From owner-freebsd-hackers@FreeBSD.ORG Thu Apr 15 19:04:14 2010 Return-Path: Delivered-To: freebsd-hackers@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id BDBCD106564A for ; Thu, 15 Apr 2010 19:04:14 +0000 (UTC) (envelope-from ticso@cicely7.cicely.de) Received: from raven.bwct.de (raven.bwct.de [85.159.14.73]) by mx1.freebsd.org (Postfix) with ESMTP id 2AFED8FC08 for ; Thu, 15 Apr 2010 19:04:13 +0000 (UTC) Received: from mail.cicely.de ([10.1.1.37]) by raven.bwct.de (8.13.4/8.13.4) with ESMTP id o3FJ4BXr098517 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Thu, 15 Apr 2010 21:04:11 +0200 (CEST) (envelope-from ticso@cicely7.cicely.de) Received: from cicely7.cicely.de (cicely7.cicely.de [10.1.1.9]) by mail.cicely.de (8.14.3/8.14.3) with ESMTP id o3FJ45rk014139 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Thu, 15 Apr 2010 21:04:05 +0200 (CEST) (envelope-from ticso@cicely7.cicely.de) Received: from cicely7.cicely.de (localhost [127.0.0.1]) by cicely7.cicely.de (8.14.2/8.14.2) with ESMTP id o3FJ45rW034021; Thu, 15 Apr 2010 21:04:05 +0200 (CEST) (envelope-from ticso@cicely7.cicely.de) Received: (from ticso@localhost) by cicely7.cicely.de (8.14.2/8.14.2/Submit) id o3FJ4535034020; Thu, 15 Apr 2010 21:04:05 +0200 (CEST) (envelope-from ticso) Date: Thu, 15 Apr 2010 21:04:05 +0200 From: Bernd Walter To: Mike Tancsa Message-ID: <20100415190405.GC31933@cicely7.cicely.de> References: <201004141357.o3EDvuxt067902@lava.sentex.ca> <20100415173659.GB31933@cicely7.cicely.de> <201004151745.o3FHjXI2077062@lava.sentex.ca> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <201004151745.o3FHjXI2077062@lava.sentex.ca> X-Operating-System: FreeBSD cicely7.cicely.de 7.0-STABLE i386 User-Agent: Mutt/1.5.11 X-Spam-Status: No, score=-2.9 required=5.0 tests=ALL_TRUSTED=-1, BAYES_00=-1.9, T_RP_MATCHES_RCVD=-0.01 autolearn=ham version=3.3.0 X-Spam-Checker-Version: SpamAssassin 3.3.0 (2010-01-18) on spamd.cicely.de Cc: freebsd-hackers@freebsd.org, ticso@cicely.de Subject: Re: disabling all serial input / output at boot time X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list Reply-To: ticso@cicely.de List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 15 Apr 2010 19:04:14 -0000 On Thu, Apr 15, 2010 at 01:45:36PM -0400, Mike Tancsa wrote: > At 01:36 PM 4/15/2010, Bernd Walter wrote: > > >Is the sensor prohibiting the use of USB RS232 in any way? > > Just our wallets :) Extra cost to include it and the case would need > to change as well as its in an environment where it can get hit by water. Ok - that's an understandable reason. The unfortunate thing is that the bootcode reacts on buffered input and the BIOS might already have buffered some bytes. This has nothing to do with FreeBSDs knowledge about comconsole because the BIOS translates it. IIRC the Soekris BIOS has an option to disable the SIO support, maybe your board has something similar. Otherwise this means you need to disable the bootcode (including boot0) to process any kind of input. This shouldn't be too hard to code since the code is well documented. It happens in at least boot0 and loader - the later likely can be handled by using a customized loader.rc script, which wraps to nullconsole. -- B.Walter http://www.bwct.de Modbus/TCP Ethernet I/O Baugruppen, ARM basierte FreeBSD Rechner uvm.