1 | /** |
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2 | * @file |
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3 | * |
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4 | * @ingroup rtems_bdpart |
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5 | * |
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6 | * Block device partition management. |
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7 | */ |
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8 | |
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9 | /* |
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10 | * Copyright (c) 2009, 2010 |
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11 | * embedded brains GmbH |
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12 | * Obere Lagerstr. 30 |
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13 | * D-82178 Puchheim |
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14 | * Germany |
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15 | * <rtems@embedded-brains.de> |
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16 | * |
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17 | * The license and distribution terms for this file may be |
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18 | * found in the file LICENSE in this distribution or at |
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19 | * http://www.rtems.com/license/LICENSE. |
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20 | */ |
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21 | |
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22 | #ifdef HAVE_CONFIG_H |
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23 | #include "config.h" |
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24 | #endif |
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25 | |
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26 | #include <rtems.h> |
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27 | #include <rtems/bdpart.h> |
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28 | |
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29 | rtems_status_code rtems_bdpart_create( |
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30 | const char *disk_name, |
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31 | const rtems_bdpart_format *format, |
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32 | rtems_bdpart_partition *pt, |
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33 | const unsigned *dist, |
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34 | size_t count |
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35 | ) |
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36 | { |
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37 | rtems_status_code sc = RTEMS_SUCCESSFUL; |
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38 | bool dos_compatibility = format != NULL |
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39 | && format->type == RTEMS_BDPART_FORMAT_MBR |
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40 | && format->mbr.dos_compatibility; |
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41 | rtems_blkdev_bnum disk_end = 0; |
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42 | rtems_blkdev_bnum pos = 0; |
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43 | rtems_blkdev_bnum dist_sum = 0; |
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44 | rtems_blkdev_bnum record_space = |
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45 | dos_compatibility ? RTEMS_BDPART_MBR_CYLINDER_SIZE : 1; |
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46 | rtems_blkdev_bnum overhead = 0; |
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47 | rtems_blkdev_bnum free_space = 0; |
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48 | dev_t disk = 0; |
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49 | size_t i = 0; |
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50 | |
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51 | /* Check if we have something to do */ |
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52 | if (count == 0) { |
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53 | /* Nothing to do */ |
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54 | return RTEMS_SUCCESSFUL; |
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55 | } |
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56 | |
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57 | /* Check parameter */ |
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58 | if (format == NULL || pt == NULL || dist == NULL) { |
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59 | return RTEMS_INVALID_ADDRESS; |
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60 | } |
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61 | |
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62 | /* Get disk data */ |
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63 | sc = rtems_bdpart_get_disk_data( disk_name, &disk, &disk_end); |
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64 | if (sc != RTEMS_SUCCESSFUL) { |
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65 | return sc; |
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66 | } |
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67 | |
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68 | /* Get distribution sum and check for overflow */ |
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69 | for (i = 0; i < count; ++i) { |
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70 | unsigned prev_sum = dist_sum; |
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71 | |
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72 | dist_sum += dist [i]; |
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73 | |
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74 | if (dist_sum < prev_sum) { |
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75 | return RTEMS_INVALID_NUMBER; |
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76 | } |
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77 | |
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78 | if (dist [i] == 0) { |
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79 | return RTEMS_INVALID_NUMBER; |
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80 | } |
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81 | } |
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82 | |
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83 | /* Check format */ |
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84 | if (format->type != RTEMS_BDPART_FORMAT_MBR) { |
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85 | return RTEMS_NOT_IMPLEMENTED; |
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86 | } |
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87 | |
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88 | /* Align end of disk on cylinder boundary if necessary */ |
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89 | if (dos_compatibility) { |
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90 | disk_end -= (disk_end % record_space); |
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91 | } |
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92 | |
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93 | /* |
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94 | * We need at least space for the MBR and the compatibility space for the |
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95 | * first primary partition. |
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96 | */ |
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97 | overhead += record_space; |
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98 | |
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99 | /* |
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100 | * In case we need an extended partition and logical partitions we have to |
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101 | * account for the space of each EBR. |
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102 | */ |
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103 | if (count > 4) { |
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104 | overhead += (count - 3) * record_space; |
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105 | } |
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106 | |
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107 | /* |
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108 | * Account space to align every partition on cylinder boundaries if |
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109 | * necessary. |
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110 | */ |
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111 | if (dos_compatibility) { |
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112 | overhead += (count - 1) * record_space; |
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113 | } |
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114 | |
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115 | /* Check disk space */ |
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116 | if ((overhead + count) > disk_end) { |
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117 | return RTEMS_IO_ERROR; |
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118 | } |
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119 | |
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120 | /* Begin of first primary partition */ |
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121 | pos = record_space; |
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122 | |
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123 | /* Space for partitions */ |
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124 | free_space = disk_end - overhead; |
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125 | |
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126 | for (i = 0; i < count; ++i) { |
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127 | rtems_bdpart_partition *p = pt + i; |
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128 | |
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129 | /* Partition size */ |
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130 | rtems_blkdev_bnum s = free_space * dist [i]; |
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131 | if (s < free_space || s < dist [i]) { |
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132 | /* TODO: Calculate without overflow */ |
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133 | return RTEMS_INVALID_NUMBER; |
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134 | } |
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135 | s /= dist_sum; |
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136 | |
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137 | /* Ensure that the partition is not empty */ |
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138 | if (s == 0) { |
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139 | s = 1; |
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140 | } |
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141 | |
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142 | /* Align partition upwards */ |
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143 | s += record_space - (s % record_space); |
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144 | |
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145 | /* Partition begin and end */ |
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146 | p->begin = pos; |
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147 | pos += s; |
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148 | p->end = pos; |
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149 | |
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150 | /* Reserve space for the EBR if necessary */ |
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151 | if (count > 4 && i > 2) { |
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152 | p->begin += record_space; |
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153 | } |
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154 | } |
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155 | |
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156 | /* Expand the last partition to the disk end */ |
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157 | pt [count - 1].end = disk_end; |
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158 | |
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159 | return RTEMS_SUCCESSFUL; |
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160 | } |
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