//////////////////////////////////////////////////////////////////////////////// // File : fat32.h // Date : 01/09/2013 // Author : Alain Greiner / Marco Jankovic // Copyright (c) UPMC-LIP6 //////////////////////////////////////////////////////////////////////////////// #ifndef _FAT32_H #define _FAT32_H #include "giet_config.h" #include "kernel_locks.h" /*************** Partition Boot Sector Format **********************************/ // offset | length #define BS_JMPBOOT 0 , 3 #define BS_OEMNAME 3 , 8 #define BPB_BYTSPERSEC 11 , 2 #define BPB_SECPERCLUS 13 , 1 #define BPB_RSVDSECCNT 14 , 2 #define BPB_NUMFATS 16 , 1 #define BPB_ROOTENTCNT 17 , 2 #define BPB_TOTSEC16 19 , 2 #define BPB_MEDIA 21 , 1 #define BPB_FATSZ16 22 , 2 #define BPB_SECPERTRK 24 , 2 #define BPB_NUMHEADS 26 , 2 #define BPB_HIDDSEC 28 , 4 #define BPB_TOTSEC32 32 , 4 #define BPB_PARTITION_TABLE 446 , 64 // FAT 32 #define BPB_FAT32_FATSZ32 36 , 4 #define BPB_FAT32_EXTFLAGS 40 , 2 #define BPB_FAT32_FSVER 42 , 2 #define BPB_FAT32_ROOTCLUS 44 , 4 #define BPB_FAT32_FSINFO 48 , 2 #define BPB_FAT32_BKBOOTSEC 50 , 2 #define BS_FAT32_DRVNUM 64 , 1 #define BS_FAT32_BOOTSIG 66 , 1 #define BS_FAT32_VOLID 67 , 4 #define BS_FAT32_VOLLAB 71 , 11 #define BS_FAT32_FILSYSTYPE 82 , 8 // Partitions #define FIRST_PARTITION_ACTIVE 446 , 8 #define FIRST_PARTITION_BEGIN_LBA 454 , 4 #define FIRST_PARTITION_SIZE 458 , 4 #define SECOND_PARTITION_ACTIVE 462 , 8 #define SECOND_PARTITION_BEGIN_LBA 470 , 4 #define SECOND_PARTITION_SIZE 474 , 4 #define THIRD_PARTITION_ACTIVE 478 , 8 #define THIRD_PARTITION_BEGIN_LBA 486 , 4 #define THIRD_PARTITION_SIZE 490 , 4 #define FOURTH_PARTITION_ACTIVE 494 , 8 #define FOURTH_PARTITION_BEGIN_LBA 502 , 4 #define FOURTH_PARTITION_SIZE 506 , 4 /*******************************************************************************/ #define MBR_SIGNATURE_POSITION 510 , 2 #define MBR_SIGNATURE_VALUE 0xAA55 /************** FAT_FS_INFO SECTOR ********************************************/ #define FS_SIGNATURE_VALUE_1 0x52526141 #define FS_SIGNATURE_VALUE_2 0x72724161 #define FS_SIGNATURE_VALUE_3 0x000055AA #define FS_SIGNATURE_POSITION_1 0 , 4 #define FS_SIGNATURE_POSITION_2 484 , 4 #define FS_SIGNATURE_POSITION_3 508 , 4 #define FS_FREE_CLUSTERS 488 , 4 #define FS_FREE_CLUSTER_HINT 492 , 4 /*******************************************************************************/ #define DIR_ENTRY_SIZE 32 #define NAME_MAX_SIZE 31 /******* Directory Entry Structure (32 bytes) **********************************/ // offset | length #define DIR_NAME 0 , 11 // dir_entry name #define DIR_ATTR 11 , 1 // attributes #define DIR_NTRES 12 , 1 // reserved for the OS #define DIR_CRT_TIMES_TENTH 13 , 1 #define DIR_FST_CLUS_HI 20 , 2 // cluster index 16 MSB bits #define DIR_WRT_TIME 22 , 2 // time of last write #define DIR_WRT_DATE 24 , 2 // date of last write #define DIR_FST_CLUS_LO 26 , 2 // cluster index 16 LSB bit #define DIR_FILE_SIZE 28 , 4 // file size (up to 4 giga bytes) /*******************************************************************************/ /******* LFN Directory Entry Structure (32 bytes) *****************************/ // offset | length #define LDIR_ORD 0 , 1 // Sequence number (from 0x01 to 0x0f) #define LDIR_NAME_1 1 , 10 // name broken into 3 parts #define LDIR_ATTR 11 , 1 // attributes (must be 0x0F) #define LDIR_TYPE 12 , 1 // directory type (must be 0x00) #define LDIR_CHKSUM 13 , 1 // checksum of name in short dir #define LDIR_NAME_2 14 , 12 #define LDIR_RSVD 26 , 2 // artifact of previous fat (must be 0) #define LDIR_NAME_3 28 , 4 /*******************************************************************************/ /*********************** DIR_ATTR values (attributes) ************************/ #define ATTR_READ_ONLY 0x01 #define ATTR_HIDDEN 0x02 #define ATTR_SYSTEM 0x04 #define ATTR_VOLUME_ID 0x08 #define ATTR_DIRECTORY 0x10 #define ATTR_ARCHIVE 0x20 #define ATTR_LONG_NAME_MASK 0x0f // READ_ONLY|HIDDEN|SYSTEM|VOLUME_ID /*******************************************************************************/ /********************* DIR_ORD special values **********************************/ #define FREE_ENTRY 0xE5 // this entry is free in the directory #define NO_MORE_ENTRY 0x00 // no more entry in the directory /*******************************************************************************/ /******************** CLuster Index Special Values *****************************/ #define FREE_CLUSTER 0x00000000 #define RESERVED_CLUSTER 0x00000001 #define BAD_CLUSTER 0x0FFFFFF7 #define END_OF_CHAIN_CLUSTER_MIN 0x0ffffff8 #define END_OF_CHAIN_CLUSTER_MAX 0x0fffffff /*******************************************************************************/ #define FAT_INITIALISED 0xBABEF00D #ifndef _FAT32_SHARED #define _FAT32_SHARED typedef struct fat_file_info_s { unsigned int size; unsigned int offset; unsigned int is_dir; } fat_file_info_t; typedef struct fat_dirent_s { unsigned int cluster; unsigned int size; unsigned int is_dir; char name[36]; } fat_dirent_t; #define SEEK_SET 0 #define SEEK_CUR 1 #define O_RDONLY 0x01 #define O_TRUNC 0x10 #define O_CREATE 0x20 #endif // _FAT32_SHARED /******************************************************************************** This struct defines a non terminal node in a 64-tree implementing a File-Cache associated to an open file, or the Fat-Cache, associated to the FAT itself. Each node has 64 children, and we use the void* type, because the children can be non-terminal (fat_cache_node_t) or terminal (fat_cache_cluster_t). ********************************************************************************/ typedef struct fat_cache_node_s { void* children[64]; // pointers on the 64 children } fat_cache_node_t; /******************************************************************************** This struct defines a cluster descriptor, that is a leaf cell in a 64-tree. Each cluster descriptor contains a pointer on a 4K bytes buffer, and the lba on block device. ********************************************************************************/ typedef struct fat_cache_desc_s { unsigned int lba; // cluster lba on block device unsigned int dirty; // modified if non zero unsigned char* buffer; // pointer on the 4 Kbytes buffer } fat_cache_desc_t; /******************************************************************************** This struct defines a file/directory inode / size = 64 bytes ********************************************************************************/ typedef struct fat_inode_s { struct fat_inode_s* parent; // parent directory inode struct fat_inode_s* next; // next inode in same directory struct fat_inode_s* child; // first children inode (dir only) fat_cache_node_t* cache; // pointer on the file_cache root unsigned int cluster; // first cluster index in FAT unsigned int size; // number of bytes (file only) unsigned int count; // number open if file / 0 if dir unsigned short dentry; // directory entry index in parent unsigned char levels; // number of levels in file_cache unsigned char is_dir; // directory if non zero char name[32]; // file directory name } fat_inode_t; /******************************************************************************** This struct defines a file descriptor (handler) / size = 16 bytes ********************************************************************************/ typedef struct fat_file_desc_s { unsigned int seek; // current offset value (bytes) fat_inode_t* inode; // pointer on inode char allocated; // file descriptor allocated char read_only; // write protected char reserved[6]; // reserved } fat_file_desc_t; /******************************************************************************** This struct defines a FAT32 File system descriptor *******************************************************************************/ typedef struct fat_desc_s { unsigned char block_buffer[512]; // one block buffer (for FS_INFO) fat_file_desc_t fd[GIET_OPEN_FILES_MAX]; // file descriptors array spin_lock_t fat_lock; // global lock protecting FAT fat_inode_t* inode_tree_root; // Inode-Tree root pointer fat_cache_node_t* fat_cache_root; // Fat_Cache root pointer unsigned int fat_cache_levels; // number of levels in Fat-Cache unsigned int block_buffer_lba; // lba of block in block_buffer unsigned int initialised; // 0xBABEF00D when FAT initialised unsigned int sector_size; // must be 512 unsigned int cluster_size; // must be 4096 unsigned int fat_lba; // lba of first FAT sector unsigned int fat_sectors; // number of sectors in FAT region unsigned int data_lba; // lba of first DATA sector unsigned int data_sectors; // number of sectors inf DATA region unsigned int fs_info_lba; // lba of fs_info unsigned int first_free_cluster; // free cluster with smallest index unsigned int free_clusters_number; // total number of free clusters } fat_desc_t; /*********************** Extern Functions *************************************/ extern int _fat_init(); extern int _fat_open( char* pathname, // path from root unsigned int flags ); // O_CREATE/O_RDONLY extern int _fat_close( unsigned int fd_id ); // file descriptor extern int _fat_file_info( unsigned int fd_id, // file descriptor fat_file_info_t* info ); // file info struct extern int _fat_read( unsigned int fd_id, // file descriptor void* buffer, // destination buffer unsigned int count ); // number of bytes extern int _fat_write( unsigned int fd_id, // file descriptor void* buffer, // source buffer unsigned int count ); // number of bytes extern int _fat_lseek( unsigned int fd_id, // file descriptor unsigned int offset, // new offset value unsigned int whence ); // command type extern int _fat_remove( char* pathname, // path from root unsigned int should_be_dir ); // for checking extern int _fat_rename( char* old_path, // path from root char* new_path ); // path from root extern int _fat_mkdir( char* pathname ); // path from root extern int _fat_opendir( char* pathname ); // path from root extern int _fat_closedir( unsigned int fd_id ); // file descriptor extern int _fat_readdir( unsigned int fd_id, // file descriptor fat_dirent_t* entry ); // directory entry extern int _fat_load_no_cache( char* pathname, // path from root unsigned int buffer_vbase, // buffer base unsigned int buffer_size ); // buffer size /*******************************************************************************/ #endif // Local Variables: // tab-width: 4 // c-basic-offset: 4 // c-file-offsets:((innamespace . 0)(inline-open . 0)) // indent-tabs-mode: nil // End: // vim: filetype=c:expandtab:shiftwidth=4:tabstop=4:softtabstop=4