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 <env.h>
  29#include <env_internal.h>
  30#include <asm/global_data.h>
  31#include <linux/stddef.h>
  32#include <search.h>
  33#include <errno.h>
  34#include <u-boot/crc.h>
  35
  36DECLARE_GLOBAL_DATA_PTR;
  37
  38#ifdef CONFIG_SYS_NVRAM_ACCESS_ROUTINE
  39extern void *nvram_read(void *dest, const long src, size_t count);
  40extern void nvram_write(long dest, const void *src, size_t count);
  41#else
  42static env_t *env_ptr = (env_t *)CONFIG_ENV_ADDR;
  43#endif
  44
  45#ifdef CONFIG_SYS_NVRAM_ACCESS_ROUTINE
  46/** Call this function from overridden env_get_char_spec() if you need
  47 * this functionality.
  48 */
  49int env_nvram_get_char(int index)
  50{
  51        uchar c;
  52
  53        nvram_read(&c, CONFIG_ENV_ADDR + index, 1);
  54
  55        return c;
  56}
  57#endif
  58
  59static int env_nvram_load(void)
  60{
  61        char buf[CONFIG_ENV_SIZE];
  62
  63#if defined(CONFIG_SYS_NVRAM_ACCESS_ROUTINE)
  64        nvram_read(buf, CONFIG_ENV_ADDR, CONFIG_ENV_SIZE);
  65#else
  66        memcpy(buf, (void *)CONFIG_ENV_ADDR, CONFIG_ENV_SIZE);
  67#endif
  68        return env_import(buf, 1, H_EXTERNAL);
  69}
  70
  71static int env_nvram_save(void)
  72{
  73        env_t   env_new;
  74        int     rcode = 0;
  75
  76        rcode = env_export(&env_new);
  77        if (rcode)
  78                return rcode;
  79
  80#ifdef CONFIG_SYS_NVRAM_ACCESS_ROUTINE
  81        nvram_write(CONFIG_ENV_ADDR, &env_new, CONFIG_ENV_SIZE);
  82#else
  83        if (memcpy((char *)CONFIG_ENV_ADDR, &env_new, CONFIG_ENV_SIZE) == NULL)
  84                rcode = 1;
  85#endif
  86        return rcode;
  87}
  88
  89/*
  90 * Initialize Environment use
  91 *
  92 * We are still running from ROM, so data use is limited
  93 */
  94static int env_nvram_init(void)
  95{
  96#if defined(CONFIG_SYS_NVRAM_ACCESS_ROUTINE)
  97        ulong crc;
  98        uchar data[ENV_SIZE];
  99
 100        nvram_read(&crc, CONFIG_ENV_ADDR, sizeof(ulong));
 101        nvram_read(data, CONFIG_ENV_ADDR + sizeof(ulong), ENV_SIZE);
 102
 103        if (crc32(0, data, ENV_SIZE) == crc) {
 104                gd->env_addr    = (ulong)CONFIG_ENV_ADDR + sizeof(long);
 105#else
 106        if (crc32(0, env_ptr->data, ENV_SIZE) == env_ptr->crc) {
 107                gd->env_addr    = (ulong)&env_ptr->data;
 108#endif
 109                gd->env_valid = ENV_VALID;
 110        } else {
 111                gd->env_addr    = (ulong)&default_environment[0];
 112                gd->env_valid   = ENV_INVALID;
 113        }
 114
 115        return 0;
 116}
 117
 118U_BOOT_ENV_LOCATION(nvram) = {
 119        .location       = ENVL_NVRAM,
 120        ENV_NAME("NVRAM")
 121        .load           = env_nvram_load,
 122        .save           = env_save_ptr(env_nvram_save),
 123        .init           = env_nvram_init,
 124};
 125