gdb/m68k-bsd-nat.c

   1 /* Native-dependent code for Motorola 68000 BSD's.
   2
   3    Copyright (C) 2004-2020 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 /* We define this to get types like register_t.  */
  21 #define _KERNTYPES
  22 #include "defs.h"
  23 #include "gdbcore.h"
  24 #include "inferior.h"
  25 #include "regcache.h"
  26
  27 #include <sys/types.h>
  28 #include <sys/ptrace.h>
  29 #include <machine/reg.h>
  30
  31 #include "m68k-tdep.h"
  32 #include "inf-ptrace.h"
  33 #include "nbsd-nat.h"
  34
  35 struct m68k_bsd_nat_target final : public nbsd_nat_target
  36 {
  37   void fetch_registers (struct regcache *, int) override;
  38   void store_registers (struct regcache *, int) override;
  39 };
  40
  41 static m68k_bsd_nat_target the_m68k_bsd_nat_target;
  42
  43 static int
  44 m68kbsd_gregset_supplies_p (int regnum)
  45 {
  46   return (regnum >= M68K_D0_REGNUM && regnum <= M68K_PC_REGNUM);
  47 }
  48
  49 static int
  50 m68kbsd_fpregset_supplies_p (int regnum)
  51 {
  52   return (regnum >= M68K_FP0_REGNUM && regnum <= M68K_FPI_REGNUM);
  53 }
  54
  55 /* Supply the general-purpose registers stored in GREGS to REGCACHE.  */
  56
  57 static void
  58 m68kbsd_supply_gregset (struct regcache *regcache, const void *gregs)
  59 {
  60   const gdb_byte *regs = (const gdb_byte *) gregs;
  61   int regnum;
  62
  63   for (regnum = M68K_D0_REGNUM; regnum <= M68K_PC_REGNUM; regnum++)
  64     regcache->raw_supply (regnum, regs + regnum * 4);
  65 }
  66
  67 /* Supply the floating-point registers stored in FPREGS to REGCACHE.  */
  68
  69 static void
  70 m68kbsd_supply_fpregset (struct regcache *regcache, const void *fpregs)
  71 {
  72   struct gdbarch *gdbarch = regcache->arch ();
  73   const gdb_byte *regs = (const gdb_byte *) fpregs;
  74   int regnum;
  75
  76   for (regnum = M68K_FP0_REGNUM; regnum <= M68K_FPI_REGNUM; regnum++)
  77     regcache->raw_supply (regnum,
  78                           regs + m68kbsd_fpreg_offset (gdbarch, regnum));
  79 }
  80
  81 /* Collect the general-purpose registers from REGCACHE and store them
  82    in GREGS.  */
  83
  84 static void
  85 m68kbsd_collect_gregset (const struct regcache *regcache,
  86                          void *gregs, int regnum)
  87 {
  88   gdb_byte *regs = (gdb_byte *) gregs;
  89   int i;
  90
  91   for (i = M68K_D0_REGNUM; i <= M68K_PC_REGNUM; i++)
  92     {
  93       if (regnum == -1 || regnum == i)
  94         regcache->raw_collect (i, regs + i * 4);
  95     }
  96 }
  97
  98 /* Collect the floating-point registers from REGCACHE and store them
  99    in FPREGS.  */
 100
 101 static void
 102 m68kbsd_collect_fpregset (struct regcache *regcache,
 103                           void *fpregs, int regnum)
 104 {
 105   struct gdbarch *gdbarch = regcache->arch ();
 106   char *regs = fpregs;
 107   int i;
 108
 109   for (i = M68K_FP0_REGNUM; i <= M68K_FPI_REGNUM; i++)
 110     {
 111       if (regnum == -1 || regnum == i)
 112         regcache->raw_collect (i, regs + m68kbsd_fpreg_offset (gdbarch, i));
 113     }
 114 }
 115 \f
 116
 117 /* Fetch register REGNUM from the inferior.  If REGNUM is -1, do this
 118    for all registers (including the floating-point registers).  */
 119
 120 void
 121 m68k_bsd_nat_target::fetch_registers (struct regcache *regcache, int regnum)
 122 {
 123   pid_t pid = regcache->ptid ().pid ();
 124   int lwp = regcache->ptid ().lwp ();
 125
 126   if (regnum == -1 || m68kbsd_gregset_supplies_p (regnum))
 127     {
 128       struct reg regs;
 129
 130       if (ptrace (PT_GETREGS, pid, (PTRACE_TYPE_ARG3) &regs, lwp) == -1)
 131         perror_with_name (_("Couldn't get registers"));
 132
 133       m68kbsd_supply_gregset (regcache, &regs);
 134     }
 135
 136   if (regnum == -1 || m68kbsd_fpregset_supplies_p (regnum))
 137     {
 138       struct fpreg fpregs;
 139
 140       if (ptrace (PT_GETFPREGS, pid, (PTRACE_TYPE_ARG3) &fpregs, lwp) == -1)
 141         perror_with_name (_("Couldn't get floating point status"));
 142
 143       m68kbsd_supply_fpregset (regcache, &fpregs);
 144     }
 145 }
 146
 147 /* Store register REGNUM back into the inferior.  If REGNUM is -1, do
 148    this for all registers (including the floating-point registers).  */
 149
 150 void
 151 m68k_bsd_nat_target::store_registers (struct regcache *regcache, int regnum)
 152 {
 153   pid_t pid = regcache->ptid ().pid ();
 154   int lwp = regcache->ptid ().lwp ();
 155
 156   if (regnum == -1 || m68kbsd_gregset_supplies_p (regnum))
 157     {
 158       struct reg regs;
 159
 160       if (ptrace (PT_GETREGS, pid, (PTRACE_TYPE_ARG3) &regs, lwp) == -1)
 161         perror_with_name (_("Couldn't get registers"));
 162
 163       m68kbsd_collect_gregset (regcache, &regs, regnum);
 164
 165       if (ptrace (PT_SETREGS, pid, (PTRACE_TYPE_ARG3) &regs, lwp) == -1)
 166         perror_with_name (_("Couldn't write registers"));
 167     }
 168
 169   if (regnum == -1 || m68kbsd_fpregset_supplies_p (regnum))
 170     {
 171       struct fpreg fpregs;
 172
 173       if (ptrace (PT_GETFPREGS, pid, (PTRACE_TYPE_ARG3) &fpregs, lwp) == -1)
 174         perror_with_name (_("Couldn't get floating point status"));
 175
 176       m68kbsd_collect_fpregset (regcache, &fpregs, regnum);
 177
 178       if (ptrace (PT_SETFPREGS, pid, (PTRACE_TYPE_ARG3) &fpregs, lwp) == -1)
 179         perror_with_name (_("Couldn't write floating point status"));
 180     }
 181 }
 182 \f
 183
 184 /* Support for debugging kernel virtual memory images.  */
 185
 186 #include <machine/pcb.h>
 187
 188 #include "bsd-kvm.h"
 189
 190 /* OpenBSD doesn't have these.  */
 191 #ifndef PCB_REGS_FP
 192 #define PCB_REGS_FP 10
 193 #endif
 194 #ifndef PCB_REGS_SP
 195 #define PCB_REGS_SP 11
 196 #endif
 197
 198 static int
 199 m68kbsd_supply_pcb (struct regcache *regcache, struct pcb *pcb)
 200 {
 201   int regnum, tmp;
 202   int i = 0;
 203
 204   /* The following is true for NetBSD 1.6.2:
 205
 206      The pcb contains %d2...%d7, %a2...%a7 and %ps.  This accounts for
 207      all callee-saved registers.  From this information we reconstruct
 208      the register state as it would look when we just returned from
 209      cpu_switch().  */
 210
 211   /* The stack pointer shouldn't be zero.  */
 212   if (pcb->pcb_regs[PCB_REGS_SP] == 0)
 213     return 0;
 214
 215   for (regnum = M68K_D2_REGNUM; regnum <= M68K_D7_REGNUM; regnum++)
 216     regcache->raw_supply (regnum, &pcb->pcb_regs[i++]);
 217   for (regnum = M68K_A2_REGNUM; regnum <= M68K_SP_REGNUM; regnum++)
 218     regcache->raw_supply (regnum, &pcb->pcb_regs[i++]);
 219
 220   tmp = pcb->pcb_ps & 0xffff;
 221   regcache->raw_supply (M68K_PS_REGNUM, &tmp);
 222
 223   read_memory (pcb->pcb_regs[PCB_REGS_FP] + 4, (gdb_byte *) &tmp, sizeof tmp);
 224   regcache->raw_supply (M68K_PC_REGNUM, &tmp);
 225
 226   return 1;
 227 }
 228
 229 void _initialize_m68kbsd_nat ();
 230 void
 231 _initialize_m68kbsd_nat ()
 232 {
 233   add_inf_child_target (&the_m68k_bsd_nat_target);
 234
 235   /* Support debugging kernel virtual memory images.  */
 236   bsd_kvm_add_target (m68kbsd_supply_pcb);
 237 }