path: root/c/src/lib/libbsp/i386/go32/timer/timerisr.s

#  timer_isr()
#
#  This routine provides the ISR for the timer.   The timer is set up 
#  to generate an interrupt at maximum intervals.
#
#  Input parameters:  NONE
#
#  Output parameters:  NONE
#
#  COPYRIGHT (c) 1989, 1990, 1991, 1992, 1993, 1994.
#  On-Line Applications Research Corporation (OAR).
#  All rights assigned to U.S. Government, 1994.
#
#  This material may be reproduced by or for the U.S. Government pursuant
#  to the copyright license under the clause at DFARS 252.227-7013.  This
#  notice must appear in all copies of this file and its derivatives.
#
#  $Id$
#

#include "asm.h"

        BEGIN_CODE

        EXTERN(_Ttimer_val)

        PUBLIC(timerisr)

SYM (timerisr): 
        addl    $250,_Ttimer_val   # another 250 microseconds
        push    edx
        push    eax
        movw    $0x20,dx
        mov     edx,eax
        outb    al,(dx) # touch interrupt controller
        pop     eax
        pop     edx
        iret

END_CODE
END