bfd/elf32-arc.c

   1 /* ARC-specific support for 32-bit ELF
   2    Copyright (C) 1994-2015 Free Software Foundation, Inc.
   3    Contributed by Doug Evans (dje@cygnus.com).
   4
   5    This file is part of BFD, the Binary File Descriptor library.
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 3 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program; if not, write to the Free Software
  19    Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
  20    MA 02110-1301, USA.  */
  21
  22 #include "sysdep.h"
  23 #include "bfd.h"
  24 #include "libbfd.h"
  25 #include "elf-bfd.h"
  26 #include "elf/arc.h"
  27 #include "libiberty.h"
  28
  29 /* Try to minimize the amount of space occupied by relocation tables
  30    on the ROM (not that the ROM won't be swamped by other ELF overhead).  */
  31
  32 #define USE_REL 1
  33
  34 static bfd_reloc_status_type
  35 arc_elf_b22_pcrel (bfd * abfd,
  36                    arelent * reloc_entry,
  37                    asymbol * symbol,
  38                    void * data,
  39                    asection * input_section,
  40                    bfd * output_bfd,
  41                    char ** error_message)
  42 {
  43   /* If linking, back up the final symbol address by the address of the
  44      reloc.  This cannot be accomplished by setting the pcrel_offset
  45      field to TRUE, as bfd_install_relocation will detect this and refuse
  46      to install the offset in the first place, but bfd_perform_relocation
  47      will still insist on removing it.  */
  48   if (output_bfd == NULL)
  49     reloc_entry->addend -= reloc_entry->address;
  50
  51   /* Fall through to the default elf reloc handler.  */
  52   return bfd_elf_generic_reloc (abfd, reloc_entry, symbol, data,
  53                                 input_section, output_bfd, error_message);
  54 }
  55
  56 static reloc_howto_type elf_arc_howto_table[] =
  57 {
  58   /* This reloc does nothing.  */
  59   HOWTO (R_ARC_NONE,            /* Type.  */
  60          0,                     /* Rightshift.  */
  61          3,                     /* Size (0 = byte, 1 = short, 2 = long).  */
  62          0,                     /* Bitsize.  */
  63          FALSE,                 /* PC_relative.  */
  64          0,                     /* Bitpos.  */
  65          complain_overflow_bitfield, /* Complain_on_overflow.  */
  66          bfd_elf_generic_reloc, /* Special_function.  */
  67          "R_ARC_NONE",          /* Name.  */
  68          TRUE,                  /* Partial_inplace.  */
  69          0,                     /* Src_mask.  */
  70          0,                     /* Dst_mask.  */
  71          FALSE),                /* PCrel_offset.  */
  72
  73   /* A standard 32 bit relocation.  */
  74   HOWTO (R_ARC_32,              /* Type.  */
  75          0,                     /* Rightshift.  */
  76          2,                     /* Size (0 = byte, 1 = short, 2 = long).  */
  77          32,                    /* Bitsize.  */
  78          FALSE,                 /* PC_relative.  */
  79          0,                     /* Bitpos.  */
  80          complain_overflow_bitfield, /* Complain_on_overflow.  */
  81          bfd_elf_generic_reloc, /* Special_function.  */
  82          "R_ARC_32",            /* Name.  */
  83          TRUE,                  /* Partial_inplace.  */
  84          0xffffffff,            /* Src_mask.  */
  85          0xffffffff,            /* Dst_mask.  */
  86          FALSE),                /* PCrel_offset.  */
  87
  88   /* A 26 bit absolute branch, right shifted by 2.  */
  89   HOWTO (R_ARC_B26,             /* Type.  */
  90          2,                     /* Rightshift.  */
  91          2,                     /* Size (0 = byte, 1 = short, 2 = long).  */
  92          26,                    /* Bitsize.  */
  93          FALSE,                 /* PC_relative.  */
  94          0,                     /* Bitpos.  */
  95          complain_overflow_bitfield, /* Complain_on_overflow.  */
  96          bfd_elf_generic_reloc, /* Special_function.  */
  97          "R_ARC_B26",           /* Name.  */
  98          TRUE,                  /* Partial_inplace.  */
  99          0x00ffffff,            /* Src_mask.  */
 100          0x00ffffff,            /* Dst_mask.  */
 101          FALSE),                /* PCrel_offset.  */
 102
 103   /* A relative 22 bit branch; bits 21-2 are stored in bits 26-7.  */
 104   HOWTO (R_ARC_B22_PCREL,       /* Type.  */
 105          2,                     /* Rightshift.  */
 106          2,                     /* Size (0 = byte, 1 = short, 2 = long).  */
 107          22,                    /* Bitsize.  */
 108          TRUE,                  /* PC_relative.  */
 109          7,                     /* Bitpos.  */
 110          complain_overflow_signed, /* Complain_on_overflow.  */
 111          arc_elf_b22_pcrel,     /* Special_function.  */
 112          "R_ARC_B22_PCREL",     /* Name.  */
 113          TRUE,                  /* Partial_inplace.  */
 114          0x07ffff80,            /* Src_mask.  */
 115          0x07ffff80,            /* Dst_mask.  */
 116          FALSE),                /* PCrel_offset.  */
 117 };
 118
 119 /* Map BFD reloc types to ARC ELF reloc types.  */
 120
 121 struct arc_reloc_map
 122 {
 123   bfd_reloc_code_real_type bfd_reloc_val;
 124   unsigned char elf_reloc_val;
 125 };
 126
 127 static const struct arc_reloc_map arc_reloc_map[] =
 128 {
 129   { BFD_RELOC_NONE, R_ARC_NONE, },
 130   { BFD_RELOC_32, R_ARC_32 },
 131   { BFD_RELOC_CTOR, R_ARC_32 },
 132   { BFD_RELOC_ARC_B26, R_ARC_B26 },
 133   { BFD_RELOC_ARC_B22_PCREL, R_ARC_B22_PCREL },
 134 };
 135
 136 static reloc_howto_type *
 137 bfd_elf32_bfd_reloc_type_lookup (bfd *abfd ATTRIBUTE_UNUSED,
 138                                  bfd_reloc_code_real_type code)
 139 {
 140   unsigned int i;
 141
 142   for (i = ARRAY_SIZE (arc_reloc_map); i--;)
 143     if (arc_reloc_map[i].bfd_reloc_val == code)
 144       return elf_arc_howto_table + arc_reloc_map[i].elf_reloc_val;
 145
 146   return NULL;
 147 }
 148
 149 static reloc_howto_type *
 150 bfd_elf32_bfd_reloc_name_lookup (bfd *abfd ATTRIBUTE_UNUSED,
 151                                  const char *r_name)
 152 {
 153   unsigned int i;
 154
 155   for (i = 0;
 156        i < sizeof (elf_arc_howto_table) / sizeof (elf_arc_howto_table[0]);
 157        i++)
 158     if (elf_arc_howto_table[i].name != NULL
 159         && strcasecmp (elf_arc_howto_table[i].name, r_name) == 0)
 160       return &elf_arc_howto_table[i];
 161
 162   return NULL;
 163 }
 164
 165 /* Set the howto pointer for an ARC ELF reloc.  */
 166
 167 static void
 168 arc_info_to_howto_rel (bfd *abfd ATTRIBUTE_UNUSED,
 169                        arelent *cache_ptr,
 170                        Elf_Internal_Rela *dst)
 171 {
 172   unsigned int r_type;
 173
 174   r_type = ELF32_R_TYPE (dst->r_info);
 175   if (r_type >= (unsigned int) R_ARC_max)
 176     {
 177       _bfd_error_handler (_("%A: invalid ARC reloc number: %d"), abfd, r_type);
 178       r_type = 0;
 179     }
 180   cache_ptr->howto = &elf_arc_howto_table[r_type];
 181 }
 182
 183 /* Set the right machine number for an ARC ELF file.  */
 184
 185 static bfd_boolean
 186 arc_elf_object_p (bfd *abfd)
 187 {
 188   unsigned int mach = bfd_mach_arc_6;
 189
 190   if (elf_elfheader(abfd)->e_machine == EM_ARC)
 191     {
 192       unsigned long arch = elf_elfheader (abfd)->e_flags & EF_ARC_MACH;
 193
 194       switch (arch)
 195         {
 196         case E_ARC_MACH_ARC5:
 197           mach = bfd_mach_arc_5;
 198           break;
 199         default:
 200         case E_ARC_MACH_ARC6:
 201           mach = bfd_mach_arc_6;
 202           break;
 203         case E_ARC_MACH_ARC7:
 204           mach = bfd_mach_arc_7;
 205           break;
 206         case E_ARC_MACH_ARC8:
 207           mach = bfd_mach_arc_8;
 208           break;
 209         }
 210     }
 211   return bfd_default_set_arch_mach (abfd, bfd_arch_arc, mach);
 212 }
 213
 214 /* The final processing done just before writing out an ARC ELF object file.
 215    This gets the ARC architecture right based on the machine number.  */
 216
 217 static void
 218 arc_elf_final_write_processing (bfd *abfd,
 219                                 bfd_boolean linker ATTRIBUTE_UNUSED)
 220 {
 221   unsigned long val;
 222
 223   switch (bfd_get_mach (abfd))
 224     {
 225     case bfd_mach_arc_5:
 226       val = E_ARC_MACH_ARC5;
 227       break;
 228     default:
 229     case bfd_mach_arc_6:
 230       val = E_ARC_MACH_ARC6;
 231       break;
 232     case bfd_mach_arc_7:
 233       val = E_ARC_MACH_ARC7;
 234       break;
 235     case bfd_mach_arc_8:
 236       val = E_ARC_MACH_ARC8;
 237       break;
 238     }
 239   elf_elfheader (abfd)->e_flags &=~ EF_ARC_MACH;
 240   elf_elfheader (abfd)->e_flags |= val;
 241 }
 242
 243 #define TARGET_LITTLE_SYM   arc_elf32_le_vec
 244 #define TARGET_LITTLE_NAME  "elf32-littlearc"
 245 #define TARGET_BIG_SYM      arc_elf32_be_vec
 246 #define TARGET_BIG_NAME     "elf32-bigarc"
 247 #define ELF_ARCH            bfd_arch_arc
 248 #define ELF_MACHINE_CODE    EM_ARC
 249 #define ELF_MAXPAGESIZE     0x1000
 250
 251 #define elf_info_to_howto                   0
 252 #define elf_info_to_howto_rel               arc_info_to_howto_rel
 253 #define elf_backend_object_p                arc_elf_object_p
 254 #define elf_backend_final_write_processing  arc_elf_final_write_processing
 255
 256 #include "elf32-target.h"