nvram.c 3.0 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 <environment.h>
  27. #include <linux/stddef.h>
  28. #include <search.h>
  29. #include <errno.h>
  30. DECLARE_GLOBAL_DATA_PTR;
  31. #ifdef CONFIG_SYS_NVRAM_ACCESS_ROUTINE
  32. extern void *nvram_read(void *dest, const long src, size_t count);
  33. extern void nvram_write(long dest, const void *src, size_t count);
  34. #else
  35. env_t *env_ptr = (env_t *)CONFIG_ENV_ADDR;
  36. #endif
  37. #ifdef CONFIG_SYS_NVRAM_ACCESS_ROUTINE
  38. /** Call this function from overridden env_get_char_spec() if you need
  39. * this functionality.
  40. */
  41. int env_nvram_get_char(int index)
  42. {
  43. uchar c;
  44. nvram_read(&c, CONFIG_ENV_ADDR + index, 1);
  45. return c;
  46. }
  47. #endif
  48. static int env_nvram_load(void)
  49. {
  50. char buf[CONFIG_ENV_SIZE];
  51. #if defined(CONFIG_SYS_NVRAM_ACCESS_ROUTINE)
  52. nvram_read(buf, CONFIG_ENV_ADDR, CONFIG_ENV_SIZE);
  53. #else
  54. memcpy(buf, (void *)CONFIG_ENV_ADDR, CONFIG_ENV_SIZE);
  55. #endif
  56. return env_import(buf, 1);
  57. }
  58. static int env_nvram_save(void)
  59. {
  60. env_t env_new;
  61. int rcode = 0;
  62. rcode = env_export(&env_new);
  63. if (rcode)
  64. return rcode;
  65. #ifdef CONFIG_SYS_NVRAM_ACCESS_ROUTINE
  66. nvram_write(CONFIG_ENV_ADDR, &env_new, CONFIG_ENV_SIZE);
  67. #else
  68. if (memcpy((char *)CONFIG_ENV_ADDR, &env_new, CONFIG_ENV_SIZE) == NULL)
  69. rcode = 1;
  70. #endif
  71. return rcode;
  72. }
  73. /*
  74. * Initialize Environment use
  75. *
  76. * We are still running from ROM, so data use is limited
  77. */
  78. static int env_nvram_init(void)
  79. {
  80. #if defined(CONFIG_SYS_NVRAM_ACCESS_ROUTINE)
  81. ulong crc;
  82. uchar data[ENV_SIZE];
  83. nvram_read(&crc, CONFIG_ENV_ADDR, sizeof(ulong));
  84. nvram_read(data, CONFIG_ENV_ADDR + sizeof(ulong), ENV_SIZE);
  85. if (crc32(0, data, ENV_SIZE) == crc) {
  86. gd->env_addr = (ulong)CONFIG_ENV_ADDR + sizeof(long);
  87. #else
  88. if (crc32(0, env_ptr->data, ENV_SIZE) == env_ptr->crc) {
  89. gd->env_addr = (ulong)&env_ptr->data;
  90. #endif
  91. gd->env_valid = ENV_VALID;
  92. } else {
  93. gd->env_addr = (ulong)&default_environment[0];
  94. gd->env_valid = ENV_INVALID;
  95. }
  96. return 0;
  97. }
  98. U_BOOT_ENV_LOCATION(nvram) = {
  99. .location = ENVL_NVRAM,
  100. ENV_NAME("NVRAM")
  101. .load = env_nvram_load,
  102. .save = env_save_ptr(env_nvram_save),
  103. .init = env_nvram_init,
  104. };