SteeMan

This video should give you the information you need for setting up a usb debug uart connection:

At this point you seem to have done everything properly. The next step would be to find the uart connection point on you board and hook up a usb-uart reader so you can see the debug output from uboot to see what is happening.

That is enabling multiboot (what enabled either Armbian or android to boot. I'm going through with you all the basics that you didn't mention in your original post (and that others often forget to do), to eliminate all the basic things. You say "maintain it", but you shouldn't hold that button too long, a few seconds (10 at most is all you need). Holding too long will not work.

This is required to use Armbian on the amlogic TV boxes. Enabling multiboot is one of the steps on the install instructions.

You don't need to decompile.this as the original source dts is available in the Linux git source code.

Have you used Armbian on other amlogic TV Boxes? I would never recommend using an amlogic TV Box as a mini pc. The graphical performance is poor. See the FAQ for TV boxes pined in this forum.

Why are you using USB? Does the box not have an SD card slot? Also what method are you using to enable multiboot?

Please explain in more detail what you mean by these statements. "put dtb file" - there is no dtb file to put, just test the ones that are in the build and I would start with meson-sm1-sei610.dtb (which is the reference board for the s905x3 cpu). And what u-boot-* are you using? Also have you run any other linux distribution on this box other than an official Armbian build downloaded from this site?

That isn't what you use for amlogic tv boxes. Follow the instructions linked from the download page: https://www.armbian.com/amlogic-s9xx-tv-box

@SuzSinclair Start by reading the first post of this thread, which has all the information you should need to get started.

What exact image are you running? Or better yet providing full logs with armbianmonitor -u

There is no gpu support in these amlogic tvbox builds.

@user03 Given that you now have a working uboot installed on the emmc, I'm 95% confident that following the standard instructions will let you move your SD card install to emmc. But there are no guarantees.

@kingbecher This is now off topic for this thread, but you need to look at: https://www.armbian.com/amlogic-s9xx-tv-box

@kingbecher Why do you believe this isn't an Amlogic s905w? Those cpus are also cortex-a53. I see Amlogic references throughout the boot log you posted