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- /****************************************************************************
- * fs/cromfs/cromfs.h
- *
- * Copyright (C) 2018 Gregory Nutt. All rights reserved.
- * Author: Gregory Nutt <gnutt@nuttx.org>
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
- * are met:
- *
- * 1. Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- * 2. 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.
- * 3. Neither the name NuttX nor the names of its contributors may be
- * used to endorse or promote products derived from this software
- * without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "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
- * COPYRIGHT OWNER OR CONTRIBUTORS 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.
- *
- ****************************************************************************/
- #ifndef __FS_CROMFS_CROMFS_H
- #define __FS_CROMFS_CROMFS_H
- /****************************************************************************
- * Included Files
- ****************************************************************************/
- #include <sys/types.h>
- #include <stdint.h>
- /****************************************************************************
- * Public Types
- ****************************************************************************/
- /* Maximum size of an offset. This should normally be size_t since this is
- * an in-memory file system. However, uint32_t is 32-bits on most 32-bit
- * target machines but 64-bits on 64-host machines. We restrict offsets to
- * 32-bits for commonality (limiting the size of the CROMFS image to 4Gb).
- *
- * REVISIT: What about small memory systems where the size_t is only 16-bits?
- *
- * Similarly, the NuttX mode_t is only 16-bits so uint16_t is explicitly used
- * for NuttX file modes.
- */
- /* This structure describes the CROMFS volume. It provides most of the
- * information needed for statfs() including:
- *
- * f_type - Type of filesystem
- * Return cv_magic (CROMFS_MAGIC)
- * f_namelen - Maximum length of filenames
- * Return NAME_MAX
- * f_bsize - Optimal block size for transfers
- * Return cv_bsize, the block size used when file system was
- * compressed
- * f_blocks - Total data blocks in the file system
- * - Return cv_nblocks
- * f_bfree - Free blocks in the file system
- * Return 0
- * f_bavail - Free blocks avail to non-superuser
- * Return 0
- * f_files - Total file nodes in the file system
- * - Return cv_nnodes
- * f_ffree - Free file nodes in the file system
- * Return 0
- *
- * The volume header is followed immediately by the root directory node. An
- * offset to that node is used to permit future variable length data (such as
- * a volume name) which may intervene.
- */
- struct cromfs_volume_s
- {
- uint32_t cv_magic; /* Must be first. Must be CROMFS_MAGIC */
- uint16_t cv_nnodes; /* Total number of nodes in-use */
- uint16_t cv_nblocks; /* Total number of data blocks in-use */
- uint32_t cv_root; /* Offset to the first node in the root file system */
- uint32_t cv_fsize; /* Size of the compressed file system image */
- uint32_t cv_bsize; /* Optimal block size for transfers */
- };
- /* This describes one node in the CROMFS file system. It holds node meta data
- * that provides the information that will be return by stat() or fstat()
- * and also provides the information needed by the CROMFS file system to
- * access the node data.
- *
- * Relationship to struct stat:
- *
- * st_mode - File type, attributes, and access mode bits
- * Return cn_mode from the node structure
- * st_size - Size of file/directory, in bytes
- * Return cn_size from the node structure
- * st_blksize - Block size used for filesystem I/O
- * Return cv_bsize from the volume header.
- * st_blocks - Number of blocks allocated
- * Return (cn_size + (cv_bsize - 1)) / cv_bsize
- * st_atime - Time of last access
- * Return 0
- * st_mtime - Time of last modification
- * Return 0
- * st_ctime - Time of last status change
- * Return 0
- */
- struct cromfs_node_s
- {
- uint16_t cn_mode; /* File type, attributes, and access mode bits */
- uint16_t cn_pad; /* Not used */
- uint32_t cn_name; /* Offset from the beginning of the volume header to the
- * node name string. NUL-terminated. */
- uint32_t cn_size; /* Size of the uncompressed data (in bytes) */
- uint32_t cn_peer; /* Offset to next node in this directory (for readdir()) */
- union
- {
- uint32_t cn_child; /* Offset to first node in sub-directory (directories only) */
- uint32_t cn_link; /* Offset to an arbitrary node (for hard link) */
- uint32_t cn_blocks; /* Offset to first block of compressed data (for read) */
- } u;
- };
- #endif /* __FS_CROMFS_CROMFS_H */
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