From neversetsun@ustc.edu Fri Mar 28 09:17:03 2008 Received: from smtp.ustc.edu.cn ([202.38.64.16] helo=ustc.edu.cn) by stoneboat.aleph1.co.uk with smtp (Exim 4.63) (envelope-from ) id 1JfAhY-0005HW-Tj for yaffs@lists.aleph1.co.uk; Fri, 28 Mar 2008 09:17:03 +0000 Received: (eyou send program); Fri, 28 Mar 2008 17:16:54 +0800 Message-ID: <406695814.23298@ustc.edu.cn> X-EYOUMAIL-SMTPAUTH: shizheng@mail.ustc.edu.cn Received: from unknown (HELO [127.0.0.1]) (219.219.218.106) by 202.38.64.8 with SMTP; Fri, 28 Mar 2008 17:16:54 +0800 Message-ID: <47ECB76E.8030103@ustc.edu> Date: Fri, 28 Mar 2008 17:16:30 +0800 From: shizheng User-Agent: Thunderbird 2.0.0.12 (Windows/20080213) MIME-Version: 1.0 To: Charles Manning References: <47CD76CA.2050008@ustc.edu> <200803051123.16629.manningc2@actrix.gen.nz> In-Reply-To: <200803051123.16629.manningc2@actrix.gen.nz> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-SA-Exim-Connect-IP: 202.38.64.16 X-SA-Exim-Mail-From: neversetsun@ustc.edu X-Spam-Checker-Version: SpamAssassin 3.2.3 (2007-08-08) on stoneboat.aleph1.co.uk X-Spam-Level: X-Spam-Status: No, score=-1.8 required=5.0 tests=BAYES_00, MSGID_FROM_MTA_HEADER,SPF_HELO_PASS autolearn=no version=3.2.3 X-SA-Exim-Version: 4.2.1 (built Tue, 09 Jan 2007 17:23:22 +0000) X-SA-Exim-Scanned: Yes (on stoneboat.aleph1.co.uk) Cc: yaffs@lists.aleph1.co.uk Subject: Re: [Yaffs] Source code mismatching development notes of Yaffs2? X-BeenThere: yaffs@lists.aleph1.co.uk X-Mailman-Version: 2.1.9 Precedence: list List-Id: Discussion of YAFFS NAND flash filesystem List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 28 Mar 2008 09:17:03 -0000 Hi, Could you please give any further explanation about bad block handling? Since it's handled by nand driver, what is confusing? BTW: There're two yaffs_mtdif2.c in cvs. One is $(SRC_ROOT)/yaffs_mtdif2.c, another one is $(SRC_ROOT)/patches/yaffs_mtdif2.c. Is the second one still useful under linux 2.6.24? best wishes, shizheng Charles Manning wrote: > On Wednesday 05 March 2008 05:20:26 shizheng wrote: > >> I'm viewing the latest source from cvs and I've got >> a few questions about Yaffs2, especially when I compared >> the code to the development notes(http://www.yaffs.net/node/38): >> >> >> 1. tag information stored in NAND oob >> In the development notes, it says Yaffs2 has these tag information >> including blockState, chunkId, objectId, nBytes, blockSequence, tagsEcc >> and ecc. >> But in yaffs_packedtags2.h, it defines >> typedef struct { >> unsigned sequenceNumber; >> unsigned objectId; >> unsigned chunkId; >> unsigned byteCount; >> } yaffs_PackedTags2TagsPart; >> >> typedef struct { >> yaffs_PackedTags2TagsPart t; >> yaffs_ECCOther ecc; >> } yaffs_PackedTags2; >> >> and blockState and ecc on data are missing. I have no idea >> about the MTD layer of linux, so I don't know whether the >> two tags are handled by MTD. >> > > The difference is because the one structure is the yaffs_ExtendedTags > structure which is an abstracted form of the tags. This is the structure that > is passed around within yaffs. > > The packed tags are the tags as packed down for writing into NAND. If you look > at the yaffs_packedtags2.c file you will see the conversion beween these two > forms. > > The block state is managed by a slightly different mechanism, by directly > querying the nand driver. > > This stuff can be a bit confusing at times and I hope to refactor this to be > far clearer. > > > >> 2. The file $(SRC_ROOT)/patches/yaffs_mtdif2.c isn't useful, is it? >> I have checkouted the source code, and done make/insmod directly on linux >> without merging Yaffs into kernel tree. >> > I think I must be missing your point here. THis file converts the more > abstract NAND interface into calls to mtd to provide the services. > > >> The module works well without any patch when simple file operation is >> tested on NANDSim(2kB page, 64B oob, 512MB chipsize). >> > > Glad to hear it. > > >> best wishes, shizheng >> >> >> >> _______________________________________________ >> yaffs mailing list >> yaffs@lists.aleph1.co.uk >> http://lists.aleph1.co.uk/cgi-bin/mailman/listinfo/yaffs >> > > > >