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Diffstat (limited to 'roms/u-boot/doc/README.JFFS2')
-rw-r--r-- | roms/u-boot/doc/README.JFFS2 | 40 |
1 files changed, 40 insertions, 0 deletions
diff --git a/roms/u-boot/doc/README.JFFS2 b/roms/u-boot/doc/README.JFFS2 new file mode 100644 index 000000000..0245da048 --- /dev/null +++ b/roms/u-boot/doc/README.JFFS2 @@ -0,0 +1,40 @@ +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). |