Control passes to __rt_entry after all scatter-loaded regions have been relocated to their execution addresses.

Usage

The default implementation of __rt_entry:

1. Performs hardware initialization by calling _platform_pre_stackheap_init(), if this function is defined.
2. Sets up the heap and stack.
3. Initializes the C library by calling __rt_lib_init.
4. Calls main().
5. Shuts down the C library, by calling __rt_lib_shutdown.
6. Exits.

__rt_entry must end with a call to one of the following functions:

exit()

Calls atexit()-registered functions and shuts down the library.

__rt_exit()

Shuts down the library but does not call atexit() functions.

_sys_exit()

Exits directly to the execution environment. It does not shut down the library and does not call atexit() functions.