Introduction to Assembly Language

Assembly language is a low-level programming language that provides direct control over hardware. It is specific to a computer's architecture and is often used to write performance-critical code.

Why Learn Assembly?

• Direct hardware control.
• Optimized performance for critical tasks.
• Understanding how computers work at a fundamental level.

Basic Structure of Assembly Code

An assembly program consists of three main sections:

• Data Section: Defines variables.
• BSS Section: Defines uninitialized variables.
• Text Section: Contains the code instructions.

Sample Program: Hello, World

section .data
    msg db "Hello, World!", 0xA  ; Message with a newline
    len equ $ - msg             ; Length of the message

section .text
    global _start

_start:
    mov rax, 1          ; System call: write
    mov rdi, 1          ; File descriptor: stdout
    mov rsi, msg        ; Message address
    mov rdx, len        ; Message length
    syscall             ; Make the system call

    mov rax, 60         ; System call: exit
    xor rdi, rdi        ; Exit code: 0
    syscall             ; Make the system call
    

This code, written for Linux x86-64 architecture, outputs "Hello, World!" to the terminal.