Interview Question - What is a start-up routine for the processor and, what does this routine do

Embedded C interview Question

What is a start-up routine for the processor and, what does this routine do.

A startup or entry routine in native assembly code is linked into the source code subsequently programmed into the EPROM’s.

The routine is responsible for the following:

• Initializes the stack pointer (SP). 
• Initializes the frame pointer (FP). 
• Clears the zero vars section. 
• Initializes the I/O system. 
• Sets up the exception vector tables. 
• Copies initialized data to the vars section from ROM to RAM. 
• Calls the main () function