NASM syntax basics
| Sections | |
| Labels | |
| Operands |
Sections
A NASM program is divided into sections. .text holds code, .data holds initialized data, and .bss holds uninitialized reserves. The section directive switches between them:
section .text
mov rax, 1
section .data
count dq 0
Labels
A label names a position in the code or a byte of data. Labels end with a colon, and the assembler turns them into addresses:
start:
mov rax, 1
jmp start
Operands
Most instructions take two operands: destination first, source second. The destination is where the result lands, and the source is what gets moved or added. Comments start with a semicolon:
mov rax, rbx ; copy rbx into rax
add rax, 1 ; rax = rax + 1
Next: Your first program
Article author: Arthur Isaev
