/*
 * (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\n", (ulong)flash_addr, end_addr);

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

	debug("Protect off %08lX ... %08lX\n",
		(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\n", 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\n", up_data);
	if (up_data) {
		saved_data = malloc(up_data);
		if (saved_data == NULL) {
			printf("Unable to save the rest of sector (%ld)\n",
				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\n",
			(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\n",
			(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\n");

	{
		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\n", up_data);
	if (up_data) {
		saved_data = malloc(up_data);
		if (saved_data == NULL) {
			printf("Unable to save the rest of sector (%ld)\n",
				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\n",
			(ulong)flash_addr + CONFIG_ENV_SIZE,
			up_data,
			(ulong)saved_data);
	}
#endif	/* CONFIG_ENV_SECT_SIZE */

	debug("Protect off %08lX ... %08lX\n", (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\n", 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\n",
			(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\n");
	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\n\n");
#endif /* CONFIG_ENV_ADDR_REDUND */

	env_import((char *)flash_addr, 1);
}