[meta-intel] [OE-core] [Patch-v2 1/1] mesa: avoid unnecessary rerunning of tasks

[Otavio Salvador]

On Fri, Sep 6, 2013 at 3:36 PM, Burton, Ross <ross.burton at intel.com> wrote:
> On 5 September 2013 09:33, Richard Purdie
> <richard.purdie at linuxfoundation.org> wrote:
>> I'd also appreciate someone (Ross maybe?) confirming that if we build
>> application A against mesa, then change over to a machine that uses emgd
>> and swizzle the libs around in the sysroot, do we need to recompile the
>> app? This approach is assuming we do not need to do that. If we do,
>> there is a different approach we need to take.
>
> So what's happening is that we're revising the original OpenGL policy
> that I posted in October last year:
>
> http://lists.openembedded.org/pipermail/openembedded-core/2012-October/070122.html
>
> tl;dr: I proposed that 1) we rename all GL packages so they identify
> their provider (ie libgl-mesa, we do that), 2) no dependencies on
> specific GL implementations, 3) only Mesa stages.  The theory was that
> Mesa can be considered a canonical implementation of the various GL
> platforms and that we can *build* against Mesa but *install* the right
> hardware-specific GL implementation into the images.
>
> Nice in theory and it should work, but sadly that isn't the case - the
> thread has more details.  Short version is that some applications *do*
> rely on specific GL headers, so you can't just swap them around in
> reality.
>
> Maybe it is time to have a mesa-gl recipe alongside mesa that *just*
> builds the GL libraries.  EMGD can depend on it for the driver modules
> it installs, and presumably other vendors with binary drivers can
> install it for the software rendering/GLX support (Otavio etc, please
> step in here!).

Yes; we have both situations at Freescale ARM BSP.

For the AMD GPU binaries, which are used in MX5 SoCs we *just* use
mesa GL and do software rendering. For Vivante GPU binaries, used for
MX6, we use mesa GL *headers* but Vivante provides a libGL binary.

-- 
Otavio Salvador                             O.S. Systems
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