Date: Thu, 27 Mar 1997 13:52:49 +0300 (IDT)
From: Eli Zaretskii <eliz AT is DOT elta DOT co DOT il>
To: Heo Sung-Gwan <heo AT turbotek DOT co DOT kr>
cc: djgpp AT delorie DOT com
Subject: Re: FPU and protected mode
In-Reply-To: <3339DFBB.3A4B@turbotek.co.kr>
Message-ID: <Pine.SUN.3.91.970327135039.9299Y-100000@is>
MIME-Version: 1.0
Content-Type: TEXT/PLAIN; charset=US-ASCII


On Thu, 27 Mar 1997, Heo Sung-Gwan wrote:

> I am coding FPU context switch with Pentium processor using fnsave and
> frstor FPU instructions. And I found these FPU instructions behaves
> differently between real mode and protected mode.

The layout of the buffer saved and restored by FNSAVE/FRSTOR instructions
is indeed different in real and protected modes.  You should look up its
description in any of the available manuals on protected-mode programming
in assembly.  A reference on Intel instructions should also describe this.