User's Manual

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 ARRA LSIZE
CALL PROC_N+1 ----- ..... ~ PROC_N+1:
PUSH BP
PUSH CX
MOV BP, SP
SUB SP, WORK_SPACE
"PROCEDURE
BODY"
MOF BOTTO
S TACK
t
I
1"'--'
I BP
L __ ..I
--
'['
.-
---
MOV SP, BP
POP CX
POP BP
RET
PARAMETERS
RETURN
ADDR
REGISTERS
WORK_SPACE
PARAMETERS
RETURN
ADDR
REGISTERS
WORK_SPACE
r
PROCEDURE N STACK FRAME
PROCEDURE
N+ 1 STACK FRAME
I
DYNAMICALLY ALLOCATED ON
DEMAND RATHER THAN STATICALLY
TOP OF
STACK
STACK SEGMENT BASE
Figure 2-9. BP Usage as a Stack Frame Base Pointer
2-13
G30108