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 * $FreeBSD: head/sys/amd64/amd64/bios.c 148231 2005-07-21 09:48:37Z phk $ 28 */ 29 30 /* 31 * Subset of the i386 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. 34 */ 35 36 #include <sys/param.h> 37 #include <sys/systm.h> 38 #include <sys/kernel.h> 39 #include <vm/vm.h> 40 #include <vm/pmap.h> 41 #include <machine/vmparam.h> 42 #include <machine/pc/bios.h> 43 44 #define BIOS_START 0xe0000 45 #define BIOS_SIZE 0x20000 46 47 /* 48 * bios_sigsearch 49 * 50 * Search some or all of the BIOS region for a signature string. 51 * 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. 61 * 62 * Returns the _physical_ address of the found signature, 0 if the 63 * signature was not found. 64 */ 65 66 u_int32_t 67 bios_sigsearch(u_int32_t start, u_char *sig, int siglen, int paralen, int sigofs) 68 { 69 u_char *sp, *end; 70 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); 76 } else { 77 return 0; /* bogus start address */ 78 } 79 80 /* compute the end address */ 81 end = (u_char *)BIOS_PADDRTOVADDR(BIOS_START + BIOS_SIZE); 82 83 /* loop searching */ 84 while ((sp + sigofs + siglen) < end) { 85 86 /* compare here */ 87 if (!bcmp(sp + sigofs, sig, siglen)) { 88 /* convert back to physical address */ 89 return((u_int32_t)(uintptr_t)BIOS_VADDRTOPADDR(sp)); 90 } 91 sp += paralen; 92 } 93 return(0); 94 } 95