Re: [PATCH v4 edk2-platforms 06/23] Platform/Raspberry/Pi3: Add RTC library

[Leif Lindholm <leif.lindholm@linaro.org>]

First of all - this is something I would like to see contributed
directly to edk2 EmbeddedPkg. It's something me and Ard have discussed
adding at some point, but never getting around to.

I would also like to look into whether we could replace
PcdBootEpochSeconds with a -DBUILD_EPOCH=`date +%s` addition to the
CFLAGS in the .inf.

Regards,

Leif

On Tue, Jan 29, 2019 at 04:26:38PM +0000, Pete Batard wrote:
> Contributed-under: TianoCore Contribution Agreement 1.1
> Signed-off-by: Pete Batard <pete@akeo.ie>
> ---
>  Platform/Raspberry/Pi3/Library/VirtualRealTimeClockLib/VirtualRealTimeClockLib.c   | 221 ++++++++++++++++++++
>  Platform/Raspberry/Pi3/Library/VirtualRealTimeClockLib/VirtualRealTimeClockLib.inf |  43 ++++
>  2 files changed, 264 insertions(+)
> 
> diff --git a/Platform/Raspberry/Pi3/Library/VirtualRealTimeClockLib/VirtualRealTimeClockLib.c b/Platform/Raspberry/Pi3/Library/VirtualRealTimeClockLib/VirtualRealTimeClockLib.c
> new file mode 100644
> index 000000000000..dea621ff03ef
> --- /dev/null
> +++ b/Platform/Raspberry/Pi3/Library/VirtualRealTimeClockLib/VirtualRealTimeClockLib.c
> @@ -0,0 +1,221 @@
> +/** @file
> + *
> + *  Implement dummy EFI RealTimeClock runtime services.
> + *
> + *  Copyright (c) 2018, Andrei Warkentin <andrey.warkentin@gmail.com>
> + *  Copyright (c) Microsoft Corporation. All rights reserved.
> + *
> + *  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.
> + *
> + **/
> +
> +#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>
> +#include <Library/ArmGenericTimerCounterLib.h>
> +
> +/**
> +   Returns the current time and date information, and the time-keeping capabilities
> +   of the virtual RTC.
> +
> +   For simplicity, this LibGetTime does not report Years/Months, instead it will only report current
> +   Day, Hours, Minutes and Seconds starting from the begining of CPU up-time. Otherwise, a more
> +   complex logic will be required to account for leap years and days/month differences.
> +
> +   @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
> +  )
> +{
> +  UINTN DataSize;
> +  UINT64 Counter;
> +  EFI_STATUS Status;
> +  UINTN ElapsedSeconds;
> +  UINT32 Remainder;
> +  UINT32 Freq = ArmGenericTimerGetTimerFreq ();
> +
> +  if (Time == NULL) {
> +    return EFI_INVALID_PARAMETER;
> +  }
> +
> +  //
> +  // Depend on ARM generic timer to report date/time relative to the
> +  // start of CPU timer counting where date and time will always
> +  // be relative to the date/time 1/1/1900 00H:00M:00S
> +  //
> +
> +  ASSERT (Freq != 0);
> +  if (Freq == 0) {
> +    return EFI_DEVICE_ERROR;
> +  }
> +
> +  if (Capabilities) {
> +    Capabilities->Accuracy = 0;
> +    Capabilities->Resolution = Freq;
> +    Capabilities->SetsToZero = FALSE;
> +  }
> +
> +  DataSize = sizeof (UINTN);
> +  ElapsedSeconds = 0;
> +  Status = EfiGetVariable (L"RtcEpochSeconds",
> +             &gEfiCallerIdGuid,
> +             NULL,
> +             &DataSize,
> +             &ElapsedSeconds);
> +  if (EFI_ERROR (Status)) {
> +    ElapsedSeconds = PcdGet64 (PcdBootEpochSeconds);
> +  }
> +  Counter = GetPerformanceCounter ();
> +  ElapsedSeconds += DivU64x32Remainder (Counter, Freq, &Remainder);
> +  EpochToEfiTime (ElapsedSeconds, Time);
> +
> +  //
> +  // Frequency < 0x100000000, so Remainder < 0x100000000, then (Remainder * 1,000,000,000)
> +  // will not overflow 64-bit.
> +  //
> +  Time->Nanosecond = DivU64x32 (MultU64x64 ((UINT64)Remainder, 1000000000U), Freq);
> +
> +  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
> +  )
> +{
> +  UINTN Epoch;
> +
> +  if (!IsTimeValid (Time)) {
> +    return EFI_INVALID_PARAMETER;
> +  }
> +
> +  Epoch = EfiTimeToEpoch (Time);
> +  return EfiSetVariable (L"RtcEpochSeconds", &gEfiCallerIdGuid,
> +           EFI_VARIABLE_BOOTSERVICE_ACCESS |
> +           EFI_VARIABLE_RUNTIME_ACCESS |
> +           EFI_VARIABLE_NON_VOLATILE,
> +           sizeof (Epoch),
> +           &Epoch);
> +}
> +
> +
> +/**
> +   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/Platform/Raspberry/Pi3/Library/VirtualRealTimeClockLib/VirtualRealTimeClockLib.inf b/Platform/Raspberry/Pi3/Library/VirtualRealTimeClockLib/VirtualRealTimeClockLib.inf
> new file mode 100644
> index 000000000000..5c39e4df4c34
> --- /dev/null
> +++ b/Platform/Raspberry/Pi3/Library/VirtualRealTimeClockLib/VirtualRealTimeClockLib.inf
> @@ -0,0 +1,43 @@
> +#/** @file
> +#
> +#  Implement dummy EFI RealTimeClock runtime services.
> +#
> +#  Copyright (c) 2018, Andrei Warkentin <andrey.warkentin@gmail.com>
> +#  Copyright (c) Microsoft Corporation. All rights reserved.
> +#
> +#  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]
> +  ArmPkg/ArmPkg.dec
> +  MdePkg/MdePkg.dec
> +  EmbeddedPkg/EmbeddedPkg.dec
> +  Platform/Raspberry/Pi3/RPi3.dec
> +
> +[LibraryClasses]
> +  IoLib
> +  DebugLib
> +  TimerLib
> +  TimeBaseLib
> +  UefiRuntimeLib
> +
> +[Pcd]
> +  gRaspberryPiTokenSpaceGuid.PcdBootEpochSeconds
> -- 
> 2.17.0.windows.1
>