On Wed, Oct 15, 2025 at 03:30:53PM +0200, Daniel Kiper via Grub-devel wrote:
> On Tue, Oct 14, 2025 at 10:17:45AM -0500, Andrew Hamilton wrote:
> > Daniel - can you take a look at this one to see if we can get it pulled in 
> > to
> > help those affected by this issue?
> 
> I am not entirely sure it [1] is correct.

Well.  Underlying problem is that there are two drivers active for one
piece of hardware.  The driver which comes with the EFI firmware, and
the grub driver.  Which is /never/ a good idea.  In this specific case
the effect is very visible, with other hardware the problems can be more
obscure or with luck not present.

The by far easiest way to handle this properly to allow only the efi_*
drivers on all EFI platforms.  The patch does just that (limited to
video drivers).

Alternatively you can check for conflicts.  Check which physical device
backs efi_gop, block that from being used by grub drivers.  Same for
all other device types.

The latter would handle the corner case that there is hardware which is
(a) supported by grub, and (b) not supported by the firmware, and (c)
essential to boot the system.  Not sure how relevant that is in
practice, most EFI firmware I've seen recently is pretty complete when
it comes to hardware support.  NIC drivers are missing sometimes, iPXE
to the rescue ;)

Note that the same conflict exists for filesystem drivers too, usually
both EFI and grub FAT drivers are active.  Luckily write access to
the ESP is very rare, so this isn't much of a problem in practice.

take care,
  Gerd


_______________________________________________
Grub-devel mailing list
[email protected]
https://lists.gnu.org/mailman/listinfo/grub-devel

Reply via email to