Draft: Support thumb-mode Armv7-R, Armv7-A and Armv8-R

.cargo/config.toml

@@ -2,27 +2,45 @@
 # Note, this requires QEMU 9 or higher
 runner = "qemu-system-arm -machine mps3-an536 -cpu cortex-r52 -semihosting -nographic -audio none -kernel"
 
+[target.thumbv8r-none-eabihf]
+# Note, this requires QEMU 9 or higher
+runner = "qemu-system-arm -machine mps3-an536 -cpu cortex-r52 -semihosting -nographic -audio none -kernel"
+
 [target.armv7r-none-eabihf]
 runner = "qemu-system-arm -machine versatileab -cpu cortex-r5f -semihosting -nographic -audio none -kernel"
 
+[target.thumbv7r-none-eabihf]
+runner = "qemu-system-arm -machine versatileab -cpu cortex-r5f -semihosting -nographic -audio none -kernel"
+
 [target.armv7r-none-eabi]
 # change '-mcpu=cortex-r5' to '-mcpu=cortex-r5f' if you use eabi-fpu feature, otherwise
 # qemu-system-arm will lock up
 runner = "qemu-system-arm -machine versatileab -cpu cortex-r5 -semihosting -nographic -audio none -kernel"
 
+[target.thumbv7r-none-eabi]
+# change '-mcpu=cortex-r5' to '-mcpu=cortex-r5f' if you use eabi-fpu feature, otherwise
+# qemu-system-arm will lock up
+runner = "qemu-system-arm -machine versatileab -cpu cortex-r5 -semihosting -nographic -audio none -kernel"
+
 [target.armv7a-none-eabihf]
 runner = "qemu-system-arm -machine versatileab -cpu cortex-a8 -semihosting -nographic -audio none -kernel"
 
+[target.thumbv7a-none-eabihf]
+runner = "qemu-system-arm -machine versatileab -cpu cortex-a8 -semihosting -nographic -audio none -kernel"
+
 [target.armv7a-none-eabi]
 runner = "qemu-system-arm -machine versatileab -cpu cortex-a8 -semihosting -nographic -audio none -kernel"
 
+[target.thumbv7a-none-eabi]
+runner = "qemu-system-arm -machine versatileab -cpu cortex-a8 -semihosting -nographic -audio none -kernel"
+
 [target.armv5te-none-eabi]
 runner = "qemu-system-arm -machine versatileab -cpu arm926 -semihosting -nographic -audio none -kernel"
 
-[target.armv4t-none-eabi]
+[target.thumbv5te-none-eabi]
 runner = "qemu-system-arm -machine versatileab -cpu arm926 -semihosting -nographic -audio none -kernel"
 
-[target.thumbv5te-none-eabi]
+[target.armv4t-none-eabi]
 runner = "qemu-system-arm -machine versatileab -cpu arm926 -semihosting -nographic -audio none -kernel"
 
 [target.thumbv4t-none-eabi]

.github/workflows/build.yml

@@ -33,16 +33,16 @@ jobs:
     steps:
       - name: Checkout
         uses: actions/checkout@v4
-      - name: Install rust
+      - name: Install Just
+        uses: taiki-e/install-action@just
+      - name: Install Rust
         run: |
           rustup install ${{ matrix.rust }}
           rustup default ${{ matrix.rust }}
           rustup target add ${{ matrix.target }}
       - name: Build
         run: |
-          cargo build --target ${{ matrix.target }}
-          cargo build --target ${{ matrix.target }} --features "serde, defmt, critical-section-multi-core, check-asm"
-          cargo build --target ${{ matrix.target }} --features "serde, defmt, critical-section-single-core, check-asm"
+          just build-tier2 ${{ matrix.target }}
 
   # These targets need build-std, and have no atomics
   build-tier3-no-atomics:
@@ -58,39 +58,41 @@ jobs:
     steps:
       - name: Checkout
         uses: actions/checkout@v4
-      - name: Install rust
+      - name: Install Just
+        uses: taiki-e/install-action@just
+      - name: Install Rust
         run: |
           rustup install nightly-2025-10-29
           rustup component add rust-src --toolchain nightly-2025-10-29
+          rustup default nightly-2025-10-29
       - name: Build
         run: |
-          cargo +nightly-2025-10-29 build --target ${{ matrix.target }} -Zbuild-std=core
-          cargo +nightly-2025-10-29 build --target ${{ matrix.target }} -Zbuild-std=core --features "serde, defmt, check-asm"
+          just build-tier3-no-atomics ${{ matrix.target }}
 
-  # Build the host tools
-  build-host:
+  # Build the host-only stuff
+  build-arm-targets:
     runs-on: ubuntu-24.04
     needs: setup
     strategy:
       matrix:
-        rust: [stable, 1.59]
+        rust: ${{ fromJSON(needs.setup.outputs.rust-versions) }}
     steps:
       - name: Checkout
         uses: actions/checkout@v4
-      - name: Install rust
+      - name: Install Just
+        uses: taiki-e/install-action@just
+      - name: Install Rust
         run: |
           rustup install ${{ matrix.rust }}
           rustup default ${{ matrix.rust }}
       - name: Build
         run: |
-          cd arm-targets
-          cargo build
-          cargo test
+          just build-arm-targets
 
   # Gather all the above build jobs together for the purposes of getting an overall pass-fail
   build-all:
     runs-on: ubuntu-24.04
-    needs: [build-tier2, build-tier3-no-atomics, build-host]
+    needs: [build-tier2, build-tier3-no-atomics, build-arm-targets]
     steps:
       - run: /bin/true
 
@@ -110,7 +112,7 @@ jobs:
     steps:
       - name: Checkout
         uses: actions/checkout@v4
-      - name: Install rust
+      - name: Install Rust
         run: |
           rustup install ${{ matrix.rust }}
           rustup default ${{ matrix.rust }}
@@ -130,7 +132,7 @@ jobs:
     steps:
       - name: Checkout
         uses: actions/checkout@v4
-      - name: Install rust
+      - name: Install Rust
         run: |
           rustup install ${{ matrix.rust }}
           rustup default ${{ matrix.rust }}
@@ -147,95 +149,86 @@ jobs:
       - run: /bin/true
 
   # Format the workspace
-  fmt:
+  fmt-all:
     runs-on: ubuntu-24.04
     steps:
       - name: Checkout
         uses: actions/checkout@v4
-      - name: Install rust
+      - name: Install Just
+        uses: taiki-e/install-action@just
+      - name: Install Rust
         run: |
           rustup install stable
           rustup default stable
           rustup component add rustfmt
       - name: Format
         run: |
-          cargo fmt --check
+          just fmt-check
 
-  # Format the host tools
-  fmt-host:
+  # Run clippy on the workpace
+  clippy:
     runs-on: ubuntu-24.04
+    needs: setup
+    strategy:
+      matrix:
+        target: ${{ fromJSON(needs.setup.outputs.stable-targets) }}
     steps:
       - name: Checkout
         uses: actions/checkout@v4
-      - name: Install rust
+      - name: Install Just
+        uses: taiki-e/install-action@just
+      - name: Install Rust
         run: |
-          rustup install stable
-          rustup default stable
-          rustup component add rustfmt
-      - name: Format
+          rustup toolchain install 1.92
+          rustup default 1.92
+          rustup target add ${{ matrix.target }}
+          rustup component add clippy
+      - name: Clippy
         run: |
-          cd arm-targets
-          cargo fmt --check
+          just clippy-target ${{ matrix.target }}
 
-  # Gather all the above fmt jobs together for the purposes of getting an overall pass-fail
-  fmt-all:
-    runs-on: ubuntu-24.04
-    needs: [fmt, fmt-host]
-    steps:
-      - run: /bin/true
-
-  # Run clippy on the workpace
-  clippy:
+  # Run clippy on the examples
+  clippy-examples:
     runs-on: ubuntu-24.04
     needs: setup
-    strategy:
-      matrix:
-        rust: ${{ fromJSON(needs.setup.outputs.rust-versions) }}
-        target: ${{ fromJSON(needs.setup.outputs.stable-targets) }}
-        exclude:
-          - rust: 1.83
-            target: armv7a-none-eabihf
-          - rust: 1.83
-            target: armv8r-none-eabihf
     steps:
       - name: Checkout
         uses: actions/checkout@v4
-      - name: Install rust
+      - name: Install Just
+        uses: taiki-e/install-action@just
+      - name: Install Rust
         run: |
-          rustup install ${{ matrix.rust }}
-          rustup default ${{ matrix.rust }}
-          rustup target add ${{ matrix.target }}
+          rustup toolchain install 1.92
+          rustup default 1.92
+          rustup target add armv7r-none-eabihf
+          rustup target add armv8r-none-eabihf
           rustup component add clippy
       - name: Clippy
         run: |
-          cargo clippy --target ${{ matrix.target }}
-          cargo clippy --target ${{ matrix.target }} --no-default-features
-          cargo clippy --target ${{ matrix.target }} --all-features
+          just clippy-examples
 
   # Run clippy on the host tools
   clippy-host:
     runs-on: ubuntu-24.04
     needs: setup
-    strategy:
-      matrix:
-        rust: ${{ fromJSON(needs.setup.outputs.rust-versions) }}
     steps:
       - name: Checkout
         uses: actions/checkout@v4
-      - name: Install rust
+      - name: Install Just
+        uses: taiki-e/install-action@just
+      - name: Install Rust
         run: |
-          rustup install ${{ matrix.rust }}
-          rustup default ${{ matrix.rust }}
+          rustup toolchain install 1.92
+          rustup default 1.92
           rustup component add clippy
       - name: Clippy
         run: |
-          cd arm-targets
-          cargo clippy
+          just clippy-host
 
   # Gather all the above clippy jobs together for the purposes of getting an overall pass-fail
   clippy-all:
     runs-on: ubuntu-24.04
-    needs: [clippy, clippy-host]
+    needs: [clippy, clippy-examples, clippy-host]
     steps:
       - run: /bin/true
 
@@ -245,13 +238,14 @@ jobs:
     steps:
       - name: Checkout
         uses: actions/checkout@v4
-      - name: Install rust
+      - name: Install Just
+        uses: taiki-e/install-action@just
+      - name: Install Rust
         run: |
           rustup install stable
           rustup default stable
-      - name: Run cargo test
-        run: |
-          cargo test --manifest-path aarch32-cpu/Cargo.toml
+      - run: |
+          just test-cargo
 
   # Run some programs in QEMU 9
   # These tests build with nightly as pinned by the rust-toolchain.toml file, because they include Tier 3 targets
@@ -261,6 +255,8 @@ jobs:
     steps:
       - name: Checkout
         uses: actions/checkout@v4
+      - name: Install Just
+        uses: taiki-e/install-action@just
       - name: Install Dependencies
         run: |
           sudo apt-get -y update
@@ -271,7 +267,7 @@ jobs:
       - name: Run tests in QEMU
         run: |
           export PATH=/opt/qemu/bin:$PATH
-          ./tests.sh
+          just test-qemu
 
   # Gather all the above xxx-all jobs together for the purposes of getting an overall pass-fail
   all:

.gitignore

@@ -1,2 +1,8 @@
 target
+examples/mps3-an536/target
+examples/mps3-an536/target-d32
+examples/versatileab/target
+examples/versatileab/target-d32
 Cargo.lock
+**/.DS_Store
+

aarch32-rt/src/arch_v7/svc.rs

@@ -21,10 +21,14 @@ core::arch::global_asm!(
     r#"
         mrs     r0, spsr                 // Load processor status that was banked on entry
         tst     r0, {t_bit}              // SVC occurred from Thumb state?
-        ldrhne  r0, [lr,#-2]             // Yes: Load halfword and...
-        bicne   r0, r0, #0xFF00          // ...extract comment field
-        ldreq   r0, [lr,#-4]             // No: Load word and...
-        biceq   r0, r0, #0xFF000000      // ...extract comment field
+        beq     1f
+        ldrh    r0, [lr,#-2]             // Yes: Load halfword and...
+        bic     r0, r0, #0xFF00          // ...extract comment field
+        b       2f
+    1:
+        ldr     r0, [lr,#-4]             // No: Load word and...
+        bic     r0, r0, #0xFF000000      // ...extract comment field
+    2:
         // r0 now contains SVC number
         bl      _svc_handler
     "#,

aarch32-rt/src/lib.rs

@@ -274,7 +274,7 @@
 //! use aarch32_rt::exception;
 //!
 //! #[exception(PrefetchAbort)]
-//! fn my_handler(addr: usize) -> usize {
+//! unsafe fn my_handler(addr: usize) -> usize {
 //!     // do stuff, then go back to the instruction after the one that failed
 //!     addr + 4
 //! }

arm-targets/Cargo.toml

@@ -11,7 +11,7 @@ name = "arm-targets"
 readme = "README.md"
 repository = "https://github.com/rust-embedded/aarch32.git"
 homepage = "https://github.com/rust-embedded/aarch32"
-rust-version = "1.59"
+rust-version = "1.83"
 version = "0.4.0"
 
 [dependencies]

arm-targets/README.md

@@ -29,7 +29,7 @@ This allows you to write Rust code in your firmware like:
 
 ## Minimum Supported Rust Version (MSRV)
 
-This crate is guaranteed to compile on stable Rust 1.59.0 and up, as recorded
+This crate is guaranteed to compile on stable Rust 1.83.0 and up, as recorded
 by the `package.rust-version` property in `Cargo.toml`.
 
 Increasing the MSRV is not considered a breaking change and may occur in a