bfd/cpu-i386.c

   1 /* BFD support for the Intel 386 architecture.
   2    Copyright 1992, 1994, 1995, 1996, 1998, 2000, 2001, 2002, 2004, 2005,
   3    2007, 2009, 2010, 2011
   4    Free Software Foundation, Inc.
   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 "libiberty.h"
  27
  28 extern void * bfd_arch_i386_short_nop_fill (bfd_size_type, bfd_boolean,
  29                                             bfd_boolean);
  30
  31 static const bfd_arch_info_type *
  32 bfd_i386_compatible (const bfd_arch_info_type *a,
  33                      const bfd_arch_info_type *b)
  34 {
  35   const bfd_arch_info_type *compat = bfd_default_compatible (a, b);
  36
  37   /* Don't allow mixing x64_32 with x86_64.  */
  38   if (compat
  39       && (a->mach & bfd_mach_x64_32) != (b->mach & bfd_mach_x64_32))
  40     compat = NULL;
  41
  42   return compat;
  43 }
  44
  45 /* Fill the buffer with zero or nop instruction if CODE is TRUE.  Use
  46    multi byte nop instructions if LONG_NOP is TRUE.  */
  47
  48 static void *
  49 bfd_arch_i386_fill (bfd_size_type count, bfd_boolean code,
  50                     bfd_boolean long_nop)
  51 {
  52   /* nop */
  53   static const char nop_1[] = { 0x90 };
  54   /* xchg %ax,%ax */
  55   static const char nop_2[] = { 0x66, 0x90 };
  56   /* nopl (%[re]ax) */
  57   static const char nop_3[] = { 0x0f, 0x1f, 0x00 };
  58   /* nopl 0(%[re]ax) */
  59   static const char nop_4[] = { 0x0f, 0x1f, 0x40, 0x00 };
  60   /* nopl 0(%[re]ax,%[re]ax,1) */
  61   static const char nop_5[] = { 0x0f, 0x1f, 0x44, 0x00, 0x00 };
  62   /* nopw 0(%[re]ax,%[re]ax,1) */
  63   static const char nop_6[] = { 0x66, 0x0f, 0x1f, 0x44, 0x00, 0x00 };
  64   /* nopl 0L(%[re]ax) */
  65   static const char nop_7[] = { 0x0f, 0x1f, 0x80, 0x00, 0x00, 0x00, 0x00 };
  66   /* nopl 0L(%[re]ax,%[re]ax,1) */
  67   static const char nop_8[] =
  68     { 0x0f, 0x1f, 0x84, 0x00, 0x00, 0x00, 0x00, 0x00};
  69   /* nopw 0L(%[re]ax,%[re]ax,1) */
  70   static const char nop_9[] =
  71     { 0x66, 0x0f, 0x1f, 0x84, 0x00, 0x00, 0x00, 0x00, 0x00 };
  72   /* nopw %cs:0L(%[re]ax,%[re]ax,1) */
  73   static const char nop_10[] =
  74     { 0x66, 0x2e, 0x0f, 0x1f, 0x84, 0x00, 0x00, 0x00, 0x00, 0x00 };
  75   static const char *const nops[] =
  76     { nop_1, nop_2, nop_3, nop_4, nop_5,
  77       nop_6, nop_7, nop_8, nop_9, nop_10 };
  78   bfd_size_type nop_size = long_nop ? ARRAY_SIZE (nops) : 2;
  79
  80   void *fill = bfd_malloc (count);
  81   if (fill == NULL)
  82     return fill;
  83
  84   if (code)
  85     {
  86       bfd_byte *p = fill;
  87       while (count >= nop_size)
  88         {
  89           memcpy (p, nops[nop_size - 1], nop_size);
  90           p += nop_size;
  91           count -= nop_size;
  92         }
  93       if (count != 0)
  94         memcpy (p, nops[count - 1], count);
  95     }
  96   else
  97     memset (fill, 0, count);
  98
  99   return fill;
 100 }
 101
 102 /* Fill the buffer with zero or short nop instruction if CODE is TRUE.  */
 103
 104 void *
 105 bfd_arch_i386_short_nop_fill (bfd_size_type count,
 106                               bfd_boolean is_bigendian ATTRIBUTE_UNUSED,
 107                               bfd_boolean code)
 108 {
 109   return bfd_arch_i386_fill (count, code, FALSE);
 110 }
 111
 112 /* Fill the buffer with zero or long nop instruction if CODE is TRUE.  */
 113
 114 static void *
 115 bfd_arch_i386_long_nop_fill (bfd_size_type count,
 116                              bfd_boolean is_bigendian ATTRIBUTE_UNUSED,
 117                              bfd_boolean code)
 118 {
 119   return bfd_arch_i386_fill (count, code, TRUE);
 120 }
 121
 122 static const bfd_arch_info_type bfd_x64_32_arch_intel_syntax =
 123 {
 124   64, /* 64 bits in a word */
 125   64, /* 64 bits in an address */
 126   8,  /* 8 bits in a byte */
 127   bfd_arch_i386,
 128   bfd_mach_x64_32_intel_syntax,
 129   "i386:intel",
 130   "i386:x64-32:intel",
 131   3,
 132   FALSE,
 133   bfd_i386_compatible,
 134   bfd_default_scan,
 135   bfd_arch_i386_long_nop_fill,
 136   0
 137 };
 138
 139 static const bfd_arch_info_type bfd_x86_64_arch_intel_syntax =
 140 {
 141   64, /* 64 bits in a word */
 142   64, /* 64 bits in an address */
 143   8,  /* 8 bits in a byte */
 144   bfd_arch_i386,
 145   bfd_mach_x86_64_intel_syntax,
 146   "i386:intel",
 147   "i386:x86-64:intel",
 148   3,
 149   FALSE,
 150   bfd_i386_compatible,
 151   bfd_default_scan,
 152   bfd_arch_i386_long_nop_fill,
 153   &bfd_x64_32_arch_intel_syntax,
 154 };
 155
 156 static const bfd_arch_info_type bfd_i386_arch_intel_syntax =
 157 {
 158   32,   /* 32 bits in a word */
 159   32,   /* 32 bits in an address */
 160   8,    /* 8 bits in a byte */
 161   bfd_arch_i386,
 162   bfd_mach_i386_i386_intel_syntax,
 163   "i386:intel",
 164   "i386:intel",
 165   3,
 166   TRUE,
 167   bfd_i386_compatible,
 168   bfd_default_scan,
 169   bfd_arch_i386_short_nop_fill,
 170   &bfd_x86_64_arch_intel_syntax
 171 };
 172
 173 static const bfd_arch_info_type i8086_arch =
 174 {
 175   32,   /* 32 bits in a word */
 176   32,   /* 32 bits in an address (well, not really) */
 177   8,    /* 8 bits in a byte */
 178   bfd_arch_i386,
 179   bfd_mach_i386_i8086,
 180   "i8086",
 181   "i8086",
 182   3,
 183   FALSE,
 184   bfd_i386_compatible,
 185   bfd_default_scan,
 186   bfd_arch_i386_short_nop_fill,
 187   &bfd_i386_arch_intel_syntax
 188 };
 189
 190 static const bfd_arch_info_type bfd_x64_32_arch =
 191 {
 192   64, /* 64 bits in a word */
 193   64, /* 64 bits in an address */
 194   8,  /* 8 bits in a byte */
 195   bfd_arch_i386,
 196   bfd_mach_x64_32,
 197   "i386",
 198   "i386:x64-32",
 199   3,
 200   FALSE,
 201   bfd_i386_compatible,
 202   bfd_default_scan,
 203   bfd_arch_i386_long_nop_fill,
 204   &i8086_arch
 205 };
 206
 207 static const bfd_arch_info_type bfd_x86_64_arch =
 208 {
 209   64, /* 64 bits in a word */
 210   64, /* 64 bits in an address */
 211   8,  /* 8 bits in a byte */
 212   bfd_arch_i386,
 213   bfd_mach_x86_64,
 214   "i386",
 215   "i386:x86-64",
 216   3,
 217   FALSE,
 218   bfd_i386_compatible,
 219   bfd_default_scan,
 220   bfd_arch_i386_long_nop_fill,
 221   &bfd_x64_32_arch
 222 };
 223
 224 const bfd_arch_info_type bfd_i386_arch =
 225 {
 226   32,   /* 32 bits in a word */
 227   32,   /* 32 bits in an address */
 228   8,    /* 8 bits in a byte */
 229   bfd_arch_i386,
 230   bfd_mach_i386_i386,
 231   "i386",
 232   "i386",
 233   3,
 234   TRUE,
 235   bfd_i386_compatible,
 236   bfd_default_scan,
 237   bfd_arch_i386_short_nop_fill,
 238   &bfd_x86_64_arch
 239 };