irq.s

一个简单实用的嵌入式操作系统,实现了嵌入式操作系统的基本模块：内存管理、系统调度 、系统调用等。

;/*
; *  kernel/asm/irq_novic.s
; *
; *  Copyright (C) 2008/05/22 Wang Qiang
; *
; * This program is free software; you can redistribute it and/or modify
; * it under the terms of the GNU General Public License version 2 as
; * published by the Free Software Foundation.
; *
; * history: 
; * 2008/05/22, wangqiang , [e-mail]
; *   copy from irq.s, modify for the no vic mcu, s3c24xx serial for example
; */

    INCLUDE asm\config.inc
    INCLUDE mcu\memregions.inc
    IMPORT irq_addr_table
    EXPORT irq_handler
    CODE32

    AREA    IRQ,CODE,READONLY
irq_handler
    sub     lr, lr, #4
    stmfd   sp!, {r0-r3,r12,lr}
    ldr     r1, =INTOFFSET          ; get the interrupt offset register
    ldr     r2, [r1]                ; get the interrupt offset value
    ldr     r1, =irq_addr_table
    add     r2, r1, r2, lsl #2      ; get vic addr address
    ldr     r2, [r2]                ; get the interrupt service routine
    mov     lr, pc
    mov     pc, r2                  ; go to the ISR
irq_end
    ldmfd   sp!, {r0-r3, r12, pc}^
    END