bfd/cpu-arm.c

   1 /* BFD support for the ARM processor
   2    Copyright (C) 1994-2019 Free Software Foundation, Inc.
   3    Contributed by Richard Earnshaw (rwe@pegasus.esprit.ec.org)
   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 "libiberty.h"
  26 #include "cpu-arm.h"
  27
  28 /* This routine is provided two arch_infos and works out which ARM
  29    machine which would be compatible with both and returns a pointer
  30    to its info structure.  */
  31
  32 static const bfd_arch_info_type *
  33 compatible (const bfd_arch_info_type *a, const bfd_arch_info_type *b)
  34 {
  35   /* If a & b are for different architecture we can do nothing.  */
  36   if (a->arch != b->arch)
  37       return NULL;
  38
  39   /* If a & b are for the same machine then all is well.  */
  40   if (a->mach == b->mach)
  41     return a;
  42
  43   /* Otherwise if either a or b is the 'default' machine
  44      then it can be polymorphed into the other.  */
  45   if (a->the_default)
  46     return b;
  47
  48   if (b->the_default)
  49     return a;
  50
  51   /* So far all newer ARM architecture cores are
  52      supersets of previous cores.  */
  53   if (a->mach < b->mach)
  54     return b;
  55   else if (a->mach > b->mach)
  56     return a;
  57
  58   /* Never reached!  */
  59   return NULL;
  60 }
  61
  62 static struct
  63 {
  64   unsigned int mach;
  65   char *       name;
  66 }
  67 processors[] =
  68 {
  69   { bfd_mach_arm_2,       "arm2"            },
  70   { bfd_mach_arm_2a,      "arm250"          },
  71   { bfd_mach_arm_2a,      "arm3"            },
  72   { bfd_mach_arm_3,       "arm6"            },
  73   { bfd_mach_arm_3,       "arm60"           },
  74   { bfd_mach_arm_3,       "arm600"          },
  75   { bfd_mach_arm_3,       "arm610"          },
  76   { bfd_mach_arm_3,       "arm620"          },
  77   { bfd_mach_arm_3,       "arm7"            },
  78   { bfd_mach_arm_3,       "arm70"           },
  79   { bfd_mach_arm_3,       "arm700"          },
  80   { bfd_mach_arm_3,       "arm700i"         },
  81   { bfd_mach_arm_3,       "arm710"          },
  82   { bfd_mach_arm_3,       "arm7100"         },
  83   { bfd_mach_arm_3,       "arm710c"         },
  84   { bfd_mach_arm_4T,      "arm710t"         },
  85   { bfd_mach_arm_3,       "arm720"          },
  86   { bfd_mach_arm_4T,      "arm720t"         },
  87   { bfd_mach_arm_4T,      "arm740t"         },
  88   { bfd_mach_arm_3,       "arm7500"         },
  89   { bfd_mach_arm_3,       "arm7500fe"       },
  90   { bfd_mach_arm_3,       "arm7d"           },
  91   { bfd_mach_arm_3,       "arm7di"          },
  92   { bfd_mach_arm_3M,      "arm7dm"          },
  93   { bfd_mach_arm_3M,      "arm7dmi"         },
  94   { bfd_mach_arm_4T,      "arm7t"           },
  95   { bfd_mach_arm_4T,      "arm7tdmi"        },
  96   { bfd_mach_arm_4T,      "arm7tdmi-s"      },
  97   { bfd_mach_arm_3M,      "arm7m"           },
  98   { bfd_mach_arm_4,       "arm8"            },
  99   { bfd_mach_arm_4,       "arm810"          },
 100   { bfd_mach_arm_4,       "arm9"            },
 101   { bfd_mach_arm_4T,      "arm920"          },
 102   { bfd_mach_arm_4T,      "arm920t"         },
 103   { bfd_mach_arm_4T,      "arm922t"         },
 104   { bfd_mach_arm_5TEJ,    "arm926ej"        },
 105   { bfd_mach_arm_5TEJ,    "arm926ejs"       },
 106   { bfd_mach_arm_5TEJ,    "arm926ej-s"      },
 107   { bfd_mach_arm_4T,      "arm940t"         },
 108   { bfd_mach_arm_5TE,     "arm946e"         },
 109   { bfd_mach_arm_5TE,     "arm946e-r0"      },
 110   { bfd_mach_arm_5TE,     "arm946e-s"       },
 111   { bfd_mach_arm_5TE,     "arm966e"         },
 112   { bfd_mach_arm_5TE,     "arm966e-r0"      },
 113   { bfd_mach_arm_5TE,     "arm966e-s"       },
 114   { bfd_mach_arm_5TE,     "arm968e-s"       },
 115   { bfd_mach_arm_5TE,     "arm9e"           },
 116   { bfd_mach_arm_5TE,     "arm9e-r0"        },
 117   { bfd_mach_arm_4T,      "arm9tdmi"        },
 118   { bfd_mach_arm_5TE,     "arm1020"         },
 119   { bfd_mach_arm_5T,      "arm1020t"        },
 120   { bfd_mach_arm_5TE,     "arm1020e"        },
 121   { bfd_mach_arm_5TE,     "arm1022e"        },
 122   { bfd_mach_arm_5TEJ,    "arm1026ejs"      },
 123   { bfd_mach_arm_5TEJ,    "arm1026ej-s"     },
 124   { bfd_mach_arm_5TE,     "arm10e"          },
 125   { bfd_mach_arm_5T,      "arm10t"          },
 126   { bfd_mach_arm_5T,      "arm10tdmi"       },
 127   { bfd_mach_arm_6,       "arm1136j-s"      },
 128   { bfd_mach_arm_6,       "arm1136js"       },
 129   { bfd_mach_arm_6,       "arm1136jf-s"     },
 130   { bfd_mach_arm_6,       "arm1136jfs"      },
 131   { bfd_mach_arm_6KZ,     "arm1176jz-s"     },
 132   { bfd_mach_arm_6KZ,     "arm1176jzf-s"    },
 133   { bfd_mach_arm_6T2,     "arm1156t2-s"     },
 134   { bfd_mach_arm_6T2,     "arm1156t2f-s"    },
 135   { bfd_mach_arm_7,       "cortex-a5"       },
 136   { bfd_mach_arm_7,       "cortex-a7"       },
 137   { bfd_mach_arm_7,       "cortex-a8"       },
 138   { bfd_mach_arm_7,       "cortex-a9"       },
 139   { bfd_mach_arm_7,       "cortex-a12"      },
 140   { bfd_mach_arm_7,       "cortex-a15"      },
 141   { bfd_mach_arm_7,       "cortex-a17"      },
 142   { bfd_mach_arm_8,       "cortex-a32"      },
 143   { bfd_mach_arm_8,       "cortex-a35"      },
 144   { bfd_mach_arm_8,       "cortex-a53"      },
 145   { bfd_mach_arm_8,       "cortex-a55"      },
 146   { bfd_mach_arm_8,       "cortex-a57"      },
 147   { bfd_mach_arm_8,       "cortex-a72"      },
 148   { bfd_mach_arm_8,       "cortex-a73"      },
 149   { bfd_mach_arm_8,       "cortex-a75"      },
 150   { bfd_mach_arm_8,       "cortex-a76"      },
 151   { bfd_mach_arm_8,       "cortex-a76ae"    },
 152   { bfd_mach_arm_8,       "cortex-a77"      },
 153   { bfd_mach_arm_6SM,     "cortex-m0"       },
 154   { bfd_mach_arm_6SM,     "cortex-m0plus"   },
 155   { bfd_mach_arm_6SM,     "cortex-m1"       },
 156   { bfd_mach_arm_8M_BASE, "cortex-m23"      },
 157   { bfd_mach_arm_7,       "cortex-m3"       },
 158   { bfd_mach_arm_8M_MAIN, "cortex-m33"      },
 159   { bfd_mach_arm_8M_MAIN, "cortex-m35p"     },
 160   { bfd_mach_arm_7EM,     "cortex-m4"       },
 161   { bfd_mach_arm_7EM,     "cortex-m7"       },
 162   { bfd_mach_arm_7,       "cortex-r4"       },
 163   { bfd_mach_arm_7,       "cortex-r4f"      },
 164   { bfd_mach_arm_7,       "cortex-r5"       },
 165   { bfd_mach_arm_8R,      "cortex-r52"      },
 166   { bfd_mach_arm_7,       "cortex-r7"       },
 167   { bfd_mach_arm_7,       "cortex-r8"       },
 168   { bfd_mach_arm_4T,      "ep9312"          },
 169   { bfd_mach_arm_8,       "exynos-m1"       },
 170   { bfd_mach_arm_4,       "fa526"           },
 171   { bfd_mach_arm_5TE,     "fa606te"         },
 172   { bfd_mach_arm_5TE,     "fa616te"         },
 173   { bfd_mach_arm_4,       "fa626"           },
 174   { bfd_mach_arm_5TE,     "fa626te"         },
 175   { bfd_mach_arm_5TE,     "fa726te"         },
 176   { bfd_mach_arm_5TE,     "fmp626"          },
 177   { bfd_mach_arm_XScale,  "i80200"          },
 178   { bfd_mach_arm_7,       "marvell-pj4"     },
 179   { bfd_mach_arm_7,       "marvell-whitney" },
 180   { bfd_mach_arm_6K,      "mpcore"          },
 181   { bfd_mach_arm_6K,      "mpcorenovfp"     },
 182   { bfd_mach_arm_4,       "sa1"             },
 183   { bfd_mach_arm_4,       "strongarm"       },
 184   { bfd_mach_arm_4,       "strongarm1"      },
 185   { bfd_mach_arm_4,       "strongarm110"    },
 186   { bfd_mach_arm_4,       "strongarm1100"   },
 187   { bfd_mach_arm_4,       "strongarm1110"   },
 188   { bfd_mach_arm_XScale,  "xscale"          },
 189   { bfd_mach_arm_8,       "xgene1"          },
 190   { bfd_mach_arm_8,       "xgene2"          },
 191   { bfd_mach_arm_ep9312,  "ep9312"          },
 192   { bfd_mach_arm_iWMMXt,  "iwmmxt"          },
 193   { bfd_mach_arm_iWMMXt2, "iwmmxt2"         },
 194   { bfd_mach_arm_unknown, "arm_any"         }
 195 };
 196
 197 static bfd_boolean
 198 scan (const struct bfd_arch_info *info, const char *string)
 199 {
 200   int  i;
 201
 202   /* First test for an exact match.  */
 203   if (strcasecmp (string, info->printable_name) == 0)
 204     return TRUE;
 205
 206   /* Next check for a processor name instead of an Architecture name.  */
 207   for (i = sizeof (processors) / sizeof (processors[0]); i--;)
 208     {
 209       if (strcasecmp (string, processors [i].name) == 0)
 210         break;
 211     }
 212
 213   if (i != -1 && info->mach == processors [i].mach)
 214     return TRUE;
 215
 216   /* Finally check for the default architecture.  */
 217   if (strcasecmp (string, "arm") == 0)
 218     return info->the_default;
 219
 220   return FALSE;
 221 }
 222
 223 #define N(number, print, default, next)  \
 224 {  32, 32, 8, bfd_arch_arm, number, "arm", print, 4, default, compatible, \
 225     scan, bfd_arch_default_fill, next, 0 }
 226
 227 static const bfd_arch_info_type arch_info_struct[] =
 228 {
 229   N (bfd_mach_arm_2,         "armv2",          FALSE, & arch_info_struct[1]),
 230   N (bfd_mach_arm_2a,        "armv2a",         FALSE, & arch_info_struct[2]),
 231   N (bfd_mach_arm_3,         "armv3",          FALSE, & arch_info_struct[3]),
 232   N (bfd_mach_arm_3M,        "armv3m",         FALSE, & arch_info_struct[4]),
 233   N (bfd_mach_arm_4,         "armv4",          FALSE, & arch_info_struct[5]),
 234   N (bfd_mach_arm_4T,        "armv4t",         FALSE, & arch_info_struct[6]),
 235   N (bfd_mach_arm_5,         "armv5",          FALSE, & arch_info_struct[7]),
 236   N (bfd_mach_arm_5T,        "armv5t",         FALSE, & arch_info_struct[8]),
 237   N (bfd_mach_arm_5TE,       "armv5te",        FALSE, & arch_info_struct[9]),
 238   N (bfd_mach_arm_XScale,    "xscale",         FALSE, & arch_info_struct[10]),
 239   N (bfd_mach_arm_ep9312,    "ep9312",         FALSE, & arch_info_struct[11]),
 240   N (bfd_mach_arm_iWMMXt,    "iwmmxt",         FALSE, & arch_info_struct[12]),
 241   N (bfd_mach_arm_iWMMXt2,   "iwmmxt2",        FALSE, & arch_info_struct[13]),
 242   N (bfd_mach_arm_5TEJ,      "armv5tej",       FALSE, & arch_info_struct[14]),
 243   N (bfd_mach_arm_6,         "armv6",          FALSE, & arch_info_struct[15]),
 244   N (bfd_mach_arm_6KZ,       "armv6kz",        FALSE, & arch_info_struct[16]),
 245   N (bfd_mach_arm_6T2,       "armv6t2",        FALSE, & arch_info_struct[17]),
 246   N (bfd_mach_arm_6K,        "armv6k",         FALSE, & arch_info_struct[18]),
 247   N (bfd_mach_arm_7,         "armv7",          FALSE, & arch_info_struct[19]),
 248   N (bfd_mach_arm_6M,        "armv6-m",        FALSE, & arch_info_struct[20]),
 249   N (bfd_mach_arm_6SM,       "armv6s-m",       FALSE, & arch_info_struct[21]),
 250   N (bfd_mach_arm_7EM,       "armv7e-m",       FALSE, & arch_info_struct[22]),
 251   N (bfd_mach_arm_8,         "armv8-a",        FALSE, & arch_info_struct[23]),
 252   N (bfd_mach_arm_8R,        "armv8-r",        FALSE, & arch_info_struct[24]),
 253   N (bfd_mach_arm_8M_BASE,   "armv8-m.base",   FALSE, & arch_info_struct[25]),
 254   N (bfd_mach_arm_8M_MAIN,   "armv8-m.main",   FALSE, & arch_info_struct[26]),
 255   N (bfd_mach_arm_8_1M_MAIN, "armv8.1-m.main", FALSE, & arch_info_struct[27]),
 256   N (bfd_mach_arm_unknown,   "arm_any",        FALSE, NULL)
 257 };
 258
 259 const bfd_arch_info_type bfd_arm_arch =
 260   N (0, "arm", TRUE, & arch_info_struct[0]);
 261
 262 /* Support functions used by both the COFF and ELF versions of the ARM port.  */
 263
 264 /* Handle the merging of the 'machine' settings of input file IBFD
 265    and an output file OBFD.  These values actually represent the
 266    different possible ARM architecture variants.
 267    Returns TRUE if they were merged successfully or FALSE otherwise.  */
 268
 269 bfd_boolean
 270 bfd_arm_merge_machines (bfd *ibfd, bfd *obfd)
 271 {
 272   unsigned int in  = bfd_get_mach (ibfd);
 273   unsigned int out = bfd_get_mach (obfd);
 274
 275   /* If the output architecture is unknown, we now have a value to set.  */
 276   if (out == bfd_mach_arm_unknown)
 277     bfd_set_arch_mach (obfd, bfd_arch_arm, in);
 278
 279   /* If the input architecture is unknown,
 280      then so must be the output architecture.  */
 281   else if (in == bfd_mach_arm_unknown)
 282     /* FIXME: We ought to have some way to
 283        override this on the command line.  */
 284     bfd_set_arch_mach (obfd, bfd_arch_arm, bfd_mach_arm_unknown);
 285
 286   /* If they are the same then nothing needs to be done.  */
 287   else if (out == in)
 288     ;
 289
 290   /* Otherwise the general principle that a earlier architecture can be
 291      linked with a later architecture to produce a binary that will execute
 292      on the later architecture.
 293
 294      We fail however if we attempt to link a Cirrus EP9312 binary with an
 295      Intel XScale binary, since these architecture have co-processors which
 296      will not both be present on the same physical hardware.  */
 297   else if (in == bfd_mach_arm_ep9312
 298            && (out == bfd_mach_arm_XScale
 299                || out == bfd_mach_arm_iWMMXt
 300                || out == bfd_mach_arm_iWMMXt2))
 301     {
 302       /* xgettext: c-format */
 303       _bfd_error_handler (_("\
 304 error: %pB is compiled for the EP9312, whereas %pB is compiled for XScale"),
 305                           ibfd, obfd);
 306       bfd_set_error (bfd_error_wrong_format);
 307       return FALSE;
 308     }
 309   else if (out == bfd_mach_arm_ep9312
 310            && (in == bfd_mach_arm_XScale
 311                || in == bfd_mach_arm_iWMMXt
 312                || in == bfd_mach_arm_iWMMXt2))
 313     {
 314       /* xgettext: c-format */
 315       _bfd_error_handler (_("\
 316 error: %pB is compiled for the EP9312, whereas %pB is compiled for XScale"),
 317                           obfd, ibfd);
 318       bfd_set_error (bfd_error_wrong_format);
 319       return FALSE;
 320     }
 321   else if (in > out)
 322     bfd_set_arch_mach (obfd, bfd_arch_arm, in);
 323   /* else
 324      Nothing to do.  */
 325
 326   return TRUE;
 327 }
 328
 329 typedef struct
 330 {
 331   unsigned char namesz[4];      /* Size of entry's owner string.  */
 332   unsigned char descsz[4];      /* Size of the note descriptor.  */
 333   unsigned char type[4];        /* Interpretation of the descriptor.  */
 334   char          name[1];        /* Start of the name+desc data.  */
 335 } arm_Note;
 336
 337 static bfd_boolean
 338 arm_check_note (bfd *abfd,
 339                 bfd_byte *buffer,
 340                 bfd_size_type buffer_size,
 341                 const char *expected_name,
 342                 char **description_return)
 343 {
 344   unsigned long namesz;
 345   unsigned long descsz;
 346   unsigned long type;
 347   char *        descr;
 348
 349   if (buffer_size < offsetof (arm_Note, name))
 350     return FALSE;
 351
 352   /* We have to extract the values this way to allow for a
 353      host whose endian-ness is different from the target.  */
 354   namesz = bfd_get_32 (abfd, buffer);
 355   descsz = bfd_get_32 (abfd, buffer + offsetof (arm_Note, descsz));
 356   type   = bfd_get_32 (abfd, buffer + offsetof (arm_Note, type));
 357   descr  = (char *) buffer + offsetof (arm_Note, name);
 358
 359   /* Check for buffer overflow.  */
 360   if (namesz + descsz + offsetof (arm_Note, name) > buffer_size)
 361     return FALSE;
 362
 363   if (expected_name == NULL)
 364     {
 365       if (namesz != 0)
 366         return FALSE;
 367     }
 368   else
 369     {
 370       if (namesz != ((strlen (expected_name) + 1 + 3) & ~3))
 371         return FALSE;
 372
 373       if (strcmp (descr, expected_name) != 0)
 374         return FALSE;
 375
 376       descr += (namesz + 3) & ~3;
 377     }
 378
 379   /* FIXME: We should probably check the type as well.  */
 380   (void) type;
 381
 382   if (description_return != NULL)
 383     * description_return = descr;
 384
 385   return TRUE;
 386 }
 387
 388 #define NOTE_ARCH_STRING        "arch: "
 389
 390 bfd_boolean
 391 bfd_arm_update_notes (bfd *abfd, const char *note_section)
 392 {
 393   asection *     arm_arch_section;
 394   bfd_size_type  buffer_size;
 395   bfd_byte *     buffer;
 396   char *         arch_string;
 397   char *         expected;
 398
 399   /* Look for a note section.  If one is present check the architecture
 400      string encoded in it, and set it to the current architecture if it is
 401      different.  */
 402   arm_arch_section = bfd_get_section_by_name (abfd, note_section);
 403
 404   if (arm_arch_section == NULL)
 405     return TRUE;
 406
 407   buffer_size = arm_arch_section->size;
 408   if (buffer_size == 0)
 409     return FALSE;
 410
 411   if (!bfd_malloc_and_get_section (abfd, arm_arch_section, &buffer))
 412     goto FAIL;
 413
 414   /* Parse the note.  */
 415   if (! arm_check_note (abfd, buffer, buffer_size, NOTE_ARCH_STRING, & arch_string))
 416     goto FAIL;
 417
 418   /* Check the architecture in the note against the architecture of the bfd.
 419      Newer architectures versions should not be added here as build attribute
 420      are a better mechanism to convey ISA used.  */
 421   switch (bfd_get_mach (abfd))
 422     {
 423     default:
 424     case bfd_mach_arm_unknown: expected = "unknown"; break;
 425     case bfd_mach_arm_2:       expected = "armv2"; break;
 426     case bfd_mach_arm_2a:      expected = "armv2a"; break;
 427     case bfd_mach_arm_3:       expected = "armv3"; break;
 428     case bfd_mach_arm_3M:      expected = "armv3M"; break;
 429     case bfd_mach_arm_4:       expected = "armv4"; break;
 430     case bfd_mach_arm_4T:      expected = "armv4t"; break;
 431     case bfd_mach_arm_5:       expected = "armv5"; break;
 432     case bfd_mach_arm_5T:      expected = "armv5t"; break;
 433     case bfd_mach_arm_5TE:     expected = "armv5te"; break;
 434     case bfd_mach_arm_XScale:  expected = "XScale"; break;
 435     case bfd_mach_arm_ep9312:  expected = "ep9312"; break;
 436     case bfd_mach_arm_iWMMXt:  expected = "iWMMXt"; break;
 437     case bfd_mach_arm_iWMMXt2: expected = "iWMMXt2"; break;
 438     }
 439
 440   if (strcmp (arch_string, expected) != 0)
 441     {
 442       strcpy ((char *) buffer + (offsetof (arm_Note, name)
 443                                  + ((strlen (NOTE_ARCH_STRING) + 3) & ~3)),
 444               expected);
 445
 446       if (! bfd_set_section_contents (abfd, arm_arch_section, buffer,
 447                                       (file_ptr) 0, buffer_size))
 448         {
 449           _bfd_error_handler
 450             /* xgettext: c-format */
 451             (_("warning: unable to update contents of %s section in %pB"),
 452              note_section, abfd);
 453           goto FAIL;
 454         }
 455     }
 456
 457   free (buffer);
 458   return TRUE;
 459
 460  FAIL:
 461   if (buffer != NULL)
 462     free (buffer);
 463   return FALSE;
 464 }
 465
 466
 467 static struct
 468 {
 469   const char * string;
 470   unsigned int mach;
 471 }
 472
 473 /* Newer architectures versions should not be added here as build attribute are
 474    a better mechanism to convey ISA used.  */
 475 architectures[] =
 476 {
 477   { "armv2",   bfd_mach_arm_2 },
 478   { "armv2a",  bfd_mach_arm_2a },
 479   { "armv3",   bfd_mach_arm_3 },
 480   { "armv3M",  bfd_mach_arm_3M },
 481   { "armv4",   bfd_mach_arm_4 },
 482   { "armv4t",  bfd_mach_arm_4T },
 483   { "armv5",   bfd_mach_arm_5 },
 484   { "armv5t",  bfd_mach_arm_5T },
 485   { "armv5te", bfd_mach_arm_5TE },
 486   { "XScale",  bfd_mach_arm_XScale },
 487   { "ep9312",  bfd_mach_arm_ep9312 },
 488   { "iWMMXt",  bfd_mach_arm_iWMMXt },
 489   { "iWMMXt2", bfd_mach_arm_iWMMXt2 },
 490   { "arm_any", bfd_mach_arm_unknown }
 491 };
 492
 493 /* Extract the machine number stored in a note section.  */
 494 unsigned int
 495 bfd_arm_get_mach_from_notes (bfd *abfd, const char *note_section)
 496 {
 497   asection *     arm_arch_section;
 498   bfd_size_type  buffer_size;
 499   bfd_byte *     buffer;
 500   char *         arch_string;
 501   int            i;
 502
 503   /* Look for a note section.  If one is present check the architecture
 504      string encoded in it, and set it to the current architecture if it is
 505      different.  */
 506   arm_arch_section = bfd_get_section_by_name (abfd, note_section);
 507
 508   if (arm_arch_section == NULL)
 509     return bfd_mach_arm_unknown;
 510
 511   buffer_size = arm_arch_section->size;
 512   if (buffer_size == 0)
 513     return bfd_mach_arm_unknown;
 514
 515   if (!bfd_malloc_and_get_section (abfd, arm_arch_section, &buffer))
 516     goto FAIL;
 517
 518   /* Parse the note.  */
 519   if (! arm_check_note (abfd, buffer, buffer_size, NOTE_ARCH_STRING, & arch_string))
 520     goto FAIL;
 521
 522   /* Interpret the architecture string.  */
 523   for (i = ARRAY_SIZE (architectures); i--;)
 524     if (strcmp (arch_string, architectures[i].string) == 0)
 525       {
 526         free (buffer);
 527         return architectures[i].mach;
 528       }
 529
 530  FAIL:
 531   if (buffer != NULL)
 532     free (buffer);
 533   return bfd_mach_arm_unknown;
 534 }
 535
 536 bfd_boolean
 537 bfd_is_arm_special_symbol_name (const char * name, int type)
 538 {
 539   /* The ARM compiler outputs several obsolete forms.  Recognize them
 540      in addition to the standard $a, $t and $d.  We are somewhat loose
 541      in what we accept here, since the full set is not documented.  */
 542   if (!name || name[0] != '$')
 543     return FALSE;
 544   if (name[1] == 'a' || name[1] == 't' || name[1] == 'd')
 545     type &= BFD_ARM_SPECIAL_SYM_TYPE_MAP;
 546   else if (name[1] == 'm' || name[1] == 'f' || name[1] == 'p')
 547     type &= BFD_ARM_SPECIAL_SYM_TYPE_TAG;
 548   else if (name[1] >= 'a' && name[1] <= 'z')
 549     type &= BFD_ARM_SPECIAL_SYM_TYPE_OTHER;
 550   else
 551     return FALSE;
 552
 553   return (type != 0 && (name[2] == 0 || name[2] == '.'));
 554 }
 555