CryptoPkg/Library/OpensslLib/rand_pool_noise_tsc.c

   1 /** @file
   2   Provide rand noise source.
   3
   4 Copyright (c) 2019, Intel Corporation. All rights reserved.<BR>
   5 SPDX-License-Identifier: BSD-2-Clause-Patent
   6
   7 **/
   8
   9 #include <Library/BaseLib.h>
  10 #include <Library/DebugLib.h>
  11 #include <Library/TimerLib.h>
  12
  13 /**
  14   Get 64-bit noise source
  15
  16   @param[out] Rand         Buffer pointer to store 64-bit noise source
  17
  18   @retval TRUE             Get randomness successfully.
  19   @retval FALSE            Failed to generate
  20 **/
  21 BOOLEAN
  22 EFIAPI
  23 GetRandomNoise64 (
  24   OUT UINT64         *Rand
  25   )
  26 {
  27   UINT32 Index;
  28   UINT32 *RandPtr;
  29
  30   if (NULL == Rand) {
  31     return FALSE;
  32   }
  33
  34   RandPtr = (UINT32 *)Rand;
  35
  36   for (Index = 0; Index < 2; Index ++) {
  37     *RandPtr = (UINT32) ((AsmReadTsc ()) & 0xFF);
  38     RandPtr++;
  39     MicroSecondDelay (10);
  40   }
  41
  42   return TRUE;
  43 }