获取程序集错误：行

Question

我试图用汇编语言（nasm，ubuntu）编写一个简单的程序来添加2个数字。我坚持这个错误

  

错误：行开头预期的标签或说明

我在运行在线编译器上的代码时没有遇到上述错误。但是如果尝试在ubuntu环境中运行相同的代码，那么我就会遇到错误提及。

代码I使用

;The following Program performs addition of two numbers

section .data
    msg1 db 'Enter 1st digit: ', 0xa
    len1 equ $-msg1
    msg2 db 'Enter 2nd digit: ', 0xa
    len2 equ $-msg2
    msg3 db 'The sum is: '
    len3 equ $-msg3

section .bss
    num1 resb 2
    num2 resb 2
    res  resb 1

section .text
    global _start       ;must be declared for using gcc

_start:                 ;tell linker entry point

    mov ebx, 1
    mov ecx, msg1
    mov edx, len1
    mov eax, 4  
    int 0x80

    mov ebx, 0
    mov ecx, num1
    mov edx, 2
    mov eax, 3  
    int 0x80

    mov ebx, 1
    mov ecx, msg2
    mov edx, len2
    mov eax, 4  
    int 0x80

    mov ebx, 0
    mov ecx, num2
    mov edx, 2
    mov eax, 3  
    int 0x80

    ;O/Ps "The sum is:"
    mov ebx, 1
    mov ecx, msg3
    mov edx, len3
    mov eax, 4  
    int 0x80

    ;moving the first number to eax register and second number to ebx and subtracting ascii '0' to convert it into a decimal number
    mov eax, [num1]
    sub eax, '0'
    mov ebx, [num2]
    sub ebx, '0'

    ;add eax & ebx then add '0' to convert the sum from decimal to ASCII
    add eax, ebx
    add eax, '0'

    ;storing the sum in memory location res
    mov [res], eax

    ;print the sum
    mov ebx, 1
    mov ecx, res
    mov edx, 1
    mov eax, 4
    int 0x80

    ;Exit
    mov eax, 1
    int 0x80