Re: grub2 boot menu

[didier gaumet <didier.gaumet@gmail.com>]

Le vendredi 25 juin 2021 à 11:40 -0400, Cindy Sue Causey a écrit :
> On 6/24/21, didier gaumet <didier.gaumet@gmail.com> wrote:
> 
[...]
> > 'GRUB_OS_PROBER_SKIP_LIST'
> >     List of space-separated FS UUIDs of filesystems to be ignored
> > from
> >      os-prober output.  For efi chainloaders it's <UUID>@<EFIFILE>"
[...]
> it would surely help if someone could point GRUB
> Users to what that "<EFI FILE>" is referencing.
[...]

My laptop (with an EFI firmware) has a dual boot with Debian Bullseye
and Windows 10. In this Windows 10 case, it is an EFI chainloading
(that would not be the case (chainloading) with another OS without its
self bootloader installed and properly configured)

My /boot/grub.grub.cfg contains:
"[...]
### BEGIN /etc/grub.d/30_os-prober ###
menuentry 'Windows Boot Manager (on /dev/nvme0n1p3)' --class windows --
class os $menuentry_id_option 'osprober-efi-FAF2-88F6' {
	insmod part_gpt
	insmod fat
	if [ x$feature_platform_search_hint = xy ]; then
	  search --no-floppy --fs-uuid --set=root  FAF2-88F6
	else
	  search --no-floppy --fs-uuid --set=root FAF2-88F6
	fi
	chainloader /EFI/Microsoft/Boot/bootmgfw.efi
}
### END /etc/grub.d/30_os-prober ###
[...]"

I edit /etc/default/grub to add this line:
GRUB_OS_PROBER_SKIP_LIST='FAF2-88F6@/EFI/Microsoft/Boot/bootmgfw.efi'

then I update the config:
didier@hp-notebook14:~$ sudo update-grub
Generating grub configuration file ...
Found background image: /usr/share/images/desktop-base/desktop-grub.png
Found linux image: /boot/vmlinuz-5.10.0-7-amd64
Found initrd image: /boot/initrd.img-5.10.0-7-amd64
Skipped Windows Boot Manager on
/dev/nvme0n1p3@/EFI/Microsoft/Boot/bootmgfw.efi by user request.
Adding boot menu entry for EFI firmware configuration
done

So the Windows 10 entry has been skipped

It is confirmed by inspecting /boot/grub/grub.cfg:
"[...]
### BEGIN /etc/grub.d/30_os-prober ###
### END /etc/grub.d/30_os-prober ###
[...]"

Cheers :-)