source: rtems/c/src/lib/libbsp/i386/i386ex/startup/setvec.c @ 60e2964

4.104.114.84.95
Last change on this file since 60e2964 was 752cd8f, checked in by Joel Sherrill <joel.sherrill@…>, on 10/15/96 at 20:57:04

initial version from Erik

  • Property mode set to 100644
File size: 1.8 KB
Line 
1/*  set_vector
2 *
3 *  This routine installs an interrupt vector on the Force CPU-386.
4 *
5 *  INPUT:
6 *    handler - interrupt handler entry point
7 *    vector  - vector number
8 *    type    - 0 indicates raw hardware connect
9 *              1 indicates RTEMS interrupt connect
10 *
11 *  RETURNS:
12 *    address of previous interrupt handler
13 *
14 *  COPYRIGHT (c) 1989, 1990, 1991, 1992, 1993, 1994.
15 *  On-Line Applications Research Corporation (OAR).
16 *  All rights assigned to U.S. Government, 1994.
17 *
18 *  This material may be reproduced by or for the U.S. Government pursuant
19 *  to the copyright license under the clause at DFARS 252.227-7013.  This
20 *  notice must appear in all copies of this file and its derivatives.
21 *
22 *  $Id$
23 */
24
25#include <rtems.h>
26#include <bsp.h>
27
28i386_isr_entry set_vector(                      /* returns old vector */
29  rtems_isr_entry     handler,                  /* isr routine        */
30  rtems_vector_number vector,                   /* vector number      */
31  int                 type                      /* RTEMS or RAW intr  */
32)
33{
34  i386_isr_entry previous_isr;
35  i386_IDT_slot  idt;
36
37  if ( type )
38    rtems_interrupt_catch( handler, vector, (rtems_isr_entry *) &previous_isr );
39  else {
40    /* get the address of the old handler */
41
42    idt = Interrupt_descriptor_table[ vector ];
43
44    previous_isr = (i386_isr_entry)
45                      ((idt.offset_16_31 << 16) | idt.offset_0_15);
46
47    /* build the IDT entry */
48    idt.offset_0_15      = ((rtems_unsigned32) handler) & 0xffff;
49    idt.segment_selector = get_cs();
50    idt.reserved         = 0x00;
51    idt.p_dpl            = 0x8e;         /* present, ISR */
52    idt.offset_16_31     = ((rtems_unsigned32) handler) >> 16;
53
54    /* install the IDT entry */
55    Interrupt_descriptor_table[ vector ] = idt;
56  }
57  return previous_isr;
58}
59
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