And so far, have been unable to successfully boot into the machine.
This is on an Intel Mac Pro. I'm trying to do it *without* rEFIt.
I've compiled grub2 on a linux machine and copied it to a HFS+ partition. As well as the vfat GPT partition.
I then booted into OS X and blessed it, tried both the HFS+ and the vfat partition.
When holding down the alt key during boot, it does not show up in the menu.
However, when I use the refit boot CD, it detects that I have grub.efi on the HFS partition. If I select that partition for booting, it errors out, and I get the message:
"Error: Unsupported while loading grub.efi"
So, refit *knows* that the efi is there, how do I get the Mac itself to understand that?