# >>>>>>>>>>>>> ELF FILE HEADER <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<< # All numbers (except in names) are in base sixteen (hexadecimal) # 00 <- number of bytes listed so far 7F 45 4C 46 # 04 e_ident[EI_MAG]: ELF magic number 01 # 05 e_ident[EI_CLASS]: 1: 32-bit, 2: 64-bit 01 # 06 e_ident[EI_DATA]: 1: little-endian, 2: big-endian 01 # 07 e_ident[EI_VERSION]: ELF header version; must be 1 00 # 08 e_ident[EI_OSABI]: Target OS ABI; should be 0 00 # 09 e_ident[EI_ABIVERSION]: ABI version; 0 is ok for Linux 00 00 00 # 0C e_ident[EI_PAD]: unused, should be 0 00 00 00 00 # 10 02 00 # 12 e_type: object file type; 2: executable 03 00 # 14 e_machine: instruction set architecture; 3: x86, 3E: amd64 01 00 00 00 # 18 e_version: ELF identification version; must be 1 54 80 04 08 # 1C e_entry: memory address of entry point (where process starts) 34 00 00 00 # 20 e_phoff: file offset where program headers begin 00 00 00 00 # 24 e_shoff: file offset where section headers begin 00 00 00 00 # 28 e_flags: 0 for x86 34 00 # 2A e_ehsize: size of this header (34: 32-bit, 40: 64-bit) 20 00 # 2C e_phentsize: size of each program header (20: 32-bit, 38: 64-bit) 01 00 # 2E e_phnum: #program headers 28 00 # 30 e_shentsize: size of each section header (28: 32-bit, 40: 64-bit) 00 00 # 32 e_shnum: #section headers 00 00 # 34 e_shstrndx: index of section header containing section names # >>>>>>>>>>>>> ELF PROGRAM HEADER <<<<<<<<<<<<<<<<<<<<<<<< 01 00 00 00 # 38 p_type: segment type; 1: loadable 00 00 00 00 # 3C p_offset: file offset where segment begins 00 80 04 08 # 40 p_vaddr: virtual address of segment in memory (x86: 08048000) 00 00 00 00 # 44 p_paddr: physical address of segment, unspecified by 386 supplement 6E 00 00 00 # 48 p_filesz: size in bytes of the segment in the file image ############ 00 80 FB 77 # 4C p_memsz: size in bytes of the segment in memory; p_filesz <= p_memsz 07 00 00 00 # 50 p_flags: segment-dependent flags (1: X, 2: W, 4: R) 00 10 00 00 # 54 p_align: 1000 for x86 # >>>> DMP <<<< # INTENTION 54 INSTRUCTION OPCODE NOTE E9 07 00 00 00 # jump Begin 59 jmp rel32 E9 cd # SetStatus: # 59 8B 1D 6A 80 04 08 # ebx = [status] mov r32, r/m32 8B /r 00 011 101 C3 # return ret C3 # Begin: # 60 31 C0 40 # eax = 1 (exit) xor r/m32, r32; inc 31 /r 11 000 000 E8 F1 FF FF FF # call SetStatus 68 call rel32 E8 cd CD 80 # syscall int imm8 CD ib # status: # 6A 17 00 00 00 # 6E