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 #include <sys/errno.h> 29 #include <stdint.h> 30 #include <stdlib.h> 31 #include <string.h> 32 33 #include <mbr.h> 34 35 #include "endian.h" 36 #include "image.h" 37 #include "mkimg.h" 38 #include "scheme.h" 39 40 static struct mkimg_alias mbr_aliases[] = { 41 { ALIAS_EBR, ALIAS_INT2TYPE(DOSPTYP_EXT) }, 42 { ALIAS_EFI, ALIAS_INT2TYPE(DOSPTYP_EFI) }, 43 { ALIAS_FAT16B, ALIAS_INT2TYPE(DOSPTYP_FAT16) }, 44 { ALIAS_FAT32, ALIAS_INT2TYPE(DOSPTYP_FAT32) }, 45 { ALIAS_FAT32LBA, ALIAS_INT2TYPE(DOSPTYP_FAT32LBA) }, 46 { ALIAS_FREEBSD, ALIAS_INT2TYPE(DOSPTYP_386BSD) }, 47 { ALIAS_NTFS, ALIAS_INT2TYPE(DOSPTYP_NTFS) }, 48 { ALIAS_PPCBOOT, ALIAS_INT2TYPE(DOSPTYP_PPCBOOT) }, 49 { ALIAS_NONE, 0 } /* Keep last! */ 50 }; 51 52 static lba_t 53 mbr_metadata(u_int where, lba_t blk) 54 { 55 56 blk += (where == SCHEME_META_IMG_START) ? 1 : 0; 57 return (round_track(blk)); 58 } 59 60 static void 61 mbr_chs(u_char *cylp, u_char *hdp, u_char *secp, lba_t lba) 62 { 63 u_int cyl, hd, sec; 64 65 mkimg_chs(lba, 1023, &cyl, &hd, &sec); 66 *cylp = cyl; 67 *hdp = hd; 68 *secp = (sec & 0x3f) | ((cyl >> 2) & 0xc0); 69 } 70 71 static int 72 mbr_write(lba_t imgsz __unused, void *bootcode) 73 { 74 u_char *mbr; 75 struct dos_partition *dpbase, *dp; 76 struct part *part; 77 lba_t size; 78 int error; 79 80 mbr = malloc(secsz); 81 if (mbr == NULL) 82 return (ENOMEM); 83 if (bootcode != NULL) { 84 memcpy(mbr, bootcode, DOSPARTOFF); 85 memset(mbr + DOSPARTOFF, 0, secsz - DOSPARTOFF); 86 } else 87 memset(mbr, 0, secsz); 88 le16enc(mbr + DOSMAGICOFFSET, DOSMAGIC); 89 dpbase = (void *)(mbr + DOSPARTOFF); 90 TAILQ_FOREACH(part, &partlist, link) { 91 size = round_track(part->size); 92 dp = dpbase + part->index; 93 if (active_partition != 0) 94 dp->dp_flag = 95 (part->index + 1 == active_partition) ? 0x80 : 0; 96 else 97 dp->dp_flag = 98 (part->index == 0 && bootcode != NULL) ? 0x80 : 0; 99 mbr_chs(&dp->dp_scyl, &dp->dp_shd, &dp->dp_ssect, 100 part->block); 101 dp->dp_typ = ALIAS_TYPE2INT(part->type); 102 mbr_chs(&dp->dp_ecyl, &dp->dp_ehd, &dp->dp_esect, 103 part->block + size - 1); 104 le32enc(&dp->dp_start, part->block); 105 le32enc(&dp->dp_size, size); 106 } 107 error = image_write(0, mbr, 1); 108 free(mbr); 109 return (error); 110 } 111 112 static struct mkimg_scheme mbr_scheme = { 113 .name = "mbr", 114 .description = "Master Boot Record", 115 .aliases = mbr_aliases, 116 .metadata = mbr_metadata, 117 .write = mbr_write, 118 .bootcode = 512, 119 .nparts = NDOSPART, 120 .maxsecsz = 4096 121 }; 122 123 SCHEME_DEFINE(mbr_scheme); 124