I've been testing out creating using a hybrid GPT+MBR stick so that EFI and
BIOS-based systems can boot off of the one stick and share a persistent
home. The good news is that it works and the changes are fairly simple -
essentially, I just removed the conditional statements that prevented the
non-mactel stuff from being executed when --mactell was passed. I also had
to rearrange a few blocks so that the GPT partitions happens first, since
the MBR should only be installed after GPT has initialized (and therefore it
will install to GPT's protective MBR).
The bad news is syslinux doesn't support GPT at the moment because we can't
set a MBR partition as "bootable" in a GPT partition table. GRUB doesn't
seem to care about this and will boot fine once installed to /dev/sdb,
although the only bug I hit then was that booting from "USB-HDD" and
"USB-ZIP" in the BIOS didn't work... I had to select "HDD" and
"USB-0". Is this why the scripts currently use syslinux instead of making
the jump to GRUB?
Even if we only use GRUB as a last resort (when --mactel is passed), I still
think this is a worthfile feature most recent motherboards support booting
from USB as a HDD instead of USB-ZIP.