1 /* Target-dependent code for NetBSD/i386.
3 Copyright (C) 1988, 1989, 1991, 1992, 1994, 1996, 2000, 2001, 2002, 2003,
4 2004, 2007 Free Software Foundation, Inc.
6 This file is part of GDB.
8 This program is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 3 of the License, or
11 (at your option) any later version.
13 This program is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with this program. If not, see <http://www.gnu.org/licenses/>. */
22 #include "arch-utils.h"
30 #include "gdb_assert.h"
31 #include "gdb_string.h"
33 #include "i386-tdep.h"
34 #include "i387-tdep.h"
35 #include "nbsd-tdep.h"
36 #include "solib-svr4.h"
38 /* From <machine/reg.h>. */
39 static int i386nbsd_r_reg_offset
[] =
60 i386nbsd_aout_supply_regset (const struct regset
*regset
,
61 struct regcache
*regcache
, int regnum
,
62 const void *regs
, size_t len
)
64 const struct gdbarch_tdep
*tdep
= gdbarch_tdep (regset
->arch
);
66 gdb_assert (len
>= tdep
->sizeof_gregset
+ I387_SIZEOF_FSAVE
);
68 i386_supply_gregset (regset
, regcache
, regnum
, regs
, tdep
->sizeof_gregset
);
69 i387_supply_fsave (regcache
, regnum
, (char *) regs
+ tdep
->sizeof_gregset
);
72 static const struct regset
*
73 i386nbsd_aout_regset_from_core_section (struct gdbarch
*gdbarch
,
74 const char *sect_name
,
77 struct gdbarch_tdep
*tdep
= gdbarch_tdep (gdbarch
);
79 /* NetBSD a.out core dumps don't use seperate register sets for the
80 general-purpose and floating-point registers. */
82 if (strcmp (sect_name
, ".reg") == 0
83 && sect_size
>= tdep
->sizeof_gregset
+ I387_SIZEOF_FSAVE
)
85 if (tdep
->gregset
== NULL
)
87 regset_alloc (gdbarch
, i386nbsd_aout_supply_regset
, NULL
);
94 /* Under NetBSD/i386, signal handler invocations can be identified by the
95 designated code sequence that is used to return from a signal handler.
96 In particular, the return address of a signal handler points to the
97 following code sequence:
102 movl $0x127, %eax # __sigreturn14
105 Each instruction has a unique encoding, so we simply attempt to match
106 the instruction the PC is pointing to with any of the above instructions.
107 If there is a hit, we know the offset to the start of the designated
108 sequence and can then check whether we really are executing in the
109 signal trampoline. If not, -1 is returned, otherwise the offset from the
110 start of the return sequence is returned. */
111 #define RETCODE_INSN1 0x8d
112 #define RETCODE_INSN2 0x50
113 #define RETCODE_INSN3 0x50
114 #define RETCODE_INSN4 0xb8
115 #define RETCODE_INSN5 0xcd
117 #define RETCODE_INSN2_OFF 4
118 #define RETCODE_INSN3_OFF 5
119 #define RETCODE_INSN4_OFF 6
120 #define RETCODE_INSN5_OFF 11
122 static const unsigned char sigtramp_retcode
[] =
124 RETCODE_INSN1
, 0x44, 0x24, 0x10,
127 RETCODE_INSN4
, 0x27, 0x01, 0x00, 0x00,
132 i386nbsd_sigtramp_offset (struct frame_info
*next_frame
)
134 CORE_ADDR pc
= frame_pc_unwind (next_frame
);
135 unsigned char ret
[sizeof(sigtramp_retcode
)], insn
;
139 if (!safe_frame_unwind_memory (next_frame
, pc
, &insn
, 1))
149 /* INSN2 and INSN3 are the same. Read at the location of PC+1
150 to determine if we're actually looking at INSN2 or INSN3. */
151 if (!safe_frame_unwind_memory (next_frame
, pc
+ 1, &insn
, 1))
154 if (insn
== RETCODE_INSN3
)
155 off
= RETCODE_INSN2_OFF
;
157 off
= RETCODE_INSN3_OFF
;
161 off
= RETCODE_INSN4_OFF
;
165 off
= RETCODE_INSN5_OFF
;
174 if (!safe_frame_unwind_memory (next_frame
, pc
, ret
, sizeof (ret
)))
177 if (memcmp (ret
, sigtramp_retcode
, sizeof (ret
)) == 0)
183 /* Return whether the frame preceding NEXT_FRAME corresponds to a
184 NetBSD sigtramp routine. */
187 i386nbsd_sigtramp_p (struct frame_info
*next_frame
)
189 CORE_ADDR pc
= frame_pc_unwind (next_frame
);
192 find_pc_partial_function (pc
, &name
, NULL
, NULL
);
193 return (nbsd_pc_in_sigtramp (pc
, name
)
194 || i386nbsd_sigtramp_offset (next_frame
) >= 0);
197 /* From <machine/signal.h>. */
198 int i386nbsd_sc_reg_offset
[] =
209 13 * 4, /* %eflags */
219 i386nbsd_init_abi (struct gdbarch_info info
, struct gdbarch
*gdbarch
)
221 struct gdbarch_tdep
*tdep
= gdbarch_tdep (gdbarch
);
223 /* Obviously NetBSD is BSD-based. */
224 i386bsd_init_abi (info
, gdbarch
);
226 /* NetBSD has a different `struct reg'. */
227 tdep
->gregset_reg_offset
= i386nbsd_r_reg_offset
;
228 tdep
->gregset_num_regs
= ARRAY_SIZE (i386nbsd_r_reg_offset
);
229 tdep
->sizeof_gregset
= 16 * 4;
231 /* NetBSD has different signal trampoline conventions. */
232 tdep
->sigtramp_start
= 0;
233 tdep
->sigtramp_end
= 0;
234 tdep
->sigtramp_p
= i386nbsd_sigtramp_p
;
236 /* NetBSD uses -freg-struct-return by default. */
237 tdep
->struct_return
= reg_struct_return
;
239 /* NetBSD has a `struct sigcontext' that's different from the
241 tdep
->sc_reg_offset
= i386nbsd_sc_reg_offset
;
242 tdep
->sc_num_regs
= ARRAY_SIZE (i386nbsd_sc_reg_offset
);
248 i386nbsdaout_init_abi (struct gdbarch_info info
, struct gdbarch
*gdbarch
)
250 i386nbsd_init_abi (info
, gdbarch
);
252 /* NetBSD a.out has a single register set. */
253 set_gdbarch_regset_from_core_section
254 (gdbarch
, i386nbsd_aout_regset_from_core_section
);
260 i386nbsdelf_init_abi (struct gdbarch_info info
, struct gdbarch
*gdbarch
)
262 struct gdbarch_tdep
*tdep
= gdbarch_tdep (gdbarch
);
264 /* It's still NetBSD. */
265 i386nbsd_init_abi (info
, gdbarch
);
268 i386_elf_init_abi (info
, gdbarch
);
270 /* NetBSD ELF uses SVR4-style shared libraries. */
271 set_solib_svr4_fetch_link_map_offsets
272 (gdbarch
, svr4_ilp32_fetch_link_map_offsets
);
274 /* NetBSD ELF uses -fpcc-struct-return by default. */
275 tdep
->struct_return
= pcc_struct_return
;
279 _initialize_i386nbsd_tdep (void)
281 gdbarch_register_osabi (bfd_arch_i386
, 0, GDB_OSABI_NETBSD_AOUT
,
282 i386nbsdaout_init_abi
);
283 gdbarch_register_osabi (bfd_arch_i386
, 0, GDB_OSABI_NETBSD_ELF
,
284 i386nbsdelf_init_abi
);