title: How to draw a pixel on the screen in protected mode in x86 assembly?
body: <p>I am creating a little bootloader+kernel and till now I managed to read disk, load second sector, load GDT, open A20 and enable pmode.</p>
  
  <p>I jumped to the 32-bits function that show me a character on the screen, using the video memory for textual content (0x000B0000 - 0x000B7777)</p>
  
  <pre><code>pusha
  mov edi, 0xB8000
  mov bl, '.'
  mov dl, bl
  mov dh, 63
  mov word [edi], dx
  popa
  </code></pre>
  
  <p>Now, I would like to go a little further and draw a single pixel on the screen. As I read on some website, if I want to use the graphics mode of the VGA, I have to write my pixel at location 0x000A0000. Is that right?</p>
  
  <p>Now, what is the format of a single pixel? For a single character you need ASCII code and attribute, but what do you need to define a pixel (if it works the same way as the textual mode)?</p>