What are the start-up code steps ?

Start-up code for C programs usually consists of the following actions, performed in the order described:

    1.    Disable all interrupts.
    2.    Copy any initialized data from ROM to RAM.
    3.    Zero the uninitialized data area.
    4.    Allocate space for and initialize the stack.
    5.    Initialize the processor’s stack pointer.
    6.    Create and initialize the heap.
    7.    Enable interrupts.
    8.    Call main.