     1                                  ; nasm -f elf hello.asm		# this will produce hello.o ELF object file
     2                                  ; ld -s -o hello hello.o	# this will produce hello executable
     3                                  
     4                                  section	.text
     5                                      global _start			;must be declared for linker (ld)
     6                                  
     7                                  _start:					;tell linker entry point
     8                                  
     9 00000000 BA0E000000              	mov	edx,len	;message length
    10 00000005 B9[00000000]            	mov	ecx,msg	;message to write
    11 0000000A BB01000000              	mov	ebx,1	;file descriptor (stdout)
    12 0000000F B804000000              	mov	eax,4	;system call number (sys_write)
    13 00000014 CD80                    	int	0x80	;call kernel
    14                                  
    15 00000016 B801000000              	mov	eax,1	;system call number (sys_exit)
    16 0000001B CD80                    	int	0x80	;call kernel
    17                                  
    18                                  section	.data
    19                                  
    20 00000000 48656C6C6F2C20776F-     msg	db	'Hello, world!',0xa	;our dear string
    21 00000009 726C64210A         
    22                                  len	equ	$ - msg			;length of our dear string
    23                                  
