GPT BIOS boot partition and installing to a partition

[Dave Vasilevsky]

On my GPT-partitioned MacBook, I seem to have two options for booting
with grub-pc:

1. Install grub to the start of an existing partition. This coexists
well with the rEFIt boot menu, but requires blocklists to load
core.img.
2. Use a BIOS boot partition. This allows embedding core.img, but
installs to the MBR and makes rEFIt unhappy.

I had the idea that we could get the advantages of both: Install the
boot-image to an existing partition, but load core.img from a BIOS
boot partition. With some creative hex-editing I got this working
without much difficulty.

Is there a technical reason why grub doesn't support this setup? If I
were to write a patch allowing this, what behaviour would be
preferred: Should 'grub-setup (hdX,Y)' automatically use a BIOS boot
partition if one exists, or should a command-line flag be required?

Dave Vasilevsky