slimbootloader/BootloaderCommonPkg/Library/HobLib/HobLib.c

/** @file
  Provide Hob Library functions for Pei phase.

Copyright (c) 2007 - 2017, Intel Corporation. All rights reserved.<BR>
SPDX-License-Identifier: BSD-2-Clause-Patent

**/

#include <PiPei.h>

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

/**
  Returns the pointer to the HOB list.

  If the pointer to the HOB list is NULL, then ASSERT().

  @return The pointer to the HOB list.

**/
VOID *
EFIAPI
GetHobList (
  VOID
  )
{
  return GetHobListPtr();
}

/**
  Returns the next instance of a HOB type from the starting HOB.

  This function searches the first instance of a HOB type from the starting HOB pointer.
  If there does not exist such HOB type from the starting HOB pointer, it will return NULL.
  In contrast with macro GET_NEXT_HOB(), this function does not skip the starting HOB pointer
  unconditionally: it returns HobStart back if HobStart itself meets the requirement;
  caller is required to use GET_NEXT_HOB() if it wishes to skip current HobStart.

  If HobStart is NULL, then ASSERT().

  @param  Type          The HOB type to return.
  @param  HobStart      The starting HOB pointer to search from.

  @return The next instance of a HOB type from the starting HOB.

**/
VOID *
EFIAPI
GetNextHob (
  IN UINT16                 Type,
  IN CONST VOID             *HobStart
  )
{
  EFI_PEI_HOB_POINTERS  Hob;

  ASSERT (HobStart != NULL);

  Hob.Raw = (UINT8 *) HobStart;
  //
  // Parse the HOB list until end of list or matching type is found.
  //
  while (!END_OF_HOB_LIST (Hob)) {
    if (Hob.Header->HobType == Type) {
      return Hob.Raw;
    }
    Hob.Raw = GET_NEXT_HOB (Hob);
  }
  return NULL;
}

/**
  Returns the first instance of a HOB type among the whole HOB list.

  This function searches the first instance of a HOB type among the whole HOB list.
  If there does not exist such HOB type in the HOB list, it will return NULL.

  If the pointer to the HOB list is NULL, then ASSERT().

  @param  Type          The HOB type to return.

  @return The next instance of a HOB type from the starting HOB.

**/
VOID *
EFIAPI
GetFirstHob (
  IN UINT16                 Type
  )
{
  VOID      *HobList;

  HobList = GetHobList ();
  return GetNextHob (Type, HobList);
}

/**
  Returns the next instance of the matched GUID HOB from the starting HOB.

  This function searches the first instance of a HOB from the starting HOB pointer.
  Such HOB should satisfy two conditions:
  its HOB type is EFI_HOB_TYPE_GUID_EXTENSION and its GUID Name equals to the input Guid.
  If there does not exist such HOB from the starting HOB pointer, it will return NULL.
  Caller is required to apply GET_GUID_HOB_DATA () and GET_GUID_HOB_DATA_SIZE ()
  to extract the data section and its size information, respectively.
  In contrast with macro GET_NEXT_HOB(), this function does not skip the starting HOB pointer
  unconditionally: it returns HobStart back if HobStart itself meets the requirement;
  caller is required to use GET_NEXT_HOB() if it wishes to skip current HobStart.

  If Guid is NULL, then ASSERT().
  If HobStart is NULL, then ASSERT().

  @param  Guid          The GUID to match with in the HOB list.
  @param  HobStart      A pointer to a Guid.

  @return The next instance of the matched GUID HOB from the starting HOB.

**/
VOID *
EFIAPI
GetNextGuidHob (
  IN CONST EFI_GUID         *Guid,
  IN CONST VOID             *HobStart
  )
{
  EFI_PEI_HOB_POINTERS  GuidHob;

  GuidHob.Raw = (UINT8 *) HobStart;
  while ((GuidHob.Raw = GetNextHob (EFI_HOB_TYPE_GUID_EXTENSION, GuidHob.Raw)) != NULL) {
    if (CompareGuid (Guid, &GuidHob.Guid->Name)) {
      break;
    }
    GuidHob.Raw = GET_NEXT_HOB (GuidHob);
  }
  return GuidHob.Raw;
}

/**
  Returns the first instance of the matched GUID HOB among the whole HOB list.

  This function searches the first instance of a HOB among the whole HOB list.
  Such HOB should satisfy two conditions:
  its HOB type is EFI_HOB_TYPE_GUID_EXTENSION and its GUID Name equals to the input Guid.
  If there does not exist such HOB from the starting HOB pointer, it will return NULL.
  Caller is required to apply GET_GUID_HOB_DATA () and GET_GUID_HOB_DATA_SIZE ()
  to extract the data section and its size information, respectively.

  If the pointer to the HOB list is NULL, then ASSERT().
  If Guid is NULL, then ASSERT().

  @param  Guid          The GUID to match with in the HOB list.

  @return The first instance of the matched GUID HOB among the whole HOB list.

**/
VOID *
EFIAPI
GetFirstGuidHob (
  IN CONST EFI_GUID         *Guid
  )
{
  VOID      *HobList;

  HobList = GetHobList ();
  return GetNextGuidHob (Guid, HobList);
}