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

["Philippe Mathieu-Daudé" <philmd@redhat.com>]

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`
>