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wdenk7a8e9bed2003-05-31 18:35:21 +00001NAND FLASH commands and notes
2
Wolfgang Denk4e3ccd22006-03-06 11:25:22 +01003See NOTE below!!!
4
wdenk7a8e9bed2003-05-31 18:35:21 +00005# (C) Copyright 2003
6# Dave Ellis, SIXNET, dge@sixnetio.com
7#
8# See file CREDITS for list of people who contributed to this
9# project.
10#
11# This program is free software; you can redistribute it and/or
12# modify it under the terms of the GNU General Public License as
13# published by the Free Software Foundation; either version 2 of
14# the License, or (at your option) any later version.
15#
16# This program is distributed in the hope that it will be useful,
17# but WITHOUT ANY WARRANTY; without even the implied warranty of
18# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
19# GNU General Public License for more details.
20#
21# You should have received a copy of the GNU General Public License
22# along with this program; if not, write to the Free Software
23# Foundation, Inc., 59 Temple Place, Suite 330, Boston,
24# MA 02111-1307 USA
25
26Commands:
27
28 nand bad
29 Print a list of all of the bad blocks in the current device.
30
31 nand device
32 Print information about the current NAND device.
33
34 nand device num
35 Make device `num' the current device and print information about it.
36
Stefan Roese856f0542006-10-28 15:55:52 +020037 nand erase off|partition size
38 nand erase clean [off|partition size]
39 Erase `size' bytes starting at offset `off'. Alternatively partition
40 name can be specified, in this case size will be eventually limited
41 to not exceed partition size (this behaviour applies also to read
42 and write commands). Only complete erase blocks can be erased.
43
44 If `erase' is specified without an offset or size, the entire flash
45 is erased. If `erase' is specified with partition but without an
46 size, the entire partition is erased.
wdenk7a8e9bed2003-05-31 18:35:21 +000047
48 If `clean' is specified, a JFFS2-style clean marker is written to
Stefan Roese856f0542006-10-28 15:55:52 +020049 each block after it is erased.
wdenk7a8e9bed2003-05-31 18:35:21 +000050
51 This command will not erase blocks that are marked bad. There is
52 a debug option in cmd_nand.c to allow bad blocks to be erased.
53 Please read the warning there before using it, as blocks marked
54 bad by the manufacturer must _NEVER_ be erased.
55
56 nand info
57 Print information about all of the NAND devices found.
58
Stefan Roese856f0542006-10-28 15:55:52 +020059 nand read addr ofs|partition size
Scott Wood984e03c2008-06-12 13:13:23 -050060 Read `size' bytes from `ofs' in NAND flash to `addr'. Blocks that
61 are marked bad are skipped. If a page cannot be read because an
62 uncorrectable data error is found, the command stops with an error.
wdenk7a8e9bed2003-05-31 18:35:21 +000063
Stefan Roese856f0542006-10-28 15:55:52 +020064 nand read.oob addr ofs|partition size
wdenk7a8e9bed2003-05-31 18:35:21 +000065 Read `size' bytes from the out-of-band data area corresponding to
66 `ofs' in NAND flash to `addr'. This is limited to the 16 bytes of
67 data for one 512-byte page or 2 256-byte pages. There is no check
68 for bad blocks or ECC errors.
69
Stefan Roese856f0542006-10-28 15:55:52 +020070 nand write addr ofs|partition size
Scott Wood984e03c2008-06-12 13:13:23 -050071 Write `size' bytes from `addr' to `ofs' in NAND flash. Blocks that
72 are marked bad are skipped. If a page cannot be read because an
73 uncorrectable data error is found, the command stops with an error.
wdenk7a8e9bed2003-05-31 18:35:21 +000074
Scott Wood984e03c2008-06-12 13:13:23 -050075 As JFFS2 skips blocks similarly, this allows writing a JFFS2 image,
76 as long as the image is short enough to fit even after skipping the
77 bad blocks. Compact images, such as those produced by mkfs.jffs2
78 should work well, but loading an image copied from another flash is
79 going to be trouble if there are any bad blocks.
wdenk7a8e9bed2003-05-31 18:35:21 +000080
Ben Gardinerc9494862011-06-14 16:35:07 -040081 nand write.trimffs addr ofs|partition size
82 Enabled by the CONFIG_CMD_NAND_TRIMFFS macro. This command will write to
83 the NAND flash in a manner identical to the 'nand write' command
84 described above -- with the additional check that all pages at the end
85 of eraseblocks which contain only 0xff data will not be written to the
86 NAND flash. This behaviour is required when flashing UBI images
87 containing UBIFS volumes as per the UBI FAQ[1].
88
89 [1] http://www.linux-mtd.infradead.org/doc/ubi.html#L_flasher_algo
90
Stefan Roese856f0542006-10-28 15:55:52 +020091 nand write.oob addr ofs|partition size
wdenk7a8e9bed2003-05-31 18:35:21 +000092 Write `size' bytes from `addr' to the out-of-band data area
93 corresponding to `ofs' in NAND flash. This is limited to the 16 bytes
94 of data for one 512-byte page or 2 256-byte pages. There is no check
95 for bad blocks.
96
Scott Wood418396e2012-03-02 14:01:57 -060097 nand read.raw addr ofs|partition [count]
98 nand write.raw addr ofs|partition [count]
99 Read or write one or more pages at "ofs" in NAND flash, from or to
100 "addr" in memory. This is a raw access, so ECC is avoided and the
101 OOB area is transferred as well. If count is absent, it is assumed
102 to be one page. As with .yaffs2 accesses, the data is formatted as
103 a packed sequence of "data, oob, data, oob, ..." -- no alignment of
104 individual pages is maintained.
Marek Vasutfb3659a2011-09-23 15:43:10 +0200105
wdenk7a8e9bed2003-05-31 18:35:21 +0000106Configuration Options:
107
Jon Loeligerb5501f72007-07-09 19:10:03 -0500108 CONFIG_CMD_NAND
109 Enables NAND support and commmands.
wdenk7a8e9bed2003-05-31 18:35:21 +0000110
111 CONFIG_MTD_NAND_ECC_JFFS2
112 Define this if you want the Error Correction Code information in
113 the out-of-band data to be formatted to match the JFFS2 file system.
114 CONFIG_MTD_NAND_ECC_YAFFS would be another useful choice for
115 someone to implement.
116
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +0200117 CONFIG_SYS_MAX_NAND_DEVICE
wdenk7a8e9bed2003-05-31 18:35:21 +0000118 The maximum number of NAND devices you want to support.
119
Scott Wood99067b02009-04-01 15:33:24 -0500120 CONFIG_SYS_NAND_MAX_CHIPS
121 The maximum number of NAND chips per device to be supported.
wdenk7a8e9bed2003-05-31 18:35:21 +0000122
Scott Wood578931b2012-01-12 19:07:23 -0600123 CONFIG_SYS_NAND_SELF_INIT
124 Traditionally, glue code in drivers/mtd/nand/nand.c has driven
125 the initialization process -- it provides the mtd and nand
126 structs, calls a board init function for a specific device,
127 calls nand_scan(), and registers with mtd.
128
129 This arrangement does not provide drivers with the flexibility to
130 run code between nand_scan_ident() and nand_scan_tail(), or other
131 deviations from the "normal" flow.
132
133 If a board defines CONFIG_SYS_NAND_SELF_INIT, drivers/mtd/nand/nand.c
134 will make one call to board_nand_init(), with no arguments. That
135 function is responsible for calling a driver init function for
136 each NAND device on the board, that performs all initialization
137 tasks except setting mtd->name, and registering with the rest of
138 U-Boot. Those last tasks are accomplished by calling nand_register()
139 on the new mtd device.
140
141 Example of new init to be added to the end of an existing driver
142 init:
143
144 /*
145 * devnum is the device number to be used in nand commands
146 * and in mtd->name. Must be less than
147 * CONFIG_SYS_NAND_MAX_DEVICE.
148 */
149 mtd = &nand_info[devnum];
150
151 /* chip is struct nand_chip, and is now provided by the driver. */
152 mtd->priv = &chip;
153
154 /*
155 * Fill in appropriate values if this driver uses these fields,
156 * or uses the standard read_byte/write_buf/etc. functions from
157 * nand_base.c that use these fields.
158 */
159 chip.IO_ADDR_R = ...;
160 chip.IO_ADDR_W = ...;
161
162 if (nand_scan_ident(mtd, CONFIG_SYS_MAX_NAND_CHIPS, NULL))
163 error out
164
165 /*
166 * Insert here any code you wish to run after the chip has been
167 * identified, but before any other I/O is done.
168 */
169
170 if (nand_scan_tail(mtd))
171 error out
172
173 if (nand_register(devnum))
174 error out
175
176 In addition to providing more flexibility to the driver, it reduces
177 the difference between a U-Boot driver and its Linux counterpart.
178 nand_init() is now reduced to calling board_nand_init() once, and
179 printing a size summary. This should also make it easier to
180 transition to delayed NAND initialization.
181
182 Please convert your driver even if you don't need the extra
183 flexibility, so that one day we can eliminate the old mechanism.
184
Wolfgang Denk4e3ccd22006-03-06 11:25:22 +0100185NOTE:
186=====
187
Scott Wood99067b02009-04-01 15:33:24 -0500188The current NAND implementation is based on what is in recent
Scott Woodbe33b042009-04-01 15:02:13 -0500189Linux kernels. The old legacy implementation has been removed.
Wolfgang Denk4e3ccd22006-03-06 11:25:22 +0100190
Scott Wood99067b02009-04-01 15:33:24 -0500191If you have board code which used CONFIG_NAND_LEGACY, you'll need
192to convert to the current NAND interface for it to continue to work.
Wolfgang Denk4e3ccd22006-03-06 11:25:22 +0100193
Scott Wood99067b02009-04-01 15:33:24 -0500194The Disk On Chip driver is currently broken and has been for some time.
195There is a driver in drivers/mtd/nand, taken from Linux, that works with
196the current NAND system but has not yet been adapted to the u-boot
197environment.
Stefan Roese2255b2d2006-10-10 12:36:02 +0200198
Stefan Roese2255b2d2006-10-10 12:36:02 +0200199Additional improvements to the NAND subsystem by Guido Classen, 10-10-2006
200
201JFFS2 related commands:
202
203 implement "nand erase clean" and old "nand erase"
204 using both the new code which is able to skip bad blocks
205 "nand erase clean" additionally writes JFFS2-cleanmarkers in the oob.
206
Stefan Roese2255b2d2006-10-10 12:36:02 +0200207Miscellaneous and testing commands:
208 "markbad [offset]"
209 create an artificial bad block (for testing bad block handling)
210
211 "scrub [offset length]"
212 like "erase" but don't skip bad block. Instead erase them.
213 DANGEROUS!!! Factory set bad blocks will be lost. Use only
214 to remove artificial bad blocks created with the "markbad" command.
215
216
217NAND locking command (for chips with active LOCKPRE pin)
218
219 "nand lock"
220 set NAND chip to lock state (all pages locked)
221
222 "nand lock tight"
223 set NAND chip to lock tight state (software can't change locking anymore)
224
225 "nand lock status"
226 displays current locking status of all pages
227
228 "nand unlock [offset] [size]"
229 unlock consecutive area (can be called multiple times for different areas)
230
231
232I have tested the code with board containing 128MiB NAND large page chips
233and 32MiB small page chips.