[e51bd96] | 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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