Rewrite filesystem code (WIP)

This patch redoes the filesystem code from the FAT driver up to the
clipboard code in onplay.c.

Not every aspect of this is finished therefore it is still "WIP". I
don't wish to do too much at once (haha!). What is left to do is get
dircache back in the sim and find an implementation for the dircache
indicies in the tagcache and playlist code or do something else that
has the same benefit. Leaving these out for now does not make anything
unusable. All the basics are done.

Phone app code should probably get vetted (and app path handling
just plain rewritten as environment expansions); the SDL app and
Android run well.

Main things addressed:
1) Thread safety: There is none right now in the trunk code. Most of
what currently works is luck when multiple threads are involved or
multiple descriptors to the same file are open.

2) POSIX compliance: Many of the functions behave nothing like their
counterparts on a host system. This leads to inconsistent code or very
different behavior from native to hosted. One huge offender was
rename(). Going point by point would fill a book.

3) Actual running RAM usage: Many targets will use less RAM and less
stack space (some more RAM because I upped the number of cache buffers
for large memory). There's very little memory lying fallow in rarely-used
areas (see 'Key core changes' below). Also, all targets may open the same
number of directory streams whereas before those with less than 8MB RAM
were limited to 8, not 12 implying those targets will save slightly
less.

4) Performance: The test_disk plugin shows markedly improved performance,
particularly in the area of (uncached) directory scanning, due partly to
more optimal directory reading and to a better sector cache algorithm.
Uncached times tend to be better while there is a bit of a slowdown in
dircache due to it being a bit heavier of an implementation. It's not
noticeable by a human as far as I can say.

Key core changes:
1) Files and directories share core code and data structures.

2) The filesystem code knows which descriptors refer to same file.
This ensures that changes from one stream are appropriately reflected
in every open descriptor for that file (fileobj_mgr.c).

3) File and directory cache buffers are borrowed from the main sector
cache. This means that when they are not in use by a file, they are not
wasted, but used for the cache. Most of the time, only a few of them
are needed. It also means that adding more file and directory handles
is less expensive. All one must do in ensure a large enough cache to
borrow from.

4) Relative path components are supported and the namespace is unified.
It does not support full relative paths to an implied current directory;
what is does support is use of "." and "..". Adding the former would
not be very difficult. The namespace is unified in the sense that
volumes may be specified several times along with relative parts, e.g.:
"/<0>/foo/../../<1>/bar" :<=> "/<1>/bar".

5) Stack usage is down due to sharing of data, static allocation and
less duplication of strings on the stack. This requires more
serialization than I would like but since the number of threads is
limited to a low number, the tradoff in favor of the stack seems
reasonable.

6) Separates and heirarchicalizes (sic) the SIM and APP filesystem
code. SIM path and volume handling is just like the target. Some
aspects of the APP file code get more straightforward (e.g. no path
hashing is needed).

Dircache:
Deserves its own section. Dircache is new but pays homage to the old.
The old one was not compatible and so it, since it got redone, does
all the stuff it always should have done such as:

1) It may be update and used at any time during the build process.
No longer has one to wait for it to finish building to do basic file
management (create, remove, rename, etc.).

2) It does not need to be either fully scanned or completely disabled;
it can be incomplete (i.e. overfilled, missing paths), still be
of benefit and be correct.

3) Handles mounting and dismounting of individual volumes which means
a full rebuild is not needed just because you pop a new SD card in the
slot. Now, because it reuses its freed entry data, may rebuild only
that volume.

4) Much more fundamental to the file code. When it is built, it is
the keeper of the master file list whether enabled or not ("disabled"
is just a state of the cache). Its must always to ready to be started
and bind all streams opened prior to being enabled.

5) Maintains any short filenames in OEM format which means that it does
not need to be rebuilt when changing the default codepage.

Miscellaneous Compatibility:
1) Update any other code that would otherwise not work such as the
hotswap mounting code in various card drivers.

2) File management: Clipboard needed updating because of the behavioral
changes. Still needs a little more work on some finer points.

3) Remove now-obsolete functionality such as the mutex's "no preempt"
flag (which was only for the prior FAT driver).

4) struct dirinfo uses time_t rather than raw FAT directory entry
time fields. I plan to follow up on genericizing everything there
(i.e. no FAT attributes).

5) unicode.c needed some redoing so that the file code does not try
try to load codepages during a scan, which is actually a problem with
the current code. The default codepage, if any is required, is now
kept in RAM separarately (bufalloced) from codepages specified to
iso_decode() (which must not be bufalloced because the conversion
may be done by playback threads).

Brings with it some additional reusable core code:
1) Revised file functions: Reusable code that does things such as
safe path concatenation and parsing without buffer limitations or
data duplication. Variants that copy or alter the input path may be
based off these.

To do:
1) Put dircache functionality back in the sim. Treating it internally
as a different kind of file system seems the best approach at this
time.

2) Restore use of dircache indexes in the playlist and database or
something effectively the same. Since the cache doesn't have to be
complete in order to be used, not getting a hit on the cache doesn't
unambiguously say if the path exists or not.

Change-Id: Ia30f3082a136253e3a0eae0784e3091d138915c8
Reviewed-on: http://gerrit.rockbox.org/566
Reviewed-by: Michael Sevakis <jethead71@rockbox.org>
Tested: Michael Sevakis <jethead71@rockbox.org>

12 files changed, 1133 insertions, 272 deletions

diff --git a/firmware/include/dir.h b/firmware/include/dir.h
index 6e8b70588e..f7719823a9 100644
--- a/firmware/include/dir.h
+++ b/firmware/include/dir.h
@@ -18,46 +18,71 @@
  * KIND, either express or implied.
  *
  ****************************************************************************/
-
 #ifndef _DIR_H_
 #define _DIR_H_
 
+#include <sys/types.h>
+#include <fcntl.h>
+#include <time.h>
 #include "config.h"
+#include "fs_attr.h"
 
-#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_VOLUME      0x40 /* this is a volume, not a real directory */
-#define ATTR_LINK        0x80
-
-#ifdef HAVE_DIRCACHE
-# include "dircache.h"
-# define DIR DIR_CACHED
-# define dirent dirent_cached
-# define opendir opendir_cached
-# define closedir closedir_cached
-# define readdir readdir_cached
-# define closedir closedir_cached
-# define mkdir mkdir_cached
-# define rmdir rmdir_cached
+#if defined (APPLICATION)
+#include "filesystem-app.h"
+#elif defined(SIMULATOR) || defined(__PCTOOL__)
+#include "../../uisimulator/common/filesystem-sim.h"
 #else
-# include "dir_uncached.h"
-# define DIR DIR_UNCACHED
-# define dirent dirent_uncached
-# define opendir opendir_uncached
-# define closedir closedir_uncached
-# define readdir readdir_uncached
-# define closedir closedir_uncached
-# define mkdir mkdir_uncached
-# define rmdir rmdir_uncached
+#include "filesystem-native.h"
+#endif
+
+#ifndef DIRFUNCTIONS_DEFINED
+#ifndef opendir
+#define opendir         FS_PREFIX(opendir)
+#endif
+#ifndef readdir
+#define readdir         FS_PREFIX(readdir)
+#endif
+#ifndef readdir_r
+#define readdir_r       FS_PREFIX(readdir_r)
+#endif
+#ifndef rewinddir
+#define rewinddir       FS_PREFIX(rewinddir)
 #endif
+#ifndef closedir
+#define closedir        FS_PREFIX(closedir)
+#endif
+#ifndef mkdir
+#define mkdir           FS_PREFIX(mkdir)
+#endif
+#ifndef rmdir
+#define rmdir           FS_PREFIX(rmdir)
+#endif
+#ifndef samedir
+#define samedir         FS_PREFIX(samedir)
+#endif
+#ifndef dir_exists
+#define dir_exists      FS_PREFIX(dir_exists)
+#endif
+#endif /* !DIRFUNCTIONS_DEFINED */
 
+#ifndef DIRENT_DEFINED
+struct DIRENT
+{
+    struct dirinfo_native info; /* platform extra info */
+    char d_name[MAX_PATH];      /* UTF-8 name of entry (last!) */
+};
+#endif /* DIRENT_DEFINED */
 
-typedef DIR* (*opendir_func)(const char* name);
-typedef int (*closedir_func)(DIR* dir);
-typedef struct dirent* (*readdir_func)(DIR* dir);
+struct dirinfo
+{
+    unsigned int attribute; /* attribute bits of file */
+    off_t        size;      /* binary size of file */
+    time_t       mtime;     /* local file time */
+};
 
-#endif
+#ifndef DIRFUNCTIONS_DECLARED
+/* TIP: set errno to zero before calling to see if anything failed */
+struct dirinfo dir_get_info(DIR *dirp, struct DIRENT *entry);
+#endif /* !DIRFUNCTIONS_DECLARED */
+
+#endif /* _DIR_H_ */
diff --git a/firmware/include/dir_uncached.h b/firmware/include/dir_uncached.h
deleted file mode 100644
index 6443d5ba97..0000000000
--- a/firmware/include/dir_uncached.h
+++ /dev/null
@@ -1,107 +0,0 @@
-/***************************************************************************
- *             __________               __   ___.
- *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
- *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
- *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
- *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
- *                     \/            \/     \/    \/            \/
- * $Id: dir.h 13741 2007-06-30 02:08:27Z jethead71 $
- *
- * Copyright (C) 2002 by Björn Stenberg
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License
- * as published by the Free Software Foundation; either version 2
- * of the License, or (at your option) any later version.
- *
- * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
- * KIND, either express or implied.
- *
- ****************************************************************************/
-#ifndef _DIR_UNCACHED_H_
-#define _DIR_UNCACHED_H_
-
-#include "config.h"
-
-struct dirinfo {
-    int attribute;
-    long size;
-    unsigned short wrtdate;
-    unsigned short wrttime;
-};
-
-#include <stdbool.h>
-#include "file.h"
-
-#if defined(SIMULATOR) || defined(__PCTOOL__)
-#   define dirent_uncached sim_dirent
-#   define DIR_UNCACHED SIM_DIR
-#   define opendir_uncached sim_opendir
-#   define readdir_uncached sim_readdir
-#   define closedir_uncached sim_closedir
-#   define mkdir_uncached sim_mkdir
-#   define rmdir_uncached sim_rmdir
-#elif defined(APPLICATION)
-#   include "rbpaths.h"
-#   define DIRENT_DEFINED
-#   define DIR_DEFINED
-#   define dirent_uncached dirent
-#   define DIR_UNCACHED DIR
-#   define opendir_uncached app_opendir
-#   define readdir_uncached app_readdir
-#   define closedir_uncached app_closedir
-#   define mkdir_uncached app_mkdir
-#   define rmdir_uncached app_rmdir
-#endif
-
-
-#ifndef DIRENT_DEFINED
-struct dirent_uncached {
-    unsigned char d_name[MAX_PATH];
-    struct dirinfo info;
-    long startcluster;
-};
-#endif
-
-#include "fat.h"
-
-#ifndef DIR_DEFINED
-typedef struct {
-#if (CONFIG_PLATFORM & PLATFORM_NATIVE)
-    struct fat_dir fatdir CACHEALIGN_ATTR;
-    bool busy;
-    long startcluster;
-    struct dirent_uncached theent;
-#ifdef HAVE_MULTIVOLUME
-    int volumecounter; /* running counter for faked volume entries */
-#endif
-#else
-    /* simulator/application: */
-    void *dir; /* actually a DIR* dir */
-    char *name;
-#endif
-} DIR_UNCACHED CACHEALIGN_ATTR;
-#endif
-
-#ifdef HAVE_HOTSWAP
-char *get_volume_name(int volume);
-#endif
-
-#ifdef HAVE_MULTIVOLUME
-    int strip_volume(const char*, char*);
-#endif
-
-#ifndef DIRFUNCTIONS_DEFINED
-
-extern DIR_UNCACHED* opendir_uncached(const char* name);
-extern int closedir_uncached(DIR_UNCACHED* dir);
-extern int mkdir_uncached(const char* name);
-extern int rmdir_uncached(const char* name);
-
-extern struct dirent_uncached* readdir_uncached(DIR_UNCACHED* dir);
-
-extern int release_dirs(int volume);
-
-#endif /* DIRFUNCTIONS_DEFINED */
-
-#endif
diff --git a/firmware/include/dircache.h b/firmware/include/dircache.h
index 019ccf49b7..7e8c764e7f 100644
--- a/firmware/include/dircache.h
+++ b/firmware/include/dircache.h
@@ -8,6 +8,7 @@
  * $Id$
  *
  * Copyright (C) 2005 by Miika Pekkarinen
+ * Copyright (C) 2014 by Michael Sevakis
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License
@@ -21,84 +22,154 @@
 #ifndef _DIRCACHE_H
 #define _DIRCACHE_H
 
-#include "config.h"
-#include "dir_uncached.h"
-#include <string.h> /* size_t */
+#include "mv.h"
+#include <string.h>    /* size_t */
+#include <sys/types.h> /* ssize_t */
 
 #ifdef HAVE_DIRCACHE
 
-#define DIRCACHE_RESERVE  (1024*64)
-#define DIRCACHE_LIMIT    (1024*1024*6)
-
-#define DIRCACHE_APPFLAG_TAGCACHE  0x0001
-#define DIRCACHE_APPFLAG_PLAYLIST  0x0002
-
-/* Internal structures. */
-struct travel_data {
-    struct dircache_entry *first;
-    struct dircache_entry *ce;
-    struct dircache_entry *down_entry;
-#if (CONFIG_PLATFORM & PLATFORM_HOSTED)
-    DIR_UNCACHED *dir, *newdir;
-    struct dirent_uncached *entry;
-#else
-    struct fat_dir *dir;
-    struct fat_dir newdir;
-    struct fat_direntry entry;
+/****************************************************************************
+ ** Configurable values
+ **/
+
+#if 0
+/* enable dumping code */
+#define DIRCACHE_DUMPSTER
+#define DIRCACHE_DUMPSTER_BIN   "/dircache_dump.bin"
+#define DIRCACHE_DUMPSTER_CSV   "/dircache_dump.csv"
 #endif
-    int pathpos;
+
+/* dircache builds won't search below this but will work down to this point
+   while below it the cache will just pass requests through to the storage;
+   the limiting factor is the scanning thread stack size, not the
+   implementation -- tune the two together */
+#define DIRCACHE_MAX_DEPTH  15
+#define DIRCACHE_STACK_SIZE (DEFAULT_STACK_SIZE + 0x100)
+
+/* memory buffer constants that control allocation */
+#define DIRCACHE_RESERVE (1024*64)     /* 64 KB - new entry slack */
+#define DIRCACHE_MIN     (1024*1024*1) /* 1 MB - provision min size */
+#define DIRCACHE_LIMIT   (1024*1024*6) /* 6 MB - provision max size */
+
+/* make it easy to change serialnumber size without modifying anything else;
+   32 bits allows 21845 builds before wrapping in a 6MB cache that is filled
+   exclusively with entries and nothing else (32 byte entries), making that
+   figure pessimistic */
+typedef uint32_t dc_serial_t;
+
+/**
+ ****************************************************************************/
+
+#if CONFIG_PLATFORM & PLATFORM_NATIVE
+/* native dircache is lower-level than on a hosted target */
+#define DIRCACHE_NATIVE
+#endif
+
+struct dircache_file
+{
+    int         idx;        /* this file's cache index */
+    dc_serial_t serialnum;  /* this file's serial number */
 };
 
-struct dirent_cached {
-    struct dirinfo info;
-    char *d_name;
-    long startcluster;
+enum dircache_status
+{
+    DIRCACHE_IDLE     = 0,  /* no volume is initialized */
+    DIRCACHE_SCANNING = 1,  /* dircache is scanning a volume */
+    DIRCACHE_READY    = 2,  /* dircache is ready to be used */
+};
+
+/** Dircache control **/
+void dircache_wait(void);
+void dircache_suspend(void);
+int dircache_resume(void);
+int dircache_enable(void);
+void dircache_disable(void);
+void dircache_free_buffer(void);
+
+/** Volume mounting **/
+void dircache_mount(void); /* always tries building everything it can */
+void dircache_unmount(IF_MV_NONVOID(int volume));
+
+
+/** File API service functions **/
+
+/* avoid forcing #include of file_internal.h, fat.h and dir.h */
+struct filestr_base;
+struct file_base_info;
+struct file_base_binding;
+struct dirent;
+struct dirscan_info;
+struct dirinfo_native;
+
+int dircache_readdir_dirent(struct filestr_base *stream,
+                            struct dirscan_info *scanp,
+                            struct dirent *entry);
+void dircache_rewinddir_dirent(struct dirscan_info *scanp);
+
+#ifdef DIRCACHE_NATIVE
+struct fat_direntry;
+int dircache_readdir_internal(struct filestr_base *stream,
+                              struct file_base_info *infop,
+                              struct fat_direntry *fatent);
+void dircache_rewinddir_internal(struct file_base_info *info);
+#endif /* DIRCACHE_NATIVE */
+
+
+/** Dircache live updating **/
+
+void dircache_get_rootinfo(struct file_base_info *infop);
+void dircache_bind_file(struct file_base_binding *bindp);
+void dircache_unbind_file(struct file_base_binding *bindp);
+void dircache_fileop_create(struct file_base_info *dirinfop,
+                            struct file_base_binding *bindp,
+                            const char *basename,
+                            const struct dirinfo_native *dinp);
+void dircache_fileop_rename(struct file_base_info *dirinfop,
+                            struct file_base_binding *bindp,
+                            const char *basename);
+void dircache_fileop_remove(struct file_base_binding *bindp);
+void dircache_fileop_sync(struct file_base_binding *infop,
+                          const struct dirinfo_native *dinp);
+
+
+/** Dircache paths and files **/
+ssize_t dircache_get_path(const struct dircache_file *dcfilep, char *buf,
+                          size_t size);
+int dircache_get_file(const char *path, struct dircache_file *dcfilep);
+
+
+/** Debug screen/info stuff **/
+
+struct dircache_info
+{
+    enum dircache_status status; /* current composite status value */
+    const char   *statusdesc;    /* pointer to string describing 'status' */
+    size_t       last_size;      /* cache size after last build */
+    size_t       size;           /* total size of entries (with holes) */
+    size_t       sizeused;       /* bytes of 'size' actually utilized */
+    size_t       size_limit;     /* maximum possible size */
+    size_t       reserve;        /* size of reserve area */
+    size_t       reserve_used;   /* amount of reserve used */
+    unsigned int entry_count;    /* number of cache entries */
+    long         build_ticks;    /* total time used to build cache */
 };
 
-typedef struct {
-    bool busy;
-    struct dirent_cached theent; /* .attribute is set to -1 on init(opendir) */
-    int internal_entry;          /* the current entry in the directory */
-    DIR_UNCACHED *regulardir;
-} DIR_CACHED;
+void dircache_get_info(struct dircache_info *info);
+#ifdef DIRCACHE_DUMPSTER
+void dircache_dump(void);
+#endif /* DIRCACHE_DUMPSTER */
+
 
-void dircache_init(void) INIT_ATTR;
+/** Misc. stuff **/
+void dircache_dcfile_init(struct dircache_file *dcfilep);
+
+#ifdef HAVE_EEPROM_SETTINGS
 int dircache_load(void);
 int dircache_save(void);
-int dircache_build(int last_size);
-void* dircache_steal_buffer(size_t *size);
-bool dircache_is_enabled(void);
-bool dircache_is_initializing(void);
-void dircache_set_appflag(long mask);
-bool dircache_get_appflag(long mask);
-int dircache_get_entry_count(void);
-int dircache_get_cache_size(void);
-int dircache_get_reserve_used(void);
-int dircache_get_build_ticks(void);
-void dircache_disable(void);
-void dircache_suspend(void);
-bool dircache_resume(void);
-int dircache_get_entry_id(const char *filename);
-size_t dircache_copy_path(int index, char *buf, size_t size);
-
-/* the next two are internal for file.c */
-long _dircache_get_entry_startcluster(int id);
-struct dirinfo* _dircache_get_entry_dirinfo(int id);
-
-void dircache_bind(int fd, const char *path);
-void dircache_update_filesize(int fd, long newsize, long startcluster);
-void dircache_update_filetime(int fd);
-void dircache_mkdir(const char *path);
-void dircache_rmdir(const char *path);
-void dircache_remove(const char *name);
-void dircache_rename(const char *oldpath, const char *newpath);
-void dircache_add_file(const char *path, long startcluster);
-
-DIR_CACHED* opendir_cached(const char* name);
-struct dirent_cached* readdir_cached(DIR_CACHED* dir);
-int closedir_cached(DIR_CACHED *dir);
-int mkdir_cached(const char *name);
-int rmdir_cached(const char* name);
-#endif /* !HAVE_DIRCACHE */
+#endif /* HAVE_EEPROM_SETTINGS */
 
-#endif
+void dircache_init(size_t last_size) INIT_ATTR;
+
+#endif /* HAVE_DIRCACHE */
+
+#endif /* _DIRCACHE_H */
diff --git a/firmware/include/dircache_redirect.h b/firmware/include/dircache_redirect.h
new file mode 100644
index 0000000000..15fb4bc38d
--- /dev/null
+++ b/firmware/include/dircache_redirect.h
@@ -0,0 +1,198 @@
+/***************************************************************************
+ *             __________               __   ___.
+ *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
+ *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
+ *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
+ *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
+ *                     \/            \/     \/    \/            \/
+ * $Id$
+ *
+ * Copyright (C) 2014 by Michael Sevakis
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+ * KIND, either express or implied.
+ *
+ ****************************************************************************/
+#ifndef _DIRCACHE_REDIRECT_H_
+
+#include "dir.h"
+
+/***
+ ** Internal redirects that depend upon whether or not dircache is made
+ **/
+
+/** File binding **/
+
+static inline void get_rootinfo_internal(struct file_base_info *infop)
+{
+#ifdef HAVE_DIRCACHE
+    dircache_get_rootinfo(infop);
+#else
+    (void)infop;
+#endif
+}
+
+static inline void fileobj_bind_file(struct file_base_binding *bindp)
+{
+#ifdef HAVE_DIRCACHE
+    dircache_bind_file(bindp);
+#else
+    file_binding_insert_last(bindp);
+#endif
+}
+
+static inline void fileobj_unbind_file(struct file_base_binding *bindp)
+{
+#ifdef HAVE_DIRCACHE
+    dircache_unbind_file(bindp);
+#else
+    file_binding_remove(bindp);
+#endif
+}
+
+
+/** File event handlers **/
+
+static inline void fileop_onopen_internal(struct filestr_base *stream,
+                                          struct file_base_info *srcinfop,
+                                          unsigned int callflags)
+{
+    fileobj_fileop_open(stream, srcinfop, callflags);
+}
+
+static inline void fileop_onclose_internal(struct filestr_base *stream)
+{
+    fileobj_fileop_close(stream);
+}
+
+static inline void fileop_oncreate_internal(struct filestr_base *stream,
+                                            struct file_base_info *srcinfop,
+                                            unsigned int callflags,
+                                            struct file_base_info *dirinfop,
+                                            const char *basename)
+{
+#ifdef HAVE_DIRCACHE
+    dircache_dcfile_init(&srcinfop->dcfile);
+#endif
+    fileobj_fileop_create(stream, srcinfop, callflags);
+#ifdef HAVE_DIRCACHE
+    struct dirinfo_native din;
+    fill_dirinfo_native(&din);
+    dircache_fileop_create(dirinfop, stream->bindp, basename, &din);
+#endif
+    (void)dirinfop; (void)basename;
+}
+
+static inline void fileop_onremove_internal(struct filestr_base *stream,
+                                            struct file_base_info *oldinfop)
+{
+    fileobj_fileop_remove(stream, oldinfop);
+#ifdef HAVE_DIRCACHE
+    dircache_fileop_remove(stream->bindp);
+#endif
+}
+
+static inline void fileop_onrename_internal(struct filestr_base *stream,
+                                            struct file_base_info *oldinfop,
+                                            struct file_base_info *dirinfop,
+                                            const char *basename)
+{
+    fileobj_fileop_rename(stream, oldinfop);
+#ifdef HAVE_DIRCACHE
+    dircache_fileop_rename(dirinfop, stream->bindp, basename);
+#endif
+    (void)dirinfop; (void)basename;
+}
+
+static inline void fileop_onsync_internal(struct filestr_base *stream)
+{
+    fileobj_fileop_sync(stream);
+#ifdef HAVE_DIRCACHE
+    struct dirinfo_native din;
+    fill_dirinfo_native(&din);
+    dircache_fileop_sync(stream->bindp, &din);
+#endif
+}
+
+static inline void fileop_ontruncate_internal(struct filestr_base *stream)
+{
+    fileobj_fileop_truncate(stream);
+}
+
+static inline void volume_onmount_internal(IF_MV_NONVOID(int volume))
+{
+#ifdef HAVE_DIRCACHE
+    dircache_mount();
+#endif
+    IF_MV( (void)volume; )
+}
+
+static inline void volume_onunmount_internal(IF_MV_NONVOID(int volume))
+{
+    fileobj_mgr_unmount(IF_MV(volume));
+#ifdef HAVE_DIRCACHE
+    dircache_unmount(IF_MV(volume));
+#endif
+}
+
+
+/** Directory reading **/
+
+static inline int readdir_dirent(struct filestr_base *stream,
+                                 struct dirscan_info *scanp,
+                                 struct dirent *entry)
+{
+#ifdef HAVE_DIRCACHE
+    return dircache_readdir_dirent(stream, scanp, entry);
+#else
+    return uncached_readdir_dirent(stream, scanp, entry);
+#endif
+}
+
+static inline void rewinddir_dirent(struct dirscan_info *scanp)
+{
+#ifdef HAVE_DIRCACHE
+    dircache_rewinddir_dirent(scanp);
+#else
+    uncached_rewinddir_dirent(scanp);
+#endif
+}
+
+static inline int readdir_internal(struct filestr_base *stream,
+                                   struct file_base_info *infop,
+                                   struct fat_direntry *fatent)
+{
+#ifdef HAVE_DIRCACHE
+    return dircache_readdir_internal(stream, infop, fatent);
+#else
+    return uncached_readdir_internal(stream, infop, fatent);
+#endif
+}
+
+static inline void rewinddir_internal(struct file_base_info *infop)
+{
+#ifdef HAVE_DIRCACHE
+    dircache_rewinddir_internal(infop);
+#else
+    uncached_rewinddir_internal(infop);
+#endif
+}
+
+
+/** Misc. stuff **/
+
+static inline struct fat_direntry *get_dir_fatent_dircache(void)
+{
+#ifdef HAVE_DIRCACHE
+    return get_dir_fatent();
+#else
+    return NULL;
+#endif
+}
+
+#endif /* _DIRCACHE_REDIRECT_H_ */
diff --git a/firmware/include/disk_cache.h b/firmware/include/disk_cache.h
new file mode 100644
index 0000000000..725b3778cc
--- /dev/null
+++ b/firmware/include/disk_cache.h
@@ -0,0 +1,83 @@
+/***************************************************************************
+ *             __________               __   ___.
+ *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
+ *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
+ *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
+ *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
+ *                     \/            \/     \/    \/            \/
+ * $Id$
+ *
+ * Copyright (C) 2014 by Michael Sevakis
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+ * KIND, either express or implied.
+ *
+ ****************************************************************************/
+#ifndef DISK_CACHE_H
+#define DISK_CACHE_H
+
+/* This needs enough for all file handles to have a buffer in the worst case
+ * plus at least one reserved exclusively for the cache client and a couple
+ * for other file system code. The buffers are put to use by the cache if not
+ * taken for another purpose (meaning nothing is wasted sitting fallow).
+ *
+ * One map per volume is maintained in order to avoid collisions between
+ * volumes that would slow cache probing. DC_MAP_NUM_ENTRIES is the number
+ * for each map per volume. The buffers themselves are shared.
+ */
+#if MEMORYSIZE < 8
+#define DC_NUM_ENTRIES      32
+#define DC_MAP_NUM_ENTRIES  128
+#elif MEMORYSIZE <= 32
+#define DC_NUM_ENTRIES      48
+#define DC_MAP_NUM_ENTRIES  128
+#else /* MEMORYSIZE > 32 */
+#define DC_NUM_ENTRIES      64
+#define DC_MAP_NUM_ENTRIES  256
+#endif /* MEMORYSIZE */
+
+/* this _could_ be larger than a sector if that would ever be useful */
+#define DC_CACHE_BUFSIZE    SECTOR_SIZE
+
+#include "mutex.h"
+#include "mv.h"
+
+static inline void dc_lock_cache(void)
+{
+    extern struct mutex disk_cache_mutex;
+    mutex_lock(&disk_cache_mutex);
+}
+
+static inline void dc_unlock_cache(void)
+{
+    extern struct mutex disk_cache_mutex;
+    mutex_unlock(&disk_cache_mutex);
+}
+
+void * dc_cache_probe(IF_MV(int volume,) unsigned long secnum,
+                      unsigned int *flags);
+void dc_dirty_buf(void *buf);
+void dc_discard_buf(void *buf);
+void dc_commit_all(IF_MV_NONVOID(int volume));
+void dc_discard_all(IF_MV_NONVOID(int volume));
+
+void dc_init(void) INIT_ATTR;
+
+/* in addition to filling, writeback is implemented by the client */
+extern void dc_writeback_callback(IF_MV(int volume, ) unsigned long sector,
+                                  void *buf);
+
+
+/** These synchronize and can be called by anyone **/
+
+/* expropriate a buffer from the cache of DC_CACHE_BUFSIZE bytes */
+void * dc_get_buffer(void);
+/* return buffer to the cache by buffer */
+void dc_release_buffer(void *buf);
+
+#endif /* DISK_CACHE_H */
diff --git a/firmware/include/file.h b/firmware/include/file.h
index 77930864c7..8e5bacec0e 100644
--- a/firmware/include/file.h
+++ b/firmware/include/file.h
@@ -18,81 +18,88 @@
  * KIND, either express or implied.
  *
  ****************************************************************************/
-
 #ifndef _FILE_H_
 #define _FILE_H_
 
 #include <sys/types.h>
-#include "config.h"
-#include "gcc_extensions.h"
+#include <stdbool.h>
 #include <fcntl.h>
 #ifdef WIN32
 /* this has SEEK_SET et al */
 #include <stdio.h>
 #endif
-
+#include "config.h"
+#include "gcc_extensions.h"
 
 #undef MAX_PATH /* this avoids problems when building simulator */
 #define MAX_PATH 260
-#define MAX_OPEN_FILES 11
 
-#if !defined(PLUGIN) && !defined(CODEC)
-#if defined(APPLICATION) && !defined(__PCTOOL__)
-#include "rbpaths.h"
-#   define open(x, ...)     app_open(x, __VA_ARGS__)
-#   define creat(x,m)       app_creat(x, m)
-#   define remove(x)        app_remove(x)
-#   define rename(x,y)      app_rename(x,y)
-#   define readlink(x,y,z)  app_readlink(x,y,z)
-#   if (CONFIG_PLATFORM & (PLATFORM_SDL|PLATFORM_MAEMO|PLATFORM_PANDORA))
-/* SDL overrides a few more */
-#   define read(x,y,z)      sim_read(x,y,z)
-#   define write(x,y,z)     sim_write(x,y,z)
-#   endif
-#elif defined(SIMULATOR) || defined(DBTOOL)
-#   define open(x, ...)     sim_open(x, __VA_ARGS__)
-#   define creat(x,m)       sim_creat(x,m)
-#   define remove(x)        sim_remove(x)
-#   define rename(x,y)      sim_rename(x,y)
-#   define fsync(x)         sim_fsync(x)
-#   define ftruncate(x,y)   sim_ftruncate(x,y)
-#   define lseek(x,y,z)     sim_lseek(x,y,z)
-#   define read(x,y,z)      sim_read(x,y,z)
-#   define write(x,y,z)     sim_write(x,y,z)
-#   define close(x)         sim_close(x)
-/* readlink() not used in the sim yet */
-extern int sim_open(const char *name, int o, ...);
-extern int sim_creat(const char *name, mode_t mode);
-#endif
+enum relate_result
+{
+                          /* < 0 == failure */
+    RELATE_DIFFERENT = 0, /* the two paths are different objects */
+    RELATE_SAME,          /* the two paths are the same object */
+    RELATE_PREFIX,        /* the path2 contains path1 as a prefix */
+};
 
-typedef int (*open_func)(const char* pathname, int flags, ...);
-typedef ssize_t (*read_func)(int fd, void *buf, size_t count);
-typedef int (*creat_func)(const char *pathname, mode_t mode);
-typedef ssize_t (*write_func)(int fd, const void *buf, size_t count);
-typedef void (*qsort_func)(void *base, size_t nmemb,  size_t size,
-                           int(*_compar)(const void *, const void *));
+#if defined(APPLICATION)
+#include "filesystem-app.h"
+#elif defined(SIMULATOR) || defined(__PCTOOL__)
+#include "../../uisimulator/common/filesystem-sim.h"
+#else
+#include "filesystem-native.h"
+#endif
 
-extern int file_open(const char* pathname, int flags);
-extern int close(int fd);
-extern int fsync(int fd);
-extern ssize_t read(int fd, void *buf, size_t count);
-extern off_t lseek(int fildes, off_t offset, int whence);
-extern int file_creat(const char *pathname);
-#if ((CONFIG_PLATFORM & PLATFORM_NATIVE) && !defined(__PCTOOL__)) || \
-    defined(TEST_FAT)
-#define creat(x, y) file_creat(x)
+#ifndef FILEFUNCTIONS_DECLARED
+int fdprintf(int fildes, const char *fmt, ...) ATTRIBUTE_PRINTF(2, 3);
+#endif /* FILEFUNCTIONS_DECLARED */
 
-#if !defined(CODEC) && !defined(PLUGIN)
-#define open(x, y, ...) file_open(x,y)
+#ifndef FILEFUNCTIONS_DEFINED
+#ifndef open
+#define open            FS_PREFIX(open)
 #endif
+#ifndef creat
+#define creat           FS_PREFIX(creat)
 #endif
-
-extern ssize_t write(int fd, const void *buf, size_t count);
-extern int remove(const char* pathname);
-extern int rename(const char* path, const char* newname);
-extern int ftruncate(int fd, off_t length);
-extern off_t filesize(int fd);
-extern int release_files(int volume);
-int fdprintf (int fd, const char *fmt, ...) ATTRIBUTE_PRINTF(2, 3);
-#endif /* !CODEC && !PLUGIN */
+#ifndef close
+#define close           FS_PREFIX(close)
+#endif
+#ifndef ftruncate
+#define ftruncate       FS_PREFIX(ftruncate)
+#endif
+#ifndef fsync
+#define fsync           FS_PREFIX(fsync)
 #endif
+#ifndef lseek
+#define lseek           FS_PREFIX(lseek)
+#endif
+#ifndef read
+#define read            FS_PREFIX(read)
+#endif
+#ifndef write
+#define write           FS_PREFIX(write)
+#endif
+#ifndef remove
+#define remove          FS_PREFIX(remove)
+#endif
+#ifndef rename
+#define rename          FS_PREFIX(rename)
+#endif
+#ifndef filesize
+#define filesize        FS_PREFIX(filesize)
+#endif
+#ifndef fsamefile
+#define fsamefile       FS_PREFIX(fsamefile)
+#endif
+#ifndef file_exists
+#define file_exists     FS_PREFIX(file_exists)
+#endif
+#ifndef relate
+#define relate          FS_PREFIX(relate)
+#endif
+#ifndef readlink
+#define readlink        FS_PREFIX(readlink)
+#endif
+#endif /* FILEFUNCTIONS_DEFINED */
+
+#endif /* _FILE_H_ */
diff --git a/firmware/include/file_internal.h b/firmware/include/file_internal.h
new file mode 100644
index 0000000000..d1bb67406a
--- /dev/null
+++ b/firmware/include/file_internal.h
@@ -0,0 +1,371 @@
+/***************************************************************************
+ *             __________               __   ___.
+ *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
+ *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
+ *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
+ *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
+ *                     \/            \/     \/    \/            \/
+ * $Id$
+ *
+ * Copyright (C) 2014 by Michael Sevakis
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+ * KIND, either express or implied.
+ *
+ ****************************************************************************/
+#ifndef _FILE_INTERNAL_H_
+#define _FILE_INTERNAL_H_
+
+#include <sys/types.h>
+#include <stdlib.h>
+#include "mv.h"
+#include "linked_list.h"
+#include "mutex.h"
+#include "mrsw_lock.h"
+#include "fs_attr.h"
+#include "fat.h"
+#ifdef HAVE_DIRCACHE
+#include "dircache.h"
+#endif
+
+/** Tuneable parameters **/
+
+/* limits for number of open descriptors - if you increase these values, make
+   certain that the disk cache has enough available buffers */
+#define MAX_OPEN_FILES 11
+#define MAX_OPEN_DIRS  12
+#define MAX_OPEN_HANDLES (MAX_OPEN_FILES+MAX_OPEN_DIRS)
+
+/* internal functions open streams as well; make sure they don't fail if all
+   user descs are busy; this needs to be at least the greatest quantity needed
+   at once by all internal functions */
+#ifdef HAVE_DIRCACHE
+#define AUX_FILEOBJS 3
+#else
+#define AUX_FILEOBJS 2
+#endif
+
+/* number of components statically allocated to handle the vast majority
+   of path depths; should maybe be tuned for >= 90th percentile but for now,
+   imma just guessing based on something like:
+        root + 'Music' + 'Artist' + 'Album' + 'Disc N' + filename */
+#define STATIC_PATHCOMP_NUM 6
+
+#define MAX_NAME    255
+
+/* unsigned value that will also hold the off_t range we need without
+   overflow */
+#define file_size_t uint32_t
+
+#ifdef __USE_FILE_OFFSET64
+/* if we want, we can deal with files up to 2^32-1 bytes-- the full FAT16/32
+   range */
+#define FILE_SIZE_MAX   (0xffffffffu)
+#else
+/* file contents and size will be preserved by the APIs so long as ftruncate()
+   isn't used; bytes passed 2^31-1 will not accessible nor will writes succeed
+   that would extend the file beyond the max for a 32-bit off_t */
+#define FILE_SIZE_MAX   (0x7fffffffu)
+#endif
+
+/* if file is "large(ish)", then get rid of the contents now rather than
+   lazily when the file is synced or closed in order to free-up space */
+#define O_TRUNC_THRESH 65536
+
+/* default attributes when creating new files and directories */
+#define ATTR_NEW_FILE       (ATTR_ARCHIVE)
+#define ATTR_NEW_DIRECTORY  (ATTR_DIRECTORY)
+
+#define ATTR_MOUNT_POINT    (ATTR_VOLUME | ATTR_DIRECTORY)
+
+/** File sector cache **/
+
+enum filestr_cache_flags
+{
+    FSC_DIRTY = 0x1,        /* buffer is dirty (needs writeback) */
+    FSC_NEW   = 0x2,        /* buffer is new (never yet written) */
+};
+
+struct filestr_cache
+{
+    uint8_t       *buffer;  /* buffer to hold sector */
+    unsigned long sector;   /* file sector that is in buffer */
+    unsigned int  flags;    /* FSC_* bits */
+};
+
+void file_cache_init(struct filestr_cache *cachep);
+void file_cache_reset(struct filestr_cache *cachep);
+void file_cache_alloc(struct filestr_cache *cachep);
+void file_cache_free(struct filestr_cache *cachep);
+
+
+/** Common bitflags used throughout **/
+
+/* bitflags used by open files and descriptors */
+enum fildes_and_obj_flags
+{
+    /* used in descriptor and common */
+    FDO_BUSY       = 0x0001, /* descriptor/object is in use */
+    /* only used in individual stream descriptor */
+    FD_WRITE       = 0x0002, /* descriptor has write mode */
+    FD_WRONLY      = 0x0004, /* descriptor is write mode only */
+    FD_APPEND      = 0x0008, /* descriptor is append mode */
+    /* only used as common flags */
+    FO_DIRECTORY   = 0x0010, /* fileobj is a directory */
+    FO_TRUNC       = 0x0020, /* fileobj is opened to be truncated */
+    FO_REMOVED     = 0x0040, /* fileobj was deleted while open */
+    FO_SINGLE      = 0x0080, /* fileobj has only one stream open */
+    FDO_MASK       = 0x00ff,
+    /* bitflags that instruct various 'open' functions how to behave */
+    FF_FILE        = 0x0000, /* expect file; accept file only */
+    FF_DIR         = 0x0100, /* expect dir; accept dir only */
+    FF_ANYTYPE     = 0x0200, /* succeed if either file or dir */
+    FF_TYPEMASK    = 0x0300, /* mask of typeflags */
+    FF_CREAT       = 0x0400, /* create if file doesn't exist */
+    FF_EXCL        = 0x0800, /* fail if creating and file exists */
+    FF_CHECKPREFIX = 0x1000, /* detect if file is prefix of path */
+    FF_NOISO       = 0x2000, /* do not decode ISO filenames to UTF-8 */
+    FF_MASK        = 0x3f00,
+    /* special values used in isolation */
+    FV_NONEXIST    = 0x8000, /* closed but not freed (unmounted) */
+    FV_OPENSYSROOT = 0xc001, /* open sysroot, volume 0 not mounted */
+};
+
+
+/** Common data structures used throughout **/
+
+/* basic file information about its location */
+struct file_base_info
+{
+    union {
+#ifdef HAVE_MULTIVOLUME
+    int                  volume;  /* file's volume (overlaps fatfile.volume) */
+#endif
+#if CONFIG_PLATFORM & PLATFORM_NATIVE
+    struct fat_file      fatfile; /* FS driver file info */
+#endif
+    };
+#ifdef HAVE_DIRCACHE
+    struct dircache_file dcfile;  /* dircache file info */
+#endif
+};
+
+#define BASEINFO_VOL(infop) \
+    IF_MV_VOL((infop)->volume)
+
+/* open files binding item */
+struct file_base_binding
+{
+    struct ll_node        node;   /* list item node (first!) */
+    struct file_base_info info;   /* basic file info */
+};
+
+#define BASEBINDING_VOL(bindp) \
+    BASEINFO_VOL(&(bindp)->info)
+
+/* directory scanning position info */
+struct dirscan_info
+{
+#if CONFIG_PLATFORM & PLATFORM_NATIVE
+    struct fat_dirscan_info fatscan; /* FS driver scan info */
+#endif
+#ifdef HAVE_DIRCACHE
+    struct dircache_file    dcscan;  /* dircache scan info */
+#endif
+};
+
+/* describes the file as an open stream */
+struct filestr_base
+{
+    struct ll_node           node;    /* list item node (first!) */
+    uint16_t                 flags;   /* FD_* bits of this stream */
+    uint16_t                 unused;  /* not used */
+    struct filestr_cache     cache;   /* stream-local cache */
+    struct filestr_cache     *cachep; /* the cache in use (local or shared) */
+    struct file_base_info    *infop;  /* base file information */
+    struct fat_filestr       fatstr;  /* FS driver information */
+    struct file_base_binding *bindp;  /* common binding for file/dir */
+    struct mutex             *mtx;    /* serialization for this stream */
+};
+
+void filestr_base_init(struct filestr_base *stream);
+void filestr_base_destroy(struct filestr_base *stream);
+void filestr_alloc_cache(struct filestr_base *stream);
+void filestr_free_cache(struct filestr_base *stream);
+void filestr_assign_cache(struct filestr_base *stream,
+                          struct filestr_cache *cachep);
+void filestr_copy_cache(struct filestr_base *stream,
+                        struct filestr_cache *cachep);
+void filestr_discard_cache(struct filestr_base *stream);
+
+/* allocates a cache buffer if needed and returns the cache pointer */
+static inline struct filestr_cache *
+filestr_get_cache(struct filestr_base *stream)
+{
+    struct filestr_cache *cachep = stream->cachep;
+
+    if (!cachep->buffer)
+        filestr_alloc_cache(stream);
+
+    return cachep;
+}
+
+static inline void filestr_lock(struct filestr_base *stream)
+{
+    mutex_lock(stream->mtx);
+}
+
+static inline void filestr_unlock(struct filestr_base *stream)
+{
+    mutex_unlock(stream->mtx);
+}
+
+/* stream lock doesn't have to be used if getting RW lock writer access */
+#define FILESTR_WRITER 0
+#define FILESTR_READER 1
+
+#define FILESTR_LOCK(type, stream) \
+    ({ if (FILESTR_##type) filestr_lock(stream); })
+
+#define FILESTR_UNLOCK(type, stream) \
+    ({ if (FILESTR_##type) filestr_unlock(stream); })
+
+#define ATTR_PREFIX (0x8000) /* out of the way of all ATTR_* bits */
+
+/* structure to return detailed information about what you opened */
+struct path_component_info
+{
+    const char   *name;               /* pointer to name within 'path' */
+    size_t       length;              /* length of component within 'path' */
+    file_size_t  filesize;            /* size of the opened file (0 if dir) */
+    unsigned int attr;                /* attributes of this component */
+    struct file_base_info *prefixp;   /* base info to check as prefix (IN) */
+    struct file_base_info parentinfo; /* parent directory info of file */
+};
+
+int open_stream_internal(const char *path, unsigned int callflags,
+                         struct filestr_base *stream,
+                         struct path_component_info *compinfo);
+int close_stream_internal(struct filestr_base *stream);
+int create_stream_internal(struct file_base_info *parentinfop,
+                           const char *basename, size_t length,
+                           unsigned int attr, unsigned int callflags,
+                           struct filestr_base *stream);
+int remove_stream_internal(const char *path, struct filestr_base *stream,
+                           unsigned int callflags);
+int test_stream_exists_internal(const char *path, unsigned int callflags);
+
+int open_noiso_internal(const char *path, int oflag); /* file.c */
+
+struct dirent;
+int uncached_readdir_dirent(struct filestr_base *stream,
+                            struct dirscan_info *scanp,
+                            struct dirent *entry);
+void uncached_rewinddir_dirent(struct dirscan_info *scanp);
+
+int uncached_readdir_internal(struct filestr_base *stream,
+                              struct file_base_info *infop,
+                              struct fat_direntry *fatent);
+void uncached_rewinddir_internal(struct file_base_info *infop);
+
+int test_dir_empty_internal(struct filestr_base *stream);
+
+struct dirinfo_internal
+{
+    unsigned int attr;
+    file_size_t  size;
+    uint16_t     wrtdate;
+    uint16_t     wrttime;
+};
+
+/** Synchronization used throughout **/
+
+/* acquire the filesystem lock as READER */
+static inline void file_internal_lock_READER(void)
+{
+    extern struct mrsw_lock file_internal_mrsw;
+    mrsw_read_acquire(&file_internal_mrsw);
+}
+
+/* release the filesystem lock as READER */
+static inline void file_internal_unlock_READER(void)
+{
+    extern struct mrsw_lock file_internal_mrsw;
+    mrsw_read_release(&file_internal_mrsw);
+}
+
+/* acquire the filesystem lock as WRITER */
+static inline void file_internal_lock_WRITER(void)
+{
+    extern struct mrsw_lock file_internal_mrsw;
+    mrsw_write_acquire(&file_internal_mrsw);
+}
+
+/* release the filesystem lock as WRITER */
+static inline void file_internal_unlock_WRITER(void)
+{
+    extern struct mrsw_lock file_internal_mrsw;
+    mrsw_write_release(&file_internal_mrsw);
+}
+
+#define ERRNO 0 /* maintain errno value */
+#define RC    0 /* maintain rc value */
+
+/* NOTES: if _errno is a non-constant expression, it must set an error
+ *        number and not return the ERRNO constant which will merely set
+ *        errno to zero, not preserve the current value; if you must set
+ *        errno to zero, set it explicitly, not in the macro
+ *
+ *        if _rc is constant-expression evaluation to 'RC', then rc will
+ *        NOT be altered; i.e. if you must set rc to zero, set it explicitly,
+ *        not in the macro
+ */
+
+/* set errno and rc and proceed to the "file_error:" label */
+#define FILE_ERROR(_errno, _rc) \
+    ({  __builtin_constant_p(_errno) ?                       \
+            ({ if ((_errno) != ERRNO) errno = (_errno); }) : \
+            ({ errno = (_errno); });                         \
+        __builtin_constant_p(_rc) ?                          \
+            ({ if ((_rc) != RC) rc = (_rc); }) :             \
+            ({ rc = (_rc); });                               \
+        goto file_error; })
+
+/* set errno and return a value at the point of invocation */
+#define FILE_ERROR_RETURN(_errno, _rc...) \
+    ({  __builtin_constant_p(_errno) ?                       \
+            ({ if ((_errno) != ERRNO) errno = (_errno); }) : \
+            ({ errno = (_errno); });                         \
+        return _rc; })
+
+
+/** Misc. stuff **/
+
+/* iterate through all the volumes if volume < 0, else just the given volume */
+#define FOR_EACH_VOLUME(volume, i) \
+    for (int i = (IF_MV_VOL(volume) >= 0 ? IF_MV_VOL(volume) : 0), \
+             _end = (IF_MV_VOL(volume) >= 0 ? i : NUM_VOLUMES-1);  \
+         i <= _end; i++)
+
+/* return a pointer to the static struct fat_direntry */
+static inline struct fat_direntry *get_dir_fatent(void)
+{
+    extern struct fat_direntry dir_fatent;
+    return &dir_fatent;
+}
+
+void iso_decode_d_name(char *d_name);
+
+#ifdef HAVE_DIRCACHE
+void empty_dirent(struct dirent *entry);
+void fill_dirinfo_native(struct dirinfo_native *din);
+#endif /* HAVE_DIRCACHE */
+
+void filesystem_init(void) INIT_ATTR;
+
+#endif /* _FILE_INTERNAL_H_ */
diff --git a/firmware/include/fileobj_mgr.h b/firmware/include/fileobj_mgr.h
new file mode 100644
index 0000000000..c90a59bea0
--- /dev/null
+++ b/firmware/include/fileobj_mgr.h
@@ -0,0 +1,56 @@
+/***************************************************************************
+ *             __________               __   ___.
+ *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
+ *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
+ *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
+ *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
+ *                     \/            \/     \/    \/            \/
+ * $Id$
+ *
+ * Copyright (C) 2014 by Michael Sevakis
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+ * KIND, either express or implied.
+ *
+ ****************************************************************************/
+#ifndef _FILEOBJ_MGR_H_
+#define _FILEOBJ_MGR_H_
+
+#include "file_internal.h"
+
+void file_binding_insert_first(struct file_base_binding *bindp);
+void file_binding_insert_last(struct file_base_binding *bindp);
+void file_binding_remove(struct file_base_binding *bindp);
+void file_binding_remove_next(struct file_base_binding *prevp,
+                              struct file_base_binding *bindp);
+
+void fileobj_fileop_open(struct filestr_base *stream,
+                         const struct file_base_info *srcinfop,
+                         unsigned int callflags);
+void fileobj_fileop_close(struct filestr_base *stream);
+void fileobj_fileop_create(struct filestr_base *stream,
+                           const struct file_base_info *srcinfop,
+                           unsigned int callflags);
+void fileobj_fileop_rename(struct filestr_base *stream,
+                           const struct file_base_info *oldinfop);
+void fileobj_fileop_remove(struct filestr_base *stream,
+                           const struct file_base_info *oldinfop);
+void fileobj_fileop_sync(struct filestr_base *stream);
+void fileobj_fileop_truncate(struct filestr_base *stream);
+extern void ftruncate_internal_callback(struct filestr_base *stream,
+                                        struct filestr_base *s);
+
+file_size_t * fileobj_get_sizep(const struct filestr_base *stream);
+unsigned int fileobj_get_flags(const struct filestr_base *stream);
+void fileobj_change_flags(struct filestr_base *stream,
+                          unsigned int flags, unsigned int mask);
+void fileobj_mgr_unmount(IF_MV_NONVOID(int volume));
+
+void fileobj_mgr_init(void) INIT_ATTR;
+
+#endif /* _FILEOBJ_MGR_H_ */
diff --git a/firmware/include/filesystem-native.h b/firmware/include/filesystem-native.h
new file mode 100644
index 0000000000..640e179890
--- /dev/null
+++ b/firmware/include/filesystem-native.h
@@ -0,0 +1,107 @@
+/***************************************************************************
+ *             __________               __   ___.
+ *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
+ *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
+ *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
+ *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
+ *                     \/            \/     \/    \/            \/
+ * $Id$
+ *
+ * Copyright (C) 2002 by Björn Stenberg
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+ * KIND, either express or implied.
+ *
+ ****************************************************************************/
+#ifndef _FILESYSTEM_NATIVE_H_
+#define _FILESYSTEM_NATIVE_H_
+
+#if defined(PLUGIN) || defined(CODEC)
+#define FILEFUNCTIONS_DECLARED
+#define FILEFUNCTIONS_DEFINED
+#define DIRFUNCTIONS_DECLARED
+#define DIRFUNCTIONS_DEFINED
+#endif /* PLUGIN || CODEC */
+
+#define FS_PREFIX(_x_) _x_
+#endif /* _FILESYSTEM_NATIVE_H_ */
+
+#ifdef _FILE_H_
+#ifndef _FILESYSTEM_NATIVE__FILE_H_
+#define _FILESYSTEM_NATIVE__FILE_H_
+
+#ifdef RB_FILESYSTEM_OS
+#define FILEFUNCTIONS_DEFINED
+#endif
+
+#ifndef FILEFUNCTIONS_DECLARED
+#define __OPEN_MODE_ARG
+#define __CREAT_MODE_ARG
+
+int     open(const char *name, int oflag);
+int     creat(const char *name);
+int     close(int fildes);
+int     ftruncate(int fildes, off_t length);
+int     fsync(int fildes);
+off_t   lseek(int fildes, off_t offset, int whence);
+ssize_t read(int fildes, void *buf, size_t nbyte);
+ssize_t write(int fildes, const void *buf, size_t nbyte);
+int     remove(const char *path);
+int     rename(const char *old, const char *new);
+off_t   filesize(int fildes);
+int     fsamefile(int fildes1, int fildes2);
+int     relate(const char *path1, const char *path2);
+bool    file_exists(const char *path);
+#endif /* !FILEFUNCTIONS_DECLARED */
+
+#if !defined(RB_FILESYSTEM_OS) && !defined (FILEFUNCTIONS_DEFINED)
+#define open(path, oflag, ...) open(path, oflag)
+#define creat(path, mode)      creat(path)
+#endif /* FILEFUNCTIONS_DEFINED */
+
+#endif /* _FILESYSTEM_NATIVE__FILE_H_ */
+#endif /* _FILE_H_ */
+
+#ifdef _DIR_H_
+#ifndef _FILESYSTEM_NATIVE__DIR_H_
+#define _FILESYSTEM_NATIVE__DIR_H_
+
+#define DIRENT dirent
+struct dirent;
+
+struct dirinfo_native
+{
+    unsigned int attr;
+    off_t        size;
+    uint16_t     wrtdate;
+    uint16_t     wrttime;
+};
+
+typedef struct {} DIR;
+
+#ifndef DIRFUNCTIONS_DECLARED
+#define __MKDIR_MODE_ARG
+
+#ifdef RB_FILESYSTEM_OS
+#define DIRFUNCTIONS_DEFINED
+#endif
+
+DIR *  opendir(const char *dirname);
+struct dirent * readdir(DIR *dirp);
+int    readdir_r(DIR *dirp, struct dirent *entry,
+                 struct dirent **result);
+void   rewinddir(DIR *dirp);
+int    closedir(DIR *dirp);
+int    mkdir(const char *path);
+int    rmdir(const char *path);
+int    samedir(DIR *dirp1, DIR *dirp2);
+bool   dir_exists(const char *dirname);
+#endif /* !DIRFUNCTIONS_DECLARED */
+
+#endif /* _FILESYSTEM_NATIVE__DIR_H_ */
+#endif /* _DIR_H_ */
diff --git a/firmware/include/fs_attr.h b/firmware/include/fs_attr.h
new file mode 100644
index 0000000000..0e1d25e1de
--- /dev/null
+++ b/firmware/include/fs_attr.h
@@ -0,0 +1,39 @@
+/***************************************************************************
+ *             __________               __   ___.
+ *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
+ *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
+ *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
+ *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
+ *                     \/            \/     \/    \/            \/
+ * $Id$
+ *
+ * Copyright (C) 2007 by Kévin Ferrare
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+ * KIND, either express or implied.
+ *
+ ****************************************************************************/
+#ifndef _FS_ATTR_H_
+#define _FS_ATTR_H_
+
+#include <stdbool.h>
+
+#undef MAX_PATH /* this avoids problems when building simulator */
+#define MAX_PATH 260
+
+/* also used by fat.c so values must not change */
+#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_VOLUME      0x40 /* this is a volume, not a real directory */
+#define ATTR_LINK        0x80
+
+#endif /* _FS_ATTR_H_ */
diff --git a/firmware/include/rb-loader.h b/firmware/include/rb-loader.h
index e1e756dba9..86c5026af9 100644
--- a/firmware/include/rb-loader.h
+++ b/firmware/include/rb-loader.h
@@ -18,5 +18,4 @@
  *
  ****************************************************************************/
 
-const char *rb_strerror(int8_t errno);
 int load_firmware(unsigned char* buf, const char* firmware, int buffer_size);
diff --git a/firmware/include/rbunicode.h b/firmware/include/rbunicode.h
index 3c28b3031e..077029304d 100644
--- a/firmware/include/rbunicode.h
+++ b/firmware/include/rbunicode.h
@@ -51,7 +51,8 @@ enum codepages {
     KSX_1001,       /* Korean */
     BIG_5,          /* Trad. Chinese */
     UTF_8,          /* Unicode */
-    NUM_CODEPAGES
+    NUM_CODEPAGES,
+    INIT_CODEPAGE = ISO_8859_1,
 };
 
 #else /* !HAVE_LCD_BITMAP, reduced support */
@@ -65,7 +66,8 @@ enum codepages {
     WIN_1250,       /* Central European */
     WIN_1252,       /* Western European */
     UTF_8,          /* Unicode */
-    NUM_CODEPAGES
+    NUM_CODEPAGES,
+    INIT_CODEPAGE = ISO_8859_1,
 };
 
 #endif
@@ -78,9 +80,19 @@ unsigned char* utf16BEdecode(const unsigned char *utf16, unsigned char *utf8, in
 unsigned long utf8length(const unsigned char *utf8);
 const unsigned char* utf8decode(const unsigned char *utf8, unsigned short *ucs);
 void set_codepage(int cp);
+int get_codepage(void);
 int utf8seek(const unsigned char* utf8, int offset);
 const char* get_codepage_name(int cp);
-#if defined(APPLICATION) && defined(__linux__)
+#ifdef APPLICATION
+#if defined(__linux__)
 const char *get_current_codepage_name_linux(void);
 #endif
+#endif /* APPLICATION */
+
+#if 0 /* not needed just now */
+void unicode_init(void);
+#else
+#define unicode_init() do {} while (0)
+#endif
+
 #endif /* _RBUNICODE_H_ */