Resigning system.img on a device

Question

I am working on an automatic app updating solution for devices (LG p509 - Optimus 1) which we deploy to our customers. We have control of these devices and currently install a c

Answer 1

The "system apk" is /system/framework/framework.jar. I've never tried to re-sign the system image but I've written code which was part of the system image (not within a normal apk project) and it became part of this jar. There are additional jars in this directory which may need to be re-signed also.

The signature is created randomly and placed in two files in your build environment, build/target/product/security/platform.pk8 and build/target/product/security/platform.x509.pem. I don't know how to extract these from a normal key store, however I've been able to copy them from one firmware build to another to ensure that both images had the same platform key. Also, I've been able to change the signature of APKs with this command: java -jar signapk.jar platform.x509.pem platform.pk8 Old.apk New.apk. You'll find signapk.jar in your build, at out/host/linux-x86/framework/signapk.jar