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"
33 #include "gdb_assert.h"
34 #include "gdb_string.h"
36 #include "i386-tdep.h"
37 #include "i387-tdep.h"
38 #include "nbsd-tdep.h"
39 #include "solib-svr4.h"
41 /* From <machine/reg.h>. */
42 static int i386nbsd_r_reg_offset[] =
63 i386nbsd_aout_supply_regset (const struct regset *regset,
64 struct regcache *regcache, int regnum,
65 const void *regs, size_t len)
67 const struct gdbarch_tdep *tdep = regset->descr;
69 gdb_assert (len >= tdep->sizeof_gregset + I387_SIZEOF_FSAVE);
71 i386_supply_gregset (regset, regcache, regnum, regs, tdep->sizeof_gregset);
72 i387_supply_fsave (regcache, regnum, (char *) regs + tdep->sizeof_gregset);
75 static const struct regset *
76 i386nbsd_aout_regset_from_core_section (struct gdbarch *gdbarch,
77 const char *sect_name,
80 struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
82 /* NetBSD a.out core dumps don't use seperate register sets for the
83 general-purpose and floating-point registers. */
85 if (strcmp (sect_name, ".reg") == 0
86 && sect_size >= tdep->sizeof_gregset + I387_SIZEOF_FSAVE)
88 if (tdep->gregset == NULL)
90 tdep->gregset = XMALLOC (struct regset);
91 tdep->gregset->descr = tdep;
92 tdep->gregset->supply_regset = i386nbsd_aout_supply_regset;
100 /* Under NetBSD/i386, signal handler invocations can be identified by the
101 designated code sequence that is used to return from a signal handler.
102 In particular, the return address of a signal handler points to the
103 following code sequence:
105 leal 0x10(%esp), %eax
108 movl $0x127, %eax # __sigreturn14
111 Each instruction has a unique encoding, so we simply attempt to match
112 the instruction the PC is pointing to with any of the above instructions.
113 If there is a hit, we know the offset to the start of the designated
114 sequence and can then check whether we really are executing in the
115 signal trampoline. If not, -1 is returned, otherwise the offset from the
116 start of the return sequence is returned. */
117 #define RETCODE_INSN1 0x8d
118 #define RETCODE_INSN2 0x50
119 #define RETCODE_INSN3 0x50
120 #define RETCODE_INSN4 0xb8
121 #define RETCODE_INSN5 0xcd
123 #define RETCODE_INSN2_OFF 4
124 #define RETCODE_INSN3_OFF 5
125 #define RETCODE_INSN4_OFF 6
126 #define RETCODE_INSN5_OFF 11
128 static const unsigned char sigtramp_retcode[] =
130 RETCODE_INSN1, 0x44, 0x24, 0x10,
133 RETCODE_INSN4, 0x27, 0x01, 0x00, 0x00,
138 i386nbsd_sigtramp_offset (CORE_ADDR pc)
140 unsigned char ret[sizeof(sigtramp_retcode)], insn;
144 if (read_memory_nobpt (pc, &insn, 1) != 0)
154 /* INSN2 and INSN3 are the same. Read at the location of PC+1
155 to determine if we're actually looking at INSN2 or INSN3. */
156 if (read_memory_nobpt (pc + 1, &insn, 1) != 0)
159 if (insn == RETCODE_INSN3)
160 off = RETCODE_INSN2_OFF;
162 off = RETCODE_INSN3_OFF;
166 off = RETCODE_INSN4_OFF;
170 off = RETCODE_INSN5_OFF;
179 if (read_memory_nobpt (pc, (char *) ret, sizeof (ret)) != 0)
182 if (memcmp (ret, sigtramp_retcode, sizeof (ret)) == 0)
188 /* Return whether the frame preceding NEXT_FRAME corresponds to a
189 NetBSD sigtramp routine. */
192 i386nbsd_sigtramp_p (struct frame_info *next_frame)
194 CORE_ADDR pc = frame_pc_unwind (next_frame);
197 find_pc_partial_function (pc, &name, NULL, NULL);
198 return (nbsd_pc_in_sigtramp (pc, name)
199 || i386nbsd_sigtramp_offset (pc) >= 0);
202 /* From <machine/signal.h>. */
203 int i386nbsd_sc_reg_offset[] =
214 13 * 4, /* %eflags */
224 i386nbsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
226 struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
228 /* Obviously NetBSD is BSD-based. */
229 i386bsd_init_abi (info, gdbarch);
231 /* NetBSD has a different `struct reg'. */
232 tdep->gregset_reg_offset = i386nbsd_r_reg_offset;
233 tdep->gregset_num_regs = ARRAY_SIZE (i386nbsd_r_reg_offset);
234 tdep->sizeof_gregset = 16 * 4;
236 /* NetBSD has different signal trampoline conventions. */
237 tdep->sigtramp_start = 0;
238 tdep->sigtramp_end = 0;
239 tdep->sigtramp_p = i386nbsd_sigtramp_p;
241 /* NetBSD uses -freg-struct-return by default. */
242 tdep->struct_return = reg_struct_return;
244 /* NetBSD has a `struct sigcontext' that's different from the
246 tdep->sc_reg_offset = i386nbsd_sc_reg_offset;
247 tdep->sc_num_regs = ARRAY_SIZE (i386nbsd_sc_reg_offset);
253 i386nbsdaout_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
255 i386nbsd_init_abi (info, gdbarch);
257 /* NetBSD a.out has a single register set. */
258 set_gdbarch_regset_from_core_section
259 (gdbarch, i386nbsd_aout_regset_from_core_section);
265 i386nbsdelf_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
267 struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
269 /* It's still NetBSD. */
270 i386nbsd_init_abi (info, gdbarch);
273 i386_elf_init_abi (info, gdbarch);
275 /* NetBSD ELF uses SVR4-style shared libraries. */
276 set_gdbarch_in_solib_call_trampoline
277 (gdbarch, generic_in_solib_call_trampoline);
278 set_solib_svr4_fetch_link_map_offsets
279 (gdbarch, svr4_ilp32_fetch_link_map_offsets);
281 /* NetBSD ELF uses -fpcc-struct-return by default. */
282 tdep->struct_return = pcc_struct_return;
286 _initialize_i386nbsd_tdep (void)
288 gdbarch_register_osabi (bfd_arch_i386, 0, GDB_OSABI_NETBSD_AOUT,
289 i386nbsdaout_init_abi);
290 gdbarch_register_osabi (bfd_arch_i386, 0, GDB_OSABI_NETBSD_ELF,
291 i386nbsdelf_init_abi);