u-boot/include/env.h

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/* 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_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: actual length of the variable value excluding the terminating
* NULL-byte, or -1 if the variable is 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_get_autostart() - Check if autostart is enabled
*
* Return: true if the "autostart" env var exists and is set to "yes"
*/
bool env_get_autostart(void);
/**
* 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_reload() - Re-Load the environment from current storage
*
* Return: 0 if OK, -ve on error
*/
int env_reload(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_select() - Select the environment storage
*
* Return: 0 if OK, -ve on error
*/
int env_select(const char *name);
/**
* 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
* @flags: Flags controlling matching (H_... - see search.h)
* 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, int flags);
/**
* 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_check_redund() - check the two redundant environments
* and find out, which is the valid one.
*
* @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_check_redund(const char *buf1, int buf1_read_fail,
const char *buf2, int buf2_read_fail);
/**
* 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
* @flags: Flags controlling matching (H_... - see search.h)
* 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,
int flags);
/**
* 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_reloc() - Relocate the 'env' sub-commands
*
* This is used for those unfortunate archs with crappy toolchains
*/
void env_reloc(void);
/**
* env_import_fdt() - Import environment values from device tree blob
*
* This uses the value of the environment variable "env_fdt_path" as a
* path to an fdt node, whose property/value pairs are added to the
* environment.
*/
#ifdef CONFIG_ENV_IMPORT_FDT
void env_import_fdt(void);
#else
static inline void env_import_fdt(void) {}
#endif
#endif