arch/arc/lib/relocate.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * Copyright (C) 2013-2014 Synopsys, Inc. All rights reserved.
   4  */
   5
   6 #include <common.h>
   7 #include <elf.h>
   8 #include <asm-generic/sections.h>
   9
  10 extern ulong __image_copy_start;
  11 extern ulong __ivt_end;
  12
  13 DECLARE_GLOBAL_DATA_PTR;
  14
  15 int copy_uboot_to_ram(void)
  16 {
  17         size_t len = (size_t)&__image_copy_end - (size_t)&__image_copy_start;
  18
  19         if (gd->flags & GD_FLG_SKIP_RELOC)
  20                 return 0;
  21
  22         memcpy((void *)gd->relocaddr, (void *)&__image_copy_start, len);
  23
  24         return 0;
  25 }
  26
  27 int clear_bss(void)
  28 {
  29         ulong dst_addr = (ulong)&__bss_start + gd->reloc_off;
  30         size_t len = (size_t)&__bss_end - (size_t)&__bss_start;
  31
  32         memset((void *)dst_addr, 0x00, len);
  33
  34         return 0;
  35 }
  36
  37 /*
  38  * Base functionality is taken from x86 version with added ARC-specifics
  39  */
  40 int do_elf_reloc_fixups(void)
  41 {
  42         Elf32_Rela *re_src = (Elf32_Rela *)(&__rel_dyn_start);
  43         Elf32_Rela *re_end = (Elf32_Rela *)(&__rel_dyn_end);
  44
  45         if (gd->flags & GD_FLG_SKIP_RELOC)
  46                 return 0;
  47
  48         debug("Section .rela.dyn is located at %08x-%08x\n",
  49               (unsigned int)re_src, (unsigned int)re_end);
  50
  51         Elf32_Addr *offset_ptr_rom, *last_offset = NULL;
  52         Elf32_Addr *offset_ptr_ram;
  53
  54         do {
  55                 /* Get the location from the relocation entry */
  56                 offset_ptr_rom = (Elf32_Addr *)re_src->r_offset;
  57
  58                 /* Check that the location of the relocation is in .text */
  59                 if (offset_ptr_rom >= (Elf32_Addr *)&__image_copy_start &&
  60                     offset_ptr_rom > last_offset) {
  61                         unsigned int val;
  62                         /* Switch to the in-RAM version */
  63                         offset_ptr_ram = (Elf32_Addr *)((ulong)offset_ptr_rom +
  64                                                         gd->reloc_off);
  65
  66                         debug("Patching value @ %08x (relocated to %08x)\n",
  67                               (unsigned int)offset_ptr_rom,
  68                               (unsigned int)offset_ptr_ram);
  69
  70                         /*
  71                          * Use "memcpy" because target location might be
  72                          * 16-bit aligned on ARC so we may need to read
  73                          * byte-by-byte. On attempt to read entire word by
  74                          * CPU throws an exception
  75                          */
  76                         memcpy(&val, offset_ptr_ram, sizeof(int));
  77
  78 #ifdef __LITTLE_ENDIAN__
  79                         /* If location in ".text" section swap value */
  80                         if ((unsigned int)offset_ptr_rom <
  81                             (unsigned int)&__ivt_end)
  82                                 val = (val << 16) | (val >> 16);
  83 #endif
  84
  85                         /* Check that the target points into executable */
  86                         if (val >= (unsigned int)&__image_copy_start && val <=
  87                             (unsigned int)&__image_copy_end) {
  88                                 val += gd->reloc_off;
  89 #ifdef __LITTLE_ENDIAN__
  90                                 /* If location in ".text" section swap value */
  91                                 if ((unsigned int)offset_ptr_rom <
  92                                     (unsigned int)&__ivt_end)
  93                                         val = (val << 16) | (val >> 16);
  94 #endif
  95                                 memcpy(offset_ptr_ram, &val, sizeof(int));
  96                         }
  97                 }
  98                 last_offset = offset_ptr_rom;
  99
 100         } while (++re_src < re_end);
 101
 102         return 0;
 103 }