Arm System Developer’s Guide

By Andrew Sloss, Dominic Symes and Chris Wright

Over the last ten years, the ARM architecture has become one of the most pervasive architectures in the world, with more than 2 billion ARM-based processors embedded in products ranging from cell phones to automotive braking systems. A world-wide community of ARM developers in semiconductor and product design companies includes software developers, system designers and hardware engineers. To date no book has directly addressed their need to develop the system and software for an ARM-based system. This text fills that gap. This book provides a comprehensive description of the operation of the ARM core from a developer's perspective with a clear emphasis on software. It demonstrates not only how to write efficient ARM software in C and assembly but also how to optimize code. Example code throughout the book can be integrated into commercial products or used as templates to enable quick creation of productive software. The book covers both the ARM and Thumb instruction sets, covers Intel's XScale Processors, outlines distinctions among the versions of the ARM architecture, demonstrates how to implement DSP algorithms, explains exception and interrupt handling, describes the cache technologies that surround the ARM cores as well as the most efficient memory management techniques. A final chapter looks forward to the future of the ARM architecture considering ARMv6, the latest change to the instruction set, which has been designed to improve the DSP and media processing capabilities of the architecture.

Table of Contents:1. ARM Embedded Systems 1.1 The RISC Design Philosophy 1.2 The ARM Design Philosophy 1.3 Embedded System Hardware 1.4 Embedded System Software 1.5 Summary 2 ARM Processor Fundamentals2.1 Registers 2.2 Current Program Status Register2.3 Pipeline2.4 Exceptions, Interrupts, and the Vector Table 2.5 Core Extensions2.6 Architecture Revisions 2.7 ARM Processor Families2.8 Summary3 Introduction to the ARM Instruction Set 3.1 Data Processing Instructions 3.2 Branch Instructions 3.3 Load-Store Instructions 3.4 Software Interrupt Instruction 3.5 Program Status Register Instructions 3.6 Loading Constants 3.7 ARMv5E Extensions 3.8 Conditional Execution 3.9 Summary4 Introduction to the Thumb Instruction Set4.1 Thumb Register Usage4.2 ARM-Thumb Interworking4.3 Other Branch Instructions4.4 Data Processing Instructions4.5 Single-Register Load-Store Instructions4.6 Multiple-Register Load-Store Instructions4.7 Stack Instructions4.8 Software Interrupt Instruction4.9 Summary5 Efficient C Programming5.1 Overview of C Compilers and Optimization 5.2 Basic C Data Types5.3 C Looping Structures 5.4 Register Allocation5.5 Function Calls5.6 Pointer Aliasing5.7 Structure Arrangement5.8 Bit-fields5.9 Unaligned Data and Endianness5.10 Division5.11 Floating Point5.12 Inline Functions and Inline Assembly5.13 Portability Issues5.14 Summary6 Writing and Optimizing ARM Assembly Code6.1 Writing Assembly Code 6.2 Profiling and Cycle Counting 6.3 Instruction Scheduling6.4 Register Allocation 6.5 Conditional Execution 6.6 Looping Constructs 6.7 Bit Manipulation 6.8 Efficient Switches6.9 Handling Unaligned Data6.10 Summary 7 Optimized Primitives 7.1 Double-Precision Integer Multiplication 7.2 Integer Normalization and Count Leading Zeros7.3 Division 7.4 Square Roots 7.5 Transcendental Functions: log, exp, sin, cos 7.6 Endian Reversal and Bit Operations7.7 Saturated and Rounded Arithmetic7.8 Random Number Generation7.9 Summary 8 Digital Signal Processing 8.1 Representing a Digital Signal8.2 Introduction to DSP on the ARM8.3 FIR filters8.4 IIR Filters 8.5 The Discrete Fourier Transform8.6 Summary9 Exception and Interruput Handling9.1 Exception Handling9.2 Interrupts9.3 Interrupt Handling Schemes9.4 Summary10 Firmware 10.1 Firmware and Bootloader 10.2 Example: Sandstone 10.3 Summary 11 Embedded Operating Systems 11.1 Fundamental Components 11.2 Example: Simple Little Operating System 11.3 Summary 12 Caches 12.1 The Memory Hierarchy and Cache Memory 12.2 Cache Architecture 12.3 Cache Policy 12.4 Coprocessor 15 and Caches 12.5 Flushing and Cleaning Cache Memory 12.6 Cache Lockdown 12.7 Caches and Software Performance 12.8 Summary 13 Memory Protection Units 13.1 Protected Regions 13.2 Initializing the MPU, Caches, and Write Buffer 13.3 Demonstration of an MPU system 13.4 Summary 14 Memory Management Units 14.1 Moving from an MPU to an MMU 14.2 How Virtual Memory Works 14.3 Details of the ARM MMU 14.4 Page Tables 14.5 The Translation Lookaside Buffer 14.6 Domains and Memory Access Permission 14.7 The Caches and Write Buffer 14.8 Coprocessor 15 and MMU Configuration 14.9 The Fast Context Switch Extension 14.10 Demonstration: A Small Virtual Memory System 14.11 The Demonstration as mmuSLOS 14.12 Summary 15 The Future of the Architectureby John Rayfield 15.1 Advanced DSP and SIMD Support in ARMv6 15.2 System and Multiprocessor Support Additions to ARMv6 15.3 ARMv6 Implementations 15.4 Future Technologies beyond ARMv6 15.5 Conclusions Appendix A: ARM and Thumb Assembler Instructions Appendix: B ARM and Thumb Instruction Encodings Appendix C: Processors and Architecture Appendix D: Instruction Cycle Timings Appendix E: Suggested Reading Index