Exit
Exit function is one of the most important system-calls. The function ends the user's program. Every user's program need to be end using it.
Description: The function ends the user's program with specific error code.
Gets: Error Code - On the stack.
0 means the program ended without error.
Any other number indicates about error.
Returns: Nothing.
Example:
.text
# User program here
# ...
pushl $0
calls $1, .exit # Exit with error code 0