Stage 23

docs/stage23.md

@@ -0,0 +1,47 @@
+# CLeonOS Stage23
+
+## Stage Goal
+- Add a kernel shell command `rusttest`.
+- Implement `rusttest` logic in Rust (`no_std`) instead of C.
+- Link Rust object into the kernel ELF so command runs in kernel mode.
+
+## What Was Implemented
+- Kernel Rust source added:
+  - `clks/rust/src/lib.rs`
+  - exports `clks_rusttest_hello()`
+  - output text: `Hello world!`
+- Kernel build integration (CMake):
+  - build `libclks_kernel_rust.a`
+  - link kernel ELF with `${KERNEL_RUST_LIB}`
+- Shell integration:
+  - add command `rusttest`
+  - `rusttest` calls Rust symbol `clks_rusttest_hello()`
+- Compatibility symbols for Rust link:
+  - add `clks/lib/libc_compat.c` for `memcpy/memset/memmove/memcmp/bcmp`
+- Stage banner updated:
+  - `CLEONOS Stage23 START`
+
+## Acceptance Criteria
+- Kernel boots and prints `CLEONOS Stage23 START`.
+- `help` contains `rusttest`.
+- Running `rusttest` prints exactly:
+  - `Hello world!`
+- No regression to existing shell commands.
+
+## Build Targets
+- `make setup`
+- `make userapps`
+- `make iso`
+- `make run`
+- `make debug`
+
+## QEMU Command
+- `qemu-system-x86_64 -M q35 -m 1024M -cdrom build/CLeonOS-x86_64.iso -serial stdio`
+
+## Common Bugs and Debugging
+- Rust link undefined symbols (`memcpy/memset/...`):
+  - Ensure `clks/lib/libc_compat.c` is included in kernel source set.
+- Panic-related undefined symbol:
+  - Ensure Rust file keeps `#[panic_handler]` and `rust_eh_personality` stub.
+- `rusttest` command not found:
+  - Confirm `help` output includes `rusttest` and shell dispatch branch exists.