I think it’s possible. To do this, you need to make changes to the ENV variables to specify u-boot, check the system startup from USB (for tests, you can use the UART console). I still do not have enough free time to do it as a ready-made solution (to do it for RK, on the principle of universal multiloading , as I do for Amlogic). If you do it immediately in the Android firmware, then all users will automatically be able to do so. 