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 = NULL;
  56 #else
  57 env_t *env_ptr = (env_t *)CONFIG_ENV_ADDR;
  58 #endif
  59
  60 char * env_name_spec = "NVRAM";
  61
  62 extern uchar default_environment[];
  63
  64 uchar env_get_char_spec(int index)
  65 {
  66 #ifdef CONFIG_SYS_NVRAM_ACCESS_ROUTINE
  67         uchar c;
  68
  69         nvram_read(&c, CONFIG_ENV_ADDR+index, 1);
  70
  71         return c;
  72 #else
  73         return *((uchar *)(gd->env_addr + index));
  74 #endif
  75 }
  76
  77 void env_relocate_spec(void)
  78 {
  79         char buf[CONFIG_ENV_SIZE];
  80
  81 #if defined(CONFIG_SYS_NVRAM_ACCESS_ROUTINE)
  82         nvram_read(buf, CONFIG_ENV_ADDR, CONFIG_ENV_SIZE);
  83 #else
  84         memcpy(buf, (void*)CONFIG_ENV_ADDR, CONFIG_ENV_SIZE);
  85 #endif
  86         env_import(buf, 1);
  87 }
  88
  89 int saveenv(void)
  90 {
  91         env_t   env_new;
  92         ssize_t len;
  93         char    *res;
  94         int     rcode = 0;
  95
  96         res = (char *)&env_new.data;
  97         len = hexport('\0', &res, ENV_SIZE);
  98         if (len < 0) {
  99                 error("Cannot export environment: errno = %d\n", errno);
 100                 return 1;
 101         }
 102         env_new.crc = crc32(0, env_new.data, ENV_SIZE);
 103
 104 #ifdef CONFIG_SYS_NVRAM_ACCESS_ROUTINE
 105         nvram_write(CONFIG_ENV_ADDR, &env_new, CONFIG_ENV_SIZE);
 106 #else
 107         if (memcpy((char *)CONFIG_ENV_ADDR, &env_new, CONFIG_ENV_SIZE) == NULL)
 108                 rcode = 1;
 109 #endif
 110         return rcode;
 111 }
 112
 113
 114 /*
 115  * Initialize Environment use
 116  *
 117  * We are still running from ROM, so data use is limited
 118  */
 119 int env_init(void)
 120 {
 121 #if defined(CONFIG_SYS_NVRAM_ACCESS_ROUTINE)
 122         ulong crc;
 123         uchar data[ENV_SIZE];
 124
 125         nvram_read(&crc, CONFIG_ENV_ADDR, sizeof(ulong));
 126         nvram_read(data, CONFIG_ENV_ADDR+sizeof(ulong), ENV_SIZE);
 127
 128         if (crc32(0, data, ENV_SIZE) == crc) {
 129                 gd->env_addr  = (ulong)CONFIG_ENV_ADDR + sizeof(long);
 130 #else
 131         if (crc32(0, env_ptr->data, ENV_SIZE) == env_ptr->crc) {
 132                 gd->env_addr  = (ulong)&(env_ptr->data);
 133 #endif
 134                 gd->env_valid = 1;
 135         } else {
 136                 gd->env_addr  = (ulong)&default_environment[0];
 137                 gd->env_valid = 0;
 138         }
 139         return (0);
 140 }