LXR uboot/env/nvram.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/*
  11 * 09-18-2001 Andreas Heppel, Sysgo RTS GmbH <aheppel@sysgo.de>
  12 *
  13 * It might not be possible in all cases to use 'memcpy()' to copy
  14 * the environment to NVRAM, as the NVRAM might not be mapped into
  15 * the memory space. (I.e. this is the case for the BAB750). In those
  16 * cases it might be possible to access the NVRAM using a different
  17 * method. For example, the RTC on the BAB750 is accessible in IO
  18 * space using its address and data registers. To enable usage of
  19 * NVRAM in those cases I invented the functions 'nvram_read()' and
  20 * 'nvram_write()', which will be activated upon the configuration
  21 * #define CONFIG_SYS_NVRAM_ACCESS_ROUTINE. Note, that those functions are
  22 * strongly dependent on the used HW, and must be redefined for each
  23 * board that wants to use them.
  24 */
  25
  26#include <common.h>
  27#include <command.h>
  28#include <environment.h>
  29#include <linux/stddef.h>
  30#include <search.h>
  31#include <errno.h>
  32
  33DECLARE_GLOBAL_DATA_PTR;
  34
  35#ifdef CONFIG_SYS_NVRAM_ACCESS_ROUTINE
  36extern void *nvram_read(void *dest, const long src, size_t count);
  37extern void nvram_write(long dest, const void *src, size_t count);
  38#else
  39env_t *env_ptr = (env_t *)CONFIG_ENV_ADDR;
  40#endif
  41
  42#ifdef CONFIG_SYS_NVRAM_ACCESS_ROUTINE
  43/** Call this function from overridden env_get_char_spec() if you need
  44 * this functionality.
  45 */
  46int env_nvram_get_char(int index)
  47{
  48        uchar c;
  49
  50        nvram_read(&c, CONFIG_ENV_ADDR + index, 1);
  51
  52        return c;
  53}
  54#endif
  55
  56static int env_nvram_load(void)
  57{
  58        char buf[CONFIG_ENV_SIZE];
  59
  60#if defined(CONFIG_SYS_NVRAM_ACCESS_ROUTINE)
  61        nvram_read(buf, CONFIG_ENV_ADDR, CONFIG_ENV_SIZE);
  62#else
  63        memcpy(buf, (void *)CONFIG_ENV_ADDR, CONFIG_ENV_SIZE);
  64#endif
  65        return env_import(buf, 1);
  66}
  67
  68static int env_nvram_save(void)
  69{
  70        env_t   env_new;
  71        int     rcode = 0;
  72
  73        rcode = env_export(&env_new);
  74        if (rcode)
  75                return rcode;
  76
  77#ifdef CONFIG_SYS_NVRAM_ACCESS_ROUTINE
  78        nvram_write(CONFIG_ENV_ADDR, &env_new, CONFIG_ENV_SIZE);
  79#else
  80        if (memcpy((char *)CONFIG_ENV_ADDR, &env_new, CONFIG_ENV_SIZE) == NULL)
  81                rcode = 1;
  82#endif
  83        return rcode;
  84}
  85
  86/*
  87 * Initialize Environment use
  88 *
  89 * We are still running from ROM, so data use is limited
  90 */
  91static int env_nvram_init(void)
  92{
  93#if defined(CONFIG_SYS_NVRAM_ACCESS_ROUTINE)
  94        ulong crc;
  95        uchar data[ENV_SIZE];
  96
  97        nvram_read(&crc, CONFIG_ENV_ADDR, sizeof(ulong));
  98        nvram_read(data, CONFIG_ENV_ADDR + sizeof(ulong), ENV_SIZE);
  99
 100        if (crc32(0, data, ENV_SIZE) == crc) {
 101                gd->env_addr    = (ulong)CONFIG_ENV_ADDR + sizeof(long);
 102#else
 103        if (crc32(0, env_ptr->data, ENV_SIZE) == env_ptr->crc) {
 104                gd->env_addr    = (ulong)&env_ptr->data;
 105#endif
 106                gd->env_valid = ENV_VALID;
 107        } else {
 108                gd->env_addr    = (ulong)&default_environment[0];
 109                gd->env_valid   = ENV_INVALID;
 110        }
 111
 112        return 0;
 113}
 114
 115U_BOOT_ENV_LOCATION(nvram) = {
 116        .location       = ENVL_NVRAM,
 117        ENV_NAME("NVRAM")
 118        .load           = env_nvram_load,
 119        .save           = env_save_ptr(env_nvram_save),
 120        .init           = env_nvram_init,
 121};
 122