Comment by kevinoid

This approach sounds similar to Petitboot <http://www.kernel.org/pub/linux/kernel/people/geoff/petitboo...> which is a kexec-based bootloader that I used on the Playstation 3 many years ago. Apparently it now targets many other systems and there is a (dead?) fork for Coreboot <https://github.com/ArthurHeymans/petitboot_for_coreboot>.