From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailout05.sul.t-online.com ([194.25.134.82]) by canuck.infradead.org with esmtp (Exim 4.33 #1 (Red Hat Linux)) id 1BTefX-0003AH-5u for linux-mtd@lists.infradead.org; Fri, 28 May 2004 06:32:57 -0400 From: tglx@linutronix.de (Thomas Gleixner) To: Andy Hawkins , linux-mtd@lists.infradead.org Date: Fri, 28 May 2004 12:27:34 +0200 References: <1085737289.5617.3.camel@adh> In-Reply-To: <1085737289.5617.3.camel@adh> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Content-Disposition: inline Message-Id: <200405281227.34312.tglx@linutronix.de> Cc: Subject: Re: Large flash concatenation Reply-To: tglx@linutronix.de List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Friday 28 May 2004 11:41, Andy Hawkins wrote: > Hi, > > I'm trying to add support to the kernel for concatenating a number of > large flash devices (1Gb Samsung K9F1G08). > > I've added the following line to nand_ids.c: > > {"NAND 1GiB 3,3V", 0xf1, 30, 0x4000, 0}, > > and the devices are correctly detected (I've also written the required > code in drivers/mtd/nand), showing a size of 0x40000000 for each device. The device size is not 1GiB in words: One GigaByte. The device size for chips with the id code 0xf1 is 1 GigaBit which is 128 MegaByte The erasesize is wrong, as it is 64KiB and not 16KiB, but see below (1.) > However, when I concatenate 15 of these devices, I end up with a > partition of size 0xc000000. I assume that this is because the total > size is stored in 32 bits, and as such is overflowing. 15 * 128 Megabyte =3D 2013265920 Bytes =3D 0x78000000 which fits into 32 bit 1. Please use the latest NAND code, as the support for the larger devices i= s=20 already there and the old code does not handle the large page devices. We have actually problems with CVS access (is IPV6 only). I can provide a=20 current snapshot on request. 2. The nand driver itself can handle multiple chips now. The scan function supports multiple chip detection. Do not use the concat function for this=20 purpose. The chips are provided as one big device to the MTD layer if you d= o=20 not use partitions. > I want to be able to use these multiple chips as a single flash > filesystem (probably JFFS2). It might turn out that JFFS2 is not the first choice for this concatenated= =20 device size, but it should work. Maybe YAFFS2 would be more suitable. It's= =20 not released yet AFAIK, but it should be available soon.=20 You can join #mtd on irc.freenode.net if you want. =2D-=20 Thomas ________________________________________________________________________ Steve Ballmer quotes the statistic that IT pros spend 70 percent of their=20 time managing existing systems. That couldn=E2=80=99t have anything to do w= ith=20 the fact that 99 percent of these systems run Windows, could it? ________________________________________________________________________ linutronix - competence in embedded & realtime linux http://www.linutronix.de mail: tglx@linutronix.de