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 #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 (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 (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 (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 (i, regs + m68kbsd_fpreg_offset (gdbarch, i));
 110     }
 111 }
 112 \f
 113
 114 /* Fetch register REGNUM from the inferior.  If REGNUM is -1, do this
 115    for all registers (including the floating-point registers).  */
 116
 117 void
 118 m68k_bsd_nat_target::fetch_registers (struct regcache *regcache, int regnum)
 119 {
 120   pid_t pid = regcache->ptid ().pid ();
 121
 122   if (regnum == -1 || m68kbsd_gregset_supplies_p (regnum))
 123     {
 124       struct reg regs;
 125
 126       if (ptrace (PT_GETREGS, pid, (PTRACE_TYPE_ARG3) &regs, 0) == -1)
 127         perror_with_name (_("Couldn't get registers"));
 128
 129       m68kbsd_supply_gregset (regcache, &regs);
 130     }
 131
 132   if (regnum == -1 || m68kbsd_fpregset_supplies_p (regnum))
 133     {
 134       struct fpreg fpregs;
 135
 136       if (ptrace (PT_GETFPREGS, pid, (PTRACE_TYPE_ARG3) &fpregs, 0) == -1)
 137         perror_with_name (_("Couldn't get floating point status"));
 138
 139       m68kbsd_supply_fpregset (regcache, &fpregs);
 140     }
 141 }
 142
 143 /* Store register REGNUM back into the inferior.  If REGNUM is -1, do
 144    this for all registers (including the floating-point registers).  */
 145
 146 void
 147 m68k_bsd_nat_target::store_registers (struct regcache *regcache, int regnum)
 148 {
 149   pid_t pid = regcache->ptid ().pid ();
 150
 151   if (regnum == -1 || m68kbsd_gregset_supplies_p (regnum))
 152     {
 153       struct reg regs;
 154
 155       if (ptrace (PT_GETREGS, pid, (PTRACE_TYPE_ARG3) &regs, 0) == -1)
 156         perror_with_name (_("Couldn't get registers"));
 157
 158       m68kbsd_collect_gregset (regcache, &regs, regnum);
 159
 160       if (ptrace (PT_SETREGS, pid, (PTRACE_TYPE_ARG3) &regs, 0) == -1)
 161         perror_with_name (_("Couldn't write registers"));
 162     }
 163
 164   if (regnum == -1 || m68kbsd_fpregset_supplies_p (regnum))
 165     {
 166       struct fpreg fpregs;
 167
 168       if (ptrace (PT_GETFPREGS, pid, (PTRACE_TYPE_ARG3) &fpregs, 0) == -1)
 169         perror_with_name (_("Couldn't get floating point status"));
 170
 171       m68kbsd_collect_fpregset (regcache, &fpregs, regnum);
 172
 173       if (ptrace (PT_SETFPREGS, pid, (PTRACE_TYPE_ARG3) &fpregs, 0) == -1)
 174         perror_with_name (_("Couldn't write floating point status"));
 175     }
 176 }
 177 \f
 178
 179 /* Support for debugging kernel virtual memory images.  */
 180
 181 #include <machine/pcb.h>
 182
 183 #include "bsd-kvm.h"
 184
 185 /* OpenBSD doesn't have these.  */
 186 #ifndef PCB_REGS_FP
 187 #define PCB_REGS_FP 10
 188 #endif
 189 #ifndef PCB_REGS_SP
 190 #define PCB_REGS_SP 11
 191 #endif
 192
 193 static int
 194 m68kbsd_supply_pcb (struct regcache *regcache, struct pcb *pcb)
 195 {
 196   int regnum, tmp;
 197   int i = 0;
 198
 199   /* The following is true for NetBSD 1.6.2:
 200
 201      The pcb contains %d2...%d7, %a2...%a7 and %ps.  This accounts for
 202      all callee-saved registers.  From this information we reconstruct
 203      the register state as it would look when we just returned from
 204      cpu_switch().  */
 205
 206   /* The stack pointer shouldn't be zero.  */
 207   if (pcb->pcb_regs[PCB_REGS_SP] == 0)
 208     return 0;
 209
 210   for (regnum = M68K_D2_REGNUM; regnum <= M68K_D7_REGNUM; regnum++)
 211     regcache->raw_supply (regnum, &pcb->pcb_regs[i++]);
 212   for (regnum = M68K_A2_REGNUM; regnum <= M68K_SP_REGNUM; regnum++)
 213     regcache->raw_supply (regnum, &pcb->pcb_regs[i++]);
 214
 215   tmp = pcb->pcb_ps & 0xffff;
 216   regcache->raw_supply (M68K_PS_REGNUM, &tmp);
 217
 218   read_memory (pcb->pcb_regs[PCB_REGS_FP] + 4, (char *) &tmp, sizeof tmp);
 219   regcache->raw_supply (M68K_PC_REGNUM, &tmp);
 220
 221   return 1;
 222 }
 223
 224 void
 225 _initialize_m68kbsd_nat (void)
 226 {
 227   add_inf_child_target (&the_m68k_bsd_nat_target);
 228
 229   /* Support debugging kernel virtual memory images.  */
 230   bsd_kvm_add_target (m68kbsd_supply_pcb);
 231 }