1/* Target-dependent code for FreeBSD/aarch64.
2
3   Copyright (C) 2017-2020 Free Software Foundation, Inc.
4
5   This file is part of GDB.
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, see <http://www.gnu.org/licenses/>.  */
19
20#include "defs.h"
21
22#include "gdbarch.h"
23#include "fbsd-tdep.h"
24#include "aarch64-tdep.h"
25#include "aarch64-fbsd-tdep.h"
26#include "osabi.h"
27#include "solib-svr4.h"
28#include "target.h"
29#include "tramp-frame.h"
30#include "trad-frame.h"
31
32/* Register maps.  */
33
34static const struct regcache_map_entry aarch64_fbsd_gregmap[] =
35  {
36    { 30, AARCH64_X0_REGNUM, 8 }, /* x0 ... x29 */
37    { 1, AARCH64_LR_REGNUM, 8 },
38    { 1, AARCH64_SP_REGNUM, 8 },
39    { 1, AARCH64_PC_REGNUM, 8 },
40    { 1, AARCH64_CPSR_REGNUM, 4 },
41    { 0 }
42  };
43
44static const struct regcache_map_entry aarch64_fbsd_fpregmap[] =
45  {
46    { 32, AARCH64_V0_REGNUM, 16 }, /* v0 ... v31 */
47    { 1, AARCH64_FPSR_REGNUM, 4 },
48    { 1, AARCH64_FPCR_REGNUM, 4 },
49    { 0 }
50  };
51
52/* In a signal frame, sp points to a 'struct sigframe' which is
53   defined as:
54
55   struct sigframe {
56	   siginfo_t	sf_si;
57	   ucontext_t	sf_uc;
58   };
59
60   ucontext_t is defined as:
61
62   struct __ucontext {
63	   sigset_t	uc_sigmask;
64	   mcontext_t	uc_mcontext;
65	   ...
66   };
67
68   The mcontext_t contains the general purpose register set followed
69   by the floating point register set.  The floating point register
70   set is only valid if the _MC_FP_VALID flag is set in mc_flags.  */
71
72#define AARCH64_SIGFRAME_UCONTEXT_OFFSET	80
73#define AARCH64_UCONTEXT_MCONTEXT_OFFSET	16
74#define	AARCH64_MCONTEXT_FPREGS_OFFSET		272
75#define	AARCH64_MCONTEXT_FLAGS_OFFSET		800
76#define AARCH64_MCONTEXT_FLAG_FP_VALID		0x1
77
78/* Implement the "init" method of struct tramp_frame.  */
79
80static void
81aarch64_fbsd_sigframe_init (const struct tramp_frame *self,
82			     struct frame_info *this_frame,
83			     struct trad_frame_cache *this_cache,
84			     CORE_ADDR func)
85{
86  struct gdbarch *gdbarch = get_frame_arch (this_frame);
87  enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
88  CORE_ADDR sp = get_frame_register_unsigned (this_frame, AARCH64_SP_REGNUM);
89  CORE_ADDR mcontext_addr
90    = (sp
91       + AARCH64_SIGFRAME_UCONTEXT_OFFSET
92       + AARCH64_UCONTEXT_MCONTEXT_OFFSET);
93  gdb_byte buf[4];
94
95  trad_frame_set_reg_regmap (this_cache, aarch64_fbsd_gregmap, mcontext_addr,
96			     regcache_map_entry_size (aarch64_fbsd_gregmap));
97
98  if (target_read_memory (mcontext_addr + AARCH64_MCONTEXT_FLAGS_OFFSET, buf,
99			  4) == 0
100      && (extract_unsigned_integer (buf, 4, byte_order)
101	  & AARCH64_MCONTEXT_FLAG_FP_VALID))
102    trad_frame_set_reg_regmap (this_cache, aarch64_fbsd_fpregmap,
103			       mcontext_addr + AARCH64_MCONTEXT_FPREGS_OFFSET,
104			       regcache_map_entry_size (aarch64_fbsd_fpregmap));
105
106  trad_frame_set_id (this_cache, frame_id_build (sp, func));
107}
108
109static const struct tramp_frame aarch64_fbsd_sigframe =
110{
111  SIGTRAMP_FRAME,
112  4,
113  {
114    {0x910003e0, ULONGEST_MAX},		/* mov  x0, sp  */
115    {0x91014000, ULONGEST_MAX},		/* add  x0, x0, #SF_UC  */
116    {0xd2803428, ULONGEST_MAX},		/* mov  x8, #SYS_sigreturn  */
117    {0xd4000001, ULONGEST_MAX},		/* svc  0x0  */
118    {TRAMP_SENTINEL_INSN, ULONGEST_MAX}
119  },
120  aarch64_fbsd_sigframe_init
121};
122
123/* Register set definitions.  */
124
125const struct regset aarch64_fbsd_gregset =
126  {
127    aarch64_fbsd_gregmap,
128    regcache_supply_regset, regcache_collect_regset
129  };
130
131const struct regset aarch64_fbsd_fpregset =
132  {
133    aarch64_fbsd_fpregmap,
134    regcache_supply_regset, regcache_collect_regset
135  };
136
137/* Implement the "iterate_over_regset_sections" gdbarch method.  */
138
139static void
140aarch64_fbsd_iterate_over_regset_sections (struct gdbarch *gdbarch,
141					   iterate_over_regset_sections_cb *cb,
142					   void *cb_data,
143					   const struct regcache *regcache)
144{
145  cb (".reg", AARCH64_FBSD_SIZEOF_GREGSET, AARCH64_FBSD_SIZEOF_GREGSET,
146      &aarch64_fbsd_gregset, NULL, cb_data);
147  cb (".reg2", AARCH64_FBSD_SIZEOF_FPREGSET, AARCH64_FBSD_SIZEOF_FPREGSET,
148      &aarch64_fbsd_fpregset, NULL, cb_data);
149}
150
151/* Implement the 'init_osabi' method of struct gdb_osabi_handler.  */
152
153static void
154aarch64_fbsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
155{
156  struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
157
158  /* Generic FreeBSD support.  */
159  fbsd_init_abi (info, gdbarch);
160
161  set_solib_svr4_fetch_link_map_offsets (gdbarch,
162					 svr4_lp64_fetch_link_map_offsets);
163
164  tramp_frame_prepend_unwinder (gdbarch, &aarch64_fbsd_sigframe);
165
166  /* Enable longjmp.  */
167  tdep->jb_pc = 13;
168
169  set_gdbarch_iterate_over_regset_sections
170    (gdbarch, aarch64_fbsd_iterate_over_regset_sections);
171}
172
173void _initialize_aarch64_fbsd_tdep ();
174void
175_initialize_aarch64_fbsd_tdep ()
176{
177  gdbarch_register_osabi (bfd_arch_aarch64, 0, GDB_OSABI_FREEBSD,
178			  aarch64_fbsd_init_abi);
179}
180