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Diffstat (limited to 'c/src/exec/libfs/src/dosfs/fat_file.h')
| -rw-r--r-- | c/src/exec/libfs/src/dosfs/fat_file.h | 195 |
1 files changed, 195 insertions, 0 deletions
diff --git a/c/src/exec/libfs/src/dosfs/fat_file.h b/c/src/exec/libfs/src/dosfs/fat_file.h new file mode 100644 index 0000000000..2821a27cf7 --- /dev/null +++ b/c/src/exec/libfs/src/dosfs/fat_file.h @@ -0,0 +1,195 @@ +/* + * fat_file.h + * + * Constants/data structures/prototypes for operations on "fat-file" + * + * Copyright (C) 2001 OKTET Ltd., St.-Petersburg, Russia + * Author: Eugeny S. Mints <Eugeny.Mints@oktet.ru> + * + * The license and distribution terms for this file may be + * found in the file LICENSE in this distribution or at + * http://www.OARcorp.com/rtems/license.html. + * + * @(#) $Id$ + */ +#ifndef __DOSFS_FAT_FILE_H__ +#define __DOSFS_FAT_FILE_H__ + +#ifdef __cplusplus +extern "C" { +#endif + +#include <rtems.h> +#include <rtems/libio_.h> + +#include <time.h> + +/* "fat-file" representation + * + * the idea is: fat-file is nothing but a cluster chain, any open fat-file is + * represented in system by fat-file descriptor and has well-known + * file interface: + * + * fat_file_open() + * fat_file_close() + * fat_file_read() + * fat_file_write() + * + * Such interface hides the architecture of fat-file and represents it like + * linear file + */ + +typedef rtems_filesystem_node_types_t fat_file_type_t; + +#define FAT_DIRECTORY RTEMS_FILESYSTEM_DIRECTORY +#define FAT_FILE RTEMS_FILESYSTEM_MEMORY_FILE + +typedef struct fat_file_map_s +{ + unsigned32 file_cln; + unsigned32 disk_cln; + unsigned32 last_cln; +} fat_file_map_t; +/* + * descriptor of a fat-file + * + * To each particular clusters chain + */ +typedef struct fat_file_fd_s +{ + Chain_Node link; /* + * fat-file descriptors organized into hash; + * collision lists are handled via link + * field + */ + unsigned32 links_num; /* + * the number of fat_file_open call on + * this fat-file + */ + unsigned32 ino; /* inode, file serial number :)))) */ + fat_file_type_t fat_file_type; + unsigned32 size_limit; + unsigned32 fat_file_size; /* length */ + unsigned32 info_cln; + unsigned32 cln; + unsigned16 info_ofs; + unsigned char first_char; + unsigned8 flags; + fat_file_map_t map; + time_t mtime; + +} fat_file_fd_t; + + +#define FAT_FILE_REMOVED 0x01 + +#define FAT_FILE_IS_REMOVED(p)\ + (((p)->flags & FAT_FILE_REMOVED) ? 1 : 0) + +/* ioctl macros */ +#define F_CLU_NUM 0x01 + +/* + * Each file and directory on a MSDOS volume is unique identified by it + * location, i.e. location of it 32 Bytes Directory Entry Structure. We can + * distinguish them by cluster number it locates on and offset inside this + * cluster. But root directory on any volumes (FAT12/16/32) has no 32 Bytes + * Directory Entry Structure corresponded to it. So we assume 32 Bytes + * Directory Entry Structure of root directory locates at cluster 1 (invalid + * cluaster number) and offset 0 + */ +#define FAT_ROOTDIR_CLUSTER_NUM 0x01 + +#define FAT_FD_OF_ROOT_DIR(fat_fd) \ + ((fat_fd->info_cln == FAT_ROOTDIR_CLUSTER_NUM ) && \ + (fat_fd->info_ofs == 0)) + +#define FAT_EOF 0x00 + +/* fat_construct_key -- + * Construct key for hash access: convert (cluster num, offset) to + * (sector512 num, new offset) and than construct key as + * key = (sector512 num) << 4 | (new offset) + * + * PARAMETERS: + * cl - cluster number + * ofs - offset inside cluster 'cl' + * mt_entry - mount table entry + * + * RETURNS: + * constructed key + */ +static inline unsigned32 +fat_construct_key( + rtems_filesystem_mount_table_entry_t *mt_entry, + unsigned32 cl, + unsigned32 ofs) +{ + return ( ((fat_cluster_num_to_sector512_num(mt_entry, cl) + + (ofs >> FAT_SECTOR512_BITS)) << 4) + + ((ofs >> 5) & (FAT_DIRENTRIES_PER_SEC512 - 1)) ); +} + +/* Prototypes for "fat-file" operations */ +int +fat_file_open(rtems_filesystem_mount_table_entry_t *mt_entry, + unsigned32 cln, + unsigned32 ofs, + fat_file_fd_t **fat_fd); + +int +fat_file_reopen(fat_file_fd_t *fat_fd); + +int +fat_file_close(rtems_filesystem_mount_table_entry_t *mt_entry, + fat_file_fd_t *fat_fd); + +ssize_t +fat_file_read(rtems_filesystem_mount_table_entry_t *mt_entry, + fat_file_fd_t *fat_fd, + unsigned32 start, + unsigned32 count, + char *buf); + +ssize_t +fat_file_write(rtems_filesystem_mount_table_entry_t *mt_entry, + fat_file_fd_t *fat_fd, + unsigned32 start, + unsigned32 count, + char *buf); + +int +fat_file_extend(rtems_filesystem_mount_table_entry_t *mt_entry, + fat_file_fd_t *fat_fd, + unsigned32 new_length, + unsigned32 *a_length); + +int +fat_file_truncate(rtems_filesystem_mount_table_entry_t *mt_entry, + fat_file_fd_t *fat_fd, + unsigned32 new_length); + +int +fat_file_datasync(rtems_filesystem_mount_table_entry_t *mt_entry, + fat_file_fd_t *fat_fd); + + +int +fat_file_ioctl(rtems_filesystem_mount_table_entry_t *mt_entry, + fat_file_fd_t *fat_fd, + int cmd, + ...); + +int +fat_file_size(rtems_filesystem_mount_table_entry_t *mt_entry, + fat_file_fd_t *fat_fd); + +void +fat_file_mark_removed(rtems_filesystem_mount_table_entry_t *mt_entry, + fat_file_fd_t *fat_fd); + +#ifdef __cplusplus +} +#endif + +#endif /* __DOSFS_FAT_FILE_H__ */ |