Support/Haswell

Intel processors with Haswell cores are very popular in 2013-era ChromeOS devices.

Factory firmware support for coreboot and SeaBIOS is common, but custom firmware is also available for all Haswell models from John Lewis: https://johnlewis.ie/custom-chromebook-firmware/rom-download/.

There are three firmware update options available:

1. RW_LEGACY
   • 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
   • Haswell: Most models ship with this feature enabled, but a few are buggy
2. BOOT_STUB
   • Bypasses the white "OS verification is OFF" screen
   • Removes the ability to run ChromeOS natively, creating a small risk of bricking your device
   • Leaves the “REFRESH + POWER” functionality of the stock ROM intact
     • If you engage this key sequence, device will reboot and try to run ChromeOS Recovery (which will fail)
     • This process will repeat on every boot until you disassemble the device and briefly disconnect the battery
3. Full ROM
   • Installs a complete ROM containing a coreboot build and a working SeaBIOS
   • 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