I'm using DM646x_FlashAndBootUtils_1_50 and the sfh_DM646x.exe application to program the nand with UBL and U-Boot onto a custom board. NAND boot fails because "No valid boot image found!". By adding debug statements to the UBL, the reason is because DEVICE_NAND_ECC_correct function fails (i.e. the calculated ecc doesn't match the ecc in the spare bytes). I think the problem is that the serial flash loader tool doesn't program the spare bytes with the ecc. Is an extra flag or step required to program the ecc of u-boot?