[1/1] mxc_nand : allow swapping the Bad block Indicator for NFC v1.

[Juergen Beisert]

Gaëtan Carlier wrote:
> Hi Javier,
>
> On 09/06/2012 11:14 AM, javier Martin wrote:
> > Hi Gaëtan,
> > has this behavior been documented by Freescale anywhere?

There is an application note available 
called "FSL_AppNote_Nand_Flash_Bad_Block_Management_for_Linux_BSP.pdf"
which describes the behaviour.

After reading a page from NAND into the internal NFC's SRAM, the data layout 
looks like:

SRAM Offset               real NAND's Data
---------------- SRAM data area ---------------------
  0
  .                     [   0 ...  511] 512 Byte page data
 511
 512
  .                     [ 528 ... 1039] 512 Byte page data
1023
1024
  .                     [1056 ... 1567] 512 Byte page data
1535
1536
  .                     [1584 ... 2047] 464 Byte page data
1999
2000
  .                     [   0 ...   47] 48 Byte OOB data
2047

-------------- SRAM OOB area ----------------------------
2048     0x800
  .                     [ 512 ...  527] 16 Byte page data
2063
2064     0x810
  .                     [1040 ... 1055] 16 Byte page data
2079
2080     0x820
  .                     [1568 ... 1583] 16 Byte page data
2095
2096     0x830
  .                     [  48 ...   63] 16 Byte OOB data
2112

> > Furthermore, what I can't guess is where that 0x7D0 comes from. I know
> > Jürgen described something related to the spare area being mixed with
> > the data (main) area but, is there any documentation about it we can
> > check?

See the table above: if you are interested in the byte at offset 0 in the 
NAND's OOB area, you must read the byte at offset 2000 (= 0x7D0) in the SRAM 
area instead.

Regards,
Juergen

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