1 /* Target-dependent code for NetBSD/i386.
3 Copyright 1988, 1989, 1991, 1992, 1994, 1996, 2000, 2001, 2002,
5 Free Software Foundation, Inc.
7 This file is part of GDB.
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 2 of the License, or
12 (at your option) any later version.
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.
19 You should have received a copy of the GNU General Public License
20 along with this program; if not, write to the Free Software
21 Foundation, Inc., 59 Temple Place - Suite 330,
22 Boston, MA 02111-1307, USA. */
25 #include "arch-utils.h"
31 #include "gdb_assert.h"
32 #include "gdb_string.h"
34 #include "i386-tdep.h"
35 #include "i387-tdep.h"
36 #include "nbsd-tdep.h"
37 #include "solib-svr4.h"
39 /* From <machine/reg.h>. */
40 static int i386nbsd_r_reg_offset[] =
61 i386nbsd_aout_supply_regset (const struct regset *regset,
62 struct regcache *regcache, int regnum,
63 const void *regs, size_t len)
65 const struct gdbarch_tdep *tdep = regset->descr;
67 gdb_assert (len >= tdep->sizeof_gregset + I387_SIZEOF_FSAVE);
69 i386_supply_gregset (regset, regcache, regnum, regs, tdep->sizeof_gregset);
70 i387_supply_fsave (regcache, regnum, (char *) regs + tdep->sizeof_gregset);
73 static const struct regset *
74 i386nbsd_aout_regset_from_core_section (struct gdbarch *gdbarch,
75 const char *sect_name,
78 struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
80 /* NetBSD a.out core dumps don't use seperate register sets for the
81 general-purpose and floating-point registers. */
83 if (strcmp (sect_name, ".reg") == 0
84 && sect_size >= tdep->sizeof_gregset + I387_SIZEOF_FSAVE)
86 if (tdep->gregset == NULL)
88 tdep->gregset = XMALLOC (struct regset);
89 tdep->gregset->descr = tdep;
90 tdep->gregset->supply_regset = i386nbsd_aout_supply_regset;
98 /* Under NetBSD/i386, signal handler invocations can be identified by the
99 designated code sequence that is used to return from a signal handler.
100 In particular, the return address of a signal handler points to the
101 following code sequence:
103 leal 0x10(%esp), %eax
106 movl $0x127, %eax # __sigreturn14
109 Each instruction has a unique encoding, so we simply attempt to match
110 the instruction the PC is pointing to with any of the above instructions.
111 If there is a hit, we know the offset to the start of the designated
112 sequence and can then check whether we really are executing in the
113 signal trampoline. If not, -1 is returned, otherwise the offset from the
114 start of the return sequence is returned. */
115 #define RETCODE_INSN1 0x8d
116 #define RETCODE_INSN2 0x50
117 #define RETCODE_INSN3 0x50
118 #define RETCODE_INSN4 0xb8
119 #define RETCODE_INSN5 0xcd
121 #define RETCODE_INSN2_OFF 4
122 #define RETCODE_INSN3_OFF 5
123 #define RETCODE_INSN4_OFF 6
124 #define RETCODE_INSN5_OFF 11
126 static const unsigned char sigtramp_retcode[] =
128 RETCODE_INSN1, 0x44, 0x24, 0x10,
131 RETCODE_INSN4, 0x27, 0x01, 0x00, 0x00,
136 i386nbsd_sigtramp_offset (CORE_ADDR pc)
138 unsigned char ret[sizeof(sigtramp_retcode)], insn;
142 if (read_memory_nobpt (pc, &insn, 1) != 0)
152 /* INSN2 and INSN3 are the same. Read at the location of PC+1
153 to determine if we're actually looking at INSN2 or INSN3. */
154 if (read_memory_nobpt (pc + 1, &insn, 1) != 0)
157 if (insn == RETCODE_INSN3)
158 off = RETCODE_INSN2_OFF;
160 off = RETCODE_INSN3_OFF;
164 off = RETCODE_INSN4_OFF;
168 off = RETCODE_INSN5_OFF;
177 if (read_memory_nobpt (pc, (char *) ret, sizeof (ret)) != 0)
180 if (memcmp (ret, sigtramp_retcode, sizeof (ret)) == 0)
187 i386nbsd_pc_in_sigtramp (CORE_ADDR pc, char *name)
189 return (nbsd_pc_in_sigtramp (pc, name)
190 || i386nbsd_sigtramp_offset (pc) >= 0);
193 /* From <machine/signal.h>. */
194 int i386nbsd_sc_reg_offset[] =
205 13 * 4, /* %eflags */
215 i386nbsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
217 struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
219 /* Obviously NetBSD is BSD-based. */
220 i386bsd_init_abi (info, gdbarch);
222 /* NetBSD has a different `struct reg'. */
223 tdep->gregset_reg_offset = i386nbsd_r_reg_offset;
224 tdep->gregset_num_regs = ARRAY_SIZE (i386nbsd_r_reg_offset);
225 tdep->sizeof_gregset = 16 * 4;
227 /* NetBSD has different signal trampoline conventions. */
228 set_gdbarch_deprecated_pc_in_sigtramp (gdbarch, i386nbsd_pc_in_sigtramp);
229 /* FIXME: kettenis/20020906: We should probably provide
230 NetBSD-specific versions of these functions if we want to
231 recognize signal trampolines that live on the stack. */
232 set_gdbarch_deprecated_sigtramp_start (gdbarch, NULL);
233 set_gdbarch_deprecated_sigtramp_end (gdbarch, NULL);
235 /* NetBSD uses -freg-struct-return by default. */
236 tdep->struct_return = reg_struct_return;
238 /* NetBSD has a `struct sigcontext' that's different from the
240 tdep->sc_reg_offset = i386nbsd_sc_reg_offset;
241 tdep->sc_num_regs = ARRAY_SIZE (i386nbsd_sc_reg_offset);
247 i386nbsdaout_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
249 i386nbsd_init_abi (info, gdbarch);
251 /* NetBSD a.out has a single register set. */
252 set_gdbarch_regset_from_core_section
253 (gdbarch, i386nbsd_aout_regset_from_core_section);
259 i386nbsdelf_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
261 struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
263 /* It's still NetBSD. */
264 i386nbsd_init_abi (info, gdbarch);
267 i386_elf_init_abi (info, gdbarch);
269 /* NetBSD ELF uses SVR4-style shared libraries. */
270 set_gdbarch_in_solib_call_trampoline
271 (gdbarch, generic_in_solib_call_trampoline);
272 set_solib_svr4_fetch_link_map_offsets
273 (gdbarch, svr4_ilp32_fetch_link_map_offsets);
275 /* NetBSD ELF uses -fpcc-struct-return by default. */
276 tdep->struct_return = pcc_struct_return;
280 _initialize_i386nbsd_tdep (void)
282 gdbarch_register_osabi (bfd_arch_i386, 0, GDB_OSABI_NETBSD_AOUT,
283 i386nbsdaout_init_abi);
284 gdbarch_register_osabi (bfd_arch_i386, 0, GDB_OSABI_NETBSD_ELF,
285 i386nbsdelf_init_abi);