Bi-Endian issue

Michel Dänzer michel at
Wed Nov 29 00:31:07 PST 2006

On Tue, 2006-11-28 at 18:26 +0100, Laurent Lagrange wrote: 
> I am writing a DDX driver for my graphics card and I have endian problems. I
> work on a powerpc (big endian) with a pci graphics card (little endian
> framebuffer). My board doesn't have endian conversion flags and this leads
> to bad colors.
> Is there a way to describe in my driver the bi-endian configuration ? How
> can I correctly handle byte swapping, without patching (I use
> 6.8.2 and I can't recompile it).

I'm afraid the only option is to use a shadow framebuffer in system
memory and fix the byte order on copying the data to the real
framebuffer. This will unfortunately prevent hardware acceleration for
rendering but not for things like hardware cursor or video overlay.

Earthling Michel Dänzer           |
Libre software enthusiast         |          Debian, X and DRI developer

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