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_init() - Set up the pre-relocation environment 77 * 78 * This locates the environment or uses the default if nothing is available. 79 * This must be called before env_get() will work. 80 * 81 * @return 0 if OK, -ENODEV if no environment drivers are enabled 82 */ 83int env_init(void); 84 85/** 86 * env_relocate() - Set up the post-relocation environment 87 * 88 * This loads the environment into RAM so that it can be modified. This is 89 * called after relocation, before the environment is used 90 */ 91void env_relocate(void); 92 93/** 94 * env_match() - Match a name / name=value pair 95 * 96 * This is used prior to relocation for finding envrionment variables 97 * 98 * @name: A simple 'name', or a 'name=value' pair. 99 * @index: The environment index for a 'name2=value2' pair. 100 * @return index for the value if the names match, else -1. 101 */ 102int env_match(unsigned char *name, int index); 103 104/** 105 * env_get() - Look up the value of an environment variable 106 * 107 * In U-Boot proper this can be called before relocation (which is when the 108 * environment is loaded from storage, i.e. GD_FLG_ENV_READY is 0). In that 109 * case this function calls env_get_f(). 110 * 111 * @varname: Variable to look up 112 * @return value of variable, or NULL if not found 113 */ 114char *env_get(const char *varname); 115 116/* 117 * Like env_get, but prints an error if envvar isn't defined in the 118 * environment. It always returns what env_get does, so it can be used in 119 * place of env_get without changing error handling otherwise. 120 * 121 * @varname: Variable to look up 122 * @return value of variable, or NULL if not found 123 */ 124char *from_env(const char *envvar); 125 126/** 127 * env_get_f() - Look up the value of an environment variable (early) 128 * 129 * This function is called from env_get() if the environment has not been 130 * loaded yet (GD_FLG_ENV_READY flag is 0). Some environment locations will 131 * support reading the value (slowly) and some will not. 132 * 133 * @varname: Variable to look up 134 * @return value of variable, or NULL if not found 135 */ 136int env_get_f(const char *name, char *buf, unsigned int len); 137 138/** 139 * env_get_yesno() - Read an environment variable as a boolean 140 * 141 * @return 1 if yes/true (Y/y/T/t), -1 if variable does not exist (i.e. default 142 * to true), 0 if otherwise 143 */ 144int env_get_yesno(const char *var); 145 146/** 147 * env_set() - set an environment variable 148 * 149 * This sets or deletes the value of an environment variable. For setting the 150 * value the variable is created if it does not already exist. 151 * 152 * @varname: Variable to adjust 153 * @value: Value to set for the variable, or NULL or "" to delete the variable 154 * @return 0 if OK, 1 on error 155 */ 156int env_set(const char *varname, const char *value); 157 158/** 159 * env_get_ulong() - Return an environment variable as an integer value 160 * 161 * Most U-Boot environment variables store hex values. For those which store 162 * (e.g.) base-10 integers, this function can be used to read the value. 163 * 164 * @name: Variable to look up 165 * @base: Base to use (e.g. 10 for base 10, 2 for binary) 166 * @default_val: Default value to return if no value is found 167 * @return the value found, or @default_val if none 168 */ 169ulong env_get_ulong(const char *name, int base, ulong default_val); 170 171/** 172 * env_set_ulong() - set an environment variable to an integer 173 * 174 * @varname: Variable to adjust 175 * @value: Value to set for the variable (will be converted to a string) 176 * @return 0 if OK, 1 on error 177 */ 178int env_set_ulong(const char *varname, ulong value); 179 180/** 181 * env_get_hex() - Return an environment variable as a hex value 182 * 183 * Decode an environment as a hex number (it may or may not have a 0x 184 * prefix). If the environment variable cannot be found, or does not start 185 * with hex digits, the default value is returned. 186 * 187 * @varname: Variable to decode 188 * @default_val: Value to return on error 189 */ 190ulong env_get_hex(const char *varname, ulong default_val); 191 192/** 193 * env_set_hex() - set an environment variable to a hex value 194 * 195 * @varname: Variable to adjust 196 * @value: Value to set for the variable (will be converted to a hex string) 197 * @return 0 if OK, 1 on error 198 */ 199int env_set_hex(const char *varname, ulong value); 200 201/** 202 * env_set_addr - Set an environment variable to an address in hex 203 * 204 * @varname: Environment variable to set 205 * @addr: Value to set it to 206 * @return 0 if ok, 1 on error 207 */ 208static inline int env_set_addr(const char *varname, const void *addr) 209{ 210 return env_set_hex(varname, (ulong)addr); 211} 212 213/** 214 * env_complete() - return an auto-complete for environment variables 215 * 216 * @var: partial name to auto-complete 217 * @maxv: Maximum number of matches to return 218 * @cmdv: Returns a list of possible matches 219 * @maxsz: Size of buffer to use for matches 220 * @buf: Buffer to use for matches 221 * @dollar_comp: non-zero to wrap each match in ${...} 222 * @return number of matches found (in @cmdv) 223 */ 224int env_complete(char *var, int maxv, char *cmdv[], int maxsz, char *buf, 225 bool dollar_comp); 226 227/** 228 * eth_env_get_enetaddr() - Get an ethernet address from the environmnet 229 * 230 * @name: Environment variable to get (e.g. "ethaddr") 231 * @enetaddr: Place to put MAC address (6 bytes) 232 * @return 0 if OK, 1 on error 233 */ 234int eth_env_get_enetaddr(const char *name, uint8_t *enetaddr); 235 236/** 237 * eth_env_set_enetaddr() - Set an ethernet address in the environmnet 238 * 239 * @name: Environment variable to set (e.g. "ethaddr") 240 * @enetaddr: Pointer to MAC address to put into the variable (6 bytes) 241 * @return 0 if OK, 1 on error 242 */ 243int eth_env_set_enetaddr(const char *name, const uint8_t *enetaddr); 244 245/** 246 * env_fix_drivers() - Updates envdriver as per relocation 247 */ 248void env_fix_drivers(void); 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/* [re]set to the default environment */ 360void env_set_default(const char *s, int flags); 361 362/** 363 * env_get_char() - Get a character from the early environment 364 * 365 * This reads from the pre-relocation environment 366 * 367 * @index: Index of character to read (0 = first) 368 * @return character read, or -ve on error 369 */ 370int env_get_char(int index); 371 372/** 373 * env_reloc() - Relocate the 'env' sub-commands 374 * 375 * This is used for those unfortunate archs with crappy toolchains 376 */ 377void env_reloc(void); 378 379 380/** 381 * env_import_fdt() - Import environment values from device tree blob 382 * 383 * This uses the value of the environment variable "env_fdt_path" as a 384 * path to an fdt node, whose property/value pairs are added to the 385 * environment. 386 */ 387#ifdef CONFIG_ENV_IMPORT_FDT 388void env_import_fdt(void); 389#else 390static inline void env_import_fdt(void) {} 391#endif 392 393#endif 394