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