1 /* Target-dependent code for OpenBSD/powerpc.
3 Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011
4 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"
24 #include "frame-unwind.h"
30 #include "trad-frame.h"
32 #include "gdb_assert.h"
33 #include "gdb_string.h"
36 #include "ppcobsd-tdep.h"
37 #include "solib-svr4.h"
39 /* Register offsets from <machine/reg.h>. */
40 struct ppc_reg_offsets ppcobsd_reg_offsets;
41 struct ppc_reg_offsets ppcobsd_fpreg_offsets;
44 /* Core file support. */
46 /* Supply register REGNUM in the general-purpose register set REGSET
47 from the buffer specified by GREGS and LEN to register cache
48 REGCACHE. If REGNUM is -1, do this for all registers in REGSET. */
51 ppcobsd_supply_gregset (const struct regset *regset,
52 struct regcache *regcache, int regnum,
53 const void *gregs, size_t len)
55 ppc_supply_gregset (regset, regcache, regnum, gregs, len);
56 ppc_supply_fpregset (regset, regcache, regnum, gregs, len);
59 /* Collect register REGNUM in the general-purpose register set
60 REGSET. from register cache REGCACHE into the buffer specified by
61 GREGS and LEN. If REGNUM is -1, do this for all registers in
65 ppcobsd_collect_gregset (const struct regset *regset,
66 const struct regcache *regcache, int regnum,
67 void *gregs, size_t len)
69 ppc_collect_gregset (regset, regcache, regnum, gregs, len);
70 ppc_collect_fpregset (regset, regcache, regnum, gregs, len);
73 /* OpenBSD/powerpc register set. */
75 struct regset ppcobsd_gregset =
78 ppcobsd_supply_gregset
81 struct regset ppcobsd_fpregset =
83 &ppcobsd_fpreg_offsets,
87 /* Return the appropriate register set for the core section identified
88 by SECT_NAME and SECT_SIZE. */
90 static const struct regset *
91 ppcobsd_regset_from_core_section (struct gdbarch *gdbarch,
92 const char *sect_name, size_t sect_size)
94 if (strcmp (sect_name, ".reg") == 0 && sect_size >= 412)
95 return &ppcobsd_gregset;
101 /* Signal trampolines. */
103 /* Since OpenBSD 3.2, the sigtramp routine is mapped at a random page
104 in virtual memory. The randomness makes it somewhat tricky to
105 detect it, but fortunately we can rely on the fact that the start
106 of the sigtramp routine is page-aligned. We recognize the
107 trampoline by looking for the code that invokes the sigreturn
108 system call. The offset where we can find that code varies from
111 By the way, the mapping mentioned above is read-only, so you cannot
112 place a breakpoint in the signal trampoline. */
114 /* Default page size. */
115 static const int ppcobsd_page_size = 4096;
117 /* Offset for sigreturn(2). */
118 static const int ppcobsd_sigreturn_offset[] = {
119 0x98, /* OpenBSD 3.8 */
120 0x0c, /* OpenBSD 3.2 */
125 ppcobsd_sigtramp_frame_sniffer (const struct frame_unwind *self,
126 struct frame_info *this_frame,
129 struct gdbarch *gdbarch = get_frame_arch (this_frame);
130 enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
131 CORE_ADDR pc = get_frame_pc (this_frame);
132 CORE_ADDR start_pc = (pc & ~(ppcobsd_page_size - 1));
136 find_pc_partial_function (pc, &name, NULL, NULL);
140 for (offset = ppcobsd_sigreturn_offset; *offset != -1; offset++)
142 gdb_byte buf[2 * PPC_INSN_SIZE];
145 if (!safe_frame_unwind_memory (this_frame, start_pc + *offset,
149 /* Check for "li r0,SYS_sigreturn". */
150 insn = extract_unsigned_integer (buf, PPC_INSN_SIZE, byte_order);
151 if (insn != 0x38000067)
154 /* Check for "sc". */
155 insn = extract_unsigned_integer (buf + PPC_INSN_SIZE,
156 PPC_INSN_SIZE, byte_order);
157 if (insn != 0x44000002)
166 static struct trad_frame_cache *
167 ppcobsd_sigtramp_frame_cache (struct frame_info *this_frame, void **this_cache)
169 struct gdbarch *gdbarch = get_frame_arch (this_frame);
170 struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
171 enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
172 struct trad_frame_cache *cache;
173 CORE_ADDR addr, base, func;
174 gdb_byte buf[PPC_INSN_SIZE];
175 unsigned long insn, sigcontext_offset;
181 cache = trad_frame_cache_zalloc (this_frame);
184 func = get_frame_pc (this_frame);
185 func &= ~(ppcobsd_page_size - 1);
186 if (!safe_frame_unwind_memory (this_frame, func, buf, sizeof buf))
189 /* Calculate the offset where we can find `struct sigcontext'. We
190 base our calculation on the amount of stack space reserved by the
191 first instruction of the signal trampoline. */
192 insn = extract_unsigned_integer (buf, PPC_INSN_SIZE, byte_order);
193 sigcontext_offset = (0x10000 - (insn & 0x0000ffff)) + 8;
195 base = get_frame_register_unsigned (this_frame, gdbarch_sp_regnum (gdbarch));
196 addr = base + sigcontext_offset + 2 * tdep->wordsize;
197 for (i = 0; i < ppc_num_gprs; i++, addr += tdep->wordsize)
199 int regnum = i + tdep->ppc_gp0_regnum;
200 trad_frame_set_reg_addr (cache, regnum, addr);
202 trad_frame_set_reg_addr (cache, tdep->ppc_lr_regnum, addr);
203 addr += tdep->wordsize;
204 trad_frame_set_reg_addr (cache, tdep->ppc_cr_regnum, addr);
205 addr += tdep->wordsize;
206 trad_frame_set_reg_addr (cache, tdep->ppc_xer_regnum, addr);
207 addr += tdep->wordsize;
208 trad_frame_set_reg_addr (cache, tdep->ppc_ctr_regnum, addr);
209 addr += tdep->wordsize;
210 trad_frame_set_reg_addr (cache, gdbarch_pc_regnum (gdbarch), addr);
212 addr += tdep->wordsize;
214 /* Construct the frame ID using the function start. */
215 trad_frame_set_id (cache, frame_id_build (base, func));
221 ppcobsd_sigtramp_frame_this_id (struct frame_info *this_frame,
222 void **this_cache, struct frame_id *this_id)
224 struct trad_frame_cache *cache =
225 ppcobsd_sigtramp_frame_cache (this_frame, this_cache);
227 trad_frame_get_id (cache, this_id);
230 static struct value *
231 ppcobsd_sigtramp_frame_prev_register (struct frame_info *this_frame,
232 void **this_cache, int regnum)
234 struct trad_frame_cache *cache =
235 ppcobsd_sigtramp_frame_cache (this_frame, this_cache);
237 return trad_frame_get_register (cache, this_frame, regnum);
240 static const struct frame_unwind ppcobsd_sigtramp_frame_unwind = {
242 ppcobsd_sigtramp_frame_this_id,
243 ppcobsd_sigtramp_frame_prev_register,
245 ppcobsd_sigtramp_frame_sniffer
250 ppcobsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
252 /* OpenBSD doesn't support the 128-bit `long double' from the psABI. */
253 set_gdbarch_long_double_bit (gdbarch, 64);
254 set_gdbarch_long_double_format (gdbarch, floatformats_ieee_double);
256 /* OpenBSD currently uses a broken GCC. */
257 set_gdbarch_return_value (gdbarch, ppc_sysv_abi_broken_return_value);
259 /* OpenBSD uses SVR4-style shared libraries. */
260 set_solib_svr4_fetch_link_map_offsets
261 (gdbarch, svr4_ilp32_fetch_link_map_offsets);
263 set_gdbarch_regset_from_core_section
264 (gdbarch, ppcobsd_regset_from_core_section);
266 frame_unwind_append_unwinder (gdbarch, &ppcobsd_sigtramp_frame_unwind);
270 /* OpenBSD uses uses the traditional NetBSD core file format, even for
271 ports that use ELF. */
272 #define GDB_OSABI_NETBSD_CORE GDB_OSABI_OPENBSD_ELF
274 static enum gdb_osabi
275 ppcobsd_core_osabi_sniffer (bfd *abfd)
277 if (strcmp (bfd_get_target (abfd), "netbsd-core") == 0)
278 return GDB_OSABI_NETBSD_CORE;
280 return GDB_OSABI_UNKNOWN;
284 /* Provide a prototype to silence -Wmissing-prototypes. */
285 void _initialize_ppcobsd_tdep (void);
288 _initialize_ppcobsd_tdep (void)
290 /* BFD doesn't set a flavour for NetBSD style a.out core files. */
291 gdbarch_register_osabi_sniffer (bfd_arch_powerpc, bfd_target_unknown_flavour,
292 ppcobsd_core_osabi_sniffer);
294 gdbarch_register_osabi (bfd_arch_rs6000, 0, GDB_OSABI_OPENBSD_ELF,
296 gdbarch_register_osabi (bfd_arch_powerpc, 0, GDB_OSABI_OPENBSD_ELF,
299 /* Avoid initializing the register offsets again if they were
300 already initailized by ppcobsd-nat.c. */
301 if (ppcobsd_reg_offsets.pc_offset == 0)
303 /* General-purpose registers. */
304 ppcobsd_reg_offsets.r0_offset = 0;
305 ppcobsd_reg_offsets.gpr_size = 4;
306 ppcobsd_reg_offsets.xr_size = 4;
307 ppcobsd_reg_offsets.pc_offset = 384;
308 ppcobsd_reg_offsets.ps_offset = 388;
309 ppcobsd_reg_offsets.cr_offset = 392;
310 ppcobsd_reg_offsets.lr_offset = 396;
311 ppcobsd_reg_offsets.ctr_offset = 400;
312 ppcobsd_reg_offsets.xer_offset = 404;
313 ppcobsd_reg_offsets.mq_offset = 408;
315 /* Floating-point registers. */
316 ppcobsd_reg_offsets.f0_offset = 128;
317 ppcobsd_reg_offsets.fpscr_offset = -1;
319 /* AltiVec registers. */
320 ppcobsd_reg_offsets.vr0_offset = 0;
321 ppcobsd_reg_offsets.vscr_offset = 512;
322 ppcobsd_reg_offsets.vrsave_offset = 520;
325 if (ppcobsd_fpreg_offsets.fpscr_offset == 0)
327 /* Floating-point registers. */
328 ppcobsd_reg_offsets.f0_offset = 0;
329 ppcobsd_reg_offsets.fpscr_offset = 256;
330 ppcobsd_reg_offsets.fpscr_size = 4;