A pattern language for porting micro-kernels

Micro-kernels are difficult to port to a new hardware platform. During the initial phases of a port, much time and effort is lost on debugging critical machine-dependent subsystems. These subsystems are generally very tightly coupled and cannot be tested in an incremental fashion. Tight coupling occurs because the subsystems share many global variables forcing them to be debugged with the complete micro-kernel code. The problem of organizing and documenting new micro-kernel ports has so far received little attention, and the work described in the paper is an attempt to fill this gap. The paper describes a set of patterns (pattern language) which captures the design decisions of the initial porting procedure of micro-kernels for embedded systems in a systematic and incremental fashion. The problem, context, and solution behind major design patterns is presented along with an outline of their consequences, constraints and applicability to the port. In the course of several iterations, this pattern language has been refined through their use in porting of existing embedded micro-kernels to different hardware platforms.