section .data
    buf times 1920 db 0

section .text
_start:
    mov rsi, buf     ; 書き込み位置
    mov rcx, 640       ; 4文字

loop:
    mov al, 'w'
    mov [rsi], al
    inc rsi
    mov al, 'W'
    mov [rsi], al
    inc rsi
    mov al, 'v'
    mov [rsi], al
    inc rsi
    loop loop

    mov rax, 1
    mov rdi, 1
    mov rsi, buf
    mov rdx, 1920
    syscall

    mov rax, 60
    xor rdi, rdi
    syscall