Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752579Ab1CaMhq (ORCPT ); Thu, 31 Mar 2011 08:37:46 -0400 Received: from 30.mail-out.ovh.net ([213.186.62.213]:48440 "HELO 30.mail-out.ovh.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1751303Ab1CaMho (ORCPT ); Thu, 31 Mar 2011 08:37:44 -0400 Date: Thu, 31 Mar 2011 14:23:08 +0200 From: Jean-Christophe PLAGNIOL-VILLARD To: Russell King - ARM Linux Cc: Alan Cox , david@lang.hm, Arnd Bergmann , Nicolas Pitre , Tony Lindgren , Dave Airlie , lkml , Catalin Marinas , David Brown , linux-omap@vger.kernel.org, Linus Torvalds , linux-arm-kernel@lists.infradead.org Subject: Re: [GIT PULL] omap changes for v2.6.39 merge window Message-ID: <20110331122308.GG7420@game.jcrosoft.org> References: <20110331105440.42692165@lxorguk.ukuu.org.uk> <20110331105000.GC14323@n2100.arm.linux.org.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20110331105000.GC14323@n2100.arm.linux.org.uk> X-PGP-Key: http://uboot.jcrosoft.org/plagnioj.asc X-PGP-key-fingerprint: 6309 2BBA 16C8 3A07 1772 CC24 DEFC FFA3 279C CE7C User-Agent: Mutt/1.5.20 (2009-06-14) X-Ovh-Tracer-Id: 8348266334807501747 X-Ovh-Remote: 213.251.161.87 (ns32433.ovh.net) X-Ovh-Local: 213.186.33.20 (ns0.ovh.net) X-Spam-Check: DONE|U 0.5/N Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1864 Lines: 39 On 11:50 Thu 31 Mar , Russell King - ARM Linux wrote: > On Thu, Mar 31, 2011 at 10:54:40AM +0100, Alan Cox wrote: > > If I boot it on a current PC I'm booting on a multiprocessor system with > > different timers, totally different IRQ controllers, different keyboard > > controllers (USB), PCI Express, an IOMMU, NCQ SATA, ACPI, graphics > > running in shared host memory able to give/take pages from the host, > > extra instructions, etc etc > > > > And the same kernel boots just fine on both just fine. > > We've been there for a long time with ARM. Right from the start I had > a single kernel image which booted over a range of ARM CPUs and > platforms. > > As far as ARM CPU architectures go, today we can have a single kernel > image which covers ARMv3 to ARMv5, and a separate kernel image which > covers ARMv6 to ARMv7 including SMP and UP variants. The thing which > currently stops ARMv3 to ARMv7 all together is the different page table > layouts, the ASID tagging, the exclusive load/store support for cmpxchg > and other atomic operations, etc. As we can see a lots of people work on this, to now do not add thousand of boards but try to have only a few Personnaly I do it on at91 as example and will continue to try to have one board in the kernel with board information pass via Barebox, when it's possible. I think it's a common effort doen by the ARM Community and this will imply a lots of changesets. The work done by Linaro with the device tree will help a lot to simplify the pass of the information from the boot loader to the kernel. But we can already do it today. Best Regards, J. -- 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/