NASM
Comprehensive study of nasm covering fundamental concepts and advanced applications.
Basic Concepts
Registers and Memory in x86
Meet the CPU Registers
Registers are tiny storage locations inside the CPU. They are lightning-fast and essential for all calculations and data movement.
Common x86 Registers
eax
,ebx
,ecx
,edx
: General-purpose registersesi
,edi
: Used for string and memory operationsesp
,ebp
: Stack pointer and base pointer
Memory Access
NASM allows you to read from and write to memory using operands and addresses. Data can be moved between registers and memory with the mov
instruction.
Example
mov eax, [myVar] ; Load value from memory
mov [myVar], ebx ; Store value into memory
Why Are Registers Important?
- They make your code super fast.
- You must manage them carefully — using the wrong register can cause bugs.
Real-World Analogy
Think of registers as your computer's "scratchpad" for doing calculations, while memory is like a giant notebook you can store things in.
Understanding registers and memory is the key to mastering NASM!
Examples
Using
eax
to perform calculations.Storing and retrieving data from memory using NASM.
In a Nutshell
Registers are the CPU's fast storage; memory holds data for the program.