Addes CROMFS prototype. CROMFS is a commpressed, in-memory read-only file system based on LZF.

Squashed commit of the following:

    fs/cromfs:  Now depends on EXPERIMENTAL because it is not yet verified.
    fs/cromfs:  This commit brings the CROMFS file system to code complete.  Still completely untested.  Next steps:  Need a tool to generate CROMFS file system images and a test case under apps/
    fs/cromfs:  Add logic to traverse the in-memory file system nodes.
    fs/cromfs:  Add initial support for an in-memory, compressed, read-only file system.

fs/Kconfig

@@ -81,6 +81,7 @@ source fs/fat/Kconfig
 source fs/nfs/Kconfig
 source fs/nxffs/Kconfig
 source fs/romfs/Kconfig
+source fs/cromfs/Kconfig
 source fs/tmpfs/Kconfig
 source fs/smartfs/Kconfig
 source fs/binfs/Kconfig

fs/Makefile

@@ -1,7 +1,7 @@
 ############################################################################
 # fs/Makefile
 #
-#   Copyright (C) 2007, 2008, 2011-2014, 2016-2017 Gregory Nutt. All rights
+#   Copyright (C) 2007, 2008, 2011-2014, 2016-2018 Gregory Nutt. All rights
 #     reserved.
 #   Author: Gregory Nutt <gnutt@nuttx.org>
 #
@@ -65,6 +65,7 @@ ifneq ($(CONFIG_DISABLE_MOUNTPOINT),y)
 include mount/Make.defs
 include fat/Make.defs
 include romfs/Make.defs
+include cromfs/Make.defs
 include tmpfs/Make.defs
 include nxffs/Make.defs
 include nfs/Make.defs

fs/cromfs/Kconfig

@@ -0,0 +1,15 @@
+#
+# For a description of the syntax of this configuration file,
+# see the file kconfig-language.txt in the NuttX tools repository.
+#
+
+config FS_CROMFS
+	bool "CROMFS file system"
+	default n
+	depends on !DISABLE_MOUNTPOINT && EXPERIMENTAL
+	select FS_READABLE
+	---help---
+		Enable Compessed Read-Only Filesystem (CROMFS) support
+
+if FS_CROMFS
+endif

fs/cromfs/Make.defs

@@ -0,0 +1,47 @@
+############################################################################
+# fs/cromfs/Make.defs
+#
+#   Copyright (C) 2008 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.
+#
+############################################################################
+
+ifeq ($(CONFIG_FS_CROMFS),y)
+# Files required for CROMFS file system support
+
+ASRCS +=
+CSRCS += fs_cromfs.c
+
+# Include ROMFS build support
+
+DEPPATH += --dep-path cromfs
+VPATH += :cromfs
+
+endif

fs/cromfs/cromfs.h

@@ -0,0 +1,127 @@
+/****************************************************************************
+ * 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 1
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <sys/types.h>
+#include <stdint.h>
+
+/****************************************************************************
+ * Public Types
+ ****************************************************************************/
+
+/* 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 volumne name) which may intervene.
+ *
+ * Since this is an in-memory file system, size_t is the most relevant type for
+ * internal file system offsets.
+ */
+
+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 */
+  size_t cv_root;        /* Offset to the first node in the root file system */
+  size_t cv_fsize;       /* Size of the compressed file system image */
+  size_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
+{
+  mode_t cn_mode;        /* File type, attributes, and access mode bits */
+  size_t cn_name;        /* Offset from the beginning of the volume header to the
+                          * node name string.  NUL-terminated. */
+  size_t cn_size;        /* Size of the uncompressed data (in bytes) */
+  size_t cn_peer;        /* Offset to next node in this directory (for readdir())*/
+  union                  /* Must be last */
+  {
+    size_t cn_child;     /* Offset to first node in sub-directory (directories only) */
+    size_t cn_link;      /* Offset to an arbitrary node (for hard link) */
+    size_t cn_blocks;    /* Offset to first block of compressed data (for read) */
+  } u;
+};
+
+#endif /* __FS_CROMFS_CROMFS_H */

fs/mount/fs_mount.c

@@ -79,7 +79,8 @@
 
 #if defined(CONFIG_FS_NXFFS) || defined(CONFIG_FS_BINFS) || \
     defined(CONFIG_FS_PROCFS) || defined(CONFIG_NFS) || \
-    defined(CONFIG_FS_TMPFS) || defined(CONFIG_FS_USERFS)
+    defined(CONFIG_FS_TMPFS) || defined(CONFIG_FS_USERFS) || \
+    defined(CONFIG_FS_CROMFS)
 #  define NONBDFS_SUPPORT
 #endif
 
@@ -145,6 +146,9 @@ extern const struct mountpt_operations userfs_operations;
 #ifdef CONFIG_FS_HOSTFS
 extern const struct mountpt_operations hostfs_operations;
 #endif
+#ifdef CONFIG_FS_CROMFS
+extern const struct mountpt_operations cromfs_operations;
+#endif
 
 static const struct fsmap_t g_nonbdfsmap[] =
 {
@@ -168,6 +172,9 @@ static const struct fsmap_t g_nonbdfsmap[] =
 #endif
 #ifdef CONFIG_FS_HOSTFS
     { "hostfs", &hostfs_operations },
+#endif
+#ifdef CONFIG_FS_CROMFS
+    { "cromfs", &cromfs_operations },
 #endif
     { NULL, NULL },
 };

include/nuttx/fs/dirent.h

@@ -1,7 +1,8 @@
 /****************************************************************************
  * include/nuttx/fs/dirent.h
  *
- *   Copyright (C) 2007, 2009, 2011-2013, 2015 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2007, 2009, 2011-2013, 2015, 20189 Gregory Nutt. All
+ *     rights reserved.
  *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -102,6 +103,16 @@ struct fs_romfsdir_s
 };
 #endif /* CONFIG_FS_ROMFS */
 
+#ifdef CONFIG_FS_CROMFS
+/* For CROMFS, we need to return the next compressed node to be examined. */
+
+struct fs_cromfsdir_s
+{
+  off_t        cr_firstoffset;         /* Offset to the first entry in the directory */
+  off_t        cr_curroffset;          /* Current offset into the directory contents */
+};
+#endif /* CONFIG_FS_ROMFS */
+
 #ifdef CONFIG_FS_TMPFS
 /* For TMPFS, we need the directory object and an index into the directory
  * entries.
@@ -244,6 +255,9 @@ struct fs_dirent_s
 #ifdef CONFIG_FS_ROMFS
       struct fs_romfsdir_s   romfs;
 #endif
+#ifdef CONFIG_FS_ROMFS
+      struct fs_cromfsdir_s  cromfs;
+#endif
 #ifdef CONFIG_FS_TMPFS
       struct fs_tmpfsdir_s   tmpfs;
 #endif

include/sys/stat.h

@@ -122,9 +122,9 @@ struct stat
 {
   /* Required, standard fields */
 
-  mode_t    st_mode;    /* File type, atributes, and access mode bits */
+  mode_t    st_mode;    /* File type, attributes, and access mode bits */
   off_t     st_size;    /* Size of file/directory, in bytes */
-  blksize_t st_blksize; /* Blocksize used for filesystem I/O */
+  blksize_t st_blksize; /* Block size used for filesystem I/O */
   blkcnt_t  st_blocks;  /* Number of blocks allocated */
   time_t    st_atime;   /* Time of last access */
   time_t    st_mtime;   /* Time of last modification */

include/sys/statfs.h

@@ -105,6 +105,7 @@
 #define UNIONFS_MAGIC         0x53464e55
 #define HOSTFS_MAGIC          0x54534f48
 #define USERFS_MAGIC          0x52455355
+#define CROMFS_MAGIC          0x4d4f5243
 
 /****************************************************************************
  * Type Definitions