To root your Xiaomi Redmia 8A device, you need to use Magisk. However, Magisk boot patching is not working right now, due to which you must download the appropriate prebuilt boot image and flash it to the device to obtain root. This works both on MIUI and GSI.
Download vbmeta.img - this is mandatory to prevent bootloop.
Verify the download checksum matches the one in the checksum file after downloading the file to ensure authenticity.
I do not provide any support for this boot image. You are flashing it at your own risk, and I am not responsible for any possible eventual damage to your device.
To flash a custom boot image you need to unlock your device, which takes 168 hours and is done with Mi Unlock. Unlocking the bootloader will void your warranty.
To flash the boot image, reboot into FASTBOOT mode, install the USB drivers and Android Platform Tools, and run the following command (in the folder where you downloaded the recovery):
fastboot flash boot boot.img
fastboot flash --disable-verity vbmeta vbmeta.img
Then, reboot your phone, and it will be rooted with Magisk. If appropriate, install Magisk Manager apk.
To learn more about Magisk, visit the official Documentation.
This project is not sponsored, approved or endorsed by Xiaomi, Google, Qualcomm, or John Wu.
Kernel binary distribution NOTICE: In accordance with Section 3c of GPL v2, I am distributing the device kernel in binary form with a forwarded written notice of copyright and source code distribution from Xiaomi. The kernel is being distributed under the terms of the GPL v2 license by Xiaomi and the claimed source code is available here: https://github.com/MiCode/Xiaomi_Kernel_OpenSource/tree/olive-p-oss
For GPL compliance in case of the precompiled redistributed kernel contact the manufacturer at their official website mi.com.
This post was last updated on January 26th, 2020.