RTEMS Porting Guide
The CPU_STACK_GROWS_UP macro is set based upon the answer to the following question: Does the stack grow up (toward higher addresses) or down (toward lower addresses)? If the stack grows upward in memory, then this macro should be set to TRUE. Otherwise, it should be set to FALSE to indicate that the stack grows downward toward smaller addresses.
The following illustrates how the CPU_STACK_GROWS_UP macro is set:
#define CPU_STACK_GROWS_UP TRUE
RTEMS Porting Guide
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