X11 drivers for SoCs

[Robert Swindells <rjs%fdy2.co.uk@localhost>]

I have been trying to work out the best way to add some accelerated
X11 support for the AllWinner ARM SoCs but the possible solutions
may be useful for things like the CI20 MIPS SoC too.

The GPUs on them are undocumented but several SoCs also have 2d and
video hardware that is documented.

There is a Linux driver xf86-video-fbturbo that is derived from the
unaccelerated xf86-video-fbdev driver. It adds support for HW cursors,
video and the hooks for the Mali GPU when run on AllWinner ARM SoCs.

The HW cursor code duplicates what we have in wsdisplay(4) in the
kernel.

I don't know whether we need to think about hooks for the Mali (or
PowerVR) 3D GPUs. If we don't think we will ever use these GPUs then
maybe don't need DRI either.

The options that I can think of are:

      Add NetBSD conditional code to xf86-video-fbturbo.

      Fork xf86-video-wsfb for each SoC and add video and 2d support.

      Add conditional code to xf86-video-wsfb.

Thoughts ?

Robert Swindells