In http://code.turnkeylinux.org/di-live/d-i/source/grub-installer/grub-inst... there is some evidence that turnkey might install using grub-efi instead of grub-pc:

	case $ARCH in
    i386/mac|amd64/mac)

However 3 lines below there is:

	# This point can't be reached (yet).  See debian/isinstallable.

Does this mean that on a mac always grub-pc will be installed?

When efi installation on a mac is possible, what are its requirements?

As current turnkey core version 11.1 (ubuntu 10.04.1) seems to install using grub-pc (bios) instead of grub-efi (on a drive that was partitioned using MBR and did not already contain a bootable FAT32 EFI partition).

Roughly which steps should be taken to convert current turnkey core installation with grub-pc to grub-efi?

1. backup partitions
2. GUID partition the drive (instead of MBR)
3. create 100MB bootable FAT32 EFI partition
4. copy grub.efi and rename (/EFI/BOOT/BOOTIA32.EFI) to this partition
5. copy *.mod and *.lst to the same directory as BOOTIA32.EFI
6. restore (and resize) old partitions
7. ?