1 /* $OpenBSD: smpprobe.c,v 1.6 2004/03/09 19:12:13 tom Exp $ */ 2 3 /* 4 * Copyright (c) 1997 Tobias Weingartner 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 18 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 27 * 28 */ 29 30 #include <sys/param.h> 31 #include <machine/biosvar.h> 32 #include "libsa.h" 33 34 extern int debug; 35 36 extern u_int cnvmem, extmem; 37 #define MP_FLOAT_SIG 0x5F504D5F /* _MP_ */ 38 #define MP_CONF_SIG 0x504D4350 /* PCMP */ 39 40 typedef struct _mp_float { 41 u_int32_t signature; 42 u_int32_t conf_addr; 43 u_int8_t length; 44 u_int8_t spec_rev; 45 u_int8_t checksum; 46 u_int8_t feature[5]; 47 } mp_float_t; 48 49 50 static __inline int 51 mp_checksum(u_int8_t *ptr, int len) 52 { 53 register int i, sum = 0; 54 55 #ifdef DEBUG 56 printf("Checksum %p for %d\n", ptr, len); 57 #endif 58 59 for (i = 0; i < len; i++) 60 sum += *(ptr + i); 61 62 return (!(sum & 0xff)); 63 } 64 65 66 static mp_float_t * 67 mp_probefloat(u_int8_t *ptr, int len) 68 { 69 mp_float_t *mpp = NULL; 70 int i; 71 72 #ifdef DEBUG 73 if (debug) 74 printf("Checking %p for %d\n", ptr, len); 75 #endif 76 for (i = 0; i < 1024; i++) { 77 mp_float_t *tmp = (mp_float_t*)(ptr + i); 78 79 if (tmp->signature == MP_FLOAT_SIG) { 80 printf("Found possible MP signature at: %p\n", ptr); 81 82 mpp = tmp; 83 break; 84 } 85 if ((tmp->signature == MP_FLOAT_SIG) && 86 mp_checksum((u_int8_t *)tmp, tmp->length*16)) { 87 #ifdef DEBUG 88 if (debug) 89 printf("Found valid MP signature at: %p\n", 90 ptr); 91 #endif 92 mpp = tmp; 93 break; 94 } 95 } 96 97 return mpp; 98 } 99 100 101 void 102 smpprobe(void) 103 { 104 mp_float_t *mp = NULL; 105 106 /* Check EBDA */ 107 if (!(mp = mp_probefloat((void *)((*((u_int32_t*)0x4e)) * 16), 1024)) && 108 /* Check BIOS ROM 0xE0000 - 0xFFFFF */ 109 !(mp = mp_probefloat((void *)(0xE0000), 0x1FFFF)) && 110 /* Check last 1K of base RAM */ 111 !(mp = mp_probefloat((void *)(cnvmem * 1024), 1024)) && 112 /* Check last 1K of extended RAM XXX */ 113 !(mp = mp_probefloat((void *)(extmem * 1024 - 1024), 1024))) { 114 /* No valid MP signature found */ 115 #if DEBUG 116 if (debug) 117 printf("No valid MP signature found.\n"); 118 #endif 119 return; 120 } 121 122 /* Valid MP signature found */ 123 printf(" smp"); 124 125 #if DEBUG 126 if (debug) 127 printf("Floating Structure:\n" 128 "\tSignature: %x\n" 129 "\tConfig at: %x\n" 130 "\tLength: %d\n" 131 "\tRev: 1.%d\n" 132 "\tFeature: %x %x %x %x %x\n", 133 mp->signature, mp->conf_addr, mp->length, mp->spec_rev, 134 mp->feature[0], mp->feature[1], mp->feature[2], 135 mp->feature[3], mp->feature[4]); 136 #endif 137 } 138