# (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
+# SPDX-License-Identifier: GPL-2.0+
Commands:
CONFIG_CMD_NAND
Enables NAND support and commmands.
+ CONFIG_CMD_NAND_TORTURE
+ Enables the torture command (see description of this command below).
+
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_SYS_MAX_NAND_DEVICE
The maximum number of NAND devices you want to support.
+ CONFIG_SYS_NAND_MAX_ECCPOS
+ If specified, overrides the maximum number of ECC bytes
+ supported. Useful for reducing image size, especially with SPL.
+ This must be at least 48 if nand_base.c is used.
+
+ CONFIG_SYS_NAND_MAX_OOBFREE
+ If specified, overrides the maximum number of free OOB regions
+ supported. Useful for reducing image size, especially with SPL.
+ This must be at least 2 if nand_base.c is used.
+
CONFIG_SYS_NAND_MAX_CHIPS
The maximum number of NAND chips per device to be supported.
Please convert your driver even if you don't need the extra
flexibility, so that one day we can eliminate the old mechanism.
+
+ CONFIG_SYS_NAND_ONFI_DETECTION
+ Enables detection of ONFI compliant devices during probe.
+ And fetching device parameters flashed on device, by parsing
+ ONFI parameter page.
+
+ CONFIG_BCH
+ Enables software based BCH ECC algorithm present in lib/bch.c
+ This is used by SoC platforms which do not have built-in ELM
+ hardware engine required for BCH ECC correction.
+
+
+Platform specific options
+=========================
+ CONFIG_NAND_OMAP_GPMC
+ Enables omap_gpmc.c driver for OMAPx and AMxxxx platforms.
+ GPMC controller is used for parallel NAND flash devices, and can
+ do ECC calculation (not ECC error detection) for HAM1, BCH4, BCH8
+ and BCH16 ECC algorithms.
+
+ CONFIG_NAND_OMAP_ELM
+ Enables omap_elm.c driver for OMAPx and AMxxxx platforms.
+ ELM controller is used for ECC error detection (not ECC calculation)
+ of BCH4, BCH8 and BCH16 ECC algorithms.
+ Some legacy platforms like OMAP3xx do not have in-built ELM h/w engine,
+ thus such SoC platforms need to depend on software library for ECC error
+ detection. However ECC calculation on such plaforms would still be
+ done by GPMC controller.
+
+ CONFIG_NAND_OMAP_ECCSCHEME
+ On OMAP platforms, this CONFIG specifies NAND ECC scheme.
+ It can take following values:
+ OMAP_ECC_HAM1_CODE_SW
+ 1-bit Hamming code using software lib.
+ (for legacy devices only)
+ OMAP_ECC_HAM1_CODE_HW
+ 1-bit Hamming code using GPMC hardware.
+ (for legacy devices only)
+ OMAP_ECC_BCH4_CODE_HW_DETECTION_SW
+ 4-bit BCH code (unsupported)
+ OMAP_ECC_BCH4_CODE_HW
+ 4-bit BCH code (unsupported)
+ OMAP_ECC_BCH8_CODE_HW_DETECTION_SW
+ 8-bit BCH code with
+ - ecc calculation using GPMC hardware engine,
+ - error detection using software library.
+ - requires CONFIG_BCH to enable software BCH library
+ (For legacy device which do not have ELM h/w engine)
+ OMAP_ECC_BCH8_CODE_HW
+ 8-bit BCH code with
+ - ecc calculation using GPMC hardware engine,
+ - error detection using ELM hardware engine.
+
NOTE:
=====
DANGEROUS!!! Factory set bad blocks will be lost. Use only
to remove artificial bad blocks created with the "markbad" command.
+ "torture offset"
+ Torture block to determine if it is still reliable.
+ Enabled by the CONFIG_CMD_NAND_TORTURE configuration option.
+ This command returns 0 if the block is still reliable, else 1.
+ If the block is detected as unreliable, it is up to the user to decide to
+ mark this block as bad.
+ The analyzed block is put through 3 erase / write cycles (or less if the block
+ is detected as unreliable earlier).
+ This command can be used in scripts, e.g. together with the markbad command to
+ automate retries and handling of possibly newly detected bad blocks if the
+ nand write command fails.
+ It can also be used manually by users having seen some NAND errors in logs to
+ search the root cause of these errors.
+ The underlying nand_torture() function is also useful for code willing to
+ automate actions following a nand->write() error. This would e.g. be required
+ in order to program or update safely firmware to NAND, especially for the UBI
+ part of such firmware.
+
NAND locking command (for chips with active LOCKPRE pin)
projects / karo-tx-uboot.git / blobdiff