DESCRIPTION

This Root method use magisk app auto patch..
i use boot.img from stock rom of MiA2 then patched it to get rooted phone.

Step apply this root :

0. Install Magisk Manager 5.8.3 or higer in your phone
1. Download adb minimal tools from google and install it
2. Download this rom will containt MiA2_boot.img
3. Put boot.img in adb minimal tools folder on your pc
4. Put the device in fastboot mode, install the drivers (if necessary),
5. Unlock the bootloader (if did not do this earlier)
6. Load the boot.img:
Temporarily load the modified kernel:
fastboot boot MiA2_boot.img
Attention: At this stage, you have already received the temporary root-rights (act before the reboot)! If you do not need a permanent root (for example for the Camera2 API) and it's important to preserve the possibility of OTA updates – do not take any further action! 

7. Go to the Magisk Manager: " Installation " -> " Installation " -> " Direct installation (Recommended) ". Wait until the process is complete and restart the device. 
8. Everything, the root is received

※Please make a backup of your device before installing or updating ROM