Good evening everyone and thanks in advance for any help or advice you can give me.
I have two RK3318 TV Boxes, officially they are model A95X R5, which have a different motherboard, but apparently identical in terms of components and the exact same Android firmware loaded on them.
if can be useful here is the link to the original Android firmware loaded on these boards:
Looking at the components, the only ones that apparently seem grossly different to me are the eMMC and the LAN controller.
These are some pictures of the two boards:
On both I still have the same old version of Armbian installed and perfectly running, compiled and adapted in 2021 on Buster distro kernel 4 (everything working apart from wifi and some specific leds), sharing the same dtb and the same system configuration and loading using the old uboot.img and trust.img method.
Due to the need to start over with a more updated version of kernel and OS I tried to compile a more recent release based on current Bullseye kernel 5.15 and here the difficulties begin.
On the first board (the green one), which I've always used for preliminary tests, no problem and I was able to start everything strictly necessary right away with just a few modifications to the dtb rk3318-box.dtb.
On the second board (the blue one) I can't start any build I tried to compile. The box remains stucked with the screen off, without anything being loaded. If I re-flesh Android it works, if I try to boot from a SD / flash the old system works. I had no results neither trying booting from SD (with both eMMC erased and the old Armbian flashed) nor from the eMMC using the Multitool (I had to unbrick the memory at least a dozen of times till now). The biggest difficulty arises from the impossibility when it comes to check trough the serial port what is happening on the board during boot process, as the SMDs have not been set up on the blue model to make the port work.
I know that with so little information it is not easy to investigate and understand the source of these issues, but would you have any idea what could be the cause of this strange behavior of the board? There is something I'm missing?
Thanks in advance for any suggestions