1 /* Target-dependent code for OpenBSD/powerpc.
3 Copyright (C) 2004, 2005, 2006, 2007 Free Software Foundation, Inc.
5 This file is part of GDB.
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.
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.
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/>. */
21 #include "arch-utils.h"
23 #include "frame-unwind.h"
29 #include "trad-frame.h"
31 #include "gdb_assert.h"
32 #include "gdb_string.h"
35 #include "ppcobsd-tdep.h"
36 #include "solib-svr4.h"
38 /* Register offsets from <machine/reg.h>. */
39 struct ppc_reg_offsets ppcobsd_reg_offsets;
40 struct ppc_reg_offsets ppcobsd_fpreg_offsets;
43 /* Core file support. */
45 /* Supply register REGNUM in the general-purpose register set REGSET
46 from the buffer specified by GREGS and LEN to register cache
47 REGCACHE. If REGNUM is -1, do this for all registers in REGSET. */
50 ppcobsd_supply_gregset (const struct regset *regset,
51 struct regcache *regcache, int regnum,
52 const void *gregs, size_t len)
54 /* FIXME: jimb/2004-05-05: Some PPC variants don't have floating
55 point registers. Traditionally, GDB's register set has still
56 listed the floating point registers for such machines, so this
57 code is harmless. However, the new E500 port actually omits the
58 floating point registers entirely from the register set --- they
59 don't even have register numbers assigned to them.
61 It's not clear to me how best to update this code, so this assert
62 will alert the first person to encounter the OpenBSD/E500
63 combination to the problem. */
64 gdb_assert (ppc_floating_point_unit_p (current_gdbarch));
66 ppc_supply_gregset (regset, regcache, regnum, gregs, len);
67 ppc_supply_fpregset (regset, regcache, regnum, gregs, len);
70 /* Collect register REGNUM in the general-purpose register set
71 REGSET. from register cache REGCACHE into the buffer specified by
72 GREGS and LEN. If REGNUM is -1, do this for all registers in
76 ppcobsd_collect_gregset (const struct regset *regset,
77 const struct regcache *regcache, int regnum,
78 void *gregs, size_t len)
80 /* FIXME: jimb/2004-05-05: Some PPC variants don't have floating
81 point registers. Traditionally, GDB's register set has still
82 listed the floating point registers for such machines, so this
83 code is harmless. However, the new E500 port actually omits the
84 floating point registers entirely from the register set --- they
85 don't even have register numbers assigned to them.
87 It's not clear to me how best to update this code, so this assert
88 will alert the first person to encounter the OpenBSD/E500
89 combination to the problem. */
90 gdb_assert (ppc_floating_point_unit_p (current_gdbarch));
92 ppc_collect_gregset (regset, regcache, regnum, gregs, len);
93 ppc_collect_fpregset (regset, regcache, regnum, gregs, len);
96 /* OpenBSD/powerpc register set. */
98 struct regset ppcobsd_gregset =
100 &ppcobsd_reg_offsets,
101 ppcobsd_supply_gregset
104 struct regset ppcobsd_fpregset =
106 &ppcobsd_fpreg_offsets,
110 /* Return the appropriate register set for the core section identified
111 by SECT_NAME and SECT_SIZE. */
113 static const struct regset *
114 ppcobsd_regset_from_core_section (struct gdbarch *gdbarch,
115 const char *sect_name, size_t sect_size)
117 if (strcmp (sect_name, ".reg") == 0 && sect_size >= 412)
118 return &ppcobsd_gregset;
124 /* Signal trampolines. */
126 /* Since OpenBSD 3.2, the sigtramp routine is mapped at a random page
127 in virtual memory. The randomness makes it somewhat tricky to
128 detect it, but fortunately we can rely on the fact that the start
129 of the sigtramp routine is page-aligned. We recognize the
130 trampoline by looking for the code that invokes the sigreturn
131 system call. The offset where we can find that code varies from
134 By the way, the mapping mentioned above is read-only, so you cannot
135 place a breakpoint in the signal trampoline. */
137 /* Default page size. */
138 static const int ppcobsd_page_size = 4096;
140 /* Offset for sigreturn(2). */
141 static const int ppcobsd_sigreturn_offset[] = {
142 0x98, /* OpenBSD 3.8 */
143 0x0c, /* OpenBSD 3.2 */
148 ppcobsd_sigtramp_p (struct frame_info *next_frame)
150 CORE_ADDR pc = frame_pc_unwind (next_frame);
151 CORE_ADDR start_pc = (pc & ~(ppcobsd_page_size - 1));
155 find_pc_partial_function (pc, &name, NULL, NULL);
159 for (offset = ppcobsd_sigreturn_offset; *offset != -1; offset++)
161 gdb_byte buf[2 * PPC_INSN_SIZE];
164 if (!safe_frame_unwind_memory (next_frame, start_pc + *offset,
168 /* Check for "li r0,SYS_sigreturn". */
169 insn = extract_unsigned_integer (buf, PPC_INSN_SIZE);
170 if (insn != 0x38000067)
173 /* Check for "sc". */
174 insn = extract_unsigned_integer (buf + PPC_INSN_SIZE, PPC_INSN_SIZE);
175 if (insn != 0x44000002)
184 static struct trad_frame_cache *
185 ppcobsd_sigtramp_frame_cache (struct frame_info *next_frame, void **this_cache)
187 struct gdbarch *gdbarch = get_frame_arch (next_frame);
188 struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
189 struct trad_frame_cache *cache;
190 CORE_ADDR addr, base, func;
191 gdb_byte buf[PPC_INSN_SIZE];
192 unsigned long insn, sigcontext_offset;
198 cache = trad_frame_cache_zalloc (next_frame);
201 func = frame_pc_unwind (next_frame);
202 func &= ~(ppcobsd_page_size - 1);
203 if (!safe_frame_unwind_memory (next_frame, func, buf, sizeof buf))
206 /* Calculate the offset where we can find `struct sigcontext'. We
207 base our calculation on the amount of stack space reserved by the
208 first instruction of the signal trampoline. */
209 insn = extract_unsigned_integer (buf, PPC_INSN_SIZE);
210 sigcontext_offset = (0x10000 - (insn & 0x0000ffff)) + 8;
212 base = frame_unwind_register_unsigned (next_frame,
213 gdbarch_sp_regnum (current_gdbarch));
214 addr = base + sigcontext_offset + 2 * tdep->wordsize;
215 for (i = 0; i < ppc_num_gprs; i++, addr += tdep->wordsize)
217 int regnum = i + tdep->ppc_gp0_regnum;
218 trad_frame_set_reg_addr (cache, regnum, addr);
220 trad_frame_set_reg_addr (cache, tdep->ppc_lr_regnum, addr);
221 addr += tdep->wordsize;
222 trad_frame_set_reg_addr (cache, tdep->ppc_cr_regnum, addr);
223 addr += tdep->wordsize;
224 trad_frame_set_reg_addr (cache, tdep->ppc_xer_regnum, addr);
225 addr += tdep->wordsize;
226 trad_frame_set_reg_addr (cache, tdep->ppc_ctr_regnum, addr);
227 addr += tdep->wordsize;
228 trad_frame_set_reg_addr (cache, gdbarch_pc_regnum (current_gdbarch), addr);
230 addr += tdep->wordsize;
232 /* Construct the frame ID using the function start. */
233 trad_frame_set_id (cache, frame_id_build (base, func));
239 ppcobsd_sigtramp_frame_this_id (struct frame_info *next_frame,
240 void **this_cache, struct frame_id *this_id)
242 struct trad_frame_cache *cache =
243 ppcobsd_sigtramp_frame_cache (next_frame, this_cache);
245 trad_frame_get_id (cache, this_id);
249 ppcobsd_sigtramp_frame_prev_register (struct frame_info *next_frame,
250 void **this_cache, int regnum,
251 int *optimizedp, enum lval_type *lvalp,
252 CORE_ADDR *addrp, int *realnump,
255 struct trad_frame_cache *cache =
256 ppcobsd_sigtramp_frame_cache (next_frame, this_cache);
258 trad_frame_get_register (cache, next_frame, regnum,
259 optimizedp, lvalp, addrp, realnump, valuep);
262 static const struct frame_unwind ppcobsd_sigtramp_frame_unwind = {
264 ppcobsd_sigtramp_frame_this_id,
265 ppcobsd_sigtramp_frame_prev_register
268 static const struct frame_unwind *
269 ppcobsd_sigtramp_frame_sniffer (struct frame_info *next_frame)
271 if (ppcobsd_sigtramp_p (next_frame))
272 return &ppcobsd_sigtramp_frame_unwind;
279 ppcobsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
281 /* OpenBSD doesn't support the 128-bit `long double' from the psABI. */
282 set_gdbarch_long_double_bit (gdbarch, 64);
283 set_gdbarch_long_double_format (gdbarch, floatformats_ieee_double);
285 /* OpenBSD currently uses a broken GCC. */
286 set_gdbarch_return_value (gdbarch, ppc_sysv_abi_broken_return_value);
288 /* OpenBSD uses SVR4-style shared libraries. */
289 set_solib_svr4_fetch_link_map_offsets
290 (gdbarch, svr4_ilp32_fetch_link_map_offsets);
292 set_gdbarch_regset_from_core_section
293 (gdbarch, ppcobsd_regset_from_core_section);
295 frame_unwind_append_sniffer (gdbarch, ppcobsd_sigtramp_frame_sniffer);
299 /* OpenBSD uses uses the traditional NetBSD core file format, even for
300 ports that use ELF. */
301 #define GDB_OSABI_NETBSD_CORE GDB_OSABI_OPENBSD_ELF
303 static enum gdb_osabi
304 ppcobsd_core_osabi_sniffer (bfd *abfd)
306 if (strcmp (bfd_get_target (abfd), "netbsd-core") == 0)
307 return GDB_OSABI_NETBSD_CORE;
309 return GDB_OSABI_UNKNOWN;
313 /* Provide a prototype to silence -Wmissing-prototypes. */
314 void _initialize_ppcobsd_tdep (void);
317 _initialize_ppcobsd_tdep (void)
319 /* BFD doesn't set a flavour for NetBSD style a.out core files. */
320 gdbarch_register_osabi_sniffer (bfd_arch_powerpc, bfd_target_unknown_flavour,
321 ppcobsd_core_osabi_sniffer);
323 gdbarch_register_osabi (bfd_arch_rs6000, 0, GDB_OSABI_OPENBSD_ELF,
325 gdbarch_register_osabi (bfd_arch_powerpc, 0, GDB_OSABI_OPENBSD_ELF,
328 /* Avoid initializing the register offsets again if they were
329 already initailized by ppcobsd-nat.c. */
330 if (ppcobsd_reg_offsets.pc_offset == 0)
332 /* General-purpose registers. */
333 ppcobsd_reg_offsets.r0_offset = 0;
334 ppcobsd_reg_offsets.pc_offset = 384;
335 ppcobsd_reg_offsets.ps_offset = 388;
336 ppcobsd_reg_offsets.cr_offset = 392;
337 ppcobsd_reg_offsets.lr_offset = 396;
338 ppcobsd_reg_offsets.ctr_offset = 400;
339 ppcobsd_reg_offsets.xer_offset = 404;
340 ppcobsd_reg_offsets.mq_offset = 408;
342 /* Floating-point registers. */
343 ppcobsd_reg_offsets.f0_offset = 128;
344 ppcobsd_reg_offsets.fpscr_offset = -1;
346 /* AltiVec registers. */
347 ppcobsd_reg_offsets.vr0_offset = 0;
348 ppcobsd_reg_offsets.vscr_offset = 512;
349 ppcobsd_reg_offsets.vrsave_offset = 520;
352 if (ppcobsd_fpreg_offsets.fpscr_offset == 0)
354 /* Floating-point registers. */
355 ppcobsd_reg_offsets.f0_offset = 0;
356 ppcobsd_reg_offsets.fpscr_offset = 256;