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 0; 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 1; 129 } 130 131 pr_err("Cannot import environment: errno = %d\n", errno); 132 133 set_default_env("!import failed"); 134 135 return 0; 136 } 137 138 #ifdef CONFIG_SYS_REDUNDAND_ENVIRONMENT 139 static unsigned char env_flags; 140 141 int env_import_redund(const char *buf1, const char *buf2) 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 crc1_ok = crc32(0, tmp_env1->data, ENV_SIZE) == 150 tmp_env1->crc; 151 crc2_ok = crc32(0, tmp_env2->data, ENV_SIZE) == 152 tmp_env2->crc; 153 154 if (!crc1_ok && !crc2_ok) { 155 set_default_env("!bad CRC"); 156 return 0; 157 } else if (crc1_ok && !crc2_ok) { 158 gd->env_valid = ENV_VALID; 159 } else if (!crc1_ok && crc2_ok) { 160 gd->env_valid = ENV_REDUND; 161 } else { 162 /* both ok - check serial */ 163 if (tmp_env1->flags == 255 && tmp_env2->flags == 0) 164 gd->env_valid = ENV_REDUND; 165 else if (tmp_env2->flags == 255 && tmp_env1->flags == 0) 166 gd->env_valid = ENV_VALID; 167 else if (tmp_env1->flags > tmp_env2->flags) 168 gd->env_valid = ENV_VALID; 169 else if (tmp_env2->flags > tmp_env1->flags) 170 gd->env_valid = ENV_REDUND; 171 else /* flags are equal - almost impossible */ 172 gd->env_valid = ENV_VALID; 173 } 174 175 if (gd->env_valid == ENV_VALID) 176 ep = tmp_env1; 177 else 178 ep = tmp_env2; 179 180 env_flags = ep->flags; 181 return env_import((char *)ep, 0); 182 } 183 #endif /* CONFIG_SYS_REDUNDAND_ENVIRONMENT */ 184 185 /* Export the environment and generate CRC for it. */ 186 int env_export(env_t *env_out) 187 { 188 char *res; 189 ssize_t len; 190 191 res = (char *)env_out->data; 192 len = hexport_r(&env_htab, '\0', 0, &res, ENV_SIZE, 0, NULL); 193 if (len < 0) { 194 pr_err("Cannot export environment: errno = %d\n", errno); 195 return 1; 196 } 197 198 env_out->crc = crc32(0, env_out->data, ENV_SIZE); 199 200 #ifdef CONFIG_SYS_REDUNDAND_ENVIRONMENT 201 env_out->flags = ++env_flags; /* increase the serial */ 202 #endif 203 204 return 0; 205 } 206 207 void env_relocate(void) 208 { 209 #if defined(CONFIG_NEEDS_MANUAL_RELOC) 210 env_reloc(); 211 env_htab.change_ok += gd->reloc_off; 212 #endif 213 if (gd->env_valid == ENV_INVALID) { 214 #if defined(CONFIG_ENV_IS_NOWHERE) || defined(CONFIG_SPL_BUILD) 215 /* Environment not changable */ 216 set_default_env(NULL); 217 #else 218 bootstage_error(BOOTSTAGE_ID_NET_CHECKSUM); 219 set_default_env("!bad CRC"); 220 #endif 221 } else { 222 env_load(); 223 } 224 } 225 226 #if defined(CONFIG_AUTO_COMPLETE) && !defined(CONFIG_SPL_BUILD) 227 int env_complete(char *var, int maxv, char *cmdv[], int bufsz, char *buf) 228 { 229 ENTRY *match; 230 int found, idx; 231 232 idx = 0; 233 found = 0; 234 cmdv[0] = NULL; 235 236 while ((idx = hmatch_r(var, idx, &match, &env_htab))) { 237 int vallen = strlen(match->key) + 1; 238 239 if (found >= maxv - 2 || bufsz < vallen) 240 break; 241 242 cmdv[found++] = buf; 243 memcpy(buf, match->key, vallen); 244 buf += vallen; 245 bufsz -= vallen; 246 } 247 248 qsort(cmdv, found, sizeof(cmdv[0]), strcmp_compar); 249 250 if (idx) 251 cmdv[found++] = "..."; 252 253 cmdv[found] = NULL; 254 return found; 255 } 256 #endif 257