Symptoms: You see "Invalid IMEI" or cannot register on network. Solution:
If you cannot find a dedicated port, you can try a Generic System Image (GSI). Since MT6580 is 32-bit & A-only, you need specific GSIs. mt6580 firmware android 9 install
You will see a red bar (100%), then a purple/yellow bar (downloading). This takes 3-7 minutes. Symptoms: You see "Invalid IMEI" or cannot register