Warning to be added for users on untested upgrade builds

cpu_cores: '8'

cpu_freq: 4 x 2.45 GHz + 4 x 1.9 GHz

current_branch: 16.0

custom_recovery_link: https://www.androidfilehost.com/?fid=6006931924117938176

custom_recovery_link:

custom_unlock_cmd: 'fastboot flashing unlock_critical'

depth: 7.8 mm (0.31 in)

download_boot: With the device powered off, hold <kbd>Volume Down</kbd> + <kbd>Power</kbd>.

  > In Linux prepend sudo to any adb or fastboot command For e.g. “sudo fastboot reboot” and

    in Windows start the command window as administrator.

{% if device.untested_build %}

### Warning:

  > - Please note this upgrade build for the {{ device.codename }} could not be tested as there were no device specific testers available.

  > - Some devices may need a revert to stock ROM prior to upgrade.

  > - To flash the stock ROM you would need to use a tool provided by your vendor

  > - You may also need to download TWRP built specifically for your device.

{% endif %}

### Download

* Download Upgrade Build for the {{ device.codename }} here

## Notes

Some useful additional information can be found at:

1. https://forum.xda-developers.com/essential-phone/development/rom-lineageos-14-1-essential-ph-1-mata-t3703759

1. https://forum.xda-developers.com/essential-phone/development/stock-7-1-1-nmj20d-t3701681

1. https://mata.readthedocs.io/en/latest/

{% assign device = site.data.devices[page.device] %}

## Unlocking the bootloader

1. Unlock bootloader

    ```shell

    fastboot flashing unlock

    ```

1. Unlock critical partition

{% include alerts/warning_unlocking_bootloader.md %}

    ```shell

    fastboot flashing unlock_critical

    ```

## Flashing firmwares

1. Connect your device to your PC via USB.

1. Download the [NMJ88C archive](https://mega.nz/#!1CgF3SLa!CHLLA0HvtDtzzDnOl3CbJ1EUnhR6vFb4NA9IG6au3to) and unzip it

1. Reboot in bootloader mode

1. Enable OEM unlock in the Developer options under device Settings, if present.

    ```shell

1. On the computer, open a command prompt (on Windows) or terminal (on Linux or macOS) window, and type:

    ```

    adb reboot bootloader

    ```

1. execute the script:

    On Linux or MacOS X:

    ```shell

    ./flash-all.sh

1. Once the device is in fastboot mode, verify your PC finds it by typing:

    ```

    fastboot devices

    ```

    On Windows:

1. Unlock bootloader

    ```shell

    ./flash-all.bat

    fastboot flashing unlock

    ```

(it takes a while to complete)

## Installing a custom recovery: TWRP for Mata

1. Download [TWRP for Mata](https://androidfilehost.com/?fid=818070582850502775)

1. Connect your device to your PC via USB.

1. Flash TWRP to the boot partition:

1. Unlock critical partition

    ```shell

    fastboot -w

    fastboot flash boot twrp-mata_11.img

    fastboot flashing unlock_critical

    ```

1. Stay in bootloader mode, and use the volume down to select "Recovery mode". Then  hit the power button: this should boot you in to recovery mode (TWRP). If it's asking for a password, enter your previous lockscreen password or pin, this will decrypt your data partition. Note: don't be surprised that TWRP will be erased at next boot. Therefore, you will have to reinstall it if you want to install another ROM on your device.

{% include templates/recovery_install_fastboot_ab.md %}