reactos/subsys/csrss/video.c

   1 /* $Id$
   2  *
   3  * ReactOS Project
   4  */
   5
   6 #include <csrss.h>
   7
   8 #define NDEBUG
   9 #include <debug.h>
  10
  11 ULONG
  12 InitializeVideoAddressSpace(VOID)
  13 {
  14    OBJECT_ATTRIBUTES ObjectAttributes;
  15    UNICODE_STRING PhysMemName = RTL_CONSTANT_STRING(L"\\Device\\PhysicalMemory");
  16    NTSTATUS Status;
  17    HANDLE PhysMemHandle;
  18    PVOID BaseAddress;
  19    PVOID NullAddress;
  20    LARGE_INTEGER Offset;
  21    ULONG ViewSize;
  22    CHAR IVT[1024];
  23    CHAR BDA[256];
  24
  25    /*
  26     * Open the physical memory section
  27     */
  28    InitializeObjectAttributes(&ObjectAttributes,
  29                               &PhysMemName,
  30                               0,
  31                               NULL,
  32                               NULL);
  33    Status = ZwOpenSection(&PhysMemHandle, SECTION_ALL_ACCESS,
  34                           &ObjectAttributes);
  35    if (!NT_SUCCESS(Status))
  36      {
  37         DbgPrint("Couldn't open \\Device\\PhysicalMemory\n");
  38         return(0);
  39      }
  40
  41    /*
  42     * Map the BIOS and device registers into the address space
  43     */
  44    Offset.QuadPart = 0xa0000;
  45    ViewSize = 0x100000 - 0xa0000;
  46    BaseAddress = (PVOID)0xa0000;
  47    Status = NtMapViewOfSection(PhysMemHandle,
  48                                NtCurrentProcess(),
  49                                &BaseAddress,
  50                                0,
  51                                8192,
  52                                &Offset,
  53                                &ViewSize,
  54                                ViewUnmap,
  55                                0,
  56                                PAGE_EXECUTE_READWRITE);
  57    if (!NT_SUCCESS(Status))
  58      {
  59         DbgPrint("Couldn't map physical memory (%x)\n", Status);
  60         NtClose(PhysMemHandle);
  61         return(0);
  62      }
  63    NtClose(PhysMemHandle);
  64    if (BaseAddress != (PVOID)0xa0000)
  65      {
  66        DbgPrint("Couldn't map physical memory at the right address "
  67                 "(was %x)\n", BaseAddress);
  68        return(0);
  69      }
  70
  71    /*
  72     * Map some memory to use for the non-BIOS parts of the v86 mode address
  73     * space
  74     */
  75    BaseAddress = (PVOID)0x1;
  76    ViewSize = 0xa0000 - 0x1000;
  77    Status = ZwAllocateVirtualMemory(NtCurrentProcess(),
  78                                     &BaseAddress,
  79                                     0,
  80                                     &ViewSize,
  81                                     MEM_COMMIT,
  82                                     PAGE_EXECUTE_READWRITE);
  83    if (!NT_SUCCESS(Status))
  84      {
  85        DbgPrint("Failed to allocate virtual memory (Status %x)\n", Status);
  86        return(0);
  87      }
  88    if (BaseAddress != (PVOID)0x0)
  89      {
  90        DbgPrint("Failed to allocate virtual memory at right address "
  91                 "(was %x)\n", BaseAddress);
  92        return(0);
  93      }
  94
  95    /*
  96     * Get the real mode IVT from the kernel
  97     */
  98    Status = NtVdmControl(0, IVT);
  99    if (!NT_SUCCESS(Status))
 100      {
 101        DbgPrint("NtVdmControl failed (status %x)\n", Status);
 102        return(0);
 103      }
 104
 105    /*
 106     * Copy the real mode IVT into the right place
 107     */
 108    NullAddress = (PVOID)0x0; /* Workaround for GCC 3.4 */
 109    memcpy(NullAddress, IVT, 1024);
 110
 111    /*
 112     * Get the BDA from the kernel
 113     */
 114    Status = NtVdmControl(1, BDA);
 115    if (!NT_SUCCESS(Status))
 116      {
 117        DbgPrint("NtVdmControl failed (status %x)\n", Status);
 118        return(0);
 119      }
 120
 121    /*
 122     * Copy the BDA into the right place
 123     */
 124    memcpy((PVOID)0x400, BDA, 256);
 125
 126    return(1);
 127 }
 128
 129
 130 /* EOF */