gersones

wtf...why?
that's a lesson: never buy unknown chinese products again.
thanks, @hotnikq

Some Russians are investigate this device for fake RAM....
Try to read this 4pda forum
https://4pda.to/forum/index.php?showtopic=1058561&st=20

some armbian builds
https://disk.yandex.ru/d/Bt5wObnYekq8FQ
not mine, i just found

@ufsm
Thanks so much
Unfortunately, none recognized 8gb of ram BUT they'd worked* (updates included, except for the linux-headers-* and/or linux-image-*, because it says there's no space left in the disk (partition I believe)).
Xfce worked almost perfectly (only superficial tests) while in Gnome there are micro stuttering (only tested these) but I think it's because the box's hardware is weak.
*no sound while station-m3 have sound
 
 
@hotnikq
Thanks for complementary instructions.
I'll try to do the tutorials asap.
 
One more thing guys: using the tool I mentioned to extract the .dtb files from boot.img is okay or do I have to use the imgRePackerRK_107 once more on boot.img (because I did it and it generated a "dtb" (no extension) and "dtb.cfg".

@gersones @Werner Please move this topic to chinese gadgets more complicated than my ex girlfriend

This is the Vontar kk Max?
That's happens because incompatible loader.Bin 
Your device uses different memory.
 
 

@hotnikq
I have downloaded the firmware root.img and update.img
When I use RkDevTool v2.86 to select the Firmware update.img follow step1, there is a error "Loading firmware failed!" at the RkDevTool 
Is the reason for the error due to the fact that the firmware is not FIT firmware?  
How can I flash the two firmware, THX!