title: `fbcon/cursor_blink` permissions reset at reboot
body: <h2>Context</h2>
  <p>I need to stop the cursor from blinking on an external screen of my raspberry-pi in order to display a home-made interface on <code>/dev/fb0</code>.</p>
  <p>For this purpose I created a group <code>cursor_blink</code> in which I put my user and changed the permissions of the file <code>/sys/class/graphics/fbcon/cursor_blink</code> as follow:</p>
  <pre><code>chown root:cursor_blink /sys/class/graphics/fbcon/cursor_blink
  chmod 664 /sys/class/graphics/fbcon/cursor_blink
  </code></pre>
  <p>So my user in the group <code>cursor_blink</code> can write <code>1</code> or <code>0</code> to display and hide the cursor from the screen.</p>
  <h2>Problem</h2>
  <p>I had this working, but reinstalling it on another system makes that this file is now reset to the default permissions every time I reboot, the mode becomes again <code>600</code> and the owner <code>root:root</code> after reboot instead of <code>660</code> and <code>root:cursor_blink</code></p>
  <p>It seems that <strong>the file is recreated</strong> (some digging in the last edit times with <code>stat</code> corroborate this element).</p>
  <h2>Question</h2>
  <p>Is there a way to keep the permissions as set, and prevent them of being reset ?</p>