1/* SPDX-License-Identifier: GPL-2.0+ */ 2/* 3 * Common environment functions and definitions 4 * 5 * (C) Copyright 2000-2009 6 * Wolfgang Denk, DENX Software Engineering, wd@denx.de. 7 */ 8 9#ifndef __ENV_H 10#define __ENV_H 11 12#include <compiler.h> 13#include <stdbool.h> 14#include <linux/types.h> 15 16struct environment_s; 17 18/* Value for environment validity */ 19enum env_valid { 20 ENV_INVALID, /* No valid environment */ 21 ENV_VALID, /* First or only environment is valid */ 22 ENV_REDUND, /* Redundant environment is valid */ 23}; 24 25/** enum env_op - environment callback operation */ 26enum env_op { 27 env_op_create, 28 env_op_delete, 29 env_op_overwrite, 30}; 31 32/** struct env_clbk_tbl - declares a new callback */ 33struct env_clbk_tbl { 34 const char *name; /* Callback name */ 35 int (*callback)(const char *name, const char *value, enum env_op op, 36 int flags); 37}; 38 39/* 40 * Define a callback that can be associated with variables. 41 * when associated through the ".callbacks" environment variable, the callback 42 * will be executed any time the variable is inserted, overwritten, or deleted. 43 * 44 * For SPL these are silently dropped to reduce code size, since environment 45 * callbacks are not supported with SPL. 46 */ 47#ifdef CONFIG_SPL_BUILD 48#define U_BOOT_ENV_CALLBACK(name, callback) \ 49 static inline __maybe_unused void _u_boot_env_noop_##name(void) \ 50 { \ 51 (void)callback; \ 52 } 53#else 54#define U_BOOT_ENV_CALLBACK(name, callback) \ 55 ll_entry_declare(struct env_clbk_tbl, name, env_clbk) = \ 56 {#name, callback} 57#endif 58 59/** enum env_redund_flags - Flags for the redundand_environment */ 60enum env_redund_flags { 61 ENV_REDUND_OBSOLETE = 0, 62 ENV_REDUND_ACTIVE = 1, 63}; 64 65/** 66 * env_get_id() - Gets a sequence number for the environment 67 * 68 * This value increments every time the environment changes, so can be used an 69 * an indication of this 70 * 71 * Return: environment ID 72 */ 73int env_get_id(void); 74 75/** 76 * env_inc_id() - Increase the sequence number for the environment 77 * 78 * Increment the value that is used by env_get_id() to inform callers 79 * if the environment has changed since they last checked. 80 */ 81void env_inc_id(void); 82 83/** 84 * env_init() - Set up the pre-relocation environment 85 * 86 * This locates the environment or uses the default if nothing is available. 87 * This must be called before env_get() will work. 88 * 89 * Return: 0 if OK, -ENODEV if no environment drivers are enabled 90 */ 91int env_init(void); 92 93/** 94 * env_relocate() - Set up the post-relocation environment 95 * 96 * This loads the environment into RAM so that it can be modified. This is 97 * called after relocation, before the environment is used 98 */ 99void env_relocate(void); 100 101/** 102 * env_get() - Look up the value of an environment variable 103 * 104 * In U-Boot proper this can be called before relocation (which is when the 105 * environment is loaded from storage, i.e. GD_FLG_ENV_READY is 0). In that 106 * case this function calls env_get_f(). 107 * 108 * @varname: Variable to look up 109 * Return: value of variable, or NULL if not found 110 */ 111char *env_get(const char *varname); 112 113/* 114 * Like env_get, but prints an error if envvar isn't defined in the 115 * environment. It always returns what env_get does, so it can be used in 116 * place of env_get without changing error handling otherwise. 117 * 118 * @varname: Variable to look up 119 * Return: value of variable, or NULL if not found 120 */ 121char *from_env(const char *envvar); 122 123/** 124 * env_get_f() - Look up the value of an environment variable (early) 125 * 126 * This function is called from env_get() if the environment has not been 127 * loaded yet (GD_FLG_ENV_READY flag is 0). Some environment locations will 128 * support reading the value (slowly) and some will not. 129 * 130 * @varname: Variable to look up 131 * Return: actual length of the variable value excluding the terminating 132 * NULL-byte, or -1 if the variable is not found 133 */ 134int env_get_f(const char *name, char *buf, unsigned int len); 135 136/** 137 * env_get_yesno() - Read an environment variable as a boolean 138 * 139 * Return: 1 if yes/true (Y/y/T/t), -1 if variable does not exist (i.e. default 140 * to true), 0 if otherwise 141 */ 142int env_get_yesno(const char *var); 143 144/** 145 * env_get_autostart() - Check if autostart is enabled 146 * 147 * Return: true if the "autostart" env var exists and is set to "yes" 148 */ 149bool env_get_autostart(void); 150 151/** 152 * env_set() - set an environment variable 153 * 154 * This sets or deletes the value of an environment variable. For setting the 155 * value the variable is created if it does not already exist. 156 * 157 * @varname: Variable to adjust 158 * @value: Value to set for the variable, or NULL or "" to delete the variable 159 * Return: 0 if OK, 1 on error 160 */ 161int env_set(const char *varname, const char *value); 162 163/** 164 * env_get_ulong() - Return an environment variable as an integer value 165 * 166 * Most U-Boot environment variables store hex values. For those which store 167 * (e.g.) base-10 integers, this function can be used to read the value. 168 * 169 * @name: Variable to look up 170 * @base: Base to use (e.g. 10 for base 10, 2 for binary) 171 * @default_val: Default value to return if no value is found 172 * Return: the value found, or @default_val if none 173 */ 174ulong env_get_ulong(const char *name, int base, ulong default_val); 175 176/** 177 * env_set_ulong() - set an environment variable to an integer 178 * 179 * @varname: Variable to adjust 180 * @value: Value to set for the variable (will be converted to a string) 181 * Return: 0 if OK, 1 on error 182 */ 183int env_set_ulong(const char *varname, ulong value); 184 185/** 186 * env_get_hex() - Return an environment variable as a hex value 187 * 188 * Decode an environment as a hex number (it may or may not have a 0x 189 * prefix). If the environment variable cannot be found, or does not start 190 * with hex digits, the default value is returned. 191 * 192 * @varname: Variable to decode 193 * @default_val: Value to return on error 194 */ 195ulong env_get_hex(const char *varname, ulong default_val); 196 197/** 198 * env_set_hex() - set an environment variable to a hex value 199 * 200 * @varname: Variable to adjust 201 * @value: Value to set for the variable (will be converted to a hex string) 202 * Return: 0 if OK, 1 on error 203 */ 204int env_set_hex(const char *varname, ulong value); 205 206/** 207 * env_set_addr - Set an environment variable to an address in hex 208 * 209 * @varname: Environment variable to set 210 * @addr: Value to set it to 211 * Return: 0 if ok, 1 on error 212 */ 213static inline int env_set_addr(const char *varname, const void *addr) 214{ 215 return env_set_hex(varname, (ulong)addr); 216} 217 218/** 219 * env_complete() - return an auto-complete for environment variables 220 * 221 * @var: partial name to auto-complete 222 * @maxv: Maximum number of matches to return 223 * @cmdv: Returns a list of possible matches 224 * @maxsz: Size of buffer to use for matches 225 * @buf: Buffer to use for matches 226 * @dollar_comp: non-zero to wrap each match in ${...} 227 * Return: number of matches found (in @cmdv) 228 */ 229int env_complete(char *var, int maxv, char *cmdv[], int maxsz, char *buf, 230 bool dollar_comp); 231 232/** 233 * eth_env_get_enetaddr() - Get an ethernet address from the environmnet 234 * 235 * @name: Environment variable to get (e.g. "ethaddr") 236 * @enetaddr: Place to put MAC address (6 bytes) 237 * Return: 1 if OK, 0 on error 238 */ 239int eth_env_get_enetaddr(const char *name, uint8_t *enetaddr); 240 241/** 242 * eth_env_set_enetaddr() - Set an ethernet address in the environmnet 243 * 244 * @name: Environment variable to set (e.g. "ethaddr") 245 * @enetaddr: Pointer to MAC address to put into the variable (6 bytes) 246 * Return: 0 if OK, non-zero otherwise 247 */ 248int eth_env_set_enetaddr(const char *name, const uint8_t *enetaddr); 249 250/** 251 * env_set_default_vars() - reset variables to their default value 252 * 253 * This resets individual variables to their value in the default environment 254 * 255 * @nvars: Number of variables to set/reset 256 * @vars: List of variables to set/reset 257 * @flags: Flags controlling matching (H_... - see search.h) 258 */ 259int env_set_default_vars(int nvars, char *const vars[], int flags); 260 261/** 262 * env_load() - Load the environment from storage 263 * 264 * Return: 0 if OK, -ve on error 265 */ 266int env_load(void); 267 268/** 269 * env_reload() - Re-Load the environment from current storage 270 * 271 * Return: 0 if OK, -ve on error 272 */ 273int env_reload(void); 274 275/** 276 * env_save() - Save the environment to storage 277 * 278 * Return: 0 if OK, -ve on error 279 */ 280int env_save(void); 281 282/** 283 * env_erase() - Erase the environment on storage 284 * 285 * Return: 0 if OK, -ve on error 286 */ 287int env_erase(void); 288 289/** 290 * env_select() - Select the environment storage 291 * 292 * Return: 0 if OK, -ve on error 293 */ 294int env_select(const char *name); 295 296/** 297 * env_import() - Import from a binary representation into hash table 298 * 299 * This imports the environment from a buffer. The format for each variable is 300 * var=value\0 with a double \0 at the end of the buffer. 301 * 302 * @buf: Buffer containing the environment (struct environemnt_s *) 303 * @check: non-zero to check the CRC at the start of the environment, 0 to 304 * ignore it 305 * @flags: Flags controlling matching (H_... - see search.h) 306 * Return: 0 if imported successfully, -ENOMSG if the CRC was bad, -EIO if 307 * something else went wrong 308 */ 309int env_import(const char *buf, int check, int flags); 310 311/** 312 * env_export() - Export the environment to a buffer 313 * 314 * Export from hash table into binary representation 315 * 316 * @env_out: Buffer to contain the environment (must be large enough!) 317 * Return: 0 if OK, 1 on error 318 */ 319int env_export(struct environment_s *env_out); 320 321/** 322 * env_check_redund() - check the two redundant environments 323 * and find out, which is the valid one. 324 * 325 * @buf1: First environment (struct environemnt_s *) 326 * @buf1_read_fail: 0 if buf1 is valid, non-zero if invalid 327 * @buf2: Second environment (struct environemnt_s *) 328 * @buf2_read_fail: 0 if buf2 is valid, non-zero if invalid 329 * Return: 0 if OK, 330 * -EIO if no environment is valid, 331 * -ENOMSG if the CRC was bad 332 */ 333 334int env_check_redund(const char *buf1, int buf1_read_fail, 335 const char *buf2, int buf2_read_fail); 336 337/** 338 * env_import_redund() - Select and import one of two redundant environments 339 * 340 * @buf1: First environment (struct environemnt_s *) 341 * @buf1_read_fail: 0 if buf1 is valid, non-zero if invalid 342 * @buf2: Second environment (struct environemnt_s *) 343 * @buf2_read_fail: 0 if buf2 is valid, non-zero if invalid 344 * @flags: Flags controlling matching (H_... - see search.h) 345 * Return: 0 if OK, -EIO if no environment is valid, -ENOMSG if the CRC was bad 346 */ 347int env_import_redund(const char *buf1, int buf1_read_fail, 348 const char *buf2, int buf2_read_fail, 349 int flags); 350 351/** 352 * env_get_default() - Look up a variable from the default environment 353 * 354 * @name: Variable to look up 355 * Return: value if found, NULL if not found in default environment 356 */ 357char *env_get_default(const char *name); 358 359/** 360 * env_get_default_into() - Look up a variable from the default environment and 361 * copy its value in buf. 362 * 363 * @name: Variable to look up 364 * Return: actual length of the variable value excluding the terminating 365 * NULL-byte, or -1 if the variable is not found 366 */ 367int env_get_default_into(const char *name, char *buf, unsigned int len); 368 369/* [re]set to the default environment */ 370void env_set_default(const char *s, int flags); 371 372/** 373 * env_import_fdt() - Import environment values from device tree blob 374 * 375 * This uses the value of the environment variable "env_fdt_path" as a 376 * path to an fdt node, whose property/value pairs are added to the 377 * environment. 378 */ 379#ifdef CONFIG_ENV_IMPORT_FDT 380void env_import_fdt(void); 381#else 382static inline void env_import_fdt(void) {} 383#endif 384 385#endif 386