From owner-freebsd-current@FreeBSD.ORG Thu May 25 17:57:06 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 E1E9316B18B; Thu, 25 May 2006 17:57:06 +0000 (UTC) (envelope-from ATRENS@nortel.com) Received: from zcars04f.nortel.com (zcars04f.nortel.com [47.129.242.57]) by mx1.FreeBSD.org (Postfix) with ESMTP id 72F5043D8A; Thu, 25 May 2006 17:56:46 +0000 (GMT) (envelope-from ATRENS@nortel.com) Received: from zcarhxm2.corp.nortel.com (zcarhxm2.corp.nortel.com [47.129.230.99]) by zcars04f.nortel.com (Switch-2.2.6/Switch-2.2.0) with ESMTP id k4PHuQS19545; Thu, 25 May 2006 13:56:26 -0400 (EDT) Received: from [10.0.10.2] ([47.128.166.148] RDNS failed) by zcarhxm2.corp.nortel.com with Microsoft SMTPSVC(6.0.3790.1830); Thu, 25 May 2006 13:56:25 -0400 Message-ID: <4475EFC1.1020504@nortel.com> Date: Thu, 25 May 2006 13:56:17 -0400 From: "Andrew Atrens" User-Agent: Mozilla Thunderbird 1.0.7 (X11/20051129) X-Accept-Language: en-us, en MIME-Version: 1.0 To: Poul-Henning Kamp References: <3981.1148578569@critter.freebsd.dk> In-Reply-To: <3981.1148578569@critter.freebsd.dk> X-Enigmail-Version: 0.93.0.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit X-OriginalArrivalTime: 25 May 2006 17:56:25.0253 (UTC) FILETIME=[8A34C550:01C68024] X-Mailman-Approved-At: Thu, 25 May 2006 17:58:47 +0000 Cc: Alexander Leidinger , Jim Thompson , small@freebsd.org, current@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: Thu, 25 May 2006 17:57:14 -0000 -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Poul-Henning Kamp wrote: > In message <4475E99C.5000502@nortel.com>, "Andrew Atrens" writes: > >>-----BEGIN PGP SIGNED MESSAGE----- >>Hash: SHA1 >> >>Seems to me you'd want a kernel that could boot off raw >>flash and run in RAM off a small RAM disk. >> >>Said kernel would have a low level driver that makes plain >>old flash chips look (and behave) like a disk. It would support >>wear-levelling, [...] >> >>Then you could throw FFS on top of that. > > > This is exactly what you do not want to do. > > You want to write a flash friendly filesystem which knows what > a flash is, and which does the wear levelling internally. > > The reason Flash Adaptation Layers came about in the first place > is that W95 didn't support anything but FAT. Hmm. I was thinking about partitioning the problem actually. Make flash look like a disk and then you can put any filesystem on it that you want. Seems a heck of a lot simpler .. and I'm not sure if I see any drawbacks to doing it that way ... Having said that, it would be great if we had a solid log-structured filesystem for *BSD. Andrew. -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.2 (FreeBSD) Comment: Using GnuPG with Thunderbird - http://enigmail.mozdev.org iD8DBQFEde/B8It2CaCdeMwRAjQUAJ90eJNuU2aJW8UogdMPSC3RTfBwqwCfWdvB lKUuNnxUbyP6LM5vKrdLs2o= =E72s -----END PGP SIGNATURE-----