gdb/ppc-nbsd-nat.c

   1 /* Native-dependent code for NetBSD/powerpc.
   2
   3    Copyright (C) 2002-2020 Free Software Foundation, Inc.
   4
   5    Contributed by Wasabi Systems, Inc.
   6
   7    This file is part of GDB.
   8
   9    This program is free software; you can redistribute it and/or modify
  10    it under the terms of the GNU General Public License as published by
  11    the Free Software Foundation; either version 3 of the License, or
  12    (at your option) any later version.
  13
  14    This program is distributed in the hope that it will be useful,
  15    but WITHOUT ANY WARRANTY; without even the implied warranty of
  16    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17    GNU General Public License for more details.
  18
  19    You should have received a copy of the GNU General Public License
  20    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  21
  22 #include "defs.h"
  23
  24 #include <sys/types.h>
  25 #include <sys/ptrace.h>
  26 #include <machine/reg.h>
  27 #include <machine/frame.h>
  28 #include <machine/pcb.h>
  29
  30 #include "gdbcore.h"
  31 #include "inferior.h"
  32 #include "regcache.h"
  33
  34 #include "ppc-tdep.h"
  35 #include "ppc-nbsd-tdep.h"
  36 #include "bsd-kvm.h"
  37 #include "inf-ptrace.h"
  38
  39 struct ppc_nbsd_nat_target final : public inf_ptrace_target
  40 {
  41   void fetch_registers (struct regcache *, int) override;
  42   void store_registers (struct regcache *, int) override;
  43 };
  44
  45 static ppc_nbsd_nat_target the_ppc_nbsd_nat_target;
  46
  47 /* Returns true if PT_GETREGS fetches this register.  */
  48
  49 static int
  50 getregs_supplies (struct gdbarch *gdbarch, int regnum)
  51 {
  52   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
  53
  54   return ((regnum >= tdep->ppc_gp0_regnum
  55            && regnum < tdep->ppc_gp0_regnum + ppc_num_gprs)
  56           || regnum == tdep->ppc_lr_regnum
  57           || regnum == tdep->ppc_cr_regnum
  58           || regnum == tdep->ppc_xer_regnum
  59           || regnum == tdep->ppc_ctr_regnum
  60           || regnum == gdbarch_pc_regnum (gdbarch));
  61 }
  62
  63 /* Like above, but for PT_GETFPREGS.  */
  64
  65 static int
  66 getfpregs_supplies (struct gdbarch *gdbarch, int regnum)
  67 {
  68   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
  69
  70   /* FIXME: jimb/2004-05-05: Some PPC variants don't have floating
  71      point registers.  Traditionally, GDB's register set has still
  72      listed the floating point registers for such machines, so this
  73      code is harmless.  However, the new E500 port actually omits the
  74      floating point registers entirely from the register set --- they
  75      don't even have register numbers assigned to them.
  76
  77      It's not clear to me how best to update this code, so this assert
  78      will alert the first person to encounter the NetBSD/E500
  79      combination to the problem.  */
  80   gdb_assert (ppc_floating_point_unit_p (gdbarch));
  81
  82   return ((regnum >= tdep->ppc_fp0_regnum
  83            && regnum < tdep->ppc_fp0_regnum + ppc_num_fprs)
  84           || regnum == tdep->ppc_fpscr_regnum);
  85 }
  86
  87 void
  88 ppc_nbsd_nat_target::fetch_registers (struct regcache *regcache, int regnum)
  89 {
  90   struct gdbarch *gdbarch = regcache->arch ();
  91   pid_t pid = regcache->ptid ().pid ();
  92
  93   if (regnum == -1 || getregs_supplies (gdbarch, regnum))
  94     {
  95       struct reg regs;
  96
  97       if (ptrace (PT_GETREGS, pid, (PTRACE_TYPE_ARG3) &regs, 0) == -1)
  98         perror_with_name (_("Couldn't get registers"));
  99
 100       ppc_supply_gregset (&ppcnbsd_gregset, regcache,
 101                           regnum, &regs, sizeof regs);
 102     }
 103
 104   if (regnum == -1 || getfpregs_supplies (gdbarch, regnum))
 105     {
 106       struct fpreg fpregs;
 107
 108       if (ptrace (PT_GETFPREGS, pid, (PTRACE_TYPE_ARG3) &fpregs, 0) == -1)
 109         perror_with_name (_("Couldn't get FP registers"));
 110
 111       ppc_supply_fpregset (&ppcnbsd_fpregset, regcache,
 112                            regnum, &fpregs, sizeof fpregs);
 113     }
 114 }
 115
 116 void
 117 ppc_nbsd_nat_target::store_registers (struct regcache *regcache, int regnum)
 118 {
 119   struct gdbarch *gdbarch = regcache->arch ();
 120   pid_t pid = regcache->ptid ().pid ();
 121
 122   if (regnum == -1 || getregs_supplies (gdbarch, 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       ppc_collect_gregset (&ppcnbsd_gregset, regcache,
 130                            regnum, &regs, sizeof regs);
 131
 132       if (ptrace (PT_SETREGS, pid, (PTRACE_TYPE_ARG3) &regs, 0) == -1)
 133         perror_with_name (_("Couldn't write registers"));
 134     }
 135
 136   if (regnum == -1 || getfpregs_supplies (gdbarch, regnum))
 137     {
 138       struct fpreg fpregs;
 139
 140       if (ptrace (PT_GETFPREGS, pid, (PTRACE_TYPE_ARG3) &fpregs, 0) == -1)
 141         perror_with_name (_("Couldn't get FP registers"));
 142
 143       ppc_collect_fpregset (&ppcnbsd_fpregset, regcache,
 144                             regnum, &fpregs, sizeof fpregs);
 145
 146       if (ptrace (PT_SETFPREGS, pid, (PTRACE_TYPE_ARG3) &fpregs, 0) == -1)
 147         perror_with_name (_("Couldn't set FP registers"));
 148     }
 149 }
 150
 151 static int
 152 ppcnbsd_supply_pcb (struct regcache *regcache, struct pcb *pcb)
 153 {
 154   struct switchframe sf;
 155   struct callframe cf;
 156   struct gdbarch *gdbarch = regcache->arch ();
 157   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
 158   int i;
 159
 160   /* The stack pointer shouldn't be zero.  */
 161   if (pcb->pcb_sp == 0)
 162     return 0;
 163
 164   read_memory (pcb->pcb_sp, (gdb_byte *)&sf, sizeof sf);
 165   regcache->raw_supply (tdep->ppc_cr_regnum, &sf.cr);
 166   regcache->raw_supply (tdep->ppc_gp0_regnum + 2, &sf.fixreg2);
 167   for (i = 0 ; i < 19 ; i++)
 168     regcache->raw_supply (tdep->ppc_gp0_regnum + 13 + i, &sf.fixreg[i]);
 169
 170   read_memory(sf.sp, (gdb_byte *)&cf, sizeof(cf));
 171   regcache->raw_supply (tdep->ppc_gp0_regnum + 30, &cf.r30);
 172   regcache->raw_supply (tdep->ppc_gp0_regnum + 31, &cf.r31);
 173   regcache->raw_supply (tdep->ppc_gp0_regnum + 1, &cf.sp);
 174
 175   read_memory(cf.sp, (gdb_byte *)&cf, sizeof(cf));
 176   regcache->raw_supply (tdep->ppc_lr_regnum, &cf.lr);
 177   regcache->raw_supply (gdbarch_pc_regnum (gdbarch), &cf.lr);
 178
 179   return 1;
 180 }
 181
 182 void _initialize_ppcnbsd_nat ();
 183 void
 184 _initialize_ppcnbsd_nat ()
 185 {
 186   /* Support debugging kernel virtual memory images.  */
 187   bsd_kvm_add_target (ppcnbsd_supply_pcb);
 188
 189   add_inf_child_target (&the_ppc_nbsd_nat_target);
 190 }