Re: [OE-core] [wrynose][PATCH] kernel-yocto-rust: skip recipe for riscv64 when Rust support is enabled

[Harish Sadineni <Harish.Sadineni@windriver.com>]

On 04-09-2026 03:04 am, Yoann Congal wrote:
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> On Tue Aug 11, 2026 at 1:58 PM CEST, Harish via lists.openembedded.org Sadineni wrote:
>> From: Harish Sadineni <Harish.Sadineni@windriver.com>
>>
>> Kernel Rust support on riscv64 requires building the kernel with Clang.
>> Since Wrynose does not provide Clang toolchian support for kernel
>> builds, skip the recipe when TARGET_ARCH is riscv64.
> Hello,
>
> OE-Core/wrynose indeed does not but meta-clang seem to do that:
> https://github.com/kraj/meta-clang/blob/wrynose/conf/nonclangable.conf#L369
>
> Wouldn't this patch needlessly prevent user from using meta-clang to get
> a RISCV rust-enabled kernel?
>
> I wonder if we need a patch more like master's:
> 2b228490b7e (kernel-yocto-rust: Add clang toolchain check for riscv64, 2026-08-05)
>
> What do you think?
Hi Yoann,

I understood what you meant, If someone uses 'linux-yocto_%.bbappend' to 
build the kernel with the clang toolchain [1],
this patch would prevent them from using rust in the kernel. Is my 
understanding correct?

If so, I'll implement the same clang toolchain check as 
'kernel-yocto-rust: Add clang toolchain check for riscv64' for wrynose,
and just adjust the error message accordingly.

[1]https://github.com/kraj/meta-clang/blob/wrynose/README.md#kernel-build-with-clang

<https://github.com/kraj/meta-clang/blob/wrynose/README.md#kernel-build-with-clang>Thanks,
harish
>> This avoids attempting an unsupported kernel Rust build and provides a
>> clear parse-time error explaining the limitation.
>>
>> Signed-off-by: Harish Sadineni <Harish.Sadineni@windriver.com>
>> ---
>>   meta/classes-recipe/kernel-yocto-rust.bbclass | 9 +++++++++
>>   1 file changed, 9 insertions(+)
>>
>> diff --git a/meta/classes-recipe/kernel-yocto-rust.bbclass b/meta/classes-recipe/kernel-yocto-rust.bbclass
>> index 49f2bfc1ae..6be97c2db8 100644
>> --- a/meta/classes-recipe/kernel-yocto-rust.bbclass
>> +++ b/meta/classes-recipe/kernel-yocto-rust.bbclass
>> @@ -25,3 +25,12 @@ do_kernel_configme:append () {
>>   # More details in: https://lists.openembedded.org/g/openembedded-core/message/229336
>>   # Disable ccache for kernel build if kernel rust support is enabled to workaround this.
>>   CCACHE_DISABLE ?= "1"
>> +
>> +python () {
>> +    if d.getVar('TARGET_ARCH') == 'riscv64' :
>> +        raise bb.parse.SkipRecipe(
>> +            "Rust support in the kernel on riscv64 requires kernel to build with clang, "
>> +            "Wrynose doesn't have clang toolchain support for kernel. See "
>> +            "https://docs.kernel.org/rust/arch-support.html for details."
>> +        )
>> +}
> Regards,
> --
> Yoann Congal
> Smile ECS