biossmap.c revision 153535
1/*- 2 * Copyright (c) 1998 Michael Smith <msmith@freebsd.org> 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 */ 26 27#include <sys/cdefs.h> 28__FBSDID("$FreeBSD: head/sys/boot/i386/libi386/biossmap.c 153535 2005-12-19 09:00:11Z sobomax $"); 29 30/* 31 * Obtain memory configuration information from the BIOS 32 */ 33#include <stand.h> 34#include <sys/param.h> 35#include <sys/linker.h> 36#include <machine/metadata.h> 37#include "bootstrap.h" 38#include "libi386.h" 39#include "btxv86.h" 40 41#define SMAPSIG 0x534D4150 42 43struct smap { 44 u_int64_t base; 45 u_int64_t length; 46 u_int32_t type; 47} __packed; 48 49static struct smap smap; 50 51static struct smap *smapbase; 52static int smaplen; 53 54void 55bios_getsmap(void) 56{ 57 int n; 58 59 n = 0; 60 smaplen = 0; 61 /* Count up segments in system memory map */ 62 v86.ebx = 0; 63 do { 64 v86.ctl = V86_FLAGS; 65 v86.addr = 0x15; /* int 0x15 function 0xe820*/ 66 v86.eax = 0xe820; 67 v86.ecx = sizeof(struct smap); 68 v86.edx = SMAPSIG; 69 v86.es = VTOPSEG(&smap); 70 v86.edi = VTOPOFF(&smap); 71 v86int(); 72 if ((v86.efl & 1) || (v86.eax != SMAPSIG)) 73 break; 74 n++; 75 } while (v86.ebx != 0); 76 if (n == 0) 77 return; 78 n += 10; /* spare room */ 79 smapbase = malloc(n * sizeof(*smapbase)); 80 81 /* Save system memory map */ 82 v86.ebx = 0; 83 do { 84 v86.ctl = V86_FLAGS; 85 v86.addr = 0x15; /* int 0x15 function 0xe820*/ 86 v86.eax = 0xe820; 87 v86.ecx = sizeof(struct smap); 88 v86.edx = SMAPSIG; 89 v86.es = VTOPSEG(&smap); 90 v86.edi = VTOPOFF(&smap); 91 v86int(); 92 bcopy(&smap, &smapbase[smaplen], sizeof(struct smap)); 93 smaplen++; 94 if ((v86.efl & 1) || (v86.eax != SMAPSIG)) 95 break; 96 } while (v86.ebx != 0 && smaplen < n); 97} 98void 99bios_addsmapdata(struct preloaded_file *kfp) 100{ 101 int len; 102 103 if (smapbase == 0 || smaplen == 0) 104 return; 105 len = smaplen * sizeof(*smapbase); 106 file_addmetadata(kfp, MODINFOMD_SMAP, len, smapbase); 107} 108