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- /** @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));
- }
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