From mboxrd@z Thu Jan 1 00:00:00 1970 Received: (from majordomo@localhost) by oss.sgi.com (8.11.2/8.11.3) id g15LOOI15252 for linux-mips-outgoing; Tue, 5 Feb 2002 13:24:24 -0800 Received: from real.realitydiluted.com (real.realitydiluted.com [208.242.241.164]) by oss.sgi.com (8.11.2/8.11.3) with SMTP id g15LOLA15248 for ; Tue, 5 Feb 2002 13:24:21 -0800 Received: from localhost.localdomain ([127.0.0.1] helo=cotw.com) by real.realitydiluted.com with esmtp (Exim 3.22 #1 (Red Hat Linux)) id 16YD4W-0000aG-00; Tue, 05 Feb 2002 15:24:12 -0600 Message-ID: <3C604D73.88F1CDCE@cotw.com> Date: Tue, 05 Feb 2002 15:24:03 -0600 From: "Steven J. Hill" Reply-To: sjhill@cotw.com X-Mailer: Mozilla 4.77 [en] (X11; U; Linux 2.4.17-xfs i686) X-Accept-Language: en MIME-Version: 1.0 To: Pete Popov CC: Hartvig Ekner , linux-mips Subject: Re: What is the maximum physical RAM for a 32bit MIPS core? References: <200202051747.SAA21696@copsun18.mips.com> <3C6044A7.13FEB2E2@cotw.com> <1012943709.10659.106.camel@zeus> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: owner-linux-mips@oss.sgi.com Precedence: bulk Pete Popov wrote: > > I'm not sure if it's a "little" though. Ralf has already done the work > for 64bit memory support on 32bit kernels, but that only works currently > on 64bit CPUs. I started hacking on the 64bit memory patch to get it to > work on 32bit processors, but had to put that aside for a few weeks. I > hope to get back to it soon. > Sure, the "little" is a relative term. As far as your patch is concerned, you are essentially trying to use a true 32-bit processor (my definition being that it is not a 64-bit processor running in 32-bit mode), to address address more than 4GB of physical memory. I don't see how that is possible with just the MMU and TLB unless you are using chip selects and customm logic. -Steve -- Steven J. Hill - Embedded SW Engineer