The configuration file used for LiS is modeled after the SVR4 sdevice and mdevice files. However, LiS syntax is different and combines into a single file the functions that SVR4 used two files to specify. They all get combined into one master config file, which is then used to configure LiS at build time. It is not hard-wired into the kernel. Messages can be queued for deferred processing, as LiS guarantees to call service procedures when queued messages could be processed.
Messages carry a type code and are made of one or more message blocks.
Only pointers to messages are passed from one module to the next, so there is no data copy overhead. This allows companies such as Gcom which have proprietary drivers to port their driver code to LiS and distribute binaries. Debug Facilities LiS debugging features are especially convenient and show another departure point from SVR4. The memory allocator keeps file and line numbers close to allocated memory areas. Combine that with the ability to print out all the in-use memory areas, and you have a tool for finding memory leaks in your drivers.