Comment 5 for bug 1851955

On Mon, Jan 06, 2020 at 05:46:14PM -0000, Sri wrote:
> Setting up grub-efi-amd64-signed (1.128.1+2.04-1ubuntu12.1) ...
> Installing for x86_64-efi platform.
> grub-install: warning: Cannot set EFI variable Boot0000.
> grub-install: warning: efivarfs_set_variable: writing to fd 7 failed: Invalid argument.
> grub-install: warning: _efi_set_variable_mode: ops->set_variable() failed: Invalid argument.
> grub-install: error: failed to register the EFI boot entry: Invalid argument.

> Any clue on where I should start looking?

Look into reports of problems with your specific firmware for your specific
device. See if an update is available. See if there are options in the
BIOS menu that control whether these variables are locked.

What is the output of 'efibootmgr -v' on this system?

If Ubuntu can't control the boot variables, then it can't reliably boot on
the system; so the package install failure is intentional.

However you also mention that this started happening to you on upgrade and
there has been a change in grub's implementation between 18.04 and 19.10,
where previously grub shelled out to efibootmgr and now it writes the
variables directly. So it's possible there is a bug in the grub
implementation.