The whizz kids over at xda-developers are at it again. They have managed to port the stock Android 4.1.2 Jelly Bean firmware to the Xperia U (ST25). XDA member munjeni managed to create a customised kernel for the handset, whilst lee480 has put the ROM together. It only works for Xperia U handsets with unlocked bootloaders. The ROM can be installed by recovery along with the kernel.
However, the ROM is not intended for daily use at this stage with a number of bugs including a non-working camera and LED bar, rotational problems, buggy capacitive buttons and severe battery drain. However, it’s early days yet and as Sony has not earmarked the Xperia U to receive an official Jelly Bean update, let’s hope it’s not too long before we see a stable JB port.