===== reload NAND

http://code.google.com/p/beagleboard/wiki/BeagleNANDFlashing

mmcinit

fatload mmc 0 0x80200000 x-load.bin.ift
nand unlock

nand ecc hw  <--fails
nand device 0 ecc hw
nand erase 0 80000

nand write.i 0x80200000 0 80000
fatload mmc 0 0x80200000 flash-uboot.bin

nand unlock
nand ecc sw <--fails
nand device 0 ecc sw

nand erase 80000 160000
nand write.i 0x80200000 80000 160000