From owner-freebsd-embedded@freebsd.org Tue Mar 8 22:31:48 2016 Return-Path: Delivered-To: freebsd-embedded@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id B911BAC8417 for ; Tue, 8 Mar 2016 22:31:48 +0000 (UTC) (envelope-from mah@jump-ing.de) Received: from mail.ud03.udmedia.de (ud03.udmedia.de [194.117.254.43]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-SHA256 (128/128 bits)) (Client CN "root.udmedia.de", Issuer "StartCom Class 3 Primary Intermediate Server CA" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 2857BD2A for ; Tue, 8 Mar 2016 22:31:47 +0000 (UTC) (envelope-from mah@jump-ing.de) DKIM-Signature: v=1; a=rsa-sha256; c=simple; d=mail.ud03.udmedia.de; h= subject:to:references:from:message-id:date:mime-version :in-reply-to:content-type:content-transfer-encoding; s=beta; bh= iRqFTN4dXT+KHXmvY4c4DNMQYW/91jA3dS3lPpXeR2k=; b=M+EN+fvZC8H0cRlS aRF1kOKLCZQzggW0ZdUXJbQS0jsveAfWjA3e7Sbrd8KRYTO2kLvQEG9WZ/FoC/KQ R8UCHsTm73LNVWO/PQxc7bjryGZDFhj55wYnT0PvYR95u+2ixs35uwHJ2BcnmIwI N1Gh2a/VKhClxMITd0Ts+8IWI0A= Received: (qmail 29185 invoked from network); 8 Mar 2016 23:25:03 +0100 Received: from hsi-kbw-37-209-85-196.hsi15.kabel-badenwuerttemberg.de (HELO ?10.0.0.102?) (ud03?291p1@37.209.85.196) by mail.ud03.udmedia.de with ESMTPSA (ECDHE-RSA-AES128-GCM-SHA256 encrypted, authenticated); 8 Mar 2016 23:25:03 +0100 Subject: Re: ? about kernel size.. To: freebsd-embedded@freebsd.org References: <1457473674.1406.46.camel@freebsd.org> From: Markus Hitter X-Enigmail-Draft-Status: N1110 Message-ID: <56DF513E.9000405@jump-ing.de> Date: Tue, 8 Mar 2016 23:25:02 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.5.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit X-BeenThere: freebsd-embedded@freebsd.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: Dedicated and Embedded Systems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 08 Mar 2016 22:31:48 -0000 Am 08.03.2016 um 22:56 schrieb Brad Walker: > But, are you saying that no engineering has been done on this yet OR no > amount of engineering could make it work? If I recall correctly from some 25 years ago, memory address mapping (which is what a MMU does) is mandatory for preemtive multitasking. An i286 can't run a Unix-like OS either. In 2008 I tried to get FreeBSD down to its minimum, too. The success post is about all what's left today: https://lists.freebsd.org/pipermail/freebsd-embedded/2008-October/000604.html The task to get there is simple and straightforward, but time consuming: go step by step through the kernel configuration to disable whatever you can spare. Configure, build, try, repeat. If you need a small entire system, do the same for packages and every single file you copy into your system image. Markus -- - - - - - - - - - - - - - - - - - - - Dipl. Ing. (FH) Markus Hitter http://www.jump-ing.de/