BITS 64

org 0x400000

elf_ident:

db 0x7F, "ELF" ; EI_MAG = ELF magic

db 2 ; EI_CLASS = ELFCLASS64 (elf64)

db 1 ; EI_DATA = ELFDATA2LSB (little-endian)

db 1 ; EI_VERSION = EV_CURRENT

db 0 ; null terminator

db 0 ; ABI version

db 0 ; alignment padding

start:

inc eax

mov bl, 42

int 0x80

times 6 + start - $ db 0 ; padding

elf_hdr:

dw 2 ; Elf64_Half e_type = ET_EXEC

dw 0x3E ; Elf64_Half e_machine = AMD x64

dd 1 ; Elf64_Word e_version = 1

dq start ; Elf64_Addr e_entry = start offset

dq prog_hdr - $$ ; Elf64_Off e_phoff = prog_hdr offset

dq 0 ; Elf64_Off e_shoff = 0 (we don't have one)

dd 0 ; Elf64_Word e_flags = 0 (nothing special, i guess)

dw prog_hdr - elf_ident ; Elf64_Half e_ehsize = elf_hdr_size

dw end - prog_hdr ; Elf64_Half e_phentsize

dw 1 ; Elf64_Half e_phnum = 1 (we only need one)

dw 0x40 ; Elf64_Half e_shentsize = 64 (required)

dw 0 ; Elf64_Half e_shnum = 0 (we don't have any)

dw 0 ; Elf64_Half e_shstrndx = 0 (we still don't have any)

prog_hdr:

dd 1 ; Elf64_Word p_type = 1

dd 5 ; Elf64_Word p_flags = PF_R | PF_X

dq 0 ; Elf64_Off p_offset = 0

dq $$ ; Elf64_Addr p_vaddr = org

dq $$ ; Elf64_Addr p_paddr = org

dq end - $$ ; Elf64_Xword p_filesz = size of file

dq end - $$ ; Elf64_Xword p_memsz = size of file

dq 0x200000 ; Elf64_Xword p_align

end: ; nothing after this line