View source for COMBO HMI ENGINEERING MENU in Audi MHI2

By looking at the LSD.JXE and digging inside the key combos, it seams that there's a HMI hidden menu in Audi, Porsche, and Bentley builds.

== What's the key combination for HMI_EM? ==
<code>Keycode ID</code> for it is <code>26</code>, and it's called <code>KEY_COMBO_HMI_EM</code>. Here's part of the code responsible for triggering the menu:

 private void triggerComboKeyAction(int n, int n2) {
  int n3 = this.getComboKeyCombination(n, n2);
  if (n3 == 8) {
   if (!this.framework.isPBuild()) {
    this.kbdListener.triggerHmiKeyPressedEvent(26, this.key1TerminalID);
   }
  }
 }

What does it mean? Allow me to fill in couple variables with specific values:

 private void triggerComboKeyAction(3, 11) { //this is triggered by key TEL (3) and SW_NE (11)
  int n3 = this.getComboKeyCombination(3, 11); // this will return n3 = 8
  if (n3 == 8) {
   if (!this.framework.isPBuild()) { //this checks if the build is NOT flagged as production release
    this.kbdListener.triggerHmiKeyPressedEvent(26, this.key1TerminalID); //this triggers the HMI_EM (26) keycode
   }
  }
 }

<code>SW_NE</code> is the upper-right software button. Sadly it is not present in Audi A3 8V facelift.

== How to mark release as not production build? ==
Let's check how the <code>isPBuild()</code> function looks like.

 public boolean isPBuild() {
  return this.getVersionInfo().isProductionVersion();
 }

...and let's look for the <code>isProductionVersion()</code> function.

 public boolean isProductionVersion() {
  return Boolean.getBoolean("IS_PRODUCTION_MODE");
 }

This looks like one of the VMOPTIONS flag. So let's modify the <code>run_lsd.sh</code> script by editing this part and setting it to <code>false</code>:

 ## Mark as production version which disables some developer features
 VMOPTIONS="$VMOPTIONS -DIS_PRODUCTION_MODE=false"