We need a jffs2/ubi depending on the age of the hardware and
maybe a tar.bz2 so we can easily inspect an image without
playing with mtdram. We almost never need a ubifs and certainly
not a cpio.
The rootfs in the UBI is configured to grow to the full size of the
UBI, currently these are 999 LEBs (when there is no kernel volume)
but we had limited the LEBs the filesystem can hold to 400. After
this change the filesystem will grow from the 42MB to more than 120
MB.
I'm not sure if we really want to have a rootfs of that size but we
can at least experiment with it and see if the failure rate is changing
or not.
RevB and RevC feature different kind of nand flash. RevB is still
pre-production hardware so for the few units allow to set the right
flash parameters in the local.conf.