/*
   * LowLevel function for DataFlash environment support

   * Author : Gilles Gastaldi (Atmel)
   *

   * SPDX-License-Identifier:	GPL-2.0+

   */
  #include <common.h>

  #include <command.h>
  #include <environment.h>
  #include <linux/stddef.h>

  #include <dataflash.h>

  #include <search.h>
  #include <errno.h>

  DECLARE_GLOBAL_DATA_PTR;

  env_t *env_ptr;

  char *env_name_spec = "dataflash";

  uchar env_get_char_spec(int index)

  {
  	uchar c;

  	read_dataflash(CONFIG_ENV_ADDR + index + offsetof(env_t, data),

  			1, (char *)&c);

  	return c;

  }

  void env_relocate_spec(void)

  {

  	ulong crc, new = 0;
  	unsigned off;

  	char buf[CONFIG_ENV_SIZE];

  	/* Read old CRC */
  	read_dataflash(CONFIG_ENV_ADDR + offsetof(env_t, crc),
  		       sizeof(ulong), (char *)&crc);
  
  	/* Read whole environment */

  	read_dataflash(CONFIG_ENV_ADDR, CONFIG_ENV_SIZE, buf);

  	/* Calculate the CRC */
  	off = offsetof(env_t, data);
  	new = crc32(new, (unsigned char *)(buf + off), ENV_SIZE);
  
  	if (crc == new)
  		env_import(buf, 1);
  	else
  		set_default_env("!bad CRC");

  }

  #ifdef CONFIG_ENV_OFFSET_REDUND
  #error No support for redundant environment on dataflash yet!
  #endif

  int saveenv(void)
  {

  	env_t	env_new;

  	ssize_t	len;
  	char	*res;

  	res = (char *)&env_new.data;

  	len = hexport_r(&env_htab, '\0', 0, &res, ENV_SIZE, 0, NULL);

  	if (len < 0) {
  		error("Cannot export environment: errno = %d
  ", errno);
  		return 1;
  	}

  	env_new.crc = crc32(0, env_new.data, ENV_SIZE);

  
  	return write_dataflash(CONFIG_ENV_ADDR,

  				(unsigned long)&env_new,

  				CONFIG_ENV_SIZE);

  }

  /*
   * Initialize environment use

   *

   * We are still running from ROM, so data use is limited.

   * Use a (moderately small) buffer on the stack
   */
  int env_init(void)
  {

  	/* use default */
  	gd->env_addr = (ulong)&default_environment[0];
  	gd->env_valid = 1;

  	return 0;

  }