Inside Macintosh: Operating System Utilities /

Chapter 9 - Start Manager

This chapter describes the system initialization and system startup process performed by the Macintosh computer. It describes the Start Manager, which lets you specify a few global settings that affect the startup process, and it describes initialization-dependent code, such as system extensions, that the system runs while starting up the computer.

You should read this chapter if you are developing a device driver or other code that is installed at some point during the system initialization and startup process, or if you want to use the Start Manager routines.

This chapter begins with a description of the initialization and startup process performed on Macintosh computers. It then

• describes the boot blocks and defines the fields in the boot block header
• defines global variables that provide timing information
• discusses the Start Manager routines you can use to identify and set default devices and to get and set the timeout interval for the startup drive
• describes how to write a system extension

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Chapter Contents

System Initialization and Startup

System Initialization

System Startup

Boot Blocks

Global Timing Variables

About the Start Manager

Using the Start Manager

Writing a System Extension

Profile of a System Extension

Defining the User Interface for a System Extension

Creating a System Extension's Resources

Creating Icons for a System Extension

Creating a System Heap Zone Resource for a System Extension

Building a System Extension

Start Manager Reference

Data Structures

The Default Startup Device Parameter Block

The Default Video Device Parameter Block

The Default Operating System Parameter Block

Routines

Identifying and Setting the Default Startup Device

Identifying and Setting the Default Video Device

Identifying and Setting the Default Operating System

Getting and Setting the Timeout Interval

Summary of the Start Manager

Pascal Summary

Data Types

Routines

C Summary

Data Types

Routines

Assembly-Language Summary

Data Structures

Trap Macros

Global Variables