env/dataflash.c

   1 /*
   2  * LowLevel function for DataFlash environment support
   3  * Author : Gilles Gastaldi (Atmel)
   4  *
   5  * SPDX-License-Identifier:     GPL-2.0+
   6  */
   7 #include <common.h>
   8 #include <command.h>
   9 #include <environment.h>
  10 #include <linux/stddef.h>
  11 #include <dataflash.h>
  12 #include <search.h>
  13 #include <errno.h>
  14
  15 DECLARE_GLOBAL_DATA_PTR;
  16
  17 env_t *env_ptr;
  18
  19 char *env_name_spec = "dataflash";
  20
  21 static unsigned char env_dataflash_get_char(int index)
  22 {
  23         uchar c;
  24
  25         read_dataflash(CONFIG_ENV_ADDR + index + offsetof(env_t, data),
  26                         1, (char *)&c);
  27         return c;
  28 }
  29
  30 static void env_dataflash_load(void)
  31 {
  32         ulong crc, new = 0;
  33         unsigned off;
  34         char buf[CONFIG_ENV_SIZE];
  35
  36         /* Read old CRC */
  37         read_dataflash(CONFIG_ENV_ADDR + offsetof(env_t, crc),
  38                        sizeof(ulong), (char *)&crc);
  39
  40         /* Read whole environment */
  41         read_dataflash(CONFIG_ENV_ADDR, CONFIG_ENV_SIZE, buf);
  42
  43         /* Calculate the CRC */
  44         off = offsetof(env_t, data);
  45         new = crc32(new, (unsigned char *)(buf + off), ENV_SIZE);
  46
  47         if (crc == new)
  48                 env_import(buf, 1);
  49         else
  50                 set_default_env("!bad CRC");
  51 }
  52
  53 #ifdef CONFIG_ENV_OFFSET_REDUND
  54 #error No support for redundant environment on dataflash yet!
  55 #endif
  56
  57 static int env_dataflash_save(void)
  58 {
  59         env_t env_new;
  60         int ret;
  61
  62         ret = env_export(&env_new);
  63         if (ret)
  64                 return ret;
  65
  66         return write_dataflash(CONFIG_ENV_ADDR,
  67                                 (unsigned long)&env_new,
  68                                 CONFIG_ENV_SIZE);
  69 }
  70
  71 U_BOOT_ENV_LOCATION(dataflash) = {
  72         .location       = ENVL_DATAFLASH,
  73         .get_char       = env_dataflash_get_char,
  74         .load           = env_dataflash_load,
  75         .save           = env_save_ptr(env_dataflash_save),
  76 };