From mboxrd@z Thu Jan 1 00:00:00 1970 From: Maciej Hrebien Subject: Re: switching to real mode? Date: Fri, 25 Jul 2003 19:20:24 +0200 Sender: linux-assembly-owner@vger.kernel.org Message-ID: <3F2166D8.65AE79D8@wp.pl> References: Reply-To: m_hrebien@wp.pl Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Return-path: List-Id: Content-Type: text/plain; charset="us-ascii" To: linux-assembly@vger.kernel.org Wolfgang Huber wrote: > > Hi! > > I know this question sounds a bit silly... > How would one switch to real mode in Linux, are there any caveats? > > Wolfgang For what purpose you need it? From linux x86 users point of view: you just can't, or am i wrong? ;) Generally once you switch to protected mode you don't need real one and if you want to run some code written for real mode you just run it in vm86 mode rather than switching it back (as i remember dosemu does something like this). If you are interested in "hard" switch i suggest to read ie. intel's "software developers manual vol. 3, system programming", chapter 8 "processor management and initialization", point 8 "mode switching" (1999 version). Correct me linux-assemblers if i'm wrong! -- Maciej Hrebien