Nokia X2 Open Source Release CD that I just received from Microsoft Mobile can be downloaded from:
URL NOT HERE DUE TO XDA ANTI-SPAM RIGIDITY! See the link in my profile's Github section, go to Releases and download rm-1013_188.8.131.52.tar (only file there)
Sorry about the tar-blob format, kernel source for X2 is there but I'm terribly busy today so no neat kernel source repo merged top of correct CAF tag at the moment.
Use msm8610_defconfig or msm8610-sales_defconfig for building debug (eng) or final (user) SW.
On behalf of Microsoft's Nokia-X Linux kernel devs, have fun modding this!