Xiaomi MIX 3 (perseus) 

Make a backup now, as your device will be wiped.

Downloading the needed files and tools

Please download the belowed needed files and tools:

Device preparation

  • A USB 2.0 port/hub with an actual USB 2.0 controller is recommended (Using fastboot on a USB 3.0 port may cause errors with some Xiaomi devices)
  • Save your APN (Android)
    • The Access Point Name or APN can be found in the Settings menu of Android
    • Take a piece of paper or a text editor, and write down everything that you see on that screen
    • These are likely to include a URL (e. g., internet.carrier.net), a username, and possibly a password
  • Unlock the bootloader (using Computer)
    • Refer to the instructions provided by the device manufacturer
    • Other useful sources include the LineageOS wiki and xda-developers Flash recovery (using Computer)
    • Flash TWRP to your device by running fastboot flash recovery twrp-VERSION-perseus.img
    • Boot into recovery by pressing Vol+ and Power
    • If your device boots to the stock recovery menu at some point, you should repeat this step.
  • Wipe the device (using TWRP)
    • Go to the Wipe menu
    • Select Advanced wipe
    • Tick the boxes called Dalvik / ART cache, Cache, System, Data
    • Swipe to Wipe
    • Go back to the previous menu
    • Choose Format data and type yes
    • Go back to the main menu and select Reboot
    • Choose Recovery
  • Copy the files to the device (Computer)
    • When TWRP is booted, open the device’s Internal storage from your computer
    • Copy all of the files you downloaded to this folder

Droidian installation

  • Install the required base Android version (9)
    • Install the file called fw-vendor_perseus_miui_MIMIX3_9.9.3_a9dbc91c30_9.0.zip as a Zip file using TWRP
    • Alternatively, you can enter ADB sideload mode and run adb sideload fw-vendor_perseus_miui_MIMIX3_9.9.3_a9dbc91c30_9.0.zip
  • Install Droidian rootfs
    • Install the file called droidian-rootfs-arm64_YYYYMMDD.zip as a Zip file
    • Alternatively, you can enter ADB sideload mode and run adb sideload droidian-OFFICIAL-phosh-phone-rootfs-apiXX-arm64_YYYYMMDD.zip
    • Installing devtools
    • Installation of devtools is optional for stable releases, but it is recommended as it helps with debugging.
    • Install the file called droidian-devtools-arm64_YYYYMMDD.zip as a Zip file
    • Alternatively, you can enter ADB sideload mode and run adb sideload droidian-devtools-arm64_YYYYMMDD.zip

Finalizing the installation

  • Install adaptation package as a flashable zip (TWRP)
    • Install the file called android-recovery-perseus-adaptation_YYYYMMDD.zip as a Zip file
    • Alternatively, you can enter ADB sideload mode and run adb sideload android-recovery-perseus-adaptation_YYYYMMDD.zip
  • Boot your device
    • Go to the Reboot menu and choose System
    • TWRP might complain that there is no OS installed, but that’s fine
    • The first boot may take longer, and at least one spontaneous reboot is expected during the process
    • You should be greeted with the lock screen, the default password is 1234

Congratulations, if everything went well you should be booted into Droidian.

Notes

SIM slot

Dual-SIM mode is not supported as of now. Only the SIM1 slot is active.

Extras

For other tweaks, open the Console terminal app, and run perseus-extras.sh. This includes dark mode switch and automated installation of Waydroid.

SSH access

Flashing the devtools zip enables SSH over USB. To use it, connect your phone to your computer and type ssh droidian@10.15.19.82, the password is 1234 (on Windows, you may need PuTTY)

Applications

You can find a list of mobile-friendly Linux applications at LinuxPhoneApps

Credit

Joel Selvaraj

1petro

Perseus X

Droidian Mobian UBports

You can ask for assistance specific to this device at Mi MIX 3 Community Telegram Group.