How to flash coreboot to the thinkpad x60 the proper way
-> https://blog.aheymans.xyz/old-how-to-flash-coreboot-to-the-thinkpad-x60-the-proper-way/ is more up to date
What is so special about the x60 when running vendor bios?
Vendor BIOS write protects its bootblock, which means the lowest 64K of the flash can't be modified
This is a problem since the first code that runs on the CPU comes from there and if we ever want to run coreboot the cpu must start with coreboot code. This write protection is set in the PBR (protect bios range) registers on the southbridge, there is currently no known way to change them back once they are locked by setting the SPI Configuration Lock-Down bit.