1 files changed, 181 insertions, 0 deletions
diff --git a/nuttx/fs/nxffs/nxffs_util.c b/nuttx/fs/nxffs/nxffs_util.c
new file mode 100644
index 000000000..ea2e97967
--- /dev/null
+++ b/nuttx/fs/nxffs/nxffs_util.c
@@ -0,0 +1,181 @@
+/****************************************************************************
+ * fs/nxffs/nxffs_util.c
+ *
+ *   Copyright (C) 2011 Gregory Nutt. All rights reserved.
+ *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
+ *
+ * References: Linux/Documentation/filesystems/romfs.txt
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name NuttX nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <string.h>
+
+#include "nxffs.h"
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Types
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Variables
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: nxffs_rdle16
+ *
+ * Description:
+ *   Get a (possibly unaligned) 16-bit little endian value.
+ *
+ * Input Parameters:
+ *   val - A pointer to the first byte of the little endian value.
+ *
+ * Returned Value:
+ *   A uint16_t representing the whole 16-bit integer value
+ *
+ ****************************************************************************/
+
+uint16_t nxffs_rdle16(FAR const uint8_t *val)
+{
+  return (uint16_t)val[1] << 8 | (uint16_t)val[0];
+}
+
+/****************************************************************************
+ * Name: nxffs_wrle16
+ *
+ * Description:
+ *   Put a (possibly unaligned) 16-bit little endian value.
+ *
+ * Input Parameters:
+ *   dest - A pointer to the first byte to save the little endian value.
+ *   val - The 16-bit value to be saved.
+ *
+ * Returned Value:
+ *   None
+ *
+ ****************************************************************************/
+
+void nxffs_wrle16(uint8_t *dest, uint16_t val)
+{
+  dest[0] = val & 0xff; /* Little endian means LS byte first in byte stream */
+  dest[1] = val >> 8;
+}
+
+/****************************************************************************
+ * Name: nxffs_rdle32
+ *
+ * Description:
+ *   Get a (possibly unaligned) 32-bit little endian value.
+ *
+ * Input Parameters:
+ *   val - A pointer to the first byte of the little endian value.
+ *
+ * Returned Value:
+ *   A uint32_t representing the whole 32-bit integer value
+ *
+ ****************************************************************************/
+
+uint32_t nxffs_rdle32(FAR const uint8_t *val)
+{
+ /* Little endian means LS halfword first in byte stream */
+
+  return (uint32_t)nxffs_rdle16(&val[2]) << 16 | (uint32_t)nxffs_rdle16(val);
+}
+
+/****************************************************************************
+ * Name: nxffs_wrle32
+ *
+ * Description:
+ *   Put a (possibly unaligned) 32-bit little endian value.
+ *
+ * Input Parameters:
+ *   dest - A pointer to the first byte to save the little endian value.
+ *   val - The 32-bit value to be saved.
+ *
+ * Returned Value:
+ *   None
+ *
+ ****************************************************************************/
+
+void nxffs_wrle32(uint8_t *dest, uint32_t val)
+{
+  /* Little endian means LS halfword first in byte stream */
+
+  nxffs_wrle16(dest, (uint16_t)(val & 0xffff));
+  nxffs_wrle16(dest+2, (uint16_t)(val >> 16));
+}
+
+/****************************************************************************
+ * Name: nxffs_erased
+ *
+ * Description:
+ *   Check if a block of memory is in the erased state.
+ *
+ * Input Parameters:
+ *   buffer - Address of the start of the memory to check.
+ *   buflen - The number of bytes to check.
+ *
+ * Returned Values:
+ *   The number of erased bytes found at the beginning of the memory region.
+ *
+ ****************************************************************************/
+
+size_t nxffs_erased(FAR const uint8_t *buffer, size_t buflen)
+{
+  size_t nerased = 0;
+
+  for (; nerased < buflen; nerased++)
+    {
+      if (*buffer != CONFIG_NXFFS_ERASEDSTATE)
+        {
+          break;
+        }
+      buffer++;
+    }
+
+  return nerased;
+}