[RFC PATCH 6/7] linux-yocto: enable Rust support in kernel configuration

[Harish.Sadineni@windriver.com]

From: Harish Sadineni <Harish.Sadineni@windriver.com>

Add initial support for building the Linux kernel with Rust enabled:

- Introduce `rust.cfg` to set Rust-related kernel config options, including:
  - `CONFIG_RUST`, `CONFIG_HAVE_RUST`, and `CONFIG_RUST_IS_AVAILABLE`
  - Rust sample modules and developer checks (overflow/debug assertions)
  - Disable BTF and module versioning for compatibility

- Add `rust.scc` to include `rust.cfg` via `kconf` in the kernel feature stack

- Update `linux-yocto_${PV}.bb` to:
  - Append `rust.scc` to `SRC_URI` and `KERNEL_FEATURES`
  - Suppress `buildpaths` QA warning due to Rust path inclusion during builds

Signed-off-by: Harish Sadineni <Harish.Sadineni@windriver.com>
---
 meta/recipes-kernel/linux/files/rust.cfg      | 20 +++++++++++++++++++
 meta/recipes-kernel/linux/files/rust.scc      |  1 +
 meta/recipes-kernel/linux/linux-yocto_6.16.bb |  4 ++++
 3 files changed, 25 insertions(+)
 create mode 100644 meta/recipes-kernel/linux/files/rust.cfg
 create mode 100644 meta/recipes-kernel/linux/files/rust.scc

diff --git a/meta/recipes-kernel/linux/files/rust.cfg b/meta/recipes-kernel/linux/files/rust.cfg
new file mode 100644
index 0000000000..293438e8e0
--- /dev/null
+++ b/meta/recipes-kernel/linux/files/rust.cfg
@@ -0,0 +1,20 @@
+CONFIG_RUST=y
+CONFIG_SAMPLES_RUST=y
+CONFIG_SAMPLE_RUST_MINIMAL=y
+CONFIG_SAMPLE_RUST_PRINT=y
+CONFIG_SAMPLE_RUST_HOSTPROGS=y
+CONFIG_RUST_DEBUG_ASSERTIONS=y
+CONFIG_RUST_OVERFLOW_CHECKS=y
+CONFIG_RUST_BUILD_ASSERT_ALLOW=y
+# Disable module versioning
+CONFIG_MODVERSIONS=n
+
+# Disable BTF debug info
+CONFIG_DEBUG_INFO_BTF=n
+
+# Rust availability
+CONFIG_RUST_IS_AVAILABLE=y
+
+# Indicate Rust support present
+CONFIG_HAVE_RUST=y
+
diff --git a/meta/recipes-kernel/linux/files/rust.scc b/meta/recipes-kernel/linux/files/rust.scc
new file mode 100644
index 0000000000..4686d9ce5e
--- /dev/null
+++ b/meta/recipes-kernel/linux/files/rust.scc
@@ -0,0 +1 @@
+kconf hardware rust.cfg
diff --git a/meta/recipes-kernel/linux/linux-yocto_6.16.bb b/meta/recipes-kernel/linux/linux-yocto_6.16.bb
index 2188c7fed2..fda964e78d 100644
--- a/meta/recipes-kernel/linux/linux-yocto_6.16.bb
+++ b/meta/recipes-kernel/linux/linux-yocto_6.16.bb
@@ -77,3 +77,7 @@ KERNEL_FEATURES:append:powerpc64le = " arch/powerpc/powerpc-debug.scc"
 # Check again during next major version upgrade
 KERNEL_FEATURES:remove:riscv32 = "features/debug/debug-kernel.scc"
 INSANE_SKIP:kernel-vmlinux:qemuppc64 = "textrel"
+INSANE_SKIP:kernel-vmlinux = "buildpaths"
+INSANE_SKIP:kernel-dbg = "buildpaths"
+SRC_URI += "file://rust.scc"
+KERNEL_FEATURES += "rust.scc"
-- 
2.49.0