Richard Purdie
5317a214c5
This change implements a toolchain selection mechanism. Selection is made using a set of variables, primarily PREFERRED_TOOLCHAIN_TARGET which defaults to gcc. It uses the familiar name for toolchain e.g. "gcc" which selects GNU compiler + binutils as default C/C++ toolchain or "clang" which will use LLVM/Clang Compiler. Layers an add their own toolchain definitions too. There are also PREFERRED_TOOLCHAIN_NATIVE and PREFERRED_TOOLCHAIN_SDK which will ulitmately allow selection of the toolchain used for the native/cross and nativesdk/crosssdk compilers. This currently isn't functional but is essential to the patch to ensure things are set to the existing gcc support in those cases. Users would most commonly want to set: PREFERRED_TOOLCHAIN_TARGET ?= "clang" in local.conf or other distro specific global configuration metadata. It is also selectable at recipe scope, since not all packages are buildable with either clang or gcc, a recipe can explicitly require a given toolchain using the TOOLCAHIN variable, e.g. glibc can not be built with clang therefore glibc recipe sets: TOOLCHAIN = "gcc" The TOOLCHAIN variable is distinct from the user preference so recipes with specific requirements can be identified. This also allows different polcies to be be specified for native/SDK cases in the future. (From OE-Core rev: 45bdedd213aff8df3214b95ef2a8551c0abd93a0) 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
Please refer to our contributor guide here: https://docs.yoctoproject.org/dev/contributor-guide/ for full details on how to submit changes.
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.