[U-Boot] [PATCH 4/9] imx: nand: Place BBT patterns into free OOB region

Scott Wood
2012-04-13T17:19:11Z

On 04/13/2012 06:20 AM, Timo Ketola wrote:
> First two bytes of the first OOB of erase block are reserved for factory
> bad block marking, usually.
>
> Signed-off-by: Timo Ketola <timo@exertus.fi>
> ---
> drivers/mtd/nand/mxc_nand.c | 35 +++++++++++++++++++++++++++++++++++
> 1 files changed, 35 insertions(+), 0 deletions(-)

So what happened before? The default is at offset 8, which doesn't
conflict with the bad block marker. It seems the actual issue is a
conflict with ECC?

And NAND_USE_FLASH_BBT wasn't defined before, so a better subject line
for this patch would be "nand/mxc: support flash-based BBT".

> diff --git a/drivers/mtd/nand/mxc_nand.c b/drivers/mtd/nand/mxc_nand.c
> index 35e89a0..73813a2 100644
> --- a/drivers/mtd/nand/mxc_nand.c
> +++ b/drivers/mtd/nand/mxc_nand.c
> @@ -1302,12 +1302,47 @@ static void mxc_setup_config1(void)
> #define mxc_setup_config1()
> #endif
>
> +#ifdef CONFIG_SYS_NAND_USE_FLASH_BBT
> +
> +static u8 bbt_pattern[] = {'B', 'b', 't', '0' };
> +static u8 mirror_pattern[] = {'1', 't', 'b', 'B' };
> +
> +static struct nand_bbt_descr bbt_main_descr = {
> + .options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE | NAND_BBT_WRITE |
> + NAND_BBT_2BIT | NAND_BBT_VERSION | NAND_BBT_PERCHIP,
> + .offs = 2,
> + .len = 4,
> + .veroffs = 6,
> + .maxblocks = 4,
> + .pattern = bbt_pattern,
> +};
> +
> +static struct nand_bbt_descr bbt_mirror_descr = {
> + .options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE | NAND_BBT_WRITE |
> + NAND_BBT_2BIT | NAND_BBT_VERSION | NAND_BBT_PERCHIP,
> + .offs = 2,
> + .len = 4,
> + .veroffs = 6,
> + .maxblocks = 4,
> + .pattern = mirror_pattern,
> +};
> +
> +#endif
> +

Won't veroffs = 6 conflict with ECC in the MXC_NFC_V1 case?

What about 8-bit small page support, in which case the bad block marker
is at offset 5?

> int board_nand_init(struct nand_chip *this)
> {
> struct mtd_info *mtd;
> uint16_t tmp;
> int err = 0;
>
> +#ifdef CONFIG_SYS_NAND_USE_FLASH_BBT
> +
> + this->options = NAND_USE_FLASH_BBT;
> + this->bbt_td = &bbt_main_descr;
> + this->bbt_md = &bbt_mirror_descr;
> +
> +#endif

Please remove those blank lines inside the ifdef.

-Scott