/*

   DPMICALL.C

   Verschiedene DPMI Aufrufe

   Achtung: 16-Bit: LARGE
            32-Bit: SMALL (linear executable)

   (c) 1996 Oliver Kraus

   kraus@lrs.e-technik.uni-erlangen.de

*/

#include "dpmicall.h"
#ifdef C_DPMI

#ifdef __WATCOMC__
#include <i86.h>
#endif

#include <dos.h>
#include <stdio.h>
#include <string.h>

void DPMI_FAR *dpmi_get_dos_ptr(short selector)
{
#ifdef C_DPMI386
   return MK_FP(selector,0);
#else
   return (void DPMI_FAR *)(((unsigned long)selector)<<16);
#endif
}

void dpmi_copy_to_dos(short selector, void *ptr, size_t len)
{
   void DPMI_FAR *dest_ptr;
   dest_ptr = dpmi_get_dos_ptr(selector);
#ifdef C_DPMI386
   _fmemcpy(dest_ptr, ptr, len);
#else
   memcpy(dest_ptr, ptr, len);
#endif
}

void dpmi_copy_from_dos(short selector, void *ptr, size_t len)
{
   void DPMI_FAR *src_ptr;
   src_ptr = dpmi_get_dos_ptr(selector);
#ifdef C_DPMI386
   _fmemcpy(ptr, src_ptr, len);
#else
   memcpy(ptr, src_ptr, len);
#endif
}


int dpmi_alloc_dos_memory(int size, short *selector, short *segment )
{
#ifdef C_DPMI386
	union REGS regs;
   struct SREGS sregs;

	memset(&sregs,0,sizeof(sregs));
	regs.w.ax=0x0100;
   regs.w.bx=(unsigned short)((size+15)/16);
   int386x( 0x031, &regs, &regs, &sregs);

   if ( segment != NULL )
      *segment=regs.w.ax;
   if ( selector != NULL )
      *selector=regs.w.dx;

   return 1;
#else
   union REGS regs;
   regs.x.ax=0x04800;
   regs.x.bx=(unsigned)((size+15)/16);
   int86( 0x021, &regs, &regs);
   if ( segment != NULL )
      *segment=(short)(unsigned short)regs.x.ax;
   if ( selector != NULL )
      *selector=(short)(unsigned short)regs.x.ax;

   return 1;
#endif
}

int dpmi_free_dos_memory(short selector)
{
#ifdef C_DPMI386
	union REGS regs;
   struct SREGS sregs;

   segread(&sregs);

   regs.w.ax=0x0101;
   regs.w.dx=(unsigned short)(selector);
   int386x( 0x031, &regs, &regs, &sregs);

   return 1;
#else
   union REGS regs;
   struct SREGS sregs;

   segread(&sregs);

   regs.x.ax=0x04900;
   sregs.es=selector;
   int86x( 0x021, &regs, &regs, &sregs);

   return 1;
#endif
}

unsigned dpmi_simulate_rmi(int int_no, rminfo_struct *rmi)
{
#ifdef C_DPMI386
	union REGS regs;
	struct SREGS sregs;

   /* stack soll vom host bereitgestellt werden */
   rmi->sp = 0;
   rmi->ss = 0;
   rmi->ip = 0;
   rmi->cs = 0;

   segread(&sregs);

	regs.w.ax = 0x0300;
   regs.h.bl = int_no;
	regs.h.bh = 0;
	regs.w.cx = 0;
   sregs.es = FP_SEG(rmi);
   regs.x.edi = FP_OFF(rmi);
   int386x( 0x31, &regs, &regs, &sregs );

   return rmi->flags & 1;
#else
	union REGS regs;
   struct SREGS sregs;

   segread(&sregs);

   regs.x.ax = (unsigned)rmi->eax;
   regs.x.bx = (unsigned)rmi->ebx;
   regs.x.cx = (unsigned)rmi->ecx;
   regs.x.dx = (unsigned)rmi->edx;
   regs.x.di = (unsigned)rmi->edi;
   regs.x.si = (unsigned)rmi->esi;

   sregs.es = rmi->es;
   sregs.ds = rmi->ds;

   int86x( int_no, &regs, &regs, &sregs );

   rmi->es = (short)(unsigned short)sregs.es;
   rmi->ds = (short)(unsigned short)sregs.ds;

   rmi->eax = (long)(unsigned long)regs.x.ax;
   rmi->ebx = (long)(unsigned long)regs.x.bx;
   rmi->ecx = (long)(unsigned long)regs.x.cx;
   rmi->edx = (long)(unsigned long)regs.x.dx;
   rmi->edi = (long)(unsigned long)regs.x.di;
   rmi->esi = (long)(unsigned long)regs.x.si;

   return regs.x.cflag & 1;
#endif
}

#ifdef dpmicall_main

void main(void)
{
   char *s = "Hello DPMI!$";
   rminfo_struct rmi;
   short selector, segment;

   dpmi_alloc_dos_memory(strlen(s)+1, &selector, &segment );
   dpmi_copy_to_dos(selector, s, strlen(s)+1);
   rmi.eax = 0x0900;
   rmi.ds = segment;
   rmi.edx = 0;
   dpmi_simulate_rmi(0x021, &rmi);
   dpmi_free_dos_memory(selector );

   rmi.eax = 0x03000;
   dpmi_simulate_rmi(0x021, &rmi);
   printf("\nDOS Version: %d.%d\n",
      (int)(rmi.eax&255), (int)((rmi.eax>>8)&255));

}


#endif

#endif /* C_DPMI */