Add MTD loop driver (use filemtd)

include/nuttx/fs/loopmtd.h

@@ -0,0 +1,107 @@
+/****************************************************************************
+ * include/nuttx/fs/loopmtd.h
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.  The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+#ifndef __INCLUDE_NUTTX_FS_LOOPMTD_H
+#define __INCLUDE_NUTTX_FS_LOOPMTD_H
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <sys/types.h>
+#include <sys/ioctl.h>
+#include <stdint.h>
+#include <stdbool.h>
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+#ifdef CONFIG_MTD_LOOP
+/* Loop device IOCTL commands */
+
+/* Command:      MTD_LOOPIOC_SETUP
+ * Description:  Setup the loop device
+ * Argument:     A pointer to a read-only instance of struct losetup_s.
+ * Dependencies: The loop device must be enabled (CONFIG_MTD_LOOP=y)
+ */
+
+/* Command:      MTD_LOOPIOC_TEARDOWN
+ * Description:  Teardown a loop device previously setup vis LOOPIOC_SETUP
+ * Argument:     A read-able pointer to the path of the device to be
+ *               torn down
+ * Dependencies: The loop device must be enabled (CONFIG_MTD_LOOP=y)
+ */
+
+#define MTD_LOOPIOC_SETUP     _LOOPIOC(0x0001)
+#define MTD_LOOPIOC_TEARDOWN  _LOOPIOC(0x0002)
+
+#endif
+
+/****************************************************************************
+ * Public Types
+ ****************************************************************************/
+
+#ifdef CONFIG_MTD_LOOP
+/* This is the structure referred to in the argument to the LOOPIOC_SETUP
+ * IOCTL command.
+ */
+
+struct mtd_losetup_s
+{
+  FAR const char *devname;      /* The loop mtd device to be created */
+  FAR const char *filename;     /* The file or character device to use */
+  size_t          erasesize;    /* The erase size to use on the file */
+  size_t          sectsize;     /* The sector / page size of the file */
+  off_t           offset;       /* An offset that may be applied to the device */
+};
+#endif
+
+/****************************************************************************
+ * Public Data
+ ****************************************************************************/
+
+#ifndef __ASSEMBLY__
+
+#ifdef __cplusplus
+#define EXTERN extern "C"
+extern "C"
+{
+#else
+#define EXTERN extern
+#endif
+
+/****************************************************************************
+ * Public Function Prototypes
+ ****************************************************************************/
+
+#ifdef CONFIG_MTD_LOOP
+int mtd_loop_register(void);
+#endif
+
+#undef EXTERN
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* __ASSEMBLY__ */
+#endif /* __INCLUDE_NUTTX_FS_LOOPMTD_H */