1 /* Target-dependent code for OpenBSD/powerpc.
3 Copyright (C) 2004, 2005, 2006, 2007, 2008 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 ppc_supply_gregset (regset, regcache, regnum, gregs, len);
55 ppc_supply_fpregset (regset, regcache, regnum, gregs, len);
58 /* Collect register REGNUM in the general-purpose register set
59 REGSET. from register cache REGCACHE into the buffer specified by
60 GREGS and LEN. If REGNUM is -1, do this for all registers in
64 ppcobsd_collect_gregset (const struct regset *regset,
65 const struct regcache *regcache, int regnum,
66 void *gregs, size_t len)
68 ppc_collect_gregset (regset, regcache, regnum, gregs, len);
69 ppc_collect_fpregset (regset, regcache, regnum, gregs, len);
72 /* OpenBSD/powerpc register set. */
74 struct regset ppcobsd_gregset =
77 ppcobsd_supply_gregset
80 struct regset ppcobsd_fpregset =
82 &ppcobsd_fpreg_offsets,
86 /* Return the appropriate register set for the core section identified
87 by SECT_NAME and SECT_SIZE. */
89 static const struct regset *
90 ppcobsd_regset_from_core_section (struct gdbarch *gdbarch,
91 const char *sect_name, size_t sect_size)
93 if (strcmp (sect_name, ".reg") == 0 && sect_size >= 412)
94 return &ppcobsd_gregset;
100 /* Signal trampolines. */
102 /* Since OpenBSD 3.2, the sigtramp routine is mapped at a random page
103 in virtual memory. The randomness makes it somewhat tricky to
104 detect it, but fortunately we can rely on the fact that the start
105 of the sigtramp routine is page-aligned. We recognize the
106 trampoline by looking for the code that invokes the sigreturn
107 system call. The offset where we can find that code varies from
110 By the way, the mapping mentioned above is read-only, so you cannot
111 place a breakpoint in the signal trampoline. */
113 /* Default page size. */
114 static const int ppcobsd_page_size = 4096;
116 /* Offset for sigreturn(2). */
117 static const int ppcobsd_sigreturn_offset[] = {
118 0x98, /* OpenBSD 3.8 */
119 0x0c, /* OpenBSD 3.2 */
124 ppcobsd_sigtramp_p (struct frame_info *next_frame)
126 CORE_ADDR pc = frame_pc_unwind (next_frame);
127 CORE_ADDR start_pc = (pc & ~(ppcobsd_page_size - 1));
131 find_pc_partial_function (pc, &name, NULL, NULL);
135 for (offset = ppcobsd_sigreturn_offset; *offset != -1; offset++)
137 gdb_byte buf[2 * PPC_INSN_SIZE];
140 if (!safe_frame_unwind_memory (next_frame, start_pc + *offset,
144 /* Check for "li r0,SYS_sigreturn". */
145 insn = extract_unsigned_integer (buf, PPC_INSN_SIZE);
146 if (insn != 0x38000067)
149 /* Check for "sc". */
150 insn = extract_unsigned_integer (buf + PPC_INSN_SIZE, PPC_INSN_SIZE);
151 if (insn != 0x44000002)
160 static struct trad_frame_cache *
161 ppcobsd_sigtramp_frame_cache (struct frame_info *next_frame, void **this_cache)
163 struct gdbarch *gdbarch = get_frame_arch (next_frame);
164 struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
165 struct trad_frame_cache *cache;
166 CORE_ADDR addr, base, func;
167 gdb_byte buf[PPC_INSN_SIZE];
168 unsigned long insn, sigcontext_offset;
174 cache = trad_frame_cache_zalloc (next_frame);
177 func = frame_pc_unwind (next_frame);
178 func &= ~(ppcobsd_page_size - 1);
179 if (!safe_frame_unwind_memory (next_frame, func, buf, sizeof buf))
182 /* Calculate the offset where we can find `struct sigcontext'. We
183 base our calculation on the amount of stack space reserved by the
184 first instruction of the signal trampoline. */
185 insn = extract_unsigned_integer (buf, PPC_INSN_SIZE);
186 sigcontext_offset = (0x10000 - (insn & 0x0000ffff)) + 8;
188 base = frame_unwind_register_unsigned (next_frame,
189 gdbarch_sp_regnum (gdbarch));
190 addr = base + sigcontext_offset + 2 * tdep->wordsize;
191 for (i = 0; i < ppc_num_gprs; i++, addr += tdep->wordsize)
193 int regnum = i + tdep->ppc_gp0_regnum;
194 trad_frame_set_reg_addr (cache, regnum, addr);
196 trad_frame_set_reg_addr (cache, tdep->ppc_lr_regnum, addr);
197 addr += tdep->wordsize;
198 trad_frame_set_reg_addr (cache, tdep->ppc_cr_regnum, addr);
199 addr += tdep->wordsize;
200 trad_frame_set_reg_addr (cache, tdep->ppc_xer_regnum, addr);
201 addr += tdep->wordsize;
202 trad_frame_set_reg_addr (cache, tdep->ppc_ctr_regnum, addr);
203 addr += tdep->wordsize;
204 trad_frame_set_reg_addr (cache, gdbarch_pc_regnum (gdbarch), addr);
206 addr += tdep->wordsize;
208 /* Construct the frame ID using the function start. */
209 trad_frame_set_id (cache, frame_id_build (base, func));
215 ppcobsd_sigtramp_frame_this_id (struct frame_info *next_frame,
216 void **this_cache, struct frame_id *this_id)
218 struct trad_frame_cache *cache =
219 ppcobsd_sigtramp_frame_cache (next_frame, this_cache);
221 trad_frame_get_id (cache, this_id);
225 ppcobsd_sigtramp_frame_prev_register (struct frame_info *next_frame,
226 void **this_cache, int regnum,
227 int *optimizedp, enum lval_type *lvalp,
228 CORE_ADDR *addrp, int *realnump,
231 struct trad_frame_cache *cache =
232 ppcobsd_sigtramp_frame_cache (next_frame, this_cache);
234 trad_frame_get_register (cache, next_frame, regnum,
235 optimizedp, lvalp, addrp, realnump, valuep);
238 static const struct frame_unwind ppcobsd_sigtramp_frame_unwind = {
240 ppcobsd_sigtramp_frame_this_id,
241 ppcobsd_sigtramp_frame_prev_register
244 static const struct frame_unwind *
245 ppcobsd_sigtramp_frame_sniffer (struct frame_info *next_frame)
247 if (ppcobsd_sigtramp_p (next_frame))
248 return &ppcobsd_sigtramp_frame_unwind;
255 ppcobsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
257 /* OpenBSD doesn't support the 128-bit `long double' from the psABI. */
258 set_gdbarch_long_double_bit (gdbarch, 64);
259 set_gdbarch_long_double_format (gdbarch, floatformats_ieee_double);
261 /* OpenBSD currently uses a broken GCC. */
262 set_gdbarch_return_value (gdbarch, ppc_sysv_abi_broken_return_value);
264 /* OpenBSD uses SVR4-style shared libraries. */
265 set_solib_svr4_fetch_link_map_offsets
266 (gdbarch, svr4_ilp32_fetch_link_map_offsets);
268 set_gdbarch_regset_from_core_section
269 (gdbarch, ppcobsd_regset_from_core_section);
271 frame_unwind_append_sniffer (gdbarch, ppcobsd_sigtramp_frame_sniffer);
275 /* OpenBSD uses uses the traditional NetBSD core file format, even for
276 ports that use ELF. */
277 #define GDB_OSABI_NETBSD_CORE GDB_OSABI_OPENBSD_ELF
279 static enum gdb_osabi
280 ppcobsd_core_osabi_sniffer (bfd *abfd)
282 if (strcmp (bfd_get_target (abfd), "netbsd-core") == 0)
283 return GDB_OSABI_NETBSD_CORE;
285 return GDB_OSABI_UNKNOWN;
289 /* Provide a prototype to silence -Wmissing-prototypes. */
290 void _initialize_ppcobsd_tdep (void);
293 _initialize_ppcobsd_tdep (void)
295 /* BFD doesn't set a flavour for NetBSD style a.out core files. */
296 gdbarch_register_osabi_sniffer (bfd_arch_powerpc, bfd_target_unknown_flavour,
297 ppcobsd_core_osabi_sniffer);
299 gdbarch_register_osabi (bfd_arch_rs6000, 0, GDB_OSABI_OPENBSD_ELF,
301 gdbarch_register_osabi (bfd_arch_powerpc, 0, GDB_OSABI_OPENBSD_ELF,
304 /* Avoid initializing the register offsets again if they were
305 already initailized by ppcobsd-nat.c. */
306 if (ppcobsd_reg_offsets.pc_offset == 0)
308 /* General-purpose registers. */
309 ppcobsd_reg_offsets.r0_offset = 0;
310 ppcobsd_reg_offsets.gpr_size = 4;
311 ppcobsd_reg_offsets.xr_size = 4;
312 ppcobsd_reg_offsets.pc_offset = 384;
313 ppcobsd_reg_offsets.ps_offset = 388;
314 ppcobsd_reg_offsets.cr_offset = 392;
315 ppcobsd_reg_offsets.lr_offset = 396;
316 ppcobsd_reg_offsets.ctr_offset = 400;
317 ppcobsd_reg_offsets.xer_offset = 404;
318 ppcobsd_reg_offsets.mq_offset = 408;
320 /* Floating-point registers. */
321 ppcobsd_reg_offsets.f0_offset = 128;
322 ppcobsd_reg_offsets.fpscr_offset = -1;
324 /* AltiVec registers. */
325 ppcobsd_reg_offsets.vr0_offset = 0;
326 ppcobsd_reg_offsets.vscr_offset = 512;
327 ppcobsd_reg_offsets.vrsave_offset = 520;
330 if (ppcobsd_fpreg_offsets.fpscr_offset == 0)
332 /* Floating-point registers. */
333 ppcobsd_reg_offsets.f0_offset = 0;
334 ppcobsd_reg_offsets.fpscr_offset = 256;
335 ppcobsd_reg_offsets.fpscr_size = 4;