blob: 6d1f10630a9042e170ca95f0fb878e66eb14e522 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
|
/** @file
X64 arch function to access IDT vector.
Copyright (c) 2013 - 2018, Intel Corporation. All rights reserved.<BR>
SPDX-License-Identifier: BSD-2-Clause-Patent
**/
#include <PeCoffExtraActionLib.h>
/**
Read IDT entry to check if IDT entries are setup by Debug Agent.
@param[in] IdtDescriptor Pointer to IDT Descriptor.
@param[in] InterruptType Interrupt type.
@retval TRUE IDT entries were setup by Debug Agent.
@retval FALSE IDT entries were not setuo by Debug Agent.
**/
BOOLEAN
CheckDebugAgentHandler (
IN IA32_DESCRIPTOR *IdtDescriptor,
IN UINTN InterruptType
)
{
IA32_IDT_GATE_DESCRIPTOR *IdtEntry;
UINTN InterruptHandler;
IdtEntry = (IA32_IDT_GATE_DESCRIPTOR *) IdtDescriptor->Base;
if (IdtEntry == NULL) {
return FALSE;
}
InterruptHandler = IdtEntry[InterruptType].Bits.OffsetLow +
(((UINTN)IdtEntry[InterruptType].Bits.OffsetHigh) << 16) +
(((UINTN)IdtEntry[InterruptType].Bits.OffsetUpper) << 32);
if (InterruptHandler >= sizeof (UINT32) && *(UINT32 *)(InterruptHandler - sizeof (UINT32)) == AGENT_HANDLER_SIGNATURE) {
return TRUE;
} else {
return FALSE;
}
}
/**
Save IDT entry for INT1 and update it.
@param[in] IdtDescriptor Pointer to IDT Descriptor.
@param[out] SavedIdtEntry Original IDT entry returned.
**/
VOID
SaveAndUpdateIdtEntry1 (
IN IA32_DESCRIPTOR *IdtDescriptor,
OUT IA32_IDT_GATE_DESCRIPTOR *SavedIdtEntry
)
{
IA32_IDT_GATE_DESCRIPTOR *IdtEntry;
UINT16 CodeSegment;
UINTN InterruptHandler;
IdtEntry = (IA32_IDT_GATE_DESCRIPTOR *) IdtDescriptor->Base;
CopyMem (SavedIdtEntry, &IdtEntry[1], sizeof (IA32_IDT_GATE_DESCRIPTOR));
//
// Use current CS as the segment selector of interrupt gate in IDT
//
CodeSegment = AsmReadCs ();
InterruptHandler = (UINTN) &AsmInterruptHandle;
IdtEntry[1].Bits.OffsetLow = (UINT16)(UINTN)InterruptHandler;
IdtEntry[1].Bits.OffsetHigh = (UINT16)((UINTN)InterruptHandler >> 16);
IdtEntry[1].Bits.OffsetUpper = (UINT32)((UINTN)InterruptHandler >> 32);
IdtEntry[1].Bits.Selector = CodeSegment;
IdtEntry[1].Bits.GateType = IA32_IDT_GATE_TYPE_INTERRUPT_32;
}
/**
Restore IDT entry for INT1.
@param[in] IdtDescriptor Pointer to IDT Descriptor.
@param[in] RestoredIdtEntry IDT entry to be restored.
**/
VOID
RestoreIdtEntry1 (
IN IA32_DESCRIPTOR *IdtDescriptor,
IN IA32_IDT_GATE_DESCRIPTOR *RestoredIdtEntry
)
{
IA32_IDT_GATE_DESCRIPTOR *IdtEntry;
IdtEntry = (IA32_IDT_GATE_DESCRIPTOR *) IdtDescriptor->Base;
CopyMem (&IdtEntry[1], RestoredIdtEntry, sizeof (IA32_IDT_GATE_DESCRIPTOR));
}
|