1 | //////////////////////////////////////////////////////////////////////////////// |
---|
2 | // File : fat32.h |
---|
3 | // Date : 01/09/2013 |
---|
4 | // Author : Alain Greiner / Marco Jankovic |
---|
5 | // Copyright (c) UPMC-LIP6 |
---|
6 | //////////////////////////////////////////////////////////////////////////////// |
---|
7 | |
---|
8 | #ifndef _FAT32_H |
---|
9 | #define _FAT32_H |
---|
10 | |
---|
11 | #include "fat32_shared.h" |
---|
12 | #include "giet_config.h" |
---|
13 | #include "kernel_locks.h" |
---|
14 | #include "mapping_info.h" |
---|
15 | |
---|
16 | /*************** Partition Boot Sector Format **********************************/ |
---|
17 | // offset | length |
---|
18 | #define BS_JMPBOOT 0 , 3 |
---|
19 | #define BS_OEMNAME 3 , 8 |
---|
20 | #define BPB_BYTSPERSEC 11 , 2 |
---|
21 | #define BPB_SECPERCLUS 13 , 1 |
---|
22 | #define BPB_RSVDSECCNT 14 , 2 |
---|
23 | #define BPB_NUMFATS 16 , 1 |
---|
24 | #define BPB_ROOTENTCNT 17 , 2 |
---|
25 | #define BPB_TOTSEC16 19 , 2 |
---|
26 | #define BPB_MEDIA 21 , 1 |
---|
27 | #define BPB_FATSZ16 22 , 2 |
---|
28 | #define BPB_SECPERTRK 24 , 2 |
---|
29 | #define BPB_NUMHEADS 26 , 2 |
---|
30 | #define BPB_HIDDSEC 28 , 4 |
---|
31 | #define BPB_TOTSEC32 32 , 4 |
---|
32 | #define BPB_PARTITION_TABLE 446 , 64 |
---|
33 | |
---|
34 | // FAT 32 |
---|
35 | #define BPB_FAT32_FATSZ32 36 , 4 |
---|
36 | #define BPB_FAT32_EXTFLAGS 40 , 2 |
---|
37 | #define BPB_FAT32_FSVER 42 , 2 |
---|
38 | #define BPB_FAT32_ROOTCLUS 44 , 4 |
---|
39 | #define BPB_FAT32_FSINFO 48 , 2 |
---|
40 | #define BPB_FAT32_BKBOOTSEC 50 , 2 |
---|
41 | #define BS_FAT32_DRVNUM 64 , 1 |
---|
42 | #define BS_FAT32_BOOTSIG 66 , 1 |
---|
43 | #define BS_FAT32_VOLID 67 , 4 |
---|
44 | #define BS_FAT32_VOLLAB 71 , 11 |
---|
45 | #define BS_FAT32_FILSYSTYPE 82 , 8 |
---|
46 | |
---|
47 | // Partitions |
---|
48 | #define FIRST_PARTITION_ACTIVE 446 , 8 |
---|
49 | #define FIRST_PARTITION_BEGIN_LBA 454 , 4 |
---|
50 | #define FIRST_PARTITION_SIZE 458 , 4 |
---|
51 | #define SECOND_PARTITION_ACTIVE 462 , 8 |
---|
52 | #define SECOND_PARTITION_BEGIN_LBA 470 , 4 |
---|
53 | #define SECOND_PARTITION_SIZE 474 , 4 |
---|
54 | #define THIRD_PARTITION_ACTIVE 478 , 8 |
---|
55 | #define THIRD_PARTITION_BEGIN_LBA 486 , 4 |
---|
56 | #define THIRD_PARTITION_SIZE 490 , 4 |
---|
57 | #define FOURTH_PARTITION_ACTIVE 494 , 8 |
---|
58 | #define FOURTH_PARTITION_BEGIN_LBA 502 , 4 |
---|
59 | #define FOURTH_PARTITION_SIZE 506 , 4 |
---|
60 | /*******************************************************************************/ |
---|
61 | |
---|
62 | #define MBR_SIGNATURE_POSITION 510 , 2 |
---|
63 | #define MBR_SIGNATURE_VALUE 0xAA55 |
---|
64 | |
---|
65 | /************** FAT_FS_INFO SECTOR ********************************************/ |
---|
66 | #define FS_SIGNATURE_VALUE_1 0x52526141 |
---|
67 | #define FS_SIGNATURE_VALUE_2 0x72724161 |
---|
68 | #define FS_SIGNATURE_VALUE_3 0x000055AA |
---|
69 | #define FS_SIGNATURE_POSITION_1 0 , 4 |
---|
70 | #define FS_SIGNATURE_POSITION_2 484 , 4 |
---|
71 | #define FS_SIGNATURE_POSITION_3 508 , 4 |
---|
72 | #define FS_FREE_CLUSTERS 488 , 4 |
---|
73 | #define FS_FREE_CLUSTER_HINT 492 , 4 |
---|
74 | /*******************************************************************************/ |
---|
75 | |
---|
76 | #define DIR_ENTRY_SIZE 32 |
---|
77 | |
---|
78 | #define NAME_MAX_SIZE 31 |
---|
79 | |
---|
80 | /******* Directory Entry Structure (32 bytes) **********************************/ |
---|
81 | // offset | length |
---|
82 | #define DIR_NAME 0 , 11 // dir_entry name |
---|
83 | #define DIR_ATTR 11 , 1 // attributes |
---|
84 | #define DIR_NTRES 12 , 1 // reserved for the OS |
---|
85 | #define DIR_CRT_TIMES_TENTH 13 , 1 |
---|
86 | #define DIR_FST_CLUS_HI 20 , 2 // cluster index 16 MSB bits |
---|
87 | #define DIR_WRT_TIME 22 , 2 // time of last write |
---|
88 | #define DIR_WRT_DATE 24 , 2 // date of last write |
---|
89 | #define DIR_FST_CLUS_LO 26 , 2 // cluster index 16 LSB bit |
---|
90 | #define DIR_FILE_SIZE 28 , 4 // file size (up to 4 giga bytes) |
---|
91 | /*******************************************************************************/ |
---|
92 | |
---|
93 | /******* LFN Directory Entry Structure (32 bytes) *****************************/ |
---|
94 | // offset | length |
---|
95 | #define LDIR_ORD 0 , 1 // Sequence number (from 0x01 to 0x0f) |
---|
96 | #define LDIR_NAME_1 1 , 10 // name broken into 3 parts |
---|
97 | #define LDIR_ATTR 11 , 1 // attributes (must be 0x0F) |
---|
98 | #define LDIR_TYPE 12 , 1 // directory type (must be 0x00) |
---|
99 | #define LDIR_CHKSUM 13 , 1 // checksum of name in short dir |
---|
100 | #define LDIR_NAME_2 14 , 12 |
---|
101 | #define LDIR_RSVD 26 , 2 // artifact of previous fat (must be 0) |
---|
102 | #define LDIR_NAME_3 28 , 4 |
---|
103 | /*******************************************************************************/ |
---|
104 | |
---|
105 | /*********************** DIR_ATTR values (attributes) ************************/ |
---|
106 | #define ATTR_READ_ONLY 0x01 |
---|
107 | #define ATTR_HIDDEN 0x02 |
---|
108 | #define ATTR_SYSTEM 0x04 |
---|
109 | #define ATTR_VOLUME_ID 0x08 |
---|
110 | #define ATTR_DIRECTORY 0x10 |
---|
111 | #define ATTR_ARCHIVE 0x20 |
---|
112 | #define ATTR_LONG_NAME_MASK 0x0f // READ_ONLY|HIDDEN|SYSTEM|VOLUME_ID |
---|
113 | /*******************************************************************************/ |
---|
114 | |
---|
115 | /********************* DIR_ORD special values **********************************/ |
---|
116 | #define FREE_ENTRY 0xE5 // this entry is free in the directory |
---|
117 | #define NO_MORE_ENTRY 0x00 // no more entry in the directory |
---|
118 | /*******************************************************************************/ |
---|
119 | |
---|
120 | /******************** CLuster Index Special Values *****************************/ |
---|
121 | #define FREE_CLUSTER 0x00000000 |
---|
122 | #define RESERVED_CLUSTER 0x00000001 |
---|
123 | #define BAD_CLUSTER 0x0FFFFFF7 |
---|
124 | #define END_OF_CHAIN_CLUSTER_MIN 0x0ffffff8 |
---|
125 | #define END_OF_CHAIN_CLUSTER_MAX 0x0fffffff |
---|
126 | /*******************************************************************************/ |
---|
127 | |
---|
128 | #define FAT_INITIALIZED 0xBABEF00D |
---|
129 | |
---|
130 | /******************************************************************************** |
---|
131 | This struct defines a non terminal node in a 64-tree implementing a File-Cache |
---|
132 | associated to an open file, or the Fat-Cache, associated to the FAT itself. |
---|
133 | Each node has 64 children, and we use the void* type, because the children |
---|
134 | can be non-terminal (fat_cache_node_t) or terminal (fat_cache_cluster_t). |
---|
135 | ********************************************************************************/ |
---|
136 | |
---|
137 | typedef struct fat_cache_node_s |
---|
138 | { |
---|
139 | void* children[64]; // pointers on the 64 children |
---|
140 | } fat_cache_node_t; |
---|
141 | |
---|
142 | |
---|
143 | /******************************************************************************** |
---|
144 | This struct defines a cluster descriptor, that is a leaf cell in a 64-tree. |
---|
145 | Each cluster descriptor contains a pointer on a 4K bytes buffer, and the |
---|
146 | lba on block device. |
---|
147 | ********************************************************************************/ |
---|
148 | |
---|
149 | typedef struct fat_cache_desc_s |
---|
150 | { |
---|
151 | unsigned int lba; // cluster lba on block device |
---|
152 | unsigned int dirty; // modified if non zero |
---|
153 | unsigned char* buffer; // pointer on the 4 Kbytes buffer |
---|
154 | } fat_cache_desc_t; |
---|
155 | |
---|
156 | |
---|
157 | /******************************************************************************** |
---|
158 | This struct defines a file/directory inode / size = 64 bytes |
---|
159 | ********************************************************************************/ |
---|
160 | |
---|
161 | typedef struct fat_inode_s |
---|
162 | { |
---|
163 | struct fat_inode_s* parent; // parent directory inode |
---|
164 | struct fat_inode_s* next; // next inode in same directory |
---|
165 | struct fat_inode_s* child; // first children inode (dir only) |
---|
166 | fat_cache_node_t* cache; // pointer on the file_cache root |
---|
167 | unsigned int cluster; // first cluster index in FAT |
---|
168 | unsigned int size; // number of bytes (file only) |
---|
169 | unsigned int count; // number open if file / 0 if dir |
---|
170 | unsigned short dentry; // directory entry index in parent |
---|
171 | unsigned char levels; // number of levels in file_cache |
---|
172 | unsigned char is_dir; // directory if non zero |
---|
173 | char name[32]; // file directory name |
---|
174 | } fat_inode_t; |
---|
175 | |
---|
176 | /******************************************************************************** |
---|
177 | This struct defines a file descriptor (handler) / size = 16 bytes |
---|
178 | ********************************************************************************/ |
---|
179 | |
---|
180 | typedef struct fat_file_desc_s |
---|
181 | { |
---|
182 | unsigned int seek; // current offset value (bytes) |
---|
183 | fat_inode_t* inode; // pointer on inode |
---|
184 | char allocated; // file descriptor allocated |
---|
185 | char read_only; // write protected |
---|
186 | char reserved[6]; // reserved |
---|
187 | } fat_file_desc_t; |
---|
188 | |
---|
189 | /******************************************************************************** |
---|
190 | This struct defines a FAT32 File system descriptor |
---|
191 | *******************************************************************************/ |
---|
192 | |
---|
193 | typedef struct fat_desc_s |
---|
194 | { |
---|
195 | unsigned char block_buffer[512]; // one block buffer (for FS_INFO) |
---|
196 | fat_file_desc_t fd[GIET_OPEN_FILES_MAX]; // file descriptors array |
---|
197 | spin_lock_t fat_lock; // global lock protecting FAT |
---|
198 | fat_inode_t* inode_tree_root; // Inode-Tree root pointer |
---|
199 | fat_cache_node_t* fat_cache_root; // Fat_Cache root pointer |
---|
200 | unsigned int fat_cache_levels; // number of levels in Fat-Cache |
---|
201 | unsigned int block_buffer_lba; // lba of block in block_buffer |
---|
202 | unsigned int initialized; // 0xBABEF00D when FAT initialized |
---|
203 | unsigned int sector_size; // must be 512 |
---|
204 | unsigned int cluster_size; // must be 4096 |
---|
205 | unsigned int fat_lba; // lba of first FAT sector |
---|
206 | unsigned int fat_sectors; // number of sectors in FAT region |
---|
207 | unsigned int data_lba; // lba of first DATA sector |
---|
208 | unsigned int data_sectors; // number of sectors inf DATA region |
---|
209 | unsigned int fs_info_lba; // lba of fs_info |
---|
210 | unsigned int first_free_cluster; // free cluster with smallest index |
---|
211 | unsigned int free_clusters_number; // total number of free clusters |
---|
212 | } fat_desc_t; |
---|
213 | |
---|
214 | |
---|
215 | /*********************** Extern Functions *************************************/ |
---|
216 | |
---|
217 | extern int _fat_init(); |
---|
218 | |
---|
219 | extern int _fat_open( char* pathname, // path from root |
---|
220 | unsigned int flags ); // O_CREATE/O_RDONLY |
---|
221 | |
---|
222 | extern int _fat_close( unsigned int fd_id ); // file descriptor |
---|
223 | |
---|
224 | extern int _fat_file_info( unsigned int fd_id, // file descriptor |
---|
225 | fat_file_info_t* info ); // file info struct |
---|
226 | |
---|
227 | extern int _fat_read( unsigned int fd_id, // file descriptor |
---|
228 | unsigned int vaddr, // destination buffer |
---|
229 | unsigned int count, // number of bytes |
---|
230 | unsigned int extend ); // physical addressing |
---|
231 | |
---|
232 | extern int _fat_write( unsigned int fd_id, // file descriptor |
---|
233 | unsigned int vaddr, // source buffer |
---|
234 | unsigned int count, // number of bytes |
---|
235 | unsigned int extend ); // physical addressing |
---|
236 | |
---|
237 | extern int _fat_lseek( unsigned int fd_id, // file descriptor |
---|
238 | unsigned int offset, // new offset value |
---|
239 | unsigned int whence ); // command type |
---|
240 | |
---|
241 | extern int _fat_remove( char* pathname, // path from root |
---|
242 | unsigned int should_be_dir ); // for checking |
---|
243 | |
---|
244 | extern int _fat_rename( char* old_path, // path from root |
---|
245 | char* new_path ); // path from root |
---|
246 | |
---|
247 | extern int _fat_mkdir( char* pathname ); // path from root |
---|
248 | |
---|
249 | extern int _fat_opendir( char* pathname ); // path from root |
---|
250 | |
---|
251 | extern int _fat_closedir( unsigned int fd_id ); // file descriptor |
---|
252 | |
---|
253 | extern int _fat_readdir( unsigned int fd_id, // file descriptor |
---|
254 | fat_dirent_t* entry ); // directory entry |
---|
255 | |
---|
256 | extern int _fat_load_no_cache( char* pathname, // path from root |
---|
257 | unsigned int buffer_vbase, // buffer base |
---|
258 | unsigned int buffer_size ); // buffer size |
---|
259 | |
---|
260 | /*******************************************************************************/ |
---|
261 | |
---|
262 | |
---|
263 | #endif |
---|
264 | |
---|
265 | |
---|
266 | // Local Variables: |
---|
267 | // tab-width: 4 |
---|
268 | // c-basic-offset: 4 |
---|
269 | // c-file-offsets:((innamespace . 0)(inline-open . 0)) |
---|
270 | // indent-tabs-mode: nil |
---|
271 | // End: |
---|
272 | // vim: filetype=c:expandtab:shiftwidth=4:tabstop=4:softtabstop=4 |
---|
273 | |
---|