/*
   * kernel/configs.c
   * Echo the kernel .config file used to build the kernel
   *
   * Copyright (C) 2002 Khalid Aziz <khalid_aziz@hp.com>

   * Copyright (C) 2002 Randy Dunlap <rdunlap@xenotime.net>

   * Copyright (C) 2002 Al Stone <ahs3@fc.hp.com>
   * Copyright (C) 2002 Hewlett-Packard Company
   *
   * This program is free software; you can redistribute it and/or modify
   * it under the terms of the GNU General Public License as published by
   * the Free Software Foundation; either version 2 of the License, or (at
   * your option) any later version.
   *
   * This program is distributed in the hope that it will be useful, but
   * WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
   * NON INFRINGEMENT.  See the GNU General Public License for more
   * details.
   *
   * You should have received a copy of the GNU General Public License
   * along with this program; if not, write to the Free Software
   * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
   */

  #include <linux/kernel.h>
  #include <linux/module.h>
  #include <linux/proc_fs.h>
  #include <linux/seq_file.h>
  #include <linux/init.h>
  #include <asm/uaccess.h>
  
  /**************************************************/
  /* the actual current config file                 */
  
  /*
   * Define kernel_config_data and kernel_config_data_size, which contains the
   * wrapped and compressed configuration file.  The file is first compressed
   * with gzip and then bounded by two eight byte magic numbers to allow
   * extraction from a binary kernel image:
   *
   *   IKCFG_ST
   *   <image>
   *   IKCFG_ED
   */
  #define MAGIC_START	"IKCFG_ST"
  #define MAGIC_END	"IKCFG_ED"
  #include "config_data.h"
  
  
  #define MAGIC_SIZE (sizeof(MAGIC_START) - 1)
  #define kernel_config_data_size \
  	(sizeof(kernel_config_data) - 1 - MAGIC_SIZE * 2)
  
  #ifdef CONFIG_IKCONFIG_PROC

  static ssize_t
  ikconfig_read_current(struct file *file, char __user *buf,
  		      size_t len, loff_t * offset)
  {

  	return simple_read_from_buffer(buf, len, offset,
  				       kernel_config_data + MAGIC_SIZE,
  				       kernel_config_data_size);

  }

  static const struct file_operations ikconfig_file_ops = {

  	.owner = THIS_MODULE,
  	.read = ikconfig_read_current,

  	.llseek = default_llseek,

  };

  static int __init ikconfig_init(void)
  {
  	struct proc_dir_entry *entry;
  
  	/* create the current config file */

  	entry = proc_create("config.gz", S_IFREG | S_IRUGO, NULL,
  			    &ikconfig_file_ops);

  	if (!entry)
  		return -ENOMEM;

  	proc_set_size(entry, kernel_config_data_size);

  
  	return 0;
  }

  static void __exit ikconfig_cleanup(void)
  {

  	remove_proc_entry("config.gz", NULL);

  }
  
  module_init(ikconfig_init);
  module_exit(ikconfig_cleanup);

  #endif /* CONFIG_IKCONFIG_PROC */

  MODULE_LICENSE("GPL");
  MODULE_AUTHOR("Randy Dunlap");
  MODULE_DESCRIPTION("Echo the kernel .config file used to build the kernel");