+
+static struct trad_frame_cache *
+ppcobsd_sigtramp_frame_cache (struct frame_info *this_frame, void **this_cache)
+{
+ struct gdbarch *gdbarch = get_frame_arch (this_frame);
+ struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
+ enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
+ struct trad_frame_cache *cache;
+ CORE_ADDR addr, base, func;
+ gdb_byte buf[PPC_INSN_SIZE];
+ unsigned long insn, sigcontext_offset;
+ int i;
+
+ if (*this_cache)
+ return *this_cache;
+
+ cache = trad_frame_cache_zalloc (this_frame);
+ *this_cache = cache;
+
+ func = get_frame_pc (this_frame);
+ func &= ~(ppcobsd_page_size - 1);
+ if (!safe_frame_unwind_memory (this_frame, func, buf, sizeof buf))
+ return cache;
+
+ /* Calculate the offset where we can find `struct sigcontext'. We
+ base our calculation on the amount of stack space reserved by the
+ first instruction of the signal trampoline. */
+ insn = extract_unsigned_integer (buf, PPC_INSN_SIZE, byte_order);
+ sigcontext_offset = (0x10000 - (insn & 0x0000ffff)) + 8;
+
+ base = get_frame_register_unsigned (this_frame, gdbarch_sp_regnum (gdbarch));
+ addr = base + sigcontext_offset + 2 * tdep->wordsize;
+ for (i = 0; i < ppc_num_gprs; i++, addr += tdep->wordsize)
+ {
+ int regnum = i + tdep->ppc_gp0_regnum;
+ trad_frame_set_reg_addr (cache, regnum, addr);
+ }
+ trad_frame_set_reg_addr (cache, tdep->ppc_lr_regnum, addr);
+ addr += tdep->wordsize;
+ trad_frame_set_reg_addr (cache, tdep->ppc_cr_regnum, addr);
+ addr += tdep->wordsize;
+ trad_frame_set_reg_addr (cache, tdep->ppc_xer_regnum, addr);
+ addr += tdep->wordsize;
+ trad_frame_set_reg_addr (cache, tdep->ppc_ctr_regnum, addr);
+ addr += tdep->wordsize;
+ trad_frame_set_reg_addr (cache, gdbarch_pc_regnum (gdbarch), addr);
+ /* SRR0? */
+ addr += tdep->wordsize;
+
+ /* Construct the frame ID using the function start. */
+ trad_frame_set_id (cache, frame_id_build (base, func));
+
+ return cache;
+}
+
+static void
+ppcobsd_sigtramp_frame_this_id (struct frame_info *this_frame,
+ void **this_cache, struct frame_id *this_id)
+{
+ struct trad_frame_cache *cache =
+ ppcobsd_sigtramp_frame_cache (this_frame, this_cache);
+
+ trad_frame_get_id (cache, this_id);
+}
+
+static struct value *
+ppcobsd_sigtramp_frame_prev_register (struct frame_info *this_frame,
+ void **this_cache, int regnum)
+{
+ struct trad_frame_cache *cache =
+ ppcobsd_sigtramp_frame_cache (this_frame, this_cache);
+
+ return trad_frame_get_register (cache, this_frame, regnum);
+}
+
+static const struct frame_unwind ppcobsd_sigtramp_frame_unwind = {
+ SIGTRAMP_FRAME,
+ default_frame_unwind_stop_reason,
+ ppcobsd_sigtramp_frame_this_id,
+ ppcobsd_sigtramp_frame_prev_register,
+ NULL,
+ ppcobsd_sigtramp_frame_sniffer
+};