common/env_nvram.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 /*
  28  * 09-18-2001 Andreas Heppel, Sysgo RTS GmbH <aheppel@sysgo.de>
  29  *
  30  * It might not be possible in all cases to use 'memcpy()' to copy
  31  * the environment to NVRAM, as the NVRAM might not be mapped into
  32  * the memory space. (I.e. this is the case for the BAB750). In those
  33  * cases it might be possible to access the NVRAM using a different
  34  * method. For example, the RTC on the BAB750 is accessible in IO
  35  * space using its address and data registers. To enable usage of
  36  * NVRAM in those cases I invented the functions 'nvram_read()' and
  37  * 'nvram_write()', which will be activated upon the configuration
  38  * #define CONFIG_SYS_NVRAM_ACCESS_ROUTINE. Note, that those functions are
  39  * strongly dependent on the used HW, and must be redefined for each
  40  * board that wants to use them.
  41  */
  42
  43 #include <common.h>
  44 #include <command.h>
  45 #include <environment.h>
  46 #include <linux/stddef.h>
  47 #include <search.h>
  48 #include <errno.h>
  49
  50 DECLARE_GLOBAL_DATA_PTR;
  51
  52 #ifdef CONFIG_SYS_NVRAM_ACCESS_ROUTINE
  53 extern void *nvram_read(void *dest, const long src, size_t count);
  54 extern void nvram_write(long dest, const void *src, size_t count);
  55 env_t *env_ptr;
  56 #else
  57 env_t *env_ptr = (env_t *)CONFIG_ENV_ADDR;
  58 #endif
  59
  60 char *env_name_spec = "NVRAM";
  61
  62 #ifdef CONFIG_SYS_NVRAM_ACCESS_ROUTINE
  63 static char env_buf[CONFIG_ENV_SIZE];
  64 #endif
  65
  66 #ifdef CONFIG_SYS_NVRAM_ACCESS_ROUTINE
  67 uchar env_get_char_spec(int index)
  68 {
  69         uchar c;
  70
  71         nvram_read(&c, CONFIG_ENV_ADDR + index, 1);
  72
  73         return c;
  74 }
  75 #endif
  76
  77 void env_relocate_spec(void)
  78 {
  79         char *buf;
  80
  81 #if defined(CONFIG_SYS_NVRAM_ACCESS_ROUTINE)
  82         buf = env_buf;
  83         nvram_read(buf, CONFIG_ENV_ADDR, CONFIG_ENV_SIZE);
  84 #else
  85         buf = (void *)CONFIG_ENV_ADDR;
  86 #endif
  87         env_import(buf, 1);
  88 }
  89
  90 int saveenv(void)
  91 {
  92 #ifdef CONFIG_SYS_NVRAM_ACCESS_ROUTINE
  93         env_t   *env_new = (env_t *)env_buf;
  94 #else
  95         env_t   *env_new = (env_t *)CONFIG_ENV_ADDR;
  96 #endif
  97         ssize_t len;
  98         char    *res;
  99         int     rcode = 0;
 100
 101         res = (char *)env_new->data;
 102         len = hexport_r(&env_htab, '\0', 0, &res, ENV_SIZE, 0, NULL);
 103         if (len < 0) {
 104                 error("Cannot export environment: errno = %d\n", errno);
 105                 return 1;
 106         }
 107         env_new->crc = crc32(0, env_new->data, ENV_SIZE);
 108
 109 #ifdef CONFIG_SYS_NVRAM_ACCESS_ROUTINE
 110         nvram_write(CONFIG_ENV_ADDR, env_new, CONFIG_ENV_SIZE);
 111 #endif
 112         return rcode;
 113 }
 114
 115 /*
 116  * Initialize Environment use
 117  *
 118  * We are still running from ROM, so data use is limited
 119  */
 120 int env_init(void)
 121 {
 122 #if defined(CONFIG_SYS_NVRAM_ACCESS_ROUTINE)
 123         ulong crc;
 124         uchar *data = env_buf;
 125
 126         nvram_read(&crc, CONFIG_ENV_ADDR, sizeof(ulong));
 127         nvram_read(data, CONFIG_ENV_ADDR + sizeof(ulong), ENV_SIZE);
 128
 129         if (crc32(0, data, ENV_SIZE) == crc) {
 130                 gd->env_addr    = (ulong)CONFIG_ENV_ADDR + sizeof(long);
 131 #else
 132         if (crc32(0, env_ptr->data, ENV_SIZE) == env_ptr->crc) {
 133                 gd->env_addr    = (ulong)&env_ptr->data;
 134 #endif
 135                 gd->env_valid   = 1;
 136         } else {
 137                 gd->env_addr    = (ulong)&default_environment[0];
 138                 gd->env_valid   = 0;
 139         }
 140
 141         return 0;
 142 }