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- A replacement master boot record
- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
- Contents
- ~~~~~~~~
- 1. Copyright
- 2. Introduction
- 3. Basic Installation
- 4. The boot process
- 5. Configuration
- 6. Acknowledgements
-
- 1. Copyright
- ~~~~~~~~~~~~
-
- Copyright (C) 1995, 1999 Neil Turton
-
- This program is free software; you can redistribute it and/or modify
- it under the terms of the GNU General Public License as published by
- the Free Software Foundation; either version 2 of the License, or
- (at your option) any later version.
-
- This program is distributed in the hope that it will be useful,
- but WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- GNU General Public License for more details.
-
- You should have received a copy of the GNU General Public License
- along with this program; if not, write to the Free Software
- Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
-
- See file COPYING for details
-
- 2. Introduction
- ~~~~~~~~~~~~~~~
-
- When a PC is reset, it goes through a series of self tests, and then
- attempts to load an operating system. The loading process requires a
- number of steps. When booting from a hard disk, these are to read and
- execute the first sector of the first hard disk, called the master
- boot record, which in turn, reads and executes the first sector of one
- of the partitions on that disk, called a boot sector. The program
- code on this sector then loads the operating system. The standard MBR
- (master boot record) which comes with MSDOS is fairly simple, and
- limited in a number of ways. The MSDOS MBR is also non-free which
- means that it cannot form part of a completely free system. This MBR
- is more complicated, and aims to overcome these limitations.
-
- 3. Basic Installation
- ~~~~~~~~~~~~~~~~~~~~~
-
- See the file 'INSTALL' for generic building instructions. By default
- this package installs the program install-mbr in /usr/local/sbin.
- This program is used to install the MBR and contains a copy of the
- MBR within itself.
-
- Before you begin, make sure you have an alternative way of booting
- your computer (ie. boot floppy). When all fails and your computer
- sits there asking you to insert a system disk, you'll be stuck if you
- don't have one.
-
- Installation is done using the program called install-mbr. If this
- program is not on your path, you will have to invoke it as
- <dir>/install-mbr (./install-mbr if it is in the current directory).
- It is recomended that you test the master boot record with your system
- before you install it on the first sector of your hard disk. You may
- wish to skip this step if you took my earlier advice and made a boot
- floppy. To do this, put a blank floppy disk in your first disk drive,
- and type the command:
- install-mbr /dev/fd0 -T /dev/hda
-
- If your primary disk is a SCSI disk, you will have to replace hda in
- the command above with sda. This command tells install-mbr to install
- it's built-in copy of the master boot record on the first floppy drive
- (/dev/fd0), taking the partition table from the first IDE hard disk
- (/dev/hda). Booting from the floppy disk should load your operating
- system as usual.
-
- Once the master boot record has been tested, you can install it on
- your hard disk using the following command:
- install-mbr /dev/hda
-
- 4. The boot process
- ~~~~~~~~~~~~~~~~~~~
-
- When the MBR is first loaded it waits for a configurable length of
- time (1 second by default), monitoring the keyboard, for key presses.
- If the MBR detects a key press, it will interrupt the boot process,
- and display it's prompt. Otherwise, it will load the first sector of
- the default partition, and execute it. If a disk error occours, the
- MBR will display it's prompt.
-
- 4.1 The boot prompt
- ~~~~~~~~~~~~~~~~~~~
-
- The boot prompt looks something like this:
-
- 14FA:
-
- This is the list of valid keys which may be pressed. This means that
- partitions 1, and 4 can be booted, also the first floppy drive
- (F). The 'A' means that 'advanced' mode may be entered, in which any
- partition may be booted. The prompt for this mode looks like this:
-
- 1234F:
-
- The only other valid key which may be pressed is RETURN, which
- continues booting with the default partition.
-
- 5. Acknowledgements
- ~~~~~~~~~~~~~~~~~~~
- Many thanks to all who have contributed to this package. Please read
- the AUTHORS file.
-