arch/arc/lib/relocate.c

   1 /*
   2  * Copyright (C) 2013-2014 Synopsys, Inc. All rights reserved.
   3  *
   4  * SPDX-License-Identifier:     GPL-2.0+
   5  */
   6
   7 #include <common.h>
   8 #include <elf.h>
   9 #include <asm/sections.h>
  10
  11 DECLARE_GLOBAL_DATA_PTR;
  12
  13 /*
  14  * Base functionality is taken from x86 version with added ARC-specifics
  15  */
  16 int do_elf_reloc_fixups(void)
  17 {
  18         Elf32_Rela *re_src = (Elf32_Rela *)(&__rel_dyn_start);
  19         Elf32_Rela *re_end = (Elf32_Rela *)(&__rel_dyn_end);
  20
  21         Elf32_Addr *offset_ptr_rom, *last_offset = NULL;
  22         Elf32_Addr *offset_ptr_ram;
  23
  24         do {
  25                 /* Get the location from the relocation entry */
  26                 offset_ptr_rom = (Elf32_Addr *)re_src->r_offset;
  27
  28                 /* Check that the location of the relocation is in .text */
  29                 if (offset_ptr_rom >= (Elf32_Addr *)&__image_copy_start &&
  30                     offset_ptr_rom > last_offset) {
  31                         unsigned int val;
  32                         /* Switch to the in-RAM version */
  33                         offset_ptr_ram = (Elf32_Addr *)((ulong)offset_ptr_rom +
  34                                                         gd->reloc_off);
  35
  36                         /*
  37                          * Use "memcpy" because target location might be
  38                          * 16-bit aligned on ARC so we may need to read
  39                          * byte-by-byte. On attempt to read entire word by
  40                          * CPU throws an exception
  41                          */
  42                         memcpy(&val, offset_ptr_ram, sizeof(int));
  43
  44 #ifdef __LITTLE_ENDIAN__
  45                         /* If location in ".text" section swap value */
  46                         if ((unsigned int)offset_ptr_rom <
  47                             (unsigned int)&__ivt_end)
  48                                 val = (val << 16) | (val >> 16);
  49 #endif
  50
  51                         /* Check that the target points into executable */
  52                         if (val >= (unsigned int)&__image_copy_start && val <=
  53                             (unsigned int)&__image_copy_end) {
  54                                 val += gd->reloc_off;
  55 #ifdef __LITTLE_ENDIAN__
  56                                 /* If location in ".text" section swap value */
  57                                 if ((unsigned int)offset_ptr_rom <
  58                                     (unsigned int)&__ivt_end)
  59                                         val = (val << 16) | (val >> 16);
  60 #endif
  61                                 memcpy(offset_ptr_ram, &val, sizeof(int));
  62                         }
  63                 }
  64                 last_offset = offset_ptr_rom;
  65
  66         } while (++re_src < re_end);
  67
  68         return 0;
  69 }