LXR uboot/env/common.c

   1// SPDX-License-Identifier: GPL-2.0+
   2/*
   3 * (C) Copyright 2000-2010
   4 * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
   5 *
   6 * (C) Copyright 2001 Sysgo Real-Time Solutions, GmbH <www.elinos.com>
   7 * Andreas Heppel <aheppel@sysgo.de>
   8 */
   9
  10#include <common.h>
  11#include <bootstage.h>
  12#include <command.h>
  13#include <env.h>
  14#include <env_internal.h>
  15#include <log.h>
  16#include <sort.h>
  17#include <asm/global_data.h>
  18#include <linux/stddef.h>
  19#include <search.h>
  20#include <errno.h>
  21#include <malloc.h>
  22#include <u-boot/crc.h>
  23#include <dm/ofnode.h>
  24
  25DECLARE_GLOBAL_DATA_PTR;
  26
  27/************************************************************************
  28 * Default settings to be used when no valid environment is found
  29 */
  30#include <env_default.h>
  31
  32struct hsearch_data env_htab = {
  33        .change_ok = env_flags_validate,
  34};
  35
  36/*
  37 * Read an environment variable as a boolean
  38 * Return -1 if variable does not exist (default to true)
  39 */
  40int env_get_yesno(const char *var)
  41{
  42        char *s = env_get(var);
  43
  44        if (s == NULL)
  45                return -1;
  46        return (*s == '1' || *s == 'y' || *s == 'Y' || *s == 't' || *s == 'T') ?
  47                1 : 0;
  48}
  49
  50/*
  51 * Look up the variable from the default environment
  52 */
  53char *env_get_default(const char *name)
  54{
  55        char *ret_val;
  56        unsigned long really_valid = gd->env_valid;
  57        unsigned long real_gd_flags = gd->flags;
  58
  59        /* Pretend that the image is bad. */
  60        gd->flags &= ~GD_FLG_ENV_READY;
  61        gd->env_valid = ENV_INVALID;
  62        ret_val = env_get(name);
  63        gd->env_valid = really_valid;
  64        gd->flags = real_gd_flags;
  65        return ret_val;
  66}
  67
  68void env_set_default(const char *s, int flags)
  69{
  70        if (sizeof(default_environment) > ENV_SIZE) {
  71                puts("*** Error - default environment is too large\n\n");
  72                return;
  73        }
  74
  75        if (s) {
  76                if ((flags & H_INTERACTIVE) == 0) {
  77                        printf("*** Warning - %s, "
  78                                "using default environment\n\n", s);
  79                } else {
  80                        puts(s);
  81                }
  82        } else {
  83                debug("Using default environment\n");
  84        }
  85
  86        flags |= H_DEFAULT;
  87        if (himport_r(&env_htab, (char *)default_environment,
  88                        sizeof(default_environment), '\0', flags, 0,
  89                        0, NULL) == 0)
  90                pr_err("## Error: Environment import failed: errno = %d\n",
  91                       errno);
  92
  93        gd->flags |= GD_FLG_ENV_READY;
  94        gd->flags |= GD_FLG_ENV_DEFAULT;
  95}
  96
  97
  98/* [re]set individual variables to their value in the default environment */
  99int env_set_default_vars(int nvars, char * const vars[], int flags)
 100{
 101        /*
 102         * Special use-case: import from default environment
 103         * (and use \0 as a separator)
 104         */
 105        flags |= H_NOCLEAR | H_DEFAULT;
 106        return himport_r(&env_htab, (const char *)default_environment,
 107                                sizeof(default_environment), '\0',
 108                                flags, 0, nvars, vars);
 109}
 110
 111/*
 112 * Check if CRC is valid and (if yes) import the environment.
 113 * Note that "buf" may or may not be aligned.
 114 */
 115int env_import(const char *buf, int check, int flags)
 116{
 117        env_t *ep = (env_t *)buf;
 118
 119        if (check) {
 120                uint32_t crc;
 121
 122                memcpy(&crc, &ep->crc, sizeof(crc));
 123
 124                if (crc32(0, ep->data, ENV_SIZE) != crc) {
 125                        env_set_default("bad CRC", 0);
 126                        return -ENOMSG; /* needed for env_load() */
 127                }
 128        }
 129
 130        if (himport_r(&env_htab, (char *)ep->data, ENV_SIZE, '\0', flags, 0,
 131                        0, NULL)) {
 132                gd->flags |= GD_FLG_ENV_READY;
 133                return 0;
 134        }
 135
 136        pr_err("Cannot import environment: errno = %d\n", errno);
 137
 138        env_set_default("import failed", 0);
 139
 140        return -EIO;
 141}
 142
 143#ifdef CONFIG_SYS_REDUNDAND_ENVIRONMENT
 144static unsigned char env_flags;
 145
 146int env_check_redund(const char *buf1, int buf1_read_fail,
 147                     const char *buf2, int buf2_read_fail)
 148{
 149        int crc1_ok = 0, crc2_ok = 0;
 150        env_t *tmp_env1, *tmp_env2;
 151
 152        tmp_env1 = (env_t *)buf1;
 153        tmp_env2 = (env_t *)buf2;
 154
 155        if (buf1_read_fail && buf2_read_fail) {
 156                puts("*** Error - No Valid Environment Area found\n");
 157                return -EIO;
 158        } else if (buf1_read_fail || buf2_read_fail) {
 159                puts("*** Warning - some problems detected ");
 160                puts("reading environment; recovered successfully\n");
 161        }
 162
 163        if (!buf1_read_fail)
 164                crc1_ok = crc32(0, tmp_env1->data, ENV_SIZE) ==
 165                                tmp_env1->crc;
 166        if (!buf2_read_fail)
 167                crc2_ok = crc32(0, tmp_env2->data, ENV_SIZE) ==
 168                                tmp_env2->crc;
 169
 170        if (!crc1_ok && !crc2_ok) {
 171                return -ENOMSG; /* needed for env_load() */
 172        } else if (crc1_ok && !crc2_ok) {
 173                gd->env_valid = ENV_VALID;
 174        } else if (!crc1_ok && crc2_ok) {
 175                gd->env_valid = ENV_REDUND;
 176        } else {
 177                /* both ok - check serial */
 178                if (tmp_env1->flags == 255 && tmp_env2->flags == 0)
 179                        gd->env_valid = ENV_REDUND;
 180                else if (tmp_env2->flags == 255 && tmp_env1->flags == 0)
 181                        gd->env_valid = ENV_VALID;
 182                else if (tmp_env1->flags > tmp_env2->flags)
 183                        gd->env_valid = ENV_VALID;
 184                else if (tmp_env2->flags > tmp_env1->flags)
 185                        gd->env_valid = ENV_REDUND;
 186                else /* flags are equal - almost impossible */
 187                        gd->env_valid = ENV_VALID;
 188        }
 189
 190        return 0;
 191}
 192
 193int env_import_redund(const char *buf1, int buf1_read_fail,
 194                      const char *buf2, int buf2_read_fail,
 195                      int flags)
 196{
 197        env_t *ep;
 198        int ret;
 199
 200        ret = env_check_redund(buf1, buf1_read_fail, buf2, buf2_read_fail);
 201
 202        if (ret == -EIO) {
 203                env_set_default("bad env area", 0);
 204                return -EIO;
 205        } else if (ret == -ENOMSG) {
 206                env_set_default("bad CRC", 0);
 207                return -ENOMSG;
 208        }
 209
 210        if (gd->env_valid == ENV_VALID)
 211                ep = (env_t *)buf1;
 212        else
 213                ep = (env_t *)buf2;
 214
 215        env_flags = ep->flags;
 216
 217        return env_import((char *)ep, 0, flags);
 218}
 219#endif /* CONFIG_SYS_REDUNDAND_ENVIRONMENT */
 220
 221/* Export the environment and generate CRC for it. */
 222int env_export(env_t *env_out)
 223{
 224        char *res;
 225        ssize_t len;
 226
 227        res = (char *)env_out->data;
 228        len = hexport_r(&env_htab, '\0', 0, &res, ENV_SIZE, 0, NULL);
 229        if (len < 0) {
 230                pr_err("Cannot export environment: errno = %d\n", errno);
 231                return 1;
 232        }
 233
 234        env_out->crc = crc32(0, env_out->data, ENV_SIZE);
 235
 236#ifdef CONFIG_SYS_REDUNDAND_ENVIRONMENT
 237        env_out->flags = ++env_flags; /* increase the serial */
 238#endif
 239
 240        return 0;
 241}
 242
 243void env_relocate(void)
 244{
 245#if defined(CONFIG_NEEDS_MANUAL_RELOC)
 246        env_reloc();
 247        env_fix_drivers();
 248        env_htab.change_ok += gd->reloc_off;
 249#endif
 250        if (gd->env_valid == ENV_INVALID) {
 251#if defined(CONFIG_ENV_IS_NOWHERE) || defined(CONFIG_SPL_BUILD)
 252                /* Environment not changable */
 253                env_set_default(NULL, 0);
 254#else
 255                bootstage_error(BOOTSTAGE_ID_NET_CHECKSUM);
 256                env_set_default("bad CRC", 0);
 257#endif
 258        } else {
 259                env_load();
 260        }
 261}
 262
 263#ifdef CONFIG_AUTO_COMPLETE
 264int env_complete(char *var, int maxv, char *cmdv[], int bufsz, char *buf,
 265                 bool dollar_comp)
 266{
 267        struct env_entry *match;
 268        int found, idx;
 269
 270        if (dollar_comp) {
 271                /*
 272                 * When doing $ completion, the first character should
 273                 * obviously be a '$'.
 274                 */
 275                if (var[0] != '$')
 276                        return 0;
 277
 278                var++;
 279
 280                /*
 281                 * The second one, if present, should be a '{', as some
 282                 * configuration of the u-boot shell expand ${var} but not
 283                 * $var.
 284                 */
 285                if (var[0] == '{')
 286                        var++;
 287                else if (var[0] != '\0')
 288                        return 0;
 289        }
 290
 291        idx = 0;
 292        found = 0;
 293        cmdv[0] = NULL;
 294
 295
 296        while ((idx = hmatch_r(var, idx, &match, &env_htab))) {
 297                int vallen = strlen(match->key) + 1;
 298
 299                if (found >= maxv - 2 ||
 300                    bufsz < vallen + (dollar_comp ? 3 : 0))
 301                        break;
 302
 303                cmdv[found++] = buf;
 304
 305                /* Add the '${' prefix to each var when doing $ completion. */
 306                if (dollar_comp) {
 307                        strcpy(buf, "${");
 308                        buf += 2;
 309                        bufsz -= 3;
 310                }
 311
 312                memcpy(buf, match->key, vallen);
 313                buf += vallen;
 314                bufsz -= vallen;
 315
 316                if (dollar_comp) {
 317                        /*
 318                         * This one is a bit odd: vallen already contains the
 319                         * '\0' character but we need to add the '}' suffix,
 320                         * hence the buf - 1 here. strcpy() will add the '\0'
 321                         * character just after '}'. buf is then incremented
 322                         * to account for the extra '}' we just added.
 323                         */
 324                        strcpy(buf - 1, "}");
 325                        buf++;
 326                }
 327        }
 328
 329        qsort(cmdv, found, sizeof(cmdv[0]), strcmp_compar);
 330
 331        if (idx)
 332                cmdv[found++] = dollar_comp ? "${...}" : "...";
 333
 334        cmdv[found] = NULL;
 335        return found;
 336}
 337#endif
 338
 339#ifdef CONFIG_ENV_IMPORT_FDT
 340void env_import_fdt(void)
 341{
 342        const char *path;
 343        struct ofprop prop;
 344        ofnode node;
 345        int res;
 346
 347        path = env_get("env_fdt_path");
 348        if (!path || !path[0])
 349                return;
 350
 351        node = ofnode_path(path);
 352        if (!ofnode_valid(node)) {
 353                printf("Warning: device tree node '%s' not found\n", path);
 354                return;
 355        }
 356
 357        for (res = ofnode_get_first_property(node, &prop);
 358             !res;
 359             res = ofnode_get_next_property(&prop)) {
 360                const char *name, *val;
 361
 362                val = ofnode_get_property_by_prop(&prop, &name, NULL);
 363                env_set(name, val);
 364        }
 365}
 366#endif
 367