bfd/cpu-riscv.c

   1 /* BFD backend for RISC-V
   2    Copyright (C) 2011-2022 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 "cpu-riscv.h"
  27
  28 static const bfd_arch_info_type *
  29 riscv_compatible (const bfd_arch_info_type *a, const bfd_arch_info_type *b)
  30 {
  31   if (a->arch != b->arch)
  32     return NULL;
  33
  34   /* Machine compatibility is checked in
  35      _bfd_riscv_elf_merge_private_bfd_data.  */
  36
  37   return a;
  38 }
  39
  40 /* Return TRUE if STRING matches the architecture described by INFO.  */
  41
  42 static bool
  43 riscv_scan (const struct bfd_arch_info *info, const char *string)
  44 {
  45   if (bfd_default_scan (info, string))
  46     return true;
  47
  48   /* The incoming STRING might take the form of riscv:rvXXzzz, where XX is
  49      32 or 64, and zzz are one or more extension characters.  As we
  50      currently only have 3 architectures defined, 'riscv', 'riscv:rv32',
  51      and 'riscv:rv64', we would like to ignore the zzz for the purpose of
  52      matching here.
  53
  54      However, we don't want the default 'riscv' to match over a more
  55      specific 'riscv:rv32' or 'riscv:rv64', so in the case of the default
  56      architecture (with the shorter 'riscv' name) we don't allow any
  57      special matching, but for the 'riscv:rvXX' cases, we allow a match
  58      with any additional trailing characters being ignored.  */
  59   if (!info->the_default
  60       && strncasecmp (string, info->printable_name,
  61                       strlen (info->printable_name)) == 0)
  62     return true;
  63
  64   return false;
  65 }
  66
  67 #define N(BITS, NUMBER, PRINT, DEFAULT, NEXT)                   \
  68   {                                                             \
  69     BITS,      /* Bits in a word.  */                           \
  70     BITS,      /* Bits in an address.  */                       \
  71     8,         /* Bits in a byte.  */                           \
  72     bfd_arch_riscv,                                             \
  73     NUMBER,                                                     \
  74     "riscv",                                                    \
  75     PRINT,                                                      \
  76     3,                                                          \
  77     DEFAULT,                                                    \
  78     riscv_compatible,                                           \
  79     riscv_scan,                                                 \
  80     bfd_arch_default_fill,                                      \
  81     NEXT,                                                       \
  82     0 /* Maximum offset of a reloc from the start of an insn.  */\
  83   }
  84
  85 /* This enum must be kept in the same order as arch_info_struct.  */
  86 enum
  87 {
  88   I_riscv64,
  89   I_riscv32
  90 };
  91
  92 #define NN(index) (&arch_info_struct[(index) + 1])
  93
  94 /* This array must be kept in the same order as the anonymous enum above,
  95    and each entry except the last should end with NN (my enum value).  */
  96 static const bfd_arch_info_type arch_info_struct[] =
  97 {
  98   N (64, bfd_mach_riscv64, "riscv:rv64", false, NN (I_riscv64)),
  99   N (32, bfd_mach_riscv32, "riscv:rv32", false, NULL)
 100 };
 101
 102 /* The default architecture is riscv:rv64.  */
 103 const bfd_arch_info_type bfd_riscv_arch =
 104   N (64, 0, "riscv", true, &arch_info_struct[0]);
 105
 106 /* List for all supported ISA spec versions.  */
 107 const struct riscv_spec riscv_isa_specs[] =
 108 {
 109   {"2.2",      ISA_SPEC_CLASS_2P2},
 110   {"20190608", ISA_SPEC_CLASS_20190608},
 111   {"20191213", ISA_SPEC_CLASS_20191213},
 112 };
 113
 114 /* List for all supported privileged spec versions.  */
 115 const struct riscv_spec riscv_priv_specs[] =
 116 {
 117   {"1.9.1", PRIV_SPEC_CLASS_1P9P1},
 118   {"1.10",  PRIV_SPEC_CLASS_1P10},
 119   {"1.11",  PRIV_SPEC_CLASS_1P11},
 120   {"1.12",  PRIV_SPEC_CLASS_1P12},
 121 };
 122
 123 /* Get the corresponding CSR version class by giving privilege
 124    version numbers.  It is usually used to convert the priv
 125    attribute numbers into the corresponding class.  */
 126
 127 void
 128 riscv_get_priv_spec_class_from_numbers (unsigned int major,
 129                                         unsigned int minor,
 130                                         unsigned int revision,
 131                                         enum riscv_spec_class *class)
 132 {
 133   enum riscv_spec_class class_t = *class;
 134   char buf[36];
 135
 136   if (revision != 0)
 137     snprintf (buf, sizeof (buf), "%u.%u.%u", major, minor, revision);
 138   else
 139     snprintf (buf, sizeof (buf), "%u.%u", major, minor);
 140
 141   RISCV_GET_PRIV_SPEC_CLASS (buf, class_t);
 142   *class = class_t;
 143 }
 144
 145 /* Define mapping symbols for riscv.  */
 146
 147 bool
 148 riscv_elf_is_mapping_symbols (const char *name)
 149 {
 150   return (!strncmp (name, "$d", 2)
 151           || !strncmp (name, "$x", 2));
 152 }