OS X and iOS Kernel Programming

Modifying Driver Properties

Once an application has located the driver object that it is interested in, it can interact with the driver and the hardware device that it controls. The I/O Kit framework provides two ways to interact with a driver from user space. One method requires the application to open a connection to the driver and then to use that connection to send control requests to the driver and receive status. A connection-based approach is necessary if the driver needs to maintain the state of a client or needs access control to ensure that only one client at a time can access the hardware device. This is discussed later in this chapter.

Another method, which is far simpler, is to allow an application to read and write key/value property ...