[OE-core] How to override bitbake.conf defaults in layers properly?

[Koen Kooi]

Hi,

I spent the morning backporting kernel.bbclass changes to the meta-oe denzil branch and I've run into a problem: STAGING_KERNEL_DIR needs to change to match the updated class. In this specific case I can work with Scott and Eric to see if those kernel.bbclass changes can go into oe-core and meta-oe at the same time. That's something for next week :) In the meantime I'm wondering what the best way is to fix this in cases where you can't influence oe-core.

I see a number of options:

1) set STAGING_KERNEL_DIR in layer.conf. I don't know if that's parsed before or after bitbake.conf, but it feels like the cleanest solution
2) set it in $DISTRO.conf. Easy enough, breaks every other distro out there
3) copy over bitbake.conf. Might work with some BBPATH magic, but in the end doesn't scale when >1 layers do it
4) provide a custom denzil branch of oe-core, another easy way, but very antisocial

I'm not into the layering details enough to see what the effects of 1) would be, could the knowledgable people chime in please?

regards,

Koen