disint.s

使用广泛的日本著名的开源嵌入式实时操作系统T-Kernel的源码

/*
 *----------------------------------------------------------------------
 *    T-Kernel
 *
 *    Copyright (C) 2004-2006 by Ken Sakamura. All rights reserved.
 *    T-Kernel is distributed under the T-License.
 *----------------------------------------------------------------------
 *
 *    Version:   1.02.02
 *    Released by T-Engine Forum(http://www.t-engine.org) at 2006/8/9.
 *
 *----------------------------------------------------------------------
 */

/*
 *	@(#)disint.S (libtk/M32104)
 *
 *	Enable/disable external interrupt 
 */

#include <machine.h>
#include <tk/sysdef.h>

/*
 * Disable external interrupt 
 * UINT disint( void )
 *	PSW.IE = 0; return value is ~PSW prior to change.
 */
	.text
	.balign	4
	.globl	Csym(disint)
	.type	Csym(disint), @function
Csym(disint):
	mvfc	r0, psw
	ldi	r1, #~PSW_IE
	and	r1, r0
	not	r0, r0
	mvtc	r1, psw
	jmp	lr

/*
 * Enable external interrupt (restore to original state)
 * UINT enaint( UINT intsts )
 *	PSW.IE = ~intsts.IE;  Only PSW.IE changes; all else remains unchanged. 
 *	The return value is ~PSW prior to the change.
 */
	.text
	.balign	4
	.globl	Csym(enaint)
	.type	Csym(enaint), @function
Csym(enaint):
	mvfc	r4, psw
	and3	r5, r0, #PSW_IE
	or3	r6, r4, #PSW_IE
	not	r0, r4
	xor	r6, r5
	mvtc	r6, psw
	jmp	lr