Skip site navigation (1)Skip section navigation (2)
Date:      Thu, 2 Aug 2001 14:55:28 -0400 (EDT)
From:      Kenneth Wayne Culver <culverk@wam.umd.edu>
To:        Julian Elischer <julian@elischer.org>
Cc:        John Baldwin <jhb@FreeBSD.org>, freebsd-hackers@FreeBSD.org, craig <craiglei@pasia.com.cn>, Terry Lambert <tlambert2@mindspring.com>, Rik van Riel <riel@conectiva.com.br>
Subject:   Re: How to visit physical memory above 4G?
Message-ID:  <Pine.GSO.4.21.0108021454210.20844-100000@rac2.wam.umd.edu>
In-Reply-To: <Pine.BSF.4.21.0108021353000.41008-100000@InterJet.elischer.org>

next in thread | previous in thread | raw e-mail | index | archive | help
> No
> The space is linear in physical space and if you have PCI/64
> capable devices they can access it all too.
> 
> (In fact 64 bit addresses have been supported even in 32 bit wide PCI 
> since day 1).

OK, then what was that whole paging thing everyone was talking about, I
thought that was partially done in hardware on the chipset of the
motherboard... or was that completely in the operating system?

Ken


> 
> On Thu, 2 Aug 2001, 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
> > 
> > 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/
> > > 
> > 
> > 
> > To Unsubscribe: send mail to majordomo@FreeBSD.org
> > with "unsubscribe freebsd-hackers" in the body of the message
> > 
> 
> 


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




Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?Pine.GSO.4.21.0108021454210.20844-100000>