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

/** @file\r
  IA32 specific debug support functions\r
\r
Copyright (c) 2006 - 2008, Intel Corporation\r
All rights reserved. This program and the accompanying materials\r
are licensed and made available under the terms and conditions of the BSD License\r
which accompanies this distribution.  The full text of the license may be found at\r
http://opensource.org/licenses/bsd-license.php\r
\r
THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,\r
WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.\r
\r
**/\r
\r
//\r
// private header files\r
//\r
#include "PlDebugSupport.h"\r
\r
//\r
// This the global main table to keep track of the interrupts\r
//\r
IDT_ENTRY   *IdtEntryTable  = NULL;\r
DESCRIPTOR  NullDesc        = 0;\r
\r
/**\r
  Allocate pool for a new IDT entry stub.\r
\r
  Copy the generic stub into the new buffer and fixup the vector number\r
  and jump target address.\r
\r
  @param  ExceptionType   This is the exception type that the new stub will be created\r
                          for.\r
  @param  Stub            On successful exit, *Stub contains the newly allocated entry stub.\r
\r
  @retval EFI_SUCCESS     Always.\r
\r
**/\r
EFI_STATUS\r
CreateEntryStub (\r
  IN EFI_EXCEPTION_TYPE     ExceptionType,\r
  OUT VOID                  **Stub\r
  )\r
{\r
  UINT8       *StubCopy;\r
\r
  StubCopy = *Stub;\r
\r
  //\r
  // Fixup the stub code for this vector\r
  //\r
\r
  // The stub code looks like this:\r
  //\r
  //    00000000  89 25 00000004 R  mov     AppEsp, esp             ; save stack top\r
  //    00000006  BC 00008014 R     mov     esp, offset DbgStkBot   ; switch to debugger stack\r
  //    0000000B  6A 00             push    0                       ; push vector number - will be modified before installed\r
  //    0000000D  E9                db      0e9h                    ; jump rel32\r
  //    0000000E  00000000          dd      0                       ; fixed up to relative address of CommonIdtEntry\r
  //\r
\r
  //\r
  // poke in the exception type so the second push pushes the exception type\r
  //\r
  StubCopy[0x0c] = (UINT8) ExceptionType;\r
\r
  //\r
  // fixup the jump target to point to the common entry\r
  //\r
  *(UINT32 *) &StubCopy[0x0e] = (UINT32) CommonIdtEntry - (UINT32) &StubCopy[StubSize];\r
\r
  return EFI_SUCCESS;\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
  @retval EFI_SUCCESS        Always.\r
\r
**/\r
EFI_STATUS\r
HookEntry (\r
  IN EFI_EXCEPTION_TYPE            ExceptionType,\r
  IN VOID                         (*NewCallback) ()\r
  )\r
{\r
  BOOLEAN     OldIntFlagState;\r
  EFI_STATUS  Status;\r
\r
  Status = CreateEntryStub (ExceptionType, (VOID **) &IdtEntryTable[ExceptionType].StubEntry);\r
  if (Status == EFI_SUCCESS) {\r
    OldIntFlagState = WriteInterruptFlag (0);\r
    READ_IDT (ExceptionType, &(IdtEntryTable[ExceptionType].OrigDesc));\r
\r
    ((UINT16 *) &IdtEntryTable[ExceptionType].OrigVector)[0]  = ((UINT16 *) &IdtEntryTable[ExceptionType].OrigDesc)[0];\r
    ((UINT16 *) &IdtEntryTable[ExceptionType].OrigVector)[1]  = ((UINT16 *) &IdtEntryTable[ExceptionType].OrigDesc)[3];\r
\r
    Vect2Desc (&IdtEntryTable[ExceptionType].NewDesc, IdtEntryTable[ExceptionType].StubEntry);\r
    IdtEntryTable[ExceptionType].RegisteredCallback = NewCallback;\r
    WRITE_IDT (ExceptionType, &(IdtEntryTable[ExceptionType].NewDesc));\r
    WriteInterruptFlag (OldIntFlagState);\r
  }\r
\r
  return Status;\r
}\r
\r
/**\r
  Undoes HookEntry. This code executes in boot services context.\r
\r
  @param  ExceptionType   Specifies which entry to unhook\r
\r
  @retval EFI_SUCCESS     Always.\r
\r
**/\r
EFI_STATUS\r
UnhookEntry (\r
  IN EFI_EXCEPTION_TYPE           ExceptionType\r
  )\r
{\r
  BOOLEAN     OldIntFlagState;\r
\r
  OldIntFlagState = WriteInterruptFlag (0);\r
  WRITE_IDT (ExceptionType, &(IdtEntryTable[ExceptionType].OrigDesc));\r
  WriteInterruptFlag (OldIntFlagState);\r
\r
  return EFI_SUCCESS;\r
}\r
\r
/**\r
  This is the main worker function that manages the state of the interrupt\r
  handlers.  It both installs and uninstalls interrupt handlers based on the\r
  value of NewCallback.  If NewCallback is NULL, then uninstall is indicated.\r
  If NewCallback is non-NULL, then install is indicated.\r
\r
  @param  NewCallback   If non-NULL, NewCallback specifies the new handler to register.\r
                        If NULL, specifies that the previously registered handler should\r
                        be uninstalled.\r
  @param  ExceptionType Indicates which entry to manage.\r
\r
  @retval EFI_SUCCESS            Process is ok.\r
  @retval EFI_INVALID_PARAMETER  Requested uninstalling a handler from a vector that has\r
                                 no handler registered for it\r
  @retval EFI_ALREADY_STARTED    Requested install to a vector that already has a handler registered.\r
  @retval others                 Possible return values are passed through from UnHookEntry and HookEntry.\r
\r
**/\r
EFI_STATUS\r
ManageIdtEntryTable (\r
  VOID (*NewCallback)(),\r
  EFI_EXCEPTION_TYPE ExceptionType\r
  )\r
{\r
  EFI_STATUS  Status;\r
\r
  Status = EFI_SUCCESS;\r
\r
  if (!FeaturePcdGet (PcdNtEmulatorEnable)) {\r
    if (COMPARE_DESCRIPTOR (&IdtEntryTable[ExceptionType].NewDesc, &NullDesc)) {\r
      //\r
      // we've already installed to this vector\r
      //\r
      if (NewCallback != NULL) {\r
        //\r
        // if the input handler is non-null, error\r
        //\r
        Status = EFI_ALREADY_STARTED;\r
      } else {\r
        Status = UnhookEntry (ExceptionType);\r
      }\r
    } else {\r
      //\r
      // no user handler installed on this vector\r
      //\r
      if (NewCallback == NULL) {\r
        //\r
        // if the input handler is null, error\r
        //\r
        Status = EFI_INVALID_PARAMETER;\r
      } else {\r
        Status = HookEntry (ExceptionType, NewCallback);\r
      }\r
    }\r
  }\r
\r
  return Status;\r
}\r
\r
/**\r
  This is a DebugSupport protocol member function, hard\r
  coded to support only 1 processor for now.\r
\r
  @param  This                The DebugSupport instance\r
  @param  MaxProcessorIndex   The maximuim supported processor index\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
  DebugSupport protocol member function.\r
\r
  @param  This               The DebugSupport instance\r
  @param  ProcessorIndex     Which processor the callback applies to.\r
  @param  PeriodicCallback   Callback function\r
\r
  @retval EFI_SUCCESS        Indicates the callback was registered.\r
  @retval others             Callback was not registered.\r
\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
  DebugSupport protocol member function.\r
\r
  This code executes in boot services context.\r
\r
  @param  This              The DebugSupport instance\r
  @param  ProcessorIndex    Which processor the callback applies to.\r
  @param  NewCallback       Callback function\r
  @param  ExceptionType     Which exception to hook\r
\r
  @retval EFI_SUCCESS        Indicates the callback was registered.\r
  @retval others             Callback was not registered.\r
\r
**/\r
EFI_STATUS\r
EFIAPI\r
RegisterExceptionCallback (\r
  IN EFI_DEBUG_SUPPORT_PROTOCOL *This,\r
  IN UINTN                      ProcessorIndex,\r
  IN EFI_EXCEPTION_CALLBACK     NewCallback,\r
  IN EFI_EXCEPTION_TYPE         ExceptionType\r
  )\r
{\r
  return ManageIdtEntryTable (NewCallback, ExceptionType);\r
}\r
\r
/**\r
  DebugSupport protocol member function.  Calls assembly routine to flush cache.\r
\r
  @param  This              The DebugSupport instance\r
  @param  ProcessorIndex    Which processor the callback applies to.\r
  @param  Start             Physical base of the memory range to be invalidated\r
  @param  Length            mininum number of bytes in instruction 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
  Initializes driver's handler registration databas. \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 processor does not support FXSTOR/FXRSTOR instructions,\r
                                the context save will fail, so these processor's 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
  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
    CopyMem ((VOID *)(UINTN)IdtEntryTable[ExceptionType].StubEntry, InterruptEntryStub, StubSize);\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
  FreePool (IdtEntryTable);\r
\r
  return EFI_OUT_OF_RESOURCES;\r
}\r
\r
/**\r
  This is the callback that is written to the LoadedImage 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
\r
  FreePool (IdtEntryTable);\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
\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
Commit	Line	Data
	1	/** @file\r
	2	IA32 specific debug support functions\r
	3	\r
	4	Copyright (c) 2006 - 2008, Intel Corporation\r
	5	All rights reserved. This program and the accompanying materials\r
	6	are licensed and made available under the terms and conditions of the BSD License\r
	7	which accompanies this distribution. The full text of the license may be found at\r
	8	http://opensource.org/licenses/bsd-license.php\r
	9	\r
	10	THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,\r
	11	WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.\r
	12	\r
	13	**/\r
	14	\r
	15	//\r
	16	// private header files\r
	17	//\r
	18	#include "PlDebugSupport.h"\r
	19	\r
	20	//\r
	21	// This the global main table to keep track of the interrupts\r
	22	//\r
	23	IDT_ENTRY *IdtEntryTable = NULL;\r
	24	DESCRIPTOR NullDesc = 0;\r
	25	\r
	26	/**\r
	27	Allocate pool for a new IDT entry stub.\r
	28	\r
	29	Copy the generic stub into the new buffer and fixup the vector number\r
	30	and jump target address.\r
	31	\r
	32	@param ExceptionType This is the exception type that the new stub will be created\r
	33	for.\r
	34	@param Stub On successful exit, *Stub contains the newly allocated entry stub.\r
	35	\r
	36	@retval EFI_SUCCESS Always.\r
	37	\r
	38	**/\r
	39	EFI_STATUS\r
	40	CreateEntryStub (\r
	41	IN EFI_EXCEPTION_TYPE ExceptionType,\r
	42	OUT VOID **Stub\r
	43	)\r
	44	{\r
	45	UINT8 *StubCopy;\r
	46	\r
	47	StubCopy = *Stub;\r
	48	\r
	49	//\r
	50	// Fixup the stub code for this vector\r
	51	//\r
	52	\r
	53	// The stub code looks like this:\r
	54	//\r
	55	// 00000000 89 25 00000004 R mov AppEsp, esp ; save stack top\r
	56	// 00000006 BC 00008014 R mov esp, offset DbgStkBot ; switch to debugger stack\r
	57	// 0000000B 6A 00 push 0 ; push vector number - will be modified before installed\r
	58	// 0000000D E9 db 0e9h ; jump rel32\r
	59	// 0000000E 00000000 dd 0 ; fixed up to relative address of CommonIdtEntry\r
	60	//\r
	61	\r
	62	//\r
	63	// poke in the exception type so the second push pushes the exception type\r
	64	//\r
	65	StubCopy[0x0c] = (UINT8) ExceptionType;\r
	66	\r
	67	//\r
	68	// fixup the jump target to point to the common entry\r
	69	//\r
	70	(UINT32 ) &StubCopy[0x0e] = (UINT32) CommonIdtEntry - (UINT32) &StubCopy[StubSize];\r
	71	\r
	72	return EFI_SUCCESS;\r
	73	}\r
	74	\r
	75	/**\r
	76	Creates a nes entry stub. Then saves the current IDT entry and replaces it\r
	77	with an interrupt gate for the new entry point. The IdtEntryTable is updated\r
	78	with the new registered function.\r
	79	\r
	80	This code executes in boot services context. The stub entry executes in interrupt\r
	81	context.\r
	82	\r
	83	@param ExceptionType Specifies which vector to hook.\r
	84	@param NewCallback A pointer to the new function to be registered.\r
	85	\r
	86	@retval EFI_SUCCESS Always.\r
	87	\r
	88	**/\r
	89	EFI_STATUS\r
	90	HookEntry (\r
	91	IN EFI_EXCEPTION_TYPE ExceptionType,\r
	92	IN VOID (*NewCallback) ()\r
	93	)\r
	94	{\r
	95	BOOLEAN OldIntFlagState;\r
	96	EFI_STATUS Status;\r
	97	\r
	98	Status = CreateEntryStub (ExceptionType, (VOID **) &IdtEntryTable[ExceptionType].StubEntry);\r
	99	if (Status == EFI_SUCCESS) {\r
	100	OldIntFlagState = WriteInterruptFlag (0);\r
	101	READ_IDT (ExceptionType, &(IdtEntryTable[ExceptionType].OrigDesc));\r
	102	\r
	103	((UINT16 ) &IdtEntryTable[ExceptionType].OrigVector)[0] = ((UINT16 ) &IdtEntryTable[ExceptionType].OrigDesc)[0];\r
	104	((UINT16 ) &IdtEntryTable[ExceptionType].OrigVector)[1] = ((UINT16 ) &IdtEntryTable[ExceptionType].OrigDesc)[3];\r
	105	\r
	106	Vect2Desc (&IdtEntryTable[ExceptionType].NewDesc, IdtEntryTable[ExceptionType].StubEntry);\r
	107	IdtEntryTable[ExceptionType].RegisteredCallback = NewCallback;\r
	108	WRITE_IDT (ExceptionType, &(IdtEntryTable[ExceptionType].NewDesc));\r
	109	WriteInterruptFlag (OldIntFlagState);\r
	110	}\r
	111	\r
	112	return Status;\r
	113	}\r
	114	\r
	115	/**\r
	116	Undoes HookEntry. This code executes in boot services context.\r
	117	\r
	118	@param ExceptionType Specifies which entry to unhook\r
	119	\r
	120	@retval EFI_SUCCESS Always.\r
	121	\r
	122	**/\r
	123	EFI_STATUS\r
	124	UnhookEntry (\r
	125	IN EFI_EXCEPTION_TYPE ExceptionType\r
	126	)\r
	127	{\r
	128	BOOLEAN OldIntFlagState;\r
	129	\r
	130	OldIntFlagState = WriteInterruptFlag (0);\r
	131	WRITE_IDT (ExceptionType, &(IdtEntryTable[ExceptionType].OrigDesc));\r
	132	WriteInterruptFlag (OldIntFlagState);\r
	133	\r
	134	return EFI_SUCCESS;\r
	135	}\r
	136	\r
	137	/**\r
	138	This is the main worker function that manages the state of the interrupt\r
	139	handlers. It both installs and uninstalls interrupt handlers based on the\r
	140	value of NewCallback. If NewCallback is NULL, then uninstall is indicated.\r
	141	If NewCallback is non-NULL, then install is indicated.\r
	142	\r
	143	@param NewCallback If non-NULL, NewCallback specifies the new handler to register.\r
	144	If NULL, specifies that the previously registered handler should\r
	145	be uninstalled.\r
	146	@param ExceptionType Indicates which entry to manage.\r
	147	\r
	148	@retval EFI_SUCCESS Process is ok.\r
	149	@retval EFI_INVALID_PARAMETER Requested uninstalling a handler from a vector that has\r
	150	no handler registered for it\r
	151	@retval EFI_ALREADY_STARTED Requested install to a vector that already has a handler registered.\r
	152	@retval others Possible return values are passed through from UnHookEntry and HookEntry.\r
	153	\r
	154	**/\r
	155	EFI_STATUS\r
	156	ManageIdtEntryTable (\r
	157	VOID (*NewCallback)(),\r
	158	EFI_EXCEPTION_TYPE ExceptionType\r
	159	)\r
	160	{\r
	161	EFI_STATUS Status;\r
	162	\r
	163	Status = EFI_SUCCESS;\r
	164	\r
	165	if (!FeaturePcdGet (PcdNtEmulatorEnable)) {\r
	166	if (COMPARE_DESCRIPTOR (&IdtEntryTable[ExceptionType].NewDesc, &NullDesc)) {\r
	167	//\r
	168	// we've already installed to this vector\r
	169	//\r
	170	if (NewCallback != NULL) {\r
	171	//\r
	172	// if the input handler is non-null, error\r
	173	//\r
	174	Status = EFI_ALREADY_STARTED;\r
	175	} else {\r
	176	Status = UnhookEntry (ExceptionType);\r
	177	}\r
	178	} else {\r
	179	//\r
	180	// no user handler installed on this vector\r
	181	//\r
	182	if (NewCallback == NULL) {\r
	183	//\r
	184	// if the input handler is null, error\r
	185	//\r
	186	Status = EFI_INVALID_PARAMETER;\r
	187	} else {\r
	188	Status = HookEntry (ExceptionType, NewCallback);\r
	189	}\r
	190	}\r
	191	}\r
	192	\r
	193	return Status;\r
	194	}\r
	195	\r
	196	/**\r
	197	This is a DebugSupport protocol member function, hard\r
	198	coded to support only 1 processor for now.\r
	199	\r
	200	@param This The DebugSupport instance\r
	201	@param MaxProcessorIndex The maximuim supported processor index\r
	202	\r
	203	@retval EFI_SUCCESS Always returned with **MaxProcessorIndex set to 0.\r
	204	\r
	205	**/\r
	206	EFI_STATUS\r
	207	EFIAPI\r
	208	GetMaximumProcessorIndex (\r
	209	IN EFI_DEBUG_SUPPORT_PROTOCOL *This,\r
	210	OUT UINTN *MaxProcessorIndex\r
	211	)\r
	212	{\r
	213	*MaxProcessorIndex = 0;\r
	214	return (EFI_SUCCESS);\r
	215	}\r
	216	\r
	217	/**\r
	218	DebugSupport protocol member function.\r
	219	\r
	220	@param This The DebugSupport instance\r
	221	@param ProcessorIndex Which processor the callback applies to.\r
	222	@param PeriodicCallback Callback function\r
	223	\r
	224	@retval EFI_SUCCESS Indicates the callback was registered.\r
	225	@retval others Callback was not registered.\r
	226	\r
	227	**/\r
	228	EFI_STATUS\r
	229	EFIAPI\r
	230	RegisterPeriodicCallback (\r
	231	IN EFI_DEBUG_SUPPORT_PROTOCOL *This,\r
	232	IN UINTN ProcessorIndex,\r
	233	IN EFI_PERIODIC_CALLBACK PeriodicCallback\r
	234	)\r
	235	{\r
	236	return ManageIdtEntryTable (PeriodicCallback, SYSTEM_TIMER_VECTOR);\r
	237	}\r
	238	\r
	239	/**\r
	240	DebugSupport protocol member function.\r
	241	\r
	242	This code executes in boot services context.\r
	243	\r
	244	@param This The DebugSupport instance\r
	245	@param ProcessorIndex Which processor the callback applies to.\r
	246	@param NewCallback Callback function\r
	247	@param ExceptionType Which exception to hook\r
	248	\r
	249	@retval EFI_SUCCESS Indicates the callback was registered.\r
	250	@retval others Callback was not registered.\r
	251	\r
	252	**/\r
	253	EFI_STATUS\r
	254	EFIAPI\r
	255	RegisterExceptionCallback (\r
	256	IN EFI_DEBUG_SUPPORT_PROTOCOL *This,\r
	257	IN UINTN ProcessorIndex,\r
	258	IN EFI_EXCEPTION_CALLBACK NewCallback,\r
	259	IN EFI_EXCEPTION_TYPE ExceptionType\r
	260	)\r
	261	{\r
	262	return ManageIdtEntryTable (NewCallback, ExceptionType);\r
	263	}\r
	264	\r
	265	/**\r
	266	DebugSupport protocol member function. Calls assembly routine to flush cache.\r
	267	\r
	268	@param This The DebugSupport instance\r
	269	@param ProcessorIndex Which processor the callback applies to.\r
	270	@param Start Physical base of the memory range to be invalidated\r
	271	@param Length mininum number of bytes in instruction cache to invalidate\r
	272	\r
	273	@retval EFI_SUCCESS Always returned.\r
	274	\r
	275	**/\r
	276	EFI_STATUS\r
	277	EFIAPI\r
	278	InvalidateInstructionCache (\r
	279	IN EFI_DEBUG_SUPPORT_PROTOCOL *This,\r
	280	IN UINTN ProcessorIndex,\r
	281	IN VOID *Start,\r
	282	IN UINT64 Length\r
	283	)\r
	284	{\r
	285	AsmWbinvd ();\r
	286	return EFI_SUCCESS;\r
	287	}\r
	288	\r
	289	/**\r
	290	Initializes driver's handler registration databas. \r
	291	\r
	292	This code executes in boot services context\r
	293	Must be public because it's referenced from DebugSupport.c\r
	294	\r
	295	@retval EFI_UNSUPPORTED If IA32 processor does not support FXSTOR/FXRSTOR instructions,\r
	296	the context save will fail, so these processor's are not supported.\r
	297	@retval EFI_OUT_OF_RESOURCES Fails to allocate memory.\r
	298	@retval EFI_SUCCESS Initializes successfully.\r
	299	\r
	300	**/\r
	301	EFI_STATUS\r
	302	PlInitializeDebugSupportDriver (\r
	303	VOID\r
	304	)\r
	305	{\r
	306	EFI_EXCEPTION_TYPE ExceptionType;\r
	307	\r
	308	if (!FxStorSupport ()) {\r
	309	return EFI_UNSUPPORTED;\r
	310	}\r
	311	\r
	312	IdtEntryTable = AllocateZeroPool (sizeof (IDT_ENTRY) * NUM_IDT_ENTRIES);\r
	313	if (IdtEntryTable == NULL) {\r
	314	return EFI_OUT_OF_RESOURCES;\r
	315	}\r
	316	\r
	317	for (ExceptionType = 0; ExceptionType < NUM_IDT_ENTRIES; ExceptionType++) {\r
	318	IdtEntryTable[ExceptionType].StubEntry = (DEBUG_PROC) (UINTN) AllocatePool (StubSize);\r
	319	if (IdtEntryTable[ExceptionType].StubEntry == NULL) {\r
	320	goto ErrorCleanup;\r
	321	}\r
	322	\r
	323	CopyMem ((VOID *)(UINTN)IdtEntryTable[ExceptionType].StubEntry, InterruptEntryStub, StubSize);\r
	324	}\r
	325	return EFI_SUCCESS;\r
	326	\r
	327	ErrorCleanup:\r
	328	\r
	329	for (ExceptionType = 0; ExceptionType < NUM_IDT_ENTRIES; ExceptionType++) {\r
	330	if (IdtEntryTable[ExceptionType].StubEntry != NULL) {\r
	331	FreePool ((VOID *)(UINTN)IdtEntryTable[ExceptionType].StubEntry);\r
	332	}\r
	333	}\r
	334	FreePool (IdtEntryTable);\r
	335	\r
	336	return EFI_OUT_OF_RESOURCES;\r
	337	}\r
	338	\r
	339	/**\r
	340	This is the callback that is written to the LoadedImage protocol instance\r
	341	on the image handle. It uninstalls all registered handlers and frees all entry\r
	342	stub memory.\r
	343	\r
	344	@param ImageHandle The firmware allocated handle for the EFI image.\r
	345	\r
	346	@retval EFI_SUCCESS Always.\r
	347	\r
	348	**/\r
	349	EFI_STATUS\r
	350	EFIAPI\r
	351	PlUnloadDebugSupportDriver (\r
	352	IN EFI_HANDLE ImageHandle\r
	353	)\r
	354	{\r
	355	EFI_EXCEPTION_TYPE ExceptionType;\r
	356	\r
	357	for (ExceptionType = 0; ExceptionType < NUM_IDT_ENTRIES; ExceptionType++) {\r
	358	ManageIdtEntryTable (NULL, ExceptionType);\r
	359	}\r
	360	\r
	361	FreePool (IdtEntryTable);\r
	362	return EFI_SUCCESS;\r
	363	}\r
	364	\r
	365	/**\r
	366	Common piece of code that invokes the registered handlers.\r
	367	\r
	368	This code executes in exception context so no efi calls are allowed.\r
	369	\r
	370	@param ExceptionType Exception type\r
	371	@param ContextRecord System context\r
	372	\r
	373	**/\r
	374	VOID\r
	375	InterruptDistrubutionHub (\r
	376	EFI_EXCEPTION_TYPE ExceptionType,\r
	377	EFI_SYSTEM_CONTEXT_IA32 *ContextRecord\r
	378	)\r
	379	{\r
	380	if (IdtEntryTable[ExceptionType].RegisteredCallback != NULL) {\r
	381	if (ExceptionType != SYSTEM_TIMER_VECTOR) {\r
	382	IdtEntryTable[ExceptionType].RegisteredCallback (ExceptionType, ContextRecord);\r
	383	} else {\r
	384	OrigVector = IdtEntryTable[ExceptionType].OrigVector;\r
	385	IdtEntryTable[ExceptionType].RegisteredCallback (ContextRecord);\r
	386	}\r
	387	}\r
	388	}\r