From owner-freebsd-current@FreeBSD.ORG Tue May 30 04:42:41 2006 Return-Path: X-Original-To: current@freebsd.org Delivered-To: freebsd-current@FreeBSD.ORG Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 2B9C216A445; Tue, 30 May 2006 04:42:41 +0000 (UTC) (envelope-from jim@netgate.com) Received: from netgate.com (mail.netgate.com [64.62.194.115]) by mx1.FreeBSD.org (Postfix) with ESMTP id DB39643D48; Tue, 30 May 2006 04:42:40 +0000 (GMT) (envelope-from jim@netgate.com) Received: from [192.168.2.184] (rrcs-67-52-77-54.west.biz.rr.com [67.52.77.54]) by netgate.com (Postfix) with ESMTP id 30C3628000B; Mon, 29 May 2006 21:42:16 -0700 (PDT) In-Reply-To: <20060530040220.GA59831@what-creek.com> References: <447B6870.8020704@nortel.com> <20060530040220.GA59831@what-creek.com> Mime-Version: 1.0 (Apple Message framework v750) Content-Type: text/plain; charset=US-ASCII; delsp=yes; format=flowed Message-Id: Content-Transfer-Encoding: 7bit From: Jim Thompson Date: Mon, 29 May 2006 18:42:14 -1000 To: John Birrell X-Mailer: Apple Mail (2.750) X-Mailman-Approved-At: Tue, 30 May 2006 12:28:52 +0000 Cc: Alexander Leidinger , Poul-Henning Kamp , Andrew Atrens , current@freebsd.org, small@freebsd.org Subject: Re: FreeBSD's embedded agenda X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 30 May 2006 04:42:41 -0000 On May 29, 2006, at 6:02 PM, John Birrell wrote: > On Mon, May 29, 2006 at 05:32:32PM -0400, Andrew Atrens wrote: >> So then we agree - write a driver that makes raw flash look like a >> CF, >> and does wear-levelling, gc, etc, under the hood. Then put whatever >> f/s you want on it. it's a start at least. Then build your kick-ass >> NAND-aware (or NOR aware or both) fs on top of that that makes use of >> some extensions that the driver provides. Okay, that's quite the >> arm wave ... I must admit that I don't know so much about the >> existing >> fs<->disk interface... > > Writing a NAND driver for FreeBSD using geom is a trivial matter. It > only takes a few days or a week at the most. > > I don't really understand what all the fuss is here. I've built > FreeBSD > embedded systems that are smaller than all the picobsd etc > configurations > which all rely on choosing programs out of the standard FreeBSD > tree and > putting them on a 'disk'. Everything you wrote is true, if (and only if) your application can deal with having the non-vm-based filesystem(s) be RO. But it was true for linux prior to JFFS/JFFS2 as well.