+#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);
+}