add cortex-m0 support for testsuite

Author: robamu

.github/workflows/on-target.yml

@@ -9,6 +9,8 @@ name: cortex-m on-target tests
 jobs:
 
   hil-qemu:
+    env:
+      PATH: /opt/qemu/bin:$PATH
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
@@ -23,11 +25,14 @@ jobs:
       - name: Install custom QEMU into /opt
         run: |
           curl -sSL https://github.com/jonathanpallant/qemu9-for-ubuntu-2404/releases/download/qemu-9.2.3%2Bbuild0/qemu-9.2.3-ubuntu-24.04.tar.gz | sudo tar xvzf - -C /
-      - name: Run testsuite
+          echo "/opt/qemu/bin" >> "$GITHUB_PATH"
+      - name: Install toolchains
         uses: dtolnay/rust-toolchain@stable
         with:
-          targets: thumbv7em-none-eabihf
-      - name: Run testsuite
+          targets: thumbv7em-none-eabihf, thumbv6m-none-eabi
+      - name: Run testsuite Cortex-M3
         run: |
-          export PATH=/opt/qemu/bin:$PATH
-          cd testsuite && cargo test --features qemu
+          cd testsuite && cargo test --features qemu --target thumbv7em-none-eabihf
+      - name: Run testsuite Cortex-M0
+        run: |
+          cd testsuite && cargo test --features qemu --target thumbv6m-none-eabi

justfile

@@ -0,0 +1,20 @@
+
+LOG_FORMAT := " --log-format \"{[{L}]%bold} {s} {({ff}:{l:1})%dimmed}\""
+QEMU_RUN_CORTEX_M3 := "qemu-run --machine lm3s6965evb --cpu cortex-m3"
+QEMU_RUN_CORTEX_M0 := "qemu-run --machine microbit --cpu cortex-m0"
+
+[working-directory: "testsuite"]
+run-cortex-m0 binary:
+  {{QEMU_RUN_CORTEX_M0}} {{binary}}
+
+[working-directory: "testsuite"]
+run-cortex-m3 binary:
+  {{QEMU_RUN_CORTEX_M3}} {{binary}}
+
+[working-directory: "testsuite"]
+run-cortex-m3-test:
+  cargo test --features qemu --target thumbv7em-none-eabihf
+
+[working-directory: "testsuite"]
+run-cortex-m0-test:
+  cargo test --features qemu --target thumbv6m-none-eabi --release

testsuite/.cargo/config.toml

@@ -1,23 +1,19 @@
+
 [target.'cfg(all(target_arch = "arm", target_os = "none"))']
 rustflags = [
   "-C", "link-arg=-Tlink.x",
   "-C", "link-arg=-Tdefmt.x",
 ]
-runner = [
-  "qemu-run",
-  "--machine",
-  "lm3s6965evb",
-  "--cpu",
-  "cortex-m3",
-  "--log-format",
-  "{[{L}]%bold} {s} {({ff}:{l:1})%dimmed}"
-]
-# For running on actual hardware.
-# runner = "probe-rs run --chip <your-chip> --allow-erase-all"
+
+[target.thumbv7em-none-eabihf]
+runner = "qemu-run --machine lm3s6965evb --cpu cortex-m3"
+
+[target.thumbv6m-none-eabi]
+runner = "qemu-run --machine microbit --cpu cortex-m0"
 
 [build]
 # target = "thumbv6m-none-eabi"  # Cortex-M0
-target = "thumbv7em-none-eabihf"
+target = "thumbv7em-none-eabihf"  # Cortex-M3
 
 [env]
 DEFMT_LOG = "info"

testsuite/Cargo.toml

@@ -8,6 +8,7 @@ rust-version = "1.85"
 [features]
 hardware = ["dep:defmt-rtt"]
 qemu = ["dep:defmt-semihosting"]
+# microbit = ["dep:nrf-pac"]
 
 [dependencies]
 cortex-m-rt = { path = "../cortex-m-rt" }
@@ -16,6 +17,7 @@ critical-section = "1"
 cortex-m-semihosting = { path = "../cortex-m-semihosting"}
 defmt-semihosting = { version = "0.3", optional = true }
 defmt-rtt = { version = "1", optional = true }
+# nrf-pac = { version = "0.3", features = ["nrf51", "rt"], optional = true }
 defmt = "1"
 
 [dev-dependencies]
@@ -32,3 +34,8 @@ test = false
 [patch.crates-io]
 cortex-m = { path = "../cortex-m" }
 cortex-m-rt = { path = "../cortex-m-rt" }
+
+[profile.release]
+opt-level = "z"     # Optimize for size
+lto = true          # Enable Link Time Optimization
+codegen-units = 1   # Better optimization at cost of compile time

testsuite/build.rs

@@ -1,8 +1,10 @@
-use std::{
-    env,
-    path::{Path, PathBuf},
-};
+use std::{env, path::PathBuf};
 
+#[derive(Debug, PartialEq, Eq, Clone, Copy)]
+pub enum MemorySelect {
+    CortexM0,
+    CortexM3,
+}
 fn main() {
     let target = std::env::var("TARGET").unwrap();
 
@@ -13,11 +15,15 @@ fn main() {
     println!("cargo:rustc-check-cfg=cfg(armv8m_base)");
     println!("cargo:rustc-check-cfg=cfg(armv8m_main)");
 
+    let mut memory_select = None;
     if target.starts_with("thumbv6m-") {
+        memory_select = Some(MemorySelect::CortexM0);
         println!("cargo:rustc-cfg=armv6m");
     } else if target.starts_with("thumbv7m-") {
+        memory_select = Some(MemorySelect::CortexM3);
         println!("cargo:rustc-cfg=armv7m");
     } else if target.starts_with("thumbv7em-") {
+        memory_select = Some(MemorySelect::CortexM3);
         println!("cargo:rustc-cfg=armv7m");
         println!("cargo:rustc-cfg=armv7em"); // (not currently used)
     } else if target.starts_with("thumbv8m.base") {
@@ -28,26 +34,33 @@ fn main() {
         println!("cargo:rustc-cfg=armv8m_main");
     }
 
-    // Put `memory.x` in our output directory and ensure it's
-    // on the linker search path.
     let out = PathBuf::from(env::var_os("OUT_DIR").unwrap());
-    let memory_x_path = out.join("memory.x");
+    let memory_x_file = match memory_select {
+        Some(MemorySelect::CortexM0) => {
+            // Put `memory.x` in our output directory and ensure it's
+            // on the linker search path.
+            "memory_microbit.x"
+        }
+        Some(MemorySelect::CortexM3) => {
+            // Put `memory.x` in our output directory and ensure it's
+            // on the linker search path.
+            "memory_m3.x"
+        }
+        // TODO: Copy memory.x if it exists?
+        None => panic!("Unsupported target architecture: {}", target),
+    };
+    let target_path = out.join("memory.x");
 
     // Copy memory.x from parent directory only if it doesn't exist locally
-    if !Path::new("memory.x").exists() {
-        std::fs::copy("../memory.x", &memory_x_path)
-            .unwrap_or_else(|e| panic!("Failed to copy memory.x from parent: {}", e));
-    } else {
-        std::fs::copy("memory.x", &memory_x_path)
-            .unwrap_or_else(|e| panic!("Failed to copy memory.x: {}", e));
-    }
+    std::fs::copy(memory_x_file, &target_path)
+        .unwrap_or_else(|e| panic!("Failed to copy memory.x: {}", e));
 
     println!("cargo:rustc-link-search={}", out.display());
 
     // By default, Cargo will re-run a build script whenever
     // any file in the project changes. By specifying `memory.x`
     // here, we ensure the build script is only re-run when
     // `memory.x` is changed.
-    println!("cargo:rerun-if-changed=memory.x");
-    println!("cargo:rerun-if-changed=../memory.x");
+    println!("cargo:rerun-if-changed=memory_m3.x");
+    println!("cargo:rerun-if-changed=memory_microbit.x");
 }

testsuite/memory_m3.x

@@ -0,0 +1,23 @@
+/* Sample memory.x file used for cortex-m-rt examples and tests only.
+ * You must provide your own memory.x with values correct for your device,
+ * don't just copy these.
+ */
+
+MEMORY
+{
+  /* FLASH and RAM are mandatory memory regions */
+  /* Update examples/data_overflow.rs if you change these sizes. */
+  FLASH : ORIGIN = 0x00000000, LENGTH = 256K
+  RAM : ORIGIN = 0x20000000, LENGTH = 64K
+
+  /* More memory regions can declared: for example this is a second RAM region */
+  /* CCRAM : ORIGIN = 0x10000000, LENGTH = 8K */
+}
+
+/* The location of the stack can be overridden using the `_stack_start` symbol.
+   By default it will be placed at the end of the RAM region */
+/* _stack_start = ORIGIN(CCRAM) + LENGTH(CCRAM); */
+
+/* The location of the .text section can be overridden using the `_stext` symbol.
+   By default it will place after .vector_table */
+/* _stext = ORIGIN(FLASH) + 0x40c; */

testsuite/memory_microbit.x

@@ -0,0 +1,6 @@
+MEMORY
+{
+  /* NOTE K = KiBi = 1024 bytes */
+  FLASH : ORIGIN = 0x00000000, LENGTH = 256K
+  RAM : ORIGIN = 0x20000000, LENGTH = 16K
+}

testsuite/src/lib.rs

@@ -170,7 +170,7 @@ mod tests {
     // this test must be last!
     #[test]
     fn run_psp() {
-        static STACK: cortex_m::psp::Stack<4096> = cortex_m::psp::Stack::new();
+        static STACK: cortex_m::psp::Stack<2048> = cortex_m::psp::Stack::new();
         info!("Switching to PSP...");
         cortex_m::psp::switch_to_unprivileged_psp(STACK.take_handle(), crate::user_fn);
     }