Sender: nate AT cartsys DOT com
Message-ID: <370A7FE1.6081C6FA@cartsys.com>
Date: Tue, 06 Apr 1999 14:42:57 -0700
From: Nate Eldredge <nate AT cartsys DOT com>
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To: djgpp AT delorie DOT com
Subject: Re: INT in INT handler
References: <7e7ibo$cr4$3 AT news DOT luth DOT se> <37082B22 DOT B96BA80D AT cartsys DOT com> <7ec6tc$a1l$1 AT news DOT luth DOT se>
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Reply-To: djgpp AT delorie DOT com

Martin Str|mberg wrote:
> 
> Nate Eldredge (nate AT cartsys DOT com) wrote:
> : The INT instruction works even with interrupts disabled.
> 
> How can that be? How can I issue an INT when interrupts are disabled?

The IF flag actually enables and disables only hardware interrupts. 
From the 386 manual:

"The IF (interrupt-enable flag) controls the acceptance of external
interrupts signalled via the INTR pin."

In fact, it explains that software interrupts (INT etc) are actually
handled as exceptions.
 
> : Whether the other INT 0x31 handler is okay with having interrupts
> : disabled on entry is another question, though.  But I suspect it's
> : probably okay.
> 
> Aren't interrupts disabled on entry of an interrupt handler?

In most cases.  You should probably consult the DPMI spec for the real
story, though.
-- 

Nate Eldredge
nate AT cartsys DOT com