/* SPDX-License-Identifier: GPL-2.0+ */
  /*

   * Common environment functions and definitions

   *
   * (C) Copyright 2000-2009
   * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
   */
  
  #ifndef __ENV_H
  #define __ENV_H

  #include <compiler.h>

  #include <stdbool.h>

  #include <linux/types.h>

  struct environment_s;

  /* Value for environment validity */
  enum env_valid {
  	ENV_INVALID,	/* No valid environment */
  	ENV_VALID,	/* First or only environment is valid */
  	ENV_REDUND,	/* Redundant environment is valid */
  };

  /** enum env_op - environment callback operation */
  enum env_op {
  	env_op_create,
  	env_op_delete,
  	env_op_overwrite,
  };
  
  /** struct env_clbk_tbl - declares a new callback */
  struct env_clbk_tbl {
  	const char *name;		/* Callback name */
  	int (*callback)(const char *name, const char *value, enum env_op op,
  			int flags);
  };
  
  /*
   * Define a callback that can be associated with variables.
   * when associated through the ".callbacks" environment variable, the callback
   * will be executed any time the variable is inserted, overwritten, or deleted.
   *
   * For SPL these are silently dropped to reduce code size, since environment
   * callbacks are not supported with SPL.
   */
  #ifdef CONFIG_SPL_BUILD
  #define U_BOOT_ENV_CALLBACK(name, callback) \
  	static inline __maybe_unused void _u_boot_env_noop_##name(void) \
  	{ \
  		(void)callback; \
  	}
  #else
  #define U_BOOT_ENV_CALLBACK(name, callback) \
  	ll_entry_declare(struct env_clbk_tbl, name, env_clbk) = \
  	{#name, callback}
  #endif

  /** enum env_redund_flags - Flags for the redundand_environment */
  enum env_redund_flags {
  	ENV_REDUND_OBSOLETE = 0,
  	ENV_REDUND_ACTIVE = 1,
  };

  /**

   * env_get_id() - Gets a sequence number for the environment
   *
   * This value increments every time the environment changes, so can be used an
   * an indication of this
   *
   * @return environment ID
   */
  int env_get_id(void);
  
  /**

   * env_init() - Set up the pre-relocation environment
   *
   * This locates the environment or uses the default if nothing is available.
   * This must be called before env_get() will work.
   *
   * @return 0 if OK, -ENODEV if no environment drivers are enabled
   */
  int env_init(void);
  
  /**

   * env_relocate() - Set up the post-relocation environment
   *
   * This loads the environment into RAM so that it can be modified. This is
   * called after relocation, before the environment is used
   */
  void env_relocate(void);
  
  /**

   * env_match() - Match a name / name=value pair
   *
   * This is used prior to relocation for finding envrionment variables
   *
   * @name: A simple 'name', or a 'name=value' pair.
   * @index: The environment index for a 'name2=value2' pair.
   * @return index for the value if the names match, else -1.
   */
  int env_match(unsigned char *name, int index);
  
  /**

   * env_get() - Look up the value of an environment variable
   *
   * In U-Boot proper this can be called before relocation (which is when the
   * environment is loaded from storage, i.e. GD_FLG_ENV_READY is 0). In that
   * case this function calls env_get_f().
   *
   * @varname:	Variable to look up
   * @return value of variable, or NULL if not found
   */
  char *env_get(const char *varname);

  /*
   * Like env_get, but prints an error if envvar isn't defined in the
   * environment.  It always returns what env_get does, so it can be used in
   * place of env_get without changing error handling otherwise.
   *
   * @varname:	Variable to look up
   * @return value of variable, or NULL if not found
   */
  char *from_env(const char *envvar);

  /**

   * env_get_f() - Look up the value of an environment variable (early)
   *
   * This function is called from env_get() if the environment has not been
   * loaded yet (GD_FLG_ENV_READY flag is 0). Some environment locations will
   * support reading the value (slowly) and some will not.
   *
   * @varname:	Variable to look up
   * @return value of variable, or NULL if not found
   */
  int env_get_f(const char *name, char *buf, unsigned int len);
  
  /**

   * env_get_yesno() - Read an environment variable as a boolean
   *
   * @return 1 if yes/true (Y/y/T/t), -1 if variable does not exist (i.e. default
   *	to true), 0 if otherwise
   */
  int env_get_yesno(const char *var);
  
  /**

   * env_set() - set an environment variable
   *
   * This sets or deletes the value of an environment variable. For setting the
   * value the variable is created if it does not already exist.
   *
   * @varname: Variable to adjust
   * @value: Value to set for the variable, or NULL or "" to delete the variable
   * @return 0 if OK, 1 on error
   */
  int env_set(const char *varname, const char *value);
  
  /**

   * env_get_ulong() - Return an environment variable as an integer value
   *
   * Most U-Boot environment variables store hex values. For those which store
   * (e.g.) base-10 integers, this function can be used to read the value.
   *
   * @name:	Variable to look up
   * @base:	Base to use (e.g. 10 for base 10, 2 for binary)
   * @default_val: Default value to return if no value is found
   * @return the value found, or @default_val if none
   */
  ulong env_get_ulong(const char *name, int base, ulong default_val);
  
  /**

   * env_set_ulong() - set an environment variable to an integer
   *
   * @varname: Variable to adjust
   * @value: Value to set for the variable (will be converted to a string)
   * @return 0 if OK, 1 on error
   */
  int env_set_ulong(const char *varname, ulong value);
  
  /**

   * env_get_hex() - Return an environment variable as a hex value
   *
   * Decode an environment as a hex number (it may or may not have a 0x
   * prefix). If the environment variable cannot be found, or does not start
   * with hex digits, the default value is returned.
   *
   * @varname:		Variable to decode
   * @default_val:	Value to return on error
   */
  ulong env_get_hex(const char *varname, ulong default_val);
  
  /**

   * env_set_hex() - set an environment variable to a hex value
   *
   * @varname: Variable to adjust
   * @value: Value to set for the variable (will be converted to a hex string)
   * @return 0 if OK, 1 on error
   */
  int env_set_hex(const char *varname, ulong value);
  
  /**
   * env_set_addr - Set an environment variable to an address in hex
   *
   * @varname:	Environment variable to set
   * @addr:	Value to set it to
   * @return 0 if ok, 1 on error
   */
  static inline int env_set_addr(const char *varname, const void *addr)
  {
  	return env_set_hex(varname, (ulong)addr);
  }
  
  /**

   * env_complete() - return an auto-complete for environment variables
   *
   * @var: partial name to auto-complete
   * @maxv: Maximum number of matches to return
   * @cmdv: Returns a list of possible matches
   * @maxsz: Size of buffer to use for matches
   * @buf: Buffer to use for matches
   * @dollar_comp: non-zero to wrap each match in ${...}
   * @return number of matches found (in @cmdv)
   */
  int env_complete(char *var, int maxv, char *cmdv[], int maxsz, char *buf,
  		 bool dollar_comp);

  /**
   * eth_env_get_enetaddr() - Get an ethernet address from the environmnet
   *
   * @name: Environment variable to get (e.g. "ethaddr")
   * @enetaddr: Place to put MAC address (6 bytes)
   * @return 0 if OK, 1 on error
   */
  int eth_env_get_enetaddr(const char *name, uint8_t *enetaddr);
  
  /**
   * eth_env_set_enetaddr() - Set an ethernet address in the environmnet
   *
   * @name: Environment variable to set (e.g. "ethaddr")
   * @enetaddr: Pointer to MAC address to put into the variable (6 bytes)
   * @return 0 if OK, 1 on error
   */
  int eth_env_set_enetaddr(const char *name, const uint8_t *enetaddr);

  /**
   * env_fix_drivers() - Updates envdriver as per relocation
   */
  void env_fix_drivers(void);

  /**
   * env_set_default_vars() - reset variables to their default value
   *
   * This resets individual variables to their value in the default environment
   *
   * @nvars: Number of variables to set/reset
   * @vars: List of variables to set/reset
   * @flags: Flags controlling matching (H_... - see search.h)
   */
  int env_set_default_vars(int nvars, char *const vars[], int flags);

  /**
   * env_load() - Load the environment from storage
   *
   * @return 0 if OK, -ve on error
   */
  int env_load(void);
  
  /**
   * env_save() - Save the environment to storage
   *
   * @return 0 if OK, -ve on error
   */
  int env_save(void);
  
  /**
   * env_erase() - Erase the environment on storage
   *
   * @return 0 if OK, -ve on error
   */
  int env_erase(void);

  /**
   * env_import() - Import from a binary representation into hash table
   *
   * This imports the environment from a buffer. The format for each variable is
   * var=value\0 with a double \0 at the end of the buffer.
   *
   * @buf: Buffer containing the environment (struct environemnt_s *)
   * @check: non-zero to check the CRC at the start of the environment, 0 to
   *	ignore it
   * @return 0 if imported successfully, -ENOMSG if the CRC was bad, -EIO if
   *	something else went wrong
   */
  int env_import(const char *buf, int check);
  
  /**
   * env_export() - Export the environment to a buffer
   *
   * Export from hash table into binary representation
   *
   * @env_out: Buffer to contain the environment (must be large enough!)
   * @return 0 if OK, 1 on error
   */
  int env_export(struct environment_s *env_out);
  
  /**
   * env_import_redund() - Select and import one of two redundant environments
   *
   * @buf1: First environment (struct environemnt_s *)
   * @buf1_read_fail: 0 if buf1 is valid, non-zero if invalid
   * @buf2: Second environment (struct environemnt_s *)
   * @buf2_read_fail: 0 if buf2 is valid, non-zero if invalid
   * @return 0 if OK, -EIO if no environment is valid, -ENOMSG if the CRC was bad
   */
  int env_import_redund(const char *buf1, int buf1_read_fail,
  		      const char *buf2, int buf2_read_fail);

  /**
   * env_get_default() - Look up a variable from the default environment
   *
   * @name: Variable to look up
   * @return value if found, NULL if not found in default environment
   */
  char *env_get_default(const char *name);
  
  /* [re]set to the default environment */
  void env_set_default(const char *s, int flags);

  /**
   * env_get_char() - Get a character from the early environment
   *
   * This reads from the pre-relocation environment
   *
   * @index: Index of character to read (0 = first)
   * @return character read, or -ve on error
   */
  int env_get_char(int index);

  /**
   * env_reloc() - Relocate the 'env' sub-commands
   *
   * This is used for those unfortunate archs with crappy toolchains
   */
  void env_reloc(void);

  #ifdef ENV_IS_EMBEDDED
  #define env_get_offset(x) x
  #else
  long long env_get_offset(long long defautl_offset);
  #endif

  #endif