1 /* Target-dependent code for NetBSD/mips.
3 Copyright (C) 2002, 2003, 2004, 2006, 2007, 2008
4 Free Software Foundation, Inc.
6 Contributed by Wasabi Systems, Inc.
8 This file is part of GDB.
10 This program is free software; you can redistribute it and/or modify
11 it under the terms of the GNU General Public License as published by
12 the Free Software Foundation; either version 3 of the License, or
13 (at your option) any later version.
15 This program is distributed in the hope that it will be useful,
16 but WITHOUT ANY WARRANTY; without even the implied warranty of
17 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 GNU General Public License for more details.
20 You should have received a copy of the GNU General Public License
21 along with this program. If not, see <http://www.gnu.org/licenses/>. */
31 #include "gdb_assert.h"
32 #include "gdb_string.h"
34 #include "nbsd-tdep.h"
35 #include "mipsnbsd-tdep.h"
36 #include "mips-tdep.h"
38 #include "solib-svr4.h"
40 /* Shorthand for some register numbers used below. */
41 #define MIPS_PC_REGNUM MIPS_EMBED_PC_REGNUM
42 #define MIPS_FP0_REGNUM MIPS_EMBED_FP0_REGNUM
43 #define MIPS_FSR_REGNUM MIPS_EMBED_FP0_REGNUM + 32
45 /* Core file support. */
47 /* Number of registers in `struct reg' from <machine/reg.h>. */
48 #define MIPSNBSD_NUM_GREGS 38
50 /* Number of registers in `struct fpreg' from <machine/reg.h>. */
51 #define MIPSNBSD_NUM_FPREGS 33
53 /* Supply register REGNUM from the buffer specified by FPREGS and LEN
54 in the floating-point register set REGSET to register cache
55 REGCACHE. If REGNUM is -1, do this for all registers in REGSET. */
58 mipsnbsd_supply_fpregset (const struct regset *regset,
59 struct regcache *regcache,
60 int regnum, const void *fpregs, size_t len)
62 size_t regsize = mips_isa_regsize (get_regcache_arch (regcache));
63 const char *regs = fpregs;
66 gdb_assert (len >= MIPSNBSD_NUM_FPREGS * regsize);
68 for (i = MIPS_FP0_REGNUM; i <= MIPS_FSR_REGNUM; i++)
70 if (regnum == i || regnum == -1)
71 regcache_raw_supply (regcache, i,
72 regs + (i - MIPS_FP0_REGNUM) * regsize);
76 /* Supply register REGNUM from the buffer specified by GREGS and LEN
77 in the general-purpose register set REGSET to register cache
78 REGCACHE. If REGNUM is -1, do this for all registers in REGSET. */
81 mipsnbsd_supply_gregset (const struct regset *regset,
82 struct regcache *regcache, int regnum,
83 const void *gregs, size_t len)
85 size_t regsize = mips_isa_regsize (get_regcache_arch (regcache));
86 const char *regs = gregs;
89 gdb_assert (len >= MIPSNBSD_NUM_GREGS * regsize);
91 for (i = 0; i <= MIPS_PC_REGNUM; i++)
93 if (regnum == i || regnum == -1)
94 regcache_raw_supply (regcache, i, regs + i * regsize);
97 if (len >= (MIPSNBSD_NUM_GREGS + MIPSNBSD_NUM_FPREGS) * regsize)
99 regs += MIPSNBSD_NUM_GREGS * regsize;
100 len -= MIPSNBSD_NUM_GREGS * regsize;
101 mipsnbsd_supply_fpregset (regset, regcache, regnum, regs, len);
105 /* NetBSD/mips register sets. */
107 static struct regset mipsnbsd_gregset =
110 mipsnbsd_supply_gregset
113 static struct regset mipsnbsd_fpregset =
116 mipsnbsd_supply_fpregset
119 /* Return the appropriate register set for the core section identified
120 by SECT_NAME and SECT_SIZE. */
122 static const struct regset *
123 mipsnbsd_regset_from_core_section (struct gdbarch *gdbarch,
124 const char *sect_name, size_t sect_size)
126 size_t regsize = mips_isa_regsize (gdbarch);
128 if (strcmp (sect_name, ".reg") == 0
129 && sect_size >= MIPSNBSD_NUM_GREGS * regsize)
130 return &mipsnbsd_gregset;
132 if (strcmp (sect_name, ".reg2") == 0
133 && sect_size >= MIPSNBSD_NUM_FPREGS * regsize)
134 return &mipsnbsd_fpregset;
140 /* Conveniently, GDB uses the same register numbering as the
141 ptrace register structure used by NetBSD/mips. */
144 mipsnbsd_supply_reg (struct regcache *regcache, const char *regs, int regno)
146 struct gdbarch *gdbarch = get_regcache_arch (regcache);
149 for (i = 0; i <= gdbarch_pc_regnum (gdbarch); i++)
151 if (regno == i || regno == -1)
153 if (gdbarch_cannot_fetch_register (gdbarch, i))
154 regcache_raw_supply (regcache, i, NULL);
156 regcache_raw_supply (regcache, i,
157 regs + (i * mips_isa_regsize (gdbarch)));
163 mipsnbsd_fill_reg (const struct regcache *regcache, char *regs, int regno)
165 struct gdbarch *gdbarch = get_regcache_arch (regcache);
168 for (i = 0; i <= gdbarch_pc_regnum (gdbarch); i++)
169 if ((regno == i || regno == -1)
170 && ! gdbarch_cannot_store_register (gdbarch, i))
171 regcache_raw_collect (regcache, i,
172 regs + (i * mips_isa_regsize (gdbarch)));
176 mipsnbsd_supply_fpreg (struct regcache *regcache, const char *fpregs, int regno)
178 struct gdbarch *gdbarch = get_regcache_arch (regcache);
181 for (i = gdbarch_fp0_regnum (gdbarch);
182 i <= mips_regnum (gdbarch)->fp_implementation_revision;
185 if (regno == i || regno == -1)
187 if (gdbarch_cannot_fetch_register (gdbarch, i))
188 regcache_raw_supply (regcache, i, NULL);
190 regcache_raw_supply (regcache, i,
192 + ((i - gdbarch_fp0_regnum (gdbarch))
193 * mips_isa_regsize (gdbarch)));
199 mipsnbsd_fill_fpreg (const struct regcache *regcache, char *fpregs, int regno)
201 struct gdbarch *gdbarch = get_regcache_arch (regcache);
204 for (i = gdbarch_fp0_regnum (gdbarch);
205 i <= mips_regnum (gdbarch)->fp_control_status;
207 if ((regno == i || regno == -1)
208 && ! gdbarch_cannot_store_register (gdbarch, i))
209 regcache_raw_collect (regcache, i,
210 fpregs + ((i - gdbarch_fp0_regnum (gdbarch))
211 * mips_isa_regsize (gdbarch)));
214 /* Under NetBSD/mips, signal handler invocations can be identified by the
215 designated code sequence that is used to return from a signal handler.
216 In particular, the return address of a signal handler points to the
217 following code sequence:
220 li v0, 295 # __sigreturn14
223 Each instruction has a unique encoding, so we simply attempt to match
224 the instruction the PC is pointing to with any of the above instructions.
225 If there is a hit, we know the offset to the start of the designated
226 sequence and can then check whether we really are executing in the
227 signal trampoline. If not, -1 is returned, otherwise the offset from the
228 start of the return sequence is returned. */
230 #define RETCODE_NWORDS 3
231 #define RETCODE_SIZE (RETCODE_NWORDS * 4)
233 static const unsigned char sigtramp_retcode_mipsel[RETCODE_SIZE] =
235 0x10, 0x00, 0xa4, 0x27, /* addu a0, sp, 16 */
236 0x27, 0x01, 0x02, 0x24, /* li v0, 295 */
237 0x0c, 0x00, 0x00, 0x00, /* syscall */
240 static const unsigned char sigtramp_retcode_mipseb[RETCODE_SIZE] =
242 0x27, 0xa4, 0x00, 0x10, /* addu a0, sp, 16 */
243 0x24, 0x02, 0x01, 0x27, /* li v0, 295 */
244 0x00, 0x00, 0x00, 0x0c, /* syscall */
248 mipsnbsd_sigtramp_offset (struct frame_info *this_frame)
250 CORE_ADDR pc = get_frame_pc (this_frame);
251 const char *retcode = gdbarch_byte_order (get_frame_arch (this_frame))
252 == BFD_ENDIAN_BIG ? sigtramp_retcode_mipseb :
253 sigtramp_retcode_mipsel;
254 unsigned char ret[RETCODE_SIZE], w[4];
258 if (!safe_frame_unwind_memory (this_frame, pc, w, sizeof (w)))
261 for (i = 0; i < RETCODE_NWORDS; i++)
263 if (memcmp (w, retcode + (i * 4), 4) == 0)
266 if (i == RETCODE_NWORDS)
272 if (!safe_frame_unwind_memory (this_frame, pc, ret, sizeof (ret)))
275 if (memcmp (ret, retcode, RETCODE_SIZE) == 0)
281 /* Figure out where the longjmp will land. We expect that we have
282 just entered longjmp and haven't yet setup the stack frame, so the
283 args are still in the argument regs. MIPS_A0_REGNUM points at the
284 jmp_buf structure from which we extract the PC that we will land
285 at. The PC is copied into *pc. This routine returns true on
288 #define NBSD_MIPS_JB_PC (2 * 4)
289 #define NBSD_MIPS_JB_ELEMENT_SIZE mips_isa_regsize (current_gdbarch)
290 #define NBSD_MIPS_JB_OFFSET (NBSD_MIPS_JB_PC * \
291 NBSD_MIPS_JB_ELEMENT_SIZE)
294 mipsnbsd_get_longjmp_target (struct frame_info *frame, CORE_ADDR *pc)
299 buf = alloca (NBSD_MIPS_JB_ELEMENT_SIZE);
301 jb_addr = get_frame_register_unsigned (frame, MIPS_A0_REGNUM);
303 if (target_read_memory (jb_addr + NBSD_MIPS_JB_OFFSET, buf,
304 NBSD_MIPS_JB_ELEMENT_SIZE))
307 *pc = extract_unsigned_integer (buf, NBSD_MIPS_JB_ELEMENT_SIZE);
313 mipsnbsd_cannot_fetch_register (struct gdbarch *gdbarch, int regno)
315 return (regno == MIPS_ZERO_REGNUM
316 || regno == mips_regnum (gdbarch)->fp_implementation_revision);
320 mipsnbsd_cannot_store_register (struct gdbarch *gdbarch, int regno)
322 return (regno == MIPS_ZERO_REGNUM
323 || regno == mips_regnum (gdbarch)->fp_implementation_revision);
326 /* Shared library support. */
328 /* NetBSD/mips uses a slightly different `struct link_map' than the
329 other NetBSD platforms. */
331 static struct link_map_offsets *
332 mipsnbsd_ilp32_fetch_link_map_offsets (void)
334 static struct link_map_offsets lmo;
335 static struct link_map_offsets *lmp = NULL;
341 lmo.r_version_offset = 0;
342 lmo.r_version_size = 4;
343 lmo.r_map_offset = 4;
344 lmo.r_brk_offset = 8;
345 lmo.r_ldsomap_offset = -1;
347 /* Everything we need is in the first 24 bytes. */
348 lmo.link_map_size = 24;
349 lmo.l_addr_offset = 4;
350 lmo.l_name_offset = 8;
351 lmo.l_ld_offset = 12;
352 lmo.l_next_offset = 16;
353 lmo.l_prev_offset = 20;
359 static struct link_map_offsets *
360 mipsnbsd_lp64_fetch_link_map_offsets (void)
362 static struct link_map_offsets lmo;
363 static struct link_map_offsets *lmp = NULL;
369 lmo.r_version_offset = 0;
370 lmo.r_version_size = 4;
371 lmo.r_map_offset = 8;
372 lmo.r_brk_offset = 16;
373 lmo.r_ldsomap_offset = -1;
375 /* Everything we need is in the first 40 bytes. */
376 lmo.link_map_size = 48;
377 lmo.l_addr_offset = 0;
378 lmo.l_name_offset = 16;
379 lmo.l_ld_offset = 24;
380 lmo.l_next_offset = 32;
381 lmo.l_prev_offset = 40;
389 mipsnbsd_init_abi (struct gdbarch_info info,
390 struct gdbarch *gdbarch)
392 set_gdbarch_regset_from_core_section
393 (gdbarch, mipsnbsd_regset_from_core_section);
395 set_gdbarch_get_longjmp_target (gdbarch, mipsnbsd_get_longjmp_target);
397 set_gdbarch_cannot_fetch_register (gdbarch, mipsnbsd_cannot_fetch_register);
398 set_gdbarch_cannot_store_register (gdbarch, mipsnbsd_cannot_store_register);
400 set_gdbarch_software_single_step (gdbarch, mips_software_single_step);
402 /* NetBSD/mips has SVR4-style shared libraries. */
403 set_solib_svr4_fetch_link_map_offsets
404 (gdbarch, (gdbarch_ptr_bit (gdbarch) == 32 ?
405 mipsnbsd_ilp32_fetch_link_map_offsets :
406 mipsnbsd_lp64_fetch_link_map_offsets));
410 static enum gdb_osabi
411 mipsnbsd_core_osabi_sniffer (bfd *abfd)
413 if (strcmp (bfd_get_target (abfd), "netbsd-core") == 0)
414 return GDB_OSABI_NETBSD_ELF;
416 return GDB_OSABI_UNKNOWN;
420 _initialize_mipsnbsd_tdep (void)
422 gdbarch_register_osabi (bfd_arch_mips, 0, GDB_OSABI_NETBSD_ELF,