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 <ntoskrnl.h>
  14
  15 #define NDEBUG
  16 #include <internal/debug.h>
  17
  18
  19 /* GLOBALS *******************************************************************/
  20
  21 static UCHAR OrigIVT[1024];
  22 static UCHAR OrigBDA[256];
  23 /* static UCHAR OrigEBDA[]; */
  24
  25 /* FUNCTIONS *****************************************************************/
  26
  27 VOID
  28 NtEarlyInitVdm(VOID)
  29 {
  30   /*
  31    * Save various BIOS data tables. At this point the lower 4MB memory
  32    * map is still active so we can just copy the data from low memory.
  33    */
  34   memcpy(OrigIVT, (PVOID)0x0, 1024);
  35   memcpy(OrigBDA, (PVOID)0x400, 256);
  36 }
  37
  38 NTSTATUS STDCALL
  39 NtVdmControl(IN ULONG  ControlCode,
  40   IN PVOID  ControlData)
  41 {
  42   switch (ControlCode)
  43     {
  44     case 0:
  45       memcpy(ControlData, OrigIVT, 1024);
  46       break;
  47
  48     case 1:
  49       memcpy(ControlData, OrigBDA, 256);
  50       break;
  51     }
  52   return(STATUS_SUCCESS);
  53 }
  54
  55 /* EOF */