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 DECLARE_GLOBAL_DATA_PTR;
  30
  31 env_t *env_ptr = NULL;
  32
  33 char * env_name_spec = "dataflash";
  34
  35 extern int read_dataflash (unsigned long addr, unsigned long size, char
  36 *result);
  37 extern int write_dataflash (unsigned long addr_dest, unsigned long addr_src,
  38                      unsigned long size);
  39 extern int AT91F_DataflashInit (void);
  40 extern uchar default_environment[];
  41 /* extern int default_environment_size; */
  42
  43
  44 uchar env_get_char_spec (int index)
  45 {
  46         uchar c;
  47         read_dataflash(CFG_ENV_ADDR + index + offsetof(env_t,data),
  48         1, (char *)&c);
  49         return (c);
  50 }
  51
  52 void env_relocate_spec (void)
  53 {
  54         read_dataflash(CFG_ENV_ADDR, CFG_ENV_SIZE, (char *)env_ptr);
  55 }
  56
  57 int saveenv(void)
  58 {
  59         /* env must be copied to do not alter env structure in memory*/
  60         unsigned char temp[CFG_ENV_SIZE];
  61         memcpy(temp, env_ptr, CFG_ENV_SIZE);
  62         return write_dataflash(CFG_ENV_ADDR, (unsigned long)temp, CFG_ENV_SIZE);
  63 }
  64
  65 /************************************************************************
  66  * Initialize Environment use
  67  *
  68  * We are still running from ROM, so data use is limited
  69  * Use a (moderately small) buffer on the stack
  70  */
  71 int env_init(void)
  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),
  81                         sizeof(ulong), (char *)&crc);
  82                 new = 0;
  83                 len = ENV_SIZE;
  84                 off = offsetof(env_t,data);
  85                 while (len > 0) {
  86                         int n = (len > sizeof(buf)) ? sizeof(buf) : len;
  87                         read_dataflash(CFG_ENV_ADDR + off, n, (char *)buf);
  88                         new = crc32 (new, buf, n);
  89                         len -= n;
  90                         off += n;
  91                 }
  92                 if (crc == new) {
  93                         gd->env_addr  = offsetof(env_t,data);
  94                         gd->env_valid = 1;
  95                 } else {
  96                         gd->env_addr  = (ulong)&default_environment[0];
  97                         gd->env_valid = 0;
  98                 }
  99         }
 100
 101         return (0);
 102 }
 103
 104 #endif /* CFG_ENV_IS_IN_DATAFLASH */