Mounting mtd block device raises "Block device required"

Hinko Kocevar hinko.kocevar at
Wed Jun 11 04:55:01 EDT 2008

Andre Puschmann wrote:
> Hi list,
> I am successfully running kernel 2.6.21 on a custom AT91RM9200-based
> board. I now updated to kernel 2.6.25 for various reasons.
> Now, we use the _new_ atmel_spi driver and mtd_dataflash driver (but the
> problem also exist if I use the legacy one). If I try to mount a
> jffs2 or cramfs image on dataflash I get the following error:
> # mount /dev/mtdblock5 /mnt/flash
> mount: mounting /dev/mtdblock5 on /mnt/flash failed: Block device required
> Exactly the same line works with the 2.6.21 kernel. Also doing a cat
> on the normal /dev/mtd* nodes also works.

Char device seems to work..

> "cat /proc/devices" shows:
> Block devices:
>   7 loop
>  31 mtdblock
> So I have no idea here. Any hints?

What is the ls -l /dev/mtdblock5 output?
Also could you try:
mount -t jffs2 /dev/mtdblock5 /mnt/flash


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