From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from gate.crashing.org (gate.crashing.org [63.228.1.57]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id 632DCDDF57 for ; Thu, 28 Aug 2008 22:18:17 +1000 (EST) Message-Id: <69759E45-CCB6-4D5C-B671-AD8930C8E566@kernel.crashing.org> From: Kumar Gala To: David Woodhouse In-Reply-To: <1219925555.7107.276.camel@pmac.infradead.org> Content-Type: text/plain; charset=US-ASCII; format=flowed; delsp=yes Mime-Version: 1.0 (Apple Message framework v926) Subject: Re: [PATCH 0/5] Relocatable 64-bit kernel using linker PIE support Date: Thu, 28 Aug 2008 07:18:05 -0500 References: <18594.14443.340604.693747@cargo.ozlabs.ibm.com> <1219925555.7107.276.camel@pmac.infradead.org> 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 Aug 28, 2008, at 7:12 AM, David Woodhouse wrote: > On Wed, 2008-08-13 at 11:27 +1000, Paul Mackerras wrote: >> The following series of patches implement support for a relocatable >> kernel by building it as a position-independent executable (PIE). >> When the linker is given the -pie flag, it creates an executable that >> contains dynamic relocations which can be used to relocate the image >> at boot time for any desired base address. This patch series adds a >> CONFIG_RELOCATABLE config option for 64-bit which links the kernel >> with -pie and arranges to process the relocations in early boot. >> >> With the first 4 patches applied, a relocatable kernel will still >> copy >> itself down to real address 0. The last patch changes things so that >> a relocatable kernel will run wherever it was loaded. This last >> patch >> is pretty much just a proof of concept since it doesn't do anything >> to >> ensure appropriate alignment of the base address (the base address >> needs to be 16kB aligned). We probably want to work out whether we >> are a kdump kernel and run in-place if so, or copy down to 0 if not. > > Is this mature enough for us to consider putting it in Fedora? We'd > _love_ to stop building a separate kdump kernel for ppc64... Also, can we get this on ppc32 (head_32.S)? - k