Assembly

Low-level language with a very strong correspondence between the instruction in the language and the architecture's machine code instructions.

When to Use

• Operating System Kernels
• Embedded Systems / Microcontrollers
• Reverse Engineering
• Extreme optimization (rarely needed today)

Quick Start (x86_64 Linux)

section .data
    msg db "Hello, World!", 0xa
    len equ $ - msg

section .text
    global _start

_start:
    mov rax, 1      ; write syscall
    mov rdi, 1      ; stdout
    mov rsi, msg    ; buffer
    mov rdx, len    ; length
    syscall

    mov rax, 60     ; exit syscall
    xor rdi, rdi    ; exit code 0
    syscall

Core Concepts

Registers

Small, fast storage locations directly in the CPU (e.g., RAX, RBX, RIP).