Hello. I bought a A5x max with android 9.0 https://pt.geekbuying.com/item/A5X-MAX-RK3328-4GB-32GB-TV-Box-398231.html I can only boot in the combined mode (i.e. with an SD card + USB). I tried to boot to emmc doing the procedure described here    However without luck so far. It didn't boot. Do I need a diferent uboot.img to be able to boot from emmc ? Is there any procedure so that I can boot from the SD card instead of the combined mode? What is the best