Re: [REGRESSION] Re: [PATCH v4 5/5] efi: Use generic EFI loader for x86_64 and i386

[Jan Čermák]

Hi Ard

On 28. 06. 24 19:28, Ard Biesheuvel wrote:
> Given that you carry your own GRUB build, I would recommend reverting
> to non-EFI stub boot for affected Atom systems, identified by DMI
> data, which should be easy to access on such systems.
>
> Look for 'goto fallback' in the existing loader logic in
> grub-core/loader/efi/linux.c - you'd need to jump to the same point to
> use the GRUB 2.06 logic for systems that fail that cannot load the EFI
> stub kernel image.

Thanks for the suggestion, that sounds like a more acceptable solution 
(than the revert). However, would a quirk like that be acceptable in 
upstream code as well? In long term, we'd like to only support hardware 
that is supported in upstream, instead of taking the maintenance burden 
of carrying custom patches indefinitely, so if it is GRUB's maintainers' 
decision to abandon support for old buggy hardware, we shall declare it 
abandoned as well.

> Out of curiosity - these are all x86_64 Atoms right? How old are they?

Yes, they are, e.g. Atom D525 [1], but from the reports we've received 
it seems the problem is with the NM10 chipset [2] in general (as I 
stated in the first message in the thread). They are ~14 years old so 
pretty archaic I'd say O:-)

Regards,
Jan

[1] 
https://ark.intel.com/content/www/us/en/ark/products/49490/intel-atom-processor-d525-1m-cache-1-80-ghz.html
[2] 
https://www.intel.com/content/www/us/en/products/sku/47610/intel-nm10-express-chipset/specifications.html