OK, I took a look at the code. Nice to see such a simple startup, reminds of linuxbios v1 days. At least if this is the right one: http://fossies.org/linux/misc/grub-2.00.tar.gz:a/grub-2.00/grub-core/boot/mi...
I don't see a problem pulling this in to coreboot. We'd probably trim some bits out and let ramstage take over, but for a first cut it could be used as is. This code is very similar in how it works to many linuxbios/coreboot platforms and hence should fit into the coreboot structure with ease.
The first step remains the same: set up crossgcc. I talked to stefan yesterday about incorporating extant loongson patches into a gcc build and he mentioned that the utility is designed to allow you to specify patches to be pulled at build time.
So, let's start with crossgcc for mips/loongson. This is a minimum requirement.