gdb/i386-nat.h

   1 /* Native-dependent code for the i386.
   2
   3    Low level functions to implement Oeprating System specific
   4    code to manipulate I386 debug registers.
   5
   6    Copyright (C) 2009-2013 Free Software Foundation, Inc.
   7
   8    This file is part of GDB.
   9
  10    This program is free software; you can redistribute it and/or modify
  11    it under the terms of the GNU General Public License as published by
  12    the Free Software Foundation; either version 3 of the License, or
  13    (at your option) any later version.
  14
  15    This program is distributed in the hope that it will be useful,
  16    but WITHOUT ANY WARRANTY; without even the implied warranty of
  17    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18    GNU General Public License for more details.
  19
  20    You should have received a copy of the GNU General Public License
  21    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  22
  23 #ifndef I386_NAT_H
  24 #define I386_NAT_H 1
  25
  26 /* Hardware-assisted breakpoints and watchpoints.  */
  27
  28 /* Add watchpoint methods to the provided target_ops.
  29    Targets using i386 family debug registers for watchpoints should call
  30    this.  */
  31 struct target_ops;
  32 extern void i386_use_watchpoints (struct target_ops *);
  33
  34 /* Support for hardware watchpoints and breakpoints using the i386
  35    debug registers.
  36
  37    This provides several functions for inserting and removing
  38    hardware-assisted breakpoints and watchpoints, testing if one or
  39    more of the watchpoints triggered and at what address, checking
  40    whether a given region can be watched, etc.
  41
  42    In addition, each target should provide several low-level functions
  43    regrouped into i386_dr_low_type struct below.  These functions
  44    that will be called to insert watchpoints and hardware breakpoints
  45    into the inferior, remove them, and check their status.  These
  46    functions are:
  47
  48       set_control              -- set the debug control (DR7)
  49                                   register to a given value for all LWPs
  50
  51       set_addr                 -- put an address into one debug
  52                                   register for all LWPs
  53
  54       get_addr                 -- return the address in a given debug
  55                                   register of the current LWP
  56
  57       get_status               -- return the value of the debug
  58                                   status (DR6) register for current LWP
  59
  60       get_control               -- return the value of the debug
  61                                   control (DR7) register for current LWP
  62
  63    Additionally, the native file should set the debug_register_length
  64    field to 4 or 8 depending on the number of bytes used for
  65    deubg registers.  */
  66
  67 struct i386_dr_low_type
  68   {
  69     void (*set_control) (unsigned long);
  70     void (*set_addr) (int, CORE_ADDR);
  71     CORE_ADDR (*get_addr) (int);
  72     unsigned long (*get_status) (void);
  73     unsigned long (*get_control) (void);
  74     int debug_register_length;
  75   };
  76
  77 extern struct i386_dr_low_type i386_dr_low;
  78
  79 /* Debug registers' indices.  */
  80 #define DR_FIRSTADDR 0
  81 #define DR_LASTADDR  3
  82 #define DR_NADDR     4  /* The number of debug address registers.  */
  83 #define DR_STATUS    6  /* Index of debug status register (DR6).  */
  84 #define DR_CONTROL   7  /* Index of debug control register (DR7).  */
  85
  86 /* Global state needed to track h/w watchpoints.  */
  87
  88 struct i386_debug_reg_state
  89 {
  90   /* Mirror the inferior's DRi registers.  We keep the status and
  91      control registers separated because they don't hold addresses.
  92      Note that since we can change these mirrors while threads are
  93      running, we never trust them to explain a cause of a trap.
  94      For that, we need to peek directly in the inferior registers.  */
  95   CORE_ADDR dr_mirror[DR_NADDR];
  96   unsigned dr_status_mirror, dr_control_mirror;
  97
  98   /* Reference counts for each debug register.  */
  99   int dr_ref_count[DR_NADDR];
 100 };
 101
 102 /* Use this function to set i386_dr_low debug_register_length field
 103    rather than setting it directly to check that the length is only
 104    set once.  It also enables the 'maint set/show show-debug-regs'
 105    command.  */
 106
 107 extern void i386_set_debug_register_length (int len);
 108
 109 /* Use this function to reset the i386-nat.c debug register state.  */
 110
 111 extern void i386_cleanup_dregs (void);
 112
 113 /* Return a pointer to the the local mirror of the inferior's debug
 114    registers.  */
 115
 116 extern struct i386_debug_reg_state *i386_debug_reg_state (void);
 117
 118 #endif /* I386_NAT_H */