title: Android HAL debugging: How to enable logcat
body: <p>How do I get Android logs if device doesn't boot to UI?</p>
  
  <p>Background:</p>
  
  <p>I am attempting to add a new HAL to AOSP. Details on platform:
  AOSP 6.0.1_r25
  Nexus 7 2013 (flo)
  build type: eng</p>
  
  <p>I added a new Audio HAL to AOSP, under devices/asus/flo/audio, built and flashed image.</p>
  
  <p>Device doesn't boot beyond Android logo during boot.</p>
  
  <p>adb shell says:</p>
  
  <p><code>error: insufficient permissions for device</code></p>
  
  <p>adb logcat is just</p>
  
  <p><code>- waiting for device -</code></p>
  
  <p>I know these work when I select any option other than <code>"USB for Charging"</code> but I can't get to that without booting fully.</p>
  
  <p>Now I could debug issues in my code, if only I could get logs..</p>