Specifying stack and heap using the scatter file
The ARM C library provides multiple implementations of the function __user_setup_stackheap(), and can select the correct one for you automatically from information given in a scatter file.
To select the two region memory model, define two special execution regions in your scatter file named ARM_LIB_HEAP and ARM_LIB_STACK. Both regions have the EMPTY attribute. This causes the library to select the non-default implementation of __user_setup_stackheap() that uses the value of the symbols
