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 (short for Team Win Recovery Project). 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.
Notes
- Installation_from_recovery_mode gives brief tutorial to install pmOS by android recovery
- Possible GUI framework, might require hardware acceleration
- Unl0kr, pmOS' initramfs disk unlocker UI written in C using LVGL which runs on the Linux framebuffer without hardware acceleration
See also
- Android Recovery: general tips and tricks for postmarketOS and the recovery system
- Initramfs/Inspecting: using the postmarketOS initramfs debug shell