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Reactos
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
16PCHAR NmiBegin = "NMI4NMI@";
17
18FORCEINLINE
19VOID
20NmiClearFlag(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
36BOOLEAN
37NTAPI
38NmiDbgCallback(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
55NTSTATUS
56NTAPI
57DriverEntry(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 */