[mirror_edk2.git] / EmulatorPkg / TimerDxe / Timer.c

/*++ @file\r
  Emu Emulation Timer Architectural Protocol Driver as defined in DXE CIS\r
\r
  This Timer module uses an Emu Thread to simulate the timer-tick driven\r
  timer service.  In the future, the Thread creation should possibly be\r
  abstracted by the CPU architectural protocol\r
\r
Copyright (c) 2004 - 2016, Intel Corporation. All rights reserved.<BR>\r
Portions copyright (c) 2010 - 2011, Apple Inc. All rights reserved.\r
SPDX-License-Identifier: BSD-2-Clause-Patent\r
\r
\r
**/\r
\r
#include "PiDxe.h"\r
#include <Protocol/Timer.h>\r
#include <Protocol/Cpu.h>\r
#include "Timer.h"\r
#include <Library/BaseLib.h>\r
#include <Library/DebugLib.h>\r
#include <Library/UefiLib.h>\r
#include <Library/UefiDriverEntryPoint.h>\r
#include <Library/MemoryAllocationLib.h>\r
#include <Library/UefiBootServicesTableLib.h>\r
#include <Library/EmuThunkLib.h>\r
\r
//\r
// Pointer to the CPU Architectural Protocol instance\r
//\r
EFI_CPU_ARCH_PROTOCOL   *mCpu;\r
\r
//\r
// The Timer Architectural Protocol that this driver produces\r
//\r
EFI_TIMER_ARCH_PROTOCOL mTimer = {\r
  EmuTimerDriverRegisterHandler,\r
  EmuTimerDriverSetTimerPeriod,\r
  EmuTimerDriverGetTimerPeriod,\r
  EmuTimerDriverGenerateSoftInterrupt\r
};\r
\r
//\r
// The notification function to call on every timer interrupt\r
//\r
EFI_TIMER_NOTIFY        mTimerNotifyFunction = NULL;\r
\r
//\r
// The current period of the timer interrupt\r
//\r
UINT64                  mTimerPeriodMs;\r
\r
\r
VOID\r
EFIAPI\r
TimerCallback (UINT64 DeltaMs)\r
{\r
  EFI_TPL           OriginalTPL;\r
  EFI_TIMER_NOTIFY  CallbackFunction;\r
\r
\r
  OriginalTPL = gBS->RaiseTPL (TPL_HIGH_LEVEL);\r
\r
  if (OriginalTPL < TPL_HIGH_LEVEL) {\r
    CallbackFunction = mTimerNotifyFunction;\r
\r
    //\r
    // Only invoke the callback function if a Non-NULL handler has been\r
    // registered. Assume all other handlers are legal.\r
    //\r
    if (CallbackFunction != NULL) {\r
      CallbackFunction (MultU64x32 (DeltaMs, 10000));\r
    }\r
  }\r
\r
  gBS->RestoreTPL (OriginalTPL);\r
\r
}\r
\r
EFI_STATUS\r
EFIAPI\r
EmuTimerDriverRegisterHandler (\r
  IN EFI_TIMER_ARCH_PROTOCOL           *This,\r
  IN EFI_TIMER_NOTIFY                  NotifyFunction\r
  )\r
/*++\r
\r
Routine Description:\r
\r
  This function registers the handler NotifyFunction so it is called every time\r
  the timer interrupt fires.  It also passes the amount of time since the last\r
  handler call to the NotifyFunction.  If NotifyFunction is NULL, then the\r
  handler is unregistered.  If the handler is registered, then EFI_SUCCESS is\r
  returned.  If the CPU does not support registering a timer interrupt handler,\r
  then EFI_UNSUPPORTED is returned.  If an attempt is made to register a handler\r
  when a handler is already registered, then EFI_ALREADY_STARTED is returned.\r
  If an attempt is made to unregister a handler when a handler is not registered,\r
  then EFI_INVALID_PARAMETER is returned.  If an error occurs attempting to\r
  register the NotifyFunction with the timer interrupt, then EFI_DEVICE_ERROR\r
  is returned.\r
\r
Arguments:\r
\r
  This           - The EFI_TIMER_ARCH_PROTOCOL instance.\r
\r
  NotifyFunction - The function to call when a timer interrupt fires.  This\r
                   function executes at TPL_HIGH_LEVEL.  The DXE Core will\r
                   register a handler for the timer interrupt, so it can know\r
                   how much time has passed.  This information is used to\r
                   signal timer based events.  NULL will unregister the handler.\r
\r
Returns:\r
\r
  EFI_SUCCESS           - The timer handler was registered.\r
\r
  EFI_UNSUPPORTED       - The platform does not support timer interrupts.\r
\r
  EFI_ALREADY_STARTED   - NotifyFunction is not NULL, and a handler is already\r
                          registered.\r
\r
  EFI_INVALID_PARAMETER - NotifyFunction is NULL, and a handler was not\r
                          previously registered.\r
\r
  EFI_DEVICE_ERROR      - The timer handler could not be registered.\r
\r
**/\r
{\r
  //\r
  // Check for invalid parameters\r
  //\r
  if (NotifyFunction == NULL && mTimerNotifyFunction == NULL) {\r
    return EFI_INVALID_PARAMETER;\r
  }\r
\r
  if (NotifyFunction != NULL && mTimerNotifyFunction != NULL) {\r
    return EFI_ALREADY_STARTED;\r
  }\r
\r
  if (NotifyFunction == NULL) {\r
    /* Disable timer.  */\r
    gEmuThunk->SetTimer (0, TimerCallback);\r
  } else if (mTimerNotifyFunction == NULL) {\r
    /* Enable Timer.  */\r
    gEmuThunk->SetTimer (mTimerPeriodMs, TimerCallback);\r
  }\r
  mTimerNotifyFunction = NotifyFunction;\r
\r
  return EFI_SUCCESS;\r
}\r
\r
EFI_STATUS\r
EFIAPI\r
EmuTimerDriverSetTimerPeriod (\r
  IN EFI_TIMER_ARCH_PROTOCOL  *This,\r
  IN UINT64                   TimerPeriod\r
  )\r
/*++\r
\r
Routine Description:\r
\r
  This function adjusts the period of timer interrupts to the value specified\r
  by TimerPeriod.  If the timer period is updated, then the selected timer\r
  period is stored in EFI_TIMER.TimerPeriod, and EFI_SUCCESS is returned.  If\r
  the timer hardware is not programmable, then EFI_UNSUPPORTED is returned.\r
  If an error occurs while attempting to update the timer period, then the\r
  timer hardware will be put back in its state prior to this call, and\r
  EFI_DEVICE_ERROR is returned.  If TimerPeriod is 0, then the timer interrupt\r
  is disabled.  This is not the same as disabling the CPU's interrupts.\r
  Instead, it must either turn off the timer hardware, or it must adjust the\r
  interrupt controller so that a CPU interrupt is not generated when the timer\r
  interrupt fires.\r
\r
Arguments:\r
\r
  This        - The EFI_TIMER_ARCH_PROTOCOL instance.\r
\r
  TimerPeriod - The rate to program the timer interrupt in 100 nS units.  If\r
                the timer hardware is not programmable, then EFI_UNSUPPORTED is\r
                returned.  If the timer is programmable, then the timer period\r
                will be rounded up to the nearest timer period that is supported\r
                by the timer hardware.  If TimerPeriod is set to 0, then the\r
                timer interrupts will be disabled.\r
\r
Returns:\r
\r
  EFI_SUCCESS      - The timer period was changed.\r
\r
  EFI_UNSUPPORTED  - The platform cannot change the period of the timer interrupt.\r
\r
  EFI_DEVICE_ERROR - The timer period could not be changed due to a device error.\r
\r
**/\r
{\r
\r
  //\r
  // If TimerPeriod is 0, then the timer thread should be canceled\r
  // If the TimerPeriod is valid, then create and/or adjust the period of the timer thread\r
  //\r
  if (TimerPeriod == 0\r
      || ((TimerPeriod > TIMER_MINIMUM_VALUE)\r
    && (TimerPeriod < TIMER_MAXIMUM_VALUE))) {\r
    mTimerPeriodMs = DivU64x32 (TimerPeriod + 5000, 10000);\r
\r
    gEmuThunk->SetTimer (mTimerPeriodMs, TimerCallback);\r
  }\r
\r
  return EFI_SUCCESS;\r
}\r
\r
EFI_STATUS\r
EFIAPI\r
EmuTimerDriverGetTimerPeriod (\r
  IN EFI_TIMER_ARCH_PROTOCOL            *This,\r
  OUT UINT64                            *TimerPeriod\r
  )\r
/*++\r
\r
Routine Description:\r
\r
  This function retrieves the period of timer interrupts in 100 ns units,\r
  returns that value in TimerPeriod, and returns EFI_SUCCESS.  If TimerPeriod\r
  is NULL, then EFI_INVALID_PARAMETER is returned.  If a TimerPeriod of 0 is\r
  returned, then the timer is currently disabled.\r
\r
Arguments:\r
\r
  This        - The EFI_TIMER_ARCH_PROTOCOL instance.\r
\r
  TimerPeriod - A pointer to the timer period to retrieve in 100 ns units.  If\r
                0 is returned, then the timer is currently disabled.\r
\r
Returns:\r
\r
  EFI_SUCCESS           - The timer period was returned in TimerPeriod.\r
\r
  EFI_INVALID_PARAMETER - TimerPeriod is NULL.\r
\r
**/\r
{\r
  if (TimerPeriod == NULL) {\r
    return EFI_INVALID_PARAMETER;\r
  }\r
\r
  *TimerPeriod = MultU64x32 (mTimerPeriodMs, 10000);\r
\r
  return EFI_SUCCESS;\r
}\r
\r
EFI_STATUS\r
EFIAPI\r
EmuTimerDriverGenerateSoftInterrupt (\r
  IN EFI_TIMER_ARCH_PROTOCOL  *This\r
  )\r
/*++\r
\r
Routine Description:\r
\r
  This function generates a soft timer interrupt. If the platform does not support soft\r
  timer interrupts, then EFI_UNSUPPORTED is returned. Otherwise, EFI_SUCCESS is returned.\r
  If a handler has been registered through the EFI_TIMER_ARCH_PROTOCOL.RegisterHandler()\r
  service, then a soft timer interrupt will be generated. If the timer interrupt is\r
  enabled when this service is called, then the registered handler will be invoked. The\r
  registered handler should not be able to distinguish a hardware-generated timer\r
  interrupt from a software-generated timer interrupt.\r
\r
Arguments:\r
\r
  This  -  The EFI_TIMER_ARCH_PROTOCOL instance.\r
\r
Returns:\r
\r
  EFI_SUCCESS       - The soft timer interrupt was generated.\r
\r
  EFI_UNSUPPORTED   - The platform does not support the generation of soft timer interrupts.\r
\r
**/\r
{\r
  return EFI_UNSUPPORTED;\r
}\r
\r
EFI_STATUS\r
EFIAPI\r
EmuTimerDriverInitialize (\r
  IN EFI_HANDLE        ImageHandle,\r
  IN EFI_SYSTEM_TABLE  *SystemTable\r
  )\r
/*++\r
\r
Routine Description:\r
\r
  Initialize the Timer Architectural Protocol driver\r
\r
Arguments:\r
\r
  ImageHandle - ImageHandle of the loaded driver\r
\r
  SystemTable - Pointer to the System Table\r
\r
Returns:\r
\r
  EFI_SUCCESS           - Timer Architectural Protocol created\r
\r
  EFI_OUT_OF_RESOURCES  - Not enough resources available to initialize driver.\r
\r
  EFI_DEVICE_ERROR      - A device error occured attempting to initialize the driver.\r
\r
**/\r
{\r
  EFI_STATUS  Status;\r
  EFI_HANDLE  Handle;\r
\r
  //\r
  // Make sure the Timer Architectural Protocol is not already installed in the system\r
  //\r
  ASSERT_PROTOCOL_ALREADY_INSTALLED (NULL, &gEfiTimerArchProtocolGuid);\r
\r
  //\r
  // Get the CPU Architectural Protocol instance\r
  //\r
  Status = gBS->LocateProtocol (&gEfiCpuArchProtocolGuid, NULL, (void *)&mCpu);\r
  ASSERT_EFI_ERROR (Status);\r
\r
  //\r
  // Start the timer thread at the default timer period\r
  //\r
  Status = mTimer.SetTimerPeriod (&mTimer, DEFAULT_TIMER_TICK_DURATION);\r
  if (EFI_ERROR (Status)) {\r
    return Status;\r
  }\r
\r
  //\r
  // Install the Timer Architectural Protocol onto a new handle\r
  //\r
  Handle = NULL;\r
  Status = gBS->InstallProtocolInterface (\r
                  &Handle,\r
                  &gEfiTimerArchProtocolGuid,\r
                  EFI_NATIVE_INTERFACE,\r
                  &mTimer\r
                  );\r
  if (EFI_ERROR (Status)) {\r
    return Status;\r
  }\r
\r
\r
  return EFI_SUCCESS;\r
}\r
Commit	Line	Data
949f388f	1	/*++ @file\r
	2	Emu Emulation Timer Architectural Protocol Driver as defined in DXE CIS\r
	3	\r
	4	This Timer module uses an Emu Thread to simulate the timer-tick driven\r
	5	timer service. In the future, the Thread creation should possibly be\r
	6	abstracted by the CPU architectural protocol\r
	7	\r
daea123d	8	Copyright (c) 2004 - 2016, Intel Corporation. All rights reserved.<BR>\r
949f388f	9	Portions copyright (c) 2010 - 2011, Apple Inc. All rights reserved.\r
e3ba31da	10	SPDX-License-Identifier: BSD-2-Clause-Patent\r
949f388f	11	\r
	12	\r
	13	**/\r
	14	\r
	15	#include "PiDxe.h"\r
	16	#include <Protocol/Timer.h>\r
	17	#include <Protocol/Cpu.h>\r
	18	#include "Timer.h"\r
	19	#include <Library/BaseLib.h>\r
	20	#include <Library/DebugLib.h>\r
	21	#include <Library/UefiLib.h>\r
	22	#include <Library/UefiDriverEntryPoint.h>\r
	23	#include <Library/MemoryAllocationLib.h>\r
	24	#include <Library/UefiBootServicesTableLib.h>\r
	25	#include <Library/EmuThunkLib.h>\r
	26	\r
	27	//\r
	28	// Pointer to the CPU Architectural Protocol instance\r
	29	//\r
	30	EFI_CPU_ARCH_PROTOCOL *mCpu;\r
	31	\r
	32	//\r
	33	// The Timer Architectural Protocol that this driver produces\r
	34	//\r
	35	EFI_TIMER_ARCH_PROTOCOL mTimer = {\r
	36	EmuTimerDriverRegisterHandler,\r
	37	EmuTimerDriverSetTimerPeriod,\r
	38	EmuTimerDriverGetTimerPeriod,\r
	39	EmuTimerDriverGenerateSoftInterrupt\r
	40	};\r
	41	\r
	42	//\r
	43	// The notification function to call on every timer interrupt\r
	44	//\r
	45	EFI_TIMER_NOTIFY mTimerNotifyFunction = NULL;\r
	46	\r
	47	//\r
	48	// The current period of the timer interrupt\r
	49	//\r
	50	UINT64 mTimerPeriodMs;\r
	51	\r
	52	\r
	53	VOID\r
	54	EFIAPI\r
	55	TimerCallback (UINT64 DeltaMs)\r
	56	{\r
	57	EFI_TPL OriginalTPL;\r
	58	EFI_TIMER_NOTIFY CallbackFunction;\r
	59	\r
	60	\r
	61	OriginalTPL = gBS->RaiseTPL (TPL_HIGH_LEVEL);\r
	62	\r
	63	if (OriginalTPL < TPL_HIGH_LEVEL) {\r
	64	CallbackFunction = mTimerNotifyFunction;\r
	65	\r
	66	//\r
	67	// Only invoke the callback function if a Non-NULL handler has been\r
	68	// registered. Assume all other handlers are legal.\r
	69	//\r
	70	if (CallbackFunction != NULL) {\r
e148512e	71	CallbackFunction (MultU64x32 (DeltaMs, 10000));\r
949f388f	72	}\r
	73	}\r
	74	\r
	75	gBS->RestoreTPL (OriginalTPL);\r
	76	\r
	77	}\r
	78	\r
	79	EFI_STATUS\r
	80	EFIAPI\r
	81	EmuTimerDriverRegisterHandler (\r
	82	IN EFI_TIMER_ARCH_PROTOCOL *This,\r
	83	IN EFI_TIMER_NOTIFY NotifyFunction\r
	84	)\r
	85	/*++\r
	86	\r
	87	Routine Description:\r
	88	\r
	89	This function registers the handler NotifyFunction so it is called every time\r
	90	the timer interrupt fires. It also passes the amount of time since the last\r
	91	handler call to the NotifyFunction. If NotifyFunction is NULL, then the\r
	92	handler is unregistered. If the handler is registered, then EFI_SUCCESS is\r
	93	returned. If the CPU does not support registering a timer interrupt handler,\r
	94	then EFI_UNSUPPORTED is returned. If an attempt is made to register a handler\r
	95	when a handler is already registered, then EFI_ALREADY_STARTED is returned.\r
	96	If an attempt is made to unregister a handler when a handler is not registered,\r
	97	then EFI_INVALID_PARAMETER is returned. If an error occurs attempting to\r
	98	register the NotifyFunction with the timer interrupt, then EFI_DEVICE_ERROR\r
	99	is returned.\r
	100	\r
	101	Arguments:\r
	102	\r
	103	This - The EFI_TIMER_ARCH_PROTOCOL instance.\r
	104	\r
	105	NotifyFunction - The function to call when a timer interrupt fires. This\r
	106	function executes at TPL_HIGH_LEVEL. The DXE Core will\r
	107	register a handler for the timer interrupt, so it can know\r
	108	how much time has passed. This information is used to\r
	109	signal timer based events. NULL will unregister the handler.\r
	110	\r
	111	Returns:\r
	112	\r
	113	EFI_SUCCESS - The timer handler was registered.\r
	114	\r
	115	EFI_UNSUPPORTED - The platform does not support timer interrupts.\r
	116	\r
	117	EFI_ALREADY_STARTED - NotifyFunction is not NULL, and a handler is already\r
	118	registered.\r
	119	\r
	120	EFI_INVALID_PARAMETER - NotifyFunction is NULL, and a handler was not\r
	121	previously registered.\r
	122	\r
	123	EFI_DEVICE_ERROR - The timer handler could not be registered.\r
	124	\r
	125	**/\r
	126	{\r
	127	//\r
	128	// Check for invalid parameters\r
	129	//\r
	130	if (NotifyFunction == NULL && mTimerNotifyFunction == NULL) {\r
	131	return EFI_INVALID_PARAMETER;\r
	132	}\r
	133	\r
	134	if (NotifyFunction != NULL && mTimerNotifyFunction != NULL) {\r
	135	return EFI_ALREADY_STARTED;\r
136	}\r
137	\r
138	if (NotifyFunction == NULL) {\r
139	/* Disable timer. */\r
140	gEmuThunk->SetTimer (0, TimerCallback);\r
141	} else if (mTimerNotifyFunction == NULL) {\r
142	/* Enable Timer. */\r
143	gEmuThunk->SetTimer (mTimerPeriodMs, TimerCallback);\r
144	}\r
145	mTimerNotifyFunction = NotifyFunction;\r
146	\r
147	return EFI_SUCCESS;\r
148	}\r
149	\r
150	EFI_STATUS\r
151	EFIAPI\r
152	EmuTimerDriverSetTimerPeriod (\r
153	IN EFI_TIMER_ARCH_PROTOCOL *This,\r
154	IN UINT64 TimerPeriod\r
155	)\r
156	/*++\r
157	\r
158	Routine Description:\r
159	\r
160	This function adjusts the period of timer interrupts to the value specified\r
161	by TimerPeriod. If the timer period is updated, then the selected timer\r
162	period is stored in EFI_TIMER.TimerPeriod, and EFI_SUCCESS is returned. If\r
163	the timer hardware is not programmable, then EFI_UNSUPPORTED is returned.\r
164	If an error occurs while attempting to update the timer period, then the\r
165	timer hardware will be put back in its state prior to this call, and\r
166	EFI_DEVICE_ERROR is returned. If TimerPeriod is 0, then the timer interrupt\r
167	is disabled. This is not the same as disabling the CPU's interrupts.\r
168	Instead, it must either turn off the timer hardware, or it must adjust the\r
169	interrupt controller so that a CPU interrupt is not generated when the timer\r
170	interrupt fires.\r
171	\r
172	Arguments:\r
173	\r
174	This - The EFI_TIMER_ARCH_PROTOCOL instance.\r
175	\r
176	TimerPeriod - The rate to program the timer interrupt in 100 nS units. If\r
177	the timer hardware is not programmable, then EFI_UNSUPPORTED is\r
178	returned. If the timer is programmable, then the timer period\r
179	will be rounded up to the nearest timer period that is supported\r
180	by the timer hardware. If TimerPeriod is set to 0, then the\r
181	timer interrupts will be disabled.\r
182	\r
183	Returns:\r
184	\r
185	EFI_SUCCESS - The timer period was changed.\r
186	\r
187	EFI_UNSUPPORTED - The platform cannot change the period of the timer interrupt.\r
188	\r
189	EFI_DEVICE_ERROR - The timer period could not be changed due to a device error.\r
190	\r
191	**/\r
192	{\r
193	\r
194	//\r
195	// If TimerPeriod is 0, then the timer thread should be canceled\r
196	// If the TimerPeriod is valid, then create and/or adjust the period of the timer thread\r
197	//\r
198	if (TimerPeriod == 0\r
199	\|\| ((TimerPeriod > TIMER_MINIMUM_VALUE)\r
200	&& (TimerPeriod < TIMER_MAXIMUM_VALUE))) {\r
201	mTimerPeriodMs = DivU64x32 (TimerPeriod + 5000, 10000);\r
202	\r
203	gEmuThunk->SetTimer (mTimerPeriodMs, TimerCallback);\r
204	}\r
205	\r
206	return EFI_SUCCESS;\r
207	}\r
208	\r
209	EFI_STATUS\r
210	EFIAPI\r
211	EmuTimerDriverGetTimerPeriod (\r
212	IN EFI_TIMER_ARCH_PROTOCOL *This,\r
213	OUT UINT64 *TimerPeriod\r
214	)\r
215	/*++\r
216	\r
217	Routine Description:\r
218	\r
219	This function retrieves the period of timer interrupts in 100 ns units,\r
220	returns that value in TimerPeriod, and returns EFI_SUCCESS. If TimerPeriod\r
221	is NULL, then EFI_INVALID_PARAMETER is returned. If a TimerPeriod of 0 is\r
222	returned, then the timer is currently disabled.\r
223	\r
224	Arguments:\r
225	\r
226	This - The EFI_TIMER_ARCH_PROTOCOL instance.\r
227	\r
228	TimerPeriod - A pointer to the timer period to retrieve in 100 ns units. If\r
229	0 is returned, then the timer is currently disabled.\r
230	\r
231	Returns:\r
232	\r
233	EFI_SUCCESS - The timer period was returned in TimerPeriod.\r
234	\r
235	EFI_INVALID_PARAMETER - TimerPeriod is NULL.\r
236	\r
237	**/\r
238	{\r
239	if (TimerPeriod == NULL) {\r
240	return EFI_INVALID_PARAMETER;\r
241	}\r
242	\r
e148512e	243	*TimerPeriod = MultU64x32 (mTimerPeriodMs, 10000);\r
949f388f	244	\r
	245	return EFI_SUCCESS;\r
	246	}\r
	247	\r
	248	EFI_STATUS\r
	249	EFIAPI\r
	250	EmuTimerDriverGenerateSoftInterrupt (\r
	251	IN EFI_TIMER_ARCH_PROTOCOL *This\r
	252	)\r
	253	/*++\r
	254	\r
	255	Routine Description:\r
	256	\r
	257	This function generates a soft timer interrupt. If the platform does not support soft\r
	258	timer interrupts, then EFI_UNSUPPORTED is returned. Otherwise, EFI_SUCCESS is returned.\r
	259	If a handler has been registered through the EFI_TIMER_ARCH_PROTOCOL.RegisterHandler()\r
	260	service, then a soft timer interrupt will be generated. If the timer interrupt is\r
	261	enabled when this service is called, then the registered handler will be invoked. The\r
	262	registered handler should not be able to distinguish a hardware-generated timer\r
	263	interrupt from a software-generated timer interrupt.\r
	264	\r
	265	Arguments:\r
	266	\r
	267	This - The EFI_TIMER_ARCH_PROTOCOL instance.\r
	268	\r
	269	Returns:\r
	270	\r
	271	EFI_SUCCESS - The soft timer interrupt was generated.\r
	272	\r
daea123d	273	EFI_UNSUPPORTED - The platform does not support the generation of soft timer interrupts.\r
949f388f	274	\r
	275	**/\r
	276	{\r
	277	return EFI_UNSUPPORTED;\r
	278	}\r
	279	\r
	280	EFI_STATUS\r
	281	EFIAPI\r
	282	EmuTimerDriverInitialize (\r
	283	IN EFI_HANDLE ImageHandle,\r
	284	IN EFI_SYSTEM_TABLE *SystemTable\r
	285	)\r
	286	/*++\r
	287	\r
	288	Routine Description:\r
	289	\r
	290	Initialize the Timer Architectural Protocol driver\r
	291	\r
	292	Arguments:\r
	293	\r
	294	ImageHandle - ImageHandle of the loaded driver\r
	295	\r
	296	SystemTable - Pointer to the System Table\r
	297	\r
	298	Returns:\r
	299	\r
	300	EFI_SUCCESS - Timer Architectural Protocol created\r
	301	\r
	302	EFI_OUT_OF_RESOURCES - Not enough resources available to initialize driver.\r
	303	\r
	304	EFI_DEVICE_ERROR - A device error occured attempting to initialize the driver.\r
	305	\r
	306	**/\r
	307	{\r
	308	EFI_STATUS Status;\r
	309	EFI_HANDLE Handle;\r
	310	\r
	311	//\r
	312	// Make sure the Timer Architectural Protocol is not already installed in the system\r
	313	//\r
	314	ASSERT_PROTOCOL_ALREADY_INSTALLED (NULL, &gEfiTimerArchProtocolGuid);\r
	315	\r
	316	//\r
	317	// Get the CPU Architectural Protocol instance\r
	318	//\r
	319	Status = gBS->LocateProtocol (&gEfiCpuArchProtocolGuid, NULL, (void *)&mCpu);\r
	320	ASSERT_EFI_ERROR (Status);\r
	321	\r
1ef41207	322	//\r
	323	// Start the timer thread at the default timer period\r
	324	//\r
	325	Status = mTimer.SetTimerPeriod (&mTimer, DEFAULT_TIMER_TICK_DURATION);\r
	326	if (EFI_ERROR (Status)) {\r
	327	return Status;\r
	328	}\r
	329	\r
949f388f	330	//\r
	331	// Install the Timer Architectural Protocol onto a new handle\r
	332	//\r
	333	Handle = NULL;\r
	334	Status = gBS->InstallProtocolInterface (\r
	335	&Handle,\r
	336	&gEfiTimerArchProtocolGuid,\r
	337	EFI_NATIVE_INTERFACE,\r
	338	&mTimer\r
	339	);\r
	340	if (EFI_ERROR (Status)) {\r
	341	return Status;\r
	342	}\r
	343	\r
949f388f	344	\r
	345	return EFI_SUCCESS;\r
	346	}\r