title: load warning: cannot find entry symbol _start
body: <p>I'm learning assembly programming. Below is the simple program that prints 'Hello, World!'. While the program runs perfectly, I'm getting the warning message while <code>loading</code></p>
  
  <blockquote>
    <p>ld: warning: cannot find entry symbol _start; defaulting to 0000000008048080</p>
  </blockquote>
  
  <p>Here is the code :</p>
  
  <pre><code>section .data
      msg db 'Hello, world!', 0xa
      len equ $ - msg
  
  section .text
      global main
  
  main:
  
      mov ebx, 1
      mov ecx, msg
      mov edx, len
      mov eax, 4
      int 0x80
  
      mov eax, 1
      int 0x80
  </code></pre>
  
  <p>Can anybody explain the meaning of this warning. I'm using <code>nasm</code> with <code>ubuntu 14</code>. </p>