We have a choice of policy with hashequivalence - whether to reduce sstate duplication in the sstate feed to a minimum or have maximal sstate reuse from the user's perspective. The challenge is that non-matching outhashes are generated due to determinism issues, or due to differences in host gcc version, architecture and so on and the question is how to reconcile then. The approach before this patch is that any new match is added and matches can update. This has the side effect that a queried value from the server can change due to the replacement and you may not always get the same value from the server. With the client side caching bitbake has, this can be suboptimal and when using the autobuilder sstate feed, it results in poor artefact reuse. This patch switches to the other possible behaviour, once a hash is assigned, it doesn't change. This means some sstate artefacts may be duplicated but dependency chains aren't invalidated which I suspect may give better overall performance. Update the tests to match the new behaviour. (Bitbake rev: 20d6ac753efa364349100cdc863e5eabec8e5b78) Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
Poky
Poky is an integration of various components to form a pre-packaged build system and development environment which is used as a development and validation tool by the Yocto Project. It features support for building customised embedded style device images and custom containers. There are reference demo images ranging from X11/GTK+ to Weston, commandline and more. The system supports cross-architecture application development using QEMU emulation and a standalone toolchain and SDK suitable for 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 BSP layers which extend the systems capabilities in a modular way. Many layers are available and can be found through the layer index.
As an integration layer Poky consists of several upstream projects such as BitBake, OpenEmbedded-Core, Yocto documentation, the 'meta-yocto' layer which has configuration and hardware support components. These components are all part of the Yocto Project and OpenEmbedded ecosystems.
The Yocto Project has extensive documentation about the system including a reference manual which can be found at https://docs.yoctoproject.org/
OpenEmbedded is the build architecture used by Poky and the Yocto project. For information about OpenEmbedded, see the OpenEmbedded website.
Contribution Guidelines
The project works using a mailing list patch submission process. Patches should be sent to the mailing list for the repository the components originate from (see below). Throughout the Yocto Project, the README files in the component in question should detail where to send patches, who the maintainers are and where bugs should be reported.
A guide to submitting patches to OpenEmbedded is available at:
https://www.openembedded.org/wiki/How_to_submit_a_patch_to_OpenEmbedded
There is good documentation on how to write/format patches at:
https://www.openembedded.org/wiki/Commit_Patch_Message_Guidelines
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:
OpenEmbedded-Core (files in meta/, meta-selftest/, meta-skeleton/, scripts/):
- Git repository: https://git.openembedded.org/openembedded-core/
- Mailing list: openembedded-core@lists.openembedded.org
BitBake (files in bitbake/):
- Git repository: https://git.openembedded.org/bitbake/
- Mailing list: bitbake-devel@lists.openembedded.org
Documentation (files in documentation/):
- Git repository: https://git.yoctoproject.org/cgit/cgit.cgi/yocto-docs/
- Mailing list: docs@lists.yoctoproject.org
meta-yocto (files in meta-poky/, meta-yocto-bsp/):
- Git repository: https://git.yoctoproject.org/cgit/cgit.cgi/meta-yocto
- Mailing list: poky@lists.yoctoproject.org
If in doubt, check the openembedded-core git repository for the content you intend to modify as most files are from there unless clearly one of the above categories. Before sending, be sure the patches apply cleanly to the current git repository branch in question.