Linux Guide

This guide pertains to x86 hosts with the GRUB payload, and does not cover supported CrOS/ARM chromebooks. For ARM targets, you should refer to u-boot documentation. SeaBIOS users should just use it like a traditional BIOS. From now on this document assumes the GRUB payload.

General idea of how Libreboot’s GRUB works

Libreboot’s GRUB, in the flash, finds and loads a distro’s grub.cfg file. It does not load the distro’s GRUB itself.

Useful GRUB guides

These are too large and have been moved to separate pages.

• Encrypted /boot via LUKS2 with Argon2
• Prepare and Boot a USB Installer in Libreboot Systems
• Modifying the GRUB Configuration in libreboot Systems
• How to Harden Your GRUB Configuration, for Security
• How to add custom keyboard layouts to your GRUB

GRUB and VGA modes

Libreboot GRUB boots in text mode or uses the coreboot framebuffer. Setting GRUB_TERMINAL=console prevents GRUB from switching video modes which is unsupported.

On most distributions, you can edit /etc/default/grub as root, and uncomment or add GRUB_TERMINAL=console, then run /sbin/update-grub or grub-mkconfig -o /boot/grub/grub.cfg.

Fedora won’t boot?

This may also apply to CentOS or Redhat. Chroot guide can be found on Fedora website.

linux16 issue

Libreboot’s default GRUB config sources fedora’s grub config grub.cfg (in /boot/grub2/grub.cfg), fedora by default makes use of the linux16 command, where it should be saying linux.

Open /etc/grub.d/10_linux and set the sixteenbit variable to an empty string, then run grub2-mkconfig -o /boot/grub2/grub.cfg.

BLS issue

With newer versions of fedora, scripts from grub package default to generating BLS instead of grub.cfg. BLS is not recognized by Libreboot’s GRUB payload. To change that behaviour set following line in /etc/default/grub:

GRUB_ENABLE_BLSCFG=false

Then generate grub.cfg with grub2-mkconfig -o /boot/grub2/grub.cfg.