Booting to the Linux Loader (ELILO.EFI)

On HP Integrity servers you can access the Linux loader (ELILO.EFI) by using the following procedure to boot ELILO.EFI and type any key to stop the boot process at the "ELILO boot" prompt.

From ELILO you can boot Linux, list devices and configuration entries, or exit ELILO by typing Esc (the escape key) then Enter.

The ELILO loader and configuration files are at the following locations on the EFI System Partition for the Linux boot device.

ELILO Loader Files for Red Hat Enterprise Linux. On a Red Hat Enterprise Linux boot device EFI System Partition, the full paths to the loader and configuration files are: \EFI\redhat\elilo.efi and \EFI\redhat\elilo.conf
ELILO Loader Files for SuSE Linux Enterprise Server. On a SuSE Linux Enterprise Server boot device EFI System Partition, the full paths to the loader and configuration files are: \efi\SuSE\elilo.efi and \efi\SuSE\elilo.conf




	NOTE: The Linux loader (`ELILO.EFI`) is available only on HP Integrity servers (Intel® Itanium®-based systems).

See “Using Linux Loader (ELILO) Commands” for details on issuing Linux loader commands. Also see “Linux Boot Option Management” for information about ELILO and elilo.conf.

Procedure 5-54 Linux Loader (ELILO.EFI) Booting and Access

Use this procedure to access the ELILO Linux loader.

Load the ELILO.EFI Linux loader.
Either select a Linux entry from the EFI Boot Manager menu (the boot options list for the nPartition), or invoke the ELILO.EFI Linux loader from the EFI Shell.
Type any key when the "ELILO boot" prompt is displayed to stop the boot process at ELILO.
After you type a key (for example, space) the ELILO loader remains at the "ELILO boot" prompt, rather than loading the default Linux kernel entry in the elilo.conf file.
Issue ELILO loader commands or enter the kernel path or label (from the elilo.conf file) that you wish to boot.
To exit the ELILO loader, type Esc then Enter at the "ELILO boot" prompt. To list labels in the current elilo.conf file, type Tab. For details see “Using Linux Loader (ELILO) Commands”.

Linux Boot Option Management

You can manage Linux boot options by interacting with the Linux loader interface (elilo.efi, the "ELILO boot" prompt) and by editing the Linux loader configuration file (elilo.conf).

The elilo.efi Linux loader boots a Linux kernel and can apply boot options that are specified in an elilo.conf file entry or are manually specified.
- You can select any of the Linux kernel boot configuration entries in the boot device's elilo.conf file. To select a boot entry, enter its label at the "ELILO boot" prompt along with any additional boot options to be passed to the kernel.
- You also can directly specify a kernel file to be loaded at the "ELILO boot" prompt along with any kernel boot options.
See “Using Linux Loader (ELILO) Commands” for details.
The elilo.conf Linux loader configuration file defines the kernel boot configurations that are available to be selected from a Linux boot device.
Each boot configuration has a multiple-line entry in the elilo.conf file that included the label used to identify the entry, the kernel image to be booted, and other details such as kernel boot options.
This file also can specify the default boot entry to be loaded from the boot device and the amount of time given before automatically loading the default.
See “Linux Loader Configuration File (elilo.conf)” for details.

Refer to the following Linux manpages for more details, but note that specific details may differ on your particular system:

bootparam(7) — Introduction to Linux boot time kernel parameters.

grubby(8) — Information about boot loader configuration files.

init(8) — Introduction to process initialization and runlevel details.

Linux Loader Configuration File (elilo.conf)

Boot configuration entries in the elilo.conf file enable you to establish a collection of bootable Linux configuration, any one of which can be selected at the "ELILO boot" prompt.




	CAUTION: Save a backup copy of the `elilo.conf` file before making changes to customize the file.

Sample elilo.conf File. The following sample elilo.conf file has two boot entries, labeled "linux" and "linux-up".

prompt
timeout=50
default=linux

image=vmlinuz-2.4.18-e.12smp
        label=linux
        initrd=initrd-2.4.18-e.12smp.img
        read-only
        root=/dev/sda2
        append="console=ttyS0"

image=vmlinuz-2.4.18-e.12
        label=linux-up
        initrd=initrd-2.4.18-e.12.img
        read-only
        root=/dev/sda2
        append="console=ttyS0"

elilo.conf File Boot Options. You can specify the following options, among others, in an elilo.conf file to configure a Linux device's boot behavior. For more details refer to the documentation for the Linux distribution you are using.

prompt — Specifies to make the "ELILO boot" prompt available without requiring anything to be typed.
timeout=tsecs — Sets the timeout duration in tenths of seconds. Following the timeout period, either the default boot entry is selected, or if no default is specified the first boot entry is selected.
default=name — Sets the boot option entry that is selected by default. The name listed must match the name specified by a label option in the same elilo.conf file. When no default is specified, then the first boot entry is chosen if no other boot entry is requested.
image=kernel — Specifies the Linux kernel to boot. Typically, the kernel specified is a vmlinuz file. For example, the file vmlinuz-2.4.18-e.12smp is a kernel that resides on the EFI partition as \efi\redhat\vmlinuz-2.4.18-e.12smp.
label=name — The name defined by the label option is the identifier you can reference to invoke the boot entry for loading.
You can use the specified name at the "ELILO boot" prompt, or in a default option line in the same elilo.conf file, to cause the boot entry to be used for loading Linux.
initrd=image — Specifies the initial RAM disk image used to initialize and start services for booting the Linux kernel. The image file typically resides on the EFI partition in the same directory as the corresponding Linux kernel file specified by the image option.
read-only — Specifies that the root disk partition (specified by the root option) cannot be modified during the Linux boot process.
root=diskptn — Indicates which device (diskptn) to mount as the root disk partition.
append="options" — Specifies boot-time kernel options that are passed to the Linux kernel when it is loaded.

Booting to the Linux Loader (ELILO.EFI)

Technical documentation

» Table of Contents

Linux Boot Option Management

Linux Loader Configuration File (elilo.conf)