Install / Pixel 3a XL

Terminology

• Factory Image: This is a zip file that contains the entire CalyxOS operating system to be installed on your device.
• Flashing: On Android devices, installing a new operating system is called “flashing,” because it writes a new factory image to the device’s flash memory.
• Android Device: The device that you are installing CalyxOS on to.
• Host Computer: The Windows computer used to send commands to the Android Device. You will connect this computer to the Android device and run device-flasher to install CalyxOS.
• Fastboot: A mode of the Android device needed to install a custom Operating System. At various stages, you will be asked to put your Android device in Fastboot mode.

Prepare your Android device

There are a few things you must do to prepare your device to accept a new operating system:

Remove SIM card

On brand new devices, especially those obtained from a carrier, it’s better to remove the SIM card from the device before starting it for the first time, to help with the “OEM Unlocking” step below.

Enable Developer Options

Settings → About Phone → tap Build number 7 times

Enable USB debugging

Settings → System → Advanced → Developer Options → USB Debugging

Enable OEM Unlocking

Settings → System → Advanced → Developer Options → OEM unlocking

This step might fail if there is no internet connection. In that case, connect to a WiFi network and then try again.

Prepare your host computer

Install USB drivers for Windows

Windows requires specific USB drivers in order for device-flasher to work.

Download Google USB Driver

Open that page, click Click here to download Google USB Driver ZIP file, then accept the terms and conditions. Save the ZIP file to your host computer.

1. Put your Android device in Fastboot mode.
2. Connect your Android device to your computer’s USB port.
3. On the Windows computer, extract the downloaded Google USB Driver ZIP file.
4. Right-click on the Android_winusb.inf file and hit install. Note: Install may show under “Show more options”.

For more information, see Android developer site.

Download device-flasher

Download device-flasher.exe

Save this executable to a new directory, where you will also later save the CalyxOS image.

Verify Digest

This is an optional step, useful for ensuring you have the correct device-flasher executable. Open a terminal on your host computer, change to the directory where you saved device-flasher, and then run:

CertUtil -hashfile device-flasher.exe SHA256

And ensure the result says 0e97823c27e9ed8d98cdab61e09fbaf9ae6d102913fa75df16ed1b7010100127. This is the unique digest of the device-flasher. If it doesn’t match, then you have a corrupted or incorrect file.

Download factory image

Download CalyxOS Image

Save this image in the same directory as device-flasher. This image will only work for Pixel 3a XL (bonito). Any attempt to install this image on a different device model may brick (destroy) the Android device.

Do not extract or rename the zip, simply copy it as-is.

Once downloaded, the next step is to verify the image. This step is optional, but verification helps ensure that you downloaded the image correctly, and that you got the correct image.

Verify Digest

To verify the image, open a terminal window on the host computer where you saved the image and run the command:

CertUtil -hashfile bonito-factory-24512012.zip SHA256

And ensure the result says 04e7a76073b98b35c3ef345f95b8d5d81a394c9fd1e6a3de1df779b9daaad84f. This is the unique digest of the image file. If it doesn’t match, then you have a corrupted or incorrect file.

Verify Signature

For the highest level of confidence, you can optionally download the signature file and then verify image signature.

Install CalyxOS

Run device-flasher

Now you are ready to install. Ensure that both the CalyxOS image and device-flasher are in the same directory.

Step 1. Connect the USB cable between the computer and the Android device.

Step 2. Run device-flasher

Double-click device-flasher to run it.

Your anti-virus may falsely flag device-flasher as infected. This is because the program is written in the Go programming language, see the Go FAQ for more information.

Unlock the bootloader

At some point in the installation process, it will ask you to unlock the bootloader.

NOTE: if the bootloader is already unlocked, you will not see the unlock bootloader menu and installation will proceed automatically without you needing to touch anything.

The bootloader unlock menu looks like this:

Press a volume key to select UNLOCK THE BOOTLOADER option. Then press the power key to activate that option.

Success?

Once device-flasher is finished, you should now have a fully functional CalyxOS device. If not, please see our Community page for where you can post your questions.

Troubleshooting

Error running device-flasher

If you get a mysterious error when running device-flasher, or if device-flasher hangs, it may be a USB problem. Try connecting to a different USB port on your computer (yes, not all USB ports are created equal) or a different USB cable.

How do I tell if the bootloader is locked?

In Fastboot “Device State: locked” means the bootloader is locked.

On the initial boot screen, you may also see this if the bootloader is unlocked:

The bootloader is unlocked and software integrity cannot be guaranteed. Any data stored on the device may be available to attackers. Do not store sensitive data on the device.

Back to Stock

If you would like to return to the default operating system, please see Back to Stock Android.

Security Notes