From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752628AbZAUUhv (ORCPT ); Wed, 21 Jan 2009 15:37:51 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752438AbZAUUhi (ORCPT ); Wed, 21 Jan 2009 15:37:38 -0500 Received: from 74-93-104-97-Washington.hfc.comcastbusiness.net ([74.93.104.97]:38623 "EHLO sunset.davemloft.net" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1752374AbZAUUhh (ORCPT ); Wed, 21 Jan 2009 15:37:37 -0500 Date: Wed, 21 Jan 2009 12:37:39 -0800 (PST) Message-Id: <20090121.123739.97186745.davem@davemloft.net> To: gerickson@nuovations.com Cc: linux-kernel@vger.kernel.org Subject: Re: [RFC] Add Alternative Log Buffer Support for printk Messages From: David Miller In-Reply-To: <1232559586-9164-1-git-send-email-gerickson@nuovations.com> References: <1232559586-9164-1-git-send-email-gerickson@nuovations.com> X-Mailer: Mew version 6.1 on Emacs 22.1 / Mule 5.0 (SAKAKI) 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 From: Grant Erickson Date: Wed, 21 Jan 2009 09:39:46 -0800 > This merges support for the previously DENX-only kernel feature of > specifying an alternative, "external" buffer for kernel printk > messages and their associated metadata. In addition, this ports > architecture support for this feature from arch/ppc to arch/powerpc. > > When this option is enabled, an architecture- or machine-specific log > buffer is used for all printk messages. This allows entities such as > boot loaders (e.g. U-Boot) to place printk-compatible messages into > this buffer and for the kernel to coalesce them with its normal > messages. > > Signed-off-by: Grant Erickson Nice. This would also be useful on Sparc where it is possible to tell the firmware to set aside a piece of physical memory which survives soft resets and thus can be inspected post reboot.