From owner-freebsd-fs Fri Mar 15 18:26:12 2002 Delivered-To: freebsd-fs@freebsd.org Received: from magic.adaptec.com (magic.adaptec.com [208.236.45.80]) by hub.freebsd.org (Postfix) with ESMTP id 0000137B430; Fri, 15 Mar 2002 18:25:50 -0800 (PST) Received: from redfish.adaptec.com (redfish.adaptec.com [162.62.50.11]) by magic.adaptec.com (8.10.2+Sun/8.10.2) with ESMTP id g2G2Poj27257; Fri, 15 Mar 2002 18:25:50 -0800 (PST) Received: from btc.btc.adaptec.com (btc.btc.adaptec.com [162.62.64.10]) by redfish.adaptec.com (8.8.8+Sun/8.8.8) with ESMTP id SAA22321; Fri, 15 Mar 2002 18:25:49 -0800 (PST) Received: from hollin.btc.adaptec.com (hollin [162.62.149.56]) by btc.btc.adaptec.com (8.8.8+Sun/8.8.8) with ESMTP id TAA17335; Fri, 15 Mar 2002 19:25:47 -0700 (MST) Received: (from scottl@localhost) by hollin.btc.adaptec.com (8.11.6/8.11.6) id g2G2NZM00263; Fri, 15 Mar 2002 19:23:35 -0700 (MST) (envelope-from scottl) Date: Fri, 15 Mar 2002 19:02:26 -0700 From: Scott Long To: Chris Dillon Cc: freebsd-scsi@freebsd.org, freebsd-fs@freebsd.org Subject: Re: CD-MRW a.k.a Mt. Rainier support Message-ID: <20020316020226.GA12097@bunsenhoneydew.btc.adaptec.com> References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.3.28i Sender: owner-freebsd-fs@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.org On Wed, Mar 13, 2002 at 11:59:06AM -0600, Chris Dillon wrote: > > CC'd to freebsd-fs since this is somewhat fs-related... > > Is anyone working on implementing support for CD-MRW (apparently > included in MMC-3) into either the SCSI cd driver or the ATAPI cd > driver? Where/how would be the best place to implement this so that > it will work with either ATAPI or SCSI drives? Would implementing it > in the SCSI cd driver be best, since we now have the option of using > ATAPI drives with CAM? > > In case anyone is wondering what CD-MRW (Mt. Rainier Re-Writable) is, > it is a new standard (currently only available in the Yamaha CRW3200 > series, that I know of), that allows on-the-fly transparent > formatting, hardware defect management, and 2K-block logical > addressing of CD-RW discs and specifies a specialized UDF filesystem > to be used along with these hardware abilities. This will make drives > supporting this standard act like a more traditional magnetic-media > removable drive, thus greatly simplifying reading/writing to CD-RW > discs. Since MRW uses a new format it is not backwards compatible > with any existing CD-RW formats, though it is possible to _read_ a MRW > formatted disc in a regular drive with the proper software support. > MRW uses UDF as its standard filesystem, which we do not yet support, > though I envision using the hardware MRW support of the drive to put > just about anything you want onto it, including FAT or UFS, to use it > as a "regular" drive. > > I'd love to take a shot at implementing this if someone isn't already, > though I'll need to find the specs for the hardware side of Mt. > Rainier. Apprently it is implemented in the new MMC-3 command set. > Anyone have any pointers? This drive sounds very interesting. Unfortunaley, until the standard becomes ubiquitous, any UDF implementation will still need to understand read-modify-write and sparing tables. UDF is the natural format for it since with removable media you want inter-changability with other systems, but there should be nothing stopping you from putting UFS on it too. I've already started a UDF implementation for FreeBSD. Patches for 5.0-CURRENT can be found at http://people.freebsd.org/~scottl, along with a link for slightly older -STABLE patches. The current status is that CD-RWs and DVD-ROMs can be read (though Sparing Tables are still missing for CD-RW), and once I've cleaned up and filled in the code some more, I intend for it to go into 5.0-RELEASE. I'd welcome any help on the project, escpecially if someone wants to tackle the writing support. Scott To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-fs" in the body of the message