bfd/cpu-riscv.c

   1 /* BFD backend for RISC-V
   2    Copyright (C) 2011-2021 Free Software Foundation, Inc.
   3
   4    Contributed by Andrew Waterman (andrew@sifive.com).
   5    Based on MIPS target.
   6
   7    This file is part of BFD, the Binary File Descriptor library.
   8
   9    This program is free software; you can redistribute it and/or modify
  10    it under the terms of the GNU General Public License as published by
  11    the Free Software Foundation; either version 3 of the License, or
  12    (at your option) any later version.
  13
  14    This program is distributed in the hope that it will be useful,
  15    but WITHOUT ANY WARRANTY; without even the implied warranty of
  16    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17    GNU General Public License for more details.
  18
  19    You should have received a copy of the GNU General Public License
  20    along with this program; see the file COPYING3. If not,
  21    see <http://www.gnu.org/licenses/>.  */
  22
  23 #include "sysdep.h"
  24 #include "bfd.h"
  25 #include "libbfd.h"
  26 #include "elfxx-riscv.h"
  27
  28 /* Record the priv spec version string and the corresponding class.  */
  29
  30 struct priv_spec_t
  31 {
  32   const char *name;
  33   enum riscv_priv_spec_class class;
  34 };
  35
  36 /* List for all supported privilege versions.  */
  37
  38 static const struct priv_spec_t priv_specs[] =
  39 {
  40   {"1.9.1", PRIV_SPEC_CLASS_1P9P1},
  41   {"1.10",  PRIV_SPEC_CLASS_1P10},
  42   {"1.11",  PRIV_SPEC_CLASS_1P11},
  43
  44 /* Terminate the list.  */
  45   {NULL, 0}
  46 };
  47
  48 /* Get the corresponding CSR version class by giving a privilege
  49    version string.  */
  50
  51 int
  52 riscv_get_priv_spec_class (const char *s,
  53                            enum riscv_priv_spec_class *class)
  54 {
  55   const struct priv_spec_t *version;
  56
  57   if (s == NULL)
  58     return 0;
  59
  60   for (version = &priv_specs[0]; version->name != NULL; ++version)
  61     if (strcmp (version->name, s) == 0)
  62       {
  63         *class = version->class;
  64         return 1;
  65       }
  66
  67   /* Can not find the supported privilege version.  */
  68   return 0;
  69 }
  70
  71 /* Get the corresponding CSR version class by giving privilege
  72    version numbers.  It is usually used to convert the priv
  73    attribute numbers into the corresponding class.  */
  74
  75 int
  76 riscv_get_priv_spec_class_from_numbers (unsigned int major,
  77                                         unsigned int minor,
  78                                         unsigned int revision,
  79                                         enum riscv_priv_spec_class *class)
  80 {
  81   char buf[36];
  82
  83   if (major == 0 && minor == 0 && revision == 0)
  84     {
  85       *class = PRIV_SPEC_CLASS_NONE;
  86       return 1;
  87     }
  88
  89   if (revision != 0)
  90     snprintf (buf, sizeof (buf), "%u.%u.%u", major, minor, revision);
  91   else
  92     snprintf (buf, sizeof (buf), "%u.%u", major, minor);
  93
  94   return riscv_get_priv_spec_class (buf, class);
  95 }
  96
  97 /* Get the corresponding privilege version string by giving a CSR
  98    version class.  */
  99
 100 const char *
 101 riscv_get_priv_spec_name (enum riscv_priv_spec_class class)
 102 {
 103   /* The first enum is PRIV_SPEC_CLASS_NONE.  */
 104   return priv_specs[class - 1].name;
 105 }
 106
 107 /* This routine is provided two arch_infos and returns an arch_info
 108    that is compatible with both, or NULL if none exists.  */
 109
 110 static const bfd_arch_info_type *
 111 riscv_compatible (const bfd_arch_info_type *a, const bfd_arch_info_type *b)
 112 {
 113   if (a->arch != b->arch)
 114     return NULL;
 115
 116   /* Machine compatibility is checked in
 117      _bfd_riscv_elf_merge_private_bfd_data.  */
 118
 119   return a;
 120 }
 121
 122 /* Return TRUE if STRING matches the architecture described by INFO.  */
 123
 124 static bfd_boolean
 125 riscv_scan (const struct bfd_arch_info *info, const char *string)
 126 {
 127   if (bfd_default_scan (info, string))
 128     return TRUE;
 129
 130   /* The incoming STRING might take the form of riscv:rvXXzzz, where XX is
 131      32 or 64, and zzz are one or more extension characters.  As we
 132      currently only have 3 architectures defined, 'riscv', 'riscv:rv32',
 133      and 'riscv:rv64', we would like to ignore the zzz for the purpose of
 134      matching here.
 135
 136      However, we don't want the default 'riscv' to match over a more
 137      specific 'riscv:rv32' or 'riscv:rv64', so in the case of the default
 138      architecture (with the shorter 'riscv' name) we don't allow any
 139      special matching, but for the 'riscv:rvXX' cases, we allow a match
 140      with any additional trailing characters being ignored.  */
 141   if (!info->the_default
 142       && strncasecmp (string, info->printable_name,
 143                       strlen (info->printable_name)) == 0)
 144     return TRUE;
 145
 146   return FALSE;
 147 }
 148
 149 #define N(BITS, NUMBER, PRINT, DEFAULT, NEXT)                   \
 150   {                                                             \
 151     BITS,      /* Bits in a word.  */                           \
 152     BITS,      /* Bits in an address.  */                       \
 153     8,         /* Bits in a byte.  */                           \
 154     bfd_arch_riscv,                                             \
 155     NUMBER,                                                     \
 156     "riscv",                                                    \
 157     PRINT,                                                      \
 158     3,                                                          \
 159     DEFAULT,                                                    \
 160     riscv_compatible,                                           \
 161     riscv_scan,                                                 \
 162     bfd_arch_default_fill,                                      \
 163     NEXT,                                                       \
 164     0 /* Maximum offset of a reloc from the start of an insn.  */\
 165   }
 166
 167 /* This enum must be kept in the same order as arch_info_struct.  */
 168 enum
 169 {
 170   I_riscv64,
 171   I_riscv32
 172 };
 173
 174 #define NN(index) (&arch_info_struct[(index) + 1])
 175
 176 /* This array must be kept in the same order as the anonymous enum above,
 177    and each entry except the last should end with NN (my enum value).  */
 178 static const bfd_arch_info_type arch_info_struct[] =
 179 {
 180   N (64, bfd_mach_riscv64, "riscv:rv64", FALSE, NN (I_riscv64)),
 181   N (32, bfd_mach_riscv32, "riscv:rv32", FALSE, NULL)
 182 };
 183
 184 /* The default architecture is riscv:rv64.  */
 185
 186 const bfd_arch_info_type bfd_riscv_arch =
 187   N (64, 0, "riscv", TRUE, &arch_info_struct[0]);