gdb/gdbserver/linux-m68k-low.c

   1 /* GNU/Linux/m68k specific low level interface, for the remote server for GDB.
   2    Copyright (C) 1995-2013 Free Software Foundation, Inc.
   3
   4    This file is part of GDB.
   5
   6    This program is free software; you can redistribute it and/or modify
   7    it under the terms of the GNU General Public License as published by
   8    the Free Software Foundation; either version 3 of the License, or
   9    (at your option) any later version.
  10
  11    This program is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  18
  19 #include "server.h"
  20 #include "linux-low.h"
  21
  22 /* Defined in auto-generated file reg-m68k.c.  */
  23 void init_registers_m68k (void);
  24
  25 #ifdef HAVE_SYS_REG_H
  26 #include <sys/reg.h>
  27 #endif
  28
  29 #define m68k_num_regs 29
  30 #define m68k_num_gregs 18
  31
  32 /* This table must line up with REGISTER_NAMES in tm-m68k.h */
  33 static int m68k_regmap[] =
  34 {
  35 #ifdef PT_D0
  36   PT_D0 * 4, PT_D1 * 4, PT_D2 * 4, PT_D3 * 4,
  37   PT_D4 * 4, PT_D5 * 4, PT_D6 * 4, PT_D7 * 4,
  38   PT_A0 * 4, PT_A1 * 4, PT_A2 * 4, PT_A3 * 4,
  39   PT_A4 * 4, PT_A5 * 4, PT_A6 * 4, PT_USP * 4,
  40   PT_SR * 4, PT_PC * 4,
  41 #else
  42   14 * 4, 0 * 4, 1 * 4, 2 * 4, 3 * 4, 4 * 4, 5 * 4, 6 * 4,
  43   7 * 4, 8 * 4, 9 * 4, 10 * 4, 11 * 4, 12 * 4, 13 * 4, 15 * 4,
  44   17 * 4, 18 * 4,
  45 #endif
  46 #ifdef PT_FP0
  47   PT_FP0 * 4, PT_FP1 * 4, PT_FP2 * 4, PT_FP3 * 4,
  48   PT_FP4 * 4, PT_FP5 * 4, PT_FP6 * 4, PT_FP7 * 4,
  49   PT_FPCR * 4, PT_FPSR * 4, PT_FPIAR * 4
  50 #else
  51   21 * 4, 24 * 4, 27 * 4, 30 * 4, 33 * 4, 36 * 4,
  52   39 * 4, 42 * 4, 45 * 4, 46 * 4, 47 * 4
  53 #endif
  54 };
  55
  56 static int
  57 m68k_cannot_store_register (int regno)
  58 {
  59   return (regno >= m68k_num_regs);
  60 }
  61
  62 static int
  63 m68k_cannot_fetch_register (int regno)
  64 {
  65   return (regno >= m68k_num_regs);
  66 }
  67
  68 #ifdef HAVE_PTRACE_GETREGS
  69 #include <sys/procfs.h>
  70 #include <sys/ptrace.h>
  71
  72 static void
  73 m68k_fill_gregset (struct regcache *regcache, void *buf)
  74 {
  75   int i;
  76
  77   for (i = 0; i < m68k_num_gregs; i++)
  78     collect_register (regcache, i, (char *) buf + m68k_regmap[i]);
  79 }
  80
  81 static void
  82 m68k_store_gregset (struct regcache *regcache, const void *buf)
  83 {
  84   int i;
  85
  86   for (i = 0; i < m68k_num_gregs; i++)
  87     supply_register (regcache, i, (const char *) buf + m68k_regmap[i]);
  88 }
  89
  90 static void
  91 m68k_fill_fpregset (struct regcache *regcache, void *buf)
  92 {
  93   int i;
  94
  95   for (i = m68k_num_gregs; i < m68k_num_regs; i++)
  96     collect_register (regcache, i, ((char *) buf
  97                          + (m68k_regmap[i] - m68k_regmap[m68k_num_gregs])));
  98 }
  99
 100 static void
 101 m68k_store_fpregset (struct regcache *regcache, const void *buf)
 102 {
 103   int i;
 104
 105   for (i = m68k_num_gregs; i < m68k_num_regs; i++)
 106     supply_register (regcache, i, ((const char *) buf
 107                          + (m68k_regmap[i] - m68k_regmap[m68k_num_gregs])));
 108 }
 109
 110 #endif /* HAVE_PTRACE_GETREGS */
 111
 112 struct regset_info target_regsets[] = {
 113 #ifdef HAVE_PTRACE_GETREGS
 114   { PTRACE_GETREGS, PTRACE_SETREGS, 0, sizeof (elf_gregset_t),
 115     GENERAL_REGS,
 116     m68k_fill_gregset, m68k_store_gregset },
 117   { PTRACE_GETFPREGS, PTRACE_SETFPREGS, 0, sizeof (elf_fpregset_t),
 118     FP_REGS,
 119     m68k_fill_fpregset, m68k_store_fpregset },
 120 #endif /* HAVE_PTRACE_GETREGS */
 121   { 0, 0, 0, -1, -1, NULL, NULL }
 122 };
 123
 124 static const unsigned char m68k_breakpoint[] = { 0x4E, 0x4F };
 125 #define m68k_breakpoint_len 2
 126
 127 static CORE_ADDR
 128 m68k_get_pc (struct regcache *regcache)
 129 {
 130   unsigned long pc;
 131
 132   collect_register_by_name (regcache, "pc", &pc);
 133   return pc;
 134 }
 135
 136 static void
 137 m68k_set_pc (struct regcache *regcache, CORE_ADDR value)
 138 {
 139   unsigned long newpc = value;
 140
 141   supply_register_by_name (regcache, "pc", &newpc);
 142 }
 143
 144 static int
 145 m68k_breakpoint_at (CORE_ADDR pc)
 146 {
 147   unsigned char c[2];
 148
 149   read_inferior_memory (pc, c, 2);
 150   if (c[0] == 0x4E && c[1] == 0x4F)
 151     return 1;
 152
 153   return 0;
 154 }
 155
 156 #include <asm/ptrace.h>
 157
 158 #ifdef PTRACE_GET_THREAD_AREA
 159 /* Fetch the thread-local storage pointer for libthread_db.  */
 160
 161 ps_err_e
 162 ps_get_thread_area (const struct ps_prochandle *ph,
 163                     lwpid_t lwpid, int idx, void **base)
 164 {
 165   if (ptrace (PTRACE_GET_THREAD_AREA, lwpid, NULL, base) != 0)
 166     return PS_ERR;
 167
 168   /* IDX is the bias from the thread pointer to the beginning of the
 169      thread descriptor.  It has to be subtracted due to implementation
 170      quirks in libthread_db.  */
 171   *base = (void *) ((char *)*base - idx);
 172
 173   return PS_OK;
 174 }
 175 #endif /* PTRACE_GET_THREAD_AREA */
 176
 177 struct linux_target_ops the_low_target = {
 178   init_registers_m68k,
 179   m68k_num_regs,
 180   m68k_regmap,
 181   NULL,
 182   m68k_cannot_fetch_register,
 183   m68k_cannot_store_register,
 184   NULL, /* fetch_register */
 185   m68k_get_pc,
 186   m68k_set_pc,
 187   m68k_breakpoint,
 188   m68k_breakpoint_len,
 189   NULL,
 190   2,
 191   m68k_breakpoint_at,
 192 };