From owner-freebsd-hackers Mon Dec 7 14:19:38 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id OAA24115 for freebsd-hackers-outgoing; Mon, 7 Dec 1998 14:19:38 -0800 (PST) (envelope-from owner-freebsd-hackers@FreeBSD.ORG) Received: from numeri.campus.luth.se (numeri.campus.luth.se [130.240.197.103]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id OAA24110 for ; Mon, 7 Dec 1998 14:19:35 -0800 (PST) (envelope-from k@numeri.campus.luth.se) Received: from numeri.campus.luth.se (localhost [127.0.0.1]) by numeri.campus.luth.se (8.8.8/8.8.8) with ESMTP id XAA03758; Mon, 7 Dec 1998 23:23:56 +0100 (CET) (envelope-from k@numeri.campus.luth.se) Message-Id: <199812072223.XAA03758@numeri.campus.luth.se> X-Mailer: exmh version 2.0.2 2/24/98 To: "Ron G. Minnich" cc: hackers@FreeBSD.ORG Subject: Re: write combining memory on pci In-reply-to: Your message of "Mon, 07 Dec 1998 15:48:33 EST." Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Date: Mon, 07 Dec 1998 23:23:56 +0100 From: Johan Karlsson Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from quoted-printable to 8bit by hub.freebsd.org id OAA24111 Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG At Mon, 07 Dec 1998 15:48:33 EST, "Ron G. Minnich" wrote: >any good ideas on how to turn this on in 3.0 for a given memory address >range? > This can be done using the MTRRs (Memory Type Range Registers) on a Ppro or PII. There are some functions in i386/i386/pmap.c to read and write those registers. (I don't know if the registers are enabled by default) For more info about the registers see http://www.intel.com/design/pro/manuals chapter 9 in "Intel Architecture Software Developer's Manual, Volume 3: System Programming Guide" Usualy the BIOS sets these registers. You can screw up the memory management bad if you don't know what you are doing. Take small steps :-) /Johan K -- Johan Karlsson mailto:k@numeri.campus.luth.se SWEDEN To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message