218b81acb6
This patch adds the notion of supporting multiple configurations within a single build. To enable it, set a line in local.conf like: BBMULTICONFIG = "configA configB configC" This would tell bitbake that before it parses the base configuration, it should load conf/configA.conf and so on for each different configuration. These would contain lines like: MACHINE = "A" or other variables which can be set which can be built in the same build directory (or change TMPDIR not to conflict). One downside I've already discovered is that if we want to inherit this file right at the start of parsing, the only place you can put the configurations is in "cwd", since BBPATH isn't constructed until the layers are parsed and therefore using it as a preconf file isn't possible unless its located there. Execution of these targets takes the form "bitbake multiconfig:configA:core-image-minimal core-image-sato" so similar to our virtclass approach for native/nativesdk/multilib using BBCLASSEXTEND. Implementation wise, the implication is that instead of tasks being uniquely referenced with "recipename/fn:task" it now needs to be "configuration:recipename:task". We already started using "virtual" filenames for recipes when we implemented BBCLASSEXTEND and this patch adds a new prefix to these, "multiconfig:<configname>:" and hence avoid changes to a large part of the codebase thanks to this. databuilder has an internal array of data stores and uses the right one depending on the supplied virtual filename. That trick allows us to use the existing parsing code including the multithreading mostly unchanged as well as most of the cache code. For recipecache, we end up with a dict of these accessed by multiconfig (mc). taskdata and runqueue can only cope with one recipecache so for taskdata, we pass in each recipecache and have it compute the result and end up with an array of taskdatas. We can only have one runqueue so there extensive changes there. This initial implementation has some drawbacks: a) There are no inter-multi-configuration dependencies as yet b) There are no sstate optimisations. This means if the build uses the same object twice in say two different TMPDIRs, it will either load from an existing sstate cache at the start or build it twice. We can then in due course look at ways in which it would only build it once and then reuse it. This will likely need significant changes to the way sstate currently works to make that possible. (Bitbake rev: 5287991691578825c847bac2368e9b51c0ede3f0) Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org> |
||
|---|---|---|
| bitbake | ||
| documentation | ||
| meta | ||
| meta-poky | ||
| meta-selftest | ||
| meta-skeleton | ||
| meta-yocto/conf | ||
| meta-yocto-bsp | ||
| scripts | ||
| .gitignore | ||
| .templateconf | ||
| LICENSE | ||
| README | ||
| README.hardware | ||
| oe-init-build-env | ||
| oe-init-build-env-memres | ||
README
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.