The Art of Assembly Language, 2nd Edition

5.14 The Standard Entry Sequence

The caller of a procedure is responsible for pushing the parameters onto the stack. Of course, the call instruction pushes the return address onto the stack. It is the procedure's responsibility to construct the rest of the activation record. You can accomplish this by using the following "standard entry sequence" code:

push( ebp );         // Save a copy of the old ebp value.
 mov( esp, ebp );     // Get pointer to base of activation record into ebp.
 sub( NumVars, esp ); // Allocate storage for local variables.

If the procedure doesn't have any local variables, the third instruction above, sub( NumVars, esp );, isn't necessary. NumVars represents the number of bytes of local variables needed by the procedure. This is a constant ...