On Mon, 1 Jun 2020 10:10:41 -0400
Jonathan Billings <billings(a)negate.org> wrote:
If you see in the Fedora entry, it has:
HD(3,GPT,a5c3bc11-e83b-48d0-be96-783af37228f1,0x2001800\
,0xfa000)/File(\EFI\FEDORA\GRUBX64.EFI)
That means to look for a volume with the 3rd GPT partition, with the
UUID of a5c3bc11-e83b-48d0-be96-783af37228f1 (and some other data).
On that disk, look for the /EFI/FEDORA/GRUBX64.EFI executable
(remember, this is a DOS filesystem so it's case-insensitive).
Run 'blkid' on a running system, and you'll see that the PARTUUID of
the EFI volume matches the UUID in the above EFI entry.
You can have an EFI volume on multiple disks. EFI also supports
things like network boot, which has a different syntax EFI entry. The
efibootmgr command does a lot of the hard work of figuring that out
for you, so you don't need to manually enter that information.
You seem knowledgeable, so I'll ask you. How does the efi firmware
decide which /boot/efi to use as the source when the computer is
started? Does it have to be selected from the efi firmware menu at
each boot?