This article mainly documents a detailed tutorial on flashing Lineage OS 15.1 (Android 8.1) onto the Nubia Z17 mini, for my roommate Sun Wei’s reference. The flashing process is relatively complicated because it requires a high version of TWRP (what is TWRP? TWRP is the most famous third-party REC). Let’s get straight to the point. Many images below.

Flashing a Third-Party REC

High-energy content ahead QWQ

Unlocking OEM (BL)

1. Go to “Settings - About phone”.
2. Tap “Build number” seven times consecutively.
3. Return to “Advanced settings - Developer options”.
4. Enable “OEM unlocking”.

Downloading TWRP

Find the TWRP compiled by the expert @时代的导航者 in the Nubia community and download it directly.

Extracting the Archive

Double-click 努比亚 Z17 Mini 刷机工具箱.

Starting the Flash

After completing the previous step, wait a moment until the following content appears:

Press any key to continue.

Critical steps!!!

1. Power off the phone and wait until it has completely shut down.
2. Press and hold the power button + volume-down button to enter BOOT (after entering, press the volume-down button once more, otherwise it will restart after 10 seconds).
3. Connect the phone to the computer with a data cable.
4. Enter 3 in 刷入工具 and press Enter.

5. Enter 1 and press Enter.

6. Press any key (or press Enter directly).

If the following content appears, it means that the Nubia phone driver has not been installed or the bootloader has not been unlocked:

Driver download link: Nubia phone driver download.

After installing the driver, perform the above steps again.

If the following content appears, TWRP has been flashed successfully:

Continue pressing the Enter key to reboot into REC:

Upgrading TWRP

Flashing a system above Android 8.0 requires a higher version of TWRP, so download TWRP 3.2.1.

1. Enter REC (press and hold the power button + volume-up button).
2. Tap the first “Install” button in the upper-left corner.
3. Find the TWRP 3.2.1 downloaded earlier:

4. Flash it directly.
5. After flashing, clear the cache and reboot into REC.

Flashing Lineage OS 15.1

Downloading the Flashing Package

All of the following steps require a VPN:

1. Open the XDA forum.
2. Download lineage-15.1-20180611-UNOFFICIAL-nx569j.zip.

Removing the Model Verification

The downloaded flashing package is compatible with the lower-spec Z17 Mini (NX569J). The higher-spec version (NX569H) requires the model verification to be removed:

1. Extract the flashing package:

2. Open the \META-INF\com\google\android\updater-script file.
3. Delete the content before ui_print("Target.
4. Repack the ROM:

Flashing the ROM

1. Transfer the flashing package to the phone:

2. Disconnect the data cable.
3. Enter the TWRP interface and select “Wipe”:

4. Swipe to perform a factory reset (that is, a dual wipe).
5. Return to the home page, tap “Install”, and select the ROM (such as lineage.zip):

6. Swipe to start flashing:

7. Wait a moment, then clear Cache:

8. Reboot the system:

Notes

On the initial setup screen, setting a PIN password for encryption is not recommended. A PIN encrypts the Data partition, which means that subsequent flashing requires formatting it and is relatively troublesome.