Tracing built-in drivers ?

Hi, I know I can use ftrace or perf to do tracing on modules that I can load from the userspace. But what if I want to do tracing on a driver which is built in ? For example, i915. There wouldnt be any userspace to trigger a trace when it does an init. Even if I recompile i915 as a module, I am not able to unload it. Are there any specific tools or techniques for doing this ? -- Thanks and Regards, Aurabindo J