| wdenk | c609719 | 2002-11-03 00:24:07 +0000 | [diff] [blame] | 1 | JFFS2 options and usage. |
| 2 | ----------------------- |
| 3 | |
| 4 | JFFS2 in U-Boot is a read only implementation of the file system in |
| Jon Loeliger | b3aff0c | 2007-07-10 11:19:50 -0500 | [diff] [blame] | 5 | Linux with the same name. To use JFFS2 define CONFIG_CMD_JFFS2. |
| wdenk | c609719 | 2002-11-03 00:24:07 +0000 | [diff] [blame] | 6 | |
| 7 | The module adds three new commands. |
| 8 | fsload - load binary file from a file system image |
| 9 | fsinfo - print information about file systems |
| 10 | ls - list files in a directory |
| wdenk | f39748a | 2004-06-09 13:37:52 +0000 | [diff] [blame] | 11 | chpart - change active partition |
| wdenk | c609719 | 2002-11-03 00:24:07 +0000 | [diff] [blame] | 12 | |
| Simon Glass | 59e12a4 | 2017-05-17 03:25:38 -0600 | [diff] [blame] | 13 | If you do now need the commands, you can enable the filesystem separately |
| 14 | with CONFIG_FS_JFFS2 and call the jffs2 functions yourself. |
| 15 | |
| wdenk | 06d01db | 2003-03-14 20:47:52 +0000 | [diff] [blame] | 16 | If you boot from a partition which is mounted writable, and you |
| 17 | update your boot environment by replacing single files on that |
| Jean-Christophe PLAGNIOL-VILLARD | 6d0f6bc | 2008-10-16 15:01:15 +0200 | [diff] [blame] | 18 | partition, you should also define CONFIG_SYS_JFFS2_SORT_FRAGMENTS. Scanning |
| wdenk | 06d01db | 2003-03-14 20:47:52 +0000 | [diff] [blame] | 19 | the JFFS2 filesystem takes *much* longer with this feature, though. |
| 20 | Sorting is done while inserting into the fragment list, which is |
| 21 | more or less a bubble sort. That algorithm is known to be O(n^2), |
| 22 | thus you should really consider if you can avoid it! |
| 23 | |
| wdenk | c609719 | 2002-11-03 00:24:07 +0000 | [diff] [blame] | 24 | |
| Simon Glass | b2482df | 2016-10-02 18:00:59 -0600 | [diff] [blame] | 25 | There only one way for JFFS2 to find the disk. It uses the flash_info |
| 26 | structure to find the start of a JFFS2 disk (called partition in the code) |
| 27 | and you can change where the partition is with two defines. |
| wdenk | c609719 | 2002-11-03 00:24:07 +0000 | [diff] [blame] | 28 | |
| Jean-Christophe PLAGNIOL-VILLARD | 6d0f6bc | 2008-10-16 15:01:15 +0200 | [diff] [blame] | 29 | CONFIG_SYS_JFFS2_FIRST_BANK |
| wdenk | c609719 | 2002-11-03 00:24:07 +0000 | [diff] [blame] | 30 | defined the first flash bank to use |
| 31 | |
| Jean-Christophe PLAGNIOL-VILLARD | 6d0f6bc | 2008-10-16 15:01:15 +0200 | [diff] [blame] | 32 | CONFIG_SYS_JFFS2_FIRST_SECTOR |
| wdenk | c609719 | 2002-11-03 00:24:07 +0000 | [diff] [blame] | 33 | defines the first sector to use |
| wdenk | c609719 | 2002-11-03 00:24:07 +0000 | [diff] [blame] | 34 | --- |
| 35 | |
| 36 | TODO. |
| 37 | |
| wdenk | 8bde7f7 | 2003-06-27 21:31:46 +0000 | [diff] [blame] | 38 | Remove the assumption that JFFS can dereference a pointer |
| 39 | into the disk. The current code do not work with memory holes |
| 40 | or hardware with a sliding window (PCMCIA). |