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ChorusOS 4.0 Porting Guide

Introduction

Sun Embedded Workshop provides reference implementations of the ChorusOS operating system as a set of binary products, each one for a specific target family of processors. The processors within a target family are electronically different but are identical in their interactions with the operating system. The binary product for a given family consists of:

The generic runtime is compiled for the given family of processors. For example, the ChorusOS operating system for PPC60x generic runtime will work with the PowerPC 603[ev], 604[ev], and 750 processors. The generic runtime needs to be complemented with board-specific components in order to produce a system that can boot and do useful work. In particular, you need to add a boot program and a set of device drivers. The set of items that you need to add to support a specific board is called the board support package (BSP).

The set of boot programs and device drivers provided with the binary product will work with the reference platforms. However, you might need to customize these components to, for example, optimize your system.

When you have selected the board on which you will run your system, choose the reference implementation from the board family that most closely resembles your target board. Use this reference implementation as the basis for your ChorusOS operating system, porting the components as necessary.

To create a BSP for a specific target board, you need to provide four components:

The boot program and host bus driver are heavily dependent on the board, and need to be re-written. However, using the Sun Embedded Workshop device driver framework, you might be able to reuse existing drivers for managing the board's other devices. See ChorusOS 4.0 Device Driver Framework Guide for information about writing device drivers and using the device driver framework.