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Richard Purdie
ccb2d1b481
"Incremental builds do not work well when renaming recipes or changing architecture" is a long standing issue which causes people considerable pain. We've struggled for a long time to come up with a way to generically address the problem. There are additional issues where removal of a layer caused data to continue to exist and additionally, changing DISTRO_FEATURES also caused problems in an existing TMPDIR. This patch attempts to address this by adding a mapping between stamp files and manifests. After parsing we can easily tell which stamp files are still reachable, if any manifest has a stamp that can no longer be reached, we can remove it. Since this code ties this to the sstate architecture list, it will not remove data from other than the current MACHINE (and its active architectures). It does not clean the sstate cache so if another build activates something which was cleaned, it should reinstall from sstate. We can also go one step further, depending on the setting of SSTATE_PRUNE_OBSOLETEWORKDIR, workdirs which are no longer active can also be removed. This avoids the buildup of many old copies of data in WORKDIR for example when versions are upgraded. The one thing which may surprise people with this change is if you remove a layer, data added by that layer will be "uninstalled" before the next build continues. I believe this is a feature and a good thing to do though. This code is safe with existing builds. If something isn't in the new index it simply isn't removed. Since changes to the sstate code trigger a rebuild, after this merges, we can assume the code will start to detect changes from that point onwards. [YOCTO #4102] (From OE-Core rev: 4ea39427eedeadd51439a62fa015c86be30c3445) 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-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.