audk/FatPkg/FatPei/Part.c

/** @file
  Routines supporting partition discovery and
  logical device reading

Copyright (c) 2006 - 2019, 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 "FatLitePeim.h"

/**
  This function finds Eltorito partitions. Main algorithm
  is ported from DXE partition driver.

  @param[in]  PrivateData       The global memory map
  @param[in]  ParentBlockDevNo  The parent block device

  @retval TRUE              New partitions are detected and logical block devices
                            are added to block device array
  @retval FALSE             No new partitions are added

**/
BOOLEAN
FatFindEltoritoPartitions (
  IN  PEI_FAT_PRIVATE_DATA *PrivateData,
  IN  UINTN                ParentBlockDevNo
  );

/**
  This function finds Mbr partitions. Main algorithm
  is ported from DXE partition driver.

  @param[in]  PrivateData       The global memory map
  @param[in]  ParentBlockDevNo  The parent block device

  @retval TRUE              New partitions are detected and logical block devices
                            are added to block device array
  @retval FALSE             No new partitions are added

**/
BOOLEAN
FatFindMbrPartitions (
  IN  PEI_FAT_PRIVATE_DATA *PrivateData,
  IN  UINTN                ParentBlockDevNo
  );

/**
  This function is used for finding GPT partition on block device.
  As follow UEFI spec we should check protective MBR first and then
  try to check both primary/backup GPT structures.

  @param[in]  PrivateData       The global memory map
  @param[in]  ParentBlockDevNo  The parent block device

  @retval TRUE              New partitions are detected and logical block devices
                            are added to block device array
  @retval FALSE             No new partitions are added

**/
BOOLEAN
FatFindGptPartitions (
  IN  PEI_FAT_PRIVATE_DATA *PrivateData,
  IN  UINTN                ParentBlockDevNo
  );

/**
  This function finds partitions (logical devices) in physical block devices.

  @param  PrivateData       Global memory map for accessing global variables.

**/
VOID
FatFindPartitions (
  IN  PEI_FAT_PRIVATE_DATA  *PrivateData
  )
{
  BOOLEAN Found;
  UINTN   Index;

  do {
    Found = FALSE;

    for (Index = 0; Index < PrivateData->BlockDeviceCount; Index++) {
      if (!PrivateData->BlockDevice[Index].PartitionChecked) {
        if (FatFindGptPartitions (PrivateData, Index)) {
          Found = TRUE;
          continue;
        }

        if (FatFindMbrPartitions (PrivateData, Index)) {
          Found = TRUE;
          continue;
        }

        if (FatFindEltoritoPartitions (PrivateData, Index)) {
          Found = TRUE;
          continue;
        }
      }
    }
  } while (Found && PrivateData->BlockDeviceCount <= PEI_FAT_MAX_BLOCK_DEVICE);
}