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 * $FreeBSD: src/sys/boot/i386/libi386/biossmap.c,v 1.2 2003/08/25 23:28:31 obrien Exp $ 27 */ 28 29 /* 30 * Obtain memory configuration information from the BIOS 31 */ 32 #include <stand.h> 33 #include <sys/param.h> 34 #include <sys/linker.h> 35 #include <machine/metadata.h> 36 #include <machine/pc/bios.h> 37 #include <machine/psl.h> 38 #include "bootstrap.h" 39 #include "libi386.h" 40 #include "btxv86.h" 41 42 static struct bios_smap smap; 43 44 static struct bios_smap *smapbase; 45 static int smaplen; 46 47 void 48 bios_getsmap(void) 49 { 50 int n; 51 52 n = 0; 53 smaplen = 0; 54 /* Count up segments in system memory map */ 55 v86.ebx = 0; 56 do { 57 v86.ctl = V86_FLAGS; 58 v86.addr = 0x15; /* int 0x15 function 0xe820*/ 59 v86.eax = 0xe820; 60 v86.ecx = sizeof(struct bios_smap); 61 v86.edx = SMAP_SIG; 62 v86.es = VTOPSEG(&smap); 63 v86.edi = VTOPOFF(&smap); 64 v86int(); 65 if ((v86.efl & PSL_C) || (v86.eax != SMAP_SIG)) 66 break; 67 n++; 68 } while (v86.ebx != 0); 69 if (n == 0) 70 return; 71 n += 10; /* spare room */ 72 smapbase = malloc(n * sizeof(*smapbase)); 73 74 /* Save system memory map */ 75 v86.ebx = 0; 76 do { 77 v86.ctl = V86_FLAGS; 78 v86.addr = 0x15; /* int 0x15 function 0xe820*/ 79 v86.eax = 0xe820; 80 v86.ecx = sizeof(struct bios_smap); 81 v86.edx = SMAP_SIG; 82 v86.es = VTOPSEG(&smap); 83 v86.edi = VTOPOFF(&smap); 84 v86int(); 85 86 /* 87 * Our heap is now in high memory and must be removed from 88 * the smap so the kernel does not blow away passed-in 89 * arguments, smap, kenv, etc. 90 * 91 * This wastes a little memory. 92 */ 93 if (smap.type == SMAP_TYPE_MEMORY && 94 smap.base + smap.length > heapbase && 95 smap.base < memtop) { 96 if (smap.base <= heapbase) { 97 if (heapbase - smap.base) { 98 smapbase[smaplen] = smap; 99 smapbase[smaplen].length = 100 heapbase - smap.base; 101 ++smaplen; 102 } 103 } 104 if (smap.base + smap.length >= memtop) { 105 if (smap.base + smap.length - memtop) { 106 smapbase[smaplen] = smap; 107 smapbase[smaplen].base = memtop; 108 smapbase[smaplen].length = 109 smap.base + smap.length - 110 memtop; 111 ++smaplen; 112 } 113 } 114 } else { 115 smapbase[smaplen] = smap; 116 ++smaplen; 117 } 118 if ((v86.efl & PSL_C) || (v86.eax != SMAP_SIG)) 119 break; 120 } while (v86.ebx != 0 && smaplen < n); 121 } 122 void 123 bios_addsmapdata(struct preloaded_file *kfp) 124 { 125 int len; 126 127 if (smapbase == NULL || smaplen == 0) 128 return; 129 len = smaplen * sizeof(*smapbase); 130 file_addmetadata(kfp, MODINFOMD_SMAP, len, smapbase); 131 /* Temporary compatibility with older development kernels */ 132 file_addmetadata(kfp, 0x0009, len, smapbase); 133 } 134