irq_handler.s

ARM嵌入式系统开发--软件设计与优化随书源代码。开发环境asm+c

;  ____________________________________________________________________
; 
;  Copyright (c) 2002, Andrew N. Sloss, Chris Wright and Dominic Symes
;  All rights reserved.
;  ____________________________________________________________________
; 
;  NON-COMMERCIAL USE License
;  
;  Redistribution and use in source and binary forms, with or without 
;  modification, are permitted provided that the following conditions 
;  are met: 
;  
;  1. For NON-COMMERCIAL USE only.
; 
;  2. Redistributions of source code must retain the above copyright 
;     notice, this list of conditions and the following disclaimer. 
; 
;  3. Redistributions in binary form must reproduce the above 
;     copyright notice, this list of conditions and the following 
;     disclaimer in the documentation and/or other materials provided 
;     with the distribution. 
; 
;  4. All advertising materials mentioning features or use of this 
;     software must display the following acknowledgement:
; 
;     This product includes software developed by Andrew N. Sloss,
;     Chris Wright and Dominic Symes. 
; 
;   THIS SOFTWARE IS PROVIDED BY THE CONTRIBUTORS ``AS IS'' AND ANY 
;   EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 
;   IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 
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; 
; **********************************************************************
; * Simple Little Operating System - SLOS
; **********************************************************************

; **********************************************************************
; *
; * Module      : handler.s
; * Description : handles the irq events
; * OS          : SLOS
; * Platform    : Integrator/AP 940  
; * History     :
; *
; * 21 December 2001 Andrew N. Sloss
; * - started working on the handlers
; *   
; * 19th April 2002 Andrew N. Sloss
; * - added support for Integrator 940
; *
; * 30th April 2002 Andrew N. Sloss
; * - remove the button service routine
; *
; **********************************************************************  

; **********************************************************************
; * EXPORT
; **********************************************************************

     EXPORT     events_irq_cm920iap_handler

; **********************************************************************
; * IMPORT
; **********************************************************************

     IMPORT     events_tick_cm920iap_service
     IMPORT     Kernel_Scheduler

; **********************************************************************
; * ROUTINES
; **********************************************************************

     AREA IRQI940,CODE,READONLY

CMRegisterBase DCD     0x10000000
IRQ0_BASE      DCD     0x14000000

TIMERINT2      EQU     0x00000080
STATUS         EQU     0x00000000

; -- events_irq_handler ----------------------------------------------------------
;
; Description	: handles the IRQ interrupt and determines the source and then
;		  vectors to the correct interrupt rountine.
;

events_irq_cm920iap_handler

     SUB     r14, r14, #4
     STMFD   r13!, {r0-r3, r12, r14}         ; save current context    	
     LDR     r0, IRQ0_BASE                   ; Load Base address of Int Ctlr
     LDR     r0, [r0,#STATUS]                ; Read Interrupt status
     LDR     r1, =0x000001ff                 ; load value to mask off upper bits
     AND     r0, r0, r1                      ; mask off unused interrupts
     TST     r0, #TIMERINT2
     BNE     events_tick_cm920iap_veneer
	LDMFD   r13!, {r0-r3, r12, pc}^         ; unknown event ignore

events_tick_cm920iap_veneer

     BL      events_tick_cm920iap_service
     B       Kernel_Scheduler
     END
	
; **********************************************************************
; * END of handler.s
; **********************************************************************