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 2 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, write to the Free Software
20 Foundation, Inc., 51 Franklin Street, Fifth Floor,
21 Boston, MA 02110-1301, USA. */
24 #include "arch-utils.h"
32 #include "gdb_assert.h"
33 #include "gdb_string.h"
35 #include "i386-tdep.h"
36 #include "i387-tdep.h"
37 #include "nbsd-tdep.h"
38 #include "solib-svr4.h"
40 /* From <machine/reg.h>. */
41 static int i386nbsd_r_reg_offset[] =
62 i386nbsd_aout_supply_regset (const struct regset *regset,
63 struct regcache *regcache, int regnum,
64 const void *regs, size_t len)
66 const struct gdbarch_tdep *tdep = gdbarch_tdep (regset->arch);
68 gdb_assert (len >= tdep->sizeof_gregset + I387_SIZEOF_FSAVE);
70 i386_supply_gregset (regset, regcache, regnum, regs, tdep->sizeof_gregset);
71 i387_supply_fsave (regcache, regnum, (char *) regs + tdep->sizeof_gregset);
74 static const struct regset *
75 i386nbsd_aout_regset_from_core_section (struct gdbarch *gdbarch,
76 const char *sect_name,
79 struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
81 /* NetBSD a.out core dumps don't use seperate register sets for the
82 general-purpose and floating-point registers. */
84 if (strcmp (sect_name, ".reg") == 0
85 && sect_size >= tdep->sizeof_gregset + I387_SIZEOF_FSAVE)
87 if (tdep->gregset == NULL)
89 regset_alloc (gdbarch, i386nbsd_aout_supply_regset, NULL);
96 /* Under NetBSD/i386, signal handler invocations can be identified by the
97 designated code sequence that is used to return from a signal handler.
98 In particular, the return address of a signal handler points to the
99 following code sequence:
101 leal 0x10(%esp), %eax
104 movl $0x127, %eax # __sigreturn14
107 Each instruction has a unique encoding, so we simply attempt to match
108 the instruction the PC is pointing to with any of the above instructions.
109 If there is a hit, we know the offset to the start of the designated
110 sequence and can then check whether we really are executing in the
111 signal trampoline. If not, -1 is returned, otherwise the offset from the
112 start of the return sequence is returned. */
113 #define RETCODE_INSN1 0x8d
114 #define RETCODE_INSN2 0x50
115 #define RETCODE_INSN3 0x50
116 #define RETCODE_INSN4 0xb8
117 #define RETCODE_INSN5 0xcd
119 #define RETCODE_INSN2_OFF 4
120 #define RETCODE_INSN3_OFF 5
121 #define RETCODE_INSN4_OFF 6
122 #define RETCODE_INSN5_OFF 11
124 static const unsigned char sigtramp_retcode[] =
126 RETCODE_INSN1, 0x44, 0x24, 0x10,
129 RETCODE_INSN4, 0x27, 0x01, 0x00, 0x00,
134 i386nbsd_sigtramp_offset (struct frame_info *next_frame)
136 CORE_ADDR pc = frame_pc_unwind (next_frame);
137 unsigned char ret[sizeof(sigtramp_retcode)], insn;
141 if (!safe_frame_unwind_memory (next_frame, pc, &insn, 1))
151 /* INSN2 and INSN3 are the same. Read at the location of PC+1
152 to determine if we're actually looking at INSN2 or INSN3. */
153 if (!safe_frame_unwind_memory (next_frame, pc + 1, &insn, 1))
156 if (insn == RETCODE_INSN3)
157 off = RETCODE_INSN2_OFF;
159 off = RETCODE_INSN3_OFF;
163 off = RETCODE_INSN4_OFF;
167 off = RETCODE_INSN5_OFF;
176 if (!safe_frame_unwind_memory (next_frame, pc, ret, sizeof (ret)))
179 if (memcmp (ret, sigtramp_retcode, sizeof (ret)) == 0)
185 /* Return whether the frame preceding NEXT_FRAME corresponds to a
186 NetBSD sigtramp routine. */
189 i386nbsd_sigtramp_p (struct frame_info *next_frame)
191 CORE_ADDR pc = frame_pc_unwind (next_frame);
194 find_pc_partial_function (pc, &name, NULL, NULL);
195 return (nbsd_pc_in_sigtramp (pc, name)
196 || i386nbsd_sigtramp_offset (next_frame) >= 0);
199 /* From <machine/signal.h>. */
200 int i386nbsd_sc_reg_offset[] =
211 13 * 4, /* %eflags */
221 i386nbsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
223 struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
225 /* Obviously NetBSD is BSD-based. */
226 i386bsd_init_abi (info, gdbarch);
228 /* NetBSD has a different `struct reg'. */
229 tdep->gregset_reg_offset = i386nbsd_r_reg_offset;
230 tdep->gregset_num_regs = ARRAY_SIZE (i386nbsd_r_reg_offset);
231 tdep->sizeof_gregset = 16 * 4;
233 /* NetBSD has different signal trampoline conventions. */
234 tdep->sigtramp_start = 0;
235 tdep->sigtramp_end = 0;
236 tdep->sigtramp_p = i386nbsd_sigtramp_p;
238 /* NetBSD uses -freg-struct-return by default. */
239 tdep->struct_return = reg_struct_return;
241 /* NetBSD has a `struct sigcontext' that's different from the
243 tdep->sc_reg_offset = i386nbsd_sc_reg_offset;
244 tdep->sc_num_regs = ARRAY_SIZE (i386nbsd_sc_reg_offset);
250 i386nbsdaout_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
252 i386nbsd_init_abi (info, gdbarch);
254 /* NetBSD a.out has a single register set. */
255 set_gdbarch_regset_from_core_section
256 (gdbarch, i386nbsd_aout_regset_from_core_section);
262 i386nbsdelf_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
264 struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
266 /* It's still NetBSD. */
267 i386nbsd_init_abi (info, gdbarch);
270 i386_elf_init_abi (info, gdbarch);
272 /* NetBSD ELF uses SVR4-style shared libraries. */
273 set_solib_svr4_fetch_link_map_offsets
274 (gdbarch, svr4_ilp32_fetch_link_map_offsets);
276 /* NetBSD ELF uses -fpcc-struct-return by default. */
277 tdep->struct_return = pcc_struct_return;
281 _initialize_i386nbsd_tdep (void)
283 gdbarch_register_osabi (bfd_arch_i386, 0, GDB_OSABI_NETBSD_AOUT,
284 i386nbsdaout_init_abi);
285 gdbarch_register_osabi (bfd_arch_i386, 0, GDB_OSABI_NETBSD_ELF,
286 i386nbsdelf_init_abi);