gdb/gdbserver/win32-i386-low.c

   1 /* Copyright (C) 2007 Free Software Foundation, Inc.
   2
   3    This file is part of GDB.
   4
   5    This program is free software; you can redistribute it and/or modify
   6    it under the terms of the GNU General Public License as published by
   7    the Free Software Foundation; either version 2 of the License, or
   8    (at your option) any later version.
   9
  10    This program is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13    GNU General Public License for more details.
  14
  15    You should have received a copy of the GNU General Public License
  16    along with this program; if not, write to the Free Software
  17    Foundation, Inc., 51 Franklin Street, Fifth Floor,
  18    Boston, MA 02110-1301, USA.  */
  19
  20 #include "server.h"
  21 #include "win32-low.h"
  22
  23 #define FCS_REGNUM 27
  24 #define FOP_REGNUM 31
  25
  26 #define FLAG_TRACE_BIT 0x100
  27
  28 static unsigned dr[8];
  29
  30 static int debug_registers_changed = 0;
  31 static int debug_registers_used = 0;
  32
  33 static void
  34 i386_initial_stuff (void)
  35 {
  36   memset (&dr, 0, sizeof (dr));
  37   debug_registers_changed = 0;
  38   debug_registers_used = 0;
  39 }
  40
  41 static void
  42 i386_get_thread_context (win32_thread_info *th, DEBUG_EVENT* current_event)
  43 {
  44   th->context.ContextFlags = \
  45     CONTEXT_FULL | \
  46     CONTEXT_FLOATING_POINT | \
  47     CONTEXT_EXTENDED_REGISTERS | \
  48     CONTEXT_DEBUG_REGISTERS;
  49
  50   GetThreadContext (th->h, &th->context);
  51
  52   debug_registers_changed = 0;
  53
  54   if (th->tid == current_event->dwThreadId)
  55     {
  56       /* Copy dr values from the current thread.  */
  57       dr[0] = th->context.Dr0;
  58       dr[1] = th->context.Dr1;
  59       dr[2] = th->context.Dr2;
  60       dr[3] = th->context.Dr3;
  61       dr[6] = th->context.Dr6;
  62       dr[7] = th->context.Dr7;
  63     }
  64 }
  65
  66 static void
  67 i386_set_thread_context (win32_thread_info *th, DEBUG_EVENT* current_event)
  68 {
  69   if (debug_registers_changed)
  70     {
  71       th->context.Dr0 = dr[0];
  72       th->context.Dr1 = dr[1];
  73       th->context.Dr2 = dr[2];
  74       th->context.Dr3 = dr[3];
  75       /* th->context.Dr6 = dr[6];
  76          FIXME: should we set dr6 also ?? */
  77       th->context.Dr7 = dr[7];
  78     }
  79
  80   SetThreadContext (th->h, &th->context);
  81 }
  82
  83 static void
  84 i386_thread_added (win32_thread_info *th)
  85 {
  86   /* Set the debug registers for the new thread if they are used.  */
  87   if (debug_registers_used)
  88     {
  89       th->context.ContextFlags = CONTEXT_DEBUG_REGISTERS;
  90       GetThreadContext (th->h, &th->context);
  91
  92       th->context.Dr0 = dr[0];
  93       th->context.Dr1 = dr[1];
  94       th->context.Dr2 = dr[2];
  95       th->context.Dr3 = dr[3];
  96       /* th->context.Dr6 = dr[6];
  97          FIXME: should we set dr6 also ?? */
  98       th->context.Dr7 = dr[7];
  99
 100       SetThreadContext (th->h, &th->context);
 101       th->context.ContextFlags = 0;
 102     }
 103 }
 104
 105 static void
 106 i386_single_step (win32_thread_info *th)
 107 {
 108   th->context.EFlags |= FLAG_TRACE_BIT;
 109 }
 110
 111 /* An array of offset mappings into a Win32 Context structure.
 112    This is a one-to-one mapping which is indexed by gdb's register
 113    numbers.  It retrieves an offset into the context structure where
 114    the 4 byte register is located.
 115    An offset value of -1 indicates that Win32 does not provide this
 116    register in it's CONTEXT structure.  In this case regptr will return
 117    a pointer into a dummy register.  */
 118 #define context_offset(x) ((int)&(((CONTEXT *)NULL)->x))
 119 static const int mappings[] = {
 120   context_offset (Eax),
 121   context_offset (Ecx),
 122   context_offset (Edx),
 123   context_offset (Ebx),
 124   context_offset (Esp),
 125   context_offset (Ebp),
 126   context_offset (Esi),
 127   context_offset (Edi),
 128   context_offset (Eip),
 129   context_offset (EFlags),
 130   context_offset (SegCs),
 131   context_offset (SegSs),
 132   context_offset (SegDs),
 133   context_offset (SegEs),
 134   context_offset (SegFs),
 135   context_offset (SegGs),
 136   context_offset (FloatSave.RegisterArea[0 * 10]),
 137   context_offset (FloatSave.RegisterArea[1 * 10]),
 138   context_offset (FloatSave.RegisterArea[2 * 10]),
 139   context_offset (FloatSave.RegisterArea[3 * 10]),
 140   context_offset (FloatSave.RegisterArea[4 * 10]),
 141   context_offset (FloatSave.RegisterArea[5 * 10]),
 142   context_offset (FloatSave.RegisterArea[6 * 10]),
 143   context_offset (FloatSave.RegisterArea[7 * 10]),
 144   context_offset (FloatSave.ControlWord),
 145   context_offset (FloatSave.StatusWord),
 146   context_offset (FloatSave.TagWord),
 147   context_offset (FloatSave.ErrorSelector),
 148   context_offset (FloatSave.ErrorOffset),
 149   context_offset (FloatSave.DataSelector),
 150   context_offset (FloatSave.DataOffset),
 151   context_offset (FloatSave.ErrorSelector),
 152   /* XMM0-7 */
 153   context_offset (ExtendedRegisters[10 * 16]),
 154   context_offset (ExtendedRegisters[11 * 16]),
 155   context_offset (ExtendedRegisters[12 * 16]),
 156   context_offset (ExtendedRegisters[13 * 16]),
 157   context_offset (ExtendedRegisters[14 * 16]),
 158   context_offset (ExtendedRegisters[15 * 16]),
 159   context_offset (ExtendedRegisters[16 * 16]),
 160   context_offset (ExtendedRegisters[17 * 16]),
 161   /* MXCSR */
 162   context_offset (ExtendedRegisters[24])
 163 };
 164 #undef context_offset
 165
 166 /* Fetch register from gdbserver regcache data.  */
 167 static void
 168 i386_fetch_inferior_register (win32_thread_info *th, int r)
 169 {
 170   char *context_offset = (char *) &th->context + mappings[r];
 171
 172   long l;
 173   if (r == FCS_REGNUM)
 174     {
 175       l = *((long *) context_offset) & 0xffff;
 176       supply_register (r, (char *) &l);
 177     }
 178   else if (r == FOP_REGNUM)
 179     {
 180       l = (*((long *) context_offset) >> 16) & ((1 << 11) - 1);
 181       supply_register (r, (char *) &l);
 182     }
 183   else
 184     supply_register (r, context_offset);
 185 }
 186
 187 /* Store a new register value into the thread context of TH.  */
 188 static void
 189 i386_store_inferior_register (win32_thread_info *th, int r)
 190 {
 191   char *context_offset = (char *) &th->context + mappings[r];
 192   collect_register (r, context_offset);
 193 }
 194
 195 struct win32_target_ops the_low_target = {
 196   sizeof (mappings) / sizeof (mappings[0]),
 197   i386_initial_stuff,
 198   i386_get_thread_context,
 199   i386_set_thread_context,
 200   i386_thread_added,
 201   i386_fetch_inferior_register,
 202   i386_store_inferior_register,
 203   i386_single_step,
 204   NULL, /* breakpoint */
 205   0, /* breakpoint_len */
 206   "i386" /* arch_string */
 207 };