env_dataflash.c 2.6 KB

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  1. /*
  2. * LowLevel function for DataFlash environment support
  3. * Author : Gilles Gastaldi (Atmel)
  4. *
  5. * This program is free software; you can redistribute it and/or
  6. * modify it under the terms of the GNU General Public License as
  7. * published by the Free Software Foundation; either version 2 of
  8. * the License, or (at your option) any later version.
  9. *
  10. * This program is distributed in the hope that it will be useful,
  11. * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12. * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13. * GNU General Public License for more details.
  14. *
  15. * You should have received a copy of the GNU General Public License
  16. * along with this program; if not, write to the Free Software
  17. * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
  18. * MA 02111-1307 USA
  19. */
  20. #include <common.h>
  21. #include <command.h>
  22. #include <environment.h>
  23. #include <linux/stddef.h>
  24. #include <dataflash.h>
  25. #include <search.h>
  26. #include <errno.h>
  27. DECLARE_GLOBAL_DATA_PTR;
  28. env_t *env_ptr;
  29. char *env_name_spec = "dataflash";
  30. uchar env_get_char_spec(int index)
  31. {
  32. uchar c;
  33. read_dataflash(CONFIG_ENV_ADDR + index + offsetof(env_t, data),
  34. 1, (char *)&c);
  35. return c;
  36. }
  37. void env_relocate_spec(void)
  38. {
  39. char buf[CONFIG_ENV_SIZE];
  40. read_dataflash(CONFIG_ENV_ADDR, CONFIG_ENV_SIZE, buf);
  41. env_import(buf, 1);
  42. }
  43. #ifdef CONFIG_ENV_OFFSET_REDUND
  44. #error No support for redundant environment on dataflash yet!
  45. #endif
  46. int saveenv(void)
  47. {
  48. env_t env_new;
  49. ssize_t len;
  50. char *res;
  51. res = (char *)&env_new.data;
  52. len = hexport_r(&env_htab, '\0', &res, ENV_SIZE, 0, NULL);
  53. if (len < 0) {
  54. error("Cannot export environment: errno = %d\n", errno);
  55. return 1;
  56. }
  57. env_new.crc = crc32(0, env_new.data, ENV_SIZE);
  58. return write_dataflash(CONFIG_ENV_ADDR,
  59. (unsigned long)&env_new,
  60. CONFIG_ENV_SIZE);
  61. }
  62. /*
  63. * Initialize environment use
  64. *
  65. * We are still running from ROM, so data use is limited.
  66. * Use a (moderately small) buffer on the stack
  67. */
  68. int env_init(void)
  69. {
  70. ulong crc, len = ENV_SIZE, new = 0;
  71. unsigned off;
  72. uchar buf[64];
  73. if (gd->env_valid)
  74. return 0;
  75. AT91F_DataflashInit(); /* prepare for DATAFLASH read/write */
  76. /* read old CRC */
  77. read_dataflash(CONFIG_ENV_ADDR + offsetof(env_t, crc),
  78. sizeof(ulong), (char *)&crc);
  79. off = offsetof(env_t, data);
  80. while (len > 0) {
  81. int n = (len > sizeof(buf)) ? sizeof(buf) : len;
  82. read_dataflash(CONFIG_ENV_ADDR + off, n, (char *)buf);
  83. new = crc32(new, buf, n);
  84. len -= n;
  85. off += n;
  86. }
  87. if (crc == new) {
  88. gd->env_addr = offsetof(env_t, data);
  89. gd->env_valid = 1;
  90. } else {
  91. gd->env_addr = (ulong)&default_environment[0];
  92. gd->env_valid = 0;
  93. }
  94. return 0;
  95. }