Nanddump bug? Offset error?

As we all know on the Pogoplug V4, the original U-Boot envs are stored at address A5000 (dec 675840) in mtd0.

However when backing up mtd0 from Debian, the original envs are now located at A0000 (dec 655360). How come?

I did take a backup of mtd0 before upgrading U-Boot under the main Debian installation, this was done from Pogoplug OS.

If i compare the two nanddumps, they differ in size also - which is wierd.

Pogoplug OS dump: 2,06 MB (2 162 688 byte)
Debian dump: 2,00 MB (2 097 152 byte)
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Bodhis dump of mtd0 looks the same as mine taken from Pogoplug OS.
http://archlinuxarm.org/forum/viewtopic.php?f=53&t=6147#p34646
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I use this command in Debian:

root@pogo02:~# nanddump -nf /dev/mtd0.oob /dev/mtd0
Block size 131072, page size 2048, OOB size 64
Dumping data starting at 0x00000000 and ending at 0x00200000...

Any ideas?

/John

JohnW,

> As we all know on the Pogoplug V4, the original
> U-Boot envs are stored at address A5000 (dec
> 675840) in mtd0.

Not true.

>
> However when backing up mtd0 from Debian, the
> original envs are now located at A0000 (dec
> 655360). How come?
>

It is at A0000.

-bodhi
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You are right Bodhi...
I've got the answer why the files turn up different. -o = Dump OOB data...

nanddump -nof mtd0 /dev/mtd0 = filesize 2162688 (don't fit when writing to mtd0), the original envs get pushed to A5000...

nandwrite /dev/mtd0 uboot.mtd0.pogo02.original.kwb
Image 2162688 bytes, NAND page 2048 bytes, OOB area 64 bytes, device size 2097152 bytes
nandwrite: error!: Input file does not fit into device
           error 0 (Success)
nandwrite: error!: Data was only partially written due to error
           error 0 (Success)

nanddump -nf mtd0 /dev/mtd0 = the right way of dumping mtd0....

Bodhi: Your dumps that you uploaded to Dropbox (https://www.dropbox.com/s/58vs4o47y4kjgs3/pogoplug_v4_mtd_original.tar.bz2) includes oob-data so they won't fit...

Also when dumping mtd0 i got a bunch of ECC-errors. After clearing/erasing mtd0, re-writing everything - the ECC are gone when dumping for the second time. Wierd.

You can restore dumps with oob-data using "-o", my bad...

JohnW,

Glad you've figured it out! Indeed, we always need the original nanddump command to restore it with nandwrite correctly.

-bodhi
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Just a big note!!!

When following Qui's blog on "hacking" the Pogoplugs you download nanddump.

This seems to be a old version of the program in which "-o" means "omit oob-data". In Debian this is the other way around.

If you're backing up a mtd-partition to write it to another Pogoplug you don't want the oob-data-version because it contains bad-block info etc, which is specific to the unit only.

Do when backing up from Pogoplug OS with Que's nanddump, use -o omit oob-data.
Under Debian -o means "Dump oob-data", so just use "-nf" not -"nof" here.

/John
===========================
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http://forum.doozan.com/read.php?3,16789,16789#msg-16789

-bodhi
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