bfd/elf32-arc.c

   1 /* ARC-specific support for 32-bit ELF
   2    Copyright 1994, 1995, 1997, 1999, 2001, 2002
   3    Free Software Foundation, Inc.
   4    Contributed by Doug Evans (dje@cygnus.com).
   5
   6    This file is part of BFD, the Binary File Descriptor library.
   7
   8    This program is free software; you can redistribute it and/or modify
   9    it under the terms of the GNU General Public License as published by
  10    the Free Software Foundation; either version 2 of the License, or
  11    (at your option) any later version.
  12
  13    This program is distributed in the hope that it will be useful,
  14    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16    GNU General Public License for more details.
  17
  18    You should have received a copy of the GNU General Public License
  19    along with this program; if not, write to the Free Software
  20    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
  21
  22 #include "bfd.h"
  23 #include "sysdep.h"
  24 #include "libbfd.h"
  25 #include "elf-bfd.h"
  26 #include "elf/arc.h"
  27 #include "libiberty.h"
  28
  29 static reloc_howto_type *bfd_elf32_bfd_reloc_type_lookup
  30   PARAMS ((bfd *abfd, bfd_reloc_code_real_type code));
  31 static void arc_info_to_howto_rel
  32   PARAMS ((bfd *, arelent *, Elf_Internal_Rela *));
  33 static boolean arc_elf_object_p
  34   PARAMS ((bfd *));
  35 static void arc_elf_final_write_processing
  36   PARAMS ((bfd *, boolean));
  37 static bfd_reloc_status_type arc_elf_b22_pcrel
  38   PARAMS ((bfd *, arelent *, asymbol *, PTR, asection *, bfd *, char **));
  39
  40 /* Try to minimize the amount of space occupied by relocation tables
  41    on the ROM (not that the ROM won't be swamped by other ELF overhead).  */
  42
  43 #define USE_REL 1
  44
  45 static reloc_howto_type elf_arc_howto_table[] =
  46 {
  47   /* This reloc does nothing.  */
  48   HOWTO (R_ARC_NONE,            /* type  */
  49          0,                     /* rightshift  */
  50          2,                     /* size (0 = byte, 1 = short, 2 = long)  */
  51          32,                    /* bitsize  */
  52          false,                 /* pc_relative  */
  53          0,                     /* bitpos  */
  54          complain_overflow_bitfield, /* complain_on_overflow  */
  55          bfd_elf_generic_reloc, /* special_function  */
  56          "R_ARC_NONE",          /* name  */
  57          true,                  /* partial_inplace  */
  58          0,                     /* src_mask  */
  59          0,                     /* dst_mask  */
  60          false),                /* pcrel_offset  */
  61
  62   /* A standard 32 bit relocation.  */
  63   HOWTO (R_ARC_32,              /* type  */
  64          0,                     /* rightshift  */
  65          2,                     /* size (0 = byte, 1 = short, 2 = long)  */
  66          32,                    /* bitsize  */
  67          false,                 /* pc_relative  */
  68          0,                     /* bitpos  */
  69          complain_overflow_bitfield, /* complain_on_overflow  */
  70          bfd_elf_generic_reloc, /* special_function  */
  71          "R_ARC_32",            /* name  */
  72          true,                  /* partial_inplace  */
  73          0xffffffff,            /* src_mask  */
  74          0xffffffff,            /* dst_mask  */
  75          false),                /* pcrel_offset  */
  76
  77   /* A 26 bit absolute branch, right shifted by 2.  */
  78   HOWTO (R_ARC_B26,             /* type  */
  79          2,                     /* rightshift  */
  80          2,                     /* size (0 = byte, 1 = short, 2 = long)  */
  81          26,                    /* bitsize  */
  82          false,                 /* pc_relative  */
  83          0,                     /* bitpos  */
  84          complain_overflow_bitfield, /* complain_on_overflow  */
  85          bfd_elf_generic_reloc, /* special_function  */
  86          "R_ARC_B26",           /* name  */
  87          true,                  /* partial_inplace  */
  88          0x00ffffff,            /* src_mask  */
  89          0x00ffffff,            /* dst_mask  */
  90          false),                /* pcrel_offset  */
  91
  92   /* A relative 22 bit branch; bits 21-2 are stored in bits 26-7.  */
  93   HOWTO (R_ARC_B22_PCREL,       /* type  */
  94          2,                     /* rightshift  */
  95          2,                     /* size (0 = byte, 1 = short, 2 = long)  */
  96          22,                    /* bitsize  */
  97          true,                  /* pc_relative  */
  98          7,                     /* bitpos  */
  99          complain_overflow_signed, /* complain_on_overflow  */
 100          arc_elf_b22_pcrel,     /* special_function  */
 101          "R_ARC_B22_PCREL",     /* name  */
 102          true,                  /* partial_inplace  */
 103          0x07ffff80,            /* src_mask  */
 104          0x07ffff80,            /* dst_mask  */
 105          false),                /* pcrel_offset  */
 106 };
 107
 108 /* Map BFD reloc types to ARC ELF reloc types.  */
 109
 110 struct arc_reloc_map
 111 {
 112   bfd_reloc_code_real_type bfd_reloc_val;
 113   unsigned char elf_reloc_val;
 114 };
 115
 116 static const struct arc_reloc_map arc_reloc_map[] =
 117 {
 118   { BFD_RELOC_NONE, R_ARC_NONE, },
 119   { BFD_RELOC_32, R_ARC_32 },
 120   { BFD_RELOC_CTOR, R_ARC_32 },
 121   { BFD_RELOC_ARC_B26, R_ARC_B26 },
 122   { BFD_RELOC_ARC_B22_PCREL, R_ARC_B22_PCREL },
 123 };
 124
 125 static reloc_howto_type *
 126 bfd_elf32_bfd_reloc_type_lookup (abfd, code)
 127      bfd *abfd ATTRIBUTE_UNUSED;
 128      bfd_reloc_code_real_type code;
 129 {
 130   unsigned int i;
 131
 132   for (i = ARRAY_SIZE (arc_reloc_map); i--;)
 133     if (arc_reloc_map[i].bfd_reloc_val == code)
 134       return elf_arc_howto_table + arc_reloc_map[i].elf_reloc_val;
 135
 136   return NULL;
 137 }
 138
 139 /* Set the howto pointer for an ARC ELF reloc.  */
 140
 141 static void
 142 arc_info_to_howto_rel (abfd, cache_ptr, dst)
 143      bfd *abfd ATTRIBUTE_UNUSED;
 144      arelent *cache_ptr;
 145      Elf_Internal_Rela *dst;
 146 {
 147   unsigned int r_type;
 148
 149   r_type = ELF32_R_TYPE (dst->r_info);
 150   BFD_ASSERT (r_type < (unsigned int) R_ARC_max);
 151   cache_ptr->howto = &elf_arc_howto_table[r_type];
 152 }
 153
 154 /* Set the right machine number for an ARC ELF file.  */
 155
 156 static boolean
 157 arc_elf_object_p (abfd)
 158      bfd *abfd;
 159 {
 160   unsigned int mach = bfd_mach_arc_6;
 161
 162   if (elf_elfheader(abfd)->e_machine == EM_ARC)
 163     {
 164       unsigned long arch = elf_elfheader (abfd)->e_flags & EF_ARC_MACH;
 165
 166       switch (arch)
 167         {
 168         case E_ARC_MACH_ARC5:
 169           mach = bfd_mach_arc_5;
 170           break;
 171         default:
 172         case E_ARC_MACH_ARC6:
 173           mach = bfd_mach_arc_6;
 174           break;
 175         case E_ARC_MACH_ARC7:
 176           mach = bfd_mach_arc_7;
 177           break;
 178         case E_ARC_MACH_ARC8:
 179           mach = bfd_mach_arc_8;
 180           break;
 181         }
 182     }
 183   return bfd_default_set_arch_mach (abfd, bfd_arch_arc, mach);
 184 }
 185
 186 /* The final processing done just before writing out an ARC ELF object file.
 187    This gets the ARC architecture right based on the machine number.  */
 188
 189 static void
 190 arc_elf_final_write_processing (abfd, linker)
 191      bfd *abfd;
 192      boolean linker ATTRIBUTE_UNUSED;
 193 {
 194   unsigned long val;
 195
 196   switch (bfd_get_mach (abfd))
 197     {
 198     case bfd_mach_arc_5:
 199       val = E_ARC_MACH_ARC5;
 200       break;
 201     default:
 202     case bfd_mach_arc_6:
 203       val = E_ARC_MACH_ARC6;
 204       break;
 205     case bfd_mach_arc_7:
 206       val = E_ARC_MACH_ARC7;
 207       break;
 208     case bfd_mach_arc_8:
 209       val = E_ARC_MACH_ARC8;
 210       break;
 211     }
 212   elf_elfheader (abfd)->e_flags &=~ EF_ARC_MACH;
 213   elf_elfheader (abfd)->e_flags |= val;
 214 }
 215
 216 bfd_reloc_status_type
 217 arc_elf_b22_pcrel (abfd, reloc_entry, symbol, data, input_section,
 218                    output_bfd, error_message)
 219      bfd * abfd;
 220      arelent * reloc_entry;
 221      asymbol * symbol;
 222      PTR data;
 223      asection * input_section;
 224      bfd * output_bfd;
 225      char ** error_message;
 226 {
 227   /* If linking, back up the final symbol address by the address of the
 228      reloc.  This cannot be accomplished by setting the pcrel_offset
 229      field to true, as bfd_install_relocation will detect this and refuse
 230      to install the offset in the first place, but bfd_perform_relocation
 231      will still insist on removing it.  */
 232   if (output_bfd == (bfd *) NULL)
 233     reloc_entry->addend -= reloc_entry->address;
 234
 235   /* Fall through to the default elf reloc handler.  */
 236   return bfd_elf_generic_reloc (abfd, reloc_entry, symbol, data,
 237                                 input_section, output_bfd, error_message);
 238 }
 239
 240 #define TARGET_LITTLE_SYM bfd_elf32_littlearc_vec
 241 #define TARGET_LITTLE_NAME "elf32-littlearc"
 242 #define TARGET_BIG_SYM bfd_elf32_bigarc_vec
 243 #define TARGET_BIG_NAME "elf32-bigarc"
 244 #define ELF_ARCH bfd_arch_arc
 245 #define ELF_MACHINE_CODE EM_ARC
 246 #define ELF_MAXPAGESIZE 0x1000
 247
 248 #define elf_info_to_howto 0
 249 #define elf_info_to_howto_rel arc_info_to_howto_rel
 250 #define elf_backend_object_p arc_elf_object_p
 251 #define elf_backend_final_write_processing arc_elf_final_write_processing
 252
 253 #include "elf32-target.h"