[android-security-discuss] How the security works in android?

[Chieh-Wen Cheng]

Hi all,
We want to know how the security works in android. For example, if we
want to access the camera deivce, the permission
"android.permission.CAMERA" must be added into AndroidManifest.xml. We
want to know how to check permission and which components are involved
in android.
We plan to learn by tracing the code. May i ask you where might be a
good start point to trace the code in android?