Re: X.org and A1200 AGA Graphics

[David Brownlee <abs%absd.org@localhost>]

On Sun, 17 Oct 2021 at 18:34, Jukka Andberg <jukka.andberg%welho.com@localhost> wrote:
>
> David Brownlee wrote Sat, 16 Oct 2021 21:16:21 +0100:
>
> > netbsd-9 builds of the WSCONS kernel (from nyftp.netbsd.org) include
> > it from a day or so ago, and it will be in NetBSD 9.3 and 10.0
> >
> > It would be an interesting project to try to build a kernel which can
> > provide the ite interfaces used by the X11R6 x11 drivers as well as
> > WSCONS. That would allow the GENERIC kernel to use wscons (for all the
> > console styling benefits and Xwsfb usage), while still allowing X11R6
> > X binaries to continue to run. Of course the real challenge after that
> > would be to look to port one or more of the X11R6 X servers to modern
> > Xorg :-p
>
> As far as I can remember, ite was not needed for the old X server and
> it was possible to run it with WSCONS kernel (at least with native graphics).

Urk, shows my lack of understanding there - thanks

So, if that's still true, that removes a blocker from switching amiga
to WSCONS kernels by default...

On a related note I had a brief chat with macallan@ and he suggested
that one approach for an X11 driver would be to write an EXA driver
which (if my understanding is correct) would essentially need to be
able to do three things, with appropriate conversion between X PixMap
and planar data
- Copy rectangle
- Solid fill
- UploadToScreen
- DownloadFromScreen

There seems to be a scarcity of docs on writing an EXA driver - the
best information appears to be in the .h file (which is definitely a
good place to have useful information!)
https://nxr.netbsd.org/xref/xsrc/external/mit/xorg-server/dist/exa/exa.h

There are a fair number of existing EXA using drivers in tree
https://nxr.netbsd.org/source/s?refs=exaDriverInit&project=xsrc

I'm assuming it would be possible to take one of the XAA using drivers
and convert to EXA, its just... quite some work :/

David