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 local mirror of the debug registers of 114 process PID. */ 115 116 extern struct i386_debug_reg_state *i386_debug_reg_state (pid_t pid); 117 118 /* Called whenever GDB is no longer debugging process PID. It deletes 119 data structures that keep track of debug register state. */ 120 121 extern void i386_forget_process (pid_t pid); 122 123 #endif /* I386_NAT_H */ 124