System App Mode

For developers and power users who want the highest privilege level. Requires flashing a custom AOSP system image.

Why System App Mode?

	Standard Mode	System App Mode
Install method	APK install	Flash system image
Privilege source	ADB wireless	Platform signing
Screenshot method	Mirror VD + ImageReader	SurfaceControl.screenshot()
Input method	AIDL proxy to PrivilegedService	InputManager reflection
VD task management	PrivilegedService proxy	ActivityTaskManager reflection
Performance	~50ms screenshot latency	~5ms screenshot latency

Same AI engine, same UI, same capabilities. The difference is only in how the app obtains system permissions.

Setup

1. Build the APK

git clone https://github.com/opencyvis/opencyvis-phone.git
cd opencyvis-phone/android
./gradlew assembleSystemRelease

The output APK is at android/app/build/outputs/apk/systemRelease/.

2. Build the AOSP Image

You need a custom AOSP image built with the same platform signing key as the APK. OpenCyvis uses the standard AOSP test platform key.

See the Emulator Setup guide for step-by-step instructions on building an AOSP image with Docker.

3. Deploy

Push the APK to /system/priv-app/ on the device:

adb root
adb remount
adb push app-system-release.apk /system/priv-app/OpenCyvis/OpenCyvis.apk
adb reboot

After reboot, OpenCyvis will detect it has platform-level privileges and automatically use SystemBackend.

🚫 Danger System App Mode requires an unlocked bootloader and a custom system image. It does not work on locked retail phones.