helloasm.s

# PURPOSE:  Simple program that exits and 
#           returns a status code back to the Linux kernel

# INPUT:    none

# OUTPUT:   returns a status code
#           This can be viewed by typing
#                   echo $?
#           after running the program

# VARIABLES:
# %eax holds the system call number
# %ebx holds the return status


.section .data

.section .text
.globl _start
_start:

movl $1, %eax       # this is the 
                    # linux kernel command number (system call) 
                    # for exiting a program

movl $3, %ebx      # this is the 
                    # status number 
                    # we will return to the operating system.

int $0x80           # this wakes up the kernel to run
                    # the exit command