It was recently revealed that the Sony Xperia SP would not be receiving the official Android 4.4 KitKat update from Sony, which expectedly left many owners rather confused and disappointed. Because after all, its specs shows that the Xperia SP is more than capable of running the update, and the fact that it was released last year doesn’t really help explain things. However, not everything is terrible for Xperia SP users at this time, as they have something else to play with on their devices, being Firefox OS.
Ported by XDA Forum Member boylush, the Firefox OS build for the Xperia SP is based on CM 10.2 and is relatively stable for the time being. Main functions such as 3G data, messaging, calls and WiFi are all working properly, while the known bugs include:
Headphones do not work
MTP does not work
To install this port, all you need to do is download the provided ZIP package, extract and flash the boot.img, boot into recovery, flash the ZIP package, and reboot.
If you would like to see what Firefox OS feels like running on your Xperia SP, check out the Firefox OS port thread for more information.