Re: [PATCH] Remove warning in efi_enter_virtual_mode

[Josh Triplett <josh@joshtriplett.org>]

On Thu, Apr 18, 2013 at 12:00:26PM +0100, Matt Fleming wrote:
> > No, no - we *don't* have a BGRT object at all.
> > 
> > We have a completely clean memory map - but the BGRT code is causing the
> > is_ram() failure.
>  
> You assume that mapping of the Boot Services regions is done purely for
> the benefit of pulling out the bgrt image - it's not, see the above
> commit log - and I assumed that you had an ACPI bgrt pointer in your
> memory map, but you don't.
> 
> Darren, Josh, have you ever seen an i386 machine with a bgrt pointer? If
> not, and given that we've never seen an i386 firmware that requires the
> above workaround from Matthew, combined with the fact that there are so
> few i386 implementations out there, I'm inclined to apply the patch
> below, because anything else is a lot more work. We can address this
> properly if we ever start seeing i386 machines with bgrt pointers that
> reference highmem.

The machine I developed the BGRT changes on kept the image below the 4G
mark, inside one of the memory regions reclaimable via
ExitBootServices().

- Josh Triplett