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         Elf32_Addr *offset_ptr_rom, *last_offset = NULL;
  41         Elf32_Addr *offset_ptr_ram;
  42
  43         do {
  44                 /* Get the location from the relocation entry */
  45                 offset_ptr_rom = (Elf32_Addr *)re_src->r_offset;
  46
  47                 /* Check that the location of the relocation is in .text */
  48                 if (offset_ptr_rom >= (Elf32_Addr *)&__image_copy_start &&
  49                     offset_ptr_rom > last_offset) {
  50                         unsigned int val;
  51                         /* Switch to the in-RAM version */
  52                         offset_ptr_ram = (Elf32_Addr *)((ulong)offset_ptr_rom +
  53                                                         gd->reloc_off);
  54
  55                         /*
  56                          * Use "memcpy" because target location might be
  57                          * 16-bit aligned on ARC so we may need to read
  58                          * byte-by-byte. On attempt to read entire word by
  59                          * CPU throws an exception
  60                          */
  61                         memcpy(&val, offset_ptr_ram, sizeof(int));
  62
  63 #ifdef __LITTLE_ENDIAN__
  64                         /* If location in ".text" section swap value */
  65                         if ((unsigned int)offset_ptr_rom <
  66                             (unsigned int)&__ivt_end)
  67                                 val = (val << 16) | (val >> 16);
  68 #endif
  69
  70                         /* Check that the target points into executable */
  71                         if (val >= (unsigned int)&__image_copy_start && val <=
  72                             (unsigned int)&__image_copy_end) {
  73                                 val += gd->reloc_off;
  74 #ifdef __LITTLE_ENDIAN__
  75                                 /* If location in ".text" section swap value */
  76                                 if ((unsigned int)offset_ptr_rom <
  77                                     (unsigned int)&__ivt_end)
  78                                         val = (val << 16) | (val >> 16);
  79 #endif
  80                                 memcpy(offset_ptr_ram, &val, sizeof(int));
  81                         }
  82                 }
  83                 last_offset = offset_ptr_rom;
  84
  85         } while (++re_src < re_end);
  86
  87         return 0;
  88 }