From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756105AbXIQQ1Y (ORCPT ); Mon, 17 Sep 2007 12:27:24 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752682AbXIQQ1R (ORCPT ); Mon, 17 Sep 2007 12:27:17 -0400 Received: from nef2.ens.fr ([129.199.96.40]:1127 "EHLO nef2.ens.fr" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752070AbXIQQ1R (ORCPT ); Mon, 17 Sep 2007 12:27:17 -0400 X-Greylist: delayed 2120 seconds by postgrey-1.27 at vger.kernel.org; Mon, 17 Sep 2007 12:27:17 EDT Date: Mon, 17 Sep 2007 17:51:49 +0200 From: David Madore To: linux-kernel@vger.kernel.org Subject: patch/option to wipe memory at boot? Message-ID: <20070917155149.GA5453@clipper.ens.fr> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.9i X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-3.1.4 (nef2.ens.fr [129.199.96.32]); Mon, 17 Sep 2007 17:51:50 +0200 (CEST) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Hi, Is there a patch or a boot option or something which wipes all available (physical) RAM at boot (or better, fills it with a fixed signature like 0xdeadbeef)? I'm getting phony ECC errors and I'd like to test whether they go away when the RAM is properly initialized. Also, I'd like to know exactly which parts of RAM are being used and which are untouched since boot (hence the 0xdeadbeef signature). If this patch/option doesn't exist, can anyone give me a hint as to where and how it would be best to add this? (I'm afraid I'm very ignorant as to how Linux sets up its RAM mapping.) I'm concerned about x86 and x86_64. PS: I'm not finicky: it's all right if a couple of megabytes at the bottom of RAM are not scrubbed (I'm more interested about the top gigabyte-or-so), especially if they're guaranteed to be used by the kernel. Happy hacking, -- David A. Madore (david.madore@ens.fr, http://www.madore.org/~david/ )