From owner-freebsd-mips@FreeBSD.ORG Thu Jul 24 21:39:20 2008 Return-Path: Delivered-To: freebsd-mips@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id B52531065677 for ; Thu, 24 Jul 2008 21:39:20 +0000 (UTC) (envelope-from gonzo@freebsd.org) Received: from luidgi.portaone.com (luidgi.portaone.com [195.138.219.143]) by mx1.freebsd.org (Postfix) with ESMTP id 9FC9C8FC12 for ; Thu, 24 Jul 2008 21:39:20 +0000 (UTC) (envelope-from gonzo@freebsd.org) Received: from mail.pbxpress.com ([65.61.203.142] helo=leaf.pbxpress.com) by luidgi.portaone.com (8.11.3/8.11.3) with ESMTP (TLSv1:AES256-SHA:256)id 1KM8Wu-0005gw-6X; Thu, 24 Jul 2008 14:39:20 -0700 Received: from jeeves.bluezbox.com (82.193.112.144.ipnet.kiev.ua [82.193.112.144]) (authenticated bits=0) by leaf.pbxpress.com (8.13.3/8.13.3) with ESMTP id m6OLgeTu052969 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Thu, 24 Jul 2008 14:42:53 -0700 (PDT) (envelope-from gonzo@freebsd.org) Message-ID: <4888F674.4010004@freebsd.org> Date: Fri, 25 Jul 2008 00:39:00 +0300 From: Oleksandr Tymoshenko User-Agent: Thunderbird 2.0.0.14 (X11/20080704) MIME-Version: 1.0 To: Jerry Toung References: <86068e730807241333v4d9f35d4ve4e4a266bb6d8121@mail.gmail.com> In-Reply-To: <86068e730807241333v4d9f35d4ve4e4a266bb6d8121@mail.gmail.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Spam-Status: No, recieved from trusted server Cc: freebsd-mips@freebsd.org Subject: Re: mips_phys_mask define X-BeenThere: freebsd-mips@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Porting FreeBSD to MIPS List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 24 Jul 2008 21:39:20 -0000 Jerry Toung wrote: > Hello list, > still learning. Could someone explain why > MIPS_PHYS_MASK is 0x1fffffff and not 0x7fffffff when you want to convert a > program's address > back to physical? MIPS_PHYS_MASK is used to convert addresses from KSEG0 and KSEG1 to physical ones. KSEG0 and KSEG1 are 2**29 bytes each. So the mask should be 2**29 - 1. That gives us 0x1fffffff. I'd suggest you to read MIPS32(tm) Architecture For Programmers Volume III: The MIPS32(tm) Privileged Resource Architecture. It's a nice starting point. You can download the document from mips.com site. -- gonzo