Re: Can you really write a jffs2 image with nandwrite?

[Thomas Gleixner <tglx@linutronix.de>]

On Mon, 2005-02-28 at 19:14 -0700, Peter Grayson wrote:
> From reading the mkfs.jffs2 code, it seems that mkfs.jffs2 has no
> concept of out-of-bounds data. Consequently, it appears that the
> nandwrite expects to find out-of-bounds data immediately after the in-
> bounds data for every page. I have looked at the bits of the jffs2 image
> produced by mkfs.jffs2 and I can see that it does not really produce out
> of bounds data.

nandwrite does not expect oob data for jffs2 images.

> Below is the mkfs.jffs2 command line I am using. I have tried many other
> combinations of options, but they do not yield appreciably different
> results.
> 
> mkfs.jffs2
>  	--pagesize=2048 \
> 	--eraseblock=128 \
			
This one if definitely wrong. You meant 128kiB or 131072. 
	
> 	--pad \
> 	--output=image.jffs2 \
> 	--compression-mode none \

Why do you switch off compression ?

> 	--no-cleanmarkers \
> 	--big-endian \
> 	--squash \
> 	--verbose \
> 	--root=$ROOT_DIR
> 
> When I try using this image with "nandwrite -j", the image appears to be
> written successfully, but when I try to mount the new filesystem, mount
> fails with the following error message:
> 
>   mount: Mounting /dev/mtdblock0 on /mnt failed: Invalid argument

Did you ?
mount -t jffs2 /dev/mtdblock0 /mnt

> If I try to use "nandwrite -j -o", nandwrite complains about the image
> not being aligned:

JFFS2 has no oob data. nandwrite -j is correct.

> Is there something obvious I am missing? I have read the FAQ at:
> 
>   http://www.linux-mtd.infradead.org/tech/faq.html

I'm happy that somebody actually read it :)

> so I know that the working theory is that this should work, but it is
> not working for me. Has anyone else had a similar experience?

Before using nandwrite please erase the flash with 
flash_eraseall -j /dev/mtd0 .

tglx