Continued mkfatfs work

git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@802 42af7a65-404d-4744-a932-0658087f49c3

fs/fat/Make.defs

@@ -39,8 +39,8 @@ ifeq ($(CONFIG_FS_FAT),y)
 ASRCS		+=
 CSRCS		+= fs_fat32.c fs_fat32attrib.c fs_fat32util.c
 
-# File required for mkfatfs utility function
+# Files required for mkfatfs utility function
 
 ASRCS		+=
-CSRCS		+= fs_writefat.c
+CSRCS		+= fs_configfat.c fs_writefat.c
 endif

fs/fat/fs_configfat.c

@@ -0,0 +1,94 @@
+/****************************************************************************
+ * fs/fat/fs_configfat.c
+ *
+ *   Copyright (C) 2008 Gregory Nutt. All rights reserved.
+ *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
+ *
+ * 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.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+#include <sys/types.h>
+
+#include <string.h>
+#include <errno.h>
+
+#include <nuttx/fs.h>
+#include <nuttx/fat.h>
+#include <nuttx/mkfatfs.h>
+
+#include "fs_internal.h"
+#include "fs_fat32.h"
+#include "fs_mkfatfs.h"
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: 
+ *
+ * Description:
+ *
+ * Input:
+ *
+ * Return:
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Global Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: mkfatfs_configfatfs
+ *
+ * Description:
+ *   Based on the geometry of the block device and upon the caller-selected
+ *   values, configure the FAT filesystem for the device.
+ *
+ * Input:
+ *    fmt  - Caller specified format parameters
+ *    var  - Holds disk geomtry data.  Also, the location to return FAT
+ *           configuration data
+ *
+ * Return:
+ *    Zero on success; negated errno on failure
+ *
+ ****************************************************************************/
+int mkfatfs_configfatfs(FAR struct fat_format_s *fmt,
+                        FAR struct fat_var_s *var)
+{
+  return OK;
+}
+

fs/fat/fs_fat32.h

@@ -194,6 +194,31 @@
 #define FAT_EOF      0x0ffffff8
 #define FAT_BAD      0x0ffffff7
 
+/****************************************************************************
+ * Maximum cluster by FAT type.  This is the key value used to distinquish
+ * between FAT12, 16, and 32.
+ */
+
+/* FAT12: For M$, the calculation is ((1 << 12) - 19).  But we will follow the
+ * Linux tradition of allowing slightly more clusters for FAT12.
+ */
+
+#define FAT_MAXCLUST12 ((1 << 12) - 16)
+
+/* FAT16: For M$, the calculation is ((1 << 16) - 19). */
+  
+#define FAT_MINCLUST16 (FAT_MAXCLUST12 + 1)
+#define FAT_MAXCLUST16 ((1 << 16) - 16)
+
+/* FAT32: M$ reserves the MS 4 bits of a FAT32 FAT entry so only 18 bits are
+ * available.  For M$, the calculation is ((1 << 28) - 19).
+ */
+
+#define FAT_MINCLUST32  65524
+/* #define FAT_MINCLUST32  (FAT_MAXCLUST16 + 1) */
+#define FAT_MAXCLUST32  ((1 << 28) - 16)
+
+
 /****************************************************************************
  * Access to data in raw sector data */
 

fs/fat/fs_fat32util.c

@@ -303,11 +303,12 @@ static int fat_checkbootrecord(struct fat_mountpt_s *fs)
 
   /* Verify the FAT32 file system type. The determination of the file
    * system type is based on the number of clusters on the volume:  FAT12
-   * volume has < 4085 cluseter, a FAT16 volume has fewer than 65,525
+   * volume has <= FAT_MAXCLUST12 (4084) clusters, a FAT16 volume has <=
-   * clusters, and any larger is FAT32.
+   * FAT_MINCLUST16 (microsfoft says < 65,525) clusters, and any larger
+   * is FAT32.
    *
    * Get the number of 32-bit directory entries in root directory (zero
-   * for FAT32.
+   * for FAT32).
    */
 
   fs->fs_rootentcnt = MBR_GETROOTENTCNT(fs->fs_buffer);
@@ -382,12 +383,12 @@ static int fat_checkbootrecord(struct fat_mountpt_s *fs)
 
   /* Finally, the test: */
 
-  if (fs->fs_nclusters < 4085)
+  if (fs->fs_nclusters <= FAT_MAXCLUST12)
     {
       fs->fs_fsinfo = 0;
       fs->fs_type   = FSTYPE_FAT12;
     }
-  else if (fs->fs_nclusters < 65525)
+  else if (fs->fs_nclusters <= FAT_MAXCLUST16)
     {
       fs->fs_fsinfo = 0;
       fs->fs_type   = FSTYPE_FAT16;

fs/fat/fs_mkfatfs.h

@@ -125,6 +125,25 @@ extern "C" {
 #define EXTERN extern
 #endif
 
+/****************************************************************************
+ * Name: mkfatfs_configfatfs
+ *
+ * Description:
+ *   Based on the geometry of the block device and upon the caller-selected
+ *   values, configure the FAT filesystem for the device.
+ *
+ * Input:
+ *    fmt  - Caller specified format parameters
+ *    var  - Holds disk geomtry data.  Also, the location to return FAT
+ *           configuration data
+ *
+ * Return:
+ *    Zero on success; negated errno on failure
+ *
+ ****************************************************************************/
+EXTERN int mkfatfs_configfatfs(FAR struct fat_format_s *fmt,
+                               FAR struct fat_var_s *var);
+
 /****************************************************************************
  * Name: mkfatfs_writefat
  *
@@ -132,8 +151,9 @@ extern "C" {
  *   Write the configured fat filesystem to the block device
  *
  * Input:
- *    fmt  - User specified format parameters
+ *    fmt  - Caller specified format parameters
- *    var  - Other format parameters that are not user specifiable
+ *    var  - Other format parameters that are not caller specifiable. (Most
+ *           set by mkfatfs_configfatfs()).
  *
  * Return:
  *    Zero on success; negated errno on failure

fs/fat/fs_writefat.c

@@ -1,5 +1,5 @@
 /****************************************************************************
- * fs/fat/fs_write.c
+ * fs/fat/fs_writefat.c
  *
  *   Copyright (C) 2008 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
@@ -504,8 +504,9 @@ static inline int mkfatfs_writerootdir(FAR struct fat_format_s *fmt,
  *   Write the configured fat filesystem to the block device
  *
  * Input:
- *    fmt  - User specified format parameters
+ *    fmt  - Caller specified format parameters
- *    var  - Other format parameters that are not user specifiable
+ *    var  - Other format parameters that are not caller specifiable. (Most
+ *           set by mkfatfs_configfatfs()).
  *
  * Return:
  *    Zero on success; negated errno on failure