The design and implementation of a new UNIX kernel
Charles Crowley · 1981
A project to produce a kernel-based, message-passing version of UNIX is described. The system is designed to be (1) useful in teaching operating systems, (2) easily changeable, (3) easily portable, and (4) a vehicle for studying the message-passing approach to operating systems design. The system calls normally handled by the UNIX kernel are handled by system processes, each of which operates in its own address space. Interprocess communication and process environment management is done by a small kernel. The design and implementation of the system are described. Message passing as a system design method is evaluated in this context and compared with the procedure call orientation of standard UNIX. The message-based design proved successful in creating a modular and understandable system.