1 /* Target-dependent code for NetBSD/alpha.
3 Copyright (C) 2002-2015 Free Software Foundation, Inc.
5 Contributed by Wasabi Systems, Inc.
7 This file is part of GDB.
9 This program is free software; you can redistribute it and/or modify
10 it under the terms of the GNU General Public License as published by
11 the Free Software Foundation; either version 3 of the License, or
12 (at your option) any later version.
14 This program is distributed in the hope that it will be useful,
15 but WITHOUT ANY WARRANTY; without even the implied warranty of
16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 GNU General Public License for more details.
19 You should have received a copy of the GNU General Public License
20 along with this program. If not, see <http://www.gnu.org/licenses/>. */
30 #include "alpha-tdep.h"
31 #include "alphabsd-tdep.h"
32 #include "nbsd-tdep.h"
33 #include "solib-svr4.h"
36 /* Core file support. */
38 /* Even though NetBSD/alpha used ELF since day one, it used the
39 traditional a.out-style core dump format before NetBSD 1.6. */
41 /* Sizeof `struct reg' in <machine/reg.h>. */
42 #define ALPHANBSD_SIZEOF_GREGS (32 * 8)
44 /* Sizeof `struct fpreg' in <machine/reg.h. */
45 #define ALPHANBSD_SIZEOF_FPREGS ((32 * 8) + 8)
47 /* Supply register REGNUM from the buffer specified by FPREGS and LEN
48 in the floating-point register set REGSET to register cache
49 REGCACHE. If REGNUM is -1, do this for all registers in REGSET. */
52 alphanbsd_supply_fpregset (const struct regset *regset,
53 struct regcache *regcache,
54 int regnum, const void *fpregs, size_t len)
56 const gdb_byte *regs = (const gdb_byte *) fpregs;
59 gdb_assert (len >= ALPHANBSD_SIZEOF_FPREGS);
61 for (i = ALPHA_FP0_REGNUM; i < ALPHA_FP0_REGNUM + 31; i++)
63 if (regnum == i || regnum == -1)
64 regcache_raw_supply (regcache, i, regs + (i - ALPHA_FP0_REGNUM) * 8);
67 if (regnum == ALPHA_FPCR_REGNUM || regnum == -1)
68 regcache_raw_supply (regcache, ALPHA_FPCR_REGNUM, regs + 32 * 8);
71 /* Supply register REGNUM from the buffer specified by GREGS and LEN
72 in the general-purpose register set REGSET to register cache
73 REGCACHE. If REGNUM is -1, do this for all registers in REGSET. */
76 alphanbsd_aout_supply_gregset (const struct regset *regset,
77 struct regcache *regcache,
78 int regnum, const void *gregs, size_t len)
80 const gdb_byte *regs = (const gdb_byte *) gregs;
83 /* Table to map a GDB register number to a trapframe register index. */
84 static const int regmap[] =
96 gdb_assert (len >= ALPHANBSD_SIZEOF_GREGS);
98 for (i = 0; i < ARRAY_SIZE(regmap); i++)
100 if (regnum == i || regnum == -1)
101 regcache_raw_supply (regcache, i, regs + regmap[i] * 8);
104 if (regnum == ALPHA_PC_REGNUM || regnum == -1)
105 regcache_raw_supply (regcache, ALPHA_PC_REGNUM, regs + 31 * 8);
107 if (len >= ALPHANBSD_SIZEOF_GREGS + ALPHANBSD_SIZEOF_FPREGS)
109 regs += ALPHANBSD_SIZEOF_GREGS;
110 len -= ALPHANBSD_SIZEOF_GREGS;
111 alphanbsd_supply_fpregset (regset, regcache, regnum, regs, len);
115 /* Supply register REGNUM from the buffer specified by GREGS and LEN
116 in the general-purpose register set REGSET to register cache
117 REGCACHE. If REGNUM is -1, do this for all registers in REGSET. */
120 alphanbsd_supply_gregset (const struct regset *regset,
121 struct regcache *regcache,
122 int regnum, const void *gregs, size_t len)
124 const gdb_byte *regs = (const gdb_byte *) gregs;
127 if (len >= ALPHANBSD_SIZEOF_GREGS + ALPHANBSD_SIZEOF_FPREGS)
129 alphanbsd_aout_supply_gregset (regset, regcache, regnum, gregs, len);
133 for (i = 0; i < ALPHA_ZERO_REGNUM; i++)
135 if (regnum == i || regnum == -1)
136 regcache_raw_supply (regcache, i, regs + i * 8);
139 if (regnum == ALPHA_PC_REGNUM || regnum == -1)
140 regcache_raw_supply (regcache, ALPHA_PC_REGNUM, regs + 31 * 8);
143 /* NetBSD/alpha register sets. */
145 static const struct regset alphanbsd_gregset =
148 alphanbsd_supply_gregset,
153 static const struct regset alphanbsd_fpregset =
156 alphanbsd_supply_fpregset
159 /* Iterate over supported core file register note sections. */
162 alphanbsd_iterate_over_regset_sections (struct gdbarch *gdbarch,
163 iterate_over_regset_sections_cb *cb,
165 const struct regcache *regcache)
167 cb (".reg", ALPHANBSD_SIZEOF_GREGS, &alphanbsd_gregset, NULL, cb_data);
168 cb (".reg2", ALPHANBSD_SIZEOF_FPREGS, &alphanbsd_fpregset, NULL, cb_data);
172 /* Signal trampolines. */
174 /* Under NetBSD/alpha, signal handler invocations can be identified by the
175 designated code sequence that is used to return from a signal handler.
176 In particular, the return address of a signal handler points to the
177 following code sequence:
181 lda v0, 295(zero) # __sigreturn14
184 Each instruction has a unique encoding, so we simply attempt to match
185 the instruction the PC is pointing to with any of the above instructions.
186 If there is a hit, we know the offset to the start of the designated
187 sequence and can then check whether we really are executing in the
188 signal trampoline. If not, -1 is returned, otherwise the offset from the
189 start of the return sequence is returned. */
190 static const gdb_byte sigtramp_retcode[] =
192 0x00, 0x00, 0x1e, 0xa6, /* ldq a0, 0(sp) */
193 0x10, 0x00, 0xde, 0x23, /* lda sp, 16(sp) */
194 0x27, 0x01, 0x1f, 0x20, /* lda v0, 295(zero) */
195 0x83, 0x00, 0x00, 0x00, /* call_pal callsys */
197 #define RETCODE_NWORDS 4
198 #define RETCODE_SIZE (RETCODE_NWORDS * 4)
201 alphanbsd_sigtramp_offset (struct gdbarch *gdbarch, CORE_ADDR pc)
203 gdb_byte ret[RETCODE_SIZE], w[4];
207 if (target_read_memory (pc, w, 4) != 0)
210 for (i = 0; i < RETCODE_NWORDS; i++)
212 if (memcmp (w, sigtramp_retcode + (i * 4), 4) == 0)
215 if (i == RETCODE_NWORDS)
221 if (target_read_memory (pc, ret, sizeof (ret)) != 0)
224 if (memcmp (ret, sigtramp_retcode, RETCODE_SIZE) == 0)
231 alphanbsd_pc_in_sigtramp (struct gdbarch *gdbarch,
232 CORE_ADDR pc, const char *func_name)
234 return (nbsd_pc_in_sigtramp (pc, func_name)
235 || alphanbsd_sigtramp_offset (gdbarch, pc) >= 0);
239 alphanbsd_sigcontext_addr (struct frame_info *frame)
241 /* FIXME: This is not correct for all versions of NetBSD/alpha.
242 We will probably need to disassemble the trampoline to figure
243 out which trampoline frame type we have. */
244 if (!get_next_frame (frame))
246 return get_frame_base (get_next_frame (frame));
251 alphanbsd_init_abi (struct gdbarch_info info,
252 struct gdbarch *gdbarch)
254 struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
256 /* Hook into the DWARF CFI frame unwinder. */
257 alpha_dwarf2_init_abi (info, gdbarch);
259 /* Hook into the MDEBUG frame unwinder. */
260 alpha_mdebug_init_abi (info, gdbarch);
262 /* NetBSD/alpha does not provide single step support via ptrace(2); we
263 must use software single-stepping. */
264 set_gdbarch_software_single_step (gdbarch, alpha_software_single_step);
266 /* NetBSD/alpha has SVR4-style shared libraries. */
267 set_solib_svr4_fetch_link_map_offsets
268 (gdbarch, svr4_lp64_fetch_link_map_offsets);
270 tdep->dynamic_sigtramp_offset = alphanbsd_sigtramp_offset;
271 tdep->pc_in_sigtramp = alphanbsd_pc_in_sigtramp;
272 tdep->sigcontext_addr = alphanbsd_sigcontext_addr;
275 tdep->jb_elt_size = 8;
277 set_gdbarch_iterate_over_regset_sections
278 (gdbarch, alphanbsd_iterate_over_regset_sections);
282 static enum gdb_osabi
283 alphanbsd_core_osabi_sniffer (bfd *abfd)
285 if (strcmp (bfd_get_target (abfd), "netbsd-core") == 0)
286 return GDB_OSABI_NETBSD_ELF;
288 return GDB_OSABI_UNKNOWN;
292 /* Provide a prototype to silence -Wmissing-prototypes. */
293 void _initialize_alphanbsd_tdep (void);
296 _initialize_alphanbsd_tdep (void)
298 /* BFD doesn't set a flavour for NetBSD style a.out core files. */
299 gdbarch_register_osabi_sniffer (bfd_arch_alpha, bfd_target_unknown_flavour,
300 alphanbsd_core_osabi_sniffer);
302 gdbarch_register_osabi (bfd_arch_alpha, 0, GDB_OSABI_NETBSD_ELF,