subsys/csrss/video.c

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