1 /* Target-dependent code for OpenBSD/alpha.
3 Copyright (C) 2006 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 2 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, write to the Free Software
19 Foundation, Inc., 51 Franklin Street, Fifth Floor,
20 Boston, MA 02110-1301, USA. */
27 #include "alpha-tdep.h"
28 #include "alphabsd-tdep.h"
29 #include "solib-svr4.h"
31 /* Signal trampolines. */
33 /* The OpenBSD kernel maps the signal trampoline at some random
34 location in user space, which means that the traditional BSD way of
35 detecting it won't work.
37 The signal trampoline will be mapped at an address that is page
38 aligned. We recognize the signal trampoline by looking for the
39 sigreturn system call. */
41 static const int alphaobsd_page_size = 8192;
44 alphaobsd_sigtramp_offset (CORE_ADDR pc)
46 return (pc & (alphaobsd_page_size - 1));
50 alphaobsd_pc_in_sigtramp (CORE_ADDR pc, char *name)
52 CORE_ADDR start_pc = (pc & ~(alphaobsd_page_size - 1));
59 insn = alpha_read_insn (start_pc + 5 * ALPHA_INSN_SIZE);
60 if (insn != 0x201f0067)
64 insn = alpha_read_insn (start_pc + 6 * ALPHA_INSN_SIZE);
65 if (insn != 0x00000083)
72 alphaobsd_sigcontext_addr (struct frame_info *next_frame)
74 CORE_ADDR pc = frame_pc_unwind (next_frame);
76 if (alphaobsd_sigtramp_offset (pc) < 3 * ALPHA_INSN_SIZE)
78 /* On entry, a pointer the `struct sigcontext' is passed in %a2. */
79 return frame_unwind_register_unsigned (next_frame, ALPHA_A0_REGNUM + 2);
81 else if (alphaobsd_sigtramp_offset (pc) < 4 * ALPHA_INSN_SIZE)
83 /* It is stored on the stack Before calling the signal handler. */
85 sp = frame_unwind_register_unsigned (next_frame, ALPHA_SP_REGNUM);
86 return get_frame_memory_unsigned (next_frame, sp, 8);
90 /* It is reloaded into %a0 for the sigreturn(2) call. */
91 return frame_unwind_register_unsigned (next_frame, ALPHA_A0_REGNUM);
97 alphaobsd_init_abi(struct gdbarch_info info, struct gdbarch *gdbarch)
99 struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
101 /* Hook into the DWARF CFI frame unwinder. */
102 alpha_dwarf2_init_abi (info, gdbarch);
104 /* Hook into the MDEBUG frame unwinder. */
105 alpha_mdebug_init_abi (info, gdbarch);
107 /* OpenBSD/alpha 3.0 and earlier does not provide single step
108 support via ptrace(2); use software single-stepping for now. */
109 set_gdbarch_software_single_step (gdbarch, alpha_software_single_step);
111 /* OpenBSD/alpha has SVR4-style shared libraries. */
112 set_solib_svr4_fetch_link_map_offsets
113 (gdbarch, svr4_lp64_fetch_link_map_offsets);
115 tdep->dynamic_sigtramp_offset = alphaobsd_sigtramp_offset;
116 tdep->pc_in_sigtramp = alphaobsd_pc_in_sigtramp;
117 tdep->sigcontext_addr = alphaobsd_sigcontext_addr;
120 tdep->jb_elt_size = 8;
122 set_gdbarch_regset_from_core_section
123 (gdbarch, alphanbsd_regset_from_core_section);
127 /* Provide a prototype to silence -Wmissing-prototypes. */
128 void _initialize_alphaobsd_tdep (void);
131 _initialize_alphaobsd_tdep (void)
133 gdbarch_register_osabi (bfd_arch_alpha, 0, GDB_OSABI_OPENBSD_ELF,