[SeaBIOS] [PATCH] mark VBE mapping as reserved in e820

Kevin O'Connor kevin at koconnor.net
Sat Jan 23 21:37:12 CET 2010

On Sat, Jan 23, 2010 at 04:02:05PM -0200, Marcelo Tosatti wrote:
> Izik, is this still needed? 
> From: Izik Eidus <ieidus at redhat.com>
> The vbe was not registered as reserved memory, and therefore windows was
> able to try to map pci devices into this address range.
> Signed-off-by: Marcelo Tosatti <mtosatti at redhat.com>

It is not normal to add e820 entries for device memory.  Also, it is
not normal for a BIOS to add special mappings for video cards (how
would it know what needed to be mapped).  One exception to this would
be machines with built-in video adapters where the video ram is shared
with system ram - however, in that case the memory area would almost
certainly be at the end of ram and not at a fixed location.

So, in general, this looks like a hack for VBE - can't we just fix
this in the VBE code instead of adding it to the BIOS?


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