From owner-freebsd-current@FreeBSD.ORG  Sat Apr 26 15:04:41 2003
Return-Path: <owner-freebsd-current@FreeBSD.ORG>
Delivered-To: freebsd-current@freebsd.org
Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125])
	by hub.freebsd.org (Postfix) with ESMTP
	id 093D637B401; Sat, 26 Apr 2003 15:04:41 -0700 (PDT)
Received: from franky.speednet.com.au (franky.speednet.com.au [203.57.65.5])
	by mx1.FreeBSD.org (Postfix) with ESMTP
	id C9F5A43FCB; Sat, 26 Apr 2003 15:04:39 -0700 (PDT)
	(envelope-from andyf@speednet.com.au)
Received: from hewey.af.speednet.com.au (hewey.af.speednet.com.au
	[203.38.96.242])h3QM4bUv047957;	Sun, 27 Apr 2003 08:04:37 +1000 (EST)
	(envelope-from andyf@speednet.com.au)
Received: from hewey.af.speednet.com.au (hewey.af.speednet.com.au
	[172.22.2.1])h3QM4Zg9042973;	Sun, 27 Apr 2003 08:04:35 +1000 (EST)
	(envelope-from andyf@speednet.com.au)
Date: Sun, 27 Apr 2003 08:04:35 +1000 (EST)
From: Andy Farkas <andyf@speednet.com.au>
X-X-Sender: andyf@hewey.af.speednet.com.au
To: Ruslan Ermilov <ru@freebsd.org>
In-Reply-To: <20030426204542.GD66677@sunbay.com>
Message-ID: <20030427075835.Q42886-100000@hewey.af.speednet.com.au>
MIME-Version: 1.0
Content-Type: TEXT/PLAIN; charset=US-ASCII
cc: current@freebsd.org
Subject: Re: i386/loader compiled with NOFORTH
X-BeenThere: freebsd-current@freebsd.org
X-Mailman-Version: 2.1.1
Precedence: list
List-Id: Discussions about the use of FreeBSD-current
	<freebsd-current.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-current>,
	<mailto:freebsd-current-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-current>
List-Post: <mailto:freebsd-current@freebsd.org>
List-Help: <mailto:freebsd-current-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-current>,
	<mailto:freebsd-current-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Sat, 26 Apr 2003 22:04:41 -0000

On Sat, 26 Apr 2003, Ruslan Ermilov wrote:
> On Fri, Apr 25, 2003 at 02:46:26PM -0700, Terry Lambert wrote:
> > John Baldwin wrote:
> > > >
> > > > John, is there a way to fix btx/loader/whatever so that
> > > > heap memory is not limited to 640K?
> > >
> > > Not really.  At least, not easily.  We load the kernel up above 1mb,
> > > but we don't know how much memory lives up above 1mb and we assume
> > > that there is enough for the kernel and that's it.
> >
> > You are limited to what you can access in real mode, without
> > Gate A20 (16M, at which point the address space wraps).
> >
> Shhh, don't tell this anyone!  ;-)
>
> A20 (21th address line) allows one to access up to ffff:ffff
> byte, that is (1M + 64K - 16) bytes of memory.

Actually, you can access the entire 4GB of memory in "unreal" mode.

<http://x86.ddj.com/ddj/aug98/aug98.htm>

--

 :{ andyf@speednet.com.au

        Andy Farkas
    System Administrator
   Speednet Communications
 http://www.speednet.com.au/