      last_error_.code = ERROR_MEMORY_INVALID;
-      last_error_.address = offset;
-      return false;
+      return;
     }
 
     if (shdr.sh_type == SHT_SYMTAB || shdr.sh_type == SHT_DYNSYM) {
@@ -277,18 +267,14 @@
       // the string terminated names.
       ShdrType str_shdr;
       if (shdr.sh_link >= ehdr.e_shnum) {
-        last_error_.code = ERROR_UNWIND_INFO;
-        return false;
+        continue;
       }
       uint64_t str_offset = ehdr.e_shoff + shdr.sh_link * ehdr.e_shentsize;
       if (!memory_->Read(str_offset, &str_shdr, sizeof(str_shdr))) {
-        last_error_.code = ERROR_MEMORY_INVALID;
-        last_error_.address = str_offset;
-        return false;
+        continue;
       }
       if (str_shdr.sh_type != SHT_STRTAB) {
-        last_error_.code = ERROR_UNWIND_INFO;
-        return false;
+        continue;
       }
       symbols_.push_back(new Symbols(shdr.sh_offset, shdr.sh_size, shdr.sh_entsize,
                                      str_shdr.sh_offset, str_shdr.sh_size));
@@ -324,7 +310,6 @@
                                                             static_cast<uint64_t>(shdr.sh_offset)));
     }
   }
-  return true;
 }
 
 template <typename DynType>
@@ -499,11 +484,13 @@
 template bool ElfInterface::ReadAllHeaders<Elf32_Ehdr, Elf32_Phdr, Elf32_Shdr>(uint64_t*);
 template bool ElfInterface::ReadAllHeaders<Elf64_Ehdr, Elf64_Phdr, Elf64_Shdr>(uint64_t*);
 
-template bool ElfInterface::ReadProgramHeaders<Elf32_Ehdr, Elf32_Phdr>(const Elf32_Ehdr&, uint64_t*);
-template bool ElfInterface::ReadProgramHeaders<Elf64_Ehdr, Elf64_Phdr>(const Elf64_Ehdr&, uint64_t*);
+template void ElfInterface::ReadProgramHeaders<Elf32_Ehdr, Elf32_Phdr>(const Elf32_Ehdr&,
+                                                                       uint64_t*);
+template void ElfInterface::ReadProgramHeaders<Elf64_Ehdr, Elf64_Phdr>(const Elf64_Ehdr&,
+                                                                       uint64_t*);
 
-template bool ElfInterface::ReadSectionHeaders<Elf32_Ehdr, Elf32_Shdr>(const Elf32_Ehdr&);
-template bool ElfInterface::ReadSectionHeaders<Elf64_Ehdr, Elf64_Shdr>(const Elf64_Ehdr&);
+template void ElfInterface::ReadSectionHeaders<Elf32_Ehdr, Elf32_Shdr>(const Elf32_Ehdr&);
+template void ElfInterface::ReadSectionHeaders<Elf64_Ehdr, Elf64_Shdr>(const Elf64_Ehdr&);
 
 template bool ElfInterface::GetSonameWithTemplate<Elf32_Dyn>(std::string*);
 template bool ElfInterface::GetSonameWithTemplate<Elf64_Dyn>(std::string*);
diff --git a/libunwindstack/RegsInfo.h b/libunwindstack/RegsInfo.h
index 47825f5..e6dd33c 100644
--- a/libunwindstack/RegsInfo.h
+++ b/libunwindstack/RegsInfo.h
@@ -25,11 +25,13 @@
 
 template <typename AddressType>
 struct RegsInfo {
+  static constexpr size_t MAX_REGISTERS = 64;
+
   RegsInfo(RegsImpl<AddressType>* regs) : regs(regs) {}
 
   RegsImpl<AddressType>* regs = nullptr;
   uint64_t saved_reg_map = 0;
-  AddressType saved_regs[64];
+  AddressType saved_regs[MAX_REGISTERS];
 
   inline AddressType Get(uint32_t reg) {
     if (IsSaved(reg)) {
@@ -39,23 +41,23 @@
   }
 
   inline AddressType* Save(uint32_t reg) {
-    if (reg > sizeof(saved_regs) / sizeof(AddressType)) {
-      // This should never happen as since all currently supported
-      // architectures have the total number of registers < 64.
+    if (reg > MAX_REGISTERS) {
+      // This should never happen since all currently supported
+      // architectures have < 64 total registers.
       abort();
     }
-    saved_reg_map |= 1 << reg;
+    saved_reg_map |= 1ULL << reg;
     saved_regs[reg] = (*regs)[reg];
     return &(*regs)[reg];
   }
 
   inline bool IsSaved(uint32_t reg) {
-    if (reg > sizeof(saved_regs) / sizeof(AddressType)) {
-      // This should never happen as since all currently supported
-      // architectures have the total number of registers < 64.
+    if (reg > MAX_REGISTERS) {
+      // This should never happen since all currently supported
+      // architectures have < 64 total registers.
       abort();
     }
-    return saved_reg_map & (1 << reg);
+    return saved_reg_map & (1ULL << reg);
   }
 
   inline uint16_t Total() { return regs->total_regs(); }
diff --git a/libunwindstack/include/unwindstack/ElfInterface.h b/libunwindstack/include/unwindstack/ElfInterface.h
index 5c1210d..a45eba8 100644
--- a/libunwindstack/include/unwindstack/ElfInterface.h
+++ b/libunwindstack/include/unwindstack/ElfInterface.h
@@ -104,10 +104,10 @@
   bool ReadAllHeaders(uint64_t* load_bias);
 
   template <typename EhdrType, typename PhdrType>
-  bool ReadProgramHeaders(const EhdrType& ehdr, uint64_t* load_bias);
+  void ReadProgramHeaders(const EhdrType& ehdr, uint64_t* load_bias);
 
   template <typename EhdrType, typename ShdrType>
-  bool ReadSectionHeaders(const EhdrType& ehdr);
+  void ReadSectionHeaders(const EhdrType& ehdr);
 
   template <typename DynType>
   bool GetSonameWithTemplate(std::string* soname);
diff --git a/libunwindstack/tests/ElfInterfaceTest.cpp b/libunwindstack/tests/ElfInterfaceTest.cpp
index aa6df84..9326bff 100644
--- a/libunwindstack/tests/ElfInterfaceTest.cpp
+++ b/libunwindstack/tests/ElfInterfaceTest.cpp
@@ -97,9 +97,15 @@
   template <typename ElfType>
   void InitHeadersDebugFrameFail();
 
+  template <typename Ehdr, typename Phdr, typename ElfInterfaceType>
+  void InitProgramHeadersMalformed();
+
   template <typename Ehdr, typename Shdr, typename ElfInterfaceType>
   void InitSectionHeadersMalformed();
 
+  template <typename Ehdr, typename Shdr, typename ElfInterfaceType>
+  void InitSectionHeadersMalformedSymData();
+
   template <typename Ehdr, typename Shdr, typename Sym, typename ElfInterfaceType>
   void InitSectionHeaders(uint64_t entry_size);
 
@@ -677,6 +683,29 @@
   InitHeadersDebugFrame<ElfInterface64Fake>();
 }
 
+template <typename Ehdr, typename Phdr, typename ElfInterfaceType>
+void ElfInterfaceTest::InitProgramHeadersMalformed() {
+  std::unique_ptr<ElfInterfaceType> elf(new ElfInterfaceType(&memory_));
+
+  Ehdr ehdr = {};
+  ehdr.e_phoff = 0x100;
+  ehdr.e_phnum = 3;
+  ehdr.e_phentsize = sizeof(Phdr);
+  memory_.SetMemory(0, &ehdr, sizeof(ehdr));
+
+  uint64_t load_bias = 0;
+  ASSERT_TRUE(elf->Init(&load_bias));
+  EXPECT_EQ(0U, load_bias);
+}
+
+TEST_F(ElfInterfaceTest, init_program_headers_malformed32) {
+  InitProgramHeadersMalformed<Elf32_Ehdr, Elf32_Phdr, ElfInterface32>();
+}
+
+TEST_F(ElfInterfaceTest, init_program_headers_malformed64) {
+  InitProgramHeadersMalformed<Elf64_Ehdr, Elf64_Phdr, ElfInterface64>();
+}
+
 template <typename Ehdr, typename Shdr, typename ElfInterfaceType>
 void ElfInterfaceTest::InitSectionHeadersMalformed() {
   std::unique_ptr<ElfInterfaceType> elf(new ElfInterfaceType(&memory_));
@@ -700,6 +729,80 @@
   InitSectionHeadersMalformed<Elf64_Ehdr, Elf64_Shdr, ElfInterface64>();
 }
 
+template <typename Ehdr, typename Shdr, typename ElfInterfaceType>
+void ElfInterfaceTest::InitSectionHeadersMalformedSymData() {
+  std::unique_ptr<ElfInterfaceType> elf(new ElfInterfaceType(&memory_));
+
+  uint64_t offset = 0x1000;
+
+  Ehdr ehdr = {};
+  ehdr.e_shoff = offset;
+  ehdr.e_shnum = 5;
+  ehdr.e_shentsize = sizeof(Shdr);
+  memory_.SetMemory(0, &ehdr, sizeof(ehdr));
+
+  offset += ehdr.e_shentsize;
+
+  Shdr shdr = {};
+  shdr.sh_type = SHT_SYMTAB;
+  shdr.sh_link = 4;
+  shdr.sh_addr = 0x5000;
+  shdr.sh_offset = 0x5000;
+  shdr.sh_entsize = 0x100;
+  shdr.sh_size = shdr.sh_entsize * 10;
+  memory_.SetMemory(offset, &shdr, sizeof(shdr));
+  offset += ehdr.e_shentsize;
+
+  memset(&shdr, 0, sizeof(shdr));
+  shdr.sh_type = SHT_DYNSYM;
+  shdr.sh_link = 10;
+  shdr.sh_addr = 0x6000;
+  shdr.sh_offset = 0x6000;
+  shdr.sh_entsize = 0x100;
+  shdr.sh_size = shdr.sh_entsize * 10;
+  memory_.SetMemory(offset, &shdr, sizeof(shdr));
+  offset += ehdr.e_shentsize;
+
+  memset(&shdr, 0, sizeof(shdr));
+  shdr.sh_type = SHT_DYNSYM;
+  shdr.sh_link = 2;
+  shdr.sh_addr = 0x6000;
+  shdr.sh_offset = 0x6000;
+  shdr.sh_entsize = 0x100;
+  shdr.sh_size = shdr.sh_entsize * 10;
+  memory_.SetMemory(offset, &shdr, sizeof(shdr));
+  offset += ehdr.e_shentsize;
+
+  // The string data for the entries.
+  memset(&shdr, 0, sizeof(shdr));
+  shdr.sh_type = SHT_STRTAB;
+  shdr.sh_name = 0x20000;
+  shdr.sh_offset = 0xf000;
+  shdr.sh_size = 0x1000;
+  memory_.SetMemory(offset, &shdr, sizeof(shdr));
+  offset += ehdr.e_shentsize;
+
+  uint64_t load_bias = 0;
+  ASSERT_TRUE(elf->Init(&load_bias));
+  EXPECT_EQ(0U, load_bias);
+  EXPECT_EQ(0U, elf->debug_frame_offset());
+  EXPECT_EQ(0U, elf->debug_frame_size());
+  EXPECT_EQ(0U, elf->gnu_debugdata_offset());
+  EXPECT_EQ(0U, elf->gnu_debugdata_size());
+
+  std::string name;
+  uint64_t name_offset;
+  ASSERT_FALSE(elf->GetFunctionName(0x90010, &name, &name_offset));
+}
+
+TEST_F(ElfInterfaceTest, init_section_headers_malformed_symdata32) {
+  InitSectionHeadersMalformedSymData<Elf32_Ehdr, Elf32_Shdr, ElfInterface32>();
+}
+
+TEST_F(ElfInterfaceTest, init_section_headers_malformed_symdata64) {
+  InitSectionHeadersMalformedSymData<Elf64_Ehdr, Elf64_Shdr, ElfInterface64>();
+}
+
 template <typename Ehdr, typename Shdr, typename Sym, typename ElfInterfaceType>
 void ElfInterfaceTest::InitSectionHeaders(uint64_t entry_size) {
   std::unique_ptr<ElfInterfaceType> elf(new ElfInterfaceType(&memory_));
@@ -708,7 +811,7 @@
 
   Ehdr ehdr = {};
   ehdr.e_shoff = offset;
-  ehdr.e_shnum = 10;
+  ehdr.e_shnum = 5;
   ehdr.e_shentsize = entry_size;
   memory_.SetMemory(0, &ehdr, sizeof(ehdr));
 
@@ -795,7 +898,7 @@
 
   Ehdr ehdr = {};
   ehdr.e_shoff = offset;
-  ehdr.e_shnum = 10;
+  ehdr.e_shnum = 6;
   ehdr.e_shentsize = sizeof(Shdr);
   ehdr.e_shstrndx = 2;
   memory_.SetMemory(0, &ehdr, sizeof(ehdr));
diff --git a/libunwindstack/tests/MapInfoGetElfTest.cpp b/libunwindstack/tests/MapInfoGetElfTest.cpp
index f599503..861b82f 100644
--- a/libunwindstack/tests/MapInfoGetElfTest.cpp
+++ b/libunwindstack/tests/MapInfoGetElfTest.cpp
@@ -319,7 +319,7 @@
   TestInitEhdr<Elf64_Ehdr>(&ehdr, ELFCLASS64, EM_AARCH64);
   ehdr.e_shoff = 0x2000;
   ehdr.e_shentsize = sizeof(Elf64_Shdr) + 100;
-  ehdr.e_shnum = 4;
+  ehdr.e_shnum = 0;
   memory_->SetMemory(0x9000, &ehdr, sizeof(ehdr));
 
   Elf* elf = info.GetElf(process_memory_, false);
@@ -341,7 +341,7 @@
   TestInitEhdr<Elf64_Ehdr>(&ehdr, ELFCLASS64, EM_X86_64);
   ehdr.e_shoff = 0x2000;
   ehdr.e_shentsize = sizeof(Elf64_Shdr) + 100;
-  ehdr.e_shnum = 4;
+  ehdr.e_shnum = 0;
   memory_->SetMemory(0x7000, &ehdr, sizeof(ehdr));
 
   Elf* elf = info.GetElf(process_memory_, false);
@@ -368,7 +368,7 @@
   TestInitEhdr<Elf64_Ehdr>(&ehdr, ELFCLASS64, EM_X86_64);
   ehdr.e_shoff = 0x2000;
   ehdr.e_shentsize = sizeof(Elf64_Shdr) + 100;
-  ehdr.e_shnum = 4;
+  ehdr.e_shnum = 0;
   memory_->SetMemory(0x7000, &ehdr, sizeof(ehdr));
 
   Elf* elf_in_threads[kNumConcurrentThreads];
diff --git a/libunwindstack/tests/RegsInfoTest.cpp b/libunwindstack/tests/RegsInfoTest.cpp
new file mode 100644
index 0000000..052b5bf
--- /dev/null
+++ b/libunwindstack/tests/RegsInfoTest.cpp
@@ -0,0 +1,85 @@
+/*
+ * Copyright (C) 2018 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 <stdint.h>
+
+#include <gtest/gtest.h>
+
+#include <unwindstack/Regs.h>
+
+#include "RegsFake.h"
+#include "RegsInfo.h"
+
+namespace unwindstack {
+
+TEST(RegsInfoTest, single_uint32_t) {
+  RegsImplFake<uint32_t> regs(10);
+  RegsInfo<uint32_t> info(&regs);
+
+  regs[1] = 0x100;
+  ASSERT_FALSE(info.IsSaved(1));
+  ASSERT_EQ(0x100U, info.Get(1));
+  ASSERT_EQ(10, info.Total());
+
+  uint32_t* value = info.Save(1);
+  ASSERT_EQ(value, &regs[1]);
+  regs[1] = 0x200;
+  ASSERT_TRUE(info.IsSaved(1));
+  ASSERT_EQ(0x100U, info.Get(1));
+  ASSERT_EQ(0x200U, regs[1]);
+}
+
+TEST(RegsInfoTest, single_uint64_t) {
+  RegsImplFake<uint64_t> regs(20);
+  RegsInfo<uint64_t> info(&regs);
+
+  regs[3] = 0x300;
+  ASSERT_FALSE(info.IsSaved(3));
+  ASSERT_EQ(0x300U, info.Get(3));
+  ASSERT_EQ(20, info.Total());
+
+  uint64_t* value = info.Save(3);
+  ASSERT_EQ(value, &regs[3]);
+  regs[3] = 0x400;
+  ASSERT_TRUE(info.IsSaved(3));
+  ASSERT_EQ(0x300U, info.Get(3));
+  ASSERT_EQ(0x400U, regs[3]);
+}
+
+TEST(RegsInfoTest, all) {
+  RegsImplFake<uint64_t> regs(64);
+  RegsInfo<uint64_t> info(&regs);
+
+  for (uint32_t i = 0; i < 64; i++) {
+    regs[i] = i * 0x100;
+    ASSERT_EQ(i * 0x100, info.Get(i)) << "Reg " + std::to_string(i) + " failed.";
+  }
+
+  for (uint32_t i = 0; i < 64; i++) {
+    ASSERT_FALSE(info.IsSaved(i)) << "Reg " + std::to_string(i) + " failed.";
+    uint64_t* reg = info.Save(i);
+    ASSERT_EQ(reg, &regs[i]) << "Reg " + std::to_string(i) + " failed.";
+    *reg = i * 0x1000 + 0x100;
+    ASSERT_EQ(i * 0x1000 + 0x100, regs[i]) << "Reg " + std::to_string(i) + " failed.";
+  }
+
+  for (uint32_t i = 0; i < 64; i++) {
+    ASSERT_TRUE(info.IsSaved(i)) << "Reg " + std::to_string(i) + " failed.";
+    ASSERT_EQ(i * 0x100, info.Get(i)) << "Reg " + std::to_string(i) + " failed.";
+  }
+}
+
+}  // namespace unwindstack
diff --git a/lmkd/Android.bp b/lmkd/Android.bp
index 2efda86..9ac082f 100644
--- a/lmkd/Android.bp
+++ b/lmkd/Android.bp
@@ -7,17 +7,8 @@
         "liblog",
     ],
     local_include_dirs: ["include"],
-    cflags: ["-Werror"],
-
+    cflags: ["-Werror", "-DLMKD_TRACE_KILLS"],
     init_rc: ["lmkd.rc"],
-
-    product_variables: {
-        debuggable: {
-            cflags: [
-                "-DLMKD_TRACE_KILLS"
-            ],
-        },
-    },
 }
 
 cc_library_static {
diff --git a/lmkd/lmkd.c b/lmkd/lmkd.c
index c2487d6..1a14be3 100644
--- a/lmkd/lmkd.c
+++ b/lmkd/lmkd.c
@@ -52,8 +52,8 @@
 
 #else /* LMKD_TRACE_KILLS */
 
-#define TRACE_KILL_START(pid)
-#define TRACE_KILL_END()
+#define TRACE_KILL_START(pid) ((void)(pid))
+#define TRACE_KILL_END() ((void)0)
 
 #endif /* LMKD_TRACE_KILLS */
 
@@ -111,6 +111,7 @@
 static bool kill_heaviest_task;
 static unsigned long kill_timeout_ms;
 static bool use_minfree_levels;
+static bool per_app_memcg;
 
 /* data required to handle events */
 struct event_handler_info {
@@ -472,7 +473,7 @@
         return;
     }
 
-    if (low_ram_device) {
+    if (per_app_memcg) {
         if (params.oomadj >= 900) {
             soft_limit_mult = 0;
         } else if (params.oomadj >= 800) {
@@ -1481,6 +1482,8 @@
         (unsigned long)property_get_int32("ro.lmk.kill_timeout_ms", 0);
     use_minfree_levels =
         property_get_bool("ro.lmk.use_minfree_levels", false);
+    per_app_memcg =
+        property_get_bool("ro.config.per_app_memcg", low_ram_device);
 
     if (!init()) {
         if (!use_inkernel_interface) {
diff --git a/watchdogd/Android.bp b/watchdogd/Android.bp
new file mode 100644
index 0000000..0fbc33c
--- /dev/null
+++ b/watchdogd/Android.bp
@@ -0,0 +1,14 @@
+cc_binary {
+    name: "watchdogd",
+    recovery_available: true,
+    srcs: ["watchdogd.cpp"],
+    cflags: [
+        "-Wall",
+        "-Wextra",
+        "-Werror",
+    ],
+    shared_libs: ["libbase"],
+    sanitize: {
+        misc_undefined: ["signed-integer-overflow"],
+    },
+}
diff --git a/init/watchdogd.cpp b/watchdogd/watchdogd.cpp
similarity index 79%
rename from init/watchdogd.cpp
rename to watchdogd/watchdogd.cpp
index e03a2c3..5dc41e6 100644
--- a/init/watchdogd.cpp
+++ b/watchdogd/watchdogd.cpp
@@ -23,16 +23,9 @@
 
 #include <android-base/logging.h>
 
-#ifdef _INIT_INIT_H
-#error "Do not include init.h in files used by ueventd or watchdogd; it will expose init's globals"
-#endif
-
 #define DEV_NAME "/dev/watchdog"
 
-namespace android {
-namespace init {
-
-int watchdogd_main(int argc, char **argv) {
+int main(int argc, char** argv) {
     android::base::InitLogging(argv, &android::base::KernelLogger);
 
     int interval = 10;
@@ -43,7 +36,7 @@
 
     LOG(INFO) << "watchdogd started (interval " << interval << ", margin " << margin << ")!";
 
-    int fd = open(DEV_NAME, O_RDWR|O_CLOEXEC);
+    int fd = open(DEV_NAME, O_RDWR | O_CLOEXEC);
     if (fd == -1) {
         PLOG(ERROR) << "Failed to open " << DEV_NAME;
         return 1;
@@ -63,9 +56,8 @@
                 interval = 1;
             }
             LOG(WARNING) << "Adjusted interval to timeout returned by driver: "
-                         << "timeout " << timeout
-                         << ", interval " << interval
-                         << ", margin " << margin;
+                         << "timeout " << timeout << ", interval " << interval << ", margin "
+                         << margin;
         }
     }
 
@@ -74,6 +66,3 @@
         sleep(interval);
     }
 }
-
-}  // namespace init
-}  // namespace android