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 static int env_dataflash_get_char(int index)
  18 {
  19         uchar c;
  20
  21         read_dataflash(CONFIG_ENV_ADDR + index + offsetof(env_t, data),
  22                         1, (char *)&c);
  23         return c;
  24 }
  25
  26 static int env_dataflash_load(void)
  27 {
  28         ulong crc, new = 0;
  29         unsigned off;
  30         char buf[CONFIG_ENV_SIZE];
  31
  32         /* Read old CRC */
  33         read_dataflash(CONFIG_ENV_ADDR + offsetof(env_t, crc),
  34                        sizeof(ulong), (char *)&crc);
  35
  36         /* Read whole environment */
  37         read_dataflash(CONFIG_ENV_ADDR, CONFIG_ENV_SIZE, buf);
  38
  39         /* Calculate the CRC */
  40         off = offsetof(env_t, data);
  41         new = crc32(new, (unsigned char *)(buf + off), ENV_SIZE);
  42
  43         if (crc == new)
  44                 env_import(buf, 1);
  45         else
  46                 set_default_env("!bad CRC");
  47
  48         return 0;
  49 }
  50
  51 #ifdef CONFIG_ENV_OFFSET_REDUND
  52 #error No support for redundant environment on dataflash yet!
  53 #endif
  54
  55 static int env_dataflash_save(void)
  56 {
  57         env_t env_new;
  58         int ret;
  59
  60         ret = env_export(&env_new);
  61         if (ret)
  62                 return ret;
  63
  64         return write_dataflash(CONFIG_ENV_ADDR,
  65                                 (unsigned long)&env_new,
  66                                 CONFIG_ENV_SIZE);
  67 }
  68
  69 U_BOOT_ENV_LOCATION(dataflash) = {
  70         .location       = ENVL_DATAFLASH,
  71         ENV_NAME("dataflash")
  72         .get_char       = env_dataflash_get_char,
  73         .load           = env_dataflash_load,
  74         .save           = env_save_ptr(env_dataflash_save),
  75 };