Loadable Module Entry Points
All drivers are required to implement the loadable
module entry points _init(9E), _fini(9E), and _info(9E) to load, unload, and report
information about the driver module.
Drivers should allocate and initialize any global resources in _init(9E). Drivers should release their
resources in _fini(9E).
In the Solaris OS, only the loadable module routines must be visible
outside the driver object module. Other routines can have the storage class static.