int 0x80 and hello world ...

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james

Joined: 07 Sep 2005
Posts: 45
Location: Australia

james 02 Oct 2005, 03:57

In the FASM hello world example 'hello.asm'
output is written out using int 0x80.

Im curious why the example does this

Code:

mov eax, 1
xor ebx, ebx
int 0x80

Is it necessary to write null out ?

Rgs, James.

02 Oct 2005, 03:57

crc

Joined: 21 Jun 2003
Posts: 637
Location: Penndel, PA [USA]

crc 02 Oct 2005, 04:10

that's the exit system call.

eax = 1 (sys_exit)
ebx = return value (0 = successful, any other represents an error)

02 Oct 2005, 04:10

james

Joined: 07 Sep 2005
Posts: 45
Location: Australia

james 02 Oct 2005, 05:20

oh, thanks. I was looking for that as well.

02 Oct 2005, 05:20

rob.rice

Joined: 20 Dec 2003
Posts: 54

rob.rice 06 Nov 2005, 21:02

for more info on int 0x80 goto
http://linuxassembly.org
there are links to web pages on the subjict

06 Nov 2005, 21:02

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