Bug#1093820: boot ends in grub command prompt after fresh debian install

[M. Dietrich]

Hi Pascal,

i am very happy with your answers (while i am not so happy 
that there isnt a simple solution ;) ) so i would suggest to 
close this ticket. Thank you very much for all your 
explanations.

Best regards, Michael

> On 24/01/2025 at 09:14, M. Dietrich wrote:
> >> On Wed, 22 Jan 2025 23:07:54 +0000 Pascal Hambourg wrote:
> >> On 23/01/2025 at 00:07, M. Dietrich wrote:
> >>
> >> And not in /boot/efi/EFI/BOOT ?
> >>
> > no, a `find /boot/efi` would have shown (i added the ubuntu
> > here manually, but that's how it was if i remember correctly):
> > 
> > /boot/efi/EFI/Boot
> > /boot/efi/EFI/Boot/bootx64.efi
> > /boot/efi/EFI/Boot/fbx64.efi
> > /boot/efi/EFI/Boot/mmx64.efi
> 
> This is what I asked about, so it is actually present.
> FAT is case-insensitive. This location is called "removable media path" 
> because it is used to boot from removable media.
> 
> When the UEFI firmware does not or cannot use EFI boot variables to 
> select the right boot loader, it tries to boot 
> /boot/efi/EFI/Boot/bootx64.efi. If this one was installed by Ubuntu 
> (Debian installer does not install it by default unless requested in 
> expert install), then it is not surprising that it loads Ubuntu's GRUB.
> 
> > when i issue a `efibootmgr` it shows the list of efi variables
> > (here i again added the ubuntu entry manually as i remember
> > it):
> > 
> > BootCurrent: 0001
> > Timeout: 1 seconds
> > BootOrder: 0001,0002,0003,0004,0005,0006
> > Boot0000  Windows Boot Manager	HD(1,GPT,...
> > Boot0001* debian	HD(1,GPT,...
> > Boot0002* ubuntu	HD(1,GPT,...
> (...)
> > as far as i understand the system uses BootOrder to determin
> > what to boot.
> 
> Yes, in theory.
> 
> > it starts with 0001 which is debian, not
> > ubuntu. so i wonder why the leftover ubuntu grub was booted as
> > you say (which i believe, i am not an efi expert).
> 
> Unfortunately some UEFI firmware do not use BootOrder properly. When 
> that happens the UEFI firmware may use another boot entry than the first 
> one in BootOrder, or the removable media path.
> 
> >>> i dont know if it was just my mistake not to delete that dir when wiping
> >>> ubuntu from the system  or the debian installer should notice that or
> >> Notice what ?
> > 
> > that the system wont be able to boot into debian.
> 
> How would the installer know that the UEFI firmware is flawed ?
> 
> > maybe it could change BootOrder to point to the debian entry
> > only?
> 
> It won't help if the firmware ignores BootOrder.
> A usual workaround is to force GRUB installation into the "removable 
> media path", but the option is offered only in expert install.
> A patch to do it by default when the removable media path does not exist 
> has been submitted, but it would not help in your case.
> 
>