[Xiaomi Redmi 8 Guides, News, & Discussion] ferabot:
I'm not a developer, this is ROM from official lineage website and I just wanted to post it here ( because nobody posted it yet ), also

*** Disclaimer
I am not responsible for any damage you made to your device
You have been warned

What is working:

Almost Everything works

Bugs

ussd not working for SEA region.

Requirements :​

Unlocked bootloader.

Base Android installed is Android 10 firmware, MIUI ≥ V11.0.2.0.QC*** . You can download the latest version here (this link for Redmi 8). If you currently using another ROM/GSI please do clean install by flashing base firmware to avoid bugs.

Latest platform-tools. You can download here. In this guide is preferable to use Linux, but if you only have Windows there's workaround too.

Installation guide :​

Reboot to fastboot mode

Flash dtbo with: fastboot flash dtbo dtbo.img

Flash vbmeta with: fastboot flash vbmeta vbmeta.img

Flash super partition with: fastboot wipe-super super_empty.img

Spoiler content hidden.

Flash recovery with: fastboot flash recovery recovery.img

Reboot with fastboot reboot and boot recovery with Volume Up + Power

Now tap Factory Reset, then Format data / factory reset and continue with the formatting process.

From recovery, select “Apply Update”, then “Apply from ADB” to begin sideload

On host machine, Sideload the rom file with: adb sideload lineage-21.0-********-nightly-Mi439-signed.zip ( don't forget change **** with file name you download )

(Optional) If you want install Gapps you can use MindTheGapps from link below then sideload the package with: adb sideload MindTheGapps-14.0.0-arm64-*****.zip ( don't forget change **** with the filename you download )

(Optional) If you want install Magisk to be installed in your phone then : Rename Magisk-v27.0.apk → Magisk-v27.0.zip, sideload the package with: adb sideload Magisk-v27.0.zip

Reboot and enjoy!

Extra step for Magisk (optional)

If magisk still not installed after step 11, then follow this instruction :

Install Magisk app from official website a.k.a Github link below.

Copy boot.img that you already download from Lineage website to your phone.

Press the Install button in the Magisk card, Choose “Select and Patch a File” in method, and select the boot image.

Copy patched boot.img from your phone download folder to your PC.

Reboot your phone, go to fastboot (Volume Down + Power).

Flash boot with : fastboot flash boot magisk_patched-27***.img ( don't forget change **** with file name you copy)

Reboot and enjoy!

Update LineageOS​

Open Settings, navigate to “System”, then “Updater”.

Click the Refresh Icon in the top right corner.

Choose which update you’d like and press “Download”.

When the download completes, click “Install”. Your device will reboot to recovery and install the update, then reboot to the updated installation.

Update LineageOS from Recovery​

Boot recovery with Volume Up + Power

From recovery, select “Apply Update”, then “Apply from ADB” to begin sideload

On host machine, Sideload the rom file with adb sideload lineage-21.0-********-nightly-Mi439-signed.zip ( don't forget change **** with file name you download )

Reboot and enjoy!

Known quirks​

Device integrity

All the development credits for this wonderful ROM go to the LineageOS team

Maintainer : https://github.com/me-cafebabe

Download link :

ROM + extra files : LinageOS 21

Magisk : topjohnwu Github

MindTheGapps : MindTheGapps-14

Sources :

https://github.com/LineageOS/android_device_xiaomi_Mi439

https://github.com/LineageOS