pc386/btimer/timerisr.S

0001 /*-------------------------------------------------------------------------+
0002 | timerisr.s v1.1 - PC386 BSP - 1997/08/07
0003 +--------------------------------------------------------------------------+
0004 | This file contains the PC386 timer interrupt handler.
0005 +--------------------------------------------------------------------------+
0006 | (C) Copyright 1997 -
0007 | - NavIST Group - Real-Time Distributed Systems and Industrial Automation
0008 |
0009 | http://pandora.ist.utl.pt
0010 |
0011 | Instituto Superior Tecnico * Lisboa * PORTUGAL
0012 +--------------------------------------------------------------------------+
0013 | Disclaimer:
0014 |
0015 | This file is provided "AS IS" without warranty of any kind, either
0016 | expressed or implied.
0017 +--------------------------------------------------------------------------+
0018 | This code is base on:
0019 |   timerisr.s,v 1.5 1995/12/19 20:07:45 joel Exp - go32 BSP
0020 | With the following copyright notice:
0021 | **************************************************************************
0022 | *  COPYRIGHT (c) 1989-1999.
0023 | *  On-Line Applications Research Corporation (OAR).
0024 | *
0025 | *  The license and distribution terms for this file may be
0026 | *  found in the file LICENSE in this distribution or at
0027 | *  http://www.rtems.org/license/LICENSE.
0028 | **************************************************************************
0029 +--------------------------------------------------------------------------*/
0030
0031 #include <rtems/asm.h>
0032
0033 BEGIN_CODE
0034
0035     EXTERN(Ttimer_val)
0036
0037 /*-------------------------------------------------------------------------+
0038 |         Function: rtems_isr timerisr(rtems_vector_number);
0039 |      Description: ISR for the timer. The timer is set up to generate an
0040 |                   interrupt at maximum intervals.
0041 | Global Variables: None.
0042 |        Arguments: standard - see RTEMS documentation.
0043 |          Returns: standard return value - see RTEMS documentation.
0044 +--------------------------------------------------------------------------*/
0045     PUBLIC(timerisr)
0046 SYM (timerisr):
0047     incl    Ttimer_val  # another tick
0048     pushl   eax
0049     movb    $0x20, al
0050     outb    al, $0x20   # signal generic End Of Interrupt (EOI) to PIC
0051     popl    eax
0052     iret
0053
0054 END_CODE
0055
0056 END