Changes the startup flow to the ff:
hardware -> core libraries init -> other libraries init -> os
init (optional) -> app_main
- hardware init resides in the port layer, and is the entry point
- core libraries init executes init functions of core components
- other libraries init executes init functions of other components (weak
references)
- after other lib is init, the app_main function is called, however,
an OS can wrap the real call to app_main to init its own stuff, and
*then* call the real app_main
