If I would like to port sfdroid to Oneplus X (CM12.1 based) would I need to compile e.g. the libhardware stuff (sfdroid_sensors.default.so and sharebuffer.default.so) in a clean CM12.1 android build env or can I also use the mer-hybris build env which I already have for the Oneplus X?

If I need a clean CM12.1 build env is it possible and sufficient to just build the needed pieces (single modules) or do I need to first build the whole source tree including the kernel for the Oneplus X?
The problem might be that I don't have a complete CM12.1 build env for Oneplus X as there is no official support for it from Cyanogenmod. The CM12.1 build for Oneplus X is a community port and based on top of that SFOS is running...