fix(esp32c3): use semihosting _exit for QEMU emulator support

.github/actions/setup-embed-deps/action.yml

@@ -0,0 +1,35 @@
+name: "Setup Embedded Dependencies"
+description: "Install dependencies required for embedded QEMU tests"
+
+runs:
+  using: "composite"
+  steps:
+    - name: Install macOS embedded dependencies
+      if: runner.os == 'macOS'
+      shell: bash
+      env:
+        HOMEBREW_NO_INSTALLED_DEPENDENTS_CHECK: 1
+      run: |
+        brew update
+        brew install sdl2
+
+    - name: Install Ubuntu embedded dependencies
+      if: runner.os == 'Linux'
+      shell: bash
+      run: |
+        sudo apt-get update
+        sudo apt-get install -y libsdl2-2.0-0
+
+    - name: Install ESP32 RISC-V QEMU
+      shell: bash
+      run: |
+        chmod +x .github/workflows/install-esp-qemu.sh
+        QEMU_DIR=".cache/qemu"
+        .github/workflows/install-esp-qemu.sh "$QEMU_DIR"
+        echo "${PWD}/${QEMU_DIR}/bin" >> $GITHUB_PATH
+
+    - name: Verify ESP32 RISC-V QEMU installation
+      shell: bash
+      run: |
+        which qemu-system-riscv32
+        qemu-system-riscv32 --version

.github/workflows/go.yml

@@ -34,6 +34,9 @@ jobs:
         with:
           llvm-version: ${{matrix.llvm}}
 
+      - name: Install embedded dependencies
+        uses: ./.github/actions/setup-embed-deps
+
       - name: Clang information
         run: |
           echo $PATH

.github/workflows/install-esp-qemu.sh

@@ -0,0 +1,58 @@
+#!/bin/bash
+set -e
+
+# Installation directory (from argument or default)
+INSTALL_DIR="${1:-.cache/qemu}"
+
+# Detect platform
+OS=$(uname -s | tr '[:upper:]' '[:lower:]')
+ARCH=$(uname -m)
+
+# Map architecture names
+case "$ARCH" in
+  x86_64|amd64)
+    ARCH="x86_64"
+    ;;
+  aarch64|arm64)
+    ARCH="aarch64"
+    ;;
+  *)
+    echo "Unsupported architecture: $ARCH"
+    exit 1
+    ;;
+esac
+
+# Map OS names
+case "$OS" in
+  darwin)
+    PLATFORM="${ARCH}-apple-darwin"
+    ;;
+  linux)
+    PLATFORM="${ARCH}-linux-gnu"
+    ;;
+  *)
+    echo "Unsupported OS: $OS"
+    exit 1
+    ;;
+esac
+
+# Download URL
+VERSION="esp_develop_9.2.2_20250817"
+FILENAME="qemu-riscv32-softmmu-${VERSION}-${PLATFORM}.tar.xz"
+URL="https://github.com/espressif/qemu/releases/download/esp-develop-9.2.2-20250817/${FILENAME}"
+
+echo "Detected platform: $PLATFORM"
+echo "Installing to: ${INSTALL_DIR}"
+echo "Downloading ESP32 RISC-V QEMU from: $URL"
+
+# Download and extract
+mkdir -p "$INSTALL_DIR"
+curl -fsSL "$URL" | tar -xJ -C "$INSTALL_DIR" --strip-components=1
+
+# Verify installation
+if [ ! -f "${INSTALL_DIR}/bin/qemu-system-riscv32" ]; then
+  echo "Error: qemu-system-riscv32 not found after extraction"
+  exit 1
+fi
+
+echo "ESP32 RISC-V QEMU installed successfully to: ${INSTALL_DIR}"

.github/workflows/llgo.yml

@@ -51,6 +51,8 @@ jobs:
         uses: ./.github/actions/setup-deps
         with:
           llvm-version: ${{matrix.llvm}}
+      - name: Install embedded dependencies
+        uses: ./.github/actions/setup-embed-deps
       - name: Download model artifact
         uses: actions/download-artifact@v7
         with:
@@ -209,7 +211,6 @@ jobs:
         run: |
           llgo test ./...
 
-
   hello:
     continue-on-error: true
     timeout-minutes: 30

.github/workflows/targets.yml

@@ -1,4 +1,3 @@
-
 name: Targets
 
 on:

_demo/embed/test_esp32c3_startup.sh

@@ -1,6 +1,9 @@
 #!/bin/bash
 # ESP32-C3 Startup and .init_array Regression Test
 #
+# This script verifies ESP32-C3 compilation and runs the program in QEMU
+# emulator to ensure basic functionality works correctly.
+#
 # Verifies:
 # 1. _start uses newlib's __libc_init_array (not TinyGo's start.S)
 # 2. .init_array section is merged into .rodata section
@@ -9,7 +12,9 @@
 set -e
 
 SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
-TEMP_DIR=$(mktemp -d)
+# Create temp dir inside _demo/embed/ to use existing go.mod
+TEMP_DIR="$SCRIPT_DIR/.test_tmp_$$"
+mkdir -p "$TEMP_DIR"
 TEST_GO="$TEMP_DIR/main.go"
 TEST_ELF="test.elf"
 TEST_BIN="test.bin"
@@ -32,7 +37,11 @@ echo "==> Creating minimal test program..."
 cat > "$TEST_GO" << 'EOF'
 package main
 
-func main() {}
+import "github.com/goplus/lib/c"
+
+func main() {
+	c.Printf(c.Str("Hello World\n"))
+}
 EOF
 
 echo "==> Building for ESP32-C3 target (ELF + BIN)..."
@@ -223,11 +232,29 @@ else
     exit 1
 fi
 
+echo ""
+echo "=== Test 4: Verify QEMU output ==="
+
+# Ignore emulator boot logs and validate the last non-empty line.
+RUN_OUT=$(llgo run -a -target=esp32c3-basic -emulator . 2>&1)
+LAST_LINE=$(printf "%s\n" "$RUN_OUT" | tr -d '\r' | awk 'NF{line=$0} END{print line}')
+if [ "$LAST_LINE" = "Hello World" ]; then
+    echo "✓ PASS: QEMU output ends with Hello World"
+else
+    echo "✗ FAIL: QEMU output mismatch"
+    echo "Last line: $LAST_LINE"
+    echo ""
+    echo "Full output:"
+    echo "$RUN_OUT"
+    exit 1
+fi
+
 echo ""
 echo "=== All Tests Passed ==="
 echo "✓ ESP32-C3 uses newlib startup (_start calls __libc_init_array)"
 echo "✓ .init_array merged into .rodata section"
 echo "✓ .rodata (including .init_array) included in BIN file"
+echo "✓ QEMU output ends with Hello World"
 echo "✓ Constructor function pointers will be correctly flashed to ESP32-C3"
 
 exit 0

internal/crosscompile/compile/libc/libc_test.go

@@ -17,23 +17,23 @@ func TestGetNewlibESP32Config_LibConfig(t *testing.T) {
 		t.Errorf("Expected Name '%s', got '%s'", expectedName, config.Name)
 	}
 
-	expectedVersion := "esp-4.3.0_20250211-patch4"
+	expectedVersion := "esp-4.3.0_20250211-patch5"
 	if config.Version != expectedVersion {
 		t.Errorf("Expected Version '%s', got '%s'", expectedVersion, config.Version)
 	}
 
-	expectedUrl := "https://github.com/goplus/newlib/archive/refs/tags/esp-4.3.0_20250211-patch4.tar.gz"
+	expectedUrl := "https://github.com/goplus/newlib/archive/refs/tags/esp-4.3.0_20250211-patch5.tar.gz"
 	if config.Url != expectedUrl {
 		t.Errorf("Expected Url '%s', got '%s'", expectedUrl, config.Url)
 	}
 
-	expectedArchiveSrcDir := "newlib-esp-4.3.0_20250211-patch4"
+	expectedArchiveSrcDir := "newlib-esp-4.3.0_20250211-patch5"
 	if config.ResourceSubDir != expectedArchiveSrcDir {
 		t.Errorf("Expected ResourceSubDir '%s', got '%s'", expectedArchiveSrcDir, config.ResourceSubDir)
 	}
 
 	// Test String() method
-	expectedString := "newlib-esp32-esp-4.3.0_20250211-patch4"
+	expectedString := "newlib-esp32-esp-4.3.0_20250211-patch5"
 	if config.String() != expectedString {
 		t.Errorf("Expected String() '%s', got '%s'", expectedString, config.String())
 	}
@@ -333,20 +333,19 @@ func TestGetNewlibESP32ConfigRISCV(t *testing.T) {
 	}
 
 	// Test Groups configuration
-	if len(config.Groups) != 3 {
-		t.Errorf("Expected 3 groups, got %d", len(config.Groups))
+	if len(config.Groups) != 4 {
+		t.Errorf("Expected 4 groups, got %d", len(config.Groups))
 	} else {
-		// Group 0: libcrt0
+		// Group 0: libsemihost
 		group0 := config.Groups[0]
-		expectedOutput0 := "libcrt0-" + target + ".a"
+		expectedOutput0 := "libsemihost-" + target + ".a"
 		if group0.OutputFileName != expectedOutput0 {
 			t.Errorf("Group0 OutputFileName expected '%s', got '%s'", expectedOutput0, group0.OutputFileName)
 		}
 
 		// Check sample files in group0
 		sampleFiles0 := []string{
-			filepath.Join(baseDir, "libgloss", "riscv", "esp", "esp_board.c"),
-			filepath.Join(baseDir, "libgloss", "riscv", "esp", "crt1-board.S"),
+			filepath.Join(baseDir, "libgloss", "riscv", "semihost-sys_exit.c"),
 		}
 		for _, sample := range sampleFiles0 {
 			found := false
@@ -361,17 +360,17 @@ func TestGetNewlibESP32ConfigRISCV(t *testing.T) {
 			}
 		}
 
-		// Group 1: libgloss
+		// Group 1: libcrt0
 		group1 := config.Groups[1]
-		expectedOutput1 := "libgloss-" + target + ".a"
+		expectedOutput1 := "libcrt0-" + target + ".a"
 		if group1.OutputFileName != expectedOutput1 {
 			t.Errorf("Group1 OutputFileName expected '%s', got '%s'", expectedOutput1, group1.OutputFileName)
 		}
 
 		// Check sample files in group1
 		sampleFiles1 := []string{
-			filepath.Join(baseDir, "libgloss", "libnosys", "close.c"),
-			filepath.Join(baseDir, "libgloss", "libnosys", "sbrk.c"),
+			filepath.Join(baseDir, "libgloss", "riscv", "esp", "esp_board.c"),
+			filepath.Join(baseDir, "libgloss", "riscv", "esp", "crt1-board.S"),
 		}
 		for _, sample := range sampleFiles1 {
 			found := false
@@ -386,17 +385,17 @@ func TestGetNewlibESP32ConfigRISCV(t *testing.T) {
 			}
 		}
 
-		// Group 2: libc
+		// Group 2: libgloss
 		group2 := config.Groups[2]
-		expectedOutput2 := "libc-" + target + ".a"
+		expectedOutput2 := "libgloss-" + target + ".a"
 		if group2.OutputFileName != expectedOutput2 {
 			t.Errorf("Group2 OutputFileName expected '%s', got '%s'", expectedOutput2, group2.OutputFileName)
 		}
 
 		// Check sample files in group2
 		sampleFiles2 := []string{
-			filepath.Join(libcDir, "string", "memcpy.c"),
-			filepath.Join(libcDir, "stdlib", "malloc.c"),
+			filepath.Join(baseDir, "libgloss", "libnosys", "close.c"),
+			filepath.Join(baseDir, "libgloss", "libnosys", "sbrk.c"),
 		}
 		for _, sample := range sampleFiles2 {
 			found := false
@@ -411,24 +410,49 @@ func TestGetNewlibESP32ConfigRISCV(t *testing.T) {
 			}
 		}
 
-		// Test CFlags for group2
-		expectedCFlagsGroup2 := []string{
+		// Group 3: libc
+		group3 := config.Groups[3]
+		expectedOutput3 := "libc-" + target + ".a"
+		if group3.OutputFileName != expectedOutput3 {
+			t.Errorf("Group3 OutputFileName expected '%s', got '%s'", expectedOutput3, group3.OutputFileName)
+		}
+
+		// Check sample files in group3
+		sampleFiles3 := []string{
+			filepath.Join(libcDir, "string", "memcpy.c"),
+			filepath.Join(libcDir, "stdlib", "malloc.c"),
+		}
+		for _, sample := range sampleFiles3 {
+			found := false
+			for _, file := range group3.Files {
+				if file == sample {
+					found = true
+					break
+				}
+			}
+			if !found {
+				t.Errorf("Expected file '%s' not found in group3 files", sample)
+			}
+		}
+
+		// Test CFlags for group3 (libc)
+		expectedCFlagsGroup3 := []string{
 			"-DHAVE_CONFIG_H",
 			"-D_LIBC",
 			"-DHAVE_NANOSLEEP",
 			"-D__NO_SYSCALLS__",
 			// ... (other expected flags)
 		}
-		for _, expectedFlag := range expectedCFlagsGroup2 {
+		for _, expectedFlag := range expectedCFlagsGroup3 {
 			found := false
-			for _, flag := range group2.CFlags {
+			for _, flag := range group3.CFlags {
 				if flag == expectedFlag {
 					found = true
 					break
 				}
 			}
 			if !found {
-				t.Errorf("Expected flag '%s' not found in group2 CFlags", expectedFlag)
+				t.Errorf("Expected flag '%s' not found in group3 CFlags", expectedFlag)
 			}
 		}
 
@@ -564,8 +588,8 @@ func TestEdgeCases(t *testing.T) {
 	t.Run("EmptyTarget_RISCV", func(t *testing.T) {
 		config := getNewlibESP32ConfigRISCV("/test/base", "")
 
-		// Check output file name formatting
-		expectedOutput := "libcrt0-.a"
+		// Check output file name formatting (first group is libsemihost)
+		expectedOutput := "libsemihost-.a"
 		if config.Groups[0].OutputFileName != expectedOutput {
 			t.Errorf("Expected OutputFileName '%s', got '%s'", expectedOutput, config.Groups[0].OutputFileName)
 		}
@@ -599,8 +623,8 @@ func TestGroupConfiguration(t *testing.T) {
 
 	t.Run("RISCV_GroupCount", func(t *testing.T) {
 		config := getNewlibESP32ConfigRISCV(baseDir, target)
-		if len(config.Groups) != 3 {
-			t.Errorf("Expected 3 groups for RISCV, got %d", len(config.Groups))
+		if len(config.Groups) != 4 {
+			t.Errorf("Expected 4 groups for RISCV, got %d", len(config.Groups))
 		}
 	})
 
@@ -614,6 +638,7 @@ func TestGroupConfiguration(t *testing.T) {
 	t.Run("RISCV_GroupNames", func(t *testing.T) {
 		config := getNewlibESP32ConfigRISCV(baseDir, target)
 		expectedNames := []string{
+			"libsemihost-" + target + ".a",
 			"libcrt0-" + target + ".a",
 			"libgloss-" + target + ".a",
 			"libc-" + target + ".a",
@@ -650,7 +675,7 @@ func TestCompilerFlags(t *testing.T) {
 
 	t.Run("RISCV_CFlags", func(t *testing.T) {
 		config := getNewlibESP32ConfigRISCV(baseDir, target)
-		group := config.Groups[2] // libc group
+		group := config.Groups[3] // libc group (index 3: libsemihost=0, libcrt0=1, libgloss=2, libc=3)
 
 		requiredFlags := []string{
 			"-DHAVE_CONFIG_H",