#include <Uefi.h>
#include <Protocol/DebugSupport.h>
#include <Protocol/LoadedImage.h>
#include <Library/DebugLib.h>
#include <Library/UefiDriverEntryPoint.h>
#include <Library/BaseMemoryLib.h>
#include <Library/MemoryAllocationLib.h>
#include <Library/UefiBootServicesTableLib.h>
#include <Library/BaseLib.h>

Data Structures
struct	IDT_ENTRY

Macros
#define	NUM_IDT_ENTRIES 0x78

#define	SYSTEM_TIMER_VECTOR 0x68

Typedefs
typedef VOID(*	DEBUG_PROC) (VOID)

typedef VOID(EFIAPI *	CALLBACK_FUNC) ()

Functions
VOID	CommonIdtEntry (VOID)

BOOLEAN	FxStorSupport (VOID)

VOID	Vect2Desc (IA32_IDT_GATE_DESCRIPTOR DestDesc, VOID(Vector)(VOID))

EFI_STATUS	PlInitializeDebugSupportDriver (VOID)

EFI_STATUS EFIAPI	PlUnloadDebugSupportDriver (IN EFI_HANDLE ImageHandle)

EFI_STATUS EFIAPI	GetMaximumProcessorIndex (IN EFI_DEBUG_SUPPORT_PROTOCOL This, OUT UINTN MaxProcessorIndex)

EFI_STATUS EFIAPI	RegisterPeriodicCallback (IN EFI_DEBUG_SUPPORT_PROTOCOL *This, IN UINTN ProcessorIndex, IN EFI_PERIODIC_CALLBACK PeriodicCallback)

EFI_STATUS EFIAPI	RegisterExceptionCallback (IN EFI_DEBUG_SUPPORT_PROTOCOL *This, IN UINTN ProcessorIndex, IN EFI_EXCEPTION_CALLBACK ExceptionCallback, IN EFI_EXCEPTION_TYPE ExceptionType)

EFI_STATUS EFIAPI	InvalidateInstructionCache (IN EFI_DEBUG_SUPPORT_PROTOCOL This, IN UINTN ProcessorIndex, IN VOID Start, IN UINT64 Length)

VOID	CreateEntryStub (IN EFI_EXCEPTION_TYPE ExceptionType, OUT VOID **Stub)

UINTN	GetInterruptHandleFromIdt (IN IA32_IDT_GATE_DESCRIPTOR *IdtGateDecriptor)

EFI_STATUS	ManageIdtEntryTable (CALLBACK_FUNC NewCallback, EFI_EXCEPTION_TYPE ExceptionType)

VOID	HookEntry (IN EFI_EXCEPTION_TYPE ExceptionType, IN CALLBACK_FUNC NewCallback)

VOID	UnhookEntry (IN EFI_EXCEPTION_TYPE ExceptionType)

Variables
UINT8	InterruptEntryStub []

UINT32	StubSize

VOID(*	OrigVector )(VOID)

IDT_ENTRY *	IdtEntryTable

IA32_IDT_GATE_DESCRIPTOR	NullDesc

Detailed Description

Generic debug support macros, typedefs and prototypes for IA32/x64.

Copyright (c) 2006 - 2018, Intel Corporation. All rights reserved.
SPDX-License-Identifier: BSD-2-Clause-Patent

Definition in file DebugSupport.h.

Macro Definition Documentation

◆ NUM_IDT_ENTRIES

#define NUM_IDT_ENTRIES 0x78

Definition at line 24 of file DebugSupport.h.

◆ SYSTEM_TIMER_VECTOR

#define SYSTEM_TIMER_VECTOR 0x68

Definition at line 25 of file DebugSupport.h.

Typedef Documentation

◆ CALLBACK_FUNC

typedef VOID(EFIAPI * CALLBACK_FUNC) ()

Definition at line 34 of file DebugSupport.h.

◆ DEBUG_PROC

typedef VOID(* DEBUG_PROC) (VOID)

Definition at line 28 of file DebugSupport.h.

Function Documentation

◆ CommonIdtEntry()

VOID CommonIdtEntry ( VOID )

Generic IDT entry.

◆ CreateEntryStub()

VOID CreateEntryStub	(	IN EFI_EXCEPTION_TYPE	ExceptionType,
		OUT VOID **	Stub
	)

Allocate pool for a new IDT entry stub.

Copy the generic stub into the new buffer and fixup the vector number and jump target address.

Parameters

ExceptionType	This is the exception type that the new stub will be created for.
Stub	On successful exit, *Stub contains the newly allocated entry stub.

Definition at line 52 of file PlDebugSupportIa32.c.

◆ FxStorSupport()

BOOLEAN FxStorSupport ( VOID )

Check whether FXSTOR is supported

Return values

TRUE	FXSTOR is supported.
FALSE	FXSTOR is not supported.

◆ GetInterruptHandleFromIdt()

UINTN GetInterruptHandleFromIdt ( IN IA32_IDT_GATE_DESCRIPTOR * IdtGateDecriptor )

Get Interrupt Handle from IDT Gate Descriptor.

Parameters

IdtGateDecriptor IDT Gate Descriptor.

Returns: Interrupt Handle stored in IDT Gate Descriptor.

Get Interrupt Handle from IDT Gate Descriptor.

Parameters

IdtGateDescriptor IDT Gate Descriptor.

Returns: Interrupt Handle stored in IDT Gate Descriptor.

Definition at line 24 of file PlDebugSupportIa32.c.

◆ GetMaximumProcessorIndex()

EFI_STATUS EFIAPI GetMaximumProcessorIndex	(	IN EFI_DEBUG_SUPPORT_PROTOCOL *	This,
		OUT UINTN *	MaxProcessorIndex
	)

Returns the maximum value that may be used for the ProcessorIndex parameter in RegisterPeriodicCallback() and RegisterExceptionCallback().

Hard coded to support only 1 processor for now.

Parameters

This	A pointer to the EFI_DEBUG_SUPPORT_PROTOCOL instance.
MaxProcessorIndex	Pointer to a caller-allocated UINTN in which the maximum supported processor index is returned. Always 0 returned.

Return values

EFI_SUCCESS Always returned with **MaxProcessorIndex set to 0.

Definition at line 164 of file PlDebugSupport.c.

◆ HookEntry()

VOID HookEntry	(	IN EFI_EXCEPTION_TYPE	ExceptionType,
		IN CALLBACK_FUNC	NewCallback
	)

Creates a nes entry stub. Then saves the current IDT entry and replaces it with an interrupt gate for the new entry point. The IdtEntryTable is updated with the new registered function.

This code executes in boot services context. The stub entry executes in interrupt context.

Parameters

ExceptionType	Specifies which vector to hook.
NewCallback	A pointer to the new function to be registered.

Definition at line 73 of file PlDebugSupport.c.

◆ InvalidateInstructionCache()

EFI_STATUS EFIAPI InvalidateInstructionCache	(	IN EFI_DEBUG_SUPPORT_PROTOCOL *	This,
		IN UINTN	ProcessorIndex,
		IN VOID *	Start,
		IN UINT64	Length
	)

Invalidates processor instruction cache for a memory range. Subsequent execution in this range causes a fresh memory fetch to retrieve code to be executed.

Parameters

This	A pointer to the EFI_DEBUG_SUPPORT_PROTOCOL instance.
ProcessorIndex	Specifies which processor's instruction cache is to be invalidated.
Start	Specifies the physical base of the memory range to be invalidated.
Length	Specifies the minimum number of bytes in the processor's instruction cache to invalidate.

Return values

EFI_SUCCESS Always returned.

Definition at line 242 of file PlDebugSupport.c.

◆ ManageIdtEntryTable()

EFI_STATUS ManageIdtEntryTable	(	CALLBACK_FUNC	NewCallback,
		EFI_EXCEPTION_TYPE	ExceptionType
	)

This is the main worker function that manages the state of the interrupt handlers. It both installs and uninstalls interrupt handlers based on the value of NewCallback. If NewCallback is NULL, then uninstall is indicated. If NewCallback is non-NULL, then install is indicated.

Parameters

NewCallback	If non-NULL, NewCallback specifies the new handler to register. If NULL, specifies that the previously registered handler should be uninstalled.
ExceptionType	Indicates which entry to manage.

Return values

EFI_SUCCESS	Process is ok.
EFI_INVALID_PARAMETER	Requested uninstalling a handler from a vector that has no handler registered for it
EFI_ALREADY_STARTED	Requested install to a vector that already has a handler registered.
others	Possible return values are passed through from UnHookEntry and HookEntry.

This is the main worker function that manages the state of the interrupt handlers. It both installs and uninstalls interrupt handlers based on the value of NewCallback. If NewCallback is NULL, then uninstall is indicated. If NewCallback is non-NULL, then install is indicated.

Parameters

NewCallback	If non-NULL, NewCallback specifies the new handler to register. If NULL, specifies that the previously registered handler should be uninstalled.
ExceptionType	Indicates which entry to manage.

Return values

EFI_SUCCESS	Installing or Uninstalling operation is ok.
EFI_INVALID_PARAMETER	Requested uninstalling a handler from a vector that has no handler registered for it
EFI_ALREADY_STARTED	Requested install to a vector that already has a handler registered.

Definition at line 105 of file PlDebugSupportIa32.c.

◆ PlInitializeDebugSupportDriver()

EFI_STATUS PlInitializeDebugSupportDriver ( VOID )

Initializes driver's handler registration database.

This code executes in boot services context Must be public because it's referenced from DebugSupport.c

Return values

EFI_UNSUPPORTED	If IA32 processor does not support FXSTOR/FXRSTOR instructions, the context save will fail, so these processor's are not supported.
EFI_OUT_OF_RESOURCES	Fails to allocate memory.
EFI_SUCCESS	Initializes successfully.

Initializes driver's handler registration database.

This code executes in boot services context. Must be public because it's referenced from DebugSupport.c

Return values

EFI_UNSUPPORTED	If IA32/x64 processor does not support FXSTOR/FXRSTOR instructions, the context save will fail, so these processors are not supported.
EFI_OUT_OF_RESOURCES	Fails to allocate memory.
EFI_SUCCESS	Initializes successfully.

Definition at line 325 of file PlDebugSupport.c.

◆ PlUnloadDebugSupportDriver()

EFI_STATUS EFIAPI PlUnloadDebugSupportDriver ( IN EFI_HANDLE ImageHandle )

This is the callback that is written to the LoadedImage protocol instance on the image handle. It uninstalls all registered handlers and frees all entry stub memory.

Parameters

ImageHandle The firmware allocated handle for the EFI image.

Return values

EFI_SUCCESS Always.

This is the callback that is written to the Loaded Image protocol instance on the image handle. It uninstalls all registered handlers and frees all entry stub memory.

Parameters

ImageHandle The firmware allocated handle for the EFI image.

Return values

EFI_SUCCESS Always.

Definition at line 291 of file PlDebugSupport.c.

◆ RegisterExceptionCallback()

EFI_STATUS EFIAPI RegisterExceptionCallback	(	IN EFI_DEBUG_SUPPORT_PROTOCOL *	This,
		IN UINTN	ProcessorIndex,
		IN EFI_EXCEPTION_CALLBACK	ExceptionCallback,
		IN EFI_EXCEPTION_TYPE	ExceptionType
	)

Registers a function to be called when a given processor exception occurs.

This code executes in boot services context.

Parameters

This	A pointer to the EFI_DEBUG_SUPPORT_PROTOCOL instance.
ProcessorIndex	Specifies which processor the callback function applies to.
ExceptionCallback	A pointer to a function of type EXCEPTION_CALLBACK that is called when the processor exception specified by ExceptionType occurs.
ExceptionType	Specifies which processor exception to hook.

Return values

EFI_SUCCESS	The function completed successfully.
EFI_ALREADY_STARTED	Non-NULL PeriodicCallback parameter when a callback function was previously registered.
EFI_OUT_OF_RESOURCES	System has insufficient memory resources to register new callback function.

Definition at line 217 of file PlDebugSupport.c.

◆ RegisterPeriodicCallback()

EFI_STATUS EFIAPI RegisterPeriodicCallback	(	IN EFI_DEBUG_SUPPORT_PROTOCOL *	This,
		IN UINTN	ProcessorIndex,
		IN EFI_PERIODIC_CALLBACK	PeriodicCallback
	)

Registers a function to be called back periodically in interrupt context.

Parameters

This	A pointer to the EFI_DEBUG_SUPPORT_PROTOCOL instance.
ProcessorIndex	Specifies which processor the callback function applies to.
PeriodicCallback	A pointer to a function of type PERIODIC_CALLBACK that is the main periodic entry point of the debug agent.

Return values

EFI_SUCCESS	The function completed successfully.
EFI_ALREADY_STARTED	Non-NULL PeriodicCallback parameter when a callback function was previously registered.
EFI_OUT_OF_RESOURCES	System has insufficient memory resources to register new callback function.

Definition at line 189 of file PlDebugSupport.c.

◆ UnhookEntry()

VOID UnhookEntry ( IN EFI_EXCEPTION_TYPE ExceptionType )

Undoes HookEntry. This code executes in boot services context.

Parameters

ExceptionType Specifies which entry to unhook

Definition at line 125 of file PlDebugSupport.c.

◆ Vect2Desc()

VOID Vect2Desc	(	IA32_IDT_GATE_DESCRIPTOR *	DestDesc,
		VOID(*)(VOID)	Vector
	)

Encodes an IDT descriptor with the given physical address.

Parameters

DestDesc	The IDT descriptor address.
Vecotr	The interrupt vector entry.

Variable Documentation

◆ IdtEntryTable

IDT_ENTRY* IdtEntryTable

extern

Definition at line 14 of file PlDebugSupport.c.

◆ NullDesc

IA32_IDT_GATE_DESCRIPTOR NullDesc

extern

Definition at line 11 of file PlDebugSupportIa32.c.

Data Structures

Macros

Typedefs

Functions

Variables

Detailed Description

Macro Definition Documentation

◆ NUM_IDT_ENTRIES

◆ SYSTEM_TIMER_VECTOR

Typedef Documentation

◆ CALLBACK_FUNC

◆ DEBUG_PROC

Function Documentation

◆ CommonIdtEntry()

◆ CreateEntryStub()

◆ FxStorSupport()

◆ GetInterruptHandleFromIdt()

◆ GetMaximumProcessorIndex()

◆ HookEntry()

◆ InvalidateInstructionCache()

◆ ManageIdtEntryTable()

◆ PlInitializeDebugSupportDriver()

◆ PlUnloadDebugSupportDriver()

◆ RegisterExceptionCallback()

◆ RegisterPeriodicCallback()

◆ UnhookEntry()

◆ Vect2Desc()

Variable Documentation

◆ IdtEntryTable

◆ NullDesc