"soft_bch".
- nand-bus-width : 8 or 16 bus width if not present 8
- nand-on-flash-bbt: boolean to enable on flash bbt option if not present false
+- nand-no-oob-bbm: boolean to disable writing bad block markers to flash
- nand-ecc-strength: integer representing the number of bits to correct
per ECC step.