common/env_dataflash.c

   1 /*
   2  * LowLevel function for DataFlash environment support
   3  * Author : Gilles Gastaldi (Atmel)
   4  *
   5  * This program is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU General Public License as
   7  * published by the Free Software Foundation; either version 2 of
   8  * the License, or (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, write to the Free Software
  17  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
  18  * MA 02111-1307 USA
  19  */
  20 #include <common.h>
  21 #include <command.h>
  22 #include <environment.h>
  23 #include <linux/stddef.h>
  24 #include <dataflash.h>
  25 #include <search.h>
  26 #include <errno.h>
  27
  28 DECLARE_GLOBAL_DATA_PTR;
  29
  30 env_t *env_ptr;
  31
  32 char *env_name_spec = "dataflash";
  33
  34 uchar env_get_char_spec(int index)
  35 {
  36         uchar c;
  37
  38         read_dataflash(CONFIG_ENV_ADDR + index + offsetof(env_t, data),
  39                         1, (char *)&c);
  40         return c;
  41 }
  42
  43 void env_relocate_spec(void)
  44 {
  45         char buf[CONFIG_ENV_SIZE];
  46
  47         read_dataflash(CONFIG_ENV_ADDR, CONFIG_ENV_SIZE, buf);
  48
  49         env_import(buf, 1);
  50 }
  51
  52 #ifdef CONFIG_ENV_OFFSET_REDUND
  53 #error No support for redundant environment on dataflash yet!
  54 #endif
  55
  56 int saveenv(void)
  57 {
  58         env_t   env_new;
  59         ssize_t len;
  60         char    *res;
  61
  62         res = (char *)&env_new.data;
  63         len = hexport_r(&env_htab, '\0', 0, &res, ENV_SIZE, 0, NULL);
  64         if (len < 0) {
  65                 error("Cannot export environment: errno = %d\n", errno);
  66                 return 1;
  67         }
  68         env_new.crc = crc32(0, env_new.data, ENV_SIZE);
  69
  70         return write_dataflash(CONFIG_ENV_ADDR,
  71                                 (unsigned long)&env_new,
  72                                 CONFIG_ENV_SIZE);
  73 }
  74
  75 /*
  76  * Initialize environment use
  77  *
  78  * We are still running from ROM, so data use is limited.
  79  * Use a (moderately small) buffer on the stack
  80  */
  81 int env_init(void)
  82 {
  83         ulong crc, len = ENV_SIZE, new = 0;
  84         unsigned off;
  85         uchar buf[64];
  86
  87         if (gd->env_valid)
  88                 return 0;
  89
  90         AT91F_DataflashInit();  /* prepare for DATAFLASH read/write */
  91
  92         /* read old CRC */
  93         read_dataflash(CONFIG_ENV_ADDR + offsetof(env_t, crc),
  94                 sizeof(ulong), (char *)&crc);
  95
  96         off = offsetof(env_t, data);
  97         while (len > 0) {
  98                 int n = (len > sizeof(buf)) ? sizeof(buf) : len;
  99
 100                 read_dataflash(CONFIG_ENV_ADDR + off, n, (char *)buf);
 101
 102                 new = crc32(new, buf, n);
 103                 len -= n;
 104                 off += n;
 105         }
 106
 107         if (crc == new) {
 108                 gd->env_addr    = offsetof(env_t, data);
 109                 gd->env_valid   = 1;
 110         } else {
 111                 gd->env_addr    = (ulong)&default_environment[0];
 112                 gd->env_valid   = 0;
 113         }
 114
 115         return 0;
 116 }