X-Git-Url: https://git.karo-electronics.de/?a=blobdiff_plain;f=doc%2FREADME.nand;h=0ff56331d5f92ec1ba0dbea186e40d36b4a06cb2;hb=9324fbff8526f41ded10032493d162536824e062;hp=70cf768d237056460e0bd1261a3bb0c980c4dc30;hpb=84f24ac8278d287581e5a559a7299e1dc2b53481;p=karo-tx-uboot.git diff --git a/doc/README.nand b/doc/README.nand index 70cf768d23..0ff56331d5 100644 --- a/doc/README.nand +++ b/doc/README.nand @@ -89,18 +89,16 @@ Commands: Configuration Options: + CONFIG_SYS_NAND_U_BOOT_OFFS + NAND Offset from where SPL will read u-boot image. This is the starting + address of u-boot MTD partition in NAND. + 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_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. @@ -190,24 +188,6 @@ Configuration Options: This is used by SoC platforms which do not have built-in ELM hardware engine required for BCH ECC correction. - CONFIG_SYS_NAND_BUSWIDTH_16BIT - Indicates that NAND device has 16-bit wide data-bus. In absence of this - config, bus-width of NAND device is assumed to be either 8-bit and later - determined by reading ONFI params. - Above config is useful when NAND device's bus-width information cannot - be determined from on-chip ONFI params, like in following scenarios: - - SPL boot does not support reading of ONFI parameters. This is done to - keep SPL code foot-print small. - - In current U-Boot flow using nand_init(), driver initialization - happens in board_nand_init() which is called before any device probe - (nand_scan_ident + nand_scan_tail), thus device's ONFI parameters are - not available while configuring controller. So a static CONFIG_NAND_xx - is needed to know the device's bus-width in advance. - Some drivers using above config are: - drivers/mtd/nand/mxc_nand.c - drivers/mtd/nand/ndfc.c - drivers/mtd/nand/omap_gpmc.c - Platform specific options ========================= @@ -226,6 +206,14 @@ Platform specific options detection. However ECC calculation on such plaforms would still be done by GPMC controller. + CONFIG_SPL_NAND_AM33XX_BCH + Enables SPL-NAND driver (am335x_spl_bch.c) which supports ELM based + hardware ECC correction. This is useful for platforms which have ELM + hardware engine and use NAND boot mode. + Some legacy platforms like OMAP3xx do not have in-built ELM h/w engine, + so those platforms should use CONFIG_SPL_NAND_SIMPLE for enabling + SPL-NAND driver with software ECC correction support. + CONFIG_NAND_OMAP_ECCSCHEME On OMAP platforms, this CONFIG specifies NAND ECC scheme. It can take following values: @@ -292,15 +280,14 @@ Platform specific options Thus BCH16 can be supported on 4K page NAND. + CONFIG_NAND_OMAP_GPMC_PREFETCH + On OMAP platforms that use the GPMC controller + (CONFIG_NAND_OMAP_GPMC_PREFETCH), this options enables the code that + uses the prefetch mode to speed up read operations. + NOTE: ===== -The current NAND implementation is based on what is in recent -Linux kernels. The old legacy implementation has been removed. - -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