UEFI-capable custom firmware is now available for most ChromeOS devices -- see: https://mrchromebox.tech/#devices.
GalliumOS 2.1, currently in beta, fully supports UEFI booting on ChromeOS hardware running MrChromebox's UEFI firmware.
SandyBridge/IvyBridge based devices are reportedly having issues booting install media created from the 2.1 beta ISO - we are looking into it. For now, SNB/IVB users may want to hold tight.
The current stable GalliumOS release (2.0) does not support UEFI booting, though it can be configured manually. If you're running UEFI firmware, be sure to use the 2.1 beta ISO for installation.
UEFI support is appealing for a couple reasons:
- UEFI booting should improve boot time by a few seconds
- UEFI might be a good reusable solution for future Braswell support, and possibly for some ARM Chromebooks and non-ChromeOS devices
NOTE: UEFI support is not included in factory firmware on any ChromeOS devices. Adding support will require flashing "full" firmware, and will therefore prevent dual-booting alongside ChromeOS.