Assembly exercise - write "Hello world" to a new file called "test"

write.asm

SECTION .data
msg   db  "Hello world"
len   equ $ - msg 
fname db  "test", 0

SECTION .text
global _start
_start:
  mov     rdi, fname  ;param1 to open(), file name
  mov     rsi, 101    ;param2 to open(), file mode
  mov     rdx, 0q666  ;param3 to open(), file permissions
  mov     rax, 2      ;open()
  syscall
  mov     rdi, rax    ;put file handle as param1 to write()
  mov     rsi, msg    ;param2 to write(), our message
  mov     rdx, len    ;param3 to write(), msg length
  mov     rax, 1      ;write()
  syscall
  mov     rax, 3      ;close(), file handle should already be in rdi
  syscall
  mov     rax, 60     ;exit()
  syscall