reactos/ntoskrnl/ke/i386/vdm.c

   1 /* $Id:$
   2  *
   3  * COPYRIGHT:       See COPYING in the top level directory
   4  * PROJECT:         ReactOS kernel
   5  * FILE:            ntoskrnl/ke/i386/vdm.c
   6  * PURPOSE:         Virtual DOS machine support
   7  *
   8  * PROGRAMMERS:     David Welch (welch@mcmail.com)
   9  */
  10
  11 /* INCLUDES *****************************************************************/
  12
  13 #include <ntoskrnl.h>
  14 #include <internal/debug.h>
  15
  16 /* GLOBALS *******************************************************************/
  17
  18 static UCHAR OrigIVT[1024];
  19 static UCHAR OrigBDA[256];
  20 /* static UCHAR OrigEBDA[]; */
  21
  22 extern VOID Ki386RetToV86Mode(PKV86M_REGISTERS InRegs,
  23                               PKV86M_REGISTERS OutRegs);
  24
  25 /* FUNCTIONS *****************************************************************/
  26
  27 VOID INIT_FUNCTION
  28 NtEarlyInitVdm(VOID)
  29 {
  30   /* GCC 3.4 warns if NULL is passed in parameter 2 to the standard function memcpy */
  31   PVOID start = (PVOID)0x0;
  32
  33   /*
  34    * Save various BIOS data tables. At this point the lower 4MB memory
  35    * map is still active so we can just copy the data from low memory.
  36    */
  37   memcpy(OrigIVT, start, 1024);
  38   memcpy(OrigBDA, (PVOID)0x400, 256);
  39 }
  40
  41 /*
  42  * @implemented
  43  */
  44 NTSTATUS STDCALL NtVdmControl(ULONG ControlCode,
  45                               PVOID ControlData)
  46 {
  47   switch (ControlCode)
  48   {
  49     case 0:
  50       memcpy(ControlData, OrigIVT, 1024);
  51       break;
  52
  53     case 1:
  54       memcpy(ControlData, OrigBDA, 256);
  55       break;
  56
  57     case 2:
  58     {
  59       KV86M_REGISTERS V86Registers;
  60       ULONG ret;
  61
  62       ret = MmCopyFromCaller(&V86Registers,
  63                              ControlData,
  64                              sizeof(KV86M_REGISTERS));
  65       if(!NT_SUCCESS(ret)) return ret;
  66
  67       KeGetCurrentProcess()->NtVdmFlag = 1;
  68       Ki386RetToV86Mode(&V86Registers, &V86Registers);
  69       KeGetCurrentProcess()->NtVdmFlag = 0;
  70
  71       ret = MmCopyToCaller(ControlData,
  72                            &V86Registers,
  73                            sizeof(KV86M_REGISTERS));
  74       if(!NT_SUCCESS(ret)) return ret;
  75
  76       break;
  77     }
  78   }
  79   return(STATUS_SUCCESS);
  80 }
  81
  82 /* EOF */