The smallest program in Assembly

Load the exit syscall's number and make the call: five lines.

; The smallest program: set up the exit syscall and make it.
        global _start

        section .text
_start:
        mov rax, 60             ; syscall number for exit
        xor rdi, rdi            ; status 0, the cheap way
        syscall

How it works

1. global _start exports the entry point the linker expects.
2. mov rax, 60 selects sys_exit; rdi carries the status.
3. xor rdi, rdi zeroes a register in the cheapest encoding.

Keywords and builtins used here

• global
• mov
• rax
• rdi
• section
• syscall
• xor

The run, in numbers

Lines

8

Characters to type

205

Tokens

17

Three-star pace

65 tpm

At the three-star pace of 65 tokens a minute, this run takes about 16 seconds.

Type this snippet

Step 1 of 3 in First programs, step 1 of 31 in Language basics.

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