X-Git-Url: https://git.librecmc.org/?a=blobdiff_plain;f=doc%2FREADME.nand;h=ec461b2dc933b315a971607ee24a14e03a35e024;hb=e836a71b700862b4eacc20209ec225aa427c56e3;hp=e29188f1ec0cd4dd97a38ddb4bb7ed85645f83fe;hpb=362f16b1e9e94024a511adae9977d145ef942b50;p=oweals%2Fu-boot.git diff --git a/doc/README.nand b/doc/README.nand index e29188f1ec..ec461b2dc9 100644 --- a/doc/README.nand +++ b/doc/README.nand @@ -1,3 +1,4 @@ +# SPDX-License-Identifier: GPL-2.0+ NAND FLASH commands and notes See NOTE below!!! @@ -5,7 +6,6 @@ See NOTE below!!! # (C) Copyright 2003 # Dave Ellis, SIXNET, dge@sixnetio.com # -# SPDX-License-Identifier: GPL-2.0+ Commands: @@ -94,17 +94,11 @@ Configuration Options: address of u-boot MTD partition in NAND. CONFIG_CMD_NAND - Enables NAND support and commmands. + Enables NAND support and commands. 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. @@ -122,7 +116,7 @@ Configuration Options: The maximum number of NAND chips per device to be supported. CONFIG_SYS_NAND_SELF_INIT - Traditionally, glue code in drivers/mtd/nand/nand.c has driven + Traditionally, glue code in drivers/mtd/nand/raw/nand.c has driven the initialization process -- it provides the mtd and nand structs, calls a board init function for a specific device, calls nand_scan(), and registers with mtd. @@ -131,7 +125,7 @@ Configuration Options: run code between nand_scan_ident() and nand_scan_tail(), or other deviations from the "normal" flow. - If a board defines CONFIG_SYS_NAND_SELF_INIT, drivers/mtd/nand/nand.c + If a board defines CONFIG_SYS_NAND_SELF_INIT, drivers/mtd/nand/raw/nand.c will make one call to board_nand_init(), with no arguments. That function is responsible for calling a driver init function for each NAND device on the board, that performs all initialization @@ -142,15 +136,8 @@ Configuration Options: Example of new init to be added to the end of an existing driver init: - /* - * devnum is the device number to be used in nand commands - * and in mtd->name. Must be less than - * CONFIG_SYS_NAND_MAX_DEVICE. - */ - mtd = &nand_info[devnum]; - /* chip is struct nand_chip, and is now provided by the driver. */ - mtd->priv = &chip; + mtd = nand_to_mtd(&chip); /* * Fill in appropriate values if this driver uses these fields, @@ -171,7 +158,11 @@ Configuration Options: if (nand_scan_tail(mtd)) error out - if (nand_register(devnum)) + /* + * devnum is the device number to be used in nand commands + * and in mtd->name. Must be less than CONFIG_SYS_MAX_NAND_DEVICE. + */ + if (nand_register(devnum, mtd)) error out In addition to providing more flexibility to the driver, it reduces @@ -189,30 +180,6 @@ Configuration Options: 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. - - 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 ========================= CONFIG_NAND_OMAP_GPMC @@ -298,23 +265,22 @@ Platform specific options However, for 4K pagesize NAND NAND_PAGESIZE = 4096 - NAND_OOBSIZE = 64 + NAND_OOBSIZE = 224 ECC_BYTES = 26 2 + (4096 / 512) * 26 = 210 < NAND_OOBSIZE 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 +There is a driver in drivers/mtd/nand/raw, taken from Linux, that works with the current NAND system but has not yet been adapted to the u-boot environment. @@ -335,7 +301,7 @@ Miscellaneous and testing commands: DANGEROUS!!! Factory set bad blocks will be lost. Use only to remove artificial bad blocks created with the "markbad" command. - "torture offset" + "torture offset [size]" 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. @@ -352,6 +318,10 @@ Miscellaneous and testing commands: 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. + Optionally, a second parameter size can be given to test multiple blocks with + one call. If size is not a multiple of the NAND's erase size, then the block + that contains offset + size will be tested in full. If used with size, this + command returns 0 if all tested blocks have been found reliable, else 1. NAND locking command (for chips with active LOCKPRE pin)