• The RK3566 boot ROM will search for a valid ID BLOCK in the following order on the support boot media:

    • SPI NOR flash
    • SPI NAND flash
    • eMMC
    • SD-Card

    ... if this fails, the boot ROM will initialize the USB0 port and wait for a connection from the Rockchip flash/boot tools.

    Quelle: https://wiki.pine64.org/wiki/Quartz64_Development