1 | /*-------------------------------------------------------------------------+ |
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2 | | timerisr.s v1.1 - PC386 BSP - 1997/08/07 |
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3 | +--------------------------------------------------------------------------+ |
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4 | | This file contains the PC386 timer interrupt handler. |
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5 | +--------------------------------------------------------------------------+ |
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6 | | (C) Copyright 1997 - |
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7 | | - NavIST Group - Real-Time Distributed Systems and Industrial Automation |
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8 | | |
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9 | | http://pandora.ist.utl.pt |
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10 | | |
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11 | | Instituto Superior Tecnico * Lisboa * PORTUGAL |
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12 | +--------------------------------------------------------------------------+ |
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13 | | Disclaimer: |
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14 | | |
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15 | | This file is provided "AS IS" without warranty of any kind, either |
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16 | | expressed or implied. |
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17 | +--------------------------------------------------------------------------+ |
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18 | | This code is base on: |
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19 | | timerisr.s,v 1.5 1995/12/19 20:07:45 joel Exp - go32 BSP |
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20 | | With the following copyright notice: |
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21 | | ************************************************************************** |
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22 | | * COPYRIGHT (c) 1989-1998. |
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23 | | * On-Line Applications Research Corporation (OAR). |
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24 | | * Copyright assigned to U.S. Government, 1994. |
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25 | | * |
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26 | | * The license and distribution terms for this file may be |
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27 | | * found in found in the file LICENSE in this distribution or at |
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28 | | * http://www.OARcorp.com/rtems/license.html. |
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29 | | ************************************************************************** |
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30 | | |
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31 | | $Id$ |
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32 | +--------------------------------------------------------------------------*/ |
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33 | |
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34 | |
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35 | #include "asm.h" |
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36 | |
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37 | BEGIN_CODE |
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38 | |
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39 | EXTERN(Ttimer_val) |
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40 | |
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41 | /*-------------------------------------------------------------------------+ |
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42 | | Function: rtems_isr timerisr(rtems_vector_number); |
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43 | | Description: ISR for the timer. The timer is set up to generate an |
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44 | | interrupt at maximum intervals. |
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45 | | Global Variables: None. |
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46 | | Arguments: standard - see RTEMS documentation. |
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47 | | Returns: standard return value - see RTEMS documentation. |
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48 | +--------------------------------------------------------------------------*/ |
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49 | PUBLIC(timerisr) |
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50 | SYM (timerisr): |
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51 | incl Ttimer_val # another tick |
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52 | pushl eax |
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53 | movb $0x20, al |
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54 | outb al, $0x20 # signal generic End Of Interrupt (EOI) to PIC |
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55 | popl eax |
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56 | iret |
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57 | |
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58 | END_CODE |
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59 | |
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60 | END |
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61 | |
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