99067b08f4
Legacy NAND is marked for feature removal after April 2009 (i.e. this upcoming release). There are still several boards that reference it (though many do so only for disk-on-chip support which has been silently disabled for a while now). These boards will now fail to build with #error, though the code is still there if the user removes #error. The plan is to remove the code outright in the next release, along with any board code that refers to it (such as board/esd/common/auto_update.c). Also, remove the legacy NAND API description from README.nand. Signed-off-by: Scott Wood <scottwood@freescale.com>
163 lines
6.1 KiB
Plaintext
163 lines
6.1 KiB
Plaintext
NAND FLASH commands and notes
|
|
|
|
See NOTE below!!!
|
|
|
|
# (C) Copyright 2003
|
|
# Dave Ellis, SIXNET, dge@sixnetio.com
|
|
#
|
|
# See file CREDITS for list of people who contributed to this
|
|
# project.
|
|
#
|
|
# This program is free software; you can redistribute it and/or
|
|
# modify it under the terms of the GNU General Public License as
|
|
# published by the Free Software Foundation; either version 2 of
|
|
# the License, or (at your option) any later version.
|
|
#
|
|
# This program is distributed in the hope that it will be useful,
|
|
# but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
# GNU General Public License for more details.
|
|
#
|
|
# You should have received a copy of the GNU General Public License
|
|
# along with this program; if not, write to the Free Software
|
|
# Foundation, Inc., 59 Temple Place, Suite 330, Boston,
|
|
# MA 02111-1307 USA
|
|
|
|
Commands:
|
|
|
|
nand bad
|
|
Print a list of all of the bad blocks in the current device.
|
|
|
|
nand device
|
|
Print information about the current NAND device.
|
|
|
|
nand device num
|
|
Make device `num' the current device and print information about it.
|
|
|
|
nand erase off|partition size
|
|
nand erase clean [off|partition size]
|
|
Erase `size' bytes starting at offset `off'. Alternatively partition
|
|
name can be specified, in this case size will be eventually limited
|
|
to not exceed partition size (this behaviour applies also to read
|
|
and write commands). Only complete erase blocks can be erased.
|
|
|
|
If `erase' is specified without an offset or size, the entire flash
|
|
is erased. If `erase' is specified with partition but without an
|
|
size, the entire partition is erased.
|
|
|
|
If `clean' is specified, a JFFS2-style clean marker is written to
|
|
each block after it is erased.
|
|
|
|
This command will not erase blocks that are marked bad. There is
|
|
a debug option in cmd_nand.c to allow bad blocks to be erased.
|
|
Please read the warning there before using it, as blocks marked
|
|
bad by the manufacturer must _NEVER_ be erased.
|
|
|
|
nand info
|
|
Print information about all of the NAND devices found.
|
|
|
|
nand read addr ofs|partition size
|
|
Read `size' bytes from `ofs' in NAND flash to `addr'. Blocks that
|
|
are marked bad are skipped. If a page cannot be read because an
|
|
uncorrectable data error is found, the command stops with an error.
|
|
|
|
nand read.oob addr ofs|partition size
|
|
Read `size' bytes from the out-of-band data area corresponding to
|
|
`ofs' in NAND flash to `addr'. This is limited to the 16 bytes of
|
|
data for one 512-byte page or 2 256-byte pages. There is no check
|
|
for bad blocks or ECC errors.
|
|
|
|
nand write addr ofs|partition size
|
|
Write `size' bytes from `addr' to `ofs' in NAND flash. Blocks that
|
|
are marked bad are skipped. If a page cannot be read because an
|
|
uncorrectable data error is found, the command stops with an error.
|
|
|
|
As JFFS2 skips blocks similarly, this allows writing a JFFS2 image,
|
|
as long as the image is short enough to fit even after skipping the
|
|
bad blocks. Compact images, such as those produced by mkfs.jffs2
|
|
should work well, but loading an image copied from another flash is
|
|
going to be trouble if there are any bad blocks.
|
|
|
|
nand write.oob addr ofs|partition size
|
|
Write `size' bytes from `addr' to the out-of-band data area
|
|
corresponding to `ofs' in NAND flash. This is limited to the 16 bytes
|
|
of data for one 512-byte page or 2 256-byte pages. There is no check
|
|
for bad blocks.
|
|
|
|
Configuration Options:
|
|
|
|
CONFIG_CMD_NAND
|
|
Enables NAND support and commmands.
|
|
|
|
CONFIG_MTD_NAND_ECC_JFFS2
|
|
Define this if you want the Error Correction Code information in
|
|
the out-of-band data to be formatted to match the JFFS2 file system.
|
|
CONFIG_MTD_NAND_ECC_YAFFS would be another useful choice for
|
|
someone to implement.
|
|
|
|
CONFIG_SYS_MAX_NAND_DEVICE
|
|
The maximum number of NAND devices you want to support.
|
|
|
|
CONFIG_SYS_NAND_MAX_CHIPS
|
|
The maximum number of NAND chips per device to be supported.
|
|
|
|
CONFIG_SYS_DAVINCI_BROKEN_ECC
|
|
Versions of U-Boot <= 1.3.3 and Montavista Linux kernels
|
|
generated bogus ECCs on large-page NAND. Both large and small page
|
|
NAND ECCs were incompatible with the Linux davinci git tree (since
|
|
NAND was integrated in 2.6.24).
|
|
Turn this ON if you want backwards compatibility.
|
|
Turn this OFF if you want U-Boot and the Linux davinci git kernel
|
|
to use the same ECC format.
|
|
|
|
NOTE:
|
|
=====
|
|
|
|
The current NAND implementation is based on what is in recent
|
|
Linux kernels. The old legacy implementation has been disabled,
|
|
and will be removed soon.
|
|
|
|
If you have board code which used CONFIG_NAND_LEGACY, you'll need
|
|
to convert to the current NAND interface for it to continue to work.
|
|
|
|
The Disk On Chip driver is currently broken and has been for some time.
|
|
There is a driver in drivers/mtd/nand, taken from Linux, that works with
|
|
the current NAND system but has not yet been adapted to the u-boot
|
|
environment.
|
|
|
|
Additional improvements to the NAND subsystem by Guido Classen, 10-10-2006
|
|
|
|
JFFS2 related commands:
|
|
|
|
implement "nand erase clean" and old "nand erase"
|
|
using both the new code which is able to skip bad blocks
|
|
"nand erase clean" additionally writes JFFS2-cleanmarkers in the oob.
|
|
|
|
Miscellaneous and testing commands:
|
|
"markbad [offset]"
|
|
create an artificial bad block (for testing bad block handling)
|
|
|
|
"scrub [offset length]"
|
|
like "erase" but don't skip bad block. Instead erase them.
|
|
DANGEROUS!!! Factory set bad blocks will be lost. Use only
|
|
to remove artificial bad blocks created with the "markbad" command.
|
|
|
|
|
|
NAND locking command (for chips with active LOCKPRE pin)
|
|
|
|
"nand lock"
|
|
set NAND chip to lock state (all pages locked)
|
|
|
|
"nand lock tight"
|
|
set NAND chip to lock tight state (software can't change locking anymore)
|
|
|
|
"nand lock status"
|
|
displays current locking status of all pages
|
|
|
|
"nand unlock [offset] [size]"
|
|
unlock consecutive area (can be called multiple times for different areas)
|
|
|
|
|
|
I have tested the code with board containing 128MiB NAND large page chips
|
|
and 32MiB small page chips.
|