env/eeprom.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * (C) Copyright 2000-2010
   4  * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
   5  *
   6  * (C) Copyright 2001 Sysgo Real-Time Solutions, GmbH <www.elinos.com>
   7  * Andreas Heppel <aheppel@sysgo.de>
   8  */
   9
  10 #include <common.h>
  11 #include <command.h>
  12 #include <eeprom.h>
  13 #include <env.h>
  14 #include <env_internal.h>
  15 #include <asm/global_data.h>
  16 #include <linux/stddef.h>
  17 #include <u-boot/crc.h>
  18 #include <search.h>
  19 #include <errno.h>
  20 #include <linux/compiler.h>     /* for BUG_ON */
  21
  22 DECLARE_GLOBAL_DATA_PTR;
  23
  24 static int env_eeprom_load(void)
  25 {
  26         char buf_env[CONFIG_ENV_SIZE];
  27         unsigned int off = CONFIG_ENV_OFFSET;
  28
  29 #ifdef CONFIG_ENV_OFFSET_REDUND
  30         ulong len, crc[2], crc_tmp;
  31         unsigned int off_env[2];
  32         uchar rdbuf[64], flags[2];
  33         int i, crc_ok[2] = {0, 0};
  34
  35         eeprom_init(-1);        /* prepare for EEPROM read/write */
  36
  37         off_env[0] = CONFIG_ENV_OFFSET;
  38         off_env[1] = CONFIG_ENV_OFFSET_REDUND;
  39
  40         for (i = 0; i < 2; i++) {
  41                 /* read CRC */
  42                 eeprom_read(CONFIG_SYS_I2C_EEPROM_ADDR,
  43                                 off_env[i] + offsetof(env_t, crc),
  44                                 (uchar *)&crc[i], sizeof(ulong));
  45                 /* read FLAGS */
  46                 eeprom_read(CONFIG_SYS_I2C_EEPROM_ADDR,
  47                                 off_env[i] + offsetof(env_t, flags),
  48                                 (uchar *)&flags[i], sizeof(uchar));
  49
  50                 crc_tmp = 0;
  51                 len = ENV_SIZE;
  52                 off = off_env[i] + offsetof(env_t, data);
  53                 while (len > 0) {
  54                         int n = (len > sizeof(rdbuf)) ? sizeof(rdbuf) : len;
  55
  56                         eeprom_read(CONFIG_SYS_I2C_EEPROM_ADDR, off,
  57                                         rdbuf, n);
  58
  59                         crc_tmp = crc32(crc_tmp, rdbuf, n);
  60                         len -= n;
  61                         off += n;
  62                 }
  63
  64                 if (crc_tmp == crc[i])
  65                         crc_ok[i] = 1;
  66         }
  67
  68         if (!crc_ok[0] && !crc_ok[1]) {
  69                 gd->env_addr    = 0;
  70                 gd->env_valid = ENV_INVALID;
  71         } else if (crc_ok[0] && !crc_ok[1]) {
  72                 gd->env_valid = ENV_VALID;
  73         } else if (!crc_ok[0] && crc_ok[1]) {
  74                 gd->env_valid = ENV_REDUND;
  75         } else {
  76                 /* both ok - check serial */
  77                 if (flags[0] == ENV_REDUND_ACTIVE &&
  78                     flags[1] == ENV_REDUND_OBSOLETE)
  79                         gd->env_valid = ENV_VALID;
  80                 else if (flags[0] == ENV_REDUND_OBSOLETE &&
  81                          flags[1] == ENV_REDUND_ACTIVE)
  82                         gd->env_valid = ENV_REDUND;
  83                 else if (flags[0] == 0xFF && flags[1] == 0)
  84                         gd->env_valid = ENV_REDUND;
  85                 else if (flags[1] == 0xFF && flags[0] == 0)
  86                         gd->env_valid = ENV_VALID;
  87                 else /* flags are equal - almost impossible */
  88                         gd->env_valid = ENV_VALID;
  89         }
  90
  91 #else /* CONFIG_ENV_OFFSET_REDUND */
  92         ulong crc, len, new;
  93         uchar rdbuf[64];
  94
  95         eeprom_init(-1);        /* prepare for EEPROM read/write */
  96
  97         /* read old CRC */
  98         eeprom_read(CONFIG_SYS_I2C_EEPROM_ADDR,
  99                         CONFIG_ENV_OFFSET + offsetof(env_t, crc),
 100                         (uchar *)&crc, sizeof(ulong));
 101
 102         new = 0;
 103         len = ENV_SIZE;
 104         off = offsetof(env_t, data);
 105         while (len > 0) {
 106                 int n = (len > sizeof(rdbuf)) ? sizeof(rdbuf) : len;
 107
 108                 eeprom_read(CONFIG_SYS_I2C_EEPROM_ADDR,
 109                                 CONFIG_ENV_OFFSET + off, rdbuf, n);
 110                 new = crc32(new, rdbuf, n);
 111                 len -= n;
 112                 off += n;
 113         }
 114
 115         if (crc == new) {
 116                 gd->env_valid = ENV_VALID;
 117         } else {
 118                 gd->env_valid = ENV_INVALID;
 119         }
 120 #endif /* CONFIG_ENV_OFFSET_REDUND */
 121
 122         off = CONFIG_ENV_OFFSET;
 123 #ifdef CONFIG_ENV_OFFSET_REDUND
 124         if (gd->env_valid == ENV_REDUND)
 125                 off = CONFIG_ENV_OFFSET_REDUND;
 126 #endif
 127
 128         eeprom_read(CONFIG_SYS_I2C_EEPROM_ADDR,
 129                 off, (uchar *)buf_env, CONFIG_ENV_SIZE);
 130
 131         return env_import(buf_env, 1, H_EXTERNAL);
 132 }
 133
 134 static int env_eeprom_save(void)
 135 {
 136         env_t   env_new;
 137         int     rc;
 138         unsigned int off        = CONFIG_ENV_OFFSET;
 139 #ifdef CONFIG_ENV_OFFSET_REDUND
 140         unsigned int off_red    = CONFIG_ENV_OFFSET_REDUND;
 141         char flag_obsolete      = ENV_REDUND_OBSOLETE;
 142 #endif
 143
 144         rc = env_export(&env_new);
 145         if (rc)
 146                 return rc;
 147
 148 #ifdef CONFIG_ENV_OFFSET_REDUND
 149         if (gd->env_valid == ENV_VALID) {
 150                 off     = CONFIG_ENV_OFFSET_REDUND;
 151                 off_red = CONFIG_ENV_OFFSET;
 152         }
 153
 154         env_new.flags = ENV_REDUND_ACTIVE;
 155 #endif
 156
 157         rc = eeprom_write(CONFIG_SYS_I2C_EEPROM_ADDR,
 158                               off, (uchar *)&env_new, CONFIG_ENV_SIZE);
 159
 160 #ifdef CONFIG_ENV_OFFSET_REDUND
 161         if (rc == 0) {
 162                 eeprom_write(CONFIG_SYS_I2C_EEPROM_ADDR,
 163                                  off_red + offsetof(env_t, flags),
 164                                  (uchar *)&flag_obsolete, 1);
 165
 166                 if (gd->env_valid == ENV_VALID)
 167                         gd->env_valid = ENV_REDUND;
 168                 else
 169                         gd->env_valid = ENV_VALID;
 170         }
 171 #endif
 172         return rc;
 173 }
 174
 175 U_BOOT_ENV_LOCATION(eeprom) = {
 176         .location       = ENVL_EEPROM,
 177         ENV_NAME("EEPROM")
 178         .load           = env_eeprom_load,
 179         .save           = env_save_ptr(env_eeprom_save),
 180 };