/*
   * (C) Copyright 2000-2010
   * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
   *
   * (C) Copyright 2001 Sysgo Real-Time Solutions, GmbH <www.elinos.com>
   * Andreas Heppel <aheppel@sysgo.de>
  
   * SPDX-License-Identifier:	GPL-2.0+
   */
  
  /*
   * 09-18-2001 Andreas Heppel, Sysgo RTS GmbH <aheppel@sysgo.de>
   *
   * It might not be possible in all cases to use 'memcpy()' to copy
   * the environment to NVRAM, as the NVRAM might not be mapped into
   * the memory space. (I.e. this is the case for the BAB750). In those
   * cases it might be possible to access the NVRAM using a different
   * method. For example, the RTC on the BAB750 is accessible in IO
   * space using its address and data registers. To enable usage of
   * NVRAM in those cases I invented the functions 'nvram_read()' and
   * 'nvram_write()', which will be activated upon the configuration
   * #define CONFIG_SYS_NVRAM_ACCESS_ROUTINE. Note, that those functions are
   * strongly dependent on the used HW, and must be redefined for each
   * board that wants to use them.
   */
  
  #include <common.h>
  #include <command.h>
  #include <environment.h>
  #include <linux/stddef.h>
  #include <search.h>
  #include <errno.h>
  
  DECLARE_GLOBAL_DATA_PTR;
  
  #ifdef CONFIG_SYS_NVRAM_ACCESS_ROUTINE
  extern void *nvram_read(void *dest, const long src, size_t count);
  extern void nvram_write(long dest, const void *src, size_t count);
  env_t *env_ptr;
  #else
  env_t *env_ptr = (env_t *)CONFIG_ENV_ADDR;
  #endif
  
  char *env_name_spec = "NVRAM";
  
  #ifdef CONFIG_SYS_NVRAM_ACCESS_ROUTINE
  uchar env_get_char_spec(int index)
  {
  	uchar c;
  
  	nvram_read(&c, CONFIG_ENV_ADDR + index, 1);
  
  	return c;
  }
  #endif
  
  void env_relocate_spec(void)
  {
  	char buf[CONFIG_ENV_SIZE];
  
  #if defined(CONFIG_SYS_NVRAM_ACCESS_ROUTINE)
  	nvram_read(buf, CONFIG_ENV_ADDR, CONFIG_ENV_SIZE);
  #else
  	memcpy(buf, (void *)CONFIG_ENV_ADDR, CONFIG_ENV_SIZE);
  #endif
  	env_import(buf, 1);
  }
  
  int saveenv(void)
  {
  	env_t	env_new;
  	int	rcode = 0;
  
  	rcode = env_export(&env_new);
  	if (rcode)
  		return rcode;
  
  #ifdef CONFIG_SYS_NVRAM_ACCESS_ROUTINE
  	nvram_write(CONFIG_ENV_ADDR, &env_new, CONFIG_ENV_SIZE);
  #else
  	if (memcpy((char *)CONFIG_ENV_ADDR, &env_new, CONFIG_ENV_SIZE) == NULL)
  		rcode = 1;
  #endif
  	return rcode;
  }
  
  /*
   * Initialize Environment use
   *
   * We are still running from ROM, so data use is limited
   */
  int env_init(void)
  {
  #if defined(CONFIG_SYS_NVRAM_ACCESS_ROUTINE)
  	ulong crc;
  	uchar data[ENV_SIZE];
  
  	nvram_read(&crc, CONFIG_ENV_ADDR, sizeof(ulong));
  	nvram_read(data, CONFIG_ENV_ADDR + sizeof(ulong), ENV_SIZE);
  
  	if (crc32(0, data, ENV_SIZE) == crc) {
  		gd->env_addr	= (ulong)CONFIG_ENV_ADDR + sizeof(long);
  #else
  	if (crc32(0, env_ptr->data, ENV_SIZE) == env_ptr->crc) {
  		gd->env_addr	= (ulong)&env_ptr->data;
  #endif
  		gd->env_valid	= 1;
  	} else {
  		gd->env_addr	= (ulong)&default_environment[0];
  		gd->env_valid	= 0;
  	}
  
  	return 0;
  }