A key factor that hindered the development of custom ROMs for owners of the Xperia go, Xperia P, Xperia sola and Xperia U was the lack of source code from the ST-Ericsson NovaThor U8500 chipset that powered each phone.
Well it appears that the complete source code for this chipset has leaked, giving hope to these Xperia owners of better custom ROMs and the potential of a dedicated partition for recovery. The leak includes the source for the kernel and all related hardware too.
One issue that appears to be under question is the legality of the sources and where they originated from. That point remains unresolved right now, so whilst some recognised developers such as Munjeni from XDA are testing these sources privately, there are no plans to release anything publicly until the legality is confirmed. If you want to find further information including download links then click the link below.