Create System Application

Question

What I should to do to create a system app (to obtain rights to use android:sharedUserId=\"android.uid.system\"in manifest file without receiving an error from

Answer 1

A system app must be signed with the platform key. This is done by developers deploying an android platform on their own device, or mobile carriers.

If that is your case, the easiest way is to add this to your Android.mk:

LOCAL_CERTIFICATE := platform
LOCAL_PRIVILEGED_MODULE := true

If you add those lines without adding android:sharedUserId="android.uid.system" to your manifest, you will be a platform_app. A system app is more privileged than a platform app. That uses the platform key and runs as the system user.

If you are not the platform vendor, the platform vendor would need to sign your application using their platform key. Some vendors, including my company, will do this for 3rd parties demonstrating a valid reason for doing so.

Without the signature, your application can only be used on rooted devices.