IntelFspWrapperPkg/Library/SecPeiFspPlatformSecLibSample/SecPlatformInformation.c

/** @file
  Sample to provide SecPlatformInformation function.

  Copyright (c) 2014, Intel Corporation. All rights reserved.<BR>
  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 <PiPei.h>

#include <Ppi/SecPlatformInformation.h>
#include <Ppi/TopOfTemporaryRam.h>

#include <Library/BaseMemoryLib.h>
#include <Library/DebugLib.h>

/**
  This interface conveys state information out of the Security (SEC) phase into PEI.

  @param[in]     PeiServices               Pointer to the PEI Services Table.
  @param[in,out] StructureSize             Pointer to the variable describing size of the input buffer.
  @param[out]    PlatformInformationRecord Pointer to the EFI_SEC_PLATFORM_INFORMATION_RECORD.

  @retval EFI_SUCCESS           The data was successfully returned.
  @retval EFI_BUFFER_TOO_SMALL  The buffer was too small.

**/
EFI_STATUS
EFIAPI
SecPlatformInformation (
  IN CONST EFI_PEI_SERVICES                     **PeiServices,
  IN OUT   UINT64                               *StructureSize,
     OUT   EFI_SEC_PLATFORM_INFORMATION_RECORD  *PlatformInformationRecord
  )
{
  UINT32      *Bist;
  UINT32      Size;
  UINT32      Count;
  UINT32      TopOfTemporaryRam;
  VOID        *TopOfTemporaryRamPpi;
  EFI_STATUS  Status;

  DEBUG ((DEBUG_INFO, "SecPlatformInformation\n"));

  Status = (*PeiServices)->LocatePpi (
                             PeiServices,
                             &gTopOfTemporaryRamPpiGuid,
                             0,
                             NULL,
                             (VOID **) &TopOfTemporaryRamPpi
                             );
  if (EFI_ERROR (Status)) {
    return EFI_NOT_FOUND;
  }

  //
  // The entries of BIST information, together with the number of them,
  // reside in the bottom of stack, left untouched by normal stack operation.
  // This routine copies the BIST information to the buffer pointed by
  // PlatformInformationRecord for output.
  //
  TopOfTemporaryRam = (UINT32)(UINTN)TopOfTemporaryRamPpi - sizeof (UINT32);
  TopOfTemporaryRam -= sizeof(UINT32) * 2;
  Count             = *((UINT32 *)(UINTN) (TopOfTemporaryRam - sizeof (UINT32)));
  Size              = Count * sizeof (IA32_HANDOFF_STATUS);

  if ((*StructureSize) < (UINT64) Size) {
    *StructureSize = Size;
    return EFI_BUFFER_TOO_SMALL;
  }

  *StructureSize  = Size;
  Bist            = (UINT32 *) (TopOfTemporaryRam - sizeof (UINT32) - Size);

  CopyMem (PlatformInformationRecord, Bist, Size);

  return EFI_SUCCESS;
}