Inside Macintosh: Mac OS Runtime Architectures /

Chapter 1 - CFM-Based Runtime Architecture

The CFM-based runtime architecture relies on fragments and the Code Fragment Manager (CFM) for its operation. This architecture has been implemented as the default architecture for PowerPC-based Mac OS computers and an optional one, CFM-68K, for 68K-based machines. The key concepts are identical for both implementations, so you should read this chapter if you plan to write either PowerPC or CFM-68K code.

In addition, you should read Chapter 2, "Indirect Addressing in the CFM-Based Architecture," which contains more information related to the CFM-based architecture. Chapter 3, "Programming for the CFM-Based Runtime Architecture," contains additional practical information that you may find useful when writing CFM-based programs.

For specific information about the implementation of the CFM-based architecture on the PowerPC and 68K microprocessors, you should read the following chapters:

• Chapter 4, "PowerPC Runtime Conventions," for PowerPC information
• Chapter 9, "CFM-68K Application and Shared Library Structure," and Chapter 5, "CFM-68K Runtime Conventions," for CFM-68K information

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Chapter Contents

Overview

Closures

Code and Data Sections

Reference Counts

Using Code Fragment Manager Options

Preparing a Closure

Searching for Import Libraries

Checking for Compatible Import Libraries

The Structure of Fragments

Fragment Storage

The Code Fragment Resource

Extensions to Code Fragment Resource Entries

Sample Code Fragment Resource Entry Definitions

A PowerPC Application 'cfrg' 0 Resource Definition

A CFM-68K Application 'cfrg' 0 Resource Definition

A Shared Library 'cfrg' 0 Resource Definition

Special Symbols

The Main Symbol

The Initialization Function

The Termination Routine