cleonos/docs/stage23.md

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.