进入recovery有两种方式，一种是通过组合键进入recovery，另一种是上层应用设置中执行安装/重置/清除缓存等操作进行recovery。这篇文档主要讲解上层应用是如何进入到recovery的。本文以高通平台为例。
1.app执行安装/重置/清楚缓存操作调用代码文件frameworks/base/core/java/android/os/RecoverySystem.java
不同的操作使用不同的方法：
安装升级包 -------- installPackage
清除用户数据------ rebootWipeUserData
清楚缓存 ----------- rebootWipeCache
上面的所有操作都是往/cache/recovery/command文件中写入不同的命令，在进入recovery后（recovery.cpp）对command的关键字进行判断，执行相应的操作，下文会详细讲解，这里先简单提及。
bootable/recovery/recovery.appstatic const struct option OPTIONS[] = {
{ "send_intent", required_argument, NULL, ‘i‘ },
{ "update_package", required_argument, NULL, ‘u‘ },
// [FEATURE]-ADD-BEGIN by TCTSH
#ifdef TARGET_USE_REDBEND_FOTA
{ "omadm_package", required_argument, NULL, ‘o‘ },
#endif
// [FEATURE]-ADD-END
{ "wipe_data", no_argument, NULL, ‘w‘ },
{ "wipe_cache", no_argument, NULL, ‘c‘ },
{ "show_text", no_argument, NULL, ‘t‘ },
{ "sideload", no_argument, NULL, ‘s‘ },
{ "sideload_auto_reboot", no_argument, NULL, ‘a‘ },
{ "just_exit", no_argument, NULL, ‘x‘ },
{ "locale", required_argument, NULL, ‘l‘ },
{ "stages", required_argument, NULL, ‘g‘ },
{ "shutdown_after", no_argument, NULL, ‘p‘ },
{ "reason", required_argument, NULL, ‘r‘ },
{ NULL, 0, NULL, 0 },
};
..................
intmain(int argc, char **argv) {....get_args(&argc, &argv); //提取cache/recovery/command中的信息....while ((arg = getopt_long(argc, argv, "", OPTIONS, NULL)) != -1) { //解析cache/recovery/command文件中的信息 printf("***** xiaolei 2\n"); switch (arg) { case ‘i‘: send_intent = optarg; break; case ‘u‘: update_package = optarg; break;// [FEATURE]-ADD-BEGIN by TCTSH
case ‘o‘: omadm_package = optarg; break;
// [FEATURE]-ADD-END case ‘w‘: should_wipe_data = true; break; case ‘c‘: should_wipe_cache = true; break; case ‘t‘: show_text = true; break; case ‘s‘: sideload = true; break; case ‘a‘: sideload = true; sideload_auto_reboot = true; break; case ‘x‘: just_exit = true; break; case ‘l‘: locale = optarg; break; case ‘g‘: { if (stage == NULL || *stage == ‘\0‘) { char buffer[20] = "1/"; strncat(buffer, optarg, sizeof(buffer)-3); stage = strdup(buffer); } break; } case ‘p‘: shutdown_after = true; break; case ‘r‘: reason = optarg; break; case ‘?‘: LOGE("Invalid command argument\n"); continue; } }}
本文以installPackage为例：
frameworks/base/core/java/android/os/RecoverySystem.javapublic static void installPackage(Context context, File packageFile)
throws IOException {
String filename = packageFile.getCanonicalPath(); //获取升级包路径
String internalPath = Environment.maybeTranslateEmulatedPathToInternal(new File(filename)).getPath();
FileWriter uncryptFile = new FileWriter(UNCRYPT_FILE);
try {
uncryptFile.write(internalPath + "\n");
} finally {
uncryptFile.close();
}
Log.w(TAG, "!!! REBOOTING TO INSTALL " + filename + " !!!");
Log.w(TAG, "!!! REBOOTING TO INSTALL REALPATH " + internalPath + " !!!");
// If the package is on the /data partition, write the block map file
// If the package is on internal storage sdcard,write the block map file
// into COMMAND_FILE instead.
if (filename.startsWith("/data/") //加密处理，block.map是解密的映射文件
||filename.startsWith("/storage/emulated/0/")) {
filename = "@/cache/recovery/block.map";
}
final String filenameArg = "--update_package=" + filename; //把“--update_package=path” 通过bootCommand方法写入到cache/recovery/command文件中
final String localeArg = "--locale=" + Locale.getDefault().toString(); //recovery显示语言
bootCommand(context, filenameArg, localeArg);
}
installPackage方法会嗲用bootCommand()方法，此时参数为（context,向cache/recovery/command文件中写入的信息，语言信息）
private static void bootCommand(Context context, String... args) throws IOException {
RECOVERY_DIR.mkdirs(); // In case we need it
COMMAND_FILE.delete(); // In case it‘s not writable
LOG_FILE.delete();
FileWriter command = new FileWriter(COMMAND_FILE); //向/cache/recovery/command中写入--update_package=path
try {
for (String arg : args) {
if (!TextUtils.isEmpty(arg)) {
command.write(arg);
command.write("\n");
}
}
} finally {
command.close();
}
// Having written the command file, go ahead and reboot
PowerManager pm = (PowerManager) context.getSystemService(Context.POWER_SERVICE);
pm.reboot(PowerManager.REBOOT_RECOVERY); //PowerManager.REBOOT_RECOVERY的值为字符串"recovery"
throw new IOException("Reboot failed (no permissions?)");
}
pm.reboot(PowerManager.REBOOT_RECOVERY); 参数为字符串("recovery")
frameworks/base/core/java/android/os/PowerMangager.java
public void reboot(String reason) {
try {
mService.reboot(false, reason, true);
} catch (RemoteException e) {
}
}
mService.reboot(false, reason, true); 参数为(false,"recovery",true)
frameworks/base/services/core/java/com/android/server/power/PowerManagerService.java
public void reboot(boolean confirm, String reason, boolean wait) {
mContext.enforceCallingOrSelfPermission(android.Manifest.permission.REBOOT, null);
if (PowerManager.REBOOT_RECOVERY.equals(reason)) {
mContext.enforceCallingOrSelfPermission(android.Manifest.permission.RECOVERY, null);
}
final long ident = Binder.clearCallingIdentity();
try {
shutdownOrRebootInternal(false, confirm, reason, wait);
} finally {
Binder.restoreCallingIdentity(ident);
}
}
shutdownOrRebootInternal(false, confirm, reason, wait); 参数为(false,false,"recovery",true)
frameworks/base/services/core/java/com/android/server/power/PowerManagerService.java
private void shutdownOrRebootInternal(final boolean shutdown, final boolean confirm,
final String reason, boolean wait) {
if (mHandler == null || !mSystemReady) {
throw new IllegalStateException("Too early to call shutdown() or reboot()");
}
Runnable runnable = new Runnable() {
@Override
public void run() {
synchronized (this) {
if (shutdown) { //此处shutdown=false
ShutdownThread.shutdown(mContext, confirm);
} else {
ShutdownThread.reboot(mContext, reason, confirm); //执行此处代码
}
}
}
};
// ShutdownThread must run on a looper capable of displaying the UI.
Message msg = Message.obtain(mHandler, runnable);
msg.setAsynchronous(true);
mHandler.sendMessage(msg);
// PowerManager.reboot() is documented not to return so just wait for the inevitable.
if (wait) {
synchronized (runnable) {
while (true) {
try {
runnable.wait();
} catch (InterruptedException e) {
}
}
}
}
}
ShutdownThread.reboot(mContext, reason, confirm); 参数为(mContex,"recovery",false)此处开了一个线程处理reboot
frameworks/base/services/core/java/com/android/server/power/ShutdownThread.java
public static void reboot(final Context context, String reason, boolean confirm) { //方法中的变量为全局变量
mReboot = true;
mRebootSafeMode = false;
mRebootUpdate = false;
mRebootReason = reason;
shutdownInner(context, confirm); //此方法是在手机界面上弹出一个确认框，是否重启，此处的代码不再追了
}
//程序一定会执行run()方法
/***********************
mReboot = true;
mRebootSafeMode = false;
mRebootUpdate = false;
mRebootReason = "recovery";***********************/public void run() { BroadcastReceiver br = new BroadcastReceiver() { @Override public void onReceive(Context context, Intent intent) { // We don‘t allow apps to cancel this, so ignore the result. actionDone(); } };
/* * Write a system property in case the system_server reboots before we * get to the actual hardware restart. If that happens, we‘ll retry at * the beginning of the SystemServer startup. */ { String reason = (mReboot ? "1" : "0") + (mRebootReason != null ? mRebootReason : ""); //reason的值为"recovery" SystemProperties.set(SHUTDOWN_ACTION_PROPERTY, reason); //设置系统属性sys.shutdown.requested = "recovery" }
/* * If we are rebooting into safe mode, write a system property * indicating so. */ if (mRebootSafeMode) { SystemProperties.set(REBOOT_SAFEMODE_PROPERTY, "1"); }
Log.i(TAG, "Sending shutdown broadcast..."); // [BUGFIX]-ADD-BEGIN BY TCTNB.BinhongWang,01/28/2016,Defect-1305415 setBootValue("silent_mode",mAudioManager.isSilentMode() ? "1" : "0"); if(checkAnimationFileExist() && mContext.getResources(). getBoolean(com.android.internal.R.bool.feature_tctfw_shutdown_animation_on) && !mRebootUpdate) { lockDevice(); showShutdownAnimation(); } // [BUGFIX]-ADD-END BY TCTNB.BinhongWang,01/28/2016,Defect-1305415
// First send the high-level shut down broadcast. mActionDone = false; Intent intent = new Intent(Intent.ACTION_SHUTDOWN); intent.addFlags(Intent.FLAG_RECEIVER_FOREGROUND); mContext.sendOrderedBroadcastAsUser(intent, UserHandle.ALL, null, br, mHandler, 0, null, null);
final long endTime = SystemClock.elapsedRealtime() + MAX_BROADCAST_TIME; synchronized (mActionDoneSync) { while (!mActionDone) { long delay = endTime - SystemClock.elapsedRealtime(); if (delay <= 0) { Log.w(TAG, "Shutdown broadcast timed out"); break; } else if (mRebootUpdate) { int status = (int)((MAX_BROADCAST_TIME - delay) * 1.0 * BROADCAST_STOP_PERCENT / MAX_BROADCAST_TIME); sInstance.setRebootProgress(status, null); } try { mActionDoneSync.wait(Math.min(delay, PHONE_STATE_POLL_SLEEP_MSEC)); } catch (InterruptedException e) { } } } if (mRebootUpdate) { sInstance.setRebootProgress(BROADCAST_STOP_PERCENT, null); } Log.i(TAG, "Shutting down activity manager...");
final IActivityManager am = ActivityManagerNative.asInterface(ServiceManager.checkService("activity")); if (am != null) { try { am.shutdown(MAX_BROADCAST_TIME); } catch (RemoteException e) { } } if (mRebootUpdate) { sInstance.setRebootProgress(ACTIVITY_MANAGER_STOP_PERCENT, null); }
Log.i(TAG, "Shutting down package manager...");
final PackageManagerService pm = (PackageManagerService) ServiceManager.getService("package"); if (pm != null) { pm.shutdown(); } if (mRebootUpdate) { sInstance.setRebootProgress(PACKAGE_MANAGER_STOP_PERCENT, null); }
// Shutdown radios. shutdownRadios(MAX_RADIO_WAIT_TIME); if (mRebootUpdate) { sInstance.setRebootProgress(RADIO_STOP_PERCENT, null); }
// Mod-by-yanxi.liu, for sdcard upgrade uncrypt, Defect-1357392 if (mRebootUpdate) { sInstance.setRebootProgress(MOUNT_SERVICE_STOP_PERCENT, null); // If it‘s to reboot to install update, invoke uncrypt via init service. uncrypt(); } // Mod-by-yanxi.liu, for sdcard upgrade uncrypt, Defect-1357392
// Shutdown MountService to ensure media is in a safe state IMountShutdownObserver observer = new IMountShutdownObserver.Stub() { public void onShutDownComplete(int statusCode) throws RemoteException { Log.w(TAG, "Result code " + statusCode + " from MountService.shutdown"); actionDone(); } };
Log.i(TAG, "Shutting down MountService");
// Set initial variables and time out time. mActionDone = false; final long endShutTime = SystemClock.elapsedRealtime() + MAX_SHUTDOWN_WAIT_TIME; synchronized (mActionDoneSync) { try { final IMountService mount = IMountService.Stub.asInterface( ServiceManager.checkService("mount")); if (mount != null) { mount.shutdown(observer); } else { Log.w(TAG, "MountService unavailable for shutdown"); } } catch (Exception e) { Log.e(TAG, "Exception during MountService shutdown", e); } while (!mActionDone) { long delay = endShutTime - SystemClock.elapsedRealtime(); if (delay <= 0) { Log.w(TAG, "Shutdown wait timed out"); break; } else if (mRebootUpdate) { int status = (int)((MAX_SHUTDOWN_WAIT_TIME - delay) * 1.0 * (MOUNT_SERVICE_STOP_PERCENT - RADIO_STOP_PERCENT) / MAX_SHUTDOWN_WAIT_TIME); status += RADIO_STOP_PERCENT; sInstance.setRebootProgress(status, null); } try { mActionDoneSync.wait(Math.min(delay, PHONE_STATE_POLL_SLEEP_MSEC)); } catch (InterruptedException e) { } } } // add by feikuang for defect 1453123 start isVibrate = mContext.getResources().getBoolean(com.android.internal.R.bool.config_isVibrate); Log.i(TAG,"isVibrate " + isVibrate); // add by feikuang for defect 1453123 end waitShutDownAnimationCompleted(); rebootOrShutdown(mContext, mReboot, mRebootReason); //程序执行到这里 }
rebootOrShutdown(mContext, mReboot, mRebootReason); 参数为(mContext,true,"recovery")
frameworks/base/services/core/java/com/android/server/power/ShutdownThread.java
public static void rebootOrShutdown(final Context context, boolean reboot, String reason) {
deviceRebootOrShutdown(reboot, reason);
//[FEATURE]-Add-BEGIN by TSNJ.shu.wang,11/06/2015,TASK-871146
String bootAlarms = SystemProperties.get("sys.boot.alarm");
boolean isBootAlarms = bootAlarms != null && bootAlarms.equals("1");
if (reboot) {
Log.i(TAG, "Rebooting, reason: " + reason);
PowerManagerService.lowLevelReboot(reason); //程序执行到这里
Log.e(TAG, "Reboot failed, will attempt shutdown instead");
} else if (SHUTDOWN_VIBRATE_MS > 0 && context != null && !isBootAlarms && isVibrate) {
//[FEATURE]-Add-END by TSNJ.shu.wang,11/06/2015,TASK-871146
// vibrate before shutting down
Vibrator vibrator = new SystemVibrator(context);
try {
vibrator.vibrate(SHUTDOWN_VIBRATE_MS, VIBRATION_ATTRIBUTES);
} catch (Exception e) {
// Failure to vibrate shouldn‘t interrupt shutdown. Just log it.
Log.w(TAG, "Failed to vibrate during shutdown.", e);
}
// vibrator is asynchronous so we need to wait to avoid shutting down too soon.
try {
Thread.sleep(SHUTDOWN_VIBRATE_MS);
} catch (InterruptedException unused) {
}
}
// Shutdown power
Log.i(TAG, "Performing low-level shutdown...");
PowerManagerService.lowLevelShutdown();
}
PowerManagerService.lowLevelReboot(reason); 参数为"recovery"
frameworks/base/services/core/java/com/android/server/power/PowerManagerService.java
public static void lowLevelReboot(String reason) {
if (reason == null) {
reason = "";
}
if (reason.equals(PowerManager.REBOOT_RECOVERY)) {
// If we are rebooting to go into recovery, instead of
// setting sys.powerctl directly we‘ll start the
// pre-recovery service which will do some preparation for
// recovery and then reboot for us.
SystemProperties.set("ctl.start", "pre-recovery"); //到这里可以知道，一个新的进程会被enable
} else {
SystemProperties.set("sys.powerctl", "reboot," + reason);
}
try {
Thread.sleep(20 * 1000L);
} catch (InterruptedException e) {
Thread.currentThread().interrupt();
}
Slog.wtf(TAG, "Unexpected return from lowLevelReboot!");
}
SystemProperties.set("ctl.start", "pre-recovery"); //到这里可以知道，一个新的进程会被enable
system/core/rootdir/init.rc
service pre-recovery /system/bin/uncrypt --reboot
class main
disabled
oneshot
service pre-recovery /system/bin/uncrypt --reboot system/bin/uncrypt 这个程序会被执行，传入的参数是--rebootuncrypt的源码位于bootable/recovery/uncrypt/uncrypt.cpp，下面对uncrypt进行分析
bootable/recovery/uncrypt/uncrypt.cppint main(int argc, char** argv) { //此处argc为2 argv[1]="--reboot"
const char* input_path;
const char* map_file;
if (argc != 3 && argc != 1 && (argc == 2 && strcmp(argv[1], "--reboot") != 0)) {
fprintf(stderr, "usage: %s [--reboot] [<transform_path> <map_file>]\n", argv[0]);
return 2;
}
// When uncrypt is started with "--reboot", it wipes misc and reboots.
// Otherwise it uncrypts the package and writes the block map.
if (argc == 2) { //程序执行到此处
if (read_fstab() == NULL) {
return 1;
}
wipe_misc(); //擦出misc分区内容
reboot_to_recovery(); //重启到recovery
} else {
// The pipe has been created by the system server.
int status_fd = open(status_file.c_str(), O_WRONLY | O_CREAT | O_SYNC, S_IRUSR | S_IWUSR);
if (status_fd == -1) {
ALOGE("failed to open pipe \"%s\": %s\n", status_file.c_str(), strerror(errno));
return 1;
}
std::string package;
if (argc == 3) {
// when command-line args are given this binary is being used
// for debugging.
input_path = argv[1];
map_file = argv[2];
} else {
if (!find_uncrypt_package(package)) {
android::base::WriteStringToFd("-1\n", status_fd);
close(status_fd);
return 1;
}
input_path = package.c_str();
map_file = cache_block_map.c_str();
}
int status = uncrypt(input_path, map_file, status_fd);
if (status != 0) {
android::base::WriteStringToFd("-1\n", status_fd);
close(status_fd);
return 1;
}
android::base::WriteStringToFd("100\n", status_fd);
close(status_fd);
}
return 0;
}
reboot_to_recovery();
bootable/recovery/uncrpty/uncrpty.cpp
static void reboot_to_recovery() {
ALOGI("rebooting to recovery");
property_set("sys.powerctl", "reboot,recovery");
sleep(10);
ALOGE("reboot didn‘t succeed?");
}
property_set("sys.powerctl", "reboot,recovery"); sys.powerctl属性出发开关在init.rc中
system/core/rootdir/init.rc
on property:sys.powerctl=*
powerctl ${sys.powerctl}
system/core/init/keywords.hKEYWORD(powerctl, COMMAND, 1, do_powerctl
system/core/init/builtins.cpp
int do_powerctl(int nargs, char **args) //传入的参数为字符串"reboot,recovery"
{
char command[PROP_VALUE_MAX];
int res;
int len = 0;
int cmd = 0;
const char *reboot_target;
res = expand_props(command, args[1], sizeof(command));
if (res) {
ERROR("powerctl: cannot expand ‘%s‘\n", args[1]);
return -EINVAL;
}
if (strncmp(command, "shutdown", 8) == 0) {
cmd = ANDROID_RB_POWEROFF;
len = 8;
} else if (strncmp(command, "reboot", 6) == 0) { //程序走到这，cmd=ANDROID_RB_RESTART2
cmd = ANDROID_RB_RESTART2;
len = 6;
} else {
ERROR("powerctl: unrecognized command ‘%s‘\n", command);
return -EINVAL;
}
if (command[len] == ‘,‘) {
char prop_value[PROP_VALUE_MAX] = {0};
reboot_target = &command[len + 1]; //设置reboot_target = recovery
if ((property_get("init.svc.recovery", prop_value) == 0) &&
(strncmp(reboot_target, "keys", 4) == 0)) {
ERROR("powerctl: permission denied\n");
return -EINVAL;
}
} else if (command[len] == ‘\0‘) {
reboot_target = "";
} else {
ERROR("powerctl: unrecognized reboot target ‘%s‘\n", &command[len]);
return -EINVAL;
}
return android_reboot(cmd, 0, reboot_target);
}
android_reboot(cmd, 0, reboot_target); 参数为(ANDROID_RB_RESTART2, 0, "recovery")
system/core/libcutils/android_reboot.c
int android_reboot(int cmd, int flags UNUSED, const char *arg)
{
int ret;
sync();
remount_ro();
switch (cmd) {
case ANDROID_RB_RESTART:
ret = reboot(RB_AUTOBOOT);
break;
case ANDROID_RB_POWEROFF:
ret = reboot(RB_POWER_OFF);
break;
case ANDROID_RB_RESTART2: //程序跑到这里其中arg="recovery"
ret = syscall(__NR_reboot, LINUX_REBOOT_MAGIC1, LINUX_REBOOT_MAGIC2,
LINUX_REBOOT_CMD_RESTART2, arg);
break;
default:
ret = -1;
}
return ret;
}
ret = syscall(__NR_reboot, LINUX_REBOOT_MAGIC1, LINUX_REBOOT_MAGIC2,
LINUX_REBOOT_CMD_RESTART2, arg);
kernel/include/uapi/asm-generic/unistd.h #define __NR_reboot 142 __SYSCALL(__NR_reboot, sys_reboot）
__NR_reboot被映射到sys_reboot上
时间： 2024-11-10 18:32:52