1/* Target-dependent code for Motorola 68000 BSD's.
2
3   Copyright (C) 2004, 2005, 2007 Free Software Foundation, Inc.
4
5   This file is part of GDB.
6
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 3 of the License, or
10   (at your option) any later version.
11
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.
16
17   You should have received a copy of the GNU General Public License
18   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
19
20#include "defs.h"
21#include "arch-utils.h"
22#include "frame.h"
23#include "osabi.h"
24#include "regcache.h"
25#include "regset.h"
26#include "trad-frame.h"
27#include "tramp-frame.h"
28
29#include "gdb_assert.h"
30#include "gdb_string.h"
31
32#include "m68k-tdep.h"
33#include "solib-svr4.h"
34
35/* Core file support.  */
36
37/* Sizeof `struct reg' in <machine/reg.h>.  */
38#define M68KBSD_SIZEOF_GREGS	(18 * 4)
39
40/* Sizeof `struct fpreg' in <machine/reg.h.  */
41#define M68KBSD_SIZEOF_FPREGS	(((8 * 3) + 3) * 4)
42
43int
44m68kbsd_fpreg_offset (int regnum)
45{
46  int fp_len = TYPE_LENGTH (gdbarch_register_type (current_gdbarch, regnum));
47
48  if (regnum >= M68K_FPC_REGNUM)
49    return 8 * fp_len + (regnum - M68K_FPC_REGNUM) * 4;
50
51  return (regnum - M68K_FP0_REGNUM) * fp_len;
52}
53
54/* Supply register REGNUM from the buffer specified by FPREGS and LEN
55   in the floating-point register set REGSET to register cache
56   REGCACHE.  If REGNUM is -1, do this for all registers in REGSET.  */
57
58static void
59m68kbsd_supply_fpregset (const struct regset *regset,
60			 struct regcache *regcache,
61			 int regnum, const void *fpregs, size_t len)
62{
63  const gdb_byte *regs = fpregs;
64  int i;
65
66  gdb_assert (len >= M68KBSD_SIZEOF_FPREGS);
67
68  for (i = M68K_FP0_REGNUM; i <= M68K_PC_REGNUM; i++)
69    {
70      if (regnum == i || regnum == -1)
71	regcache_raw_supply (regcache, i, regs + m68kbsd_fpreg_offset (i));
72    }
73}
74
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.  */
78
79static void
80m68kbsd_supply_gregset (const struct regset *regset,
81			struct regcache *regcache,
82			int regnum, const void *gregs, size_t len)
83{
84  const gdb_byte *regs = gregs;
85  int i;
86
87  gdb_assert (len >= M68KBSD_SIZEOF_GREGS);
88
89  for (i = M68K_D0_REGNUM; i <= M68K_PC_REGNUM; i++)
90    {
91      if (regnum == i || regnum == -1)
92	regcache_raw_supply (regcache, i, regs + i * 4);
93    }
94
95  if (len >= M68KBSD_SIZEOF_GREGS + M68KBSD_SIZEOF_FPREGS)
96    {
97      regs += M68KBSD_SIZEOF_GREGS;
98      len -= M68KBSD_SIZEOF_GREGS;
99      m68kbsd_supply_fpregset (regset, regcache, regnum, regs, len);
100    }
101}
102
103/* Motorola 68000 register sets.  */
104
105static struct regset m68kbsd_gregset =
106{
107  NULL,
108  m68kbsd_supply_gregset
109};
110
111static struct regset m68kbsd_fpregset =
112{
113  NULL,
114  m68kbsd_supply_fpregset
115};
116
117/* Return the appropriate register set for the core section identified
118   by SECT_NAME and SECT_SIZE.  */
119
120static const struct regset *
121m68kbsd_regset_from_core_section (struct gdbarch *gdbarch,
122				  const char *sect_name, size_t sect_size)
123{
124  if (strcmp (sect_name, ".reg") == 0 && sect_size >= M68KBSD_SIZEOF_GREGS)
125    return &m68kbsd_gregset;
126
127  if (strcmp (sect_name, ".reg2") == 0 && sect_size >= M68KBSD_SIZEOF_FPREGS)
128    return &m68kbsd_fpregset;
129
130  return NULL;
131}
132
133
134/* Signal trampolines.  */
135
136static void
137m68kobsd_sigtramp_cache_init (const struct tramp_frame *self,
138			      struct frame_info *next_frame,
139			      struct trad_frame_cache *this_cache,
140			      CORE_ADDR func)
141{
142  CORE_ADDR addr, base, pc;
143  int regnum;
144
145  base = frame_unwind_register_unsigned (next_frame, M68K_SP_REGNUM);
146
147  /* The 'addql #4,%sp' instruction at offset 8 adjusts the stack
148     pointer.  Adjust the frame base accordingly.  */
149  pc = frame_unwind_register_unsigned (next_frame, M68K_PC_REGNUM);
150  if ((pc - func) > 8)
151    base -= 4;
152
153  /* Get frame pointer, stack pointer, program counter and processor
154     state from `struct sigcontext'.  */
155  addr = get_frame_memory_unsigned (next_frame, base + 8, 4);
156  trad_frame_set_reg_addr (this_cache, M68K_FP_REGNUM, addr + 8);
157  trad_frame_set_reg_addr (this_cache, M68K_SP_REGNUM, addr + 12);
158  trad_frame_set_reg_addr (this_cache, M68K_PC_REGNUM, addr + 20);
159  trad_frame_set_reg_addr (this_cache, M68K_PS_REGNUM, addr + 24);
160
161  /* The sc_ap member of `struct sigcontext' points to additional
162     hardware state.  Here we find the missing registers.  */
163  addr = get_frame_memory_unsigned (next_frame, addr + 16, 4) + 4;
164  for (regnum = M68K_D0_REGNUM; regnum < M68K_FP_REGNUM; regnum++, addr += 4)
165    trad_frame_set_reg_addr (this_cache, regnum, addr);
166
167  /* Construct the frame ID using the function start.  */
168  trad_frame_set_id (this_cache, frame_id_build (base, func));
169}
170
171static const struct tramp_frame m68kobsd_sigtramp = {
172  SIGTRAMP_FRAME,
173  2,
174  {
175    { 0x206f, -1 }, { 0x000c, -1},	/* moveal %sp@(12),%a0 */
176    { 0x4e90, -1 },			/* jsr %a0@ */
177    { 0x588f, -1 },			/* addql #4,%sp */
178    { 0x4e41, -1 },			/* trap #1 */
179    { 0x2f40, -1 }, { 0x0004, -1 },	/* moveal %d0,%sp@(4) */
180    { 0x7001, -1 },			/* moveq #SYS_exit,%d0 */
181    { 0x4e40, -1 },			/* trap #0 */
182    { TRAMP_SENTINEL_INSN, -1 }
183  },
184  m68kobsd_sigtramp_cache_init
185};
186
187
188static void
189m68kbsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
190{
191  struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
192
193  tdep->jb_pc = 5;
194  tdep->jb_elt_size = 4;
195
196  set_gdbarch_decr_pc_after_break (gdbarch, 2);
197
198  set_gdbarch_regset_from_core_section
199    (gdbarch, m68kbsd_regset_from_core_section);
200}
201
202/* OpenBSD and NetBSD a.out.  */
203
204static void
205m68kbsd_aout_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
206{
207  struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
208
209  m68kbsd_init_abi (info, gdbarch);
210
211  tdep->struct_return = reg_struct_return;
212
213  tramp_frame_prepend_unwinder (gdbarch, &m68kobsd_sigtramp);
214}
215
216/* NetBSD ELF.  */
217
218static void
219m68kbsd_elf_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
220{
221  struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
222
223  m68kbsd_init_abi (info, gdbarch);
224
225  /* NetBSD ELF uses the SVR4 ABI.  */
226  m68k_svr4_init_abi (info, gdbarch);
227  tdep->struct_return = pcc_struct_return;
228
229  /* NetBSD ELF uses SVR4-style shared libraries.  */
230  set_solib_svr4_fetch_link_map_offsets
231    (gdbarch, svr4_ilp32_fetch_link_map_offsets);
232}
233
234
235static enum gdb_osabi
236m68kbsd_aout_osabi_sniffer (bfd *abfd)
237{
238  if (strcmp (bfd_get_target (abfd), "a.out-m68k-netbsd") == 0
239      || strcmp (bfd_get_target (abfd), "a.out-m68k4k-netbsd") == 0)
240    return GDB_OSABI_NETBSD_AOUT;
241
242  return GDB_OSABI_UNKNOWN;
243}
244
245static enum gdb_osabi
246m68kbsd_core_osabi_sniffer (bfd *abfd)
247{
248  if (strcmp (bfd_get_target (abfd), "netbsd-core") == 0)
249    return GDB_OSABI_NETBSD_AOUT;
250
251  return GDB_OSABI_UNKNOWN;
252}
253
254
255/* Provide a prototype to silence -Wmissing-prototypes.  */
256void _initialize_m68kbsd_tdep (void);
257
258void
259_initialize_m68kbsd_tdep (void)
260{
261  gdbarch_register_osabi_sniffer (bfd_arch_m68k, bfd_target_aout_flavour,
262				  m68kbsd_aout_osabi_sniffer);
263
264  /* BFD doesn't set a flavour for NetBSD style a.out core files.  */
265  gdbarch_register_osabi_sniffer (bfd_arch_m68k, bfd_target_unknown_flavour,
266				  m68kbsd_core_osabi_sniffer);
267
268  gdbarch_register_osabi (bfd_arch_m68k, 0, GDB_OSABI_NETBSD_AOUT,
269			  m68kbsd_aout_init_abi);
270  gdbarch_register_osabi (bfd_arch_m68k, 0, GDB_OSABI_NETBSD_ELF,
271			  m68kbsd_elf_init_abi);
272}
273