9 files changed, 429 insertions, 85 deletions

diff --git a/Android.bp b/Android.bp
index 137004c07..582f3b623 100644
--- a/Android.bp
+++ b/Android.bp
@@ -112,7 +112,6 @@ cc_binary {
     ],
 
     shared_libs: [
-        "libminadbd_services",
         "librecovery_ui",
     ],
 
@@ -124,6 +123,7 @@ cc_binary {
     required: [
         "e2fsdroid.recovery",
         "librecovery_ui_ext",
+        "minadbd",
         "mke2fs.conf.recovery",
         "mke2fs.recovery",
         "recovery_deps",
diff --git a/install/Android.bp b/install/Android.bp
index 85cf9ac4a..2ffc4421c 100644
--- a/install/Android.bp
+++ b/install/Android.bp
@@ -19,6 +19,10 @@ cc_defaults {
         "recovery_defaults",
     ],
 
+    header_libs: [
+        "libminadbd_headers",
+    ],
+
     shared_libs: [
         "libbase",
         "libbootloader_message",
diff --git a/install/adb_install.cpp b/install/adb_install.cpp
index 5296ff608..dc7ee0b32 100644
--- a/install/adb_install.cpp
+++ b/install/adb_install.cpp
@@ -21,97 +21,286 @@
 #include <signal.h>
 #include <stdlib.h>
 #include <string.h>
+#include <sys/epoll.h>
+#include <sys/socket.h>
 #include <sys/stat.h>
 #include <sys/types.h>
 #include <sys/wait.h>
 #include <unistd.h>
 
+#include <atomic>
+#include <functional>
+#include <map>
+
+#include <android-base/file.h>
 #include <android-base/logging.h>
+#include <android-base/memory.h>
 #include <android-base/properties.h>
+#include <android-base/strings.h>
+#include <android-base/unique_fd.h>
 
 #include "fuse_sideload.h"
 #include "install/install.h"
+#include "minadbd_types.h"
 #include "recovery_ui/ui.h"
 
+using CommandFunction = std::function<bool()>;
+
 static bool SetUsbConfig(const std::string& state) {
   android::base::SetProperty("sys.usb.config", state);
   return android::base::WaitForProperty("sys.usb.state", state);
 }
 
-int apply_from_adb(bool* wipe_cache, RecoveryUI* ui) {
-  // 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.
-  if (usb_state != "none" && !SetUsbConfig("none")) {
-    LOG(ERROR) << "Failed to clear USB config";
-    return INSTALL_ERROR;
+// Parses the minadbd command in |message|; returns MinadbdCommands::kError upon errors.
+static MinadbdCommands ParseMinadbdCommands(const std::string& message) {
+  if (!android::base::StartsWith(message, kMinadbdCommandPrefix)) {
+    LOG(ERROR) << "Failed to parse command in message " << message;
+    return MinadbdCommands::kError;
   }
 
-  ui->Print(
-      "\n\nNow send the package you want to apply\n"
-      "to the device with \"adb sideload <filename>\"...\n");
-
-  pid_t child;
-  if ((child = fork()) == 0) {
-    execl("/system/bin/recovery", "recovery", "--adbd", nullptr);
-    _exit(EXIT_FAILURE);
+  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)) {
+    LOG(ERROR) << "Unsupported command code: " << cmd_code;
+    return MinadbdCommands::kError;
   }
 
-  if (!SetUsbConfig("sideload")) {
-    LOG(ERROR) << "Failed to set usb config to sideload";
-    return INSTALL_ERROR;
-  }
+  return static_cast<MinadbdCommands>(cmd_code);
+}
 
-  // How long (in seconds) we wait for the host to start sending us a package, before timing out.
-  static constexpr int ADB_INSTALL_TIMEOUT = 300;
+static bool WriteStatusToFd(MinadbdCommandStatus status, int fd) {
+  char message[kMinadbdMessageSize];
+  memcpy(message, kMinadbdStatusPrefix, strlen(kMinadbdStatusPrefix));
+  android::base::put_unaligned(message + strlen(kMinadbdStatusPrefix), status);
 
-  // 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.)
-  int result = INSTALL_ERROR;
-  int status;
-  bool waited = false;
-  for (int i = 0; i < ADB_INSTALL_TIMEOUT; ++i) {
-    if (waitpid(child, &status, WNOHANG) != 0) {
-      result = INSTALL_ERROR;
-      waited = true;
-      break;
-    }
+  if (!android::base::WriteFully(fd, message, kMinadbdMessageSize)) {
+    PLOG(ERROR) << "Failed to write message " << message;
+    return false;
+  }
+  return true;
+}
 
+// Installs the package from FUSE. Returns true if the installation succeeds, and false otherwise.
+static bool AdbInstallPackageHandler(bool* wipe_cache, 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;
+  *result = INSTALL_ERROR;
+  for (int i = 0; i < ADB_INSTALL_TIMEOUT; ++i) {
     struct stat st;
     if (stat(FUSE_SIDELOAD_HOST_PATHNAME, &st) != 0) {
       if (errno == ENOENT && i < ADB_INSTALL_TIMEOUT - 1) {
         sleep(1);
         continue;
       } else {
-        ui->Print("\nTimed out waiting for package.\n\n");
-        result = INSTALL_ERROR;
-        kill(child, SIGKILL);
+        ui->Print("\nTimed out waiting for fuse to be ready.\n\n");
         break;
       }
     }
-    result = install_package(FUSE_SIDELOAD_HOST_PATHNAME, wipe_cache, false, 0, ui);
+    *result = install_package(FUSE_SIDELOAD_HOST_PATHNAME, wipe_cache, false, 0, ui);
     break;
   }
 
-  if (!waited) {
-    // Calling stat() on this magic filename signals the minadbd subprocess to shut down.
-    struct stat st;
-    stat(FUSE_SIDELOAD_HOST_EXIT_PATHNAME, &st);
+  // 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;
+}
+
+// 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) {
+  char buffer[kMinadbdMessageSize];
+  if (!android::base::ReadFully(socket_fd, buffer, kMinadbdMessageSize)) {
+    PLOG(ERROR) << "Failed to read message from minadbd";
+    return false;
+  }
+
+  std::string message(buffer, buffer + kMinadbdMessageSize);
+  auto command_type = ParseMinadbdCommands(message);
+  if (command_type == MinadbdCommands::kError) {
+    return false;
+  }
+  if (command_map.find(command_type) == command_map.end()) {
+    LOG(ERROR) << "Unsupported command: "
+               << android::base::get_unaligned<unsigned int>(
+                      message.substr(strlen(kMinadbdCommandPrefix)).c_str());
+    return false;
+  }
+
+  // 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);
+  }
+  return WriteStatusToFd(MinadbdCommandStatus::kSuccess, socket_fd);
+}
+
+// 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) {
+  android::base::unique_fd epoll_fd(epoll_create1(O_CLOEXEC));
+  if (epoll_fd == -1) {
+    PLOG(ERROR) << "Failed to create epoll";
+    kill(minadbd_pid, SIGKILL);
+    return;
+  }
+
+  constexpr int EPOLL_MAX_EVENTS = 10;
+  struct epoll_event ev = {};
+  ev.events = EPOLLIN | EPOLLHUP;
+  ev.data.fd = socket_fd.get();
+  struct epoll_event events[EPOLL_MAX_EVENTS];
+  if (epoll_ctl(epoll_fd.get(), EPOLL_CTL_ADD, socket_fd.get(), &ev) == -1) {
+    PLOG(ERROR) << "Failed to add socket fd to epoll";
+    kill(minadbd_pid, SIGKILL);
+    return;
+  }
+
+  // Set the timeout to be 300s when waiting for minadbd commands.
+  constexpr int TIMEOUT_MILLIS = 300 * 1000;
+  while (true) {
+    // Poll for the status change of the socket_fd, and handle the message if the fd is ready to
+    // read.
+    int event_count =
+        TEMP_FAILURE_RETRY(epoll_wait(epoll_fd.get(), events, EPOLL_MAX_EVENTS, TIMEOUT_MILLIS));
+    if (event_count == -1) {
+      PLOG(ERROR) << "Failed to wait for epoll events";
+      kill(minadbd_pid, SIGKILL);
+      return;
+    }
+    if (event_count == 0) {
+      LOG(ERROR) << "Timeout waiting for messages from minadbd";
+      kill(minadbd_pid, SIGKILL);
+      return;
+    }
+
+    for (int n = 0; n < event_count; n++) {
+      if (events[n].events & EPOLLHUP) {
+        LOG(INFO) << "Socket has been closed";
+        kill(minadbd_pid, SIGKILL);
+        return;
+      }
+      if (!HandleMessageFromMinadbd(socket_fd.get(), command_map)) {
+        kill(minadbd_pid, SIGKILL);
+        return;
+      }
+    }
+  }
+}
+
+// Recovery starts minadbd service as a child process, and spawns another thread to listen for the
+// message from minadbd through a socket pair. Here is an example to execute one command from adb
+// host.
+//  a. recovery                    b. listener thread               c. minadbd service
+//
+//  a1. create socket pair
+//  a2. fork minadbd service
+//                                                                c3. wait for the adb commands
+//                                                                    from host
+//                                                                c4. after receiving host commands:
+//                                                                  1) set up pre-condition (i.e.
+//                                                                     start fuse for adb sideload)
+//                                                                  2) issue command through
+//                                                                     socket.
+//                                                                  3) wait for result
+//  a5. start listener thread
+//                               b6. listen for message from
+//                                   minadbd in a loop.
+//                               b7. After receiving a minadbd
+//                                   command from socket
+//                                 1) execute the command function
+//                                 2) send the result back to
+//                                    minadbd
+//  ......
+//                                                                 c8. exit upon receiving the
+//                                                                     result
+// a9.  wait for listener thread
+//      to exit.
+//
+// a10. wait for minadbd to
+//      exit
+//                               b11. exit the listening loop
+//
+static void CreateMinadbdServiceAndExecuteCommands(
+    const std::map<MinadbdCommands, CommandFunction>& command_map) {
+  signal(SIGPIPE, SIG_IGN);
+
+  android::base::unique_fd recovery_socket;
+  android::base::unique_fd minadbd_socket;
+  if (!android::base::Socketpair(AF_UNIX, SOCK_STREAM, 0, &recovery_socket, &minadbd_socket)) {
+    PLOG(ERROR) << "Failed to create socket";
+    return;
+  }
+
+  pid_t child = fork();
+  if (child == -1) {
+    PLOG(ERROR) << "Failed to fork child process";
+    return;
+  }
+  if (child == 0) {
+    recovery_socket.reset();
+    execl("/system/bin/minadbd", "minadbd", "--socket_fd",
+          std::to_string(minadbd_socket.release()).c_str(), nullptr);
+
+    _exit(EXIT_FAILURE);
+  }
+
+  minadbd_socket.reset();
+
+  // We need to call SetUsbConfig() after forking minadbd service. Because the function waits for
+  // the usb state to be updated, which depends on sys.usb.ffs.ready=1 set in the adb daemon.
+  if (!SetUsbConfig("sideload")) {
+    LOG(ERROR) << "Failed to set usb config to sideload";
+    return;
+  }
+
+  std::thread listener_thread(ListenAndExecuteMinadbdCommands, child, std::move(recovery_socket),
+                              std::ref(command_map));
 
-    // TODO: there should be a way to cancel waiting for a package (by pushing some button combo on
-    // the device). For now you just have to 'adb sideload' a file that's not a valid package, like
-    // "/dev/null".
-    waitpid(child, &status, 0);
+  if (listener_thread.joinable()) {
+    listener_thread.join();
   }
 
+  int status;
+  waitpid(child, &status, 0);
   if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) {
-    if (WEXITSTATUS(status) == 3) {
-      ui->Print("\nYou need adb 1.0.32 or newer to sideload\nto this device.\n\n");
+    if (WEXITSTATUS(status) == MinadbdErrorCode::kMinadbdAdbVersionError) {
+      LOG(ERROR) << "\nYou need adb 1.0.32 or newer to sideload\nto this device.\n";
     } else if (!WIFSIGNALED(status)) {
-      ui->Print("\n(adbd status %d)\n", WEXITSTATUS(status));
+      LOG(ERROR) << "\n(adbd status " << WEXITSTATUS(status) << ")";
     }
   }
 
+  signal(SIGPIPE, SIG_DFL);
+}
+
+int apply_from_adb(bool* wipe_cache, RecoveryUI* ui) {
+  // 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.
+  if (usb_state != "none" && !SetUsbConfig("none")) {
+    LOG(ERROR) << "Failed to clear USB config";
+    return INSTALL_ERROR;
+  }
+
+  ui->Print(
+      "\n\nNow send the package you want to apply\n"
+      "to the device with \"adb sideload <filename>\"...\n");
+
+  int install_result = INSTALL_ERROR;
+  std::map<MinadbdCommands, CommandFunction> command_map{
+    { MinadbdCommands::kInstall,
+      std::bind(&AdbInstallPackageHandler, wipe_cache, ui, &install_result) },
+  };
+
+  CreateMinadbdServiceAndExecuteCommands(command_map);
+
   // Clean up before switching to the older state, for example setting the state
   // to none sets sys/class/android_usb/android0/enable to 0.
   if (!SetUsbConfig("none")) {
@@ -124,5 +313,5 @@ int apply_from_adb(bool* wipe_cache, RecoveryUI* ui) {
     }
   }
 
-  return result;
+  return install_result;
 }
diff --git a/minadbd/Android.bp b/minadbd/Android.bp
index 9b889f4a2..e4f7712e5 100644
--- a/minadbd/Android.bp
+++ b/minadbd/Android.bp
@@ -40,7 +40,6 @@ cc_library {
 
     srcs: [
         "fuse_adb_provider.cpp",
-        "minadbd.cpp",
         "minadbd_services.cpp",
     ],
 
@@ -52,6 +51,36 @@ cc_library {
     ],
 }
 
+cc_library_headers {
+    name: "libminadbd_headers",
+    recovery_available: true,
+    // TODO create a include dir
+    export_include_dirs: [
+        ".",
+    ],
+}
+
+cc_binary {
+    name: "minadbd",
+    recovery: true,
+
+    defaults: [
+        "minadbd_defaults",
+    ],
+
+    srcs: [
+        "minadbd.cpp",
+    ],
+
+    shared_libs: [
+        "libadbd",
+        "libbase",
+        "libcrypto",
+        "libfusesideload",
+        "libminadbd_services",
+    ],
+}
+
 cc_test {
     name: "minadbd_test",
     isolated: true,
diff --git a/minadbd/minadbd.cpp b/minadbd/minadbd.cpp
index 349189cc7..57158ad57 100644
--- a/minadbd/minadbd.cpp
+++ b/minadbd/minadbd.cpp
@@ -14,30 +14,54 @@
  * limitations under the License.
  */
 
-#include "minadbd.h"
-
 #include <errno.h>
+#include <fcntl.h>
 #include <signal.h>
 #include <stdio.h>
 #include <stdlib.h>
+#include <strings.h>
+
+#include <android-base/logging.h>
+#include <android-base/parseint.h>
 
 #include "adb.h"
 #include "adb_auth.h"
 #include "transport.h"
 
-int minadbd_main() {
-    adb_device_banner = "sideload";
+#include "minadbd_services.h"
+#include "minadbd_types.h"
+
+int main(int argc, char** argv) {
+  android::base::InitLogging(argv, &android::base::StderrLogger);
+  // TODO(xunchang) implement a command parser
+  if (argc != 3 || strcmp("--socket_fd", argv[1]) != 0) {
+    LOG(ERROR) << "minadbd has invalid arguments, argc: " << argc;
+    exit(kMinadbdArgumentsParsingError);
+  }
+
+  int socket_fd;
+  if (!android::base::ParseInt(argv[2], &socket_fd)) {
+    LOG(ERROR) << "Failed to parse int in " << argv[2];
+    exit(kMinadbdArgumentsParsingError);
+  }
+  if (fcntl(socket_fd, F_GETFD, 0) == -1) {
+    PLOG(ERROR) << "Failed to get minadbd socket";
+    exit(kMinadbdSocketIOError);
+  }
+  SetMinadbdSocketFd(socket_fd);
+
+  adb_device_banner = "sideload";
 
-    signal(SIGPIPE, SIG_IGN);
+  signal(SIGPIPE, SIG_IGN);
 
-    // We can't require authentication for sideloading. http://b/22025550.
-    auth_required = false;
+  // We can't require authentication for sideloading. http://b/22025550.
+  auth_required = false;
 
-    init_transport_registration();
-    usb_init();
+  init_transport_registration();
+  usb_init();
 
-    VLOG(ADB) << "Event loop starting";
-    fdevent_loop();
+  VLOG(ADB) << "Event loop starting";
+  fdevent_loop();
 
-    return 0;
+  return 0;
 }
diff --git a/minadbd/minadbd_services.cpp b/minadbd/minadbd_services.cpp
index 6fe5c79bc..79e6fc4e0 100644
--- a/minadbd/minadbd_services.cpp
+++ b/minadbd/minadbd_services.cpp
@@ -14,6 +14,8 @@
  * limitations under the License.
  */
 
+#include "minadbd_services.h"
+
 #include <errno.h>
 #include <inttypes.h>
 #include <stdio.h>
@@ -27,38 +29,95 @@
 #include <string_view>
 #include <thread>
 
+#include <android-base/file.h>
+#include <android-base/logging.h>
+#include <android-base/memory.h>
+#include <android-base/stringprintf.h>
+#include <android-base/strings.h>
+
 #include "adb.h"
 #include "adb_unique_fd.h"
 #include "fdevent.h"
 #include "fuse_adb_provider.h"
 #include "fuse_sideload.h"
+#include "minadbd_types.h"
 #include "services.h"
 #include "sysdeps.h"
 
+static int minadbd_socket = -1;
+void SetMinadbdSocketFd(int socket_fd) {
+  minadbd_socket = socket_fd;
+}
+
+static bool WriteCommandToFd(MinadbdCommands cmd, int fd) {
+  char message[kMinadbdMessageSize];
+  memcpy(message, kMinadbdCommandPrefix, strlen(kMinadbdStatusPrefix));
+  android::base::put_unaligned(message + strlen(kMinadbdStatusPrefix), cmd);
+
+  if (!android::base::WriteFully(fd, message, kMinadbdMessageSize)) {
+    PLOG(ERROR) << "Failed to write message " << message;
+    return false;
+  }
+  return true;
+}
+
+// Blocks and reads the command status from |fd|. Returns false if the received message has a
+// format error.
+static bool WaitForCommandStatus(int fd, MinadbdCommandStatus* status) {
+  char buffer[kMinadbdMessageSize];
+  if (!android::base::ReadFully(fd, buffer, kMinadbdMessageSize)) {
+    PLOG(ERROR) << "Failed to response status from socket";
+    exit(kMinadbdSocketIOError);
+  }
+
+  std::string message(buffer, buffer + kMinadbdMessageSize);
+  if (!android::base::StartsWith(message, kMinadbdStatusPrefix)) {
+    LOG(ERROR) << "Failed to parse status in " << message;
+    return false;
+  }
+
+  *status = android::base::get_unaligned<MinadbdCommandStatus>(
+      message.substr(strlen(kMinadbdStatusPrefix)).c_str());
+  return true;
+}
+
 static void sideload_host_service(unique_fd sfd, const std::string& args) {
   int64_t file_size;
   int block_size;
   if ((sscanf(args.c_str(), "%" SCNd64 ":%d", &file_size, &block_size) != 2) || file_size <= 0 ||
       block_size <= 0) {
-    printf("bad sideload-host arguments: %s\n", args.c_str());
-    exit(1);
+    LOG(ERROR) << "bad sideload-host arguments: " << args;
+    exit(kMinadbdPackageSizeError);
   }
 
-  printf("sideload-host file size %" PRId64 " block size %d\n", file_size, block_size);
+  LOG(INFO) << "sideload-host file size " << file_size << ", block size " << block_size;
+
+  if (!WriteCommandToFd(MinadbdCommands::kInstall, minadbd_socket)) {
+    exit(kMinadbdSocketIOError);
+  }
 
   auto adb_data_reader =
       std::make_unique<FuseAdbDataProvider>(std::move(sfd), file_size, block_size);
-  int result = run_fuse_sideload(std::move(adb_data_reader));
+  if (int result = run_fuse_sideload(std::move(adb_data_reader)); result != 0) {
+    LOG(ERROR) << "Failed to start fuse";
+    exit(kMinadbdFuseStartError);
+  }
+
+  MinadbdCommandStatus status;
+  if (!WaitForCommandStatus(minadbd_socket, &status)) {
+    exit(kMinadbdMessageFormatError);
+  }
+  LOG(INFO) << "Got command status: " << static_cast<unsigned int>(status);
 
-  printf("sideload_host finished\n");
-  exit(result == 0 ? 0 : 1);
+  LOG(INFO) << "sideload_host finished";
+  exit(kMinadbdSuccess);
 }
 
 unique_fd daemon_service_to_fd(std::string_view name, atransport* /* transport */) {
   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).
-    exit(3);
+    exit(kMinadbdAdbVersionError);
   } else if (name.starts_with("sideload-host:")) {
     std::string arg(name.substr(strlen("sideload-host:")));
     return create_service_thread("sideload-host",
diff --git a/minadbd/minadbd.h b/minadbd/minadbd_services.h
index 3570a5da5..6835bd770 100644
--- a/minadbd/minadbd.h
+++ b/minadbd/minadbd_services.h
@@ -14,9 +14,6 @@
  * limitations under the License.
  */
 
-#ifndef MINADBD_H__
-#define MINADBD_H__
+#pragma once
 
-int minadbd_main();
-
-#endif
+void SetMinadbdSocketFd(int socket_fd);
diff --git a/minadbd/minadbd_types.h b/minadbd/minadbd_types.h
new file mode 100644
index 000000000..7bd69096a
--- /dev/null
+++ b/minadbd/minadbd_types.h
@@ -0,0 +1,53 @@
+/*
+ * Copyright (C) 2019 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#pragma once
+
+#include <stdint.h>
+
+// The message between recovery and minadbd is 8 bytes in size unless the length is explicitly
+// specified. Both the command and status has the format |prefix(4 bytes) + encoded enum(4 bytes)|.
+constexpr size_t kMinadbdMessageSize = 8;
+constexpr char const kMinadbdCommandPrefix[] = "COMD";
+constexpr char const kMinadbdStatusPrefix[] = "STAT";
+
+enum MinadbdErrorCode : int {
+  kMinadbdSuccess = 0,
+  kMinadbdArgumentsParsingError = 1,
+  kMinadbdSocketIOError = 2,
+  kMinadbdMessageFormatError = 3,
+  kMinadbdAdbVersionError = 4,
+  kMinadbdPackageSizeError = 5,
+  kMinadbdFuseStartError = 6,
+  kMinadbdUnsupportedCommandError = 7,
+  kMinadbdCommandExecutionError = 8,
+  kMinadbdErrorUnknown = 9,
+};
+
+enum class MinadbdCommandStatus : uint32_t {
+  kSuccess = 0,
+  kFailure = 1,
+};
+
+enum class MinadbdCommands : uint32_t {
+  kInstall = 0,
+  kUiPrint = 1,
+  kError = 2,
+};
+
+static_assert(kMinadbdMessageSize == sizeof(kMinadbdCommandPrefix) - 1 + sizeof(MinadbdCommands));
+static_assert(kMinadbdMessageSize ==
+              sizeof(kMinadbdStatusPrefix) - 1 + sizeof(MinadbdCommandStatus));
diff --git a/recovery_main.cpp b/recovery_main.cpp
index b41368d7b..8b4ad5a32 100644
--- a/recovery_main.cpp
+++ b/recovery_main.cpp
@@ -51,7 +51,6 @@
 #include "common.h"
 #include "fastboot/fastboot.h"
 #include "logging.h"
-#include "minadbd/minadbd.h"
 #include "otautil/paths.h"
 #include "otautil/roots.h"
 #include "otautil/sysutil.h"
@@ -322,16 +321,6 @@ int main(int argc, char** argv) {
   // Take action to refresh pmsg contents
   __android_log_pmsg_file_read(LOG_ID_SYSTEM, ANDROID_LOG_INFO, filter, logrotate, &do_rotate);
 
-  // If this binary is started with the single argument "--adbd", instead of being the normal
-  // recovery binary, it turns into kind of a stripped-down version of adbd that only supports the
-  // 'sideload' command.  Note this must be a real argument, not anything in the command file or
-  // bootloader control block; the only way recovery should be run with this argument is when it
-  // starts a copy of itself from the apply_from_adb() function.
-  if (argc == 2 && strcmp(argv[1], "--adbd") == 0) {
-    minadbd_main();
-    return 0;
-  }
-
   time_t start = time(nullptr);
 
   // redirect_stdio should be called only in non-sideload mode. Otherwise we may have two logger