I think the unerlying issue is that Yosemite will not load kext (kernel extensions) unless they are signed by an authorized kernel extension developer. However in 10.8 and earlier, kexts could not be signed and signed kexts for 10.9+ will not load in <10.9.
You can override this behavior and allow the cpfw.kext to load in Yosemite by putting your computer into kext developer mode. This essentially reverts to the 10.9 behavior by allowing unsigned kexts to load.
sudo nvram boot-args="kext-dev-mode=1"
Now reboot and your kext should load.
You can revert by doing this:
sudo nvram -d boot-args