I have a Thinkpad W541. I don't see it in the list of supported boards:
https://coreboot.org/status/board-status.html
I have read some things about removing the whitelist in the BIOS, but it
seems a bit risky.
I never said it was impossible to get this working :)
I'm open to try to get this working, but I think it would cost money + risk
of bricking my laptop. Right now I don't know if I care to take that risk.
I have been working on building a desktop and if that goes well, I may
consider "gaining experience" with doing this proceedure on my laptop.