alder_lake_bios/Lcfc/LfcPkg/RemoveRtcBattery/RemoveRtcBatteryDxe/RemoveRtcBatteryDxe.c

/** @file
 ;******************************************************************************
 ;*
 ;* Copyright (c) 2012 - 2020, Hefei LCFC Information Technology Co.Ltd. 
 ;* And/or its affiliates. All rights reserved. 
 ;* Hefei LCFC Information Technology Co.Ltd. PROPRIETARY/CONFIDENTIAL. 
 ;* Use is subject to license terms.
 ;* 
 ;******************************************************************************
*/

#include <Library/UefiRuntimeServicesTableLib.h>
#include <Library/BaseLib.h>
#include <Library/IoLib.h>
#include <Library/UefiLib.h>
#include <Library/DebugLib.h>
#include <Protocol/LenovoVariable.h>
#include <Guid/LfcVariableGuid.h>
#include <Library/LfcEcLib.h>

/**
 Check if it is a leap year.

 @param[in] Time   The time to be checked.

 @retval TRUE      It is a leap year.
 @retval FALSE     It is NOT a leap year.
**/
BOOLEAN
IsItLeapYear (
  IN EFI_TIME   *Time
  )
{
  if (Time->Year % 4 == 0) {
    if (Time->Year % 100 == 0) {
      if (Time->Year % 400 == 0) {
        return TRUE;
      } else {
        return FALSE;
      }
    } else {
      return TRUE;
    }
  } else {
    return FALSE;
  }
}

EFI_STATUS
TimeAddHours (
  IN OUT EFI_TIME  *Time,
  IN UINT16        AddHours
  )
{
  EFI_TIME          TheTime;
  UINT8             MonthDays[13];
  UINT8             MonthDaysLeapYear[13] =      { 0, 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 };
  UINT8             MonthDaysNoLeapYear[13] =    { 0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 };
  UINT16            MonthDaysSum[13];
  UINT16            MonthDaysSumLeapYear[13] =   { 0, 31, 60, 91, 121, 152, 182, 213, 244, 274, 305, 335, 366 };
  UINT16            MonthDaysSumNoLeapYear[13] = { 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334, 365 };
  UINTN             Index;
  UINTN             Days = 0;
  UINTN             Hours = 0;

  TheTime = *Time;

  //Based on beginning of saved time year, get saved time hours sum.
  if (IsItLeapYear(&TheTime)) {
    for (Index = 0; Index < 13; Index++) {
      MonthDays[Index] = MonthDaysLeapYear[Index];
    }
  } else {
    for (Index = 0; Index < 13; Index++) {
      MonthDays[Index] = MonthDaysNoLeapYear[Index];
    }
  }

  for (Index = 0; Index < TheTime.Month; Index++) {
    Days += MonthDays[Index];
  }
  Days += TheTime.Day;

  Hours = (Days - 1) * 24 + TheTime.Hour;

  //Add parameter AddHours
  Hours += AddHours;

  //Get wanted time
  Days = (Hours / 24) + 1;
  TheTime.Hour = Hours % 24;

  while (TRUE) {
    if (IsItLeapYear(&TheTime)) {
      for (Index = 0; Index < 13; Index++) {
        MonthDaysSum[Index] = MonthDaysSumLeapYear[Index];
      }
    } else {
      for (Index = 0; Index < 13; Index++) {
        MonthDaysSum[Index] = MonthDaysSumNoLeapYear[Index];
      }
    }

    if (Days > MonthDaysSum[12]) {
      TheTime.Year++;
      Days -= MonthDaysSum[12];
    } else {
      break;
    }
  }

  for (Index = 0; Index < 13; Index++) {
    if (Days <= MonthDaysSum[Index]) {
      TheTime.Month = (UINT8) Index;
      TheTime.Day = (UINT8) (Days - MonthDaysSum[Index-1]);
      break;
    }
  }

  if (TheTime.Year < 2099) {
    *Time = TheTime;
    return EFI_SUCCESS;
  } else {
    return EFI_UNSUPPORTED;
  }
}

/**
 Correct RTC time, year support to 2099.
**/
EFI_STATUS
RollbackRtcTimeCallBack (
  IN EFI_EVENT  Event,
  IN VOID       *Context
  )
{
  EFI_STATUS                 Status;
  UINT8                      SaveTime[6] = {0};
  UINTN                      TempDataLength = sizeof (SaveTime);
  EFI_TIME                   TheTime;
  UINT16                     BatteryTimerCount;

  //Get saved time from variable - "SaveCurrentTime"
  Status = gRT->GetVariable (
                  L"SaveCurrentTime",
                  &gLfcVariableGuid,
                  NULL,
                  &TempDataLength,
                  SaveTime
                  );
  if (EFI_ERROR (Status)) {
    return Status;
  }

  //Get system default time format
  Status = gRT->GetTime (&TheTime, NULL);
  if (EFI_ERROR (Status)) {
    return Status;
  }
  
  TheTime.Second   = BcdToDecimal8(SaveTime[0]);
  TheTime.Minute   = BcdToDecimal8(SaveTime[1]);
  TheTime.Hour     = BcdToDecimal8(SaveTime[2]);
  TheTime.Day      = BcdToDecimal8(SaveTime[3]);
  TheTime.Month    = BcdToDecimal8(SaveTime[4]);
  TheTime.Year     = 2000 + BcdToDecimal8(SaveTime[5]);
  TheTime.TimeZone = EFI_UNSPECIFIED_TIMEZONE;
  TheTime.Daylight = 0;

  //Get battery timer count from EC - hours.
  Status = LfcEcLibGetBatteryTimerCount(&BatteryTimerCount);
  if (EFI_ERROR (Status)) {
    return Status;
  }

  //Time add battery timer count (hours)
  Status = TimeAddHours(&TheTime, BatteryTimerCount);
  if (EFI_ERROR (Status)) {
    return Status;
  }

  //Set new Time
  Status = gRT->SetTime(&TheTime);
  if (EFI_ERROR (Status)) {
    return Status;
  }

  //Delete variable - "SaveCurrentTime"
  Status = gRT->SetVariable (
                  L"SaveCurrentTime",
                  &gLfcVariableGuid,
                  EFI_VARIABLE_BOOTSERVICE_ACCESS | EFI_VARIABLE_RUNTIME_ACCESS | EFI_VARIABLE_NON_VOLATILE,
                  0,
                  SaveTime
                  );
  if (EFI_ERROR (Status)) {
    return Status;
  }

  // Add battery first use data
  Status = LfcEcLibGetBatteryFirstUsedDate();

  return EFI_SUCCESS;
}


/**
  Remove RTC Battery DXE entry.

  Remove RTC battery then ship support, RTC time will lost.
  This solution will save current RTC time, then add battery count, generate new time and set it.

  @param  ImageHandle                   The firmware allocated handle for the UEFI image.
  @param  SystemTable                   A pointer to the EFI System Table.

  @retval EFI_SUCCESS                   The operation completed successfully.
  @retval Others                        An unexpected error occurred.
**/
EFI_STATUS
L05RemoveRtcBatteryDxeEntry (
  IN EFI_HANDLE                         ImageHandle,
  IN EFI_SYSTEM_TABLE                   *SystemTable
  )
{
  EFI_STATUS                 Status;
  EFI_EVENT                  Event;

  Status = EfiCreateEventReadyToBootEx (
           TPL_CALLBACK,
           RollbackRtcTimeCallBack,
           NULL,
           &Event
           );
  if (EFI_ERROR (Status)) {
    return Status;
  }

  return EFI_SUCCESS;
}