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![Simon Glass](/assets/img/avatar_default.png)
Rather than using CMD_JFFS2 for both the filesystem and its command, we should have a separate option for each. This allows us to enable JFFS2 support without the command, if desired, which reduces U-Boot's size slightly. Signed-off-by: Simon Glass <sjg@chromium.org>
41 lines
1.5 KiB
Plaintext
41 lines
1.5 KiB
Plaintext
JFFS2 options and usage.
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-----------------------
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JFFS2 in U-Boot is a read only implementation of the file system in
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Linux with the same name. To use JFFS2 define CONFIG_CMD_JFFS2.
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The module adds three new commands.
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fsload - load binary file from a file system image
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fsinfo - print information about file systems
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ls - list files in a directory
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chpart - change active partition
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If you do now need the commands, you can enable the filesystem separately
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with CONFIG_FS_JFFS2 and call the jffs2 functions yourself.
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If you boot from a partition which is mounted writable, and you
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update your boot environment by replacing single files on that
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partition, you should also define CONFIG_SYS_JFFS2_SORT_FRAGMENTS. Scanning
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the JFFS2 filesystem takes *much* longer with this feature, though.
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Sorting is done while inserting into the fragment list, which is
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more or less a bubble sort. That algorithm is known to be O(n^2),
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thus you should really consider if you can avoid it!
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There only one way for JFFS2 to find the disk. It uses the flash_info
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structure to find the start of a JFFS2 disk (called partition in the code)
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and you can change where the partition is with two defines.
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CONFIG_SYS_JFFS2_FIRST_BANK
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defined the first flash bank to use
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CONFIG_SYS_JFFS2_FIRST_SECTOR
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defines the first sector to use
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---
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TODO.
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Remove the assumption that JFFS can dereference a pointer
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into the disk. The current code do not work with memory holes
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or hardware with a sliding window (PCMCIA).
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