To use microlib, you must specify an initial pointer for the stack. You can use either of the following methods to do this:

The scatter file method uses ARM_LIB_STACK and ARM_LIB_STACKHEAP.

Otherwise, specify the initial stack pointer by defining a symbol, __initial_sp, to be equal to the top of the stack. The initial stack pointer must be aligned to a multiple of eight bytes.

Example 15 shows how to set up the initial stack pointer using assembly language.

    EXPORT __initial_sp
__initial_sp EQU 0x100000        ; equal to the top of the stack

Example 16 shows how to set up the initial stack pointer using embedded assembler in C.

__asm void dummy_function(void)
{
    EXPORT __initial_sp
__initial_sp EQU 0x100000        ; equal to the top of the stack
}