85 lines
2.5 KiB
C
85 lines
2.5 KiB
C
/*
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* Copyright 2000 Brian S. Dean <bsd@bsdhome.com>
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* All Rights Reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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*
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY BRIAN S. DEAN ``AS IS'' AND ANY
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* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
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* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL BRIAN S. DEAN BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
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* OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
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* BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
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* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE
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* USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
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* DAMAGE.
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*/
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#include <sys/cdefs.h>
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__FBSDID("$FreeBSD$");
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#include <machine/reg.h>
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#include <machine/sysarch.h>
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int
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i386_set_watch(int watchnum, unsigned int watchaddr, int size,
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int access, struct dbreg * d)
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{
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int i;
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unsigned int mask;
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if (watchnum == -1) {
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for (i = 0, mask = 0x3; i < 4; i++, mask <<= 2)
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if ((d->dr7 & mask) == 0)
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break;
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if (i < 4)
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watchnum = i;
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else
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return -1;
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}
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switch (access) {
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case DBREG_DR7_EXEC:
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size = 1; /* size must be 1 for an execution breakpoint */
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/* fall through */
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case DBREG_DR7_WRONLY:
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case DBREG_DR7_RDWR:
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break;
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default : return -1; break;
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}
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/*
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* we can watch a 1, 2, or 4 byte sized location
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*/
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switch (size) {
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case 1 : mask = 0x00; break;
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case 2 : mask = 0x01 << 2; break;
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case 4 : mask = 0x03 << 2; break;
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default : return -1; break;
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}
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mask |= access;
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/* clear the bits we are about to affect */
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d->dr7 &= ~((0x3 << (watchnum*2)) | (0x0f << (watchnum*4+16)));
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/* set drN register to the address, N=watchnum */
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DBREG_DRX(d,watchnum) = watchaddr;
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/* enable the watchpoint */
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d->dr7 |= (0x2 << (watchnum*2)) | (mask << (watchnum*4+16));
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return watchnum;
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}
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