From owner-freebsd-hackers Sun Jul 26 14:12:10 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id OAA08026 for freebsd-hackers-outgoing; Sun, 26 Jul 1998 14:12:10 -0700 (PDT) (envelope-from owner-freebsd-hackers@FreeBSD.ORG) Received: from nlsystems.com (nlsys.demon.co.uk [158.152.125.33]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id OAA08013 for ; Sun, 26 Jul 1998 14:12:02 -0700 (PDT) (envelope-from dfr@nlsystems.com) Received: from herring.nlsystems.com (herring.nlsystems.com [10.0.0.2]) by nlsystems.com (8.8.8/8.8.5) with SMTP id WAA28386; Sun, 26 Jul 1998 22:12:41 +0100 (BST) Date: Sun, 26 Jul 1998 22:12:41 +0100 (BST) From: Doug Rabson To: zhihuizhang cc: hackers Subject: Re: APTDpde question (pmap) In-Reply-To: Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG On Sun, 26 Jul 1998, zhihuizhang wrote: > > In pmap.c module, we set PTDPTDI entry of the page directory page to point > to itself. So PTDpde and PTmap works well. However, I do not find a > similar setting of APTDTDI (=1023) in pmap.c. My question is how APTDpde > and the alternate address space it's supposed to relate to (APTmap) are > used. (has something to do with pmap copy?) > > Any help is appreciated. I believe that APTD is used to access the ptes of a pmap which is not currently active. The function get_ptbase() sets this up if necessary. -- Doug Rabson Mail: dfr@nlsystems.com Nonlinear Systems Ltd. Phone: +44 181 951 1891 Fax: +44 181 381 1039 To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message