Install LineageOS on z3c

Special Requirements

Warning: Before following these instructions please ensure that the device is on firmware version 23.5.A.1.291. To discern this, you can run the command adb shell getprop ro.build.display.id on the stock ROM after following the steps under the Basic Requirements header below. If the device is not on the specified version, please follow the instructions below to install it.

Note: Flashtool version 0.9.19.9 or later is required.

Download and install Flashtool on your machine
- If you’re are a Windows user of any version, open a file explorer and navigate to C:\Flashtool\drivers folder, then install the drivers found within
- Additionally, if you are a Windows 8.1 (x64) user you will need a patch found here
Reboot your machine
On the device, navigate to the Settings app, in the System menu, under the About this device listing, and take note of your model number & carrier
Open Flashtool
Click the symbol to download and open XperiFirm (round button on the right) to download the latest firmware for your device
In XPeriFirm, select your device and an appropriate firmware on the middle column with the version 23.5.A.1.291. Then click on the firmware on the right side below Available Firmware and download it
After the download finished, close XperiFirm. Flashtool now automatically recognizes the downloaded files and prepares the image to be flashed
Now click on the lightning symbol (flash device), select Flashmode and click on OK
Select the firmware file you just downloaded above
Check all the boxes under the “Wipe” menu
Click “Flash”
Tip: It may take a few minutes for the flashing progress indicator to pop up.
Turn off your phone
Hold the volume-down button and keep holding while connecting the device to your PC
Once the flashing process has started, release the volume rocker as soon as possible
Warning: Ensure the USB cable doesn’t come unplugged during the flashing process!
When the flash finishes, boot up the device and once booted, please proceed with the instructions

Basic requirements

Important: Please read through the instructions at least once before actually following them, so as to avoid any problems due to any missed steps!

Make sure your computer has 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. Please note that OEM backup solutions like Samsung and Motorola backup may not be accessible from LineageOS once installed. 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 off, 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 generate an unlock code for your bootloader.
Use your code to unlock the bootloader of your device:
```
fastboot oem unlock <your_unlock_code>
```
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 Lineage Recovery. Simply download the latest recovery file, named something like lineage-17.1-20200912-recovery-z3c.img.
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 off, 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 <recovery_filename>.img
```
Tip: The file may not be named identically to what stands in this command, so adjust accordingly.

Tip: Some devices have buggy USB support while in bootloader mode, if you see fastboot hanging with no output when using commands such as fastboot getvar .. , fastboot boot ..., fastboot flash ... you may want to try a different USB port (preferably a USB Type-A 2.0 one) or a USB hub.
Now reboot into recovery to verify the installation:
- With the device powered off, hold Volume Down + Power. Keep holding both buttons until the device vibrates, then release.

Installing LineageOS from recovery

Download the LineageOS installation package that you would like to install or build the package yourself.
- Optionally, download additional application packages such as Google Apps (use the arm architecture).
If you are not in recovery, reboot into recovery:
- With the device powered off, hold Volume Down + Power. Keep holding both buttons until the device vibrates, then release.
Now tap Factory Reset, then Format data / factory reset and continue with the formatting process. This will remove encryption and delete all files stored in the internal storage, as well as format your cache partition (if you have one).
Return to the main menu.
Sideload the LineageOS .zip package:
- On the device, select “Apply Update”, then “Apply from ADB” to begin sideload.
- On the host machine, sideload the package using: adb sideload filename.zip
(Optionally): If you want to install any additional add-ons, repeat the sideload steps above for those packages in sequence.

Note: Additional add-ons aren’t signed with LineageOS’s official key, and therefore when they are sideloaded, Lineage Recovery will present a screen that says Signature verification failed, this is expected, please click Continue.

Note: If you want Google Apps on your device, you must follow this step before booting into LineageOS for the first time!
Once you have installed everything successfully, click the back arrow in the top left of the screen, then “Reboot system now”.

Warning: Depending on which recovery you use, you may be prompted to install additional apps and services. We strongly advise you to opt out of installing these, as they may cause your device to bootloop, as well as attempt to access or corrupt your data.

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.