0,0 → 1,227 |
/* |
* Copyright (c) 2008 Jakub Jermar |
* All rights reserved. |
* |
* Redistribution and use in source and binary forms, with or without |
* modification, are permitted provided that the following conditions |
* are met: |
* |
* - Redistributions of source code must retain the above copyright |
* notice, this list of conditions and the following disclaimer. |
* - Redistributions in binary form must reproduce the above copyright |
* notice, this list of conditions and the following disclaimer in the |
* documentation and/or other materials provided with the distribution. |
* - The name of the author may not be used to endorse or promote products |
* derived from this software without specific prior written permission. |
* |
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR |
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. |
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, |
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
*/ |
|
/** @addtogroup fs |
* @{ |
*/ |
|
#ifndef FAT_FAT_H_ |
#define FAT_FAT_H_ |
|
#include <ipc/ipc.h> |
#include <libfs.h> |
#include <atomic.h> |
#include <sys/types.h> |
#include <bool.h> |
#include "../../vfs/vfs.h" |
|
#define dprintf(...) printf(__VA_ARGS__) |
|
typedef struct { |
uint8_t ji[3]; /**< Jump instruction. */ |
uint8_t oem_name[8]; |
/* BIOS Parameter Block */ |
uint16_t bps; /**< Bytes per sector. */ |
uint8_t spc; /**< Sectors per cluster. */ |
uint16_t rscnt; /**< Reserved sector count. */ |
uint8_t fatcnt; /**< Number of FATs. */ |
uint16_t root_ent_max; /**< Maximum number of root directory |
entries. */ |
uint16_t totsec16; /**< Total sectors. 16-bit version. */ |
uint8_t mdesc; /**< Media descriptor. */ |
uint16_t sec_per_fat; /**< Sectors per FAT12/FAT16. */ |
uint16_t sec_per_track; /**< Sectors per track. */ |
uint16_t headcnt; /**< Number of heads. */ |
uint32_t hidden_sec; /**< Hidden sectors. */ |
uint32_t totsec32; /**< Total sectors. 32-bit version. */ |
|
union { |
struct { |
/* FAT12/FAT16 only: Extended BIOS Parameter Block */ |
/** Physical drive number. */ |
uint8_t pdn; |
uint8_t reserved; |
/** Extended boot signature. */ |
uint8_t ebs; |
/** Serial number. */ |
uint32_t id; |
/** Volume label. */ |
uint8_t label[11]; |
/** FAT type. */ |
uint8_t type[8]; |
/** Boot code. */ |
uint8_t boot_code[448]; |
/** Boot sector signature. */ |
uint16_t signature; |
} __attribute__ ((packed)); |
struct { |
/* FAT32 only */ |
/** Sectors per FAT. */ |
uint32_t sectors_per_fat; |
/** FAT flags. */ |
uint16_t flags; |
/** Version. */ |
uint16_t version; |
/** Cluster number of root directory. */ |
uint32_t root_cluster; |
/** Sector number of file system information sector. */ |
uint16_t fsinfo_sec; |
/** Sector number of boot sector copy. */ |
uint16_t bscopy_sec; |
uint8_t reserved1[12]; |
/** Physical drive number. */ |
uint8_t pdn; |
uint8_t reserved2; |
/** Extended boot signature. */ |
uint8_t ebs; |
/** Serial number. */ |
uint32_t id; |
/** Volume label. */ |
uint8_t label[11]; |
/** FAT type. */ |
uint8_t type[8]; |
/** Boot code. */ |
uint8_t boot_code[420]; |
/** Signature. */ |
uint16_t signature; |
} __attribute__ ((packed)); |
}; |
} __attribute__ ((packed)) fat_bs_t; |
|
#define FAT_ATTR_RDONLY (1 << 0) |
#define FAT_ATTR_VOLLABEL (1 << 3) |
#define FAT_ATTR_SUBDIR (1 << 4) |
|
typedef struct { |
uint8_t name[8]; |
uint8_t ext[3]; |
uint8_t attr; |
uint8_t reserved; |
uint8_t ctime_fine; |
uint16_t ctime; |
uint16_t cdate; |
uint16_t adate; |
union { |
uint16_t eaidx; /* FAT12/FAT16 */ |
uint16_t firstc_hi; /* FAT32 */ |
}; |
uint16_t mtime; |
uint16_t mdate; |
union { |
uint16_t firstc; /* FAT12/FAT16 */ |
uint16_t firstc_lo; /* FAT32 */ |
}; |
uint32_t size; |
} __attribute__ ((packed)) fat_dentry_t; |
|
typedef uint16_t fat_cluster_t; |
|
typedef enum { |
FAT_INVALID, |
FAT_DIRECTORY, |
FAT_FILE |
} fat_node_type_t; |
|
struct fat_node; |
|
/** FAT index structure. |
* |
* This structure exists to help us to overcome certain limitations of the FAT |
* file system design. The problem with FAT is that it is hard to find |
* an entity which could represent a VFS index. There are two candidates: |
* |
* a) number of the node's first cluster |
* b) the pair of the parent directory's first cluster and the dentry index |
* within the parent directory |
* |
* We need VFS indices to be: |
* A) unique |
* B) stable in time, at least until the next mount |
* |
* Unfortunately a) does not meet the A) criterion because zero-length files |
* will have the first cluster field cleared. And b) does not meet the B) |
* criterion because unlink() and rename() will both free up the original |
* dentry, which contains all the essential info about the file. |
* |
* Therefore, a completely opaque indices are used and the FAT server maintains |
* a mapping between them and otherwise nice b) variant. On rename(), the VFS |
* index stays unaltered, while the internal FAT "physical tree address" |
* changes. The unlink case is also handled this way thanks to an in-core node |
* pointer embedded in the index structure. |
*/ |
typedef struct { |
/** Used indices (position) hash table link. */ |
link_t uph_link; |
/** Used indices (index) hash table link. */ |
link_t uih_link; |
|
dev_handle_t dev_handle; |
fs_index_t index; |
/** |
* Parent node's first cluster. |
* Zero is used if this node is not linked, in which case nodep must |
* contain a pointer to the in-core node structure. |
* One is used when the parent is the root directory. |
*/ |
fat_cluster_t pfc; |
/** Directory entry index within the parent node. */ |
unsigned pdi; |
/** Pointer to in-core node instance. */ |
struct fat_node *nodep; |
} fat_idx_t; |
|
/** FAT in-core node. */ |
typedef struct fat_node { |
fat_node_type_t type; |
fat_idx_t *idx; |
/** |
* Node's first cluster. |
* Zero is used for zero-length nodes. |
* One is used to mark root directory. |
*/ |
fat_cluster_t firstc; |
/** FAT in-core node free list link. */ |
link_t ffn_link; |
size_t size; |
unsigned lnkcnt; |
unsigned refcnt; |
bool dirty; |
} fat_node_t; |
|
extern fs_reg_t fat_reg; |
|
extern void fat_lookup(ipc_callid_t, ipc_call_t *); |
|
extern fat_idx_t *fat_idx_get_by_pos(dev_handle_t, fat_cluster_t, unsigned); |
extern fat_idx_t *fat_idx_get_by_index(dev_handle_t, fs_index_t); |
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#endif |
|
/** |
* @} |
*/ |