From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from wx-out-0506.google.com (wx-out-0506.google.com [66.249.82.228]) by ozlabs.org (Postfix) with ESMTP id 306F6DDE17 for ; Thu, 23 Oct 2008 01:23:10 +1100 (EST) Received: by wx-out-0506.google.com with SMTP id s6so1598159wxc.15 for ; Wed, 22 Oct 2008 07:23:09 -0700 (PDT) Message-ID: <48FF3743.1000007@genesi-usa.com> Date: Wed, 22 Oct 2008 09:22:59 -0500 From: Matt Sealey MIME-Version: 1.0 To: Kumar Gala Subject: Re: Extended Addressing Mode References: <48FEEB88.6050505@kontron.com> <83735324-C37B-4C57-A50F-FFF0D133E4E3@kernel.crashing.org> <48FF23C4.5030408@kontron.com> <88C8EDEB-C9A5-4876-AF7D-55CBABBE111D@kernel.crashing.org> <48FF2DDE.9060301@genesi-usa.com> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Sender: Matt Sealey Cc: linuxppc-dev@ozlabs.org, =?ISO-8859-1?Q?R=E9gis_Odey=E9?= List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Kumar Gala wrote: > > > Your bigger issue is if you can setup the DDR controller for the hole > you want. I just remembered;; ~~ The CCSR window always takes precedence over all local access windows. However, the CCSR window must not overlap an LAW that maps to the DDR controller. Otherwise, undefined behavior occurs. ~~ So, it's not really possible to map 4GB of RAM in the lower 32-bit area, without interacting badly with the CCSR. This means you're forced to select a 2GB LAW for DDR, then leave 2GB free, then map the rest above.. using more than 2Gb therefore absolutely requires non-contiguous memory..? -- Matt Sealey Genesi, Manager, Developer Relations