1/* GNU/Linux/PowerPC64 specific low level interface, for the remote server for
2   GDB.
3   Copyright (C) 1995, 1996, 1998, 1999, 2000, 2001, 2002, 2005, 2007
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 "server.h"
22#include "linux-low.h"
23
24#include <asm/ptrace.h>
25
26#define ppc_num_regs 71
27
28/* We use a constant for FPSCR instead of PT_FPSCR, because
29   many shipped PPC64 kernels had the wrong value in ptrace.h.  */
30static int ppc_regmap[] =
31 {PT_R0 * 8,     PT_R1 * 8,     PT_R2 * 8,     PT_R3 * 8,
32  PT_R4 * 8,     PT_R5 * 8,     PT_R6 * 8,     PT_R7 * 8,
33  PT_R8 * 8,     PT_R9 * 8,     PT_R10 * 8,    PT_R11 * 8,
34  PT_R12 * 8,    PT_R13 * 8,    PT_R14 * 8,    PT_R15 * 8,
35  PT_R16 * 8,    PT_R17 * 8,    PT_R18 * 8,    PT_R19 * 8,
36  PT_R20 * 8,    PT_R21 * 8,    PT_R22 * 8,    PT_R23 * 8,
37  PT_R24 * 8,    PT_R25 * 8,    PT_R26 * 8,    PT_R27 * 8,
38  PT_R28 * 8,    PT_R29 * 8,    PT_R30 * 8,    PT_R31 * 8,
39  PT_FPR0*8,     PT_FPR0*8 + 8, PT_FPR0*8+16,  PT_FPR0*8+24,
40  PT_FPR0*8+32,  PT_FPR0*8+40,  PT_FPR0*8+48,  PT_FPR0*8+56,
41  PT_FPR0*8+64,  PT_FPR0*8+72,  PT_FPR0*8+80,  PT_FPR0*8+88,
42  PT_FPR0*8+96,  PT_FPR0*8+104,  PT_FPR0*8+112,  PT_FPR0*8+120,
43  PT_FPR0*8+128, PT_FPR0*8+136,  PT_FPR0*8+144,  PT_FPR0*8+152,
44  PT_FPR0*8+160,  PT_FPR0*8+168,  PT_FPR0*8+176,  PT_FPR0*8+184,
45  PT_FPR0*8+192,  PT_FPR0*8+200,  PT_FPR0*8+208,  PT_FPR0*8+216,
46  PT_FPR0*8+224,  PT_FPR0*8+232,  PT_FPR0*8+240,  PT_FPR0*8+248,
47  PT_NIP * 8,    PT_MSR * 8,    PT_CCR * 8,    PT_LNK * 8,
48  PT_CTR * 8,    PT_XER * 8,    PT_FPR0*8 + 256 };
49
50static int
51ppc_cannot_store_register (int regno)
52{
53  return 0;
54}
55
56static int
57ppc_cannot_fetch_register (int regno)
58{
59  return 0;
60}
61
62static CORE_ADDR
63ppc_get_pc (void)
64{
65  unsigned long pc;
66
67  collect_register_by_name ("pc", &pc);
68  return (CORE_ADDR) pc;
69}
70
71static void
72ppc_set_pc (CORE_ADDR pc)
73{
74  unsigned long newpc = pc;
75
76  supply_register_by_name ("pc", &newpc);
77}
78
79/* Correct in either endianness.
80   This instruction is "twge r2, r2", which GDB uses as a software
81   breakpoint.  */
82static const unsigned int ppc_breakpoint = 0x7d821008;
83#define ppc_breakpoint_len 4
84
85static int
86ppc_breakpoint_at (CORE_ADDR where)
87{
88  unsigned int insn;
89
90  (*the_target->read_memory) (where, (unsigned char *) &insn, 4);
91  if (insn == ppc_breakpoint)
92    return 1;
93  /* If necessary, recognize more trap instructions here.  GDB only uses the
94     one.  */
95  return 0;
96}
97
98/* Provide only a fill function for the general register set.  ps_lgetregs
99   will use this for NPTL support.  */
100
101static void ppc_fill_gregset (void *buf)
102{
103  int i;
104
105  for (i = 0; i < 32; i++)
106    collect_register (i, (char *) buf + ppc_regmap[i]);
107
108  for (i = 64; i < 70; i++)
109    collect_register (i, (char *) buf + ppc_regmap[i]);
110}
111
112struct regset_info target_regsets[] = {
113  { 0, 0, 0, GENERAL_REGS, ppc_fill_gregset, NULL },
114  { 0, 0, -1, -1, NULL, NULL }
115};
116
117struct linux_target_ops the_low_target = {
118  ppc_num_regs,
119  ppc_regmap,
120  ppc_cannot_fetch_register,
121  ppc_cannot_store_register,
122  ppc_get_pc,
123  ppc_set_pc,
124  (const unsigned char *) &ppc_breakpoint,
125  ppc_breakpoint_len,
126  NULL,
127  0,
128  ppc_breakpoint_at,
129  NULL,
130  NULL,
131  NULL,
132  NULL,
133  1
134};
135