relocate.c 3.7 KB

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135
  1. // SPDX-License-Identifier: GPL-2.0+
  2. /*
  3. * Copyright (C) 2013-2014 Synopsys, Inc. All rights reserved.
  4. */
  5. #include <common.h>
  6. #include <elf.h>
  7. #include <asm-generic/sections.h>
  8. extern ulong __image_copy_start;
  9. extern ulong __ivt_start;
  10. extern ulong __ivt_end;
  11. extern ulong __text_end;
  12. DECLARE_GLOBAL_DATA_PTR;
  13. int copy_uboot_to_ram(void)
  14. {
  15. size_t len = (size_t)&__image_copy_end - (size_t)&__image_copy_start;
  16. if (gd->flags & GD_FLG_SKIP_RELOC)
  17. return 0;
  18. memcpy((void *)gd->relocaddr, (void *)&__image_copy_start, len);
  19. return 0;
  20. }
  21. int clear_bss(void)
  22. {
  23. ulong dst_addr = (ulong)&__bss_start + gd->reloc_off;
  24. size_t len = (size_t)&__bss_end - (size_t)&__bss_start;
  25. memset((void *)dst_addr, 0x00, len);
  26. return 0;
  27. }
  28. /*
  29. * Base functionality is taken from x86 version with added ARC-specifics
  30. */
  31. int do_elf_reloc_fixups(void)
  32. {
  33. Elf32_Rela *re_src = (Elf32_Rela *)(&__rel_dyn_start);
  34. Elf32_Rela *re_end = (Elf32_Rela *)(&__rel_dyn_end);
  35. if (gd->flags & GD_FLG_SKIP_RELOC)
  36. return 0;
  37. debug("Section .rela.dyn is located at %08x-%08x\n",
  38. (unsigned int)re_src, (unsigned int)re_end);
  39. Elf32_Addr *offset_ptr_rom;
  40. Elf32_Addr *offset_ptr_ram;
  41. do {
  42. /* Get the location from the relocation entry */
  43. offset_ptr_rom = (Elf32_Addr *)re_src->r_offset;
  44. /* Check that the location of the relocation is in .text */
  45. if (offset_ptr_rom >= (Elf32_Addr *)&__image_copy_start &&
  46. offset_ptr_rom < (Elf32_Addr *)&__image_copy_end) {
  47. unsigned int val, do_swap = 0;
  48. /* Switch to the in-RAM version */
  49. offset_ptr_ram = (Elf32_Addr *)((ulong)offset_ptr_rom +
  50. gd->reloc_off);
  51. #ifdef __LITTLE_ENDIAN__
  52. /* If location in ".text" section swap value */
  53. if (((u32)offset_ptr_rom >= (u32)&__text_start &&
  54. (u32)offset_ptr_rom <= (u32)&__text_end)
  55. #if defined(__ARC700__) || defined(__ARC600__)
  56. || ((u32)offset_ptr_rom >= (u32)&__ivt_start &&
  57. (u32)offset_ptr_rom <= (u32)&__ivt_end)
  58. #endif
  59. )
  60. do_swap = 1;
  61. #endif
  62. debug("Patching value @ %08x (relocated to %08x)%s\n",
  63. (unsigned int)offset_ptr_rom,
  64. (unsigned int)offset_ptr_ram,
  65. do_swap ? ", middle-endian encoded" : "");
  66. /*
  67. * Use "memcpy" because target location might be
  68. * 16-bit aligned on ARC so we may need to read
  69. * byte-by-byte. On attempt to read entire word by
  70. * CPU throws an exception
  71. */
  72. memcpy(&val, offset_ptr_ram, sizeof(int));
  73. if (do_swap)
  74. val = (val << 16) | (val >> 16);
  75. /* Check that the target points into executable */
  76. if (val < (unsigned int)&__image_copy_start ||
  77. val > (unsigned int)&__image_copy_end) {
  78. /* TODO: Use panic() instead of debug()
  79. *
  80. * For some reason GCC might generate
  81. * fake relocation even for LD/SC of constant
  82. * inderectly. See an example below:
  83. * ----------------------->8--------------------
  84. * static int setup_mon_len(void)
  85. * {
  86. * gd->mon_len = (ulong)&__bss_end - CONFIG_SYS_MONITOR_BASE;
  87. * return 0;
  88. * }
  89. * ----------------------->8--------------------
  90. *
  91. * And that's what we get in the binary:
  92. * ----------------------->8--------------------
  93. * 10005cb4 <setup_mon_len>:
  94. * 10005cb4: 193c 3f80 0003 2f80 st 0x32f80,[r25,60]
  95. * 10005cb8: R_ARC_RELATIVE *ABS*-0x10000000
  96. * 10005cbc: 7fe0 j_s.d [blink]
  97. * 10005cbe: 700c mov_s r0,0
  98. * ----------------------->8--------------------
  99. */
  100. debug("Relocation target %08x points outside of image\n",
  101. val);
  102. }
  103. val += gd->reloc_off;
  104. if (do_swap)
  105. val = (val << 16) | (val >> 16);
  106. memcpy(offset_ptr_ram, &val, sizeof(int));
  107. }
  108. } while (++re_src < re_end);
  109. return 0;
  110. }