Here's a copy of the coreboot ROM I built. I reflashed it on my T500 and confirmed it allows running all 4 cores at maximum speed (2.53ghz in my case). The build date is 7/21/2020. I don't have the original build directory or config files. It boots straight to SeaBIOS, no grub, no proprietary VBIOS, no microcode. The SeaBIOS 'nvramcui' and 'coreinfo' boot options show the first screen aren't interactive. Booting from SATA or USB works fine.
6 months ago