From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from main.gmane.org ([80.91.229.2] helo=ciao.gmane.org) by canuck.infradead.org with esmtps (Exim 4.63 #1 (Red Hat Linux)) id 1HU070-00029x-Uz for linux-mtd@lists.infradead.org; Wed, 21 Mar 2007 08:40:20 -0400 Received: from list by ciao.gmane.org with local (Exim 4.43) id 1HU06t-0005eF-NS for linux-mtd@lists.infradead.org; Wed, 21 Mar 2007 13:40:11 +0100 Received: from office.ubiquisys.com ([88.96.204.222]) by main.gmane.org with esmtp (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Wed, 21 Mar 2007 13:40:11 +0100 Received: from mw_phil by office.ubiquisys.com with local (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Wed, 21 Mar 2007 13:40:11 +0100 To: linux-mtd@lists.infradead.org From: MikeW Subject: Re: Clarification on multiple mtdram devices - HowTo Date: Wed, 21 Mar 2007 12:39:54 +0000 (UTC) Message-ID: References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: news List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MikeW yahoo.co.uk> writes: > >>From a (much) earlier post, I note that the mtdram driver can emulate >several /dev/mtd's by "loading the driver more than once". > >Does this mean modprobing *once* but then setting up multiple >device nodes with the same major number and different minor numbers ? > >I presume this also implies that each device must have the same size & erasesize. > > Regards, > MikeW Found out about doing this here: http://electrons.psychogenic.com/modules/wordpress/rants/ 2005/08/28/13/linux-on-the-go-exploring-ipaq-options.html (I would like a section doing this properly on the MTD website FAQ written by an authoritative person - please !) >>>>> To start we load a few modules, creating a fake 32M flash device in RAM and ensure we have appropriate /dev/ entries: # modprobe mtdcore # modprobe mtdram total_size=32768 erase_size=256 # mkdir /dev/mtdblock ; for i in 0 1 2 3 ; do mknod /dev/mtdblock/$i b 31 $i; done Then we write the contents of one of the JFFS2 images to the MTD RAM device, and take a look: # dd if=gpe-image-h3600-20050407124742.rootfs.jffs2 of=/dev/mtdblock/0 # mkdir -p /mnt/ipaq/ # mount -t jffs2 /dev/mtdblock/0 /mnt/ipaq # cd /mnt/ipaq; ls; The output will be something like: bin boot dev etc home lib media mnt proc sbin sys tmp usr var <<<<