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- The qemux86 port for helloworld-baremetal builds in the standard way, however, it uses NASM syntax for the startup code, hence we include a dependency to nasm-native, QEMU forces us to use an ELF file rather than a bin file to boot from this architecture using the -kernel parameter. - QEMU refuses to boot using the -kernel parameter for files containing an ELF64 header [1], instead, it requires a multiboot2 compatible image. We could create an image that contains a multiboot2 header by piggybacking into grub2-native, specifically grub-mkrescue, but it requires some extra runtime dependencies (xorriso which is currently part of meta-oe), and assumes a grub installation exists on the host. Due to host contamination and dependency complications, we dont rely on grub2, but rather do this process manually instead, the x86-64 port contains a stage1 bootloader, stage2 bootloader and a 64 bit baremetal app (multiboot2 compatible), booting into real (16 bit), protected (32 bit) and long (64 bit) modes, eventually running the helloworld-baremetal app. This is the reason why we need the code changes to use a separate Makefile, and create an image specifically for qemux86-64. $ runqemu nographic Booting from ROM.. Hello OpenEmbedded on x86! $ runqemu nographic Starting Stage 1 Bootloader Loading Stage 2 Bootloader Stage 2 Loaded. Jumping to Stage2 Bootloader In Stage 2 Done Hello OpenEmbedded on x86-64! [1] https://gitlab.com/qemu-project/qemu/-/blob/v7.2.0/hw/i386/multiboot.c#L199 (From OE-Core rev: 1dffd81b2991f90ab95cb36d8ff7626efd21434f) Signed-off-by: Alejandro Enedino Hernandez Samaniego <alejandro@enedino.org> Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com> 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.