Sony is one of the best OEMs when it comes to providing support for community developments and giving users the tools to truly own their devices. The Open Device program provides useful resources and guides for developers interested in developing AOSP builds and custom software for the Xperia series devices. As you may already know, in order to install a custom software or making any system level changes to the original software, the device's bootloader must be unlocked.

That said, Sony's Open Device project has posted an updated method on how to unlock the bootloader of an Xperia device. In order to unlock the bootloader of your Xperia device, you'll need to generate a unique code that you'll be required to enter at the time of the unlocking process. The process of requesting the unique code is very simple; just head over to the official page here and choose your Xperia device from the supported device list and click continue.

Next, you'll be asked to provide a valid email address; simply enter your email address, accept terms and conditions, and hit the submit button to receive a confirmation link. Follow the link in the email, it will take you to the page where you'll need to enter your IMEI code to generate a unique code. After submitting the IMEI code you'll receive your unique code via an email.

After receiving the code, the rest of the process is pretty straight forward given that you've some previous experience unlocking the bootloader. You will need to download the Android SDK on your PC in case you don't have it installed already; alternatively, you can also choose to download only the ADB/fastboot binaries, as downloading an entire SDK can be a tedious task.

Now connect your Xperia device to your PC in fastboot mode and open up the command prompt window. Navigate to the platform-tools folder and enter fastboot devices -- if it lists your device ID in rerun, you are good to proceed further. Now simply copy and paste the command with the unlock code you received from Sony earlier into the command window and hit enter. That's it, your device should now have an unlocked bootloader!

For step-by-step instructions on unlocking the bootloader, you can also check out the official video below.

[button link= http://developer.sonymobile.com/2017/02/10/updated-video-how-to-unlock-the-boot-loader-of-an-xperia-device/ icon="Select a Icon" side="left" target="" color="f85050" textcolor="ffffff"]Source: Sony Developer Blog[/button]