reactos/subsys/csrss/video.c

   1 /* $Id: video.c,v 1.7 2003/10/20 18:02:04 gvg Exp $
   2  *
   3  * ReactOS Project
   4  */
   5 #include <ddk/ntddk.h>
   6
   7 ULONG
   8 InitializeVideoAddressSpace(VOID)
   9 {
  10    OBJECT_ATTRIBUTES ObjectAttributes;
  11    UNICODE_STRING PhysMemName;
  12    NTSTATUS Status;
  13    HANDLE PhysMemHandle;
  14    PVOID BaseAddress;
  15    LARGE_INTEGER Offset;
  16    ULONG ViewSize;
  17    CHAR IVT[1024];
  18    CHAR BDA[256];
  19
  20    /*
  21     * Open the physical memory section
  22     */
  23    RtlInitUnicodeStringFromLiteral(&PhysMemName, L"\\Device\\PhysicalMemory");
  24    InitializeObjectAttributes(&ObjectAttributes,
  25                               &PhysMemName,
  26                               0,
  27                               NULL,
  28                               NULL);
  29    Status = NtOpenSection(&PhysMemHandle, SECTION_ALL_ACCESS,
  30                           &ObjectAttributes);
  31    if (!NT_SUCCESS(Status))
  32      {
  33         DbgPrint("Couldn't open \\Device\\PhysicalMemory\n");
  34         return(0);
  35      }
  36
  37    /*
  38     * Map the BIOS and device registers into the address space
  39     */
  40    Offset.QuadPart = 0xa0000;
  41    ViewSize = 0x100000 - 0xa0000;
  42    BaseAddress = (PVOID)0xa0000;
  43    Status = NtMapViewOfSection(PhysMemHandle,
  44                                NtCurrentProcess(),
  45                                &BaseAddress,
  46                                0,
  47                                8192,
  48                                &Offset,
  49                                &ViewSize,
  50                                ViewUnmap,
  51                                0,
  52                                PAGE_EXECUTE_READWRITE);
  53    if (!NT_SUCCESS(Status))
  54      {
  55         DbgPrint("Couldn't map physical memory (%x)\n", Status);
  56         NtClose(PhysMemHandle);
  57         return(0);
  58      }
  59    NtClose(PhysMemHandle);
  60    if (BaseAddress != (PVOID)0xa0000)
  61      {
  62        DbgPrint("Couldn't map physical memory at the right address "
  63                 "(was %x)\n", BaseAddress);
  64        return(0);
  65      }
  66
  67    /*
  68     * Map some memory to use for the non-BIOS parts of the v86 mode address
  69     * space
  70     */
  71    BaseAddress = (PVOID)0x1;
  72    ViewSize = 0xa0000 - 0x1000;
  73    Status = ZwAllocateVirtualMemory(NtCurrentProcess(),
  74                                     &BaseAddress,
  75                                     0,
  76                                     &ViewSize,
  77                                     MEM_COMMIT,
  78                                     PAGE_EXECUTE_READWRITE);
  79    if (!NT_SUCCESS(Status))
  80      {
  81        DbgPrint("Failed to allocate virtual memory (Status %x)\n", Status);
  82        return(0);
  83      }
  84    if (BaseAddress != (PVOID)0x0)
  85      {
  86        DbgPrint("Failed to allocate virtual memory at right address "
  87                 "(was %x)\n", BaseAddress);
  88        return(0);
  89      }
  90
  91    /*
  92     * Get the real mode IVT from the kernel
  93     */
  94    Status = NtVdmControl(0, IVT);
  95    if (!NT_SUCCESS(Status))
  96      {
  97        DbgPrint("NtVdmControl failed (status %x)\n", Status);
  98        return(0);
  99      }
 100
 101    /*
 102     * Copy the real mode IVT into the right place
 103     */
 104    memcpy((PVOID)0x0, IVT, 1024);
 105
 106    /*
 107     * Get the BDA from the kernel
 108     */
 109    Status = NtVdmControl(1, BDA);
 110    if (!NT_SUCCESS(Status))
 111      {
 112        DbgPrint("NtVdmControl failed (status %x)\n", Status);
 113        return(0);
 114      }
 115
 116    /*
 117     * Copy the BDA into the right place
 118     */
 119    memcpy((PVOID)0x400, BDA, 256);
 120
 121    return(1);
 122 }
 123
 124
 125 /* EOF */