Home | History | Annotate | Download | only in fatblock
      1 /*
      2  * Copyright (C) 2010 The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 #ifndef FAT_H
     18 #define FAT_H
     19 
     20 #include <stdint.h>
     21 
     22 #include "fatblock.h"
     23 
     24 typedef uint32_t cluster_t;
     25 typedef uint64_t sector_t;
     26 typedef cluster_t fat_entry_t;
     27 
     28 struct fat_boot_sector {
     29 	uint8_t jump[3];
     30 	char name[8];
     31 	uint16_t sector_size;
     32 	uint8_t sectors_per_cluster;
     33 	uint16_t reserved_sectors;
     34 	uint8_t fats;
     35 	uint16_t rootdir_size;
     36 	uint16_t sectors16;
     37 	uint8_t media_desc;
     38 	uint16_t fat_sectors16;
     39 	uint16_t sectors_per_track;
     40 	uint16_t heads;
     41 	uint32_t hidden_sectors;
     42 	uint32_t sectors32;
     43 	uint32_t fat_sectors32;
     44 	uint16_t fat_flags;
     45 	uint16_t version;
     46 	cluster_t rootdir_start;
     47 	uint16_t fs_info_sector;
     48 	uint16_t backup_boot_sector;
     49 	uint8_t reserved1[12];
     50 	uint8_t phys_drive;
     51 	uint8_t reserved2;
     52 	uint8_t ext_boot_sig;
     53 	uint32_t serial;
     54 	char vol_label[11];
     55 	char type[8];
     56 	char boot_code[420];
     57 	uint8_t boot_sig[2];
     58 } __attribute__((__packed__));
     59 
     60 #define FAT_MEDIA_DESC_FIXED 0xF8
     61 
     62 #define FAT_PHYS_DRIVE_REMOVABLE 0x00
     63 #define FAT_PHYS_DRIVE_FIXED     0x80
     64 
     65 #define FAT_EXT_BOOT_SIG 0x29
     66 
     67 extern const char FAT_BOOT_SIG[2];
     68 
     69 extern const char FAT_INFO_SIG1[4];
     70 extern const char FAT_INFO_SIG2[4];
     71 #define FAT_INFO_SIG3 FAT_BOOT_SIG
     72 
     73 struct fat_info_sector {
     74 	char info_sig1[4];
     75 	char reserved1[480];
     76 	char info_sig2[4];
     77 	cluster_t free_clusters;
     78 	cluster_t last_cluster;
     79 	char reserved2[14];
     80 	char info_sig3[2];
     81 } __attribute__((__packed__));
     82 
     83 struct fat_bootinfo {
     84 	struct fat_boot_sector boot;
     85 	struct fat_info_sector info;
     86 } __attribute__((__packed__));
     87 
     88 struct fat_dirent {
     89 	char name[11];
     90 	uint8_t attr;
     91 	uint8_t reserved;
     92 	uint8_t ctime_ms;
     93 	uint16_t ctime;
     94 	uint16_t cdate;
     95 	uint16_t adate;
     96 	uint16_t first_cluster_hi;
     97 	uint16_t mtime;
     98 	uint16_t mdate;
     99 	uint16_t first_cluster_lo;
    100 	uint32_t size;
    101 } __attribute__((__packed__));
    102 
    103 #define FAT_ATTR_READONLY 0x01
    104 #define FAT_ATTR_HIDDEN   0x02
    105 #define FAT_ATTR_SYSTEM   0x04
    106 #define FAT_ATTR_VOLLABEL 0x08
    107 #define FAT_ATTR_SUBDIR   0x10
    108 #define FAT_ATTR_ARCHIVE  0x20
    109 #define FAT_ATTR_DEVICE   0x40
    110 
    111 #define FAT_ENTRY_FREE  0x00000000
    112 #define FAT_ENTRY_BAD   0x0FFFFFF7
    113 #define FAT_ENTRY_EOC   0x0FFFFFF8
    114 
    115 #define FAT_SECTOR_SIZE 512
    116 #define FAT_CLUSTER_ZERO 2
    117 #define FAT_ENTRIES_PER_SECTOR ((SECTOR_SIZE) / (sizeof(fat_entry_t)))
    118 
    119 void fat_dirent_set_first_cluster(struct fat_dirent *de, cluster_t cluster);
    120 void fat_dirent_set(struct fat_dirent *de,
    121                     char *name, uint8_t attr,
    122                     cluster_t first_cluster, uint32_t size);
    123 
    124 #endif
    125