From: Jeff Garzik <jgarzik@pobox.com>
  To  : ggi-develop@eskimo.com
  Date: Thu, 12 Aug 1999 17:58:52 -0400

Re: GGI and XFree86 and stuff

"Jon M. Taylor" wrote:
>         Sure, since Trio and Virge also have STREAMS.  The STREAMS is
> Savage4 is mostly the same.  STREAMS basically gives you another hardware
> viewport which can address its own linear framebuffer region and can be
> sized and positioned independently of the primary framebuffer stream.  It

Could it be used for DGA-in-a-window?


>         Actually I have permission to release binaries now, but I haven't
> run across anyone besides myself who uses KGI and has a Savage4.  Also
> the 3D accel performance is atrocious right now - since ping-pong buffers

Why not simply allocate one or two DMA buffers and go with a simple
scheme until PP bufs arrive.  You can use the G200-GLX technique of
reserving memory on bootup specifically for KGIcon, for example
'mem=120M' if you have 128MB of RAM.  Then you have a guaranteed 8MB for
KGIcon to play with.  Anything should be faster than ioctl...

FWIW I may crib a lot of your 3D code once s3lib's 2D capabilities are
solid.  s3lib is the Borg  ;-)


> > >         Hm.  Well, an SUIDKGI-XFree86 4.0 wrapper layer will instantly
> > > give XFree86 4.0 full accelerated support for pretty much all S3 chipsets
> > > ever made, including Savage4 (my driver), so I basically consider this a
> > > nonproblem.  You would be much better served by writing that wrapper layer
> > > instead of S3lib, IMHO.  Much less work for much more gain.
> >
> > I think the Trio driver may need work too, I haven't tested it.
> 
>         Well, I wrote it and unless someone has improved it a lot since
> then it does indeed need work.  Backporting fixes from Jos' ViRGE driver
> would probably take care of the bulk of it.

Or migrating the logic into s3lib, and having a single generic s3lib GGI
driver eventually...


>         No, but all the major _families_ are supported, and IIRC all the
> Pre-Trio chipsets and ramdacs are fully supported.  The Trio64V2,
> Aurora64, etc are special cases of the existing drivers and would be easy
> to add support for.

I am not sure the older 801/805's are supported, but haven't looked
closely.  All the RAMDACs look to be supported already.  Some of the
extra code to support 64V2 and A64 should be in s3lib already, as I
stole it from the XF86 v3 server.


> > On a related note -- is there any way to get monitor specs out of S3
> > cards without using BIOS calls?
> 
>         VESA DDC.  I have specs as part of the Savage4 docs, but I don't
> recall if they are otherwise publically accessible.

AFAIK they are not.

Is DDC possible w/out BIOS?  For example, will DDC code work on Alpha,
PPC, etc.?  And is there generic DDC in GGI?  I know there is a bit in
XF86 but I haven't looked at it.

Regards,

	Jeff




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Entropy requires no maintenance.
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