[f36a7bfc] | 1 | /* |
---|
| 2 | * fat_file.h |
---|
| 3 | * |
---|
| 4 | * Constants/data structures/prototypes for operations on "fat-file" |
---|
| 5 | * |
---|
| 6 | * Copyright (C) 2001 OKTET Ltd., St.-Petersburg, Russia |
---|
| 7 | * Author: Eugeny S. Mints <Eugeny.Mints@oktet.ru> |
---|
| 8 | * |
---|
| 9 | * The license and distribution terms for this file may be |
---|
| 10 | * found in the file LICENSE in this distribution or at |
---|
[cf0539b1] | 11 | * http://www.rtems.com/license/LICENSE. |
---|
[f36a7bfc] | 12 | * |
---|
| 13 | * @(#) $Id$ |
---|
| 14 | */ |
---|
| 15 | #ifndef __DOSFS_FAT_FILE_H__ |
---|
| 16 | #define __DOSFS_FAT_FILE_H__ |
---|
| 17 | |
---|
| 18 | #ifdef __cplusplus |
---|
| 19 | extern "C" { |
---|
| 20 | #endif |
---|
| 21 | |
---|
| 22 | #include <rtems.h> |
---|
| 23 | #include <rtems/libio_.h> |
---|
| 24 | |
---|
| 25 | #include <time.h> |
---|
| 26 | |
---|
| 27 | /* "fat-file" representation |
---|
| 28 | * |
---|
| 29 | * the idea is: fat-file is nothing but a cluster chain, any open fat-file is |
---|
| 30 | * represented in system by fat-file descriptor and has well-known |
---|
| 31 | * file interface: |
---|
| 32 | * |
---|
| 33 | * fat_file_open() |
---|
| 34 | * fat_file_close() |
---|
| 35 | * fat_file_read() |
---|
| 36 | * fat_file_write() |
---|
| 37 | * |
---|
| 38 | * Such interface hides the architecture of fat-file and represents it like |
---|
| 39 | * linear file |
---|
| 40 | */ |
---|
| 41 | |
---|
| 42 | typedef rtems_filesystem_node_types_t fat_file_type_t; |
---|
| 43 | |
---|
| 44 | #define FAT_DIRECTORY RTEMS_FILESYSTEM_DIRECTORY |
---|
| 45 | #define FAT_FILE RTEMS_FILESYSTEM_MEMORY_FILE |
---|
| 46 | |
---|
| 47 | typedef struct fat_file_map_s |
---|
| 48 | { |
---|
| 49 | unsigned32 file_cln; |
---|
| 50 | unsigned32 disk_cln; |
---|
| 51 | unsigned32 last_cln; |
---|
| 52 | } fat_file_map_t; |
---|
| 53 | /* |
---|
| 54 | * descriptor of a fat-file |
---|
| 55 | * |
---|
| 56 | * To each particular clusters chain |
---|
| 57 | */ |
---|
| 58 | typedef struct fat_file_fd_s |
---|
| 59 | { |
---|
| 60 | Chain_Node link; /* |
---|
| 61 | * fat-file descriptors organized into hash; |
---|
| 62 | * collision lists are handled via link |
---|
| 63 | * field |
---|
| 64 | */ |
---|
| 65 | unsigned32 links_num; /* |
---|
| 66 | * the number of fat_file_open call on |
---|
| 67 | * this fat-file |
---|
| 68 | */ |
---|
| 69 | unsigned32 ino; /* inode, file serial number :)))) */ |
---|
| 70 | fat_file_type_t fat_file_type; |
---|
| 71 | unsigned32 size_limit; |
---|
| 72 | unsigned32 fat_file_size; /* length */ |
---|
| 73 | unsigned32 info_cln; |
---|
| 74 | unsigned32 cln; |
---|
| 75 | unsigned16 info_ofs; |
---|
| 76 | unsigned char first_char; |
---|
| 77 | unsigned8 flags; |
---|
| 78 | fat_file_map_t map; |
---|
| 79 | time_t mtime; |
---|
| 80 | |
---|
| 81 | } fat_file_fd_t; |
---|
| 82 | |
---|
| 83 | |
---|
| 84 | #define FAT_FILE_REMOVED 0x01 |
---|
| 85 | |
---|
| 86 | #define FAT_FILE_IS_REMOVED(p)\ |
---|
| 87 | (((p)->flags & FAT_FILE_REMOVED) ? 1 : 0) |
---|
| 88 | |
---|
| 89 | /* ioctl macros */ |
---|
| 90 | #define F_CLU_NUM 0x01 |
---|
| 91 | |
---|
| 92 | /* |
---|
| 93 | * Each file and directory on a MSDOS volume is unique identified by it |
---|
| 94 | * location, i.e. location of it 32 Bytes Directory Entry Structure. We can |
---|
| 95 | * distinguish them by cluster number it locates on and offset inside this |
---|
| 96 | * cluster. But root directory on any volumes (FAT12/16/32) has no 32 Bytes |
---|
| 97 | * Directory Entry Structure corresponded to it. So we assume 32 Bytes |
---|
| 98 | * Directory Entry Structure of root directory locates at cluster 1 (invalid |
---|
| 99 | * cluaster number) and offset 0 |
---|
| 100 | */ |
---|
| 101 | #define FAT_ROOTDIR_CLUSTER_NUM 0x01 |
---|
| 102 | |
---|
| 103 | #define FAT_FD_OF_ROOT_DIR(fat_fd) \ |
---|
| 104 | ((fat_fd->info_cln == FAT_ROOTDIR_CLUSTER_NUM ) && \ |
---|
| 105 | (fat_fd->info_ofs == 0)) |
---|
| 106 | |
---|
| 107 | #define FAT_EOF 0x00 |
---|
| 108 | |
---|
| 109 | /* fat_construct_key -- |
---|
| 110 | * Construct key for hash access: convert (cluster num, offset) to |
---|
| 111 | * (sector512 num, new offset) and than construct key as |
---|
| 112 | * key = (sector512 num) << 4 | (new offset) |
---|
| 113 | * |
---|
| 114 | * PARAMETERS: |
---|
| 115 | * cl - cluster number |
---|
| 116 | * ofs - offset inside cluster 'cl' |
---|
| 117 | * mt_entry - mount table entry |
---|
| 118 | * |
---|
| 119 | * RETURNS: |
---|
| 120 | * constructed key |
---|
| 121 | */ |
---|
| 122 | static inline unsigned32 |
---|
| 123 | fat_construct_key( |
---|
| 124 | rtems_filesystem_mount_table_entry_t *mt_entry, |
---|
| 125 | unsigned32 cl, |
---|
| 126 | unsigned32 ofs) |
---|
| 127 | { |
---|
| 128 | return ( ((fat_cluster_num_to_sector512_num(mt_entry, cl) + |
---|
| 129 | (ofs >> FAT_SECTOR512_BITS)) << 4) + |
---|
| 130 | ((ofs >> 5) & (FAT_DIRENTRIES_PER_SEC512 - 1)) ); |
---|
| 131 | } |
---|
| 132 | |
---|
| 133 | /* Prototypes for "fat-file" operations */ |
---|
| 134 | int |
---|
| 135 | fat_file_open(rtems_filesystem_mount_table_entry_t *mt_entry, |
---|
| 136 | unsigned32 cln, |
---|
| 137 | unsigned32 ofs, |
---|
| 138 | fat_file_fd_t **fat_fd); |
---|
| 139 | |
---|
| 140 | int |
---|
| 141 | fat_file_reopen(fat_file_fd_t *fat_fd); |
---|
| 142 | |
---|
| 143 | int |
---|
| 144 | fat_file_close(rtems_filesystem_mount_table_entry_t *mt_entry, |
---|
| 145 | fat_file_fd_t *fat_fd); |
---|
| 146 | |
---|
| 147 | ssize_t |
---|
| 148 | fat_file_read(rtems_filesystem_mount_table_entry_t *mt_entry, |
---|
| 149 | fat_file_fd_t *fat_fd, |
---|
| 150 | unsigned32 start, |
---|
| 151 | unsigned32 count, |
---|
| 152 | char *buf); |
---|
| 153 | |
---|
| 154 | ssize_t |
---|
| 155 | fat_file_write(rtems_filesystem_mount_table_entry_t *mt_entry, |
---|
| 156 | fat_file_fd_t *fat_fd, |
---|
| 157 | unsigned32 start, |
---|
| 158 | unsigned32 count, |
---|
[9fff6bf] | 159 | const char *buf); |
---|
[f36a7bfc] | 160 | |
---|
| 161 | int |
---|
| 162 | fat_file_extend(rtems_filesystem_mount_table_entry_t *mt_entry, |
---|
| 163 | fat_file_fd_t *fat_fd, |
---|
| 164 | unsigned32 new_length, |
---|
| 165 | unsigned32 *a_length); |
---|
| 166 | |
---|
| 167 | int |
---|
| 168 | fat_file_truncate(rtems_filesystem_mount_table_entry_t *mt_entry, |
---|
| 169 | fat_file_fd_t *fat_fd, |
---|
| 170 | unsigned32 new_length); |
---|
| 171 | |
---|
| 172 | int |
---|
| 173 | fat_file_datasync(rtems_filesystem_mount_table_entry_t *mt_entry, |
---|
| 174 | fat_file_fd_t *fat_fd); |
---|
| 175 | |
---|
| 176 | |
---|
| 177 | int |
---|
| 178 | fat_file_ioctl(rtems_filesystem_mount_table_entry_t *mt_entry, |
---|
| 179 | fat_file_fd_t *fat_fd, |
---|
| 180 | int cmd, |
---|
| 181 | ...); |
---|
| 182 | |
---|
| 183 | int |
---|
| 184 | fat_file_size(rtems_filesystem_mount_table_entry_t *mt_entry, |
---|
| 185 | fat_file_fd_t *fat_fd); |
---|
| 186 | |
---|
| 187 | void |
---|
| 188 | fat_file_mark_removed(rtems_filesystem_mount_table_entry_t *mt_entry, |
---|
| 189 | fat_file_fd_t *fat_fd); |
---|
| 190 | |
---|
| 191 | #ifdef __cplusplus |
---|
| 192 | } |
---|
| 193 | #endif |
---|
| 194 | |
---|
| 195 | #endif /* __DOSFS_FAT_FILE_H__ */ |
---|