common/env_dataflash.c

   1 /* LowLevel function for DataFlash environment support
   2  * Author : Gilles Gastaldi (Atmel)
   3  *
   4  * This program is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU General Public License as
   6  * published by the Free Software Foundation; either version 2 of
   7  * the License, or (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write to the Free Software
  16  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
  17  * MA 02111-1307 USA
  18  *
  19  */
  20 #include <common.h>
  21
  22 #if defined(CFG_ENV_IS_IN_DATAFLASH) /* Environment is in DataFlash */
  23
  24 #include <command.h>
  25 #include <environment.h>
  26 #include <linux/stddef.h>
  27 #include <dataflash.h>
  28
  29 env_t *env_ptr = NULL;
  30
  31 char * env_name_spec = "dataflash";
  32
  33 extern int read_dataflash (unsigned long addr, unsigned long size, char
  34 *result);
  35 extern int write_dataflash (unsigned long addr_dest, unsigned long addr_src,
  36                      unsigned long size);
  37 extern int AT91F_DataflashInit (void);
  38 extern uchar default_environment[];
  39 /* extern int default_environment_size; */
  40
  41
  42 uchar env_get_char_spec (int index)
  43 {
  44         uchar c;
  45         read_dataflash (CFG_ENV_ADDR+index+offsetof(env_t,data),1,&c);
  46         return (c);
  47 }
  48
  49 void env_relocate_spec (void)
  50 {
  51         read_dataflash (CFG_ENV_ADDR,CFG_ENV_SIZE,(uchar *)env_ptr);
  52 }
  53
  54 int saveenv(void)
  55 {
  56 /* env must be copied to do not alter env structure in memory*/
  57 unsigned char temp[CFG_ENV_SIZE];
  58 int i;
  59         memcpy(temp, env_ptr, CFG_ENV_SIZE);
  60         return write_dataflash (CFG_ENV_ADDR, (unsigned long)temp, CFG_ENV_SIZE);
  61 }
  62
  63 /************************************************************************
  64  * Initialize Environment use
  65  *
  66  * We are still running from ROM, so data use is limited
  67  * Use a (moderately small) buffer on the stack
  68  */
  69 int env_init(void)
  70 {
  71         DECLARE_GLOBAL_DATA_PTR;
  72
  73         ulong crc, len, new;
  74         unsigned off;
  75         uchar buf[64];
  76         if (gd->env_valid == 0){
  77                 AT91F_DataflashInit();  /* prepare for DATAFLASH read/write */
  78
  79                 /* read old CRC */
  80                 read_dataflash (CFG_ENV_ADDR+offsetof(env_t,crc),sizeof(ulong),&crc);
  81                 new = 0;
  82                 len = ENV_SIZE;
  83                 off = offsetof(env_t,data);
  84                 while (len > 0) {
  85                         int n = (len > sizeof(buf)) ? sizeof(buf) : len;
  86                         read_dataflash (CFG_ENV_ADDR+off,n , buf);
  87                         new = crc32 (new, buf, n);
  88                         len -= n;
  89                         off += n;
  90                 }
  91                 if (crc == new) {
  92                         gd->env_addr  = offsetof(env_t,data);
  93                         gd->env_valid = 1;
  94                 } else {
  95                         gd->env_addr  = (ulong)&default_environment[0];
  96                         gd->env_valid = 0;
  97                 }
  98         }
  99
 100         return (0);
 101 }
 102
 103 #endif /* CFG_ENV_IS_IN_DATAFLASH */