common/env_nvram.c

   1 /*
   2  * (C) Copyright 2000-2002
   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
  48 DECLARE_GLOBAL_DATA_PTR;
  49
  50 #ifdef CONFIG_SYS_NVRAM_ACCESS_ROUTINE
  51 extern void *nvram_read(void *dest, const long src, size_t count);
  52 extern void nvram_write(long dest, const void *src, size_t count);
  53 env_t *env_ptr = NULL;
  54 #else
  55 env_t *env_ptr = (env_t *)CONFIG_ENV_ADDR;
  56 #endif
  57
  58 char * env_name_spec = "NVRAM";
  59
  60 extern uchar default_environment[];
  61
  62 uchar env_get_char_spec (int index)
  63 {
  64 #ifdef CONFIG_SYS_NVRAM_ACCESS_ROUTINE
  65         uchar c;
  66
  67         nvram_read(&c, CONFIG_ENV_ADDR+index, 1);
  68
  69         return c;
  70 #else
  71         return *((uchar *)(gd->env_addr + index));
  72 #endif
  73 }
  74
  75 void env_relocate_spec (void)
  76 {
  77 #if defined(CONFIG_SYS_NVRAM_ACCESS_ROUTINE)
  78         nvram_read(env_ptr, CONFIG_ENV_ADDR, CONFIG_ENV_SIZE);
  79 #else
  80         memcpy (env_ptr, (void*)CONFIG_ENV_ADDR, CONFIG_ENV_SIZE);
  81 #endif
  82 }
  83
  84 int saveenv (void)
  85 {
  86         int rcode = 0;
  87 #ifdef CONFIG_SYS_NVRAM_ACCESS_ROUTINE
  88         nvram_write(CONFIG_ENV_ADDR, env_ptr, CONFIG_ENV_SIZE);
  89 #else
  90         if (memcpy ((char *)CONFIG_ENV_ADDR, env_ptr, CONFIG_ENV_SIZE) == NULL)
  91                     rcode = 1 ;
  92 #endif
  93         return rcode;
  94 }
  95
  96
  97 /************************************************************************
  98  * Initialize Environment use
  99  *
 100  * We are still running from ROM, so data use is limited
 101  */
 102 int env_init (void)
 103 {
 104 #if defined(CONFIG_SYS_NVRAM_ACCESS_ROUTINE)
 105         ulong crc;
 106         uchar data[ENV_SIZE];
 107         nvram_read (&crc, CONFIG_ENV_ADDR, sizeof(ulong));
 108         nvram_read (data, CONFIG_ENV_ADDR+sizeof(ulong), ENV_SIZE);
 109
 110         if (crc32(0, data, ENV_SIZE) == crc) {
 111                 gd->env_addr  = (ulong)CONFIG_ENV_ADDR + sizeof(long);
 112 #else
 113         if (crc32(0, env_ptr->data, ENV_SIZE) == env_ptr->crc) {
 114                 gd->env_addr  = (ulong)&(env_ptr->data);
 115 #endif
 116                 gd->env_valid = 1;
 117         } else {
 118                 gd->env_addr  = (ulong)&default_environment[0];
 119                 gd->env_valid = 0;
 120         }
 121         return (0);
 122 }