int386x

interrupt the CPU

Synopsis:

#include <i86.h>
int int386x( int inter_no,
         const union REGS *in_regs,
         union REGS *out_regs,
         struct SREGS *seg_regs );

Description:

The int386x() function causes the computer's central processor (CPU) to be interrupted with an interrupt whose number is given by inter_no. This function is present in the 32-bit C libraries, and may be executed on Intel 386 compatible systems. Before the interrupt, the CPU registers are loaded from the structure located by in_regs, and the DS, ES, FS and GS segment registers are loaded from the structure located by seg_regs.

All of the segment registers must contain valid values. Failure to do so will cause a segment violation when running in protect mode. If you don't care about a particular segment register, then it can be set to 0, which will not cause a segment violation. The function segread() can be used to initialize seg_regs to their current values.

Following the interrupt, the structure located by out_regs is filled with the contents of the CPU registers. The in_regs and out_regs structures may be located at the same location in memory. The original values of the DS, ES, FS and GS registers are restored. The structure seg_regs is updated with the values of the segment registers following the interrupt.

Returns:

the value of the CPU EAX register after the interrupt

See also:

int386(), int86(), int86x(), intr(), segread()

Examples:

#include <stdio.h>
#include <i86.h>

/* get current mouse interrupt handler address */

void main()
  {
    union REGS r;
    struct SREGS s;

    s.ds = s.es = s.fs = s.gs = FP_SEG( &s );

#if defined(__PHARLAP__)
    r.w.ax = 0x2503;    /* get real-mode vector */
    r.h.cl = 0x33;      /* interrupt vector 0x33 */
    int386( 0x21, &r, &r );
    printf( "mouse handler real-mode address="
        "%lx\n", r.x.ebx );
    r.w.ax = 0x2502;    /* get protected-mode vector */
    r.h.cl = 0x33;      /* interrupt vector 0x33 */
    int386x( 0x21, &r, &r, &s );
    printf( "mouse handler protected-mode address="
        "%x:%lx\n", s.es, r.x.ebx );

#else
    r.h.ah = 0x35;  /* get vector */
    r.h.al = 0x33;  /* vector 0x33 */
    int386x( 0x21, &r, &r, &s );
    printf( "mouse handler protected-mode address="
        "%x:%lx\n", s.es, r.x.ebx );
#endif
  }

Classification:

Intel

Systems:

DOS/32, QNX/32, Netware