Re: Question about NV18 and GBM library.

[Pekka Paalanen <pq-X3B1VOXEql0@public.gmane.org>]

On Fri, 27 Apr 2012 21:11:35 -0300
gabriel muguerza <glmcabra-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> wrote:

> On Thu, Apr 26, 2012 at 2:41 PM, Lucas Stach <dev-8ppwABl0HbeELgA04lAiVw@public.gmane.org>
> wrote:
> 
> > Am Mittwoch, den 25.04.2012, 12:34 -0300 schrieb gabriel
> > muguerza:
> >
> > > Hi,
> > >
> > > I have a geforce 4mx 440 agp 8x, and I'm trying to use the GBM
> > > library,
> > > (as jbarnes in:
> > > http://virtuousgeek.org/blog/index.php/jbarnes/2011/10/
> > > and David Hermann in KMSCON:
> > > https://github.com/dvdhrm/kmscon), without success.
> > >
> > > when I try to create a gbm_device, I get: (below the code.)
> > >
> > > nouveau_drm_screen_create: unknown chipset nv18
> > > dri_init_screen_helper: failed to create pipe_screen
> > > loaded /usr/lib/gbm/pipe_nouveau.so
> > > nouveau_drm_screen_create: unknown chipset nv18
> > > failed to load driver: nouveau
> > >
> > >
> > > My question is:
> > > Is this not supported by the driver?,
> > > It's a GBM problem? or am I doing something wrong?
> > >
> > Yep, you are right, your GPU is simply too old. GBM is only
> > supported with the nouveau gallium drivers, which start with
> > the nv30 generation. The nouveau_vieux driver for your card
> > does not support GBM.
> >
> > -- Lucas
> >
> >
> Ok, thank you.
> (and nor Wayland works, I guess).

You mean Weston. Weston uses GL ES 2, which relies on shaders and
does not have a fixed-function pipeline. NV18 AFAIK does not have
any shader capability, but only a fixed-function pipeline. This
is another big obstacle.

Wayland could be made to work, but it would need some work:
- writing a Wayland server on fixed-function OpenGL
- writing the infrastructure for using EGL/OpenGL on the
  framebuffer offered by DRM

and maybe something else I overlooked.

-- 
Pekka Paalanen
http://www.iki.fi/pq/