9 files changed, 176 insertions, 60 deletions

diff --git a/install/adb_install.cpp b/install/adb_install.cpp
index f430920a4..d79f6f4b0 100644
--- a/install/adb_install.cpp
+++ b/install/adb_install.cpp
@@ -31,6 +31,7 @@
 #include <atomic>
 #include <functional>
 #include <map>
+#include <utility>
 #include <vector>
 
 #include <android-base/file.h>
@@ -44,30 +45,34 @@
 #include "install/install.h"
 #include "minadbd_types.h"
 #include "otautil/sysutil.h"
+#include "recovery_ui/device.h"
 #include "recovery_ui/ui.h"
 
-using CommandFunction = std::function<bool()>;
+// A CommandFunction returns a pair of (result, should_continue), which indicates the command
+// execution result and whether it should proceed to the next iteration. The execution result will
+// always be sent to the minadbd side.
+using CommandFunction = std::function<std::pair<bool, bool>()>;
 
 static bool SetUsbConfig(const std::string& state) {
   android::base::SetProperty("sys.usb.config", state);
   return android::base::WaitForProperty("sys.usb.state", state);
 }
 
-// Parses the minadbd command in |message|; returns MinadbdCommands::kError upon errors.
-static MinadbdCommands ParseMinadbdCommands(const std::string& message) {
+// Parses the minadbd command in |message|; returns MinadbdCommand::kError upon errors.
+static MinadbdCommand ParseMinadbdCommand(const std::string& message) {
   if (!android::base::StartsWith(message, kMinadbdCommandPrefix)) {
     LOG(ERROR) << "Failed to parse command in message " << message;
-    return MinadbdCommands::kError;
+    return MinadbdCommand::kError;
   }
 
   auto cmd_code_string = message.substr(strlen(kMinadbdCommandPrefix));
   auto cmd_code = android::base::get_unaligned<uint32_t>(cmd_code_string.c_str());
-  if (cmd_code >= static_cast<uint32_t>(MinadbdCommands::kError)) {
+  if (cmd_code >= static_cast<uint32_t>(MinadbdCommand::kError)) {
     LOG(ERROR) << "Unsupported command code: " << cmd_code;
-    return MinadbdCommands::kError;
+    return MinadbdCommand::kError;
   }
 
-  return static_cast<MinadbdCommands>(cmd_code);
+  return static_cast<MinadbdCommand>(cmd_code);
 }
 
 static bool WriteStatusToFd(MinadbdCommandStatus status, int fd) {
@@ -82,13 +87,15 @@ static bool WriteStatusToFd(MinadbdCommandStatus status, int fd) {
   return true;
 }
 
-// Installs the package from FUSE. Returns true if the installation succeeds, and false otherwise.
-static bool AdbInstallPackageHandler(RecoveryUI* ui, int* result) {
+// Installs the package from FUSE. Returns the installation result and whether it should continue
+// waiting for new commands.
+static auto AdbInstallPackageHandler(RecoveryUI* ui, int* result) {
   // How long (in seconds) we wait for the package path to be ready. It doesn't need to be too long
   // because the minadbd service has already issued an install command. FUSE_SIDELOAD_HOST_PATHNAME
   // will start to exist once the host connects and starts serving a package. Poll for its
   // appearance. (Note that inotify doesn't work with FUSE.)
   constexpr int ADB_INSTALL_TIMEOUT = 15;
+  bool should_continue = true;
   *result = INSTALL_ERROR;
   for (int i = 0; i < ADB_INSTALL_TIMEOUT; ++i) {
     struct stat st;
@@ -97,6 +104,7 @@ static bool AdbInstallPackageHandler(RecoveryUI* ui, int* result) {
         sleep(1);
         continue;
       } else {
+        should_continue = false;
         ui->Print("\nTimed out waiting for fuse to be ready.\n\n");
         break;
       }
@@ -108,13 +116,39 @@ static bool AdbInstallPackageHandler(RecoveryUI* ui, int* result) {
   // Calling stat() on this magic filename signals the FUSE to exit.
   struct stat st;
   stat(FUSE_SIDELOAD_HOST_EXIT_PATHNAME, &st);
-  return *result == INSTALL_SUCCESS;
+  return std::make_pair(*result == INSTALL_SUCCESS, should_continue);
 }
 
-// Parses and executes the command from minadbd. Returns false if we enter an invalid state so that
-// the caller can kill the minadbd service properly.
-static bool HandleMessageFromMinadbd(
-    int socket_fd, const std::map<MinadbdCommands, CommandFunction>& command_map) {
+static auto AdbRebootHandler(MinadbdCommand command, int* result,
+                             Device::BuiltinAction* reboot_action) {
+  switch (command) {
+    case MinadbdCommand::kRebootBootloader:
+      *reboot_action = Device::REBOOT_BOOTLOADER;
+      break;
+    case MinadbdCommand::kRebootFastboot:
+      *reboot_action = Device::ENTER_FASTBOOT;
+      break;
+    case MinadbdCommand::kRebootRecovery:
+      *reboot_action = Device::ENTER_RECOVERY;
+      break;
+    case MinadbdCommand::kRebootRescue:
+      // Use Device::REBOOT_RESCUE instead of Device::ENTER_RESCUE. This allows rebooting back into
+      // rescue mode (potentially using a newly installed recovery image).
+      *reboot_action = Device::REBOOT_RESCUE;
+      break;
+    case MinadbdCommand::kRebootAndroid:
+    default:
+      *reboot_action = Device::REBOOT;
+      break;
+  }
+  *result = INSTALL_REBOOT;
+  return std::make_pair(true, false);
+}
+
+// Parses and executes the command from minadbd. Returns whether the caller should keep waiting for
+// next command.
+static bool HandleMessageFromMinadbd(int socket_fd,
+                                     const std::map<MinadbdCommand, CommandFunction>& command_map) {
   char buffer[kMinadbdMessageSize];
   if (!android::base::ReadFully(socket_fd, buffer, kMinadbdMessageSize)) {
     PLOG(ERROR) << "Failed to read message from minadbd";
@@ -122,8 +156,8 @@ static bool HandleMessageFromMinadbd(
   }
 
   std::string message(buffer, buffer + kMinadbdMessageSize);
-  auto command_type = ParseMinadbdCommands(message);
-  if (command_type == MinadbdCommands::kError) {
+  auto command_type = ParseMinadbdCommand(message);
+  if (command_type == MinadbdCommand::kError) {
     return false;
   }
   if (command_map.find(command_type) == command_map.end()) {
@@ -135,17 +169,19 @@ static bool HandleMessageFromMinadbd(
 
   // We have received a valid command, execute the corresponding function.
   const auto& command_func = command_map.at(command_type);
-  if (!command_func()) {
-    LOG(ERROR) << "Failed to execute command " << static_cast<unsigned int>(command_type);
-    return WriteStatusToFd(MinadbdCommandStatus::kFailure, socket_fd);
+  const auto [result, should_continue] = command_func();
+  LOG(INFO) << "Command " << static_cast<uint32_t>(command_type) << " finished with " << result;
+  if (!WriteStatusToFd(result ? MinadbdCommandStatus::kSuccess : MinadbdCommandStatus::kFailure,
+                       socket_fd)) {
+    return false;
   }
-  return WriteStatusToFd(MinadbdCommandStatus::kSuccess, socket_fd);
+  return should_continue;
 }
 
 // TODO(xunchang) add a wrapper function and kill the minadbd service there.
 static void ListenAndExecuteMinadbdCommands(
     pid_t minadbd_pid, android::base::unique_fd&& socket_fd,
-    const std::map<MinadbdCommands, CommandFunction>& command_map) {
+    const std::map<MinadbdCommand, CommandFunction>& command_map) {
   android::base::unique_fd epoll_fd(epoll_create1(O_CLOEXEC));
   if (epoll_fd == -1) {
     PLOG(ERROR) << "Failed to create epoll";
@@ -230,7 +266,7 @@ static void ListenAndExecuteMinadbdCommands(
 //                               b11. exit the listening loop
 //
 static void CreateMinadbdServiceAndExecuteCommands(
-    const std::map<MinadbdCommands, CommandFunction>& command_map, bool rescue_mode) {
+    const std::map<MinadbdCommand, CommandFunction>& command_map, bool rescue_mode) {
   signal(SIGPIPE, SIG_IGN);
 
   android::base::unique_fd recovery_socket;
@@ -271,7 +307,6 @@ static void CreateMinadbdServiceAndExecuteCommands(
 
   std::thread listener_thread(ListenAndExecuteMinadbdCommands, child, std::move(recovery_socket),
                               std::ref(command_map));
-
   if (listener_thread.joinable()) {
     listener_thread.join();
   }
@@ -289,7 +324,7 @@ static void CreateMinadbdServiceAndExecuteCommands(
   signal(SIGPIPE, SIG_DFL);
 }
 
-int ApplyFromAdb(RecoveryUI* ui, bool rescue_mode) {
+int ApplyFromAdb(RecoveryUI* ui, bool rescue_mode, Device::BuiltinAction* reboot_action) {
   // Save the usb state to restore after the sideload operation.
   std::string usb_state = android::base::GetProperty("sys.usb.state", "none");
   // Clean up state and stop adbd.
@@ -307,8 +342,19 @@ int ApplyFromAdb(RecoveryUI* ui, bool rescue_mode) {
   }
 
   int install_result = INSTALL_ERROR;
-  std::map<MinadbdCommands, CommandFunction> command_map{
-    { MinadbdCommands::kInstall, std::bind(&AdbInstallPackageHandler, ui, &install_result) },
+  std::map<MinadbdCommand, CommandFunction> command_map{
+    { MinadbdCommand::kInstall, std::bind(&AdbInstallPackageHandler, ui, &install_result) },
+    { MinadbdCommand::kRebootAndroid, std::bind(&AdbRebootHandler, MinadbdCommand::kRebootAndroid,
+                                                &install_result, reboot_action) },
+    { MinadbdCommand::kRebootBootloader,
+      std::bind(&AdbRebootHandler, MinadbdCommand::kRebootBootloader, &install_result,
+                reboot_action) },
+    { MinadbdCommand::kRebootFastboot, std::bind(&AdbRebootHandler, MinadbdCommand::kRebootFastboot,
+                                                 &install_result, reboot_action) },
+    { MinadbdCommand::kRebootRecovery, std::bind(&AdbRebootHandler, MinadbdCommand::kRebootRecovery,
+                                                 &install_result, reboot_action) },
+    { MinadbdCommand::kRebootRescue,
+      std::bind(&AdbRebootHandler, MinadbdCommand::kRebootRescue, &install_result, reboot_action) },
   };
 
   CreateMinadbdServiceAndExecuteCommands(command_map, rescue_mode);
diff --git a/install/include/install/adb_install.h b/install/include/install/adb_install.h
index 208d0c780..49b32b54f 100644
--- a/install/include/install/adb_install.h
+++ b/install/include/install/adb_install.h
@@ -16,6 +16,10 @@
 
 #pragma once
 
+#include <recovery_ui/device.h>
 #include <recovery_ui/ui.h>
 
-int ApplyFromAdb(RecoveryUI* ui, bool rescue_mode);
+// Applies a package via `adb sideload` or `adb rescue`. Returns the install result (in `enum
+// InstallResult`). When a reboot has been requested, INSTALL_REBOOT will be the return value, with
+// the reboot target set in reboot_action.
+int ApplyFromAdb(RecoveryUI* ui, bool rescue_mode, Device::BuiltinAction* reboot_action);
diff --git a/install/include/install/install.h b/install/include/install/install.h
index 1e41b4843..c0a8f1f4c 100644
--- a/install/include/install/install.h
+++ b/install/include/install/install.h
@@ -34,7 +34,8 @@ enum InstallResult {
   INSTALL_NONE,
   INSTALL_SKIPPED,
   INSTALL_RETRY,
-  INSTALL_KEY_INTERRUPTED
+  INSTALL_KEY_INTERRUPTED,
+  INSTALL_REBOOT,
 };
 
 enum class OtaType {
diff --git a/minadbd/minadbd_services.cpp b/minadbd/minadbd_services.cpp
index f6aff71f8..9b1999d90 100644
--- a/minadbd/minadbd_services.cpp
+++ b/minadbd/minadbd_services.cpp
@@ -64,7 +64,7 @@ void SetSideloadMountPoint(const std::string& path) {
   sideload_mount_point = path;
 }
 
-static bool WriteCommandToFd(MinadbdCommands cmd, int fd) {
+static bool WriteCommandToFd(MinadbdCommand cmd, int fd) {
   char message[kMinadbdMessageSize];
   memcpy(message, kMinadbdCommandPrefix, strlen(kMinadbdStatusPrefix));
   android::base::put_unaligned(message + strlen(kMinadbdStatusPrefix), cmd);
@@ -109,7 +109,7 @@ static MinadbdErrorCode RunAdbFuseSideload(int sfd, const std::string& args,
 
   LOG(INFO) << "sideload-host file size " << file_size << ", block size " << block_size;
 
-  if (!WriteCommandToFd(MinadbdCommands::kInstall, minadbd_socket)) {
+  if (!WriteCommandToFd(MinadbdCommand::kInstall, minadbd_socket)) {
     return kMinadbdSocketIOError;
   }
 
@@ -175,7 +175,45 @@ static void RescueGetpropHostService(unique_fd sfd, const std::string& prop) {
   }
 }
 
+// Reboots into the given target. We don't reboot directly from minadbd, but going through recovery
+// instead. This allows recovery to finish all the pending works (clear BCB, save logs etc) before
+// the reboot.
+static void RebootHostService(unique_fd /* sfd */, const std::string& target) {
+  MinadbdCommand command;
+  if (target == "bootloader") {
+    command = MinadbdCommand::kRebootBootloader;
+  } else if (target == "rescue") {
+    command = MinadbdCommand::kRebootRescue;
+  } else if (target == "recovery") {
+    command = MinadbdCommand::kRebootRecovery;
+  } else if (target == "fastboot") {
+    command = MinadbdCommand::kRebootFastboot;
+  } else {
+    command = MinadbdCommand::kRebootAndroid;
+  }
+  if (!WriteCommandToFd(command, minadbd_socket)) {
+    exit(kMinadbdSocketIOError);
+  }
+  MinadbdCommandStatus status;
+  if (!WaitForCommandStatus(minadbd_socket, &status)) {
+    exit(kMinadbdMessageFormatError);
+  }
+}
+
 unique_fd daemon_service_to_fd(std::string_view name, atransport* /* transport */) {
+  // Common services that are supported both in sideload and rescue modes.
+  if (ConsumePrefix(&name, "reboot:")) {
+    // "reboot:<target>", where target must be one of the following.
+    std::string args(name);
+    if (args.empty() || args == "bootloader" || args == "rescue" || args == "recovery" ||
+        args == "fastboot") {
+      return create_service_thread("reboot",
+                                   std::bind(RebootHostService, std::placeholders::_1, args));
+    }
+    return unique_fd{};
+  }
+
+  // Rescue-specific services.
   if (rescue_mode) {
     if (ConsumePrefix(&name, "rescue-install:")) {
       // rescue-install:<file-size>:<block-size>
@@ -191,6 +229,7 @@ unique_fd daemon_service_to_fd(std::string_view name, atransport* /* transport *
     return unique_fd{};
   }
 
+  // Sideload-specific services.
   if (name.starts_with("sideload:")) {
     // This exit status causes recovery to print a special error message saying to use a newer adb
     // (that supports sideload-host).
diff --git a/minadbd/minadbd_services_test.cpp b/minadbd/minadbd_services_test.cpp
index 413ba0df6..593180bb3 100644
--- a/minadbd/minadbd_services_test.cpp
+++ b/minadbd/minadbd_services_test.cpp
@@ -62,7 +62,7 @@ class MinadbdServicesTest : public ::testing::Test {
     signal(SIGPIPE, SIG_DFL);
   }
 
-  void ReadAndCheckCommandMessage(int fd, MinadbdCommands expected_command) {
+  void ReadAndCheckCommandMessage(int fd, MinadbdCommand expected_command) {
     std::vector<uint8_t> received(kMinadbdMessageSize, '\0');
     ASSERT_TRUE(android::base::ReadFully(fd, received.data(), kMinadbdMessageSize));
 
@@ -147,7 +147,7 @@ TEST_F(MinadbdServicesTest, SideloadHostService_wrong_command_format) {
     unique_fd fd = daemon_service_to_fd(command, nullptr);
     ASSERT_NE(-1, fd);
     WaitForFusePath();
-    ReadAndCheckCommandMessage(recovery_socket_, MinadbdCommands::kInstall);
+    ReadAndCheckCommandMessage(recovery_socket_, MinadbdCommand::kInstall);
 
     struct stat sb;
     ASSERT_EQ(0, stat(exit_flag_.c_str(), &sb));
@@ -188,7 +188,7 @@ TEST_F(MinadbdServicesTest, SideloadHostService_read_data_from_fuse) {
 
     unique_fd fd = daemon_service_to_fd("sideload-host:4096:4096", nullptr);
     ASSERT_NE(-1, fd);
-    ReadAndCheckCommandMessage(recovery_socket_, MinadbdCommands::kInstall);
+    ReadAndCheckCommandMessage(recovery_socket_, MinadbdCommand::kInstall);
 
     // Mimic the response from adb host.
     std::string adb_message(8, '\0');
diff --git a/minadbd/minadbd_types.h b/minadbd/minadbd_types.h
index 5fb7803e7..b370b7952 100644
--- a/minadbd/minadbd_types.h
+++ b/minadbd/minadbd_types.h
@@ -43,12 +43,19 @@ enum class MinadbdCommandStatus : uint32_t {
   kFailure = 1,
 };
 
-enum class MinadbdCommands : uint32_t {
+enum class MinadbdCommand : uint32_t {
   kInstall = 0,
   kUiPrint = 1,
-  kError = 2,
+  kRebootAndroid = 2,
+  kRebootBootloader = 3,
+  kRebootFastboot = 4,
+  kRebootRecovery = 5,
+  kRebootRescue = 6,
+
+  // Last but invalid command.
+  kError,
 };
 
-static_assert(kMinadbdMessageSize == sizeof(kMinadbdCommandPrefix) - 1 + sizeof(MinadbdCommands));
+static_assert(kMinadbdMessageSize == sizeof(kMinadbdCommandPrefix) - 1 + sizeof(MinadbdCommand));
 static_assert(kMinadbdMessageSize ==
               sizeof(kMinadbdStatusPrefix) - 1 + sizeof(MinadbdCommandStatus));
diff --git a/recovery.cpp b/recovery.cpp
index ce29cb27b..5bd9b1728 100644
--- a/recovery.cpp
+++ b/recovery.cpp
@@ -512,6 +512,7 @@ static Device::BuiltinAction prompt_and_wait(Device* device, int status) {
       case Device::REBOOT:
       case Device::SHUTDOWN:
       case Device::REBOOT_BOOTLOADER:
+      case Device::REBOOT_RESCUE:
       case Device::ENTER_FASTBOOT:
       case Device::ENTER_RECOVERY:
         return chosen_action;
@@ -537,32 +538,36 @@ static Device::BuiltinAction prompt_and_wait(Device* device, int status) {
         if (!ui->IsTextVisible()) return Device::NO_ACTION;
         break;
       }
+
       case Device::APPLY_ADB_SIDELOAD:
       case Device::APPLY_SDCARD:
       case Device::ENTER_RESCUE: {
         save_current_log = true;
 
         bool adb = true;
+        Device::BuiltinAction reboot_action;
         if (chosen_action == Device::ENTER_RESCUE) {
           // Switch to graphics screen.
           ui->ShowText(false);
-          status = ApplyFromAdb(ui, true /* rescue_mode */);
-          ui->ShowText(true);
+          status = ApplyFromAdb(ui, true /* rescue_mode */, &reboot_action);
         } else if (chosen_action == Device::APPLY_ADB_SIDELOAD) {
-          status = ApplyFromAdb(ui, false /* rescue_mode */);
+          status = ApplyFromAdb(ui, false /* rescue_mode */, &reboot_action);
         } else {
           adb = false;
           status = ApplyFromSdcard(device, ui);
         }
 
+        ui->Print("\nInstall from %s completed with status %d.\n", adb ? "ADB" : "SD card", status);
+        if (status == INSTALL_REBOOT) {
+          return reboot_action;
+        }
+
         if (status != INSTALL_SUCCESS) {
           ui->SetBackground(RecoveryUI::ERROR);
           ui->Print("Installation aborted.\n");
           copy_logs(save_current_log, has_cache, sehandle);
         } else if (!ui->IsTextVisible()) {
           return Device::NO_ACTION;  // reboot if logs aren't visible
-        } else {
-          ui->Print("\nInstall from %s complete.\n", adb ? "ADB" : "SD card");
         }
         break;
       }
@@ -841,6 +846,9 @@ Device::BuiltinAction start_recovery(Device* device, const std::vector<std::stri
   ui->Print("Supported API: %d\n", kRecoveryApiVersion);
 
   int status = INSTALL_SUCCESS;
+  // next_action indicates the next target to reboot into upon finishing the install. It could be
+  // overridden to a different reboot target per user request.
+  Device::BuiltinAction next_action = shutdown_after ? Device::SHUTDOWN : Device::REBOOT;
 
   if (update_package != nullptr) {
     // It's not entirely true that we will modify the flash. But we want
@@ -924,19 +932,18 @@ Device::BuiltinAction start_recovery(Device* device, const std::vector<std::stri
       status = INSTALL_ERROR;
     }
   } else if (sideload) {
-    // 'adb reboot sideload' acts the same as user presses key combinations
-    // to enter the sideload mode. When 'sideload-auto-reboot' is used, text
-    // display will NOT be turned on by default. And it will reboot after
-    // sideload finishes even if there are errors. Unless one turns on the
-    // text display during the installation. This is to enable automated
+    // 'adb reboot sideload' acts the same as user presses key combinations to enter the sideload
+    // mode. When 'sideload-auto-reboot' is used, text display will NOT be turned on by default. And
+    // it will reboot after sideload finishes even if there are errors. This is to enable automated
     // testing.
     save_current_log = true;
     if (!sideload_auto_reboot) {
       ui->ShowText(true);
     }
-    status = ApplyFromAdb(ui, false /* rescue_mode */);
+    status = ApplyFromAdb(ui, false /* rescue_mode */, &next_action);
     ui->Print("\nInstall from ADB complete (status: %d).\n", status);
     if (sideload_auto_reboot) {
+      status = INSTALL_REBOOT;
       ui->Print("Rebooting automatically.\n");
     }
   } else if (fsck_unshare_blocks) {
@@ -961,23 +968,26 @@ Device::BuiltinAction start_recovery(Device* device, const std::vector<std::stri
     }
   }
 
-  Device::BuiltinAction after = shutdown_after ? Device::SHUTDOWN : Device::REBOOT;
-  // 1. If the recovery menu is visible, prompt and wait for commands.
-  // 2. If the state is INSTALL_NONE, wait for commands. (i.e. In user build, manually reboot into
-  //    recovery to sideload a package.)
-  // 3. sideload_auto_reboot is an option only available in user-debug build, reboot the device
-  //    without waiting.
-  // 4. In all other cases, reboot the device. Therefore, normal users will observe the device
-  //    reboot after it shows the "error" screen for 5s.
-  if ((status == INSTALL_NONE && !sideload_auto_reboot) || ui->IsTextVisible()) {
-    Device::BuiltinAction temp = prompt_and_wait(device, status);
-    if (temp != Device::NO_ACTION) {
-      after = temp;
+  // Determine the next action.
+  //  - If the state is INSTALL_REBOOT, device will reboot into the target as specified in
+  //    `next_action`.
+  //  - If the recovery menu is visible, prompt and wait for commands.
+  //  - If the state is INSTALL_NONE, wait for commands (e.g. in user build, one manually boots
+  //    into recovery to sideload a package or to wipe the device).
+  //  - In all other cases, reboot the device. Therefore, normal users will observe the device
+  //    rebooting a) immediately upon successful finish (INSTALL_SUCCESS); or b) an "error" screen
+  //    for 5s followed by an automatic reboot.
+  if (status != INSTALL_REBOOT) {
+    if (status == INSTALL_NONE || ui->IsTextVisible()) {
+      Device::BuiltinAction temp = prompt_and_wait(device, status);
+      if (temp != Device::NO_ACTION) {
+        next_action = temp;
+      }
     }
   }
 
   // Save logs and clean up before rebooting or shutting down.
   finish_recovery();
 
-  return after;
+  return next_action;
 }
diff --git a/recovery_main.cpp b/recovery_main.cpp
index 37d9da0d7..0eb2962e1 100644
--- a/recovery_main.cpp
+++ b/recovery_main.cpp
@@ -477,6 +477,11 @@ int main(int argc, char** argv) {
         android::base::SetProperty(ANDROID_RB_PROPERTY, "reboot,bootloader");
         break;
 
+      case Device::REBOOT_RESCUE:
+        ui->Print("Rebooting to rescue...\n");
+        android::base::SetProperty(ANDROID_RB_PROPERTY, "reboot,rescue");
+        break;
+
       case Device::ENTER_FASTBOOT:
         if (logical_partitions_mapped()) {
           ui->Print("Partitions may be mounted - rebooting to enter fastboot.");
diff --git a/recovery_ui/include/recovery_ui/device.h b/recovery_ui/include/recovery_ui/device.h
index 8f17639d6..09b5d1f4d 100644
--- a/recovery_ui/include/recovery_ui/device.h
+++ b/recovery_ui/include/recovery_ui/device.h
@@ -50,7 +50,11 @@ class Device {
     KEY_INTERRUPTED = 13,
     ENTER_FASTBOOT = 14,
     ENTER_RECOVERY = 15,
+    // ENTER vs REBOOT: The latter will trigger a reboot that uses `rescue` as the reboot target.
+    // So it goes from rescue -> bootloader -> rescue, whereas ENTER_RESCUE switches from recovery
+    // -> rescue directly.
     ENTER_RESCUE = 16,
+    REBOOT_RESCUE = 17,
   };
 
   explicit Device(RecoveryUI* ui);