Assembly on x86_64 Linux

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Some instructions in Intel assembly set are invalid in x86_64 env.

e.g.

aaa

push eax

...

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Solutions

• Use 64-bit instructions instead.(You can refer to Intel developer manual)

• Add 32-bit options:

  For nasm:
  
  
  nasm -f elf32 xxx.asm

  For ld:
  
  
  ld -o xxx -m elf_i386 xxx.o

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If you want to use gcc for linking (do what the author of Assembly Language Step by Step does), you will meet some new troubles.

Solutions

• Use 64-bit instructions instead and:

  nasm -f elf64 xxx.asm
  gcc -o xxx xxx.o -nostartfiles

• Use 32-bit libraries:

  dpkg --print-architecture # to ensure your 64-bit kernel
  dpkg --print-foreign-architectures # To ensure you have turned on function for support of multi-architecture.
  # And if the output is "i386", it is OK. Or you'd better follow:
  # sudo dpkg --add-architecture i386
  # sudo apt-get update
  # sudo apt-get dist-upgrade
  # Then:
  sudo apt-get install gcc-multilib g++-multilib
  # Bingo !
  # Now you can use instructions below to continue your progress:
  nasm -f elf xxx.asm
  gcc -o xxx xxx.o -m32
  (if using GDB) nasm -f elf -g -F stabs xxx.asm

For more details, please refer to "man gcc"