Recovery

The stock recovery used on Android is a Linux kernel with an initramfs that can usually be controlled with volume buttons. It was previously commonly replaced with ClockWorkMod and nowadays mostly TWRP. TWRP is based on the vendor kernel and makes use of the Android build system, which is complicated. It also uses a tool from Google to create a framebuffer, which is not needed on mainline kernels. It is also build against the bionic libc, which is different from musl used in Alpine.

Using pmbootstrap, it can be possible to create a more simplified recovery that is also more suitable for pmOS, instead of only Android. Writing a new GUI from scratch is likely easier than using the TWRP code on top of mainline.