Why assembly doesnt outputing text?

Question

Idk why Assembly is cant output text:
section .text
global _start
_start:
mov edx,len
mov ecx,msg
mov ebx,1
mov eax,4
int 0x80
mov eax,1
int 0x80
section .data
msg: db 'Walled', 0xa
len: equ $-msg

Answer 1

Russian Man try placing the .data section first, before the .text section. The problem might be that the assembler does not have a definition for msg and len before they are referenced.