Header with duplicated information from kernel.

diff --git a/sysdeps/unix/sysv/linux/i386/sys/debugreg.h b/sysdeps/unix/sysv/linux/i386/sys/debugreg.h
new file mode 100644 (file)
index 0000000..8aafd67
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/i386/sys/debugreg.h
@@ -0,0 +1,81 @@
+/* Copyright (C) 1998 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Library General Public License as
+   published by the Free Software Foundation; either version 2 of the
+   License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Library General Public License for more details.
+
+   You should have received a copy of the GNU Library General Public
+   License along with the GNU C Library; see the file COPYING.LIB.  If not,
+   write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+   Boston, MA 02111-1307, USA.  */
+
+#ifndef _SYS_DEBUGREG_H
+#define _SYS_DEBUGREG_H        1
+
+/* Indicate the register numbers for a number of the specific
+   debug registers.  Registers 0-3 contain the addresses we wish to trap on */
+#define DR_FIRSTADDR 0        /* u_debugreg[DR_FIRSTADDR] */
+#define DR_LASTADDR 3         /* u_debugreg[DR_LASTADDR]  */
+
+#define DR_STATUS 6           /* u_debugreg[DR_STATUS]     */
+#define DR_CONTROL 7          /* u_debugreg[DR_CONTROL] */
+
+/* Define a few things for the status register.  We can use this to determine
+   which debugging register was responsible for the trap.  The other bits
+   are either reserved or not of interest to us. */
+
+#define DR_TRAP0       (0x1)           /* db0 */
+#define DR_TRAP1       (0x2)           /* db1 */
+#define DR_TRAP2       (0x4)           /* db2 */
+#define DR_TRAP3       (0x8)           /* db3 */
+
+#define DR_STEP                (0x4000)        /* single-step */
+#define DR_SWITCH      (0x8000)        /* task switch */
+
+/* Now define a bunch of things for manipulating the control register.
+   The top two bytes of the control register consist of 4 fields of 4
+   bits - each field corresponds to one of the four debug registers,
+   and indicates what types of access we trap on, and how large the data
+   field is that we are looking at */
+
+#define DR_CONTROL_SHIFT 16   /* Skip this many bits in ctl register */
+#define DR_CONTROL_SIZE  4    /* 4 control bits per register */
+
+#define DR_RW_EXECUTE  (0x0) /* Settings for the access types to trap on */
+#define DR_RW_WRITE    (0x1)
+#define DR_RW_READ     (0x3)
+
+#define DR_LEN_1 (0x0)       /* Settings for data length to trap on */
+#define DR_LEN_2 (0x4)
+#define DR_LEN_4 (0xC)
+
+/* The low byte to the control register determine which registers are
+   enabled.  There are 4 fields of two bits.  One bit is "local", meaning
+   that the processor will reset the bit after a task switch and the other
+   is global meaning that we have to explicitly reset the bit.  With linux,
+   you can use either one, since we explicitly zero the register when we enter
+   kernel mode. */
+
+#define DR_LOCAL_ENABLE_SHIFT  0   /* Extra shift to the local enable bit */
+#define DR_GLOBAL_ENABLE_SHIFT 1   /* Extra shift to the global enable bit */
+#define DR_ENABLE_SIZE        2   /* 2 enable bits per register */
+
+#define DR_LOCAL_ENABLE_MASK  (0x55) /* Set  local bits for all 4 regs */
+#define DR_GLOBAL_ENABLE_MASK (0xAA) /* Set global bits for all 4 regs */
+
+/* The second byte to the control register has a few special things.
+   We can slow the instruction pipeline for instructions coming via the
+   gdt or the ldt if we want to.  I am not sure why this is an advantage */
+
+#define DR_CONTROL_RESERVED (0xFC00) /* Reserved by Intel */
+#define DR_LOCAL_SLOWDOWN   (0x100)  /* Local slow the pipeline */
+#define DR_GLOBAL_SLOWDOWN  (0x200)  /* Global slow the pipeline */
+
+#endif /* sys/debugreg.h */