bfd/elf32-arc.c

   1 /* ARC-specific support for 32-bit ELF
   2    Copyright 1994, 1995, 1997, 1999, 2001, 2002, 2005, 2007
   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 3 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., 51 Franklin Street - Fifth Floor, Boston,
  21    MA 02110-1301, USA.  */
  22
  23 #include "sysdep.h"
  24 #include "bfd.h"
  25 #include "libbfd.h"
  26 #include "elf-bfd.h"
  27 #include "elf/arc.h"
  28 #include "libiberty.h"
  29
  30 /* Try to minimize the amount of space occupied by relocation tables
  31    on the ROM (not that the ROM won't be swamped by other ELF overhead).  */
  32
  33 #define USE_REL 1
  34
  35 static bfd_reloc_status_type
  36 arc_elf_b22_pcrel (bfd * abfd,
  37                    arelent * reloc_entry,
  38                    asymbol * symbol,
  39                    void * data,
  40                    asection * input_section,
  41                    bfd * output_bfd,
  42                    char ** error_message)
  43 {
  44   /* If linking, back up the final symbol address by the address of the
  45      reloc.  This cannot be accomplished by setting the pcrel_offset
  46      field to TRUE, as bfd_install_relocation will detect this and refuse
  47      to install the offset in the first place, but bfd_perform_relocation
  48      will still insist on removing it.  */
  49   if (output_bfd == NULL)
  50     reloc_entry->addend -= reloc_entry->address;
  51
  52   /* Fall through to the default elf reloc handler.  */
  53   return bfd_elf_generic_reloc (abfd, reloc_entry, symbol, data,
  54                                 input_section, output_bfd, error_message);
  55 }
  56
  57 static reloc_howto_type elf_arc_howto_table[] =
  58 {
  59   /* This reloc does nothing.  */
  60   HOWTO (R_ARC_NONE,            /* Type.  */
  61          0,                     /* Rightshift.  */
  62          2,                     /* Size (0 = byte, 1 = short, 2 = long).  */
  63          32,                    /* Bitsize.  */
  64          FALSE,                 /* PC_relative.  */
  65          0,                     /* Bitpos.  */
  66          complain_overflow_bitfield, /* Complain_on_overflow.  */
  67          bfd_elf_generic_reloc, /* Special_function.  */
  68          "R_ARC_NONE",          /* Name.  */
  69          TRUE,                  /* Partial_inplace.  */
  70          0,                     /* Src_mask.  */
  71          0,                     /* Dst_mask.  */
  72          FALSE),                /* PCrel_offset.  */
  73
  74   /* A standard 32 bit relocation.  */
  75   HOWTO (R_ARC_32,              /* Type.  */
  76          0,                     /* Rightshift.  */
  77          2,                     /* Size (0 = byte, 1 = short, 2 = long).  */
  78          32,                    /* Bitsize.  */
  79          FALSE,                 /* PC_relative.  */
  80          0,                     /* Bitpos.  */
  81          complain_overflow_bitfield, /* Complain_on_overflow.  */
  82          bfd_elf_generic_reloc, /* Special_function.  */
  83          "R_ARC_32",            /* Name.  */
  84          TRUE,                  /* Partial_inplace.  */
  85          0xffffffff,            /* Src_mask.  */
  86          0xffffffff,            /* Dst_mask.  */
  87          FALSE),                /* PCrel_offset.  */
  88
  89   /* A 26 bit absolute branch, right shifted by 2.  */
  90   HOWTO (R_ARC_B26,             /* Type.  */
  91          2,                     /* Rightshift.  */
  92          2,                     /* Size (0 = byte, 1 = short, 2 = long).  */
  93          26,                    /* Bitsize.  */
  94          FALSE,                 /* PC_relative.  */
  95          0,                     /* Bitpos.  */
  96          complain_overflow_bitfield, /* Complain_on_overflow.  */
  97          bfd_elf_generic_reloc, /* Special_function.  */
  98          "R_ARC_B26",           /* Name.  */
  99          TRUE,                  /* Partial_inplace.  */
 100          0x00ffffff,            /* Src_mask.  */
 101          0x00ffffff,            /* Dst_mask.  */
 102          FALSE),                /* PCrel_offset.  */
 103
 104   /* A relative 22 bit branch; bits 21-2 are stored in bits 26-7.  */
 105   HOWTO (R_ARC_B22_PCREL,       /* Type.  */
 106          2,                     /* Rightshift.  */
 107          2,                     /* Size (0 = byte, 1 = short, 2 = long).  */
 108          22,                    /* Bitsize.  */
 109          TRUE,                  /* PC_relative.  */
 110          7,                     /* Bitpos.  */
 111          complain_overflow_signed, /* Complain_on_overflow.  */
 112          arc_elf_b22_pcrel,     /* Special_function.  */
 113          "R_ARC_B22_PCREL",     /* Name.  */
 114          TRUE,                  /* Partial_inplace.  */
 115          0x07ffff80,            /* Src_mask.  */
 116          0x07ffff80,            /* Dst_mask.  */
 117          FALSE),                /* PCrel_offset.  */
 118 };
 119
 120 /* Map BFD reloc types to ARC ELF reloc types.  */
 121
 122 struct arc_reloc_map
 123 {
 124   bfd_reloc_code_real_type bfd_reloc_val;
 125   unsigned char elf_reloc_val;
 126 };
 127
 128 static const struct arc_reloc_map arc_reloc_map[] =
 129 {
 130   { BFD_RELOC_NONE, R_ARC_NONE, },
 131   { BFD_RELOC_32, R_ARC_32 },
 132   { BFD_RELOC_CTOR, R_ARC_32 },
 133   { BFD_RELOC_ARC_B26, R_ARC_B26 },
 134   { BFD_RELOC_ARC_B22_PCREL, R_ARC_B22_PCREL },
 135 };
 136
 137 static reloc_howto_type *
 138 bfd_elf32_bfd_reloc_type_lookup (bfd *abfd ATTRIBUTE_UNUSED,
 139                                  bfd_reloc_code_real_type code)
 140 {
 141   unsigned int i;
 142
 143   for (i = ARRAY_SIZE (arc_reloc_map); i--;)
 144     if (arc_reloc_map[i].bfd_reloc_val == code)
 145       return elf_arc_howto_table + arc_reloc_map[i].elf_reloc_val;
 146
 147   return NULL;
 148 }
 149
 150 static reloc_howto_type *
 151 bfd_elf32_bfd_reloc_name_lookup (bfd *abfd ATTRIBUTE_UNUSED,
 152                                  const char *r_name)
 153 {
 154   unsigned int i;
 155
 156   for (i = 0;
 157        i < sizeof (elf_arc_howto_table) / sizeof (elf_arc_howto_table[0]);
 158        i++)
 159     if (elf_arc_howto_table[i].name != NULL
 160         && strcasecmp (elf_arc_howto_table[i].name, r_name) == 0)
 161       return &elf_arc_howto_table[i];
 162
 163   return NULL;
 164 }
 165
 166 /* Set the howto pointer for an ARC ELF reloc.  */
 167
 168 static void
 169 arc_info_to_howto_rel (bfd *abfd ATTRIBUTE_UNUSED,
 170                        arelent *cache_ptr,
 171                        Elf_Internal_Rela *dst)
 172 {
 173   unsigned int r_type;
 174
 175   r_type = ELF32_R_TYPE (dst->r_info);
 176   BFD_ASSERT (r_type < (unsigned int) R_ARC_max);
 177   cache_ptr->howto = &elf_arc_howto_table[r_type];
 178 }
 179
 180 /* Set the right machine number for an ARC ELF file.  */
 181
 182 static bfd_boolean
 183 arc_elf_object_p (bfd *abfd)
 184 {
 185   unsigned int mach = bfd_mach_arc_6;
 186
 187   if (elf_elfheader(abfd)->e_machine == EM_ARC)
 188     {
 189       unsigned long arch = elf_elfheader (abfd)->e_flags & EF_ARC_MACH;
 190
 191       switch (arch)
 192         {
 193         case E_ARC_MACH_ARC5:
 194           mach = bfd_mach_arc_5;
 195           break;
 196         default:
 197         case E_ARC_MACH_ARC6:
 198           mach = bfd_mach_arc_6;
 199           break;
 200         case E_ARC_MACH_ARC7:
 201           mach = bfd_mach_arc_7;
 202           break;
 203         case E_ARC_MACH_ARC8:
 204           mach = bfd_mach_arc_8;
 205           break;
 206         }
 207     }
 208   return bfd_default_set_arch_mach (abfd, bfd_arch_arc, mach);
 209 }
 210
 211 /* The final processing done just before writing out an ARC ELF object file.
 212    This gets the ARC architecture right based on the machine number.  */
 213
 214 static void
 215 arc_elf_final_write_processing (bfd *abfd,
 216                                 bfd_boolean linker ATTRIBUTE_UNUSED)
 217 {
 218   unsigned long val;
 219
 220   switch (bfd_get_mach (abfd))
 221     {
 222     case bfd_mach_arc_5:
 223       val = E_ARC_MACH_ARC5;
 224       break;
 225     default:
 226     case bfd_mach_arc_6:
 227       val = E_ARC_MACH_ARC6;
 228       break;
 229     case bfd_mach_arc_7:
 230       val = E_ARC_MACH_ARC7;
 231       break;
 232     case bfd_mach_arc_8:
 233       val = E_ARC_MACH_ARC8;
 234       break;
 235     }
 236   elf_elfheader (abfd)->e_flags &=~ EF_ARC_MACH;
 237   elf_elfheader (abfd)->e_flags |= val;
 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"