When and How android initializes SIM card info

Question

I would like to know two things regarding to Android SIM initialization process:

1. Which Service is responsible to retrieve SIM card information?
2. When the Android framework retrieve that information at runtime / on reboot?

Answer 1

How android initializes SIM card?

This is done by the TelephonyManager and its different getSimSerialNumber() (Also see other getSim* methods).

When android initializes SIM card?

This is happend a lot inside framework (You can see here any time this method is being called), But in general any time the phone is reboot or the phone come back from Flight State.