disint.s

日本著名的的嵌入式实时操作系统T-Kernel的源码及用户手册。

/*
 *----------------------------------------------------------------------
 *    T-Kernel
 *
 *    Copyright (C) 2004 by Ken Sakamura. All rights reserved.
 *    T-Kernel is distributed under the T-License.
 *----------------------------------------------------------------------
 *
 *    Version:   1.01.00
 *    Released by T-Engine Forum(http://www.t-engine.org) at 2004/6/28.
 *
 *----------------------------------------------------------------------
 */

/*
 *	@(#)disint.S (libtk/S1C38K)
 *
 *	Enable/disable external interrupt
 */

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

/*
 * Disable external interrupt
 * UINT disint( void )
 *	CPSR interrupt flag is in disabled status.
 *	Return value is CPSR prior to change.
 */
	.text
	.balign	4
	.globl	Csym(disint)
	.type	Csym(disint), %function
Csym(disint):
	mrs	r0, cpsr
	orr	ip, r0, #PSR_DI
	msr	cpsr_c, ip
	bx	lr


/*
 * Enable external interrupt (restore to original state) 
 * UINT enaint( UINT intsts )
 *	Updates CPSR interrupt disabled flag with the intsts interrupt
 *	disabled flag.
 *	CPSR remains unchanged apart from the interrupt disabled flag.
 *	The return value is CPSR prior to change.
 */
	.text
	.balign	4
	.globl	Csym(enaint)
	.type	Csym(enaint), %function
Csym(enaint):
	and	r3, r0, #PSR_DI
	mrs	r0, cpsr
	bic	r2, r0, #PSR_DI
	orr	r2, r2, r3
	msr	cpsr_c, r2
	bx	lr