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