bench-kernel: replace #[naked] with #[unsafe(naked)] for stable Rust

Replace the #[naked] attribute with #[unsafe(naked)] in the bench-kernel
module to ensure compatibility with the latest stable Rust compiler.
This follows the stabilization in rust-lang/rust#134213 and avoids
build failures when using the stable Rust toolchain.

Specific changes include:
- Replace `#[naked]` with `#[unsafe(naked)]` across all relevant functions.
- Remove `#![feature(naked_functions, asm_const)]` as they are no longer
  needed on stable with `#[unsafe(naked)]`.
- Switch to the `naked_asm!` macro to comply with new naked function
  requirements introduced alongside `#[unsafe(naked)]`.
- Remove `options(noreturn)`, which is disallowed within `naked_asm!`.
- Update `put_char` and `put_str` implementations in
  `impl rcore_console::Console for Console` to avoid errors from creating
  shared references to mutable statics.
- Update GitHub Actions workflow files to use `ubuntu-22.04` instead of
  `ubuntu-20.04` for CI compatibility.

The changes build and pass tests successfully on both stable and nightly Rust.

Fix:
rustsbi/rustsbi#63

Refs:
- Issue: rustsbi/rustsbi#63
- Upstream PR: rust-lang/rust#134213

Signed-off-by: manchangfengxu <[email protected]>

Author: manchangfengxu

.github/workflows/workflow.yml

@@ -7,7 +7,7 @@ on:
 
 jobs:
   build:
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-22.04
     steps:
       - uses: actions/checkout@v3
 

CHANGELOG.md

@@ -55,6 +55,19 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 - Fixes on usage of CLINT peripheral, thanks to @duskmoon314
 - Numerous fixes to HSM module implementation, more documents
 
+## [0.1.1] - 2025-04-22
+
+### Modified
+- Replaced #[naked] with #[unsafe(naked)] across all relevant functions.
+- Removed `#![feature(naked_functions, asm_const)]` as they are no longer needed.
+- Switched to the `naked_asm!` macro to comply with new naked function requirements.
+- Removed `options(noreturn)`, which is not allowed in `naked_asm!`.
+- Updated implementations of `put_char` and `put_str` in 
+  `impl rcore_console::Console for Console` to avoid errors caused by 
+  creating shared references to mutable statics.
+- Updated GitHub Actions YAML workflow files to replace `ubuntu-20.04` with 
+  `ubuntu-22.04` for CI compatibility.
+  
 [Unreleased]: https://github.com/rustsbi/rustsbi-qemu/compare/v0.1.1...HEAD
 [0.1.1]: https://github.com/rustsbi/rustsbi-qemu/compare/v0.1.0...v0.1.1
 [0.1.0]: https://github.com/rustsbi/rustsbi-qemu/releases/tag/v0.1.0

bench-kernel/src/main.rs

@@ -1,14 +1,13 @@
 #![no_std]
 #![no_main]
-#![feature(naked_functions, asm_const)]
 #![deny(warnings)]
 
 use rcore_console::log;
 use riscv::register::*;
 use sbi_rt::*;
 use uart16550::Uart16550;
 
-#[naked]
+#[unsafe(naked)]
 #[no_mangle]
 #[link_section = ".text.entry"]
 unsafe extern "C" fn _start(hartid: usize, device_tree_paddr: usize) -> ! {
@@ -17,13 +16,12 @@ unsafe extern "C" fn _start(hartid: usize, device_tree_paddr: usize) -> ! {
     #[link_section = ".bss.uninit"]
     static mut STACK: [u8; STACK_SIZE] = [0u8; STACK_SIZE];
 
-    core::arch::asm!(
+    core::arch::naked_asm!(
         "la sp,  {stack} + {stack_size}",
         "j  {main}",
         stack_size = const STACK_SIZE,
         stack      = sym   STACK,
         main       = sym   rust_main,
-        options(noreturn),
     )
 }
 
@@ -127,11 +125,17 @@ impl Uart16550Map {
 impl rcore_console::Console for Console {
     #[inline]
     fn put_char(&self, c: u8) {
-        unsafe { UART.get().write(core::slice::from_ref(&c)) };
+        unsafe {
+            let mut_ref_uart = (*(&raw mut UART)).get();
+            mut_ref_uart.write(core::slice::from_ref(&c))
+        };
     }
 
     #[inline]
     fn put_str(&self, s: &str) {
-        unsafe { UART.get().write(s.as_bytes()) };
+        unsafe {
+            let mut_ref_uart = (*(&raw mut UART)).get();
+            mut_ref_uart.write(s.as_bytes())
+        };
     }
 }