From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from majordomo by infradead.org with local (Exim 3.20 #2) id 14rg7Y-00052s-00 for mtd-list@infradead.org; Mon, 23 Apr 2001 14:11:16 +0100 Received: from dell-paw-3.cambridge.redhat.com ([195.224.55.237] helo=passion.cambridge.redhat.com) by infradead.org with esmtp (Exim 3.20 #2) id 14rg7X-00052m-00 for mtd@infradead.org; Mon, 23 Apr 2001 14:11:16 +0100 From: David Woodhouse In-Reply-To: <01042312512000.00451@rob> References: <01042312512000.00451@rob> <01041713245700.01481@rob> <005801c0cbd3$2bdb3c60$4d02010a@lrpeople.com> To: rob@sysgo.de Cc: "Alexander Melichenko" , mtd@infradead.org Subject: Re: Elan SC520 - problem with MTD Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Date: Mon, 23 Apr 2001 14:10:38 +0100 Message-ID: <6654.988031438@redhat.com> Sender: owner-mtd@infradead.org List-ID: rob@sysgo.de said: > Some Background info: > In order to persuade the BIOS to boot from the Flash, you have to > enable it's "disk" emulation: the BIOS can treat each of the flash > banks as an emulated disk. So far so good, but: these "disk" functions > are only accessible through the BIOS int 13h call, thus, you can't > access it from Linux. > Worse even, the BIOS insists on doing "wear levelling" (i.e. it tries > to distribute erases evenly over all flash blocks). It does this by > remapping flash blocks when they have seen to many write erases. > Therefore, if you write a continuous stream of data to the flash > using the BIOS int13h function, the BIOS will scatter your data all > over the flash memory in an unpredictable way. There is no way (other > than buying a customized BIOS from General Software) to disable his > wear levelling. So the bottom line is: Has nobody tried to reverse-engineer the format they use for this and provide a driver in Linux? See the FTL and NFTL drivers for examples and ideas on how the BIOS might be doing the translation. -- dwmw2 To unsubscribe, send "unsubscribe mtd" to majordomo@infradead.org