2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
4 * Copyright 2000 Brian S. Dean <bsd@bsdhome.com>
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
17 * THIS SOFTWARE IS PROVIDED BY BRIAN S. DEAN ``AS IS'' AND ANY
18 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
20 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL BRIAN S. DEAN BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
22 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
23 * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
24 * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
25 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
26 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE
27 * USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
31 #include <sys/cdefs.h>
32 __FBSDID("$FreeBSD$");
34 #include <machine/reg.h>
35 #include <machine/sysarch.h>
38 i386_set_watch(int watchnum, unsigned int watchaddr, int size,
39 int access, struct dbreg * d)
45 for (i = 0, mask = 0x3; i < 4; i++, mask <<= 2)
46 if ((DBREG_DRX(d,7) & mask) == 0)
56 size = 1; /* size must be 1 for an execution breakpoint */
58 case DBREG_DR7_WRONLY:
61 default : return -1; break;
65 * we can watch a 1, 2, or 4 byte sized location
68 case 1 : mask = 0x00; break;
69 case 2 : mask = 0x01 << 2; break;
70 case 4 : mask = 0x03 << 2; break;
71 default : return -1; break;
76 /* clear the bits we are about to affect */
77 DBREG_DRX(d,7) &= ~((0x3 << (watchnum*2)) | (0x0f << (watchnum*4+16)));
79 /* set drN register to the address, N=watchnum */
80 DBREG_DRX(d,watchnum) = watchaddr;
82 /* enable the watchpoint */
83 DBREG_DRX(d,7) |= (0x2 << (watchnum*2)) | (mask << (watchnum*4+16));