1/* Target-dependent code for NetBSD/powerpc.
2
3   Copyright (C) 2002, 2003, 2004, 2005, 2006, 2007
4   Free Software Foundation, Inc.
5
6   Contributed by Wasabi Systems, Inc.
7
8   This file is part of GDB.
9
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.
14
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.
19
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/>.  */
22
23#include "defs.h"
24#include "gdbtypes.h"
25#include "osabi.h"
26#include "regcache.h"
27#include "regset.h"
28#include "trad-frame.h"
29#include "tramp-frame.h"
30
31#include "gdb_assert.h"
32#include "gdb_string.h"
33
34#include "ppc-tdep.h"
35#include "ppcnbsd-tdep.h"
36#include "solib-svr4.h"
37
38/* Register offsets from <machine/reg.h>.  */
39struct ppc_reg_offsets ppcnbsd_reg_offsets;
40
41
42/* Core file support.  */
43
44/* NetBSD/powerpc register sets.  */
45
46struct regset ppcnbsd_gregset =
47{
48  &ppcnbsd_reg_offsets,
49  ppc_supply_gregset
50};
51
52struct regset ppcnbsd_fpregset =
53{
54  &ppcnbsd_reg_offsets,
55  ppc_supply_fpregset
56};
57
58/* Return the appropriate register set for the core section identified
59   by SECT_NAME and SECT_SIZE.  */
60
61static const struct regset *
62ppcnbsd_regset_from_core_section (struct gdbarch *gdbarch,
63				  const char *sect_name, size_t sect_size)
64{
65  if (strcmp (sect_name, ".reg") == 0 && sect_size >= 148)
66    return &ppcnbsd_gregset;
67
68  if (strcmp (sect_name, ".reg2") == 0 && sect_size >= 264)
69    return &ppcnbsd_fpregset;
70
71  return NULL;
72}
73
74
75/* NetBSD is confused.  It appears that 1.5 was using the correct SVR4
76   convention but, 1.6 switched to the below broken convention.  For
77   the moment use the broken convention.  Ulgh!.  */
78
79static enum return_value_convention
80ppcnbsd_return_value (struct gdbarch *gdbarch, struct type *valtype,
81		      struct regcache *regcache, gdb_byte *readbuf,
82		      const gdb_byte *writebuf)
83{
84#if 0
85  if ((TYPE_CODE (valtype) == TYPE_CODE_STRUCT
86       || TYPE_CODE (valtype) == TYPE_CODE_UNION)
87      && !((TYPE_LENGTH (valtype) == 16 || TYPE_LENGTH (valtype) == 8)
88	    && TYPE_VECTOR (valtype))
89      && !(TYPE_LENGTH (valtype) == 1
90	   || TYPE_LENGTH (valtype) == 2
91	   || TYPE_LENGTH (valtype) == 4
92	   || TYPE_LENGTH (valtype) == 8))
93    return RETURN_VALUE_STRUCT_CONVENTION;
94  else
95#endif
96    return ppc_sysv_abi_broken_return_value (gdbarch, valtype, regcache,
97					     readbuf, writebuf);
98}
99
100
101/* Signal trampolines.  */
102
103static const struct tramp_frame ppcnbsd2_sigtramp;
104
105static void
106ppcnbsd_sigtramp_cache_init (const struct tramp_frame *self,
107			     struct frame_info *next_frame,
108			     struct trad_frame_cache *this_cache,
109			     CORE_ADDR func)
110{
111  struct gdbarch *gdbarch = get_frame_arch (next_frame);
112  struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
113  CORE_ADDR addr, base;
114  int i;
115
116  base = frame_unwind_register_unsigned (next_frame,
117					 gdbarch_sp_regnum (current_gdbarch));
118  if (self == &ppcnbsd2_sigtramp)
119    addr = base + 0x10 + 2 * tdep->wordsize;
120  else
121    addr = base + 0x18 + 2 * tdep->wordsize;
122  for (i = 0; i < ppc_num_gprs; i++, addr += tdep->wordsize)
123    {
124      int regnum = i + tdep->ppc_gp0_regnum;
125      trad_frame_set_reg_addr (this_cache, regnum, addr);
126    }
127  trad_frame_set_reg_addr (this_cache, tdep->ppc_lr_regnum, addr);
128  addr += tdep->wordsize;
129  trad_frame_set_reg_addr (this_cache, tdep->ppc_cr_regnum, addr);
130  addr += tdep->wordsize;
131  trad_frame_set_reg_addr (this_cache, tdep->ppc_xer_regnum, addr);
132  addr += tdep->wordsize;
133  trad_frame_set_reg_addr (this_cache, tdep->ppc_ctr_regnum, addr);
134  addr += tdep->wordsize;
135  trad_frame_set_reg_addr (this_cache,
136			   gdbarch_pc_regnum (current_gdbarch),
137			   addr); /* SRR0? */
138  addr += tdep->wordsize;
139
140  /* Construct the frame ID using the function start.  */
141  trad_frame_set_id (this_cache, frame_id_build (base, func));
142}
143
144static const struct tramp_frame ppcnbsd_sigtramp =
145{
146  SIGTRAMP_FRAME,
147  4,
148  {
149    { 0x3821fff0, -1 },		/* add r1,r1,-16 */
150    { 0x4e800021, -1 },		/* blrl */
151    { 0x38610018, -1 },		/* addi r3,r1,24 */
152    { 0x38000127, -1 },		/* li r0,295 */
153    { 0x44000002, -1 },		/* sc */
154    { 0x38000001, -1 },		/* li r0,1 */
155    { 0x44000002, -1 },		/* sc */
156    { TRAMP_SENTINEL_INSN, -1 }
157  },
158  ppcnbsd_sigtramp_cache_init
159};
160
161/* NetBSD 2.0 introduced a slightly different signal trampoline.  */
162
163static const struct tramp_frame ppcnbsd2_sigtramp =
164{
165  SIGTRAMP_FRAME,
166  4,
167  {
168    { 0x3821fff0, -1 },		/* add r1,r1,-16 */
169    { 0x4e800021, -1 },		/* blrl */
170    { 0x38610010, -1 },		/* addi r3,r1,16 */
171    { 0x38000127, -1 },		/* li r0,295 */
172    { 0x44000002, -1 },		/* sc */
173    { 0x38000001, -1 },		/* li r0,1 */
174    { 0x44000002, -1 },		/* sc */
175    { TRAMP_SENTINEL_INSN, -1 }
176  },
177  ppcnbsd_sigtramp_cache_init
178};
179
180
181static void
182ppcnbsd_init_abi (struct gdbarch_info info,
183                  struct gdbarch *gdbarch)
184{
185  /* For NetBSD, this is an on again, off again thing.  Some systems
186     do use the broken struct convention, and some don't.  */
187  set_gdbarch_return_value (gdbarch, ppcnbsd_return_value);
188
189  /* NetBSD uses SVR4-style shared libraries.  */
190  set_solib_svr4_fetch_link_map_offsets
191    (gdbarch, svr4_ilp32_fetch_link_map_offsets);
192
193  set_gdbarch_regset_from_core_section
194    (gdbarch, ppcnbsd_regset_from_core_section);
195
196  tramp_frame_prepend_unwinder (gdbarch, &ppcnbsd_sigtramp);
197  tramp_frame_prepend_unwinder (gdbarch, &ppcnbsd2_sigtramp);
198}
199
200
201/* Provide a prototype to silence -Wmissing-prototypes.  */
202void _initialize_ppcnbsd_tdep (void);
203
204void
205_initialize_ppcnbsd_tdep (void)
206{
207  gdbarch_register_osabi (bfd_arch_powerpc, 0, GDB_OSABI_NETBSD_ELF,
208			  ppcnbsd_init_abi);
209
210  /* Avoid initializing the register offsets again if they were
211     already initailized by ppcnbsd-nat.c.  */
212  if (ppcnbsd_reg_offsets.pc_offset == 0)
213    {
214      /* General-purpose registers.  */
215      ppcnbsd_reg_offsets.r0_offset = 0;
216      ppcnbsd_reg_offsets.gpr_size = 4;
217      ppcnbsd_reg_offsets.xr_size = 4;
218      ppcnbsd_reg_offsets.lr_offset = 128;
219      ppcnbsd_reg_offsets.cr_offset = 132;
220      ppcnbsd_reg_offsets.xer_offset = 136;
221      ppcnbsd_reg_offsets.ctr_offset = 140;
222      ppcnbsd_reg_offsets.pc_offset = 144;
223      ppcnbsd_reg_offsets.ps_offset = -1;
224      ppcnbsd_reg_offsets.mq_offset = -1;
225
226      /* Floating-point registers.  */
227      ppcnbsd_reg_offsets.f0_offset = 0;
228      ppcnbsd_reg_offsets.fpscr_offset = 256;
229      ppcnbsd_reg_offsets.fpscr_size = 4;
230
231      /* AltiVec registers.  */
232      ppcnbsd_reg_offsets.vr0_offset = 0;
233      ppcnbsd_reg_offsets.vrsave_offset = 512;
234      ppcnbsd_reg_offsets.vscr_offset = 524;
235    }
236}
237