Well, since it's a Solaris driver, first you need to find up some docs on how Solaris drivers communicate with the kernel (or kernel with them). A quick search turned up this:
_init() initializes a loadable module. It is called before any other routine in a loadable module. _init() returns the value returned by
mod_install(9F) . The module may ...
CrackZ still has one of the best references on FLEXlm.
That stuff went thru a couple of iterations. The documents there are mostly Windows stuff but they are helpful to understand the whole system.
Good luck on that project, should be fun to crack for Sparc :-)