1/*-
2 * Copyright (c) 1997 Michael Smith
3 * Copyright (c) 1998 Jonathan Lemon
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 *    notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 *    notice, this list of conditions and the following disclaimer in the
13 *    documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25 * SUCH DAMAGE.
26 */
27
28#include <sys/cdefs.h>
29__FBSDID("$FreeBSD$");
30
31/*
32 * Subset of the i386 bios support code.  We cannot make bios16 nor bios32
33 * calls, so we can leave that out.  However, searching for bios rom
34 * signatures can be useful for locating tables, eg: powernow settings.
35 */
36
37#include <sys/param.h>
38#include <sys/systm.h>
39#include <sys/kernel.h>
40#include <vm/vm.h>
41#include <vm/pmap.h>
42#include <machine/vmparam.h>
43#include <machine/pc/bios.h>
44
45#define BIOS_START	0xe0000
46#define BIOS_SIZE	0x20000
47
48/*
49 * bios_sigsearch
50 *
51 * Search some or all of the BIOS region for a signature string.
52 *
53 * (start)	Optional offset returned from this function
54 *		(for searching for multiple matches), or NULL
55 *		to start the search from the base of the BIOS.
56 *		Note that this will be a _physical_ address in
57 *		the range 0xe0000 - 0xfffff.
58 * (sig)	is a pointer to the byte(s) of the signature.
59 * (siglen)	number of bytes in the signature.
60 * (paralen)	signature paragraph (alignment) size.
61 * (sigofs)	offset of the signature within the paragraph.
62 *
63 * Returns the _physical_ address of the found signature, 0 if the
64 * signature was not found.
65 */
66
67u_int32_t
68bios_sigsearch(u_int32_t start, u_char *sig, int siglen, int paralen, int sigofs)
69{
70    u_char	*sp, *end;
71
72    /* compute the starting address */
73    if ((start >= BIOS_START) && (start <= (BIOS_START + BIOS_SIZE))) {
74	sp = (char *)BIOS_PADDRTOVADDR(start);
75    } else if (start == 0) {
76	sp = (char *)BIOS_PADDRTOVADDR(BIOS_START);
77    } else {
78	return 0;				/* bogus start address */
79    }
80
81    /* compute the end address */
82    end = (u_char *)BIOS_PADDRTOVADDR(BIOS_START + BIOS_SIZE);
83
84    /* loop searching */
85    while ((sp + sigofs + siglen) < end) {
86
87	/* compare here */
88	if (!bcmp(sp + sigofs, sig, siglen)) {
89	    /* convert back to physical address */
90	    return((u_int32_t)(uintptr_t)BIOS_VADDRTOPADDR(sp));
91	}
92	sp += paralen;
93    }
94    return(0);
95}
96