Introduction

The ChorusOS system provides a driver framework, allowing the third-party developer to develop device drivers on top of a binary system distribution. The Driver Framework provides a well-defined, structured and easy-to-use environment to develop both new drivers and client applications for existing drivers.

Host bus drivers written with the Driver Framework are processor-family specific, meaning that they are portable within that processor family (UltraSPARC^TM, PowerPC, Intel ix86 processor families). Drivers that occupy a higher place in the hierarchical bus structure (sub-bus drivers and device drivers) are usually portable between processor families.

Device Driver implementation is based on services (provided by a set of APIs, such as PCI or ISA) which allow the developer to choose the optimizability and portability of the driver they create. This allows the driver to be written to the parent bus class, and not the underlying platform. Drivers written within the Driver Framework may also take advantage of processor-specific services, allowing maximum optimization for a particular processor family.