Practical-Foundations-ARM64 Linus Debugging- Disassembly-Reversing.png

arm.tar.gz

Codeoptmization

Pointers_to_assign

Pointers

MemoryPointers

PointersAsVariables

PointersAsVariables-optimization

SimpleStack

LocalVariables

FunctionParameters

FunctionParameters-14

solution

FunctionParameters-14-copy

RawStack

MemoryPointers-copy

The GNU Debugger (GDB) is used for debugging C/C++ programs in LINUX/UNIX environments. It is a good tool to investigate what is happening inside a program, and how the contents inside the memory are changed with the execution of the program.

The main focus of the course is the disassembly of the program. You’ll use the Linux ARM64 which is a popular RISC architecture. You’ll use simple operations in C/C++ such as assignment, increment, addition, multiplication. With the help of the GDB, you will probe into the contents of the registers and memory. You'll learn how they are changed while executing basic operations. With the help of the disassembly output, you’ll learn how a simple C/C++ program can be reconstructed. The disassembly output is important for debugging and core dump analysis.

By the end of this course, you should be able to debug the programs and memory contents at assembly level when a program executes or probe into the problem when a program crashes.

Foundations of Linux ARM64: Debug, Disassemble, and Reverse

## The `PSTATE` flags
In addition to registers, the CPU also contains a 32-bit `PSTATE` where four individual bits `N`, `Z`, `C`, and `V` are set or cleared in response to arithmetic and other operations. Separate machine instructions can manipulate some bit values, and their values affect code execution. These flags have their own special register, `NZCV`.
The illustration below shows the four individual bits:


# The `PSTATE` flags
In addition to registers, the CPU also contains a 32-bit `PSTATE` where four individual bits `N`, `Z`, `C`, and `V` are set or cleared in response to arithmetic and other operations. Separate machine instructions can manipulate some bit values, and their values affect code execution. These flags have their own special register, `NZCV`.
The illustration below shows the four individual bits:


Learn about PSTATE flags, conditional jumps, function return value, and testing for 0.

Instructions-I

Introduction to the Course

Memory, Registers, and Simple Arithmetic

Code Optimization

Number Representations

Pointers

Bytes, Half Words, Words, and Double Words

Pointers to Memory

Logical Instructions and PC

Reconstructing a Program with Pointers

Memory and Stacks

Frame Pointer and Local Variables

Function Parameters

More Instructions

Function Pointer Parameters

Conclusion

ARM64 Linux Debugging, Disassembling, Reversing Exam

Instructions-I

The `PSTATE` flags

Introduction to the Course

Memory, Registers, and Simple Arithmetic

Code Optimization

Number Representations

Pointers

Bytes, Half Words, Words, and Double Words

Pointers to Memory

Logical Instructions and PC

Reconstructing a Program with Pointers

Memory and Stacks

Frame Pointer and Local Variables

Function Parameters

More Instructions

Function Pointer Parameters

Conclusion

ARM64 Linux Debugging, Disassembling, Reversing Exam

Instructions-I

The PSTATE flags

The `PSTATE` flags