1 /* Target-dependent code for Motorola 68000 BSD's.
2
3 Copyright (C) 2004, 2005, 2007, 2008, 2009, 2010, 2011
4 Free Software Foundation, Inc.
5
6 This file is part of GDB.
7
8 This program is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 3 of the License, or
11 (at your option) any later version.
12
13 This program is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
17
18 You should have received a copy of the GNU General Public License
19 along with this program. If not, see <http://www.gnu.org/licenses/>. */
20
21 #include "defs.h"
22 #include "arch-utils.h"
23 #include "frame.h"
24 #include "osabi.h"
25 #include "regcache.h"
26 #include "regset.h"
27 #include "trad-frame.h"
28 #include "tramp-frame.h"
29 #include "gdbtypes.h"
30
31 #include "gdb_assert.h"
32 #include "gdb_string.h"
33
34 #include "m68k-tdep.h"
35 #include "solib-svr4.h"
36
37 /* Core file support. */
38
39 /* Sizeof `struct reg' in <machine/reg.h>. */
40 #define M68KBSD_SIZEOF_GREGS (18 * 4)
41
42 /* Sizeof `struct fpreg' in <machine/reg.h. */
43 #define M68KBSD_SIZEOF_FPREGS (((8 * 3) + 3) * 4)
44
45 int
m68kbsd_fpreg_offset(struct gdbarch * gdbarch,int regnum)46 m68kbsd_fpreg_offset (struct gdbarch *gdbarch, int regnum)
47 {
48 int fp_len = TYPE_LENGTH (gdbarch_register_type (gdbarch, regnum));
49
50 if (regnum >= M68K_FPC_REGNUM)
51 return 8 * fp_len + (regnum - M68K_FPC_REGNUM) * 4;
52
53 return (regnum - M68K_FP0_REGNUM) * fp_len;
54 }
55
56 /* Supply register REGNUM from the buffer specified by FPREGS and LEN
57 in the floating-point register set REGSET to register cache
58 REGCACHE. If REGNUM is -1, do this for all registers in REGSET. */
59
60 static void
m68kbsd_supply_fpregset(const struct regset * regset,struct regcache * regcache,int regnum,const void * fpregs,size_t len)61 m68kbsd_supply_fpregset (const struct regset *regset,
62 struct regcache *regcache,
63 int regnum, const void *fpregs, size_t len)
64 {
65 struct gdbarch *gdbarch = get_regcache_arch (regcache);
66 const gdb_byte *regs = fpregs;
67 int i;
68
69 gdb_assert (len >= M68KBSD_SIZEOF_FPREGS);
70
71 for (i = M68K_FP0_REGNUM; i <= M68K_PC_REGNUM; i++)
72 {
73 if (regnum == i || regnum == -1)
74 regcache_raw_supply (regcache, i,
75 regs + m68kbsd_fpreg_offset (gdbarch, i));
76 }
77 }
78
79 /* Supply register REGNUM from the buffer specified by GREGS and LEN
80 in the general-purpose register set REGSET to register cache
81 REGCACHE. If REGNUM is -1, do this for all registers in REGSET. */
82
83 static void
m68kbsd_supply_gregset(const struct regset * regset,struct regcache * regcache,int regnum,const void * gregs,size_t len)84 m68kbsd_supply_gregset (const struct regset *regset,
85 struct regcache *regcache,
86 int regnum, const void *gregs, size_t len)
87 {
88 const gdb_byte *regs = gregs;
89 int i;
90
91 gdb_assert (len >= M68KBSD_SIZEOF_GREGS);
92
93 for (i = M68K_D0_REGNUM; i <= M68K_PC_REGNUM; i++)
94 {
95 if (regnum == i || regnum == -1)
96 regcache_raw_supply (regcache, i, regs + i * 4);
97 }
98
99 if (len >= M68KBSD_SIZEOF_GREGS + M68KBSD_SIZEOF_FPREGS)
100 {
101 regs += M68KBSD_SIZEOF_GREGS;
102 len -= M68KBSD_SIZEOF_GREGS;
103 m68kbsd_supply_fpregset (regset, regcache, regnum, regs, len);
104 }
105 }
106
107 /* Motorola 68000 register sets. */
108
109 static struct regset m68kbsd_gregset =
110 {
111 NULL,
112 m68kbsd_supply_gregset
113 };
114
115 static struct regset m68kbsd_fpregset =
116 {
117 NULL,
118 m68kbsd_supply_fpregset
119 };
120
121 /* Return the appropriate register set for the core section identified
122 by SECT_NAME and SECT_SIZE. */
123
124 static const struct regset *
m68kbsd_regset_from_core_section(struct gdbarch * gdbarch,const char * sect_name,size_t sect_size)125 m68kbsd_regset_from_core_section (struct gdbarch *gdbarch,
126 const char *sect_name, size_t sect_size)
127 {
128 if (strcmp (sect_name, ".reg") == 0 && sect_size >= M68KBSD_SIZEOF_GREGS)
129 return &m68kbsd_gregset;
130
131 if (strcmp (sect_name, ".reg2") == 0 && sect_size >= M68KBSD_SIZEOF_FPREGS)
132 return &m68kbsd_fpregset;
133
134 return NULL;
135 }
136
137
138 /* Signal trampolines. */
139
140 static void
m68kobsd_sigtramp_cache_init(const struct tramp_frame * self,struct frame_info * this_frame,struct trad_frame_cache * this_cache,CORE_ADDR func)141 m68kobsd_sigtramp_cache_init (const struct tramp_frame *self,
142 struct frame_info *this_frame,
143 struct trad_frame_cache *this_cache,
144 CORE_ADDR func)
145 {
146 CORE_ADDR addr, base, pc;
147 int regnum;
148
149 base = get_frame_register_unsigned (this_frame, M68K_SP_REGNUM);
150
151 /* The 'addql #4,%sp' instruction at offset 8 adjusts the stack
152 pointer. Adjust the frame base accordingly. */
153 pc = get_frame_register_unsigned (this_frame, M68K_PC_REGNUM);
154 if ((pc - func) > 8)
155 base -= 4;
156
157 /* Get frame pointer, stack pointer, program counter and processor
158 state from `struct sigcontext'. */
159 addr = get_frame_memory_unsigned (this_frame, base + 8, 4);
160 trad_frame_set_reg_addr (this_cache, M68K_FP_REGNUM, addr + 8);
161 trad_frame_set_reg_addr (this_cache, M68K_SP_REGNUM, addr + 12);
162 trad_frame_set_reg_addr (this_cache, M68K_PC_REGNUM, addr + 20);
163 trad_frame_set_reg_addr (this_cache, M68K_PS_REGNUM, addr + 24);
164
165 /* The sc_ap member of `struct sigcontext' points to additional
166 hardware state. Here we find the missing registers. */
167 addr = get_frame_memory_unsigned (this_frame, addr + 16, 4) + 4;
168 for (regnum = M68K_D0_REGNUM; regnum < M68K_FP_REGNUM; regnum++, addr += 4)
169 trad_frame_set_reg_addr (this_cache, regnum, addr);
170
171 /* Construct the frame ID using the function start. */
172 trad_frame_set_id (this_cache, frame_id_build (base, func));
173 }
174
175 static const struct tramp_frame m68kobsd_sigtramp = {
176 SIGTRAMP_FRAME,
177 2,
178 {
179 { 0x206f, -1 }, { 0x000c, -1}, /* moveal %sp@(12),%a0 */
180 { 0x4e90, -1 }, /* jsr %a0@ */
181 { 0x588f, -1 }, /* addql #4,%sp */
182 { 0x4e41, -1 }, /* trap #1 */
183 { 0x2f40, -1 }, { 0x0004, -1 }, /* moveal %d0,%sp@(4) */
184 { 0x7001, -1 }, /* moveq #SYS_exit,%d0 */
185 { 0x4e40, -1 }, /* trap #0 */
186 { TRAMP_SENTINEL_INSN, -1 }
187 },
188 m68kobsd_sigtramp_cache_init
189 };
190
191
192 static void
m68kbsd_init_abi(struct gdbarch_info info,struct gdbarch * gdbarch)193 m68kbsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
194 {
195 struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
196
197 tdep->jb_pc = 5;
198 tdep->jb_elt_size = 4;
199
200 set_gdbarch_decr_pc_after_break (gdbarch, 2);
201
202 set_gdbarch_regset_from_core_section
203 (gdbarch, m68kbsd_regset_from_core_section);
204 }
205
206 /* OpenBSD and NetBSD a.out. */
207
208 static void
m68kbsd_aout_init_abi(struct gdbarch_info info,struct gdbarch * gdbarch)209 m68kbsd_aout_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
210 {
211 struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
212
213 m68kbsd_init_abi (info, gdbarch);
214
215 tdep->struct_return = reg_struct_return;
216
217 tramp_frame_prepend_unwinder (gdbarch, &m68kobsd_sigtramp);
218 }
219
220 /* NetBSD ELF. */
221
222 static void
m68kbsd_elf_init_abi(struct gdbarch_info info,struct gdbarch * gdbarch)223 m68kbsd_elf_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
224 {
225 struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
226
227 m68kbsd_init_abi (info, gdbarch);
228
229 /* NetBSD ELF uses the SVR4 ABI. */
230 m68k_svr4_init_abi (info, gdbarch);
231 tdep->struct_return = pcc_struct_return;
232
233 /* NetBSD ELF uses SVR4-style shared libraries. */
234 set_solib_svr4_fetch_link_map_offsets
235 (gdbarch, svr4_ilp32_fetch_link_map_offsets);
236 }
237
238
239 static enum gdb_osabi
m68kbsd_aout_osabi_sniffer(bfd * abfd)240 m68kbsd_aout_osabi_sniffer (bfd *abfd)
241 {
242 if (strcmp (bfd_get_target (abfd), "a.out-m68k-netbsd") == 0
243 || strcmp (bfd_get_target (abfd), "a.out-m68k4k-netbsd") == 0)
244 return GDB_OSABI_NETBSD_AOUT;
245
246 return GDB_OSABI_UNKNOWN;
247 }
248
249 static enum gdb_osabi
m68kbsd_core_osabi_sniffer(bfd * abfd)250 m68kbsd_core_osabi_sniffer (bfd *abfd)
251 {
252 if (strcmp (bfd_get_target (abfd), "netbsd-core") == 0)
253 return GDB_OSABI_NETBSD_AOUT;
254
255 return GDB_OSABI_UNKNOWN;
256 }
257
258
259 /* Provide a prototype to silence -Wmissing-prototypes. */
260 void _initialize_m68kbsd_tdep (void);
261
262 void
_initialize_m68kbsd_tdep(void)263 _initialize_m68kbsd_tdep (void)
264 {
265 gdbarch_register_osabi_sniffer (bfd_arch_m68k, bfd_target_aout_flavour,
266 m68kbsd_aout_osabi_sniffer);
267
268 /* BFD doesn't set a flavour for NetBSD style a.out core files. */
269 gdbarch_register_osabi_sniffer (bfd_arch_m68k, bfd_target_unknown_flavour,
270 m68kbsd_core_osabi_sniffer);
271
272 gdbarch_register_osabi (bfd_arch_m68k, 0, GDB_OSABI_NETBSD_AOUT,
273 m68kbsd_aout_init_abi);
274 gdbarch_register_osabi (bfd_arch_m68k, 0, GDB_OSABI_NETBSD_ELF,
275 m68kbsd_elf_init_abi);
276 }
277