Intel 80286, 80287 manual BP Usage as a Stack Frame Base Pointer

80286 BASE ARCHITECTURE

BP IS A CONSTANT POINTER TO STACK BASED VARIABLES AND WORK SPACE, ALL REFERENCES USE BP AND ARE INDEPENDENT OF SP, WHICH MAY VARY DURING A ROUTINE EXECUTION,

PROC N
PUSH AX
PUSH ARRALSIZE
CALL PROC_N+1	-----.....~PROC_N+1:
				PUSH BP
				PUSH CX
				MOV BP, SP
				SUB SP, WORK_SPACE
			"PROCEDURE BODY"
				MOV SP, BP
				POP CX
				POP BP
				RET
			'['	r
	BOTTOMOF		t
		S TACK		PARAMETERS
				RETURN ADDR
1"'--'			.-	REGISTERS
I	BP	I
L __ ..I

WORK_SPACE

PARAMETERS

RETURN ADDR

REGISTERS

WORK_SPACE

PROCEDURE N STACK FRAME

IPROCEDURE N+ 1 STACK FRAME

DYNAMICALLY ALLOCATED ON DEMAND RATHER THAN STATICALLY

---	TOP OF STACK
	STACK SEGMENT BASE

G30108

Figure 2-9. BP Usage as a Stack Frame Base Pointer

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