1 /* Target-dependent code for NetBSD/alpha.
3 Copyright (C) 2002-2017 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 "alpha-bsd-tdep.h"
32 #include "nbsd-tdep.h"
33 #include "solib-svr4.h"
36 /* Core file support. */
38 /* Sizeof `struct reg' in <machine/reg.h>. */
39 #define ALPHANBSD_SIZEOF_GREGS (32 * 8)
41 /* Sizeof `struct fpreg' in <machine/reg.h. */
42 #define ALPHANBSD_SIZEOF_FPREGS ((32 * 8) + 8)
44 /* Supply register REGNUM from the buffer specified by FPREGS and LEN
45 in the floating-point register set REGSET to register cache
46 REGCACHE. If REGNUM is -1, do this for all registers in REGSET. */
49 alphanbsd_supply_fpregset (const struct regset *regset,
50 struct regcache *regcache,
51 int regnum, const void *fpregs, size_t len)
53 const gdb_byte *regs = (const gdb_byte *) fpregs;
56 gdb_assert (len >= ALPHANBSD_SIZEOF_FPREGS);
58 for (i = ALPHA_FP0_REGNUM; i < ALPHA_FP0_REGNUM + 31; i++)
60 if (regnum == i || regnum == -1)
61 regcache_raw_supply (regcache, i, regs + (i - ALPHA_FP0_REGNUM) * 8);
64 if (regnum == ALPHA_FPCR_REGNUM || regnum == -1)
65 regcache_raw_supply (regcache, ALPHA_FPCR_REGNUM, regs + 32 * 8);
68 /* Supply register REGNUM from the buffer specified by GREGS and LEN
69 in the general-purpose register set REGSET to register cache
70 REGCACHE. If REGNUM is -1, do this for all registers in REGSET. */
73 alphanbsd_aout_supply_gregset (const struct regset *regset,
74 struct regcache *regcache,
75 int regnum, const void *gregs, size_t len)
77 const gdb_byte *regs = (const gdb_byte *) gregs;
80 /* Table to map a GDB register number to a trapframe register index. */
81 static const int regmap[] =
93 gdb_assert (len >= ALPHANBSD_SIZEOF_GREGS);
95 for (i = 0; i < ARRAY_SIZE(regmap); i++)
97 if (regnum == i || regnum == -1)
98 regcache_raw_supply (regcache, i, regs + regmap[i] * 8);
101 if (regnum == ALPHA_PC_REGNUM || regnum == -1)
102 regcache_raw_supply (regcache, ALPHA_PC_REGNUM, regs + 31 * 8);
104 if (len >= ALPHANBSD_SIZEOF_GREGS + ALPHANBSD_SIZEOF_FPREGS)
106 regs += ALPHANBSD_SIZEOF_GREGS;
107 len -= ALPHANBSD_SIZEOF_GREGS;
108 alphanbsd_supply_fpregset (regset, regcache, regnum, regs, len);
112 /* Supply register REGNUM from the buffer specified by GREGS and LEN
113 in the general-purpose register set REGSET to register cache
114 REGCACHE. If REGNUM is -1, do this for all registers in REGSET. */
117 alphanbsd_supply_gregset (const struct regset *regset,
118 struct regcache *regcache,
119 int regnum, const void *gregs, size_t len)
121 const gdb_byte *regs = (const gdb_byte *) gregs;
124 if (len >= ALPHANBSD_SIZEOF_GREGS + ALPHANBSD_SIZEOF_FPREGS)
126 alphanbsd_aout_supply_gregset (regset, regcache, regnum, gregs, len);
130 for (i = 0; i < ALPHA_ZERO_REGNUM; i++)
132 if (regnum == i || regnum == -1)
133 regcache_raw_supply (regcache, i, regs + i * 8);
136 if (regnum == ALPHA_PC_REGNUM || regnum == -1)
137 regcache_raw_supply (regcache, ALPHA_PC_REGNUM, regs + 31 * 8);
140 /* NetBSD/alpha register sets. */
142 static const struct regset alphanbsd_gregset =
145 alphanbsd_supply_gregset,
150 static const struct regset alphanbsd_fpregset =
153 alphanbsd_supply_fpregset
156 /* Iterate over supported core file register note sections. */
159 alphanbsd_iterate_over_regset_sections (struct gdbarch *gdbarch,
160 iterate_over_regset_sections_cb *cb,
162 const struct regcache *regcache)
164 cb (".reg", ALPHANBSD_SIZEOF_GREGS, &alphanbsd_gregset, NULL, cb_data);
165 cb (".reg2", ALPHANBSD_SIZEOF_FPREGS, &alphanbsd_fpregset, NULL, cb_data);
169 /* Signal trampolines. */
171 /* Under NetBSD/alpha, signal handler invocations can be identified by the
172 designated code sequence that is used to return from a signal handler.
173 In particular, the return address of a signal handler points to the
174 following code sequence:
178 lda v0, 295(zero) # __sigreturn14
181 Each instruction has a unique encoding, so we simply attempt to match
182 the instruction the PC is pointing to with any of the above instructions.
183 If there is a hit, we know the offset to the start of the designated
184 sequence and can then check whether we really are executing in the
185 signal trampoline. If not, -1 is returned, otherwise the offset from the
186 start of the return sequence is returned. */
187 static const gdb_byte sigtramp_retcode[] =
189 0x00, 0x00, 0x1e, 0xa6, /* ldq a0, 0(sp) */
190 0x10, 0x00, 0xde, 0x23, /* lda sp, 16(sp) */
191 0x27, 0x01, 0x1f, 0x20, /* lda v0, 295(zero) */
192 0x83, 0x00, 0x00, 0x00, /* call_pal callsys */
194 #define RETCODE_NWORDS 4
195 #define RETCODE_SIZE (RETCODE_NWORDS * 4)
198 alphanbsd_sigtramp_offset (struct gdbarch *gdbarch, CORE_ADDR pc)
200 gdb_byte ret[RETCODE_SIZE], w[4];
204 if (target_read_memory (pc, w, 4) != 0)
207 for (i = 0; i < RETCODE_NWORDS; i++)
209 if (memcmp (w, sigtramp_retcode + (i * 4), 4) == 0)
212 if (i == RETCODE_NWORDS)
218 if (target_read_memory (pc, ret, sizeof (ret)) != 0)
221 if (memcmp (ret, sigtramp_retcode, RETCODE_SIZE) == 0)
228 alphanbsd_pc_in_sigtramp (struct gdbarch *gdbarch,
229 CORE_ADDR pc, const char *func_name)
231 return (nbsd_pc_in_sigtramp (pc, func_name)
232 || alphanbsd_sigtramp_offset (gdbarch, pc) >= 0);
236 alphanbsd_sigcontext_addr (struct frame_info *frame)
238 /* FIXME: This is not correct for all versions of NetBSD/alpha.
239 We will probably need to disassemble the trampoline to figure
240 out which trampoline frame type we have. */
241 if (!get_next_frame (frame))
243 return get_frame_base (get_next_frame (frame));
248 alphanbsd_init_abi (struct gdbarch_info info,
249 struct gdbarch *gdbarch)
251 struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
253 /* Hook into the DWARF CFI frame unwinder. */
254 alpha_dwarf2_init_abi (info, gdbarch);
256 /* Hook into the MDEBUG frame unwinder. */
257 alpha_mdebug_init_abi (info, gdbarch);
259 /* NetBSD/alpha does not provide single step support via ptrace(2); we
260 must use software single-stepping. */
261 set_gdbarch_software_single_step (gdbarch, alpha_software_single_step);
263 /* NetBSD/alpha has SVR4-style shared libraries. */
264 set_solib_svr4_fetch_link_map_offsets
265 (gdbarch, svr4_lp64_fetch_link_map_offsets);
267 tdep->dynamic_sigtramp_offset = alphanbsd_sigtramp_offset;
268 tdep->pc_in_sigtramp = alphanbsd_pc_in_sigtramp;
269 tdep->sigcontext_addr = alphanbsd_sigcontext_addr;
272 tdep->jb_elt_size = 8;
274 set_gdbarch_iterate_over_regset_sections
275 (gdbarch, alphanbsd_iterate_over_regset_sections);
279 /* Provide a prototype to silence -Wmissing-prototypes. */
280 void _initialize_alphanbsd_tdep (void);
283 _initialize_alphanbsd_tdep (void)
285 /* Even though NetBSD/alpha used ELF since day one, it used the
286 traditional a.out-style core dump format before NetBSD 1.6, but
287 we don't support those. */
288 gdbarch_register_osabi (bfd_arch_alpha, 0, GDB_OSABI_NETBSD,