Re: Get/set UEFI variables or NVMe driver?

[Randy Goldenberg]

In the firmware of the computer with the NVMe drive that grub does not
"see", is there an option to set the SATA mode of the drive?  If so, does
grub see the drive when SATA mode is set to AHCI?

On Tue, Mar 26, 2024 at 6:01 PM Marek Marczykowski-Górecki <
marmarek@invisiblethingslab.com> wrote:

> Hi,
>
> Is there a command for getting/setting UEFI variables? I see
> grub_efi_{get,set}_variable functions in the source code, but can't find
> if it's connected to any command. Alternatively, is there an NVMe driver
> for grub?
>
> I know the alternative looks a bit weird, so let me explain. I use
> grub2-efi loaded over PXE to boot different systems depending on some
> external settings (a config file loaded over network too). One of the
> boot paths is booting Linux that is installed on the local disk. With
> SATA it's simple - I can load grub.cfg from the local disk and jump
> there. But for NVMe, grub doesn't see the disk when it's loaded from
> network (my guess is that firmware doesn't load its NVMe driver when
> booting from network). The same grub can access the disk when loaded
> from local disk. My current workaround is booting Linux (loaded
> from network too) that sets BootNext variable to local system and
> reboot. Booting whole Linux kernel just for that feels silly...
> So, I'd like to set the BootNext from grub directly.
>
> An NVMe driver would solve the problem for me too, but I guess that's
> much more work (for a rather niche use case, I realise). And the BootNext
> approach is more reliable anyway, because it ensures the grub version
> matching its config, and would work with non-grub bootloader too.
>
> --
> Best Regards,
> Marek Marczykowski-Górecki
> Invisible Things Lab
>