Eu estava lendoest article e, a certa altura, ele me dá este programa nasm:

; tiny.asm
BITS 32
GLOBAL main
SECTION .text
main:
              mov     eax, 42
              ret

E me diz para executar os seguintes comandos:

$ nasm -f elf tiny.asm
$ gcc -Wall -s tiny.o

Eu recebi o seguinte erro:

ld: warning: option -s is obsolete and being ignored
ld: warning: ignoring file tiny.o, file was built for unsupported file format which is not the architecture being linked (x86_64)
Undefined symbols for architecture x86_64:
  "_main", referenced from:
      start in crt1.10.6.o
ld: symbol(s) not found for architecture x86_64
collect2: ld returned 1 exit status

Eu arrisquei um palpite sobre o que poderia ser o problema e alterei a linha do BITS para ler:

 BITS 64

Mas quando eu corronasm -f elf tiny.asm Eu recebo

tiny.asm:2: error: `64' is not a valid segment size; must be 16 or 32

Como modifico o código para funcionar na minha máquina?

Editar

Aceitei o conselho de Alex nos comentários e baixei uma versão mais recente. Contudo

./nasm-2.09.10/nasm -f elf tiny.asm

reclama

tiny.asm:2: error: elf32 output format does not support 64-bit code

Por outro lado

./nasm-2.09.10/nasm -f elf64 tiny.asm
gcc -Wall -s tiny.o

reclama

ld: warning: ignoring file tiny.o, file was built for unsupported file format which is not the architecture being linked (x86_64)
Undefined symbols for architecture x86_64:
  "_main", referenced from:
      start in crt1.10.6.o
ld: symbol(s) not found for architecture x86_64
collect2: ld returned 1 exit status