From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 23934 invoked by alias); 15 May 2013 15:49:21 -0000 Mailing-List: contact ecos-discuss-help@ecos.sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: ecos-discuss-owner@ecos.sourceware.org Received: (qmail 23913 invoked by uid 89); 15 May 2013 15:49:20 -0000 X-Spam-SWARE-Status: No, score=-0.8 required=5.0 tests=AWL,BAYES_00,FREEMAIL_FROM,RCVD_IN_DNSWL_LOW,RCVD_IN_HOSTKARMA_YE,SPF_PASS autolearn=ham version=3.3.1 Received: from mail-oa0-f49.google.com (HELO mail-oa0-f49.google.com) (209.85.219.49) by sourceware.org (qpsmtpd/0.84/v0.84-167-ge50287c) with ESMTP; Wed, 15 May 2013 15:49:19 +0000 Received: by mail-oa0-f49.google.com with SMTP id k14so2350172oag.22 for ; Wed, 15 May 2013 08:49:18 -0700 (PDT) MIME-Version: 1.0 X-Received: by 10.60.121.33 with SMTP id lh1mr19160781oeb.98.1368632958454; Wed, 15 May 2013 08:49:18 -0700 (PDT) Received: by 10.76.35.228 with HTTP; Wed, 15 May 2013 08:49:18 -0700 (PDT) Date: Wed, 15 May 2013 15:49:00 -0000 Message-ID: From: =?ISO-8859-1?Q?Max_Seidenst=FCcker?= To: ecos-discuss@ecos.sourceware.org Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Subject: [ECOS] JFFS2 on NOR flash with ECC X-SW-Source: 2013-05/txt/msg00020.txt.bz2 Hi folks, we are using a =B5C that has ECC calculation on an 8 Byte boundary in its NOR flash storage. After taking a glance at the JFFS2 eCos port and the most recent Linux version I am a little lost on how to get the fastest solution to solve this. The problem with ECC'd NOR is that the obsolete-flag cannot be written. ECC is calculated after the initial write, so even this one bit flip results in an ECC error. Unfortunately the eCos port of JFFS2 doesn't support NAND flash and Linux MTD, where the NOR ECC patches (http://mhonarc.axis.se/jffs-dev/msg01398.html) would be easily ported to. So I see two possible approaches: 1. Add JFFS2 NAND support to eCos by updating JFFS2 to the newest version, which also incorporates adaption of the Linux MTD stuff 2. Increment the obsolete marker to 8 Byte and align it on an 8 Byte boundary so a obsolete marker will write to a formerly unwritten 8 Byte sector and make sure the flash writes are 8 Byte aligned. I would like to go with the second approach as it looks faster, but don't know if this easy to achieve. Any ideas or help on how to do that, is highly appreciated. Cheers Max -- Before posting, please read the FAQ: http://ecos.sourceware.org/fom/ecos and search the list archive: http://ecos.sourceware.org/ml/ecos-discuss