Add LLVM toolchain support to CI and build system

Author: G36maid

.ci/run-qemu-tests.sh

@@ -1,6 +1,5 @@
 #!/bin/bash
 set -e
-export CROSS_COMPILE=${CROSS_COMPILE:-riscv32-unknown-elf-}
 
 # Check if at least one app is provided
 if [ $# -eq 0 ]; then
@@ -11,19 +10,21 @@ fi
 
 APPS="$@"
 TIMEOUT=10
+TOOLCHAIN_TYPE=${TOOLCHAIN_TYPE:-gnu}
 
 echo "[+] Will run apps: $APPS"
+echo "[+] Using toolchain: $TOOLCHAIN_TYPE"
 echo ""
 
 # Loop through each app
 for app in $APPS; do
-    echo "=== Running $app ==="
+    echo "=== Running $app ($TOOLCHAIN_TYPE) ==="
 
     # Build the app
-    echo "[+] Building $app..."
+    echo "[+] Building $app with $TOOLCHAIN_TYPE toolchain..."
     make clean >/dev/null 2>&1
-    if ! make "$app" >/dev/null 2>&1; then
-        echo "[!] Failed to build $app"
+    if ! make "$app" TOOLCHAIN_TYPE="$TOOLCHAIN_TYPE" >/dev/null 2>&1; then
+        echo "[!] Failed to build $app with $TOOLCHAIN_TYPE"
         echo ""
         continue
     fi
@@ -46,4 +47,4 @@ for app in $APPS; do
     echo ""
 done
 
-echo "[+] All apps tested"
+echo "[+] All apps tested with $TOOLCHAIN_TYPE toolchain"

.ci/setup-toolchain.sh

@@ -1,11 +1,56 @@
 #!/bin/bash
 set -e
 
-URL="https://github.com/riscv-collab/riscv-gnu-toolchain/releases/download/2025.06.13/riscv32-elf-ubuntu-22.04-gcc-nightly-2025.06.13-nightly.tar.xz"
+# Default to GNU if no toolchain specified
+TOOLCHAIN_TYPE=${1:-gnu}
 
-echo "[+] Downloading RISC-V GNU toolchain..."
-wget "$URL"
-tar -xf "$(basename "$URL")"
+setup_gnu_toolchain() {
+    echo "[+] Setting up GNU RISC-V toolchain..."
 
-echo "[+] Exporting toolchain path..."
-echo "$PWD/riscv/bin" >> "$GITHUB_PATH"
+    local URL="https://github.com/riscv-collab/riscv-gnu-toolchain/releases/download/2025.07.03/riscv32-elf-ubuntu-24.04-gcc-nightly-2025.06.13-nightly.tar.xz"
+
+    echo "[+] Downloading RISC-V GNU toolchain..."
+    wget -q "$URL"
+    tar -xf "$(basename "$URL")"
+
+    echo "[+] Exporting GNU toolchain path..."
+    echo "$PWD/riscv/bin" >> "$GITHUB_PATH"
+
+    # Set cross-compile prefix for GNU
+    echo "CROSS_COMPILE=riscv32-unknown-elf-" >> "$GITHUB_ENV"
+    echo "TOOLCHAIN_TYPE=gnu" >> "$GITHUB_ENV"
+}
+
+setup_llvm_toolchain() {
+    echo "[+] Setting up LLVM RISC-V toolchain..."
+
+    # upstream URL for LLVM toolchain
+    local URL="https://github.com/riscv-collab/riscv-gnu-toolchain/releases/download/2025.07.03/riscv32-elf-ubuntu-24.04-llvm-nightly-2025.06.13-nightly.tar.xz"
+
+    echo "[+] Downloading RISC-V LLVM toolchain..."
+    wget -q "$URL"
+    tar -xf "$(basename "$URL")"
+
+    echo "[+] Exporting LLVM toolchain path..."
+    echo "$PWD/riscv/bin" >> "$GITHUB_PATH"
+
+    # Set cross-compile prefix for LLVM
+    echo "CROSS_COMPILE=llvm-" >> "$GITHUB_ENV"
+    echo "TOOLCHAIN_TYPE=llvm" >> "$GITHUB_ENV"
+}
+
+case "$TOOLCHAIN_TYPE" in
+    "gnu")
+        setup_gnu_toolchain
+        ;;
+    "llvm")
+        setup_llvm_toolchain
+        ;;
+    *)
+        echo "Error: Unknown toolchain type '$TOOLCHAIN_TYPE'"
+        echo "Usage: $0 [gnu|llvm]"
+        exit 1
+        ;;
+esac
+
+echo "[+] Toolchain setup complete: $TOOLCHAIN_TYPE"

.github/workflows/ci.yml

@@ -7,35 +7,43 @@ on:
     branches: [main, ci]
 
 jobs:
-  basic-tests:
+  matrix-tests:
     runs-on: ubuntu-24.04
-    name: Basic Tests
+    name: Test on ${{ matrix.toolchain }} toolchain
+
+    strategy:
+      fail-fast: false
+      matrix:
+        toolchain: [gnu, llvm]
 
     steps:
       - name: Checkout
         uses: actions/checkout@v4
 
-      - name: Install dependencies
+      - name: Install base dependencies
         run: |
           sudo apt-get update
           sudo apt-get install -y build-essential qemu-system-riscv32 wget
 
-      - name: Setup RISC-V Toolchain
-        run: .ci/setup-toolchain.sh
+      - name: Setup ${{ matrix.toolchain }} toolchain
+        run: .ci/setup-toolchain.sh ${{ matrix.toolchain }}
 
       - name: Verify toolchain installation
         run: |
-          riscv32-unknown-elf-gcc --version
+          if [ "${{ matrix.toolchain }}" = "gnu" ]; then
+            riscv32-unknown-elf-gcc --version
+          else
+            riscv32-unknown-elf-clang --version
+            riscv32-unknown-elf-llvm-objdump --version
+          fi
           qemu-system-riscv32 --version
-        env:
-          CROSS_COMPILE: riscv32-unknown-elf-
 
       - name: Build Kernel
         run: |
           make clean
           make
         env:
-          CROSS_COMPILE: riscv32-unknown-elf-
+          TOOLCHAIN_TYPE: ${{ matrix.toolchain }}
 
       - name: Run Basic Apps
         id: test
@@ -44,16 +52,35 @@ jobs:
           echo "TEST_OUTPUT<<EOF" >> $GITHUB_OUTPUT
           echo "$output" >> $GITHUB_OUTPUT
           echo "EOF" >> $GITHUB_OUTPUT
+        env:
+          TOOLCHAIN_TYPE: ${{ matrix.toolchain }}
 
       - name: Comment PR with results
         if: github.event_name == 'pull_request'
         uses: actions/github-script@v7
         with:
           script: |
             const output = `${{ steps.test.outputs.TEST_OUTPUT }}`;
+            const toolchain = `${{ matrix.toolchain }}`.toUpperCase();
             github.rest.issues.createComment({
               issue_number: context.issue.number,
               owner: context.repo.owner,
               repo: context.repo.repo,
-              body: `## Linmo QEMU App Test Result\n\n\`\`\`\n${output}\n\`\`\`\n\n_This is an automated report from CI._`
+              body: `## Linmo QEMU App Test Result (${toolchain} Toolchain)\n\n\`\`\`\n${output}\n\`\`\`\n\n_This is an automated report from CI._`
             });
+
+  # Optional: Create a summary job that depends on all matrix jobs
+  test-summary:
+    runs-on: ubuntu-24.04
+    needs: matrix-tests
+    if: always()
+
+    steps:
+      - name: Check test results
+        run: |
+          if [ "${{ needs.matrix-tests.result }}" = "success" ]; then
+            echo "✅ All toolchain tests passed!"
+          else
+            echo "❌ Some toolchain tests failed"
+            exit 1
+          fi