Expanded accumulator machine:Intel x86, Linux, GAS Hello World Example

extern printf ; Request symbol "printf".
global main   ; Declare symbol "main".

section .data
  str: DB "Hello World!", 0x0A, 0x00

section .text
main:
  PUSH str    ; Push string pointer onto stack.
  CALL printf ; Call printf.
  POP eax     ; Remove value from stack.
  MOV eax,0x0 ; \_Return value 0.
  RET         ; /