1/* BFD backend for RISC-V
2   Copyright (C) 2011-2020 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
30struct 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
38static 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
51int
52riscv_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
75int
76riscv_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
100const char *
101riscv_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
110static const bfd_arch_info_type *
111riscv_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
124static bfd_boolean
125riscv_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.  */
168enum
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).  */
178static 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
186const bfd_arch_info_type bfd_riscv_arch =
187  N (64, 0, "riscv", TRUE, &arch_info_struct[0]);
188