psplash: allow building multiple splash executables
Adds a SPLASH_IMAGES variable which you can set to include one or more
images (listed in URI form as they would appear in SRC_URI), and an
executable will be built for each one, with each executable packaged
separately and managed at runtime using the alternatives system. An
optional "outsuffix" parameter can be used to specify the suffix for the
executable/package name. The images themselves can either be
pre-processed image header files (produced using the
make-image-header.sh script that comes with psplash), or alternatively
you can provide a .png and it will be converted using the aforementioned
script on the fly (at the expense of requiring gdk-pixbuf-native at
build time).
This has been implemented in such a way that you can still just provide
your own psplash-poky-img.h in a bbappend and it will work as it did
before; the only change being that the psplash executable is provided
in a "psplash-default" package rather than in the main psplash package,
and an RRECOMMENDS is set up to ensure psplash-default gets pulled in
(if you specify your own file or change the outsuffix you will need to
either install it separately yourself or add your own RRECOMMENDS
relationship.)
Implements [YOCTO #1947]
Signed-off-by: Paul Eggleton <paul.eggleton@linux.intel.com> Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
