freebsd-skq/lib/libc/i386/sys/i386_clr_watch.c
Brian S. Dean 9d90941a83 Add a couple of debug register helper functions to assist in setting
and clearing watchpoints.

Reviewed by:	jwd@FreeBSD.org, -hackers@
2000-09-21 17:07:27 +00:00

51 lines
1.6 KiB
C

/*
* Copyright 2000 Brian S. Dean <bsd@bsdhome.com>
* All Rights Reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY BRIAN S. DEAN ``AS IS'' AND ANY
* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL BRIAN S. DEAN BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
* OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
* BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE
* USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
* DAMAGE.
*
*/
/*
* $FreeBSD$
*/
#include <machine/reg.h>
#include <machine/sysarch.h>
int
i386_clr_watch(int watchnum, struct dbreg * d)
{
if (watchnum < 0 || watchnum >= 4)
return -1;
d->dr7 = d->dr7 & ~((0x3 << (watchnum*2)) | (0x0f << (watchnum*4+16)));
DBREG_DRX(d,watchnum) = 0;
return 0;
}