Re: [Qemu-devel] gtk UI doesn't correctly byte swap 32-bit framebuffer on qemu-system-ppc little-endian host

[Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>]

On 04/06/13 08:50, Gerd Hoffmann wrote:

> On 06/04/13 01:19, Anthony Liguori wrote:
>> Mark Cave-Ayland<mark.cave-ayland@ilande.co.uk>  writes:
>>
>>> Hi all,
>>>
>>> I've just been testing some more OpenBIOS images with the new gtk UI and
>>> found that if you specify a 32-bit depth framebuffer on qemu-system-ppc
>>> running on a little-endian host then the RGB ->  BGR byteswap doesn't
>>> take place.
>>>
>>> Good:
>>> ./qemu-system-ppc -g 1024x768x32 -vnc :1
>>> ./qemu-system-ppc -g 1024x768x32 -sdl
>>>
>>> Bad:
>>> ./qemu-system-ppc -g 1024x768x32
>>
>> cairo has a pretty limited number of modes that it supports.
>>
>> I guess we could use pixman to do the conversion.  Gerd, is that the
>> right approach?
>
> Hmm, looks like we can't pass pixman format values to cairo, even though
> cairo uses pixman under the hood.  So, yes, we must convert and using
> pixman is the easiest way to get the job done.
>
>> Is there a way I can force the display API to do the
>> conversion for me?
>
> No, but asking pixman to do it is easy, see attached patch.

Hi Gerd,

A quick test of the patch shows that it solves the problem here - thanks 
a lot!


ATB,

Mark.