Xperia:Unlocking the Bootloader

The bootloader is a partition on the phone with a variety of tasks. Generally, you can think of it as being similar to a computer BIOS, with added security features that do things like checking to make sure the OS software is the right software for that model of phone, and that you're locked to the intended carrier. Stuff that will likely cause problems for you if you want to install custom ROMs and such! If you can unlock the bootloader, do so.

If you have an R800at, you CAN NOT unlock the bootloader. See the Testpoint Method section for a possible exception to this.

Check Unlock Status

First, check if your phone already has its bootloader unlocked.

1. Turn off the phone and connect a USB cable to the computer.
2. Hold down the search (magnifying lens) button on the phone and connect the USB cable to it. The light on the power button should be blue.
3. If you haven't already installed the fastboot drivers, Windows may prompt you to do so. Follow the instructions on the FlashTool page for that process.
4. Open a command prompt and enter fastboot devices to make sure your device appears.
5. Enter fastboot getvar secure. If secure is "no", then your bootloader is already unlocked and you can skip the rest of this section.

• Note: You may need to use an older version of package-tools (ADB) for this, and you may need to enter the command as fastboot -i 0x0fce getvar secure.

Check Unlock Ability

Check that your phone is able to have its bootloader unlocked.

1. Open the phone dialer app.
2. Enter *#*#7378423#*#* and a service menu should appear.
3. Go to Service Info > Configuration and look for Rooting Status. If you don't see it, or it says not allowed, you can't unlock your bootloader. However, there are reports of some phones that were missing Rooting Status and they were still able to unlock the bootloader, so it's worth a try.

Unlocking Instructions

This will factory reset your phone.

1. Open the phone dialer app.
2. Enter *#06# and the IMEI or MEID number will appear. Write down this number.
3. Turn off the phone and connect a USB cable to the computer.
4. Hold down the search (magnifying lens) button on the phone and connect the USB cable to it. The light on the power button should be blue.
5. If you haven't already installed the fastboot drivers, Windows may prompt you to do so. Follow the instructions on the FlashTool page for that process.
6. Open a web browser and go to Sony Ericsson's bootloader unlocking site:
   • https://developer.sony.com/develop/open-devices/get-started/unlock-bootloader/
   • Note: Their older site is still up, and you can try that if the newer site doesn't work for you.
     http://developer.sonymobile.com/unlockbootloader/
7. Follow the instructions, entering your IMEI or MEID, and you should receive an unlock code. Copy this code down.
8. Go back to the command prompt and enter this command, replacing the * with your unlock code:
   • fastboot oem unlock 0x*
   • Note: You may need to use an older version of package-tools (ADB) for this, and you may need to enter the command as fastboot -i 0x0fce oem unlock 0x.

Your phone should now have an unlocked bootloader!

Testpoint Method

Sony phones (and likely other models from other manufacturers) often have exposed connection points on the circuit board, accessible by removing the backplate (and sometimes the battery). One of these points is considered the "test point", which can be used to access low level functions in the phone. Typically this is used by the manufacturer or a repair center to unlock, unbrick, restore fastboot, etc. Supposedly, with a software package called SETool, the bootloader can be unlocked by accessing this testpoint. If anyone has a working copy of this tool that they're willing to share, and can demonstrate how to use it, please make a post in the /r/XperiaPlay subreddit and notify /u/Antnommer.