FatPkg/FatPei/Part.c

   1 /** @file
   2   Routines supporting partition discovery and
   3   logical device reading
   4
   5 Copyright (c) 2006 - 2019, Intel Corporation. All rights reserved.<BR>
   6
   7 SPDX-License-Identifier: BSD-2-Clause-Patent
   8
   9 **/
  10
  11 #include "FatLitePeim.h"
  12
  13 /**
  14   This function finds Eltorito partitions. Main algorithm
  15   is ported from DXE partition driver.
  16
  17   @param[in]  PrivateData       The global memory map
  18   @param[in]  ParentBlockDevNo  The parent block device
  19
  20   @retval TRUE              New partitions are detected and logical block devices
  21                             are added to block device array
  22   @retval FALSE             No new partitions are added
  23
  24 **/
  25 BOOLEAN
  26 FatFindEltoritoPartitions (
  27   IN  PEI_FAT_PRIVATE_DATA  *PrivateData,
  28   IN  UINTN                 ParentBlockDevNo
  29   );
  30
  31 /**
  32   This function finds Mbr partitions. Main algorithm
  33   is ported from DXE partition driver.
  34
  35   @param[in]  PrivateData       The global memory map
  36   @param[in]  ParentBlockDevNo  The parent block device
  37
  38   @retval TRUE              New partitions are detected and logical block devices
  39                             are added to block device array
  40   @retval FALSE             No new partitions are added
  41
  42 **/
  43 BOOLEAN
  44 FatFindMbrPartitions (
  45   IN  PEI_FAT_PRIVATE_DATA  *PrivateData,
  46   IN  UINTN                 ParentBlockDevNo
  47   );
  48
  49 /**
  50   This function is used for finding GPT partition on block device.
  51   As follow UEFI spec we should check protective MBR first and then
  52   try to check both primary/backup GPT structures.
  53
  54   @param[in]  PrivateData       The global memory map
  55   @param[in]  ParentBlockDevNo  The parent block device
  56
  57   @retval TRUE              New partitions are detected and logical block devices
  58                             are added to block device array
  59   @retval FALSE             No new partitions are added
  60
  61 **/
  62 BOOLEAN
  63 FatFindGptPartitions (
  64   IN  PEI_FAT_PRIVATE_DATA  *PrivateData,
  65   IN  UINTN                 ParentBlockDevNo
  66   );
  67
  68 /**
  69   This function finds partitions (logical devices) in physical block devices.
  70
  71   @param  PrivateData       Global memory map for accessing global variables.
  72
  73 **/
  74 VOID
  75 FatFindPartitions (
  76   IN  PEI_FAT_PRIVATE_DATA  *PrivateData
  77   )
  78 {
  79   BOOLEAN  Found;
  80   UINTN    Index;
  81
  82   do {
  83     Found = FALSE;
  84
  85     for (Index = 0; Index < PrivateData->BlockDeviceCount; Index++) {
  86       if (!PrivateData->BlockDevice[Index].PartitionChecked) {
  87         if (FatFindGptPartitions (PrivateData, Index)) {
  88           Found = TRUE;
  89           continue;
  90         }
  91
  92         if (FatFindMbrPartitions (PrivateData, Index)) {
  93           Found = TRUE;
  94           continue;
  95         }
  96
  97         if (FatFindEltoritoPartitions (PrivateData, Index)) {
  98           Found = TRUE;
  99           continue;
 100         }
 101       }
 102     }
 103   } while (Found && PrivateData->BlockDeviceCount <= PEI_FAT_MAX_BLOCK_DEVICE);
 104 }