On Mon, Oct 19, 2015 at 07:55:23PM +0300, Andrei Borzenkov wrote:
GRUB reads grub.cfg either from the device BIOS had booted from (sans
serious BIOS bugs) or from device where UUID of /boot/grub is found. At
least if this GRUB was installed by grub-install. So order of devices in
BIOS is irrelevant.
I asked him to explain how GRUB was installed on both devices but he never
replied ... besides IIRC original question of about EFI, not BIOS.
EFI would make a difference. I would very much expect EFI to tell the
bootloader which device it was started from.