ChorusOS 4.0 Porting Guide

Loading the System Image

The last action of the power-up initialization code is to hand control to the initial loader, which loads the system image into physical memory and jumps to the image entry point.

If the system image is already stored in non-volatile memory on the board, the initial loader is not required, and the initialization code terminates by jumping to the entry point of the system image.

Firmware

Most development boards are provided with a standard firmware power-up initialization code and loader in PROM. This firmware is able to download a system image from a local device or from the network.

Sun Embedded Workshop provides tools to build the ChorusOS system image in the format required by the firmware loaders supported.

ChorusOS Boot Monitor

The Boot Monitor is the initial loader provided with ChorusOS for use with the ChorusOS operating system. It is able to download the system image from the network.

The Boot Monitor is implemented as an aplication on top of a minimal ChorusOS configuration.