How to run System Android App on system user

Question

I am Working on Android System app, that means I signed it with the platform key and I pushed it into "/system/priv-app", but when I check it with "adb shell ps" I found the user is "u0_a40" not "system"

Who can explain me what happen and what can I do to run the app with the system user?

Answer 1

The AndroidManifest.xml needs to specify that your app is supposed to run as system user:

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
          package="com.example.mysystemapp"
          android:sharedUserId="android.uid.system"
          coreApp="true">

For completeness sake, if you want to compile your system app as part of the AOSP build process via an Android.mk file, you need to put this in the Android.mk:

LOCAL_PRIVILEGED_MODULE := true
LOCAL_CERTIFICATE := platform

This ensures that the app ends up in /system/priv-app and is signed by the platform key.