GRUB2 gives an ideal payload for coreboot. It's modular, extensible, supports booting off filesystems, and it has a scriptable shell. Our goal is to replace the common coreboot payload FILO with a coreboot-capable version of GRUB2.
Patrick Georgi has been working on GRUB2 for coreboot during the Google Summer of Code 2007. He made an original code submission on August 20th 2007. Please read GRUB2 on coreboot instructions for information on how to use it.
This work was subsequently rejected by the GRUB project, and was eventually re-implemented by Robert Millan, one of the GRUB project members. The re-implementation lacks a couple of fundamental features. From this new base, more work was done.
As of the time of this writing, the official GRUB2 can not be loaded in coreboot v2 without a small patch. It works fine with coreboot v3.
- A significant amount of work has been put into GRUB2 in our MonotoneRepository, which also provides snapshots.
- The mainline version of GRUB2 has a wiki page on the coreboot port
- Mainstream GRUB2's grub-mkimage needs to put the program headers right after the elf header (Fix available).
- USB stack integration (in progress)
- See more information in the "Porting GRUB2 to coreboot" milestone in the coreboot issue tracker.
How to build GRUB2 as a payload
$ # build lbgrub2: $ # target/target_alias assume that you use i386-elf-gcc $ configure --with-platform=linuxbios --prefix=$PWD/installed $ make && make install $ $PWD/installed/bin/grub-mkimage -o core.img normal fat iso9660 ext2 pc atadisk rom lar ls cat cmp hello help serial terminal test configfile multiboot boot loopback
NOTE: newer versions of GRUB2 replaced the rom module by memdisk (our changes needed for that) and the atadisk module by ata.