Re: [edk2] [PATCH 1/1] EmbeddedPkg/Library: Add VirtualRealTimeClockLib

["Pete Batard" <pete@akeo.ie>]

Hi Phil,

Not sure why this old 2019 patch suddenly appeared in your review inbox, 
but this was integrated last year as 
https://github.com/tianocore/edk2/commit/64a17fadcb79e2ce40524abb88a6863f47cbc0c7

Regards,

/Pete

On 2020.05.14 08:45, Philippe Mathieu-Daudé wrote:
> Hi Pete,
> 
> On 2/4/19 1:47 PM, Pete Batard wrote:
>> This is designed to be used on platforms where a a real RTC is not
>> available and relies on an RtcEpochSeconds variable having been set or,
>> if that is not the case, falls back to using the epoch embedded at
>> compilation time.
>>
>> Note that, in order to keep things simple for the setting of the
>> compilation time variable, only GCC environments with UNIX-like shells
>> and where a 'date' command is available are meant to be supported for
>> now.
>>
>> Contributed-under: TianoCore Contribution Agreement 1.1
>> Signed-off-by: Pete Batard <pete@akeo.ie>
>> ---
>>   
>> EmbeddedPkg/Library/VirtualRealTimeClockLib/VirtualRealTimeClockLib.c   | 
>> 400 ++++++++++++++++++++
>>   
>> EmbeddedPkg/Library/VirtualRealTimeClockLib/VirtualRealTimeClockLib.inf |  
>> 43 +++
>>   2 files changed, 443 insertions(+)
>>
>> diff --git 
>> a/EmbeddedPkg/Library/VirtualRealTimeClockLib/VirtualRealTimeClockLib.c b/EmbeddedPkg/Library/VirtualRealTimeClockLib/VirtualRealTimeClockLib.c 
>>
>> new file mode 100644
>> index 000000000000..4c354730d02b
>> --- /dev/null
>> +++ 
>> b/EmbeddedPkg/Library/VirtualRealTimeClockLib/VirtualRealTimeClockLib.c
>> @@ -0,0 +1,400 @@
>> +/** @file
>> + *
>> + *  Implement virtual EFI RealTimeClock runtime services.
>> + *
>> + *  Coypright (c) 2019, Pete Batard <pete@akeo.ie>
>> + *  Copyright (c) 2018, Andrei Warkentin <andrey.warkentin@gmail.com>
>> + *  Copyright (c) 2011-2014, ARM Ltd. All rights reserved.
>> + *  Copyright (c) 2008-2010, Apple Inc. All rights reserved.
>> + *  Copyright (c) Microsoft Corporation. All rights reserved.
> 
> You forgot the year, it should be 2019 right?
> Another occurrence below.
> 
>> + *
>> + *  This program and the accompanying materials
>> + *  are licensed and made available under the terms and conditions of 
>> the BSD License
>> + *  which accompanies this distribution.  The full text of the 
>> license may be found at
>> + *  http://opensource.org/licenses/bsd-license.php
>> + *
>> + *  THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" 
>> BASIS,
>> + *  WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS 
>> OR IMPLIED.
>> + *
>> + *  Based on 
>> ArmPlatformPkg/Library/PL031RealTimeClockLib/PL031RealTimeClockLib.inf
>> + *
>> + **/
>> +
>> +#include <PiDxe.h>
>> +#include <Library/BaseLib.h>
>> +#include <Library/DebugLib.h>
>> +#include <Library/IoLib.h>
>> +#include <Library/RealTimeClockLib.h>
>> +#include <Library/TimerLib.h>
>> +#include <Library/TimeBaseLib.h>
>> +#include <Library/UefiRuntimeLib.h>
>> +
>> +STATIC CONST CHAR16  mEpochVariableName[]     = L"RtcEpochSeconds";
>> +STATIC CONST CHAR16  mTimeZoneVariableName[]  = L"RtcTimeZone";
>> +STATIC CONST CHAR16  mDaylightVariableName[]  = L"RtcDaylight";
>> +
>> +/**
>> +   Returns the current time and date information, and the 
>> time-keeping capabilities
>> +   of the virtual RTC.
>> +
>> +   @param  Time                  A pointer to storage to receive a 
>> snapshot of the current time.
>> +   @param  Capabilities          An optional pointer to a buffer to 
>> receive the real time clock
>> +                                 device's capabilities.
>> +
>> +   @retval EFI_SUCCESS           The operation completed successfully.
>> +   @retval EFI_INVALID_PARAMETER Time is NULL.
>> +   @retval EFI_DEVICE_ERROR      The time could not be retrieved due 
>> to hardware error.
>> +
>> +**/
>> +EFI_STATUS
>> +EFIAPI
>> +LibGetTime (
>> +  OUT EFI_TIME               *Time,
>> +  OUT EFI_TIME_CAPABILITIES  *Capabilities
>> +  )
>> +{
>> +  EFI_STATUS  Status;
>> +  UINT32      EpochSeconds;
>> +  INT16       TimeZone;
>> +  UINT8       Daylight;
>> +  UINT64      Freq;
>> +  UINT64      Counter;
>> +  UINT64      Remainder;
>> +  UINTN       ElapsedSeconds;
>> +  UINTN       Size;
>> +
>> +  if (Time == NULL) {
>> +    return EFI_INVALID_PARAMETER;
>> +  }
>> +
>> +  // Get the counter frequency
>> +  Freq = GetPerformanceCounterProperties (NULL, NULL);
>> +  if (Freq == 0) {
>> +    return EFI_DEVICE_ERROR;
>> +  }
>> +
>> +  // Get the epoch time from non-volatile storage
>> +  Size = sizeof (UINTN);
>> +  ElapsedSeconds = 0;
>> +  Status = EfiGetVariable (
>> +             (CHAR16 *)mEpochVariableName,
>> +             &gEfiCallerIdGuid,
>> +             NULL,
>> +             &Size,
>> +             (VOID *)&ElapsedSeconds
>> +             );
>> +  // Fall back to compilation-time epoch if not set
>> +  if (EFI_ERROR (Status)) {
>> +    ASSERT(Status != EFI_INVALID_PARAMETER);
>> +    ASSERT(Status != EFI_BUFFER_TOO_SMALL);
>> +    //
>> +    // The following is intended to produce a compilation error on build
>> +    // environments where BUILD_EPOCH can not be set from inline shell.
>> +    // If you are attempting to use this library on such an 
>> environment, please
>> +    // contact the edk2 mailing list, so we can try to add support 
>> for it.
>> +    //
>> +    ElapsedSeconds = BUILD_EPOCH;
>> +    DEBUG ((
>> +      DEBUG_INFO,
>> +      "LibGetTime: %s non volatile variable was not found - Using 
>> compilation time epoch.\n",
>> +      mEpochVariableName
>> +      ));
>> +  }
>> +  Counter = GetPerformanceCounter ();
>> +  ElapsedSeconds += DivU64x64Remainder (Counter, Freq, &Remainder);
>> +
>> +  // Get the current time zone information from non-volatile storage
>> +  Size = sizeof (TimeZone);
>> +  Status = EfiGetVariable (
>> +             (CHAR16 *)mTimeZoneVariableName,
>> +             &gEfiCallerIdGuid,
>> +             NULL,
>> +             &Size,
>> +             (VOID *)&TimeZone
>> +             );
>> +
>> +  if (EFI_ERROR (Status)) {
>> +    ASSERT(Status != EFI_INVALID_PARAMETER);
>> +    ASSERT(Status != EFI_BUFFER_TOO_SMALL);
>> +
>> +    if (Status != EFI_NOT_FOUND) {
>> +      return Status;
>> +    }
>> +
>> +    // The time zone variable does not exist in non-volatile storage, 
>> so create it.
>> +    Time->TimeZone = EFI_UNSPECIFIED_TIMEZONE;
>> +    // Store it
>> +    Status = EfiSetVariable (
>> +               (CHAR16 *)mTimeZoneVariableName,
>> +               &gEfiCallerIdGuid,
>> +               EFI_VARIABLE_NON_VOLATILE | 
>> EFI_VARIABLE_BOOTSERVICE_ACCESS | EFI_VARIABLE_RUNTIME_ACCESS,
>> +               Size,
>> +               (VOID *)&(Time->TimeZone)
>> +               );
>> +    if (EFI_ERROR (Status)) {
>> +      DEBUG ((
>> +        DEBUG_ERROR,
>> +        "LibGetTime: Failed to save %s variable to non-volatile 
>> storage, Status = %r\n",
>> +        mTimeZoneVariableName,
>> +        Status
>> +        ));
>> +      return Status;
>> +    }
>> +  } else {
>> +    // Got the time zone
>> +    Time->TimeZone = TimeZone;
>> +
>> +    // Check TimeZone bounds: -1440 to 1440 or 2047
>> +    if (((Time->TimeZone < -1440) || (Time->TimeZone > 1440))
>> +        && (Time->TimeZone != EFI_UNSPECIFIED_TIMEZONE)) {
>> +      Time->TimeZone = EFI_UNSPECIFIED_TIMEZONE;
>> +    }
>> +
>> +    // Adjust for the correct time zone
>> +    if (Time->TimeZone != EFI_UNSPECIFIED_TIMEZONE) {
>> +      EpochSeconds += Time->TimeZone * SEC_PER_MIN;
>> +    }
>> +  }
>> +
>> +  // Get the current daylight information from non-volatile storage
>> +  Size = sizeof (Daylight);
>> +  Status = EfiGetVariable (
>> +             (CHAR16 *)mDaylightVariableName,
>> +             &gEfiCallerIdGuid,
>> +             NULL,
>> +             &Size,
>> +             (VOID *)&Daylight
>> +           );
>> +
>> +  if (EFI_ERROR (Status)) {
>> +    ASSERT(Status != EFI_INVALID_PARAMETER);
>> +    ASSERT(Status != EFI_BUFFER_TOO_SMALL);
>> +
>> +    if (Status != EFI_NOT_FOUND) {
>> +      return Status;
>> +    }
>> +
>> +    // The daylight variable does not exist in non-volatile storage, 
>> so create it.
>> +    Time->Daylight = 0;
>> +    // Store it
>> +    Status = EfiSetVariable (
>> +               (CHAR16 *)mDaylightVariableName,
>> +               &gEfiCallerIdGuid,
>> +               EFI_VARIABLE_NON_VOLATILE | 
>> EFI_VARIABLE_BOOTSERVICE_ACCESS | EFI_VARIABLE_RUNTIME_ACCESS,
>> +               Size,
>> +               (VOID *)&(Time->Daylight)
>> +               );
>> +    if (EFI_ERROR (Status)) {
>> +      DEBUG ((
>> +        DEBUG_ERROR,
>> +        "LibGetTime: Failed to save %s variable to non-volatile 
>> storage, Status = %r\n",
>> +        mDaylightVariableName,
>> +        Status
>> +        ));
>> +      return Status;
>> +    }
>> +  } else {
>> +    // Got the daylight information
>> +    Time->Daylight = Daylight;
>> +
>> +    // Adjust for the correct period
>> +    if ((Time->Daylight & EFI_TIME_IN_DAYLIGHT) == 
>> EFI_TIME_IN_DAYLIGHT) {
>> +      // Convert to adjusted time, i.e. spring forwards one hour
>> +      EpochSeconds += SEC_PER_HOUR;
>> +    }
>> +  }
>> +
>> +  EpochToEfiTime (ElapsedSeconds, Time);
>> +
>> +  // Because we use the performance counter, we can fill the 
>> Nanosecond attribute
>> +  // provided that the remainder doesn't overflow 64-bit during 
>> multiplication.
>> +  if (Remainder <= 18446744073U) {
>> +    Time->Nanosecond = MultU64x64 (Remainder, 1000000000U) / Freq;
>> +  } else {
>> +    DEBUG ((DEBUG_WARN, "LibGetTime: Nanosecond value not set (64-bit 
>> overflow).\n"));
>> +  }
>> +
>> +  if (Capabilities) {
>> +    Capabilities->Accuracy   = 0;
>> +    Capabilities->Resolution = Freq;
>> +    Capabilities->SetsToZero = FALSE;
>> +  }
>> +
>> +  return EFI_SUCCESS;
>> +}
>> +
>> +/**
>> +   Sets the current local time and date information.
>> +
>> +   @param  Time                  A pointer to the current time.
>> +
>> +   @retval EFI_SUCCESS           The operation completed successfully.
>> +   @retval EFI_INVALID_PARAMETER A time field is out of range.
>> +   @retval EFI_DEVICE_ERROR      The time could not be set due due to 
>> hardware error.
>> +
>> +**/
>> +EFI_STATUS
>> +EFIAPI
>> +LibSetTime (
>> +  IN EFI_TIME  *Time
>> +  )
>> +{
>> +  EFI_STATUS  Status;
>> +  UINTN       EpochSeconds;
>> +
>> +  if (!IsTimeValid (Time)) {
>> +    return EFI_INVALID_PARAMETER;
>> +  }
>> +
>> +  EpochSeconds = EfiTimeToEpoch (Time);
>> +
>> +  // Adjust for the correct time zone, i.e. convert to UTC time zone
>> +  if (Time->TimeZone != EFI_UNSPECIFIED_TIMEZONE) {
>> +    EpochSeconds -= Time->TimeZone * SEC_PER_MIN;
>> +  }
>> +
>> +  // Adjust for the correct period
>> +  if ((Time->Daylight & EFI_TIME_IN_DAYLIGHT) == EFI_TIME_IN_DAYLIGHT) {
>> +    // Convert to un-adjusted time, i.e. fall back one hour
>> +    EpochSeconds -= SEC_PER_HOUR;
>> +  }
>> +
>> +  // Save the current time zone information into non-volatile storage
>> +  Status = EfiSetVariable (
>> +             (CHAR16 *)mTimeZoneVariableName,
>> +             &gEfiCallerIdGuid,
>> +             EFI_VARIABLE_NON_VOLATILE | 
>> EFI_VARIABLE_BOOTSERVICE_ACCESS | EFI_VARIABLE_RUNTIME_ACCESS,
>> +             sizeof (Time->TimeZone),
>> +             (VOID *)&(Time->TimeZone)
>> +             );
>> +  if (EFI_ERROR (Status)) {
>> +    DEBUG ((
>> +      DEBUG_ERROR,
>> +      "LibSetTime: Failed to save %s variable to non-volatile 
>> storage, Status = %r\n",
>> +      mTimeZoneVariableName,
>> +      Status
>> +      ));
>> +    return Status;
>> +  }
>> +
>> +  // Save the current daylight information into non-volatile storage
>> +  Status = EfiSetVariable (
>> +             (CHAR16 *)mDaylightVariableName,
>> +             &gEfiCallerIdGuid,
>> +             EFI_VARIABLE_NON_VOLATILE | 
>> EFI_VARIABLE_BOOTSERVICE_ACCESS | EFI_VARIABLE_RUNTIME_ACCESS,
>> +             sizeof(Time->Daylight),
>> +             (VOID *)&(Time->Daylight)
>> +           );
>> +  if (EFI_ERROR (Status)) {
>> +    DEBUG ((
>> +      DEBUG_ERROR,
>> +      "LibSetTime: Failed to save %s variable to non-volatile 
>> storage, Status = %r\n",
>> +      mDaylightVariableName,
>> +      Status
>> +      ));
>> +    return Status;
>> +  }
>> +
>> +  Status = EfiSetVariable (
>> +             (CHAR16 *)mEpochVariableName,
>> +             &gEfiCallerIdGuid,
>> +             EFI_VARIABLE_NON_VOLATILE | 
>> EFI_VARIABLE_BOOTSERVICE_ACCESS | EFI_VARIABLE_RUNTIME_ACCESS,
>> +             sizeof (EpochSeconds),
>> +             &EpochSeconds
>> +             );
>> +  if (EFI_ERROR (Status)) {
>> +    DEBUG ((
>> +      DEBUG_ERROR,
>> +      "LibSetTime: Failed to save %s variable to non-volatile 
>> storage, Status = %r\n",
>> +      mDaylightVariableName,
>> +      Status
>> +      ));
>> +    return Status;
>> +  }
>> +
>> +  return EFI_SUCCESS;
>> +}
>> +
>> +/**
>> +   Returns the current wakeup alarm clock setting.
>> +
>> +   @param  Enabled               Indicates if the alarm is currently 
>> enabled or disabled.
>> +   @param  Pending               Indicates if the alarm signal is 
>> pending and requires acknowledgement.
>> +   @param  Time                  The current alarm setting.
>> +
>> +   @retval EFI_SUCCESS           The alarm settings were returned.
>> +   @retval EFI_INVALID_PARAMETER Any parameter is NULL.
>> +   @retval EFI_DEVICE_ERROR      The wakeup time could not be 
>> retrieved due to a hardware error.
>> +
>> +**/
>> +EFI_STATUS
>> +EFIAPI
>> +LibGetWakeupTime (
>> +  OUT BOOLEAN   *Enabled,
>> +  OUT BOOLEAN   *Pending,
>> +  OUT EFI_TIME  *Time
>> +  )
>> +{
>> +  return EFI_UNSUPPORTED;
>> +}
>> +
>> +/**
>> +   Sets the system wakeup alarm clock time.
>> +
>> +   @param  Enabled               Enable or disable the wakeup alarm.
>> +   @param  Time                  If Enable is TRUE, the time to set 
>> the wakeup alarm for.
>> +
>> +   @retval EFI_SUCCESS           If Enable is TRUE, then the wakeup 
>> alarm was enabled. If
>> +   Enable is FALSE, then the wakeup alarm was disabled.
>> +   @retval EFI_INVALID_PARAMETER A time field is out of range.
>> +   @retval EFI_DEVICE_ERROR      The wakeup time could not be set due 
>> to a hardware error.
>> +   @retval EFI_UNSUPPORTED       A wakeup timer is not supported on 
>> this platform.
>> +
>> +**/
>> +EFI_STATUS
>> +EFIAPI
>> +LibSetWakeupTime (
>> +  IN  BOOLEAN   Enabled,
>> +  OUT EFI_TIME  *Time
>> +  )
>> +{
>> +  return EFI_UNSUPPORTED;
>> +}
>> +
>> +/**
>> +   This is the declaration of an EFI image entry point. This can be 
>> the entry point to an application
>> +   written to this specification, an EFI boot service driver, or an 
>> EFI runtime driver.
>> +
>> +   @param  ImageHandle           Handle that identifies the loaded 
>> image.
>> +   @param  SystemTable           System Table for this image.
>> +
>> +   @retval EFI_SUCCESS           The operation completed successfully.
>> +
>> +**/
>> +EFI_STATUS
>> +EFIAPI
>> +LibRtcInitialize (
>> +  IN EFI_HANDLE        ImageHandle,
>> +  IN EFI_SYSTEM_TABLE  *SystemTable
>> +  )
>> +{
>> +  return EFI_SUCCESS;
>> +}
>> +
>> +/**
>> +   Fixup internal data so that EFI can be call in virtual mode.
>> +   Call the passed in Child Notify event and convert any pointers in
>> +   lib to virtual mode.
>> +
>> +   @param[in]    Event   The Event that is being processed
>> +   @param[in]    Context Event Context
>> +**/
>> +VOID
>> +EFIAPI
>> +LibRtcVirtualNotifyEvent (
>> +  IN EFI_EVENT  Event,
>> +  IN VOID       *Context
>> +  )
>> +{
>> +  return;
>> +}
>> diff --git 
>> a/EmbeddedPkg/Library/VirtualRealTimeClockLib/VirtualRealTimeClockLib.inf 
>> b/EmbeddedPkg/Library/VirtualRealTimeClockLib/VirtualRealTimeClockLib.inf
>> new file mode 100644
>> index 000000000000..ed69faad4205
>> --- /dev/null
>> +++ 
>> b/EmbeddedPkg/Library/VirtualRealTimeClockLib/VirtualRealTimeClockLib.inf
>> @@ -0,0 +1,43 @@
>> +#/** @file
>> +#
>> +#  Implement virtual EFI RealTimeClock runtime services.
>> +#
>> +#  Copyright (c) 2019, Pete Batard <pete@akeo.ie>
>> +#  Copyright (c) 2018, Andrei Warkentin <andrey.warkentin@gmail.com>
>> +#  Copyright (c) Microsoft Corporation. All rights reserved.
> 
> Same issue here, 2019, alright?
> 
>> +#
>> +#  This program and the accompanying materials
>> +#  are licensed and made available under the terms and conditions of 
>> the BSD License
>> +#  which accompanies this distribution.  The full text of the license 
>> may be found at
>> +#  http://opensource.org/licenses/bsd-license.php
>> +#
>> +#  THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
>> +#  WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS 
>> OR IMPLIED.
>> +#
>> +#**/
>> +
>> +[Defines]
>> +  INF_VERSION                    = 0x0001001A
>> +  BASE_NAME                      = VirtualRealTimeClockLib
>> +  FILE_GUID                      = 1E27D461-78F3-4F7D-B1C2-F72384F13A6E
>> +  MODULE_TYPE                    = BASE
>> +  VERSION_STRING                 = 1.0
>> +  LIBRARY_CLASS                  = RealTimeClockLib
>> +
>> +[Sources.common]
>> +  VirtualRealTimeClockLib.c
>> +
>> +[Packages]
>> +  MdePkg/MdePkg.dec
>> +  EmbeddedPkg/EmbeddedPkg.dec
>> +
>> +[LibraryClasses]
>> +  IoLib
>> +  DebugLib
>> +  TimerLib
>> +  TimeBaseLib
>> +  UefiRuntimeLib
>> +
>> +# Current usage of this library expects GCC in a UNIX-like shell 
>> environment with the date command
>> +[BuildOptions]
>> +  GCC:*_*_*_CC_FLAGS = -DBUILD_EPOCH=`date +%s`
>>
>