#pragma module load_ip_vcm "X-4"
/*
 *****************************************************************************
 *
 * Copyright © 1996 Digital Equipment Corporation.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms are permitted
 * provided that the above copyright notice and this paragraph are
 * duplicated in all such forms and that any documentation,
 * advertising materials, and other materials related to such
 * distribution and use acknowledge that the software was developed
 * by Digital Equipment Corporation.  The name of the
 * Corporation may not be used to endorse or promote products derived
 * from this software without specific prior written permission.
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
 * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 *
 *****************************************************************************
 *
 * Important Note:
 *
 *     This coding example uses privileged OpenVMS interfaces.
 *     OpenVMS does not guarantee that these interfaces will
 *     be supported indefinitely, and may change these interfaces
 *     without prior notice.
 *
 *****************************************************************************



	FACILITY:

		PPPD

	ABSTRACT:

  		Simple example to load example IPCP control protocol and VCM.
	This code requires that you have CMKRNL privilege, and assumes that
	the image to be loaded in sys$loadable_images, and that the image name
	is ip_vcm.exe.  You will need to change this code to suit your actual
	needs.

	AUTHOR:

		Forrest A. Kenney	13-July-1996

		Thanks to Karen Noel for providing the original code that this
	example is built off of.



	REVISION HISTORY:

        X-4     BWK004          Barry W. Kierstein      17-DEC-1996
                Replaced the standard Digital copyright with
                one compatible with the CMU copyright.

        X-3     BWK003          Barry W. Kierstein       1-AUG-1996
                Added "Important Note" disclaimer.

  	X-2	BWK002		Barry W. Kierstein	24-JUL-1996
  		Corrected copyright notice.

  	X-1	BWK001		Barry W. Kierstein	15-JUL-1996
  		Initial checkin of this module.
*/




/* Define data structures and constants */

#include 	<descrip.h>		/* Descriptors			*/
#include 	<ldrimgdef.h>		/* Loaded image data block	*/
#include 	<lnmdef.h>		/* Logical names		*/
#include 	<pdscdef.h>		/* Linkage pairs		*/
#include	<starlet.h>		/* System service proto-types	*/
#include 	<ssdef.h>		/* System service status codes	*/
#include 	<stdio.h>		/* CRTL I/O			*/
#include 	<string.h>		/* CTRL strings			*/

#define 	_lkpdef lkpdef
typedef 	struct lkpdef LKP;

typedef struct _ref_handle		/* Dynamic loader reference handle */
{
   void		*base_addr;
   LDRIMG	*ldrimg_ptr;
   int		seq_num;
} REF_HANDLE;



/*  Define special proto-types for the loader routines we need 		*/

extern int ldr$load_image (struct dsc$descriptor_s *execlet_name, int flags,
                           REF_HANDLE *reference_handle);
extern int ldr$ref_info (struct dsc$descriptor_s *execlet_name,
			 REF_HANDLE *reference_handle);



/* Define proto-type for Kernel routine					*/
int	load_execlet();



/* Global data								*/
REF_HANDLE reference_handle;		/* Dynamic loader ref handle	*/
struct dsc$descriptor_s execlet_name;	/* Execlet name			*/
char name[] = "IP_VCM.EXE";






/*
**++
**	Main - Get us started
**
** Functional description:
**
**	This routine exists to simply get us into Kernel mode to load the
**  execlet.
**
** Calling convention:
**
**	main()
**
** Input parameters:
**
**	None
**
** Output parameters:
**
**	None
**
** Return value:
**
**	Various SS$_xxxx
**
** Environment:
**
**	User mode.
**
**--
*/
int 	main()
{
int	status;
int	arglist[1];

    /* Call kernel mode routine to load execlet and read symbol vector */
    arglist[0] = 0;
    status = sys$cmkrnl(load_execlet,arglist);

    if (status & SS$_NORMAL)
    {
       printf("Execlet %s loaded\n", name);
    }
    else
    {
       printf("Status from load_execlet = %x.\n",status);
    }

    return (status);

}


/*
**++
**	load_execlet - Load the specified execlet
**
** Functional description:
**
**	This routine is called in Kernel Mode and will load the specified
**  execlet.
**
** Calling convention:
**
**	load_execlet()
**
** Input parameters:
**
**	None
**
** Output parameters:
**
**	None
**
** Return value:
**
**	Various SS$_xxx
**
** Environment:
**
**	Kernel mode
**
**--
*/
int	load_execlet ()
{
LKP 	*symvec;                            /* Pointer to symbol vector	*/
int 	status;

    /* Set up string descriptor with name of execlet image */
    execlet_name.dsc$w_length  = strlen (name);
    execlet_name.dsc$b_dtype   = 0;
    execlet_name.dsc$b_class   = 0;
    execlet_name.dsc$a_pointer = name;

    /* Try referencing execlet first, in case it is already loaded */
    status = ldr$ref_info (&execlet_name, &reference_handle);

    /* If error, must not be loaded yet */
    if (status != SS$_NORMAL)
    {
       /* Load execlet */
       status = ldr$load_image (&execlet_name, 2, &reference_handle);
    }

    return(status);

}