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。小操作系统。

;  ____________________________________________________________________
; 
;  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.
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;  2. Redistributions of source code must retain the above copyright 
;     notice, this list of conditions and the following disclaimer. 
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;  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. 
; 
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; 
; ****************************************************************************
; * Simple Little Operating System - SLOS
; ****************************************************************************

; ****************************************************************************
; *
; * Module      : handler.s
; * Description : handles the irq events
; * OS          : SLOS
; * Platform    : e7t
; * History     :
; *
; * 21 December 2001 Andrew N. Sloss
; * - started working on the handlers
; *   
; ****************************************************************************

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

     EXPORT     eventsIRQHandler

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

     IMPORT     eventTickService
     IMPORT     eventButtonService
     IMPORT     kernelScheduler

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

     AREA IRQE7T,CODE,READONLY

; -- address of the IRQ controller for the Samsung KS32C50100. 

INTPND    DCD  0x03ff4004     ; IRQ controller 

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

eventsIRQHandler

     SUB     r14, r14, #4
     STMFD   r13!, {r0-r3, r12, r14}    ; save context
	LDR     r0, INTPND	 
	LDR     r0, [r0]                   ; get IRQ source		
     TST     r0, #0x0400
     BNE     eventTickVeneer            ; if timer interrupt
     TST     r0, #0x0001		
     BNE     eventButtonVeneer          ; if button interrupt
     LDMFD   r13!, {r0-r3, r12, pc}^    ; unknown event ignore

eventButtonVeneer

     BL      eventButtonService
     LDMFD   r13!, {r0-r3, r12, pc}^    ; return to task

eventTickVeneer

     BL      eventTickService
     B       kernelScheduler
	END