From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-out.m-online.net (mail-out.m-online.net [212.18.0.9]) by ozlabs.org (Postfix) with ESMTP id E1587DEA57 for ; Thu, 3 Jul 2008 01:04:35 +1000 (EST) Date: Wed, 2 Jul 2008 17:04:32 +0200 From: Olaf Hering To: Tony Breeds Subject: Re: [PATCH v2] Change the default link address for pSeries zImage kernels. Message-ID: <20080702150432.GA5910@aepfle.de> References: <1a551391a3c4925271cc86cb2e957aaccb0b599c.1214208801.git.tony@bakeyournoodle.com> <4ca08ab3df251d90440c962ef15ead1a72d75f05.1214276944.git.tony@bakeyournoodle.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 In-Reply-To: <4ca08ab3df251d90440c962ef15ead1a72d75f05.1214276944.git.tony@bakeyournoodle.com> Cc: linuxppc-dev@ozlabs.org, Paul Mackerras List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Tue, Jun 24, Tony Breeds wrote: > Currently we set the start of the .text section to be 4Mb for pSeries. > In situations where the zImage is > 8Mb we'll fail to boot (due to > overlapping with OF). Move .text in a zImage from 4MB to 64MB (well past OF). > > We still will not be able to load large zImage unless we also move OF, > to that end, add a note to the zImage ELF to move OF to 32Mb. If this > is the very first kernel booted then we'll need to move OF manually by > setting real-base. Setting real-base to what? What currently happens with a large boot file is: Firmware loads the zImage at load-base, finds that the ELF file is too large to fit into the memory window and stops. With your patch, firmware loads 12566528 bytes, and starts the zImage. The result is a truncated file, the initrd will be corrupted, kernel panic in populate_rootfs(). The only system where firmware relocates itself from 12MB to 32MB is a p640 with firmware version NAN04194. All other systems seem to ignore the NOTE section, real-base remains at 0xc00000 So I do not think your patch is a real improvement, clear error vs. silent corruption. Do you happen to know how to automate the changing the value of real-base? The addnote change has appearently no effect on recent systems. Olaf