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Mail Archives: djgpp-workers/1999/02/17/11:13:59

From: sandmann AT clio DOT rice DOT edu (Charles Sandmann)
Message-Id: <9902171606.AA12534@clio.rice.edu>
Subject: Re: Passing FLAGS from RMCBs
To: eliz AT is DOT elta DOT co DOT il (Eli Zaretskii)
Date: Wed, 17 Feb 1999 10:06:57 -0600 (CST)
Cc: djgpp-workers AT delorie DOT com
In-Reply-To: <Pine.SUN.3.91.990217161556.17443F-100000@is> from "Eli Zaretskii" at Feb 17, 99 04:18:40 pm
X-Mailer: ELM [version 2.4 PL20]
Reply-To: djgpp-workers AT delorie DOT com

> Is it still a good idea to mask off some dangerous flags before passing 
> them back to real mode, or should we just let the lusers trash their 
> machines? ;-)

I'm in favor of leaving it alone.  You can never tell what creative uses
people will come up with.

> > The wrappers also suffer from bad stack management among other things and
> > have always needed some TLC
> 
> Can you say a couple of words about what's bad in stack management there?

There are holes in the wrappers which would allow nested interrupts to 
trash the stack.  The algorithm should be something like:

  Is my current SS on entering wrapper == my locked SS?  If not, use current
  stack change code.  If yes, don't change SS/ESP.  This would allow one
  stack for all wrappers if desired.

> And what's a TLC?

Tender Loving Care :-)

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