Factory firmware support for coreboot and SeaBIOS is limited, but custom firmware is available for many Sandy/Ivy Bridge models from MrChromebox: https://mrchromebox.tech#devices and John Lewis: https://johnlewis.ie/custom-chromebook-firmware/rom-download/.
There are two firmware update options available:
- Leaves all stock functionality intact, including the white "OS verification is OFF" screen
- Allows device to dual-boot GalliumOS alongside ChromeOS
- Some models ship with this feature enabled and including a working SeaBIOS
- On some models, includes bugfixes and enables additional functionality such as booting from SD card/eMMC
- Sandy/Ivy Bridge: only available for the Google Pixel 2013 (LINK)
- Full ROM
- Installs a complete ROM containing a coreboot build and a working SeaBIOS (or Tianocore for UEFI ROMs)
- Bypasses the white "OS verification is OFF" screen
- Removes the ability to run ChromeOS natively, creating a small risk of bricking your device
- Will wipe out all product data
- This option is the most invasive and may include bugs or idiosyncrasies that the stock firmware does not
- Sandy/Ivy Bridge: Enables hardware virtualization extensions and suspend
In addition to the notes here, it is always a good idea to check the issue tracker for open issues.
- ISO boots to GRUB shell: https://github.com/GalliumOS/galliumos-distro/issues/342