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glibc  2.9
debugreg.h
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00001 /* Copyright (C) 2001, 2003 Free Software Foundation, Inc.
00002    This file is part of the GNU C Library.
00003 
00004    The GNU C Library is free software; you can redistribute it and/or
00005    modify it under the terms of the GNU Lesser General Public
00006    License as published by the Free Software Foundation; either
00007    version 2.1 of the License, or (at your option) any later version.
00008 
00009    The GNU C Library is distributed in the hope that it will be useful,
00010    but WITHOUT ANY WARRANTY; without even the implied warranty of
00011    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00012    Lesser General Public License for more details.
00013 
00014    You should have received a copy of the GNU Lesser General Public
00015    License along with the GNU C Library; if not, write to the Free
00016    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
00017    02111-1307 USA.  */
00018 
00019 #ifndef _SYS_DEBUGREG_H
00020 #define _SYS_DEBUGREG_H     1
00021 #include <bits/wordsize.h>
00022 
00023 /* Indicate the register numbers for a number of the specific
00024    debug registers.  Registers 0-3 contain the addresses we wish to trap on */
00025 #define DR_FIRSTADDR 0        /* u_debugreg[DR_FIRSTADDR] */
00026 #define DR_LASTADDR 3         /* u_debugreg[DR_LASTADDR]  */
00027 
00028 #define DR_STATUS 6           /* u_debugreg[DR_STATUS]     */
00029 #define DR_CONTROL 7          /* u_debugreg[DR_CONTROL] */
00030 
00031 /* Define a few things for the status register.  We can use this to determine
00032    which debugging register was responsible for the trap.  The other bits
00033    are either reserved or not of interest to us. */
00034 
00035 #define DR_TRAP0     (0x1)         /* db0 */
00036 #define DR_TRAP1     (0x2)         /* db1 */
00037 #define DR_TRAP2     (0x4)         /* db2 */
00038 #define DR_TRAP3     (0x8)         /* db3 */
00039 
00040 #define DR_STEP             (0x4000)      /* single-step */
00041 #define DR_SWITCH    (0x8000)      /* task switch */
00042 
00043 /* Now define a bunch of things for manipulating the control register.
00044    The top two bytes of the control register consist of 4 fields of 4
00045    bits - each field corresponds to one of the four debug registers,
00046    and indicates what types of access we trap on, and how large the data
00047    field is that we are looking at */
00048 
00049 #define DR_CONTROL_SHIFT 16   /* Skip this many bits in ctl register */
00050 #define DR_CONTROL_SIZE  4    /* 4 control bits per register */
00051 
00052 #define DR_RW_EXECUTE       (0x0) /* Settings for the access types to trap on */
00053 #define DR_RW_WRITE  (0x1)
00054 #define DR_RW_READ   (0x3)
00055 
00056 #define DR_LEN_1 (0x0)            /* Settings for data length to trap on */
00057 #define DR_LEN_2 (0x4)
00058 #define DR_LEN_4 (0xC)
00059 #define DR_LEN_8 (0x8)
00060 
00061 /* The low byte to the control register determine which registers are
00062    enabled.  There are 4 fields of two bits.  One bit is "local", meaning
00063    that the processor will reset the bit after a task switch and the other
00064    is global meaning that we have to explicitly reset the bit.  With linux,
00065    you can use either one, since we explicitly zero the register when we enter
00066    kernel mode. */
00067 
00068 #define DR_LOCAL_ENABLE_SHIFT  0   /* Extra shift to the local enable bit */
00069 #define DR_GLOBAL_ENABLE_SHIFT 1   /* Extra shift to the global enable bit */
00070 #define DR_ENABLE_SIZE             2   /* 2 enable bits per register */
00071 
00072 #define DR_LOCAL_ENABLE_MASK  (0x55) /* Set  local bits for all 4 regs */
00073 #define DR_GLOBAL_ENABLE_MASK (0xAA) /* Set global bits for all 4 regs */
00074 
00075 /* The second byte to the control register has a few special
00076    things.  */
00077 
00078 
00079 
00080 #if __WORDSIZE == 64
00081 # define DR_CONTROL_RESERVED (0xFFFFFFFF0000FC00UL) /* Reserved */
00082 #else
00083 # define DR_CONTROL_RESERVED (0x00FC00U) /* Reserved */
00084 #endif
00085 #define DR_LOCAL_SLOWDOWN   (0x100)  /* Local slow the pipeline */
00086 #define DR_GLOBAL_SLOWDOWN  (0x200)  /* Global slow the pipeline */
00087 
00088 #endif /* sys/debugreg.h */