C++ DivU64x32函数代码示例

/**
  Initialize CPU local APIC timer.

**/
VOID
InitializeDebugTimer (
  VOID
  )
{
  UINTN       ApicTimerDivisor;
  UINT32      InitialCount;

  GetApicTimerState (&ApicTimerDivisor, NULL, NULL);

  //
  // Cpu Local Apic timer interrupt frequency, it is set to 0.1s
  //
  InitialCount = (UINT32)DivU64x32 (
                   MultU64x64 (
                     PcdGet32(PcdFSBClock) / (UINT32)ApicTimerDivisor,
                     100
                     ),
                   1000
                   );

  InitializeApicTimer (ApicTimerDivisor, InitialCount, TRUE, DEBUG_TIMER_VECTOR);

  if (MultiProcessorDebugSupport) {
    mDebugMpContext.DebugTimerInitCount = InitialCount;
  }
}

/**

  This function adjusts the period of timer interrupts to the value specified 
  by TimerPeriod.  If the timer period is updated, then the selected timer 
  period is stored in EFI_TIMER.TimerPeriod, and EFI_SUCCESS is returned.  If 
  the timer hardware is not programmable, then EFI_UNSUPPORTED is returned.  
  If an error occurs while attempting to update the timer period, then the 
  timer hardware will be put back in its state prior to this call, and 
  EFI_DEVICE_ERROR is returned.  If TimerPeriod is 0, then the timer interrupt 
  is disabled.  This is not the same as disabling the CPU's interrupts.  
  Instead, it must either turn off the timer hardware, or it must adjust the 
  interrupt controller so that a CPU interrupt is not generated when the timer 
  interrupt fires. 

  @param  This             The EFI_TIMER_ARCH_PROTOCOL instance.
  @param  TimerPeriod      The rate to program the timer interrupt in 100 nS units. If
                           the timer hardware is not programmable, then EFI_UNSUPPORTED is
                           returned. If the timer is programmable, then the timer period
                           will be rounded up to the nearest timer period that is supported
                           by the timer hardware. If TimerPeriod is set to 0, then the
                           timer interrupts will be disabled.


  @retval EFI_SUCCESS           The timer period was changed.
  @retval EFI_UNSUPPORTED       The platform cannot change the period of the timer interrupt.
  @retval EFI_DEVICE_ERROR      The timer period could not be changed due to a device error.

**/
EFI_STATUS
EFIAPI
TimerDriverSetTimerPeriod (
  IN EFI_TIMER_ARCH_PROTOCOL  *This,
  IN UINT64                   TimerPeriod
  )
{
  UINT64      TimerTicks;
  
  // Always disable the timer
  ArmArchTimerDisableTimer ();

  if (TimerPeriod != 0) {
    // Convert TimerPeriod to micro sec units
    TimerTicks = DivU64x32 (TimerPeriod, 10);

    TimerTicks = MultU64x32 (TimerTicks, (PcdGet32(PcdArmArchTimerFreqInHz)/1000000));

    ArmArchTimerSetTimerVal((UINTN)TimerTicks);

    // Enable the timer
    ArmArchTimerEnableTimer ();
  }

  // Save the new timer period
  mTimerPeriod = TimerPeriod;
  return EFI_SUCCESS;
}

/**
  Set the period for the debug agent timer. Zero means disable the timer.

  @param[in] TimerPeriodMilliseconds    Frequency of the debug agent timer.

**/
VOID
EFIAPI
DebugAgentTimerSetPeriod (
  IN  UINT32  TimerPeriodMilliseconds
  )
{
  UINT64      TimerCount;
  INT32       LoadValue;

  if (TimerPeriodMilliseconds == 0) {
    // Turn off GPTIMER3
    MmioWrite32 (gTCLR, TCLR_ST_OFF);

    DisableInterruptSource ();
  } else {
    // Calculate required timer count
    TimerCount = DivU64x32(TimerPeriodMilliseconds * 1000000, PcdGet32(PcdDebugAgentTimerFreqNanoSeconds));

    // Set GPTIMER5 Load register
    LoadValue = (INT32) -TimerCount;
    MmioWrite32 (gTLDR, LoadValue);
    MmioWrite32 (gTCRR, LoadValue);

    // Enable Overflow interrupt
    MmioWrite32 (gTIER, TIER_TCAR_IT_DISABLE | TIER_OVF_IT_ENABLE | TIER_MAT_IT_DISABLE);

    // Turn on GPTIMER3, it will reload at overflow
    MmioWrite32 (gTCLR, TCLR_AR_AUTORELOAD | TCLR_ST_ON);

    EnableInterruptSource ();
  }
}

/**
  Stalls the CPU for at least the given number of nanoseconds.

  This function wraps EsalStall function of Extended SAL Stall Services Class.
  It stalls the CPU for the number of nanoseconds specified by NanoSeconds.

  @param  NanoSeconds The minimum number of nanoseconds to delay.

  @return NanoSeconds

**/
UINTN
EFIAPI
NanoSecondDelay (
  IN      UINTN                     NanoSeconds
  )
{
  UINT64          MicroSeconds;

  //
  // The unit of ESAL Stall service is microsecond, so we turn the time interval
  // from nanosecond to microsecond, using the ceiling value to ensure stalling
  // at least the given number of nanoseconds.
  //
  MicroSeconds = DivU64x32 (NanoSeconds + 999, 1000);
  EsalCall (
    EFI_EXTENDED_SAL_STALL_SERVICES_PROTOCOL_GUID_LO,
    EFI_EXTENDED_SAL_STALL_SERVICES_PROTOCOL_GUID_HI,
    StallFunctionId,
    MicroSeconds,
    0,
    0,
    0,
    0,
    0,
    0
    );
  return NanoSeconds;
}

/**
  Initialize the BlockIO & BlockIO2 protocol of a RAM disk device.

  @param[in] PrivateData     Points to RAM disk private data.

**/
VOID
RamDiskInitBlockIo (
  IN     RAM_DISK_PRIVATE_DATA    *PrivateData
  )
{
  EFI_BLOCK_IO_PROTOCOL           *BlockIo;
  EFI_BLOCK_IO2_PROTOCOL          *BlockIo2;
  EFI_BLOCK_IO_MEDIA              *Media;

  BlockIo  = &PrivateData->BlockIo;
  BlockIo2 = &PrivateData->BlockIo2;
  Media    = &PrivateData->Media;

  CopyMem (BlockIo, &mRamDiskBlockIoTemplate, sizeof (EFI_BLOCK_IO_PROTOCOL));
  CopyMem (BlockIo2, &mRamDiskBlockIo2Template, sizeof (EFI_BLOCK_IO2_PROTOCOL));

  BlockIo->Media          = Media;
  BlockIo2->Media         = Media;
  Media->RemovableMedia   = FALSE;
  Media->MediaPresent     = TRUE;
  Media->LogicalPartition = FALSE;
  Media->ReadOnly         = FALSE;
  Media->WriteCaching     = FALSE;
  Media->BlockSize        = RAM_DISK_BLOCK_SIZE;
  Media->LastBlock        = DivU64x32 (
                              PrivateData->Size + RAM_DISK_BLOCK_SIZE - 1,
                              RAM_DISK_BLOCK_SIZE
                              ) - 1;
}

/**
  Stalls the CPU for at least the given number of nanoseconds.

  Stalls the CPU for the number of nanoseconds specified by NanoSeconds.

  @param  NanoSeconds The minimum number of nanoseconds to delay.

  @return The value of NanoSeconds inputted.

**/
UINTN
EFIAPI
NanoSecondDelay (
  IN      UINTN                     NanoSeconds
  )
{
  EFI_STATUS  Status;
  UINT64      HundredNanoseconds;
  UINTN       Index;

  if ((gTimerPeriod != 0) &&
      ((UINT64)NanoSeconds > gTimerPeriod) &&
      (EfiGetCurrentTpl () == TPL_APPLICATION)) {
    //
    // This stall is long, so use gBS->WaitForEvent () to yield CPU to DXE Core
    //

    HundredNanoseconds = DivU64x32 (NanoSeconds, 100);
    Status = gBS->SetTimer (gTimerEvent, TimerRelative, HundredNanoseconds);
    ASSERT_EFI_ERROR (Status);

    Status = gBS->WaitForEvent (sizeof (gTimerEvent)/sizeof (EFI_EVENT), &gTimerEvent, &Index);
    ASSERT_EFI_ERROR (Status);

  } else {
    gEmuThunk->Sleep (NanoSeconds);
  }
  return NanoSeconds;
}

EFI_STATUS
EFIAPI
EmuTimerDriverSetTimerPeriod (
  IN EFI_TIMER_ARCH_PROTOCOL  *This,
  IN UINT64                   TimerPeriod
  )
/*++

Routine Description:

  This function adjusts the period of timer interrupts to the value specified
  by TimerPeriod.  If the timer period is updated, then the selected timer
  period is stored in EFI_TIMER.TimerPeriod, and EFI_SUCCESS is returned.  If
  the timer hardware is not programmable, then EFI_UNSUPPORTED is returned.
  If an error occurs while attempting to update the timer period, then the
  timer hardware will be put back in its state prior to this call, and
  EFI_DEVICE_ERROR is returned.  If TimerPeriod is 0, then the timer interrupt
  is disabled.  This is not the same as disabling the CPU's interrupts.
  Instead, it must either turn off the timer hardware, or it must adjust the
  interrupt controller so that a CPU interrupt is not generated when the timer
  interrupt fires.

Arguments:

  This        - The EFI_TIMER_ARCH_PROTOCOL instance.

  TimerPeriod - The rate to program the timer interrupt in 100 nS units.  If
                the timer hardware is not programmable, then EFI_UNSUPPORTED is
                returned.  If the timer is programmable, then the timer period
                will be rounded up to the nearest timer period that is supported
                by the timer hardware.  If TimerPeriod is set to 0, then the
                timer interrupts will be disabled.

Returns:

  EFI_SUCCESS      - The timer period was changed.

  EFI_UNSUPPORTED  - The platform cannot change the period of the timer interrupt.

  EFI_DEVICE_ERROR - The timer period could not be changed due to a device error.

**/
{

  //
  // If TimerPeriod is 0, then the timer thread should be canceled
  // If the TimerPeriod is valid, then create and/or adjust the period of the timer thread
  //
  if (TimerPeriod == 0
      || ((TimerPeriod > TIMER_MINIMUM_VALUE)
    && (TimerPeriod < TIMER_MAXIMUM_VALUE))) {
    mTimerPeriodMs = DivU64x32 (TimerPeriod + 5000, 10000);

    gEmuThunk->SetTimer (mTimerPeriodMs, TimerCallback);
  }

  return EFI_SUCCESS;
}

/**

  This function adjusts the period of timer interrupts to the value specified
  by TimerPeriod.  If the timer period is updated, then the selected timer
  period is stored in EFI_TIMER.TimerPeriod, and EFI_SUCCESS is returned.  If
  the timer hardware is not programmable, then EFI_UNSUPPORTED is returned.
  If an error occurs while attempting to update the timer period, then the
  timer hardware will be put back in its state prior to this call, and
  EFI_DEVICE_ERROR is returned.  If TimerPeriod is 0, then the timer interrupt
  is disabled.  This is not the same as disabling the CPU's interrupts.
  Instead, it must either turn off the timer hardware, or it must adjust the
  interrupt controller so that a CPU interrupt is not generated when the timer
  interrupt fires.

  @param  This             The EFI_TIMER_ARCH_PROTOCOL instance.
  @param  TimerPeriod      The rate to program the timer interrupt in 100 nS units. If
                           the timer hardware is not programmable, then EFI_UNSUPPORTED is
                           returned. If the timer is programmable, then the timer period
                           will be rounded up to the nearest timer period that is supported
                           by the timer hardware. If TimerPeriod is set to 0, then the
                           timer interrupts will be disabled.


  @retval EFI_SUCCESS           The timer period was changed.
  @retval EFI_UNSUPPORTED       The platform cannot change the period of the timer interrupt.
  @retval EFI_DEVICE_ERROR      The timer period could not be changed due to a device error.

**/
STATIC
EFI_STATUS
EFIAPI
SP805SetTimerPeriod (
  IN EFI_WATCHDOG_TIMER_ARCH_PROTOCOL         *This,
  IN UINT64                                   TimerPeriod   // In 100ns units
  )
{
  EFI_STATUS  Status;
  UINT64      Ticks64bit;

  SP805Unlock ();

  Status = EFI_SUCCESS;

  if (TimerPeriod == 0) {
    // This is a watchdog stop request
    SP805Stop ();
  } else {
    // Calculate the Watchdog ticks required for a delay of (TimerTicks * 100) nanoseconds
    // The SP805 will count down to zero and generate an interrupt.
    //
    // WatchdogTicks = ((TimerPeriod * 100 * SP805_CLOCK_FREQUENCY) / 1GHz);
    //
    // i.e.:
    //
    // WatchdogTicks = (TimerPeriod * SP805_CLOCK_FREQUENCY) / 10 MHz ;

    Ticks64bit = MultU64x32 (TimerPeriod, PcdGet32 (PcdSP805WatchdogClockFrequencyInHz));
    Ticks64bit = DivU64x32 (Ticks64bit, 10 * 1000 * 1000);

    // The registers in the SP805 are only 32 bits
    if (Ticks64bit > MAX_UINT32) {
      // We could load the watchdog with the maximum supported value but
      // if a smaller value was requested, this could have the watchdog
      // triggering before it was intended.
      // Better generate an error to let the caller know.
      Status = EFI_DEVICE_ERROR;
      goto EXIT;
    }

    // Update the watchdog with a 32-bit value.
    MmioWrite32 (SP805_WDOG_LOAD_REG, (UINT32)Ticks64bit);

    // Start the watchdog
    SP805Start ();
  }

  mTimerPeriod = TimerPeriod;

EXIT:
  // Ensure the watchdog is locked before exiting.
  SP805Lock ();
  ASSERT_EFI_ERROR (Status);
  return Status;
}

/** 
  Calculate the Duration in microseconds.
  
  Duration is multiplied by 1000, instead of Frequency being divided by 1000 or
  multiplying the result by 1000, in order to maintain precision.  Since Duration is
  a 64-bit value, multiplying it by 1000 is unlikely to produce an overflow.
  
  The time is calculated as (Duration * 1000) / Timer_Frequency.
  
  @param[in]  Duration   The event duration in timer ticks.
  
  @return     A 64-bit value which is the Elapsed time in microseconds.
**/
UINT64
DurationInMicroSeconds (
  IN UINT64 Duration
  )
{
  UINT64 Temp;

  Temp = MultU64x32 (Duration, 1000);
  return DivU64x32 (Temp, TimerInfo.Frequency);
}

/**

  This function adjusts the period of timer interrupts to the value specified
  by TimerPeriod.  If the timer period is updated, then the selected timer
  period is stored in EFI_TIMER.TimerPeriod, and EFI_SUCCESS is returned.  If
  the timer hardware is not programmable, then EFI_UNSUPPORTED is returned.
  If an error occurs while attempting to update the timer period, then the
  timer hardware will be put back in its state prior to this call, and
  EFI_DEVICE_ERROR is returned.  If TimerPeriod is 0, then the timer interrupt
  is disabled.  This is not the same as disabling the CPU's interrupts.
  Instead, it must either turn off the timer hardware, or it must adjust the
  interrupt controller so that a CPU interrupt is not generated when the timer
  interrupt fires.

  @param  This             The EFI_TIMER_ARCH_PROTOCOL instance.
  @param  TimerPeriod      The rate to program the timer interrupt in 100 nS units. If
                           the timer hardware is not programmable, then EFI_UNSUPPORTED is
                           returned. If the timer is programmable, then the timer period
                           will be rounded up to the nearest timer period that is supported
                           by the timer hardware. If TimerPeriod is set to 0, then the
                           timer interrupts will be disabled.


  @retval EFI_SUCCESS           The timer period was changed.
  @retval EFI_UNSUPPORTED       The platform cannot change the period of the timer interrupt.
  @retval EFI_DEVICE_ERROR      The timer period could not be changed due to a device error.

**/
EFI_STATUS
EFIAPI
SP805SetTimerPeriod (
  IN CONST EFI_WATCHDOG_TIMER_ARCH_PROTOCOL   *This,
  IN UINT64                                   TimerPeriod   // In 100ns units
  )
{
  EFI_STATUS  Status = EFI_SUCCESS;
  UINT64      Ticks64bit;

  SP805Unlock();

  if( TimerPeriod == 0 ) {
    // This is a watchdog stop request
    SP805Stop();
    goto EXIT;
  } else {
    // Calculate the Watchdog ticks required for a delay of (TimerTicks * 100) nanoseconds
    // The SP805 will count down to ZERO once, generate an interrupt and
    // then it will again reload the initial value and start again.
    // On the second time when it reaches ZERO, it will actually reset the board.
    // Therefore, we need to load half the required delay.
    //
    // WatchdogTicks = ((TimerPeriod * 100 * SP805_CLOCK_FREQUENCY) / 1GHz) / 2 ;
    //
    // i.e.:
    //
    // WatchdogTicks = (TimerPeriod * SP805_CLOCK_FREQUENCY) / 20 MHz ;

    Ticks64bit = DivU64x32(MultU64x32(TimerPeriod, (UINTN)PcdGet32(PcdSP805WatchdogClockFrequencyInHz)), 20000000);

    // The registers in the SP805 are only 32 bits
    if(Ticks64bit > (UINT64)0xFFFFFFFF) {
      // We could load the watchdog with the maximum supported value but
      // if a smaller value was requested, this could have the watchdog
      // triggering before it was intended.
      // Better generate an error to let the caller know.
      Status = EFI_DEVICE_ERROR;
      goto EXIT;
    }

    // Update the watchdog with a 32-bit value.
    MmioWrite32(SP805_WDOG_LOAD_REG, (UINT32)Ticks64bit);

    // Start the watchdog
    SP805Start();
  }

  EXIT:
  // Ensure the watchdog is locked before exiting.
  SP805Lock();
  return Status;
}

/**
  Main entry for this driver.

  @param ImageHandle     Image handle this driver.
  @param SystemTable     Pointer to SystemTable.

  @retval EFI_SUCESS     This function always complete successfully.

**/
EFI_STATUS
EFIAPI
PlatfomrSmbiosDriverEntryPoint (
  IN EFI_HANDLE         ImageHandle,
  IN EFI_SYSTEM_TABLE   *SystemTable
  )
{
  EFI_STATUS                  Status;
  EFI_SMBIOS_HANDLE           SmbiosHandle;
  SMBIOS_STRUCTURE_POINTER    Smbios;

  // Phase 0 - Patch table to make SMBIOS 2.7 structures smaller to conform 
  //           to an early version of the specification.

  // Phase 1 - Initialize SMBIOS tables from template
  Status = SmbiosLibInitializeFromTemplate (gSmbiosTemplate);
  ASSERT_EFI_ERROR (Status);

  // Phase 2 - Patch SMBIOS table entries

  Smbios.Hdr = SmbiosLibGetRecord (EFI_SMBIOS_TYPE_BIOS_INFORMATION, 0, &SmbiosHandle);
  if (Smbios.Type0 != NULL) {
    // 64K * (n+1) bytes
    Smbios.Type0->BiosSize = (UINT8)DivU64x32 (FixedPcdGet64 (PcdEmuFirmwareFdSize), 64*1024) - 1;

    SmbiosLibUpdateUnicodeString (
      SmbiosHandle, 
      Smbios.Type0->BiosVersion, 
      (CHAR16 *) PcdGetPtr (PcdFirmwareVersionString)
      );
    SmbiosLibUpdateUnicodeString (
      SmbiosHandle, 
      Smbios.Type0->BiosReleaseDate, 
      (CHAR16 *) PcdGetPtr (PcdFirmwareReleaseDateString)
      );
  }

  // Phase 3 - Create tables from scratch 

  // Create Type 13 record from EFI Variables
  // Do we need this record for EFI as the info is availible from EFI varaibles
  // Also language types don't always match between EFI and SMBIOS
  // CreateSmbiosLanguageInformation (1, gSmbiosLangToEfiLang);

  CreatePlatformSmbiosMemoryRecords ();

  return EFI_SUCCESS;
}

/**
  Stalls the CPU for at least the given number of microseconds.

  Stalls the CPU for the number of microseconds specified by MicroSeconds.

  @param  MicroSeconds  The minimum number of microseconds to delay.

  @return MicroSeconds

**/
UINTN
   EFIAPI
   MicroSecondDelay (
   IN      UINTN                     MicroSeconds
   )
{
   InternalAcpiDelay (
      (UINT32)DivU64x32 (
      MultU64x32 (
      MicroSeconds,
      V_ACPI_TMR_FREQUENCY
      ),
      1000000u
      )
      );
   return MicroSeconds;
}

/**
  Stalls the CPU for at least the given number of nanoseconds.

  Stalls the CPU for the number of nanoseconds specified by NanoSeconds.

  @param  NanoSeconds The minimum number of nanoseconds to delay.

  @return NanoSeconds

**/
UINTN
EFIAPI
NanoSecondDelay (
  IN      UINTN                     NanoSeconds
  )
{
  InternalAcpiDelay (
    (UINT32)DivU64x32 (
              MultU64x32 (
                NanoSeconds,
                ACPI_TIMER_FREQUENCY
                ),
              1000000000u
              )
    );
  return NanoSeconds;
}

/**
  Stalls the CPU for at least the given number of nanoseconds.

  Stalls the CPU for the number of nanoseconds specified by NanoSeconds.

  @param  NanoSeconds The minimum number of nanoseconds to delay.

  @return The value of NanoSeconds inputted.

**/
UINTN
EFIAPI
NanoSecondDelay (
  IN      UINTN                     NanoSeconds
  )
{
  InternalX86Delay (
    (UINT32)DivU64x32 (
              MultU64x64 (
                InternalX86GetTimerFrequency (),
                NanoSeconds
                ),
              1000000000u
              )
    );
  return NanoSeconds;
}

EFI_STATUS
EFIAPI
UnixMetronomeDriverWaitForTick (
  IN EFI_METRONOME_ARCH_PROTOCOL  *This,
  IN UINT32                       TickNumber
  )
/*++

Routine Description:

  The WaitForTick() function waits for the number of ticks specified by
  TickNumber from a known time source in the platform.  If TickNumber of
  ticks are detected, then EFI_SUCCESS is returned.  The actual time passed
  between entry of this function and the first tick is between 0 and
  TickPeriod 100 nS units.  If you want to guarantee that at least TickPeriod
  time has elapsed, wait for two ticks.  This function waits for a hardware
  event to determine when a tick occurs.  It is possible for interrupt
  processing, or exception processing to interrupt the execution of the
  WaitForTick() function.  Depending on the hardware source for the ticks, it
  is possible for a tick to be missed.  This function cannot guarantee that
  ticks will not be missed.  If a timeout occurs waiting for the specified
  number of ticks, then EFI_TIMEOUT is returned.

Arguments:

  This       - The EFI_METRONOME_ARCH_PROTOCOL instance.
  TickNumber - Number of ticks to wait.

Returns:

  EFI_SUCCESS - The wait for the number of ticks specified by TickNumber
                succeeded.

--*/
{
  UINT64  SleepTime;

  //
  // Calculate the time to sleep.  Win API smallest unit to sleep is 1 millisec
  // Tick Period is in 100ns units, divide by 10000 to convert to ms
  //
  SleepTime = DivU64x32 (MultU64x32 ((UINT64) TickNumber, TICK_PERIOD) + 9999, 10000);
  gUnix->Sleep ((UINT32) SleepTime);

  return EFI_SUCCESS;
}