From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from bombadil.infradead.org (bombadil.infradead.org [18.85.46.34]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id 11DDCDDE00 for ; Thu, 28 Aug 2008 22:15:56 +1000 (EST) Subject: Re: [PATCH 0/5] Relocatable 64-bit kernel using linker PIE support From: David Woodhouse To: Paul Mackerras In-Reply-To: <18594.14443.340604.693747@cargo.ozlabs.ibm.com> References: <18594.14443.340604.693747@cargo.ozlabs.ibm.com> Content-Type: text/plain Date: Thu, 28 Aug 2008 13:12:34 +0100 Message-Id: <1219925555.7107.276.camel@pmac.infradead.org> Mime-Version: 1.0 Cc: linuxppc-dev@ozlabs.org List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , 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... -- dwmw2