section .data                           ;section declaration

     msg     db      "Hello, world!",0xA     ;our dear string
     len     equ     $ - msg                 ;length of our dear string

     section .text                           ;section declaration

                             ;we must export the entry point to the ELF linker or
         global _start       ;loader. They conventionally recognize _start as their
                             ;entry point. Use ld -e foo to override the default.

     _start:

     ;write our string to stdout

             mov     eax,4   ;system call number (sys_write)
             mov     ebx,1   ;first argument: file handle (stdout)
             mov     ecx,msg ;second argument: pointer to message to write
             mov     edx,len ;third argument: message length
             int     0x80    ;call kernel

     ;and exit

             mov     eax,1   ;system call number (sys_exit)
             xor     ebx,ebx ;first syscall argument: exit code
             int     0x80    ;call kernel