1 /** @file
2 Implement EFI RealTimeClock runtime services via RTC Lib.
3
4 Copyright (c) 2008 - 2010, Apple Inc. All rights reserved.<BR>
5 Copyright (c) 2011 - 2014, ARM Ltd. All rights reserved.<BR>
6
7 This program and the accompanying materials
8 are licensed and made available under the terms and conditions of the BSD License
9 which accompanies this distribution. The full text of the license may be found at
10 http://opensource.org/licenses/bsd-license.php
11
12 THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
13 WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
14
15 **/
16
17 #include <Uefi.h>
18 #include <PiDxe.h>
19 #include <Library/BaseLib.h>
20 #include <Library/DebugLib.h>
21 #include <Library/UefiLib.h>
22 #include <Library/IoLib.h>
23 #include <Library/RealTimeClockLib.h>
24 #include <Library/MemoryAllocationLib.h>
25 #include <Library/PcdLib.h>
26 #include <Library/ArmPlatformSysConfigLib.h>
27 #include <Library/DxeServicesTableLib.h>
28 #include <Library/UefiBootServicesTableLib.h>
29 #include <Library/UefiRuntimeServicesTableLib.h>
30 #include <Library/UefiRuntimeLib.h>
31
32 #include <Protocol/RealTimeClock.h>
33
34 #include <Guid/GlobalVariable.h>
35 #include <Guid/EventGroup.h>
36
37 #include <Drivers/PL031RealTimeClock.h>
38
39 #include <ArmPlatform.h>
40
41 STATIC CONST CHAR16 mTimeZoneVariableName[] = L"PL031RtcTimeZone";
42 STATIC CONST CHAR16 mDaylightVariableName[] = L"PL031RtcDaylight";
43 STATIC BOOLEAN mPL031Initialized = FALSE;
44 STATIC EFI_EVENT mRtcVirtualAddrChangeEvent;
45 STATIC UINTN mPL031RtcBase;
46
47 EFI_STATUS
IdentifyPL031(VOID)48 IdentifyPL031 (
49 VOID
50 )
51 {
52 EFI_STATUS Status;
53
54 // Check if this is a PrimeCell Peripheral
55 if ( (MmioRead8 (mPL031RtcBase + PL031_RTC_PCELL_ID0) != 0x0D)
56 || (MmioRead8 (mPL031RtcBase + PL031_RTC_PCELL_ID1) != 0xF0)
57 || (MmioRead8 (mPL031RtcBase + PL031_RTC_PCELL_ID2) != 0x05)
58 || (MmioRead8 (mPL031RtcBase + PL031_RTC_PCELL_ID3) != 0xB1)) {
59 Status = EFI_NOT_FOUND;
60 goto EXIT;
61 }
62
63 // Check if this PrimeCell Peripheral is the PL031 Real Time Clock
64 if ( (MmioRead8 (mPL031RtcBase + PL031_RTC_PERIPH_ID0) != 0x31)
65 || (MmioRead8 (mPL031RtcBase + PL031_RTC_PERIPH_ID1) != 0x10)
66 || ((MmioRead8 (mPL031RtcBase + PL031_RTC_PERIPH_ID2) & 0xF) != 0x04)
67 || (MmioRead8 (mPL031RtcBase + PL031_RTC_PERIPH_ID3) != 0x00)) {
68 Status = EFI_NOT_FOUND;
69 goto EXIT;
70 }
71
72 Status = EFI_SUCCESS;
73
74 EXIT:
75 return Status;
76 }
77
78 EFI_STATUS
InitializePL031(VOID)79 InitializePL031 (
80 VOID
81 )
82 {
83 EFI_STATUS Status;
84
85 // Prepare the hardware
86 Status = IdentifyPL031();
87 if (EFI_ERROR (Status)) {
88 goto EXIT;
89 }
90
91 // Ensure interrupts are masked. We do not want RTC interrupts in UEFI
92 if ((MmioRead32 (mPL031RtcBase + PL031_RTC_IMSC_IRQ_MASK_SET_CLEAR_REGISTER) & PL031_SET_IRQ_MASK) != PL031_SET_IRQ_MASK) {
93 MmioOr32 (mPL031RtcBase + PL031_RTC_IMSC_IRQ_MASK_SET_CLEAR_REGISTER, PL031_SET_IRQ_MASK);
94 }
95
96 // Clear any existing interrupts
97 if ((MmioRead32 (mPL031RtcBase + PL031_RTC_RIS_RAW_IRQ_STATUS_REGISTER) & PL031_IRQ_TRIGGERED) == PL031_IRQ_TRIGGERED) {
98 MmioOr32 (mPL031RtcBase + PL031_RTC_ICR_IRQ_CLEAR_REGISTER, PL031_CLEAR_IRQ);
99 }
100
101 // Start the clock counter
102 if ((MmioRead32 (mPL031RtcBase + PL031_RTC_CR_CONTROL_REGISTER) & PL031_RTC_ENABLED) != PL031_RTC_ENABLED) {
103 MmioOr32 (mPL031RtcBase + PL031_RTC_CR_CONTROL_REGISTER, PL031_RTC_ENABLED);
104 }
105
106 mPL031Initialized = TRUE;
107
108 EXIT:
109 return Status;
110 }
111
112 /**
113 Converts Epoch seconds (elapsed since 1970 JANUARY 01, 00:00:00 UTC) to EFI_TIME
114 **/
115 VOID
EpochToEfiTime(IN UINTN EpochSeconds,OUT EFI_TIME * Time)116 EpochToEfiTime (
117 IN UINTN EpochSeconds,
118 OUT EFI_TIME *Time
119 )
120 {
121 UINTN a;
122 UINTN b;
123 UINTN c;
124 UINTN d;
125 UINTN g;
126 UINTN j;
127 UINTN m;
128 UINTN y;
129 UINTN da;
130 UINTN db;
131 UINTN dc;
132 UINTN dg;
133 UINTN hh;
134 UINTN mm;
135 UINTN ss;
136 UINTN J;
137
138 J = (EpochSeconds / 86400) + 2440588;
139 j = J + 32044;
140 g = j / 146097;
141 dg = j % 146097;
142 c = (((dg / 36524) + 1) * 3) / 4;
143 dc = dg - (c * 36524);
144 b = dc / 1461;
145 db = dc % 1461;
146 a = (((db / 365) + 1) * 3) / 4;
147 da = db - (a * 365);
148 y = (g * 400) + (c * 100) + (b * 4) + a;
149 m = (((da * 5) + 308) / 153) - 2;
150 d = da - (((m + 4) * 153) / 5) + 122;
151
152 Time->Year = y - 4800 + ((m + 2) / 12);
153 Time->Month = ((m + 2) % 12) + 1;
154 Time->Day = d + 1;
155
156 ss = EpochSeconds % 60;
157 a = (EpochSeconds - ss) / 60;
158 mm = a % 60;
159 b = (a - mm) / 60;
160 hh = b % 24;
161
162 Time->Hour = hh;
163 Time->Minute = mm;
164 Time->Second = ss;
165 Time->Nanosecond = 0;
166
167 }
168
169 /**
170 Converts EFI_TIME to Epoch seconds (elapsed since 1970 JANUARY 01, 00:00:00 UTC)
171 **/
172 UINTN
EfiTimeToEpoch(IN EFI_TIME * Time)173 EfiTimeToEpoch (
174 IN EFI_TIME *Time
175 )
176 {
177 UINTN a;
178 UINTN y;
179 UINTN m;
180 UINTN JulianDate; // Absolute Julian Date representation of the supplied Time
181 UINTN EpochDays; // Number of days elapsed since EPOCH_JULIAN_DAY
182 UINTN EpochSeconds;
183
184 a = (14 - Time->Month) / 12 ;
185 y = Time->Year + 4800 - a;
186 m = Time->Month + (12*a) - 3;
187
188 JulianDate = Time->Day + ((153*m + 2)/5) + (365*y) + (y/4) - (y/100) + (y/400) - 32045;
189
190 ASSERT (JulianDate >= EPOCH_JULIAN_DATE);
191 EpochDays = JulianDate - EPOCH_JULIAN_DATE;
192
193 EpochSeconds = (EpochDays * SEC_PER_DAY) + ((UINTN)Time->Hour * SEC_PER_HOUR) + (Time->Minute * SEC_PER_MIN) + Time->Second;
194
195 return EpochSeconds;
196 }
197
198 BOOLEAN
IsLeapYear(IN EFI_TIME * Time)199 IsLeapYear (
200 IN EFI_TIME *Time
201 )
202 {
203 if (Time->Year % 4 == 0) {
204 if (Time->Year % 100 == 0) {
205 if (Time->Year % 400 == 0) {
206 return TRUE;
207 } else {
208 return FALSE;
209 }
210 } else {
211 return TRUE;
212 }
213 } else {
214 return FALSE;
215 }
216 }
217
218 BOOLEAN
DayValid(IN EFI_TIME * Time)219 DayValid (
220 IN EFI_TIME *Time
221 )
222 {
223 STATIC CONST INTN DayOfMonth[12] = { 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 };
224
225 if (Time->Day < 1 ||
226 Time->Day > DayOfMonth[Time->Month - 1] ||
227 (Time->Month == 2 && (!IsLeapYear (Time) && Time->Day > 28))
228 ) {
229 return FALSE;
230 }
231
232 return TRUE;
233 }
234
235 /**
236 Returns the current time and date information, and the time-keeping capabilities
237 of the hardware platform.
238
239 @param Time A pointer to storage to receive a snapshot of the current time.
240 @param Capabilities An optional pointer to a buffer to receive the real time clock
241 device's capabilities.
242
243 @retval EFI_SUCCESS The operation completed successfully.
244 @retval EFI_INVALID_PARAMETER Time is NULL.
245 @retval EFI_DEVICE_ERROR The time could not be retrieved due to hardware error.
246 @retval EFI_SECURITY_VIOLATION The time could not be retrieved due to an authentication failure.
247
248 **/
249 EFI_STATUS
250 EFIAPI
LibGetTime(OUT EFI_TIME * Time,OUT EFI_TIME_CAPABILITIES * Capabilities)251 LibGetTime (
252 OUT EFI_TIME *Time,
253 OUT EFI_TIME_CAPABILITIES *Capabilities
254 )
255 {
256 EFI_STATUS Status = EFI_SUCCESS;
257 UINT32 EpochSeconds;
258 INT16 TimeZone;
259 UINT8 Daylight;
260 UINTN Size;
261
262 // Initialize the hardware if not already done
263 if (!mPL031Initialized) {
264 Status = InitializePL031 ();
265 if (EFI_ERROR (Status)) {
266 goto EXIT;
267 }
268 }
269
270 // Snapshot the time as early in the function call as possible
271 // On some platforms we may have access to a battery backed up hardware clock.
272 // If such RTC exists try to use it first.
273 Status = ArmPlatformSysConfigGet (SYS_CFG_RTC, &EpochSeconds);
274 if (Status == EFI_UNSUPPORTED) {
275 // Battery backed up hardware RTC does not exist, revert to PL031
276 EpochSeconds = MmioRead32 (mPL031RtcBase + PL031_RTC_DR_DATA_REGISTER);
277 Status = EFI_SUCCESS;
278 } else if (EFI_ERROR (Status)) {
279 // Battery backed up hardware RTC exists but could not be read due to error. Abort.
280 goto EXIT;
281 } else {
282 // Battery backed up hardware RTC exists and we read the time correctly from it.
283 // Now sync the PL031 to the new time.
284 MmioWrite32 (mPL031RtcBase + PL031_RTC_LR_LOAD_REGISTER, EpochSeconds);
285 }
286
287 // Ensure Time is a valid pointer
288 if (Time == NULL) {
289 Status = EFI_INVALID_PARAMETER;
290 goto EXIT;
291 }
292
293 // Get the current time zone information from non-volatile storage
294 Size = sizeof (TimeZone);
295 Status = EfiGetVariable (
296 (CHAR16 *)mTimeZoneVariableName,
297 &gEfiCallerIdGuid,
298 NULL,
299 &Size,
300 (VOID *)&TimeZone
301 );
302
303 if (EFI_ERROR (Status)) {
304 ASSERT(Status != EFI_INVALID_PARAMETER);
305 ASSERT(Status != EFI_BUFFER_TOO_SMALL);
306
307 if (Status != EFI_NOT_FOUND)
308 goto EXIT;
309
310 // The time zone variable does not exist in non-volatile storage, so create it.
311 Time->TimeZone = EFI_UNSPECIFIED_TIMEZONE;
312 // Store it
313 Status = EfiSetVariable (
314 (CHAR16 *)mTimeZoneVariableName,
315 &gEfiCallerIdGuid,
316 EFI_VARIABLE_NON_VOLATILE | EFI_VARIABLE_BOOTSERVICE_ACCESS | EFI_VARIABLE_RUNTIME_ACCESS,
317 Size,
318 (VOID *)&(Time->TimeZone)
319 );
320 if (EFI_ERROR (Status)) {
321 DEBUG ((
322 EFI_D_ERROR,
323 "LibGetTime: Failed to save %s variable to non-volatile storage, Status = %r\n",
324 mTimeZoneVariableName,
325 Status
326 ));
327 goto EXIT;
328 }
329 } else {
330 // Got the time zone
331 Time->TimeZone = TimeZone;
332
333 // Check TimeZone bounds: -1440 to 1440 or 2047
334 if (((Time->TimeZone < -1440) || (Time->TimeZone > 1440))
335 && (Time->TimeZone != EFI_UNSPECIFIED_TIMEZONE)) {
336 Time->TimeZone = EFI_UNSPECIFIED_TIMEZONE;
337 }
338
339 // Adjust for the correct time zone
340 if (Time->TimeZone != EFI_UNSPECIFIED_TIMEZONE) {
341 EpochSeconds += Time->TimeZone * SEC_PER_MIN;
342 }
343 }
344
345 // Get the current daylight information from non-volatile storage
346 Size = sizeof (Daylight);
347 Status = EfiGetVariable (
348 (CHAR16 *)mDaylightVariableName,
349 &gEfiCallerIdGuid,
350 NULL,
351 &Size,
352 (VOID *)&Daylight
353 );
354
355 if (EFI_ERROR (Status)) {
356 ASSERT(Status != EFI_INVALID_PARAMETER);
357 ASSERT(Status != EFI_BUFFER_TOO_SMALL);
358
359 if (Status != EFI_NOT_FOUND)
360 goto EXIT;
361
362 // The daylight variable does not exist in non-volatile storage, so create it.
363 Time->Daylight = 0;
364 // Store it
365 Status = EfiSetVariable (
366 (CHAR16 *)mDaylightVariableName,
367 &gEfiCallerIdGuid,
368 EFI_VARIABLE_NON_VOLATILE | EFI_VARIABLE_BOOTSERVICE_ACCESS | EFI_VARIABLE_RUNTIME_ACCESS,
369 Size,
370 (VOID *)&(Time->Daylight)
371 );
372 if (EFI_ERROR (Status)) {
373 DEBUG ((
374 EFI_D_ERROR,
375 "LibGetTime: Failed to save %s variable to non-volatile storage, Status = %r\n",
376 mDaylightVariableName,
377 Status
378 ));
379 goto EXIT;
380 }
381 } else {
382 // Got the daylight information
383 Time->Daylight = Daylight;
384
385 // Adjust for the correct period
386 if ((Time->Daylight & EFI_TIME_IN_DAYLIGHT) == EFI_TIME_IN_DAYLIGHT) {
387 // Convert to adjusted time, i.e. spring forwards one hour
388 EpochSeconds += SEC_PER_HOUR;
389 }
390 }
391
392 // Convert from internal 32-bit time to UEFI time
393 EpochToEfiTime (EpochSeconds, Time);
394
395 // Update the Capabilities info
396 if (Capabilities != NULL) {
397 // PL031 runs at frequency 1Hz
398 Capabilities->Resolution = PL031_COUNTS_PER_SECOND;
399 // Accuracy in ppm multiplied by 1,000,000, e.g. for 50ppm set 50,000,000
400 Capabilities->Accuracy = (UINT32)PcdGet32 (PcdPL031RtcPpmAccuracy);
401 // FALSE: Setting the time does not clear the values below the resolution level
402 Capabilities->SetsToZero = FALSE;
403 }
404
405 EXIT:
406 return Status;
407 }
408
409
410 /**
411 Sets the current local time and date information.
412
413 @param Time A pointer to the current time.
414
415 @retval EFI_SUCCESS The operation completed successfully.
416 @retval EFI_INVALID_PARAMETER A time field is out of range.
417 @retval EFI_DEVICE_ERROR The time could not be set due due to hardware error.
418
419 **/
420 EFI_STATUS
421 EFIAPI
LibSetTime(IN EFI_TIME * Time)422 LibSetTime (
423 IN EFI_TIME *Time
424 )
425 {
426 EFI_STATUS Status;
427 UINTN EpochSeconds;
428
429 // Check the input parameters are within the range specified by UEFI
430 if ((Time->Year < 1900) ||
431 (Time->Year > 9999) ||
432 (Time->Month < 1 ) ||
433 (Time->Month > 12 ) ||
434 (!DayValid (Time) ) ||
435 (Time->Hour > 23 ) ||
436 (Time->Minute > 59 ) ||
437 (Time->Second > 59 ) ||
438 (Time->Nanosecond > 999999999) ||
439 (!((Time->TimeZone == EFI_UNSPECIFIED_TIMEZONE) || ((Time->TimeZone >= -1440) && (Time->TimeZone <= 1440)))) ||
440 (Time->Daylight & (~(EFI_TIME_ADJUST_DAYLIGHT | EFI_TIME_IN_DAYLIGHT)))
441 ) {
442 Status = EFI_INVALID_PARAMETER;
443 goto EXIT;
444 }
445
446 // Because the PL031 is a 32-bit counter counting seconds,
447 // the maximum time span is just over 136 years.
448 // Time is stored in Unix Epoch format, so it starts in 1970,
449 // Therefore it can not exceed the year 2106.
450 if ((Time->Year < 1970) || (Time->Year >= 2106)) {
451 Status = EFI_UNSUPPORTED;
452 goto EXIT;
453 }
454
455 // Initialize the hardware if not already done
456 if (!mPL031Initialized) {
457 Status = InitializePL031 ();
458 if (EFI_ERROR (Status)) {
459 goto EXIT;
460 }
461 }
462
463 EpochSeconds = EfiTimeToEpoch (Time);
464
465 // Adjust for the correct time zone, i.e. convert to UTC time zone
466 if (Time->TimeZone != EFI_UNSPECIFIED_TIMEZONE) {
467 EpochSeconds -= Time->TimeZone * SEC_PER_MIN;
468 }
469
470 // TODO: Automatic Daylight activation
471
472 // Adjust for the correct period
473 if ((Time->Daylight & EFI_TIME_IN_DAYLIGHT) == EFI_TIME_IN_DAYLIGHT) {
474 // Convert to un-adjusted time, i.e. fall back one hour
475 EpochSeconds -= SEC_PER_HOUR;
476 }
477
478 // On some platforms we may have access to a battery backed up hardware clock.
479 //
480 // If such RTC exists then it must be updated first, before the PL031,
481 // to minimise any time drift. This is important because the battery backed-up
482 // RTC maintains the master time for the platform across reboots.
483 //
484 // If such RTC does not exist then the following function returns UNSUPPORTED.
485 Status = ArmPlatformSysConfigSet (SYS_CFG_RTC, EpochSeconds);
486 if ((EFI_ERROR (Status)) && (Status != EFI_UNSUPPORTED)){
487 // Any status message except SUCCESS and UNSUPPORTED indicates a hardware failure.
488 goto EXIT;
489 }
490
491
492 // Set the PL031
493 MmioWrite32 (mPL031RtcBase + PL031_RTC_LR_LOAD_REGISTER, EpochSeconds);
494
495 // The accesses to Variable Services can be very slow, because we may be writing to Flash.
496 // Do this after having set the RTC.
497
498 // Save the current time zone information into non-volatile storage
499 Status = EfiSetVariable (
500 (CHAR16 *)mTimeZoneVariableName,
501 &gEfiCallerIdGuid,
502 EFI_VARIABLE_NON_VOLATILE | EFI_VARIABLE_BOOTSERVICE_ACCESS | EFI_VARIABLE_RUNTIME_ACCESS,
503 sizeof (Time->TimeZone),
504 (VOID *)&(Time->TimeZone)
505 );
506 if (EFI_ERROR (Status)) {
507 DEBUG ((
508 EFI_D_ERROR,
509 "LibSetTime: Failed to save %s variable to non-volatile storage, Status = %r\n",
510 mTimeZoneVariableName,
511 Status
512 ));
513 goto EXIT;
514 }
515
516 // Save the current daylight information into non-volatile storage
517 Status = EfiSetVariable (
518 (CHAR16 *)mDaylightVariableName,
519 &gEfiCallerIdGuid,
520 EFI_VARIABLE_NON_VOLATILE | EFI_VARIABLE_BOOTSERVICE_ACCESS | EFI_VARIABLE_RUNTIME_ACCESS,
521 sizeof(Time->Daylight),
522 (VOID *)&(Time->Daylight)
523 );
524 if (EFI_ERROR (Status)) {
525 DEBUG ((
526 EFI_D_ERROR,
527 "LibSetTime: Failed to save %s variable to non-volatile storage, Status = %r\n",
528 mDaylightVariableName,
529 Status
530 ));
531 goto EXIT;
532 }
533
534 EXIT:
535 return Status;
536 }
537
538
539 /**
540 Returns the current wakeup alarm clock setting.
541
542 @param Enabled Indicates if the alarm is currently enabled or disabled.
543 @param Pending Indicates if the alarm signal is pending and requires acknowledgement.
544 @param Time The current alarm setting.
545
546 @retval EFI_SUCCESS The alarm settings were returned.
547 @retval EFI_INVALID_PARAMETER Any parameter is NULL.
548 @retval EFI_DEVICE_ERROR The wakeup time could not be retrieved due to a hardware error.
549
550 **/
551 EFI_STATUS
552 EFIAPI
LibGetWakeupTime(OUT BOOLEAN * Enabled,OUT BOOLEAN * Pending,OUT EFI_TIME * Time)553 LibGetWakeupTime (
554 OUT BOOLEAN *Enabled,
555 OUT BOOLEAN *Pending,
556 OUT EFI_TIME *Time
557 )
558 {
559 // Not a required feature
560 return EFI_UNSUPPORTED;
561 }
562
563
564 /**
565 Sets the system wakeup alarm clock time.
566
567 @param Enabled Enable or disable the wakeup alarm.
568 @param Time If Enable is TRUE, the time to set the wakeup alarm for.
569
570 @retval EFI_SUCCESS If Enable is TRUE, then the wakeup alarm was enabled. If
571 Enable is FALSE, then the wakeup alarm was disabled.
572 @retval EFI_INVALID_PARAMETER A time field is out of range.
573 @retval EFI_DEVICE_ERROR The wakeup time could not be set due to a hardware error.
574 @retval EFI_UNSUPPORTED A wakeup timer is not supported on this platform.
575
576 **/
577 EFI_STATUS
578 EFIAPI
LibSetWakeupTime(IN BOOLEAN Enabled,OUT EFI_TIME * Time)579 LibSetWakeupTime (
580 IN BOOLEAN Enabled,
581 OUT EFI_TIME *Time
582 )
583 {
584 // Not a required feature
585 return EFI_UNSUPPORTED;
586 }
587
588 /**
589 Fixup internal data so that EFI can be call in virtual mode.
590 Call the passed in Child Notify event and convert any pointers in
591 lib to virtual mode.
592
593 @param[in] Event The Event that is being processed
594 @param[in] Context Event Context
595 **/
596 VOID
597 EFIAPI
LibRtcVirtualNotifyEvent(IN EFI_EVENT Event,IN VOID * Context)598 LibRtcVirtualNotifyEvent (
599 IN EFI_EVENT Event,
600 IN VOID *Context
601 )
602 {
603 //
604 // Only needed if you are going to support the OS calling RTC functions in virtual mode.
605 // You will need to call EfiConvertPointer (). To convert any stored physical addresses
606 // to virtual address. After the OS transitions to calling in virtual mode, all future
607 // runtime calls will be made in virtual mode.
608 //
609 EfiConvertPointer (0x0, (VOID**)&mPL031RtcBase);
610 return;
611 }
612
613 /**
614 This is the declaration of an EFI image entry point. This can be the entry point to an application
615 written to this specification, an EFI boot service driver, or an EFI runtime driver.
616
617 @param ImageHandle Handle that identifies the loaded image.
618 @param SystemTable System Table for this image.
619
620 @retval EFI_SUCCESS The operation completed successfully.
621
622 **/
623 EFI_STATUS
624 EFIAPI
LibRtcInitialize(IN EFI_HANDLE ImageHandle,IN EFI_SYSTEM_TABLE * SystemTable)625 LibRtcInitialize (
626 IN EFI_HANDLE ImageHandle,
627 IN EFI_SYSTEM_TABLE *SystemTable
628 )
629 {
630 EFI_STATUS Status;
631 EFI_HANDLE Handle;
632
633 // Initialize RTC Base Address
634 mPL031RtcBase = PcdGet32 (PcdPL031RtcBase);
635
636 // Declare the controller as EFI_MEMORY_RUNTIME
637 Status = gDS->AddMemorySpace (
638 EfiGcdMemoryTypeMemoryMappedIo,
639 mPL031RtcBase, SIZE_4KB,
640 EFI_MEMORY_UC | EFI_MEMORY_RUNTIME
641 );
642 if (EFI_ERROR (Status)) {
643 return Status;
644 }
645
646 Status = gDS->SetMemorySpaceAttributes (mPL031RtcBase, SIZE_4KB, EFI_MEMORY_UC | EFI_MEMORY_RUNTIME);
647 if (EFI_ERROR (Status)) {
648 return Status;
649 }
650
651 // Install the protocol
652 Handle = NULL;
653 Status = gBS->InstallMultipleProtocolInterfaces (
654 &Handle,
655 &gEfiRealTimeClockArchProtocolGuid, NULL,
656 NULL
657 );
658 ASSERT_EFI_ERROR (Status);
659
660 //
661 // Register for the virtual address change event
662 //
663 Status = gBS->CreateEventEx (
664 EVT_NOTIFY_SIGNAL,
665 TPL_NOTIFY,
666 LibRtcVirtualNotifyEvent,
667 NULL,
668 &gEfiEventVirtualAddressChangeGuid,
669 &mRtcVirtualAddrChangeEvent
670 );
671 ASSERT_EFI_ERROR (Status);
672
673 return Status;
674 }
675