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 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 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 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 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 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 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 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 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 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 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 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 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