I'm sorry, I forgot that in this SD I have another OS that I found, but in the same way with these installed following the same steps, Linux does not load, is there anything I can do?
I have the same problem, this is what I did:
Download the firmware from this page the xfce
https://www.armbian.com/amlogic-s9xx-tv-box/
My SD is 64 GB in FAT 32
Use BalenaEtcher and win32disk
I made a copy of "u-boot-s905x-s912" and renamed it u-boot.ext
This is my extlinux file:
I insert SD and press the AV button and connect power and it only reaches the Android recovery