Install apps silently, with granted INSTALL_PACKAGES permission

Question

I am trying to silently install apk into the system. My app is located in /system/app and successfully granted permission \"android.permission.INSTALL_PACKAGES\"

Ho

Answer 1

I have checked how ADB installs apps.
- It copies the APK to /data/local/tmp
- it runs 'shell:pm install /data/local/tmp/app.apk'

I have tried to replicate this behaviour by doing: (on pc, using usb-cable)
adb push app.apk /sdcard/app.apk
adb shell
$ pm install /sdcard/app.apk
This works. The app is installed.

I made an application (named AppInstall) which should install the other app.
(installed normally, non-rooted device)
It does:
Runtime.getRuntime().exec("pm install /sdcard/app.apk").waitFor();
But this gives the error:
java.lang.SecurityException: Neither user 10019 nor current process has android.permission.INSTALL_PACKAGES.
It seems like the error is thrown by pm, not by AppInstall.
Because the SecurityException is not catched by AppInstall and the app does not crash.

I've tried the same thing on a rooted device (same app and AppInstall) and it worked like a charm.
(Also normally installed, not in /system or anything)
AppInstall didn't even ask root-permission.
But thats because the shell is always # instead of $ on that device.

Btw, you need root to install an app in /system, correct?
I tried adb remount on the non-rooted device and got:
remount failed: Operation not permitted.
That's why I could not try the /system thing on the non-rooted device.

Conclusion: you should use a rooted device
Hope this helps :)