/****************************************************************************
 * examples/module/module_main.c
 *
 *   Copyright (C) 2015, 2017-2018 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 <nuttx/compiler.h>

#include <sys/mount.h>
#include <sys/stat.h>

#include <sys/boardctl.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
#include <string.h>
#include <syslog.h>
#include <errno.h>
#include <debug.h>

#include <nuttx/module.h>
#include <nuttx/binfmt/symtab.h>

#if  defined(CONFIG_EXAMPLES_MODULE_ROMFS)
#  include <nuttx/drivers/ramdisk.h>
#  include "drivers/romfs.h"
#elif defined(CONFIG_EXAMPLES_MODULE_CROMFS)
#  include "drivers/cromfs.h"
#endif

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

/* Check configuration.  This is not all of the configuration settings that
 * are required -- only the more obvious.
 */

#ifndef CONFIG_MODULE
#  error "You must select CONFIG_MODULE in your configuration file"
#endif

#if defined(CONFIG_EXAMPLES_MODULE_BUILTINFS)
#  if !defined(CONFIG_FS_ROMFS) && !defined(CONFIG_FS_CROMFS)
#    error "You must select CONFIG_FS_ROMFS or CONFIG_FS_CROMFS in your configuration file"
#  endif

#  ifdef CONFIG_DISABLE_MOUNTPOINT
#    error "You must not disable mountpoints via CONFIG_DISABLE_MOUNTPOINT in your configuration file"
#  endif

#  if defined(CONFIG_EXAMPLES_MODULE_ROMFS)
/* Describe the ROMFS file system */

#    define SECTORSIZE   64
#    define NSECTORS(b)  (((b)+SECTORSIZE-1)/SECTORSIZE)
#    define MOUNTPT      "/mnt/romfs"

#    ifndef CONFIG_EXAMPLES_MODULE_DEVMINOR
#      define CONFIG_EXAMPLES_MODULE_DEVMINOR 0
#    endif

#    ifndef CONFIG_EXAMPLES_MODULE_DEVPATH
#      define CONFIG_EXAMPLES_MODULE_DEVPATH "/dev/ram0"
#    endif

#  elif defined(CONFIG_EXAMPLES_MODULE_CROMFS)
/* Describe the CROMFS file system */

#    define MOUNTPT      "/mnt/cromfs"
#  endif

#  define BINDIR         MOUNTPT

#elif defined(CONFIG_EXAMPLES_MODULE_FSMOUNT)
/* Describe how to auto-mount the external file system */

#  define MOUNTPT        "/mnt/" CONFIG_EXAMPLES_MODULE_FSTYPE
#  define BINDIR         MOUNTPT

#else
/* Describe how to use the pre-mounted external file system */

#  define BINDIR         CONFIG_EXAMPLES_MODULE_BINDIR

#endif /* CONFIG_EXAMPLES_MODULE_BUILTINFS */

/****************************************************************************
 * Private data
 ****************************************************************************/

static const char g_write_string[] = "Hi there, installed driver\n";

/****************************************************************************
 * Symbols from Auto-Generated Code
 ****************************************************************************/

#ifdef CONFIG_BUILD_FLAT
extern const struct symtab_s g_mod_exports[];
extern const int g_mod_nexports;
#endif

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

/****************************************************************************
 * Name: module_main
 ****************************************************************************/

#ifdef BUILD_MODULE
int main(int argc, FAR char *argv[])
#else
int module_main(int argc, char *argv[])
#endif
{
#ifdef CONFIG_BUILD_FLAT
  struct boardioc_symtab_s symdesc;
#endif
#if defined(CONFIG_EXAMPLES_MODULE_FSMOUNT) && \
    defined(CONFIG_EXAMPLES_MODULE_FSREMOVEABLE)
  struct stat buf;
#endif
  FAR void *handle;
  char buffer[128];
  ssize_t nbytes;
  int ret;
  int fd;

#ifdef CONFIG_BUILD_FLAT
  /* Set the OS symbol table indirectly through the boardctl() */

  symdesc.symtab   = (FAR struct symtab_s *)g_mod_exports;
  symdesc.nsymbols = g_mod_nexports;
  ret = boardctl(BOARDIOC_OS_SYMTAB, (uintptr_t)&symdesc);
  if (ret < 0)
    {
      fprintf(stderr, "ERROR: boardctl(BOARDIOC_OS_SYMTAB) failed: %d\n", ret);
      exit(EXIT_FAILURE);
    }
#endif

#ifdef CONFIG_EXAMPLES_MODULE_BUILTINFS
#if defined(CONFIG_EXAMPLES_MODULE_ROMFS)
  /* Create a ROM disk for the ROMFS filesystem */

  printf("main: Registering romdisk at /dev/ram%d\n",
         CONFIG_EXAMPLES_MODULE_DEVMINOR);

#if defined(CONFIG_BUILD_FLAT)
  /* This example violates the portable POSIX interface by calling the OS
   * internal function romdisk_register() (aka ramdisk_register()).  We can
   * squeak by in with this violation in the FLAT build mode, but not in
   * other build modes.  In other build modes, the following logic must be
   * performed in the OS board initialization logic (where it really belongs
   * anyway).
   */

  ret = romdisk_register(CONFIG_EXAMPLES_MODULE_DEVMINOR, (FAR uint8_t *)romfs_img,
                         NSECTORS(romfs_img_len), SECTORSIZE);
  if (ret < 0)
    {
      /* This will happen naturally if we registered the ROM disk previously. */

      if (ret != -EEXIST)
        {
          fprintf(stderr, "ERROR: romdisk_register failed: %d\n", ret);
          exit(EXIT_FAILURE);
        }

      printf("main: ROM disk already registered\n");
    }
#endif

  /* Mount the file system */

  printf("main: Mounting ROMFS filesystem at target=%s with source=%s\n",
         MOUNTPT, CONFIG_EXAMPLES_MODULE_DEVPATH);

  ret = mount(CONFIG_EXAMPLES_MODULE_DEVPATH, MOUNTPT, "romfs",
              MS_RDONLY, NULL);
  if (ret < 0)
    {
      fprintf(stderr, "ERROR: mount(%s,%s,romfs) failed: %s\n",
              CONFIG_EXAMPLES_MODULE_DEVPATH, MOUNTPT, errno);
      exit(EXIT_FAILURE);
    }

#elif defined(CONFIG_EXAMPLES_MODULE_CROMFS)
  /* Mount the CROMFS file system */

  printf("Mounting CROMFS filesystem at target=%s\n", MOUNTPT);

  ret = mount(NULL, MOUNTPT, "cromfs", MS_RDONLY, NULL);
  if (ret < 0)
    {
      errmsg("ERROR: mount(%s, cromfs) failed: %d\n", MOUNTPT, errno);
    }

#endif /* CONFIG_EXAMPLES_MODULE_ROMFS */
#else /*  CONFIG_EXAMPLES_MODULE_BUILTINFS */
  /* An external file system is being used */

#if defined(CONFIG_EXAMPLES_MODULE_FSMOUNT)
#if defined(CONFIG_EXAMPLES_MODULE_FSREMOVEABLE)
  /* The file system is removable, wait until the block driver is available */

  do
    {
      ret = stat(CONFIG_EXAMPLES_MODULE_DEVPATH, &buf);
      if (ret < 0)
        {
          int errcode = errno;
          if (errcode == ENOENT)
            {
              printf("%s does not exist.  Waiting...\n",
                     CONFIG_EXAMPLES_MODULE_DEVPATH);
              sleep(1);
            }
          else
            {
              printf("ERROR: stat(%s) failed: %d  Aborting...\n",
                     CONFIG_EXAMPLES_MODULE_DEVPATH, errcode);
              exit(EXIT_FAILURE);
            }
        }
      else if (!S_ISBLK(buf.st_mode))
        {
          printf("ERROR: stat(%s) exists but is not a block driver: %04x\n",
                 CONFIG_EXAMPLES_MODULE_DEVPATH, buf.st_mode);
          exit(EXIT_FAILURE);
        }
    }
  while (ret < 0);
#endif  /* CONFIG_EXAMPLES_MODULE_FSREMOVEABLE */

  /* Mount the external file system */

  printf("Mounting %s filesystem at target=%s\n",
         CONFIG_EXAMPLES_MODULE_FSTYPE, MOUNTPT);

  ret = mount(CONFIG_EXAMPLES_MODULE_DEVPATH, MOUNTPT,
              CONFIG_EXAMPLES_MODULE_FSTYPE, MS_RDONLY, NULL);
  if (ret < 0)
    {
      printf("ERROR: mount(%s, %s, %s) failed: %d\n",\
             CONFIG_EXAMPLES_MODULE_DEVPATH, CONFIG_EXAMPLES_MODULE_FSTYPE,
             MOUNTPT, errno);
    }

#endif /* CONFIG_EXAMPLES_MODULE_FSMOUNT */
#endif /* CONFIG_EXAMPLES_MODULE_BUILTINFS */

  /* Install the character driver  */

  handle = insmod(BINDIR "/chardev", "chardev");
  if (handle == NULL)
    {
      int errcode = errno;
      fprintf(stderr, "ERROR: insmod(%s/chardev, chardev) failed: %d\n",
              BINDIR, errcode);
      exit(EXIT_FAILURE);
    }

  /* Open the installed character driver */

  fd = open("/dev/chardev", O_RDWR);
  if (fd < 0)
    {
      int errcode = errno;
      fprintf(stderr, "ERROR: Failed to open /dev/chardev: %d\n", errcode);
      exit(EXIT_FAILURE);
    }

  /* Read from the character driver */

  nbytes = read(fd, buffer, 128);
  if (nbytes < 0)
    {
      int errcode = errno;
      fprintf(stderr, "ERROR: Read from /dev/chardev failed: %d\n", errcode);
      close(fd);
      exit(EXIT_FAILURE);
    }

  printf("main: Read %d bytes: %d\n", (int)nbytes);
  lib_dumpbuffer("main: Bytes read", (FAR const uint8_t *)buffer, nbytes);

  /* Write to the character driver */

  nbytes = write(fd, g_write_string, strlen(g_write_string));
  if (nbytes < 0)
    {
      int errcode = errno;
      fprintf(stderr, "ERROR: Write to /dev/chardev failed: %d\n", errcode);
      close(fd);
      exit(EXIT_FAILURE);
    }

  printf("main: Wrote %d bytes: %d\n", (int)nbytes);
  lib_dumpbuffer("main: Bytes written", (FAR const uint8_t *)g_write_string, nbytes);

  close(fd);
  ret = rmmod(handle);
  if (ret < 0)
    {
      fprintf(stderr, "ERROR: rmmod failed: %d\n", ret);
      exit(EXIT_FAILURE);
    }

  return EXIT_SUCCESS;
}
