From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail.fh-wedel.de ([213.39.232.198] helo=moskovskaya.fh-wedel.de) by canuck.infradead.org with esmtps (Exim 4.43 #1 (Red Hat Linux)) id 1Coltk-0003Lr-Be for linux-mtd@lists.infradead.org; Wed, 12 Jan 2005 12:03:11 -0500 Date: Wed, 12 Jan 2005 18:02:56 +0100 From: =?iso-8859-1?Q?J=F6rn?= Engel To: Jared Hulbert Message-ID: <20050112170256.GF25638@wohnheim.fh-wedel.de> References: <20050111215102.GA6289@wohnheim.fh-wedel.de> <6934efce050112084111ef438c@mail.gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <6934efce050112084111ef438c@mail.gmail.com> Cc: MTD List , David Woodhouse Subject: Re: JFFS3 & performance List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Wed, 12 January 2005 08:41:04 -0800, Jared Hulbert wrote: > > Clarification on NOR technology. Remember that the ability to run > code XIP is effectively a requirement for a NOR chip. This means no > read errors can leave the chip. I don't see this changing in the > foreseeable future. Any read errors that do occur would probably be > caused by a failed/incomplete program. Correct. That requirement comes mostly from having to program the memory controller before being able to use DRAM. After the early boot, it's just nice to have. > We probably do want to be able to easily retire, reprogram, and/or > test those blocks/pages that get read errors. That would have to be > done in the filesystem and the chip driver needs to be able report a > read error occured. > > Any chance of being able store special files XIP in JFFS3? > Uncompressed aligned page sized chunks, etc. Would this actually be an advantage? Last time I looked, it was cheaper to use more DRAM. Most DSL routers I see advertised have a 1:4 or 1:8 ratio of NOR:DRAM, so it looks as if the prices haven't changed much. Jörn -- Correctness comes second. Features come third. Performance comes last. Maintainability is needed for all of them.