reactos/ntoskrnl/nt/vdm.c

   1 /*
   2  * COPYRIGHT:       See COPYING in the top level directory
   3  * PROJECT:         ReactOS kernel
   4  * FILE:            ntoskrnl/nt/vdm.c
   5  * PURPOSE:         Virtual DOS machine support
   6  * PROGRAMMER:      David Welch (welch@mcmail.com)
   7  * UPDATE HISTORY:
   8  *                  Created 22/05/98
   9  */
  10
  11 /* INCLUDES *****************************************************************/
  12
  13 #include <ddk/ntddk.h>
  14
  15 #include <internal/debug.h>
  16
  17 /* GLOBALS *******************************************************************/
  18
  19 static UCHAR OrigIVT[1024];
  20 static UCHAR OrigBDA[256];
  21 /* static UCHAR OrigEBDA[]; */
  22
  23 /* FUNCTIONS *****************************************************************/
  24
  25 VOID
  26 NtEarlyInitVdm(VOID)
  27 {
  28   /*
  29    * Save various BIOS data tables. At this point the lower 4MB memory
  30    * map is still active so we can just copy the data from low memory.
  31    */
  32   memcpy(OrigIVT, (PVOID)0x0, 1024);
  33   memcpy(OrigBDA, (PVOID)0x400, 256);
  34 }
  35
  36 NTSTATUS STDCALL NtVdmControl(ULONG ControlCode,
  37                               PVOID ControlData)
  38 {
  39   switch (ControlCode)
  40     {
  41     case 0:
  42       memcpy(ControlData, OrigIVT, 1024);
  43       break;
  44
  45     case 1:
  46       memcpy(ControlData, OrigBDA, 256);
  47       break;
  48     }
  49   return(STATUS_SUCCESS);
  50 }
  51
  52 /* EOF */