1 /*- 2 * Copyright (c) 2014 Juniper Networks, Inc. 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("$FreeBSD$"); 29 30 #include <sys/errno.h> 31 #include <stdint.h> 32 #include <stdlib.h> 33 #include <string.h> 34 35 #include <mbr.h> 36 37 #include "endian.h" 38 #include "image.h" 39 #include "mkimg.h" 40 #include "scheme.h" 41 42 static struct mkimg_alias mbr_aliases[] = { 43 { ALIAS_EBR, ALIAS_INT2TYPE(DOSPTYP_EXT) }, 44 { ALIAS_EFI, ALIAS_INT2TYPE(DOSPTYP_EFI) }, 45 { ALIAS_FAT16B, ALIAS_INT2TYPE(DOSPTYP_FAT16) }, 46 { ALIAS_FAT32, ALIAS_INT2TYPE(DOSPTYP_FAT32) }, 47 { ALIAS_FREEBSD, ALIAS_INT2TYPE(DOSPTYP_386BSD) }, 48 { ALIAS_NTFS, ALIAS_INT2TYPE(DOSPTYP_NTFS) }, 49 { ALIAS_PPCBOOT, ALIAS_INT2TYPE(DOSPTYP_PPCBOOT) }, 50 { ALIAS_NONE, 0 } /* Keep last! */ 51 }; 52 53 static lba_t 54 mbr_metadata(u_int where, lba_t blk) 55 { 56 57 blk += (where == SCHEME_META_IMG_START) ? 1 : 0; 58 return (round_track(blk)); 59 } 60 61 static void 62 mbr_chs(u_char *cylp, u_char *hdp, u_char *secp, lba_t lba) 63 { 64 u_int cyl, hd, sec; 65 66 mkimg_chs(lba, 1023, &cyl, &hd, &sec); 67 *cylp = cyl; 68 *hdp = hd; 69 *secp = (sec & 0x3f) | ((cyl >> 2) & 0xc0); 70 } 71 72 static int 73 mbr_write(lba_t imgsz __unused, void *bootcode) 74 { 75 u_char *mbr; 76 struct dos_partition *dpbase, *dp; 77 struct part *part; 78 lba_t size; 79 int error; 80 81 mbr = malloc(secsz); 82 if (mbr == NULL) 83 return (ENOMEM); 84 if (bootcode != NULL) { 85 memcpy(mbr, bootcode, DOSPARTOFF); 86 memset(mbr + DOSPARTOFF, 0, secsz - DOSPARTOFF); 87 } else 88 memset(mbr, 0, secsz); 89 le16enc(mbr + DOSMAGICOFFSET, DOSMAGIC); 90 dpbase = (void *)(mbr + DOSPARTOFF); 91 TAILQ_FOREACH(part, &partlist, link) { 92 size = round_track(part->size); 93 dp = dpbase + part->index; 94 if (active_partition != 0) 95 dp->dp_flag = 96 (part->index + 1 == active_partition) ? 0x80 : 0; 97 else 98 dp->dp_flag = 99 (part->index == 0 && bootcode != NULL) ? 0x80 : 0; 100 mbr_chs(&dp->dp_scyl, &dp->dp_shd, &dp->dp_ssect, 101 part->block); 102 dp->dp_typ = ALIAS_TYPE2INT(part->type); 103 mbr_chs(&dp->dp_ecyl, &dp->dp_ehd, &dp->dp_esect, 104 part->block + size - 1); 105 le32enc(&dp->dp_start, part->block); 106 le32enc(&dp->dp_size, size); 107 } 108 error = image_write(0, mbr, 1); 109 free(mbr); 110 return (error); 111 } 112 113 static struct mkimg_scheme mbr_scheme = { 114 .name = "mbr", 115 .description = "Master Boot Record", 116 .aliases = mbr_aliases, 117 .metadata = mbr_metadata, 118 .write = mbr_write, 119 .bootcode = 512, 120 .nparts = NDOSPART, 121 .maxsecsz = 4096 122 }; 123 124 SCHEME_DEFINE(mbr_scheme); 125