string equals in x86_64 nasm assembly

str.s

section .text
global start
start:
	mov rsi, s1     ; esi = &s1
	mov rdi, s2     ; edi = &s2
	xor rdx, rdx    ; edx = 0
loop:
	mov al, [rsi + rdx]
	mov bl, [rdi + rdx]
	inc rdx
	cmp al, bl      ; compare two current characters
	jne not_equal   ; not equal
	cmp al, 0       ; at end?
	je equal        ; end of both strings
	jmp loop        ; equal so far
not_equal:
	mov rdi, 1
	jmp exit
equal:
	mov rdi, 0
	jmp exit
exit:
	mov rax, 0x2000001  ; sys_exit
	; mov rdi, 0
	syscall
section .data
s1: db "string one", 0
s2: db "string on1", 0

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This code has an error at line 23. mov rax, 0x2000001 will raise segmentation fault (core dump). Use mov rax, 60 instead. 60 is the code of the system call SYS_EXIT.

This code has an error at line 23. mov rax, 0x2000001 will raise segmentation fault (core dump). Use mov rax, 60 instead. 60 is the code of the system call SYS_EXIT.

mov rax, 0x2000001 is the syscall for exit in assembly on macos.

You can also use the cmps instruction.