env/eeprom.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * (C) Copyright 2000-2010
   4  * Wolfgang Denk, DENX Software Engineering, [email protected].
   5  *
   6  * (C) Copyright 2001 Sysgo Real-Time Solutions, GmbH <www.elinos.com>
   7  * Andreas Heppel <[email protected]>
   8  */
   9
  10 #include <command.h>
  11 #include <eeprom.h>
  12 #include <env.h>
  13 #include <env_internal.h>
  14 #include <asm/global_data.h>
  15 #include <linux/stddef.h>
  16 #include <u-boot/crc.h>
  17 #include <search.h>
  18 #include <errno.h>
  19 #include <linux/compiler.h>     /* for BUG_ON */
  20
  21 DECLARE_GLOBAL_DATA_PTR;
  22
  23 static int env_eeprom_load(void)
  24 {
  25         char buf_env[CONFIG_ENV_SIZE];
  26         unsigned int off = CONFIG_ENV_OFFSET;
  27
  28 #ifdef CONFIG_ENV_OFFSET_REDUND
  29         ulong len, crc[2], crc_tmp;
  30         unsigned int off_env[2];
  31         uchar rdbuf[64], flags[2];
  32         int i, crc_ok[2] = {0, 0};
  33
  34         eeprom_init(-1);        /* prepare for EEPROM read/write */
  35
  36         off_env[0] = CONFIG_ENV_OFFSET;
  37         off_env[1] = CONFIG_ENV_OFFSET_REDUND;
  38
  39         for (i = 0; i < 2; i++) {
  40                 /* read CRC */
  41                 eeprom_read(CONFIG_SYS_I2C_EEPROM_ADDR,
  42                                 off_env[i] + offsetof(env_t, crc),
  43                                 (uchar *)&crc[i], sizeof(ulong));
  44                 /* read FLAGS */
  45                 eeprom_read(CONFIG_SYS_I2C_EEPROM_ADDR,
  46                                 off_env[i] + offsetof(env_t, flags),
  47                                 (uchar *)&flags[i], sizeof(uchar));
  48
  49                 crc_tmp = 0;
  50                 len = ENV_SIZE;
  51                 off = off_env[i] + offsetof(env_t, data);
  52                 while (len > 0) {
  53                         int n = (len > sizeof(rdbuf)) ? sizeof(rdbuf) : len;
  54
  55                         eeprom_read(CONFIG_SYS_I2C_EEPROM_ADDR, off,
  56                                         rdbuf, n);
  57
  58                         crc_tmp = crc32(crc_tmp, rdbuf, n);
  59                         len -= n;
  60                         off += n;
  61                 }
  62
  63                 if (crc_tmp == crc[i])
  64                         crc_ok[i] = 1;
  65         }
  66
  67         if (!crc_ok[0] && !crc_ok[1]) {
  68                 gd->env_addr    = 0;
  69                 gd->env_valid = ENV_INVALID;
  70         } else if (crc_ok[0] && !crc_ok[1]) {
  71                 gd->env_valid = ENV_VALID;
  72         } else if (!crc_ok[0] && crc_ok[1]) {
  73                 gd->env_valid = ENV_REDUND;
  74         } else {
  75                 /* both ok - check serial */
  76                 if (flags[0] == ENV_REDUND_ACTIVE &&
  77                     flags[1] == ENV_REDUND_OBSOLETE)
  78                         gd->env_valid = ENV_VALID;
  79                 else if (flags[0] == ENV_REDUND_OBSOLETE &&
  80                          flags[1] == ENV_REDUND_ACTIVE)
  81                         gd->env_valid = ENV_REDUND;
  82                 else if (flags[0] == 0xFF && flags[1] == 0)
  83                         gd->env_valid = ENV_REDUND;
  84                 else if (flags[1] == 0xFF && flags[0] == 0)
  85                         gd->env_valid = ENV_VALID;
  86                 else /* flags are equal - almost impossible */
  87                         gd->env_valid = ENV_VALID;
  88         }
  89
  90 #else /* CONFIG_ENV_OFFSET_REDUND */
  91         ulong crc, len, new;
  92         uchar rdbuf[64];
  93
  94         eeprom_init(-1);        /* prepare for EEPROM read/write */
  95
  96         /* read old CRC */
  97         eeprom_read(CONFIG_SYS_I2C_EEPROM_ADDR,
  98                         CONFIG_ENV_OFFSET + offsetof(env_t, crc),
  99                         (uchar *)&crc, sizeof(ulong));
 100
 101         new = 0;
 102         len = ENV_SIZE;
 103         off = offsetof(env_t, data);
 104         while (len > 0) {
 105                 int n = (len > sizeof(rdbuf)) ? sizeof(rdbuf) : len;
 106
 107                 eeprom_read(CONFIG_SYS_I2C_EEPROM_ADDR,
 108                                 CONFIG_ENV_OFFSET + off, rdbuf, n);
 109                 new = crc32(new, rdbuf, n);
 110                 len -= n;
 111                 off += n;
 112         }
 113
 114         if (crc == new) {
 115                 gd->env_valid = ENV_VALID;
 116         } else {
 117                 gd->env_valid = ENV_INVALID;
 118         }
 119 #endif /* CONFIG_ENV_OFFSET_REDUND */
 120
 121         off = CONFIG_ENV_OFFSET;
 122 #ifdef CONFIG_ENV_OFFSET_REDUND
 123         if (gd->env_valid == ENV_REDUND)
 124                 off = CONFIG_ENV_OFFSET_REDUND;
 125 #endif
 126
 127         eeprom_read(CONFIG_SYS_I2C_EEPROM_ADDR,
 128                 off, (uchar *)buf_env, CONFIG_ENV_SIZE);
 129
 130         return env_import(buf_env, 1, H_EXTERNAL);
 131 }
 132
 133 static int env_eeprom_save(void)
 134 {
 135         env_t   env_new;
 136         int     rc;
 137         unsigned int off        = CONFIG_ENV_OFFSET;
 138 #ifdef CONFIG_ENV_OFFSET_REDUND
 139         unsigned int off_red    = CONFIG_ENV_OFFSET_REDUND;
 140         char flag_obsolete      = ENV_REDUND_OBSOLETE;
 141 #endif
 142
 143         rc = env_export(&env_new);
 144         if (rc)
 145                 return rc;
 146
 147 #ifdef CONFIG_ENV_OFFSET_REDUND
 148         if (gd->env_valid == ENV_VALID) {
 149                 off     = CONFIG_ENV_OFFSET_REDUND;
 150                 off_red = CONFIG_ENV_OFFSET;
 151         }
 152
 153         env_new.flags = ENV_REDUND_ACTIVE;
 154 #endif
 155
 156         rc = eeprom_write(CONFIG_SYS_I2C_EEPROM_ADDR,
 157                               off, (uchar *)&env_new, CONFIG_ENV_SIZE);
 158
 159 #ifdef CONFIG_ENV_OFFSET_REDUND
 160         if (rc == 0) {
 161                 eeprom_write(CONFIG_SYS_I2C_EEPROM_ADDR,
 162                                  off_red + offsetof(env_t, flags),
 163                                  (uchar *)&flag_obsolete, 1);
 164
 165                 if (gd->env_valid == ENV_VALID)
 166                         gd->env_valid = ENV_REDUND;
 167                 else
 168                         gd->env_valid = ENV_VALID;
 169         }
 170 #endif
 171         return rc;
 172 }
 173
 174 U_BOOT_ENV_LOCATION(eeprom) = {
 175         .location       = ENVL_EEPROM,
 176         ENV_NAME("EEPROM")
 177         .load           = env_eeprom_load,
 178         .save           = env_save_ptr(env_eeprom_save),
 179 };