Adapt riscv-rt to edition 2024

Author: romancardenas

.github/workflows/riscv-rt.yaml

@@ -10,8 +10,8 @@ jobs:
   build-riscv:
     strategy:
       matrix:
-        # All generated code should be running on stable now, MRSV is 1.67.0
-        toolchain: [ stable, nightly, 1.67.0 ]
+        # All generated code should be running on stable now, MRSV is 1.85.0
+        toolchain: [ stable, nightly, 1.85.0 ]
         target:
           - riscv32i-unknown-none-elf
           - riscv32im-unknown-none-elf
@@ -27,11 +27,6 @@ jobs:
           # Nightly is only for reference and allowed to fail
           - toolchain: nightly
             experimental: true
-        exclude:
-          - toolchain: 1.67.0
-            target: riscv32im-unknown-none-elf
-          - toolchain: 1.67.0
-            target: riscv32imafc-unknown-none-elf
     runs-on: ubuntu-latest
     continue-on-error: ${{ matrix.experimental || false }}
     steps:

.github/workflows/tests.yaml

@@ -20,8 +20,8 @@ jobs:
   run-build:
     strategy:
       matrix:
-        # All generated code should be running on stable now, MRSV is 1.67.0
-        toolchain: [ stable, nightly, 1.67.0 ]
+        # All generated code should be running on stable now, MRSV is 1.85.0
+        toolchain: [ stable, nightly, 1.85.0 ]
         target:
           - riscv32i-unknown-none-elf
           - riscv32im-unknown-none-elf
@@ -36,11 +36,6 @@ jobs:
           # Nightly is only for reference and allowed to fail
           - toolchain: nightly
             experimental: true
-        exclude:
-          - toolchain: 1.67.0
-            target: riscv32im-unknown-none-elf
-          - toolchain: 1.67.0
-            target: riscv32imafc-unknown-none-elf
     runs-on: ubuntu-latest
     continue-on-error: ${{ matrix.experimental || false }}
     steps:

riscv-rt/CHANGELOG.md

@@ -7,6 +7,10 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 
 ## [Unreleased]
 
+### Changed
+
+- Update to Rust edition 2024 (MSRV 1.85)
+
 ## [v0.15.0] - 2025-06-10
 
 ### Added

riscv-rt/Cargo.toml

@@ -1,15 +1,15 @@
 [package]
 name = "riscv-rt"
 version = "0.15.0"
-rust-version = "1.67"
+rust-version = "1.85"
 repository = "https://github.com/rust-embedded/riscv"
 authors = ["The RISC-V Team <[email protected]>"]
 categories = ["embedded", "no-std"]
 description = "Minimal runtime / startup for RISC-V CPU's"
 documentation = "https://docs.rs/riscv-rt"
 keywords = ["riscv", "runtime", "startup"]
 license = "ISC"
-edition = "2021"
+edition = "2024"
 links = "riscv-rt" # Prevent multiple versions of riscv-rt being linked
 
 [package.metadata.docs.rs]

riscv-rt/README.md

@@ -11,7 +11,7 @@ This project is developed and maintained by the [RISC-V team][team].
 
 ## Minimum Supported Rust Version (MSRV)
 
-This crate is guaranteed to compile on stable Rust 1.61 and up. It *might*
+This crate is guaranteed to compile on stable Rust 1.85 and up. It **won't**
 compile with older versions but that may change in any new patch release.
 
 ## License

riscv-rt/examples/multi_core.rs

@@ -7,7 +7,7 @@ use riscv::asm::wfi;
 use riscv::register::{mie, mip};
 use riscv_rt::entry;
 
-#[export_name = "_mp_hook"]
+#[unsafe(export_name = "_mp_hook")]
 #[rustfmt::skip]
 pub extern "Rust" fn user_mp_hook(hartid: usize) -> bool {
     if hartid == 0 {

riscv-rt/macros/Cargo.toml

@@ -11,7 +11,7 @@ license = "MIT OR Apache-2.0"
 name = "riscv-rt-macros"
 repository = "https://github.com/rust-embedded/riscv"
 version = "0.5.0"
-edition = "2021"
+edition = "2024"
 
 [lib]
 proc-macro = true

riscv-rt/macros/src/lib.rs

@@ -4,11 +4,11 @@ use proc_macro::TokenStream;
 use proc_macro2::{Span, TokenStream as TokenStream2};
 use quote::quote;
 use syn::{
+    FnArg, ItemFn, LitInt, LitStr, PatType, Path, ReturnType, Token, Type, Visibility,
     parse::{self, Parse},
     parse_macro_input, parse_quote,
     punctuated::Punctuated,
     spanned::Spanned,
-    FnArg, ItemFn, LitInt, LitStr, PatType, Path, ReturnType, Token, Type, Visibility,
 };
 
 /// Attribute to declare the entry point of the program
@@ -136,7 +136,7 @@ pub fn entry(args: TokenStream, input: TokenStream) -> TokenStream {
 
     quote!(
         #[allow(non_snake_case)]
-        #[export_name = "main"]
+        #[unsafe(export_name = "main")]
         #(#attrs)*
         pub #unsafety fn __risc_v_rt__main(#args) -> ! {
             #(#stmts)*
@@ -248,7 +248,7 @@ pub fn pre_init(args: TokenStream, input: TokenStream) -> TokenStream {
     let block = f.block;
 
     quote!(
-        #[export_name = "__pre_init"]
+        #[unsafe(export_name = "__pre_init")]
         #(#attrs)*
         pub unsafe fn #ident() #block
     )
@@ -451,7 +451,7 @@ fn store_trap<T: FnMut(&str) -> bool>(arch: RiscvArch, mut filter: T) -> String
     arch.trap_frame()
         .iter()
         .enumerate()
-        .filter(|(_, &reg)| !reg.starts_with('_') && filter(reg))
+        .filter(|(_, reg)| !reg.starts_with('_') && filter(reg))
         .map(|(i, reg)| format!("{store} {reg}, {i}*{width}(sp)"))
         .collect::<Vec<_>>()
         .join("\n    ")
@@ -465,7 +465,7 @@ fn load_trap(arch: RiscvArch) -> String {
     arch.trap_frame()
         .iter()
         .enumerate()
-        .filter(|(_, &reg)| !reg.starts_with('_'))
+        .filter(|(_, reg)| !reg.starts_with('_'))
         .map(|(i, reg)| format!("{load} {reg}, {i}*{width}(sp)"))
         .collect::<Vec<_>>()
         .join("\n    ")
@@ -760,7 +760,7 @@ fn trap(
 
         #start_trap
 
-        #[export_name = #export_name]
+        #[unsafe(export_name = #export_name)]
         #f
     )
     .into()

riscv-rt/src/exceptions.rs

@@ -13,7 +13,7 @@
 
 use crate::TrapFrame;
 
-extern "C" {
+unsafe extern "C" {
     fn InstructionMisaligned(trap_frame: &TrapFrame);
     fn InstructionFault(trap_frame: &TrapFrame);
     fn IllegalInstruction(trap_frame: &TrapFrame);
@@ -31,7 +31,7 @@ extern "C" {
 }
 
 /// Array with all the exception handlers sorted according to their exception source code.
-#[no_mangle]
+#[unsafe(no_mangle)]
 pub static __EXCEPTIONS: [Option<unsafe extern "C" fn(&TrapFrame)>; 16] = [
     Some(InstructionMisaligned),
     Some(InstructionFault),
@@ -57,13 +57,13 @@ pub static __EXCEPTIONS: [Option<unsafe extern "C" fn(&TrapFrame)>; 16] = [
 ///
 /// This function must be called only from the [`crate::start_trap_rust`] function.
 /// Do **NOT** call this function directly.
-#[no_mangle]
+#[unsafe(no_mangle)]
 pub unsafe extern "C" fn _dispatch_exception(trap_frame: &TrapFrame, code: usize) {
-    extern "C" {
-        fn ExceptionHandler(trap_frame: &TrapFrame);
+    unsafe extern "C" {
+        unsafe fn ExceptionHandler(trap_frame: &TrapFrame);
     }
     match __EXCEPTIONS.get(code) {
-        Some(Some(handler)) => handler(trap_frame),
-        _ => ExceptionHandler(trap_frame),
+        Some(Some(handler)) => unsafe { handler(trap_frame) },
+        _ => unsafe { ExceptionHandler(trap_frame) },
     }
 }

riscv-rt/src/lib.rs

@@ -592,7 +592,7 @@ pub use riscv_rt_macros::pre_init;
 /// two copies of riscv-rt together, linking will fail. We also declare a links key in
 /// Cargo.toml which is the more modern way to solve the same problem, but we have to keep
 /// __ONCE__ around to prevent linking with versions before the links key was added.
-#[export_name = "error: riscv-rt appears more than once in the dependency graph"]
+#[unsafe(export_name = "error: riscv-rt appears more than once in the dependency graph")]
 #[doc(hidden)]
 pub static __ONCE__: () = ();
 
@@ -672,11 +672,11 @@ pub struct TrapFrame {
 /// Do **NOT** call this function directly.
 #[cfg_attr(
     any(target_arch = "riscv32", target_arch = "riscv64"),
-    link_section = ".trap.rust"
+    unsafe(link_section = ".trap.rust")
 )]
-#[export_name = "_start_trap_rust"]
+#[unsafe(export_name = "_start_trap_rust")]
 pub unsafe extern "C" fn start_trap_rust(trap_frame: *const TrapFrame) {
-    extern "C" {
+    unsafe extern "C" {
         #[cfg(not(feature = "v-trap"))]
         fn _dispatch_core_interrupt(code: usize);
         #[cfg(feature = "v-trap")]
@@ -686,10 +686,10 @@ pub unsafe extern "C" fn start_trap_rust(trap_frame: *const TrapFrame) {
 
     match xcause::read().cause() {
         #[cfg(not(feature = "v-trap"))]
-        xcause::Trap::Interrupt(code) => _dispatch_core_interrupt(code),
+        xcause::Trap::Interrupt(code) => unsafe { _dispatch_core_interrupt(code) },
         #[cfg(feature = "v-trap")]
-        xcause::Trap::Interrupt(_) => DefaultHandler(),
-        xcause::Trap::Exception(code) => _dispatch_exception(&*trap_frame, code),
+        xcause::Trap::Interrupt(_) => unsafe { DefaultHandler() },
+        xcause::Trap::Exception(code) => unsafe { _dispatch_exception(&*trap_frame, code) },
     }
 }
 
@@ -698,7 +698,7 @@ pub unsafe extern "C" fn start_trap_rust(trap_frame: *const TrapFrame) {
 /// The returned pointer is guaranteed to be 4-byte aligned.
 #[inline]
 pub fn heap_start() -> *mut usize {
-    extern "C" {
+    unsafe extern "C" {
         static mut __sheap: usize;
     }