introduction

If you use Linux on a production system, you will only see it a few times a year. If you are a hobbyist who compiles many kernels or who uses many operating systems, you may see it several times per day. Of course I mean the boot loader.

There are several different ways to boot Linux and every method has specific advantages and drawbacks. Therefore it is important to know which boot loading methods exist for Linux and how they compare to each other.

We discuss only boot loaders that meet the following criteria:

• They must support Linux. The boot loader must load the Linux kernel itself, boot loaders that could chain load another loader, which in turn boots Linux, are not discussed,
• They must run on the Intel PC platform.
• They must be freely available complete with source code.
• No network boot loaders are discussed.

We discuss the following boot loaders:

• Boot Sector of the Linux kernel.
• LILO
• GNU GRUB
• SYSLINUX
• LOADLIN

Other less well-known boot loaders do exist and may support the criteria. I know of the following:

• nuni is a boot loader that does not use BIOS, but is otherwise rather limited. It boots only from IDE disks.
• Gujin is a boot loader that understands file systems, just like GRUB.
• mbr03 and e2boot are an MBR boot selector and a matching Linux boot loader that fits into the first 1k boot block of an ext2 partition, so no file space is used by them.

Note: some boot loaders are rapidly evolving, so some features may have been added after this article was written.