title: Android emulator: Building boot.img from AOSP
body: <p>I am trying to build AOSP 4.3 (build: JSR78D; branch: android-4.3_r2) on Debian 7 (amd64). I followed the instructions listed in <a href="https://source.android.com/source/building.html" rel="nofollow noreferrer">Google Android website</a> and finished build steps successfully. At the end, I could test my newly built image with the <em>Android emulator</em>. </p>
  
  <p>Now, I have 3 image files in the <code>out/target/product/generic</code> directory: <code>system.img</code>, <code>userdata.img</code>, and <code>ramdisk.img</code>. However, <code>boot.img</code> is missing. I tried issuing the <code>make bootimage</code> command, but it did not help generating the aforesaid file. I expected <code>Makefile</code> to automatically build this file for me since it includes <code>build/core/main.mk</code> which has <code>bootimage</code> as one of its targets.</p>
  
  <p>PS. I have seen posts like <a href="https://stackoverflow.com/questions/21173628/what-is-boot-img-file-in-android">this</a>, but it is still not clear to me why <code>boot.img</code> is not built automatically.</p>