Write text to file

section .data
    filename:   db 'hello.txt',0
    text:       db 'Hello World!',10
    textLen:    equ $-text

section .bss
    fd:     resb    4

section .text
    global _start

_start:
    mov eax,8
    mov ebx,filename
    mov ecx,1
    int 80h
    mov [fd],eax

    mov eax,15
    mov ebx,filename
    mov ecx,420
    int 80h

    mov ebx,[fd]
    mov eax,4
    mov ecx,text
    mov edx,textLen
    int 80h

    mov eax,1
    mov ebx,0
    int 80h