ar7part.c 3.3 KB

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  1. // SPDX-License-Identifier: GPL-2.0-or-later
  2. /*
  3. * Copyright © 2007 Eugene Konev <[email protected]>
  4. *
  5. * TI AR7 flash partition table.
  6. * Based on ar7 map by Felix Fietkau <[email protected]>
  7. */
  8. #include <linux/kernel.h>
  9. #include <linux/slab.h>
  10. #include <linux/mtd/mtd.h>
  11. #include <linux/mtd/partitions.h>
  12. #include <linux/memblock.h>
  13. #include <linux/module.h>
  14. #include <uapi/linux/magic.h>
  15. #define AR7_PARTS 4
  16. #define ROOT_OFFSET 0xe0000
  17. #define LOADER_MAGIC1 le32_to_cpu(0xfeedfa42)
  18. #define LOADER_MAGIC2 le32_to_cpu(0xfeed1281)
  19. struct ar7_bin_rec {
  20. unsigned int checksum;
  21. unsigned int length;
  22. unsigned int address;
  23. };
  24. static int create_mtd_partitions(struct mtd_info *master,
  25. const struct mtd_partition **pparts,
  26. struct mtd_part_parser_data *data)
  27. {
  28. struct ar7_bin_rec header;
  29. unsigned int offset;
  30. size_t len;
  31. unsigned int pre_size = master->erasesize, post_size = 0;
  32. unsigned int root_offset = ROOT_OFFSET;
  33. int retries = 10;
  34. struct mtd_partition *ar7_parts;
  35. ar7_parts = kcalloc(AR7_PARTS, sizeof(*ar7_parts), GFP_KERNEL);
  36. if (!ar7_parts)
  37. return -ENOMEM;
  38. ar7_parts[0].name = "loader";
  39. ar7_parts[0].offset = 0;
  40. ar7_parts[0].size = master->erasesize;
  41. ar7_parts[0].mask_flags = MTD_WRITEABLE;
  42. ar7_parts[1].name = "config";
  43. ar7_parts[1].offset = 0;
  44. ar7_parts[1].size = master->erasesize;
  45. ar7_parts[1].mask_flags = 0;
  46. do { /* Try 10 blocks starting from master->erasesize */
  47. offset = pre_size;
  48. mtd_read(master, offset, sizeof(header), &len,
  49. (uint8_t *)&header);
  50. if (!strncmp((char *)&header, "TIENV0.8", 8))
  51. ar7_parts[1].offset = pre_size;
  52. if (header.checksum == LOADER_MAGIC1)
  53. break;
  54. if (header.checksum == LOADER_MAGIC2)
  55. break;
  56. pre_size += master->erasesize;
  57. } while (retries--);
  58. pre_size = offset;
  59. if (!ar7_parts[1].offset) {
  60. ar7_parts[1].offset = master->size - master->erasesize;
  61. post_size = master->erasesize;
  62. }
  63. switch (header.checksum) {
  64. case LOADER_MAGIC1:
  65. while (header.length) {
  66. offset += sizeof(header) + header.length;
  67. mtd_read(master, offset, sizeof(header), &len,
  68. (uint8_t *)&header);
  69. }
  70. root_offset = offset + sizeof(header) + 4;
  71. break;
  72. case LOADER_MAGIC2:
  73. while (header.length) {
  74. offset += sizeof(header) + header.length;
  75. mtd_read(master, offset, sizeof(header), &len,
  76. (uint8_t *)&header);
  77. }
  78. root_offset = offset + sizeof(header) + 4 + 0xff;
  79. root_offset &= ~(uint32_t)0xff;
  80. break;
  81. default:
  82. printk(KERN_WARNING "Unknown magic: %08x\n", header.checksum);
  83. break;
  84. }
  85. mtd_read(master, root_offset, sizeof(header), &len, (u8 *)&header);
  86. if (header.checksum != SQUASHFS_MAGIC) {
  87. root_offset += master->erasesize - 1;
  88. root_offset &= ~(master->erasesize - 1);
  89. }
  90. ar7_parts[2].name = "linux";
  91. ar7_parts[2].offset = pre_size;
  92. ar7_parts[2].size = master->size - pre_size - post_size;
  93. ar7_parts[2].mask_flags = 0;
  94. ar7_parts[3].name = "rootfs";
  95. ar7_parts[3].offset = root_offset;
  96. ar7_parts[3].size = master->size - root_offset - post_size;
  97. ar7_parts[3].mask_flags = 0;
  98. *pparts = ar7_parts;
  99. return AR7_PARTS;
  100. }
  101. static struct mtd_part_parser ar7_parser = {
  102. .parse_fn = create_mtd_partitions,
  103. .name = "ar7part",
  104. };
  105. module_mtd_part_parser(ar7_parser);
  106. MODULE_LICENSE("GPL");
  107. MODULE_AUTHOR( "Felix Fietkau <[email protected]>, "
  108. "Eugene Konev <[email protected]>");
  109. MODULE_DESCRIPTION("MTD partitioning for TI AR7");