Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932289Ab2EJLD3 (ORCPT ); Thu, 10 May 2012 07:03:29 -0400 Received: from caramon.arm.linux.org.uk ([78.32.30.218]:39006 "EHLO caramon.arm.linux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757877Ab2EJLD2 (ORCPT ); Thu, 10 May 2012 07:03:28 -0400 Date: Thu, 10 May 2012 12:02:42 +0100 From: Russell King - ARM Linux To: Ben Dooks Cc: Arnd Bergmann , Kukjin Kim , linaro-dev@lists.linaro.org, Jason Cooper , Nicolas Pitre , Tony Lindgren , Nicolas Ferre , Linus Walleij , Magnus Damm , linux-kernel@vger.kernel.org, Haojian Zhuang , Deepak Saxena , Olof Johansson , David Brown , shawn.guo@linaro.org, Jean-Christophe PLAGNIOL-VILLARD , Sascha Hauer , linux-arm-kernel@lists.infradead.org Subject: Re: Making ARM multiplatform kernels DT-only? Message-ID: <20120510110242.GE3190@n2100.arm.linux.org.uk> References: <201205031350.35476.arnd@arndb.de> <20120503141853.GC897@n2100.arm.linux.org.uk> <20120510105515.GC30103@trinity.fluff.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20120510105515.GC30103@trinity.fluff.org> User-Agent: Mutt/1.5.19 (2009-01-05) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1307 Lines: 25 On Thu, May 10, 2012 at 11:55:15AM +0100, Ben Dooks wrote: > On Thu, May 03, 2012 at 03:18:53PM +0100, Russell King - ARM Linux wrote: > > I think what you're proposing is a totally artificial restriction. > > There's no problem with a kernel supporting DT and non-DT together. > > We've proven that many many times. I prove it _every_ night that my > > build and boot system runs - the OMAP LDP boots a multiplatform kernel > > just fine without DT. > > We could have had the same for Samsung's entire range if a bit of work > had been applied to do things like PAGE_OFFSET and replaceable IRQ > controllers. We never did dynamic PAGE_OFFSET because we _had_ taken the decision with the inclusion of XIP support that we weren't going to have self-modifying code in the kernel - and loading the offset for every page table walk would have been very expensive. The self-modifying code viewpoint seems to have changed as a result of Nicolas moving jobs, from an employer who wanted XIP to one who wants a single kernel image, which in itself isn't surprising. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/