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_get() - Look up the value of an environment variable 95 * 96 * In U-Boot proper this can be called before relocation (which is when the 97 * environment is loaded from storage, i.e. GD_FLG_ENV_READY is 0). In that 98 * case this function calls env_get_f(). 99 * 100 * @varname: Variable to look up 101 * @return value of variable, or NULL if not found 102 */ 103char *env_get(const char *varname); 104 105/* 106 * Like env_get, but prints an error if envvar isn't defined in the 107 * environment. It always returns what env_get does, so it can be used in 108 * place of env_get without changing error handling otherwise. 109 * 110 * @varname: Variable to look up 111 * @return value of variable, or NULL if not found 112 */ 113char *from_env(const char *envvar); 114 115/** 116 * env_get_f() - Look up the value of an environment variable (early) 117 * 118 * This function is called from env_get() if the environment has not been 119 * loaded yet (GD_FLG_ENV_READY flag is 0). Some environment locations will 120 * support reading the value (slowly) and some will not. 121 * 122 * @varname: Variable to look up 123 * @return actual length of the variable value excluding the terminating 124 * NULL-byte, or -1 if the variable is not found 125 */ 126int env_get_f(const char *name, char *buf, unsigned int len); 127 128/** 129 * env_get_yesno() - Read an environment variable as a boolean 130 * 131 * @return 1 if yes/true (Y/y/T/t), -1 if variable does not exist (i.e. default 132 * to true), 0 if otherwise 133 */ 134int env_get_yesno(const char *var); 135 136/** 137 * env_set() - set an environment variable 138 * 139 * This sets or deletes the value of an environment variable. For setting the 140 * value the variable is created if it does not already exist. 141 * 142 * @varname: Variable to adjust 143 * @value: Value to set for the variable, or NULL or "" to delete the variable 144 * @return 0 if OK, 1 on error 145 */ 146int env_set(const char *varname, const char *value); 147 148/** 149 * env_get_ulong() - Return an environment variable as an integer value 150 * 151 * Most U-Boot environment variables store hex values. For those which store 152 * (e.g.) base-10 integers, this function can be used to read the value. 153 * 154 * @name: Variable to look up 155 * @base: Base to use (e.g. 10 for base 10, 2 for binary) 156 * @default_val: Default value to return if no value is found 157 * @return the value found, or @default_val if none 158 */ 159ulong env_get_ulong(const char *name, int base, ulong default_val); 160 161/** 162 * env_set_ulong() - set an environment variable to an integer 163 * 164 * @varname: Variable to adjust 165 * @value: Value to set for the variable (will be converted to a string) 166 * @return 0 if OK, 1 on error 167 */ 168int env_set_ulong(const char *varname, ulong value); 169 170/** 171 * env_get_hex() - Return an environment variable as a hex value 172 * 173 * Decode an environment as a hex number (it may or may not have a 0x 174 * prefix). If the environment variable cannot be found, or does not start 175 * with hex digits, the default value is returned. 176 * 177 * @varname: Variable to decode 178 * @default_val: Value to return on error 179 */ 180ulong env_get_hex(const char *varname, ulong default_val); 181 182/** 183 * env_set_hex() - set an environment variable to a hex value 184 * 185 * @varname: Variable to adjust 186 * @value: Value to set for the variable (will be converted to a hex string) 187 * @return 0 if OK, 1 on error 188 */ 189int env_set_hex(const char *varname, ulong value); 190 191/** 192 * env_set_addr - Set an environment variable to an address in hex 193 * 194 * @varname: Environment variable to set 195 * @addr: Value to set it to 196 * @return 0 if ok, 1 on error 197 */ 198static inline int env_set_addr(const char *varname, const void *addr) 199{ 200 return env_set_hex(varname, (ulong)addr); 201} 202 203/** 204 * env_complete() - return an auto-complete for environment variables 205 * 206 * @var: partial name to auto-complete 207 * @maxv: Maximum number of matches to return 208 * @cmdv: Returns a list of possible matches 209 * @maxsz: Size of buffer to use for matches 210 * @buf: Buffer to use for matches 211 * @dollar_comp: non-zero to wrap each match in ${...} 212 * @return number of matches found (in @cmdv) 213 */ 214int env_complete(char *var, int maxv, char *cmdv[], int maxsz, char *buf, 215 bool dollar_comp); 216 217/** 218 * eth_env_get_enetaddr() - Get an ethernet address from the environmnet 219 * 220 * @name: Environment variable to get (e.g. "ethaddr") 221 * @enetaddr: Place to put MAC address (6 bytes) 222 * @return 0 if OK, 1 on error 223 */ 224int eth_env_get_enetaddr(const char *name, uint8_t *enetaddr); 225 226/** 227 * eth_env_set_enetaddr() - Set an ethernet address in the environmnet 228 * 229 * @name: Environment variable to set (e.g. "ethaddr") 230 * @enetaddr: Pointer to MAC address to put into the variable (6 bytes) 231 * @return 0 if OK, 1 on error 232 */ 233int eth_env_set_enetaddr(const char *name, const uint8_t *enetaddr); 234 235/** 236 * env_fix_drivers() - Updates envdriver as per relocation 237 */ 238void env_fix_drivers(void); 239 240/** 241 * env_set_default_vars() - reset variables to their default value 242 * 243 * This resets individual variables to their value in the default environment 244 * 245 * @nvars: Number of variables to set/reset 246 * @vars: List of variables to set/reset 247 * @flags: Flags controlling matching (H_... - see search.h) 248 */ 249int env_set_default_vars(int nvars, char *const vars[], int flags); 250 251/** 252 * env_load() - Load the environment from storage 253 * 254 * @return 0 if OK, -ve on error 255 */ 256int env_load(void); 257 258/** 259 * env_reload() - Re-Load the environment from current storage 260 * 261 * @return 0 if OK, -ve on error 262 */ 263int env_reload(void); 264 265/** 266 * env_save() - Save the environment to storage 267 * 268 * @return 0 if OK, -ve on error 269 */ 270int env_save(void); 271 272/** 273 * env_erase() - Erase the environment on storage 274 * 275 * @return 0 if OK, -ve on error 276 */ 277int env_erase(void); 278 279/** 280 * env_select() - Select the environment storage 281 * 282 * @return 0 if OK, -ve on error 283 */ 284int env_select(const char *name); 285 286/** 287 * env_import() - Import from a binary representation into hash table 288 * 289 * This imports the environment from a buffer. The format for each variable is 290 * var=value\0 with a double \0 at the end of the buffer. 291 * 292 * @buf: Buffer containing the environment (struct environemnt_s *) 293 * @check: non-zero to check the CRC at the start of the environment, 0 to 294 * ignore it 295 * @flags: Flags controlling matching (H_... - see search.h) 296 * @return 0 if imported successfully, -ENOMSG if the CRC was bad, -EIO if 297 * something else went wrong 298 */ 299int env_import(const char *buf, int check, int flags); 300 301/** 302 * env_export() - Export the environment to a buffer 303 * 304 * Export from hash table into binary representation 305 * 306 * @env_out: Buffer to contain the environment (must be large enough!) 307 * @return 0 if OK, 1 on error 308 */ 309int env_export(struct environment_s *env_out); 310 311/** 312 * env_check_redund() - check the two redundant environments 313 * and find out, which is the valid one. 314 * 315 * @buf1: First environment (struct environemnt_s *) 316 * @buf1_read_fail: 0 if buf1 is valid, non-zero if invalid 317 * @buf2: Second environment (struct environemnt_s *) 318 * @buf2_read_fail: 0 if buf2 is valid, non-zero if invalid 319 * @return 0 if OK, 320 * -EIO if no environment is valid, 321 * -ENOMSG if the CRC was bad 322 */ 323 324int env_check_redund(const char *buf1, int buf1_read_fail, 325 const char *buf2, int buf2_read_fail); 326 327/** 328 * env_import_redund() - Select and import one of two redundant environments 329 * 330 * @buf1: First environment (struct environemnt_s *) 331 * @buf1_read_fail: 0 if buf1 is valid, non-zero if invalid 332 * @buf2: Second environment (struct environemnt_s *) 333 * @buf2_read_fail: 0 if buf2 is valid, non-zero if invalid 334 * @flags: Flags controlling matching (H_... - see search.h) 335 * @return 0 if OK, -EIO if no environment is valid, -ENOMSG if the CRC was bad 336 */ 337int env_import_redund(const char *buf1, int buf1_read_fail, 338 const char *buf2, int buf2_read_fail, 339 int flags); 340 341/** 342 * env_get_default() - Look up a variable from the default environment 343 * 344 * @name: Variable to look up 345 * @return value if found, NULL if not found in default environment 346 */ 347char *env_get_default(const char *name); 348 349/* [re]set to the default environment */ 350void env_set_default(const char *s, int flags); 351 352/** 353 * env_reloc() - Relocate the 'env' sub-commands 354 * 355 * This is used for those unfortunate archs with crappy toolchains 356 */ 357void env_reloc(void); 358 359 360/** 361 * env_import_fdt() - Import environment values from device tree blob 362 * 363 * This uses the value of the environment variable "env_fdt_path" as a 364 * path to an fdt node, whose property/value pairs are added to the 365 * environment. 366 */ 367#ifdef CONFIG_ENV_IMPORT_FDT 368void env_import_fdt(void); 369#else 370static inline void env_import_fdt(void) {} 371#endif 372 373#endif 374