android系统将普通应用升级为系统应用

作为一名程序员，有的时候并不是使用软件，而是去改造软件，不仅仅只是会编程而已，还要满足客户的需求。这样，才能开发出符合客户需求的应用，在关于到涉及到android底层的应用的时候，手机就需要root了，我使用的root工具是下面一款软件，这款软件对手机root之后，这款软件卸载后，手机将不具有root权限，所以使用者可以大大放心，我之前的时候担心手机root完了之后手机有风险，这下不用担心了，下图是我已经root后的手机界面：

root完手机之后，如果我们自己开发了一款app或者发现了一个好用的app，安装到手机上之后，但是我们在恢复出厂设置之后还需要重新下载安装，免不了不少麻烦，或者可能有其他的需求，需要我们将自己客户的应用变为系统的应用，不让用户随意卸载。

第一步：手机需要有root权限

android系统本是linux系统，熟悉linux命令的程序员都知道，在linux系统中，权限很重要，当普通用户切换为root用户的时候使用的是su命令，android系统的底层也是linux内核，所以一个原理，android为了系统的安全，默认的不是root角色登陆，如果想使用root权限，需要使用su命令，但是在android系统中/system是只读权限，如果想修改权限，就需要chmod命令，chmod命令又是只有root角色才可以运行，就这样形成了一个死循环，所以一般的方法就不能获得root权限。

第二步：使用命令修改权限

下面是我操作的命令：

Windows PowerShell
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PS C:UsersAdministrator> adb shell
shell@android:/ $ su
su
root@android:/ # ll
ll
drwxr-xr-x root     root              2016-01-08 15:52 acct
-rw-r--r-- root     root         2503 1970-01-01 08:00 advanced_meta_init.project.rc
-rw-r--r-- root     root        32580 1970-01-01 08:00 advanced_meta_init.rc
drwxr-xr-x system   system            1970-01-01 08:00 apps
drwxrwx--- system   cache             2016-01-08 15:35 cache
dr-x------ root     root              2016-01-08 15:52 config
lrwxrwxrwx root     root              2016-01-08 15:52 d -> /sys/kernel/debug
drwxrwx--x system   system            2016-01-08 16:04 data
-rw-r--r-- root     root          173 1970-01-01 08:00 default.prop
drwxr-xr-x root     root              2016-01-08 16:02 dev
lrwxrwxrwx root     root              1970-01-01 08:00 emmc@android -> /dev/block/mmcblk0p4
lrwxrwxrwx root     root              1970-01-01 08:00 emmc@apps -> /dev/block/mmcblk0p3
lrwxrwxrwx root     root              1970-01-01 08:00 emmc@cache -> /dev/block/mmcblk0p5
lrwxrwxrwx root     root              1970-01-01 08:00 emmc@ebr1 -> /dev/block/mmcblk0p1
lrwxrwxrwx root     root              1970-01-01 08:00 emmc@fat -> /dev/block/mmcblk0p7
lrwxrwxrwx root     root              1970-01-01 08:00 emmc@sec_ro -> /dev/block/mmcblk0p2
lrwxrwxrwx root     root              1970-01-01 08:00 emmc@usrdata -> /dev/block/mmcblk0p6
lrwxrwxrwx root     root              2016-01-08 15:52 etc -> /system/etc
lrwxrwxrwx root     root              2016-01-08 15:52 external_sd -> /mnt/sdcard/external_sd
-rwxr-x--- root     root       143920 1970-01-01 08:00 init
-rwxr-x--- root     root           93 1970-01-01 08:00 init.aee.customer.rc
-rwxr-x--- root     root        13573 1970-01-01 08:00 init.factory.rc
-rwxr-x--- root     root         2344 1970-01-01 08:00 init.goldfish.rc
-rwxr-x--- root     root         3137 1970-01-01 08:00 init.project.rc
-rwxr-x--- root     root        38576 1970-01-01 08:00 init.rc
-rwxr-x--- root     root        16181 1970-01-01 08:00 init.usb.rc
-rwxr-x--- root     root          583 1970-01-01 08:00 init.xlog.rc
-rw-r--r-- root     root        10520 1970-01-01 08:00 meta_init.rc
drwxrwxr-x root     system            2016-01-08 15:52 mnt
dr-xr-xr-x root     root              1970-01-01 08:00 proc
lrwxrwxrwx root     root              1970-01-01 08:00 res -> /system/res
drwx------ root     root              2014-10-23 17:41 root
drwxr-x--- root     root              1970-01-01 08:00 sbin
lrwxrwxrwx root     root              2016-01-08 15:52 sdcard -> /mnt/sdcard
lrwxrwxrwx root     root              2016-01-08 15:52 sdcard2 -> /mnt/sdcard/external_sd
drwxr-xr-x root     root              2016-01-08 15:52 sys
drwxr-xr-x root     root              2016-01-08 15:45 system
-rw-r--r-- root     root          272 1970-01-01 08:00 ueventd.goldfish.rc
-rw-r--r-- root     root         4866 1970-01-01 08:00 ueventd.rc
lrwxrwxrwx root     root              2016-01-08 15:52 vendor -> /system/vendor
root@android:/ # chmod 777 system
chmod 777 system
Unable to chmod system: Read-only file system
10|root@android:/ # mount -o rw,remount yaffs2 /system
mount -o rw,remount yaffs2 /system
root@android:/ # ll
ll
drwxr-xr-x root     root              2016-01-08 15:52 acct
-rw-r--r-- root     root         2503 1970-01-01 08:00 advanced_meta_init.project.rc
-rw-r--r-- root     root        32580 1970-01-01 08:00 advanced_meta_init.rc
drwxr-xr-x system   system            1970-01-01 08:00 apps
drwxrwx--- system   cache             2016-01-08 15:35 cache
dr-x------ root     root              2016-01-08 15:52 config
lrwxrwxrwx root     root              2016-01-08 15:52 d -> /sys/kernel/debug
drwxrwx--x system   system            2016-01-08 16:04 data
-rw-r--r-- root     root          173 1970-01-01 08:00 default.prop
drwxr-xr-x root     root              2016-01-08 16:02 dev
lrwxrwxrwx root     root              1970-01-01 08:00 emmc@android -> /dev/block/mmcblk0p4
lrwxrwxrwx root     root              1970-01-01 08:00 emmc@apps -> /dev/block/mmcblk0p3
lrwxrwxrwx root     root              1970-01-01 08:00 emmc@cache -> /dev/block/mmcblk0p5
lrwxrwxrwx root     root              1970-01-01 08:00 emmc@ebr1 -> /dev/block/mmcblk0p1
lrwxrwxrwx root     root              1970-01-01 08:00 emmc@fat -> /dev/block/mmcblk0p7
lrwxrwxrwx root     root              1970-01-01 08:00 emmc@sec_ro -> /dev/block/mmcblk0p2
lrwxrwxrwx root     root              1970-01-01 08:00 emmc@usrdata -> /dev/block/mmcblk0p6
lrwxrwxrwx root     root              2016-01-08 15:52 etc -> /system/etc
lrwxrwxrwx root     root              2016-01-08 15:52 external_sd -> /mnt/sdcard/external_sd
-rwxr-x--- root     root       143920 1970-01-01 08:00 init
-rwxr-x--- root     root           93 1970-01-01 08:00 init.aee.customer.rc
-rwxr-x--- root     root        13573 1970-01-01 08:00 init.factory.rc
-rwxr-x--- root     root         2344 1970-01-01 08:00 init.goldfish.rc
-rwxr-x--- root     root         3137 1970-01-01 08:00 init.project.rc
-rwxr-x--- root     root        38576 1970-01-01 08:00 init.rc
-rwxr-x--- root     root        16181 1970-01-01 08:00 init.usb.rc
-rwxr-x--- root     root          583 1970-01-01 08:00 init.xlog.rc
-rw-r--r-- root     root        10520 1970-01-01 08:00 meta_init.rc
drwxrwxr-x root     system            2016-01-08 15:52 mnt
dr-xr-xr-x root     root              1970-01-01 08:00 proc
lrwxrwxrwx root     root              1970-01-01 08:00 res -> /system/res
drwx------ root     root              2014-10-23 17:41 root
drwxr-x--- root     root              1970-01-01 08:00 sbin
lrwxrwxrwx root     root              2016-01-08 15:52 sdcard -> /mnt/sdcard
lrwxrwxrwx root     root              2016-01-08 15:52 sdcard2 -> /mnt/sdcard/external_sd
drwxr-xr-x root     root              2016-01-08 15:52 sys
drwxr-xr-x root     root              2016-01-08 15:45 system
-rw-r--r-- root     root          272 1970-01-01 08:00 ueventd.goldfish.rc
-rw-r--r-- root     root         4866 1970-01-01 08:00 ueventd.rc
lrwxrwxrwx root     root              2016-01-08 15:52 vendor -> /system/vendor
root@android:/ # chmod 777 system
chmod 777 system
root@android:/ # ll
ll
drwxr-xr-x root     root              2016-01-08 15:52 acct
-rw-r--r-- root     root         2503 1970-01-01 08:00 advanced_meta_init.project.rc
-rw-r--r-- root     root        32580 1970-01-01 08:00 advanced_meta_init.rc
drwxr-xr-x system   system            1970-01-01 08:00 apps
drwxrwx--- system   cache             2016-01-08 15:35 cache
dr-x------ root     root              2016-01-08 15:52 config
lrwxrwxrwx root     root              2016-01-08 15:52 d -> /sys/kernel/debug
drwxrwx--x system   system            2016-01-08 16:04 data
-rw-r--r-- root     root          173 1970-01-01 08:00 default.prop
drwxr-xr-x root     root              2016-01-08 16:02 dev
lrwxrwxrwx root     root              1970-01-01 08:00 emmc@android -> /dev/block/mmcblk0p4
lrwxrwxrwx root     root              1970-01-01 08:00 emmc@apps -> /dev/block/mmcblk0p3
lrwxrwxrwx root     root              1970-01-01 08:00 emmc@cache -> /dev/block/mmcblk0p5
lrwxrwxrwx root     root              1970-01-01 08:00 emmc@ebr1 -> /dev/block/mmcblk0p1
lrwxrwxrwx root     root              1970-01-01 08:00 emmc@fat -> /dev/block/mmcblk0p7
lrwxrwxrwx root     root              1970-01-01 08:00 emmc@sec_ro -> /dev/block/mmcblk0p2
lrwxrwxrwx root     root              1970-01-01 08:00 emmc@usrdata -> /dev/block/mmcblk0p6
lrwxrwxrwx root     root              2016-01-08 15:52 etc -> /system/etc
lrwxrwxrwx root     root              2016-01-08 15:52 external_sd -> /mnt/sdcard/external_sd
-rwxr-x--- root     root       143920 1970-01-01 08:00 init
-rwxr-x--- root     root           93 1970-01-01 08:00 init.aee.customer.rc
-rwxr-x--- root     root        13573 1970-01-01 08:00 init.factory.rc
-rwxr-x--- root     root         2344 1970-01-01 08:00 init.goldfish.rc
-rwxr-x--- root     root         3137 1970-01-01 08:00 init.project.rc
-rwxr-x--- root     root        38576 1970-01-01 08:00 init.rc
-rwxr-x--- root     root        16181 1970-01-01 08:00 init.usb.rc
-rwxr-x--- root     root          583 1970-01-01 08:00 init.xlog.rc
-rw-r--r-- root     root        10520 1970-01-01 08:00 meta_init.rc
drwxrwxr-x root     system            2016-01-08 15:52 mnt
dr-xr-xr-x root     root              1970-01-01 08:00 proc
lrwxrwxrwx root     root              1970-01-01 08:00 res -> /system/res
drwx------ root     root              2014-10-23 17:41 root
drwxr-x--- root     root              1970-01-01 08:00 sbin
lrwxrwxrwx root     root              2016-01-08 15:52 sdcard -> /mnt/sdcard
lrwxrwxrwx root     root              2016-01-08 15:52 sdcard2 -> /mnt/sdcard/external_sd
drwxr-xr-x root     root              2016-01-08 15:52 sys
drwxrwxrwx root     root              2016-01-08 15:45 system
-rw-r--r-- root     root          272 1970-01-01 08:00 ueventd.goldfish.rc
-rw-r--r-- root     root         4866 1970-01-01 08:00 ueventd.rc
lrwxrwxrwx root     root              2016-01-08 15:52 vendor -> /system/vendor
root@android:/ # cd system
cd system
root@android:/system # ll
ll
drwxr-xr-x root     root              2016-01-08 15:42 app
drwxr-xr-x root     shell             2016-01-08 16:02 bin
-rw-r--r-- root     root         4469 2008-08-01 20:00 build.prop
drwxr-xr-x root     root              2016-01-08 15:42 etc
drwxr-xr-x root     root              2016-01-08 15:42 fonts
drwxr-xr-x root     root              2016-01-08 15:42 framework
drwxr-xr-x root     root              2016-01-08 15:42 lib
drwxr-xr-x root     root              1970-01-01 08:00 lost+found
drwxr-xr-x root     root              2016-01-08 15:42 media
-rw-r--r-- root     root       723451 2008-08-01 20:00 recovery-from-boot.p
drwxr-xr-x root     root              2016-01-08 15:42 res
-rw-r--r-- root     root          183 2008-08-01 20:00 sdcard0.sh
-rw-r--r-- root     root          183 2008-08-01 20:00 sdcard1.sh
drwxr-xr-x root     root              1970-01-01 08:00 secro
drwxr-xr-x root     root              2016-01-08 15:42 tts
drwxr-xr-x root     root              2016-01-08 15:42 usr
drwxr-xr-x root     shell             2016-01-08 15:42 vendor
drwxr-xr-x root     root              2016-01-08 15:42 weather
drwxr-xr-x root     shell             2016-01-08 15:42 xbin
root@android:/system # chmod 777 app
chmod 777 app
root@android:/system # PS C:UsersAdministrator> adb shell

第三步：将app导入 /system/app 目录

mv weixin638android680.apk /system/app
failed on 'weixin638android680.apk' - Cross-device link