common/env_common.c

   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  * See file CREDITS for list of people who contributed to this
   9  * project.
  10  *
  11  * This program is free software; you can redistribute it and/or
  12  * modify it under the terms of the GNU General Public License as
  13  * published by the Free Software Foundation; either version 2 of
  14  * the License, or (at your option) any later version.
  15  *
  16  * This program is distributed in the hope that it will be useful,
  17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19  * GNU General Public License for more details.
  20  *
  21  * You should have received a copy of the GNU General Public License
  22  * along with this program; if not, write to the Free Software
  23  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
  24  * MA 02111-1307 USA
  25  */
  26
  27 #include <common.h>
  28 #include <command.h>
  29 #include <environment.h>
  30 #include <linux/stddef.h>
  31 #include <search.h>
  32 #include <errno.h>
  33 #include <malloc.h>
  34
  35 DECLARE_GLOBAL_DATA_PTR;
  36
  37 /************************************************************************
  38  * Default settings to be used when no valid environment is found
  39  */
  40 #include <env_default.h>
  41
  42 struct hsearch_data env_htab = {
  43         .change_ok = env_flags_validate,
  44 };
  45
  46 static uchar __env_get_char_spec(int index)
  47 {
  48         return *((uchar *)(gd->env_addr + index));
  49 }
  50 uchar env_get_char_spec(int)
  51         __attribute__((weak, alias("__env_get_char_spec")));
  52
  53 static uchar env_get_char_init(int index)
  54 {
  55         /* if crc was bad, use the default environment */
  56         if (gd->env_valid)
  57                 return env_get_char_spec(index);
  58         else
  59                 return default_environment[index];
  60 }
  61
  62 uchar env_get_char_memory(int index)
  63 {
  64         return *env_get_addr(index);
  65 }
  66
  67 uchar env_get_char(int index)
  68 {
  69         /* if relocated to RAM */
  70         if (gd->flags & GD_FLG_RELOC)
  71                 return env_get_char_memory(index);
  72         else
  73                 return env_get_char_init(index);
  74 }
  75
  76 const uchar *env_get_addr(int index)
  77 {
  78         if (gd->env_valid)
  79                 return (uchar *)(gd->env_addr + index);
  80         else
  81                 return &default_environment[index];
  82 }
  83
  84 /*
  85  * Read an environment variable as a boolean
  86  * Return -1 if variable does not exist (default to true)
  87  */
  88 int getenv_yesno(const char *var)
  89 {
  90         char *s = getenv(var);
  91
  92         if (s == NULL)
  93                 return -1;
  94         return (*s == '1' || *s == 'y' || *s == 'Y' || *s == 't' || *s == 'T') ?
  95                 1 : 0;
  96 }
  97
  98 /*
  99  * Look up the variable from the default environment
 100  */
 101 char *getenv_default(const char *name)
 102 {
 103         char *ret_val;
 104         unsigned long really_valid = gd->env_valid;
 105         unsigned long real_gd_flags = gd->flags;
 106
 107         /* Pretend that the image is bad. */
 108         gd->flags &= ~GD_FLG_ENV_READY;
 109         gd->env_valid = 0;
 110         ret_val = getenv(name);
 111         gd->env_valid = really_valid;
 112         gd->flags = real_gd_flags;
 113         return ret_val;
 114 }
 115
 116 void set_default_env(const char *s)
 117 {
 118         int flags = 0;
 119
 120         if (sizeof(default_environment) > ENV_SIZE) {
 121                 puts("*** Error - default environment is too large\n\n");
 122                 return;
 123         }
 124
 125         if (s) {
 126                 if (*s == '!') {
 127                         printf("*** Warning - %s, "
 128                                 "using default environment\n\n",
 129                                 s + 1);
 130                 } else {
 131                         flags = H_INTERACTIVE;
 132                         puts(s);
 133                 }
 134         } else {
 135                 puts("Using default environment\n\n");
 136         }
 137
 138         if (himport_r(&env_htab, (char *)default_environment,
 139                         sizeof(default_environment), '\0', flags,
 140                         0, NULL) == 0)
 141                 error("Environment import failed: errno = %d\n", errno);
 142
 143         gd->flags |= GD_FLG_ENV_READY;
 144 }
 145
 146
 147 /* [re]set individual variables to their value in the default environment */
 148 int set_default_vars(int nvars, char * const vars[])
 149 {
 150         /*
 151          * Special use-case: import from default environment
 152          * (and use \0 as a separator)
 153          */
 154         return himport_r(&env_htab, (const char *)default_environment,
 155                                 sizeof(default_environment), '\0',
 156                                 H_NOCLEAR | H_INTERACTIVE, nvars, vars);
 157 }
 158
 159 #ifndef CONFIG_SPL_BUILD
 160 /*
 161  * Check if CRC is valid and (if yes) import the environment.
 162  * Note that "buf" may or may not be aligned.
 163  */
 164 int env_import(const char *buf, int check)
 165 {
 166         env_t *ep = (env_t *)buf;
 167
 168         if (check) {
 169                 uint32_t crc;
 170
 171                 memcpy(&crc, &ep->crc, sizeof(crc));
 172
 173                 if (crc32(0, ep->data, ENV_SIZE) != crc) {
 174                         set_default_env("!bad CRC");
 175                         return 0;
 176                 }
 177         }
 178
 179         if (himport_r(&env_htab, (char *)ep->data, ENV_SIZE, '\0', 0,
 180                         0, NULL)) {
 181                 gd->flags |= GD_FLG_ENV_READY;
 182                 return 1;
 183         }
 184
 185         error("Cannot import environment: errno = %d\n", errno);
 186
 187         set_default_env("!import failed");
 188
 189         return 0;
 190 }
 191 #endif
 192
 193 void env_relocate(void)
 194 {
 195 #if defined(CONFIG_NEEDS_MANUAL_RELOC)
 196         env_reloc();
 197         env_htab.change_ok += gd->reloc_off;
 198 #endif
 199         if (gd->env_valid == 0) {
 200 #if defined(CONFIG_ENV_IS_NOWHERE) || defined(CONFIG_SPL_BUILD)
 201                 /* Environment not changable */
 202                 set_default_env(NULL);
 203 #else
 204                 bootstage_error(BOOTSTAGE_ID_NET_CHECKSUM);
 205                 set_default_env("!bad CRC");
 206 #endif
 207         } else {
 208                 env_relocate_spec();
 209         }
 210 }
 211
 212 #if defined(CONFIG_AUTO_COMPLETE) && !defined(CONFIG_SPL_BUILD)
 213 int env_complete(char *var, int maxv, char *cmdv[], int bufsz, char *buf)
 214 {
 215         ENTRY *match;
 216         int found, idx;
 217
 218         idx = 0;
 219         found = 0;
 220         cmdv[0] = NULL;
 221
 222         while ((idx = hmatch_r(var, idx, &match, &env_htab))) {
 223                 int vallen = strlen(match->key) + 1;
 224
 225                 if (found >= maxv - 2 || bufsz < vallen)
 226                         break;
 227
 228                 cmdv[found++] = buf;
 229                 memcpy(buf, match->key, vallen);
 230                 buf += vallen;
 231                 bufsz -= vallen;
 232         }
 233
 234         qsort(cmdv, found, sizeof(cmdv[0]), strcmp_compar);
 235
 236         if (idx)
 237                 cmdv[found++] = "...";
 238
 239         cmdv[found] = NULL;
 240         return found;
 241 }
 242 #endif