On Sat, Oct 12, 2013 at 4:24 AM, Robert P. J. Day <rpjday@crashcourse.ca>wrote:

>   wait, i think i might have just answered my own question ... see
> below ...
>
> On Sat, 12 Oct 2013, Robert P. J. Day wrote:
>
> >   just to make sure i'm not missing anything subtle, i know you can
> > add a "packagegroup" to your build using IMAGE_FEATURES, but given
> > that there are *lots* more packagegroup recipe files in oe-core than
> > have corresponding PACKAGE_GROUP_* definitions in core-image.bbclass:
> >
> > $ find . -name "packagegroup*bb"
> > ./recipes-gnome/packagegroups/
> packagegroup-core-standalone-gmae-sdk-target.bb
> > ./recipes-gnome/packagegroups/packagegroup-toolset-native.bb
> > ./recipes-gnome/packagegroups/packagegroup-core-sdk-gmae.bb
> > ./recipes-devtools/packagegroups/packagegroup-core-device-devel.bb
> > ./recipes-core/packagegroups/packagegroup-cross-canadian.bb
> > ./recipes-core/packagegroups/packagegroup-core-sdk.bb
> > ./recipes-core/packagegroups/packagegroup-core-ssh-openssh.bb
> > ./recipes-core/packagegroups/packagegroup-core-standalone-sdk-target.bb
> > ./recipes-core/packagegroups/packagegroup-core-boot.bb
> > ./recipes-core/packagegroups/packagegroup-core-tools-profile.bb
> > ./recipes-core/packagegroups/packagegroup-self-hosted.bb
> > ./recipes-core/packagegroups/packagegroup-core-ssh-dropbear.bb
> > ./recipes-core/packagegroups/packagegroup-core-tools-debug.bb
> > ./recipes-core/packagegroups/packagegroup-core-buildessential.bb
> > ./recipes-core/packagegroups/packagegroup-core-tools-testapps.bb
> > ./recipes-core/packagegroups/packagegroup-base.bb
> > ./recipes-core/packagegroups/packagegroup-core-nfs.bb
> > ./recipes-core/packagegroups/packagegroup-core-eclipse-debug.bb
> > ./recipes-graphics/packagegroups/packagegroup-core-x11.bb
> > ./recipes-graphics/packagegroups/packagegroup-core-x11-base.bb
> > ./recipes-graphics/packagegroups/packagegroup-core-x11-xserver.bb
> > ./recipes-graphics/packagegroups/packagegroup-core-clutter.bb
> > ./recipes-graphics/packagegroups/packagegroup-core-directfb.bb
> > ./recipes-qt/packagegroups/packagegroup-qte-toolchain-target.bb
> > ./recipes-qt/packagegroups/packagegroup-core-qt4e.bb
> > ./recipes-qt/packagegroups/packagegroup-qt-toolchain-target.bb
> > ./recipes-qt/packagegroups/packagegroup-core-qt.bb
> > ./recipes-sato/packagegroups/packagegroup-core-x11-sato.bb
> > ./recipes-extended/packagegroups/packagegroup-core-lsb.bb
> > ./recipes-extended/packagegroups/packagegroup-core-basic.bb
> > $
> >
> > is it accurate to say that you can just as equivalently add the recipe
> > file directly using, say, CORE_IMAGE_EXTRA_INSTALL? is there any
> > functional difference between those two approaches?
>
>   feeling a bit sheepish if this is the answer ... i notice that
> core-image.bbclass defines:
>
>   PACKAGE_GROUP_nfs-server = "packagegroup-core-nfs-server"
>
> however, while there is no recipe file named
> "packagegroup-core-nfs-server.bb", there is one named
> "packagegroup-core-nfs.bb", which contains:
>
>   inherit packagegroup
>
>   PACKAGES = "${PN}-server"
>
> so does defining a PACKAGE_GROUP_* entry in core-image.bbclass allow
> the packagegroup definition search to examine the internals of a
> recipe file to check the definition of "PACKAGES" to find a match? as
> opposed to referring to a recipe file directly
>

PACKAGE_GROUP_<some group that can be listed in IMAGE_FEATURES> = "<a list
of binary packages, just as you'd add to IMAGE_INSTALL or
CORE_IMAGE_EXTRA_INSTALL yourself>"

That's all there is to it. packagegroup-core-nfs-server is a binary
package. PACKAGE_GROUP_nfs-server accepts lists of binary packages, not
lists of recipes.

Things got a bit more confusing once tasks got renamed to packagegroups, as
the pure data driven package grouping mechanism (PACKAGE_GROUP) already
existed at that time.
-- 
Christopher Larson
clarson at kergoth dot com
Founder - BitBake, OpenEmbedded, OpenZaurus
Maintainer - Tslib
Senior Software Engineer, Mentor Graphics