Android恢复出厂设置流程分析【Android源码解析十】
最近看恢复出厂的一个问题，以前也查过这方面的流程，所以这里整理一些AP+framework层的流程；
在setting-->备份与重置--->恢复出厂设置--->重置手机--->清除全部内容--->手机关机--->开机--->进行恢复出厂的操作--->开机流程；
Step 1：前面找settings中的布局我就省略了，这部分相对简单一些，直接到清除全部内容这个按钮的操作，
对应的java类是setting中的MasterClearConfirm.java这个类，
private Button.OnClickListener mFinalClickListener = new Button.OnClickListener() {
public void onClick(View v) {
if (Utils.isMonkeyRunning()) {
return;
}
if (mEraseSdCard) {
Intent intent = new Intent(ExternalStorageFormatter.FORMAT_AND_FACTORY_RESET);
intent.setComponent(ExternalStorageFormatter.COMPONENT_NAME);
getActivity().startService(intent);
} else {
getActivity().sendBroadcast(new Intent("android.intent.action.MASTER_CLEAR"));
// Intent handling is asynchronous -- assume it will happen soon.
}
}
};
通过上述的代码，可以看出，实际上点击清除全部内容的时候，如果前面勾选上格式哈SD卡，就会执行mEraseSdCard为true里面的逻辑，如果没有勾选，就执行mEraseSdCard=false的逻辑，其实就是发送一个广播，
“android.intent.action.MASTER_CLEAR”
<receiver android:name="com.android.server.MasterClearReceiver"
android:permission="android.permission.MASTER_CLEAR"
android:priority="100" >
<intent-filter>
<!-- For Checkin, Settings, etc.: action=MASTER_CLEAR -->
<action android:name="android.intent.action.MASTER_CLEAR" />
<!-- MCS always uses REMOTE_INTENT: category=MASTER_CLEAR -->
<action android:name="com.google.android.c2dm.intent.RECEIVE" />
<category android:name="android.intent.category.MASTER_CLEAR" />
</intent-filter>
</receiver>
找这个MasterClearReceiver.java这个receiver，下面来看看这个onReceiver()里面做了什么操作：
public void onReceive(final Context context, final Intent intent) {
if (intent.getAction().equals(Intent.ACTION_REMOTE_INTENT)) {
if (!"google.com".equals(intent.getStringExtra("from"))) {
Slog.w(TAG, "Ignoring master clear request -- not from trusted server.");
return;
}
}
Slog.w(TAG, "!!! FACTORY RESET !!!");
// The reboot call is blocking, so we need to do it on another thread.
Thread thr = new Thread("Reboot") {
@Override
public void run() {
try {
RecoverySystem.rebootWipeUserData(context);
Log.wtf(TAG, "Still running after master clear?!");
} catch (IOException e) {
Slog.e(TAG, "Can't perform master clear/factory reset", e);
}
}
};
thr.start();
}
这个里面主要的操作是：RecoverySystem.rebootWipeUserData(context);准备做重启的动作，告诉手机要清除userData的数据；
Step 3：接着来看看RecoverySystem.rebootWipeUserData（）这个方法做了哪些操作：
public static void rebootWipeUserData(Context context) throws IOException {
final ConditionVariable condition = new ConditionVariable();
Intent intent = new Intent("android.intent.action.MASTER_CLEAR_NOTIFICATION");
context.sendOrderedBroadcastAsUser(intent, UserHandle.OWNER,
android.Manifest.permission.MASTER_CLEAR,
new BroadcastReceiver() {
@Override
public void onReceive(Context context, Intent intent) {
condition.open();
}
}, null, 0, null, null);
// Block until the ordered broadcast has completed.
condition.block();
bootCommand(context, "--wipe_data\n--locale=" + Locale.getDefault().toString());
}
这个里面的广播可以先忽略不计，重点来看看bootCommand（）这个方法，注意这个参数“--wipe_data\n--locale=”
private static void bootCommand(Context context, String arg) 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);
try {
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("recovery");
throw new IOException("Reboot failed (no permissions?)");
}
这个方法的操作大致是“写节点/cache/recovery/command”，把传递过来的字符串写进去；然后调用PowerManager进行重启操作，reboot（）；
Step 4：接着我们来看看PowerManager的reboot方法做了哪些操作：
public void reboot(String reason) {
try {
mService.reboot(false, reason, true);
} catch (RemoteException e) {
}
}
这个调用到了PowerManagerService.java这个类的reboot方法中了：
@Override // Binder call
public void reboot(boolean confirm, String reason, boolean wait) {
mContext.enforceCallingOrSelfPermission(android.Manifest.permission.REBOOT, null);
final long ident = Binder.clearCallingIdentity();
try {
shutdownOrRebootInternal(false, confirm, reason, wait);
} finally {
Binder.restoreCallingIdentity(ident);
}
}
重点来看看shutdownOrRebootInternal（）这个方法，
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) {
ShutdownThread.shutdown(mContext, confirm);
} else {
ShutdownThread.reboot(mContext, reason, confirm);
}
}
}
};
// 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) {
}
}
}
}
}
由于传递过来的shutdown为false，所以执行ShutdownThread.reboot(mContext, reason, confirm);reason：recevory
下面调用到ShutdownThread
Step 5：这个追踪ShutdownThread.reboot()这个方法，这就有点像破案电影，一点一点查找罪犯的难点；
来窥视一下这个类：
public static void reboot(final Context context, String reason, boolean confirm) {
mReboot = true;
mRebootSafeMode = false;
mRebootReason = reason;
Log.d(TAG, "reboot");
shutdownInner(context, confirm);
}
这个里面做的操作就是给这个变量mRebootReason复制“recevory”，重点调用shutdownInner（）这个方法；
static void shutdownInner(final Context context, boolean confirm) {
// ensure that only one thread is trying to power down.
// any additional calls are just returned
synchronized (sIsStartedGuard) {
if (sIsStarted) {
Log.d(TAG, "Request to shutdown already running, returning.");
return;
}
}
Log.d(TAG, "Notifying thread to start radio shutdown");
bConfirmForAnimation = confirm;
final int longPressBehavior = context.getResources().getInteger(
com.android.internal.R.integer.config_longPressOnPowerBehavior);
final int resourceId = mRebootSafeMode
? com.android.internal.R.string.reboot_safemode_confirm
: (longPressBehavior == 2
? com.android.internal.R.string.shutdown_confirm_question
: com.android.internal.R.string.shutdown_confirm);
Log.d(TAG, "Notifying thread to start shutdown longPressBehavior=" + longPressBehavior);
if (confirm) {
final CloseDialogReceiver closer = new CloseDialogReceiver(context);
if (sConfirmDialog != null) {
sConfirmDialog.dismiss();
}
if (sConfirmDialog == null) {
Log.d(TAG, "PowerOff dialog doesn't exist. Create it first");
sConfirmDialog = new AlertDialog.Builder(context)
.setTitle(mRebootSafeMode
? com.android.internal.R.string.reboot_safemode_title
: com.android.internal.R.string.power_off)
.setMessage(resourceId)
.setPositiveButton(com.android.internal.R.string.yes, new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
beginShutdownSequence(context);
if (sConfirmDialog != null) {
sConfirmDialog = null;
}
}
})
.setNegativeButton(com.android.internal.R.string.no, new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
synchronized (sIsStartedGuard) {
sIsStarted = false;
}
if (sConfirmDialog != null) {
sConfirmDialog = null;
}
}
})
.create();
sConfirmDialog.setCancelable(false);//blocking back key
sConfirmDialog.getWindow().setType(WindowManager.LayoutParams.TYPE_KEYGUARD_DIALOG);
/*if (!context.getResources().getBoolean(
com.android.internal.R.bool.config_sf_slowBlur)) {
sConfirmDialog.getWindow().addFlags(WindowManager.LayoutParams.FLAG_BLUR_BEHIND);
}*/
/* To fix video+UI+blur flick issue */
sConfirmDialog.getWindow().addFlags(WindowManager.LayoutParams.FLAG_DIM_BEHIND);
}
closer.dialog = sConfirmDialog;
sConfirmDialog.setOnDismissListener(closer);
if (!sConfirmDialog.isShowing()) {
sConfirmDialog.show();
}
} else {
beginShutdownSequence(context);
}
}
看beginShutdownSequence（）这个方法吧，重点调用到这个方法里面去了，来瞅瞅这个方法：
private static void beginShutdownSequence(Context context) {
synchronized (sIsStartedGuard) {
if (sIsStarted) {
Log.e(TAG, "ShutdownThread is already running, returning.");
return;
}
sIsStarted = true;
}
// start the thread that initiates shutdown
sInstance.mContext = context;
sInstance.mPowerManager = (PowerManager)context.getSystemService(Context.POWER_SERVICE);
sInstance.mHandler = new Handler() {
};
bPlayaudio = true;
if (!bConfirmForAnimation) {
if (!sInstance.mPowerManager.isScreenOn()) {
bPlayaudio = false;
}
}
// throw up an indeterminate system dialog to indicate radio is
// shutting down.
beginAnimationTime = 0;
boolean mShutOffAnimation = false;
try {
if (mIBootAnim == null) {
mIBootAnim = MediatekClassFactory.createInstance(IBootAnimExt.class);
}
} catch (Exception e) {
e.printStackTrace();
}
int screenTurnOffTime = mIBootAnim.getScreenTurnOffTime();
mShutOffAnimation = mIBootAnim.isCustBootAnim();
Log.e(TAG, "mIBootAnim get screenTurnOffTime : " + screenTurnOffTime);
String cust = SystemProperties.get("ro.operator.optr");
if (cust != null) {
if (cust.equals("CUST")) {
mShutOffAnimation = true;
}
}
synchronized (mEnableAnimatingSync) {
if(!mEnableAnimating) {
// sInstance.mPowerManager.setBacklightBrightness(PowerManager.BRIGHTNESS_DIM);
} else {
if (mShutOffAnimation) {
Log.e(TAG, "mIBootAnim.isCustBootAnim() is true");
bootanimCust();
} else {
pd = new ProgressDialog(context);
pd.setTitle(context.getText(com.android.internal.R.string.power_off));
pd.setMessage(context.getText(com.android.internal.R.string.shutdown_progress));
pd.setIndeterminate(true);
pd.setCancelable(false);
pd.getWindow().setType(WindowManager.LayoutParams.TYPE_KEYGUARD_DIALOG);
/* To fix video+UI+blur flick issue */
pd.getWindow().addFlags(WindowManager.LayoutParams.FLAG_DIM_BEHIND);
pd.show();
}
sInstance.mHandler.postDelayed(mDelayDim, screenTurnOffTime );
}
}
// make sure we never fall asleep again
sInstance.mCpuWakeLock = null;
try {
sInstance.mCpuWakeLock = sInstance.mPowerManager.newWakeLock(
。。。 。。。
}
这段代码有句话会影响关机动画播放不完
“sInstance.mHandler.postDelayed(mDelayDim, screenTurnOffTime ); ”
解决办法
（1）“可以把这个screenTurnOffTime时间乘以2，这个时间看log是5000毫秒，就是5秒，乘以2就是10秒，大概就能播放完全关机动画了。”
（2）把这句话注释掉，但是有可能会引起问题，导致恢复出厂设置的时候没有进行恢复出厂的操作。目前正在追踪此问题；
这段代码中还有影响关机动画是否走客制化的关机动画，如果ro.operator.optr这个属性配置的是CUST，则会走客制化的关机动画，否则走系统默认的关机动画；
String cust = SystemProperties.get("ro.operator.optr");
if (cust != null) {
if (cust.equals("CUST")) {
mShutOffAnimation = true;
}
}
然后重点看 sInstance.start();这个方法，就走到了run（）方法里满了；
Step 6： 来看看ShutDownThread.java这个类的run（）方法；
public void run() {
checkShutdownFlow();
while (mShutdownFlow == IPO_SHUTDOWN_FLOW) {
stMgr.saveStates(mContext);
stMgr.enterShutdown(mContext);
running();
}
if (mShutdownFlow != IPO_SHUTDOWN_FLOW) {
stMgr.enterShutdown(mContext);
running();
}
}
重点看running（）这个方法：
下面这个方法比较长，来分析一下：
public void running() {
if(sPreShutdownApi != null){
try {
sPreShutdownApi.onPowerOff();
} catch (RemoteException e) {
Log.e(TAG, "onPowerOff exception" + e.getMessage());
}
}else{
Log.w(TAG, "sPreShutdownApi is null");
}
command = SystemProperties.get("sys.ipo.pwrdncap");
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 : "");
SystemProperties.set(SHUTDOWN_ACTION_PROPERTY, reason);
}
/*
* 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...");
// First send the high-level shut down broadcast.
mActionDone = false;
/// M: 2012-05-20 ALPS00286063 @{
mContext.sendBroadcast(new Intent("android.intent.action.ACTION_PRE_SHUTDOWN"));
/// @} 2012-05-20
mContext.sendOrderedBroadcastAsUser((new Intent()).setAction(Intent.ACTION_SHUTDOWN).putExtra("_mode", mShutdownFlow),
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 ACTION_SHUTDOWN timed out");
if (mShutdownFlow == IPO_SHUTDOWN_FLOW) {
Log.d(TAG, "change shutdown flow from ipo to normal: ACTION_SHUTDOWN timeout");
mShutdownFlow = NORMAL_SHUTDOWN_FLOW;
}
break;
}
try {
mActionDoneSync.wait(delay);
} catch (InterruptedException e) {
}
}
}
// Also send ACTION_SHUTDOWN_IPO in IPO shut down flow
if (mShutdownFlow == IPO_SHUTDOWN_FLOW) {
mActionDone = false;
mContext.sendOrderedBroadcast(new Intent("android.intent.action.ACTION_SHUTDOWN_IPO"), null,
br, mHandler, 0, null, null);
final long endTimeIPO = SystemClock.elapsedRealtime() + MAX_BROADCAST_TIME;
synchronized (mActionDoneSync) {
while (!mActionDone) {
long delay = endTimeIPO - SystemClock.elapsedRealtime();
if (delay <= 0) {
Log.w(TAG, "Shutdown broadcast ACTION_SHUTDOWN_IPO timed out");
if (mShutdownFlow == IPO_SHUTDOWN_FLOW) {
Log.d(TAG, "change shutdown flow from ipo to normal: ACTION_SHUTDOWN_IPO timeout");
mShutdownFlow = NORMAL_SHUTDOWN_FLOW;
}
break;
}
try {
mActionDoneSync.wait(delay);
} catch (InterruptedException e) {
}
}
}
}
if (mShutdownFlow != IPO_SHUTDOWN_FLOW) {
// power off auto test, don't modify
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) {
}
}
}
// power off auto test, don't modify
// Shutdown radios.
Log.i(TAG, "Shutting down radios...");
shutdownRadios(MAX_RADIO_WAIT_TIME);
// power off auto test, don't modify
Log.i(TAG, "Shutting down MountService...");
if ( (mShutdownFlow == IPO_SHUTDOWN_FLOW) && (command.equals("1")||command.equals("3")) ) {
Log.i(TAG, "bypass MountService!");
} else {
// 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");
if (statusCode < 0) {
mShutdownFlow = NORMAL_SHUTDOWN_FLOW;
}
actionDone();
}
};
// 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");
if (mShutdownFlow == IPO_SHUTDOWN_FLOW) {
Log.d(TAG, "change shutdown flow from ipo to normal: MountService");
mShutdownFlow = NORMAL_SHUTDOWN_FLOW;
}
break;
}
try {
mActionDoneSync.wait(delay);
} catch (InterruptedException e) {
}
}
}
}
// power off auto test, don't modify
//mountSerivce ���
Log.i(TAG, "MountService shut done...");
// [MTK] fix shutdown animation timing issue
//==================================================================
try {
SystemProperties.set("service.shutanim.running","1");
Log.i(TAG, "set service.shutanim.running to 1");
} catch (Exception ex) {
Log.e(TAG, "Failed to set 'service.shutanim.running' = 1).");
}
//==================================================================
if (mShutdownFlow == IPO_SHUTDOWN_FLOW) {
if (SHUTDOWN_VIBRATE_MS > 0) {
// vibrate before shutting down
Vibrator vibrator = new SystemVibrator();
try {
vibrator.vibrate(SHUTDOWN_VIBRATE_MS);
} 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
// power off auto test, don't modify
Log.i(TAG, "Performing ipo low-level shutdown...");
delayForPlayAnimation();
if (sInstance.mScreenWakeLock != null && sInstance.mScreenWakeLock.isHeld()) {
sInstance.mScreenWakeLock.release();
sInstance.mScreenWakeLock = null;
}
sInstance.mHandler.removeCallbacks(mDelayDim);
stMgr.shutdown(mContext);
stMgr.finishShutdown(mContext);
//To void previous UI flick caused by shutdown animation stopping before BKL turning off
if (pd != null) {
pd.dismiss();
pd = null;
} else if (beginAnimationTime > 0) {
try {
SystemProperties.set("service.bootanim.exit","1");
Log.i(TAG, "set 'service.bootanim.exit' = 1).");
} catch (Exception ex) {
Log.e(TAG, "Failed to set 'service.bootanim.exit' = 1).");
}
//SystemProperties.set("ctl.stop","bootanim");
}
synchronized (sIsStartedGuard) {
sIsStarted = false;
}
sInstance.mPowerManager.setBacklightBrightnessOff(false);
sInstance.mCpuWakeLock.acquire(2000);
synchronized (mShutdownThreadSync) {
try {
mShutdownThreadSync.wait();
} catch (InterruptedException e) {
}
}
} else {
rebootOrShutdown(mReboot, mRebootReason);
}
}
这个方法做了一些列的操作，会关闭一些操作，如：
- shutdownRadios(MAX_RADIO_WAIT_TIME);
- mount.shutdown(observer);
- stMgr.shutdown(mContext);
Step 7：来看看rebootOrShutdown（）这个方法：
public static void rebootOrShutdown(boolean reboot, String reason) {
if (reboot) {
Log.i(TAG, "Rebooting, reason: " + reason);
if ( (reason != null) && reason.equals("recovery") ) {
delayForPlayAnimation();
}
try {
PowerManagerService.lowLevelReboot(reason);
} catch (Exception e) {
Log.e(TAG, "Reboot failed, will attempt shutdown instead", e);
}
} else if (SHUTDOWN_VIBRATE_MS > 0) {
// vibrate before shutting down
Vibrator vibrator = new SystemVibrator();
try {
vibrator.vibrate(SHUTDOWN_VIBRATE_MS);
} 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) {
}
}
delayForPlayAnimation();
// Shutdown power
// power off auto test, don't modify
Log.i(TAG, "Performing low-level shutdown...");
//PowerManagerService.lowLevelShutdown();
//add your func: HDMI off
//add for MFR
try {
if (ImHDMI == null)
ImHDMI=MediatekClassFactory.createInstance(IHDMINative.class);
} catch (Exception e) {
e.printStackTrace();
}
ImHDMI.hdmiPowerEnable(false);
try {
if (mTvOut == null)
mTvOut =MediatekClassFactory.createInstance(ITVOUTNative.class);
} catch (Exception e) {
e.printStackTrace();
}
mTvOut.tvoutPowerEnable(false);
//add your func: HDMI off
//unmout data/cache partitions while performing shutdown
SystemProperties.set("ctl.start", "shutdown");
/* sleep for a long time, prevent start another service */
try {
Thread.currentThread().sleep(Integer.MAX_VALUE);
} catch ( Exception e) {
Log.e(TAG, "Shutdown rebootOrShutdown Thread.currentThread().sleep exception!");
}
}
关机震动也在这个方法里面；这个方法重点看PowerManagerService.lowLevelReboot(reason);
Log.i(TAG, "Rebooting, reason: " + reason);这句log也很重要，可以有助于我们分析代码；
Step 8：下面来看看PowerManagerServices.java这个类的lowLevelReboot（）这个方法：
public static void lowLevelReboot(String reason) throws IOException {
nativeReboot(reason);
}
这个方法调用到了native里面，后面的操作我就不分析了。。。
大致流程是：
关机，然后开机，底层判断节点后进入恢复出厂模式，recevory.img释放完全后，进入开机的流程。。。
以后有进展再补充这部分的流程，整个过程大致就是这个样子了，里面的细节有好多没有分析，大家可以自行研究。。。，抛砖引玉的目的达到了。