f-stack/freebsd/amd64/amd64/bios.c

96 lines
3.2 KiB
C

/*-
* Copyright (c) 1997 Michael Smith
* Copyright (c) 1998 Jonathan Lemon
* 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 THE AUTHOR AND CONTRIBUTORS ``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 THE AUTHOR OR CONTRIBUTORS 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("$FreeBSD$");
/*
* Subset of the i386 bios support code. We cannot make bios16 nor bios32
* calls, so we can leave that out. However, searching for bios rom
* signatures can be useful for locating tables, eg: powernow settings.
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <vm/vm.h>
#include <vm/pmap.h>
#include <machine/vmparam.h>
#include <machine/pc/bios.h>
#define BIOS_START 0xe0000
#define BIOS_SIZE 0x20000
/*
* bios_sigsearch
*
* Search some or all of the BIOS region for a signature string.
*
* (start) Optional offset returned from this function
* (for searching for multiple matches), or NULL
* to start the search from the base of the BIOS.
* Note that this will be a _physical_ address in
* the range 0xe0000 - 0xfffff.
* (sig) is a pointer to the byte(s) of the signature.
* (siglen) number of bytes in the signature.
* (paralen) signature paragraph (alignment) size.
* (sigofs) offset of the signature within the paragraph.
*
* Returns the _physical_ address of the found signature, 0 if the
* signature was not found.
*/
u_int32_t
bios_sigsearch(u_int32_t start, u_char *sig, int siglen, int paralen, int sigofs)
{
u_char *sp, *end;
/* compute the starting address */
if ((start >= BIOS_START) && (start <= (BIOS_START + BIOS_SIZE))) {
sp = (char *)BIOS_PADDRTOVADDR(start);
} else if (start == 0) {
sp = (char *)BIOS_PADDRTOVADDR(BIOS_START);
} else {
return 0; /* bogus start address */
}
/* compute the end address */
end = (u_char *)BIOS_PADDRTOVADDR(BIOS_START + BIOS_SIZE);
/* loop searching */
while ((sp + sigofs + siglen) < end) {
/* compare here */
if (!bcmp(sp + sigofs, sig, siglen)) {
/* convert back to physical address */
return((u_int32_t)(uintptr_t)BIOS_VADDRTOPADDR(sp));
}
sp += paralen;
}
return(0);
}