;* Copyright 2004 Develer S.r.l. (http://www.develer.com/)
;* Copyright 1999,2000,2001 Bernardo Innocenti <bernie@develer.com>
;* This file is part of DevLib - See devlib/README for information.
;*
;* \version $Id$
;*
;* \author Bernardo Innocenti <bernie@develer.com>
;*

;* $Log$
;* Revision 1.2  2004/06/06 16:14:12  bernie
;* Add DevLib license information.
;*
;* Revision 1.1  2004/05/23 17:27:00  bernie
;* Import kern/ subdirectory.
;*
;*

!!!!!! THIS FILE HAS NOT BEEN REVISED FOR THE NEW SCHEDULER API !!!!!!



	NAME	AsmSwitch
	RSEG	CODE

	EXTERN	?LR
	EXTERN	?GR
	PUBLIC	AsmSwitchContext
	PUBLIC	AsmReplaceContext


;* Perform low-level process context switching
;*
;*	void AsmSwitchContext(cpustack_t *new_sp, cpustack_t **save_sp)
;*                                        GR+0                 SP+2
;*
;* Replace current context with new process
;*
;*	void AsmReplaceContext(cpustack_t *new_sp, cpustack_t **dummy)
;*                                         GR+0                 SP+2
;*

AsmSwitchContext:

; pop 2nd parameter from the stack
	ld	?GR+2,2[SP]

; save all registers
	push	?LR+0
	push	?LR+2
	push	?LR+4
	push	?LR+6
	push	?LR+8
	push	?LR+10
	push	?LR+12
	push	?LR+14
	push	?LR+16
	push	?LR+18
	push	?LR+20
	push	?LR+22
	push	?LR+24
	push	?LR+26
	push	?LR+28
	push	?LR+30
	st	SP,[?GR+2]		; save old stack pointer
	; fall-thru

AsmReplaceContext:
	ld	SP,?GR+0		; load new stack pointer

; restore all registers
	pop	?LR+30
	pop	?LR+28
	pop	?LR+26
	pop	?LR+24
	pop	?LR+22
	pop	?LR+20
	pop	?LR+18
	pop	?LR+16
	pop	?LR+14
	pop	?LR+12
	pop	?LR+10
	pop	?LR+8
	pop	?LR+6
	pop	?LR+4
	pop	?LR+2
	pop	?LR+0

; restore execution in new context
	ret

	END