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