Re: [RFC] Best place/method to determine BIOS version?

From: Borislav Petkov
Date: Tue Jun 10 2014 - 04:06:26 EST


On Mon, Jun 09, 2014 at 03:00:17PM -0500, Alex Thorlton wrote:
> Hi guys,
>
> We recently ran into/corrected a bug in our BIOS that was exposed by the
> recent updates to the way that the EFI code maps in memory during boot.
> Discussion here:
>
> http://comments.gmane.org/gmane.linux.kernel/1638074
>
> Anyways, we now need to find a way to determine the BIOS version before
> efi_apply_memmap_quirks is called, so that we know whether or not the
> BIOS we're running requires the quirk. We have a function in one of our
> EFI runtime services that provides this information, but I'm having a
> lot of trouble calling this function early enough in boot.
>
> It seems that all the necessary function pointers are available well
> before efi_apply_memmap_quirks is called, but when trying to use
> efi_call_phys6 to call our function,

Why not use DMI instead of EFI for getting the BIOS version? I see
dmi_scan_machine() called earlier than efi_apply_memmap_quirks() in
setup_arch()...?

--
Regards/Gruss,
Boris.

Sent from a fat crate under my desk. Formatting is fine.
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