Filesystem: Add shared device IO support

The device IO file system support in IMFS, devFS, and RFS uses now a
shared implementation.

cpukit/libcsupport/include/rtems/deviceio.h

@@ -0,0 +1,56 @@
+/*
+ *  COPYRIGHT (c) 1989-2012.
+ *  On-Line Applications Research Corporation (OAR).
+ *
+ *  The license and distribution terms for this file may be
+ *  found in the file LICENSE in this distribution or at
+ *  http://www.rtems.com/license/LICENSE.
+ */
+
+#ifndef _RTEMS_DEVICEIO_H
+#define _RTEMS_DEVICEIO_H
+
+#include <rtems/libio.h>
+
+int rtems_deviceio_errno( rtems_status_code status );
+
+int rtems_deviceio_open(
+  rtems_libio_t *iop,
+  const char *path,
+  int oflag,
+  mode_t mode,
+  rtems_device_major_number major,
+  rtems_device_minor_number minor
+);
+
+int rtems_deviceio_close(
+  rtems_libio_t *iop,
+  rtems_device_major_number major,
+  rtems_device_minor_number minor
+);
+
+ssize_t rtems_deviceio_read(
+  rtems_libio_t *iop,
+  void *buf,
+  size_t nbyte,
+  rtems_device_major_number major,
+  rtems_device_minor_number minor
+);
+
+ssize_t rtems_deviceio_write(
+  rtems_libio_t *iop,
+  const void *buf,
+  size_t nbyte,
+  rtems_device_major_number major,
+  rtems_device_minor_number minor
+);
+
+int rtems_deviceio_control(
+  rtems_libio_t *iop,
+  ioctl_command_t command,
+  void *buffer,
+  rtems_device_major_number major,
+  rtems_device_minor_number minor
+);
+
+#endif /* _RTEMS_DEVICEIO_H */