Updating

Updating an installed laptop to a newer gbOS86

1. Write the newer image to a stick (or replace the files on your existing one).
2. Boot the stick, choose 2. When it finds an installation it offers 1) Update and 2) Reinstall.
3. Choose 1. It saves the installed system's last three boots of logs to the stick, copies the new files and kernel to the laptop, verifies each one with sha256, and tells you to remove the stick. Apps, accounts and data are untouched.

Update copies the system images, scripts, patched libraries, firmware, kernel modules, audio configs, installer tools and the kernel itself, but not your MODE setting.

Moving to a newer Google build

Android's built-in updater cannot work: it expects Google's own A/B partitions and kernel. A newer Googlebook OS build is a manual process:

1. Download the new recovery image, extract the partitions and rebuild super.img.
2. Scan it for CPU instructions the emulator does not cover (AVX-512, AMX and similar).
3. Re-check every hash-pinned patch (libz, libcrypto, the software KeyMint library): a new build has new files, so patches silently stop applying until regenerated, and renamed vendor files stop being hidden.
4. Copy to the stick and run 1 (Update). Data carries over; going back to an older build requires wiping data.