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