Wayland in N900

[Sami Kyöstilä]

On Friday 17 December 2010 20:28:34 ext Esa Törmikoski wrote:
> On 12/16/2010 11:06 AM, Sami Kyöstilä wrote:
> > Hi,
> > 
> > On Wednesday 15 December 2010 20:43:13 ext Kristian Høgsberg wrote:
> >> On Wed, Dec 15, 2010 at 1:13 PM, Esa Törmikoski
> >> 
> >> <esa.tormikoski at nomovok.com>  wrote:
> >>> Looks like I'm trying to get Wayland running in Nokia N900. Is there
> >>> any experiences about that already? All help and estimations about
> >>> work amount is welcome.
> >> 
> >> Hi,
> >> 
> >> I don't know that anybody has tried that.  The big unknown is how to
> >> integrate with the graphics drivers on the device - the GL stack and
> >> modesetting.  And the GL stack has to provide a way for processes to
> >> share 2d pixel buffers (for example an EGLImage).  I've never worked
> >> with the n900 platform, so I don't know, but a good first step towards
> >> Wayland would be to try to run EGL+GLES2 on the framebuffer or such.
> > 
> > You can run the graphics stack on N900 on the framebuffer without X, but
> > the problem is there's no way to share EGLImages across processes in
> > that configuration. That is, the graphics driver does not support
> > EGL_MESA_drm_image or any equivalent.
> > 
> > With X, sharing EGLImages between processes is possible by backing them
> > with pixmaps. So in theory you could run Wayland on N900 by using X for
> > resource management -- but that would mostly defeat the purpose.
> > 
> >> Kristian
> > 
> > - Sami
> 
> Doomed right in the start :( Need to find some other topic for thesis
> work then if this is impossible..

Yeah, all the bits that would need to be modified for this are in the closed 
source graphics driver. Of course, if you're only doing this for research and 
aren't looking for an optimal system, you could implement buffer sharing with 
an explicit userspace copy (i.e., glReadPixels). The performance will be 
abysmal, though.

> -- Esa

- Sami