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

[Pete Batard <pete@akeo.ie>]

On 2019.01.30 22:22, Leif Lindholm wrote:
> 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.

Okay, I'll look into both of these items.

> 
> 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
>>