1 /* Target-dependent code for NetBSD/mips.
3 Copyright (C) 2002-2014 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 "gdb_assert.h"
33 #include "nbsd-tdep.h"
34 #include "mipsnbsd-tdep.h"
35 #include "mips-tdep.h"
37 #include "solib-svr4.h"
39 /* Shorthand for some register numbers used below. */
40 #define MIPS_PC_REGNUM MIPS_EMBED_PC_REGNUM
41 #define MIPS_FP0_REGNUM MIPS_EMBED_FP0_REGNUM
42 #define MIPS_FSR_REGNUM MIPS_EMBED_FP0_REGNUM + 32
44 /* Core file support. */
46 /* Number of registers in `struct reg' from <machine/reg.h>. */
47 #define MIPSNBSD_NUM_GREGS 38
49 /* Number of registers in `struct fpreg' from <machine/reg.h>. */
50 #define MIPSNBSD_NUM_FPREGS 33
52 /* Supply register REGNUM from the buffer specified by FPREGS and LEN
53 in the floating-point register set REGSET to register cache
54 REGCACHE. If REGNUM is -1, do this for all registers in REGSET. */
57 mipsnbsd_supply_fpregset (const struct regset *regset,
58 struct regcache *regcache,
59 int regnum, const void *fpregs, size_t len)
61 size_t regsize = mips_isa_regsize (get_regcache_arch (regcache));
62 const char *regs = fpregs;
65 gdb_assert (len >= MIPSNBSD_NUM_FPREGS * regsize);
67 for (i = MIPS_FP0_REGNUM; i <= MIPS_FSR_REGNUM; i++)
69 if (regnum == i || regnum == -1)
70 regcache_raw_supply (regcache, i,
71 regs + (i - MIPS_FP0_REGNUM) * regsize);
75 /* Supply register REGNUM from the buffer specified by GREGS and LEN
76 in the general-purpose register set REGSET to register cache
77 REGCACHE. If REGNUM is -1, do this for all registers in REGSET. */
80 mipsnbsd_supply_gregset (const struct regset *regset,
81 struct regcache *regcache, int regnum,
82 const void *gregs, size_t len)
84 size_t regsize = mips_isa_regsize (get_regcache_arch (regcache));
85 const char *regs = gregs;
88 gdb_assert (len >= MIPSNBSD_NUM_GREGS * regsize);
90 for (i = 0; i <= MIPS_PC_REGNUM; i++)
92 if (regnum == i || regnum == -1)
93 regcache_raw_supply (regcache, i, regs + i * regsize);
96 if (len >= (MIPSNBSD_NUM_GREGS + MIPSNBSD_NUM_FPREGS) * regsize)
98 regs += MIPSNBSD_NUM_GREGS * regsize;
99 len -= MIPSNBSD_NUM_GREGS * regsize;
100 mipsnbsd_supply_fpregset (regset, regcache, regnum, regs, len);
104 /* NetBSD/mips register sets. */
106 static struct regset mipsnbsd_gregset =
109 mipsnbsd_supply_gregset
112 static struct regset mipsnbsd_fpregset =
115 mipsnbsd_supply_fpregset
118 /* Return the appropriate register set for the core section identified
119 by SECT_NAME and SECT_SIZE. */
121 static const struct regset *
122 mipsnbsd_regset_from_core_section (struct gdbarch *gdbarch,
123 const char *sect_name, size_t sect_size)
125 size_t regsize = mips_isa_regsize (gdbarch);
127 if (strcmp (sect_name, ".reg") == 0
128 && sect_size >= MIPSNBSD_NUM_GREGS * regsize)
129 return &mipsnbsd_gregset;
131 if (strcmp (sect_name, ".reg2") == 0
132 && sect_size >= MIPSNBSD_NUM_FPREGS * regsize)
133 return &mipsnbsd_fpregset;
139 /* Conveniently, GDB uses the same register numbering as the
140 ptrace register structure used by NetBSD/mips. */
143 mipsnbsd_supply_reg (struct regcache *regcache, const char *regs, int regno)
145 struct gdbarch *gdbarch = get_regcache_arch (regcache);
148 for (i = 0; i <= gdbarch_pc_regnum (gdbarch); i++)
150 if (regno == i || regno == -1)
152 if (gdbarch_cannot_fetch_register (gdbarch, i))
153 regcache_raw_supply (regcache, i, NULL);
155 regcache_raw_supply (regcache, i,
156 regs + (i * mips_isa_regsize (gdbarch)));
162 mipsnbsd_fill_reg (const struct regcache *regcache, char *regs, int regno)
164 struct gdbarch *gdbarch = get_regcache_arch (regcache);
167 for (i = 0; i <= gdbarch_pc_regnum (gdbarch); i++)
168 if ((regno == i || regno == -1)
169 && ! gdbarch_cannot_store_register (gdbarch, i))
170 regcache_raw_collect (regcache, i,
171 regs + (i * mips_isa_regsize (gdbarch)));
175 mipsnbsd_supply_fpreg (struct regcache *regcache,
176 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 */
247 /* Figure out where the longjmp will land. We expect that we have
248 just entered longjmp and haven't yet setup the stack frame, so the
249 args are still in the argument regs. MIPS_A0_REGNUM points at the
250 jmp_buf structure from which we extract the PC that we will land
251 at. The PC is copied into *pc. This routine returns true on
254 #define NBSD_MIPS_JB_PC (2 * 4)
255 #define NBSD_MIPS_JB_ELEMENT_SIZE(gdbarch) mips_isa_regsize (gdbarch)
256 #define NBSD_MIPS_JB_OFFSET(gdbarch) (NBSD_MIPS_JB_PC * \
257 NBSD_MIPS_JB_ELEMENT_SIZE (gdbarch))
260 mipsnbsd_get_longjmp_target (struct frame_info *frame, CORE_ADDR *pc)
262 struct gdbarch *gdbarch = get_frame_arch (frame);
263 enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
267 buf = alloca (NBSD_MIPS_JB_ELEMENT_SIZE (gdbarch));
269 jb_addr = get_frame_register_unsigned (frame, MIPS_A0_REGNUM);
271 if (target_read_memory (jb_addr + NBSD_MIPS_JB_OFFSET (gdbarch), buf,
272 NBSD_MIPS_JB_ELEMENT_SIZE (gdbarch)))
275 *pc = extract_unsigned_integer (buf, NBSD_MIPS_JB_ELEMENT_SIZE (gdbarch),
281 mipsnbsd_cannot_fetch_register (struct gdbarch *gdbarch, int regno)
283 return (regno == MIPS_ZERO_REGNUM
284 || regno == mips_regnum (gdbarch)->fp_implementation_revision);
288 mipsnbsd_cannot_store_register (struct gdbarch *gdbarch, int regno)
290 return (regno == MIPS_ZERO_REGNUM
291 || regno == mips_regnum (gdbarch)->fp_implementation_revision);
294 /* Shared library support. */
296 /* NetBSD/mips uses a slightly different `struct link_map' than the
297 other NetBSD platforms. */
299 static struct link_map_offsets *
300 mipsnbsd_ilp32_fetch_link_map_offsets (void)
302 static struct link_map_offsets lmo;
303 static struct link_map_offsets *lmp = NULL;
309 lmo.r_version_offset = 0;
310 lmo.r_version_size = 4;
311 lmo.r_map_offset = 4;
312 lmo.r_brk_offset = 8;
313 lmo.r_ldsomap_offset = -1;
315 /* Everything we need is in the first 24 bytes. */
316 lmo.link_map_size = 24;
317 lmo.l_addr_offset = 4;
318 lmo.l_name_offset = 8;
319 lmo.l_ld_offset = 12;
320 lmo.l_next_offset = 16;
321 lmo.l_prev_offset = 20;
327 static struct link_map_offsets *
328 mipsnbsd_lp64_fetch_link_map_offsets (void)
330 static struct link_map_offsets lmo;
331 static struct link_map_offsets *lmp = NULL;
337 lmo.r_version_offset = 0;
338 lmo.r_version_size = 4;
339 lmo.r_map_offset = 8;
340 lmo.r_brk_offset = 16;
341 lmo.r_ldsomap_offset = -1;
343 /* Everything we need is in the first 40 bytes. */
344 lmo.link_map_size = 48;
345 lmo.l_addr_offset = 0;
346 lmo.l_name_offset = 16;
347 lmo.l_ld_offset = 24;
348 lmo.l_next_offset = 32;
349 lmo.l_prev_offset = 40;
357 mipsnbsd_init_abi (struct gdbarch_info info,
358 struct gdbarch *gdbarch)
360 set_gdbarch_regset_from_core_section
361 (gdbarch, mipsnbsd_regset_from_core_section);
363 set_gdbarch_get_longjmp_target (gdbarch, mipsnbsd_get_longjmp_target);
365 set_gdbarch_cannot_fetch_register (gdbarch, mipsnbsd_cannot_fetch_register);
366 set_gdbarch_cannot_store_register (gdbarch, mipsnbsd_cannot_store_register);
368 set_gdbarch_software_single_step (gdbarch, mips_software_single_step);
370 /* NetBSD/mips has SVR4-style shared libraries. */
371 set_solib_svr4_fetch_link_map_offsets
372 (gdbarch, (gdbarch_ptr_bit (gdbarch) == 32 ?
373 mipsnbsd_ilp32_fetch_link_map_offsets :
374 mipsnbsd_lp64_fetch_link_map_offsets));
378 /* Provide a prototype to silence -Wmissing-prototypes. */
379 extern initialize_file_ftype _initialize_mipsnbsd_tdep;
382 _initialize_mipsnbsd_tdep (void)
384 gdbarch_register_osabi (bfd_arch_mips, 0, GDB_OSABI_NETBSD_ELF,