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authorTom Rini <trini@ti.com>2013-11-25 10:42:13 -0500
committerTom Rini <trini@ti.com>2013-11-25 10:42:13 -0500
commitfaca8ff55f4a2cf45fb906cc37f44601149fc00e (patch)
tree181e94fa3326f2ec97f0287f3bbbe54ccd3b13d1 /doc
parent5a4fe1aaf1210b02bb98e347993ffbcffeb4ffaa (diff)
parent2c17e6d1d996a1b8b9325de15f253a13d5877dee (diff)
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Merge branch 'master' of git://git.denx.de/u-boot-nand-flash
Diffstat (limited to 'doc')
-rw-r--r--doc/README.nand63
-rw-r--r--doc/README.omap33
2 files changed, 64 insertions, 2 deletions
diff --git a/doc/README.nand b/doc/README.nand
index 913e9b5..b91f198 100644
--- a/doc/README.nand
+++ b/doc/README.nand
@@ -104,6 +104,16 @@ Configuration Options:
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.
@@ -169,6 +179,59 @@ Configuration Options:
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:
=====
diff --git a/doc/README.omap3 b/doc/README.omap3
index 1fbe79d..a62c357 100644
--- a/doc/README.omap3
+++ b/doc/README.omap3
@@ -161,8 +161,7 @@ BCH8
To enable hardware assisted BCH8 (8-bit BCH [Bose, Chaudhuri, Hocquenghem]) on
OMAP3 devices we can use the BCH library in lib/bch.c. To do so add CONFIG_BCH
-to enable the library and CONFIG_NAND_OMAP_BCH8 to to enable hardware assisted
-syndrom generation to your board config.
+and set CONFIG_NAND_OMAP_ECCSCHEME=5 (refer README.nand) for selecting BCH8_SW.
The NAND OOB layout is the same as in linux kernel, if the linux kernel BCH8
implementation for OMAP3 works for you so the u-boot version should also.
When you require the SPL to read with BCH8 there are two more configs to