This MR uses an intermediary function `start_app` to call after system
initialization instead of `app_main`.
In RTOS builds, freertos provides `start_app` and calls `app_main`.
In non-RTOS builds, user provides `start_app` directly.
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
This commit updates the watchdog timers (MWDT and RWDT)
in the following ways:
- Add seprate LL for MWDT and RWDT.
- Add a combined WDT HAL for all Watchdog Timers
- Update int_wdt.c and task_wdt.c to use WDT HAL
- Remove most dependencies on LL or direct register access
in other components. They will now use the WDT HAL
- Update use of watchdogs (including RTC WDT) in bootloader and
startup code to use the HAL layer.
