yocto-kernel-bsp

name

yocto-kernel-bsp

description

Official-doc-first Yocto kernel and BSP workflow support for AI coding agents. Use when working on Linux kernel recipes, linux-yocto, vendor kernel integration, defconfig, kernel config fragments, device tree files, KERNEL_DEVICETREE, MACHINE configuration, BSP layers, bootloader/kernel handoff issues, COMPATIBLE_MACHINE, kernel modules, or board bring-up problems in Yocto Project and OpenEmbedded workspaces.

Yocto Kernel BSP

Core Workflow

1. Identify the Yocto release, MACHINE, BSP layer, kernel provider, and kernel recipe before editing.
2. Inspect existing machine configuration, kernel recipe, .bbappend, device tree, defconfig, and config fragments.
3. Prefer the product BSP layer for local changes. Avoid editing upstream poky, meta, meta-yocto, OE-Core, or vendor layers unless preparing an upstreamable patch.
4. Separate concerns:
   • Machine selection belongs in conf/machine/*.conf.
   • Kernel source/provider policy belongs in distro or machine config only when locally justified.
   • Kernel config belongs in fragments or defconfig according to the project's existing style.
   • Device tree changes belong near existing DTS/DTSI structure or in a layer-local patch.
5. Validate with BitBake and kernel tasks before claiming success.

Commands

bitbake-layers show-recipes virtual/kernel
bitbake-layers show-appends
bitbake -e virtual/kernel
bitbake virtual/kernel
bitbake -c menuconfig virtual/kernel
bitbake -c diffconfig virtual/kernel
bitbake -c deploy virtual/kernel

Use yocto_kernel_doc_router.py with a topic name for official documentation links.

References

• kernel-bsp-workflows.md: provider discovery, recipe/appends, fragments, and validation.
• device-tree-checklist.md: DTB selection, DTS/DTSI origin, patch workflow, and deploy checks.
• machine-config-checklist.md: machine variables, provider policy, overrides, and board variants.

Guardrails

• Do not assume linux-yocto behavior applies to vendor kernels without checking the recipe/classes.
• Do not mix board variants that have different RAM, boot media, storage, or DTBs.
• Do not change PREFERRED_PROVIDER_virtual/kernel, KERNEL_DEVICETREE, or COMPATIBLE_MACHINE globally unless the blast radius is understood.
• Do not hand-edit generated kernel build output as a permanent fix; add patches, fragments, or metadata in the owning layer.