[yocto] dynamic-layers?

[Nicolas Dechesne]

On Wed, May 24, 2017 at 12:30 PM, Takashi Matsuzawa <tmatsuzawa at xevo.com> wrote:
> Hello, Yocto.
> I am a bit confused with dynamic-layers included in some of the recent
> layers in various BSPs.
>
> e.g.
>
> https://github.com/Freescale/meta-freescale/blob/master/conf/layer.conf
>
>># The .bbappend and .bb files are included if the respective layer
>># collection is available.
>>BBFILES += "${@'
>> '.join('${LAYERDIR}/dynamic-layers/%s/recipes*/*/*.bbappend' % layer \
>>               for layer in BBFILE_COLLECTIONS.split())}"
>>BBFILES += "${@' '.join('${LAYERDIR}/dynamic-layers/%s/recipes*/*/*.bb' %
>> layer \
>>               for layer in BBFILE_COLLECTIONS.split())}"
>
> In meta-freescale/dynamic-layers, there are browser-layer, efi-layer, etc.
> for conditional inclusion.
> And I think they are included only their names (browser-layer, etc.) are
> BBFILE_COLLECIONS.
>
> Question here is, who will be adding 'browser-layer' to BBFILE_COLLECTIONS
> when I want to include browser-layer in my build.
>
> Is it something to be done in my local.conf or customized distro conf file?

what that means is that recipe from the dynamic-layers/<layer> will be
parsed/added *only if* <layer> is already added in your build
environment. e.g. if you have meta-qt5 in BBLAYERS in
<build>/conf/bblayers.conf, then the recipes from
"dynamic-layers/qt5-layer" are used as well.

This is mostly to allow a BSP layer to be used with as many
combinations of layers as possible.