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 This program and the accompanying materials are licensed and made available
   8 under the terms and conditions of the BSD License which accompanies this
   9 distribution. The full text of the license may be found at
  10 http://opensource.org/licenses/bsd-license.php
  11
  12 THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  13 WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  14
  15 **/
  16
  17 #include "FatLitePeim.h"
  18
  19 /**
  20   This function finds Eltorito partitions. Main algorithm
  21   is ported from DXE partition driver.
  22
  23   @param[in]  PrivateData       The global memory map
  24   @param[in]  ParentBlockDevNo  The parent block device
  25
  26   @retval TRUE              New partitions are detected and logical block devices
  27                             are added to block device array
  28   @retval FALSE             No new partitions are added
  29
  30 **/
  31 BOOLEAN
  32 FatFindEltoritoPartitions (
  33   IN  PEI_FAT_PRIVATE_DATA *PrivateData,
  34   IN  UINTN                ParentBlockDevNo
  35   );
  36
  37 /**
  38   This function finds Mbr partitions. Main algorithm
  39   is ported from DXE partition driver.
  40
  41   @param[in]  PrivateData       The global memory map
  42   @param[in]  ParentBlockDevNo  The parent block device
  43
  44   @retval TRUE              New partitions are detected and logical block devices
  45                             are added to block device array
  46   @retval FALSE             No new partitions are added
  47
  48 **/
  49 BOOLEAN
  50 FatFindMbrPartitions (
  51   IN  PEI_FAT_PRIVATE_DATA *PrivateData,
  52   IN  UINTN                ParentBlockDevNo
  53   );
  54
  55 /**
  56   This function is used for finding GPT partition on block device.
  57   As follow UEFI spec we should check protective MBR first and then
  58   try to check both primary/backup GPT structures.
  59
  60   @param[in]  PrivateData       The global memory map
  61   @param[in]  ParentBlockDevNo  The parent block device
  62
  63   @retval TRUE              New partitions are detected and logical block devices
  64                             are added to block device array
  65   @retval FALSE             No new partitions are added
  66
  67 **/
  68 BOOLEAN
  69 FatFindGptPartitions (
  70   IN  PEI_FAT_PRIVATE_DATA *PrivateData,
  71   IN  UINTN                ParentBlockDevNo
  72   );
  73
  74 /**
  75   This function finds partitions (logical devices) in physical block devices.
  76
  77   @param  PrivateData       Global memory map for accessing global variables.
  78
  79 **/
  80 VOID
  81 FatFindPartitions (
  82   IN  PEI_FAT_PRIVATE_DATA  *PrivateData
  83   )
  84 {
  85   BOOLEAN Found;
  86   UINTN   Index;
  87
  88   do {
  89     Found = FALSE;
  90
  91     for (Index = 0; Index < PrivateData->BlockDeviceCount; Index++) {
  92       if (!PrivateData->BlockDevice[Index].PartitionChecked) {
  93         if (FatFindGptPartitions (PrivateData, Index)) {
  94           Found = TRUE;
  95           continue;
  96         }
  97
  98         if (FatFindMbrPartitions (PrivateData, Index)) {
  99           Found = TRUE;
 100           continue;
 101         }
 102
 103         if (FatFindEltoritoPartitions (PrivateData, Index)) {
 104           Found = TRUE;
 105           continue;
 106         }
 107       }
 108     }
 109   } while (Found && PrivateData->BlockDeviceCount <= PEI_FAT_MAX_BLOCK_DEVICE);
 110 }