IntelFspWrapperPkg/Library/SecPeiFspPlatformSecLibSample/SaveSecContext.c

/** @file
  Sample to provide SaveSecContext 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 <Library/DebugLib.h>

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

/**
  Save BIST value before call FspInit.

  @param[in] Bist   BIST value.
**/
VOID
AsmSaveBistValue (
  IN UINT32  Bist
  );

/**
  Save Ticker value before call FspInit.

  @param[in] Ticker   Ticker value.
**/
VOID
AsmSaveTickerValue (
  IN UINT64  Ticker
  );

/**
  Save SEC context before call FspInit.

  @param[in] PeiServices  Pointer to PEI Services Table.
**/
VOID
EFIAPI
SaveSecContext (
  IN CONST EFI_PEI_SERVICES                     **PeiServices
  )
{
  UINT32      *Bist;
  UINT64      *Ticker;
  UINT32      Size;
  UINT32      Count;
  UINT32      TopOfTemporaryRam;
  VOID        *TopOfTemporaryRamPpi;
  EFI_STATUS  Status;

  DEBUG ((DEBUG_INFO, "SaveSecContext - 0x%x\n", PeiServices));

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

  DEBUG ((DEBUG_INFO, "TopOfTemporaryRamPpi - 0x%x\n", TopOfTemporaryRamPpi));

  //
  // 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
  // |Number of BSPs|
  // |--------------|
  // |     BIST     |
  // |--------------|
  // |     ....     |
  // |--------------|
  // |  TSC[63:32]  |
  // |--------------|
  // |  TSC[31:00]  |
  // |--------------|
  //

  TopOfTemporaryRam = (UINT32)(UINTN)TopOfTemporaryRamPpi - sizeof(UINT32);
  TopOfTemporaryRam -= sizeof(UINT32) * 2;
  DEBUG ((DEBUG_INFO, "TopOfTemporaryRam - 0x%x\n", TopOfTemporaryRam));
  Count             = *(UINT32 *)(UINTN)(TopOfTemporaryRam - sizeof(UINT32));
  DEBUG ((DEBUG_INFO, "Count - 0x%x\n", Count));
  Size              = Count * sizeof (IA32_HANDOFF_STATUS);
  DEBUG ((DEBUG_INFO, "Size - 0x%x\n", Size));

  Bist   = (UINT32 *)(UINTN)(TopOfTemporaryRam - sizeof(UINT32) - Size);
  DEBUG ((DEBUG_INFO, "Bist - 0x%x\n", *Bist));
  Ticker = (UINT64 *)(UINTN)(TopOfTemporaryRam - sizeof(UINT32) - Size - sizeof(UINT64));
  DEBUG ((DEBUG_INFO, "Ticker - 0x%lx\n", *Ticker));

  // Just need record BSP
  AsmSaveBistValue (*Bist);
  AsmSaveTickerValue (*Ticker);
}