The SPL and u-boot image, must be flashed on NAND using the NXP <code>kobs-ng</code> utility. This tool is required for writing correct information needed by bootrom to identify the NAND as a boot device.
'''N.B.''' for programming the second stage, the <code>nandwrite</code> command hs has to identify a proper mtd part witch correct size. Foir For this reason, the ''mtdparts'' variable has to be modified for writing the complete u-boot image.