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When image.bbclass was first conceived (as rootfs_ipk.bbclass), oemake was unable to figure out when the inputs to do_rootfs had changed in such a way that it would need to be rerun. Absent any reliable information of this kind, it was necessary to adopt the conservative assumption that images always needed rebuilding and, to this end, do_rootfs and do_build in image recipes were marked as nostamp. (The nostamp annotation for do_build was added in oe-classic commit 80d622e0c1dbc284858e01d3eb670303a6d8cdf9 from January 2005; the exact point at which do_rootfs was made nostamp is obscure, but it predates oe-classic revision 63fad339e01d4b16105146c32a61f24460397126.) This situation persisted for the following eight years but, during that period, oemake evolved into today's sstate-enabled bitbake, oe itself gained the OEBasicHash algorithm which can reliably detect changes to the input data for do_rootfs or any other task, and OEBasicHash was made the default for oe-core in 4199efed48005a62267fa3374c33b13627d85f44 (June 2012). Given these various changes in the wider landscape, there is no longer any obvious benefit to having these two tasks marked as nostamp, and indeed having them so marked causes needless rebuilds which can be annoying. Anybody who does genuinely wish to rerun these tasks when nothing in the input has changed can run "bitbake -f", just like with any other task. So, let's remove the nostamp annotations and just let bitbake figure out when to rerun them. (From OE-Core rev: 8505008c115efb54d18e5f25441c7a938a32ffaf) Signed-off-by: Phil Blundell <philb@gnu.org> 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 = "") 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, patches against the various components should be sent to their respective upstreams.
bitbake: bitbake-devel@lists.openembedded.org
meta-yocto: poky@yoctoproject.org
Most 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. 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.