开机时 hide 某个应用，报错异常log:
02-05 06:05:19.242 1940 1940 E ActivityManager: Attempt to launch receivers of broadcast intent Intent { act=android.content.pm.action.SESSION_COMMITTED pkg=com.android.settings (has extras) } before boot completion
02-05 06:05:19.243 1940 1940 E System : ******************************************
02-05 06:05:19.245 1940 1940 E System : ************ Failure starting system services
02-05 06:05:19.245 1940 1940 E System : java.lang.IllegalStateException: Cannot broadcast before boot completed
02-05 06:05:19.245 1940 1940 E System : at com.android.server.am.ActivityManagerService.verifyBroadcastLocked(ActivityManagerService.java:16960)
02-05 06:05:19.245 1940 1940 E System : at com.android.server.am.ActivityManagerService.broadcastIntentWithFeature(ActivityManagerService.java:17006)
02-05 06:05:19.245 1940 1940 E System : at android.app.ContextImpl.sendBroadcastAsUser(ContextImpl.java:1290)
02-05 06:05:19.245 1940 1940 E System : at com.android.server.pm.PackageManagerService.sendSessionCommitBroadcast(PackageManagerService.java:21095)
02-05 06:05:19.245 1940 1940 E System : at com.android.server.pm.PackageManagerService.sendPackageAddedForUser(PackageManagerService.java:13441)
02-05 06:05:19.245 1940 1940 E System : at com.android.server.pm.PackageManagerService.setApplicationHiddenSettingAsUser(PackageManagerService.java:13578)
02-05 06:05:19.245 1940 1940 E System : at android.app.ApplicationPackageManager.setApplicationHiddenSettingAsUser(ApplicationPackageManager.java:2762)
02-05 06:05:19.245 1940 1940 E System : at com.android.server.pm.BrandedAppDiffManager.unhide(BrandedAppDiffManager.java:710)
02-05 06:05:19.245 1940 1940 E System : at com.android.server.pm.BrandedAppDiffManager.hideOtherBrandApp(BrandedAppDiffManager.java:176)
02-05 06:05:19.245 1940 1940 E System : at com.android.server.pm.BrandedAppDiffManager.systemReady(BrandedAppDiffManager.java:162)
02-05 06:05:19.245 1940 1940 E System : at com.android.server.pm.PackageManagerService.systemReady(PackageManagerService.java:22296)
02-05 06:05:19.245 1940 1940 E System : at com.android.server.SystemServer.startOtherServices(SystemServer.java:2265)
02-05 06:05:19.245 1940 1940 E System : at com.android.server.SystemServer.run(SystemServer.java:631)
02-05 06:05:19.245 1940 1940 E System : at com.android.server.SystemServer.main(SystemServer.java:433)
02-05 06:05:19.245 1940 1940 E System : at java.lang.reflect.Method.invoke(Native Method)
02-05 06:05:19.245 1940 1940 E System : at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:612)
02-05 06:05:19.245 1940 1940 E System : at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:975)
02-05 06:05:19.245 1940 1940 D SystemServerTiming: MakePackageManagerServiceReady took to complete: 454ms
02-05 06:05:19.246 1940 1940 E Zygote : System zygote died with exception
02-05 06:05:19.246 1940 1940 E Zygote : java.lang.IllegalStateException: Cannot broadcast before boot completed
02-05 06:05:19.246 1940 1940 E Zygote : at com.android.server.am.ActivityManagerService.verifyBroadcastLocked(ActivityManagerService.java:16960)
02-05 06:05:19.246 1940 1940 E Zygote : at com.android.server.am.ActivityManagerService.broadcastIntentWithFeature(ActivityManagerService.java:17006)
02-05 06:05:19.246 1940 1940 E Zygote : at android.app.ContextImpl.sendBroadcastAsUser(ContextImpl.java:1290)
02-05 06:05:19.246 1940 1940 E Zygote : at com.android.server.pm.PackageManagerService.sendSessionCommitBroadcast(PackageManagerService.java:21095)
02-05 06:05:19.246 1940 1940 E Zygote : at com.android.server.pm.PackageManagerService.sendPackageAddedForUser(PackageManagerService.java:13441)
02-05 06:05:19.246 1940 1940 E Zygote : at com.android.server.pm.PackageManagerService.setApplicationHiddenSettingAsUser(PackageManagerService.java:13578)
02-05 06:05:19.246 1940 1940 E Zygote : at android.app.ApplicationPackageManager.setApplicationHiddenSettingAsUser(ApplicationPackageManager.java:2762)
02-05 06:05:19.246 1940 1940 E Zygote : at com.android.server.pm.BrandedAppDiffManager.unhide(BrandedAppDiffManager.java:710)
02-05 06:05:19.246 1940 1940 E Zygote : at com.android.server.pm.BrandedAppDiffManager.hideOtherBrandApp(BrandedAppDiffManager.java:176)
02-05 06:05:19.246 1940 1940 E Zygote : at com.android.server.pm.BrandedAppDiffManager.systemReady(BrandedAppDiffManager.java:162)
02-05 06:05:19.246 1940 1940 E Zygote : at com.android.server.pm.PackageManagerService.systemReady(PackageManagerService.java:22296)
02-05 06:05:19.246 1940 1940 E Zygote : at com.android.server.SystemServer.startOtherServices(SystemServer.java:2265)
02-05 06:05:19.246 1940 1940 E Zygote : at com.android.server.SystemServer.run(SystemServer.java:631)
02-05 06:05:19.246 1940 1940 E Zygote : at com.android.server.SystemServer.main(SystemServer.java:433)
02-05 06:05:19.246 1940 1940 E Zygote : at java.lang.reflect.Method.invoke(Native Method)
02-05 06:05:19.246 1940 1940 E Zygote : at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:612)
02-05 06:05:19.246 1940 1940 E Zygote : at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:975)
02-05 06:05:19.247 1940 1940 D AndroidRuntime: Shutting down VM
02-05 06:05:19.247 1940 1940 E AndroidRuntime: *** FATAL EXCEPTION IN SYSTEM PROCESS: main
02-05 06:05:19.247 1940 1940 E AndroidRuntime: java.lang.IllegalStateException: Cannot broadcast before boot completed
02-05 06:05:19.247 1940 1940 E AndroidRuntime: at com.android.server.am.ActivityManagerService.verifyBroadcastLocked(ActivityManagerService.java:16960)
02-05 06:05:19.247 1940 1940 E AndroidRuntime: at com.android.server.am.ActivityManagerService.broadcastIntentWithFeature(ActivityManagerService.java:17006)
02-05 06:05:19.247 1940 1940 E AndroidRuntime: at android.app.ContextImpl.sendBroadcastAsUser(ContextImpl.java:1290)
02-05 06:05:19.247 1940 1940 E AndroidRuntime: at com.android.server.pm.PackageManagerService.sendSessionCommitBroadcast(PackageManagerService.java:21095)
02-05 06:05:19.247 1940 1940 E AndroidRuntime: at com.android.server.pm.PackageManagerService.sendPackageAddedForUser(PackageManagerService.java:13441)
02-05 06:05:19.247 1940 1940 E AndroidRuntime: at com.android.server.pm.PackageManagerService.setApplicationHiddenSettingAsUser(PackageManagerService.java:13578)
02-05 06:05:19.247 1940 1940 E AndroidRuntime: at android.app.ApplicationPackageManager.setApplicationHiddenSettingAsUser(ApplicationPackageManager.java:2762)
02-05 06:05:19.247 1940 1940 E AndroidRuntime: at com.android.server.pm.BrandedAppDiffManager.unhide(BrandedAppDiffManager.java:710)
02-05 06:05:19.247 1940 1940 E AndroidRuntime: at com.android.server.pm.BrandedAppDiffManager.hideOtherBrandApp(BrandedAppDiffManager.java:176)
02-05 06:05:19.247 1940 1940 E AndroidRuntime: at com.android.server.pm.BrandedAppDiffManager.systemReady(BrandedAppDiffManager.java:162)
02-05 06:05:19.247 1940 1940 E AndroidRuntime: at com.android.server.pm.PackageManagerService.systemReady(PackageManagerService.java:22296)
02-05 06:05:19.247 1940 1940 E AndroidRuntime: at com.android.server.SystemServer.startOtherServices(SystemServer.java:2265)
02-05 06:05:19.247 1940 1940 E AndroidRuntime: at com.android.server.SystemServer.run(SystemServer.java:631)
02-05 06:05:19.247 1940 1940 E AndroidRuntime: at com.android.server.SystemServer.main(SystemServer.java:433)
02-05 06:05:19.247 1940 1940 E AndroidRuntime: at java.lang.reflect.Method.invoke(Native Method)
02-05 06:05:19.247 1940 1940 E AndroidRuntime: at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:612)
02-05 06:05:19.247 1940 1940 E AndroidRuntime: at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:975)
02-05 06:05:19.250 1940 2007 E ActivityManager: Attempt to launch receivers of broadcast intent Intent { act=android.intent.action.LOCKED_BOOT_COMPLETED pkg=com.android.chrome } before boot completion
02-05 06:05:19.252 1940 2007 I Process : Sending signal. PID: 1940 SIG: 9
解决方法：
https://blog.csdn.net/fly_qj/article/details/41008409
11-11 05:48:57.015 E/ActivityManager(20584): Attempt to launch receivers of broadcast intent Intent { act=android.intent.action.XXX (has extras) } before boot completion
11-11 05:48:57.015 E/System (20584): ******************************************
11-11 05:48:57.015 E/System (20584): ************ Failure starting core service
11-11 05:48:57.015 E/System (20584): java.lang.IllegalStateException: Cannot broadcast before boot completed
未开机完成前不能发广播，如果需要，Android专门提供了一个标志来处理这种情况：
FLAG_RECEIVER_REGISTERED_ONLY_BEFORE_BOOT
如，BatteryService.java中：
Intent statusIntent = new Intent(Intent.ACTION_BATTERY_LOW);
statusIntent.setFlags(Intent.FLAG_RECEIVER_REGISTERED_ONLY_BEFORE_BOOT);
mContext.sendBroadcastAsUser(statusIntent, UserHandle.ALL);
估计是Framework开发者也遇到过类似问题，所以才会设置这个标志，关于这个标志的解释：
/**
* If set, when sending a broadcast <i>before boot has completed</i> only
* registered receivers will be called -- no BroadcastReceiver components
* will be launched. Sticky intent state will be recorded properly even
* if no receivers wind up being called. If {@link #FLAG_RECEIVER_REGISTERED_ONLY}
* is specified in the broadcast intent, this flag is unnecessary.
*
* <p>This flag is only for use by system sevices as a convenience to
* avoid having to implement a more complex mechanism around detection
* of boot completion.
*
* @hide
*/
public static final int FLAG_RECEIVER_REGISTERED_ONLY_BEFORE_BOOT = 0x04000000;
另外，Android还有一个属性：sys.boot_completed，尝试通过它来判断，但
经过验证，使用SystemProperties.get("sys.boot_completed", "0")的方法来判断开机时，即使其值为1（开机完成）仍然出现过“Cannot broadcast before boot completed”的问题，看来使用sys.boot_completed还是不行。