Added macho package

2025-06-30 20:31:07 +02:00 · 2025-06-30 20:31:07 +02:00 · dbc865ee67
commit dbc865ee67
parent 436691ae40
14 changed files with 317 additions and 0 deletions
--- a/src/macho/MachO.go
+++ b/src/macho/MachO.go
@ -0,0 +1,119 @@
+package macho
+
+import (
+	"encoding/binary"
+	"io"
+
+	"git.urbach.dev/cli/q/src/build"
+	"git.urbach.dev/cli/q/src/exe"
+)
+
+// MachO is the executable format used on MacOS.
+type MachO struct {
+	Header
+	PageZero   Segment64
+	CodeHeader Segment64
+	DataHeader Segment64
+	UnixThread Thread
+}
+
+// Write writes the Mach-O format to the given writer.
+func Write(writer io.WriteSeeker, b *build.Build, codeBytes []byte, dataBytes []byte) {
+	x := exe.New(HeaderEnd, b.FileAlign, b.MemoryAlign)
+	x.InitSections(codeBytes, dataBytes)
+	code := x.Sections[0]
+	data := x.Sections[1]
+	arch, microArch := Arch(b.Arch)
+	entryPoint := BaseAddress + code.MemoryOffset
+
+	m := &MachO{
+		Header: Header{
+			Magic:             0xFEEDFACF,
+			Architecture:      arch,
+			MicroArchitecture: microArch,
+			Type:              TypeExecute,
+			NumCommands:       4,
+			SizeCommands:      SizeCommands,
+			Flags:             FlagNoUndefs | FlagPIE | FlagNoHeapExecution,
+			Reserved:          0,
+		},
+		PageZero: Segment64{
+			LoadCommand:  LcSegment64,
+			Length:       72,
+			Name:         [16]byte{'_', '_', 'P', 'A', 'G', 'E', 'Z', 'E', 'R', 'O'},
+			Address:      0,
+			SizeInMemory: uint64(BaseAddress),
+			Offset:       0,
+			SizeInFile:   0,
+			NumSections:  0,
+			Flag:         0,
+			MaxProt:      0,
+			InitProt:     0,
+		},
+		CodeHeader: Segment64{
+			LoadCommand:  LcSegment64,
+			Length:       Segment64Size,
+			Name:         [16]byte{'_', '_', 'T', 'E', 'X', 'T'},
+			Address:      uint64(BaseAddress),
+			SizeInMemory: uint64(code.MemoryOffset + len(code.Bytes)),
+			Offset:       0,
+			SizeInFile:   uint64(code.FileOffset + len(code.Bytes)),
+			NumSections:  0,
+			Flag:         0,
+			MaxProt:      ProtReadable | ProtExecutable,
+			InitProt:     ProtReadable | ProtExecutable,
+		},
+		DataHeader: Segment64{
+			LoadCommand:  LcSegment64,
+			Length:       Segment64Size,
+			Name:         [16]byte{'_', '_', 'D', 'A', 'T', 'A'},
+			Address:      uint64(BaseAddress + data.MemoryOffset),
+			SizeInMemory: uint64(len(data.Bytes)),
+			Offset:       uint64(data.FileOffset),
+			SizeInFile:   uint64(len(data.Bytes)),
+			NumSections:  0,
+			Flag:         0,
+			MaxProt:      ProtReadable,
+			InitProt:     ProtReadable,
+		},
+		UnixThread: Thread{
+			LoadCommand: LcUnixthread,
+			Len:         ThreadSize,
+			Type:        0x4,
+			Data: [43]uint32{
+				42,
+				0, 0,
+				0, 0,
+				0, 0,
+				0, 0,
+				0, 0,
+				0, 0,
+				0, 0,
+				0, 0,
+				0, 0,
+				0, 0,
+				0, 0,
+				0, 0,
+				0, 0,
+				0, 0,
+				0, 0,
+				0, 0,
+				uint32(entryPoint), 0,
+				0, 0,
+				0, 0,
+				0, 0,
+				0, 0,
+			},
+		},
+	}
+
+	binary.Write(writer, binary.LittleEndian, &m.Header)
+	binary.Write(writer, binary.LittleEndian, &m.PageZero)
+	binary.Write(writer, binary.LittleEndian, &m.CodeHeader)
+	binary.Write(writer, binary.LittleEndian, &m.DataHeader)
+	binary.Write(writer, binary.LittleEndian, &m.UnixThread)
+	writer.Seek(int64(code.Padding), io.SeekCurrent)
+	writer.Write(code.Bytes)
+	writer.Seek(int64(data.Padding), io.SeekCurrent)
+	writer.Write(data.Bytes)
+}