README.JFFS2 1.5 KB

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  1. JFFS2 options and usage.
  2. -----------------------
  3. JFFS2 in U-Boot is a read only implementation of the file system in
  4. Linux with the same name. To use JFFS2 define CONFIG_CMD_JFFS2.
  5. The module adds three new commands.
  6. fsload - load binary file from a file system image
  7. fsinfo - print information about file systems
  8. ls - list files in a directory
  9. chpart - change active partition
  10. If you do now need the commands, you can enable the filesystem separately
  11. with CONFIG_FS_JFFS2 and call the jffs2 functions yourself.
  12. If you boot from a partition which is mounted writable, and you
  13. update your boot environment by replacing single files on that
  14. partition, you should also define CONFIG_SYS_JFFS2_SORT_FRAGMENTS. Scanning
  15. the JFFS2 filesystem takes *much* longer with this feature, though.
  16. Sorting is done while inserting into the fragment list, which is
  17. more or less a bubble sort. That algorithm is known to be O(n^2),
  18. thus you should really consider if you can avoid it!
  19. There only one way for JFFS2 to find the disk. It uses the flash_info
  20. structure to find the start of a JFFS2 disk (called partition in the code)
  21. and you can change where the partition is with two defines.
  22. CONFIG_SYS_JFFS2_FIRST_BANK
  23. defined the first flash bank to use
  24. CONFIG_SYS_JFFS2_FIRST_SECTOR
  25. defines the first sector to use
  26. ---
  27. TODO.
  28. Remove the assumption that JFFS can dereference a pointer
  29. into the disk. The current code do not work with memory holes
  30. or hardware with a sliding window (PCMCIA).