[oe] [Bitbake-dev] A new bitbake extension: .bbappend files

[Chris Larson]

On Tue, Aug 3, 2010 at 6:26 AM, Richard Purdie <rpurdie at rpsys.net> wrote:

> On Fri, 2010-07-16 at 15:25 +0100, Richard Purdie wrote:
> > Whilst our layers mechanism, is great it does have a drawback which has
> > bugged me for a while. If you have a recipe like pointercal which has
> > machine specific information in it and you have your new machine code in
> > a layer, how do you add a pointercal file for your machine?
> >
> > Answer is you copy the whole pointercal recipe and files into your
> > layer, then add the single file for your machine. To me this is ugly,
> > ugly, ugly. We hate code duplication and as soon as you create two
> > copies of the same information, we've failed.
> >
> > So how could we do this better? Somehow we need to say that a given
> > directory X has some information which should be merged with the
> > original recipe. I've thought through several different ways of doing
> > this and the best solution I found was "bbappend".
> >
> > The idea is that if bitbake finds any X.bbappend files, when it loads
> > X.bb, it will also include these files after it parses the base .bb file
> > (but before finalise and the anonymous methods run). This means that
> > the .bbappend file can poke around and do whatever it might want to the
> > recipe to customise it.
> >
> > I went ahead and tried it out as its quite simple to code this in
> > bitbake. I liked the result enough I've already merged this into Poky:
> >
> >
> http://git.pokylinux.org/cgit.cgi/poky/commit/?id=63e6ba85677b8aa9f4cf9942a1fccbb8a8c72660
> >
> > I'm proposing to push it to bitbake master if there are no serious
> > objections.
>
> Whilst I think there were some initial concerns the consensus seemed to
> be that this was a good thing to have in bitbake, its something that has
> been on the feature wishlist since day one so I've merged the patch into
> bitbake master.
>

Glad to hear it, nice work putting it together.
-- 
Christopher Larson
clarson at kergoth dot com
Founder - BitBake, OpenEmbedded, OpenZaurus
Maintainer - Tslib
Senior Software Engineer, Mentor Graphics