struct elf {
   struct {
      u8 ei_magic[4] | matches('\x7fELF') str;
      enum {
         CLASS_32 = 1,
         CLASS_64
      } u8 ei_class hex; // word size
      enum {
         ENDIANESS_LE = 1,
         ENDIANESS_BE
      } u8 ei_data hex; // endianess
      u8 ei_version;
      u8 ei_osabi;
      u8 ei_abi_version;
      u8 padding[7] nul;
   } header;

   struct body {
      u16 e_type hex;
      u16 e_machine hex;
      u32 e_version;
      select (header.ei_class) {
         header.CLASS_32) struct {
               u32 e_entry hex;
               u32 e_phoff;
               u32 e_shoff;
            } elf32;
         header.CLASS_64) struct {
               u64 e_entry hex;
               u64 e_phoff;
               u64 e_shoff;
            } elf64;
      } arch;
      u32 e_flags hex;
      u16 e_ehsz;
      u16 e_phentsize;
      u16 e_phnum;
      u16 e_shentsize;
      u16 e_shnum;
      u16 e_shstrndx;
   };

   select (header.ei_class) {
      1) struct body le | endianess('le');
      2) struct body be | endianess('be');
   } body;
};