Install LineageOS on sumire

Basic requirements

Important: Please read through the instructions at least once completely before actually following them to avoid any problems because you missed something!

Make sure your computer has working adb and fastboot. Setup instructions can be found here.
Enable USB debugging on your device.

Unlocking the bootloader

Note: The steps below only need to be run once per device.

Warning: Unlocking the bootloader will erase all data on your device! This also includes your DRM keys, which are stored in the Trim Area partition (also called TA). Before proceeding, ensure the data you would like to retain is backed up to your PC and/or your Google account, or equivalent. If you wish to backup the TA partition first, you can find tutorials related to your device on the internet.

On the device, dial *#*#7378423#*#* (*#*#SERVICE#*#*) to launch the service menu.
Go to service info > configuration and check rooting status - you can only continue if it says Bootloader unlock allowed: Yes.
Connect the device to your PC via USB.
On the computer, open a command prompt (on Windows) or terminal (on Linux or macOS) window, and type:
```
adb reboot bootloader
```
You can also boot into fastboot mode via a key combination:
- With the device powered down, hold Volume Up and connect the USB cable. The notification light should turn blue.
Once the device is in fastboot mode, verify your PC finds it by typing:
```
fastboot devices
```
Tip: If you see no permissions fastboot while on Linux or macOS, try running fastboot as root.
Follow the instructions on Sony’s official unlocking website to unlock your bootloader.
Since the device resets completely, you will need to re-enable USB debugging to continue.

Installing a custom recovery using `fastboot`

Download a custom recovery - you can download TWRP.
Connect your device to your PC via USB.
On the computer, open a command prompt (on Windows) or terminal (on Linux or macOS) window, and type:
```
adb reboot bootloader
```
You can also boot into fastboot mode via a key combination:
- With the device powered down, hold Volume Up and connect the USB cable. The notification light should turn blue.
Once the device is in fastboot mode, verify your PC finds it by typing:
```
fastboot devices
```
Tip: If you see no permissions fastboot while on Linux or macOS, try running fastboot as root.
Flash recovery onto your device:
```
fastboot flash recovery twrp-x.x.x-x-sumire.img
```
Tip: The file may not be named identically to what stands in this command, so adjust accordingly.
Now reboot into recovery to verify the installation:
- With the device powered down, hold the Volume Down and Power buttons.

Installing LineageOS from recovery

Download the LineageOS install package that you’d like to install or build the package yourself.
- Optionally, download 3rd party application packages such as Google Apps (use the arm64 architecture)
If you aren’t already in recovery, reboot into recovery:
- With the device powered down, hold the Volume Down and Power buttons.
(Optional, but recommended): Select the Backup button to create a backup. Make sure to create the backup in the external sdcard or copy it into your computer, since the internal storage will be formatted.
Select Wipe, then Format Data and continue with the formatting process. This will remove encryption and also delete all files stored in the internal storage.
Select Wipe and then Advanced Wipe.
Select Cache and System partitions to be wiped and then Swipe to Wipe.
Place the LineageOS .zip package, as well as any other .zip packages on the root of /sdcard:
- Using adb: adb push filename.zip /sdcard/
- You can use any method you are comfortable with. adb is universal across all devices, and works both in Android and recovery mode, providing USB debugging is enabled.
Go back to return to main menu, then select Install.
Navigate to /sdcard, and select the LineageOS .zip package.
Follow the on-screen prompts to install the package.
(Optional): Install any additional packages using the same method.

Note: If you want any Google Apps on your device, you must follow this step before the first boot into Android!
(Optional): Root the device by installing the LineageOS su add-on (use the arm64 package) or using any other method you prefer.
Once installation has finished, return to the main menu, select Reboot, and then System.

Get assistance

If you have any questions or get stuck on any of the steps, feel free to ask on our subreddit or in #LineageOS on freenode.