The original script has been created by my friend Ivan Ivanov aka qmastery [1] but I noticed that it doesn't work anymore - because a cbfstool got a lot more new dependencies: 4MB of sources, compared to the previous 2MB. Had to update this script heavily [2] and now it's working fine as of today.
[1] https://mail.coreboot.org/hyperkitty/list/seabios@seabios.org/thread/VQHRAEF... [2] https://review.coreboot.org/c/coreboot/+/51393