6.1 Overview

The Nintendo 64 system runs under a small and real-time preemptive kernel. It is supplied as a set of run-time library functions, so that only those portions that are actually used are included in the game's run-time image. In the remainder of this document, it is referred to as the operating system, although it is so minimal that it has not been given an official name.

The kernel can be considered as being layered into core functionality and higher-level system services, as illustrated in Figure 6-1.

Figure 6-1 Nintendo 64 System Kernel

Threads, messages, events, and raw I/O compose the kernel of the N64 operating system. Upon this base are built some additional services that facilitate access to the raw hardware.

In this introductory section, a brief overview of these services will be provided.