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

/*++\r
\r
Copyright (c) 2004, Intel Corporation. All rights reserved.<BR>\r
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
Module Name:\r
\r
  Timer.c\r
\r
Abstract:\r
\r
  UNIX Emulation Timer Architectural Protocol Driver as defined in DXE CIS\r
\r
  This Timer module uses an UNIX 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
--*/\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 "UnixDxe.h"\r
#include <Library/UnixLib.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
  UnixTimerDriverRegisterHandler,\r
  UnixTimerDriverSetTimerPeriod,\r
  UnixTimerDriverGetTimerPeriod,\r
  UnixTimerDriverGenerateSoftInterrupt\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
\r
Routine Description:\r
\r
  TODO: Add function description\r
\r
Arguments:\r
\r
  wTimerID  - TODO: add argument description\r
  msg       - TODO: add argument description\r
  dwUser    - TODO: add argument description\r
  dw1       - TODO: add argument description\r
  dw2       - TODO: add argument description\r
\r
Returns:\r
\r
  TODO: add return values\r
\r
--*/\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 ((UINT64) (DeltaMs * 10000));\r
    }\r
  }\r
\r
  gBS->RestoreTPL (OriginalTPL);\r
\r
}\r
\r
EFI_STATUS\r
EFIAPI\r
UnixTimerDriverRegisterHandler (\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
    gUnix->SetTimer (0, TimerCallback);\r
  } else if (mTimerNotifyFunction == NULL) {\r
    /* Enable Timer.  */\r
    gUnix->SetTimer (mTimerPeriodMs, TimerCallback);\r
  }\r
  mTimerNotifyFunction = NotifyFunction;\r
\r
  return EFI_SUCCESS;\r
}\r
\r
EFI_STATUS\r
EFIAPI\r
UnixTimerDriverSetTimerPeriod (\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
    gUnix->SetTimer (mTimerPeriodMs, TimerCallback);\r
  }\r
\r
  return EFI_SUCCESS;\r
}\r
\r
EFI_STATUS\r
EFIAPI\r
UnixTimerDriverGetTimerPeriod (\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 = mTimerPeriodMs * 10000;\r
\r
  return EFI_SUCCESS;\r
}\r
\r
EFI_STATUS\r
EFIAPI\r
UnixTimerDriverGenerateSoftInterrupt (\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_UNSUPPORTEDT  - 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
UnixTimerDriverInitialize (\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
  // 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
  // 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
  return EFI_SUCCESS;\r
}\r
Commit	Line	Data
804405e7	1	/*++\r
804405e7	2	\r
f9b8ab56	3	Copyright (c) 2004, Intel Corporation. All rights reserved.<BR>\r
124f761f	4	This program and the accompanying materials\r
	5	are licensed and made available under the terms and conditions of the BSD License\r
	6	which accompanies this distribution. The full text of the license may be found at\r
	7	http://opensource.org/licenses/bsd-license.php\r
	8	\r
	9	THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,\r
	10	WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.\r
804405e7	11	\r
	12	Module Name:\r
	13	\r
	14	Timer.c\r
	15	\r
	16	Abstract:\r
	17	\r
	18	UNIX Emulation Timer Architectural Protocol Driver as defined in DXE CIS\r
	19	\r
	20	This Timer module uses an UNIX Thread to simulate the timer-tick driven\r
124f761f	21	timer service. In the future, the Thread creation should possibly be\r
804405e7	22	abstracted by the CPU architectural protocol\r
	23	\r
	24	--*/\r
	25	#include "PiDxe.h"\r
	26	#include <Protocol/Timer.h>\r
	27	#include <Protocol/Cpu.h>\r
	28	#include "Timer.h"\r
	29	#include <Library/BaseLib.h>\r
	30	#include <Library/DebugLib.h>\r
	31	#include <Library/UefiLib.h>\r
	32	#include <Library/UefiDriverEntryPoint.h>\r
	33	#include <Library/MemoryAllocationLib.h>\r
	34	#include <Library/UefiBootServicesTableLib.h>\r
	35	#include "UnixDxe.h"\r
	36	#include <Library/UnixLib.h>\r
	37	\r
	38	//\r
	39	// Pointer to the CPU Architectural Protocol instance\r
	40	//\r
	41	EFI_CPU_ARCH_PROTOCOL *mCpu;\r
	42	\r
	43	//\r
	44	// The Timer Architectural Protocol that this driver produces\r
	45	//\r
	46	EFI_TIMER_ARCH_PROTOCOL mTimer = {\r
	47	UnixTimerDriverRegisterHandler,\r
	48	UnixTimerDriverSetTimerPeriod,\r
	49	UnixTimerDriverGetTimerPeriod,\r
	50	UnixTimerDriverGenerateSoftInterrupt\r
	51	};\r
	52	\r
	53	//\r
	54	// The notification function to call on every timer interrupt\r
	55	//\r
	56	EFI_TIMER_NOTIFY mTimerNotifyFunction = NULL;\r
	57	\r
	58	//\r
	59	// The current period of the timer interrupt\r
	60	//\r
	61	UINT64 mTimerPeriodMs;\r
	62	\r
	63	\r
	64	VOID\r
124f761f	65	EFIAPI\r
ccd55824	66	TimerCallback (UINT64 DeltaMs)\r
804405e7	67	/*++\r
	68	\r
	69	Routine Description:\r
	70	\r
	71	TODO: Add function description\r
	72	\r
	73	Arguments:\r
	74	\r
	75	wTimerID - TODO: add argument description\r
	76	msg - TODO: add argument description\r
	77	dwUser - TODO: add argument description\r
	78	dw1 - TODO: add argument description\r
	79	dw2 - TODO: add argument description\r
	80	\r
	81	Returns:\r
	82	\r
	83	TODO: add return values\r
	84	\r
	85	--*/\r
	86	{\r
	87	EFI_TPL OriginalTPL;\r
ccd55824	88	EFI_TIMER_NOTIFY CallbackFunction;\r
ccd55824	89	\r
804405e7	90	\r
	91	OriginalTPL = gBS->RaiseTPL (TPL_HIGH_LEVEL);\r
	92	\r
ccd55824	93	if (OriginalTPL < TPL_HIGH_LEVEL) {\r
804405e7	94	CallbackFunction = mTimerNotifyFunction;\r
	95	\r
	96	//\r
	97	// Only invoke the callback function if a Non-NULL handler has been\r
	98	// registered. Assume all other handlers are legal.\r
	99	//\r
	100	if (CallbackFunction != NULL) {\r
	101	CallbackFunction ((UINT64) (DeltaMs * 10000));\r
	102	}\r
ccd55824	103	}\r
804405e7	104	\r
	105	gBS->RestoreTPL (OriginalTPL);\r
	106	\r
	107	}\r
	108	\r
	109	EFI_STATUS\r
	110	EFIAPI\r
	111	UnixTimerDriverRegisterHandler (\r
	112	IN EFI_TIMER_ARCH_PROTOCOL *This,\r
	113	IN EFI_TIMER_NOTIFY NotifyFunction\r
	114	)\r
	115	/*++\r
	116	\r
	117	Routine Description:\r
	118	\r
124f761f	119	This function registers the handler NotifyFunction so it is called every time\r
	120	the timer interrupt fires. It also passes the amount of time since the last\r
	121	handler call to the NotifyFunction. If NotifyFunction is NULL, then the\r
	122	handler is unregistered. If the handler is registered, then EFI_SUCCESS is\r
	123	returned. If the CPU does not support registering a timer interrupt handler,\r
	124	then EFI_UNSUPPORTED is returned. If an attempt is made to register a handler\r
	125	when a handler is already registered, then EFI_ALREADY_STARTED is returned.\r
	126	If an attempt is made to unregister a handler when a handler is not registered,\r
	127	then EFI_INVALID_PARAMETER is returned. If an error occurs attempting to\r
	128	register the NotifyFunction with the timer interrupt, then EFI_DEVICE_ERROR\r
804405e7	129	is returned.\r
	130	\r
	131	Arguments:\r
	132	\r
	133	This - The EFI_TIMER_ARCH_PROTOCOL instance.\r
	134	\r
124f761f	135	NotifyFunction - The function to call when a timer interrupt fires. This\r
	136	function executes at TPL_HIGH_LEVEL. The DXE Core will\r
	137	register a handler for the timer interrupt, so it can know\r
	138	how much time has passed. This information is used to\r
804405e7	139	signal timer based events. NULL will unregister the handler.\r
804405e7	140	\r
124f761f	141	Returns:\r
804405e7	142	\r
	143	EFI_SUCCESS - The timer handler was registered.\r
	144	\r
	145	EFI_UNSUPPORTED - The platform does not support timer interrupts.\r
	146	\r
124f761f	147	EFI_ALREADY_STARTED - NotifyFunction is not NULL, and a handler is already\r
804405e7	148	registered.\r
804405e7	149	\r
124f761f	150	EFI_INVALID_PARAMETER - NotifyFunction is NULL, and a handler was not\r
804405e7	151	previously registered.\r
	152	\r
	153	EFI_DEVICE_ERROR - The timer handler could not be registered.\r
	154	\r
	155	--*/\r
	156	{\r
	157	//\r
	158	// Check for invalid parameters\r
	159	//\r
	160	if (NotifyFunction == NULL && mTimerNotifyFunction == NULL) {\r
	161	return EFI_INVALID_PARAMETER;\r
	162	}\r
	163	\r
	164	if (NotifyFunction != NULL && mTimerNotifyFunction != NULL) {\r
	165	return EFI_ALREADY_STARTED;\r
	166	}\r
	167	\r
ccd55824	168	if (NotifyFunction == NULL) {\r
	169	/* Disable timer. */\r
	170	gUnix->SetTimer (0, TimerCallback);\r
	171	} else if (mTimerNotifyFunction == NULL) {\r
	172	/* Enable Timer. */\r
	173	gUnix->SetTimer (mTimerPeriodMs, TimerCallback);\r
	174	}\r
804405e7	175	mTimerNotifyFunction = NotifyFunction;\r
	176	\r
	177	return EFI_SUCCESS;\r
	178	}\r
	179	\r
	180	EFI_STATUS\r
	181	EFIAPI\r
	182	UnixTimerDriverSetTimerPeriod (\r
	183	IN EFI_TIMER_ARCH_PROTOCOL *This,\r
	184	IN UINT64 TimerPeriod\r
	185	)\r
	186	/*++\r
	187	\r
	188	Routine Description:\r
	189	\r
124f761f	190	This function adjusts the period of timer interrupts to the value specified\r
	191	by TimerPeriod. If the timer period is updated, then the selected timer\r
	192	period is stored in EFI_TIMER.TimerPeriod, and EFI_SUCCESS is returned. If\r
	193	the timer hardware is not programmable, then EFI_UNSUPPORTED is returned.\r
	194	If an error occurs while attempting to update the timer period, then the\r
	195	timer hardware will be put back in its state prior to this call, and\r
	196	EFI_DEVICE_ERROR is returned. If TimerPeriod is 0, then the timer interrupt\r
	197	is disabled. This is not the same as disabling the CPU's interrupts.\r
	198	Instead, it must either turn off the timer hardware, or it must adjust the\r
	199	interrupt controller so that a CPU interrupt is not generated when the timer\r
	200	interrupt fires.\r
804405e7	201	\r
	202	Arguments:\r
	203	\r
	204	This - The EFI_TIMER_ARCH_PROTOCOL instance.\r
	205	\r
124f761f	206	TimerPeriod - The rate to program the timer interrupt in 100 nS units. If\r
	207	the timer hardware is not programmable, then EFI_UNSUPPORTED is\r
	208	returned. If the timer is programmable, then the timer period\r
	209	will be rounded up to the nearest timer period that is supported\r
	210	by the timer hardware. If TimerPeriod is set to 0, then the\r
804405e7	211	timer interrupts will be disabled.\r
804405e7	212	\r
124f761f	213	Returns:\r
804405e7	214	\r
	215	EFI_SUCCESS - The timer period was changed.\r
	216	\r
	217	EFI_UNSUPPORTED - The platform cannot change the period of the timer interrupt.\r
	218	\r
	219	EFI_DEVICE_ERROR - The timer period could not be changed due to a device error.\r
	220	\r
	221	--*/\r
	222	{\r
	223	\r
	224	//\r
	225	// If TimerPeriod is 0, then the timer thread should be canceled\r
	226	// If the TimerPeriod is valid, then create and/or adjust the period of the timer thread\r
	227	//\r
ccd55824	228	if (TimerPeriod == 0\r
ccd55824	229	\|\| ((TimerPeriod > TIMER_MINIMUM_VALUE)\r
2ac288f9	230	&& (TimerPeriod < TIMER_MAXIMUM_VALUE))) {\r
804405e7	231	mTimerPeriodMs = DivU64x32 (TimerPeriod + 5000, 10000);\r
ccd55824	232	\r
	233	gUnix->SetTimer (mTimerPeriodMs, TimerCallback);\r
	234	}\r
804405e7	235	\r
	236	return EFI_SUCCESS;\r
	237	}\r
	238	\r
	239	EFI_STATUS\r
	240	EFIAPI\r
	241	UnixTimerDriverGetTimerPeriod (\r
	242	IN EFI_TIMER_ARCH_PROTOCOL *This,\r
	243	OUT UINT64 *TimerPeriod\r
	244	)\r
	245	/*++\r
	246	\r
	247	Routine Description:\r
	248	\r
124f761f	249	This function retrieves the period of timer interrupts in 100 ns units,\r
	250	returns that value in TimerPeriod, and returns EFI_SUCCESS. If TimerPeriod\r
	251	is NULL, then EFI_INVALID_PARAMETER is returned. If a TimerPeriod of 0 is\r
804405e7	252	returned, then the timer is currently disabled.\r
	253	\r
	254	Arguments:\r
	255	\r
	256	This - The EFI_TIMER_ARCH_PROTOCOL instance.\r
	257	\r
124f761f	258	TimerPeriod - A pointer to the timer period to retrieve in 100 ns units. If\r
804405e7	259	0 is returned, then the timer is currently disabled.\r
804405e7	260	\r
124f761f	261	Returns:\r
804405e7	262	\r
	263	EFI_SUCCESS - The timer period was returned in TimerPeriod.\r
	264	\r
	265	EFI_INVALID_PARAMETER - TimerPeriod is NULL.\r
	266	\r
	267	--*/\r
	268	{\r
	269	if (TimerPeriod == NULL) {\r
	270	return EFI_INVALID_PARAMETER;\r
	271	}\r
	272	\r
	273	TimerPeriod = mTimerPeriodMs 10000;\r
	274	\r
	275	return EFI_SUCCESS;\r
	276	}\r
	277	\r
	278	EFI_STATUS\r
	279	EFIAPI\r
	280	UnixTimerDriverGenerateSoftInterrupt (\r
	281	IN EFI_TIMER_ARCH_PROTOCOL *This\r
	282	)\r
	283	/*++\r
	284	\r
	285	Routine Description:\r
	286	\r
124f761f	287	This function generates a soft timer interrupt. If the platform does not support soft\r
	288	timer interrupts, then EFI_UNSUPPORTED is returned. Otherwise, EFI_SUCCESS is returned.\r
	289	If a handler has been registered through the EFI_TIMER_ARCH_PROTOCOL.RegisterHandler()\r
	290	service, then a soft timer interrupt will be generated. If the timer interrupt is\r
	291	enabled when this service is called, then the registered handler will be invoked. The\r
	292	registered handler should not be able to distinguish a hardware-generated timer\r
804405e7	293	interrupt from a software-generated timer interrupt.\r
	294	\r
	295	Arguments:\r
	296	\r
	297	This - The EFI_TIMER_ARCH_PROTOCOL instance.\r
	298	\r
124f761f	299	Returns:\r
804405e7	300	\r
	301	EFI_SUCCESS - The soft timer interrupt was generated.\r
	302	\r
	303	EFI_UNSUPPORTEDT - The platform does not support the generation of soft timer interrupts.\r
	304	\r
	305	--*/\r
	306	{\r
	307	return EFI_UNSUPPORTED;\r
	308	}\r
	309	\r
	310	EFI_STATUS\r
	311	EFIAPI\r
	312	UnixTimerDriverInitialize (\r
	313	IN EFI_HANDLE ImageHandle,\r
	314	IN EFI_SYSTEM_TABLE *SystemTable\r
	315	)\r
	316	/*++\r
	317	\r
	318	Routine Description:\r
	319	\r
	320	Initialize the Timer Architectural Protocol driver\r
	321	\r
	322	Arguments:\r
	323	\r
	324	ImageHandle - ImageHandle of the loaded driver\r
	325	\r
	326	SystemTable - Pointer to the System Table\r
	327	\r
	328	Returns:\r
	329	\r
	330	EFI_SUCCESS - Timer Architectural Protocol created\r
	331	\r
	332	EFI_OUT_OF_RESOURCES - Not enough resources available to initialize driver.\r
124f761f	333	\r
804405e7	334	EFI_DEVICE_ERROR - A device error occured attempting to initialize the driver.\r
	335	\r
	336	--*/\r
	337	{\r
	338	EFI_STATUS Status;\r
	339	EFI_HANDLE Handle;\r
	340	\r
	341	//\r
	342	// Make sure the Timer Architectural Protocol is not already installed in the system\r
	343	//\r
	344	ASSERT_PROTOCOL_ALREADY_INSTALLED (NULL, &gEfiTimerArchProtocolGuid);\r
	345	\r
	346	//\r
	347	// Get the CPU Architectural Protocol instance\r
	348	//\r
	349	Status = gBS->LocateProtocol (&gEfiCpuArchProtocolGuid, NULL, (void *)&mCpu);\r
	350	ASSERT_EFI_ERROR (Status);\r
	351	\r
	352	//\r
	353	// Install the Timer Architectural Protocol onto a new handle\r
	354	//\r
	355	Handle = NULL;\r
	356	Status = gBS->InstallProtocolInterface (\r
	357	&Handle,\r
	358	&gEfiTimerArchProtocolGuid,\r
	359	EFI_NATIVE_INTERFACE,\r
	360	&mTimer\r
	361	);\r
	362	if (EFI_ERROR (Status)) {\r
	363	return Status;\r
	364	}\r
	365	\r
	366	//\r
	367	// Start the timer thread at the default timer period\r
	368	//\r
	369	Status = mTimer.SetTimerPeriod (&mTimer, DEFAULT_TIMER_TICK_DURATION);\r
	370	if (EFI_ERROR (Status)) {\r
	371	return Status;\r
	372	}\r
ccd55824	373	\r
804405e7	374	return EFI_SUCCESS;\r
804405e7	375	}\r