#include "DebugSupport.h"

Functions
VOID	ReadIdtGateDescriptor (IN EFI_EXCEPTION_TYPE Vector, OUT IA32_IDT_GATE_DESCRIPTOR *IdtGateDescriptor)

VOID	WriteIdtGateDescriptor (EFI_EXCEPTION_TYPE Vector, IA32_IDT_GATE_DESCRIPTOR *IdtGateDescriptor)

VOID	HookEntry (IN EFI_EXCEPTION_TYPE ExceptionType, IN CALLBACK_FUNC NewCallback)

VOID	UnhookEntry (IN EFI_EXCEPTION_TYPE ExceptionType)

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	InterruptDistrubutionHub (EFI_EXCEPTION_TYPE ExceptionType, EFI_SYSTEM_CONTEXT_IA32 *ContextRecord)

EFI_STATUS EFIAPI	PlUnloadDebugSupportDriver (IN EFI_HANDLE ImageHandle)

EFI_STATUS	PlInitializeDebugSupportDriver (VOID)

Variables
IDT_ENTRY *	IdtEntryTable = NULL

Detailed Description

IA32/x64 generic functions to support Debug Support protocol.

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

Definition in file PlDebugSupport.c.

Function Documentation

◆ 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.

◆ InterruptDistrubutionHub()

VOID InterruptDistrubutionHub	(	EFI_EXCEPTION_TYPE	ExceptionType,
		EFI_SYSTEM_CONTEXT_IA32 *	ContextRecord
	)

Common piece of code that invokes the registered handlers.

This code executes in exception context so no efi calls are allowed. This code is called from assembly file.

Parameters

ExceptionType	Exception type
ContextRecord	System context

Definition at line 264 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.

◆ 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/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 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.

◆ ReadIdtGateDescriptor()

VOID ReadIdtGateDescriptor	(	IN EFI_EXCEPTION_TYPE	Vector,
		OUT IA32_IDT_GATE_DESCRIPTOR *	IdtGateDescriptor
	)

Read IDT Gate Descriptor from IDT Table.

Parameters

Vector	Specifies vector number.
IdtGateDescriptor	Pointer to IDT Gate Descriptor read from IDT Table.

Definition at line 24 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.

◆ WriteIdtGateDescriptor()

VOID WriteIdtGateDescriptor	(	EFI_EXCEPTION_TYPE	Vector,
		IA32_IDT_GATE_DESCRIPTOR *	IdtGateDescriptor
	)

Write IDT Gate Descriptor into IDT Table.

Parameters

Vector	Specifies vector number.
IdtGateDescriptor	Pointer to IDT Gate Descriptor written into IDT Table.

Definition at line 46 of file PlDebugSupport.c.

Variable Documentation

◆ IdtEntryTable

IDT_ENTRY* IdtEntryTable = NULL

Definition at line 14 of file PlDebugSupport.c.

Functions

Variables

Detailed Description

Function Documentation

◆ GetMaximumProcessorIndex()

◆ HookEntry()

◆ InterruptDistrubutionHub()

◆ InvalidateInstructionCache()

◆ PlInitializeDebugSupportDriver()

◆ PlUnloadDebugSupportDriver()

◆ ReadIdtGateDescriptor()

◆ RegisterExceptionCallback()

◆ RegisterPeriodicCallback()

◆ UnhookEntry()

◆ WriteIdtGateDescriptor()

Variable Documentation

◆ IdtEntryTable