Can anyone think of a straightforward way to modify GRUB to boot a linux
kernel directly from RAM in protected mode?

We have an embedded system with a special BIOS that places a file (any file)
at a fixed location in RAM and executes it (in protected mode) starting at
that same fixed location.  We'd like the file to be a linux kernel (with
boot code) and we're wondering if GRUB could be adapted to do this.  We
realize that some assembly-level modifications would be needed but we aren't
sure how extensive those modifications might be expected to be.

Patrick