1/* GNU/Linux/PowerPC specific low level interface, for the remote server for
2   GDB.
3   Copyright 1995, 1996, 1998, 1999, 2000, 2001, 2002
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 2 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, write to the Free Software
20   Foundation, Inc., 59 Temple Place - Suite 330,
21   Boston, MA 02111-1307, USA.  */
22
23#include "server.h"
24#include "linux-low.h"
25
26#include <asm/ptrace.h>
27
28#define ppc_num_regs 71
29
30/* Currently, don't check/send MQ.  */
31static int ppc_regmap[] =
32 {PT_R0 * 4,     PT_R1 * 4,     PT_R2 * 4,     PT_R3 * 4,
33  PT_R4 * 4,     PT_R5 * 4,     PT_R6 * 4,     PT_R7 * 4,
34  PT_R8 * 4,     PT_R9 * 4,     PT_R10 * 4,    PT_R11 * 4,
35  PT_R12 * 4,    PT_R13 * 4,    PT_R14 * 4,    PT_R15 * 4,
36  PT_R16 * 4,    PT_R17 * 4,    PT_R18 * 4,    PT_R19 * 4,
37  PT_R20 * 4,    PT_R21 * 4,    PT_R22 * 4,    PT_R23 * 4,
38  PT_R24 * 4,    PT_R25 * 4,    PT_R26 * 4,    PT_R27 * 4,
39  PT_R28 * 4,    PT_R29 * 4,    PT_R30 * 4,    PT_R31 * 4,
40  PT_FPR0*4,     PT_FPR0*4 + 8, PT_FPR0*4+16,  PT_FPR0*4+24,
41  PT_FPR0*4+32,  PT_FPR0*4+40,  PT_FPR0*4+48,  PT_FPR0*4+56,
42  PT_FPR0*4+64,  PT_FPR0*4+72,  PT_FPR0*4+80,  PT_FPR0*4+88,
43  PT_FPR0*4+96,  PT_FPR0*4+104,  PT_FPR0*4+112,  PT_FPR0*4+120,
44  PT_FPR0*4+128, PT_FPR0*4+136,  PT_FPR0*4+144,  PT_FPR0*4+152,
45  PT_FPR0*4+160,  PT_FPR0*4+168,  PT_FPR0*4+176,  PT_FPR0*4+184,
46  PT_FPR0*4+192,  PT_FPR0*4+200,  PT_FPR0*4+208,  PT_FPR0*4+216,
47  PT_FPR0*4+224,  PT_FPR0*4+232,  PT_FPR0*4+240,  PT_FPR0*4+248,
48  PT_NIP * 4,    PT_MSR * 4,    PT_CCR * 4,    PT_LNK * 4,
49  PT_CTR * 4,    PT_XER * 4,    PT_FPSCR * 4, };
50
51static int
52ppc_cannot_store_register (int regno)
53{
54  /* Some kernels do not allow us to store fpscr.  */
55  if (regno == find_regno ("fpscr"))
56    return 2;
57
58  return 0;
59}
60
61static int
62ppc_cannot_fetch_register (int regno)
63{
64  return 0;
65}
66
67static CORE_ADDR
68ppc_get_pc (void)
69{
70  unsigned long pc;
71
72  collect_register_by_name ("pc", &pc);
73  return (CORE_ADDR) pc;
74}
75
76static void
77ppc_set_pc (CORE_ADDR pc)
78{
79  unsigned long newpc = pc;
80
81  supply_register_by_name ("pc", &newpc);
82}
83
84/* Correct in either endianness.  Note that this file is
85   for PowerPC only, not PowerPC64.
86   This instruction is "twge r2, r2", which GDB uses as a software
87   breakpoint.  */
88static const unsigned long ppc_breakpoint = 0x7d821008;
89#define ppc_breakpoint_len 4
90
91static int
92ppc_breakpoint_at (CORE_ADDR where)
93{
94  unsigned long insn;
95
96  (*the_target->read_memory) (where, (char *) &insn, 4);
97  if (insn == ppc_breakpoint)
98    return 1;
99  /* If necessary, recognize more trap instructions here.  GDB only uses the
100     one.  */
101  return 0;
102}
103
104struct linux_target_ops the_low_target = {
105  ppc_num_regs,
106  ppc_regmap,
107  ppc_cannot_fetch_register,
108  ppc_cannot_store_register,
109  ppc_get_pc,
110  ppc_set_pc,
111  (const char *) &ppc_breakpoint,
112  ppc_breakpoint_len,
113  NULL,
114  0,
115  ppc_breakpoint_at,
116};
117