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

Scott Wood
2011-09-22T16:03:43Z

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