.\" $OpenBSD: mbr.8,v 1.7 2017/07/06 17:24:49 schwarze Exp $ .\" .\" Copyright (c) 2006 Michael Shalayeff .\" All rights reserved. .\" .\" Permission to use, copy, modify, and distribute this software for any .\" purpose with or without fee is hereby granted, provided that the above .\" copyright notice and this permission notice appear in all copies. .\" .\" THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES .\" WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF .\" MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR .\" ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES .\" WHATSOEVER RESULTING FROM LOSS OF MIND, USE, DATA OR PROFITS, WHETHER IN .\" AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT .\" OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. .\" .Dd $Mdocdate: July 6 2017 $ .Dt MBR 8 landisk .Os .Sh NAME .Nm mbr .Nd LANDISK-specific Master Boot Record .Sh SYNOPSIS .Nm .Sh DESCRIPTION The .Nm MBR program comprises only one sector (512 bytes) and includes a partition table, since the disk is located in the 0th sector of the disk. Upon receiving control from the system firmware .Nm will scan the partition table for an active partition and continue loading the Primary Boot Record (PBR) from the beginning of the partition, if found. .Pp .Nm is installed on the disk by .Xr fdisk 8 , which is also used to operate the partition table. .Pp The partition table consists of four entries, only one of which may be marked as .Dq active . The PBR is loaded from there. .Sh DIAGNOSTICS A few messages are printed in case of errors: .Bl -tag -width "no_active_partitionXX" .It "No active partition" Indicates that none of the partitions are marked .Dq active . .It Read error An error occurred while fetching the primary boot loader. .It "No O/S" The partition table is empty. .El .Sh SEE ALSO .Xr boot 8 , .Xr disklabel 8 , .Xr fdisk 8 , .Xr xxboot 8