syscall OSX create file [open] - macos

Question

I intend to create a file using Mac system calls (OS X and not the bios for now). Everything compiles well, but the result that should be the creating the file "fileName db "Teste.txt", 0xA, 0x0" is not realized and I do not understand. can you help me, I also post you the source code compiled with nasm
Thank you in advance for your answers.
;------------------------------------------------------------------------------
; TITLE: SOURCE.ASM
;------------------------------------------------------------------------------
bits 64
;------------------------------------------------------------------------------
; Definition des syscall
;------------------------------------------------------------------------------
%define _stdout 0x1
%define _stderr 0x2
%define O_RDONLY 0x0000 ; open for reading only
%define O_WRONLY 0x0001 ; open for writing only
%define O_RDWR 0x0002 ; open for reading and writing
%define O_ACCMODE 0x0003 ; mask for above modes
%define O_CREAT 0x0200 ; create if nonexistant
%define O_TRUNC 0x0400 ; truncate to zero length
%define O_EXCL 0x0800 ; error if already exists
%define syscall_write 0x2000004
%define syscall_exit 0x2000001
%define syscall_open 0x2000005
%define syscall_close 0x2000006
;------------------------------------------------------------------------------
; Section code
;------------------------------------------------------------------------------
section .text
global start
start:
xor rax, rax
xor rbx, rbx
mov rbx, fileName
push mode_f
push FLAGS
push rbx
syscall
pop rax
xor rbx, rbx
mov rbx, rax
mov rax, syscall_exit
mov rdi, rbx
syscall
f_open_file:
mov rbp, rsp
push rbp
xor rax, rax
mov rax, syscall_open
mov rdi, [rbp+8]
mov rsi, [rbp+16]
mov rdx, [rbp+24]
syscall
pop rax
if: cmp rax, -1
jge else
mov rbx, rax
mov rax, syscall_close
mov rdi, rbx
syscall
pop rax
ret
else:
xor rbx, rbx
mov rbx, MsgErrr
push size_err
push rbx
call f_print_data
xor rax, rax
mov rax, -1
ret
f_print_data:
mov rbp, rsp
push rbp
mov rax, syscall_write
mov rdi, _stdout
mov rsi, [rbp+8]
mov rdx, [rbp+16]
syscall
xor rax, rax
ret
;------------------------------------------------------------------------------
; Section Data
;------------------------------------------------------------------------------
section .data
fileName db "Teste.txt", 0xA, 0x0
MsgErrr db "Erreur open File", 0xA, 0x0
size_file equ ($-fileName)
size_err equ ($-MsgErrr)
mode_f equ 0777
FLAGS equ 0xA02 ;( O_RDWR| O_CREAT| O_EXCL )

Answer 1

fileName db "Teste.txt", 0xA, 0x0
The inclusion of the newline code 0xA is fine for displaying purposes, but for opening it is no good! Drop it:
fileName db "Teste.txt", 0x0
mov rbx, fileName
push mode_f
push FLAGS
push rbx
syscall
Your code is missing the open command in order to create the file!
mov rbx, fileName
push mode_f
push FLAGS
push rbx
mov rax, syscall_open
syscall
f_open_file:
mov rbp, rsp
push rbp
To actually preserve rbp you need to swap these two instruction:
f_open_file:
push rbp
mov rbp, rsp
In doing so, you'll also need to adjust the offsets used on [rbp + ...].
All of your subroutines forget to pop rbp, and so you end up with an unbalanced stack. This leads to "segmentation faults".

Answer 2

If you want to write assembly code that makes direct system calls, use a Linux virtual machine.
The macOS system call interface is not a public API. There is no official documentation for this interface, and it differs in a number of important ways from the Linux system call interface. This makes it a terrible place for a beginner to be learning assembly!
There are much better debugging tools available on Linux as well, such as strace, which will allow you to see the exact system calls being made by your application.