1 | /* |
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2 | * logdisk.h - Physical and logical block devices (disks) support |
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3 | * |
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4 | * Copyright (C) 2001 OKTET Ltd., St.-Petersburg, Russia |
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5 | * Author: Victor V. Vengerov <vvv@oktet.ru> |
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6 | * |
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7 | * @(#) $Id$ |
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8 | */ |
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9 | |
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10 | #ifndef __RTEMS_LIBBLOCK_LOGDISK_H__ |
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11 | #define __RTEMS_LIBBLOCK_LOGDISK_H__ |
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12 | |
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13 | #ifdef __cplusplus |
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14 | extern "C" { |
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15 | #endif |
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16 | |
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17 | #include <rtems.h> |
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18 | #include <rtems/libio.h> |
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19 | #include <stdlib.h> |
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20 | |
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21 | #include "rtems/blkdev.h" |
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22 | |
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23 | /* Buffer pool identifier */ |
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24 | typedef int rtems_bdpool_id; |
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25 | |
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26 | /* Block device ioctl handler */ |
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27 | typedef int (* block_device_ioctl) (dev_t dev, int req, void *argp); |
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28 | |
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29 | /* disk_device: Entry of this type created for every disk device (both for |
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30 | * logical and physical disks). |
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31 | * Array of arrays of pointers to disk_device structures maintained. First |
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32 | * table indexed by major number and second table indexed by minor number. |
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33 | * Such data organization allow quick lookup using data structure of |
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34 | * moderated size. |
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35 | */ |
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36 | typedef struct disk_device { |
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37 | dev_t dev; /* Device ID (major + minor) */ |
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38 | struct disk_device *phys_dev; /* Physical device ID (the same |
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39 | as dev if this entry specifies |
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40 | the physical device) */ |
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41 | char *name; /* Disk device name */ |
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42 | int uses; /* Use counter. Device couldn't be |
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43 | removed if it is in use. */ |
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44 | int start; /* Starting block number (0 for |
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45 | physical devices, block offset |
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46 | on the related physical device |
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47 | for logical device) */ |
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48 | int size; /* Size of physical or logical disk |
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49 | in disk blocks */ |
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50 | int block_size; /* Size of device block (minimum |
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51 | transfer unit) in bytes |
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52 | (must be power of 2) */ |
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53 | int block_size_log2; /* log2 of block_size */ |
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54 | rtems_bdpool_id pool; /* Buffer pool assigned to this |
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55 | device */ |
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56 | block_device_ioctl ioctl; /* ioctl handler for this block |
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57 | device */ |
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58 | } disk_device; |
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59 | |
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60 | /* rtems_disk_create_phys -- |
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61 | * Create physical disk entry. This function usually invoked from |
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62 | * block device driver initialization code when physical device |
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63 | * detected in the system. Device driver should provide ioctl handler |
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64 | * to allow block device access operations. This primitive will register |
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65 | * device in rtems (invoke rtems_io_register_name). |
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66 | * |
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67 | * PARAMETERS: |
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68 | * dev - device identifier (major, minor numbers) |
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69 | * block_size - size of disk block (minimum data transfer unit); must be |
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70 | * power of 2 |
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71 | * disk_size - number of blocks on device |
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72 | * handler - IOCTL handler (function providing basic block input/output |
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73 | * request handling BIOREQUEST and other device management |
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74 | * operations) |
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75 | * name - character name of device (e.g. /dev/hda) |
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76 | * |
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77 | * RETURNS: |
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78 | * RTEMS_SUCCESSFUL if information about new physical disk added, or |
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79 | * error code if error occured (device already registered, wrong block |
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80 | * size value, no memory available). |
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81 | */ |
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82 | rtems_status_code |
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83 | rtems_disk_create_phys(dev_t dev, int block_size, int disk_size, |
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84 | block_device_ioctl handler, |
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85 | char *name); |
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86 | |
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87 | /* rtems_disk_create_log -- |
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88 | * Create logical disk entry. Logical disk is contiguous area on physical |
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89 | * disk. Disk may be splitted to several logical disks in several ways: |
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90 | * manually or using information stored in blocks on physical disk |
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91 | * (DOS-like partition table, BSD disk label, etc). This function usually |
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92 | * invoked from application when application-specific splitting are in use, |
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93 | * or from generic code which handle different logical disk organizations. |
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94 | * This primitive will register device in rtems (invoke |
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95 | * rtems_io_register_name). |
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96 | * |
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97 | * PARAMETERS: |
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98 | * dev - logical device identifier (major, minor numbers) |
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99 | * phys - physical device (block device which holds this logical disk) |
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100 | * identifier |
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101 | * start - starting block number on the physical device |
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102 | * size - logical disk size in blocks |
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103 | * name - logical disk name |
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104 | * |
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105 | * RETURNS: |
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106 | * RTEMS_SUCCESSFUL if logical device successfully added, or error code |
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107 | * if error occured (device already registered, no physical device |
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108 | * exists, logical disk is out of physical disk boundaries, no memory |
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109 | * available). |
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110 | */ |
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111 | rtems_status_code |
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112 | rtems_disk_create_log(dev_t dev, dev_t phys, int start, int size, char *name); |
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113 | |
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114 | /* rtems_disk_delete -- |
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115 | * Delete physical or logical disk device. Device may be deleted if its |
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116 | * use counter (and use counters of all logical devices - if it is |
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117 | * physical device) equal to 0. When physical device deleted, |
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118 | * all logical devices deleted inherently. Appropriate devices removed |
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119 | * from "/dev" filesystem. |
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120 | * |
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121 | * PARAMETERS: |
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122 | * dev - device identifier (major, minor numbers) |
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123 | * |
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124 | * RETURNS: |
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125 | * RTEMS_SUCCESSFUL if block device successfully deleted, or error code |
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126 | * if error occured (device is not defined, device is in use). |
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127 | */ |
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128 | rtems_status_code |
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129 | rtems_disk_delete(dev_t dev); |
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130 | |
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131 | /* rtems_disk_lookup -- |
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132 | * Find block device descriptor by its device identifier. This function |
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133 | * increment usage counter to 1. User should release disk_device structure |
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134 | * by invoking rtems_disk_release primitive. |
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135 | * |
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136 | * PARAMETERS: |
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137 | * dev - device identifier (major, minor numbers) |
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138 | * |
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139 | * RETURNS: |
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140 | * pointer to the block device descriptor, or NULL if no such device |
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141 | * exists. |
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142 | */ |
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143 | disk_device * |
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144 | rtems_disk_lookup(dev_t dev); |
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145 | |
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146 | /* rtems_disk_release -- |
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147 | * Release disk_device structure (decrement usage counter to 1). |
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148 | * |
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149 | * PARAMETERS: |
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150 | * dd - pointer to disk device structure |
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151 | * |
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152 | * RETURNS: |
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153 | * RTEMS_SUCCESSFUL |
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154 | * |
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155 | * NOTE: |
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156 | * It should be implemented as inline function. |
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157 | */ |
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158 | rtems_status_code |
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159 | rtems_disk_release(disk_device *dd); |
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160 | |
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161 | /* rtems_disk_next -- |
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162 | * Disk device enumerator. Looking for device having device number larger |
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163 | * than dev and return disk device descriptor for it. If there are no |
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164 | * such device, NULL value returned. |
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165 | * |
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166 | * PARAMETERS: |
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167 | * dev - device number (use -1 to start search) |
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168 | * |
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169 | * RETURNS: |
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170 | * Pointer to the disk descriptor for next disk device, or NULL if all |
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171 | * devices enumerated. */ |
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172 | disk_device * |
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173 | rtems_disk_next(dev_t dev); |
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174 | |
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175 | /* rtems_diskio_initialize -- |
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176 | * Initialization of disk device library (initialize all data structures, |
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177 | * etc.) |
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178 | * |
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179 | * PARAMETERS: |
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180 | * none |
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181 | * |
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182 | * RETURNS: |
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183 | * RTEMS_SUCCESSFUL if library initialized, or error code if error |
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184 | * occured. |
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185 | */ |
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186 | rtems_status_code |
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187 | rtems_disk_io_initialize(void); |
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188 | |
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189 | /* rtems_diskio_done -- |
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190 | * Release all resources allocated for disk device interface. |
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191 | * |
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192 | * PARAMETERS: |
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193 | * none |
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194 | * |
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195 | * RETURNS: |
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196 | * RTEMS_SUCCESSFUL if all resources released, or error code if error |
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197 | * occured. |
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198 | */ |
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199 | rtems_status_code |
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200 | rtems_disk_io_done(void); |
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201 | |
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202 | #ifdef __cplusplus |
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203 | } |
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204 | #endif |
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205 | |
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206 | #endif |
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