nuttx/configs/sim/src/sim_zoneinfo.c

/****************************************************************************
 * config/sim/src/sim_zoneinfo.c
 *
 *   Copyright (C) 2015 Gregory Nutt. All rights reserved.
 *   Author: Gregory Nutt <gnutt@nuttx.org>
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 * 3. Neither the name NuttX nor the names of its contributors may be
 *    used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 *
 ****************************************************************************/

/****************************************************************************
 * Included Files
 ****************************************************************************/

#include <nuttx/config.h>

#include <sys/mount.h>
#include <stdio.h>
#include <stdlib.h>
#include <errno.h>

#include <nuttx/fs/ramdisk.h>
#include <apps/zoneinfo.h>

#ifdef CONFIG_SYSTEM_ZONEINFO_ROMFS

/****************************************************************************
 * Pre-processor Definitions
 ****************************************************************************/

#ifndef CONFIG_LIBC_TZDIR
#  errror CONFIG_LIBC_TZDIR is not defined
#endif

#ifdef CONFIG_DISABLE_MOUNTPOINT
#  error "Mountpoint support is disabled"
#endif

#if CONFIG_NFILE_DESCRIPTORS < 4
#  error "Not enough file descriptors"
#endif

#ifndef CONFIG_FS_ROMFS
#  error "ROMFS support not enabled"
#endif

#define SECTORSIZE  64
#define NSECTORS(b) (((b)+SECTORSIZE-1)/SECTORSIZE)

/****************************************************************************
 * Public Functions
 ****************************************************************************/

/****************************************************************************
 * Name: sim_zoneinfo
 *
 * Description:
 *   Mount the TZ database.  The apps/system/zoneinfo directory contains
 *   logic to create a version of the TZ/Olson database.
 *   This database is required if localtime() support is selected via
 *   CONFIG_LIBC_LOCALTIME.  This logic in that directory does the following:
 *
 *   - It downloads the current TZ database from the IANA website
 *   - It downloads the current timezone tools from the same location
 *   - It builds the tools and constructs the binary TZ database
 *   - It will then, optionally, build a ROMFS filesystem image containing
 *     the data base.
 *
 *   The ROMFS filesystem image can that be mounted during the boot-up sequence
 *   so that it is available for the localtime logic.  There are two steps to
 *   doing this:
 *
 *   - First, a ROM disk device must be created.  This is done by calling
 *     the function romdisk_register() as described in
 *     nuttx/include/nuttx/fs/ramdisk.h.  This is an OS level operation
 *     and must be done in the board-level logic before your appliction
 *     starts.
 *
 *     romdisk_register() will create a block driver at /dev/ramN where N
 *     is the device minor number that was provdied to romdisk_regsiter.
 *
 *   - The second step is to mount the file system.  This step can be
 *     performed either in your board configuration logic or by your
 *     application using the mount() interface described in
 *     nuttx/include/sys/mount.h.
 *
 *     These steps, however, must be done very early in initialization,
 *     before there is any need for time-related services.
 *
 ****************************************************************************/

int sim_zoneinfo(int minor)
{
   char devname[32];
   int  ret;

  /* Create a RAM disk for the test */

  ret = romdisk_register(minor, romfs_zoneinfo_img,
                         NSECTORS(romfs_zoneinfo_img_len), SECTORSIZE);
  if (ret < 0)
    {
      printf("ERROR: Failed to create RAM disk\n");
      return ret;
    }

  /* Use the minor number to create a name for the ROM disk block device */

  snprintf(devname, 32, "/dev/ram%d", minor);

  /* Mount the ROMFS file system */

  printf("Mounting ROMFS filesystem at target=%s with source=%s\n",
         CONFIG_LIBC_TZDIR, devname);

  ret = mount(devname, CONFIG_LIBC_TZDIR, "romfs", MS_RDONLY, NULL);
  if (ret < 0)
    {
      printf("ERROR: Mount failed: %d\n", errno);
      return ret;
    }

  printf("TZ database mounted at %s\n", CONFIG_LIBC_TZDIR);
  return OK;
}

#endif /* CONFIG_SYSTEM_ZONEINFO_ROMFS */