[mirror_edk2.git] / MdeModulePkg / Universal / DebugSupportDxe / Ia32 / PlDebugSupport.c

/** @file\r
  IA32/x64 generic functions to support Debug Support protocol.\r
\r
Copyright (c) 2006 - 2018, Intel Corporation. All rights reserved.<BR>\r
SPDX-License-Identifier: BSD-2-Clause-Patent\r
\r
**/\r
\r
#include "DebugSupport.h"\r
\r
//\r
// This the global main table to keep track of the interrupts\r
//\r
IDT_ENTRY  *IdtEntryTable = NULL;\r
\r
/**\r
  Read IDT Gate Descriptor from IDT Table.\r
\r
  @param  Vector            Specifies vector number.\r
  @param  IdtGateDescriptor Pointer to IDT Gate Descriptor read from IDT Table.\r
\r
**/\r
VOID\r
ReadIdtGateDescriptor (\r
  IN  EFI_EXCEPTION_TYPE        Vector,\r
  OUT IA32_IDT_GATE_DESCRIPTOR  *IdtGateDescriptor\r
  )\r
{\r
  IA32_DESCRIPTOR           IdtrValue;\r
  IA32_IDT_GATE_DESCRIPTOR  *IdtTable;\r
\r
  AsmReadIdtr (&IdtrValue);\r
  IdtTable = (IA32_IDT_GATE_DESCRIPTOR *)IdtrValue.Base;\r
\r
  CopyMem ((VOID *)IdtGateDescriptor, (VOID *)&(IdtTable)[Vector], sizeof (IA32_IDT_GATE_DESCRIPTOR));\r
}\r
\r
/**\r
  Write IDT Gate Descriptor into IDT Table.\r
\r
  @param  Vector            Specifies vector number.\r
  @param  IdtGateDescriptor Pointer to IDT Gate Descriptor written into IDT Table.\r
\r
**/\r
VOID\r
WriteIdtGateDescriptor (\r
  EFI_EXCEPTION_TYPE        Vector,\r
  IA32_IDT_GATE_DESCRIPTOR  *IdtGateDescriptor\r
  )\r
{\r
  IA32_DESCRIPTOR           IdtrValue;\r
  IA32_IDT_GATE_DESCRIPTOR  *IdtTable;\r
\r
  AsmReadIdtr (&IdtrValue);\r
  IdtTable = (IA32_IDT_GATE_DESCRIPTOR *)IdtrValue.Base;\r
\r
  CopyMem ((VOID *)&(IdtTable)[Vector], (VOID *)IdtGateDescriptor, sizeof (IA32_IDT_GATE_DESCRIPTOR));\r
}\r
\r
/**\r
  Creates a nes entry stub.  Then saves the current IDT entry and replaces it\r
  with an interrupt gate for the new entry point.  The IdtEntryTable is updated\r
  with the new registered function.\r
\r
  This code executes in boot services context.  The stub entry executes in interrupt\r
  context.\r
\r
  @param  ExceptionType      Specifies which vector to hook.\r
  @param  NewCallback        A pointer to the new function to be registered.\r
\r
**/\r
VOID\r
HookEntry (\r
  IN EFI_EXCEPTION_TYPE  ExceptionType,\r
  IN CALLBACK_FUNC       NewCallback\r
  )\r
{\r
  BOOLEAN  OldIntFlagState;\r
\r
  CreateEntryStub (ExceptionType, (VOID **)&IdtEntryTable[ExceptionType].StubEntry);\r
\r
  //\r
  // Disables CPU interrupts and returns the previous interrupt state\r
  //\r
  OldIntFlagState = SaveAndDisableInterrupts ();\r
\r
  //\r
  // gets IDT Gate descriptor by index\r
  //\r
  ReadIdtGateDescriptor (ExceptionType, &(IdtEntryTable[ExceptionType].OrigDesc));\r
  //\r
  // stores orignal interrupt handle\r
  //\r
  IdtEntryTable[ExceptionType].OrigVector = (DEBUG_PROC)GetInterruptHandleFromIdt (&(IdtEntryTable[ExceptionType].OrigDesc));\r
\r
  //\r
  // encodes new IDT Gate descriptor by stub entry\r
  //\r
  Vect2Desc (&IdtEntryTable[ExceptionType].NewDesc, IdtEntryTable[ExceptionType].StubEntry);\r
  //\r
  // stores NewCallback\r
  //\r
  IdtEntryTable[ExceptionType].RegisteredCallback = NewCallback;\r
\r
  //\r
  // writes back new IDT Gate descriptor\r
  //\r
  WriteIdtGateDescriptor (ExceptionType, &(IdtEntryTable[ExceptionType].NewDesc));\r
\r
  //\r
  // restore interrupt state\r
  //\r
  SetInterruptState (OldIntFlagState);\r
\r
  return;\r
}\r
\r
/**\r
  Undoes HookEntry. This code executes in boot services context.\r
\r
  @param  ExceptionType   Specifies which entry to unhook\r
\r
**/\r
VOID\r
UnhookEntry (\r
  IN EFI_EXCEPTION_TYPE  ExceptionType\r
  )\r
{\r
  BOOLEAN  OldIntFlagState;\r
\r
  //\r
  // Disables CPU interrupts and returns the previous interrupt state\r
  //\r
  OldIntFlagState = SaveAndDisableInterrupts ();\r
\r
  //\r
  // restore the default IDT Date Descriptor\r
  //\r
  WriteIdtGateDescriptor (ExceptionType, &(IdtEntryTable[ExceptionType].OrigDesc));\r
\r
  //\r
  // restore interrupt state\r
  //\r
  SetInterruptState (OldIntFlagState);\r
\r
  return;\r
}\r
\r
/**\r
  Returns the maximum value that may be used for the ProcessorIndex parameter in\r
  RegisterPeriodicCallback() and RegisterExceptionCallback().\r
\r
  Hard coded to support only 1 processor for now.\r
\r
  @param  This                  A pointer to the EFI_DEBUG_SUPPORT_PROTOCOL instance.\r
  @param  MaxProcessorIndex     Pointer to a caller-allocated UINTN in which the maximum supported\r
                                processor index is returned. Always 0 returned.\r
\r
  @retval EFI_SUCCESS           Always returned with **MaxProcessorIndex set to 0.\r
\r
**/\r
EFI_STATUS\r
EFIAPI\r
GetMaximumProcessorIndex (\r
  IN EFI_DEBUG_SUPPORT_PROTOCOL  *This,\r
  OUT UINTN                      *MaxProcessorIndex\r
  )\r
{\r
  *MaxProcessorIndex = 0;\r
  return EFI_SUCCESS;\r
}\r
\r
/**\r
  Registers a function to be called back periodically in interrupt context.\r
\r
  @param  This                  A pointer to the EFI_DEBUG_SUPPORT_PROTOCOL instance.\r
  @param  ProcessorIndex        Specifies which processor the callback function applies to.\r
  @param  PeriodicCallback      A pointer to a function of type PERIODIC_CALLBACK that is the main\r
                                periodic entry point of the debug agent.\r
\r
  @retval EFI_SUCCESS           The function completed successfully.\r
  @retval EFI_ALREADY_STARTED   Non-NULL PeriodicCallback parameter when a callback\r
                                function was previously registered.\r
  @retval EFI_OUT_OF_RESOURCES  System has insufficient memory resources to register new callback\r
                                function.\r
**/\r
EFI_STATUS\r
EFIAPI\r
RegisterPeriodicCallback (\r
  IN EFI_DEBUG_SUPPORT_PROTOCOL  *This,\r
  IN UINTN                       ProcessorIndex,\r
  IN EFI_PERIODIC_CALLBACK       PeriodicCallback\r
  )\r
{\r
  return ManageIdtEntryTable (PeriodicCallback, SYSTEM_TIMER_VECTOR);\r
}\r
\r
/**\r
  Registers a function to be called when a given processor exception occurs.\r
\r
  This code executes in boot services context.\r
\r
  @param  This                  A pointer to the EFI_DEBUG_SUPPORT_PROTOCOL instance.\r
  @param  ProcessorIndex        Specifies which processor the callback function applies to.\r
  @param  ExceptionCallback     A pointer to a function of type EXCEPTION_CALLBACK that is called\r
                                when the processor exception specified by ExceptionType occurs.\r
  @param  ExceptionType         Specifies which processor exception to hook.\r
\r
  @retval EFI_SUCCESS           The function completed successfully.\r
  @retval EFI_ALREADY_STARTED   Non-NULL PeriodicCallback parameter when a callback\r
                                function was previously registered.\r
  @retval EFI_OUT_OF_RESOURCES  System has insufficient memory resources to register new callback\r
                                function.\r
**/\r
EFI_STATUS\r
EFIAPI\r
RegisterExceptionCallback (\r
  IN EFI_DEBUG_SUPPORT_PROTOCOL  *This,\r
  IN UINTN                       ProcessorIndex,\r
  IN EFI_EXCEPTION_CALLBACK      ExceptionCallback,\r
  IN EFI_EXCEPTION_TYPE          ExceptionType\r
  )\r
{\r
  return ManageIdtEntryTable (ExceptionCallback, ExceptionType);\r
}\r
\r
/**\r
  Invalidates processor instruction cache for a memory range. Subsequent execution in this range\r
  causes a fresh memory fetch to retrieve code to be executed.\r
\r
  @param  This                  A pointer to the EFI_DEBUG_SUPPORT_PROTOCOL instance.\r
  @param  ProcessorIndex        Specifies which processor's instruction cache is to be invalidated.\r
  @param  Start                 Specifies the physical base of the memory range to be invalidated.\r
  @param  Length                Specifies the minimum number of bytes in the processor's instruction\r
                                cache to invalidate.\r
\r
  @retval EFI_SUCCESS           Always returned.\r
\r
**/\r
EFI_STATUS\r
EFIAPI\r
InvalidateInstructionCache (\r
  IN EFI_DEBUG_SUPPORT_PROTOCOL  *This,\r
  IN UINTN                       ProcessorIndex,\r
  IN VOID                        *Start,\r
  IN UINT64                      Length\r
  )\r
{\r
  AsmWbinvd ();\r
  return EFI_SUCCESS;\r
}\r
\r
/**\r
  Common piece of code that invokes the registered handlers.\r
\r
  This code executes in exception context so no efi calls are allowed.\r
  This code is called from assembly file.\r
\r
  @param  ExceptionType     Exception type\r
  @param  ContextRecord     System context\r
\r
**/\r
VOID\r
InterruptDistrubutionHub (\r
  EFI_EXCEPTION_TYPE       ExceptionType,\r
  EFI_SYSTEM_CONTEXT_IA32  *ContextRecord\r
  )\r
{\r
  if (IdtEntryTable[ExceptionType].RegisteredCallback != NULL) {\r
    if (ExceptionType != SYSTEM_TIMER_VECTOR) {\r
      IdtEntryTable[ExceptionType].RegisteredCallback (ExceptionType, ContextRecord);\r
    } else {\r
      OrigVector = IdtEntryTable[ExceptionType].OrigVector;\r
      IdtEntryTable[ExceptionType].RegisteredCallback (ContextRecord);\r
    }\r
  }\r
}\r
\r
/**\r
  This is the callback that is written to the Loaded Image protocol instance\r
  on the image handle. It uninstalls all registered handlers and frees all entry\r
  stub memory.\r
\r
  @param  ImageHandle    The firmware allocated handle for the EFI image.\r
\r
  @retval EFI_SUCCESS    Always.\r
\r
**/\r
EFI_STATUS\r
EFIAPI\r
PlUnloadDebugSupportDriver (\r
  IN EFI_HANDLE  ImageHandle\r
  )\r
{\r
  EFI_EXCEPTION_TYPE  ExceptionType;\r
\r
  for (ExceptionType = 0; ExceptionType < NUM_IDT_ENTRIES; ExceptionType++) {\r
    ManageIdtEntryTable (NULL, ExceptionType);\r
    //\r
    // Free space for each Interrupt Stub precedure.\r
    //\r
    if (IdtEntryTable[ExceptionType].StubEntry != NULL) {\r
      FreePool ((VOID *)(UINTN)IdtEntryTable[ExceptionType].StubEntry);\r
    }\r
  }\r
\r
  FreePool (IdtEntryTable);\r
\r
  return EFI_SUCCESS;\r
}\r
\r
/**\r
  Initializes driver's handler registration database.\r
\r
  This code executes in boot services context.\r
  Must be public because it's referenced from DebugSupport.c\r
\r
  @retval  EFI_UNSUPPORTED      If IA32/x64 processor does not support FXSTOR/FXRSTOR instructions,\r
                                the context save will fail, so these processors are not supported.\r
  @retval  EFI_OUT_OF_RESOURCES Fails to allocate memory.\r
  @retval  EFI_SUCCESS          Initializes successfully.\r
\r
**/\r
EFI_STATUS\r
PlInitializeDebugSupportDriver (\r
  VOID\r
  )\r
{\r
  EFI_EXCEPTION_TYPE  ExceptionType;\r
\r
  //\r
  // Check whether FxStor instructions are supported.\r
  //\r
  if (!FxStorSupport ()) {\r
    return EFI_UNSUPPORTED;\r
  }\r
\r
  IdtEntryTable = AllocateZeroPool (sizeof (IDT_ENTRY) * NUM_IDT_ENTRIES);\r
  if (IdtEntryTable == NULL) {\r
    return EFI_OUT_OF_RESOURCES;\r
  }\r
\r
  for (ExceptionType = 0; ExceptionType < NUM_IDT_ENTRIES; ExceptionType++) {\r
    IdtEntryTable[ExceptionType].StubEntry = (DEBUG_PROC)(UINTN)AllocatePool (StubSize);\r
    if (IdtEntryTable[ExceptionType].StubEntry == NULL) {\r
      goto ErrorCleanup;\r
    }\r
\r
    //\r
    // Copy Interrupt stub code.\r
    //\r
    CopyMem ((VOID *)(UINTN)IdtEntryTable[ExceptionType].StubEntry, InterruptEntryStub, StubSize);\r
  }\r
\r
  return EFI_SUCCESS;\r
\r
ErrorCleanup:\r
\r
  for (ExceptionType = 0; ExceptionType < NUM_IDT_ENTRIES; ExceptionType++) {\r
    if (IdtEntryTable[ExceptionType].StubEntry != NULL) {\r
      FreePool ((VOID *)(UINTN)IdtEntryTable[ExceptionType].StubEntry);\r
    }\r
  }\r
\r
  FreePool (IdtEntryTable);\r
\r
  return EFI_OUT_OF_RESOURCES;\r
}\r
Commit	Line	Data
	1	/** @file\r
	2	IA32/x64 generic functions to support Debug Support protocol.\r
	3	\r
	4	Copyright (c) 2006 - 2018, Intel Corporation. All rights reserved.<BR>\r
	5	SPDX-License-Identifier: BSD-2-Clause-Patent\r
	6	\r
	7	**/\r
	8	\r
	9	#include "DebugSupport.h"\r
	10	\r
	11	//\r
	12	// This the global main table to keep track of the interrupts\r
	13	//\r
	14	IDT_ENTRY *IdtEntryTable = NULL;\r
	15	\r
	16	/**\r
	17	Read IDT Gate Descriptor from IDT Table.\r
	18	\r
	19	@param Vector Specifies vector number.\r
	20	@param IdtGateDescriptor Pointer to IDT Gate Descriptor read from IDT Table.\r
	21	\r
	22	**/\r
	23	VOID\r
	24	ReadIdtGateDescriptor (\r
	25	IN EFI_EXCEPTION_TYPE Vector,\r
	26	OUT IA32_IDT_GATE_DESCRIPTOR *IdtGateDescriptor\r
	27	)\r
	28	{\r
	29	IA32_DESCRIPTOR IdtrValue;\r
	30	IA32_IDT_GATE_DESCRIPTOR *IdtTable;\r
	31	\r
	32	AsmReadIdtr (&IdtrValue);\r
	33	IdtTable = (IA32_IDT_GATE_DESCRIPTOR *)IdtrValue.Base;\r
	34	\r
	35	CopyMem ((VOID )IdtGateDescriptor, (VOID )&(IdtTable)[Vector], sizeof (IA32_IDT_GATE_DESCRIPTOR));\r
	36	}\r
	37	\r
	38	/**\r
	39	Write IDT Gate Descriptor into IDT Table.\r
	40	\r
	41	@param Vector Specifies vector number.\r
	42	@param IdtGateDescriptor Pointer to IDT Gate Descriptor written into IDT Table.\r
	43	\r
	44	**/\r
	45	VOID\r
	46	WriteIdtGateDescriptor (\r
	47	EFI_EXCEPTION_TYPE Vector,\r
	48	IA32_IDT_GATE_DESCRIPTOR *IdtGateDescriptor\r
	49	)\r
	50	{\r
	51	IA32_DESCRIPTOR IdtrValue;\r
	52	IA32_IDT_GATE_DESCRIPTOR *IdtTable;\r
	53	\r
	54	AsmReadIdtr (&IdtrValue);\r
	55	IdtTable = (IA32_IDT_GATE_DESCRIPTOR *)IdtrValue.Base;\r
	56	\r
	57	CopyMem ((VOID )&(IdtTable)[Vector], (VOID )IdtGateDescriptor, sizeof (IA32_IDT_GATE_DESCRIPTOR));\r
	58	}\r
	59	\r
	60	/**\r
	61	Creates a nes entry stub. Then saves the current IDT entry and replaces it\r
	62	with an interrupt gate for the new entry point. The IdtEntryTable is updated\r
	63	with the new registered function.\r
	64	\r
	65	This code executes in boot services context. The stub entry executes in interrupt\r
	66	context.\r
	67	\r
	68	@param ExceptionType Specifies which vector to hook.\r
	69	@param NewCallback A pointer to the new function to be registered.\r
	70	\r
	71	**/\r
	72	VOID\r
	73	HookEntry (\r
	74	IN EFI_EXCEPTION_TYPE ExceptionType,\r
	75	IN CALLBACK_FUNC NewCallback\r
	76	)\r
	77	{\r
	78	BOOLEAN OldIntFlagState;\r
	79	\r
	80	CreateEntryStub (ExceptionType, (VOID **)&IdtEntryTable[ExceptionType].StubEntry);\r
	81	\r
	82	//\r
	83	// Disables CPU interrupts and returns the previous interrupt state\r
	84	//\r
	85	OldIntFlagState = SaveAndDisableInterrupts ();\r
	86	\r
	87	//\r
	88	// gets IDT Gate descriptor by index\r
	89	//\r
	90	ReadIdtGateDescriptor (ExceptionType, &(IdtEntryTable[ExceptionType].OrigDesc));\r
	91	//\r
	92	// stores orignal interrupt handle\r
	93	//\r
	94	IdtEntryTable[ExceptionType].OrigVector = (DEBUG_PROC)GetInterruptHandleFromIdt (&(IdtEntryTable[ExceptionType].OrigDesc));\r
	95	\r
	96	//\r
	97	// encodes new IDT Gate descriptor by stub entry\r
	98	//\r
	99	Vect2Desc (&IdtEntryTable[ExceptionType].NewDesc, IdtEntryTable[ExceptionType].StubEntry);\r
	100	//\r
	101	// stores NewCallback\r
	102	//\r
	103	IdtEntryTable[ExceptionType].RegisteredCallback = NewCallback;\r
	104	\r
	105	//\r
	106	// writes back new IDT Gate descriptor\r
	107	//\r
	108	WriteIdtGateDescriptor (ExceptionType, &(IdtEntryTable[ExceptionType].NewDesc));\r
	109	\r
	110	//\r
	111	// restore interrupt state\r
	112	//\r
	113	SetInterruptState (OldIntFlagState);\r
	114	\r
	115	return;\r
	116	}\r
	117	\r
	118	/**\r
	119	Undoes HookEntry. This code executes in boot services context.\r
	120	\r
	121	@param ExceptionType Specifies which entry to unhook\r
	122	\r
	123	**/\r
	124	VOID\r
	125	UnhookEntry (\r
	126	IN EFI_EXCEPTION_TYPE ExceptionType\r
	127	)\r
	128	{\r
	129	BOOLEAN OldIntFlagState;\r
	130	\r
	131	//\r
	132	// Disables CPU interrupts and returns the previous interrupt state\r
	133	//\r
	134	OldIntFlagState = SaveAndDisableInterrupts ();\r
	135	\r
	136	//\r
	137	// restore the default IDT Date Descriptor\r
	138	//\r
	139	WriteIdtGateDescriptor (ExceptionType, &(IdtEntryTable[ExceptionType].OrigDesc));\r
	140	\r
	141	//\r
	142	// restore interrupt state\r
	143	//\r
	144	SetInterruptState (OldIntFlagState);\r
	145	\r
	146	return;\r
	147	}\r
	148	\r
	149	/**\r
	150	Returns the maximum value that may be used for the ProcessorIndex parameter in\r
	151	RegisterPeriodicCallback() and RegisterExceptionCallback().\r
	152	\r
	153	Hard coded to support only 1 processor for now.\r
	154	\r
	155	@param This A pointer to the EFI_DEBUG_SUPPORT_PROTOCOL instance.\r
	156	@param MaxProcessorIndex Pointer to a caller-allocated UINTN in which the maximum supported\r
	157	processor index is returned. Always 0 returned.\r
	158	\r
	159	@retval EFI_SUCCESS Always returned with **MaxProcessorIndex set to 0.\r
	160	\r
	161	**/\r
	162	EFI_STATUS\r
	163	EFIAPI\r
	164	GetMaximumProcessorIndex (\r
	165	IN EFI_DEBUG_SUPPORT_PROTOCOL *This,\r
	166	OUT UINTN *MaxProcessorIndex\r
	167	)\r
	168	{\r
	169	*MaxProcessorIndex = 0;\r
	170	return EFI_SUCCESS;\r
	171	}\r
	172	\r
	173	/**\r
	174	Registers a function to be called back periodically in interrupt context.\r
	175	\r
	176	@param This A pointer to the EFI_DEBUG_SUPPORT_PROTOCOL instance.\r
	177	@param ProcessorIndex Specifies which processor the callback function applies to.\r
	178	@param PeriodicCallback A pointer to a function of type PERIODIC_CALLBACK that is the main\r
	179	periodic entry point of the debug agent.\r
	180	\r
	181	@retval EFI_SUCCESS The function completed successfully.\r
	182	@retval EFI_ALREADY_STARTED Non-NULL PeriodicCallback parameter when a callback\r
	183	function was previously registered.\r
	184	@retval EFI_OUT_OF_RESOURCES System has insufficient memory resources to register new callback\r
	185	function.\r
	186	**/\r
	187	EFI_STATUS\r
	188	EFIAPI\r
	189	RegisterPeriodicCallback (\r
	190	IN EFI_DEBUG_SUPPORT_PROTOCOL *This,\r
	191	IN UINTN ProcessorIndex,\r
	192	IN EFI_PERIODIC_CALLBACK PeriodicCallback\r
	193	)\r
	194	{\r
	195	return ManageIdtEntryTable (PeriodicCallback, SYSTEM_TIMER_VECTOR);\r
	196	}\r
	197	\r
	198	/**\r
	199	Registers a function to be called when a given processor exception occurs.\r
	200	\r
	201	This code executes in boot services context.\r
	202	\r
	203	@param This A pointer to the EFI_DEBUG_SUPPORT_PROTOCOL instance.\r
	204	@param ProcessorIndex Specifies which processor the callback function applies to.\r
	205	@param ExceptionCallback A pointer to a function of type EXCEPTION_CALLBACK that is called\r
	206	when the processor exception specified by ExceptionType occurs.\r
	207	@param ExceptionType Specifies which processor exception to hook.\r
	208	\r
	209	@retval EFI_SUCCESS The function completed successfully.\r
	210	@retval EFI_ALREADY_STARTED Non-NULL PeriodicCallback parameter when a callback\r
	211	function was previously registered.\r
	212	@retval EFI_OUT_OF_RESOURCES System has insufficient memory resources to register new callback\r
	213	function.\r
	214	**/\r
	215	EFI_STATUS\r
	216	EFIAPI\r
	217	RegisterExceptionCallback (\r
	218	IN EFI_DEBUG_SUPPORT_PROTOCOL *This,\r
	219	IN UINTN ProcessorIndex,\r
	220	IN EFI_EXCEPTION_CALLBACK ExceptionCallback,\r
	221	IN EFI_EXCEPTION_TYPE ExceptionType\r
	222	)\r
	223	{\r
	224	return ManageIdtEntryTable (ExceptionCallback, ExceptionType);\r
	225	}\r
	226	\r
	227	/**\r
	228	Invalidates processor instruction cache for a memory range. Subsequent execution in this range\r
	229	causes a fresh memory fetch to retrieve code to be executed.\r
	230	\r
	231	@param This A pointer to the EFI_DEBUG_SUPPORT_PROTOCOL instance.\r
	232	@param ProcessorIndex Specifies which processor's instruction cache is to be invalidated.\r
	233	@param Start Specifies the physical base of the memory range to be invalidated.\r
	234	@param Length Specifies the minimum number of bytes in the processor's instruction\r
	235	cache to invalidate.\r
	236	\r
	237	@retval EFI_SUCCESS Always returned.\r
	238	\r
	239	**/\r
	240	EFI_STATUS\r
	241	EFIAPI\r
	242	InvalidateInstructionCache (\r
	243	IN EFI_DEBUG_SUPPORT_PROTOCOL *This,\r
	244	IN UINTN ProcessorIndex,\r
	245	IN VOID *Start,\r
	246	IN UINT64 Length\r
	247	)\r
	248	{\r
	249	AsmWbinvd ();\r
	250	return EFI_SUCCESS;\r
	251	}\r
	252	\r
	253	/**\r
	254	Common piece of code that invokes the registered handlers.\r
	255	\r
	256	This code executes in exception context so no efi calls are allowed.\r
	257	This code is called from assembly file.\r
	258	\r
	259	@param ExceptionType Exception type\r
	260	@param ContextRecord System context\r
	261	\r
	262	**/\r
	263	VOID\r
	264	InterruptDistrubutionHub (\r
	265	EFI_EXCEPTION_TYPE ExceptionType,\r
	266	EFI_SYSTEM_CONTEXT_IA32 *ContextRecord\r
	267	)\r
	268	{\r
	269	if (IdtEntryTable[ExceptionType].RegisteredCallback != NULL) {\r
	270	if (ExceptionType != SYSTEM_TIMER_VECTOR) {\r
	271	IdtEntryTable[ExceptionType].RegisteredCallback (ExceptionType, ContextRecord);\r
	272	} else {\r
	273	OrigVector = IdtEntryTable[ExceptionType].OrigVector;\r
	274	IdtEntryTable[ExceptionType].RegisteredCallback (ContextRecord);\r
	275	}\r
	276	}\r
	277	}\r
	278	\r
	279	/**\r
	280	This is the callback that is written to the Loaded Image protocol instance\r
	281	on the image handle. It uninstalls all registered handlers and frees all entry\r
	282	stub memory.\r
	283	\r
	284	@param ImageHandle The firmware allocated handle for the EFI image.\r
	285	\r
	286	@retval EFI_SUCCESS Always.\r
	287	\r
	288	**/\r
	289	EFI_STATUS\r
	290	EFIAPI\r
	291	PlUnloadDebugSupportDriver (\r
	292	IN EFI_HANDLE ImageHandle\r
	293	)\r
	294	{\r
	295	EFI_EXCEPTION_TYPE ExceptionType;\r
	296	\r
	297	for (ExceptionType = 0; ExceptionType < NUM_IDT_ENTRIES; ExceptionType++) {\r
	298	ManageIdtEntryTable (NULL, ExceptionType);\r
	299	//\r
	300	// Free space for each Interrupt Stub precedure.\r
	301	//\r
	302	if (IdtEntryTable[ExceptionType].StubEntry != NULL) {\r
	303	FreePool ((VOID *)(UINTN)IdtEntryTable[ExceptionType].StubEntry);\r
	304	}\r
	305	}\r
	306	\r
	307	FreePool (IdtEntryTable);\r
	308	\r
	309	return EFI_SUCCESS;\r
	310	}\r
	311	\r
	312	/**\r
	313	Initializes driver's handler registration database.\r
	314	\r
	315	This code executes in boot services context.\r
	316	Must be public because it's referenced from DebugSupport.c\r
	317	\r
	318	@retval EFI_UNSUPPORTED If IA32/x64 processor does not support FXSTOR/FXRSTOR instructions,\r
	319	the context save will fail, so these processors are not supported.\r
	320	@retval EFI_OUT_OF_RESOURCES Fails to allocate memory.\r
	321	@retval EFI_SUCCESS Initializes successfully.\r
	322	\r
	323	**/\r
	324	EFI_STATUS\r
	325	PlInitializeDebugSupportDriver (\r
	326	VOID\r
	327	)\r
	328	{\r
	329	EFI_EXCEPTION_TYPE ExceptionType;\r
	330	\r
	331	//\r
	332	// Check whether FxStor instructions are supported.\r
	333	//\r
	334	if (!FxStorSupport ()) {\r
	335	return EFI_UNSUPPORTED;\r
	336	}\r
	337	\r
	338	IdtEntryTable = AllocateZeroPool (sizeof (IDT_ENTRY) * NUM_IDT_ENTRIES);\r
	339	if (IdtEntryTable == NULL) {\r
	340	return EFI_OUT_OF_RESOURCES;\r
	341	}\r
	342	\r
	343	for (ExceptionType = 0; ExceptionType < NUM_IDT_ENTRIES; ExceptionType++) {\r
	344	IdtEntryTable[ExceptionType].StubEntry = (DEBUG_PROC)(UINTN)AllocatePool (StubSize);\r
	345	if (IdtEntryTable[ExceptionType].StubEntry == NULL) {\r
	346	goto ErrorCleanup;\r
	347	}\r
	348	\r
	349	//\r
	350	// Copy Interrupt stub code.\r
	351	//\r
	352	CopyMem ((VOID *)(UINTN)IdtEntryTable[ExceptionType].StubEntry, InterruptEntryStub, StubSize);\r
	353	}\r
	354	\r
	355	return EFI_SUCCESS;\r
	356	\r
	357	ErrorCleanup:\r
	358	\r
	359	for (ExceptionType = 0; ExceptionType < NUM_IDT_ENTRIES; ExceptionType++) {\r
	360	if (IdtEntryTable[ExceptionType].StubEntry != NULL) {\r
	361	FreePool ((VOID *)(UINTN)IdtEntryTable[ExceptionType].StubEntry);\r
	362	}\r
	363	}\r
	364	\r
	365	FreePool (IdtEntryTable);\r
	366	\r
	367	return EFI_OUT_OF_RESOURCES;\r
	368	}\r