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 14SbZO-0004Sn-00 for mtd-list@infradead.org; Tue, 13 Feb 2001 09:16:22 +0000 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 14SbZL-0004Se-00 for mtd@infradead.org; Tue, 13 Feb 2001 09:16:20 +0000 From: David Woodhouse In-Reply-To: <3A886BED.9339AC4F@danielind.com> References: <3A886BED.9339AC4F@danielind.com> To: Vipin Malik Cc: jffs-dev , mtd Subject: Re: First cut at MTD/JFFS HOWTO Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Transfer-Encoding: 8bit Date: Tue, 13 Feb 2001 09:15:47 +0000 Message-ID: <10792.982055747@redhat.com> Sender: owner-mtd@infradead.org List-ID: vmalik@danielind.com said: > Q. Why another file system. What was wrong with ext2? > A. Standard response - need journalling pseudo-filesystem to emulate a block device and to wear levelling. then need ext3 (note 3) on that. journalling fs on top of journalling fs - not efficient. Also, no way for ext[23] to mark blocks as _deleted_ and no longer cared about. Fill ext2 partition on NFTL, empty it again, and the NFTL will still carefully copy around the blocks containing old deleted data. > Q. Do I have to have JFFS on MTD? > A. ATM yes. Once you could do it on a block device. People are talking about making me make it work on IDE devices (CF). But I don't want to :) > Q. What is DOC (disk on chip)? A. Bunch of NAND flash chips connected together with a clever ASIC which does hardware ECC. > Q. What File systems can I have on DOC? A. If you put NFTL on it to emulate a block device (the status quo) then any normal filesystem. JFFS ought to work too. > Q. What is Flash memory? A. > Q. What is CFI Flash memory? A. > Q. What is JDEC Flash memory? A. > Q. What is this "interleave" stuff? A. If you have 16-bit chips, but a 32-bit processor, it makes sense to arrange them side-by-side to fill the CPU's bus. You drive them both simultaneously. That's the arrangement we refer to as 'interleave'. Other possibilities are... 4x 8-bit chips on 32-bit bus, 2x8-bit chips on 16-bit bus, ... #include -- dwmw2 To unsubscribe, send "unsubscribe mtd" to majordomo@infradead.org