Belkin RT1800 recovery OEM firmware problem

I want reinstall OEM firmware but i have a problem with MAC address , serial number

I use openwrt for write mtd1 saved but after with OEM firmware the partition content is not the good

Why ?

With OEM firmware & mtd i have an error for write Config : " read bad address"
With Openwrt i can but that is not good

How i write the file with U-boot ?

mtd U-boot console:=> mtd

partition Config is u-boot-env

=> mtd

device nand0 <ranand>, # parts = 5
 #: name                size            offset          mask_flags
 0: u-boot              0x00080000      0x00000000      0
 1: u-boot-env          0x00080000      0x00080000      0
 2: factory             0x00080000      0x00100000      0
 3: firmware            0x03000000      0x00180000      0
 4: firmware_2          0x04e80000      0x03180000      0

active partition: nand0,0 - (u-boot) 0x00080000 @ 0x00000000

mtdids  : nand0=ranand
mtdparts: mtdparts=ranand:512k(u-boot),512k(u-boot-env),512k(factory),48m(firmware),-(firmware_2)