arch/arm/lib/reloc_arm_efi.c

   1 // SPDX-License-Identifier: BSD-3-Clause
   2 /*
   3  * reloc_arm.c - position-independent ARM ELF shared object relocator
   4  *
   5  * Copyright (C) 2014 Linaro Ltd. <ard.biesheuvel@linaro.org>
   6  * Copyright (C) 1999 Hewlett-Packard Co.
   7  * Contributed by David Mosberger <davidm@hpl.hp.com>.
   8  *
   9  * All rights reserved.
  10  *
  11  * This file is taken and modified from the gnu-efi project.
  12  */
  13
  14 #include <efi.h>
  15 #include <elf.h>
  16
  17 efi_status_t EFIAPI _relocate(long ldbase, Elf32_Dyn *dyn)
  18 {
  19         long relsz = 0, relent = 0;
  20         Elf32_Rel *rel = 0;
  21         ulong *addr;
  22         int i;
  23
  24         for (i = 0; dyn[i].d_tag != DT_NULL; ++i) {
  25                 switch (dyn[i].d_tag) {
  26                 case DT_REL:
  27                         rel = (Elf32_Rel *)((ulong)dyn[i].d_un.d_ptr
  28                                         + ldbase);
  29                         break;
  30                 case DT_RELSZ:
  31                         relsz = dyn[i].d_un.d_val;
  32                         break;
  33                 case DT_RELENT:
  34                         relent = dyn[i].d_un.d_val;
  35                         break;
  36                 default:
  37                         break;
  38                 }
  39         }
  40
  41         if (!rel && relent == 0)
  42                 return EFI_SUCCESS;
  43
  44         if (!rel || relent == 0)
  45                 return EFI_LOAD_ERROR;
  46
  47         while (relsz > 0) {
  48                 /* apply the relocs */
  49                 switch (ELF32_R_TYPE(rel->r_info)) {
  50                 case R_ARM_NONE:
  51                         break;
  52                 case R_ARM_RELATIVE:
  53                         addr = (ulong *)(ldbase + rel->r_offset);
  54                         *addr += ldbase;
  55                         break;
  56                 default:
  57                         break;
  58                 }
  59                 rel = (Elf32_Rel *)((char *)rel + relent);
  60                 relsz -= relent;
  61         }
  62
  63         return EFI_SUCCESS;
  64 }