From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.nokia.com ([192.100.122.233] helo=mgw-mx06.nokia.com) by bombadil.infradead.org with esmtps (Exim 4.68 #1 (Red Hat Linux)) id 1KDyH5-0003rq-MW for linux-mtd@lists.infradead.org; Wed, 02 Jul 2008 09:05:16 +0000 Subject: Re: Bootloader support for UBI images From: Artem Bityutskiy To: Richard Titmuss In-Reply-To: <486B34D9.2070009@logitech.com> References: <486A184B.3080708@logitech.com> <1214915164.6573.75.camel@sauron> <486B34D9.2070009@logitech.com> Content-Type: text/plain; charset=utf-8 Date: Wed, 02 Jul 2008 12:02:58 +0300 Message-Id: <1214989379.6573.85.camel@sauron> Mime-Version: 1.0 Content-Transfer-Encoding: quoted-printable Cc: linux-mtd@lists.infradead.org Reply-To: dedekind@infradead.org List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Wed, 2008-07-02 at 08:57 +0100, Richard Titmuss wrote: > Right, I was thinking that it would allow any number of volumes for=20 > renaming. I am also not sure about the interface, and was hoping to get=20 > some suggestions here. I will think about it and propose something in a=20 > few days. Do you absolutely need multiple renames? Could you live with one at a time? > > So you use the sub-page read patch BTW? > No, I'd missed that. Where is it? Here is the relevant thread. Some people already use that patch. dwmw2 was positive about it and told he would accept it. http://lists.infradead.org/pipermail/linux-mtd/2008-April/021412.html > Ok, that is possible. This would also have to include the bad block and=20 > bit flip status for each PEB. At the moment the Redboot flash api does=20 > not make this available, so it would mean extending Redboot or writing=20 > custom flash drivers to access this information. Well, bit-flip information is not mandatory and may be done later as an improvement. Bad-block information have to be available. > > I did not actually catch the second part (LER and PER) tables - this is > > something I am not aware of. UBI has only volume table on flash, the > > other things are in-memory and build by scanning. > > =20 > It was a proposal to _add_ an addition table, that provided a LER to PER=20 > mapping for static volumes. Ah, this is s/LER/LEB/, s/PER/PEB/. > If this table was stored near the beginning=20 > of the flash, then it could be accessed without a full scan. This could=20 > only be used if the UBI volume was mounted read-only, any write=20 > operations would require scanning all the flash blocks. This is an=20 > alternative approach to passing data from the bootloader to the kernel. Well, may be done, but the R/O limitation seems to be too hard. --=20 Best regards, Artem Bityutskiy (=D0=91=D0=B8=D1=82=D1=8E=D1=86=D0=BA=D0=B8=D0=B9 =D0=90= =D1=80=D1=82=D1=91=D0=BC)