I assume it was designed to bootload from external emmc card, otherwise SD card are not readable by processor.
According to schematic of EVK,
1. Connecting USB1_VBUS, USB1_D_N, USB1_D_P, USB1_TXRTUNE are enough to use NXP IMX8 Nano processor in USB Serial Download mode, correct?
2.There is no need to use USB1_ID pin (it is connected to TouchPoint on external PCB),correct?