grub.efi is irrelevant, you don't need it.
Have you updated firmware on your board as per the instructions in Getting Started Guide? Outdated firmware is the most frequent reason of not being able to boot from the SD card.
grub.efi is irrelevant, you don't need it.
Have you updated firmware on your board as per the instructions in Getting Started Guide? Outdated firmware is the most frequent reason of not being able to boot from the SD card.