drivers/base/nmidebug/nmidebug.c

   1 /*
   2  * PROJECT:         ReactOS NMI Debug Driver
   3  * LICENSE:         BSD - See COPYING.ARM in the top level directory
   4  * FILE:            drivers/base/nmidebug/nmidebug.c
   5  * PURPOSE:         Driver Code
   6  * PROGRAMMERS:     ReactOS Portable Systems Group
   7  */
   8
   9 /* INCLUDES *******************************************************************/
  10
  11 #include <ntifs.h>
  12 #include <ndk/ketypes.h>
  13
  14 /* FUNCTIONS ******************************************************************/
  15
  16 PCHAR NmiBegin = "NMI4NMI@";
  17
  18 FORCEINLINE
  19 VOID
  20 NmiClearFlag(VOID)
  21 {
  22     ((PCHAR)&KiBugCheckData[4])[0] -= (NmiBegin[3] | NmiBegin[7]);
  23     ((PCHAR)&KiBugCheckData[4])[3] |= 1;
  24 #ifdef _M_IX86
  25 #if defined(_MSC_VER) && !defined(__clang__)
  26     __asm
  27     {
  28         rcr KiBugCheckData[4], 8
  29     }
  30 #else
  31     __asm__("rcrl %b[shift], %k[retval]" : [retval] "=rm" (KiBugCheckData[4]) : "[retval]" (KiBugCheckData[4]), [shift] "Nc" (8));
  32 #endif
  33 #endif
  34 }
  35
  36 BOOLEAN
  37 NTAPI
  38 NmiDbgCallback(IN PVOID Context,
  39                IN BOOLEAN Handled)
  40 {
  41     /* Clear the NMI flag */
  42     NmiClearFlag();
  43
  44     /* Get NMI status signature */
  45     __indwordstring(0x80, (PULONG)NmiBegin, 1);
  46     ((void(*)())&KiBugCheckData[4])();
  47
  48     /* Handle the NMI safely */
  49 #ifdef _M_IX86
  50     KiEnableTimerWatchdog = (RtlCompareMemory(NmiBegin, NmiBegin + 4, 4) != 4);
  51 #endif
  52     return TRUE;
  53 }
  54
  55 NTSTATUS
  56 NTAPI
  57 DriverEntry(IN PDRIVER_OBJECT DriverObject,
  58             IN PUNICODE_STRING RegistryPath)
  59 {
  60     PAGED_CODE();
  61
  62     /* Register NMI callback */
  63     KeRegisterNmiCallback(&NmiDbgCallback, NULL);
  64
  65     /* Return success */
  66     return STATUS_SUCCESS;
  67 }
  68
  69 /* EOF */