/*****************************************************************************

 *                        I.MX6 默认打开 USB adb

 * 声明：

 *     在调试android的时候，尤其是前期，可能我们没有Touch，这样使用adb显得

 * 力不从心，因为它会弹个对话框来，可你有按不了，于是默认打开adb就成了需求。

 *

 *                                          2016-1-20 深圳 南山平山村 曾剑锋

 ****************************************************************************/

一、参考文章：

    飞思卡尔 imx6 android 调试环境搭建

        http://www.wjxfpf.com/2015/10/590190.html

    Android 4.2. 开机默认开启USB调试

        http://blog.csdn.net/zhujm320/article/details/37914487

    默认打开USB调试功能

        http://blog.csdn.net/pfgmylove/article/details/16985159

二、解决方案：

    . cat frameworks/base/services/java/com/android/server/usb/UsbDeviceManager.java

        ......

        public void systemReady() {

            if (DEBUG) Slog.d(TAG, "systemReady");

            mNotificationManager = (NotificationManager)

                mContext.getSystemService(Context.NOTIFICATION_SERVICE);

            // We do not show the USB notification if the primary volume supports mass storage.

            // The legacy mass storage UI will be used instead.

            boolean massStorageSupported = false;

            final StorageManager storageManager = StorageManager.from(mContext);

            final StorageVolume primary = storageManager.getPrimaryVolume();

            massStorageSupported = primary != null && primary.allowMassStorage();

            mUseUsbNotification = !massStorageSupported;

            // make sure the ADB_ENABLED setting value matches the current state

            //Settings.Global.putInt(mContentResolver, Settings.Global.ADB_ENABLED, mAdbEnabled ? 1 : 0);

            Settings.Global.putInt(mContentResolver, Settings.Global.ADB_ENABLED, );

            mHandler.sendEmptyMessage(MSG_SYSTEM_READY);

        }

        ......

    . cat /init.rc

        ......

        #  Enable adb security for JB4.2.2

            setprop ro.adb.secure

        ......