; These routines emulate a push-all of the
; registers and segregs before an interrupt
; is executed, and then pop them in the
; same order. 
; Note: cpopt is used for testing so we use
; a ret instead of a iret.


	TITLE    REGISTER MANIPULATION ROUTINES
	SUBTTL   Copyright 1986 by Brian Edginton 
	NAME     STORE
	INCLUDE  DOS.MAC

	DSEG
; Register and stack storage structure follows.
S	STRUC
	RAX	DW	?
	RBX	DW	?
	RCX	DW	?
	RDX	DW	?
	RSI	DW	?
	RDI	DW	?
	RDS	DW	?
	RCS	DW	?
	RSS	DW	?
	RES	DW	?
	RIP	DW	?  ; Storage for 2 words
	RBP	DW	?  ; pushed for iret
	RFL	DW	?  ; and flags.
	RRT	DW	?  ; Return address
                           ; pushed for call.
S	ENDS
STORAGE	S	<0,0,0,0,0,0,0,0,0,0,0,0>
	ENDDS

	
	PSEG

	;  name - cpush()
	;  Pushes all the registers and segregs
        ;  and flags onto the stack.  Use with
        ;  cpop() to restore in correct order.

	PUBLIC	CPUSH
	IF	LPROG
CPUSH	PROC	FAR
	ELSE
CPUSH	PROC	NEAR
	ENDIF

	POP	STORAGE.RRT
	POP	STORAGE.RIP     ; SAVE RETI IP,
	POP	STORAGE.RCS     ; SAVE RETI CS,
	POP	STORAGE.RFL     ; SAVE THE FLAGS,
	MOV	STORAGE.RAX,AX  ; AND TUCK AWAY
	MOV	STORAGE.RBX,BX  ; ALL REGISTERS.
	MOV	STORAGE.RCX,CX
	MOV	STORAGE.RDX,DX
	MOV	STORAGE.RDI,DI
	MOV	STORAGE.RSI,SI
	MOV	STORAGE.RDS,DS  ; GET THE SEGMENT
;	MOV	STORAGE.RSS,SS  ; REGISTERS.
	MOV	STORAGE.RES,ES 
	PUSH	STORAGE.RRT     ; PUT CALL RETURN
                                ; ADDRESS ON STACK.
	RET
CPUSH	ENDP
	
	PUBLIC	CPOP
	IF	LPROG
CPOP	PROC	FAR
	ELSE
CPOP	PROC	NEAR
	ENDIF

	PUSH	STORAGE.RFL     ; RESTORE FLAGS.
	PUSH	STORAGE.RCS     ; RESTORE CS, 
	PUSH	STORAGE.RIP     ; THEN IP.
	MOV	ES,STORAGE.RES
	MOV	DS,STORAGE.RDS
	MOV	SI,STORAGE.RSI
	MOV	DI,STORAGE.RDI
	MOV	DX,STORAGE.RDX
	MOV	CX,STORAGE.RCX
	MOV	BX,STORAGE.RBX  ; READY FOR IRET 
	MOV	AX,STORAGE.RAX  ; WITH OLD IP AND
	IRET                    ; STUFF ON STACK.
CPOP	ENDP

      	PUBLIC	CPOPT
	IF	LPROG
CPOPT	PROC	FAR
	ELSE
CPOPT	PROC	NEAR
	ENDIF
	PUSH	STORAGE.RFL     ; RESTORE FLAGS.
	PUSH	STORAGE.RCS     ; RESTORE CS, 
	PUSH	STORAGE.RIP     ; THEN IP.
	MOV	ES,STORAGE.RES
	MOV	DS,STORAGE.RDS
	MOV	SI,STORAGE.RSI
	MOV	DI,STORAGE.RDI
	MOV	DX,STORAGE.RDX
	MOV	CX,STORAGE.RCX
	MOV	BX,STORAGE.RBX  ; READY FOR IRET 
	MOV	AX,STORAGE.RAX  ; WITH OLD IP AND
	RET                     ; STUFF ON STACK.

CPOPT	ENDP
	ENDPS
	END