Try this:

1. boot from internal flash.
2. have more than 128MB on your vfat mmc2, /media/mmc2, ready to create virtual memory.
if you can not format, then do:

dd if=/dev/zero of=/dev/mmcblk0
sfdisk /dev/mmcblk0 -uM

to re-partition the mmc2

3. format /media/mmc2
4.create virtual memory on mmc2 (up to 128MB)