q/src/os/linux/elf/ELF.go

91 lines
2.6 KiB
Go

package elf
import (
"bytes"
"encoding/binary"
"io"
"git.akyoto.dev/cli/q/src/config"
"git.akyoto.dev/cli/q/src/os/common"
)
// ELF represents an ELF file.
type ELF struct {
Header
CodeHeader ProgramHeader
DataHeader ProgramHeader
CodePadding []byte
Code []byte
DataPadding []byte
Data []byte
}
// New creates a new ELF binary.
func New(code []byte, data []byte) *ELF {
dataOffset := CodeOffset + int64(len(code))
dataPadding := common.Padding(dataOffset, Align)
dataOffset += dataPadding
return &ELF{
Header: Header{
Magic: [4]byte{0x7F, 'E', 'L', 'F'},
Class: 2,
Endianness: LittleEndian,
Version: 1,
OSABI: 0,
ABIVersion: 0,
Type: TypeExecutable,
Architecture: ArchitectureAMD64,
FileVersion: 1,
EntryPointInMemory: config.BaseAddress + CodeOffset,
ProgramHeaderOffset: HeaderSize,
SectionHeaderOffset: 0,
Flags: 0,
Size: HeaderSize,
ProgramHeaderEntrySize: ProgramHeaderSize,
ProgramHeaderEntryCount: 2,
SectionHeaderEntrySize: SectionHeaderSize,
SectionHeaderEntryCount: 0,
SectionNameStringTableIndex: 0,
},
CodeHeader: ProgramHeader{
Type: ProgramTypeLOAD,
Flags: ProgramFlagsExecutable | ProgramFlagsReadable,
Offset: CodeOffset,
VirtualAddress: config.BaseAddress + CodeOffset,
PhysicalAddress: config.BaseAddress + CodeOffset,
SizeInFile: int64(len(code)),
SizeInMemory: int64(len(code)),
Align: Align,
},
DataHeader: ProgramHeader{
Type: ProgramTypeLOAD,
Flags: ProgramFlagsReadable,
Offset: dataOffset,
VirtualAddress: config.BaseAddress + dataOffset,
PhysicalAddress: config.BaseAddress + dataOffset,
SizeInFile: int64(len(data)),
SizeInMemory: int64(len(data)),
Align: Align,
},
CodePadding: nil,
Code: code,
DataPadding: bytes.Repeat([]byte{0}, int(dataPadding)),
Data: data,
}
}
// Write writes the ELF64 format to the given writer.
func (elf *ELF) Write(writer io.Writer) {
binary.Write(writer, binary.LittleEndian, &elf.Header)
binary.Write(writer, binary.LittleEndian, &elf.CodeHeader)
binary.Write(writer, binary.LittleEndian, &elf.DataHeader)
writer.Write(elf.CodePadding)
writer.Write(elf.Code)
if len(elf.Data) > 0 {
writer.Write(elf.DataPadding)
writer.Write(elf.Data)
}
}