The dependencies to the Android /system folder include two parts:

• All kernel modules for device drivers are located at: $OUT/system/lib/modules/4.x.x-android-x86.
• We need to run some basic Linux commands during the recovery boot process. For example, we do hardware initialization using the following command:
  on init
  exec -- /system/bin/logwrapper /system/bin/sh /system/etc/init.sh

Let's work on the preceding two points one by one in the following sections.