xref: /netbsd-src/external/gpl3/binutils/dist/bfd/cpu-riscv.c (revision dd7241df2fae9da4ea2bd20a68f001fa86ecf909)
1 /* BFD backend for RISC-V
2    Copyright (C) 2011-2024 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 *
riscv_compatible(const bfd_arch_info_type * a,const bfd_arch_info_type * b)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
riscv_scan(const struct bfd_arch_info * info,const char * string)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
riscv_get_priv_spec_class_from_numbers(unsigned int major,unsigned int minor,unsigned int revision,enum riscv_spec_class * class)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
riscv_elf_is_mapping_symbols(const char * name)148 riscv_elf_is_mapping_symbols (const char *name)
149 {
150   return (!strcmp (name, "$d")
151 	  || !strcmp (name, "$x")
152 	  || !strncmp (name, "$xrv", 4));
153 }
154