1/* Native-dependent code for PowerPC's running NetBSD, for GDB.
2   Copyright 2002, 2004 Free Software Foundation, Inc.
3   Contributed by Wasabi Systems, 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 2 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, write to the Free Software
19   Foundation, Inc., 59 Temple Place - Suite 330,
20   Boston, MA 02111-1307, USA.  */
21
22#include <sys/types.h>
23#include <sys/ptrace.h>
24#include <machine/reg.h>
25#include <machine/frame.h>
26#include <machine/pcb.h>
27
28#include "defs.h"
29#include "inferior.h"
30#include "gdb_assert.h"
31#include "gdbcore.h"
32#include "regcache.h"
33#include "bsd-kvm.h"
34
35#include "ppc-tdep.h"
36#include "ppcnbsd-tdep.h"
37
38#include "inf-ptrace.h"
39
40/* Returns true if PT_GETREGS fetches this register.  */
41static int
42getregs_supplies (int regno)
43{
44  struct gdbarch_tdep *tdep = gdbarch_tdep (current_gdbarch);
45
46  return ((regno >= tdep->ppc_gp0_regnum
47           && regno < tdep->ppc_gp0_regnum + ppc_num_gprs)
48          || regno == tdep->ppc_lr_regnum
49          || regno == tdep->ppc_cr_regnum
50          || regno == tdep->ppc_xer_regnum
51          || regno == tdep->ppc_ctr_regnum
52	  || regno == PC_REGNUM);
53}
54
55/* Like above, but for PT_GETFPREGS.  */
56static int
57getfpregs_supplies (int regno)
58{
59  struct gdbarch_tdep *tdep = gdbarch_tdep (current_gdbarch);
60
61  /* FIXME: jimb/2004-05-05: Some PPC variants don't have floating
62     point registers.  Traditionally, GDB's register set has still
63     listed the floating point registers for such machines, so this
64     code is harmless.  However, the new E500 port actually omits the
65     floating point registers entirely from the register set --- they
66     don't even have register numbers assigned to them.
67
68     It's not clear to me how best to update this code, so this assert
69     will alert the first person to encounter the NetBSD/E500
70     combination to the problem.  */
71  gdb_assert (ppc_floating_point_unit_p (current_gdbarch));
72
73  return ((regno >= tdep->ppc_fp0_regnum
74           && regno < tdep->ppc_fp0_regnum + ppc_num_fprs)
75	  || regno == tdep->ppc_fpscr_regnum);
76}
77
78static void
79ppcnbsd_fetch_inferior_registers (int regno)
80{
81  if (regno == -1 || getregs_supplies (regno))
82    {
83      struct reg regs;
84
85      if (ptrace (PT_GETREGS, PIDGET (inferior_ptid),
86		  (PTRACE_TYPE_ARG3) &regs, 0) == -1)
87        perror_with_name ("Couldn't get registers");
88
89      ppcnbsd_supply_reg ((char *) &regs, regno);
90      if (regno != -1)
91	return;
92    }
93
94  if (regno == -1 || getfpregs_supplies (regno))
95    {
96      struct fpreg fpregs;
97
98      if (ptrace (PT_GETFPREGS, PIDGET (inferior_ptid),
99		  (PTRACE_TYPE_ARG3) &fpregs, 0) == -1)
100	perror_with_name ("Couldn't get FP registers");
101
102      ppcnbsd_supply_fpreg ((char *) &fpregs, regno);
103      if (regno != -1)
104	return;
105    }
106}
107
108static void
109ppcnbsd_store_inferior_registers (int regno)
110{
111  if (regno == -1 || getregs_supplies (regno))
112    {
113      struct reg regs;
114
115      if (ptrace (PT_GETREGS, PIDGET (inferior_ptid),
116		  (PTRACE_TYPE_ARG3) &regs, 0) == -1)
117	perror_with_name ("Couldn't get registers");
118
119      ppcnbsd_fill_reg ((char *) &regs, regno);
120
121      if (ptrace (PT_SETREGS, PIDGET (inferior_ptid),
122		  (PTRACE_TYPE_ARG3) &regs, 0) == -1)
123	perror_with_name ("Couldn't write registers");
124
125      if (regno != -1)
126	return;
127    }
128
129  if (regno == -1 || getfpregs_supplies (regno))
130    {
131      struct fpreg fpregs;
132
133      if (ptrace (PT_GETFPREGS, PIDGET (inferior_ptid),
134		  (PTRACE_TYPE_ARG3) &fpregs, 0) == -1)
135	perror_with_name ("Couldn't get FP registers");
136
137      ppcnbsd_fill_fpreg ((char *) &fpregs, regno);
138
139      if (ptrace (PT_SETFPREGS, PIDGET (inferior_ptid),
140		  (PTRACE_TYPE_ARG3) &fpregs, 0) == -1)
141	perror_with_name ("Couldn't set FP registers");
142    }
143}
144
145static int
146ppcnbsd_supply_pcb (struct regcache *regcache, struct pcb *pcb)
147{
148  struct switchframe sf;
149  struct callframe cf;
150  struct gdbarch_tdep *tdep = gdbarch_tdep (current_gdbarch);
151  int i;
152
153  /* The stack pointer shouldn't be zero.  */
154  if (pcb->pcb_sp == 0)
155    return 0;
156
157  read_memory (pcb->pcb_sp, (char *) &sf, sizeof sf);
158  regcache_raw_supply (regcache, tdep->ppc_cr_regnum, &sf.cr);
159  regcache_raw_supply (regcache, tdep->ppc_gp0_regnum + 2, &sf.fixreg2);
160  for (i = 0 ; i < 19 ; i++)
161    regcache_raw_supply (regcache, tdep->ppc_gp0_regnum + 13 + i,
162			 &sf.fixreg[i]);
163
164  read_memory(sf.sp, (char *)&cf, sizeof(cf));
165  regcache_raw_supply (regcache, tdep->ppc_gp0_regnum + 30, &cf.r30);
166  regcache_raw_supply (regcache, tdep->ppc_gp0_regnum + 31, &cf.r31);
167  regcache_raw_supply (regcache, tdep->ppc_gp0_regnum + 1, &cf.sp);
168
169  read_memory(cf.sp, (char *)&cf, sizeof(cf));
170  regcache_raw_supply (regcache, tdep->ppc_lr_regnum, &cf.lr);
171  regcache_raw_supply (regcache, PC_REGNUM, &cf.lr);
172
173  return 1;
174}
175
176/* Provide a prototype to silence -Wmissing-prototypes.  */
177void _initialize_ppcnbsd_nat (void);
178
179void
180_initialize_ppcnbsd_nat (void)
181{
182  struct target_ops *t;
183  /* Support debugging kernel virtual memory images.  */
184  bsd_kvm_add_target (ppcnbsd_supply_pcb);
185  /* Add in local overrides.  */
186  t = inf_ptrace_target ();
187  t->to_fetch_registers = ppcnbsd_fetch_inferior_registers;
188  t->to_store_registers = ppcnbsd_store_inferior_registers;
189  add_target (t);
190}
191