/** @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 setup 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)); | |
} |