Chameleon Flag Must Used For Osx Yosemite
In OS X 10.10 (Yosemite), Apple has introduced a new security requirement called kext signing. (Kext is a kernel extension, or a driver on Mac OS X)The signing of the kext basically works by checking if all drivers in the system are not changed by a third party, or approved by Apple. If they have been modified, Yosemite will no longer load the drivers. This is a means to enforce security, but also a way for Apple to control what hardware that third party developers can release an OS X support for.
kext-dev-mode=1If you do not understand how the bootflag additions, you could use the help of Chameleon Wizard apps.
or you can also use the commandline via the terminal with the file leads to org.chameleon.boot.plist which is located in the /Extra folder.