From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1762627AbYDURA6 (ORCPT ); Mon, 21 Apr 2008 13:00:58 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755509AbYDURAu (ORCPT ); Mon, 21 Apr 2008 13:00:50 -0400 Received: from mail.queued.net ([207.210.101.209]:3084 "EHLO mail.queued.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755440AbYDURAt (ORCPT ); Mon, 21 Apr 2008 13:00:49 -0400 Date: Mon, 21 Apr 2008 13:03:20 -0400 From: Andres Salomon To: David Woodhouse Cc: Mitch Bradley , Yinghai Lu , "H. Peter Anvin" , "Eric W. Biederman" , Ingo Molnar , Andrew Morton , Joseph Fannin , linux-kernel@vger.kernel.org, jordan.crouse@amd.com Subject: Re: [PATCH 1/2] OLPC: Add support for calling into Open Firmware Message-ID: <20080421130320.38b5f505@ephemeral> In-Reply-To: <1208793253.9212.507.camel@pmac.infradead.org> References: <20080418014757.52fb4a4f.akpm@linux-foundation.org> <20080419031024.GC3503@nineveh.local> <20080418202925.b18452c5.akpm@linux-foundation.org> <20080419092544.378664a8@ephemeral> <20080419133909.5aa6b63e@ephemeral> <86802c440804200334t5cdcd100rfc41e9b1bf379109@mail.gmail.com> <480C0582.9010509@firmworks.com> <86802c440804202015h2605eff7vc733874dd1f22261@mail.gmail.com> <480C1286.3040307@firmworks.com> <20080421102417.6de71391@ephemeral> <1208793253.9212.507.camel@pmac.infradead.org> X-Mailer: Claws Mail 2.10.0 (GTK+ 2.12.0; i486-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 21 Apr 2008 16:54:13 +0100 David Woodhouse wrote: > On Mon, 2008-04-21 at 10:24 -0400, Andres Salomon wrote: > > I'm not actually convinced that we *do* want to keep OFW resident in memory, > > especially given the memory tricks we need to play. I also don't actually > > like the OFW interface that we. The debugging aspect of it was a > > compelling argument up until a week ago (when kernel debuggers started > > finally finding their way into the kernel). > > I don't actually think that the debugging aspect was _ever_ a compelling > argument. It might have made it theoretically possible for _Mitch_ to > debug kernel problems, should he be inclined to do so -- but for the > rest of us mere mortals it's just a PITA trying to keep OpenFirmware > live. A gdb stub is much more useful, in my experience. > > > However, until we clean up the promfs stuff, there's no chance of getting > > an OFW device tree upstream. > > I see no reason why we shouldn't be able to create a 'flattened'b > device-tree during early boot, like the PowerPC kernel does. And use it > thereafter, having quiesced OpenFirmware. Haven't we already been > working on unifying this between SPARC and PowerPC kernels? Quite simply, it's a lot more work (*and* we have to play nice w/ sparc and ppc). I had intended to eventually do it, but first I wanted to get this stuff in for 2.6.26 so that we could at least boot upstream kernels on XOs. I was also hoping to not get into this conversation, but alas.. too late. :) > > I definitely don't think we need to play these tricks to keep > OpenFirmware resident while the kernel is running. Take a look at your > second patch -- it's _all_ just lookups in the device-tree, and you're > inventing a new way to do it instead of using the existing one. > -- Need a kernel or Debian developer? Contact me, I'm looking for contracts.