ARM 64-Bit Assembly Language

Contents
List of tables
List of figures
Preface
	Choice of processor family
	General approach
1 Introduction
	1.1 Reasons to learn assembly
	1.2 The ARM processor
	1.3 Computer data
		1.3.1 Representing natural numbers
		1.3.2 Base conversion
			1.3.2.1 Base b to decimal
			1.3.2.2 Decimal to base b
			1.3.2.3 Bases that are powers-of-two
			1.3.2.4 Conversion between arbitrary bases
		1.3.3 Representing integers
			1.3.3.1 Sign-magnitude representation
			1.3.3.2 Excess-(2n-1-1) representation
			1.3.3.3 Complement representation
				Finding the complement
				Subtraction using complements
		1.3.4 Representing characters
			1.3.4.1 Non-printing characters
			1.3.4.2 Converting character strings to ASCII codes
			1.3.4.3 Interpreting data as ASCII strings
			1.3.4.4 ISO extensions to ASCII
			1.3.4.5 Unicode and UTF-8
	1.4 Memory layout of an executing program
	1.5 Chapter summary
	Exercises
2 GNU assembly syntax
	2.1 Structure of an assembly program
		2.1.1 Labels
		2.1.2 Comments
		2.1.3 Directives
		2.1.4 Assembly instructions
	2.2 What the assembler does
	2.3 GNU assembly directives
		2.3.1 Selecting the current section
		2.3.2 Allocating space for variables and constants
		2.3.3 Filling and aligning
		2.3.4 Setting and manipulating symbols
		2.3.5 Functions and objects
		2.3.6 Conditional assembly
		2.3.7 Including other source files
		2.3.8 Macros
			2.3.8.1 Macro example
			2.3.8.2 Recursive macro example
	2.4 Chapter summary
	Exercises
3 Load/store and branch instructions
	3.1 CPU components and data paths
	3.2 AArch64 user registers
		3.2.1 General purpose registers
		3.2.2 Frame pointer
		3.2.3 PSTATE register
		3.2.4 Link register
		3.2.5 Stack pointer
		3.2.6 Zero register
		3.2.7 Program counter
	3.3 Instruction components
		3.3.1 Setting and using condition flags
		3.3.2 Immediate values
		3.3.3 Addressing modes
	3.4 Load and store instructions
		3.4.1 Load/store single register
			3.4.1.1 Syntax
			3.4.1.2 Operations
			3.4.1.3 Examples
		3.4.2 Load/store single register (unscaled)
			3.4.2.1 Syntax
			3.4.2.2 Operations
			3.4.2.3 Examples
		3.4.3 Load/store pair
			3.4.3.1 Syntax
			3.4.3.2 Operations
			3.4.3.3 Examples
	3.5 Branch instructions
		3.5.1 Branch
			3.5.1.1 Syntax
			3.5.1.2 Operations
			3.5.1.3 Examples
		3.5.2 Branch register
			3.5.2.1 Syntax
			3.5.2.2 Operations
			3.5.2.3 Examples
		3.5.3 Branch and link
			3.5.3.1 Syntax
			3.5.3.2 Operations
			3.5.3.3 Examples
		3.5.4 Compare and branch
			3.5.4.1 Syntax
			3.5.4.2 Operations
			3.5.4.3 Examples
		3.5.5 Form PC-relative address
			3.5.5.1 Syntax
			3.5.5.2 Operations
			3.5.5.3 Examples
	3.6 Chapter summary
	Exercises
4 Data processing and other instructions
	4.1 Operand2
		4.1.1 Shift and rotate operations
		4.1.2 Extend operations
		4.1.3 Immediate data
	4.2 Data processing instructions
		4.2.1 Arithmetic operations
			4.2.1.1 Syntax
			4.2.1.2 Operations
			4.2.1.3 Examples
		4.2.2 Logical operations
			4.2.2.1 Syntax
			4.2.2.2 Operations
			4.2.2.3
		4.2.3 Data movement operations
			4.2.3.1 Syntax
			4.2.3.2 Operations
			4.2.3.3 Examples
		4.2.4 Shift operations
			4.2.4.1 Syntax
			4.2.4.2 Operations
			4.2.4.3 Examples
		4.2.5 Multiply operations with overflow
			4.2.5.1 Syntax
			4.2.5.2 Operations
			4.2.5.3 Examples
		4.2.6 Multiply operations with 64-bit results
			4.2.6.1 Syntax
			4.2.6.2 Operations
			4.2.6.3 Examples
		4.2.7 Multiply operations with 128-bit results
			4.2.7.1 Syntax
			4.2.7.2 Operations
			4.2.7.3 Examples
		4.2.8 Division operations
			4.2.8.1 Syntax
			4.2.8.2 Operations
			4.2.8.3 Examples
		4.2.9 Comparison operations
			4.2.9.1 Syntax
			4.2.9.2 Operations
			4.2.9.3 Examples
		4.2.10 Conditional operations
			4.2.10.1 Syntax
			4.2.10.2 Operations
			4.2.10.3 Examples
	4.3 Special instructions
		4.3.1 Count leading zeros
			4.3.1.1 Syntax
			4.3.1.2 Operations
			4.3.1.3 Example
		4.3.2 Accessing the PSTATE register
			4.3.2.1 Syntax
			4.3.2.2 Operations
			4.3.2.3 Examples
		4.3.3 Supervisor call
			4.3.3.1 Syntax
			4.3.3.2 Operations
			4.3.3.3 Example
		4.3.4 No operation
			4.3.4.1 Syntax
			4.3.4.2 Operations
			4.3.4.3 Examples
	4.4 Alphabetized list of AArch64 instructions
	4.5 Chapter summary
	Exercises
5 Structured programming
	5.1 Sequencing
	5.2 Selection
		5.2.1 If-then statement
		5.2.2 If-then-else statement
			5.2.2.1 Using branch instructions
			5.2.2.2 Using conditional selection
		5.2.3 Complex selection
	5.3 Iteration
		5.3.1 Pre-test loop
		5.3.2 Post-test loop
		5.3.3 For loop
			5.3.3.1 Pre-test conversion
			5.3.3.2 Post-test conversion
	5.4 Subroutines
		5.4.1 Advantages of subroutines
		5.4.2 Disadvantages of subroutines
		5.4.3 Standard C library functions
		5.4.4 Passing parameters
		5.4.5 Calling subroutines
			5.4.5.1 Passing arguments in registers
			5.4.5.2 Passing arguments on the stack
		5.4.6 Writing subroutines
		5.4.7 Automatic variables
		5.4.8 Recursive functions
	5.5 Aggregate data types
		5.5.1 Arrays
		5.5.2 Structured data
		5.5.3 Arrays of structured data
	5.6 Chapter summary
	Exercises
6 Abstract data types
	6.1 ADTs in assembly language
	6.2 Word frequency counts
		6.2.1 Sorting by word frequency
		6.2.2 Better performance
		6.2.3 Indexing and sorting by frequency
	6.3 Ethics case study: Therac-25
		6.3.1 History of the Therac-25
		6.3.2 Overview of design flaws
	6.4 Chapter summary
	Exercises
7 Integer mathematics
	7.1 Subtraction by addition
	7.2 Binary multiplication
		7.2.1 Multiplication by a power of two
		7.2.2 Multiplication of two variables
		7.2.3 Signed multiplication
		7.2.4 Multiplication of a variable by a constant
		7.2.5 Multiplying large numbers
	7.3 Binary division
		7.3.1 Division by a power of two
		7.3.2 Division by a variable
		7.3.3 Division by a constant
		7.3.4 Dividing large numbers
	7.4 Big integer ADT
	7.5 Chapter summary
	Exercises
8 Non-integral mathematics
	8.1 Base conversion of fractional numbers
		8.1.1 Arbitrary base to decimal
		8.1.2 Decimal to arbitrary base
			8.1.2.1 Bases that are powers-of-two
	8.2 Fractions and bases
		8.2.1 Rounding errors
		8.2.2 Implications
	8.3 Fixed point numbers
		8.3.1 Interpreting fixed point numbers
		8.3.2 Q notation
		8.3.3 Properties of fixed point numbers
	8.4 Fixed point operations
		8.4.1 Fixed point addition and subtraction
		8.4.2 Fixed point multiplication
		8.4.3 Fixed point division
			8.4.3.1 Results of fixed point division
			8.4.3.2 Maintaining precision
		8.4.4 Division by a constant
			8.4.4.1 Division by constant 23
			8.4.4.2 Division by constant -50
	8.5 Fixed point input and output
	8.6 Computing sine and cosine
		8.6.1 Formats for the powers of x
		8.6.2 Formats and constants for the factorial terms
		8.6.3 Putting it all together
		8.6.4 Performance comparison
	8.7 Floating point numbers
		8.7.1 IEEE 754 half-precision
			8.7.1.1 Examples
		8.7.2 IEEE 754 single-precision
		8.7.3 IEEE 754 double-precision
		8.7.4 IEEE 754 quad-precision
	8.8 Floating point operations
		8.8.1 Floating point addition and subtraction
		8.8.2 Floating point multiplication and division
	8.9 Ethics case study: patriot missile failure
	8.10 Chapter summary
	Exercises
9 Floating point
	9.1 Floating point overview
	9.2 Register usage rules
	9.3 Floating point control and status registers
	9.4 Load/store instructions
		9.4.1 Load/store single register
			9.4.1.1 Syntax
			9.4.1.2 Operations
			9.4.1.3 Examples
		9.4.2 Load/store single register with unscaled offset
			9.4.2.1 Syntax
			9.4.2.2 Operations
			9.4.2.3 Examples
		9.4.3 Load/store pair
			9.4.3.1 Syntax
			9.4.3.2 Operations
		9.4.4 Load/store non-temporal pair
			9.4.4.1 Syntax
			9.4.4.2 Operations
	9.5 Data movement instructions
		9.5.1 Moving between data registers
			9.5.1.1 Syntax
			9.5.1.2 Operations
			9.5.1.3 Examples
		9.5.2 Floating point move immediate
			9.5.2.1 Syntax
			9.5.2.2 Operations
			9.5.2.3 Examples
	9.6 Data conversion instructions
		9.6.1 Convert between double, single, and half precision
			9.6.1.1 Syntax
			9.6.1.2 Operations
			9.6.1.3 Examples
		9.6.2 Convert between floating point and integer
			9.6.2.1 Syntax
			9.6.2.2 Operation
			9.6.2.3 Examples
		9.6.3 Convert between fixed point and floating point
			9.6.3.1 Syntax
			9.6.3.2 Operations
			9.6.3.3 Examples
	9.7 Data processing instructions
		9.7.1 Round to integral
			9.7.1.1 Syntax
			9.7.1.2 Operations
			9.7.1.3 Examples
		9.7.2 Absolute value, negate, square root
			9.7.2.1 Syntax
			9.7.2.2 Operations
			9.7.2.3 Examples
		9.7.3 Add, subtract, multiply, and divide
			9.7.3.1 Syntax
			9.7.3.2 Operations
			9.7.3.3 Examples
		9.7.4 Multiply and accumulate
			9.7.4.1 Syntax
			9.7.4.2 Operations
			9.7.4.3 Examples
		9.7.5 Min and max
			9.7.5.1 Syntax
			9.7.5.2 Operations
			9.7.5.3 Examples
		9.7.6 Compare
			9.7.6.1 Syntax
			9.7.6.2 Operations
			9.7.6.3 Examples
		9.7.7 Conditional select
			9.7.7.1 Syntax
			9.7.7.2 Operations
			9.7.7.3 Examples
	9.8 Floating point sine function
		9.8.1 Performance comparison
	9.9 Alphabetized list of FP/NEON instructions
	9.10 Chapter summary
	Exercises
10 Advanced SIMD instructions
	10.1 Instruction syntax
	10.2 Load and store instructions
		10.2.1 Load or store single structure using one lane
			10.2.1.1 Syntax
			10.2.1.2 Operations
			10.2.1.3 Examples
		10.2.2 Load or store multiple structures
			10.2.2.1 Syntax
			10.2.2.2 Operations
			10.2.2.3 Examples
		10.2.3 Load copies of a structure to all lanes
			10.2.3.1 Syntax
			10.2.3.2 Operations
			10.2.3.3 Examples
	10.3 Data movement instructions
		10.3.1 Duplicate scalar
			10.3.1.1 Syntax
			10.3.1.2 Operations
			10.3.1.3 Examples
		10.3.2 Move vector element
			10.3.2.1 Syntax
			10.3.2.2 Operations
			10.3.2.3 Examples
		10.3.3 Move immediate
			10.3.3.1 Syntax
			10.3.3.2 Operations
			10.3.3.3 Examples
		10.3.4 Transpose matrix
			10.3.4.1 Syntax
			10.3.4.2 Operation
			10.3.4.3 Examples
		10.3.5 Vector permute
			10.3.5.1 Syntax
			10.3.5.2 Operations
			10.3.5.3 Examples
		10.3.6 Table lookup
			10.3.6.1 Syntax
			10.3.6.2 Operations
			10.3.6.3 Examples
	10.4 Data conversion
		10.4.1 Convert between integer or fixed point and floating point
			10.4.1.1 Syntax
			10.4.1.2 Operations
			10.4.1.3 Examples
		10.4.2 Convert between half, single, and double precision
			10.4.2.1 Syntax
			10.4.2.2 Operations
			10.4.2.3 Examples
		10.4.3 Round floating point to integer
			10.4.3.1 Syntax
			10.4.3.2 Operations
			10.4.3.3 Examples
	10.5 Bitwise logical operations
		10.5.1 Vector logical operations
			10.5.1.1 Syntax
			10.5.1.2 Operations
			10.5.1.3 Examples
		10.5.2 Bitwise logical operations with immediate data
			10.5.2.1 Syntax
			10.5.2.2 Operations
			10.5.2.3 Examples
	10.6 Basic arithmetic instructions
		10.6.1 Vector add and subtract
			10.6.1.1 Syntax
			10.6.1.2 Operations
			10.6.1.3 Examples
		10.6.2 Vector add and subtract with narrowing
			10.6.2.1 Syntax
			10.6.2.2 Operations
			10.6.2.3 Examples
		10.6.3 Add or subtract and divide by two
			10.6.3.1 Syntax
			10.6.3.2 Operations
			10.6.3.3 Examples
		10.6.4 Add elements pairwise
			10.6.4.1 Syntax
			10.6.4.2 Operations
			10.6.4.3 Examples
		10.6.5 Absolute difference
			10.6.5.1 Syntax
			10.6.5.2 Operations
			10.6.5.3 Examples
		10.6.6 Absolute value and negate
			10.6.6.1 Syntax
			10.6.6.2 Operations
			10.6.6.3 Examples
		10.6.7 Get maximum or minimum elements
			10.6.7.1 Syntax
			10.6.7.2 Operations
			10.6.7.3 Examples
		10.6.8 Count bits
			10.6.8.1 Syntax
			10.6.8.2 Operations
			10.6.8.3 Examples
		10.6.9 Scalar saturating operations
			10.6.9.1 Syntax
			10.6.9.2 Operations
			10.6.9.3 Examples
	10.7 Multiplication and division
		10.7.1 Vector multiply and divide
			10.7.1.1 Syntax
			10.7.1.2 Operations
			10.7.1.3 Examples
		10.7.2 Multiply vector by element
			10.7.2.1 Syntax
			10.7.2.2 Operations
			10.7.2.3 Examples
		10.7.3 Saturating vector multiply and double
			10.7.3.1 Syntax
			10.7.3.2 Operations
			10.7.3.3 Examples
		10.7.4 Saturating multiply and double (high)
			10.7.4.1 Syntax
			10.7.4.2 Operations
			10.7.4.3 Examples
		10.7.5 Estimate reciprocals
			10.7.5.1 Syntax
			10.7.5.2 Operations
			10.7.5.3 Examples
		10.7.6 Reciprocal step
			10.7.6.1 Syntax
			10.7.6.2 Operations
			10.7.6.3 Examples
		10.7.7 Multiply scalar by element
			10.7.7.1 Syntax
			10.7.7.2 Operations
			10.7.7.3 Examples
		10.7.8 Saturating multiply scalar by element and double
			10.7.8.1 Syntax
			10.7.8.2 Operations
			10.7.8.3 Examples
	10.8 Shift instructions
		10.8.1 Vector shift left by immediate
			10.8.1.1 Syntax
			10.8.1.2 Operations
			10.8.1.3 Examples
		10.8.2 Vector shift right by immediate
			10.8.2.1 Syntax
			10.8.2.2 Operations
			10.8.2.3 Examples
		10.8.3 Vector saturating shift right by immediate
			10.8.3.1 Syntax
			10.8.3.2 Operations
			10.8.3.3 Examples
		10.8.4 Shift left or right by variable
			10.8.4.1 Syntax
			10.8.4.2 Operations
			10.8.4.3 Examples
		10.8.5 Shift and insert
			10.8.5.1 Syntax
			10.8.5.2 Operations
			10.8.5.3 Examples
		10.8.6 Scalar shift left by immediate
			10.8.6.1 Syntax
			10.8.6.2 Operations
			10.8.6.3 Examples
		10.8.7 Scalar shift right by immediate
			10.8.7.1 Syntax
			10.8.7.2 Operations
			10.8.7.3 Examples
		10.8.8 Scalar saturating shift right by immediate
			10.8.8.1 Syntax
			10.8.8.2 Operations
			10.8.8.3 Examples
	10.9 Unary arithmetic
		10.9.1 Vector unary arithmetic
			10.9.1.1 Syntax
			10.9.1.2 Operations
			10.9.1.3 Examples
		10.9.2 Scalar unary arithmetic
			10.9.2.1 Syntax
			10.9.2.2 Operations
			10.9.2.3 Examples
	10.10 Vector reduce instructions
		10.10.1 Reduce across lanes
			10.10.1.1 Syntax
			10.10.1.2 Operations
			10.10.1.3 Examples
		10.10.2 Reduce pairwise
			10.10.2.1 Syntax
			10.10.2.2 Operations
			10.10.2.3 Examples
	10.11 Comparison operations
		10.11.1 Vector compare mask
			10.11.1.1 Syntax
			10.11.1.2 Operations
			10.11.1.3 Examples
		10.11.2 Vector absolute compare mask
			10.11.2.1 Syntax
			10.11.2.2 Operations
			10.11.2.3 Examples
		10.11.3 Vector test bits mask
			10.11.3.1 Syntax
			10.11.3.2 Operations
			10.11.3.3 Examples
		10.11.4 Scalar compare mask
			10.11.4.1 Syntax
			10.11.4.2 Operations
			10.11.4.3 Examples
		10.11.5 Scalar absolute compare mask
			10.11.5.1 Syntax
			10.11.5.2 Operations
			10.11.5.3 Examples
		10.11.6 Scalar test bits mask
			10.11.6.1 Syntax
			10.11.6.2 Operations
			10.11.6.3 Examples
	10.12 Performance mathematics: a final look at sine
		10.12.1 Single precision
		10.12.2 Double precision
		10.12.3 Performance comparison
	10.13 Alphabetized list of advanced SIMD instructions
	10.14 Advanced SIMD intrinsics
	10.15 Chapter summary
	Exercises
11 Devices
	11.1 Accessing devices directly under Linux
	11.2 General purpose digital input/output
		11.2.1 Typical GPIO device
		11.2.2 Raspberry Pi GPIO
			11.2.2.1 Setting the GPIO pin function
			11.2.2.2 Setting GPIO output pins
			11.2.2.3 Reading GPIO input pins
			11.2.2.4 Enabling internal pull-up or pull-down
			11.2.2.5 Detecting GPIO events
			11.2.2.6 GPIO pins available on the Raspberry Pi
	11.3 Pulse modulation
		11.3.1 Pulse density modulation
		11.3.2 Pulse width modulation
		11.3.3 Raspberry Pi PWM device
	11.4 Common system devices
		11.4.1 Clock management device
		11.4.2 Raspberry Pi clock manager
	11.5 Serial communications
		11.5.1 UART
		11.5.2 Raspberry Pi UART0
		11.5.3 Basic programming for the Raspberry Pi UART
	11.6 Chapter summary
	Exercises
12 Running without an operating system
	12.1 Exception processing
	12.2 AArch64 execution and exception states
		12.2.1 AArch64 exception levels
		12.2.2 System control and status registers
	12.3 AArch64 vector table
		12.3.1 Creating the vector tables
		12.3.2 Using the vector tables
		12.3.3 Configuring asynchronous exceptions
	12.4 The boot process
	12.5 Writing a bare metal program
		12.5.1 Startup code
		12.5.2 Main program
		12.5.3 The linker script
		12.5.4 Putting it all together
	12.6 Using an interrupt
		12.6.1 Startup code with interrupt enabling
		12.6.2 Interrupt controllers
		12.6.3 Timers
		12.6.4 Exception handling
		12.6.5 Building the interrupt-driven program
	12.7 ARM processor profiles
	12.8 Chapter summary
	Exercises
Index