[Xorg] Non-fb video driver

[Stanislaw Skowronek]

Hello!

I would like to make a SGI Octane (ImpactSR) X driver. The problem with
this device is that it is a pure graphics pipeline, i.e. there is no
directly mapped access to the framebuffer.

Accessing the framebuffer is a rather intricate process involving setup of
about 20 registers and DMA, so "just copy a virtual fb to screen" would be
too slow.

However, I can draw accelerated rectangles, pixmaps, lines, polygons (I
haven't quite worked the stipple out as yet), alpha blending, gradients
et al. And acceleration on this card is, well, SGI standard :)

How does one write a driver for a monster like this: no fb, good accel?

Stanislaw Skowronek

--<=>--
  "You're not as old as the trees, not as young as the leaves.
   Not as free as the breeze, not as open as the seas."