LILO (LInux LOader) is a simple boot loader to load Linux and other operating systems.
LILO's installation is two-fold. One is the installation of the software itself on the system (but does not activate LILO), the second one is the installation (activation) of the LILO bootloader on the disk's MBR.
USE flags for sys-boot/lilo LInux LOader, the original Linux bootloader
The software installation will only deploy the software on the file system, but will not install LILO in the MBR.
emerge --ask sys-boot/lilo
Installing LILO on the MBR
In order to install LILO on the MBR or update LILO, invoke lilo. However, before doing that, the /etc/lilo.conf file must be set up, which is covered in the Configuration section below.
An example lilo.conf file is provided at /etc/lilo.conf.example. To start configuring LILO, copy over the example file.
cp /etc/lilo.conf.example /etc/lilo.conf
Update the /etc/lilo.conf file accordingly.
First configure LILO to be deployed on the system. The
boot parameter tells LILO where to install the LILO bootloader in. Usually, this is the block device that represents the first disk (the disk that the system will boot), such as /dev/sda. Be aware that the lilo.conf.example file still uses /dev/hda so make sure that references to /dev/hda are changed to /dev/sda.
Next, tell LILO what to boot as default (if the user does not select any other option at the boot menu). The name used here is the
label value of the operating system blocks defined later in the file.
LILO will show the available options for a short while before continuing to boot the default selected operating system. How long it waits is defined by the
timeout parameter and is measured in tenths of a second (so the value 10 is one second):
Configuring the Gentoo OS block
An example configuration block for Gentoo is shown below. It is given the "Gentoo" label to match the
default parameter declared earlier.
image=/boot/kernel-3.11.2-gentoo label=Gentoo read-only root=/dev/sda4
This will boot the Linux kernel /boot/kernel-3.11.2-gentoo with root file system /dev/sda4.
Adding kernel parameters
To add additional kernel parameters to the OS block, use the
append parameter. For instance, to boot the Linux kernel silently (so it does not show any kernel messages unless critical):
image=/boot/kernel-3.11.2-gentoo label=Gentoo read-only root=/dev/sda4 append="quiet"
systemd users for instance would want to set
init=/usr/lib/systemd/systemd so that the systemd init is used:
As can be seen, additional kernel parameters are just appended to the same
Multiple block definitions
It is a good idea to keep old definitions available in case the new kernel doesn't boot successfully. This is accomplished by creating another block:
image=/boot/kernel-3.9.2-gentoo root=/dev/sda4 label=OldGentoo read-only
Updating LILO in the MBR
As mentioned earlier, lilo has to be executed in order to install LILO in the MBR. This step has to be repeated every time /etc/lilo.conf is modified or when the Linux kernel(s) that the /etc/lilo.conf file points to are updated!
Running lilo too much doesn't hurt.
Dual boot Gentoo and FreeBSD
To dual boot Gentoo and FreeBSD, edit /etc/lilo.conf as follows:
large-memory lba32 boot=/dev/sda install=menu map=/boot/map prompt default=Gentoo image=/boot/vmlinuz-2.6.26 label="Gentoo" root=/dev/sda1 append="" read-only optional other=/dev/sda3 label="FreeBSD"
Make sure to adapt the example configuration file to match the setup used.
Be sure there's another bootloader installed and properly configured before uninstalling lilo! Failing to do so will most likely result in the system failing to bootstrap.
Uninstall lilo, simply:
emerge --ask --depclean --verbose sys-boot/lilo