nvram.c 3.1 KB

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