Sad news! Now try if the partition table sticks to the device Code: sudo gainroot sfdisk -l /dev/mmcblk0 If this works finally we might start erasing the part of the card partitioned for optfs and then rebuild that partition.
sudo gainroot sfdisk -l /dev/mmcblk0
Enter 'help' for a list of built-in commands. ~ $ sudo gainroot Root shell enabled BusyBox v1.10.2 (Debian 3:1.10.2.legal-1osso30+0m5) built-in shell (ash) Enter 'help' for a list of built-in commands. /home/user # sfdisk -l /dev/mmcblk0 Disk /dev/mmcblk0: 982528 cylinders, 4 heads, 16 sectors/track Units = cylinders of 32768 bytes, blocks of 1024 bytes, counting from 0 Device Boot Start End #cyls #blocks Id System /dev/mmcblk0p1 1 693760 693760 22200320 c W95 FAT32 (LBA) /dev/mmcblk0p2 693761 955904 262144 8388608 83 Linux /dev/mmcblk0p3 955905 980480 24576 786432 82 Linux swap / Solaris /dev/mmcblk0p4 0 - 0 0 0 Empty /home/user #