Contributed by frozen on Sunday February 16, 2003 12:49AM
from the software-review dept.
What is a boot loader?
A boot loader is, at first glance, a menu that displays a list of
operating systems. Before a computer boots, the boot loader allows a
selection to be made from all available operating systems on the
computer. This allows the user to have their computer installed with,
for example, both Windows and Linux. The user can quickly choose
between the two when the computer is turned on.
Choosing the right boot loader depends on the operating system that
will be installed on the computer. This review covers six popular boot
loaders, and the features and downfalls of each.
What is a boot loader (in more depth)?
A boot loader is the first piece of software used when a computer is
booting. When the power switch is turned on the computer’s BIOS runs a
series of checks it loads from firmware. When finished, the BIOS
attempts to start an operating system from the hard drive. When a boot
loader is installed it starts instead of an operating system. An
increasing number operating systems install a boot loader by default,
even if they are the only operating system on the computer.
Loading...
In order for the BIOS to load an OS it looks for instructions on the
first sector of a hard drive. On the first sector of the hard drive
resides the master boot record (MBR), and is where a boot loader is
initialized. Depending on the boot loader, additional files may be
stored and read from a partition on the hard drive. After this step the
boot loader begins to start the operating system, and is not used again
until the next boot. If the computer has only one operating system, the
boot loader may not ask for user input. Because of this, many people do
not realize they have a boot loader installed.
Moving Beyond One Operating System
This setup using the default boot loader of the installed OS works well
and never need to be configured or interacted with, until a second OS
is to be added to the computer. Once the requirement of loading more
than one operating system exists, many boot loaders, including the one
shipped with Windows 98, no longer work. This is where a third party
boot loader must be chosen. This page will help with that decision by
comparing six popular boot loaders: LILO, GRUB, XOSL, System Commander,
Boot Magic, and NTLDR.
Comparison of the Boot Loaders
|
LILO |
GRUB |
XOSL |
System Commander 7 (V Communications) |
Boot Magic 8 (PowerQuest) |
NTLDR (Microsoft) |
Disk Support >1024 cylinders |
yes (after version 21.3) |
yes |
yes |
yes |
yes |
yes |
Dedicated Partition Required? |
no |
no |
no |
no |
no |
no |
Install through this OS |
Linux |
Linux |
DOS |
DOS, Windows 9x/NT/2000/XP |
Windows 9x/NT/2000/XP |
DOS, Windows 9x/NT/2000/XP |
OSes able to be booted |
DOS, Windows 9x/NT/2000/XP, Linux, BSD |
DOS, Windows 9x/NT/2000/XP, Linux, BSD, BEOS, SCO Unix, OS/2, Solaris |
DOS, Windows 9x/NT/2000/XP, Linux, BSD, BEOS, Solaris, VxWorks |
ALL |
DOS, Windows 9x/NT/2000/XP, Linux, BEOS |
DOS, Windows 9x/NT/2000/XP, (Linux using bootpart) |
Boot Linux Kernel? |
yes |
yes |
no |
no |
no |
no |
Contained in MBR? |
no |
no |
no |
no |
no |
no |
Filesystem Requirement (not contained in MBR) |
- |
EXT2 |
FAT |
FAT/FAT32/NTFS |
FAT/FAT32 |
FAT/FAT32/NTFS |
Number of images supported |
16 |
|
24 |
|
|
|
Resolutions Supported |
text |
text |
up to1600x1200 |
up to 1600x1200 |
640x480 |
text |
Background images |
no |
yes |
yes |
yes |
yes |
no |
PS/2 Mouse Support |
no |
no |
yes |
yes |
yes |
no |
Licence |
GPL (free) |
GPL (free) |
GPL (free) |
59.95/69.95 |
69.95 (comes with Partition Magic) |
Incuded with Windows NT/2000/XP |
Website |
Lilo Homepage |
Grub Homepage |
XOSL Homepage |
System Commander 7 |
Partition Magic |
NTLDR Hacking Guide |
LILO
LILO is short for LInux LOader. It is open source and has been
around for a long time. Its strengths include strong support from the
community, being able to load a wide variety of operating systems,
being able to load the Linux kernel, and being free. LILO must be
installed and configured from an environment that can run the LILO
executable (normally Linux and BSD). Once installed, a config file
exists on the hard drive that, when edited, will change the OSes that
can be booted. After editing this file, the LILO command will need to
be run to update the changes in the MBR. This is not required in GRUB.
One nice feature of LILO is the ability to copy itself to a floppy,
allowing normal bootup of the host PC if the normal MBR is accidentally
overwritten. The LILO menu on bootup is text-only, and can be in the
form of a menu or prompt. If nothing is displayed at the prompt, hit to display a list of booting options.
GRUB
GRUB, short for GRand Unified Bootloader, is another open source boot
loader. GRUB has been slowly taking over LILO’s place as the default
boot loader shipped with many Linux distributions. This is because of
several features GRUB has that LILO does not. The first being that GRUB
can be configured from within itself. If configured wrong, the user is
not stuck with a unbootable computer, as the configuration can be
changed from within GRUB. GRUB, while being a text menu, also supports
background images, giving it the ability to impress your friends. GRUB
also supports virtually any operating system that will run on x86
architecture. The only downfall to GRUB is that it requires files on
the hard drive, usually on a Linux (ext2) partition.
XOSL
XOSL is short for Extended Operating System Loader, and again is open
source under the GPL license. XOSL is different from LILO and GRUB
because it is a graphical boot loader, supporting resolutions up to
1600x1200. Like GRUB it supports configuration from within itself, but
has several serious drawbacks. XOSL requires installtion in a primary
FAT partition, NTFS is not supported. XOSL also cannot boot the Linux
kernel, making LILO or GRUB a required install along with it.
System Commander 7
System Commander 7 from V Communications is a great boot loader for all
different operating systems, as long as one of them is Windows or Dos.
System Commander supports installation in Fat, Fat32, and has the rare
support of installation in a NTFS partition. Like XOSL it is graphical,
supporting resolutions up to 1600x1200. System Commander is also the
only boot loader to claim support every operating system created for
x86 architecture. It is configured within itself, and supports
automatic searching for installed operating systems. The only downfall
to System Commander is its price is hard to justify next to the free
boot loaders, 59.95 for the download or 69.95 for a shipped product.
Boot Magic
Boot Magic is a boot loader that comes only with the purchase of
Partition Magic software. It differs from the other boot loaders
because it must be installed in a FAT or FAT32 partition from within
Windows. Boot Magic is also configured from within Windows, a feature
making easier initial setup, but a more difficult recovery if a problem
occurs. It’s limited support requiring Windows and a FAT partition make
boot magic a choice only for limited configurations.
NTLDR
NTLDR comes with versions of Windows based on the NT kernel, including
2000 and XP. Hidden by default and not well documented, NTLDR appears
to be designed only to switch between Windows 9x and NT. It has been
discovered that it is possible to boot older versions of DOS and even
Linux by editing the boot.ini file on the Windows partition. This is a
great option for users wanting the change the least amount of options
when installing a second operating system on their computer.
Written by Nicholas Brand
Copyright ©2003 by Nicholas Brand. All Rights Reserved
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