Since the introduction of the Treble framework in Android 8, Android has divided the system into System and Vendor parts, allowing independent upgrades of system and vendor. Subsequently, Product, ODM, and other partitions were introduced. In this context, SELinux policies are also divided into several parts: platform (system), system_ext, product, vendor, and odm. This article uses the Vendor partition as an example to analyze in detail how to include sepolicy files in the Android build system, how Android.mk variables are passed to the Soong build system, and finally how they correspond to modules and variables in Android.bp. 1. Including SELinux Policy Files in Android Makefile First, the SELinux policy files…