https://sx.ix5.org/info/android-init-stages/
.
Adapted from Jonathan Levin’s excellent Android Internals: A Confectioner’s Cookbook, chapter 4.
Programs can be started based on init stage triggers:
service my_service /bin/mysvc
user system
group system
disabled
on boot
start my_service
But it is more common to assign a class to a service, based on which it is started:
service my_service /bin/mysvc
class core
user system
group system
The service will be started based on class_start core which happens on boot.
TODO: Overview of classes
With the introduction of system-wide encryption into Android, the init process gains a few more tricks: - vold.decrypt triggers - class early_hal for crucial services needed for decryption, e.g. keymaster and gatekeeper (TODO: Add link to AOSP init.rc for class_start) - restarting framework, reboot, minimal UI stuff - nonencrypted trigger, which, despite its name, always gets triggered and which pulls in class_start main and class_start late_start
on property:vold.decrypt=trigger_restart_min_framework
class_start main
on property:vold.decrypt=trigger_restart_framework
stop surfaceflinger
start surfaceflinger
class_start main
class_start late_start
on property:vold.decrypt=trigger_shutdown_framework
class_reset late_start
class_reset main