[yocto] meta-baryon flexibility

[Joshua Lock]

On 18/07/12 04:40, James Abernathy wrote:
> On Tue, Jul 17, 2012 at 6:19 PM, Joshua Lock <josh at linux.intel.com
> <mailto:josh at linux.intel.com>> wrote:
>
>
>     On Tue, 2012-07-17 at 15:24 -0400, Jim Abernathy wrote:
>      > In an effort to explore how independent a layer could be to the
>      > underlying hardware, I took the meta-baryon NAS layer and got it
>     built
>      > from master using the n450 BSP.  With that working I decided to
>     replace
>      > the n450 with sugarbay.  While the n450 can support X11 and sato,
>     it was
>      > not generated by design in the baryon build.
>      >
>      > However, when I changed to sugarbay, the build stops because X11 is
>      > needed.  To get around this I had to comment out some things in the
>      > conf/machine/sugarbay.conf file in the BSP.
>      >
>      >
>      > #XSERVER ?= "${XSERVER_IA32_BASE} \
>      > #           ${XSERVER_IA32_EXT} \
>      > #           ${XSERVER_IA32_I965} \
>      > #           "
>      >
>      > #VA_FEATURES ?= "gst-va-intel va-intel"
>      >
>      > #MACHINE_EXTRA_RRECOMMENDS += "${VA_FEATURES}"
>      >
>      > Why didn't I have to do this in the n450??
>
>     The key piece is the MACHINE_EXTRA_RRECOMMENDS, which is telling Poky to
>     recommend the gst-va-intel and va-intel recipes when building this
>     machine.
>
>     RRECOMMENDS are automatically installed as a dependency (in this case,
>     of task-machine-base, see task-base.bbclass) but can be removed without
>     causing the package which pulled it in to be removed (see the Poky
>     reference manual glossary on *_RRECOMMENDS).
>
>     http://www.yoctoproject.org/docs/current/poky-ref-manual/poky-ref-manual.html
>
>     I'd suggest the RRECOMMENDS actually be added at a more granular level
>     than the machine. Perhaps you could file a bug against the BSP?
>
> So if I understand this, it would be better for one of the image.bb
> <http://image.bb> files that focused on media to include this particular
> RRECOMMENDS statement.  That way others not interested in media and
> graphic could still use the BSP unchanged.

Arguably, yes. But (devil's advocate) what about image recipes which 
aren't part of the core? i.e. if you've been using a different board to 
develop a custom image and then switch to using the sugarbay wouldn't 
you want the accelerated video to "just work"?

I'd suggest a possible solution would be to define an opt-in 
IMAGE_FEATURES[1][2] for multimedia which the sugarbay BSP can add these 
recipes to.

Joshua

1. 
http://www.yoctoproject.org/docs/current/poky-ref-manual/poky-ref-manual.html#var-IMAGE_FEATURES
2. 
http://www.yoctoproject.org/docs/current/poky-ref-manual/poky-ref-manual.html#ref-features-image
-- 
Joshua Lock
         Yocto Project
         Intel Open Source Technology Centre