rust-embedded · adamgreig · Sep 2, 2026 · Sep 2, 2026 · Sep 2, 2026 · Sep 2, 2026
diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
@@ -26,14 +26,11 @@ jobs:
   # Build the workspace for a target architecture using the MSRV
   build-tier2-msrv:
     runs-on: ubuntu-24.04
+    timeout-minutes: 10
     needs: setup
     strategy:
       matrix:
         target: ${{ fromJSON(needs.setup.outputs.msrv-targets) }}
-        action:
-          - build
-          - clippy
-          - doc
     steps:
       - name: Checkout
         uses: actions/checkout@v7
@@ -43,21 +40,25 @@ jobs:
         run: |
           rustup install 1.93
           rustup target add ${{ matrix.target }} --toolchain=1.93
-      - name: Run just
+          rustup component add clippy --toolchain=1.93
+      - name: Run build
         run: |
-          RUSTUP_TOOLCHAIN=1.93 just ${{ matrix.action }}-tier2 ${{ matrix.target }}
+          RUSTUP_TOOLCHAIN=1.93 just build-tier2 ${{ matrix.target }}
+      - name: Run clippy
+        run: |
+          RUSTUP_TOOLCHAIN=1.93 just clippy-tier2 ${{ matrix.target }}
+      - name: Run doc
+        run: |
+          RUSTUP_TOOLCHAIN=1.93 just doc-tier2 ${{ matrix.target }}
 
   # Build the workspace for a target architecture using latest stable
   build-tier2-stable:
     runs-on: ubuntu-24.04
+    timeout-minutes: 10
     needs: setup
     strategy:
       matrix:
         target: ${{ fromJSON(needs.setup.outputs.stable-targets) }}
-        action:
-          - build
-          - clippy
-          - doc
     steps:
       - name: Checkout
         uses: actions/checkout@v7
@@ -67,73 +68,90 @@ jobs:
         run: |
           rustup install stable
           rustup target add ${{ matrix.target }} --toolchain=stable
-      - name: Run just
+          rustup component add clippy --toolchain=stable
+      - name: Run build
+        run: |
+          RUSTUP_TOOLCHAIN=stable just build-tier2 ${{ matrix.target }}
+      - name: Run clippy
+        run: |
+          RUSTUP_TOOLCHAIN=stable just clippy-tier2 ${{ matrix.target }}
+      - name: Run doc
         run: |
-          RUSTUP_TOOLCHAIN=stable just ${{ matrix.action }}-tier2 ${{ matrix.target }}
+          RUSTUP_TOOLCHAIN=stable just doc-tier2 ${{ matrix.target }}
 
   # Build the workspace for all tier2 target architectures using rust-toolchain.toml
   build-tier2-nightly:
     runs-on: ubuntu-24.04
+    timeout-minutes: 10
     needs: setup
     strategy:
       matrix:
         target: ${{ fromJSON(needs.setup.outputs.nightly-tier2-targets) }}
-        action:
-          - build
-          - clippy
-          - doc
     steps:
       - name: Checkout
         uses: actions/checkout@v7
       - name: Install Just
         uses: taiki-e/install-action@just
-      - name: Run just
+      - name: Run build
+        run: |
+          just build-tier2 ${{ matrix.target }}
+      - name: Run clippy
+        run: |
+          just clippy-tier2 ${{ matrix.target }}
+      - name: Run doc
         run: |
-          just ${{ matrix.action }}-tier2 ${{ matrix.target }}
+          just doc-tier2 ${{ matrix.target }}
 
   # Build the workspace for all tier3 target architectures using rust-toolchain.toml
   build-tier3-nightly:
     runs-on: ubuntu-24.04
+    timeout-minutes: 10
     needs: setup
     strategy:
       matrix:
         target: ${{ fromJSON(needs.setup.outputs.nightly-tier3-targets) }}
-        action:
-          - build
-          - clippy
-          - doc
     steps:
       - name: Checkout
         uses: actions/checkout@v7
       - name: Install Just
         uses: taiki-e/install-action@just
-      - name: Run just
+      - name: Run build
+        run: |
+          just build-tier3 ${{ matrix.target }}
+      - name: Run clippy
         run: |
-          just ${{ matrix.action }}-tier3 ${{ matrix.target }}
+          just clippy-tier3 ${{ matrix.target }}
+      - name: Run doc
+        run: |
+          just doc-tier3 ${{ matrix.target }}
 
   # Build the workspace for all tier3 non atomic target architectures using rust-toolchain.toml
   build-tier3-no-atomics:
     runs-on: ubuntu-24.04
+    timeout-minutes: 10
     needs: setup
     strategy:
       matrix:
         target: ${{ fromJSON(needs.setup.outputs.nightly-tier3-noatomic-targets) }}
-        action:
-          - build
-          - clippy
-          - doc
     steps:
       - name: Checkout
         uses: actions/checkout@v7
       - name: Install Just
         uses: taiki-e/install-action@just
-      - name: Run just
+      - name: Run build
+        run: |
+          just build-tier3-no-atomics ${{ matrix.target }}
+      - name: Run clippy
+        run: |
+          just clippy-tier3-no-atomics ${{ matrix.target }}
+      - name: Run doc
         run: |
-          just ${{ matrix.action }}-tier3-no-atomics ${{ matrix.target }}
+          just doc-tier3-no-atomics ${{ matrix.target }}
 
   # Build the host-only stuff on stable and MSRV
   build-arm-targets:
     runs-on: ubuntu-24.04
+    timeout-minutes: 10
     needs: setup
     strategy:
       matrix:
@@ -165,6 +183,7 @@ jobs:
   # Gather all the above build jobs together for the purposes of getting an overall pass-fail
   build-all:
     runs-on: ubuntu-24.04
+    timeout-minutes: 10
     needs:
       - build-tier2-msrv
       - build-tier2-stable
@@ -178,6 +197,7 @@ jobs:
   # Format the workspace
   fmt-check:
     runs-on: ubuntu-24.04
+    timeout-minutes: 10
     needs: setup
     steps:
       - name: Checkout
@@ -191,6 +211,7 @@ jobs:
   # Run clippy on the examples
   clippy-examples:
     runs-on: ubuntu-24.04
+    timeout-minutes: 10
     needs: setup
     steps:
       - name: Checkout
@@ -208,6 +229,7 @@ jobs:
   # Run the unit tests
   test-cargo:
     runs-on: ubuntu-24.04
+    timeout-minutes: 10
     needs: setup
     steps:
       - name: Checkout
@@ -221,6 +243,7 @@ jobs:
   # Run some programs in QEMU 9
   test-qemu:
     runs-on: ubuntu-24.04
+    timeout-minutes: 10
     needs: setup
     strategy:
       matrix:

diff --git a/aarch32-tests/tests/tests.rs b/aarch32-tests/tests/tests.rs
@@ -137,33 +137,34 @@ fn main() {
     for group in MATRIX {
         for &target in group.targets {
             for variant in group.variants {
-                let mut name = format!("{}/{}", group.example, target);
-                if !variant.label.is_empty() {
-                    name.push_str(&format!(" [{}]", variant.label));
-                }
-
                 let example = group.example;
-                let target = target.to_string();
                 let rustflags = group.rustflags;
-                let flags: Vec<&'static str> = group
-                    .flags
-                    .iter()
-                    .chain(variant.extra_flags)
-                    .copied()
-                    .collect();
-
-                tests.push(Trial::test(name, move || {
-                    run_target(example, &target, &flags, rustflags);
-                    Ok(())
-                }));
+                let dir = test_utils::test_dir(&format!("examples/{example}"));
+                for bin in test_utils::discover_bins(&dir) {
+                    let target = target.to_string();
+                    let flags: Vec<&'static str> = group
+                        .flags
+                        .iter()
+                        .chain(variant.extra_flags)
+                        .copied()
+                        .collect();
+                    let mut name = format!("{}/{}/{}", group.example, target, bin);
+                    if !variant.label.is_empty() {
+                        name.push_str(&format!(" [{}]", variant.label));
+                    }
+                    tests.push(Trial::test(name, move || {
+                        run_target_bin(example, &bin, &target, &flags, rustflags);
+                        Ok(())
+                    }));
+                }
             }
         }
     }
 
     libtest_mimic::run(&args, tests).exit();
 }
 
-fn run_target(example: &str, target: &str, flags: &[&str], rustflags: Option<&str>) {
+fn run_target_bin(example: &str, bin: &str, target: &str, flags: &[&str], rustflags: Option<&str>) {
     let dir = test_utils::test_dir(&format!("examples/{example}"));
 
     // Per-example folder: snapshots/<example>/<bin>-<target>.snap
@@ -174,8 +175,6 @@ fn run_target(example: &str, target: &str, flags: &[&str], rustflags: Option<&st
     settings.set_prepend_module_to_snapshot(false);
     let _guard = settings.bind_to_scope();
 
-    for bin in test_utils::discover_bins(&dir) {
-        let stdout = test_utils::run_bin(&dir, &bin, target, flags, rustflags);
-        insta::assert_snapshot!(format!("{bin}-{target}"), stdout);
-    }
+    let stdout = test_utils::run_bin(&dir, &bin, target, flags, rustflags);
+    insta::assert_snapshot!(format!("{bin}-{target}"), stdout);
 }
diff --git a/examples/mps3-an536-el2/memory.x b/examples/mps3-an536-el2/memory.x
@@ -23,4 +23,18 @@ PROVIDE(_irq_stack_size = 8);
 PROVIDE(_fiq_stack_size = 8);
 PROVIDE(_sys_stack_size = 8);
 
-PROVIDE(_num_cores = 2);
+PROVIDE(_num_cores = 2);
+
+EXTERN(_unexpected_undefined_exception_handler);
+EXTERN(_unexpected_svc_exception_handler);
+EXTERN(_unexpected_hvc_exception_handler);
+EXTERN(_unexpected_prefetch_abort_exception_handler);
+EXTERN(_unexpected_data_abort_exception_handler);
+EXTERN(_unexpected_irq_exception_handler);
+
+PROVIDE(_undefined_handler      = _unexpected_undefined_exception_handler);
+PROVIDE(_svc_handler            = _unexpected_svc_exception_handler);
+PROVIDE(_hvc_handler            = _unexpected_hvc_exception_handler);
+PROVIDE(_prefetch_abort_handler = _unexpected_prefetch_abort_exception_handler);
+PROVIDE(_data_abort_handler     = _unexpected_data_abort_exception_handler);
+PROVIDE(_irq_handler            = _unexpected_irq_exception_handler);
diff --git a/examples/mps3-an536-el2/src/lib.rs b/examples/mps3-an536-el2/src/lib.rs
@@ -254,3 +254,39 @@ unsafe fn make_gic() -> arm_gic::gicv3::GicV3<'static> {
     arm_gic::gicv3::GicCpuInterface::set_priority_mask(0x80);
     gic
 }
+
+#[unsafe(no_mangle)]
+pub extern "C" fn _unexpected_undefined_exception_handler() -> ! {
+    semihosting::eprintln!("In _unexpected_undefined_exception_handler!");
+    semihosting::process::exit(1);
+}
+
+#[unsafe(no_mangle)]
+pub extern "C" fn _unexpected_svc_exception_handler() -> ! {
+    semihosting::eprintln!("In _unexpected_svc_exception_handler!");
+    semihosting::process::exit(1);
+}
+
+#[unsafe(no_mangle)]
+pub extern "C" fn _unexpected_hvc_exception_handler() -> ! {
+    semihosting::eprintln!("In _unexpected_hvc_exception_handler!");
+    semihosting::process::exit(1);
+}
+
+#[unsafe(no_mangle)]
+pub extern "C" fn _unexpected_prefetch_abort_exception_handler() -> ! {
+    semihosting::eprintln!("In _unexpected_prefetch_abort_exception_handler!");
+    semihosting::process::exit(1);
+}
+
+#[unsafe(no_mangle)]
+pub extern "C" fn _unexpected_data_abort_exception_handler() -> ! {
+    semihosting::eprintln!("In _unexpected_data_abort_exception_handler!");
+    semihosting::process::exit(1);
+}
+
+#[unsafe(no_mangle)]
+pub extern "C" fn _unexpected_irq_exception_handler() -> ! {
+    semihosting::eprintln!("In _unexpected_irq_exception_handler!");
+    semihosting::process::exit(1);
+}
diff --git a/examples/mps3-an536/memory.x b/examples/mps3-an536/memory.x
@@ -46,3 +46,17 @@ PROVIDE(_inter_stack_padding = 64);
 PROVIDE(_region_alignment = 64K);
 
 PROVIDE(_num_cores = 2);
+
+EXTERN(_unexpected_undefined_exception_handler);
+EXTERN(_unexpected_svc_exception_handler);
+EXTERN(_unexpected_hvc_exception_handler);
+EXTERN(_unexpected_prefetch_abort_exception_handler);
+EXTERN(_unexpected_data_abort_exception_handler);
+EXTERN(_unexpected_irq_exception_handler);
+
+PROVIDE(_undefined_handler      = _unexpected_undefined_exception_handler);
+PROVIDE(_svc_handler            = _unexpected_svc_exception_handler);
+PROVIDE(_hvc_handler            = _unexpected_hvc_exception_handler);
+PROVIDE(_prefetch_abort_handler = _unexpected_prefetch_abort_exception_handler);
+PROVIDE(_data_abort_handler     = _unexpected_data_abort_exception_handler);
+PROVIDE(_irq_handler            = _unexpected_irq_exception_handler);
diff --git a/examples/mps3-an536/src/lib.rs b/examples/mps3-an536/src/lib.rs
@@ -298,3 +298,39 @@ pub extern "C" fn _asm_secondary_core_park() {
     fpga_led = const FPGA_LED
     );
 }
+
+#[unsafe(no_mangle)]
+pub extern "C" fn _unexpected_undefined_exception_handler() -> ! {
+    semihosting::eprintln!("In _unexpected_undefined_exception_handler!");
+    semihosting::process::exit(1);
+}
+
+#[unsafe(no_mangle)]
+pub extern "C" fn _unexpected_svc_exception_handler() -> ! {
+    semihosting::eprintln!("In _unexpected_svc_exception_handler!");
+    semihosting::process::exit(1);
+}
+
+#[unsafe(no_mangle)]
+pub extern "C" fn _unexpected_hvc_exception_handler() -> ! {
+    semihosting::eprintln!("In _unexpected_hvc_exception_handler!");
+    semihosting::process::exit(1);
+}
+
+#[unsafe(no_mangle)]
+pub extern "C" fn _unexpected_prefetch_abort_exception_handler() -> ! {
+    semihosting::eprintln!("In _unexpected_prefetch_abort_exception_handler!");
+    semihosting::process::exit(1);
+}
+
+#[unsafe(no_mangle)]
+pub extern "C" fn _unexpected_data_abort_exception_handler() -> ! {
+    semihosting::eprintln!("In _unexpected_data_abort_exception_handler!");
+    semihosting::process::exit(1);
+}
+
+#[unsafe(no_mangle)]
+pub extern "C" fn _unexpected_irq_exception_handler() -> ! {
+    semihosting::eprintln!("In _unexpected_irq_exception_handler!");
+    semihosting::process::exit(1);
+}