From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from gate.ebshome.net (gate.ebshome.net [64.81.67.12]) (using TLSv1 with cipher EDH-RSA-DES-CBC3-SHA (168/168 bits)) (Client CN "gate.ebshome.net", Issuer "gate.ebshome.net" (not verified)) by ozlabs.org (Postfix) with ESMTP id 781CA67A33 for ; Thu, 31 Mar 2005 13:26:58 +1000 (EST) Date: Wed, 30 Mar 2005 19:26:56 -0800 From: Eugene Surovegin To: Li Yang-r58472 Message-ID: <20050331032656.GB18254@gate.ebshome.net> References: <9FCDBA58F226D911B202000BDBAD4673011732F4@zch01exm40.ap.freescale.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <9FCDBA58F226D911B202000BDBAD4673011732F4@zch01exm40.ap.freescale.net> Cc: Linux PPC Embedded list Subject: Re: Problem running Linux 2.6.11 on MPC8272ADS List-Id: Linux on Embedded PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Thu, Mar 31, 2005 at 11:03:00AM +0800, Li Yang-r58472 wrote: > Well, it seems to be a historic problem. Freescale BSP was > originally ported from u-boot-1.0.0 and linux-2.4.22. So the BCSR > was freely chosen as 0xf8000000. Later, we updated them to > u-boot-1.1.1 and linux-2.4.26, and make the BCSR consistent to older > version. However the sourceforge u-boot-1.1.1 support for > MPC8272ADS > was committed by Arabella guys, they chose BCSR mapping to > 0xf4500000. Kumar's MPC8272 support which is in 2.6.11 source was > developed using sourceforge u-boot-1.1.1 seemingly. > > This might brought up a question that if we need a convention or > something to define the recommended memory mapping for PowerPC BSPs. > As there are different groups of people around the world developing > BSPs for PowerPC platforms, and often the communication between them > is very limited. > > For now using kernel and u-boot released from the same vendor is recommended. > There is trivial solution which will work regardless on which version of U-Boot and kernel you are using. DO NOT hardcode such stuff in TWO DIFFERENT places, do this only in one, in this case it should be firmware (e.g. U-Boot). In kernel just read BRx register for that chip select and use this address for accesses from the kernel. This is how I do on all my board ports. No need to establish any artificial conventions on memory map, etc. -- Eugene