Re: [OE-core] [RFC PATCH 0/7] Enable rust support for linux kernel

["Mathieu Dubois-Briand" <mathieu.dubois-briand@bootlin.com>]

On Thu Oct 23, 2025 at 1:25 PM CEST, Harish via lists.openembedded.org Sadineni wrote:
> From: Harish Sadineni <Harish.Sadineni@windriver.com>
>
> This patch series introduces Rust support into the linux-yocto kernel recipe
> and related build infrastructure in the Yocto Project. The goal is to enable
> building the Linux kernel with Rust components and provide support for
> building kernel module which is written in rust inside sdk. 
>
> Summary of changes:
>
> - Patch 1: Extend 'bindgen-cli' to support 'nativesdk', allowing it to be available in the SDK environment.
> - Patch 2: Add required dependencies ('clang-native', 'bindgen-cli-native') to the kernel to support Rust binding generation.
> - Patch 3: Install the Rust standard library source ('library/') into `work-shared` and which will be later copied to 
>            linux-yocto recipe-sysroot-native.
> - Patch 4: Stage the Rust sources into `recipe-sysroot-native` for kernel build compatibility, making them visible during native builds.
> - Patch 5: Update `kernel-yocto.bbclass` to invoke `make rustavailable` during 'do_kernel_configme', ensuring Rust readiness.
> - Patch 6: Add kernel configuration support for Rust (via 'rust.cfg' and 'rust.scc'), enabling the Rust build options in kernel config.
> - patch 7: Copy Rust kernel sources into kernel-devsrc build directory which will be required while runnig 'make prepare' in sdk.
>
> WIP - need inputs:
> 1. In patch-3, rust sources are copied from ${RUSTSRC} to ${TMPDIR}/work-shared, which is redundant and improving it in
>  more optimized way by extracting rust directly into ${TMPDIR}/work-shared and then use it for both rust & linux-yocto recipes.
>  
> 2. In patch-6, We've suppressed a few build path QA issues with INSANE_SKIP.
> We have tried fixing those using DEBUG_PREFIX_MAP & --remap-path-prefix but unable to resolve it.
> Are there any flags for kernel or any other inputs?
>  
> 3. If rust.cfg & rust.scc changes are ok, we will send kernel configuration fragment to yocto-kernel-cache.
>
> With above considerations, We did a successful build of Enabling rust in linux kernel and 
> Tested a rust-out-of-tree kernel module in sdk for x86-64 & arm64 architectures.
>
> Harish Sadineni (7):
>   bindgen-cli: extend BBCLASSEXTEND to include nativesdk
>   linux-yocto: add clang-native and bindgen-cli-native to DEPENDS
>   rust: install Rust standard library sources for make rustavailable
>     support
>   rust: stage rustlib sources for linux-yocto make rustavailable support
>   kernel-yocto: add rust support via make rustavailable in
>     do_kernel_configme
>   linux-yocto: enable Rust support in kernel configuration
>   kernel-devsrc: copying rust-kernel soucre  to $kerneldir/build
>
>  meta/classes-recipe/kernel-yocto.bbclass      |  4 ++++
>  .../bindgen-cli/bindgen-cli_0.72.1.bb         |  2 +-
>  meta/recipes-devtools/rust/rust_1.90.0.bb     | 13 +++++++++++-
>  meta/recipes-kernel/linux/files/rust.cfg      | 20 +++++++++++++++++++
>  meta/recipes-kernel/linux/files/rust.scc      |  1 +
>  meta/recipes-kernel/linux/kernel-devsrc.bb    |  1 +
>  meta/recipes-kernel/linux/linux-yocto.inc     |  7 +++++++
>  meta/recipes-kernel/linux/linux-yocto_6.16.bb |  4 ++++
>  8 files changed, 50 insertions(+), 2 deletions(-)
>  create mode 100644 meta/recipes-kernel/linux/files/rust.cfg
>  create mode 100644 meta/recipes-kernel/linux/files/rust.scc

Hi Harish,

I know this is still an RFC, but I ran it on the autobuilder to check
how it goes. We had a some error with kernel build:

ERROR: linux-yocto-6.12.52+git-r0 do_patch: Execution of '/srv/pokybuild/yocto-worker/qemux86-alt/build/build/tmp/work/qemux86-poky-linux/linux-yocto/6.12.52+git/temp/run.do_patch.410367' failed with exit code 1
...
| cp: cannot stat '/srv/pokybuild/yocto-worker/qemux86-alt/build/build/tmp/work-shared/rust': No such file or directory

This happened in almost all builds as far as I can tell:

https://autobuilder.yoctoproject.org/valkyrie/#/builders/20/builds/2614
https://autobuilder.yoctoproject.org/valkyrie/#/builders/9/builds/2623
https://autobuilder.yoctoproject.org/valkyrie/#/builders/2/builds/2650

https://autobuilder.yoctoproject.org/valkyrie/#/builders/29/builds/2638

Thanks,
Mathieu


-- 
Mathieu Dubois-Briand, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com