Inside Macintosh: Memory /

Chapter 4 - Memory Management Utilities

This chapter describes a number of utility routines you can use to control certain aspects of the memory environment in Macintosh computers. Some features of the memory environment are controlled by the user through the Memory control panel; others are controlled by the Process Manager or other parts of the Macintosh Operating System and Toolbox. The utility routines described in this chapter allow you to modify some of the normal operations of the Operating System or the Toolbox.

You need to read this chapter if your application or driver

• installs completion routines or interrupt tasks that are executed by the Operating System or Toolbox, not directly by your application
• modifies the addressing mode or converts addresses from one form to another
• moves executable code in memory, or performs DMA operations

To use this chapter, you should be familiar with the information in the chapter "Introduction to Memory Management" earlier in this book. Also, you can read the chapter "Introduction to Processes and Tasks" in Inside Macintosh: Processes for a related discussion of the A5 register.

This chapter begins with a brief description of the Memory control panel, which allows users to alter several aspects of the Operating System's memory configuration. Then it shows how you can use the Memory Management Utilities to

• set up the A5 register so that your application-defined completion routines and interrupt tasks can access your application's global variables
• get the value of the A5 register so that you can read your application's QuickDraw global variables from within stand-alone code
• get or set a computer's address-translation mode
• strip the flag bits from a master pointer or other memory address
• convert 24-bit addresses to 32-bit addresses
• flush the microprocessor's instruction and data caches

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Chapter Contents

The Memory Control Panel

About the Memory Management Utilities

The A5 Register

Addressing Modes

Address Translation

Processor Caches

Stale Instructions

Stale Data

Using the Memory Management Utilities

Accessing the A5 World in Completion Routines

Accessing the A5 World in Interrupt Tasks

Using QuickDraw Global Variables in Stand-Alone Code

Switching Addressing Modes

Stripping Flag Bits From Memory Addresses

Translating Memory Addresses

Memory Management Utilities Reference

Routines

Setting and Restoring the A5 Register

Changing the Addressing Mode

Manipulating Memory Addresses

Manipulating the Processor Caches

Summary of the Memory Management Utilities

Pascal Summary

Constants

Routines

C Summary

Constants

Routines

Assembly-Language Summary

Trap Macros

Global Variables

Result Codes