Two questions on mtds on x86 platform
dwmw2 at infradead.org
Thu Feb 6 09:58:00 EST 2003
On Thu, 2003-02-06 at 14:43, Somashekara DM wrote:
> We want to mount jffs2 on two mtd partitions as a part of our project.
> Our platform is x86 - kernel version 2.4.13.
> 1. We are using mtdram ("Test driver using RAM") and blkmtd ("MTD
> emulation using block device")
> to create two mtd's. Our aim is to mount jffs2 on two different
OK. So you have two MTD devices listed in /proc/mtd?
> Here are the steps we have followed.
> Step1 :
> mknod /dev/mtd0 c 90 0
> mknod /dev/mtd2 c 90 2
This is incorrect. The MAKEDEV script in CVS is correct. The device
numbers for the character devices alternate between 'normal' and
read-only devices, as follows:
/dev/mtd0 c 90 0
/dev/mtdr0 c 90 1
/dev/mtd1 c 90 2
/dev/mtdr1 c 90 3
/dev/mtd2 c 90 4
/dev/mtdr2 c 90 5
So what you've called '/dev/mtd2' is in fact what _should_ be called
'/dev/mtd1', and is hence the second of the two MTD devices (In fact,
/dev/mtd2 would be a _third_ device, which does not exist in your
> mknod /dev/mtdblock0 b 31 0
> mknod /dev/mtdblock2 b 31 2
These are correct device numbers and names but as before, /dev/mtdblock2
refers to a third MTD device which does not exist in your system. Make
/dev/mtdblock1 (b 31 1) and use that.
> mount -t jffs2 /dev/mtdblock2 /mnt/jffs2drive2 //this mount fails
> error - "mount: fs type jffs2 not supported by kernel"
What it actually means is 'block device /dev/mtdblock2 does not exist'.
But mount(2) doesn't return sensible errors.
> 2. Can we create multiple partitions on the 'mtdram'?
> Can you give us the procedure for that?
No partitions, but you can load the mtdram module twice (with different
names) so that you get two devices.
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