gnu/dist/gdb6/gdb/amd64nbsd-nat.c

   1 /* Native-dependent code for NetBSD/amd64.
   2
   3    Copyright (C) 2003, 2004 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 "target.h"
  24
  25 #include "gdb_assert.h"
  26
  27 #include "nbsd-nat.h"
  28 #include "amd64-tdep.h"
  29 #include "amd64-nat.h"
  30
  31 #include <machine/frame.h>
  32 #include <machine/pcb.h>
  33
  34 /* Mapping between the general-purpose registers in NetBSD/amd64
  35    `struct reg' format and GDB's register cache layout for
  36    NetBSD/i386.
  37
  38    Note that most (if not all) NetBSD/amd64 registers are 64-bit,
  39    while the NetBSD/i386 registers are all 32-bit, but since we're
  40    little-endian we get away with that.  */
  41
  42 /* From <machine/reg.h>.  */
  43 static int amd64nbsd32_r_reg_offset[] =
  44 {
  45   14 * 8,                       /* %eax */
  46   3 * 8,                        /* %ecx */
  47   2 * 8,                        /* %edx */
  48   13 * 8,                       /* %ebx */
  49   24 * 8,                       /* %esp */
  50   12 * 8,                       /* %ebp */
  51   1 * 8,                        /* %esi */
  52   0 * 8,                        /* %edi */
  53   21 * 8,                       /* %eip */
  54   23 * 8,                       /* %eflags */
  55   22 * 8,                       /* %cs */
  56   25 * 8,                       /* %ss */
  57   18 * 8,                       /* %ds */
  58   17 * 8,                       /* %es */
  59   16 * 8,                       /* %fs */
  60   15 * 8                        /* %gs */
  61 };
  62 \f
  63
  64 static int
  65 amd64nbsd_supply_pcb (struct regcache *regcache, struct pcb *pcb)
  66 {
  67   struct switchframe sf;
  68   int regnum;
  69
  70   /* The following is true for NetBSD/amd64:
  71
  72      The pcb contains the stack pointer at the point of the context
  73      switch in cpu_switchto().  At that point we have a stack frame as
  74      described by `struct switchframe', which for NetBSD/amd64 has the
  75      following layout:
  76
  77      interrupt level
  78      %r15
  79      %r14
  80      %r13
  81      %r12
  82      %rbx
  83      return address
  84
  85      Together with %rsp in the pcb, this accounts for all callee-saved
  86      registers specified by the psABI.  From this information we
  87      reconstruct the register state as it would look when we just
  88      returned from cpu_switchto().
  89
  90      For kernel core dumps, dumpsys() builds a fake switchframe for us. */
  91
  92   /* The stack pointer shouldn't be zero.  */
  93   if (pcb->pcb_rsp == 0)
  94     return 0;
  95
  96   /* Read the stack frame, and check its validity.  */
  97   read_memory (pcb->pcb_rsp, (gdb_byte *) &sf, sizeof sf);
  98   pcb->pcb_rsp += sizeof (struct switchframe);
  99   regcache_raw_supply (regcache, 12, &sf.sf_r12);
 100   regcache_raw_supply (regcache, 13, &sf.sf_r13);
 101   regcache_raw_supply (regcache, 14, &sf.sf_r14);
 102   regcache_raw_supply (regcache, 15, &sf.sf_r15);
 103   regcache_raw_supply (regcache, AMD64_RBX_REGNUM, &sf.sf_rbx);
 104   regcache_raw_supply (regcache, AMD64_RIP_REGNUM, &sf.sf_rip);
 105
 106   regcache_raw_supply (regcache, AMD64_RSP_REGNUM, &pcb->pcb_rsp);
 107   regcache_raw_supply (regcache, AMD64_RBP_REGNUM, &pcb->pcb_rbp);
 108   regcache_raw_supply (regcache, AMD64_FS_REGNUM, &pcb->pcb_fs);
 109   regcache_raw_supply (regcache, AMD64_GS_REGNUM, &pcb->pcb_gs);
 110
 111   return 1;
 112 }
 113 /* Provide a prototype to silence -Wmissing-prototypes.  */
 114 void _initialize_amd64nbsd_nat (void);
 115
 116 void
 117 _initialize_amd64nbsd_nat (void)
 118 {
 119   struct target_ops *t;
 120
 121   amd64_native_gregset32_reg_offset = amd64nbsd32_r_reg_offset;
 122   amd64_native_gregset32_num_regs = ARRAY_SIZE (amd64nbsd32_r_reg_offset);
 123   amd64_native_gregset64_reg_offset = amd64nbsd_r_reg_offset;
 124
 125   /* Add some extra features to the common *BSD/amd64 target.  */
 126   t = amd64bsd_target ();
 127   t->to_pid_to_exec_file = nbsd_pid_to_exec_file;
 128   add_target (t);
 129
 130   /* Support debugging kernel virtual memory images.  */
 131   bsd_kvm_add_target (amd64nbsd_supply_pcb);
 132
 133 }