Sony has made great strides in completely reversing their stance towards the independent developer community recently, including being the only manufacturer to officially release beta builds of ICS for their phones. Now they have released the source for the Xperia S along with instructions on how to build the kernel. They’ve even included a proprietary file from Qualcomm, Resource Power Manager, and an image-generation script. The source is located out on their Opensource Archive, and you can see their blog post here.
XDA Recognized Developer DoomLoRD has started a nice thread over in the Sony Xperia S Android Development section to facilitate discussion around building the kernel source from Sony. Follow the thread link, and make sure to thank DoomLoRD for all he has done for the Sony Xperia line of devices._________