From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758865Ab1CaSJB (ORCPT ); Thu, 31 Mar 2011 14:09:01 -0400 Received: from mail-wy0-f174.google.com ([74.125.82.174]:49908 "EHLO mail-wy0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751330Ab1CaSI7 convert rfc822-to-8bit (ORCPT ); Thu, 31 Mar 2011 14:08:59 -0400 Subject: Re: [GIT PULL] omap changes for v2.6.39 merge window Mime-Version: 1.0 (Apple Message framework v1084) Content-Type: text/plain; charset=us-ascii From: Koen Kooi In-Reply-To: Date: Thu, 31 Mar 2011 20:08:54 +0200 Cc: Russell King - ARM Linux , Alan Cox , Nicolas Pitre , Dave Airlie , Linus Torvalds , Arnd Bergmann , Tony Lindgren , David Brown , lkml , linux-arm-kernel@lists.infradead.org, linux-omap@vger.kernel.org, Catalin Marinas Content-Transfer-Encoding: 8BIT Message-Id: References: <201103301906.42429.arnd@arndb.de> <20110331105440.42692165@lxorguk.ukuu.org.uk> <20110331105000.GC14323@n2100.arm.linux.org.uk> To: david@lang.hm X-Mailer: Apple Mail (2.1084) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Op 31 mrt 2011, om 19:22 heeft david@lang.hm het volgende geschreven: > On Thu, 31 Mar 2011, 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. > > I don't think the push is to get a single kernel image that boots absolutly everywhere. having separate ARM5 and ARM7 kernels doesn't seem to be a big deal to anyone. You mean ARMv5 and ARMv7, right? ARM5 and ARM7 are completely different things. The short, but inaccurate version: ARM9 -> ARMv4t, ARMv5te* ARM11 -> ARMv6* CORTEX-A* -> ARMv7a regards, Koen