Android: Signing my application with system key

Question

I hear that to access permission like: - READ_FRAME_BUFFER

The app needs to be signed with system key. If I understand correctly, that means the manufacturer sign the .apk file.

Question: - Is it required that the manufacturer signed .apk to be shipped with a system image? or can it still be downloaded in the market place? - In real life, after manufacture creates genetic ROM, it is the network provider (eg. Rogers, AT&T) who does little modification to the ROM. Then, who really has the

Answer 1

Not 100% sure but I think an apk signed with the system key can be added later via normal installation methods, but would end up on the /data partition.

Even if not, an OTA update.zip could do as little as changing a single file, for example installing an APK to /system

Presumably the device manufacturer and branding carrier have some arrangement between them concerning the system key - either both have it or one applies it on request of the other.

A rooted phone or custom rom make these powers available to you.