Date: Thu, 2 Aug 2001 13:55:10 -0700 (PDT) From: Julian Elischer <julian@elischer.org> To: Kenneth Wayne Culver <culverk@wam.umd.edu> 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.BSF.4.21.0108021353000.41008-100000@InterJet.elischer.org> In-Reply-To: <Pine.GSO.4.21.0108021436250.20844-100000@rac2.wam.umd.edu>
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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). 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
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