The development process to make a new device compatible with the operating system consists of creating a phone-specific package using the pmbootstrap tool. For that, the use of the Linux kernel from the device's original manufacturer is often necessary. The source code of the original kernel is often made available by compliance with the requirements of the GPLv2 license, but some drivers necessary for the operation of the device may not be available, and must, therefore, be recreated.[26][2]