2 * Copyright (c) 1997 Michael Smith
3 * Copyright (c) 1998 Jonathan Lemon
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
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.
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
27 * $FreeBSD: head/sys/amd64/amd64/bios.c 148231 2005-07-21 09:48:37Z phk $
31 * Subset of the x86 bios support code. We cannot make bios16 nor bios32
32 * calls, so we can leave that out. However, searching for bios rom
33 * signatures can be useful for locating tables, eg: powernow settings.
36 #include <sys/param.h>
37 #include <sys/systm.h>
38 #include <sys/kernel.h>
41 #include <machine/vmparam.h>
42 #include <machine/pc/bios.h>
44 #define BIOS_START 0xe0000
45 #define BIOS_SIZE 0x20000
50 * Search some or all of the BIOS region for a signature string.
52 * (start) Optional offset returned from this function
53 * (for searching for multiple matches), or NULL
54 * to start the search from the base of the BIOS.
55 * Note that this will be a _physical_ address in
56 * the range 0xe0000 - 0xfffff.
57 * (sig) is a pointer to the byte(s) of the signature.
58 * (siglen) number of bytes in the signature.
59 * (paralen) signature paragraph (alignment) size.
60 * (sigofs) offset of the signature within the paragraph.
62 * Returns the _physical_ address of the found signature, 0 if the
63 * signature was not found.
67 bios_sigsearch(u_int32_t start
, u_char
*sig
, int siglen
, int paralen
, int sigofs
)
71 /* compute the starting address */
72 if ((start
>= BIOS_START
) && (start
<= (BIOS_START
+ BIOS_SIZE
))) {
73 sp
= (char *)BIOS_PADDRTOVADDR(start
);
74 } else if (start
== 0) {
75 sp
= (char *)BIOS_PADDRTOVADDR(BIOS_START
);
77 return 0; /* bogus start address */
80 /* compute the end address */
81 end
= (u_char
*)BIOS_PADDRTOVADDR(BIOS_START
+ BIOS_SIZE
);
84 while ((sp
+ sigofs
+ siglen
) < end
) {
87 if (!bcmp(sp
+ sigofs
, sig
, siglen
)) {
88 /* convert back to physical address */
89 return((u_int32_t
)(uintptr_t)BIOS_VADDRTOPADDR(sp
));