section .data
    msg db "Hello world!", 0ah
    gsm db "world! Hello", 0ah

section .text
    global _start

_start:
    mov eax, 0
    STRT:
    cmp eax, 1  
    je  L_true    
    jmp L_end
    L_true:
        mov rax, 1
        mov rdi, 1
        mov rsi, gsm
        mov rdx, 13
        syscall
        jmp end
    L_end:
        mov rax, 1
        mov rdi, 1
        mov rsi, msg
        mov rdx, 13
        syscall
        mov eax,1
        jmp STRT
    end:
    mov rax, 60
    mov rdi, 0
    syscall