gdb/ppcnbsd-nat.c

   1 /* Native-dependent code for PowerPC's running NetBSD, for GDB.
   2    Copyright 2002, 2004 Free Software Foundation, Inc.
   3    Contributed by Wasabi Systems, 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 2 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, write to the Free Software
  19    Foundation, Inc., 59 Temple Place - Suite 330,
  20    Boston, MA 02111-1307, USA.  */
  21
  22 #include <sys/types.h>
  23 #include <sys/ptrace.h>
  24 #include <machine/reg.h>
  25 #include <machine/frame.h>
  26 #include <machine/pcb.h>
  27
  28 #include "defs.h"
  29 #include "inferior.h"
  30 #include "gdb_assert.h"
  31 #include "gdbcore.h"
  32 #include "regcache.h"
  33 #include "bsd-kvm.h"
  34
  35 #include "ppc-tdep.h"
  36 #include "ppcnbsd-tdep.h"
  37
  38 #include "inf-ptrace.h"
  39
  40 /* Returns true if PT_GETREGS fetches this register.  */
  41 static int
  42 getregs_supplies (int regno)
  43 {
  44   struct gdbarch_tdep *tdep = gdbarch_tdep (current_gdbarch);
  45
  46   return ((regno >= tdep->ppc_gp0_regnum
  47            && regno < tdep->ppc_gp0_regnum + ppc_num_gprs)
  48           || regno == tdep->ppc_lr_regnum
  49           || regno == tdep->ppc_cr_regnum
  50           || regno == tdep->ppc_xer_regnum
  51           || regno == tdep->ppc_ctr_regnum
  52           || regno == PC_REGNUM);
  53 }
  54
  55 /* Like above, but for PT_GETFPREGS.  */
  56 static int
  57 getfpregs_supplies (int regno)
  58 {
  59   struct gdbarch_tdep *tdep = gdbarch_tdep (current_gdbarch);
  60
  61   /* FIXME: jimb/2004-05-05: Some PPC variants don't have floating
  62      point registers.  Traditionally, GDB's register set has still
  63      listed the floating point registers for such machines, so this
  64      code is harmless.  However, the new E500 port actually omits the
  65      floating point registers entirely from the register set --- they
  66      don't even have register numbers assigned to them.
  67
  68      It's not clear to me how best to update this code, so this assert
  69      will alert the first person to encounter the NetBSD/E500
  70      combination to the problem.  */
  71   gdb_assert (ppc_floating_point_unit_p (current_gdbarch));
  72
  73   return ((regno >= tdep->ppc_fp0_regnum
  74            && regno < tdep->ppc_fp0_regnum + ppc_num_fprs)
  75           || regno == tdep->ppc_fpscr_regnum);
  76 }
  77
  78 static void
  79 ppcnbsd_fetch_inferior_registers (int regno)
  80 {
  81   if (regno == -1 || getregs_supplies (regno))
  82     {
  83       struct reg regs;
  84
  85       if (ptrace (PT_GETREGS, PIDGET (inferior_ptid),
  86                   (PTRACE_TYPE_ARG3) &regs, 0) == -1)
  87         perror_with_name (_("Couldn't get registers"));
  88
  89       ppcnbsd_supply_reg ((char *) &regs, regno);
  90       if (regno != -1)
  91         return;
  92     }
  93
  94   if (regno == -1 || getfpregs_supplies (regno))
  95     {
  96       struct fpreg fpregs;
  97
  98       if (ptrace (PT_GETFPREGS, PIDGET (inferior_ptid),
  99                   (PTRACE_TYPE_ARG3) &fpregs, 0) == -1)
 100         perror_with_name (_("Couldn't get FP registers"));
 101
 102       ppcnbsd_supply_fpreg ((char *) &fpregs, regno);
 103       if (regno != -1)
 104         return;
 105     }
 106 }
 107
 108 static void
 109 ppcnbsd_store_inferior_registers (int regno)
 110 {
 111   if (regno == -1 || getregs_supplies (regno))
 112     {
 113       struct reg regs;
 114
 115       if (ptrace (PT_GETREGS, PIDGET (inferior_ptid),
 116                   (PTRACE_TYPE_ARG3) &regs, 0) == -1)
 117         perror_with_name (_("Couldn't get registers"));
 118
 119       ppcnbsd_fill_reg ((char *) &regs, regno);
 120
 121       if (ptrace (PT_SETREGS, PIDGET (inferior_ptid),
 122                   (PTRACE_TYPE_ARG3) &regs, 0) == -1)
 123         perror_with_name (_("Couldn't write registers"));
 124
 125       if (regno != -1)
 126         return;
 127     }
 128
 129   if (regno == -1 || getfpregs_supplies (regno))
 130     {
 131       struct fpreg fpregs;
 132
 133       if (ptrace (PT_GETFPREGS, PIDGET (inferior_ptid),
 134                   (PTRACE_TYPE_ARG3) &fpregs, 0) == -1)
 135         perror_with_name (_("Couldn't get FP registers"));
 136
 137       ppcnbsd_fill_fpreg ((char *) &fpregs, regno);
 138
 139       if (ptrace (PT_SETFPREGS, PIDGET (inferior_ptid),
 140                   (PTRACE_TYPE_ARG3) &fpregs, 0) == -1)
 141         perror_with_name (_("Couldn't set FP registers"));
 142     }
 143 }
 144
 145 static int
 146 ppcnbsd_supply_pcb (struct regcache *regcache, struct pcb *pcb)
 147 {
 148   struct switchframe sf;
 149   struct callframe cf;
 150   struct gdbarch_tdep *tdep = gdbarch_tdep (current_gdbarch);
 151   int i;
 152
 153   /* The stack pointer shouldn't be zero.  */
 154   if (pcb->pcb_sp == 0)
 155     return 0;
 156
 157   read_memory (pcb->pcb_sp, (char *) &sf, sizeof sf);
 158   regcache_raw_supply (regcache, tdep->ppc_cr_regnum, &sf.cr);
 159   regcache_raw_supply (regcache, tdep->ppc_gp0_regnum + 2, &sf.fixreg2);
 160   for (i = 0 ; i < 19 ; i++)
 161     regcache_raw_supply (regcache, tdep->ppc_gp0_regnum + 13 + i,
 162                          &sf.fixreg[i]);
 163
 164   read_memory(sf.sp, (char *)&cf, sizeof(cf));
 165   regcache_raw_supply (regcache, tdep->ppc_gp0_regnum + 30, &cf.r30);
 166   regcache_raw_supply (regcache, tdep->ppc_gp0_regnum + 31, &cf.r31);
 167   regcache_raw_supply (regcache, tdep->ppc_gp0_regnum + 1, &cf.sp);
 168
 169   read_memory(cf.sp, (char *)&cf, sizeof(cf));
 170   regcache_raw_supply (regcache, tdep->ppc_lr_regnum, &cf.lr);
 171   regcache_raw_supply (regcache, PC_REGNUM, &cf.lr);
 172
 173   return 1;
 174 }
 175
 176 /* Provide a prototype to silence -Wmissing-prototypes.  */
 177 void _initialize_ppcnbsd_nat (void);
 178
 179 void
 180 _initialize_ppcnbsd_nat (void)
 181 {
 182   struct target_ops *t;
 183   /* Support debugging kernel virtual memory images.  */
 184   bsd_kvm_add_target (ppcnbsd_supply_pcb);
 185   /* Add in local overrides.  */
 186   t = inf_ptrace_target ();
 187   t->to_fetch_registers = ppcnbsd_fetch_inferior_registers;
 188   t->to_store_registers = ppcnbsd_store_inferior_registers;
 189   add_target (t);
 190 }