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Having do_rm_work depend on do_build had one major disadvantage: do_build depends on the do_build of other recipes, to ensure that runtime dependencies also get built. The effect is that when work on a recipe is complete and it could get cleaned up, do_rm_work still doesn't run because it waits for those other recipes, thus leading to more temporary disk space usage than really needed. The right solution is to inject do_rm_work before do_build and after all tasks of the recipe. Achieving that depends on the new bitbake bb.event.RecipeTaskPreProcess and bb.build.preceedtask(). It can't just run in an anonymous function, because other anonymous functions that run later may add more tasks. There's still such a potential conflict when some future RecipeTaskPreProcess event handler also wants to change task dependencies, but that's not a problem now. Should it ever occur, the two handlers will have to know about each other and cooperate to resolve the conflict. Benchmarking (see "rm_work + pybootchart enhancements" on the OE-core mailing list) showed that builds with the modified rm_work.bbclass were both faster (albeit not by much) and required considerably less disk space (14230MiB instead of 18740MiB for core-image-sato). Interestingly enough, builds with rm_work.bbclass were also faster than those without. (From OE-Core rev: 936179754c8d0f98e1196ddc6796fdfd72c0c3b4) Signed-off-by: Patrick Ohly <patrick.ohly@intel.com> Signed-off-by: Ross Burton <ross.burton@intel.com> Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
Poky
Poky is an integration of various components to form a complete prepackaged build system and development environment. It features support for building customised embedded device style images. There are reference demo images featuring a X11/Matchbox/GTK themed UI called Sato. The system supports cross-architecture application development using QEMU emulation and a standalone toolchain and SDK with IDE integration.
Additional information on the specifics of hardware that Poky supports is available in README.hardware. Further hardware support can easily be added in the form of layers which extend the systems capabilities in a modular way.
As an integration layer Poky consists of several upstream projects such as BitBake, OpenEmbedded-Core, Yocto documentation and various sources of information e.g. for the hardware support. Poky is in turn a component of the Yocto Project.
The Yocto Project has extensive documentation about the system including a reference manual which can be found at: http://yoctoproject.org/documentation
OpenEmbedded-Core is a layer containing the core metadata for current versions of OpenEmbedded. It is distro-less (can build a functional image with DISTRO = "nodistro") and contains only emulated machine support.
For information about OpenEmbedded, see the OpenEmbedded website: http://www.openembedded.org/
Where to Send Patches
As Poky is an integration repository (built using a tool called combo-layer), patches against the various components should be sent to their respective upstreams:
bitbake: Git repository: http://git.openembedded.org/bitbake/ Mailing list: bitbake-devel@lists.openembedded.org
documentation: Git repository: http://git.yoctoproject.org/cgit/cgit.cgi/yocto-docs/ Mailing list: yocto@yoctoproject.org
meta-poky, meta-yocto-bsp: Git repository: http://git.yoctoproject.org/cgit/cgit.cgi/meta-yocto(-bsp) Mailing list: poky@yoctoproject.org
Everything else should be sent to the OpenEmbedded Core mailing list. If in doubt, check the oe-core git repository for the content you intend to modify. Before sending, be sure the patches apply cleanly to the current oe-core git repository.
Git repository: http://git.openembedded.org/openembedded-core/
Mailing list: openembedded-core@lists.openembedded.org
Note: The scripts directory should be treated with extra care as it is a mix of oe-core and poky-specific files.