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Mail Archives: djgpp/1998/08/07/13:08:54

Message-ID: <35CB309A.69AE696C@unb.ca>
Date: Fri, 07 Aug 1998 13:51:38 -0300
From: Endlisnis <s257m AT unb DOT ca>
MIME-Version: 1.0
Newsgroups: comp.os.msdos.djgpp
To: Nate Eldredge <nate AT cartsys DOT com>
CC: Rylan <rylan AT inbtekom DOT co DOT za>, djgpp AT delorie DOT com
Subject: Re: How to generate an interrupt in AT&T asm
References: <6qbcfi$pn7$1 AT news2 DOT saix DOT net> <35CA4690 DOT 3BEBD45A AT cartsys DOT com>

Nate Eldredge wrote:

> Rylan wrote:
> Somebody correct me if I'm wrong, but a normal `int' instruction should
> work, as long as you haven't installed a protected-mode interrupt
> handler for that int (unlikely).  Ex:

main()
{
 asm volatile ("movw $0x0013, %%ax; int $0x10" : : : "ax");
 return 0;
 }

    This program compiled and ran as I expected, changing the display into
VGA
mode.  I thought you had to switch to real-mode to execute an interrupt, or
is
that done in this case by the DPMI server??  And is this dangerous in any
way?
[Something about no stack for the interrupt?]  And is it OK to just put ";"
between commands in inline asm or do you really need "\n\t"?
--
     (\/) Endlisnis (\/)
          s257m AT unb DOT ca
          Endlisnis AT GeoCities DOT com
          Endlis AT nbnet DOT nb DOT ca


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