1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause 3 * 4 * Copyright (c) 1997 Michael Smith 5 * Copyright (c) 1998 Jonathan Lemon 6 * All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 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. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 */ 29 30 #include <sys/cdefs.h> 31 __FBSDID("$FreeBSD$"); 32 33 /* 34 * Subset of the i386 bios support code. We cannot make bios16 nor bios32 35 * calls, so we can leave that out. However, searching for bios rom 36 * signatures can be useful for locating tables, eg: powernow settings. 37 */ 38 39 #include <sys/param.h> 40 #include <sys/systm.h> 41 #include <sys/kernel.h> 42 #include <vm/vm.h> 43 #include <vm/pmap.h> 44 #include <machine/vmparam.h> 45 #include <machine/pc/bios.h> 46 47 #define BIOS_START 0xe0000 48 #define BIOS_SIZE 0x20000 49 50 /* 51 * bios_sigsearch 52 * 53 * Search some or all of the BIOS region for a signature string. 54 * 55 * (start) Optional offset returned from this function 56 * (for searching for multiple matches), or NULL 57 * to start the search from the base of the BIOS. 58 * Note that this will be a _physical_ address in 59 * the range 0xe0000 - 0xfffff. 60 * (sig) is a pointer to the byte(s) of the signature. 61 * (siglen) number of bytes in the signature. 62 * (paralen) signature paragraph (alignment) size. 63 * (sigofs) offset of the signature within the paragraph. 64 * 65 * Returns the _physical_ address of the found signature, 0 if the 66 * signature was not found. 67 */ 68 69 u_int32_t 70 bios_sigsearch(u_int32_t start, u_char *sig, int siglen, int paralen, int sigofs) 71 { 72 u_char *sp, *end; 73 74 /* compute the starting address */ 75 if ((start >= BIOS_START) && (start <= (BIOS_START + BIOS_SIZE))) { 76 sp = (char *)BIOS_PADDRTOVADDR(start); 77 } else if (start == 0) { 78 sp = (char *)BIOS_PADDRTOVADDR(BIOS_START); 79 } else { 80 return 0; /* bogus start address */ 81 } 82 83 /* compute the end address */ 84 end = (u_char *)BIOS_PADDRTOVADDR(BIOS_START + BIOS_SIZE); 85 86 /* loop searching */ 87 while ((sp + sigofs + siglen) < end) { 88 /* compare here */ 89 if (!bcmp(sp + sigofs, sig, siglen)) { 90 /* convert back to physical address */ 91 return((u_int32_t)(uintptr_t)BIOS_VADDRTOPADDR(sp)); 92 } 93 sp += paralen; 94 } 95 return(0); 96 } 97