I have customized IMX7D board and can boot it by SD successfully.
Then I mount nand device, and enable nand driver in uboot and linux, and can operate everything on nand device in both uboot linux.
then I prepare the u-boot-nand.imx with mx7dsabresd_nand_defconfig, and program it on to mtd0 on nand using
$ flash_erase /dev/mtd0 0 0 $ kobs-ng init -x u-boot.imx-nand --search_exponent=1 -v
Then I reset board, I get nothing in uboot console with MODE_MODE[1:0] setting 00b.
After reading manual, I realize I can not boot device from nand flash using Fuses Mode, because device is never programmed by mfgtools, so eFUSE value is null. Then I set MODE_MODE[1:0] to be 10b, i.e internal boot mode. according to the 22.214.171.124 on manual, I can use gpio boot overrides based on table 6-26.
But my questions is how can I set these pins to make them being used in boot process.
Anybody has the similar issue ?