From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Mon, 27 May 2002 11:19:26 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Mon, 27 May 2002 11:19:25 -0400 Received: from mailout05.sul.t-online.com ([194.25.134.82]:14261 "EHLO mailout05.sul.t-online.com") by vger.kernel.org with ESMTP id ; Mon, 27 May 2002 11:19:23 -0400 To: Paratimer@aol.com Cc: rddunlap@osdl.org, lm@bitmover.com, erwin@muffin.org, yodaiken@fsmlabs.com, linux-kernel@vger.kernel.org, rtai@rtai.org From: Wolfgang Denk Subject: Re: RTAI/RtLinux X-Mailer: exmh version 2.2 Mime-version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7BIT In-Reply-To: Your message of "Mon, 27 May 2002 10:37:47 EDT." Date: Mon, 27 May 2002 17:18:48 +0200 Message-Id: <20020527151853.212DA11973@denx.denx.de> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org In message Joachim Martillo wrote: > > Did I say anything about limited resources? In any case, I have been > building and designing embedded and turnkey systems for 20 years. > I would be extremely dubious of any design that passed by my > desk that proposed the use of a general purpose multiuser, > multiprocessing, time sliced, preemptive, multimode, virtual > memory operating system for a digital video recorder. So what do you recommend when the requirement specification lists features as - Web interface (interface to electronic program guide database) - network interface (up- / download to normal PC over ethernet) - IEEE1384 interface (for digital cameras) - USB interface (for keyboard, printer) ... Would you start from scratch, or buy component by component, or just use Linux? > > Again, this is not quite correct. There have been Real-Time and > > Embedded Unix systems before (LynxOS, to name one). And there are > > other "common proprietary operating systems" that can be adapted for > > embedded needs (WinCE). > > And is there anything that can be done with WinCE or the various > RT/unix knock-off's that cannot be done better without? Please let me keep my mouth shut about WinCE. But yes, there are situations where "the various RT/unix knock-off's" are the optimal solution (fastest time to market, lowest cost, most features, highest reliability). > Excuse me, but we are talking embedded systems. At some > point there will be copyrighted tradesecreted or patented programs > in the system. Maybe. As application. So what? That does not mean that the OS kernel, device drivers etc. may not be available under GPL. > > The problems with Linux in Embedded and especially in Real-Time > > Systems are not technical ones. It is the political situation, where > > the user is left in uncertainty about what he can legally do and what > > not. > > Easy enough to deal with. One generates an appropriate real time > embedded turnkey operating system customized for the embedded > turnkey application. In my experience, it takes about 4-6 weeks > without disk management and perhaps 8-12 with disk management. I see. Yes, there are problems of that class. But that's not what I'm talking about. > And then one does not have to deal with multimegabytes of > non-locally produced code that is just lying in wait to cause > problems. ??? What are you talking about? > You may need to learn more about doing business in the USA. Definitely. I learn a lot each day. Wolfgang Denk -- Software Engineering: Embedded and Realtime Systems, Embedded Linux Phone: (+49)-8142-4596-87 Fax: (+49)-8142-4596-88 Email: wd@denx.de If ignorance is bliss, why aren't there more happy people?