From owner-freebsd-hackers@FreeBSD.ORG Sat Jun 12 04:15:36 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 A0D291065672; Sat, 12 Jun 2010 04:15:36 +0000 (UTC) (envelope-from matt.thyer@gmail.com) Received: from mail-vw0-f54.google.com (mail-vw0-f54.google.com [209.85.212.54]) by mx1.freebsd.org (Postfix) with ESMTP id 25E868FC18; Sat, 12 Jun 2010 04:15:35 +0000 (UTC) Received: by vws20 with SMTP id 20so1119562vws.13 for ; Fri, 11 Jun 2010 21:15:35 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:received:received:in-reply-to :references:date:message-id:subject:from:to:cc:content-type; bh=LN3NfMhtWvuLfehKHAAnXVpwzU9semH9KRkVgwk6EEY=; b=Ab4rThIkLo4zS6Zdhmy+dFvdw7ftTS6uvFAYmpOLIX4wEHVRQTLA14fS6PYXreg8ON N8L/httuqvR6YVuL36v/eN+k7BuEvS9xzGGxN2RmCaoNZTpaakqMc3bRwYFqwsK8Fjqv RNkuzMRL3vmqavEtDjsHKbi1Km4DOrMr3SKkY= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type; b=kClJ3JLdiUqpL/USkD0zvUdFnbCI1JHDsxdkaHzYVjBZW9WugL4QQyAK+1DbW4bUxM IfkfHv6zg0zAQJNFsnTjJxnVxZePrtqGtoTb5R7ZJQOawhtPDqy5i3m3w6hr2TaqO6Av xd25AfzCeNWJ2HDeIOkfus3XbbZ93dns1E1Do= MIME-Version: 1.0 Received: by 10.220.123.9 with SMTP id n9mr239921vcr.269.1276314562598; Fri, 11 Jun 2010 20:49:22 -0700 (PDT) Received: by 10.220.194.4 with HTTP; Fri, 11 Jun 2010 20:49:22 -0700 (PDT) In-Reply-To: References: Date: Sat, 12 Jun 2010 13:19:22 +0930 Message-ID: From: Matt Thyer To: Chargen Content-Type: text/plain; charset=ISO-8859-1 X-Mailman-Approved-At: Sat, 12 Jun 2010 04:26:05 +0000 Cc: freebsd-hackers@freebsd.org, hackers@freebsd.org, Mohammed Farrag , freebsd-current@freebsd.org Subject: Re: I need reply in Embedded FreeBSD Kernel Theme X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 12 Jun 2010 04:15:36 -0000 On 12 June 2010 12:02, Chargen wrote: > Sir, first of all: I'm no expert in this field but I've seen your document > and I'm still wondering why you should impose such a design. > > I suppose it's well thought of but still I'm a bit opposed to binary > configuration files because I think has to be some kind of dependency on how > to generate these kind of files (correct me if I'm wrong?) > > as far as your document goes: > "We will unload all the drivers that indicated with zeros in the module > metadata file. That would make the OS to be a few of Megabytes." > > unload? what is the logic here? > > I'm sorry but what is the real gain here, > > can you please elaborate? > FreeBSD is already a very modular system and the traditional way (a traditional way) to build for embedded systems is to follow the NanoBSD build method (tools included in the source tree) with a stripped down kernel in which you only load the modules your hardware requires using the FreeBSD loader (or after the initial boot). However my Soekris net4801 board still takes about 2.5 minutes to boot and I think time could be saved by parallel probing of hardware where possible. Much work has been done on fast boot times in the Linux world including an impressive demonstration by an Intel team for car instrumentation panels (on Youtube... Google for fastest Linux boot). I'd vote for more work on FreeBSD's existing boot method rather than an entirely new implementation. What problem are you trying to solve Mohammed ?