JFFS2 as rootfs on DataFlash

Mangesh Edake m_edake at yahoo.com
Thu Feb 21 11:01:06 EST 2008

Hi Michel,

Many thanks for your reply. 

I tried with removing -s 0x210 option, so command now
looks like,
mkfs.jffs2 -p -l -e 0x2100 -n -d /home/me/rootdir -o

At the same time I added erase command in the u-boot
as suggested by you. But unfortunately the result is

However I found that dataflash driver in u-boot
doesnot deal with extra 16-bytes (oob) and doesnot
write any JFFS2 specific magic bitmask, node crc,
cleanmarker etc. info to the oob. But the nand flash
(legacy) driver does the same in u-boot. Also
kernel-mtd driver for at45 dataflash is missing with
read_oob, write_oob functions whereas mtd-nand uses
those routines. So my concern is, while copying the
jffs2 image to dataflash is it necessory to write
jffs2 specific info in oob region..? My assumption is,
this info should be present in image itself and
mkfs.jffs2 must take care of this while creating an
image. (Please corret me if I'm wrong...)
I've also seen code of nandwrite (mtd utility) where
it uses -j option that takes care of jffs2_oobinfo.

So I've two problems-
i) the way I download an image (cp from u-boot method)
is wrong ? or
ii) am I creating a wrong image..? 
Please reply...

P.S. Attached here is the jffs2 image dump created as,
jffs2dump -l -c jffs2.img > dump.txt

Thanks and Regards,
Mangesh Edake.


--- michael <trimarchi at gandalf.sssup.it> wrote:

> Hi
> >> I am totally lost and cannot figure out the
> reason for
> >> the errors. I'd appericiate if anybody help to
> find
> >> out the reason.
> >>
> >> Following is the ouput LOG.
> >> ----------------------------
> >>     
> > Clean all the dataflash before, or padding the
> size with 0xff
> > If using an u-boot system add the command for
> erasing dataflash.
> >
> > Regards Michael
> >
> >   
> Do you have some news?
> Regards Michael

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