[Dri-devel] Savage and nVidia DRI drivers

[F. <j_r...@ya...>]

I've just started two branches on DRI CVS, savage-0-0-1-branch and
nv-0-0-1-branch, for the development of drivers for the Savage chips (in
particular the Savage4) and the older nVidia chips (such as the Riva
TNT Vanta). 

Both these cards are very old by now and the interest of a
DRI driver diminishes every day - including mine -, so I've decided that
it should be now or never. I chose now, even though my PhD is
demanding more and more time from me. This endeavor has no time plan.
Actually my main interest is the learning experience of making a DRI driver
from ground up - experience which I plan to share by writing a thorough
HOWTO describing the steps and explaining the working of a driver from
the high-level structure to the low-level implementation details. (You
already can see the very first writings on http://dri.sf.net/doc/howto/)

I have the Savage4 specifications (BCI documentation still missing), 
not thanks to S3 of whom I'm waiting for a final answer until today. I
don't have any documentation from nVidia - I confess I haven't contact
them yet but the impression I have is that no documentation is made
available. There is support for both these chips in the Utah-GLX
project. Also the proprietary nVidia Linux drivers come with some source
code (which was also the basis for the Utah-GLX drivers).

The plan is to:
1. Make the existing 2D drivers DRI aware.
2. Make a simple DRM which dispatches buffers to the card trhough MMIO
3. Make the Mesa driver, hopefully reusing some of the Utah-GLX code
(but probably 
4. Implement proper DMA in the kernel.

The nVidia driver will follow the Savage a little from behind to avoid
making the same mistakes twice. In the beginning it will be mainly
coding - I won't make any debugging with the cards myself until the
Mach64 is finished and in the trunk (hopefully it won't take long, but
it's not done yet).

People which are interested in having these drivers see the light of day
(I know that the Savage chip is common on laptops and AFAIK there no
nVidia proprietary drivers for non-Linux non-x86 platforms) are surely 
welcome to help, as they can turn this small project of mine in something 
definite.

I know that Max Lingua has better documentation for the Savage4 than I
and he even has the beginnings of a driver but long time I don't hear
from him, and I already had asked him to commit whatever he had to cvs
much before with no answer to that.

José Fonseca