Re: Unexpected prefix value

[Pascal Hambourg]

On 28/11/2023 at 04:44, Andrei Borzenkov wrote:
> On 27.11.2023 23:06, Pascal Hambourg wrote:
> > But if I build an EFI GRUB core image with
> >
> >    grub-mkimage --prefix='(hd0,gpt4)' --format=x86_64-efi \
> >     --output=/boot/efi/EFI/azerty/core.efi part_gpt ext2
> >
> > (no / at the end of prefix), then when booting it, the $prefix value
> > seems to be the combination of the --prefix device and the $cmdpath path:
> >
> >    cmdpath=(hd0,gpt1)/EFI/azerty
> >    prefix=(hd0,gpt4)/EFI/azerty
> >
> > Is this expected behaviour ?
>
> Yes. $prefix consists of two parts - device and the directory path. If 
> one of them is missing during initialization, grub attempts to guess and 
> fill it in.

Guessing a missing or incomplete device makes sense, but what is the use 
case for guessing a missing path when the device is present ? AFAICS if 
the devices in $cmdpath and --prefix do not match, the resulting $prefix 
is doomed to failure.