This module creates a partitioned nand filesystem image, with the first
partition as a small JFFS2 "boot" partition, and the second partition as a
UBI volume with a single ubifs "system" partition.

Output files are:
	osXXu.img
	osXXu.onu

To install on an XO, pass the onu file to the "update-nand" command at the
"ok" firmware prompt.

Options:
 - compression_type (optional; default zlib)
     Compression scheme to use for -x argument to mkfs.ubifs (e.g. lzo or zlib).
     See mkfs.ubifs documentation for available options.
 - reserved (optional; default 4MiB)
     Amount of disk space to reserve for root when disk is approaching 100%
     usage. See documentation for mkfs.ubifs -R option.


e.g.
	[ubifs_image]
	compression_type=lzo
	reserved=12MiB