From owner-freebsd-hackers Tue Jan 5 15:54:51 1999 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id PAA04953 for freebsd-hackers-outgoing; Tue, 5 Jan 1999 15:54:51 -0800 (PST) (envelope-from owner-freebsd-hackers@FreeBSD.ORG) Received: from smtp01.primenet.com (smtp01.primenet.com [206.165.6.131]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id PAA04940 for ; Tue, 5 Jan 1999 15:54:48 -0800 (PST) (envelope-from tlambert@usr05.primenet.com) Received: (from daemon@localhost) by smtp01.primenet.com (8.8.8/8.8.8) id QAA00926; Tue, 5 Jan 1999 16:54:12 -0700 (MST) Received: from usr05.primenet.com(206.165.6.205) via SMTP by smtp01.primenet.com, id smtpd000881; Tue Jan 5 16:54:07 1999 Received: (from tlambert@localhost) by usr05.primenet.com (8.8.5/8.8.5) id QAA19601; Tue, 5 Jan 1999 16:53:55 -0700 (MST) From: Terry Lambert Message-Id: <199901052353.QAA19601@usr05.primenet.com> Subject: Re: question about re-entrancy. To: wes@softweyr.com (Wes Peters) Date: Tue, 5 Jan 1999 23:53:55 +0000 (GMT) Cc: tlambert@primenet.com, bright@hotjobs.com, hackers@FreeBSD.ORG In-Reply-To: <36929290.2909A074@softweyr.com> from "Wes Peters" at Jan 5, 99 03:30:40 pm X-Mailer: ELM [version 2.4 PL25] MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG > Except that out here in the real world uITRON isn't even on the > radar screen. I know it's supposed to be big news with the Japanese > companies who created it, but the numerous projects being done here > in the USA don't even consider it. At all. Ever. There are actually quite a number of uITRON OS's from US companies, starting with eCOS from Cygnus, which is (basically) under a GPL derivative license. The Intel Video Phone Reference Implementation comes with a uITRON compliant OS from a US company ("Inferno" from Lucent): http://developer.intel.com/design/strong/webphone.htm So it's a bit more than a curiousity. Also, FreeBSD has strong Japanese support, and uITRON would only make it stronger. > If you read the RTEMS license page, it is GPL'ed with an exception, and > that exception allows you to create and distribute your product, linked > with RTEMS, without restraint. In effect, they're using the LGPL with > no source distribution clause. > > The original RTEMS license was much more Berkeley like, but they found > a couple of "clients" who were not contributing fixes back and it > sorta ticked them off, so they went with this instead. Go figure. Yeah. The problem is that they are using BSD TCP/IP code, and as a result, the requirement for source distribution is highly questionable. If you don't have a legally valid license to use the stuff, you don't have any license to use the stuff. > Whether this is a problem or not depends on your system architecture. In > embedded systems, where the interactions between parts of the architecture > are generally both simpler and more limited than in a large, general- > purpose computer, contention on the critical objects often is not much > of a consideration, because the various system objects have such limited > interactions. This is also true of, for instance, I/O processors > communicating with a main system processor. > > RTEMS remains a good example of a working object-locking system that > can scale quite easily to a moderate number of processors. OK, I'll buy that, if you'll buy that SVR4 is a good example of a working object-locking system that can only scale to 4 processors. ;-). The problem is that FreeBSD is more similar in the tasks it runs to SVR4 than it is to an RTOS. Even with RT features, I think this would stay true... Terry Lambert terry@lambert.org --- Any opinions in this posting are my own and not those of my present or previous employers. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message