On Tuesday 09 February 2010 09:57:55 Sasha Sirotkin wrote:
> Hello.
>
> I'm trying to figure out how can I change the root filesystem on my
> board. I cannot overwrite it from Linux as it is mounted and I cannot
> really not mount it, as it is a root filesystem. However, when I try to
> program it via the bootloader, it fails...
>
> Writing directly from Linux to /dev/mtd0 (my root filesystem is mounted
> on /dev/mtdblock0) fails either
> /tmp # cat rootfs.img  >
> /dev/mtd0
> cat: write error: Input/output error

Have you considered booting Linux using some other device for root. eg an MMC 
card or NFS. That way the NAND is not busy and you can copy files as you 
need.