Using the Help System

The boot loader online help is context sensitive. It gives information about the selected menu item or, if you are editing boot options, it tries to look up information about the option in which the cursor is positioned.

Navigation Keys

Up Arrow: highlight previous link
Down Arrow: highlight next link
Left Arrow, Backspace: return to previous topic
Right Arrow, Enter, Space: follow link
Page Up: scroll up one page
Page Down: scroll down one page
Home: go to page start
End: go to page end
Esc: leave help

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Language and Keyboard Layout Selection

Press F2 to change language and keyboard layout the boot loader uses.

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Choose Profile

Press F3 to select a profile. Your system will be started using the configuration saved in this profile.

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Boot Options

splash -- influence the behavior of the splash screen
apm -- toggle power management
acpi -- advanced configuration and power interface
ide -- control the IDE subsystem

Kernel Options: splash

The splash screen is the picture shown during system start-up.

splash=0
The splash screen is switched off. This may be useful with very old monitors or if some error occurs.

splash=verbose
Activates splash, kernel and boot messages are still shown.

splash=silent
Activates splash, but no messages. Instead a progress bar is drawn.

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Kernel Options: apm

APM is one of the two power management strategies used on current computers. It is mainly used with laptops for functions like suspend to disk, but it may also be responsible for switching off the computer after power down. APM relies on a correct working BIOS. If the BIOS is broken, APM may have only limited use or even prevent the computer from working. Therefore, it may be switched off with the parameter

apm=off -- switch off APM completely

Some very new computers may benefit more from the newer ACPI.

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Kernel Options: acpi

ACPI (Advanced Configuration and Power Interface) is a standard that defines power and configuration management interfaces between an operating system and the BIOS. By default, acpi is switched on when a BIOS is detected that is newer than from year 2000. There are several commonly used parameters to control the behavior of ACPI:

pci=noacpi -- do not use ACPI to route PCI interrupts acpi=oldboot -- only the parts of ACPI that are relevant for booting remain activated
acpi=off -- switch off ACPI completely
acpi=force -- switch on ACPI even if your BIOS is dated before 2000

Especially on new computers, it replaces the old apm system.

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Kernel Options: ide

IDE is, unlike SCSI, commonly used in most desktop workstations. To circumvent some hardware problems that occur with IDE systems, use the kernel parameter:

ide=nodma -- switch off dma for IDE drives


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