Re: Porting nouveau/ttm/drm to FreeBSD/OpenSolaris

["\"C. Bergström\"" <cbergstrom-Hl0AACgZOF5l57MIdRCFDg@public.gmane.org>]

Krzysztof Smiechowicz wrote:
> C. Bergström pisze:
>> Hi all,
>>
>
> Hi Christopher
>
>> nouveau itself should be relatively easy to port, but what 
>> information do others have with regards to the surrounding dependencies.
>
> I can give you some information my work porting the nouveau/drm/ttm to 
> AROS (http://www.aros.org/). AROS is AmigaOS clone and it's very very 
> very far in terms of API and concepts from Linux kernel so I think 
> it's a good example to talk about portability.
>
> Currently my work is only focused on 3D part, not touching the 2D part 
> at all. Generally it took me about 1,5 months of evenings to port the 
> current (sources from December 2009) nouvea/drm/ttm/libdrm/nouvea 
> gallium driver to AROS (I would call it alpha version of the port 
> though) however I have never been working with graphics or graphics 
> drivers before.
>
> In terms of portability I would rate the modules in following order 
> (starting from most portable)
>
> nouveau gallium 3D drivers
> nouveau NV0X-NV40 drm drivers
> libdrm
> nouveau "common code" (files named nouveau_XXX)
> drm "common code" (files named drm_XXX)
> nouveau NV50 drm driver
> ttm
>
> Basically the only module that does not seem to be specially written 
> with portability in mind and has a lot of Linux dependencies it ttm. I 
> implemented some of those dependencies in my AROS port (reference 
> counting, atomics, spin locks) and disabled some others (swapping 
> support, work queues)
>
> If you are interested in any specific topic, please let me know :)
1.5 months seems to be pretty fast work, but I think disabling some of 
those portions of the code probably helped.  For us we will be focusing 
only on libdrm, drm "common code" nouveau NV50 drm driver and a memory 
manager.  There also already an older port of drm to OpenSolaris so 
that's mostly a forward port.  I've heard others complain about ttm 
repeatedly and thought maybe we can rethink the problem and solve two 
things at once.  I'll have one of our engineers email you directly about 
ttm if we have specific questions.

Thanks

./C


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