[Nouveau] Porting nouveau/ttm/drm to FreeBSD/OpenSolaris

[Dave Airlie]

2010/1/23 "C. Bergström" <cbergstrom at pathscale.com>:
> Hi all,
>
> One of our (PathScale) engineers is planning to port nouveau and all
> dependencies to OpenSolaris.  We have two routes we can take and would
> like some feedback from the community.
>
> 1) There's an existing drm without ttm that was done by the FreeBSD
> developers.  Would anyone from the fbsd team like to go over some of the
> trouble they've had in porting ttm?
>
> 2) The engineer doing the work is much more familiar with Intel GEM and
> has said the following (which I don't honestly know if it's true or not)
>    a. Intel GEM surely will continue to be supported
>    b. It's already available on OpenSolaris
>    c. More portable than ttm
>    d. GEM doesn't have support for nvidia cards and is missing some
> important features.  (For OpenSolaris he says those can be added and is
> less effort than porting ttm)
>    e. Is probably better performance compared to ttm

I expect your engineer hasn't quite grasped the differences between GEM and TTM.

Intel's GEM code is nearly all contained in the driver, making all the
code generic
and adding the VRAM support stuff to it, is definitely a lot more work
than porting TTM.

There is a reason TTM uses Linux kernel data structures, if your OS
cannot provide
these structures then it will probably require some TTM reworking,
however you don't
need every feature of TTM to get a port mostly working, like swapping
etc are unnecessary
for the initial port.

Dave.