Re: [Yaffs] Access to files on a YAFFS2 image

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Author: McCash John-GKJN37
Date:  
To: Charles Manning, yaffs
CC: Andrew Hoog
Subject: Re: [Yaffs] Access to files on a YAFFS2 image
Charles,
    Yes. I understood that, or so I thought. When dumping with
nanddump under Linux and not including the -o flag, the output is larger
than the size listed in /proc/mtd, and can be uploaded to another mtd
device with nandwrite -o. When dumped with the -o flag, the size the
same as that specified in /proc/mtd, and the resultant file cannot be
written with nandwrite -o. When I dump from a partition of the same size
(as shown in /proc/mtd) on an android phone, using the dump_image-arm
utility I got from the nandroid package, the result is the same size as
the partition size value from /proc/mtd. My conclusion was that
dump_image-arm is not including the oob area in its output.


    I looked at the source for dump_image briefly, but I find no
mention of either "oob" or "out of bounds" anywhere. Where am I going
off in the weeds?
        Thanks
            John


-----Original Message-----
From: Charles Manning [mailto:manningc2@actrix.gen.nz]
Sent: Sunday, December 06, 2009 2:18 PM
To:
Cc: McCash John-GKJN37; Andrew Hoog
Subject: Re: [Yaffs] Access to files on a YAFFS2 image

The -o flag is tricky because the meaning is reversed between nanddump
and 
nandwrite:
Usage: nanddump [OPTIONS] MTD-device
...
-o         --omitoob            omit oob data
....
Usage: nandwrite [OPTION] MTD_DEVICE INPUTFILE
...
  -o, --oob        image contains oob data
...


The dump_image tool contains oob

Look at
http://svn.infernix.net/nandroid/nandtools/android-imagetools/dump_image
.c
to see what you're getting from dump_image.

-- Charles


On Saturday 05 December 2009 10:54:44 McCash John-GKJN37 wrote:
> Charles,
>     For what it's worth, I think I've figured out what's wrong. The
> size returned in /proc/mtd does not include the oob area. I verified
> this by creating an mtd device the same size as the one I'm trying to
> examine an image of, and then dumping it with nanddump. The resultant
> image is larger than the size of the device. I can also copy this

image
> back in with nandwrite. However if I dump it with the -o option, to
> exclude oob, the image dumped is exactly the size listed in /proc/mtd.
>
>     Now I just have to find somewhere a precompiled copy of nanddump
> for ARM. (I have a deep and abiding fear of cross-compilers.) I don't
> suppose anyone on the list could direct me to such an animal?

>
>         Thanks
>             John

>
> -----Original Message-----
> From: Charles Manning [mailto:manningc2@actrix.gen.nz]
> Sent: Tuesday, December 01, 2009 3:26 PM
> To:
> Cc: McCash John-GKJN37; Andrew Hoog
> Subject: Re: [Yaffs] Access to files on a YAFFS2 image
>
> What I suggest is that you first start off by running yaffs on the
> nandsim
> then doing a dump from that and checking that looks like it should and
> that
> you can then nandwrite that back.
>
> Once you can make the process work with just one device it is then a

lot
>
> easier to see why things don't work when importing from somewhere

else.
>
> -- Charles
>
> On Wednesday 02 December 2009 01:57:04 McCash John-GKJN37 wrote:
> > Charles,
> >     OK, so we apparently do have the OOB data in these image dumps
> > (obtained via the dump_image-arm tool included in nandroid), but

when
>
> we
>
> > attempt to upload them to a nand emulator (under Ubuntu) with
>
> 'nandwrite
>
> > -a -o', we're still getting the error:
> >
> > Input file is not page-aligned. Use the padding option.
> > Data was only partially written due to error
> >
> > : Success
> >
> >     Where do we go from here? Should this work, and if so, how do we
> > determine exactly what the problem really is?

> >
> >         Thanks much for your help
> >             John McCash

> >
> > _______________________________________________
> > yaffs mailing list
> >
> > http://lists.aleph1.co.uk/cgi-bin/mailman/listinfo/yaffs
>
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