
FlashFilesystem:  Brecis Specific information about the flash filesystem.

An initial enabling of the MTD (Memory Technology Device) and JFFS2
(Journalling Flash Filesystem 2nd version) subsystems is added to this
release.  The current device is quite suitable for storing files
containing parameters that must survive a reboot.

It has been tested only with a Toshiba TC58FVT321 device.

This 4M device has been divided up into 3 sections:

	00080000 - 003fffff   main storage partition    /dev/mtd0
	00000000 - 0006ffff   pmon storage              /dev/mtd1
	00070000 - 0007ffff   pmon startup script       /dev/mtd2

This listing is out of order for this reason: /dev/mtd0, the remaining
space, is the device we will be mostly using.

CHANGES TO PARTITIONING, etc, would be made in the file
linux/drivers/mtd/maps/brecis_flashmap.c.

QUICK START:

	ONCE, in the lifetime of the system, or to start over from
	scratch, run:

		eraseall /dev/mtd0

	That will erase the flash partition.  JFFS2 will put its own
	filesystem format on an erased partition automatically.

	EACH TIME THE SYSTEM BOOTS, run:

		mount -n -t jffs2 /dev/mtdblock0 /flash

	The jffs2 mounting operation takes an unexpectedly long time
	in my experience, especially when mounting just after the
	erase.  Be patient.

	Now you can create, destroy, read, and write files in /flash
	at your own discretion.



SUPPORTED OPERATIONS and UTILITIES:

As of the time this document was written, the following flash
utilities are supported for dealing with the flash:

erase    -- erases one or more blocks of a flash partition
	erase <device> [start] [count] [unlock]
		defaults: start = 0, count = 1, unlock = 0

eraseall -- erases a whole flash partition

	Usage: eraseall [OPTION] MTD_DEVICE
	Erases all of the specified MTD device.

	  -q, --quiet    don't display progress messages
	      --silent   same as --quiet
	      --help     display this help and exit
	      --version  output version information and exit

mtd_debug  -- debugging utility
	usage: mtd_debug info <device>
	       mtd_debug read <device> <offset> <len> <dest-filename>
	       mtd_debug write <device> <offset> <len> <source-filename>
	       mtd_debug erase <device> <offset> <len>

There are some other utilities that have yet to be ported.

