vanjeff f4a25e813f Add validation on ACPI_S3_CONTEXT.S3DebugBufferAddress, moreover only debug tip could override IDT entry for INT3.
Signed-off-by: Jeff Fan <jeff.fan@intel.com>
Reviewed-by: Liming Gao <liming.gao@intel.com>


git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@13640 6f19259b-4bc3-4df7-8a09-765794883524
2012-08-16 04:36:24 +00:00

75 lines
2.2 KiB
C

/** @file
Set a IDT entry for debug purpose
Set a IDT entry for interrupt vector 3 for debug purpose for IA32 platform
Copyright (c) 2006 - 2012, Intel Corporation. All rights reserved.<BR>
This program and the accompanying materials
are licensed and made available under the terms and conditions of the BSD License
which accompanies this distribution. The full text of the license may be found at
http://opensource.org/licenses/bsd-license.php
THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
**/
#include "ScriptExecute.h"
//
// INTERRUPT_GATE_DESCRIPTOR and SetIdtEntry () are used to setup IDT to do debug
//
#pragma pack(1)
typedef struct {
UINT16 OffsetLow;
UINT16 SegmentSelector;
UINT16 Attributes;
UINT16 OffsetHigh;
} INTERRUPT_GATE_DESCRIPTOR;
#define INTERRUPT_GATE_ATTRIBUTE 0x8e00
#pragma pack()
/**
Set a IDT entry for interrupt vector 3 for debug purpose.
@param AcpiS3Context a pointer to a structure of ACPI_S3_CONTEXT
**/
VOID
SetIdtEntry (
IN ACPI_S3_CONTEXT *AcpiS3Context
)
{
INTERRUPT_GATE_DESCRIPTOR *IdtEntry;
IA32_DESCRIPTOR *IdtDescriptor;
UINTN S3DebugBuffer;
//
// Restore IDT for debug
//
IdtDescriptor = (IA32_DESCRIPTOR *) (UINTN) (AcpiS3Context->IdtrProfile);
AsmWriteIdtr (IdtDescriptor);
//
// Setup the default CPU exception handlers
//
SetupCpuExceptionHandlers ();
DEBUG_CODE (
//
// Update IDT entry INT3 if the instruction is valid in it
//
S3DebugBuffer = (UINTN) (AcpiS3Context->S3DebugBufferAddress);
if (*(UINTN *)S3DebugBuffer != (UINTN) -1) {
IdtEntry = (INTERRUPT_GATE_DESCRIPTOR *)(IdtDescriptor->Base + (3 * sizeof (INTERRUPT_GATE_DESCRIPTOR)));
IdtEntry->OffsetLow = (UINT16)S3DebugBuffer;
IdtEntry->SegmentSelector = (UINT16)AsmReadCs ();;
IdtEntry->Attributes = (UINT16)INTERRUPT_GATE_ATTRIBUTE;
IdtEntry->OffsetHigh = (UINT16)(S3DebugBuffer >> 16);
}
);
}