Jelly Bean available for custom ROM developers [alpha ROM]

A while ago, the Sony Xperia™ News room shared an update on our plans to upgrade certain Xperia™ devices to Jelly Bean. Since then we have received quite a few requests from the Android™ developer community to release an earlier version of the Jelly Bean (JB) software for the developers. This way, advanced developers could try it out and evaluate it, in a similar way to how we did it last year with the ICS alpha release. Please note that there are several limitations to this alpha software, for instance the UI look and feel is not updated to final Sony Jelly Bean software. Read more after the jump!
We’re now making an early alpha ROM of Jelly Bean (Android 4.1) available for Xperia™ T, along with the open source archive, as a way for us to get valuable feedback from the custom ROM community (although we are not far away from the official release of JB for Xperia™ T).  Thanks to the great dialogue we have with open community developers, we see this as a great way for us to get input, and for the open developer community to get to try this alpha out hands-on.
As mentioned above, this JB alpha ROM is strictly targeting advanced developers, and it will not work for ordinary everyday usage, as it only has a limited set of features working (for example, you cannot make any phone calls). Several more legal and usage conditions apply – please see the Important information section below for more details.
Important information
Since this is not the final software upgrade roll out, there are a few requirements to pay close attention to before you flash the ROM:
You should be an advanced developer with extensive knowledge in how to flash and switch between different ROMs. If you are a consumer without these developer skills, then we strongly recommend you not do try this as you may damage your phone.
You must be using an unlocked Xperia™ T. It will not work on a locked Xperia™ T.
You must unlock your phone using Sony’s Unlock boot loader service, and agree to all the legal and warranty conditions that apply. Please note that you may void the warranty of your phone and/or any warranty from your operator if you unlock the boot loader of your phone. Sony can then no longer guarantee the full functionality of your phone, and will not be responsible for any unusable functions or loss of personal data associated to the alpha ROM being flashed to the phone.
Also, if you unlock the boot loader, you will not be able to get the final Jelly Bean upgrade from Sony. For additional information about limitations and warranty restrictions, please see Sony’s Unlock boot loader service.
You should have read through and acknowledged the limitations of the software described below.
Limitations and functionality
Only a limited number of features and functionalities are working and turned on in this alpha ROM. The reason for some features being disabled is because we have not yet passed all approvals yet. To get more information on how this work is carried out, check out our previous article about the bring up phase.
These are some of the features that are turned off or not yet working in this alpha ROM:
Google Mobile Services (GMS) apps are not included (for example, Gmail and Google Maps).
Modem is turned off and therefore the SIM card will not be recognised (this also means you can’t make any phone calls).
Bluetooth™ is turned off.
Wi-Fi® is turned off.
FM-radio is turned off.
NFC is turned off.
UI look and feel is not updated to final Sony Jelly Bean software.
In other words, this software is not intended for ordinary everyday usage – it’s for advanced developer use only. This alpha ROM includes a number of Jelly Bean features that we know will be appreciated by developers and we are thankful for the potential feedback we may get on this.
How to flash the Jelly Bean alpha ROM
To flash the alpha ROM on your unlocked Xperia™ T, use our flash tool for unlocked Xperia devices.  Check out the flash tool page for more information on how to download, install and use this tool.
The Jelly Bean alpha ROM will be a clean flash, so make sure you do a proper back up of everything on your phone before you flash it. Please note that there is another software version available for Xperia™ T smartphones in the Sony flash tool for unlocked devices, as it is possible to flash Xperia™ T with an official Ice Cream Sandwich software versions well.
Developers, please let us know what you think!
One of our ambitions with this release is to get feedback from the talented developers in the open community. So if you flash this Jelly Bean alpha ROM and download the open source archive, please go to this XDA-thread and provide us with feedback once you have tried the software. It’s very much appreciated – we will use the feedback for future product and software strategies, both short term and long term. Your voice counts!