In this guide, we document the complete process, commands, links, troubleshooting steps, and physical actions taken on a mobile device to upgrade the Ulefone Note 11P from stock Android 11 to LineageOS 20 (Android 13) Generic System Image (GSI).

This tutorial is ideal if you want to breathe new life into your phone by installing a newer Android version.

📱 Device Specifications & Baseline

  • Device Model: Ulefone Note 11P (Board: g2062upt_v1_gd_sh2_gq_r)
  • Chipset: MediaTek Helio P60 (MT6771)
  • Stock OS version: Android 11 (GQ3095RH1_G2026U_Ulefone_20210616_V02)
  • Partition Layout: Dynamic Partitions (Project Treble Enabled) with slot suffix _a (A-only system within a logical slot container).

🛠️ Prerequisites & Setup

1. Platform-Tools

You must have the official Android SDK Platform-Tools (which contains adb and fastboot) downloaded on your workstation.

2. Physical Setup

  • A reliable USB data cable.
  • An external USB-A hub or multi-port USB adapter (essential workaround for Apple Silicon Macs).

📦 Required Files & Download Links

1. LineageOS 20 GSI

We use Andy Yan’s TrebleDroid-based LineageOS 20 GSI. For a standard Google services experience, the bgN variant (includes GApps, no built-in root) is recommended.

2. Custom Disabled VBMeta Image

To disable Android Verified Boot (AVB/dm-verity), we generate a custom vbmeta_disabled.img file.

  1. Download the official AOSP avbtool.py script:
  2. Generate the image using Python 3: 
    python3 avbtool.py make_vbmeta_image --flags 2 --padding_size 4096 --output vbmeta_disabled.img

    This will output a 4096-byte vbmeta_disabled.img file in your working directory.

🔄 Step-by-Step Flashing Procedure

Step 1: Enable USB Debugging on the Phone

  1. On the phone, navigate to Settings > About phone.
  2. Scroll to the bottom and tap Build number 7 times until you see the toast message: “You are now a developer!”.
  3. Go back to Settings > System > Developer options.
  4. Enable USB debugging.
  5. Connect the phone to the computer via a USB cable.
  6. When prompted on the phone screen with “Allow USB debugging?”, check “Always allow from this computer” and tap Allow.

🔍 Troubleshooting USB Debugging:

  • Conflict with Google Chrome: If ADB fails with an endpoint error (ADB interface missing endpoints), Google Chrome may have claimed the USB interface via WebUSB. Quit Chrome completely and replug the USB cable to resolve.
  • USB Mode: If ADB still does not detect the device, swipe down on the phone screen, tap the USB charging notification, and change the USB mode from No Data Transfer to PTP (Picture Transfer Protocol) or MTP.

Step 2: Enable “OEM Unlocking” (Device Action Required)

Android security blocks bootloader unlocking unless explicitly permitted in Developer Options.

  1. Go to Settings > System > Developer options.
  2. Find the OEM unlocking toggle and turn it ON.
  3. Enter your PIN/pattern and tap Enable to confirm.

🔍 Troubleshooting Missing / Greyed-out OEM Unlocking:

On many MediaTek devices (including Ulefone), the OEM Unlocking toggle is hidden by default until a check-in with Google’s servers is successful.

  • Wi-Fi Connection: Connect the device to a working Wi-Fi network.
  • Force Server Check-in: Open the Phone/Dialer app and enter: *#*#2432546#*#* (spells *#*#CHECKIN#*#*) A notification saying “check-in succeeded” should appear. Restart the phone, and the toggle will be accessible.
  • Account Sync: Ensure you are signed in to a primary Google account on the device.

Step 3: Reboot to Bootloader & Unlock Bootloader

  1. Open your terminal in the platform-tools folder.
  2. Run the command to reboot the device: 
    ./adb reboot bootloader
  3. The phone screen will shut down and boot into a black screen with tiny white text showing “=> FASTBOOT mode” or show a boot menu.
  4. Verify the device is detected: 
    ./fastboot devices

🔍 Troubleshooting Apple Silicon (M1/M2/M3) Fastboot Connection:

  • Issue: On Apple Silicon Macs, fastboot devices will often return empty due to a handshake bug with the MediaTek fastboot interface over direct USB-C.
  • Workaround: Plug the USB cable into an external USB-A hub or adapter instead of connecting it directly to the Mac’s built-in Thunderbolt/USB-C ports. Replug the USB cable to force renegotiation.
  1. Initiate the bootloader unlock: 
    ./fastboot flashing unlock
  2. IMMEDIATE ACTION REQUIRED ON DEVICE: Watch the phone screen. A warning page will appear asking you to confirm the bootloader unlock. Press the Volume Up key immediately (within 15 seconds) to select Yes/Confirm.
  3. Confirm that the bootloader status says unlocked: yes by running: 
    ./fastboot getvar unlocked

Step 4: Flash VBMeta to Disable Verification

To prevent bootloops caused by system partition modifications, you must flash the generated disabled vbmeta image. We flash all three AVB metadata partitions (vbmeta, vbmeta_system, and vbmeta_vendor) to ensure no checks bypass:

./fastboot flash vbmeta vbmeta_disabled.img
./fastboot flash vbmeta_system vbmeta_disabled.img
./fastboot flash vbmeta_vendor vbmeta_disabled.img

Note: Do not use the --disable-verity or --disable-verification flags in fastboot when flashing vbmeta_disabled.img, as these flags expect a signed factory partition image to patch, whereas we are flashing a pre-generated disabled structure.

Step 5: Boot into Fastbootd (User-space Fastboot)

The Ulefone Note 11P uses dynamic logical partitions inside the super partition container. You cannot flash the system partition in standard bootloader mode; you must boot into the Recovery-based fastbootd interface.

  1. Run the command: 
    ./fastboot reboot fastboot
  2. The phone will reboot, and the screen will show “FASTBOOTD” (with options for Reboot system, Enter recovery, etc.).
  3. USB Replug Workaround (Apple Silicon): Since the device rebooted into a new USB state, Apple Silicon Macs may lose connection. Unplug and replug the USB cable from the phone.
  4. Verify that the device is back online: 
    ./fastboot devices
  5. Confirm that the mode is userspace: 
    ./fastboot getvar is-userspace

    (It must return is-userspace: yes)

Step 6: Flash the GSI System Image

  1. Start the flashing command, pointing to the uncompressed .img file: 
    ./fastboot flash system lineage-20.0-20251021-UNOFFICIAL-arm64_bgN-signed.img
  2. The fastboot utility will automatically resize the logical system_a partition and upload the system image in sparse chunks (typically 11 chunks of ~262 MB).
  3. Wait for the command to finish with Finished. Total time: XXs and return OKAY.

Step 7: Wipe User Data (Factory Reset)

To prevent bootlooping due to old Android 11 database structures conflicting with Android 13, you must wipe all user data:

./fastboot -w

This command will erase the userdata and metadata partitions. (If fastboot warns Formatting is not supported for file system with type 'raw', this is normal. The android recovery system will automatically format these partitions on first boot).

Step 8: Boot into LineageOS 20

Reboot the device to boot into the new OS:

./fastboot reboot

⚡ First Boot Expectations

  • Unlocked Bootloader Warning: You will see a warning message on boot screen stating: “The bootloader is unlocked…“. This is normal; it will auto-dismiss after 5 seconds.
  • First Boot Duration: The initial boot can take between 2 to 5 minutes while the phone formats the user space partitions and compiles core files.
  • Welcome Screen: Once booted, you will be greeted by the LineageOS Welcome Setup Wizard where you can configure language, Wi-Fi, and Google services.

📶 Network Troubleshooting (No Internet / Wi-Fi & Cellular)

If the device boots successfully but is unable to connect to the internet via Wi-Fi or cellular data (or says “Connected, no internet”), follow these steps:

1. Disable Restricted Networking Mode

On some GSI builds, a security policy blocks user applications from accessing network interfaces.

  1. Connect the phone to the computer via USB and ensure USB debugging is authorized.
  2. Verify the restricted networking mode state: 
    ./adb shell settings get global restricted_networking_mode
  3. If it returns 1, disable it by running: 
    ./adb shell settings put global restricted_networking_mode 0
  4. Reboot the phone: 
    ./adb reboot

2. MediaTek / Phh Treble Settings Workarounds

Generic System Images (GSIs) require specific hardware overrides to communicate properly with MediaTek devices.

  1. On the phone, navigate to Settings > Phh Treble Settings (or open the Phh Treble App).
  2. Go to Misc features or Tethering configuration.
  3. If mobile hotspot/tethering fails to share internet connection, enable “Remove eBPF for tethering” (which sets persist.sys.phh.tethering.nobpf to 1) and reboot the device.