relocate.c 3.8 KB

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  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 <log.h>
  8. #include <asm-generic/sections.h>
  9. #include <asm/global_data.h>
  10. extern ulong __image_copy_start;
  11. extern ulong __ivt_start;
  12. extern ulong __ivt_end;
  13. extern ulong __text_end;
  14. DECLARE_GLOBAL_DATA_PTR;
  15. int copy_uboot_to_ram(void)
  16. {
  17. size_t len = (size_t)&__image_copy_end - (size_t)&__image_copy_start;
  18. if (gd->flags & GD_FLG_SKIP_RELOC)
  19. return 0;
  20. memcpy((void *)gd->relocaddr, (void *)&__image_copy_start, len);
  21. return 0;
  22. }
  23. int clear_bss(void)
  24. {
  25. ulong dst_addr = (ulong)&__bss_start + gd->reloc_off;
  26. size_t len = (size_t)&__bss_end - (size_t)&__bss_start;
  27. memset((void *)dst_addr, 0x00, len);
  28. return 0;
  29. }
  30. /*
  31. * Base functionality is taken from x86 version with added ARC-specifics
  32. */
  33. int do_elf_reloc_fixups(void)
  34. {
  35. Elf32_Rela *re_src = (Elf32_Rela *)(&__rel_dyn_start);
  36. Elf32_Rela *re_end = (Elf32_Rela *)(&__rel_dyn_end);
  37. if (gd->flags & GD_FLG_SKIP_RELOC)
  38. return 0;
  39. debug("Section .rela.dyn is located at %08x-%08x\n",
  40. (unsigned int)re_src, (unsigned int)re_end);
  41. Elf32_Addr *offset_ptr_rom;
  42. Elf32_Addr *offset_ptr_ram;
  43. do {
  44. /* Get the location from the relocation entry */
  45. offset_ptr_rom = (Elf32_Addr *)re_src->r_offset;
  46. /* Check that the location of the relocation is in .text */
  47. if (offset_ptr_rom >= (Elf32_Addr *)&__image_copy_start &&
  48. offset_ptr_rom < (Elf32_Addr *)&__image_copy_end) {
  49. unsigned int val, do_swap = 0;
  50. /* Switch to the in-RAM version */
  51. offset_ptr_ram = (Elf32_Addr *)((ulong)offset_ptr_rom +
  52. gd->reloc_off);
  53. #ifdef __LITTLE_ENDIAN__
  54. /* If location in ".text" section swap value */
  55. if (((u32)offset_ptr_rom >= (u32)&__text_start &&
  56. (u32)offset_ptr_rom <= (u32)&__text_end)
  57. #if defined(__ARC700__) || defined(__ARC600__)
  58. || ((u32)offset_ptr_rom >= (u32)&__ivt_start &&
  59. (u32)offset_ptr_rom <= (u32)&__ivt_end)
  60. #endif
  61. )
  62. do_swap = 1;
  63. #endif
  64. debug("Patching value @ %08x (relocated to %08x)%s\n",
  65. (unsigned int)offset_ptr_rom,
  66. (unsigned int)offset_ptr_ram,
  67. do_swap ? ", middle-endian encoded" : "");
  68. /*
  69. * Use "memcpy" because target location might be
  70. * 16-bit aligned on ARC so we may need to read
  71. * byte-by-byte. On attempt to read entire word by
  72. * CPU throws an exception
  73. */
  74. memcpy(&val, offset_ptr_ram, sizeof(int));
  75. if (do_swap)
  76. val = (val << 16) | (val >> 16);
  77. /* Check that the target points into executable */
  78. if (val < (unsigned int)&__image_copy_start ||
  79. val > (unsigned int)&__image_copy_end) {
  80. /* TODO: Use panic() instead of debug()
  81. *
  82. * For some reason GCC might generate
  83. * fake relocation even for LD/SC of constant
  84. * inderectly. See an example below:
  85. * ----------------------->8--------------------
  86. * static int setup_mon_len(void)
  87. * {
  88. * gd->mon_len = (ulong)&__bss_end - CONFIG_SYS_MONITOR_BASE;
  89. * return 0;
  90. * }
  91. * ----------------------->8--------------------
  92. *
  93. * And that's what we get in the binary:
  94. * ----------------------->8--------------------
  95. * 10005cb4 <setup_mon_len>:
  96. * 10005cb4: 193c 3f80 0003 2f80 st 0x32f80,[r25,60]
  97. * 10005cb8: R_ARC_RELATIVE *ABS*-0x10000000
  98. * 10005cbc: 7fe0 j_s.d [blink]
  99. * 10005cbe: 700c mov_s r0,0
  100. * ----------------------->8--------------------
  101. */
  102. debug("Relocation target %08x points outside of image\n",
  103. val);
  104. }
  105. val += gd->reloc_off;
  106. if (do_swap)
  107. val = (val << 16) | (val >> 16);
  108. memcpy(offset_ptr_ram, &val, sizeof(int));
  109. }
  110. } while (++re_src < re_end);
  111. return 0;
  112. }