1 | ////////////////////////////////////////////////////////////////////////////////// |
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2 | // File : fat32.c |
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3 | // Date : 01/09/2013 |
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4 | // Authors : Marco Jankovic, Cesar Fuguet & Alain Greiner |
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5 | // Copyright (c) UPMC-LIP6 |
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6 | ////////////////////////////////////////////////////////////////////////////////// |
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7 | // The fat32.h and fat32.c files define a library of access functions |
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8 | // to a FAT32 disk on a block device. It is intended to be used |
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9 | // by the GIET_VM nano-kernel for both the boot code and the kernel code. |
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10 | // This code uses functions defined in the utils.c and drivers.c files. |
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11 | ////////////////////////////////////////////////////////////////////////////////// |
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12 | // Implementation notes: |
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13 | // 1. the "lba" (Logical Block Address) is the physical sector index on |
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14 | // the block device. The physical sector size is supposed to be 512 bytes. |
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15 | // 2. the "cluster" variable is actually a cluster index. A cluster contains |
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16 | // typically 8 sectors (4K bytes) and the cluster index is a 32 bits word. |
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17 | // 2. This FAT32 library uses a FAT cache whose storage capacity is one |
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18 | // sector (512 bytes, or 128 cluster indexes in FAT) |
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19 | // 3. This FAT32 library can be used in four modes: BOOT_PA/BOOT_VA/KERNEL/USER |
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20 | // defining different behaviours for the IOC driver. |
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21 | ////////////////////////////////////////////////////////////////////////////////// |
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22 | |
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23 | #include <giet_config.h> |
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24 | #include <fat32.h> |
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25 | #include <tty_driver.h> |
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26 | #include <ioc_driver.h> |
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27 | #include <utils.h> |
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28 | |
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29 | ////////////////////////////////////////////////////////////////////////////////// |
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30 | // Global variable used by all FAT access functions |
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31 | ////////////////////////////////////////////////////////////////////////////////// |
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32 | |
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33 | __attribute__((section (".fatdata"))) |
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34 | fat32_fs_t fat __attribute__((aligned(512))); |
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35 | |
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36 | ////////////////////////////////////////////////////////////////////////////////// |
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37 | // This function displays the content of the FAT cache |
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38 | ////////////////////////////////////////////////////////////////////////////////// |
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39 | void display_fat_cache() |
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40 | { |
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41 | unsigned int line; |
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42 | unsigned int word; |
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43 | unsigned int temp[9]; |
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44 | |
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45 | temp[8] = 0; |
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46 | |
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47 | _printf("\n*********************** fat_cache_lba = %x *****************************\n", |
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48 | fat.cache_lba ); |
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49 | |
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50 | for ( line=0 ; line<16 ; line++ ) |
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51 | { |
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52 | // display line index |
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53 | _printf( "%x : ", line ); |
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54 | |
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55 | // display data hexa |
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56 | for ( word=0 ; word<8 ; word++ ) |
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57 | { |
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58 | unsigned int byte = (line<<5) + (word<<2); |
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59 | unsigned int hexa = (fat.fat_cache[byte ]<<24) | |
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60 | (fat.fat_cache[byte+1]<<16) | |
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61 | (fat.fat_cache[byte+2]<< 8) | |
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62 | (fat.fat_cache[byte+3]); |
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63 | _printf("%x | ", hexa ); |
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64 | |
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65 | // prepare display ascii |
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66 | temp[word] = fat.fat_cache[byte] | |
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67 | (fat.fat_cache[byte+1]<<8) | |
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68 | (fat.fat_cache[byte+2]<<16) | |
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69 | (fat.fat_cache[byte+3]<<24) ; |
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70 | } |
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71 | |
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72 | // display data ascii |
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73 | _printf( (char*)temp ); |
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74 | _printf("\n"); |
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75 | } |
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76 | _printf("**************************************************************************\n"); |
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77 | } // end display_fat_cache() |
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78 | |
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79 | ////////////////////////////////////////////////////////////////////////////////// |
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80 | // This function returns the length of a FAT field. This field is identified |
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81 | // man by an (offset,length) mnemonic defined in fat32.h file. |
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82 | ////////////////////////////////////////////////////////////////////////////////// |
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83 | static inline int get_length( int offset, |
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84 | int length) |
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85 | { |
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86 | return length; |
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87 | } |
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88 | |
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89 | ////////////////////////////////////////////////////////////////////////////// |
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90 | // Write one 32 bits word "value" in a char[] buffer. |
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91 | // This field is defined by the offset and size arguments. |
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92 | ////////////////////////////////////////////////////////////////////////////// |
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93 | static void write_entry( unsigned int offset, |
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94 | unsigned int size, |
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95 | char* buffer, |
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96 | unsigned int value ) |
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97 | { |
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98 | unsigned int turn = 0; |
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99 | unsigned int res = value; |
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100 | unsigned int mask = 0x000000ff; |
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101 | |
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102 | while( turn != size - 1 ) |
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103 | { |
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104 | buffer[ offset + turn ] = res & mask; |
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105 | res = res >> 8; |
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106 | turn++; |
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107 | } |
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108 | buffer[offset + turn] = res & mask; |
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109 | } |
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110 | |
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111 | ////////////////////////////////////////////////////////////////////////////// |
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112 | // Read one 32 bits word in a char[] buffer, taking endianness into account. |
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113 | // This field is defined by the offset and size arguments. |
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114 | ////////////////////////////////////////////////////////////////////////////// |
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115 | static unsigned int read_entry( unsigned int offset, |
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116 | unsigned int size, |
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117 | char* buffer, |
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118 | unsigned int little_indian ) |
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119 | { |
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120 | unsigned int turn; |
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121 | unsigned int res = 0; |
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122 | unsigned int mask = 0x000000ff; |
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123 | |
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124 | if( little_indian ) |
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125 | { |
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126 | turn = size; |
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127 | while( turn != 1 ) |
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128 | { |
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129 | res = res | (buffer[offset + (turn-1)] & mask); |
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130 | res = res << 8; |
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131 | turn--; |
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132 | } |
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133 | res = (buffer[offset + (turn-1)] & mask) | res; |
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134 | } |
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135 | else |
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136 | { |
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137 | turn = 0; |
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138 | while( turn != size - 1 ) |
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139 | { |
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140 | |
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141 | res = res | (buffer[ offset + turn ] & mask ); |
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142 | res = res << 8; |
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143 | turn++; |
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144 | } |
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145 | res = res | (buffer[offset + turn] & mask); |
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146 | } |
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147 | return res; |
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148 | } |
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149 | |
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150 | ////////////////////////////////////////////////////////////////////////////////// |
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151 | // This function retuns the cluster index from the lba of a DATA sector. |
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152 | // The lba must be larger than the lba of the first DATA sector. |
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153 | // The DATA region indexing starts a cluster 2. |
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154 | ////////////////////////////////////////////////////////////////////////////////// |
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155 | static inline unsigned int lba_to_cluster( unsigned int lba ) |
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156 | { |
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157 | if (lba < fat.data_lba ) return 0; |
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158 | |
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159 | return ( (lba - fat.data_lba) / fat.sectors_per_cluster) + 2; |
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160 | } |
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161 | |
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162 | ////////////////////////////////////////////////////////////////////////////////// |
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163 | // This function retuns the lba of first sector in DATA region |
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164 | // from the cluster index. The cluster index must be larger than 2. |
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165 | ////////////////////////////////////////////////////////////////////////////////// |
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166 | static inline unsigned int cluster_to_lba( unsigned int cluster ) |
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167 | { |
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168 | if ( cluster < 2 ) return 0; |
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169 | |
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170 | return (fat.sectors_per_cluster * (cluster - 2)) + fat.data_lba; |
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171 | } |
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172 | |
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173 | ///////////////////////////////////////////////////////////////////////////////// |
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174 | // This function search the FAT (using the FAT cache), and returns |
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175 | // the next cluster index from the current cluster index in the FAT. |
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176 | // remark: a sector of FAT contains 128 cluster indexes. |
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177 | ///////////////////////////////////////////////////////////////////////////////// |
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178 | static unsigned int get_next_cluster_id( unsigned int mode, |
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179 | unsigned int cluster ) |
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180 | { |
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181 | // compute lba of the sector containing the cluster index |
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182 | unsigned int lba = fat.fat_lba + (cluster / 128); |
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183 | |
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184 | if ( lba == fat.cache_lba ) // hit in cache |
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185 | { |
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186 | return read_entry( ((cluster % 128) * 4), |
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187 | 4, |
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188 | fat.fat_cache, |
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189 | 1 ); |
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190 | } |
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191 | else // miss in cache |
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192 | { |
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193 | // we cannot access fat in user mode |
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194 | if( mode == IOC_USER_MODE ) mode = IOC_KERNEL_MODE; |
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195 | |
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196 | // access fat |
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197 | if( _ioc_read( 0, // channel |
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198 | mode, // mode for IOC driver |
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199 | lba, // sector index |
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200 | fat.fat_cache, // fat cache |
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201 | 1 ) ) // one sector |
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202 | { |
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203 | _printf("[FAT_ERROR] in get_next cluster_id() " |
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204 | "cannot read block %x\n", lba ); |
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205 | return 1; |
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206 | } |
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207 | fat.cache_lba = lba; |
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208 | |
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209 | return read_entry( ((cluster % 128) * 4), |
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210 | 4, |
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211 | fat.fat_cache, |
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212 | 1 ); |
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213 | } |
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214 | } |
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215 | |
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216 | ////////////////////////////////////////////////////// |
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217 | static inline unsigned char to_upper(unsigned char c) |
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218 | { |
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219 | if (c >= 'a' && c <= 'z') return (c & ~(0x20)); |
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220 | else return c; |
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221 | } |
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222 | |
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223 | //////////////////////////////////////////////////////////////// |
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224 | // This function is a filter: |
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225 | // Return the c character if c is a legal short name character |
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226 | // Return the '_' character if c is illegal |
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227 | //////////////////////////////////////////////////////////////// |
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228 | static unsigned char illegal_short(unsigned char c) |
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229 | { |
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230 | const unsigned char illegal_char [] =";+=[]â,\"*\\<>/?:|\0"; |
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231 | short i = 0; |
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232 | while (illegal_char[i]!='\0') |
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233 | { |
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234 | if (c == illegal_char[i]) |
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235 | return '_'; |
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236 | i++; |
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237 | } |
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238 | return c; |
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239 | } |
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240 | |
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241 | ///////////////////////////////////////////////////////////////////////////////// |
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242 | // This function test if the string argument is a legal SFN (Short File Name) |
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243 | // and copies this name (removing the .) in the sfn_string argument. |
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244 | // Criteria for a Short File Name are: |
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245 | // - separator is '.' (extension is not mandatory) |
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246 | // - 1 <= name length <= 8 |
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247 | // - 0 <= extension length <= 3 |
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248 | // - no illegal character (see illega_short() function) |
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249 | // Return 1 if it string is a legal SFN |
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250 | // Return 0 if not legal SFN |
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251 | ///////////////////////////////////////////////////////////////////////////////// |
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252 | static int is_short( char* string, |
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253 | char* sfn_string) |
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254 | { |
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255 | int s_size = 0; |
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256 | int dot_ext = 0; // dot offset in the filename |
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257 | int name_len = 0; // length of file name |
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258 | int ext_len = 0; // length of extension |
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259 | int i = 0; |
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260 | int sc_i = 0; |
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261 | char ch; |
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262 | |
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263 | if(string[0] == '.' && string[1] == '\0') |
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264 | { |
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265 | sfn_string[0] = '.'; |
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266 | return 1; |
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267 | } |
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268 | if(string[0] == '.' && string[1] == '.' && string[2] == '\0') |
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269 | { |
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270 | sfn_string[0] = '.'; |
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271 | sfn_string[1] = '.'; |
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272 | return 1; |
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273 | } |
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274 | sfn_string[11] = '\0'; |
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275 | while (string[s_size] != '\0') |
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276 | { |
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277 | if (string[s_size] == '.') |
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278 | { |
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279 | dot_ext = s_size; |
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280 | ext_len = -1; |
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281 | } |
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282 | ext_len++; |
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283 | s_size++; |
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284 | } |
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285 | if (dot_ext != 0) |
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286 | { |
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287 | name_len = s_size - ext_len - 1; |
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288 | } |
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289 | else |
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290 | { |
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291 | name_len = s_size; |
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292 | ext_len = 0; |
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293 | } |
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294 | if ( ext_len > 3 || ( name_len > 8)) |
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295 | { |
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296 | return 0; |
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297 | } |
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298 | if (dot_ext != 0) |
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299 | { |
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300 | while (i != ext_len) |
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301 | { |
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302 | ch = to_upper(string[dot_ext + 1 + i]); |
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303 | ch = illegal_short(ch); |
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304 | sfn_string[8+i] = ch; |
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305 | i++; |
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306 | } |
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307 | } |
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308 | i = 0; |
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309 | sc_i = 0; |
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310 | while (i!= name_len) |
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311 | { |
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312 | ch = to_upper(string[i]); |
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313 | ch = illegal_short(ch); |
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314 | if (ch != '.') sfn_string[sc_i++] = ch; |
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315 | i++; |
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316 | } |
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317 | return 1; |
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318 | } |
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319 | |
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320 | /////////////////////////////////////////////////////////////////////// |
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321 | // This function analyses the pathname argument, from the character |
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322 | // defined by the *nb_read argument. |
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323 | // It copies the found name (between '/') in the name[] buffer, |
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324 | // and updates the nb_read argument. |
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325 | // Return 1 if name found, Return 0 if NUL character found, |
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326 | /////////////////////////////////////////////////////////////////////// |
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327 | static int get_name_from_path( char* pathname, |
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328 | char* name, |
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329 | unsigned int* nb_read ) |
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330 | { |
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331 | if ( pathname[*nb_read] == 0 ) return 0; |
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332 | |
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333 | int i = (pathname[*nb_read] == '/')? (*nb_read) + 1 : *nb_read; |
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334 | int j = 0; |
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335 | |
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336 | while(pathname[i] != '/' && pathname[i] != '\0') |
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337 | { |
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338 | name[j] = pathname[i]; |
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339 | j++; |
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340 | i++; |
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341 | } |
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342 | name[j] = 0; |
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343 | |
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344 | if ( pathname[i] == '/' ) *nb_read += j+1; |
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345 | else *nb_read += j; |
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346 | |
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347 | return 1; |
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348 | } |
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349 | |
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350 | //////////////////////////////////////////////////////////////////////////////// |
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351 | static int get_name_from_short( char* dir_entry, // input: SFN dir_entry |
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352 | char* entry_name ) // output: name |
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353 | { |
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354 | unsigned int i = 0; |
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355 | unsigned int length = get_length(DIR_NAME); |
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356 | |
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357 | while ( i < length ) |
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358 | { |
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359 | entry_name[i] = dir_entry[i]; |
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360 | i++; |
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361 | } |
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362 | entry_name[i] = '\0'; |
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363 | |
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364 | return i; |
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365 | } |
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366 | |
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367 | /////////////////////////////////////////////////////////////////////////////// |
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368 | static int get_name_from_long( char *dir_entry, // input : LFN dir_entry |
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369 | char *entry_name ) // output : name |
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370 | { |
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371 | unsigned int entry_name_offset = 0; |
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372 | unsigned int dir_entry_offset = get_length(LDIR_ORD); |
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373 | unsigned int l_name_1 = get_length(LDIR_NAME_1); |
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374 | unsigned int l_name_2 = get_length(LDIR_NAME_2); |
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375 | unsigned int l_name_3 = get_length(LDIR_NAME_3); |
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376 | unsigned int l_attr = get_length(LDIR_ATTR); |
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377 | unsigned int l_type = get_length(LDIR_TYPE); |
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378 | unsigned int l_chksum = get_length(LDIR_CHKSUM); |
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379 | unsigned int l_rsvd = get_length(LDIR_RSVD); |
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380 | |
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381 | unsigned int j = 0; |
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382 | unsigned int eof = 0; |
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383 | |
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384 | while ( (dir_entry_offset != DIR_ENTRY_SIZE) && (!eof) ) |
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385 | { |
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386 | while (j != l_name_1 && !eof ) |
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387 | { |
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388 | if ( (dir_entry[dir_entry_offset] == 0x00) || |
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389 | (dir_entry[dir_entry_offset] == 0xFF) ) |
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390 | { |
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391 | eof = 1; |
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392 | continue; |
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393 | } |
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394 | entry_name[entry_name_offset] = dir_entry[dir_entry_offset]; |
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395 | dir_entry_offset += 2; |
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396 | j += 2; |
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397 | entry_name_offset++; |
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398 | } |
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399 | |
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400 | dir_entry_offset += (l_attr + l_type + l_chksum); |
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401 | j = 0; |
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402 | |
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403 | while (j != l_name_2 && !eof ) |
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404 | { |
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405 | if ( (dir_entry[dir_entry_offset] == 0x00) || |
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406 | (dir_entry[dir_entry_offset] == 0xFF) ) |
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407 | { |
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408 | eof = 1; |
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409 | continue; |
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410 | } |
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411 | entry_name[entry_name_offset] = dir_entry[dir_entry_offset]; |
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412 | dir_entry_offset += 2; |
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413 | j += 2; |
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414 | entry_name_offset++; |
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415 | } |
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416 | |
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417 | dir_entry_offset += l_rsvd; |
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418 | j = 0; |
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419 | |
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420 | while (j != l_name_3 && !eof ) |
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421 | { |
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422 | if ( (dir_entry[dir_entry_offset] == 0x00) || |
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423 | (dir_entry[dir_entry_offset] == 0xFF) ) |
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424 | { |
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425 | eof = 1; |
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426 | continue; |
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427 | } |
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428 | entry_name[entry_name_offset] = dir_entry[dir_entry_offset]; |
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429 | dir_entry_offset += 2; |
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430 | j += 2; |
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431 | entry_name_offset++; |
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432 | } |
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433 | } |
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434 | entry_name[entry_name_offset] = '\0'; |
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435 | |
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436 | return entry_name_offset; |
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437 | } // end get_name_from_long() |
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438 | |
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439 | ////////////////////////////////////////////////////////////////////////////////////// |
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440 | // This function update a DIR_ENTRY, write a new value into a specific field |
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441 | // (ex : DIR_FILE_SIZE, when we want update the file size after a fat_write) |
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442 | // Return 0 in case of success, > 0 if failure. |
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443 | ////////////////////////////////////////////////////////////////////////////////////// |
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444 | // TODO : make this function less complex |
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445 | ////////////////////////////////////////////////////////////////////////////////////// |
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446 | static inline unsigned int update_entry( unsigned int fd_id, |
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447 | unsigned int field, |
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448 | unsigned int size, |
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449 | unsigned int value ) |
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450 | { |
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451 | char dir_entry[32]; // buffer to store a full directory_entry |
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452 | char name_entry[14]; // buffer to store a 13 characters (partial) name |
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453 | char file_name[256]; // buffer to store the name (not pathname) of the file |
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454 | char sfn[12] = {[0 ... 10] = ' ', '\0'}; // buffer for a Short File Name |
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455 | |
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456 | unsigned int lba = fat.fd[fd_id].lba_dir_entry; // Lba of file dir_entry |
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457 | unsigned int is_sfn; |
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458 | unsigned int attr = 0; // directory entry attribute |
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459 | unsigned int ord = 0; // directory entry sequence |
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460 | unsigned int found = 0; // name found |
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461 | unsigned int offset = 0; |
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462 | unsigned int i = 0; |
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463 | unsigned int nb_read = 0; |
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464 | |
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465 | for ( i = 0 ; i < 32 ; i++ ) dir_entry[i] = 0; |
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466 | for ( i = 0 ; i < 14 ; i++ ) name_entry[i] = 0; |
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467 | |
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468 | // Get the name of the file. |
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469 | while ( get_name_from_path( fat.fd[fd_id].name, file_name, &nb_read ) ) |
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470 | { |
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471 | } |
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472 | |
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473 | // Check if file_name is short |
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474 | is_sfn = is_short( file_name, sfn ); |
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475 | |
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476 | if ( _ioc_read( 0, // channel |
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477 | IOC_KERNEL_MODE, // mode for IOC driver |
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478 | lba, // sector index |
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479 | fat.fat_cache, // buffer address |
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480 | 1 ) ) // one sector |
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481 | { |
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482 | _printf("[FAT ERROR] in update_entry() cannot read sector %x\n", lba ); |
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483 | return 1; |
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484 | } |
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485 | fat.cache_lba = lba; |
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486 | |
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487 | // - the offset increment is an integer number of directory entry (32 bytes) |
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488 | // - the exit condition is success (name found) or failure (end of directory) |
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489 | while ( !found ) |
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490 | { |
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491 | attr = read_entry( DIR_ATTR, fat.fat_cache + offset, 0 ); |
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492 | ord = read_entry( LDIR_ORD, fat.fat_cache + offset, 0 ); |
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493 | |
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494 | if ( is_sfn == 1 ) // searched name is short |
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495 | { |
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496 | if ( (ord != FREE_ENTRY ) && |
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497 | (ord != NO_MORE_ENTRY) && |
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498 | (attr == ATTR_LONG_NAME_MASK) ) // LFN entry : skipped |
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499 | { |
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500 | offset = offset + ((ord & 0xF) * DIR_ENTRY_SIZE); |
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501 | continue; |
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502 | } |
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503 | else if ( (attr != ATTR_LONG_NAME_MASK) && |
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504 | (ord != FREE_ENTRY) && |
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505 | (ord != NO_MORE_ENTRY ) ) // SFN entry : checked |
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506 | { |
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507 | memcpy( dir_entry, fat.fat_cache + offset, DIR_ENTRY_SIZE ); |
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508 | } |
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509 | else if (ord == NO_MORE_ENTRY ) // end of directory : return |
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510 | { |
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511 | _printf("[FAT ERROR] in update_entry() : reaches end of directory\n"); |
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512 | return 1; |
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513 | } |
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514 | else // free entry : skipped |
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515 | { |
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516 | offset = offset + DIR_ENTRY_SIZE; |
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517 | continue; |
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518 | } |
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519 | } |
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520 | else // searched name is long |
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521 | { |
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522 | if ( (attr == ATTR_LONG_NAME_MASK) && |
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523 | (ord != FREE_ENTRY) && |
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524 | (ord != NO_MORE_ENTRY) ) // LFN entry : checked |
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525 | { |
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526 | memcpy( dir_entry, fat.fat_cache + offset, DIR_ENTRY_SIZE ); |
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527 | } |
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528 | else if ( (attr != ATTR_LONG_NAME_MASK) && |
---|
529 | (ord != FREE_ENTRY) && |
---|
530 | (ord != NO_MORE_ENTRY)) // SFN entry : skipped |
---|
531 | { |
---|
532 | offset = offset + DIR_ENTRY_SIZE; |
---|
533 | continue; |
---|
534 | } |
---|
535 | else if (ord == NO_MORE_ENTRY ) // end of directory : return |
---|
536 | { |
---|
537 | _printf("[FAT ERROR] in update_entry() reaches end of directory\n"); |
---|
538 | return 1; |
---|
539 | } |
---|
540 | else // free entry : skipped |
---|
541 | { |
---|
542 | offset = offset + DIR_ENTRY_SIZE; |
---|
543 | continue; |
---|
544 | } |
---|
545 | } |
---|
546 | |
---|
547 | // testing the name extracted from dir entry |
---|
548 | |
---|
549 | if ( is_sfn == 1 ) // searched name is short |
---|
550 | { |
---|
551 | get_name_from_short( dir_entry, name_entry ); |
---|
552 | |
---|
553 | if ( _strncmp( (char*)sfn, (char*)name_entry, 13 ) == 0 ) |
---|
554 | { |
---|
555 | write_entry(offset + field, size, fat.fat_cache, value); |
---|
556 | found = 1; |
---|
557 | } |
---|
558 | else // no matching : skip |
---|
559 | { |
---|
560 | offset = offset + DIR_ENTRY_SIZE; |
---|
561 | } |
---|
562 | } |
---|
563 | else // searched name is long |
---|
564 | { |
---|
565 | get_name_from_long( dir_entry, name_entry ); |
---|
566 | |
---|
567 | unsigned shift = ((ord & 0xf) - 1) * 13; |
---|
568 | if ( _strncmp( (char*)(file_name + shift), (char*)name_entry, 13 ) == 0 ) |
---|
569 | { |
---|
570 | if ( (ord & 0xf) == 1 ) |
---|
571 | { |
---|
572 | offset = offset + DIR_ENTRY_SIZE; |
---|
573 | write_entry(offset + field, size, fat.fat_cache, value); |
---|
574 | found = 1; |
---|
575 | } |
---|
576 | offset = offset + DIR_ENTRY_SIZE; |
---|
577 | continue; |
---|
578 | } |
---|
579 | else // no matching : skip |
---|
580 | { |
---|
581 | offset = offset + ((ord & 0xf) * DIR_ENTRY_SIZE) + DIR_ENTRY_SIZE; |
---|
582 | } |
---|
583 | } |
---|
584 | } |
---|
585 | |
---|
586 | return _ioc_write( 0, // channel |
---|
587 | IOC_KERNEL_MODE, // mode |
---|
588 | lba, // sector index |
---|
589 | fat.fat_cache, // source buffer |
---|
590 | 1 ); // one sector |
---|
591 | } |
---|
592 | ////////////////////////////////////////////////////////////////////////////////// |
---|
593 | // This function update FS_INFO: |
---|
594 | // last cluster allocated and number of free cluster. |
---|
595 | // Return 0 in case of success, > 0 if failure. |
---|
596 | ////////////////////////////////////////////////////////////////////////////////// |
---|
597 | static inline unsigned int update_fs_info( ) |
---|
598 | { |
---|
599 | unsigned int lba = fat.fs_info_lba; |
---|
600 | |
---|
601 | #if GIET_DEBUG_FAT |
---|
602 | _printf("\n[FAT DEBUG] Enter update_fs_info()\n"); |
---|
603 | #endif |
---|
604 | |
---|
605 | if ( lba == fat.cache_lba ) // hit cache |
---|
606 | { |
---|
607 | write_entry( FS_FREE_CLUSTER , fat.fat_cache, fat.number_free_cluster ); |
---|
608 | write_entry( FS_FREE_CLUSTER_HINT, fat.fat_cache, fat.last_cluster_allocated ); |
---|
609 | } |
---|
610 | else // miss cache |
---|
611 | { |
---|
612 | if ( _ioc_read( 0, // channel |
---|
613 | IOC_KERNEL_MODE, // mode for IOC driver |
---|
614 | lba, // sector index |
---|
615 | fat.fat_cache, // source buffer |
---|
616 | 1 ) ) // one sector |
---|
617 | { |
---|
618 | _printf("[FAT_ERROR] in update_fat() cannot read block %x\n", lba ); |
---|
619 | return 1; |
---|
620 | } |
---|
621 | fat.cache_lba = lba; |
---|
622 | write_entry( FS_FREE_CLUSTER , fat.fat_cache, fat.number_free_cluster ); |
---|
623 | write_entry( FS_FREE_CLUSTER_HINT, fat.fat_cache, fat.last_cluster_allocated ); |
---|
624 | } |
---|
625 | return _ioc_write( 0, // channel |
---|
626 | IOC_KERNEL_MODE, // mode |
---|
627 | lba, // sector index |
---|
628 | fat.fat_cache, // source buffer |
---|
629 | 1 ); // one sector |
---|
630 | } |
---|
631 | |
---|
632 | ////////////////////////////////////////////////////////////////////////////////// |
---|
633 | // This function update FAT, write a new value into cluster index. |
---|
634 | // Used by the function _fat_allocate to update the chaining of clusters. |
---|
635 | // Return 0 in case of success, > 0 if failure. |
---|
636 | ////////////////////////////////////////////////////////////////////////////////// |
---|
637 | static inline unsigned int update_fat( unsigned int cluster, |
---|
638 | unsigned int value ) |
---|
639 | { |
---|
640 | unsigned int lba = fat.fat_lba + (cluster / 128); |
---|
641 | |
---|
642 | #if GIET_DEBUG_FAT |
---|
643 | _printf("\n[FAT DEBUG] Enter update_fat() : cluster = %x / value = %x\n", |
---|
644 | cluster, value ); |
---|
645 | #endif |
---|
646 | |
---|
647 | if ( lba == fat.cache_lba ) // hit cache |
---|
648 | { |
---|
649 | write_entry( ((cluster % 128) << 2), 4, fat.fat_cache, value ); |
---|
650 | } |
---|
651 | else // miss cache |
---|
652 | { |
---|
653 | if ( _ioc_read( 0, // channel |
---|
654 | IOC_KERNEL_MODE, // mode for IOC driver |
---|
655 | lba, // sector index |
---|
656 | fat.fat_cache, // source buffer |
---|
657 | 1 ) ) // one sector |
---|
658 | { |
---|
659 | _printf("[FAT_ERROR] in update_fat() cannot read block %x\n"); |
---|
660 | return 1; |
---|
661 | } |
---|
662 | fat.cache_lba = lba; |
---|
663 | write_entry( ((cluster % 128) << 2), 4, fat.fat_cache, value ); |
---|
664 | } |
---|
665 | return _ioc_write( 0, // channel |
---|
666 | IOC_KERNEL_MODE, // mode |
---|
667 | lba, // sector indexs |
---|
668 | fat.fat_cache, // source buffer |
---|
669 | 1 ); // one sector |
---|
670 | } |
---|
671 | |
---|
672 | ////////////////////////////////////////////////////////////////////////////////// |
---|
673 | // This function allocate a count number of cluster to a file by calling the |
---|
674 | // update_fat function that takes care to update the chaining of clusters. |
---|
675 | // return 0 if success, -1 if failure |
---|
676 | ////////////////////////////////////////////////////////////////////////////////// |
---|
677 | static inline int _fat_allocate( unsigned int fd_id, |
---|
678 | unsigned int count ) |
---|
679 | { |
---|
680 | unsigned int next_cluster = fat.fd[fd_id].first_cluster; // Get the first cluster of file |
---|
681 | unsigned int cluster_to_allocate = count; // Number of cluster to allocate |
---|
682 | |
---|
683 | unsigned int last_cluster_file; // Last cluster of the file (EOC) |
---|
684 | |
---|
685 | unsigned int free_cluster = fat.last_cluster_allocated + 1; // First free cluster |
---|
686 | |
---|
687 | // Check if free_cluster is really free (must be true) |
---|
688 | if ( get_next_cluster_id( IOC_KERNEL_MODE, free_cluster ) != FREE_CLUSTER) |
---|
689 | { |
---|
690 | _printf("\n[FAT ERROR] in _fat_allocate() : first free_cluster not free\n"); |
---|
691 | return -1; |
---|
692 | } |
---|
693 | // Check if FAT contains enough cluster free for this allocation |
---|
694 | if ( count > fat.number_free_cluster ) |
---|
695 | { |
---|
696 | _printf("\n[FAT ERROR] in _fat_allocate() : Not enough free cluster(s)\n"); |
---|
697 | return -1; |
---|
698 | } |
---|
699 | |
---|
700 | #if GIET_DEBUG_FAT |
---|
701 | _printf("\n[FAT DEBUG] Enter in _fat_allocate() for file %d\n", fd_id ); |
---|
702 | #endif |
---|
703 | |
---|
704 | // Get the last cluster allocated for the file (seek END_OF_CHAIN_CLUSTER). |
---|
705 | do{ |
---|
706 | last_cluster_file = next_cluster; |
---|
707 | next_cluster = get_next_cluster_id( IOC_KERNEL_MODE, next_cluster ); |
---|
708 | }while ( next_cluster < END_OF_CHAIN_CLUSTER ); |
---|
709 | |
---|
710 | // Loop on the number of cluster needed to be allocated |
---|
711 | while ( cluster_to_allocate > 0 ) |
---|
712 | { |
---|
713 | |
---|
714 | #if GIET_DEBUG_FAT |
---|
715 | _printf("\n[FAT DEBUG] cluster to update = %x / free cluster = %x / clusters required = %d\n", |
---|
716 | last_cluster_file, free_cluster, cluster_to_allocate ); |
---|
717 | #endif |
---|
718 | |
---|
719 | // update, in the FAT, the value of last cluster allocated by the index |
---|
720 | // of free cluster. |
---|
721 | if ( update_fat( last_cluster_file, free_cluster ) ) |
---|
722 | { |
---|
723 | _printf("\n[FAT ERROR] in _fat_allocate() : update fat failed\n"); |
---|
724 | return -1; |
---|
725 | } |
---|
726 | |
---|
727 | cluster_to_allocate = cluster_to_allocate - 1; |
---|
728 | // Last cluster allocated is then free_cluster |
---|
729 | last_cluster_file = free_cluster; |
---|
730 | |
---|
731 | // Last cluster to allocate done, then we must close the chain of clusters |
---|
732 | if ( cluster_to_allocate == 0 ) |
---|
733 | { |
---|
734 | // update, in the FAT, the value of the last cluster allocated by |
---|
735 | // END_OF_CHAIN_CLUSTER |
---|
736 | if ( update_fat( last_cluster_file, END_OF_CHAIN_CLUSTER ) ) |
---|
737 | { |
---|
738 | _printf("\n[FAT ERROR] in _fat_allocate() : update fat failed\n"); |
---|
739 | return -1; |
---|
740 | } |
---|
741 | } |
---|
742 | |
---|
743 | free_cluster = free_cluster + 1; |
---|
744 | |
---|
745 | // Check if free_cluster is really free (must be true) |
---|
746 | if ( get_next_cluster_id( IOC_KERNEL_MODE, free_cluster ) != FREE_CLUSTER) |
---|
747 | { |
---|
748 | _printf("\n[FAT ERROR] in _fat_allocate() : free_cluster not free\n"); |
---|
749 | return -1; |
---|
750 | } |
---|
751 | } |
---|
752 | |
---|
753 | // Update field number_free_cluster and last_cluster_allocated |
---|
754 | // of structure fat for next fat_allocate |
---|
755 | fat.last_cluster_allocated = last_cluster_file; |
---|
756 | fat.number_free_cluster = fat.number_free_cluster - count; |
---|
757 | |
---|
758 | if ( update_fs_info() ) |
---|
759 | { |
---|
760 | _printf("\n[FAT ERROR] in _fat_allocate() : update fs_info failed\n"); |
---|
761 | return -1; |
---|
762 | } |
---|
763 | |
---|
764 | return 0; |
---|
765 | } |
---|
766 | |
---|
767 | /////////////////////////////////////////////////////////////////////////////// |
---|
768 | // This function returns the cluster index from a (32 bytes) directory entry |
---|
769 | /////////////////////////////////////////////////////////////////////////////// |
---|
770 | static inline unsigned int read_cluster( char* buf ) |
---|
771 | { |
---|
772 | unsigned int cluster = read_entry( DIR_FST_CLUS_HI, buf, 1 ) << 16; |
---|
773 | cluster = cluster | read_entry( DIR_FST_CLUS_LO, buf, 1 ); |
---|
774 | return cluster; |
---|
775 | } |
---|
776 | |
---|
777 | |
---|
778 | //////////////////////////////////////////////////////////////////////////////////////// |
---|
779 | // This function read the blocks defined by the cluster index argument, in a data |
---|
780 | // region containing a directory to search the name of a file/firectory, |
---|
781 | // and returns the cluster index of the file/directory when the name has been found. |
---|
782 | // Return cluster index if name found / Return -1 if not found, |
---|
783 | //////////////////////////////////////////////////////////////////////////////////////// |
---|
784 | static int scan_directory( unsigned int mode, // mode for IOC driver |
---|
785 | unsigned int cluster, // cluster containing dir_entry |
---|
786 | char* file_name, // searched file/directory name |
---|
787 | unsigned int* file_size, // file size |
---|
788 | unsigned int* lba_dir_entry ) // lba of dir_entry |
---|
789 | { |
---|
790 | |
---|
791 | #if GIET_DEBUG_FAT |
---|
792 | _printf("\n[FAT DEBUG] enters _scan_directory() for dir/file %s\n", file_name ); |
---|
793 | #endif |
---|
794 | |
---|
795 | char dir_entry[32]; // buffer to store a full directory_entry |
---|
796 | char name_entry[14]; // buffer to store a 13 characters (partial) name |
---|
797 | |
---|
798 | char sfn[12] = {[0 ... 10] = ' ', '\0'}; // buffer for a Short File Name |
---|
799 | unsigned int is_sfn = is_short(file_name, sfn); // if file_name is short, sfn = 1 |
---|
800 | unsigned int offset = 0; // byte offset in block |
---|
801 | unsigned int block_id = fat.sectors_per_cluster; // sector index initialisation |
---|
802 | unsigned int lba = cluster_to_lba(cluster); |
---|
803 | unsigned int attr = 0; // directory entry attribute |
---|
804 | unsigned int ord = 0; // directory entry sequence |
---|
805 | unsigned int found = 0; // name found |
---|
806 | unsigned int i; |
---|
807 | |
---|
808 | for( i = 0 ; i < 32 ; i++ ) dir_entry[i] = 0; |
---|
809 | for( i = 0 ; i < 14 ; i++ ) name_entry[i] = 0; |
---|
810 | |
---|
811 | // load first cluster sector from DATA region into FAT cache |
---|
812 | // other sectors will be loaded inside loop as required |
---|
813 | if( _ioc_read( 0, // channel |
---|
814 | mode, // mode for IOC driver |
---|
815 | lba, // sector index |
---|
816 | fat.fat_cache, // buffer address |
---|
817 | 1 ) ) // one sector |
---|
818 | { |
---|
819 | _printf("[FAT ERROR] in scan directory() cannot read sector %x\n", lba ); |
---|
820 | return -1; |
---|
821 | } |
---|
822 | |
---|
823 | fat.cache_lba = lba; |
---|
824 | |
---|
825 | #if ( GIET_DEBUG_FAT > 1 ) |
---|
826 | display_fat_cache(); |
---|
827 | #endif |
---|
828 | |
---|
829 | // in this loop we scan all names in directory identified by cluster: |
---|
830 | // - the offset increment is an integer number of directory entry (32 bytes) |
---|
831 | // - the exit condition is success (name found) or failure (end of directory) |
---|
832 | while( 1 ) |
---|
833 | { |
---|
834 | // load a new sector if required |
---|
835 | if (offset >= 512) |
---|
836 | { |
---|
837 | if ( block_id ) // not a new cluster |
---|
838 | { |
---|
839 | lba += 1; |
---|
840 | block_id --; |
---|
841 | } |
---|
842 | else // get next cluster |
---|
843 | { |
---|
844 | cluster = get_next_cluster_id( mode, cluster ); |
---|
845 | |
---|
846 | if ( cluster >= END_OF_CHAIN_CLUSTER ) return END_OF_CHAIN_CLUSTER; |
---|
847 | |
---|
848 | lba = cluster_to_lba(cluster); |
---|
849 | block_id = fat.sectors_per_cluster; |
---|
850 | } |
---|
851 | if( _ioc_read( 0, // channel |
---|
852 | mode, // mode for IOC driver |
---|
853 | lba, // sector index |
---|
854 | fat.fat_cache, // buffer address |
---|
855 | 1 ) ) // one sector |
---|
856 | { |
---|
857 | _printf("[FAT ERROR] in scan directory() cannot read sector %x\n", lba ); |
---|
858 | return -1; |
---|
859 | } |
---|
860 | fat.cache_lba = lba; |
---|
861 | block_id--; |
---|
862 | offset = offset % 512; |
---|
863 | } |
---|
864 | |
---|
865 | // analyse a directory entry (pointed by fat.fat_cache + offset) |
---|
866 | if ( !found ) |
---|
867 | { |
---|
868 | attr = read_entry( DIR_ATTR, fat.fat_cache + offset, 0); |
---|
869 | ord = read_entry( LDIR_ORD, fat.fat_cache + offset, 0); |
---|
870 | |
---|
871 | if ( is_sfn == 1 ) // searched name is short |
---|
872 | { |
---|
873 | if ( (ord != FREE_ENTRY ) && |
---|
874 | (ord != NO_MORE_ENTRY) && |
---|
875 | (attr == ATTR_LONG_NAME_MASK) ) // LFN entry : skipped |
---|
876 | { |
---|
877 | offset = offset + ((ord & 0xF) * DIR_ENTRY_SIZE); |
---|
878 | continue; |
---|
879 | } |
---|
880 | else if ( (attr != ATTR_LONG_NAME_MASK) && |
---|
881 | (ord != FREE_ENTRY) && |
---|
882 | (ord != NO_MORE_ENTRY ) ) // SFN entry : checked |
---|
883 | { |
---|
884 | memcpy( dir_entry, fat.fat_cache + offset, DIR_ENTRY_SIZE ); |
---|
885 | offset = offset + DIR_ENTRY_SIZE; |
---|
886 | } |
---|
887 | else if (ord == NO_MORE_ENTRY ) // end of directory : return |
---|
888 | { |
---|
889 | return END_OF_CHAIN_CLUSTER; |
---|
890 | } |
---|
891 | else // free entry : skipped |
---|
892 | { |
---|
893 | offset = offset + DIR_ENTRY_SIZE; |
---|
894 | continue; |
---|
895 | } |
---|
896 | } |
---|
897 | else // searched name is long |
---|
898 | { |
---|
899 | if( (attr == ATTR_LONG_NAME_MASK) && |
---|
900 | (ord != FREE_ENTRY) && |
---|
901 | (ord != NO_MORE_ENTRY) ) // LFN entry : checked |
---|
902 | { |
---|
903 | memcpy( dir_entry, fat.fat_cache + offset, DIR_ENTRY_SIZE ); |
---|
904 | offset = offset + DIR_ENTRY_SIZE; |
---|
905 | } |
---|
906 | else if( (attr != ATTR_LONG_NAME_MASK) && |
---|
907 | (ord != FREE_ENTRY) && |
---|
908 | (ord != NO_MORE_ENTRY)) // SFN entry : skipped |
---|
909 | { |
---|
910 | offset = offset + DIR_ENTRY_SIZE; |
---|
911 | continue; |
---|
912 | } |
---|
913 | else if (ord == NO_MORE_ENTRY ) // end of director : return |
---|
914 | { |
---|
915 | return END_OF_CHAIN_CLUSTER; |
---|
916 | } |
---|
917 | else // free entry : skipped |
---|
918 | { |
---|
919 | offset = offset + DIR_ENTRY_SIZE; |
---|
920 | continue; |
---|
921 | } |
---|
922 | } |
---|
923 | |
---|
924 | // testing the name extracted from dir entry |
---|
925 | if ( is_sfn == 1 ) // searched name is short |
---|
926 | { |
---|
927 | get_name_from_short( dir_entry, name_entry ); |
---|
928 | |
---|
929 | if ( _strncmp( (char*)sfn, (char*)name_entry, 13 ) == 0 ) |
---|
930 | { |
---|
931 | *file_size = read_entry( DIR_FILE_SIZE , dir_entry, 1 ); |
---|
932 | *lba_dir_entry = lba; |
---|
933 | return read_cluster( dir_entry ); |
---|
934 | } |
---|
935 | } |
---|
936 | else // searched name is long |
---|
937 | { |
---|
938 | get_name_from_long( dir_entry, name_entry ); |
---|
939 | |
---|
940 | unsigned shift = ((ord & 0xf) - 1) * 13; |
---|
941 | if ( _strncmp( (char*)(file_name + shift), (char*)name_entry, 13 ) == 0 ) |
---|
942 | { |
---|
943 | if( (ord & 0xf) == 1 ) found = 1; |
---|
944 | continue; |
---|
945 | } |
---|
946 | else // no matching : skip |
---|
947 | { |
---|
948 | offset = offset + ((ord & 0xf) * DIR_ENTRY_SIZE); |
---|
949 | } |
---|
950 | } |
---|
951 | } |
---|
952 | else // file found |
---|
953 | { |
---|
954 | memcpy( dir_entry, fat.fat_cache + offset, DIR_ENTRY_SIZE ); |
---|
955 | offset = offset + DIR_ENTRY_SIZE; |
---|
956 | *file_size = read_entry( DIR_FILE_SIZE, dir_entry, 1 ); |
---|
957 | *lba_dir_entry = lba; |
---|
958 | |
---|
959 | return read_cluster( dir_entry ); |
---|
960 | } |
---|
961 | } |
---|
962 | return -1; |
---|
963 | } // end scan_directory() |
---|
964 | |
---|
965 | |
---|
966 | ////////////////////////////////////////////////////////////////////// |
---|
967 | // This function create a new entry in a directory identified |
---|
968 | // by "dir_cluster". The name is defined by "name". |
---|
969 | // The type (dir/file) is defined by "is_file". |
---|
970 | // Returns cluster index if success, Returns -1 if error. |
---|
971 | ////////////////////////////////////////////////////////////////////// |
---|
972 | static int fat_create( char* name, |
---|
973 | unsigned int is_file, |
---|
974 | unsigned int dir_cluster ) |
---|
975 | { |
---|
976 | _printf("\n[FAT ERROR] _fat_create() not implemented\n"); |
---|
977 | return 0; |
---|
978 | } //end _fat_create() |
---|
979 | |
---|
980 | |
---|
981 | |
---|
982 | ////////////// Extern functions ////////////////////////////////////////// |
---|
983 | |
---|
984 | ////////////////////////////////////////////////////////////////////////// |
---|
985 | // This function initializes the FAT structure, including the |
---|
986 | // files descriptors array, from informations found in the boot record. |
---|
987 | ////////////////////////////////////////////////////////////////////////// |
---|
988 | // Return 0 if success, Return -1 if failure |
---|
989 | ////////////////////////////////////////////////////////////////////////// |
---|
990 | int _fat_init( unsigned int mode ) // mode for IOC driver |
---|
991 | { |
---|
992 | unsigned int n; |
---|
993 | |
---|
994 | #if GIET_DEBUG_FAT |
---|
995 | unsigned int procid = _get_procid(); |
---|
996 | unsigned int cid = procid / NB_PROCS_MAX; |
---|
997 | unsigned int lpid = procid % NB_PROCS_MAX; |
---|
998 | unsigned int x = cid >> Y_WIDTH; |
---|
999 | unsigned int y = cid & ((1<<Y_WIDTH) - 1); |
---|
1000 | |
---|
1001 | _printf("\n[FAT DEBUG] Processor[%d,%d,%d] enters _fat_init()\n", |
---|
1002 | x, y, lpid ); |
---|
1003 | #endif |
---|
1004 | |
---|
1005 | // load Boot Record (VBR) into fat cache |
---|
1006 | if ( _ioc_read( 0, // channel |
---|
1007 | mode, // mode for IOC driver |
---|
1008 | 0, // sector index |
---|
1009 | fat.fat_cache, // buffer address |
---|
1010 | 1 ) ) // one sector |
---|
1011 | { |
---|
1012 | _printf("\n[FAT ERROR] in _fat_init() cannot load VBR\n"); |
---|
1013 | return -1; |
---|
1014 | } |
---|
1015 | fat.cache_lba = 0; |
---|
1016 | |
---|
1017 | #if GIET_DEBUG_FAT |
---|
1018 | _printf("\n[FAT DEBUG] Boot Sector Loaded\n"); |
---|
1019 | #endif |
---|
1020 | |
---|
1021 | // checking various FAT32 assuptions from boot sector |
---|
1022 | if( read_entry( BPB_BYTSPERSEC, fat.fat_cache, 1 ) != 512 ) |
---|
1023 | { |
---|
1024 | _printf("\n[FAT ERROR] The sector size must be 512 bytes\n"); |
---|
1025 | return -1; |
---|
1026 | } |
---|
1027 | if( read_entry( BPB_NUMFATS, fat.fat_cache, 1 ) != 1 ) |
---|
1028 | { |
---|
1029 | _printf("\n[FAT ERROR] The number of FAT copies in FAT region must be 1\n"); |
---|
1030 | return -1; |
---|
1031 | } |
---|
1032 | if( (read_entry( BPB_FAT32_FATSZ32, fat.fat_cache, 1 ) & 0xF) != 0 ) |
---|
1033 | { |
---|
1034 | _printf("\n[FAT ERROR] The FAT region in FAT32 must be multiple of 32 sectors\n"); |
---|
1035 | return -1; |
---|
1036 | } |
---|
1037 | if( read_entry( BPB_FAT32_ROOTCLUS, fat.fat_cache, 1 ) != 2 ) |
---|
1038 | { |
---|
1039 | _printf("\n[FAT ERROR] The first cluster index must be 2\n"); |
---|
1040 | return -1; |
---|
1041 | } |
---|
1042 | // FS Info always in sector 1 |
---|
1043 | fat.fs_info_lba = read_entry( BPB_FAT32_FSINFO, fat.fat_cache, 1 ); |
---|
1044 | |
---|
1045 | // initialise fat descriptor from VBR |
---|
1046 | fat.sectors_per_cluster = read_entry( BPB_SECPERCLUS, fat.fat_cache, 1 ); |
---|
1047 | fat.sector_size = read_entry( BPB_BYTSPERSEC, fat.fat_cache, 1 ); |
---|
1048 | fat.cluster_size = fat.sectors_per_cluster * 512; |
---|
1049 | fat.fat_sectors = read_entry( BPB_FAT32_FATSZ32, fat.fat_cache, 1 ); |
---|
1050 | fat.fat_lba = read_entry( BPB_RSVDSECCNT, fat.fat_cache, 1 ); |
---|
1051 | fat.data_lba = fat.fat_lba + fat.fat_sectors; |
---|
1052 | fat.fat_lock.value = 0; |
---|
1053 | fat.initialised = FAT_INITIALISED; |
---|
1054 | |
---|
1055 | // initialise file descriptor array |
---|
1056 | for( n = 0 ; n < GIET_OPEN_FILES_MAX ; n++ ) fat.fd[n].used = 0; |
---|
1057 | |
---|
1058 | #if GIET_DEBUG_FAT |
---|
1059 | _printf("\n[FAT DEBUG] FS_INFO Sector = %x\n", fat.fs_info_lba ); |
---|
1060 | #endif |
---|
1061 | |
---|
1062 | // load FS_INFO into fat cache |
---|
1063 | if ( _ioc_read( 0, // channel |
---|
1064 | mode, // mode for IOC driver |
---|
1065 | fat.fs_info_lba, // sector index |
---|
1066 | fat.fat_cache, // buffer address |
---|
1067 | 1 ) ) // one sector |
---|
1068 | { |
---|
1069 | _printf("\n[FAT ERROR] in _fat_init() cannot load FS_INFO Sector\n"); |
---|
1070 | return -1; |
---|
1071 | } |
---|
1072 | fat.cache_lba = fat.fs_info_lba; |
---|
1073 | |
---|
1074 | fat.number_free_cluster = read_entry( FS_FREE_CLUSTER , fat.fat_cache, 1); |
---|
1075 | fat.last_cluster_allocated = read_entry( FS_FREE_CLUSTER_HINT, fat.fat_cache, 1); |
---|
1076 | |
---|
1077 | |
---|
1078 | #if GIET_DEBUG_FAT |
---|
1079 | _printf("\n[FAT DEBUG] Processor[%d,%d,%d] initialises FAT descriptor\n", x, y, lpid ); |
---|
1080 | _fat_print(); |
---|
1081 | _printf("\n[FAT DEBUG] Processor[%d,%d,%d] exit _fat_init()\n", x, y, lpid ); |
---|
1082 | #endif |
---|
1083 | |
---|
1084 | return 0; |
---|
1085 | } // end _fat_init() |
---|
1086 | |
---|
1087 | ///////////////// |
---|
1088 | void _fat_print() |
---|
1089 | { |
---|
1090 | _printf("\n########################## FAT32 ################################"); |
---|
1091 | _printf("\nFAT initialised %x", fat.initialised ); |
---|
1092 | _printf("\nSector Size (bytes) %x", fat.sector_size ); |
---|
1093 | _printf("\nSectors per cluster %x", fat.sectors_per_cluster ); |
---|
1094 | _printf("\nFAT region first lba %x", fat.fat_lba ); |
---|
1095 | _printf("\nData region first lba %x", fat.data_lba ); |
---|
1096 | _printf("\nNumber of sectors for one FAT %x", fat.fat_sectors ); |
---|
1097 | _printf("\nNumber of free clusters %x", fat.number_free_cluster ); |
---|
1098 | _printf("\nLast allocated cluster %x", fat.last_cluster_allocated ); |
---|
1099 | _printf("\n#################################################################\n"); |
---|
1100 | } |
---|
1101 | |
---|
1102 | /////////////////////////////////////////////////////////////////////////////// |
---|
1103 | // This function checks that the kernel FAT structure has been initialised. |
---|
1104 | // It makes the FAT initialisation if it is the first open request. |
---|
1105 | // This function searches a file identified by the "pathname" argument. |
---|
1106 | // It starts from root (cluster 2) to scan successively each subdirectory. |
---|
1107 | // When the file is not found, but the path is found, and "creat" is set, |
---|
1108 | // a new file is created and introduced in the directory. |
---|
1109 | // Finally, it sets a new open file in the file descriptors array. |
---|
1110 | // The same file can be open several times by differents tasks. |
---|
1111 | /////////////////////////////////////////////////////////////////////////////// |
---|
1112 | // Returns file descriptor index if success, returns -1 if error. |
---|
1113 | /////////////////////////////////////////////////////////////////////////////// |
---|
1114 | int _fat_open( unsigned mode, |
---|
1115 | char* pathname, |
---|
1116 | unsigned int creat ) |
---|
1117 | { |
---|
1118 | char name[256]; // buffer for one name in pathname |
---|
1119 | unsigned int nb_read; // number of characters written in name[] |
---|
1120 | unsigned int cluster; // current cluster index when scanning FAT |
---|
1121 | unsigned int dir_cluster; // previous cluster index when scanning FAT |
---|
1122 | unsigned int fd_id; // index when scanning file descriptors array |
---|
1123 | unsigned int file_size = 0; // number of bytes |
---|
1124 | unsigned int last_name = 0; // directory containing file name is reached |
---|
1125 | unsigned int lba = 0; // lba of dir_entry for this file |
---|
1126 | |
---|
1127 | #if GIET_DEBUG_FAT |
---|
1128 | unsigned int procid = _get_procid(); |
---|
1129 | unsigned int cid = procid / NB_PROCS_MAX; |
---|
1130 | unsigned int lpid = procid % NB_PROCS_MAX; |
---|
1131 | unsigned int x = cid >> Y_WIDTH; |
---|
1132 | unsigned int y = cid & ((1<<Y_WIDTH) - 1); |
---|
1133 | |
---|
1134 | _printf("\n[FAT DEBUG] Processor[%d,%d,%d] enters _fat_open() for file %s\n", |
---|
1135 | x, y, lpid, pathname ); |
---|
1136 | #endif |
---|
1137 | |
---|
1138 | // checking arguments |
---|
1139 | if ( creat ) |
---|
1140 | { |
---|
1141 | _printf("[FAT ERROR] in _fat_open() : create not supported yet\n"); |
---|
1142 | return -1; |
---|
1143 | } |
---|
1144 | |
---|
1145 | // takes the FAT lock for exclusive access |
---|
1146 | _get_lock( &fat.fat_lock ); |
---|
1147 | |
---|
1148 | #if GIET_DEBUG_FAT |
---|
1149 | _printf("\n[FAT DEBUG] Processor[%d,%d,%d] takes the FAT lock\n", |
---|
1150 | x, y, lpid ); |
---|
1151 | #endif |
---|
1152 | |
---|
1153 | // FAT initialisation if required |
---|
1154 | if( fat.initialised != FAT_INITIALISED ) |
---|
1155 | { |
---|
1156 | if ( _fat_init( mode ) ) |
---|
1157 | { |
---|
1158 | _printf("[FAT ERROR] in _fat_open() : Cannot initialize FAT descriptor\n"); |
---|
1159 | _release_lock( &fat.fat_lock ); |
---|
1160 | return -1; |
---|
1161 | } |
---|
1162 | } |
---|
1163 | |
---|
1164 | // Scan the directories, starting from the root directory (cluster 2) |
---|
1165 | // - The get_name_from_path() function extracts (successively) |
---|
1166 | // each directory name from the pathname, and store it in name[] buffer |
---|
1167 | // - The scan_directory() function scan one (or several) cluster(s) containing |
---|
1168 | // a directory looking for name[], and return the cluster index |
---|
1169 | // corresponding to the directory/file found. |
---|
1170 | nb_read = 0; |
---|
1171 | cluster = 2; |
---|
1172 | last_name = 0; |
---|
1173 | while ( get_name_from_path( pathname, name, &nb_read) ) |
---|
1174 | { |
---|
1175 | |
---|
1176 | #if GIET_DEBUG_FAT |
---|
1177 | _printf("\n[FAT DEBUG] Processor[%d,%d,%d] search dir/file : %s\n", |
---|
1178 | x, y, lpid, name ); |
---|
1179 | #endif |
---|
1180 | |
---|
1181 | // test if we reach the last name (file name) |
---|
1182 | if( pathname[nb_read] == 0 ) |
---|
1183 | { |
---|
1184 | last_name = 1; |
---|
1185 | dir_cluster = cluster; |
---|
1186 | } |
---|
1187 | |
---|
1188 | // scan current directory |
---|
1189 | cluster = scan_directory( mode, cluster, name, &file_size, &lba ); |
---|
1190 | |
---|
1191 | if( cluster == END_OF_CHAIN_CLUSTER && last_name && creat ) |
---|
1192 | { |
---|
1193 | cluster = fat_create( name, 1, dir_cluster ); |
---|
1194 | } |
---|
1195 | else if ( cluster == END_OF_CHAIN_CLUSTER ) |
---|
1196 | { |
---|
1197 | _printf("\n[FAT ERROR] in _fat_open() cannot found %s\n", name ); |
---|
1198 | |
---|
1199 | // release FAT lock |
---|
1200 | _release_lock( &fat.fat_lock ); |
---|
1201 | |
---|
1202 | return -1; |
---|
1203 | } |
---|
1204 | } |
---|
1205 | |
---|
1206 | // check the next value for cluster index found |
---|
1207 | unsigned next = get_next_cluster_id( mode, cluster ); |
---|
1208 | |
---|
1209 | if ( (next != BAD_CLUSTER) && (next != FREE_CLUSTER) ) |
---|
1210 | { |
---|
1211 | // Search an empty slot scanning open file descriptors array |
---|
1212 | fd_id = 0; |
---|
1213 | while ( fat.fd[fd_id].used != 0 && fd_id < GIET_OPEN_FILES_MAX ) |
---|
1214 | { |
---|
1215 | fd_id++; |
---|
1216 | } |
---|
1217 | |
---|
1218 | // set file descriptor if found empty slot |
---|
1219 | if ( fd_id < GIET_OPEN_FILES_MAX ) |
---|
1220 | { |
---|
1221 | fat.fd[fd_id].used = 1; |
---|
1222 | fat.fd[fd_id].first_cluster = cluster; |
---|
1223 | fat.fd[fd_id].file_size = file_size; |
---|
1224 | fat.fd[fd_id].lba_dir_entry = lba; |
---|
1225 | _strcpy( fat.fd[fd_id].name, pathname ); |
---|
1226 | |
---|
1227 | #if GIET_DEBUG_FAT |
---|
1228 | _printf("\n[FAT DEBUG] Processor[%d,%d,%d] open file %s with fd = %d\n", |
---|
1229 | x, y, lpid, pathname, fd_id ); |
---|
1230 | #endif |
---|
1231 | |
---|
1232 | // release FAT lock |
---|
1233 | _release_lock( &fat.fat_lock ); |
---|
1234 | |
---|
1235 | return fd_id; |
---|
1236 | } |
---|
1237 | else |
---|
1238 | { |
---|
1239 | _printf("\n[FAT ERROR] in _fat_open() for file %s : fd array full\n", |
---|
1240 | pathname ); |
---|
1241 | |
---|
1242 | // release FAT lock |
---|
1243 | _release_lock( &fat.fat_lock ); |
---|
1244 | |
---|
1245 | return -1; |
---|
1246 | } |
---|
1247 | } |
---|
1248 | else |
---|
1249 | { |
---|
1250 | _printf("\n[FAT ERROR] in _fat_open() for file %s : bad cluster\n", |
---|
1251 | pathname ); |
---|
1252 | |
---|
1253 | // release FAT lock |
---|
1254 | _release_lock( &fat.fat_lock ); |
---|
1255 | |
---|
1256 | return -1; |
---|
1257 | } |
---|
1258 | } // end _fat_open() |
---|
1259 | |
---|
1260 | /////////////////////////////////////////////////////////////////////////////// |
---|
1261 | // For an open file, identified by the file descriptor index, transfer |
---|
1262 | // an integer number of sectors from block device to a memory buffer. |
---|
1263 | // If the number of requested sectors exceeds the file size, it is reduced. |
---|
1264 | /////////////////////////////////////////////////////////////////////////////// |
---|
1265 | // Returns number of sectors transfered if success, < 0 if error. |
---|
1266 | /////////////////////////////////////////////////////////////////////////////// |
---|
1267 | int _fat_read( unsigned int mode, // mode for IOC driver |
---|
1268 | unsigned int fd_id, // file descriptor |
---|
1269 | void* buffer, // target buffer base address |
---|
1270 | unsigned int count, // number of sector to read |
---|
1271 | unsigned int offset ) // nuber of sectors to skip in file |
---|
1272 | { |
---|
1273 | unsigned int spc = fat.sectors_per_cluster; |
---|
1274 | |
---|
1275 | unsigned int file_size; // number of bytes in file |
---|
1276 | unsigned int file_sectors; // number of sectors in file |
---|
1277 | unsigned int total_sectors; // actual number of sectors to be transfered |
---|
1278 | unsigned int cluster; // cluster index |
---|
1279 | unsigned int clusters_to_skip; // number of clusters to skip because offset |
---|
1280 | unsigned int sectors_to_skip; // number of sectors to skip in first iteration |
---|
1281 | |
---|
1282 | // arguments checking |
---|
1283 | if ( fd_id >= GIET_OPEN_FILES_MAX ) |
---|
1284 | { |
---|
1285 | _printf("\n[FAT ERROR] in _fat_read() : illegal file descriptor index\n"); |
---|
1286 | return -1; |
---|
1287 | } |
---|
1288 | if ( fat.fd[fd_id].used != 1 ) |
---|
1289 | { |
---|
1290 | _printf("\n[FAT ERROR] in _fat_read() : file not open\n"); |
---|
1291 | return -1; |
---|
1292 | } |
---|
1293 | if ( ((unsigned int)buffer & 0x1FF) != 0 ) |
---|
1294 | { |
---|
1295 | _printf("\n[FAT ERROR] in _fat_read() : memory buffer not sector aligned\n"); |
---|
1296 | return -1; |
---|
1297 | } |
---|
1298 | |
---|
1299 | // compute file size as a number of sectors |
---|
1300 | file_size = fat.fd[fd_id].file_size; |
---|
1301 | if ( file_size & 0x1FF ) file_sectors = (file_size >> 9) + 1; |
---|
1302 | else file_sectors = (file_size >> 9); |
---|
1303 | |
---|
1304 | if ( offset >= file_sectors ) |
---|
1305 | { |
---|
1306 | _printf("\n[FAT ERROR] offset larger than number of sectors\n"); |
---|
1307 | return -1; |
---|
1308 | } |
---|
1309 | |
---|
1310 | // compute total number of sectors to read |
---|
1311 | if ( file_sectors < (offset + count) ) total_sectors = file_sectors - offset; |
---|
1312 | else total_sectors = count; |
---|
1313 | |
---|
1314 | // compute clusters and sectors to be skipped |
---|
1315 | clusters_to_skip = offset / spc; |
---|
1316 | sectors_to_skip = offset % spc; |
---|
1317 | |
---|
1318 | // get first cluster index |
---|
1319 | cluster = fat.fd[fd_id].first_cluster; |
---|
1320 | |
---|
1321 | #if GIET_DEBUG_FAT |
---|
1322 | unsigned int procid = _get_procid(); |
---|
1323 | unsigned int cid = procid / NB_PROCS_MAX; |
---|
1324 | unsigned int lpid = procid % NB_PROCS_MAX; |
---|
1325 | unsigned int x = cid >> Y_WIDTH; |
---|
1326 | unsigned int y = cid & ((1<<Y_WIDTH) - 1); |
---|
1327 | |
---|
1328 | _printf("\n[FAT DEBUG] Processor[%d,%d,%d] enters _fat_read() for file %s\n" |
---|
1329 | " - buffer vbase = %x\n" |
---|
1330 | " - skipped sectors = %x\n" |
---|
1331 | " - read sectors = %x\n" |
---|
1332 | " - first cluster = %x\n" |
---|
1333 | " - skiped clusters = %x\n", |
---|
1334 | x, y, lpid, fat.fd[fd_id].name, |
---|
1335 | (unsigned int)buffer, offset, count, cluster, clusters_to_skip ); |
---|
1336 | #endif |
---|
1337 | |
---|
1338 | // compute index of first cluster to be loaded |
---|
1339 | // as we may need to scan the FAT, we use the kernel mode |
---|
1340 | while ( clusters_to_skip ) |
---|
1341 | { |
---|
1342 | cluster = get_next_cluster_id( IOC_KERNEL_MODE, cluster ); |
---|
1343 | clusters_to_skip--; |
---|
1344 | } |
---|
1345 | |
---|
1346 | // variables used in the loop on clusters |
---|
1347 | int todo_sectors; // number of sectors still to be loaded |
---|
1348 | unsigned int lba; // first sector index on device |
---|
1349 | unsigned int iter_sectors; // number of sectors to load in iteration |
---|
1350 | char* dst; // pointer on target buffer |
---|
1351 | |
---|
1352 | // initialize these variables for the first iteration |
---|
1353 | todo_sectors = total_sectors; |
---|
1354 | dst = (char*)buffer; |
---|
1355 | lba = cluster_to_lba(cluster) + sectors_to_skip; |
---|
1356 | if( total_sectors < (spc - sectors_to_skip) ) iter_sectors = total_sectors; |
---|
1357 | else iter_sectors = spc - sectors_to_skip; |
---|
1358 | |
---|
1359 | // loop on the clusters: one IOC access per cluster |
---|
1360 | while ( todo_sectors > 0 ) |
---|
1361 | { |
---|
1362 | |
---|
1363 | #if GIET_DEBUG_FAT |
---|
1364 | _printf("\n[FAT DEBUG] Processor[%d,%d,%d] makes an IOC read " |
---|
1365 | " for cluster %x : buf = %x / lba = %x / sectors = %d\n", |
---|
1366 | x, y, lpid, cluster, (unsigned int)dst, lba, iter_sectors ); |
---|
1367 | #endif |
---|
1368 | |
---|
1369 | if( _ioc_read( 0, // channel |
---|
1370 | mode, // mode for IOC driver |
---|
1371 | lba, // first sector index |
---|
1372 | dst, // buffer address |
---|
1373 | iter_sectors ) ) // number of sectors |
---|
1374 | { |
---|
1375 | _printf("\n[FAT ERROR] in _fat_read() cannot load block %x\n", lba ); |
---|
1376 | return -1; |
---|
1377 | } |
---|
1378 | |
---|
1379 | // update variables for next iteration |
---|
1380 | cluster = get_next_cluster_id( mode, cluster ); |
---|
1381 | todo_sectors = todo_sectors - iter_sectors; |
---|
1382 | dst = dst + (iter_sectors << 9); |
---|
1383 | lba = cluster_to_lba(cluster); |
---|
1384 | if ( todo_sectors > spc ) iter_sectors = spc; |
---|
1385 | else iter_sectors = todo_sectors; |
---|
1386 | } |
---|
1387 | |
---|
1388 | // returns number of sectors actually transfered |
---|
1389 | return total_sectors; |
---|
1390 | |
---|
1391 | } // end _fat_read() |
---|
1392 | |
---|
1393 | /////////////////////////////////////////////////////////////////////////////// |
---|
1394 | // For an open file, identified by the file descriptor index, transfer |
---|
1395 | // an integer number of sectors from a memory buffer to block device. |
---|
1396 | // Allocate new clusters if the offset+count larger than current file size, |
---|
1397 | // but the offset should be smaller than the current file size... |
---|
1398 | // - fat : pointer on FAT |
---|
1399 | // - mode : mode for the IOC driver |
---|
1400 | // - fd_id : open file descriptor index |
---|
1401 | // - buffer : base address of the memory buffer (must be sector aligned) |
---|
1402 | // - offset : number of sectors to skip in file |
---|
1403 | // - count : number of sectors to be written. |
---|
1404 | /////////////////////////////////////////////////////////////////////////////// |
---|
1405 | // Returns number of sectors written if success, < 0 if error. |
---|
1406 | /////////////////////////////////////////////////////////////////////////////// |
---|
1407 | int _fat_write( unsigned int mode, // mode for IOC driver |
---|
1408 | unsigned int fd_id, // file descriptor |
---|
1409 | void* buffer, // target buffer base address |
---|
1410 | unsigned int count, // number of sector to write |
---|
1411 | unsigned int offset ) // nuber of sectors to skip in file |
---|
1412 | { |
---|
1413 | |
---|
1414 | unsigned int spc = fat.sectors_per_cluster; |
---|
1415 | |
---|
1416 | unsigned int file_size; // number of bytes in file |
---|
1417 | unsigned int file_sectors; // number of sectors in file |
---|
1418 | unsigned int cluster; // cluster index |
---|
1419 | unsigned int clusters_to_skip; // number of clusters to skip because offset |
---|
1420 | unsigned int sectors_to_skip; // number of sectors to skip in first iteration |
---|
1421 | unsigned int allocate; // need allocate or not |
---|
1422 | unsigned int current_cluster; // number of cluster allocated to the file |
---|
1423 | unsigned int required_cluster; // number of cluster needed for the write |
---|
1424 | |
---|
1425 | // compute file size as a number of sectors |
---|
1426 | file_size = fat.fd[fd_id].file_size; |
---|
1427 | if ( file_size & 0x1FF ) file_sectors = (file_size >> 9) + 1; |
---|
1428 | else file_sectors = (file_size >> 9); |
---|
1429 | |
---|
1430 | // Compute the number of clusters occupied by the file |
---|
1431 | current_cluster = file_sectors / spc; |
---|
1432 | |
---|
1433 | // Compute the number of clusters that will occupy the file (after fat_write) |
---|
1434 | required_cluster = (count + offset) / spc; |
---|
1435 | |
---|
1436 | // Check if we need to allocate new cluster(s) for the file |
---|
1437 | allocate = ( required_cluster > current_cluster ); |
---|
1438 | |
---|
1439 | #if GIET_DEBUG_FAT |
---|
1440 | unsigned int procid = _get_procid(); |
---|
1441 | unsigned int cid = procid / NB_PROCS_MAX; |
---|
1442 | unsigned int lpid = procid % NB_PROCS_MAX; |
---|
1443 | unsigned int x = cid >> Y_WIDTH; |
---|
1444 | unsigned int y = cid & ((1<<Y_WIDTH) - 1); |
---|
1445 | |
---|
1446 | _printf("\n[FAT DEBUG] Processor[%d,%d,%d] enters _fat_write() for file %s\n", |
---|
1447 | " - buffer vbase = %x\n" |
---|
1448 | " - skipped sectors = %x\n" |
---|
1449 | " - write sectors = %x\n" |
---|
1450 | " - file sectors = %x\n" |
---|
1451 | " - need allocate = %d\n", |
---|
1452 | x, y, lpid, fat.fd[fd_id].name, (unsigned int)buffer, |
---|
1453 | offset, count, file_sectors, allocate ); |
---|
1454 | #endif |
---|
1455 | |
---|
1456 | // arguments checking |
---|
1457 | if ( fd_id >= GIET_OPEN_FILES_MAX ) |
---|
1458 | { |
---|
1459 | _printf("\n[FAT ERROR] in _fat_write() : illegal file descriptor index\n"); |
---|
1460 | return -1; |
---|
1461 | } |
---|
1462 | if ( fat.fd[fd_id].used != 1 ) |
---|
1463 | { |
---|
1464 | _printf("\n[FAT ERROR] in _fat_write() : file not open\n"); |
---|
1465 | return -1; |
---|
1466 | } |
---|
1467 | if ( ((unsigned int)buffer & 0x1FF) != 0 ) |
---|
1468 | { |
---|
1469 | _printf("\n[FAT ERROR] in _fat_write() : memory buffer not sector aligned\n"); |
---|
1470 | return -1; |
---|
1471 | } |
---|
1472 | |
---|
1473 | if ( allocate ) |
---|
1474 | { |
---|
1475 | if ( _fat_allocate( fd_id, (required_cluster - current_cluster) ) < 0 ) |
---|
1476 | { |
---|
1477 | _printf("\n[FAT ERROR] in _fat_write() : fat_allocate failed\n"); |
---|
1478 | return -1; |
---|
1479 | } |
---|
1480 | } |
---|
1481 | |
---|
1482 | // compute clusters and sectors to be skipped |
---|
1483 | clusters_to_skip = offset / spc; |
---|
1484 | sectors_to_skip = offset % spc; |
---|
1485 | |
---|
1486 | // get first cluster index |
---|
1487 | cluster = fat.fd[fd_id].first_cluster; |
---|
1488 | |
---|
1489 | #if GIET_DEBUG_FAT |
---|
1490 | _printf(" - first cluster = %x\n" |
---|
1491 | " - skiped clusters = %x\n", |
---|
1492 | cluster, clusters_to_skip ); |
---|
1493 | #endif |
---|
1494 | |
---|
1495 | // compute index of first cluster to be loaded |
---|
1496 | // as we may need to scan the FAT, we use the kernel mode |
---|
1497 | while ( clusters_to_skip ) |
---|
1498 | { |
---|
1499 | cluster = get_next_cluster_id( IOC_KERNEL_MODE, cluster ); |
---|
1500 | clusters_to_skip--; |
---|
1501 | } |
---|
1502 | |
---|
1503 | // variables used in the loop on clusters |
---|
1504 | int todo_sectors; // number of sectors still to be loaded |
---|
1505 | unsigned int lba; // first sector index on device |
---|
1506 | unsigned int iter_sectors; // number of sectors to load in iteration |
---|
1507 | char* src; // pointer on target buffer |
---|
1508 | |
---|
1509 | // initialize these variables for the first iteration |
---|
1510 | todo_sectors = count; |
---|
1511 | src = (char*)buffer; |
---|
1512 | lba = cluster_to_lba(cluster) + sectors_to_skip; |
---|
1513 | if( count < (spc - sectors_to_skip) ) iter_sectors = count; |
---|
1514 | else iter_sectors = spc - sectors_to_skip; |
---|
1515 | |
---|
1516 | // loop on the clusters |
---|
1517 | while ( todo_sectors > 0 ) |
---|
1518 | { |
---|
1519 | |
---|
1520 | #if GIET_DEBUG_FAT |
---|
1521 | _printf("\n[FAT DEBUG] Processor[%d,%d,%d] makes an IOC write : " |
---|
1522 | "buf = %x / lba = %x / sectors = %x\n", |
---|
1523 | x, y, lpid, (unsigned int)src, lba, iter_sectors ); |
---|
1524 | #endif |
---|
1525 | |
---|
1526 | if( _ioc_write( 0, // channel |
---|
1527 | mode, // mode for IOC driver |
---|
1528 | lba, // first sector index |
---|
1529 | src, // source buffer address |
---|
1530 | iter_sectors ) ) // number of sectors |
---|
1531 | { |
---|
1532 | _printf("\n[FAT ERROR] in _fat_write() cannot write block %x\n", lba ); |
---|
1533 | return -1; |
---|
1534 | } |
---|
1535 | |
---|
1536 | // update variables for next iteration |
---|
1537 | cluster = get_next_cluster_id( mode, cluster ); |
---|
1538 | todo_sectors = todo_sectors - iter_sectors; |
---|
1539 | src = src + (iter_sectors << 9); |
---|
1540 | lba = cluster_to_lba(cluster); |
---|
1541 | if ( todo_sectors > spc ) iter_sectors = spc; |
---|
1542 | else iter_sectors = todo_sectors; |
---|
1543 | } |
---|
1544 | |
---|
1545 | // Update structure file descriptor, field file_size with |
---|
1546 | // the new file size if the file is bigger than the previous file |
---|
1547 | if ( ( offset + count ) > file_sectors ) |
---|
1548 | { |
---|
1549 | fat.fd[fd_id].file_size = (count + offset) << 9; |
---|
1550 | } |
---|
1551 | |
---|
1552 | // Update entry of directory with the new value |
---|
1553 | // of file size (Field : DIR_FILE_SIZE) |
---|
1554 | if ( update_entry(fd_id, DIR_FILE_SIZE, fat.fd[fd_id].file_size) ) |
---|
1555 | { |
---|
1556 | _printf("\n[FAT ERROR] in _fat_write() update entry failed\n"); |
---|
1557 | return -1; |
---|
1558 | } |
---|
1559 | |
---|
1560 | // returns number of sectors actually transfered |
---|
1561 | return count; |
---|
1562 | } |
---|
1563 | |
---|
1564 | ///////////////////////////////////////////////////////////////////////////////// |
---|
1565 | // Return stats of a file identified by "fd". |
---|
1566 | // (Only the file_size in sectors for this moment) |
---|
1567 | ///////////////////////////////////////////////////////////////////////////////// |
---|
1568 | // Returns file size (on sectors) on success, -1 on failure. |
---|
1569 | ///////////////////////////////////////////////////////////////////////////////// |
---|
1570 | int _fat_fstat( unsigned int fd_id ) |
---|
1571 | { |
---|
1572 | unsigned int file_size = 0; |
---|
1573 | unsigned int file_sectors = 0; |
---|
1574 | |
---|
1575 | if( (fd_id < GIET_OPEN_FILES_MAX) ) |
---|
1576 | { |
---|
1577 | file_size = fat.fd[fd_id].file_size; |
---|
1578 | |
---|
1579 | if ( file_size & 0x1FF ) file_sectors = (file_size >> 9) + 1; |
---|
1580 | else file_sectors = (file_size >> 9); |
---|
1581 | |
---|
1582 | return file_sectors; |
---|
1583 | } |
---|
1584 | else |
---|
1585 | { |
---|
1586 | _printf("\n[FAT ERROR] in _fat_fstat() : illegal file descriptor index\n"); |
---|
1587 | return -1; |
---|
1588 | } |
---|
1589 | } // end _fat_fstat() |
---|
1590 | |
---|
1591 | ///////////////////////////////////////////////////////////////////////////////// |
---|
1592 | // Close the file identified by the file_descriptor index. |
---|
1593 | ///////////////////////////////////////////////////////////////////////////////// |
---|
1594 | // Returns 0 on success, -1 on failure. |
---|
1595 | ///////////////////////////////////////////////////////////////////////////////// |
---|
1596 | int _fat_close( unsigned int fd_id ) |
---|
1597 | { |
---|
1598 | if( (fd_id < GIET_OPEN_FILES_MAX) ) |
---|
1599 | { |
---|
1600 | fat.fd[fd_id].used = 0; |
---|
1601 | return 0; |
---|
1602 | } |
---|
1603 | else |
---|
1604 | { |
---|
1605 | _printf("\n[FAT ERROR] in _fat_close() : illegal file descriptor index\n"); |
---|
1606 | return -1; |
---|
1607 | } |
---|
1608 | } // end fat_close() |
---|
1609 | |
---|
1610 | ///////////////////////////////////////////////////////////////////////////////////// |
---|
1611 | // The following function implement the user_level system call. |
---|
1612 | // The flags argument is nor used, as file access modes are not implemented yet. |
---|
1613 | ///////////////////////////////////////////////////////////////////////////////////// |
---|
1614 | // Return the file descriptor index if success / return -1 if failure |
---|
1615 | ///////////////////////////////////////////////////////////////////////////////////// |
---|
1616 | int _fat_user_open( char* pathname, // absolute pathname from root |
---|
1617 | unsigned int flags ) // unused: TODO |
---|
1618 | { |
---|
1619 | return _fat_open( IOC_KERNEL_MODE, // we use KERNEL_MODE, because |
---|
1620 | pathname, // we need to write into FAT cache |
---|
1621 | 0 ); // no creation if not found |
---|
1622 | } |
---|
1623 | |
---|
1624 | ///////////////////////////////////////////////////////////////////////////////////// |
---|
1625 | // The following function implement the user_level system call. |
---|
1626 | // This function should be modified to respect the UNIX specification |
---|
1627 | ///////////////////////////////////////////////////////////////////////////////////// |
---|
1628 | // Return number of sectors actually transfered if success / return -1 if failure |
---|
1629 | ///////////////////////////////////////////////////////////////////////////////////// |
---|
1630 | int _fat_user_read( unsigned int fd, // file descriptor index |
---|
1631 | void* buffer, // destination buffer |
---|
1632 | unsigned int count, // number of sectors to read |
---|
1633 | unsigned int offset ) // number of sectors to skip |
---|
1634 | { |
---|
1635 | return _fat_read( IOC_USER_MODE, |
---|
1636 | fd, |
---|
1637 | buffer, |
---|
1638 | count, |
---|
1639 | offset ); |
---|
1640 | } |
---|
1641 | |
---|
1642 | ///////////////////////////////////////////////////////////////////////////////////// |
---|
1643 | // The following function implement the user_level system call. |
---|
1644 | // This function should be modified to respect the UNIX specification. |
---|
1645 | ///////////////////////////////////////////////////////////////////////////////////// |
---|
1646 | // Return number of sectors actually transfered if success / return -1 if failure |
---|
1647 | ///////////////////////////////////////////////////////////////////////////////////// |
---|
1648 | int _fat_user_write( unsigned int fd, // file descriptor |
---|
1649 | void* buffer, // source buffer |
---|
1650 | unsigned int count, // number of sectors to write |
---|
1651 | unsigned int offset ) // number of sectors to skip on file |
---|
1652 | { |
---|
1653 | return _fat_write( IOC_USER_MODE, |
---|
1654 | fd, |
---|
1655 | buffer, |
---|
1656 | count, |
---|
1657 | offset ); |
---|
1658 | } |
---|
1659 | |
---|
1660 | ///////////////////////////////////////////////////////////////////////////////////// |
---|
1661 | int _fat_user_lseek( unsigned int fd_id, |
---|
1662 | unsigned int offset, |
---|
1663 | unsigned int whence ) |
---|
1664 | { |
---|
1665 | _printf("[GIET ERROR] _fat_user_lseek() not implemented\n"); |
---|
1666 | _exit(); |
---|
1667 | return 0; |
---|
1668 | } |
---|
1669 | |
---|
1670 | |
---|
1671 | // Local Variables: |
---|
1672 | // tab-width: 4 |
---|
1673 | // c-basic-offset: 4 |
---|
1674 | // c-file-offsets:((innamespace . 0)(inline-open . 0)) |
---|
1675 | // indent-tabs-mode: nil |
---|
1676 | // End: |
---|
1677 | // vim: filetype=c:expandtab:shiftwidth=4:tabstop=4:softtabstop=4 |
---|
1678 | |
---|