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75 lines
2.1 KiB
Plaintext
75 lines
2.1 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 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 is two ways for JFFS2 to find the disk. The default way uses
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the flash_info structure to find the start of a JFFS2 disk (called
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partition in the code) and you can change where the partition is with
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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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The second way is to define CONFIG_SYS_JFFS_CUSTOM_PART and implement the
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jffs2_part_info(int part_num) function in your board specific files.
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In this mode CONFIG_SYS_JFFS2_FIRST_BANK and CONFIG_SYS_JFFS2_FIRST_SECTOR is not
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used.
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The input is a partition number starting with 0.
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Return a pointer to struct part_info or NULL for error;
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Ex jffs2_part_info() for one partition.
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---
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#if defined CONFIG_SYS_JFFS_CUSTOM_PART
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#include <jffs2/jffs2.h>
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static struct part_info part;
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struct part_info*
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jffs2_part_info(int part_num)
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{
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if(part_num==0){
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if(part.usr_priv==(void*)1)
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return ∂
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memset(&part, 0, sizeof(part));
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part.offset=(char*)0xFF800000;
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part.size=1024*1024*8;
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/* Mark the struct as ready */
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part.usr_priv=(void*)1;
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return ∂
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}
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return 0;
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}
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#endif
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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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