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/*
* 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.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <machine/reg.h>
#include <machine/sysarch.h>
int
i386_set_watch(int watchnum, unsigned int watchaddr, int size,
int access, struct dbreg * d)
{
int i;
unsigned int mask;
if (watchnum == -1) {
for (i = 0, mask = 0x3; i < 4; i++, mask <<= 2)
if ((DBREG_DRX(d,7) & mask) == 0)
break;
if (i < 4)
watchnum = i;
else
return -1;
}
switch (access) {
case DBREG_DR7_EXEC:
size = 1; /* size must be 1 for an execution breakpoint */
/* fall through */
case DBREG_DR7_WRONLY:
case DBREG_DR7_RDWR:
break;
default : return -1; break;
}
/*
* we can watch a 1, 2, or 4 byte sized location
*/
switch (size) {
case 1 : mask = 0x00; break;
case 2 : mask = 0x01 << 2; break;
case 4 : mask = 0x03 << 2; break;
default : return -1; break;
}
mask |= access;
/* clear the bits we are about to affect */
DBREG_DRX(d,7) &= ~((0x3 << (watchnum*2)) | (0x0f << (watchnum*4+16)));
/* set drN register to the address, N=watchnum */
DBREG_DRX(d,watchnum) = watchaddr;
/* enable the watchpoint */
DBREG_DRX(d,7) |= (0x2 << (watchnum*2)) | (mask << (watchnum*4+16));
return watchnum;
}
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