Android11编译第二弹：USB连接MTP模式+USB调试+USB信任
一、为什么需要开启USB信任和ADB调试
问题1：原始的AOSP，如果通过USB连接设备以后，会弹窗提示用户选择连接模式：MTP，大容量磁盘，照片等模式；
问题2：USB连接设备以后，需要开启USB调试模式，才方便操作adb调试；
问题3：USB设备连接以后，电脑会弹窗是否信任设备，需要点击信任当前设备，否则设备连接不成功。
使用场景：我们是自己的系统，需要支持设备USB连接，以及adb远程调试(USB调试和TCP调回)，因此，系统需要默认支持USB连接，支持USB调试，默认信任连接的设备。
二、集成步骤
2.1 关闭USB调试弹窗
frameworks/base/packages/SystemUI/src/com/android/systemui/usb/UsbDebuggingActivity.java
@Overridepublic void onCreate(Bundle icicle) {
...(省略)
/**final AlertController.AlertParams ap = mAlertParams;ap.mTitle = getString(R.string.usb_debugging_title);ap.mMessage = getString(R.string.usb_debugging_message, fingerprints);ap.mPositiveButtonText = getString(R.string.usb_debugging_allow);ap.mNegativeButtonText = getString(android.R.string.cancel);ap.mPositiveButtonListener = this;ap.mNegativeButtonListener = this;// add "always allow" checkboxLayoutInflater inflater = LayoutInflater.from(ap.mContext);View checkbox = inflater.inflate(com.android.internal.R.layout.always_use_checkbox, null);mAlwaysAllow = (CheckBox)checkbox.findViewById(com.android.internal.R.id.alwaysUse);mAlwaysAllow.setText(getString(R.string.usb_debugging_always));ap.mView = checkbox;window.setCloseOnTouchOutside(false);setupAlert();**/notifyService(true,true);finish();
}默认只要USB连接设备，默认就开启USB调试。关键方法是notifyService
/*** Notifies the ADB service as to whether the current ADB request should be allowed, and if* subsequent requests from this key should be allowed without user consent.** @param allow whether the connection should be allowed* @param alwaysAllow whether subsequent requests from this key should be allowed without user* consent*/private void notifyService(boolean allow, boolean alwaysAllow) {try {IBinder b = ServiceManager.getService(ADB_SERVICE);IAdbManager service = IAdbManager.Stub.asInterface(b);if (allow) {service.allowDebugging(alwaysAllow, mKey);} else {service.denyDebugging();}mServiceNotified = true;} catch (Exception e) {Log.e(TAG, "Unable to notify Usb service", e);}}
这个方法很简单，通过ADB服务，设置允许调试。
mKey是什么呢？就是设备指纹，即我们常说的设备SN。
2.2 授权ADB调试5555端口
device/qcom/lahaina/init.target.rc
#Allow access to memory hotplug device attributeschown system system /sys/kernel/mem-offline/anon_migrate# ==== modify start===== zhouronghua open adb debug port 5555setprop service.adb.tcp.port 5555# ==== modify end=====
2.3 接收到USB连接默认开启USB调试
frameworks/base/packages/SystemUI/src/com/android/systemui/usb/UsbDebuggingActivity.java
在其中有监听USB连接和断开的广播接收器UsbDisconnectedReceiver，
private class UsbDisconnectedReceiver extends BroadcastReceiver {
...(省略)@Overridepublic void onReceive(Context content, Intent intent) {String action = intent.getAction();if (!UsbManager.ACTION_USB_STATE.equals(action)) {return;}// ====== modify begin ==========// fix: zhouronghua usb debug default auth// boolean connected = intent.getBooleanExtra(UsbManager.USB_CONNECTED, false);boolean connected = false;if (!connected) {Log.d(TAG, "USB disconnected, notifying service");// notifyService(false);mActivity.finish();}try {IBinder b = ServiceManager.getService(USB_SERVICE);IUsbManager service = IUsbManager.Stub.asInterface(b);service.allowUsbDebugging(true, mKey);} catch (Exception e) { Log.e(TAG, "Unable to notify Usb service", e);}// =========== modify end ==========}}