19. Local Variables and EBP, Base Pointer Access to Stack

• In high-level languages like C local variables are visible only within a procedure.

• Local variables are usually constructed on the stack.

• Assembly-language procedure can define and use its own local variables in a similar manner.

• To use local variables, procedure makes indirect access to stack via base pointer register EBP.

• The address of the first local variable is defined as

  • [ EBP - varsize ]

  where varsize is the variable size.

• Sample program: local_vars.asm