Re: EFI boot: 'could not prepare Boot variable: Invalid argument'

[Felix Lechner via <help-guix@gnu.org>]

Hi,

On Sun, Nov 6, 2022 at 4:58 AM <post@thomasdanckaert.be> wrote:
>
> 'Could not prepare Boot variable: Invalid argument'

You have not yet rebooted, have you?

What do you see with this command?

    ls /sys/firmware/efi/vars/

You can also try 'guix install efivar' and look at the output of that
tool, but please do not attempt to change any settings yourself.

> Does anybody have a guess what can cause this (and what might solve
> it?).

Diagnosing boot problems can be difficult even when sitting in front
of the equipment. I believe your system booted via the legacy boot
sector method instead of UEFI, which made the EFI variables
unavailable.

If so, the only way to fix it is to boot via EFI.

> I fear my system is currently unbootable.

In Guix, you should have old system generations available in the GRUB
menu. That is your preferred method.

You may also be able to manually link the EFI image you wish to load
via the "removable media path". A third option that I have used is to
load your kernel directly via its EFI stub. The two latter options may
require further help from this list and lots of patience. They also
carry a higher risk of failure.

Kind regards
Felix Lechner