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