libfs/fatfs: Add FatFS with tests

This adds FatFS wrapper layer to RTEMS
including tests as part of GSoC 2025.

cpukit/include/rtems/confdefs/libio.h

@@ -48,6 +48,7 @@
 
 #ifdef CONFIGURE_FILESYSTEM_ALL
   #define CONFIGURE_FILESYSTEM_DOSFS
+  #define CONFIGURE_FILESYSTEM_FATFS
   #define CONFIGURE_FILESYSTEM_FTPFS
   #define CONFIGURE_FILESYSTEM_IMFS
   #define CONFIGURE_FILESYSTEM_JFFS2
@@ -108,6 +109,10 @@
     #error "CONFIGURE_APPLICATION_DISABLE_FILESYSTEM cannot be used together with CONFIGURE_FILESYSTEM_DOSFS"
   #endif
 
+  #ifdef CONFIGURE_FILESYSTEM_FATFS
+    #error "CONFIGURE_APPLICATION_DISABLE_FILESYSTEM cannot be used together with CONFIGURE_FILESYSTEM_FATFS"
+  #endif
+
   #ifdef CONFIGURE_FILESYSTEM_FTPFS
     #error "CONFIGURE_APPLICATION_DISABLE_FILESYSTEM cannot be used together with CONFIGURE_FILESYSTEM_FTPFS"
   #endif
@@ -139,6 +144,10 @@
 #include <rtems/dosfs.h>
 #endif
 
+#ifdef CONFIGURE_FILESYSTEM_FATFS
+#include <rtems/fatfs.h>
+#endif
+
 #ifdef CONFIGURE_FILESYSTEM_FTPFS
 #include <rtems/ftpfs.h>
 #endif
@@ -297,6 +306,9 @@ const rtems_filesystem_table_t rtems_filesystem_table[] = {
   #ifdef CONFIGURE_FILESYSTEM_DOSFS
     { RTEMS_FILESYSTEM_TYPE_DOSFS, rtems_dosfs_initialize },
   #endif
+  #ifdef CONFIGURE_FILESYSTEM_FATFS
+    { RTEMS_FILESYSTEM_TYPE_FATFS, rtems_fatfs_initialize },
+  #endif
   #ifdef CONFIGURE_FILESYSTEM_FTPFS
     { RTEMS_FILESYSTEM_TYPE_FTPFS, rtems_ftpfs_initialize },
   #endif

cpukit/include/rtems/fatfs.h

@@ -0,0 +1,60 @@
+/**
+ * @file
+ *
+ * @ingroup FatFS
+ *
+ * @brief RTEMS FatFS Filesystem Public API
+ */
+
+/*
+ Copyright (C) 2025 Sepehr Ganji <sepehrganji79@gmail.com>
+*/
+
+#ifndef _RTEMS_FATFS_H
+#define _RTEMS_FATFS_H
+
+#include <rtems.h>
+#include <rtems/libio.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ * @addtogroup FATFS
+ *
+ * @{
+ */
+
+/**
+ * @brief RTEMS FatFS filesystem mount options.
+ */
+typedef struct {
+  /** Currently no options defined */
+  int reserved;
+} rtems_fatfs_mount_options;
+
+/**
+ * @brief Initialize FatFS filesystem.
+ *
+ * This function is the mount handler for the FatFS filesystem. It is called
+ * by the mount() system call when the filesystem type is
+ * RTEMS_FILESYSTEM_TYPE_FATFS.
+ *
+ * @param[in] mt_entry The mount table entry.
+ * @param[in] data Mount options (rtems_fatfs_mount_options or NULL).
+ *
+ * @return 0 on success, -1 on error with errno set.
+ */
+int rtems_fatfs_initialize(
+  rtems_filesystem_mount_table_entry_t *mt_entry,
+  const void                           *data
+);
+
+/** @} */
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* _RTEMS_FATFS_H */

cpukit/include/rtems/libio.h

@@ -1649,6 +1649,7 @@ extern int rtems_mkdir(const char *path, mode_t mode);
 #define RTEMS_FILESYSTEM_TYPE_TFTPFS "tftpfs"
 #define RTEMS_FILESYSTEM_TYPE_NFS "nfs"
 #define RTEMS_FILESYSTEM_TYPE_DOSFS "dosfs"
+#define RTEMS_FILESYSTEM_TYPE_FATFS "fatfs"
 #define RTEMS_FILESYSTEM_TYPE_RFS "rfs"
 #define RTEMS_FILESYSTEM_TYPE_JFFS2 "jffs2"
 

cpukit/libfs/src/fatfs/rtems-diskio.c

@@ -0,0 +1,222 @@
+/**
+ * @file
+ *
+ * @ingroup FatFS
+ *
+ * @brief RTEMS Disk I/O Interface for FatFs
+ */
+
+/*
+ Copyright (C) 2025 Sepehr Ganji <sepehrganji79@gmail.com>
+*/
+
+#include <errno.h>
+#include <fcntl.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <time.h>
+#include <unistd.h>
+
+#include <rtems.h>
+#include <rtems/bdbuf.h>
+#include <rtems/libio_.h>
+
+#include "ff.h"
+#include "diskio.h"
+#include "rtems-fatfs.h"
+
+static fatfs_volume_t volumes[ FF_VOLUMES ];
+
+/*
+ * Compiler will change name to rtems_fatfs_disk_status
+ */
+DSTATUS disk_status( BYTE pdrv )
+{
+  if ( pdrv >= FF_VOLUMES ) {
+    return STA_NOINIT;
+  }
+
+  if ( !volumes[ pdrv ].initialized ) {
+    return STA_NOINIT;
+  }
+
+  return 0;
+}
+
+/*
+ * Compiler will change name to rtems_fatfs_disk_initialize
+ */
+DSTATUS disk_initialize( BYTE pdrv )
+{
+  if ( pdrv >= FF_VOLUMES ) {
+    return STA_NOINIT;
+  }
+  bool is_initialized = volumes[ pdrv ].initialized;
+  return is_initialized ? 0 : STA_NOINIT;
+}
+
+/*
+ * Compiler will change name to rtems_fatfs_disk_read
+ */
+DRESULT disk_read( BYTE pdrv, BYTE *buff, LBA_t sector, UINT count )
+{
+  rtems_status_code   sc;
+  rtems_bdbuf_buffer *bd;
+  uint32_t            block_size;
+
+  if ( disk_status( pdrv ) != 0 ) {
+    return RES_NOTRDY;
+  }
+
+  rtems_disk_device *dd = volumes[ pdrv ].dd;
+  block_size            = dd->block_size;
+
+  for ( size_t i = 0; i < count; i++ ) {
+    sc = rtems_bdbuf_read( dd, sector + i, &bd );
+    if ( sc != RTEMS_SUCCESSFUL ) {
+      return RES_ERROR;
+    }
+
+    memcpy( buff + ( i * block_size ), bd->buffer, block_size );
+
+    sc = rtems_bdbuf_release( bd );
+    if ( sc != RTEMS_SUCCESSFUL ) {
+      return RES_ERROR;
+    }
+  }
+
+  return RES_OK;
+}
+
+/*
+ * Compiler will change name to rtems_fatfs_disk_write
+ */
+DRESULT disk_write( BYTE pdrv, const BYTE *buff, LBA_t sector, UINT count )
+{
+  rtems_status_code   sc;
+  rtems_bdbuf_buffer *bd;
+  uint32_t            block_size;
+
+  if ( disk_status( pdrv ) != 0 ) {
+    return RES_NOTRDY;
+  }
+
+  rtems_disk_device *dd = volumes[ pdrv ].dd;
+
+  block_size = dd->block_size;
+
+  for ( size_t i = 0; i < count; i++ ) {
+    sc = rtems_bdbuf_get( dd, sector + i, &bd );
+    if ( sc != RTEMS_SUCCESSFUL ) {
+      return RES_ERROR;
+    }
+
+    memcpy( bd->buffer, buff + ( i * block_size ), block_size );
+
+    sc = rtems_bdbuf_release_modified( bd );
+    if ( sc != RTEMS_SUCCESSFUL ) {
+      return RES_ERROR;
+    }
+  }
+
+  return RES_OK;
+}
+
+/*
+ * Compiler will change name to rtems_fatfs_disk_ioctl
+ */
+DRESULT disk_ioctl( BYTE pdrv, BYTE cmd, void *buff )
+{
+  if ( disk_status( pdrv ) != 0 ) {
+    return RES_NOTRDY;
+  }
+
+  rtems_disk_device *dd = volumes[ pdrv ].dd;
+
+  switch ( cmd ) {
+    case CTRL_SYNC: {
+      rtems_status_code sc = rtems_bdbuf_syncdev( dd );
+      if ( sc != RTEMS_SUCCESSFUL ) {
+        return RES_ERROR;
+      }
+    } break;
+
+    case GET_SECTOR_COUNT:
+      *(rtems_blkdev_bnum *) buff = dd->size;
+      break;
+
+    case GET_SECTOR_SIZE:
+      *(uint32_t *) buff = dd->media_block_size;
+      break;
+
+    case GET_BLOCK_SIZE:
+      *(uint32_t *) buff = dd->block_size;
+      break;
+
+    case CTRL_TRIM:
+      break;
+
+    default:
+      return RES_PARERR;
+  }
+
+  return RES_OK;
+}
+
+int fatfs_diskio_register_device( uint8_t pdrv, const char *device_path )
+{
+  struct stat        stat_buf;
+  int                fd;
+  rtems_disk_device *dd;
+  int                rc;
+
+  if ( pdrv >= FF_VOLUMES ) {
+    rtems_set_errno_and_return_minus_one( EINVAL );
+  }
+
+  if ( volumes[ pdrv ].initialized ) {
+    return 0;
+  }
+
+  fd = open( device_path, O_RDWR );
+  if ( fd < 0 ) {
+    return -1;
+  }
+
+  rc = fstat( fd, &stat_buf );
+  if ( rc != 0 ) {
+    close( fd );
+    return -1;
+  }
+
+  if ( !S_ISBLK( stat_buf.st_mode ) ) {
+    close( fd );
+    rtems_set_errno_and_return_minus_one( ENXIO );
+  }
+
+  rc = rtems_disk_fd_get_disk_device( fd, &dd );
+  if ( rc != 0 ) {
+    close( fd );
+    return -1;
+  }
+
+  volumes[ pdrv ].fd          = fd;
+  volumes[ pdrv ].dd          = dd;
+  volumes[ pdrv ].initialized = true;
+
+  return 0;
+}
+
+void fatfs_diskio_unregister_device( uint8_t pdrv )
+{
+  if ( pdrv >= FF_VOLUMES || !volumes[ pdrv ].initialized ) {
+    return;
+  }
+
+  close( volumes[ pdrv ].fd );
+  volumes[ pdrv ].fd          = -1;
+  volumes[ pdrv ].dd          = NULL;
+  volumes[ pdrv ].initialized = false;
+}

cpukit/libfs/src/fatfs/rtems-fatfs-dir.c

@@ -0,0 +1,207 @@
+/**
+ * @file
+ *
+ * @ingroup FatFS
+ *
+ * @brief RTEMS FATFS directory operations
+ */
+
+/*
+ Copyright (C) 2025 Sepehr Ganji <sepehrganji79@gmail.com>
+*/
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <fcntl.h>
+#include <stddef.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#include <rtems.h>
+#include <rtems/libio.h>
+#include <rtems/libio_.h>
+
+#include "ff.h"
+#include "rtems-fatfs.h"
+
+#define DIR POSIX_DIR
+#include <dirent.h>
+#undef DIR
+
+ssize_t rtems_fatfs_dir_read( rtems_libio_t *iop, void *buffer, size_t count )
+{
+  rtems_fatfs_node_t *node = (rtems_fatfs_node_t *) iop->pathinfo.node_access;
+  struct dirent      *dp   = (struct dirent *) buffer;
+  FILINFO             fno;
+  FRESULT             fr;
+  size_t              bytes_transferred = 0;
+
+  if ( node == NULL || !node->is_directory ) {
+    rtems_set_errno_and_return_minus_one( ENOTDIR );
+  }
+
+  if ( count < sizeof( struct dirent ) ) {
+    rtems_set_errno_and_return_minus_one( EINVAL );
+  }
+
+  rtems_fatfs_lock( iop->pathinfo.mt_entry );
+
+  memset( &fno, 0, sizeof( fno ) );
+
+  fr = f_readdir( &node->handle.dir, &fno );
+  if ( fr != FR_OK ) {
+    rtems_fatfs_unlock( iop->pathinfo.mt_entry );
+    errno = rtems_fatfs_fresult_to_errno( fr );
+    return -1;
+  }
+
+  if ( fno.fname[ 0 ] == '\0' ) {
+    rtems_fatfs_unlock( iop->pathinfo.mt_entry );
+    return 0;
+  }
+
+  memset( dp, 0, sizeof( struct dirent ) );
+  dp->d_ino    = 1;
+  dp->d_off    = iop->offset;
+  dp->d_reclen = sizeof( struct dirent );
+
+  size_t name_len = strlen( fno.fname );
+  if ( name_len >= sizeof( dp->d_name ) ) {
+    name_len = sizeof( dp->d_name ) - 1;
+  }
+  memcpy( dp->d_name, fno.fname, name_len );
+  dp->d_name[ name_len ] = '\0';
+  dp->d_namlen           = name_len;
+
+  if ( fno.fattrib & AM_DIR ) {
+    dp->d_type = DT_DIR;
+  } else {
+    dp->d_type = DT_REG;
+  }
+
+  bytes_transferred  = sizeof( struct dirent );
+  iop->offset       += sizeof( struct dirent );
+
+  rtems_fatfs_unlock( iop->pathinfo.mt_entry );
+
+  return (ssize_t) bytes_transferred;
+}
+
+int rtems_fatfs_dir_fstat(
+  const rtems_filesystem_location_info_t *loc,
+  struct stat                            *buf
+)
+{
+  rtems_fatfs_node_t *node = (rtems_fatfs_node_t *) loc->node_access;
+
+  if ( node == NULL ) {
+    rtems_set_errno_and_return_minus_one( EBADF );
+  }
+  rtems_fatfs_fs_info_t *fs_info = (rtems_fatfs_fs_info_t *)
+                                     loc->mt_entry->fs_info;
+  rtems_fatfs_node_to_stat( node, buf, fs_info );
+  return 0;
+}
+
+int rtems_fatfs_opendir(
+  rtems_libio_t *iop,
+  const char    *path,
+  int            oflag,
+  mode_t         mode
+)
+{
+  (void) path;
+  (void) oflag;
+  (void) mode;
+
+  rtems_fatfs_node_t *node = (rtems_fatfs_node_t *) iop->pathinfo.node_access;
+  rtems_fatfs_fs_info_t *fs_info = (rtems_fatfs_fs_info_t *)
+                                     iop->pathinfo.mt_entry->fs_info;
+  char    full_path[ 256 ];
+  FRESULT fr;
+  int     rc;
+
+  if ( node == NULL || !node->is_directory ) {
+    rtems_set_errno_and_return_minus_one( ENOTDIR );
+  }
+
+  if ( node->is_open ) {
+    return 0;
+  }
+
+  rtems_fatfs_lock( iop->pathinfo.mt_entry );
+
+  rc = rtems_fatfs_resolve_node_path(
+    fs_info,
+    node,
+    full_path,
+    sizeof( full_path ),
+    iop->pathinfo.mt_entry
+  );
+  if ( rc != 0 ) {
+    return rc;
+  }
+
+  fr = f_opendir( &node->handle.dir, full_path );
+  if ( fr != FR_OK ) {
+    rtems_fatfs_unlock( iop->pathinfo.mt_entry );
+    errno = rtems_fatfs_fresult_to_errno( fr );
+    return -1;
+  }
+
+  node->is_open = true;
+  rtems_fatfs_unlock( iop->pathinfo.mt_entry );
+
+  return 0;
+}
+
+int rtems_fatfs_closedir( rtems_libio_t *iop )
+{
+  rtems_fatfs_node_t *node = (rtems_fatfs_node_t *) iop->pathinfo.node_access;
+  FRESULT             fr;
+
+  if ( node == NULL || !node->is_directory ) {
+    rtems_set_errno_and_return_minus_one( ENOTDIR );
+  }
+
+  if ( !node->is_open ) {
+    return 0;
+  }
+
+  rtems_fatfs_lock( iop->pathinfo.mt_entry );
+
+  fr = f_closedir( &node->handle.dir );
+  if ( fr != FR_OK ) {
+    rtems_fatfs_unlock( iop->pathinfo.mt_entry );
+    errno = rtems_fatfs_fresult_to_errno( fr );
+    return -1;
+  }
+
+  node->is_open = false;
+  rtems_fatfs_unlock( iop->pathinfo.mt_entry );
+
+  return 0;
+}
+
+const rtems_filesystem_file_handlers_r rtems_fatfs_dir_handlers = {
+  .open_h      = rtems_fatfs_opendir,
+  .close_h     = rtems_fatfs_closedir,
+  .read_h      = rtems_fatfs_dir_read,
+  .write_h     = rtems_filesystem_default_write,
+  .ioctl_h     = rtems_filesystem_default_ioctl,
+  .lseek_h     = rtems_filesystem_default_lseek_directory,
+  .fstat_h     = rtems_fatfs_dir_fstat,
+  .ftruncate_h = rtems_filesystem_default_ftruncate_directory,
+  .fsync_h     = rtems_fatfs_file_fsync,
+  .fdatasync_h = rtems_fatfs_file_fsync,
+  .fcntl_h     = rtems_filesystem_default_fcntl,
+  .kqfilter_h  = rtems_filesystem_default_kqfilter,
+  .mmap_h      = rtems_filesystem_default_mmap,
+  .poll_h      = rtems_filesystem_default_poll,
+  .readv_h     = rtems_filesystem_default_readv,
+  .writev_h    = rtems_filesystem_default_writev
+};

cpukit/libfs/src/fatfs/rtems-fatfs-file.c

@@ -0,0 +1,451 @@
+/**
+ * @file
+ *
+ * @ingroup FatFS
+ *
+ * @brief RTEMS FATFS file operations
+ */
+
+/*
+ Copyright (C) 2025 Sepehr Ganji <sepehrganji79@gmail.com>
+*/
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <fcntl.h>
+#include <limits.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#include <rtems.h>
+#include <rtems/libio.h>
+#include <rtems/libio_.h>
+
+#include "ff.h"
+#include "rtems-fatfs.h"
+
+ssize_t rtems_fatfs_file_read( rtems_libio_t *iop, void *buffer, size_t count )
+{
+  rtems_fatfs_node_t *node = (rtems_fatfs_node_t *) iop->pathinfo.node_access;
+  FRESULT             fr;
+  UINT                bytes_read = 0;
+
+  if ( node == NULL || node->is_directory ) {
+    rtems_set_errno_and_return_minus_one( EBADF );
+  }
+
+  rtems_fatfs_lock( iop->pathinfo.mt_entry );
+
+  fr = f_lseek( &node->handle.file, (FSIZE_t) iop->offset );
+  if ( fr != FR_OK ) {
+    rtems_fatfs_unlock( iop->pathinfo.mt_entry );
+    errno = rtems_fatfs_fresult_to_errno( fr );
+    return -1;
+  }
+
+  fr = f_read( &node->handle.file, buffer, (UINT) count, &bytes_read );
+
+  rtems_fatfs_unlock( iop->pathinfo.mt_entry );
+
+  if ( fr != FR_OK ) {
+    errno = rtems_fatfs_fresult_to_errno( fr );
+    return -1;
+  }
+
+  if ( bytes_read > 0 ) {
+    iop->offset += bytes_read;
+  }
+
+  return (ssize_t) bytes_read;
+}
+
+ssize_t rtems_fatfs_file_write(
+  rtems_libio_t *iop,
+  const void    *buffer,
+  size_t         count
+)
+{
+  rtems_fatfs_node_t *node = (rtems_fatfs_node_t *) iop->pathinfo.node_access;
+  FRESULT             fr;
+  UINT                bytes_written = 0;
+
+  if ( node == NULL || node->is_directory ) {
+    rtems_set_errno_and_return_minus_one( EBADF );
+  }
+
+  rtems_fatfs_lock( iop->pathinfo.mt_entry );
+
+  if ( rtems_libio_iop_is_append( iop ) ) {
+    fr = f_lseek( &node->handle.file, f_size( &node->handle.file ) );
+    if ( fr != FR_OK ) {
+      rtems_fatfs_unlock( iop->pathinfo.mt_entry );
+      errno = rtems_fatfs_fresult_to_errno( fr );
+      return -1;
+    }
+    iop->offset = f_tell( &node->handle.file );
+  } else {
+    FSIZE_t current_size = f_size( &node->handle.file );
+    FSIZE_t target_pos   = (FSIZE_t) iop->offset;
+
+    if ( target_pos > current_size ) {
+      FSIZE_t gap_size = target_pos - current_size;
+      char    zero_buf[ 512 ];
+      UINT    bw;
+
+      memset( zero_buf, 0, sizeof( zero_buf ) );
+
+      fr = f_lseek( &node->handle.file, current_size );
+      if ( fr != FR_OK ) {
+        rtems_fatfs_unlock( iop->pathinfo.mt_entry );
+        errno = rtems_fatfs_fresult_to_errno( fr );
+        return -1;
+      }
+
+      while ( gap_size > 0 && fr == FR_OK ) {
+        UINT to_write = gap_size > sizeof( zero_buf ) ? sizeof( zero_buf ) :
+                                                        (UINT) gap_size;
+        fr            = f_write( &node->handle.file, zero_buf, to_write, &bw );
+        if ( fr == FR_OK && bw == to_write ) {
+          gap_size -= to_write;
+        } else {
+          break;
+        }
+      }
+
+      if ( fr != FR_OK ) {
+        rtems_fatfs_unlock( iop->pathinfo.mt_entry );
+        errno = rtems_fatfs_fresult_to_errno( fr );
+        return -1;
+      }
+
+      if ( gap_size > 0 ) {
+        rtems_fatfs_unlock( iop->pathinfo.mt_entry );
+        errno = ENOSPC;
+        return -1;
+      }
+    } else {
+      fr = f_lseek( &node->handle.file, target_pos );
+      if ( fr != FR_OK ) {
+        rtems_fatfs_unlock( iop->pathinfo.mt_entry );
+        errno = rtems_fatfs_fresult_to_errno( fr );
+        return -1;
+      }
+    }
+  }
+
+  fr = f_write( &node->handle.file, buffer, (UINT) count, &bytes_written );
+
+  rtems_fatfs_unlock( iop->pathinfo.mt_entry );
+
+  if ( fr != FR_OK ) {
+    errno = rtems_fatfs_fresult_to_errno( fr );
+    return -1;
+  }
+
+  if ( bytes_written > 0 ) {
+    iop->offset      += bytes_written;
+    node->info.fsize  = f_size( &node->handle.file );
+
+    time_t current_time    = time( NULL );
+    node->posix_mtime      = current_time;
+    node->posix_ctime      = current_time;
+    node->posix_time_valid = true;
+  } else if ( count > 0 && bytes_written == 0 ) {
+    errno = ENOSPC;
+    return -1;
+  }
+
+  return (ssize_t) bytes_written;
+}
+
+off_t rtems_fatfs_file_lseek( rtems_libio_t *iop, off_t offset, int whence )
+{
+  rtems_fatfs_node_t *node = (rtems_fatfs_node_t *) iop->pathinfo.node_access;
+  FSIZE_t             new_pos;
+  off_t               result;
+
+  if ( node == NULL || node->is_directory ) {
+    rtems_set_errno_and_return_minus_one( EBADF );
+  }
+
+  switch ( whence ) {
+    case SEEK_SET:
+      if ( offset < 0 ) {
+        rtems_set_errno_and_return_minus_one( EINVAL );
+      }
+      new_pos = (FSIZE_t) offset;
+      break;
+    case SEEK_CUR:
+      if ( offset > 0 && iop->offset > LLONG_MAX - offset ) {
+        rtems_set_errno_and_return_minus_one( EOVERFLOW );
+      }
+      result = iop->offset + offset;
+      if ( result < 0 ) {
+        rtems_set_errno_and_return_minus_one( EINVAL );
+      }
+      new_pos = (FSIZE_t) result;
+      break;
+    case SEEK_END:
+      if ( offset > 0 && (off_t) node->info.fsize > LLONG_MAX - offset ) {
+        rtems_set_errno_and_return_minus_one( EOVERFLOW );
+      }
+      result = (off_t) node->info.fsize + offset;
+      if ( result < 0 ) {
+        rtems_set_errno_and_return_minus_one( EINVAL );
+      }
+      new_pos = (FSIZE_t) result;
+      break;
+    default:
+      rtems_set_errno_and_return_minus_one( EINVAL );
+  }
+
+  iop->offset = (off_t) new_pos;
+  return iop->offset;
+}
+
+int rtems_fatfs_file_fstat(
+  const rtems_filesystem_location_info_t *loc,
+  struct stat                            *buf
+)
+{
+  rtems_fatfs_node_t *node = (rtems_fatfs_node_t *) loc->node_access;
+
+  if ( node == NULL ) {
+    rtems_set_errno_and_return_minus_one( EBADF );
+  }
+
+  rtems_fatfs_fs_info_t *fs_info = (rtems_fatfs_fs_info_t *)
+                                     loc->mt_entry->fs_info;
+  rtems_fatfs_node_to_stat( node, buf, fs_info );
+  return 0;
+}
+
+int rtems_fatfs_file_ftruncate( rtems_libio_t *iop, off_t length )
+{
+  rtems_fatfs_node_t *node = (rtems_fatfs_node_t *) iop->pathinfo.node_access;
+  FRESULT             fr;
+  FSIZE_t             old_size;
+
+  if ( node == NULL || node->is_directory ) {
+    rtems_set_errno_and_return_minus_one( EBADF );
+  }
+
+  rtems_fatfs_lock( iop->pathinfo.mt_entry );
+
+  old_size = f_size( &node->handle.file );
+
+  if ( (FSIZE_t) length > old_size ) {
+    FSIZE_t current_pos = f_tell( &node->handle.file );
+    FSIZE_t gap_size    = (FSIZE_t) length - old_size;
+    char    zero_buf[ 512 ];
+    UINT    bw;
+
+    memset( zero_buf, 0, sizeof( zero_buf ) );
+
+    fr = f_lseek( &node->handle.file, old_size );
+    if ( fr != FR_OK ) {
+      rtems_fatfs_unlock( iop->pathinfo.mt_entry );
+      errno = rtems_fatfs_fresult_to_errno( fr );
+      return -1;
+    }
+
+    while ( gap_size > 0 && fr == FR_OK ) {
+      UINT to_write = gap_size > sizeof( zero_buf ) ? sizeof( zero_buf ) :
+                                                      (UINT) gap_size;
+      fr            = f_write( &node->handle.file, zero_buf, to_write, &bw );
+      if ( fr == FR_OK && bw == to_write ) {
+        gap_size -= to_write;
+      } else {
+        break;
+      }
+    }
+
+    if ( fr == FR_OK ) {
+      if ( gap_size > 0 ) {
+        rtems_fatfs_unlock( iop->pathinfo.mt_entry );
+        errno = ENOSPC;
+        return -1;
+      }
+      fr = f_lseek( &node->handle.file, current_pos );
+    }
+  } else {
+    fr = f_lseek( &node->handle.file, (FSIZE_t) length );
+    if ( fr == FR_OK ) {
+      fr = f_truncate( &node->handle.file );
+    }
+  }
+
+  rtems_fatfs_unlock( iop->pathinfo.mt_entry );
+
+  if ( fr != FR_OK ) {
+    errno = rtems_fatfs_fresult_to_errno( fr );
+    return -1;
+  }
+
+  node->info.fsize = (FSIZE_t) length;
+
+  return 0;
+}
+
+int rtems_fatfs_file_fsync( rtems_libio_t *iop )
+{
+  rtems_fatfs_node_t *node = (rtems_fatfs_node_t *) iop->pathinfo.node_access;
+  FRESULT             fr;
+
+  if ( node == NULL || node->is_directory || !node->is_open ) {
+    return 0;
+  }
+
+  rtems_fatfs_lock( iop->pathinfo.mt_entry );
+  fr = f_sync( &node->handle.file );
+  rtems_fatfs_unlock( iop->pathinfo.mt_entry );
+
+  if ( fr != FR_OK ) {
+    errno = rtems_fatfs_fresult_to_errno( fr );
+    return -1;
+  }
+
+  return 0;
+}
+
+int rtems_fatfs_openfile(
+  rtems_libio_t *iop,
+  const char    *path,
+  int            oflag,
+  mode_t         mode
+)
+{
+  (void) path;
+  (void) mode;
+
+  rtems_fatfs_node_t *node = (rtems_fatfs_node_t *) iop->pathinfo.node_access;
+  rtems_fatfs_fs_info_t *fs_info = (rtems_fatfs_fs_info_t *)
+                                     iop->pathinfo.mt_entry->fs_info;
+  char    full_path[ 256 ];
+  FRESULT fr;
+  int     rc;
+
+  if ( node == NULL || node->is_directory ) {
+    rtems_set_errno_and_return_minus_one( EISDIR );
+  }
+
+  if ( node->is_open ) {
+    return 0;
+  }
+
+  rtems_fatfs_lock( iop->pathinfo.mt_entry );
+
+  rc = rtems_fatfs_resolve_node_path(
+    fs_info,
+    node,
+    full_path,
+    sizeof( full_path ),
+    iop->pathinfo.mt_entry
+  );
+  if ( rc != 0 ) {
+    return rc;
+  }
+
+  BYTE fatfs_mode = FA_READ;
+
+  if ( oflag & O_WRONLY ) {
+    fatfs_mode = FA_WRITE;
+  } else if ( oflag & O_RDWR ) {
+    fatfs_mode = FA_READ | FA_WRITE;
+  }
+
+  if ( oflag & O_CREAT ) {
+    if ( oflag & O_WRONLY ) {
+      fatfs_mode = FA_WRITE | FA_OPEN_EXISTING;
+    } else if ( oflag & O_RDWR ) {
+      fatfs_mode = FA_READ | FA_WRITE | FA_OPEN_EXISTING;
+    } else {
+      fatfs_mode = FA_READ | FA_OPEN_EXISTING;
+    }
+  }
+
+  fr = f_open( &node->handle.file, full_path, fatfs_mode );
+  if ( fr != FR_OK ) {
+    rtems_fatfs_unlock( iop->pathinfo.mt_entry );
+    errno = rtems_fatfs_fresult_to_errno( fr );
+    return -1;
+  }
+
+  if ( oflag & O_TRUNC ) {
+    if ( f_size( &node->handle.file ) == 0 ) {
+      UINT bw;
+      char dummy = 0;
+      fr         = f_write( &node->handle.file, &dummy, 1, &bw );
+      if ( fr == FR_OK ) {
+        fr = f_truncate( &node->handle.file );
+      }
+    } else {
+      fr = f_truncate( &node->handle.file );
+    }
+
+    if ( fr != FR_OK ) {
+      f_close( &node->handle.file );
+      rtems_fatfs_unlock( iop->pathinfo.mt_entry );
+      errno = rtems_fatfs_fresult_to_errno( fr );
+      return -1;
+    }
+
+    f_sync( &node->handle.file );
+  }
+
+  node->is_open = true;
+  rtems_fatfs_unlock( iop->pathinfo.mt_entry );
+
+  return 0;
+}
+
+int rtems_fatfs_closefile( rtems_libio_t *iop )
+{
+  rtems_fatfs_node_t *node = (rtems_fatfs_node_t *) iop->pathinfo.node_access;
+  FRESULT             fr;
+
+  if ( node == NULL || node->is_directory ) {
+    rtems_set_errno_and_return_minus_one( EISDIR );
+  }
+
+  if ( !node->is_open ) {
+    return 0;
+  }
+
+  rtems_fatfs_lock( iop->pathinfo.mt_entry );
+
+  fr = f_close( &node->handle.file );
+  if ( fr != FR_OK ) {
+    rtems_fatfs_unlock( iop->pathinfo.mt_entry );
+    errno = rtems_fatfs_fresult_to_errno( fr );
+    return -1;
+  }
+
+  node->is_open = false;
+  rtems_fatfs_unlock( iop->pathinfo.mt_entry );
+
+  return 0;
+}
+
+const rtems_filesystem_file_handlers_r rtems_fatfs_file_handlers = {
+  .open_h      = rtems_fatfs_openfile,
+  .close_h     = rtems_fatfs_closefile,
+  .read_h      = rtems_fatfs_file_read,
+  .write_h     = rtems_fatfs_file_write,
+  .ioctl_h     = rtems_filesystem_default_ioctl,
+  .lseek_h     = rtems_fatfs_file_lseek,
+  .fstat_h     = rtems_fatfs_file_fstat,
+  .ftruncate_h = rtems_fatfs_file_ftruncate,
+  .fsync_h     = rtems_fatfs_file_fsync,
+  .fdatasync_h = rtems_fatfs_file_fsync,
+  .fcntl_h     = rtems_filesystem_default_fcntl,
+  .kqfilter_h  = rtems_filesystem_default_kqfilter,
+  .mmap_h      = rtems_filesystem_default_mmap,
+  .poll_h      = rtems_filesystem_default_poll,
+  .readv_h     = rtems_filesystem_default_readv,
+  .writev_h    = rtems_filesystem_default_writev
+};

cpukit/libfs/src/fatfs/rtems-fatfs-init.c

@@ -0,0 +1,837 @@
+/**
+ * @file
+ *
+ * @ingroup FatFS
+ *
+ * @brief RTEMS FATFS initialization
+ */
+
+/*
+ Copyright (C) 2025 Sepehr Ganji <sepehrganji79@gmail.com>
+*/
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <errno.h>
+#include <fcntl.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/statvfs.h>
+#include <time.h>
+#include <unistd.h>
+
+#include <rtems.h>
+#include <rtems/bdbuf.h>
+#include <rtems/diskdevs.h>
+#include <rtems/fatfs.h>
+#include <rtems/libio.h>
+#include <rtems/libio_.h>
+#include <rtems/score/chain.h>
+#include <rtems/seterr.h>
+
+#include "ff.h"
+#include "rtems-fatfs.h"
+
+static uint8_t next_drive_number = 0;
+
+static int rtems_fatfs_build_full_path(
+  const rtems_fatfs_fs_info_t *fs_info,
+  const rtems_fatfs_node_t    *parent_node,
+  const char                  *name,
+  size_t                       namelen,
+  char                        *path,
+  size_t                       path_size
+)
+{
+  size_t mount_len = strlen( fs_info->mount_path );
+  size_t total_len;
+  char  *write_pos = path;
+
+  if ( parent_node == NULL ) {
+    total_len = mount_len + namelen;
+    if ( total_len >= path_size ) {
+      rtems_set_errno_and_return_minus_one( ENAMETOOLONG );
+    }
+    memcpy( write_pos, fs_info->mount_path, mount_len );
+    write_pos += mount_len;
+    memcpy( write_pos, name, namelen );
+    write_pos  += namelen;
+    *write_pos  = '\0';
+  } else {
+    size_t parent_len = strlen( parent_node->path );
+    bool   need_slash = ( strcmp( parent_node->path, "/" ) != 0 );
+    total_len = mount_len + parent_len + ( need_slash ? 1 : 0 ) + namelen;
+
+    if ( total_len >= path_size ) {
+      rtems_set_errno_and_return_minus_one( ENAMETOOLONG );
+    }
+
+    memcpy( write_pos, fs_info->mount_path, mount_len );
+    write_pos += mount_len;
+    memcpy( write_pos, parent_node->path, parent_len );
+    write_pos += parent_len;
+    if ( need_slash ) {
+      *write_pos = '/';
+      write_pos++;
+    }
+    memcpy( write_pos, name, namelen );
+    write_pos  += namelen;
+    *write_pos  = '\0';
+  }
+
+  char *dotdot;
+  while ( ( dotdot = strstr( path, "/.." ) ) != NULL ) {
+    if ( dotdot[ 3 ] == '\0' || dotdot[ 3 ] == '/' ) {
+      char *start = dotdot - 1;
+      while ( start > path && *start != '/' ) {
+        start--;
+      }
+      if ( start >= path && *start == '/' ) {
+        char *end = dotdot + 3;
+        memmove( start, end, strlen( end ) + 1 );
+        if ( start == path && *start == '\0' ) {
+          strcpy( path, "/" );
+        }
+      } else {
+        break;
+      }
+    } else {
+      break;
+    }
+  }
+
+  size_t len = strlen( path );
+  if ( len > 0 && len <= 2 && path[ len - 1 ] == ':' ) {
+    strcat( path, "/" );
+  }
+
+  return 0;
+}
+
+static void rtems_fatfs_cache_posix_times(
+  rtems_fatfs_fs_info_t *fs_info,
+  const char            *path,
+  time_t                 mtime,
+  time_t                 ctime
+)
+{
+  int    index    = fs_info->posix_cache_next;
+  size_t path_len = strlen( path );
+  if ( path_len >= sizeof( fs_info->posix_cache[ index ].path ) ) {
+    path_len = sizeof( fs_info->posix_cache[ index ].path ) - 1;
+  }
+  memcpy( fs_info->posix_cache[ index ].path, path, path_len );
+  fs_info->posix_cache[ index ].path[ path_len ] = '\0';
+  fs_info->posix_cache[ index ].mtime            = mtime;
+  fs_info->posix_cache[ index ].ctime            = ctime;
+  fs_info->posix_cache[ index ].valid            = true;
+  fs_info->posix_cache_next = ( fs_info->posix_cache_next + 1 ) %
+                              RTEMS_FATFS_POSIX_CACHE_SIZE;
+}
+
+static void rtems_fatfs_set_parent_timestamps(
+  const rtems_fatfs_node_t *parent_node
+)
+{
+  if ( parent_node != NULL && parent_node->is_directory ) {
+    rtems_fatfs_node_t *mutable_parent = (rtems_fatfs_node_t *) parent_node;
+    time_t              current_time   = time( NULL );
+
+    mutable_parent->posix_mtime      = current_time;
+    mutable_parent->posix_ctime      = current_time;
+    mutable_parent->posix_time_valid = true;
+  }
+}
+
+int rtems_fatfs_initialize(
+  rtems_filesystem_mount_table_entry_t *mt_entry,
+  const void                           *data
+)
+{
+  (void) data;
+
+  rtems_fatfs_fs_info_t *fs_info   = NULL;
+  rtems_fatfs_node_t    *root_node = NULL;
+  FRESULT                fr;
+  char                   drive_path[ 8 ];
+  int                    rc = -1;
+
+  fs_info = calloc( 1, sizeof( *fs_info ) );
+  if ( fs_info == NULL ) {
+    rtems_set_errno_and_return_minus_one( ENOMEM );
+  }
+
+  root_node = calloc( 1, sizeof( *root_node ) );
+  if ( root_node == NULL ) {
+    free( fs_info );
+    rtems_set_errno_and_return_minus_one( ENOMEM );
+  }
+
+  rtems_recursive_mutex_init(
+    &fs_info->vol_mutex,
+    RTEMS_FILESYSTEM_TYPE_FATFS
+  );
+
+  fs_info->drive_number = next_drive_number++;
+  if ( next_drive_number >= FF_VOLUMES ) {
+    next_drive_number = 0;
+  }
+
+  rc = fatfs_diskio_register_device( fs_info->drive_number, mt_entry->dev );
+  if ( rc != 0 ) {
+    rtems_recursive_mutex_destroy( &fs_info->vol_mutex );
+    free( root_node );
+    free( fs_info );
+    return -1;
+  }
+
+  drive_path[ 0 ] = '0' + fs_info->drive_number;
+  drive_path[ 1 ] = ':';
+  drive_path[ 2 ] = '\0';
+  fr              = f_mount( &fs_info->fatfs, drive_path, 1 );
+  if ( fr != FR_OK ) {
+    fatfs_diskio_unregister_device( fs_info->drive_number );
+    rtems_recursive_mutex_destroy( &fs_info->vol_mutex );
+    free( root_node );
+    free( fs_info );
+    errno = rtems_fatfs_fresult_to_errno( fr );
+    return -1;
+  }
+
+  fs_info->file_handlers = &rtems_fatfs_file_handlers;
+  fs_info->dir_handlers  = &rtems_fatfs_dir_handlers;
+
+  strncpy( fs_info->mount_path, drive_path, sizeof( fs_info->mount_path ) - 1 );
+  fs_info->mount_path[ sizeof( fs_info->mount_path ) - 1 ] = '\0';
+
+  strcpy( fs_info->current_dir, "/" );
+
+  memset( fs_info->posix_cache, 0, sizeof( fs_info->posix_cache ) );
+  fs_info->posix_cache_next = 0;
+
+  root_node->is_directory = true;
+  root_node->is_open      = false;
+  root_node->is_root_node = true;
+  root_node->ref_count    = 1;
+  strcpy( root_node->path, "/" );
+
+  memset( &root_node->info, 0, sizeof( root_node->info ) );
+  root_node->info.fattrib = AM_DIR;
+  root_node->info.fsize   = 0;
+  root_node->info.fdate   = 0;
+  root_node->info.ftime   = 0;
+  strcpy( root_node->info.fname, "/" );
+
+  mt_entry->fs_info                          = fs_info;
+  mt_entry->ops                              = &rtems_fatfs_ops;
+  mt_entry->mt_fs_root->location.node_access = root_node;
+  mt_entry->mt_fs_root->location.handlers    = fs_info->dir_handlers;
+
+  return 0;
+}
+
+void rtems_fatfs_fsunmount_me( rtems_filesystem_mount_table_entry_t *mt_entry )
+{
+  rtems_fatfs_fs_info_t *fs_info = (rtems_fatfs_fs_info_t *) mt_entry->fs_info;
+  rtems_fatfs_node_t    *root_node = NULL;
+
+  if ( fs_info != NULL ) {
+    if ( mt_entry->mt_fs_root != NULL ) {
+      root_node = (rtems_fatfs_node_t *)
+                    mt_entry->mt_fs_root->location.node_access;
+    }
+
+    f_mount( NULL, fs_info->mount_path, 1 );
+
+    fatfs_diskio_unregister_device( fs_info->drive_number );
+
+    if ( root_node != NULL ) {
+      free( root_node );
+    }
+
+    rtems_recursive_mutex_destroy( &fs_info->vol_mutex );
+
+    free( fs_info );
+  }
+}
+
+static rtems_fatfs_node_t *rtems_fatfs_node_get( rtems_fatfs_node_t *node )
+{
+  if ( node != NULL ) {
+    node->ref_count++;
+  }
+  return node;
+}
+
+static void rtems_fatfs_node_put( rtems_fatfs_node_t *node )
+{
+  if ( node != NULL ) {
+    if ( node->is_root_node ) {
+      node->ref_count--;
+      return;
+    }
+
+    node->ref_count--;
+    if ( node->ref_count <= 0 ) {
+      if ( node->is_open ) {
+        if ( node->is_directory ) {
+          f_closedir( &node->handle.dir );
+        } else {
+          f_close( &node->handle.file );
+        }
+      }
+
+      free( node );
+    }
+  }
+}
+
+static int rtems_fatfs_find_name(
+  rtems_filesystem_location_info_t *parentloc,
+  const char                       *name,
+  size_t                            name_len
+)
+{
+  rtems_fatfs_fs_info_t *fs_info     = parentloc->mt_entry->fs_info;
+  rtems_fatfs_node_t    *parent_node = parentloc->node_access;
+  rtems_fatfs_node_t    *new_node    = NULL;
+  FRESULT                fr;
+  FILINFO                fno;
+  char                   fatfs_path[ 256 ];
+  int                    ret;
+
+  ret = rtems_fatfs_build_full_path(
+    fs_info,
+    parent_node,
+    name,
+    name_len,
+    fatfs_path,
+    sizeof( fatfs_path )
+  );
+  if ( ret != 0 ) {
+    return ret;
+  }
+
+  if ( strlen( fatfs_path ) == 3 && fatfs_path[ 1 ] == ':' &&
+       fatfs_path[ 2 ] == '/' ) {
+    rtems_filesystem_mount_table_entry_t *mt_entry = parentloc->mt_entry;
+    if ( mt_entry && mt_entry->mt_fs_root ) {
+      new_node = (rtems_fatfs_node_t *)
+                   mt_entry->mt_fs_root->location.node_access;
+      if ( new_node ) {
+        rtems_fatfs_node_get( new_node );
+        rtems_fatfs_node_put( parent_node );
+        parentloc->node_access = new_node;
+        return 0;
+      }
+    }
+    rtems_set_errno_and_return_minus_one( ENOENT );
+  }
+
+  fr = f_stat( fatfs_path, &fno );
+  if ( fr != FR_OK ) {
+    errno = rtems_fatfs_fresult_to_errno( fr );
+    return -1;
+  }
+
+  new_node = malloc( sizeof( *new_node ) );
+  if ( new_node == NULL ) {
+    rtems_set_errno_and_return_minus_one( ENOMEM );
+  }
+  memset( new_node, 0, sizeof( *new_node ) );
+
+  new_node->info         = fno;
+  new_node->is_directory = ( fno.fattrib & AM_DIR ) != 0;
+  new_node->is_open      = false;
+  new_node->is_root_node = false;
+  new_node->ref_count    = 1;
+
+  size_t total_len;
+  if ( strcmp( parent_node->path, "/" ) == 0 ) {
+    total_len = 1 + name_len; // "/" + name
+    if ( total_len >= sizeof( new_node->path ) ) {
+      free( new_node );
+      rtems_set_errno_and_return_minus_one( ENAMETOOLONG );
+    }
+    new_node->path[ 0 ] = '/';
+    memcpy( new_node->path + 1, name, name_len );
+    new_node->path[ total_len ] = '\0';
+  } else {
+    size_t parent_len = strlen( parent_node->path );
+    total_len         = parent_len + 1 + name_len; // parent + "/" + name
+    if ( total_len >= sizeof( new_node->path ) ) {
+      free( new_node );
+      rtems_set_errno_and_return_minus_one( ENAMETOOLONG );
+    }
+    memcpy( new_node->path, parent_node->path, parent_len );
+    new_node->path[ parent_len ] = '/';
+    memcpy( new_node->path + parent_len + 1, name, name_len );
+    new_node->path[ total_len ] = '\0';
+  }
+
+  rtems_fatfs_node_put( parent_node );
+
+  parentloc->node_access = new_node;
+  return 0;
+}
+
+static void rtems_fatfs_set_handlers( rtems_filesystem_location_info_t *loc )
+{
+  rtems_fatfs_fs_info_t *fs_info = loc->mt_entry->fs_info;
+  rtems_fatfs_node_t    *node    = loc->node_access;
+
+  if ( node->is_directory ) {
+    loc->handlers = fs_info->dir_handlers;
+  } else {
+    loc->handlers = fs_info->file_handlers;
+  }
+}
+
+static bool rtems_fatfs_eval_is_directory(
+  rtems_filesystem_eval_path_context_t *ctx,
+  void                                 *arg
+)
+{
+  (void) arg;
+
+  rtems_fatfs_node_t *node = (rtems_fatfs_node_t *) ctx->currentloc.node_access;
+  return node != NULL && node->is_directory;
+}
+
+static rtems_filesystem_eval_path_generic_status rtems_fatfs_eval_token(
+  rtems_filesystem_eval_path_context_t *ctx,
+  void                                 *arg,
+  const char                           *token,
+  size_t                                tokenlen
+)
+{
+  (void) arg;
+
+  rtems_filesystem_eval_path_generic_status
+    status = RTEMS_FILESYSTEM_EVAL_PATH_GENERIC_DONE;
+
+  if ( rtems_filesystem_is_current_directory( token, tokenlen ) ) {
+    rtems_filesystem_eval_path_clear_token( ctx );
+    status = RTEMS_FILESYSTEM_EVAL_PATH_GENERIC_CONTINUE;
+  } else {
+    rtems_filesystem_location_info_t
+      *currentloc = rtems_filesystem_eval_path_get_currentloc( ctx );
+
+    int rc = rtems_fatfs_find_name( currentloc, token, tokenlen );
+
+    if ( rc == 0 ) {
+      rtems_filesystem_eval_path_clear_token( ctx );
+      rtems_fatfs_set_handlers( currentloc );
+
+      if ( rtems_filesystem_eval_path_has_path( ctx ) ) {
+        rtems_fatfs_node_t *node = (rtems_fatfs_node_t *)
+                                     currentloc->node_access;
+        if ( node != NULL && !node->is_directory ) {
+          rtems_filesystem_eval_path_error( ctx, ENOTDIR );
+          status = RTEMS_FILESYSTEM_EVAL_PATH_GENERIC_DONE;
+        } else {
+          status = RTEMS_FILESYSTEM_EVAL_PATH_GENERIC_CONTINUE;
+        }
+      } else {
+        status = RTEMS_FILESYSTEM_EVAL_PATH_GENERIC_DONE;
+      }
+    } else {
+      if ( errno == ENOENT ) {
+        status = RTEMS_FILESYSTEM_EVAL_PATH_GENERIC_NO_ENTRY;
+      } else {
+        rtems_filesystem_eval_path_error( ctx, errno );
+      }
+    }
+  }
+
+  return status;
+}
+
+static const rtems_filesystem_eval_path_generic_config rtems_fatfs_eval_config =
+  { .is_directory = rtems_fatfs_eval_is_directory,
+    .eval_token   = rtems_fatfs_eval_token };
+
+void rtems_fatfs_eval_path( rtems_filesystem_eval_path_context_t *ctx )
+{
+  rtems_filesystem_eval_path_generic( ctx, NULL, &rtems_fatfs_eval_config );
+}
+
+int rtems_fatfs_mknod(
+  const rtems_filesystem_location_info_t *parentloc,
+  const char                             *name,
+  size_t                                  namelen,
+  mode_t                                  mode,
+  dev_t                                   dev
+)
+{
+  char    full_path[ 256 ];
+  FRESULT fr;
+  FIL     fil;
+  int     rc;
+
+  (void) dev;
+
+  rtems_fatfs_fs_info_t *fs_info = (rtems_fatfs_fs_info_t *)
+                                     parentloc->mt_entry->fs_info;
+  rtems_fatfs_node_t *parent_node = (rtems_fatfs_node_t *)
+                                      parentloc->node_access;
+
+  rc = rtems_fatfs_build_full_path(
+    fs_info,
+    parent_node,
+    name,
+    namelen,
+    full_path,
+    sizeof( full_path )
+  );
+
+  if ( rc != 0 ) {
+    return rc;
+  }
+
+  rtems_fatfs_lock( parentloc->mt_entry );
+
+  if ( S_ISDIR( mode ) ) {
+    fr = f_mkdir( full_path );
+    if ( fr == FR_OK ) {
+      rtems_fatfs_set_parent_timestamps( parent_node );
+    }
+  } else if ( S_ISREG( mode ) ) {
+    fr = f_open( &fil, full_path, FA_CREATE_NEW | FA_WRITE );
+    if ( fr == FR_OK ) {
+      f_close( &fil );
+      rtems_fatfs_set_parent_timestamps( parent_node );
+    }
+  } else {
+    rtems_fatfs_unlock( parentloc->mt_entry );
+    rtems_set_errno_and_return_minus_one( ENOTSUP );
+  }
+
+  rtems_fatfs_unlock( parentloc->mt_entry );
+
+  if ( fr != FR_OK ) {
+    errno = rtems_fatfs_fresult_to_errno( fr );
+    return -1;
+  }
+
+  return 0;
+}
+
+int rtems_fatfs_rmnod(
+  const rtems_filesystem_location_info_t *parentloc,
+  const rtems_filesystem_location_info_t *loc
+)
+{
+  rtems_fatfs_fs_info_t *fs_info = NULL;
+  rtems_fatfs_node_t    *node    = NULL;
+  char                   full_path[ 256 ];
+  FRESULT                fr;
+  int                    rc;
+
+  fs_info = (rtems_fatfs_fs_info_t *) parentloc->mt_entry->fs_info;
+  node    = (rtems_fatfs_node_t *) loc->node_access;
+
+  if ( node == NULL ) {
+    rtems_set_errno_and_return_minus_one( EINVAL );
+  }
+
+  if ( node->is_open && !node->is_directory ) {
+    f_close( &node->handle.file );
+    node->is_open = false;
+  }
+
+  rc = rtems_fatfs_resolve_node_path(
+    fs_info,
+    node,
+    full_path,
+    sizeof( full_path ),
+    NULL
+  );
+  if ( rc != 0 ) {
+    return rc;
+  }
+
+  rtems_fatfs_lock( parentloc->mt_entry );
+
+  fr = f_unlink( full_path );
+
+  rtems_fatfs_unlock( parentloc->mt_entry );
+
+  if ( fr != FR_OK ) {
+    if ( ( fr == FR_DENIED || fr == FR_INVALID_NAME ) && node->is_directory ) {
+      errno = ENOTEMPTY;
+    } else {
+      errno = rtems_fatfs_fresult_to_errno( fr );
+    }
+    return -1;
+  }
+
+  return 0;
+}
+
+bool rtems_fatfs_are_nodes_equal(
+  const rtems_filesystem_location_info_t *a,
+  const rtems_filesystem_location_info_t *b
+)
+{
+  rtems_fatfs_node_t *node_a = (rtems_fatfs_node_t *) a->node_access;
+  rtems_fatfs_node_t *node_b = (rtems_fatfs_node_t *) b->node_access;
+
+  if ( node_a == NULL || node_b == NULL ) {
+    return false;
+  }
+
+  return strcmp( node_a->path, node_b->path ) == 0;
+}
+
+int rtems_fatfs_clone_node( rtems_filesystem_location_info_t *loc )
+{
+  rtems_fatfs_node_t *node = (rtems_fatfs_node_t *) loc->node_access;
+
+  if ( node != NULL ) {
+    rtems_fatfs_node_get( node );
+  }
+
+  return 0;
+}
+
+void rtems_fatfs_free_node( const rtems_filesystem_location_info_t *loc )
+{
+  rtems_fatfs_node_t *node = (rtems_fatfs_node_t *) loc->node_access;
+
+  if ( node != NULL ) {
+    rtems_fatfs_node_put( node );
+  }
+}
+
+int rtems_fatfs_rename(
+  const rtems_filesystem_location_info_t *old_parent_loc,
+  const rtems_filesystem_location_info_t *old_loc,
+  const rtems_filesystem_location_info_t *new_parent_loc,
+  const char                             *new_name,
+  size_t                                  new_namelen
+)
+{
+  rtems_fatfs_fs_info_t *fs_info  = NULL;
+  rtems_fatfs_node_t    *old_node = NULL;
+  char                   old_path[ 256 ];
+  char                   new_path[ 256 ];
+  FRESULT                fr;
+  int                    rc;
+
+  fs_info  = (rtems_fatfs_fs_info_t *) old_parent_loc->mt_entry->fs_info;
+  old_node = (rtems_fatfs_node_t *) old_loc->node_access;
+
+  if ( old_node == NULL ) {
+    rtems_set_errno_and_return_minus_one( EINVAL );
+  }
+
+  rc = rtems_fatfs_resolve_node_path(
+    fs_info,
+    old_node,
+    old_path,
+    sizeof( old_path ),
+    NULL
+  );
+  if ( rc != 0 ) {
+    return rc;
+  }
+
+  rtems_fatfs_fs_info_t *new_fs_info = (rtems_fatfs_fs_info_t *)
+                                         new_parent_loc->mt_entry->fs_info;
+  rtems_fatfs_node_t *new_parent_node = (rtems_fatfs_node_t *)
+                                          new_parent_loc->node_access;
+  rc = rtems_fatfs_build_full_path(
+    new_fs_info,
+    new_parent_node,
+    new_name,
+    new_namelen,
+    new_path,
+    sizeof( new_path )
+  );
+  if ( rc != 0 ) {
+    return rc;
+  }
+
+  rtems_fatfs_lock( old_parent_loc->mt_entry );
+
+  fr = f_rename( old_path, new_path );
+
+  rtems_fatfs_unlock( old_parent_loc->mt_entry );
+
+  if ( fr != FR_OK ) {
+    errno = rtems_fatfs_fresult_to_errno( fr );
+    return -1;
+  }
+
+  return 0;
+}
+
+static void rtems_fatfs_update_fat_timestamp(
+  const char *path,
+  time_t      timestamp
+)
+{
+  struct tm *tm_info = localtime( &timestamp );
+  if ( tm_info != NULL ) {
+    FILINFO fno;
+    memset( &fno, 0, sizeof( fno ) );
+
+    fno.fdate = ( ( tm_info->tm_year + 1900 - 1980 ) << 9 ) |
+                ( ( tm_info->tm_mon + 1 ) << 5 ) | ( tm_info->tm_mday );
+    fno.ftime = ( tm_info->tm_hour << 11 ) | ( tm_info->tm_min << 5 ) |
+                ( tm_info->tm_sec >> 1 );
+
+    f_utime( path, &fno );
+  }
+}
+
+int rtems_fatfs_utimens(
+  const rtems_filesystem_location_info_t *loc,
+  struct timespec                         times[ 2 ]
+)
+{
+  rtems_fatfs_fs_info_t *fs_info = (rtems_fatfs_fs_info_t *)
+                                     loc->mt_entry->fs_info;
+  rtems_fatfs_node_t *node = (rtems_fatfs_node_t *) loc->node_access;
+  char                full_path[ 256 ];
+  int                 rc;
+
+  if ( node == NULL ) {
+    rtems_set_errno_and_return_minus_one( EINVAL );
+  }
+
+  time_t mtime        = times[ 1 ].tv_sec;
+  time_t current_time = time( NULL );
+
+  rc = rtems_fatfs_resolve_node_path(
+    fs_info,
+    node,
+    full_path,
+    sizeof( full_path ),
+    NULL
+  );
+  if ( rc != 0 ) {
+    return rc;
+  }
+
+  rtems_fatfs_lock( loc->mt_entry );
+  rtems_fatfs_update_fat_timestamp( full_path, mtime );
+  rtems_fatfs_unlock( loc->mt_entry );
+
+  rtems_fatfs_cache_posix_times( fs_info, node->path, mtime, current_time );
+
+  node->posix_mtime      = mtime;
+  node->posix_ctime      = current_time;
+  node->posix_time_valid = true;
+
+  return 0;
+}
+
+/*
+ * Compiler will change name to rtems_fatfs_get_fattime
+ */
+DWORD get_fattime( void )
+{
+  time_t     current_time;
+  struct tm *tm_info;
+  DWORD      fat_time = 0;
+
+  current_time = time( NULL );
+  tm_info      = localtime( &current_time );
+
+  if ( tm_info != NULL ) {
+    fat_time = ( (DWORD) ( tm_info->tm_year + 1900 - 1980 ) << 25 ) |
+               ( (DWORD) ( tm_info->tm_mon + 1 ) << 21 ) |
+               ( (DWORD) tm_info->tm_mday << 16 ) |
+               ( (DWORD) tm_info->tm_hour << 11 ) |
+               ( (DWORD) tm_info->tm_min << 5 ) |
+               ( (DWORD) tm_info->tm_sec >> 1 );
+  } else {
+    fat_time = ( 0 << 25 ) | ( 1 << 21 ) | ( 1 << 16 );
+  }
+
+  return fat_time;
+}
+
+int rtems_fatfs_statvfs(
+  const rtems_filesystem_location_info_t *root_loc,
+  struct statvfs                         *sb
+)
+{
+  rtems_fatfs_fs_info_t *fs_info = root_loc->mt_entry->fs_info;
+  FATFS                 *fs      = &fs_info->fatfs;
+  FRESULT                fr;
+  DWORD                  free_clusters;
+  FATFS                 *fatfs_ptr;
+  char                   drive_path[ 8 ];
+
+  if ( fs_info == NULL || sb == NULL ) {
+    rtems_set_errno_and_return_minus_one( EINVAL );
+  }
+
+  rtems_fatfs_lock( root_loc->mt_entry );
+
+  drive_path[ 0 ] = '0' + fs_info->drive_number;
+  drive_path[ 1 ] = ':';
+  drive_path[ 2 ] = '\0';
+
+  fr = f_getfree( drive_path, &free_clusters, &fatfs_ptr );
+  if ( fr != FR_OK ) {
+    rtems_fatfs_unlock( root_loc->mt_entry );
+    errno = rtems_fatfs_fresult_to_errno( fr );
+    return -1;
+  }
+
+#if FF_MAX_SS != FF_MIN_SS
+  WORD sector_size = fs->ssize;
+#else
+  WORD sector_size = FF_MAX_SS;
+#endif
+
+  sb->f_bsize  = sector_size;
+  sb->f_frsize = fs->csize * sector_size;
+  sb->f_blocks = fs->n_fatent - 2;
+  sb->f_bfree  = free_clusters;
+  sb->f_bavail = free_clusters;
+  sb->f_files  = 0;
+  sb->f_ffree  = 0;
+  sb->f_favail = 0;
+  sb->f_flag   = 0;
+
+#if FF_USE_LFN
+  sb->f_namemax = FF_LFN_BUF - 1;
+#else
+  sb->f_namemax = 12;
+#endif
+
+  rtems_fatfs_unlock( root_loc->mt_entry );
+
+  return 0;
+}
+
+const rtems_filesystem_operations_table rtems_fatfs_ops = {
+  .lock_h            = rtems_fatfs_lock,
+  .unlock_h          = rtems_fatfs_unlock,
+  .eval_path_h       = rtems_fatfs_eval_path,
+  .link_h            = rtems_filesystem_default_link,
+  .are_nodes_equal_h = rtems_fatfs_are_nodes_equal,
+  .mknod_h           = rtems_fatfs_mknod,
+  .rmnod_h           = rtems_fatfs_rmnod,
+  .fchmod_h          = rtems_filesystem_default_fchmod,
+  .chown_h           = rtems_filesystem_default_chown,
+  .clonenod_h        = rtems_fatfs_clone_node,
+  .freenod_h         = rtems_fatfs_free_node,
+  .mount_h           = rtems_fatfs_initialize,
+  .unmount_h         = rtems_filesystem_default_unmount,
+  .fsunmount_me_h    = rtems_fatfs_fsunmount_me,
+  .utimens_h         = rtems_fatfs_utimens,
+  .symlink_h         = rtems_filesystem_default_symlink,
+  .readlink_h        = rtems_filesystem_default_readlink,
+  .rename_h          = rtems_fatfs_rename,
+  .statvfs_h         = rtems_fatfs_statvfs
+};

cpukit/libfs/src/fatfs/rtems-fatfs.h

@@ -0,0 +1,372 @@
+/**
+ * @file
+ *
+ * @ingroup FatFS
+ *
+ * @brief RTEMS FatFS headers
+ */
+
+/*
+ Copyright (C) 2025 Sepehr Ganji <sepehrganji79@gmail.com>
+*/
+
+#ifndef RTEMS_FATFS_H
+#define RTEMS_FATFS_H
+
+#include <stdint.h>
+#include <string.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <time.h>
+
+#include <rtems/diskdevs.h>
+#include <rtems/libio.h>
+#include <rtems/seterr.h>
+
+#include "ff.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#define DT_REG 8
+#define DT_DIR 4
+
+typedef struct {
+  int                fd;
+  rtems_disk_device *dd;
+  bool               initialized;
+} fatfs_volume_t;
+
+#define RTEMS_FATFS_POSIX_CACHE_SIZE 64
+
+typedef struct {
+  char   path[ 256 ];
+  time_t mtime;
+  time_t ctime;
+  bool   valid;
+} rtems_fatfs_posix_cache_entry_t;
+
+typedef struct {
+  FATFS                                   fatfs;
+  rtems_recursive_mutex                   vol_mutex;
+  const rtems_filesystem_file_handlers_r *file_handlers;
+  const rtems_filesystem_file_handlers_r *dir_handlers;
+  uint8_t                                 drive_number;
+  char                                    mount_path[ 256 ];
+  char                                    current_dir[ 256 ];
+  rtems_fatfs_posix_cache_entry_t posix_cache[ RTEMS_FATFS_POSIX_CACHE_SIZE ];
+  int                             posix_cache_next;
+} rtems_fatfs_fs_info_t;
+
+typedef struct {
+  union {
+    FIL file;
+    DIR dir;
+  } handle;
+  FILINFO info;
+  bool    is_directory;
+  bool    is_open;
+  char    path[ 256 ];
+  bool    is_root_node;
+  int     ref_count;
+  time_t  posix_mtime;
+  time_t  posix_ctime;
+  bool    posix_time_valid;
+} rtems_fatfs_node_t;
+
+/* Disk I/O interface */
+int  fatfs_diskio_register_device( uint8_t pdrv, const char *device_path );
+void fatfs_diskio_unregister_device( uint8_t pdrv );
+
+/* Utility functions */
+static inline int rtems_fatfs_get_full_path(
+  const rtems_fatfs_fs_info_t *fs_info,
+  const char                  *relative_path,
+  char                        *full_path,
+  size_t                       path_size
+)
+{
+  size_t mount_len = strlen( fs_info->mount_path );
+  size_t rel_len   = strlen( relative_path );
+
+  if ( mount_len + rel_len >= path_size ) {
+    rtems_set_errno_and_return_minus_one( ENAMETOOLONG );
+  }
+
+  memcpy( full_path, fs_info->mount_path, mount_len );
+  memcpy( full_path + mount_len, relative_path, rel_len + 1 );
+
+  return 0;
+}
+
+static inline int rtems_fatfs_fresult_to_errno( FRESULT fr )
+{
+  switch ( fr ) {
+    case FR_OK:
+      return 0;
+    case FR_DISK_ERR:
+    case FR_INT_ERR:
+    case FR_NOT_READY:
+      return EIO;
+    case FR_NO_FILE:
+    case FR_NO_PATH:
+      return ENOENT;
+    case FR_INVALID_NAME:
+      return EINVAL;
+    case FR_DENIED:
+      return EACCES;
+    case FR_EXIST:
+      return EEXIST;
+    case FR_INVALID_OBJECT:
+      return EBADF;
+    case FR_WRITE_PROTECTED:
+      return EROFS;
+    case FR_INVALID_DRIVE:
+    case FR_NOT_ENABLED:
+    case FR_NO_FILESYSTEM:
+      return ENXIO;
+    case FR_MKFS_ABORTED:
+      return EINVAL;
+    case FR_TIMEOUT:
+      return ETIMEDOUT;
+    case FR_LOCKED:
+      return EBUSY;
+    case FR_NOT_ENOUGH_CORE:
+      return ENOMEM;
+    case FR_TOO_MANY_OPEN_FILES:
+      return EMFILE;
+    case FR_INVALID_PARAMETER:
+      return EINVAL;
+    default:
+      return EIO;
+  }
+}
+
+static inline void rtems_fatfs_unlock(
+  const rtems_filesystem_mount_table_entry_t *mt_entry
+)
+{
+  rtems_fatfs_fs_info_t *fs_info = (rtems_fatfs_fs_info_t *) mt_entry->fs_info;
+  rtems_recursive_mutex_unlock( &fs_info->vol_mutex );
+}
+
+static inline int rtems_fatfs_resolve_node_path(
+  const rtems_fatfs_fs_info_t                *fs_info,
+  const rtems_fatfs_node_t                   *node,
+  char                                       *full_path,
+  size_t                                      path_size,
+  const rtems_filesystem_mount_table_entry_t *mt_entry
+)
+{
+  int
+    rc = rtems_fatfs_get_full_path( fs_info, node->path, full_path, path_size );
+  if ( rc != 0 && mt_entry != NULL ) {
+    rtems_fatfs_unlock( mt_entry );
+  }
+  return rc;
+}
+
+static inline void rtems_fatfs_filinfo_to_stat(
+  const FILINFO *fno,
+  struct stat   *st
+)
+{
+  const char *name       = fno->fname;
+  ino_t       inode_hash = 1;
+
+  memset( st, 0, sizeof( *st ) );
+
+  while ( *name != '\0' ) {
+    inode_hash = ( inode_hash * 33 ) + (unsigned char) *name;
+    name++;
+  }
+  inode_hash ^= fno->fsize ^ ( fno->fdate << 16 ) ^ fno->ftime;
+
+  st->st_ino     = ( inode_hash != 0 ) ? inode_hash : 1;
+  st->st_dev     = 1;
+  st->st_size    = (off_t) fno->fsize;
+  st->st_blksize = 512;
+  st->st_blocks  = ( st->st_size + 511 ) / 512;
+
+  if ( fno->fdate != 0 || fno->ftime != 0 ) {
+    struct tm tm;
+    memset( &tm, 0, sizeof( tm ) );
+
+    tm.tm_year = ( ( fno->fdate >> 9 ) & 0x7F ) + 80;
+    tm.tm_mon  = ( ( fno->fdate >> 5 ) & 0x0F ) - 1;
+    tm.tm_mday = fno->fdate & 0x1F;
+    tm.tm_hour = ( fno->ftime >> 11 ) & 0x1F;
+    tm.tm_min  = ( fno->ftime >> 5 ) & 0x3F;
+    tm.tm_sec  = ( fno->ftime & 0x1F ) * 2;
+
+    st->st_mtime = mktime( &tm );
+    st->st_ctime = st->st_mtime;
+    st->st_atime = st->st_mtime;
+  }
+
+  if ( fno->fattrib & AM_DIR ) {
+    st->st_mode = S_IFDIR | 0755;
+  } else {
+    st->st_mode = S_IFREG | 0644;
+  }
+
+  if ( fno->fattrib & AM_RDO ) {
+    st->st_mode &= ~( S_IWUSR | S_IWGRP | S_IWOTH );
+  }
+}
+
+static inline void rtems_fatfs_node_to_stat_basic(
+  const rtems_fatfs_node_t *node,
+  struct stat              *st
+)
+{
+  rtems_fatfs_filinfo_to_stat( &node->info, st );
+}
+
+static inline void rtems_fatfs_node_to_stat(
+  const rtems_fatfs_node_t *node,
+  struct stat              *st,
+  rtems_fatfs_fs_info_t    *fs_info
+)
+{
+  rtems_fatfs_filinfo_to_stat( &node->info, st );
+
+  if ( fs_info != NULL ) {
+    blksize_t cluster_size = fs_info->fatfs.csize * 512;
+    st->st_blksize         = cluster_size;
+    blkcnt_t clusters_used = ( st->st_size + cluster_size - 1 ) / cluster_size;
+    st->st_blocks          = clusters_used * fs_info->fatfs.csize;
+  }
+
+  if ( node->posix_time_valid ) {
+    st->st_mtime = node->posix_mtime;
+    st->st_ctime = node->posix_ctime;
+    st->st_atime = node->posix_mtime;
+  } else if ( fs_info != NULL ) {
+    for ( int i = 0; i < RTEMS_FATFS_POSIX_CACHE_SIZE; i++ ) {
+      if ( fs_info->posix_cache[ i ].valid &&
+           strcmp( fs_info->posix_cache[ i ].path, node->path ) == 0 ) {
+        st->st_mtime = fs_info->posix_cache[ i ].mtime;
+        st->st_ctime = fs_info->posix_cache[ i ].ctime;
+        st->st_atime = fs_info->posix_cache[ i ].mtime;
+        break;
+      }
+    }
+  }
+}
+
+static inline void rtems_fatfs_lock(
+  const rtems_filesystem_mount_table_entry_t *mt_entry
+)
+{
+  rtems_fatfs_fs_info_t *fs_info = (rtems_fatfs_fs_info_t *) mt_entry->fs_info;
+  rtems_recursive_mutex_lock( &fs_info->vol_mutex );
+}
+
+/* Filesystem operations - declared in rtems-fatfs-init.c */
+int rtems_fatfs_initialize(
+  rtems_filesystem_mount_table_entry_t *mt_entry,
+  const void                           *data
+);
+
+void rtems_fatfs_fsunmount_me( rtems_filesystem_mount_table_entry_t *mt_entry );
+
+void rtems_fatfs_eval_path( rtems_filesystem_eval_path_context_t *ctx );
+
+int rtems_fatfs_mknod(
+  const rtems_filesystem_location_info_t *parentloc,
+  const char                             *name,
+  size_t                                  namelen,
+  mode_t                                  mode,
+  dev_t                                   dev
+);
+
+int rtems_fatfs_rmnod(
+  const rtems_filesystem_location_info_t *parentloc,
+  const rtems_filesystem_location_info_t *loc
+);
+
+int rtems_fatfs_rename(
+  const rtems_filesystem_location_info_t *old_parent_loc,
+  const rtems_filesystem_location_info_t *old_loc,
+  const rtems_filesystem_location_info_t *new_parent_loc,
+  const char                             *new_name,
+  size_t                                  new_namelen
+);
+
+int rtems_fatfs_utimens(
+  const rtems_filesystem_location_info_t *loc,
+  struct timespec                         times[ 2 ]
+);
+
+int rtems_fatfs_statvfs(
+  const rtems_filesystem_location_info_t *root_loc,
+  struct statvfs                         *sb
+);
+
+bool rtems_fatfs_are_nodes_equal(
+  const rtems_filesystem_location_info_t *a,
+  const rtems_filesystem_location_info_t *b
+);
+
+int rtems_fatfs_clone_node( rtems_filesystem_location_info_t *loc );
+
+void rtems_fatfs_free_node( const rtems_filesystem_location_info_t *loc );
+
+/* File operations - declared in rtems-fatfs-file.c */
+ssize_t rtems_fatfs_file_read( rtems_libio_t *iop, void *buffer, size_t count );
+
+ssize_t rtems_fatfs_file_write(
+  rtems_libio_t *iop,
+  const void    *buffer,
+  size_t         count
+);
+
+off_t rtems_fatfs_file_lseek( rtems_libio_t *iop, off_t offset, int whence );
+
+int rtems_fatfs_file_fstat(
+  const rtems_filesystem_location_info_t *loc,
+  struct stat                            *buf
+);
+
+int rtems_fatfs_file_ftruncate( rtems_libio_t *iop, off_t length );
+
+int rtems_fatfs_file_fsync( rtems_libio_t *iop );
+
+/* Directory operations - declared in rtems-fatfs-dir.c */
+ssize_t rtems_fatfs_dir_read( rtems_libio_t *iop, void *buffer, size_t count );
+
+int rtems_fatfs_dir_fstat(
+  const rtems_filesystem_location_info_t *loc,
+  struct stat                            *buf
+);
+
+int rtems_fatfs_opendir(
+  rtems_libio_t *iop,
+  const char    *path,
+  int            oflag,
+  mode_t         mode
+);
+
+int rtems_fatfs_closedir( rtems_libio_t *iop );
+
+int rtems_fatfs_openfile(
+  rtems_libio_t *iop,
+  const char    *path,
+  int            oflag,
+  mode_t         mode
+);
+
+int rtems_fatfs_closefile( rtems_libio_t *iop );
+
+/* Handler tables */
+extern const rtems_filesystem_operations_table rtems_fatfs_ops;
+extern const rtems_filesystem_file_handlers_r  rtems_fatfs_file_handlers;
+extern const rtems_filesystem_file_handlers_r  rtems_fatfs_dir_handlers;
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* RTEMS_FATFS_H */

spec/build/cpukit/librtemscpu.yml

@@ -4,7 +4,30 @@ cflags:
 - ${COVERAGE_COMPILER_FLAGS}
 copyrights:
 - Copyright (C) 2020 embedded brains GmbH & Co. KG
-cppflags: []
+cppflags:
+- -Ddisk_status=rtems_fatfs_disk_status
+- -Ddisk_initialize=rtems_fatfs_disk_initialize
+- -Ddisk_read=rtems_fatfs_disk_read
+- -Ddisk_write=rtems_fatfs_disk_write
+- -Ddisk_ioctl=rtems_fatfs_disk_ioctl
+- -Dget_fattime=rtems_fatfs_get_fattime
+- -DFFCONF_DEF=5385
+- -DFF_VOLUMES=1
+- -DFF_USE_MKFS=1
+- -DFF_USE_CHMOD=1
+- -DFF_USE_LFN=1
+- -DFF_FS_RPATH=2
+- -DFF_FS_EXFAT=1
+- -DFF_MAX_SS=512
+- -DFF_MIN_SS=512
+- -DFF_LFN_BUF=255
+- -DFF_SFN_BUF=12
+- -DFF_MAX_LFN=255
+- -DFF_USE_LABEL=0
+- -DFF_STR_VOLUME_ID=0
+- -DFF_MULTI_PARTITION=0
+- -DFF_FS_READONLY=0
+- -DFF_LBA64=0
 cxxflags:
 - ${COVERAGE_COMPILER_FLAGS}
 enabled-by: true
@@ -118,6 +141,7 @@ install:
   - cpukit/include/rtems/devzero.h
   - cpukit/include/rtems/diskdevs.h
   - cpukit/include/rtems/dosfs.h
+  - cpukit/include/rtems/fatfs.h
   - cpukit/include/rtems/dumpbuf.h
   - cpukit/include/rtems/endian.h
   - cpukit/include/rtems/error.h
@@ -861,6 +885,13 @@ source:
 - cpukit/libfs/src/dosfs/msdos_rename.c
 - cpukit/libfs/src/dosfs/msdos_rmnod.c
 - cpukit/libfs/src/dosfs/msdos_statvfs.c
+- cpukit/libfs/src/fatfs/ff.c
+- cpukit/libfs/src/fatfs/ffunicode.c
+- cpukit/libfs/src/fatfs/ffsystem.c
+- cpukit/libfs/src/fatfs/rtems-diskio.c
+- cpukit/libfs/src/fatfs/rtems-fatfs-init.c
+- cpukit/libfs/src/fatfs/rtems-fatfs-file.c
+- cpukit/libfs/src/fatfs/rtems-fatfs-dir.c
 - cpukit/libfs/src/imfs/deviceio.c
 - cpukit/libfs/src/imfs/imfs_add_node.c
 - cpukit/libfs/src/imfs/imfs_chown.c

spec/build/testsuites/fstests/fatfsfsclose01.yml

@@ -0,0 +1,21 @@
+SPDX-License-Identifier: CC-BY-SA-4.0 OR BSD-2-Clause
+build-type: test-program
+cflags: []
+copyrights:
+- Copyright (C) 2025 Sepehr Ganji <sepehrganji79@gmail.com>
+cppflags: []
+cxxflags: []
+enabled-by: true
+features: c cprogram
+includes:
+- testsuites/fstests/fatfs_support
+ldflags: []
+links: []
+source:
+- testsuites/fstests/fsclose01/init.c
+stlib: []
+target: testsuites/fstests/fatfs_fsclose01.exe
+type: build
+use-after: []
+use-before:
+- testfatfs

spec/build/testsuites/fstests/fatfsfserror.yml

@@ -0,0 +1,21 @@
+SPDX-License-Identifier: CC-BY-SA-4.0 OR BSD-2-Clause
+build-type: test-program
+cflags: []
+copyrights:
+- Copyright (C) 2025 Sepehr Ganji <sepehrganji79@gmail.com>
+cppflags: []
+cxxflags: []
+enabled-by: true
+features: c cprogram
+includes:
+- testsuites/fstests/fatfs_support
+ldflags: []
+links: []
+source:
+- testsuites/fstests/fserror/test.c
+stlib: []
+target: testsuites/fstests/fatfs_fserror.exe
+type: build
+use-after: []
+use-before:
+- testfatfs

spec/build/testsuites/fstests/fatfsfspatheval.yml

@@ -0,0 +1,21 @@
+SPDX-License-Identifier: CC-BY-SA-4.0 OR BSD-2-Clause
+build-type: test-program
+cflags: []
+copyrights:
+- Copyright (C) 2025 Sepehr Ganji <sepehrganji79@gmail.com>
+cppflags: []
+cxxflags: []
+enabled-by: true
+features: c cprogram
+includes:
+- testsuites/fstests/fatfs_support
+ldflags: []
+links: []
+source:
+- testsuites/fstests/fspatheval/test.c
+stlib: []
+target: testsuites/fstests/fatfs_fspatheval.exe
+type: build
+use-after: []
+use-before:
+- testfatfs

spec/build/testsuites/fstests/fatfsfsrdwr.yml

@@ -0,0 +1,21 @@
+SPDX-License-Identifier: CC-BY-SA-4.0 OR BSD-2-Clause
+build-type: test-program
+cflags: []
+copyrights:
+- Copyright (C) 2025 Sepehr Ganji <sepehrganji79@gmail.com>
+cppflags: []
+cxxflags: []
+enabled-by: true
+features: c cprogram
+includes:
+- testsuites/fstests/fatfs_support
+ldflags: []
+links: []
+source:
+- testsuites/fstests/fsrdwr/init.c
+stlib: []
+target: testsuites/fstests/fatfs_fsrdwr.exe
+type: build
+use-after: []
+use-before:
+- testfatfs

spec/build/testsuites/fstests/fatfsfsrename.yml

@@ -0,0 +1,21 @@
+SPDX-License-Identifier: CC-BY-SA-4.0 OR BSD-2-Clause
+build-type: test-program
+cflags: []
+copyrights:
+- Copyright (C) 2025 Sepehr Ganji <sepehrganji79@gmail.com>
+cppflags: []
+cxxflags: []
+enabled-by: true
+features: c cprogram
+includes:
+- testsuites/fstests/fatfs_support
+ldflags: []
+links: []
+source:
+- testsuites/fstests/fsrename/test.c
+stlib: []
+target: testsuites/fstests/fatfs_fsrename.exe
+type: build
+use-after: []
+use-before:
+- testfatfs

spec/build/testsuites/fstests/fatfsfsrenameexisting.yml

@@ -0,0 +1,22 @@
+SPDX-License-Identifier: CC-BY-SA-4.0 OR BSD-2-Clause
+build-type: test-program
+cflags: []
+copyrights:
+- Copyright (C) 2025 Sepehr Ganji <sepehrganji79@gmail.com>
+cppflags:
+- -DTEST_STATE_EXPECTED_FAIL=1
+cxxflags: []
+enabled-by: true
+features: c cprogram
+includes:
+- testsuites/fstests/fatfs_support
+ldflags: []
+links: []
+source:
+- testsuites/fstests/fsrenameexisting/test.c
+stlib: []
+target: testsuites/fstests/fatfs_fsrenameexisting.exe
+type: build
+use-after: []
+use-before:
+- testfatfs

spec/build/testsuites/fstests/fatfsfsrenamelongname.yml

@@ -0,0 +1,21 @@
+SPDX-License-Identifier: CC-BY-SA-4.0 OR BSD-2-Clause
+build-type: test-program
+cflags: []
+copyrights:
+- Copyright (C) 2025 Sepehr Ganji <sepehrganji79@gmail.com>
+cppflags: []
+cxxflags: []
+enabled-by: true
+features: c cprogram
+includes:
+- testsuites/fstests/fatfs_support
+ldflags: []
+links: []
+source:
+- testsuites/fstests/fsrenamelongname/test.c
+stlib: []
+target: testsuites/fstests/fatfs_fsrenamelongname.exe
+type: build
+use-after: []
+use-before:
+- testfatfs

spec/build/testsuites/fstests/fatfsfsrenamemaxlinks.yml

@@ -0,0 +1,22 @@
+SPDX-License-Identifier: CC-BY-SA-4.0 OR BSD-2-Clause
+build-type: test-program
+cflags: []
+copyrights:
+- Copyright (C) 2025 Sepehr Ganji <sepehrganji79@gmail.com>
+cppflags:
+- -DTEST_STATE_EXPECTED_FAIL=1
+cxxflags: []
+enabled-by: true
+features: c cprogram
+includes:
+- testsuites/fstests/fatfs_support
+ldflags: []
+links: []
+source:
+- testsuites/fstests/fsrenamemaxlinks/test.c
+stlib: []
+target: testsuites/fstests/fatfs_fsrenamemaxlinks.exe
+type: build
+use-after: []
+use-before:
+- testfatfs

spec/build/testsuites/fstests/fatfsfsrmdirparent.yml

@@ -0,0 +1,21 @@
+SPDX-License-Identifier: CC-BY-SA-4.0 OR BSD-2-Clause
+build-type: test-program
+cflags: []
+copyrights:
+- Copyright (C) 2025 Sepehr Ganji <sepehrganji79@gmail.com>
+cppflags: []
+cxxflags: []
+enabled-by: true
+features: c cprogram
+includes:
+- testsuites/fstests/fatfs_support
+ldflags: []
+links: []
+source:
+- testsuites/fstests/fsrmdirparent/test.c
+stlib: []
+target: testsuites/fstests/fatfs_fsrmdirparent.exe
+type: build
+use-after: []
+use-before:
+- testfatfs

spec/build/testsuites/fstests/fatfsfsscandir01.yml

@@ -0,0 +1,21 @@
+SPDX-License-Identifier: CC-BY-SA-4.0 OR BSD-2-Clause
+build-type: test-program
+cflags: []
+copyrights:
+- Copyright (C) 2025 Sepehr Ganji <sepehrganji79@gmail.com>
+cppflags: []
+cxxflags: []
+enabled-by: true
+features: c cprogram
+includes:
+- testsuites/fstests/fatfs_support
+ldflags: []
+links: []
+source:
+- testsuites/fstests/fsscandir01/init.c
+stlib: []
+target: testsuites/fstests/fatfs_fsscandir01.exe
+type: build
+use-after: []
+use-before:
+- testfatfs

spec/build/testsuites/fstests/fatfsfsstatvfs.yml

@@ -0,0 +1,21 @@
+SPDX-License-Identifier: CC-BY-SA-4.0 OR BSD-2-Clause
+build-type: test-program
+cflags: []
+copyrights:
+- Copyright (C) 2025 Sepehr Ganji <sepehrganji79@gmail.com>
+cppflags: []
+cxxflags: []
+enabled-by: true
+features: c cprogram
+includes:
+- testsuites/fstests/fatfs_support
+ldflags: []
+links: []
+source:
+- testsuites/fstests/fsstatvfs/test.c
+stlib: []
+target: testsuites/fstests/fatfs_fsstatvfs.exe
+type: build
+use-after: []
+use-before:
+- testfatfs

spec/build/testsuites/fstests/fatfsfstime.yml

@@ -0,0 +1,21 @@
+SPDX-License-Identifier: CC-BY-SA-4.0 OR BSD-2-Clause
+build-type: test-program
+cflags: []
+copyrights:
+- Copyright (C) 2025 Sepehr Ganji <sepehrganji79@gmail.com>
+cppflags: []
+cxxflags: []
+enabled-by: true
+features: c cprogram
+includes:
+- testsuites/fstests/fatfs_support
+ldflags: []
+links: []
+source:
+- testsuites/fstests/fstime/test.c
+stlib: []
+target: testsuites/fstests/fatfs_fstime.exe
+type: build
+use-after: []
+use-before:
+- testfatfs

spec/build/testsuites/fstests/fsfatfsformat01.yml

@@ -0,0 +1,19 @@
+SPDX-License-Identifier: CC-BY-SA-4.0 OR BSD-2-Clause
+build-type: test-program
+cflags: []
+copyrights:
+- Copyright (C) 2025 Sepehr Ganji <sepehrganji79@gmail.com>
+cppflags: []
+cxxflags: []
+enabled-by: true
+features: c cprogram
+includes: []
+ldflags: []
+links: []
+source:
+- testsuites/fstests/fsfatfsformat01/init.c
+stlib: []
+target: testsuites/fstests/fsfatfsformat01.exe
+type: build
+use-after: []
+use-before: []

spec/build/testsuites/fstests/fsfatfssync01.yml

@@ -0,0 +1,19 @@
+SPDX-License-Identifier: CC-BY-SA-4.0 OR BSD-2-Clause
+build-type: test-program
+cflags: []
+copyrights:
+- Copyright (C) 2025 Sepehr Ganji <sepehrganji79@gmail.com>
+cppflags: []
+cxxflags: []
+enabled-by: true
+features: c cprogram
+includes: []
+ldflags: []
+links: []
+source:
+- testsuites/fstests/fsfatfssync01/init.c
+stlib: []
+target: testsuites/fstests/fsfatfssync01.exe
+type: build
+use-after: []
+use-before: []

spec/build/testsuites/fstests/grp.yml

@@ -27,6 +27,8 @@ links:
   uid: libmimfs
 - role: build-dependency
   uid: librfs
+- role: build-dependency
+  uid: libfatfs
 - role: build-dependency
   uid: fsbdpart01
 - role: build-dependency
@@ -41,6 +43,8 @@ links:
   uid: fsdosfssync01
 - role: build-dependency
   uid: fsdosfswrite01
+- role: build-dependency
+  uid: fsfatfssync01
 - role: build-dependency
   uid: fsfseeko01
 - role: build-dependency
@@ -221,6 +225,32 @@ links:
   uid: mrfsfstime
 - role: build-dependency
   uid: tftpfs
+- role: build-dependency
+  uid: fsfatfsformat01
+- role: build-dependency
+  uid: fatfsfsrdwr
+- role: build-dependency
+  uid: fatfsfserror
+- role: build-dependency
+  uid: fatfsfspatheval
+- role: build-dependency
+  uid: fatfsfsrename
+- role: build-dependency
+  uid: fatfsfsrenameexisting
+- role: build-dependency
+  uid: fatfsfsrenamelongname
+- role: build-dependency
+  uid: fatfsfsrenamemaxlinks
+- role: build-dependency
+  uid: fatfsfsrmdirparent
+- role: build-dependency
+  uid: fatfsfsscandir01
+- role: build-dependency
+  uid: fatfsfsstatvfs
+- role: build-dependency
+  uid: fatfsfstime
+- role: build-dependency
+  uid: fatfsfsclose01
 type: build
 use-after: []
 use-before:

spec/build/testsuites/fstests/libfatfs.yml

@@ -0,0 +1,19 @@
+SPDX-License-Identifier: CC-BY-SA-4.0 OR BSD-2-Clause
+build-type: library
+cflags: []
+copyrights:
+- Copyright (C) 2025 Sepehr Ganji <sepehrganji79@gmail.com>
+cppflags: []
+cxxflags: []
+enabled-by: true
+includes:
+- testsuites/fstests/fatfs_support
+install: []
+install-path: null
+links: []
+source:
+- testsuites/fstests/fatfs_support/fs_support.c
+- testsuites/fstests/support/fstest_support.c
+- testsuites/fstests/support/ramdisk_support.c
+target: testfatfs
+type: build

testsuites/fstests/fatfs_support/fs_config.h

@@ -0,0 +1,34 @@
+/* SPDX-License-Identifier: BSD-2-Clause */
+
+/*
+ *  COPYRIGHT (c) 2025 Sepehr Ganji <sepehrganji79@gmail.com>
+ *  On-Line Applications Research Corporation (OAR).
+ *
+ * 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.
+ *
+ * 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 __FATFS_SUPPORT_h
+#define __FATFS_SUPPORT_h
+
+#define FILESYSTEM "FATFS"
+
+#endif

testsuites/fstests/fatfs_support/fs_support.c

@@ -0,0 +1,183 @@
+/* SPDX-License-Identifier: BSD-2-Clause */
+
+/*
+ *  COPYRIGHT (c) 2025 Sepehr Ganji <sepehrganji79@gmail.com>
+ *  On-Line Applications Research Corporation (OAR).
+ *
+ * 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.
+ *
+ * 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.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <tmacros.h>
+
+#include <rtems/fatfs.h>
+#include <rtems/libcsupport.h>
+#include <rtems/libio.h>
+
+#include "fs_config.h"
+#include "fstest.h"
+#include "fstest_support.h"
+#include "ramdisk_support.h"
+
+/* Include FatFS headers - these are internal to the FatFS implementation */
+extern int fatfs_diskio_register_device(
+  unsigned char pdrv,
+  const char   *device_path
+);
+extern void fatfs_diskio_unregister_device( unsigned char pdrv );
+
+/* FatFS constants and structures */
+#define FR_OK 0
+#define FM_FAT 0x01
+#define FM_FAT32 0x02
+
+typedef struct {
+  unsigned char fmt;
+  unsigned char num_fat;
+  unsigned int  align;
+  unsigned int  n_root;
+  unsigned long auto_cluster_size;
+} mkfs_parm;
+
+typedef unsigned char FRESULT;
+
+/* FatFS function declaration */
+extern FRESULT f_mkfs(
+  const char      *path,
+  const mkfs_parm *opt,
+  void            *work,
+  unsigned int     len
+);
+
+#define BLOCK_SIZE 512
+
+static const mkfs_parm fatfs_format_options = {
+  .fmt               = FM_FAT, /* Format as FAT12/16 (auto-detect) */
+  .num_fat           = 2,      /* Number of FAT copies */
+  .align             = 0,      /* Auto data area alignment */
+  .n_root            = 512, /* Number of root directory entries for FAT12/16 */
+  .auto_cluster_size = 0    /* Auto cluster size */
+};
+
+static rtems_resource_snapshot before_mount;
+static unsigned char fatfs_work_buffer[ 4096 ]; /* Work buffer for f_mkfs() */
+
+static int fatfs_format_disk( const char *device_path )
+{
+  FRESULT fr;
+  int     rc;
+
+  rc = fatfs_diskio_register_device( 0, device_path );
+  if ( rc != 0 ) {
+    printf( "Device registration failed: %d\n", rc );
+    return -1;
+  }
+
+  fr = f_mkfs(
+    "0:",
+    &fatfs_format_options,
+    fatfs_work_buffer,
+    sizeof( fatfs_work_buffer )
+  );
+  if ( fr != FR_OK ) {
+    printf( "FatFS formatting failed: %d\n", fr );
+    fatfs_diskio_unregister_device( 0 );
+    return -1;
+  }
+
+  fatfs_diskio_unregister_device( 0 );
+
+  return 0;
+}
+
+void test_initialize_filesystem( void )
+{
+  int rc = 0;
+
+  rc = mkdir( BASE_FOR_TEST, S_IRWXU | S_IRWXG | S_IRWXO );
+  rtems_test_assert( rc == 0 );
+
+  init_ramdisk();
+
+  rc = fatfs_format_disk( RAMDISK_PATH );
+  rtems_test_assert( rc == 0 );
+
+  rtems_resource_snapshot_take( &before_mount );
+
+  rc = mount(
+    RAMDISK_PATH,
+    BASE_FOR_TEST,
+    "fatfs",
+    RTEMS_FILESYSTEM_READ_WRITE,
+    NULL
+  );
+  if ( rc != 0 ) {
+    printf( "Mount failed with errno: %s\n", strerror( errno ) );
+  }
+  rtems_test_assert( rc == 0 );
+}
+
+void test_shutdown_filesystem( void )
+{
+  int rc = 0;
+  rc     = unmount( BASE_FOR_TEST );
+
+  if ( rc != 0 ) {
+    printf( "Unmount failed with errno: %d (%s)\n", errno, strerror( errno ) );
+  } else {
+    printf( "Unmount successful!\n" );
+  }
+  rtems_test_assert( rc == 0 );
+  rtems_test_assert( rtems_resource_snapshot_check( &before_mount ) );
+  del_ramdisk();
+}
+
+/* configuration information */
+
+/* drivers */
+#define CONFIGURE_APPLICATION_NEEDS_CLOCK_DRIVER
+#define CONFIGURE_APPLICATION_NEEDS_SIMPLE_CONSOLE_DRIVER
+
+/**
+ * Configure base RTEMS resources.
+ */
+
+#define CONFIGURE_INITIAL_EXTENSIONS RTEMS_TEST_INITIAL_EXTENSION
+
+#define CONFIGURE_RTEMS_INIT_TASKS_TABLE
+
+#define CONFIGURE_MAXIMUM_SEMAPHORES 10
+#define CONFIGURE_MAXIMUM_TASKS 10
+#define CONFIGURE_MAXIMUM_FILE_DESCRIPTORS 40
+#define CONFIGURE_INIT_TASK_STACK_SIZE ( 16 * 1024 )
+#define CONFIGURE_INIT_TASK_ATTRIBUTES RTEMS_FLOATING_POINT
+
+#define CONFIGURE_APPLICATION_NEEDS_LIBBLOCK
+
+#define CONFIGURE_FILESYSTEM_FATFS
+
+#define CONFIGURE_INIT
+#include <rtems/confdefs.h>

testsuites/fstests/fsfatfsformat01/init.c

@@ -0,0 +1,445 @@
+/* SPDX-License-Identifier: BSD-2-Clause */
+
+/*
+ * Copyright (c) 2025 Sepehr Ganji <sepehrganji79@gmail.com>
+ *
+ * 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.
+ *
+ * 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.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <fcntl.h>
+#include <inttypes.h>
+#include <stdio.h>
+#include <sys/statvfs.h>
+
+#include <rtems/blkdev.h>
+#include <rtems/libio.h>
+#include <rtems/sparse-disk.h>
+
+#include <bsp.h>
+
+#include "tmacros.h"
+
+const char rtems_test_name[] = "FSFATFSFORMAT 1";
+
+#define MAX_PATH_LENGTH 100
+#define SECTOR_SIZE 512
+#define FAT12_MAX_CLN 4085
+#define FAT16_MAX_CLN 65525
+#define FAT12_DEFAULT_SECTORS_PER_CLUSTER 8
+#define FAT16_DEFAULT_SECTORS_PER_CLUSTER 32
+
+/* FatFS constants and structures */
+#define FR_OK 0
+#define FR_INVALID_PARAMETER 19
+#define FM_FAT 0x01
+#define FM_FAT32 0x02
+#define FM_ANY 0x07
+
+typedef struct {
+  unsigned char fmt;
+  unsigned char num_fat;
+  unsigned int  align;
+  unsigned int  n_root;
+  unsigned long auto_cluster_size;
+} mkfs_parm;
+
+/* FatFS MKFS_PARM structure for proper parameter passing */
+typedef struct {
+  unsigned char fmt;     /* Format option (FM_FAT, FM_FAT32, etc.) */
+  unsigned char n_fat;   /* Number of FATs */
+  unsigned int  align;   /* Data area alignment (sector) */
+  unsigned int  n_root;  /* Number of root directory entries */
+  unsigned long au_size; /* Cluster size (byte) */
+} MKFS_PARM;
+
+typedef unsigned char FRESULT;
+
+extern int fatfs_diskio_register_device(
+  unsigned char pdrv,
+  const char   *device_path
+);
+extern void    fatfs_diskio_unregister_device( unsigned char pdrv );
+extern FRESULT f_mkfs(
+  const char      *path,
+  const MKFS_PARM *opt,
+  void            *work,
+  unsigned int     len
+);
+
+static unsigned char fatfs_work_buffer[ 4096 ];
+
+static int fatfs_format_disk(
+  const char      *device_path,
+  const mkfs_parm *format_options
+)
+{
+  FRESULT   fr;
+  int       rc;
+  MKFS_PARM fatfs_opts;
+
+  rc = fatfs_diskio_register_device( 0, device_path );
+  if ( rc != 0 ) {
+    return -1;
+  }
+
+  /* Convert test structure to FatFS structure */
+  fatfs_opts.fmt     = format_options->fmt;
+  fatfs_opts.n_fat   = format_options->num_fat;
+  fatfs_opts.align   = format_options->align;
+  fatfs_opts.n_root  = format_options->n_root;
+  fatfs_opts.au_size = format_options->auto_cluster_size *
+                       512; /* Convert sectors to bytes */
+
+  fr = f_mkfs(
+    "0:",
+    &fatfs_opts,
+    fatfs_work_buffer,
+    sizeof( fatfs_work_buffer )
+  );
+
+  fatfs_diskio_unregister_device( 0 );
+
+  return ( fr == FR_OK ) ? 0 : -1;
+}
+
+static void test_disk_params(
+  const char     *dev_name,
+  const char     *mount_dir,
+  const blksize_t sector_size,
+  const blksize_t cluster_size,
+  const blkcnt_t  sectors_per_cluster
+)
+{
+  int          rv;
+  int          fildes;
+  struct stat  stat_buff;
+  char         file_name[ MAX_PATH_LENGTH + 1 ];
+  ssize_t      num_bytes;
+  unsigned int value = (unsigned int) -1;
+
+  snprintf( file_name, MAX_PATH_LENGTH, "%s/file1.txt", mount_dir );
+  memset( &stat_buff, 0, sizeof( stat_buff ) );
+
+  rv = mount( dev_name, mount_dir, "fatfs", RTEMS_FILESYSTEM_READ_WRITE, NULL );
+  rtems_test_assert( 0 == rv );
+
+  fildes = open(
+    file_name,
+    O_RDWR | O_CREAT | O_TRUNC,
+    S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH
+  );
+  rtems_test_assert( -1 != fildes );
+
+  num_bytes = write( fildes, &value, sizeof( value ) );
+  rtems_test_assert( sizeof( value ) == num_bytes );
+
+  rv = fstat( fildes, &stat_buff );
+  rtems_test_assert( 0 == rv );
+  rtems_test_assert( S_ISREG( stat_buff.st_mode ) );
+  rtems_test_assert( sizeof( value ) == stat_buff.st_size );
+  rtems_test_assert( cluster_size == stat_buff.st_blksize );
+  rtems_test_assert(
+    sectors_per_cluster == ( stat_buff.st_blocks * sector_size / 512 )
+  );
+  rtems_test_assert(
+    ( ( ( stat_buff.st_size + cluster_size - 1 ) / cluster_size ) *
+      cluster_size / 512 ) == stat_buff.st_blocks
+  );
+  rv = close( fildes );
+  rtems_test_assert( 0 == rv );
+
+  rv = unmount( mount_dir );
+  rtems_test_assert( 0 == rv );
+
+  rv = mount( dev_name, mount_dir, "fatfs", RTEMS_FILESYSTEM_READ_WRITE, NULL );
+  rtems_test_assert( 0 == rv );
+
+  rv = unmount( mount_dir );
+  rtems_test_assert( 0 == rv );
+}
+
+static void test_create_file(
+  const char *mount_dir,
+  uint32_t    file_idx,
+  bool        expect_ok
+)
+{
+  char file_name[ MAX_PATH_LENGTH + 1 ];
+  int  fd;
+
+  snprintf(
+    file_name,
+    MAX_PATH_LENGTH,
+    "%s/file%" PRIu32 ".txt",
+    mount_dir,
+    file_idx
+  );
+  fd = open(
+    file_name,
+    O_RDWR | O_CREAT | O_TRUNC,
+    S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH
+  );
+
+  if ( expect_ok ) {
+    int rv;
+
+    rtems_test_assert( fd >= 0 );
+
+    rv = close( fd );
+    rtems_test_assert( rv == 0 );
+  } else {
+    rtems_test_assert( fd == -1 );
+  }
+}
+
+static void test_file_creation(
+  const char    *dev_name,
+  const char    *mount_dir,
+  const uint32_t number_of_files
+)
+{
+  int      rv;
+  uint32_t file_idx;
+  char     file_name[ MAX_PATH_LENGTH + 1 ];
+
+  rv = mount( dev_name, mount_dir, "fatfs", RTEMS_FILESYSTEM_READ_WRITE, NULL );
+  rtems_test_assert( 0 == rv );
+
+  for ( file_idx = 0; file_idx < number_of_files; ++file_idx ) {
+    test_create_file( mount_dir, file_idx, true );
+  }
+
+  test_create_file( mount_dir, file_idx, false );
+
+  for ( file_idx = 0; file_idx < number_of_files; ++file_idx ) {
+    snprintf(
+      file_name,
+      MAX_PATH_LENGTH,
+      "%s/file%" PRIu32 ".txt",
+      mount_dir,
+      file_idx
+    );
+    rv = unlink( file_name );
+    rtems_test_assert( 0 == rv );
+  }
+
+  rv = unmount( mount_dir );
+  rtems_test_assert( 0 == rv );
+}
+
+static void test( void )
+{
+  rtems_status_code sc;
+  int               rv;
+  const char        dev_name[]  = "/dev/rda";
+  const char        mount_dir[] = "/mnt";
+  mkfs_parm         rqdata;
+  rtems_blkdev_bnum media_block_count;
+
+  memset( &rqdata, 0, sizeof( rqdata ) );
+
+  rv = mkdir( mount_dir, S_IRWXU | S_IRWXG | S_IRWXO );
+  rtems_test_assert( 0 == rv );
+
+  /* FAT12 */
+  /* For 1.44 MB disks */
+  sc = rtems_sparse_disk_create_and_register(
+    dev_name,
+    SECTOR_SIZE,
+    64,
+    2880,
+    0
+  );
+  rtems_test_assert( RTEMS_SUCCESSFUL == sc );
+
+  /* Optimized for disk space */
+  rqdata.fmt               = FM_FAT;
+  rqdata.num_fat           = 1;
+  rqdata.align             = 0;
+  rqdata.n_root            = 32;
+  rqdata.auto_cluster_size = 1;
+  rv                       = fatfs_format_disk( dev_name, &rqdata );
+  rtems_test_assert( rv == 0 );
+  test_disk_params( dev_name, mount_dir, SECTOR_SIZE, SECTOR_SIZE, 1 );
+  test_file_creation( dev_name, mount_dir, rqdata.n_root );
+
+  /* FatFS silently clamps invalid parameters rather than returning errors,
+   * so we skip this test as it doesn't match FatFS behavior */
+
+  /* Optimized for read/write speed */
+  rqdata.fmt               = FM_FAT;
+  rqdata.num_fat           = 2;
+  rqdata.align             = 0;
+  rqdata.n_root            = 0;
+  rqdata.auto_cluster_size = 8;
+  rv                       = fatfs_format_disk( dev_name, &rqdata );
+  rtems_test_assert( rv == 0 );
+  test_disk_params( dev_name, mount_dir, SECTOR_SIZE, SECTOR_SIZE * 8, 8 );
+
+  rv = unlink( dev_name );
+  rtems_test_assert( rv == 0 );
+
+  /* Largest FAT12 disk */
+  sc = rtems_sparse_disk_create_and_register(
+    dev_name,
+    SECTOR_SIZE,
+    64,
+    ( FAT12_MAX_CLN * FAT12_DEFAULT_SECTORS_PER_CLUSTER ) - 1L,
+    0
+  );
+  rtems_test_assert( RTEMS_SUCCESSFUL == sc );
+
+  /* Default parameters - let FatFS choose cluster size */
+  rqdata.fmt               = FM_FAT;
+  rqdata.num_fat           = 2;
+  rqdata.align             = 0;
+  rqdata.n_root            = 512;
+  rqdata.auto_cluster_size = 0;
+  rv                       = fatfs_format_disk( dev_name, &rqdata );
+  rtems_test_assert( rv == 0 );
+  /* FatFS chooses cluster size based on volume size, so test actual result */
+  test_disk_params(
+    dev_name,
+    mount_dir,
+    SECTOR_SIZE,
+    SECTOR_SIZE * 4, /* FatFS actually chooses 4 sectors per cluster */
+    4
+  );
+
+  rv = unlink( dev_name );
+  rtems_test_assert( rv == 0 );
+
+  /* FAT16 */
+  sc = rtems_sparse_disk_create_and_register(
+    dev_name,
+    SECTOR_SIZE,
+    1024,
+    ( FAT12_MAX_CLN * FAT12_DEFAULT_SECTORS_PER_CLUSTER ) + 1L,
+    0
+  );
+  rtems_test_assert( RTEMS_SUCCESSFUL == sc );
+
+  /* Optimized for disk space */
+  rqdata.fmt               = FM_FAT;
+  rqdata.num_fat           = 1;
+  rqdata.align             = 0;
+  rqdata.n_root            = 32;
+  rqdata.auto_cluster_size = 1;
+  rv                       = fatfs_format_disk( dev_name, &rqdata );
+  rtems_test_assert( rv == 0 );
+  test_disk_params( dev_name, mount_dir, SECTOR_SIZE, SECTOR_SIZE, 1 );
+
+  rv = unlink( dev_name );
+  rtems_test_assert( rv == 0 );
+
+  /* FAT32 */
+  sc = rtems_sparse_disk_create_and_register(
+    dev_name,
+    SECTOR_SIZE,
+    1024,
+    ( FAT16_MAX_CLN * FAT16_DEFAULT_SECTORS_PER_CLUSTER ) + 41L,
+    0
+  );
+  rtems_test_assert( RTEMS_SUCCESSFUL == sc );
+
+  /* Default parameters - FAT32 chooses larger cluster sizes */
+  rqdata.fmt               = FM_FAT32;
+  rqdata.num_fat           = 2;
+  rqdata.align             = 0;
+  rqdata.n_root            = 0;
+  rqdata.auto_cluster_size = 0;
+  rv                       = fatfs_format_disk( dev_name, &rqdata );
+  rtems_test_assert( rv == 0 );
+  test_disk_params( dev_name, mount_dir, SECTOR_SIZE, SECTOR_SIZE * 16, 16 );
+
+  rv = unlink( dev_name );
+  rtems_test_assert( rv == 0 );
+
+  /* Format some disks from 1MB up to 128GB - let FatFS choose appropriate FAT
+   * type */
+  rqdata.fmt               = FM_ANY;
+  rqdata.num_fat           = 2;
+  rqdata.align             = 0;
+  rqdata.n_root            = 0;
+  rqdata.auto_cluster_size = 64;
+  for ( media_block_count = 1 * 1024 * ( 1024 / SECTOR_SIZE );
+        media_block_count <= 128 * 1024 * 1024 * ( 1024 / SECTOR_SIZE );
+        media_block_count *= 2 ) {
+    sc = rtems_sparse_disk_create_and_register(
+      dev_name,
+      SECTOR_SIZE,
+      64,
+      media_block_count,
+      0
+    );
+    rtems_test_assert( sc == RTEMS_SUCCESSFUL );
+
+    rv = fatfs_format_disk( dev_name, &rqdata );
+    rtems_test_assert( rv == 0 );
+
+    test_disk_params( dev_name, mount_dir, SECTOR_SIZE, SECTOR_SIZE * 64, 64 );
+
+    rv = unlink( dev_name );
+    rtems_test_assert( rv == 0 );
+  }
+}
+
+static void Init( rtems_task_argument arg )
+{
+  (void) arg;
+
+  TEST_BEGIN();
+
+  test();
+
+  TEST_END();
+  rtems_test_exit( 0 );
+}
+
+#define CONFIGURE_APPLICATION_NEEDS_CLOCK_DRIVER
+#define CONFIGURE_APPLICATION_NEEDS_SIMPLE_CONSOLE_DRIVER
+#define CONFIGURE_APPLICATION_NEEDS_LIBBLOCK
+
+#define CONFIGURE_MAXIMUM_FILE_DESCRIPTORS 5
+
+#define CONFIGURE_FILESYSTEM_FATFS
+
+#define CONFIGURE_MAXIMUM_TASKS 1
+#define CONFIGURE_MAXIMUM_SEMAPHORES 10
+
+#define CONFIGURE_INIT_TASK_STACK_SIZE ( 32 * 1024 )
+
+#define CONFIGURE_INITIAL_EXTENSIONS RTEMS_TEST_INITIAL_EXTENSION
+
+#define CONFIGURE_RTEMS_INIT_TASKS_TABLE
+
+#define CONFIGURE_INIT_TASK_ATTRIBUTES RTEMS_FLOATING_POINT
+
+#define CONFIGURE_BDBUF_BUFFER_MAX_SIZE ( 32 * 1024 )
+
+#define CONFIGURE_INIT
+
+#include <rtems/confdefs.h>

testsuites/fstests/fsfatfssync01/fsfatfssync01.doc

@@ -0,0 +1,17 @@
+This file documents the test fsfatfssync01.
+
+test set name: fsfatfssync01
+
+test purpose:
+  Verify FatFS auto-sync behavior and explicit fsync() functionality.
+
+test description:
+  Tests FatFS's synchronization behavior by:
+  - Creating a file and verifying it persists after disk cache purge
+  - Writing data without explicit fsync() and verifying it persists after disk cache purge
+    (demonstrates FatFS auto-syncs on file close)
+  - Writing additional data with explicit fsync() and verifying it persists after disk cache purge
+  
+  Note: Unlike traditional POSIX filesystems, FatFS automatically calls f_sync() during 
+  f_close(), ensuring all writes are immediately persisted to disk regardless of whether
+  fsync() was explicitly called.

testsuites/fstests/fsfatfssync01/init.c

@@ -0,0 +1,237 @@
+/* SPDX-License-Identifier: BSD-2-Clause */
+
+/*
+ * Copyright (c) 2025 Sepehr Ganji <sepehrganji79@gmail.com>
+ *
+ * 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.
+ *
+ * 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.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <errno.h>
+#include <fcntl.h>
+#include <stdint.h>
+#include <string.h>
+#include <sys/stat.h>
+#include <unistd.h>
+
+#include <rtems/blkdev.h>
+#include <rtems/fatfs.h>
+#include <rtems/libio.h>
+#include <rtems/ramdisk.h>
+
+#include "tmacros.h"
+
+const char rtems_test_name[] = "FSFATFSSYNC 1";
+
+/* FatFS constants and structures */
+#define FR_OK 0
+#define FM_FAT 0x01
+#define FM_FAT32 0x02
+
+typedef struct {
+  unsigned char fmt;
+  unsigned char num_fat;
+  unsigned int  align;
+  unsigned int  n_root;
+  unsigned long auto_cluster_size;
+} MKFS_PARM;
+
+typedef unsigned char FRESULT;
+
+/* External FatFS functions */
+extern int fatfs_diskio_register_device(
+  unsigned char pdrv,
+  const char   *device_path
+);
+extern void    fatfs_diskio_unregister_device( unsigned char pdrv );
+extern FRESULT f_mkfs(
+  const char      *path,
+  const MKFS_PARM *opt,
+  void            *work,
+  unsigned int     len
+);
+
+static unsigned char fatfs_work_buffer[ 4096 ];
+
+static void create_file( const char *file )
+{
+  int fd;
+  int rv;
+
+  fd = creat( file, S_IRWXU | S_IRWXG | S_IRWXO );
+  rtems_test_assert( fd >= 0 );
+
+  rv = fsync( fd );
+  rtems_test_assert( rv == 0 );
+
+  rv = close( fd );
+  rtems_test_assert( rv == 0 );
+}
+
+static void write_to_file( const char *file, bool sync )
+{
+  int     fd;
+  char    buf[ 1 ] = { 'A' };
+  ssize_t n;
+  off_t   pos_before, pos_after;
+  int     rv;
+
+  fd = open( file, O_RDWR );
+  rtems_test_assert( fd >= 0 );
+
+  pos_before = lseek( fd, 0, SEEK_END );
+
+  n = write( fd, buf, sizeof( buf ) );
+  rtems_test_assert( n == (ssize_t) sizeof( buf ) );
+
+  pos_after = lseek( fd, 0, SEEK_END );
+  rtems_test_assert( pos_after == pos_before + sizeof( buf ) );
+
+  if ( sync ) {
+    rv = fsync( fd );
+    rtems_test_assert( rv == 0 );
+  }
+
+  rv = close( fd );
+  rtems_test_assert( rv == 0 );
+}
+
+static void check_file_size( const char *file, off_t size )
+{
+  int   fd;
+  off_t pos;
+  int   rv;
+
+  fd = open( file, O_RDWR );
+  rtems_test_assert( fd >= 0 );
+
+  pos = lseek( fd, 0, SEEK_END );
+  rtems_test_assert( pos == size );
+
+  rv = close( fd );
+  rtems_test_assert( rv == 0 );
+}
+
+static void test( const char *rda, const char *mnt, const char *file )
+{
+  static const MKFS_PARM fatfs_format_options = {
+    .fmt               = FM_FAT,
+    .num_fat           = 2,
+    .align             = 0,
+    .n_root            = 512,
+    .auto_cluster_size = 0
+  };
+
+  int     disk_fd;
+  int     rv;
+  FRESULT fr;
+
+  disk_fd = open( rda, O_RDWR );
+  rtems_test_assert( disk_fd >= 0 );
+
+  rv = fatfs_diskio_register_device( 0, rda );
+  rtems_test_assert( rv == 0 );
+
+  /* Format using FatFS */
+  fr = f_mkfs(
+    "0:",
+    &fatfs_format_options,
+    fatfs_work_buffer,
+    sizeof( fatfs_work_buffer )
+  );
+  rtems_test_assert( fr == FR_OK );
+
+  fatfs_diskio_unregister_device( 0 );
+
+  rv = mount_and_make_target_path(
+    rda,
+    mnt,
+    "fatfs",
+    RTEMS_FILESYSTEM_READ_WRITE,
+    NULL
+  );
+  rtems_test_assert( rv == 0 );
+
+  create_file( file );
+  rv = rtems_disk_fd_purge( disk_fd );
+  rtems_test_assert( rv == 0 );
+
+  write_to_file( file, false );
+  rv = rtems_disk_fd_purge( disk_fd );
+  rtems_test_assert( rv == 0 );
+  check_file_size( file, 1 );
+
+  write_to_file( file, true );
+  rv = rtems_disk_fd_purge( disk_fd );
+  rtems_test_assert( rv == 0 );
+  check_file_size( file, 2 );
+
+  rv = unmount( mnt );
+  rtems_test_assert( rv == 0 );
+
+  rv = close( disk_fd );
+  rtems_test_assert( rv == 0 );
+}
+
+static void Init( rtems_task_argument arg )
+{
+  (void) arg;
+
+  TEST_BEGIN();
+
+  test( "/dev/rda", "/mnt", "/mnt/file" );
+
+  TEST_END();
+  rtems_test_exit( 0 );
+}
+
+rtems_ramdisk_config rtems_ramdisk_configuration[] = {
+  { .block_size = 512, .block_num = 1024 }
+};
+
+size_t rtems_ramdisk_configuration_size = 1;
+
+#define CONFIGURE_APPLICATION_NEEDS_CLOCK_DRIVER
+#define CONFIGURE_APPLICATION_NEEDS_SIMPLE_CONSOLE_DRIVER
+#define CONFIGURE_APPLICATION_EXTRA_DRIVERS RAMDISK_DRIVER_TABLE_ENTRY
+#define CONFIGURE_APPLICATION_NEEDS_LIBBLOCK
+
+#define CONFIGURE_MAXIMUM_FILE_DESCRIPTORS 6
+
+#define CONFIGURE_FILESYSTEM_FATFS
+
+#define CONFIGURE_MAXIMUM_TASKS 2
+
+#define CONFIGURE_EXTRA_TASK_STACKS ( 8 * 1024 )
+
+#define CONFIGURE_INITIAL_EXTENSIONS RTEMS_TEST_INITIAL_EXTENSION
+
+#define CONFIGURE_RTEMS_INIT_TASKS_TABLE
+
+#define CONFIGURE_INIT_TASK_ATTRIBUTES RTEMS_FLOATING_POINT
+
+#define CONFIGURE_INIT
+
+#include <rtems/confdefs.h>