Re: blscfg module $early_initrd and $default_kernelopts variables

[Javier Martinez Canillas]

Hello Mike,

On Wed, Aug 11, 2021 at 3:17 PM Mike Beaton <mjsbeaton@gmail.com> wrote:
>
> I was wondering if anybody could possibly help out and clarify, is there any 
> official documentation around the existence, and correct use, of the blscfg 
> $early_initrd and $default_kernelopts variables?
>

The blscfg module is not in upstream GRUB yet and it's only present in
the downstream package of some distros (e.g: Fedora Linux, Endless
OS). The mailing list is not a proper venue to discuss downstream
specific features and instead should be reported for your distribution
(i.e: Fedora's bugzilla).

> https://github.com/rhboot/grub2/blob/fedora-35/grub-core/commands/blscfg.c#L764

This variable is not used anymore and is only there for backward
compatibility. Now in Fedora the kernel command line parameter is
stored in the BLS snippets instead.

> https://github.com/rhboot/grub2/blob/fedora-35/grub-core/commands/blscfg.c#L788
>

The goal of this variable was to support the
GRUB_EARLY_INITRD_LINUX_CUSTOM option in /etc/default/grub, and so the
/etc/grub.d/10_linux script looks at this and sets the early_initrd
variable. So the use should be to set that option and then run
grub2-mkconfig as you would do on a non-BLS setup.

But I believe that instead the correct way should be for the BLS
snippet created to contain two devicetree options, and drop the
$early_initrd variable as well.

Best regards,
Javier