From article:

GNU Boot is a “100% free software project aimed at replacing the non-free boot software” and is a downstream of Coreboot, GRUB, and SeaBIOS. While priding itself on being “100% free”, last December they had to drop some motherboard support and CPU code after discovering they were shipping some files that are non-free by their free software standards. Today they announced another mistake in having inadvertently been shipping additional non-free code.