JFFS2 options and usage.
  -----------------------
  
  JFFS2 in U-Boot is a read only implementation of the file system in

  Linux with the same name. To use JFFS2 define CONFIG_CMD_JFFS2.

  
  The module adds three new commands.
  fsload  - load binary file from a file system image
  fsinfo  - print information about file systems
  ls      - list files in a directory

  chpart  - change active partition

  If you do now need the commands, you can enable the filesystem separately
  with CONFIG_FS_JFFS2 and call the jffs2 functions yourself.

  If you boot from a partition which is mounted writable, and you
  update your boot environment by replacing single files on that

  partition, you should also define CONFIG_SYS_JFFS2_SORT_FRAGMENTS. Scanning

  the JFFS2 filesystem takes *much* longer with this feature, though.
  Sorting is done while inserting into the fragment list, which is
  more or less a bubble sort. That algorithm is known to be O(n^2),
  thus you should really consider if you can avoid it!

  There only one way for JFFS2 to find the disk. It uses the flash_info
  structure to find the start of a JFFS2 disk (called partition in the code)
  and you can change where the partition is with two defines.

  CONFIG_SYS_JFFS2_FIRST_BANK

  	defined the first flash bank to use

  CONFIG_SYS_JFFS2_FIRST_SECTOR

  	defines the first sector to use

  ---
  
  TODO.

  	Remove the assumption that JFFS can dereference a pointer
  	into the disk. The current code do not work with memory holes
  	or hardware with a sliding window (PCMCIA).