include/environment.h

/*
 * (C) Copyright 2002
 * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
 *
 * See file CREDITS for list of people who contributed to this
 * project.
 *
 * 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.  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., 59 Temple Place, Suite 330, Boston,
 * MA 02111-1307 USA
 */

#ifndef _ENVIRONMENT_H_
#define _ENVIRONMENT_H_

/**************************************************************************
 *
 * The "environment" is stored as a list of '\0' terminated
 * "name=value" strings. The end of the list is marked by a double
 * '\0'. New entries are always added at the end. Deleting an entry
 * shifts the remaining entries to the front. Replacing an entry is a
 * combination of deleting the old value and adding the new one.
 *
 * The environment is preceeded by a 32 bit CRC over the data part.
 *
 **************************************************************************
 */

#if defined(CONFIG_ENV_IS_IN_FLASH)
# ifndef	CONFIG_ENV_ADDR
#  define	CONFIG_ENV_ADDR	(CONFIG_SYS_FLASH_BASE + CONFIG_ENV_OFFSET)
# endif
# ifndef	CONFIG_ENV_OFFSET
#  define	CONFIG_ENV_OFFSET (CONFIG_ENV_ADDR - CONFIG_SYS_FLASH_BASE)
# endif
# if !defined(CONFIG_ENV_ADDR_REDUND) && defined(CONFIG_ENV_OFFSET_REDUND)
#  define	CONFIG_ENV_ADDR_REDUND	\
		(CONFIG_SYS_FLASH_BASE + CONFIG_ENV_OFFSET_REDUND)
# endif
# if defined(CONFIG_ENV_SECT_SIZE) || defined(CONFIG_ENV_SIZE)
#  ifndef	CONFIG_ENV_SECT_SIZE
#   define	CONFIG_ENV_SECT_SIZE	CONFIG_ENV_SIZE
#  endif
#  ifndef	CONFIG_ENV_SIZE
#   define	CONFIG_ENV_SIZE	CONFIG_ENV_SECT_SIZE
#  endif
# else
#  error "Both CONFIG_ENV_SECT_SIZE and CONFIG_ENV_SIZE undefined"
# endif
# if defined(CONFIG_ENV_ADDR_REDUND) && !defined(CONFIG_ENV_SIZE_REDUND)
#  define CONFIG_ENV_SIZE_REDUND	CONFIG_ENV_SIZE
# endif
# if	(CONFIG_ENV_ADDR >= CONFIG_SYS_MONITOR_BASE) &&		\
	(CONFIG_ENV_ADDR + CONFIG_ENV_SIZE) <=			\
	(CONFIG_SYS_MONITOR_BASE + CONFIG_SYS_MONITOR_LEN)
#  define ENV_IS_EMBEDDED
# endif
# if defined(CONFIG_ENV_ADDR_REDUND) || defined(CONFIG_ENV_OFFSET_REDUND)
#  define CONFIG_SYS_REDUNDAND_ENVIRONMENT
# endif
# ifdef CONFIG_ENV_IS_EMBEDDED
#  error "do not define CONFIG_ENV_IS_EMBEDDED in your board config"
#  error "it is calculated automatically for you"
# endif
#endif	/* CONFIG_ENV_IS_IN_FLASH */

#if defined(CONFIG_ENV_IS_IN_NAND)
# if defined(CONFIG_ENV_OFFSET_OOB)
#  ifdef CONFIG_ENV_OFFSET_REDUND
#   error "CONFIG_ENV_OFFSET_REDUND is not supported when CONFIG_ENV_OFFSET_OOB"
#   error "is set"
#  endif
extern unsigned long nand_env_oob_offset;
#  define CONFIG_ENV_OFFSET nand_env_oob_offset
# else
#  ifndef CONFIG_ENV_OFFSET
#   error "Need to define CONFIG_ENV_OFFSET when using CONFIG_ENV_IS_IN_NAND"
#  endif
#  ifdef CONFIG_ENV_OFFSET_REDUND
#   define CONFIG_SYS_REDUNDAND_ENVIRONMENT
#  endif
# endif /* CONFIG_ENV_OFFSET_OOB */
# ifndef CONFIG_ENV_SIZE
#  error "Need to define CONFIG_ENV_SIZE when using CONFIG_ENV_IS_IN_NAND"
# endif
#endif /* CONFIG_ENV_IS_IN_NAND */

/* Embedded env is only supported for some flash types */
#ifdef CONFIG_ENV_IS_EMBEDDED
# if	!defined(CONFIG_ENV_IS_IN_FLASH)	&& \
	!defined(CONFIG_ENV_IS_IN_NAND)		&& \
	!defined(CONFIG_ENV_IS_IN_ONENAND)	&& \
	!defined(CONFIG_ENV_IS_IN_SPI_FLASH)
#  error "CONFIG_ENV_IS_EMBEDDED not supported for your flash type"
# endif
#endif

/*
 * For the flash types where embedded env is supported, but it cannot be
 * calculated automatically (i.e. NAND), take the board opt-in.
 */
#if defined(CONFIG_ENV_IS_EMBEDDED) && !defined(ENV_IS_EMBEDDED)
# define ENV_IS_EMBEDDED
#endif

/* The build system likes to know if the env is embedded */
#ifdef DO_DEPS_ONLY
# ifdef ENV_IS_EMBEDDED
#  ifndef CONFIG_ENV_IS_EMBEDDED
#   define CONFIG_ENV_IS_EMBEDDED
#  endif
# endif
#endif

#include "compiler.h"

#ifdef CONFIG_SYS_REDUNDAND_ENVIRONMENT
# define ENV_HEADER_SIZE	(sizeof(uint32_t) + 1)

# define ACTIVE_FLAG   1
# define OBSOLETE_FLAG 0
#else
# define ENV_HEADER_SIZE	(sizeof(uint32_t))
#endif

#if defined(CONFIG_CMD_SAVEENV) && !defined(CONFIG_ENV_IS_NOWHERE)
extern char *env_name_spec;
#endif

#define ENV_SIZE (CONFIG_ENV_SIZE - ENV_HEADER_SIZE)

typedef struct environment_s {
	uint32_t	crc;		/* CRC32 over data bytes	*/
#ifdef CONFIG_SYS_REDUNDAND_ENVIRONMENT
	unsigned char	flags;		/* active/obsolete flags	*/
#endif
	unsigned char	data[ENV_SIZE]; /* Environment data		*/
} env_t;

#ifdef ENV_IS_EMBEDDED
extern env_t environment;
#endif /* ENV_IS_EMBEDDED */

extern const unsigned char default_environment[];
extern env_t *env_ptr;

extern void env_relocate_spec(void);
extern unsigned char env_get_char_spec(int);

#if defined(CONFIG_NEEDS_MANUAL_RELOC)
extern void env_reloc(void);
#endif

#ifndef DO_DEPS_ONLY

#include <search.h>

extern struct hsearch_data env_htab;

/* Function that returns a character from the environment */
unsigned char env_get_char(int);

/* Function that returns a pointer to a value from the environment */
const unsigned char *env_get_addr(int);
unsigned char env_get_char_memory(int index);

/* Function that updates CRC of the enironment */
void env_crc_update(void);

/* [re]set to the default environment */
void set_default_env(const char *s);

/* [re]set individual variables to their value in the default environment */
int set_default_vars(int nvars, char * const vars[]);

/* Import from binary representation into hash table */
int env_import(const char *buf, int check);

/*
 * Check if variable "name" can be changed from oldval to newval,
 * and if so, apply the changes (e.g. baudrate).
 * When (flag & H_FORCE) is set, it does not print out any error
 * message and forces overwriting of write-once variables.
 */
int env_check_apply(const char *name, const char *oldval,
			const char *newval, int flag);

#endif /* DO_DEPS_ONLY */

#endif /* _ENVIRONMENT_H_ */