If you are a Sony Xperia user eagerly awaiting the latest OTA updates, you must remember that in order to receive the update, your phone must be running stock firmware. By unlocking the bootloader, your phone won’t be able to directly install the OTA, and will lose features such as Sony Bravia Engine. Furthermore, you may also face difficulties with your warranty. You can avoid these issues with the Backup TA for Sony Xperia tool by XDA Senior Member DevShaft. The only disadvantage is that it works only on Windows, so users must use a Windows machine or virtualization software like VirtualBox to back up and restore their keys.
Now, thanks to XDA Forum Member limiter121, Mac OS X users can use Backup TA on their machines. The developer has re-written the script, which is now compatible with Apple’s latest OS builds. And in the future, Mac OS X might be included in the official release. This tool should work with all Xperias with TA partitions, and the developer was kind enough to write a FAQ, which can be found on Bitbucket alongside source code of the tool.
More information can be found in the original thread._________