I have bought a core6818 board. (core one not the smart one).
The problem is the board always boots from EMMC unless I press the boot key button at the startup.
The point is I want a hardware/software solution to change boot priority and make sd card the first boot option.
I have tried this solution but with no success:

1. remove EMMC portions. (No success)
2. Trying to change npi-config -> boot option. (Only support allwinner chips)

The current state is like this: I plug the power and the board tries to boot from emmc but fails because there is no OS in emmc and the os is on the SD-card. it boots from sdcard when I press the boot button physically but I need to boot from an sd-card without pressing it.
Thanks in advance