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 = NULL;
  31
  32 char * env_name_spec = "dataflash";
  33
  34 extern int read_dataflash(unsigned long addr, unsigned long size,
  35         char *result);
  36 extern int write_dataflash(unsigned long addr_dest,
  37         unsigned long addr_src, unsigned long size);
  38 extern int AT91F_DataflashInit(void);
  39
  40 extern uchar default_environment[];
  41
  42 uchar env_get_char_spec(int index)
  43 {
  44         uchar c;
  45
  46         read_dataflash(CONFIG_ENV_ADDR + index + offsetof(env_t,data),
  47                         1, (char *)&c);
  48         return (c);
  49 }
  50
  51 void env_relocate_spec(void)
  52 {
  53         char buf[CONFIG_ENV_SIZE];
  54
  55         read_dataflash(CONFIG_ENV_ADDR, CONFIG_ENV_SIZE, buf);
  56
  57         env_import(buf, 1);
  58 }
  59
  60 #ifdef CONFIG_ENV_OFFSET_REDUND
  61 #error No support for redundant environment on dataflash yet!
  62 #endif
  63
  64 int saveenv(void)
  65 {
  66         env_t   env_new;
  67         ssize_t len;
  68         char    *res;
  69
  70         res = (char *)&env_new.data;
  71         len = hexport_r(&env_htab, '\0', &res, ENV_SIZE, 0, NULL);
  72         if (len < 0) {
  73                 error("Cannot export environment: errno = %d\n", errno);
  74                 return 1;
  75         }
  76         env_new.crc   = crc32(0, env_new.data, ENV_SIZE);
  77
  78         return write_dataflash(CONFIG_ENV_ADDR,
  79                                 (unsigned long)&env_new,
  80                                 CONFIG_ENV_SIZE);
  81 }
  82
  83 /*
  84  * Initialize environment use
  85  *
  86  * We are still running from ROM, so data use is limited.
  87  * Use a (moderately small) buffer on the stack
  88  */
  89 int env_init(void)
  90 {
  91         ulong crc, len, new;
  92         unsigned off;
  93         uchar buf[64];
  94
  95         if (gd->env_valid)
  96                 return 0;
  97
  98         AT91F_DataflashInit();  /* prepare for DATAFLASH read/write */
  99
 100         /* read old CRC */
 101         read_dataflash(CONFIG_ENV_ADDR + offsetof(env_t, crc),
 102                 sizeof(ulong), (char *)&crc);
 103
 104         new = 0;
 105         len = ENV_SIZE;
 106         off = offsetof(env_t,data);
 107         while (len > 0) {
 108                 int n = (len > sizeof(buf)) ? sizeof(buf) : len;
 109
 110                 read_dataflash(CONFIG_ENV_ADDR + off, n, (char *)buf);
 111
 112                 new = crc32 (new, buf, n);
 113                 len -= n;
 114                 off += n;
 115         }
 116
 117         if (crc == new) {
 118                 gd->env_addr  = offsetof(env_t,data);
 119                 gd->env_valid = 1;
 120         } else {
 121                 gd->env_addr  = (ulong)&default_environment[0];
 122                 gd->env_valid = 0;
 123         }
 124
 125         return 0;
 126 }