title: make bootable iso with only assembler
body: <p>For floppy disk, I can make a boot.img file with assembler only.</p>
  
  <p>At the end of source file, I just wrote:</p>
  
  <pre><code>org 0x7c00
  jmp start
  start:
  cli
  hlt
  times 510 - ($- $$) db 0
  db 0x55 
  db 0xaa
  times 1474560 - ($-$$) db 0
  </code></pre>
  
  <p>But now, how can I make bootable iso like above?</p>
  
  <p>in floppy case, </p>
  
  <pre><code>times 1474560 -($-$$) db 0 
  </code></pre>
  
  <p>was the key.</p>