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 VOID
  19 FORCEINLINE
  20 NmiClearFlag(VOID)
  21 {
  22     ((PCHAR)&KiBugCheckData[4])[0] -= (NmiBegin[3] | NmiBegin[7]);
  23     ((PCHAR)&KiBugCheckData[4])[3] |= 1;
  24 #ifdef _MSC_VER
  25     __asm
  26     {
  27         rcr KiBugCheckData[4], 8
  28     }
  29 #else
  30     __asm__("rcrl %b[shift], %k[retval]" : [retval] "=rm" (KiBugCheckData[4]) : "[retval]" (KiBugCheckData[4]), [shift] "Nc" (8));
  31 #endif
  32 }
  33
  34 BOOLEAN
  35 NTAPI
  36 NmiDbgCallback(IN PVOID Context,
  37                IN BOOLEAN Handled)
  38 {
  39     /* Clear the NMI flag */
  40     NmiClearFlag();
  41
  42     /* Get NMI status signature */
  43     __indwordstring(0x80, (PULONG)NmiBegin, 1);
  44     ((void(*)())&KiBugCheckData[4])();
  45
  46     /* Handle the NMI safely */
  47     KiEnableTimerWatchdog = (RtlCompareMemory(NmiBegin, NmiBegin + 4, 4) != 4);
  48     return TRUE;
  49 }
  50
  51 NTSTATUS
  52 NTAPI
  53 DriverEntry(IN PDRIVER_OBJECT DriverObject,
  54             IN PUNICODE_STRING RegistryPath)
  55 {
  56     PAGED_CODE();
  57
  58     /* Register NMI callback */
  59     KeRegisterNmiCallback(&NmiDbgCallback, NULL);
  60
  61     /* Return success */
  62     return STATUS_SUCCESS;
  63 }
  64
  65 /* EOF */