From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from utopia.booyaka.com (utopia.booyaka.com [72.9.107.138]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id BE137B6F88 for ; Wed, 31 Aug 2011 11:55:52 +1000 (EST) Date: Tue, 30 Aug 2011 19:55:48 -0600 (MDT) From: Paul Walmsley To: Gary Thomas Subject: Re: Virtual addresses in arch/powerpc/boot/dts/tqm8548*.dts ? In-Reply-To: <4E5D668B.1060609@mlbassoc.com> Message-ID: References: <4E5D668B.1060609@mlbassoc.com> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Cc: Dmitry Eremin-Solenikov , devicetree-discuss@lists.ozlabs.org, linuxppc-dev@lists.ozlabs.org List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Tue, 30 Aug 2011, Gary Thomas wrote: > On 2011-08-30 15:43, Paul Walmsley wrote: > > > So are these addresses virtual? My (perhaps incorrect) understanding of > > the device tree files was that they were intended to describe the physical > > memory map, rather than the virtual memory map. Or does this PowerPC > > variant have the ability to dynamically change its own physical address > > decoding? Or is something else going on? > > These addresses correspond to the internal registers which can be moved. > The default address is set by hardware at reset time (check out the > documentation on the hardware reset word). Obviously one board is > strapped for the IMMR at one address, another board at a different > address. I almost always configure my boards to use 0xF0000000 for the > IMMR. Got it. Thanks Gary. - Paul