gdb/m68k-bsd-nat.c

   1 /* Native-dependent code for Motorola 68000 BSD's.
   2
   3    Copyright (C) 2004-2018 Free Software Foundation, 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 3 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, see <http://www.gnu.org/licenses/>.  */
  19
  20 #include "defs.h"
  21 #include "gdbcore.h"
  22 #include "inferior.h"
  23 #include "regcache.h"
  24
  25 #include <sys/types.h>
  26 #include <sys/ptrace.h>
  27 #include <machine/reg.h>
  28
  29 #include "m68k-tdep.h"
  30 #include "inf-ptrace.h"
  31
  32 static int
  33 m68kbsd_gregset_supplies_p (int regnum)
  34 {
  35   return (regnum >= M68K_D0_REGNUM && regnum <= M68K_PC_REGNUM);
  36 }
  37
  38 static int
  39 m68kbsd_fpregset_supplies_p (int regnum)
  40 {
  41   return (regnum >= M68K_FP0_REGNUM && regnum <= M68K_FPI_REGNUM);
  42 }
  43
  44 /* Supply the general-purpose registers stored in GREGS to REGCACHE.  */
  45
  46 static void
  47 m68kbsd_supply_gregset (struct regcache *regcache, const void *gregs)
  48 {
  49   const char *regs = gregs;
  50   int regnum;
  51
  52   for (regnum = M68K_D0_REGNUM; regnum <= M68K_PC_REGNUM; regnum++)
  53     regcache_raw_supply (regcache, regnum, regs + regnum * 4);
  54 }
  55
  56 /* Supply the floating-point registers stored in FPREGS to REGCACHE.  */
  57
  58 static void
  59 m68kbsd_supply_fpregset (struct regcache *regcache, const void *fpregs)
  60 {
  61   struct gdbarch *gdbarch = regcache->arch ();
  62   const char *regs = fpregs;
  63   int regnum;
  64
  65   for (regnum = M68K_FP0_REGNUM; regnum <= M68K_FPI_REGNUM; regnum++)
  66     regcache_raw_supply (regcache, regnum,
  67                          regs + m68kbsd_fpreg_offset (gdbarch, regnum));
  68 }
  69
  70 /* Collect the general-purpose registers from REGCACHE and store them
  71    in GREGS.  */
  72
  73 static void
  74 m68kbsd_collect_gregset (const struct regcache *regcache,
  75                          void *gregs, int regnum)
  76 {
  77   char *regs = gregs;
  78   int i;
  79
  80   for (i = M68K_D0_REGNUM; i <= M68K_PC_REGNUM; i++)
  81     {
  82       if (regnum == -1 || regnum == i)
  83         regcache_raw_collect (regcache, i, regs + i * 4);
  84     }
  85 }
  86
  87 /* Collect the floating-point registers from REGCACHE and store them
  88    in FPREGS.  */
  89
  90 static void
  91 m68kbsd_collect_fpregset (struct regcache *regcache,
  92                           void *fpregs, int regnum)
  93 {
  94   struct gdbarch *gdbarch = regcache->arch ();
  95   char *regs = fpregs;
  96   int i;
  97
  98   for (i = M68K_FP0_REGNUM; i <= M68K_FPI_REGNUM; i++)
  99     {
 100       if (regnum == -1 || regnum == i)
 101         regcache_raw_collect (regcache, i,
 102                               regs + m68kbsd_fpreg_offset (gdbarch, i));
 103     }
 104 }
 105 \f
 106
 107 /* Fetch register REGNUM from the inferior.  If REGNUM is -1, do this
 108    for all registers (including the floating-point registers).  */
 109
 110 static void
 111 m68kbsd_fetch_inferior_registers (struct target_ops *ops,
 112                                   struct regcache *regcache, int regnum)
 113 {
 114   pid_t pid = ptid_get_pid (regcache_get_ptid (regcache));
 115
 116   if (regnum == -1 || m68kbsd_gregset_supplies_p (regnum))
 117     {
 118       struct reg regs;
 119
 120       if (ptrace (PT_GETREGS, pid, (PTRACE_TYPE_ARG3) &regs, 0) == -1)
 121         perror_with_name (_("Couldn't get registers"));
 122
 123       m68kbsd_supply_gregset (regcache, &regs);
 124     }
 125
 126   if (regnum == -1 || m68kbsd_fpregset_supplies_p (regnum))
 127     {
 128       struct fpreg fpregs;
 129
 130       if (ptrace (PT_GETFPREGS, pid, (PTRACE_TYPE_ARG3) &fpregs, 0) == -1)
 131         perror_with_name (_("Couldn't get floating point status"));
 132
 133       m68kbsd_supply_fpregset (regcache, &fpregs);
 134     }
 135 }
 136
 137 /* Store register REGNUM back into the inferior.  If REGNUM is -1, do
 138    this for all registers (including the floating-point registers).  */
 139
 140 static void
 141 m68kbsd_store_inferior_registers (struct target_ops *ops,
 142                                   struct regcache *regcache, int regnum)
 143 {
 144   pid_t pid = ptid_get_pid (regcache_get_ptid (regcache));
 145
 146   if (regnum == -1 || m68kbsd_gregset_supplies_p (regnum))
 147     {
 148       struct reg regs;
 149
 150       if (ptrace (PT_GETREGS, pid, (PTRACE_TYPE_ARG3) &regs, 0) == -1)
 151         perror_with_name (_("Couldn't get registers"));
 152
 153       m68kbsd_collect_gregset (regcache, &regs, regnum);
 154
 155       if (ptrace (PT_SETREGS, pid, (PTRACE_TYPE_ARG3) &regs, 0) == -1)
 156         perror_with_name (_("Couldn't write registers"));
 157     }
 158
 159   if (regnum == -1 || m68kbsd_fpregset_supplies_p (regnum))
 160     {
 161       struct fpreg fpregs;
 162
 163       if (ptrace (PT_GETFPREGS, pid, (PTRACE_TYPE_ARG3) &fpregs, 0) == -1)
 164         perror_with_name (_("Couldn't get floating point status"));
 165
 166       m68kbsd_collect_fpregset (regcache, &fpregs, regnum);
 167
 168       if (ptrace (PT_SETFPREGS, pid, (PTRACE_TYPE_ARG3) &fpregs, 0) == -1)
 169         perror_with_name (_("Couldn't write floating point status"));
 170     }
 171 }
 172 \f
 173
 174 /* Support for debugging kernel virtual memory images.  */
 175
 176 #include <machine/pcb.h>
 177
 178 #include "bsd-kvm.h"
 179
 180 /* OpenBSD doesn't have these.  */
 181 #ifndef PCB_REGS_FP
 182 #define PCB_REGS_FP 10
 183 #endif
 184 #ifndef PCB_REGS_SP
 185 #define PCB_REGS_SP 11
 186 #endif
 187
 188 static int
 189 m68kbsd_supply_pcb (struct regcache *regcache, struct pcb *pcb)
 190 {
 191   int regnum, tmp;
 192   int i = 0;
 193
 194   /* The following is true for NetBSD 1.6.2:
 195
 196      The pcb contains %d2...%d7, %a2...%a7 and %ps.  This accounts for
 197      all callee-saved registers.  From this information we reconstruct
 198      the register state as it would look when we just returned from
 199      cpu_switch().  */
 200
 201   /* The stack pointer shouldn't be zero.  */
 202   if (pcb->pcb_regs[PCB_REGS_SP] == 0)
 203     return 0;
 204
 205   for (regnum = M68K_D2_REGNUM; regnum <= M68K_D7_REGNUM; regnum++)
 206     regcache_raw_supply (regcache, regnum, &pcb->pcb_regs[i++]);
 207   for (regnum = M68K_A2_REGNUM; regnum <= M68K_SP_REGNUM; regnum++)
 208     regcache_raw_supply (regcache, regnum, &pcb->pcb_regs[i++]);
 209
 210   tmp = pcb->pcb_ps & 0xffff;
 211   regcache_raw_supply (regcache, M68K_PS_REGNUM, &tmp);
 212
 213   read_memory (pcb->pcb_regs[PCB_REGS_FP] + 4, (char *) &tmp, sizeof tmp);
 214   regcache_raw_supply (regcache, M68K_PC_REGNUM, &tmp);
 215
 216   return 1;
 217 }
 218
 219 void
 220 _initialize_m68kbsd_nat (void)
 221 {
 222   struct target_ops *t;
 223
 224   t = inf_ptrace_target ();
 225   t->to_fetch_registers = m68kbsd_fetch_inferior_registers;
 226   t->to_store_registers = m68kbsd_store_inferior_registers;
 227   add_target (t);
 228
 229   /* Support debugging kernel virtual memory images.  */
 230   bsd_kvm_add_target (m68kbsd_supply_pcb);
 231 }