From owner-freebsd-hackers  Thu Aug  2 11:55:21 2001
Delivered-To: freebsd-hackers@freebsd.org
Received: from mail.wrs.com (unknown-1-11.windriver.com [147.11.1.11])
	by hub.freebsd.org (Postfix) with ESMTP id 609FF37B401
	for <freebsd-hackers@FreeBSD.org>; Thu,  2 Aug 2001 11:55:17 -0700 (PDT)
	(envelope-from jhb@FreeBSD.org)
Received: from laptop.baldwin.cx (john@[147.11.46.217])
	by mail.wrs.com (8.9.3/8.9.1) with ESMTP id LAA05857;
	Thu, 2 Aug 2001 11:54:26 -0700 (PDT)
Message-ID: <XFMail.010802115425.jhb@FreeBSD.org>
X-Mailer: XFMail 1.4.0 on FreeBSD
X-Priority: 3 (Normal)
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 8bit
MIME-Version: 1.0
In-Reply-To: <Pine.GSO.4.21.0108021436250.20844-100000@rac2.wam.umd.edu>
Date: Thu, 02 Aug 2001 11:54:25 -0700 (PDT)
From: John Baldwin <jhb@FreeBSD.org>
To: Kenneth Wayne Culver <culverk@wam.umd.edu>
Subject: Re: How to visit physical memory above 4G?
Cc: Rik van Riel <riel@conectiva.com.br>
Cc: Rik van Riel <riel@conectiva.com.br>,
	Terry Lambert <tlambert2@mindspring.com>,
	craig <craiglei@pasia.com.cn>, freebsd-hackers@FreeBSD.org
Sender: owner-freebsd-hackers@FreeBSD.ORG
Precedence: bulk
List-ID: <freebsd-hackers.FreeBSD.ORG>
List-Archive: <http://docs.freebsd.org/mail/> (Web Archive)
List-Help: <mailto:majordomo@FreeBSD.ORG?subject=help> (List Instructions)
List-Subscribe: <mailto:majordomo@FreeBSD.ORG?subject=subscribe%20freebsd-hackers>
List-Unsubscribe: <mailto:majordomo@FreeBSD.ORG?subject=unsubscribe%20freebsd-hackers>
X-Loop: FreeBSD.ORG


On 02-Aug-01 Kenneth Wayne Culver wrote:
> BUT, don't the motherboards also have to support this? And isn't it only
> supported through some wierd segmentation thing? 
> 
> KEn

The motherboards do, yes, and they have.  It's not segmentation.  It's only in
the paging that this is done.  Go to developer.intel.com and get the IA32
manuals, specifially volume 3: system programming, then look for 'Physical
Address Extensions' and start reading.

> On Thu, 2 Aug 2001, John Baldwin wrote:
> 
>> 
>> On 02-Aug-01 Kenneth Wayne Culver wrote:
>> > Also, the PIII CAN'T natively support more than 4GB of ram. If a
>> > particular PIII motherboard supports this, then it's using some kind of
>> > wierd chipset that allows this to happen. 4GB is the limit with a 32 bit
>> > chip I believe; and the PIII is a 32-bit chip.
>> > 
>> > Ken
>> 
>> Go look at some Intel docs.  P6 chips since the Pentium Pro (yes, before
>> Pentium II) have supported PAE which allows for a 36-bit physical address.
>> 
>> -- 
>> 
>> John Baldwin <jhb@FreeBSD.org> -- http://www.FreeBSD.org/~jhb/
>> PGP Key: http://www.baldwin.cx/~john/pgpkey.asc
>> "Power Users Use the Power to Serve!"  -  http://www.FreeBSD.org/
>> 
> 

-- 

John Baldwin <jhb@FreeBSD.org> -- http://www.FreeBSD.org/~jhb/
PGP Key: http://www.baldwin.cx/~john/pgpkey.asc
"Power Users Use the Power to Serve!"  -  http://www.FreeBSD.org/

To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe freebsd-hackers" in the body of the message