gdb/vax-nat.c

   1 /* Native-dependent code for VAX UNIXen (including older BSD's).
   2
   3    Copyright (C) 2004, 2005 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 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., 51 Franklin Street, Fifth Floor,
  20    Boston, MA 02110-1301, USA.  */
  21
  22 #include "defs.h"
  23 #include "inferior.h"
  24
  25 #include "gdb_assert.h"
  26 #include <sys/types.h>
  27 #include <sys/dir.h>
  28 #include <sys/user.h>
  29
  30 #ifdef HAVE_SYS_PTRACE_H
  31 #include <sys/ptrace.h>
  32 #endif
  33
  34 #ifndef PT_READ_U
  35 #define PT_READ_U 3
  36 #endif
  37
  38 #ifdef SYS_REG_H
  39 /* UNIX 32V and derivatives (including 3BSD).  */
  40 #include <sys/reg.h>
  41 #else
  42 /* 4.2BSD and derivatives.  */
  43 #include <machine/reg.h>
  44 #endif
  45
  46 #include "vax-tdep.h"
  47 #include "inf-ptrace.h"
  48
  49 /* Address of the user structure.  This is the the value for 32V; 3BSD
  50    uses a different value, but hey, who's still using those systems?  */
  51 CORE_ADDR vax_kernel_u_addr = 0x80020000;
  52
  53 /* Location of the user's stored registers; usage is `u.u_ar0[XX]'.
  54    For 4.2BSD and ULTRIX these are negative!  See <machine/reg.h>.  */
  55 static int vax_register_index[] =
  56 {
  57   R0, R1, R2, R3, R4, R5,
  58   R6, R7, R8, R9, R10, R11,
  59   AP, FP, SP, PC, PS
  60 };
  61
  62 CORE_ADDR
  63 vax_register_u_addr (CORE_ADDR u_ar0, int regnum)
  64 {
  65   gdb_assert (regnum >= 0 && regnum < ARRAY_SIZE (vax_register_index));
  66
  67   /* Type is `int *u_ar0'.  See <sys/user.h>.  */
  68   return u_ar0 + vax_register_index[regnum - VAX_R0_REGNUM] * 4;
  69 }
  70
  71 static CORE_ADDR
  72 vax_register_u_offset (int regnum)
  73 {
  74   size_t u_ar0_offset = offsetof (struct user, u_ar0);
  75   CORE_ADDR u_ar0;
  76   int pid;
  77
  78   errno = 0;
  79   pid = PIDGET (inferior_ptid);
  80   u_ar0 = ptrace (PT_READ_U, pid, u_ar0_offset, 0);
  81   if (errno)
  82     perror_with_name (_("Unable to determine location of registers"));
  83
  84   return vax_register_u_addr (u_ar0, regnum) - vax_kernel_u_addr;
  85 }
  86 \f
  87
  88 #include <nlist.h>
  89
  90 #ifndef _PATH_UNIX
  91 #define _PATH_UNIX "/vmunix"
  92 #endif
  93
  94 /* Provide a prototype to silence -Wmissing-prototypes.  */
  95 void _initialize_vax_nat (void);
  96
  97 void
  98 _initialize_vax_nat (void)
  99 {
 100   struct nlist names[2];
 101
 102   names[0].n_name = "_u";
 103   names[1].n_name = NULL;
 104   if (nlist (_PATH_UNIX, names) == 0)
 105     vax_kernel_u_addr = names[0].n_value;
 106
 107   add_target (inf_ptrace_trad_target (vax_register_u_offset));
 108 }