[Xorg-driver-geode] GX1

[Mart Raudsepp]

On T, 2014-07-22 at 18:00 +0200, Marc Gilet wrote:
> Hello,
> I'm new to the list.
> I own 2 thinclients (Fujitsu siemens Futro B100), with a GX1 CPU, and a 
> CS5530A video chip.

CS5530A is the companion chip. The video bits are inside the CPU die.

> I've seen on the Geode driver site, that help would be appreciated for 
> the developpment of the GX1 part.
> If anyone needs help, I can send you one of my thinclients, or even test 
> things for you.

Writing/contributing dedicated hardware accelerating driver code is
probably pointless for GX1 unless you are able to do software fallbacks
in memory areas where gfx hardware acceleration calls can access it.
That is currently not the case for any geode driver, but may
theoretically be possible. Even LX hardware isn't fully UMA a la Intel
integrated graphics - hardware rendering destination must be in the
sliced out video memory part. Possibly also source pixmaps, but can't
remember 100% for sure on that.

Best to just use a generic driver, which does all rendering in CPU and
has shadowfb support. That driver though may also be the GX1 driver, but
with acceleration disabled, and made to work against a xserver without
XAA.

That, or you limit yourself to pretty much zero modern kind of drawing
with anti-aliases and such (not using XRENDER extension). Then you might
be able to benefit from 2D hardware acceleration code. Maybe with Motif
apps or something.

Efforts other than perhaps getting a software rendering driver to
properly work (and add or brush up rudimentary xvideo support) seem like
a waste of time. It's very old hardware. I'd say the same about LX
parts, but those are still somewhat useful, and probably still in the
hands of millions of kids via OLPC XO-1.

There is full documentation available from AMD for Geode family of
hardware, though I haven't personally really looked at GX1 docs. LX docs
are pretty complete, GX2 looked sound too. Haven't really looked at GX1
docs.


Mart