/*

   * (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+

   */
  
  /* #define DEBUG */
  
  #include <common.h>

  #include <command.h>
  #include <environment.h>

  #include <linux/stddef.h>

  #include <malloc.h>

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

  DECLARE_GLOBAL_DATA_PTR;

  #if defined(CONFIG_CMD_SAVEENV) && defined(CONFIG_CMD_FLASH)

  #define CMD_SAVEENV

  #elif defined(CONFIG_ENV_ADDR_REDUND)

  #error CONFIG_ENV_ADDR_REDUND must have CONFIG_CMD_SAVEENV & CONFIG_CMD_FLASH

  #endif

  #if defined(CONFIG_ENV_SIZE_REDUND) &&	\
  	(CONFIG_ENV_SIZE_REDUND < CONFIG_ENV_SIZE)

  #error CONFIG_ENV_SIZE_REDUND should not be less then CONFIG_ENV_SIZE

  #endif

  char *env_name_spec = "Flash";

  
  #ifdef ENV_IS_EMBEDDED

  env_t *env_ptr = &environment;

  static env_t *flash_addr = (env_t *)CONFIG_ENV_ADDR;

  
  #else /* ! ENV_IS_EMBEDDED */

  env_t *env_ptr = (env_t *)CONFIG_ENV_ADDR;

  static env_t *flash_addr = (env_t *)CONFIG_ENV_ADDR;

  #endif /* ENV_IS_EMBEDDED */

  #if defined(CMD_SAVEENV) || defined(CONFIG_ENV_ADDR_REDUND)
  /* CONFIG_ENV_ADDR is supposed to be on sector boundary */
  static ulong end_addr = CONFIG_ENV_ADDR + CONFIG_ENV_SECT_SIZE - 1;
  #endif

  #ifdef CONFIG_ENV_ADDR_REDUND
  static env_t *flash_addr_new = (env_t *)CONFIG_ENV_ADDR_REDUND;

  /* CONFIG_ENV_ADDR_REDUND is supposed to be on sector boundary */

  static ulong end_addr_new = CONFIG_ENV_ADDR_REDUND + CONFIG_ENV_SECT_SIZE - 1;

  #endif /* CONFIG_ENV_ADDR_REDUND */

  #ifdef CONFIG_ENV_ADDR_REDUND

  int env_init(void)

  {

  	int crc1_ok = 0, crc2_ok = 0;

  
  	uchar flag1 = flash_addr->flags;
  	uchar flag2 = flash_addr_new->flags;
  
  	ulong addr_default = (ulong)&default_environment[0];
  	ulong addr1 = (ulong)&(flash_addr->data);
  	ulong addr2 = (ulong)&(flash_addr_new->data);

  	crc1_ok = crc32(0, flash_addr->data, ENV_SIZE) == flash_addr->crc;
  	crc2_ok =
  		crc32(0, flash_addr_new->data, ENV_SIZE) == flash_addr_new->crc;
  
  	if (crc1_ok && !crc2_ok) {
  		gd->env_addr	= addr1;
  		gd->env_valid	= 1;
  	} else if (!crc1_ok && crc2_ok) {
  		gd->env_addr	= addr2;
  		gd->env_valid	= 1;
  	} else if (!crc1_ok && !crc2_ok) {
  		gd->env_addr	= addr_default;
  		gd->env_valid	= 0;

  	} else if (flag1 == ACTIVE_FLAG && flag2 == OBSOLETE_FLAG) {

  		gd->env_addr	= addr1;
  		gd->env_valid	= 1;

  	} else if (flag1 == OBSOLETE_FLAG && flag2 == ACTIVE_FLAG) {

  		gd->env_addr	= addr2;
  		gd->env_valid	= 1;

  	} else if (flag1 == flag2) {

  		gd->env_addr	= addr1;
  		gd->env_valid	= 2;

  	} else if (flag1 == 0xFF) {

  		gd->env_addr	= addr1;
  		gd->env_valid	= 2;

  	} else if (flag2 == 0xFF) {

  		gd->env_addr	= addr2;
  		gd->env_valid	= 2;

  	}

  	return 0;

  }
  
  #ifdef CMD_SAVEENV
  int saveenv(void)
  {

  	env_t	env_new;
  	ssize_t	len;

  	char	*res, *saved_data = NULL;

  	char	flag = OBSOLETE_FLAG, new_flag = ACTIVE_FLAG;

  	int	rc = 1;

  #if CONFIG_ENV_SECT_SIZE > CONFIG_ENV_SIZE

  	ulong	up_data = 0;

  #endif

  	debug("Protect off %08lX ... %08lX
  ", (ulong)flash_addr, end_addr);

  	if (flash_sect_protect(0, (ulong)flash_addr, end_addr))

  		goto done;

  	debug("Protect off %08lX ... %08lX
  ",

  		(ulong)flash_addr_new, end_addr_new);

  	if (flash_sect_protect(0, (ulong)flash_addr_new, end_addr_new))

  		goto done;

  
  	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);
  		goto done;

  	}

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

  #if CONFIG_ENV_SECT_SIZE > CONFIG_ENV_SIZE

  	up_data = end_addr_new + 1 - ((long)flash_addr_new + CONFIG_ENV_SIZE);

  	debug("Data to save 0x%lX
  ", up_data);

  	if (up_data) {

  		saved_data = malloc(up_data);
  		if (saved_data == NULL) {

  			printf("Unable to save the rest of sector (%ld)
  ",

  				up_data);

  			goto done;

  		}

  		memcpy(saved_data,

  			(void *)((long)flash_addr_new + CONFIG_ENV_SIZE),
  			up_data);

  		debug("Data (start 0x%lX, len 0x%lX) saved at 0x%p
  ",
  			(long)flash_addr_new + CONFIG_ENV_SIZE,
  			up_data, saved_data);

  	}
  #endif

  	puts("Erasing Flash...");

  	debug(" %08lX ... %08lX ...", (ulong)flash_addr_new, end_addr_new);

  	if (flash_sect_erase((ulong)flash_addr_new, end_addr_new))

  		goto done;

  	puts("Writing to Flash... ");
  	debug(" %08lX ... %08lX ...",

  		(ulong)&(flash_addr_new->data),

  		sizeof(env_ptr->data) + (ulong)&(flash_addr_new->data));
  	rc = flash_write((char *)&env_new, (ulong)flash_addr_new,
  			 sizeof(env_new));
  	if (rc)
  		goto perror;
  
  	rc = flash_write(&flag, (ulong)&(flash_addr->flags),
  			 sizeof(flash_addr->flags));
  	if (rc)
  		goto perror;

  #if CONFIG_ENV_SECT_SIZE > CONFIG_ENV_SIZE

  	if (up_data) { /* restore the rest of sector */

  		debug("Restoring the rest of data to 0x%lX len 0x%lX
  ",
  			(long)flash_addr_new + CONFIG_ENV_SIZE, up_data);

  		if (flash_write(saved_data,

  				(long)flash_addr_new + CONFIG_ENV_SIZE,

  				up_data))
  			goto perror;

  	}
  #endif

  	puts("done
  ");

  	{

  		env_t *etmp = flash_addr;

  		ulong ltmp = end_addr;
  
  		flash_addr = flash_addr_new;
  		flash_addr_new = etmp;
  
  		end_addr = end_addr_new;
  		end_addr_new = ltmp;
  	}
  
  	rc = 0;

  	goto done;
  perror:
  	flash_perror(rc);

  done:

  	if (saved_data)

  		free(saved_data);

  	/* try to re-protect */

  	flash_sect_protect(1, (ulong)flash_addr, end_addr);
  	flash_sect_protect(1, (ulong)flash_addr_new, end_addr_new);

  
  	return rc;
  }
  #endif /* CMD_SAVEENV */

  #else /* ! CONFIG_ENV_ADDR_REDUND */

  int env_init(void)

  {

  	if (crc32(0, env_ptr->data, ENV_SIZE) == env_ptr->crc) {

  		gd->env_addr	= (ulong)&(env_ptr->data);
  		gd->env_valid	= 1;
  		return 0;

  	}

  	gd->env_addr	= (ulong)&default_environment[0];
  	gd->env_valid	= 0;

  	return 0;

  }
  
  #ifdef CMD_SAVEENV

  int saveenv(void)
  {

  	env_t	env_new;
  	ssize_t	len;
  	int	rc = 1;

  	char	*res, *saved_data = NULL;

  #if CONFIG_ENV_SECT_SIZE > CONFIG_ENV_SIZE
  	ulong	up_data = 0;

  	up_data = end_addr + 1 - ((long)flash_addr + CONFIG_ENV_SIZE);

  	debug("Data to save 0x%lx
  ", up_data);
  	if (up_data) {

  		saved_data = malloc(up_data);
  		if (saved_data == NULL) {

  			printf("Unable to save the rest of sector (%ld)
  ",
  				up_data);
  			goto done;
  		}
  		memcpy(saved_data,
  			(void *)((long)flash_addr + CONFIG_ENV_SIZE), up_data);
  		debug("Data (start 0x%lx, len 0x%lx) saved at 0x%lx
  ",
  			(ulong)flash_addr + CONFIG_ENV_SIZE,
  			up_data,
  			(ulong)saved_data);
  	}

  #endif	/* CONFIG_ENV_SECT_SIZE */

  	debug("Protect off %08lX ... %08lX
  ", (ulong)flash_addr, end_addr);

  	if (flash_sect_protect(0, (long)flash_addr, end_addr))
  		goto done;

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

  	puts("Erasing Flash...");
  	if (flash_sect_erase((long)flash_addr, end_addr))
  		goto done;

  	puts("Writing to Flash... ");
  	rc = flash_write((char *)&env_new, (long)flash_addr, CONFIG_ENV_SIZE);

  	if (rc != 0)
  		goto perror;

  #if CONFIG_ENV_SECT_SIZE > CONFIG_ENV_SIZE
  	if (up_data) {	/* restore the rest of sector */
  		debug("Restoring the rest of data to 0x%lx len 0x%lx
  ",
  			(ulong)flash_addr + CONFIG_ENV_SIZE, up_data);
  		if (flash_write(saved_data,
  				(long)flash_addr + CONFIG_ENV_SIZE,

  				up_data))
  			goto perror;

  	}
  #endif
  	puts("done
  ");
  	rc = 0;

  	goto done;
  perror:
  	flash_perror(rc);

  done:
  	if (saved_data)
  		free(saved_data);

  	/* try to re-protect */

  	flash_sect_protect(1, (long)flash_addr, end_addr);

  	return rc;

  }

  #endif /* CMD_SAVEENV */

  #endif /* CONFIG_ENV_ADDR_REDUND */

  void env_relocate_spec(void)

  {

  #ifdef CONFIG_ENV_ADDR_REDUND

  	if (gd->env_addr != (ulong)&(flash_addr->data)) {

  		env_t *etmp = flash_addr;

  		ulong ltmp = end_addr;
  
  		flash_addr = flash_addr_new;
  		flash_addr_new = etmp;
  
  		end_addr = end_addr_new;
  		end_addr_new = ltmp;
  	}

  	if (flash_addr_new->flags != OBSOLETE_FLAG &&

  	    crc32(0, flash_addr_new->data, ENV_SIZE) == flash_addr_new->crc) {

  		char flag = OBSOLETE_FLAG;

  		gd->env_valid = 2;

  		flash_sect_protect(0, (ulong)flash_addr_new, end_addr_new);

  		flash_write(&flag,

  			    (ulong)&(flash_addr_new->flags),
  			    sizeof(flash_addr_new->flags));

  		flash_sect_protect(1, (ulong)flash_addr_new, end_addr_new);

  	}

  	if (flash_addr->flags != ACTIVE_FLAG &&
  	    (flash_addr->flags & ACTIVE_FLAG) == ACTIVE_FLAG) {
  		char flag = ACTIVE_FLAG;

  		gd->env_valid = 2;

  		flash_sect_protect(0, (ulong)flash_addr, end_addr);

  		flash_write(&flag,

  			    (ulong)&(flash_addr->flags),
  			    sizeof(flash_addr->flags));

  		flash_sect_protect(1, (ulong)flash_addr, end_addr);

  	}
  
  	if (gd->env_valid == 2)

  		puts("*** Warning - some problems detected "
  		     "reading environment; recovered successfully
  
  ");

  #endif /* CONFIG_ENV_ADDR_REDUND */

  
  	env_import((char *)flash_addr, 1);

  }