From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from ash.lnxi.com ([207.88.130.242] helo=DLT.linuxnetworx.com) by pentafluge.infradead.org with esmtp (Exim 3.22 #1 (Red Hat Linux)) id 17XyVx-000330-00 for ; Fri, 26 Jul 2002 07:23:50 +0100 To: , LinuxBIOS Subject: Compact Flash is a valid canidate for an MTD device. From: Eric W Biederman Date: 26 Jul 2002 00:23:44 -0600 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-mtd-admin@lists.infradead.org Errors-To: linux-mtd-admin@lists.infradead.org List-Help: List-Post: List-Subscribe: , List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: The Compact Flash extensions to the IDE command set, there is information that they can indeed be treated as a normal mtd character device. In particular the following commands were added to IDE. - CFA REQUEST EXTENDED ERROR CODE - CFA WRITE SECTORS WITHOUT ERASE - CFA ERASE SECTORS - CFA WRITE MULTIPLE WITHOUT ERASE - CFA TRANSLATE SECTOR - SET FEATURES Enable/Disable 8-bit transfer They aren't a perfectly normal flash chip but, you do have the ability to just erase or to just write sectors. CFA TRANSLATE SECTOR gives information on how many times an individual sector has been erased, so it is possible to implement wear-leveling above the CFA device. It appears to me there would be noticeable benefit to configuring a Compact Flash device as an MTD device, and running JFFS on top of it. I haven't had a chance to try it yet, but hopefully this will point someone in a useful direction. Eric