I have succesfully done the following:
dd if=/dev/mtdblock3 of=mtd3.dd.img
nanddump -nf mtd3.nan.img /dev/mtd3
then:
flash_eraseall /dev/mtd3
and the following all fail:
dd if=mtd3.dd.img of=/dev/mtdblock3
nandwrite /dev/mtd3 mtd3.nan.img
nandwrite -p /dev/mtd3 mtd3.nan.img
with i/o errors etc.
after doing:
ubiformat /dev/mtd3 -y
the dd if=mtd3.dd.img of=/dev/mtdblock3 worked (I didn't try nandwrite after that, but this already proves the point)
The question is:
What should I do before dumping the image to mtdblock3 if I can't use ubi* commands or how should I perform backup and restore?
More details:
I want to make a backup and restore it on a dockstar that is running from default pogo linux and it has no module for ubifs and ubi* commands. I don't understand what's the difference if I format mtd3 before dumping raw data to it or not.
I found a thread which - if answered - could solve my problem too:
http://forum.doozan.com/read.php?2,2775,2775#msg-2775