1 // SPDX-License-Identifier: GPL-2.0+ 2 /* 3 * (C) Copyright 2000-2010 4 * Wolfgang Denk, DENX Software Engineering, wd (at) denx.de. 5 * 6 * (C) Copyright 2001 Sysgo Real-Time Solutions, GmbH <www.elinos.com> 7 * Andreas Heppel <aheppel (at) sysgo.de> 8 */ 9 10 #include <common.h> 11 #include <command.h> 12 #include <environment.h> 13 #include <linux/stddef.h> 14 #include <search.h> 15 #include <errno.h> 16 #include <malloc.h> 17 18 DECLARE_GLOBAL_DATA_PTR; 19 20 /************************************************************************ 21 * Default settings to be used when no valid environment is found 22 */ 23 #include <env_default.h> 24 25 struct hsearch_data env_htab = { 26 .change_ok = env_flags_validate, 27 }; 28 29 /* 30 * Read an environment variable as a boolean 31 * Return -1 if variable does not exist (default to true) 32 */ 33 int env_get_yesno(const char *var) 34 { 35 char *s = env_get(var); 36 37 if (s == NULL) 38 return -1; 39 return (*s == '1' || *s == 'y' || *s == 'Y' || *s == 't' || *s == 'T') ? 40 1 : 0; 41 } 42 43 /* 44 * Look up the variable from the default environment 45 */ 46 char *env_get_default(const char *name) 47 { 48 char *ret_val; 49 unsigned long really_valid = gd->env_valid; 50 unsigned long real_gd_flags = gd->flags; 51 52 /* Pretend that the image is bad. */ 53 gd->flags &= ~GD_FLG_ENV_READY; 54 gd->env_valid = ENV_INVALID; 55 ret_val = env_get(name); 56 gd->env_valid = really_valid; 57 gd->flags = real_gd_flags; 58 return ret_val; 59 } 60 61 void set_default_env(const char *s) 62 { 63 int flags = 0; 64 65 if (sizeof(default_environment) > ENV_SIZE) { 66 puts("*** Error - default environment is too large\n\n"); 67 return; 68 } 69 70 if (s) { 71 if (*s == '!') { 72 printf("*** Warning - %s, " 73 "using default environment\n\n", 74 s + 1); 75 } else { 76 flags = H_INTERACTIVE; 77 puts(s); 78 } 79 } else { 80 debug("Using default environment\n"); 81 } 82 83 if (himport_r(&env_htab, (char *)default_environment, 84 sizeof(default_environment), '\0', flags, 0, 85 0, NULL) == 0) 86 pr_err("Environment import failed: errno = %d\n", errno); 87 88 gd->flags |= GD_FLG_ENV_READY; 89 gd->flags |= GD_FLG_ENV_DEFAULT; 90 } 91 92 93 /* [re]set individual variables to their value in the default environment */ 94 int set_default_vars(int nvars, char * const vars[]) 95 { 96 /* 97 * Special use-case: import from default environment 98 * (and use \0 as a separator) 99 */ 100 return himport_r(&env_htab, (const char *)default_environment, 101 sizeof(default_environment), '\0', 102 H_NOCLEAR | H_INTERACTIVE, 0, nvars, vars); 103 } 104 105 /* 106 * Check if CRC is valid and (if yes) import the environment. 107 * Note that "buf" may or may not be aligned. 108 */ 109 int env_import(const char *buf, int check) 110 { 111 env_t *ep = (env_t *)buf; 112 113 if (check) { 114 uint32_t crc; 115 116 memcpy(&crc, &ep->crc, sizeof(crc)); 117 118 if (crc32(0, ep->data, ENV_SIZE) != crc) { 119 set_default_env("!bad CRC"); 120 return -EIO; 121 } 122 } 123 124 if (himport_r(&env_htab, (char *)ep->data, ENV_SIZE, '\0', 0, 0, 125 0, NULL)) { 126 gd->flags |= GD_FLG_ENV_READY; 127 return 0; 128 } 129 130 pr_err("Cannot import environment: errno = %d\n", errno); 131 132 set_default_env("!import failed"); 133 134 return -EIO; 135 } 136 137 #ifdef CONFIG_SYS_REDUNDAND_ENVIRONMENT 138 static unsigned char env_flags; 139 140 int env_import_redund(const char *buf1, int buf1_read_fail, 141 const char *buf2, int buf2_read_fail) 142 { 143 int crc1_ok, crc2_ok; 144 env_t *ep, *tmp_env1, *tmp_env2; 145 146 tmp_env1 = (env_t *)buf1; 147 tmp_env2 = (env_t *)buf2; 148 149 if (buf1_read_fail && buf2_read_fail) { 150 puts("*** Error - No Valid Environment Area found\n"); 151 } else if (buf1_read_fail || buf2_read_fail) { 152 puts("*** Warning - some problems detected "); 153 puts("reading environment; recovered successfully\n"); 154 } 155 156 if (buf1_read_fail && buf2_read_fail) { 157 set_default_env("!bad env area"); 158 return -EIO; 159 } else if (!buf1_read_fail && buf2_read_fail) { 160 gd->env_valid = ENV_VALID; 161 return env_import((char *)tmp_env1, 1); 162 } else if (buf1_read_fail && !buf2_read_fail) { 163 gd->env_valid = ENV_REDUND; 164 return env_import((char *)tmp_env2, 1); 165 } 166 167 crc1_ok = crc32(0, tmp_env1->data, ENV_SIZE) == 168 tmp_env1->crc; 169 crc2_ok = crc32(0, tmp_env2->data, ENV_SIZE) == 170 tmp_env2->crc; 171 172 if (!crc1_ok && !crc2_ok) { 173 set_default_env("!bad CRC"); 174 return -EIO; 175 } else if (crc1_ok && !crc2_ok) { 176 gd->env_valid = ENV_VALID; 177 } else if (!crc1_ok && crc2_ok) { 178 gd->env_valid = ENV_REDUND; 179 } else { 180 /* both ok - check serial */ 181 if (tmp_env1->flags == 255 && tmp_env2->flags == 0) 182 gd->env_valid = ENV_REDUND; 183 else if (tmp_env2->flags == 255 && tmp_env1->flags == 0) 184 gd->env_valid = ENV_VALID; 185 else if (tmp_env1->flags > tmp_env2->flags) 186 gd->env_valid = ENV_VALID; 187 else if (tmp_env2->flags > tmp_env1->flags) 188 gd->env_valid = ENV_REDUND; 189 else /* flags are equal - almost impossible */ 190 gd->env_valid = ENV_VALID; 191 } 192 193 if (gd->env_valid == ENV_VALID) 194 ep = tmp_env1; 195 else 196 ep = tmp_env2; 197 198 env_flags = ep->flags; 199 return env_import((char *)ep, 0); 200 } 201 #endif /* CONFIG_SYS_REDUNDAND_ENVIRONMENT */ 202 203 /* Export the environment and generate CRC for it. */ 204 int env_export(env_t *env_out) 205 { 206 char *res; 207 ssize_t len; 208 209 res = (char *)env_out->data; 210 len = hexport_r(&env_htab, '\0', 0, &res, ENV_SIZE, 0, NULL); 211 if (len < 0) { 212 pr_err("Cannot export environment: errno = %d\n", errno); 213 return 1; 214 } 215 216 env_out->crc = crc32(0, env_out->data, ENV_SIZE); 217 218 #ifdef CONFIG_SYS_REDUNDAND_ENVIRONMENT 219 env_out->flags = ++env_flags; /* increase the serial */ 220 #endif 221 222 return 0; 223 } 224 225 void env_relocate(void) 226 { 227 #if defined(CONFIG_NEEDS_MANUAL_RELOC) 228 env_reloc(); 229 env_fix_drivers(); 230 env_htab.change_ok += gd->reloc_off; 231 #endif 232 if (gd->env_valid == ENV_INVALID) { 233 #if defined(CONFIG_ENV_IS_NOWHERE) || defined(CONFIG_SPL_BUILD) 234 /* Environment not changable */ 235 set_default_env(NULL); 236 #else 237 bootstage_error(BOOTSTAGE_ID_NET_CHECKSUM); 238 set_default_env("!bad CRC"); 239 #endif 240 } else { 241 env_load(); 242 } 243 } 244 245 #if defined(CONFIG_AUTO_COMPLETE) && !defined(CONFIG_SPL_BUILD) 246 int env_complete(char *var, int maxv, char *cmdv[], int bufsz, char *buf) 247 { 248 ENTRY *match; 249 int found, idx; 250 251 idx = 0; 252 found = 0; 253 cmdv[0] = NULL; 254 255 while ((idx = hmatch_r(var, idx, &match, &env_htab))) { 256 int vallen = strlen(match->key) + 1; 257 258 if (found >= maxv - 2 || bufsz < vallen) 259 break; 260 261 cmdv[found++] = buf; 262 memcpy(buf, match->key, vallen); 263 buf += vallen; 264 bufsz -= vallen; 265 } 266 267 qsort(cmdv, found, sizeof(cmdv[0]), strcmp_compar); 268 269 if (idx) 270 cmdv[found++] = "..."; 271 272 cmdv[found] = NULL; 273 return found; 274 } 275 #endif 276
