Re: [Qemu-devel] [PATCH 0/3] switch to seavgabios

[Gerd Hoffmann]

On 04/17/12 13:40, malc wrote:
> On Tue, 17 Apr 2012, Gerd Hoffmann wrote:
> 
>>   Hi,
>>
>> This patch series switches the vgabios binaries shipped by qemu from the
>> lgpl'ed vgabios to the seabios version.
>>
>> There should be no guest-visible changes (especially no regressions) in
>> theory.  The only known (and intentional) exception is the vesa 2.0
>> protected mode interface which is not implemented by the seavgabios.
> 
> What's the reason for it not being done?

In summary: Nontrivial effort for questionable gains.

First, the lgpl'ed vgabios provides the vesa pmi for the bochs interface
(-vga std) only, for the cirrus it is not available.

=> It can't be a critical feature if our default vga is not supported.

Second, the display panning via vesa pmi was broken in qemu for three
years(!) and nobody noticed.  The linux kernel's vesafb can use the vesa
pmi, it is disabled by default though due to bioses tending to be buggy.
 I'm not aware of other users.

=> Is this actually used by anyone?  Seems not ...

Also it can be used by 32bit guests only while the x86 world moves to
64bit ...

cheers,
  Gerd