diff --git a/internal/crosscompile/compile/libc/libc_test.go b/internal/crosscompile/compile/libc/libc_test.go
new file mode 100644
index 00000000..20022229
--- /dev/null
+++ b/internal/crosscompile/compile/libc/libc_test.go
@@ -0,0 +1,630 @@
+package libc
+
+import (
+	"path/filepath"
+	"testing"
+)
+
+func TestGetPicolibcConfig(t *testing.T) {
+	baseDir := "/test/base"
+	target := "test-target"
+
+	config := GetPicolibcConfig(baseDir, target)
+
+	if config.Name != "picolibc" {
+		t.Errorf("Expected Name 'picolibc', got '%s'", config.Name)
+	}
+	if config.ArchiveSrcDir != "picolibc-main" {
+		t.Errorf("Expected ArchiveSrcDir 'picolibc-main', got '%s'", config.ArchiveSrcDir)
+	}
+
+	// Test LibcCFlags
+	if len(config.LibcCFlags) != 2 {
+		t.Errorf("Expected 2 LibcCFlags, got %d", len(config.LibcCFlags))
+	} else {
+		expected := "-I" + baseDir
+		if config.LibcCFlags[0] != expected {
+			t.Errorf("Expected LibcCFlags[0] to be '%s', got '%s'", expected, config.LibcCFlags[0])
+		}
+
+		expected = "-isystem" + filepath.Join(baseDir, "newlib", "libc", "include")
+		if config.LibcCFlags[1] != expected {
+			t.Errorf("Expected LibcCFlags[1] to be '%s', got '%s'", expected, config.LibcCFlags[1])
+		}
+	}
+
+	// Test Groups configuration
+	if len(config.Groups) != 1 {
+		t.Errorf("Expected 1 group, got %d", len(config.Groups))
+	} else {
+		group := config.Groups[0]
+
+		// Test output file name
+		expectedOutput := "libc-" + target + ".a"
+		if group.OutputFileName != expectedOutput {
+			t.Errorf("Expected OutputFileName '%s', got '%s'", expectedOutput, group.OutputFileName)
+		}
+
+		// Test files list
+		if len(group.Files) == 0 {
+			t.Error("Expected non-empty files list")
+		} else {
+			// Check a few sample files
+			sampleFiles := []string{
+				filepath.Join(baseDir, "newlib", "libc", "string", "bcmp.c"),
+				filepath.Join(baseDir, "newlib", "libc", "string", "memcpy.c"),
+				filepath.Join(baseDir, "newlib", "libc", "string", "strlen.c"),
+				filepath.Join(baseDir, "newlib", "libc", "stdlib", "nano-malloc.c"),
+				filepath.Join(baseDir, "newlib", "libc", "tinystdio", "printf.c"),
+			}
+
+			for _, sample := range sampleFiles {
+				found := false
+				for _, file := range group.Files {
+					if file == sample {
+						found = true
+						break
+					}
+				}
+				if !found {
+					t.Errorf("Expected file '%s' not found in group files", sample)
+				}
+			}
+		}
+
+		// Test CFlags
+		expectedCFlags := []string{
+			"-D_COMPILING_NEWLIB",
+			"-D_HAVE_ALIAS_ATTRIBUTE",
+			"-DTINY_STDIO",
+			"-DPOSIX_IO",
+			"-DFORMAT_DEFAULT_INTEGER",
+			"-D_IEEE_LIBM",
+			"-D__OBSOLETE_MATH_FLOAT=1",
+			"-D__OBSOLETE_MATH_DOUBLE=0",
+			"-D_WANT_IO_C99_FORMATS",
+			"-nostdlib",
+			"-I" + baseDir,
+			"-isystem" + filepath.Join(baseDir, "newlib", "libc", "include"),
+			"-I" + filepath.Join(baseDir, "newlib", "libm", "common"),
+			"-I" + filepath.Join(baseDir, "newlib", "libc", "locale"),
+			"-I" + filepath.Join(baseDir, "newlib", "libc", "tinystdio"),
+		}
+
+		if len(group.CFlags) != len(expectedCFlags) {
+			t.Errorf("Expected %d CFlags, got %d", len(expectedCFlags), len(group.CFlags))
+		} else {
+			for i, expected := range expectedCFlags {
+				if group.CFlags[i] != expected {
+					t.Errorf("CFlags[%d] mismatch. Expected '%s', got '%s'", i, expected, group.CFlags[i])
+				}
+			}
+		}
+
+		// Test LDFlags and CCFlags
+		if len(group.LDFlags) == 0 {
+			t.Error("Expected non-empty LDFlags")
+		}
+		if len(group.CCFlags) == 0 {
+			t.Error("Expected non-empty CCFlags")
+		}
+	}
+}
+
+func TestGetPicolibcConfig_EdgeCases(t *testing.T) {
+	t.Run("EmptyBaseDir", func(t *testing.T) {
+		config := GetPicolibcConfig("", "test-target")
+
+		// Check that paths are constructed correctly even with empty baseDir
+		expected := "-I"
+		if config.LibcCFlags[0] != expected {
+			t.Errorf("Expected LibcCFlags[0] to be '%s', got '%s'", expected, config.LibcCFlags[0])
+		}
+
+		expected = "-isystem" + filepath.Join("", "newlib", "libc", "include")
+		if config.LibcCFlags[1] != expected {
+			t.Errorf("Expected LibcCFlags[1] to be '%s', got '%s'", expected, config.LibcCFlags[1])
+		}
+	})
+
+	t.Run("EmptyTarget", func(t *testing.T) {
+		config := GetPicolibcConfig("/test/base", "")
+
+		// Check output file name formatting
+		expectedOutput := "libc-.a"
+		if config.Groups[0].OutputFileName != expectedOutput {
+			t.Errorf("Expected OutputFileName '%s', got '%s'", expectedOutput, config.Groups[0].OutputFileName)
+		}
+	})
+}
+
+func TestGetNewlibESP32ConfigRISCV(t *testing.T) {
+	baseDir := "/test/base"
+	target := "riscv32-unknown-elf"
+
+	config := getNewlibESP32ConfigRISCV(baseDir, target)
+
+	// Test basic configuration
+	if config.Url != _newlibUrl {
+		t.Errorf("Expected URL '%s', got '%s'", _newlibUrl, config.Url)
+	}
+	if config.Name != "newlib-esp32" {
+		t.Errorf("Expected Name 'newlib-esp32', got '%s'", config.Name)
+	}
+	if config.ArchiveSrcDir != _archiveInternalSrcDir {
+		t.Errorf("Expected ArchiveSrcDir '%s', got '%s'", _archiveInternalSrcDir, config.ArchiveSrcDir)
+	}
+
+	// Test LibcCFlags
+	libcDir := filepath.Join(baseDir, "newlib", "libc")
+	expectedCFlags := []string{
+		"-isystem" + filepath.Join(libcDir, "include"),
+		"-I" + filepath.Join(baseDir, "newlib"),
+		"-I" + libcDir,
+	}
+	if len(config.LibcCFlags) != len(expectedCFlags) {
+		t.Errorf("Expected %d LibcCFlags, got %d", len(expectedCFlags), len(config.LibcCFlags))
+	} else {
+		for i, expected := range expectedCFlags {
+			if config.LibcCFlags[i] != expected {
+				t.Errorf("LibcCFlags[%d] mismatch. Expected '%s', got '%s'", i, expected, config.LibcCFlags[i])
+			}
+		}
+	}
+
+	// Test Groups configuration
+	if len(config.Groups) != 3 {
+		t.Errorf("Expected 3 groups, got %d", len(config.Groups))
+	} else {
+		// Group 0: libcrt0
+		group0 := config.Groups[0]
+		expectedOutput0 := "libcrt0-" + 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"),
+		}
+		for _, sample := range sampleFiles0 {
+			found := false
+			for _, file := range group0.Files {
+				if file == sample {
+					found = true
+					break
+				}
+			}
+			if !found {
+				t.Errorf("Expected file '%s' not found in group0 files", sample)
+			}
+		}
+
+		// Group 1: libgloss
+		group1 := config.Groups[1]
+		expectedOutput1 := "libgloss-" + 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"),
+		}
+		for _, sample := range sampleFiles1 {
+			found := false
+			for _, file := range group1.Files {
+				if file == sample {
+					found = true
+					break
+				}
+			}
+			if !found {
+				t.Errorf("Expected file '%s' not found in group1 files", sample)
+			}
+		}
+
+		// Group 2: libc
+		group2 := config.Groups[2]
+		expectedOutput2 := "libc-" + 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"),
+		}
+		for _, sample := range sampleFiles2 {
+			found := false
+			for _, file := range group2.Files {
+				if file == sample {
+					found = true
+					break
+				}
+			}
+			if !found {
+				t.Errorf("Expected file '%s' not found in group2 files", sample)
+			}
+		}
+
+		// Test CFlags for group2
+		expectedCFlagsGroup2 := []string{
+			"-DHAVE_CONFIG_H",
+			"-D_LIBC",
+			"-DHAVE_NANOSLEEP",
+			"-D__NO_SYSCALLS__",
+			// ... (other expected flags)
+		}
+		for _, expectedFlag := range expectedCFlagsGroup2 {
+			found := false
+			for _, flag := range group2.CFlags {
+				if flag == expectedFlag {
+					found = true
+					break
+				}
+			}
+			if !found {
+				t.Errorf("Expected flag '%s' not found in group2 CFlags", expectedFlag)
+			}
+		}
+
+		// Test LDFlags and CCFlags
+		if len(group0.LDFlags) == 0 {
+			t.Error("Expected non-empty LDFlags in group0")
+		}
+		if len(group0.CCFlags) == 0 {
+			t.Error("Expected non-empty CCFlags in group0")
+		}
+	}
+}
+
+func TestGetNewlibESP32ConfigXtensa(t *testing.T) {
+	baseDir := "/test/base"
+	target := "xtensa-esp32-elf"
+
+	config := getNewlibESP32ConfigXtensa(baseDir, target)
+
+	// Test basic configuration
+	if config.Url != _newlibUrl {
+		t.Errorf("Expected URL '%s', got '%s'", _newlibUrl, config.Url)
+	}
+	if config.Name != "newlib-esp32" {
+		t.Errorf("Expected Name 'newlib-esp32', got '%s'", config.Name)
+	}
+	if config.ArchiveSrcDir != _archiveInternalSrcDir {
+		t.Errorf("Expected ArchiveSrcDir '%s', got '%s'", _archiveInternalSrcDir, config.ArchiveSrcDir)
+	}
+
+	// Test LibcCFlags
+	libcDir := filepath.Join(baseDir, "newlib", "libc")
+	expectedCFlags := []string{
+		"-I" + filepath.Join(libcDir, "include"),
+		"-I" + filepath.Join(baseDir, "newlib"),
+		"-I" + libcDir,
+	}
+	if len(config.LibcCFlags) != len(expectedCFlags) {
+		t.Errorf("Expected %d LibcCFlags, got %d", len(expectedCFlags), len(config.LibcCFlags))
+	} else {
+		for i, expected := range expectedCFlags {
+			if config.LibcCFlags[i] != expected {
+				t.Errorf("LibcCFlags[%d] mismatch. Expected '%s', got '%s'", i, expected, config.LibcCFlags[i])
+			}
+		}
+	}
+
+	// Test Groups configuration
+	if len(config.Groups) != 3 {
+		t.Errorf("Expected 2 groups, got %d", len(config.Groups))
+	} else {
+		// Group 0: libcrt0
+		group0 := config.Groups[0]
+		expectedOutput0 := "libcrt0-" + 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", "xtensa", "clibrary_init.c"),
+			filepath.Join(baseDir, "libgloss", "xtensa", "crt1-boards.S"),
+		}
+		for _, sample := range sampleFiles0 {
+			found := false
+			for _, file := range group0.Files {
+				if file == sample {
+					found = true
+					break
+				}
+			}
+			if !found {
+				t.Errorf("Expected file '%s' not found in group0 files", sample)
+			}
+		}
+
+		// Group 1: libgloss + libc
+		group1 := config.Groups[1]
+		expectedOutput1 := "libgloss-" + 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"),
+		}
+		for _, sample := range sampleFiles1 {
+			found := false
+			for _, file := range group1.Files {
+				if file == sample {
+					found = true
+					break
+				}
+			}
+			if !found {
+				t.Errorf("Expected file '%s' not found in group1 files", sample)
+			}
+		}
+
+		// Test CFlags for group1
+		expectedCFlagsGroup1 := []string{
+			"-D__NO_SYSCALLS__",
+			"-D_NO_GETUT",
+			"-DHAVE_CONFIG_H",
+			"-D_LIBC",
+			// ... (other expected flags)
+		}
+		for _, expectedFlag := range expectedCFlagsGroup1 {
+			found := false
+			for _, flag := range group1.CFlags {
+				if flag == expectedFlag {
+					found = true
+					break
+				}
+			}
+			if !found {
+				t.Errorf("Expected flag '%s' not found in group1 CFlags", expectedFlag)
+			}
+		}
+
+		// Test LDFlags and CCFlags
+		if len(group0.LDFlags) == 0 {
+			t.Error("Expected non-empty LDFlags in group0")
+		}
+		if len(group0.CCFlags) == 0 {
+			t.Error("Expected non-empty CCFlags in group0")
+		}
+	}
+}
+
+func TestEdgeCases(t *testing.T) {
+	t.Run("EmptyBaseDir_RISCV", func(t *testing.T) {
+		config := getNewlibESP32ConfigRISCV("", "test-target")
+		libcDir := filepath.Join("", "newlib", "libc")
+
+		// Check that paths are constructed correctly
+		expected := "-isystem" + filepath.Join(libcDir, "include")
+		if config.LibcCFlags[0] != expected {
+			t.Errorf("Expected LibcCFlags[0] to be '%s', got '%s'", expected, config.LibcCFlags[0])
+		}
+	})
+
+	t.Run("EmptyTarget_RISCV", func(t *testing.T) {
+		config := getNewlibESP32ConfigRISCV("/test/base", "")
+
+		// Check output file name formatting
+		expectedOutput := "libcrt0-.a"
+		if config.Groups[0].OutputFileName != expectedOutput {
+			t.Errorf("Expected OutputFileName '%s', got '%s'", expectedOutput, config.Groups[0].OutputFileName)
+		}
+	})
+
+	t.Run("EmptyBaseDir_Xtensa", func(t *testing.T) {
+		config := getNewlibESP32ConfigXtensa("", "test-target")
+		libcDir := filepath.Join("", "newlib", "libc")
+
+		// Check that paths are constructed correctly
+		expected := "-I" + filepath.Join(libcDir, "include")
+		if config.LibcCFlags[0] != expected {
+			t.Errorf("Expected LibcCFlags[0] to be '%s', got '%s'", expected, config.LibcCFlags[0])
+		}
+	})
+
+	t.Run("EmptyTarget_Xtensa", func(t *testing.T) {
+		config := getNewlibESP32ConfigXtensa("/test/base", "")
+
+		// Check output file name formatting
+		expectedOutput := "libcrt0-.a"
+		if config.Groups[0].OutputFileName != expectedOutput {
+			t.Errorf("Expected OutputFileName '%s', got '%s'", expectedOutput, config.Groups[0].OutputFileName)
+		}
+	})
+}
+
+func TestGroupConfiguration(t *testing.T) {
+	baseDir := "/test/base"
+	target := "test-target"
+
+	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))
+		}
+	})
+
+	t.Run("Xtensa_GroupCount", func(t *testing.T) {
+		config := getNewlibESP32ConfigXtensa(baseDir, target)
+		if len(config.Groups) != 3 {
+			t.Errorf("Expected 2 groups for Xtensa, got %d", len(config.Groups))
+		}
+	})
+
+	t.Run("RISCV_GroupNames", func(t *testing.T) {
+		config := getNewlibESP32ConfigRISCV(baseDir, target)
+		expectedNames := []string{
+			"libcrt0-" + target + ".a",
+			"libgloss-" + target + ".a",
+			"libc-" + target + ".a",
+		}
+
+		for i, group := range config.Groups {
+			if group.OutputFileName != expectedNames[i] {
+				t.Errorf("Group %d expected name '%s', got '%s'", i, expectedNames[i], group.OutputFileName)
+			}
+		}
+	})
+
+	t.Run("Xtensa_GroupNames", func(t *testing.T) {
+		config := getNewlibESP32ConfigXtensa(baseDir, target)
+		expectedNames := []string{
+			"libcrt0-" + target + ".a",
+			"libgloss-" + target + ".a",
+		}
+
+		for i, group := range config.Groups {
+			if i >= len(expectedNames) {
+				return
+			}
+			if group.OutputFileName != expectedNames[i] {
+				t.Errorf("Group %d expected name '%s', got '%s'", i, expectedNames[i], group.OutputFileName)
+			}
+		}
+	})
+}
+
+func TestCompilerFlags(t *testing.T) {
+	baseDir := "/test/base"
+	target := "test-target"
+
+	t.Run("RISCV_CFlags", func(t *testing.T) {
+		config := getNewlibESP32ConfigRISCV(baseDir, target)
+		group := config.Groups[2] // libc group
+
+		requiredFlags := []string{
+			"-DHAVE_CONFIG_H",
+			"-D_LIBC",
+			"-D__NO_SYSCALLS__",
+			"-isystem" + filepath.Join(baseDir, "newlib", "libc", "include"),
+		}
+
+		for _, flag := range requiredFlags {
+			found := false
+			for _, cflag := range group.CFlags {
+				if cflag == flag {
+					found = true
+					break
+				}
+			}
+			if !found {
+				t.Errorf("Required flag '%s' not found in RISCV CFlags", flag)
+			}
+		}
+	})
+
+	t.Run("Xtensa_CFlags", func(t *testing.T) {
+		config := getNewlibESP32ConfigXtensa(baseDir, target)
+		group := config.Groups[1] // libgloss+libc group
+
+		requiredFlags := []string{
+			"-D__NO_SYSCALLS__",
+			"-DHAVE_CONFIG_H",
+			"-D_LIBC",
+			"-isystem" + filepath.Join(baseDir, "newlib", "libc", "include"),
+		}
+
+		for _, flag := range requiredFlags {
+			found := false
+			for _, cflag := range group.CFlags {
+				if cflag == flag {
+					found = true
+					break
+				}
+			}
+			if !found {
+				t.Errorf("Required flag '%s' not found in Xtensa CFlags", flag)
+			}
+		}
+	})
+
+	t.Run("CommonFlags", func(t *testing.T) {
+		configRISCV := getNewlibESP32ConfigRISCV(baseDir, target)
+		configXtensa := getNewlibESP32ConfigXtensa(baseDir, target)
+
+		// Test LDFlags
+		expectedLDFlags := []string{
+			"-nostdlib",
+			"-ffunction-sections",
+			"-fdata-sections",
+		}
+
+		for _, group := range configRISCV.Groups {
+			for _, expected := range expectedLDFlags {
+				found := false
+				for _, flag := range group.LDFlags {
+					if flag == expected {
+						found = true
+						break
+					}
+				}
+				if !found {
+					t.Errorf("Required LDFlag '%s' not found in RISCV group", expected)
+				}
+			}
+		}
+
+		for _, group := range configXtensa.Groups {
+			for _, expected := range expectedLDFlags {
+				found := false
+				for _, flag := range group.LDFlags {
+					if flag == expected {
+						found = true
+						break
+					}
+				}
+				if !found {
+					t.Errorf("Required LDFlag '%s' not found in Xtensa group", expected)
+				}
+			}
+		}
+
+		// Test CCFlags
+		expectedCCFlags := []string{
+			"-Oz",
+			"-fno-builtin",
+			"-ffreestanding",
+		}
+
+		for _, group := range configRISCV.Groups {
+			for _, expected := range expectedCCFlags {
+				found := false
+				for _, flag := range group.CCFlags {
+					if flag == expected {
+						found = true
+						break
+					}
+				}
+				if !found {
+					t.Errorf("Required CCFlag '%s' not found in RISCV group", expected)
+				}
+			}
+		}
+
+		for _, group := range configXtensa.Groups {
+			for _, expected := range expectedCCFlags {
+				found := false
+				for _, flag := range group.CCFlags {
+					if flag == expected {
+						found = true
+						break
+					}
+				}
+				if !found {
+					t.Errorf("Required CCFlag '%s' not found in Xtensa group", expected)
+				}
+			}
+		}
+	})
+}