Success!!!! Woo-hoo!!!!!
Charles/Andrew,
Thanks both of you for your help. I've finally managed to obtain
a copy of the actual nanddump binary, compiled for android, and the
dumpfile from that loads successfully into my emulated nandsim mtd
device under linux. I'm then able to successfully mount the mtd device
and access the files.
John
-----Original Message-----
From: Charles Manning [
mailto:manningc2@actrix.gen.nz]
Sent: Sunday, February 28, 2010 3:36 PM
To: McCash John-GKJN37
Cc:
yaffs@lists.aleph1.co.uk; Andrew Hoog
Subject: Re: [Yaffs] Access to files on a YAFFS2 image
I'm pretty sure Android on ARM is little endian.
YAFFS2 allows the driver to determine the layout of bad block markers,
tags
bytes etc. There is a very good chance that the layout on the device you
dumped is not the same as nandsim. If that is the case then you will
need to
run the spare area through some byte shuffling first.
-- Charles
On Saturday 27 February 2010 08:13:05 McCash John-GKJN37 wrote:
> Charles,
> I was sidetracked for a few weeks on other tasks, but am back to
> working on this now. I'm able to reliably dump and read back in yaffs2
> images to/from a nandsim emulated mtd device under Linux. I also have
a
> binary that appears to correctly dump the yaffs2 filesystem from an
> Android device, including the oob area. The output is the right
length,
> anyway, and structurally, the first few pages look similar to what is
> working on the Linux side. However I'm still unable to get the dumped
> Android yaffs2 image to load under Linux in such a way as to mount and
> be accessible. Whenever I mount the resultant filesystem, it only
> appears to have an empty lost+found directory, nothing else.
>
> I just came up with a possible explanation. Doesn't Android use
> big-endian byte ordering? If that's the case, then maybe the image
needs
> to be converted to little-endian format in order to mount properly
under
> Linux? Does this sound possible, or have I just wandered completely
off
> the map? If this is my problem, does anybody know where I might find a
> utility to do the conversion?
>
>
> Thanks much
> John
>
> -----Original Message-----
> From: Charles Manning [mailto:manningc2@actrix.gen.nz]
> Sent: Monday, December 07, 2009 3:55 PM
> To: yaffs@lists.aleph1.co.uk
> Cc: McCash John-GKJN37; Andrew Hoog
> Subject: Re: [Yaffs] Access to files on a YAFFS2 image
>
> On Tuesday 08 December 2009 02:27:46 McCash John-GKJN37 wrote:
> > 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.
>
> Sounds like the right conclusion.
>
> > 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?
>
> From a quick scan of the code I would expect that mtd_read_raw also
> reads oob
> while mtd_read_data does not.
>
> > Thanks
> > John
> >
> > -----Original Message-----
> > From: Charles Manning [mailto:manningc2@actrix.gen.nz]
> > Sent: Sunday, December 06, 2009 2:18 PM
> > To: yaffs@lists.aleph1.co.uk
> > 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: yaffs@lists.aleph1.co.uk
> > > 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
> > > >
> > > > _______________________________________________
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> > > > yaffs@lists.aleph1.co.uk
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> > >
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> >
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