Raspberry Pi Assembly Language Programming : ARM Processor Coding

Gain all the skills required to dive into the fundamentals of the Raspberry Pi hardware architecture and how data is stored in the Pi’s memory. This book provides you with working starting points for your own projects while you develop a working knowledge of Assembly language programming on the Raspberry Pi. You'll learn how to interface to the Pi’s hardware including accessing the GPIO ports. The book will cover the basics of code optimization as well as how to inter-operate with C and Python code, so you'll develop enough background to use the official ARM reference documentation for further projects. With __Raspberry Pi Assembly Language Programming__ as your guide you'll study how to read and reverse engineer machine code and then then apply those new skills to study code examples and take control of your Pi’s hardware and software both. **What You'll Learn*** Program basic ARM 32-Bit Assembly Language * Interface with the various hardware devices on the Raspberry Pi * Comprehend code containing Assembly language * Use the official ARM reference documentation **Who This Book Is For** Coders who have already learned to program in a higher-level language like Python, Java, C#, or C and now wish to learn Assembly programming. Table of Contents......Page 5 About the Author......Page 14 About the Technical Reviewer......Page 15 Acknowledgments......Page 16 Introduction......Page 17 Chapter 1: Getting Started......Page 19 About the ARM Processor......Page 20 What You Will Learn......Page 21 Why Use Assembly......Page 22 Tools You Need......Page 25 Computers and Numbers......Page 26 ARM Assembly Instructions......Page 29 CPU Registers......Page 30 ARM Instruction Format......Page 31 Raspberry Pi Memory......Page 33 About the GCC Assembler......Page 34 Hello World......Page 35 Where to Start......Page 38 Assembly Instructions......Page 39 Calling Linux......Page 40 Reverse Engineering Our Program......Page 41 Summary......Page 44 About Two’s Complement......Page 45 About Gnome Programmer’s Calculator......Page 47 Big vs. Little-endian......Page 48 Pros of Little-endian......Page 50 About Carry Flag......Page 51 About the Barrel Shifter......Page 52 Rotate Right......Page 53 About MOVT......Page 54 The Dreaded Flexible Operand2......Page 55 Small Number and Rotation......Page 56 MVN......Page 58 MOV Examples......Page 59 ADD/ADC......Page 63 Add with Carry......Page 65 Summary......Page 69 GNU Make......Page 70 A Rule for Building .s files......Page 71 Defining Variables......Page 72 Preparing to Debug......Page 73 Beginning GDB......Page 75 Git......Page 80 Jenkins......Page 81 Summary......Page 82 Unconditional Branch......Page 83 About the CPSR......Page 84 Branch on Condition......Page 86 Loops......Page 87 FOR Loops......Page 88 While Loops......Page 89 If/Then/Else......Page 90 AND......Page 91 BIC......Page 92 Design Patterns......Page 93 Converting Integers to ASCII......Page 94 Storing a Register to Memory......Page 98 Performance of Branch Instructions......Page 99 More Comparison Instructions......Page 100 Summary......Page 101 Chapter 5: Thanks for the Memories......Page 102 Defining Memory Contents......Page 103 PC Relative Addressing......Page 107 Loading from Memory......Page 110 Indexing Through Memory......Page 111 Write Back......Page 114 Converting to Uppercase......Page 115 Storing a Register......Page 122 Summary......Page 123 Chapter 6: Functions and the Stack......Page 124 Stacks on Raspbian......Page 125 Branch with Link......Page 126 Nesting Function Calls......Page 127 Managing the Registers......Page 129 Summary of the Function Call Algorithm......Page 130 Uppercase Revisited......Page 131 Stack Frames......Page 136 Stack Frame Example......Page 138 One More Optimization......Page 139 Macros......Page 140 Macro Definition......Page 143 Why Macros?......Page 144 Summary......Page 145 So Many Services......Page 146 Calling Convention......Page 147 Structures......Page 148 Wrappers......Page 149 Converting a File to Uppercase......Page 150 Error Checking......Page 155 Looping......Page 157 Summary......Page 158 GPIO Overview......Page 159 In Linux, Everything Is a File......Page 160 Flashing LEDs......Page 162 Moving Closer to the Metal......Page 166 Virtual Memory......Page 167 In Devices, Everything Is Memory......Page 168 Registers in Bits......Page 169 GPIO Function Select Registers......Page 170 More Flashing LEDs......Page 172 Table Driven......Page 178 Setting Pin Direction......Page 179 Setting and Clearing Pins......Page 180 Summary......Page 181 Calling C Routines......Page 182 Printing Debug Information......Page 183 Calling Printf......Page 185 Adding with Carry Revisited......Page 186 Calling Assembly Routines from C......Page 188 Static Library......Page 191 Shared Library......Page 192 Embedding Assembly Code Inside C Code......Page 195 Calling Assembly from Python......Page 198 Summary......Page 200 Multiplication......Page 201 Examples......Page 203 Division......Page 206 Example......Page 207 Multiply and Accumulate......Page 209 Vectors and Matrices......Page 210 Accumulate Instructions......Page 211 Example 1......Page 213 Accessing Matrix Elements......Page 217 Example 2......Page 218 Summary......Page 222 Chapter 11: Floating-Point Operations......Page 223 Normalization and NaNs......Page 224 Rounding Errors......Page 225 FPU Registers......Page 226 Function Call Protocol......Page 228 Loading and Saving FPU Registers......Page 229 Basic Arithmetic......Page 230 Distance Between Points......Page 232 Floating-Point Conversions......Page 236 Floating-Point Comparison......Page 237 Example......Page 239 Summary......Page 243 Chapter 12: NEON Coprocessor......Page 245 The NEON Registers......Page 246 Stay in Your Lane......Page 248 Arithmetic Operations......Page 249 4D Vector Distance......Page 250 3x3 Matrix Multiplication......Page 255 Summary......Page 260 Chapter 13: Conditional Instructions and Optimizing Code......Page 261 Improved Pipeline......Page 262 Optimizing the Uppercase Routine......Page 263 Simplifying the Range Comparison......Page 264 Using a Conditional Instruction......Page 267 Restricting the Problem Domain......Page 268 Using Parallelism with SIMD......Page 271 Summary......Page 275 Raspbian and GCC......Page 276 Division Revisited......Page 278 Code Created by GCC......Page 282 Reverse Engineering and Ghidra......Page 286 Summary......Page 290 Chapter 15: Thumb Code......Page 291 16-Bit Instruction Format......Page 292 Calling Thumb Code......Page 293 IT Blocks......Page 295 Uppercase in Thumb-2......Page 296 Use the C Compiler......Page 303 Summary......Page 305 Ubuntu MATE......Page 306 About 64 Bits......Page 307 More and Bigger Registers......Page 308 SP and Zero Register......Page 309 Function Call Interface......Page 310 Push and Pop Are Gone......Page 311 Porting from 32 Bits to 64 Bits......Page 312 Porting Uppercase to 64 Bits......Page 313 Conditional Instructions......Page 317 Example with CSEL......Page 318 Registers......Page 320 Instructions......Page 321 Example Using NEON......Page 322 Summary......Page 324 Appendix A: The ARM Instruction Set......Page 326 Linux System Call Numbers......Page 335 Linux System Call Error Codes......Page 350 Integers......Page 355 Floating-Point......Page 356 64 Bits......Page 357 Appendix D: Assembler Directives......Page 358 Appendix E: ASCII Character Set......Page 360 References......Page 372 Index......Page 373 "Gain all the skills required to dive into the fundamentals of the Raspberry Pi hardware architecture and how data is stored in the Pis memory. This book provides you with working starting points for your own projects while you develop a working knowledge of Assembly language programming on the Raspberry Pi. You'll learn how to interface to the Pis hardware including accessing the GPIO ports. The book will cover the basics of code optimization as well as how to inter-operate with C and Python code, so you'll develop enough background to use the official ARM reference documentation for further projects. With Raspberry Pi Assembly Language Programming as your guide you'll study how to read and reverse engineer machine code and then apply those new skills to study code examples and take control of your Pis hardware and software both"-- Page [4] of cover