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