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