gdb/amd64-nat.c

   1 /* Native-dependent code for AMD64.
   2
   3    Copyright (C) 2003, 2004, 2007 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 "gdbarch.h"
  24 #include "regcache.h"
  25
  26 #include "gdb_assert.h"
  27 #include "gdb_string.h"
  28
  29 #include "i386-tdep.h"
  30 #include "amd64-tdep.h"
  31
  32 /* The following bits of code help with implementing debugging 32-bit
  33    code natively on AMD64.  The idea is to define two mappings between
  34    the register number as used by GDB and the register set used by the
  35    host to represent the general-purpose registers; one for 32-bit
  36    code and one for 64-bit code.  The mappings are specified by the
  37    follwing variables and consist of an array of offsets within the
  38    register set indexed by register number, and the number of
  39    registers supported by the mapping.  We don't need mappings for the
  40    floating-point and SSE registers, since the difference between
  41    64-bit and 32-bit variants are negligable.  The difference in the
  42    number of SSE registers is already handled by the target code.  */
  43
  44 /* General-purpose register mapping for native 32-bit code.  */
  45 int *amd64_native_gregset32_reg_offset;
  46 int amd64_native_gregset32_num_regs = I386_NUM_GREGS;
  47
  48 /* General-purpose register mapping for native 64-bit code.  */
  49 int *amd64_native_gregset64_reg_offset;
  50 int amd64_native_gregset64_num_regs = AMD64_NUM_GREGS;
  51
  52 /* Return the offset of REGNUM within the appropriate native
  53    general-purpose register set.  */
  54
  55 static int
  56 amd64_native_gregset_reg_offset (int regnum)
  57 {
  58   int *reg_offset = amd64_native_gregset64_reg_offset;
  59   int num_regs = amd64_native_gregset64_num_regs;
  60
  61   gdb_assert (regnum >= 0);
  62
  63   if (gdbarch_ptr_bit (current_gdbarch) == 32)
  64     {
  65       reg_offset = amd64_native_gregset32_reg_offset;
  66       num_regs = amd64_native_gregset32_num_regs;
  67     }
  68
  69   if (num_regs > gdbarch_num_regs (current_gdbarch))
  70     num_regs = gdbarch_num_regs (current_gdbarch);
  71
  72   if (regnum < num_regs && regnum < gdbarch_num_regs (current_gdbarch))
  73     return reg_offset[regnum];
  74
  75   return -1;
  76 }
  77
  78 /* Return whether the native general-purpose register set supplies
  79    register REGNUM.  */
  80
  81 int
  82 amd64_native_gregset_supplies_p (int regnum)
  83 {
  84   return (amd64_native_gregset_reg_offset (regnum) != -1);
  85 }
  86
  87
  88 /* Supply register REGNUM, whose contents are stored in GREGS, to
  89    REGCACHE.  If REGNUM is -1, supply all appropriate registers.  */
  90
  91 void
  92 amd64_supply_native_gregset (struct regcache *regcache,
  93                              const void *gregs, int regnum)
  94 {
  95   const char *regs = gregs;
  96   struct gdbarch *gdbarch = get_regcache_arch (regcache);
  97   int num_regs = amd64_native_gregset64_num_regs;
  98   int i;
  99
 100   if (gdbarch_ptr_bit (gdbarch) == 32)
 101     num_regs = amd64_native_gregset32_num_regs;
 102
 103   if (num_regs > gdbarch_num_regs (current_gdbarch))
 104     num_regs = gdbarch_num_regs (current_gdbarch);
 105
 106   for (i = 0; i < num_regs; i++)
 107     {
 108       if (regnum == -1 || regnum == i)
 109         {
 110           int offset = amd64_native_gregset_reg_offset (i);
 111
 112           if (offset != -1)
 113             regcache_raw_supply (regcache, i, regs + offset);
 114         }
 115     }
 116 }
 117
 118 /* Collect register REGNUM from REGCACHE and store its contents in
 119    GREGS.  If REGNUM is -1, collect and store all appropriate
 120    registers.  */
 121
 122 void
 123 amd64_collect_native_gregset (const struct regcache *regcache,
 124                               void *gregs, int regnum)
 125 {
 126   char *regs = gregs;
 127   struct gdbarch *gdbarch = get_regcache_arch (regcache);
 128   int num_regs = amd64_native_gregset64_num_regs;
 129   int i;
 130
 131   if (gdbarch_ptr_bit (gdbarch) == 32)
 132     {
 133       num_regs = amd64_native_gregset32_num_regs;
 134
 135       /* Make sure %eax, %ebx, %ecx, %edx, %esi, %edi, %ebp, %esp and
 136          %eip get zero-extended to 64 bits.  */
 137       for (i = 0; i <= I386_EIP_REGNUM; i++)
 138         {
 139           if (regnum == -1 || regnum == i)
 140             memset (regs + amd64_native_gregset_reg_offset (i), 0, 8);
 141         }
 142       /* Ditto for %cs, %ss, %ds, %es, %fs, and %gs.  */
 143       for (i = I386_CS_REGNUM; i <= I386_GS_REGNUM; i++)
 144         {
 145           if (regnum == -1 || regnum == i)
 146             memset (regs + amd64_native_gregset_reg_offset (i), 0, 8);
 147         }
 148     }
 149
 150   if (num_regs > gdbarch_num_regs (current_gdbarch))
 151     num_regs = gdbarch_num_regs (current_gdbarch);
 152
 153   for (i = 0; i < num_regs; i++)
 154     {
 155       if (regnum == -1 || regnum == i)
 156         {
 157           int offset = amd64_native_gregset_reg_offset (i);
 158
 159           if (offset != -1)
 160             regcache_raw_collect (regcache, i, regs + offset);
 161         }
 162     }
 163 }