title: Arguments for mount in Android recovery update script
body: <p>When looking at the update that was released for Android 4.2.2 (see <a href="http://android.clients.google.com/packages/ota/google_nakasi/6ece895ecb23.signed-nakasi-JDQ39-from-JOP40D.6ece895e.zip" rel="nofollow noreferrer">link</a> ), I was trying to understand the scipt file they wrote.</p>
  
  <p>It contains:</p>
  
  <pre><code>mount("ext4", "EMMC", "/dev/block/platform/sdhci-tegra.3/by-name/APP", "/system");
  </code></pre>
  
  <p>I am new to writing such script files. I know linux has a <code>mount</code> command. How do the four arguments above relate to linux <code>mount</code> command and what do they mean ?</p>