From owner-freebsd-hackers Thu Aug 2 11:57:26 2001 Delivered-To: freebsd-hackers@freebsd.org Received: from po3.wam.umd.edu (po3.wam.umd.edu [128.8.10.165]) by hub.freebsd.org (Postfix) with ESMTP id B6DF737B401; Thu, 2 Aug 2001 11:57:17 -0700 (PDT) (envelope-from culverk@wam.umd.edu) Received: from rac2.wam.umd.edu (IDENT:root@rac2.wam.umd.edu [128.8.10.142]) by po3.wam.umd.edu (8.9.3/8.9.3) with ESMTP id OAA17428; Thu, 2 Aug 2001 14:57:16 -0400 (EDT) Received: from rac2.wam.umd.edu (IDENT:sendmail@localhost [127.0.0.1]) by rac2.wam.umd.edu (8.9.3/8.9.3) with SMTP id OAA01739; Thu, 2 Aug 2001 14:57:15 -0400 (EDT) Received: from localhost (culverk@localhost) by rac2.wam.umd.edu (8.9.3/8.9.3) with ESMTP id OAA01735; Thu, 2 Aug 2001 14:57:15 -0400 (EDT) X-Authentication-Warning: rac2.wam.umd.edu: culverk owned process doing -bs Date: Thu, 2 Aug 2001 14:57:15 -0400 (EDT) From: Kenneth Wayne Culver To: John Baldwin Cc: Rik van Riel , Rik van Riel , Terry Lambert , craig , freebsd-hackers@FreeBSD.org Subject: Re: How to visit physical memory above 4G? In-Reply-To: Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG On Thu, 2 Aug 2001, John Baldwin wrote: > > 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. > Alright, I guess I will later, although I doubt I'll be able to make much use of it. I usually only read the docs for hardware I'm going to write a driver for. :-) 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 -- 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 -- 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