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1 /* |
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2 * Copyright (c) 2006-2009 Nokia Corporation and/or its subsidiary(-ies). |
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3 * All rights reserved. |
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4 * This component and the accompanying materials are made available |
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5 * under the terms of the License "Eclipse Public License v1.0" |
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6 * which accompanies this distribution, and is available |
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7 * at the URL "http://www.eclipse.org/legal/epl-v10.html". |
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8 * |
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9 * Initial Contributors: |
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10 * Nokia Corporation - initial contribution. |
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11 * |
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12 * Contributors: |
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13 * |
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14 * Description: |
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15 * This class represents the boot sector of a FAT16 image. |
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16 * This class is derived from basebootsector class which is constitutes |
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17 * the common boot sector fields for FAT16 and FAT32 class. |
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18 * @internalComponent |
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19 * @released |
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20 * |
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21 */ |
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22 |
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23 #include "fat16bootsector.h" |
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24 #include <cstring> |
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25 |
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26 /** |
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27 Constructor of the fat16 boot sector class |
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28 |
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29 @internalComponent |
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30 @released |
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31 */ |
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32 TFAT16BootSector::TFAT16BootSector() |
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33 { |
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34 } |
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35 |
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36 /** |
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37 Destructor of the fat16 boot sector class |
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38 |
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39 @internalComponent |
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40 @released |
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41 */ |
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42 TFAT16BootSector::~TFAT16BootSector() |
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43 { |
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44 } |
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45 |
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46 /** |
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47 Set the file system type |
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48 |
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49 @internalComponent |
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50 @released |
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51 */ |
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52 void TFAT16BootSector::SetFileSysType() |
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53 { |
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54 strcpy(reinterpret_cast<char*>(iFileSysType),"FAT16 "); |
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55 } |
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56 /** |
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57 returns the file system type |
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58 @return file system type |
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59 |
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60 @internalComponent |
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61 @released |
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62 */ |
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63 unsigned char* TFAT16BootSector::FileSysType() |
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64 { |
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65 return iFileSysType; |
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66 } |
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67 |
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68 /** |
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69 Number of entries allowed in the root directory,specific to Fat12/16, |
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70 zero for FAT32 |
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71 |
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72 @internalComponent |
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73 @released |
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74 */ |
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75 void TFAT16BootSector::SetRootDirEntries() |
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76 { |
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77 iRootDirEntries = KDefaultRootDirEntries;; |
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78 } |
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79 |
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80 /** |
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81 Sets the number of reserved sectors on the volume |
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82 |
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83 @internalComponent |
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84 @released |
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85 */ |
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86 void TFAT16BootSector::SetReservedSectors() |
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87 { |
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88 iReservedSectors = KDefaultFat16ReservedSectors; |
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89 } |
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90 |
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91 /** |
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92 Computes the sectors per cluster ratio |
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93 To refer this mathematical computation, Please see: |
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94 Microsoft Extensible Firmware Initiative FAT32 File |
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95 System Specification document |
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96 |
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97 @internalComponent |
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98 @released |
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99 |
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100 @param aPartitionSize partition size in bytes |
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101 */ |
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102 void TFAT16BootSector::ComputeSectorsPerCluster(Long64 aPartitionSize) |
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103 { |
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104 |
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105 if(aPartitionSize > K1GB) |
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106 { |
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107 iSectorsPerCluster = K64SectorsPerCluster; |
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108 } |
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109 else if(aPartitionSize > K512MB) |
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110 { |
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111 iSectorsPerCluster = K32SectorsPerCluster; |
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112 } |
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113 else if(aPartitionSize > K256MB) |
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114 { |
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115 iSectorsPerCluster = K16SectorsPerCluster; |
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116 } |
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117 else if(aPartitionSize > K128MB) |
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118 { |
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119 iSectorsPerCluster = K8SectorsPerCluster; |
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120 } |
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121 else if(aPartitionSize > K16MB) |
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122 { |
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123 iSectorsPerCluster = K4SectorsPerCluster; |
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124 } |
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125 else |
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126 { |
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127 iSectorsPerCluster = K2SectorsPerCluster; |
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128 } |
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129 } |
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130 |
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131 /** |
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132 Sectors used for the Fat table |
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133 To refer this mathematical formulae, Please see: |
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134 Microsoft Extensible Firmware Initiative FAT32 File System Specification |
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135 document |
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136 |
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137 @internalComponent |
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138 @released |
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139 |
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140 @param aPartitionSize partition size |
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141 */ |
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142 void TFAT16BootSector::ComputeFatSectors(Long64 aPartitionSize) |
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143 { |
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144 int iRootDirSectors = ((iRootDirEntries * 32) + (iBytesPerSector - 1)) / iBytesPerSector; |
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145 int Log2OfBytesPerSector = Log2(iBytesPerSector); |
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146 unsigned long TotalSectors64 = (unsigned long)(aPartitionSize >> Log2OfBytesPerSector); |
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147 unsigned int tmpval1 = TotalSectors64 - (iReservedSectors + iRootDirSectors); |
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148 unsigned int tmpval2 =(256 * iSectorsPerCluster) + iNumberOfFats; |
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149 unsigned int FatSectors =(tmpval1 + (tmpval2 - 1)) / tmpval2; |
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150 iFatSectors = (unsigned short)FatSectors; |
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151 iFatSectors32 = 0; |
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152 } |