[U-Boot] [PATCH 2/5 V2] NAND: Add nand read.raw and write.raw commands

[Scott Wood <scottwood@freescale.com>]

On 09/21/2011 08:55 PM, Marek Vasut wrote:
> These commands should work around various "hardware" ECC and BCH methods.
> 
> Signed-off-by: Marek Vasut <marek.vasut@gmail.com>
> Cc: Scott Wood <scottwood@freescale.com>
> Cc: Stefano Babic <sbabic@denx.de>
> Cc: Wolfgang Denk <wd@denx.de>
> Cc: Detlev Zundel <dzu@denx.de>
> ---
>  common/cmd_nand.c |   19 +++++++++++++++++--
>  doc/README.nand   |    9 +++++++++
>  2 files changed, 26 insertions(+), 2 deletions(-)
> 
> V2: Add documentation.
> 
> diff --git a/common/cmd_nand.c b/common/cmd_nand.c
> index 66e06a5..72d418c 100644
> --- a/common/cmd_nand.c
> +++ b/common/cmd_nand.c
> @@ -606,6 +606,20 @@ int do_nand(cmd_tbl_t * cmdtp, int flag, int argc, char * const argv[])
>  				ret = nand->read_oob(nand, off, &ops);
>  			else
>  				ret = nand->write_oob(nand, off, &ops);
> +		} else if (!strcmp(s, ".raw")) {
> +			/* Raw access */
> +			mtd_oob_ops_t ops = {
> +				.datbuf = (u8 *)addr,
> +				.oobbuf = ((u8 *)addr) + nand->writesize,
> +				.len = nand->writesize,
> +				.ooblen = nand->oobsize,
> +				.mode = MTD_OOB_RAW
> +			};
> +
> +			if (read)
> +				ret = nand->read_oob(nand, off, &ops);
> +			else
> +				ret = nand->write_oob(nand, off, &ops);
>  		} else {
>  			printf("Unknown nand command suffix '%s'.\n", s);
>  			return 1;
> @@ -695,10 +709,11 @@ U_BOOT_CMD(
>  	"NAND sub-system",
>  	"info - show available NAND devices\n"
>  	"nand device [dev] - show or set current device\n"
> -	"nand read - addr off|partition size\n"
> -	"nand write - addr off|partition size\n"
> +	"nand read[.raw] - addr off|partition size\n"
> +	"nand write[.raw] - addr off|partition size\n"
>  	"    read/write 'size' bytes starting at offset 'off'\n"
>  	"    to/from memory address 'addr', skipping bad blocks.\n"
> +	"    Use read.raw/write.raw to avoid ECC and write the block as-is.\n"

This says that .raw takes a size parameter, but you assume one page instead.

> diff --git a/doc/README.nand b/doc/README.nand
> index 751b693..084223a 100644
> --- a/doc/README.nand
> +++ b/doc/README.nand
> @@ -94,6 +94,15 @@ Commands:
>        of data for one 512-byte page or 2 256-byte pages. There is no check
>        for bad blocks.
>  
> +   nand read.raw addr ofs|partition size
> +      Read `size' bytes from `ofs' in NAND flash to `addr'. This reads the raw
> +      block, so ECC is avoided and the OOB area is read as well.
> +
> +   nand write.raw addr ofs|partition size
> +      Write `size' bytes from `addr' to `ofs' in NAND flash. This writes the raw
> +      block, so ECC is avoided and the OOB area is written as well, making the
> +      whole block written as-is.

The current implementation reads/writes a page, not a block, and not
'size' bytes.

Should mention that the OOB is expected to immediately follow the main
area in memory.

-Scott