LXR uboot/common/env

   1/*
   2 * (C) Copyright 2000-2010
   3 * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
   4 *
   5 * (C) Copyright 2001 Sysgo Real-Time Solutions, GmbH <www.elinos.com>
   6 * Andreas Heppel <aheppel@sysgo.de>
   7
   8 * SPDX-License-Identifier:     GPL-2.0+
   9 */
  10
  11/*
  12 * 09-18-2001 Andreas Heppel, Sysgo RTS GmbH <aheppel@sysgo.de>
  13 *
  14 * It might not be possible in all cases to use 'memcpy()' to copy
  15 * the environment to NVRAM, as the NVRAM might not be mapped into
  16 * the memory space. (I.e. this is the case for the BAB750). In those
  17 * cases it might be possible to access the NVRAM using a different
  18 * method. For example, the RTC on the BAB750 is accessible in IO
  19 * space using its address and data registers. To enable usage of
  20 * NVRAM in those cases I invented the functions 'nvram_read()' and
  21 * 'nvram_write()', which will be activated upon the configuration
  22 * #define CONFIG_SYS_NVRAM_ACCESS_ROUTINE. Note, that those functions are
  23 * strongly dependent on the used HW, and must be redefined for each
  24 * board that wants to use them.
  25 */
  26
  27#include <common.h>
  28#include <command.h>
  29#include <environment.h>
  30#include <linux/stddef.h>
  31#include <search.h>
  32#include <errno.h>
  33
  34DECLARE_GLOBAL_DATA_PTR;
  35
  36#ifdef CONFIG_SYS_NVRAM_ACCESS_ROUTINE
  37extern void *nvram_read(void *dest, const long src, size_t count);
  38extern void nvram_write(long dest, const void *src, size_t count);
  39env_t *env_ptr;
  40#else
  41env_t *env_ptr = (env_t *)CONFIG_ENV_ADDR;
  42#endif
  43
  44char *env_name_spec = "NVRAM";
  45
  46#ifdef CONFIG_SYS_NVRAM_ACCESS_ROUTINE
  47uchar env_get_char_spec(int index)
  48{
  49        uchar c;
  50
  51        nvram_read(&c, CONFIG_ENV_ADDR + index, 1);
  52
  53        return c;
  54}
  55#endif
  56
  57void env_relocate_spec(void)
  58{
  59        char buf[CONFIG_ENV_SIZE];
  60
  61#if defined(CONFIG_SYS_NVRAM_ACCESS_ROUTINE)
  62        nvram_read(buf, CONFIG_ENV_ADDR, CONFIG_ENV_SIZE);
  63#else
  64        memcpy(buf, (void *)CONFIG_ENV_ADDR, CONFIG_ENV_SIZE);
  65#endif
  66        env_import(buf, 1);
  67}
  68
  69int saveenv(void)
  70{
  71        env_t   env_new;
  72        int     rcode = 0;
  73
  74        rcode = env_export(&env_new);
  75        if (rcode)
  76                return rcode;
  77
  78#ifdef CONFIG_SYS_NVRAM_ACCESS_ROUTINE
  79        nvram_write(CONFIG_ENV_ADDR, &env_new, CONFIG_ENV_SIZE);
  80#else
  81        if (memcpy((char *)CONFIG_ENV_ADDR, &env_new, CONFIG_ENV_SIZE) == NULL)
  82                rcode = 1;
  83#endif
  84        return rcode;
  85}
  86
  87/*
  88 * Initialize Environment use
  89 *
  90 * We are still running from ROM, so data use is limited
  91 */
  92int env_init(void)
  93{
  94#if defined(CONFIG_SYS_NVRAM_ACCESS_ROUTINE)
  95        ulong crc;
  96        uchar data[ENV_SIZE];
  97
  98        nvram_read(&crc, CONFIG_ENV_ADDR, sizeof(ulong));
  99        nvram_read(data, CONFIG_ENV_ADDR + sizeof(ulong), ENV_SIZE);
 100
 101        if (crc32(0, data, ENV_SIZE) == crc) {
 102                gd->env_addr    = (ulong)CONFIG_ENV_ADDR + sizeof(long);
 103#else
 104        if (crc32(0, env_ptr->data, ENV_SIZE) == env_ptr->crc) {
 105                gd->env_addr    = (ulong)&env_ptr->data;
 106#endif
 107                gd->env_valid   = 1;
 108        } else {
 109                gd->env_addr    = (ulong)&default_environment[0];
 110                gd->env_valid   = 0;
 111        }
 112
 113        return 0;
 114}
 115