Originally Posted by geekmaster
If you have mmcblk0p1 backup up, you should be able to restore it so you can boot up main.
I have all backups. But how can I do that? Menu option 3 in recovery to export MMC0 via USB is somehow disabled. Even though it is listed, I always get Unknown option '3'. I've found a discussion of yifanlu and ichinomoto, wherethey weren't able to overcome that: