Hardware options:

acpi=on

This loads support for ACPI and also causes the acpid daemon to be started by the CD on boot. This is only needed if your system requires ACPI to function properly. This is not required for Hyperthreading support.

acpi=off

Completely disables ACPI. This is useful on some older systems and is also a requirement for using APM. This will disable any Hyperthreading support of your processor.

console=X

This sets up serial console access for the CD. The first option is the device, usually ttyS0 on x86, followed by any connection options, which are comma separated. The default options are 9600,8,n,1.

dmraid=X

This allows for passing options to the device-mapper RAID subsystem. Options should be encapsulated in quotes.

doapm

This loads APM driver support. This requires you to also use acpi=off.

dopcmcia

This loads support for PCMCIA and Cardbus hardware and also causes the pcmcia cardmgr to be started by the CD on boot. This is only required when booting from PCMCIA/Cardbus devices.

doscsi

This loads support for most SCSI controllers. This is also a requirement for booting most USB devices, as they use the SCSI subsystem of the kernel.

sda=stroke

This allows you to partition the whole hard disk even when your BIOS is unable to handle large disks. This option is only used on machines with an older BIOS. Replace sda with the device that requires this option.

ide=nodma

This forces the disabling of DMA in the kernel and is required by some IDE chipsets and also by some CDROM drives. If your system is having trouble reading from your IDE CDROM, try this option. This also disables the default hdparm settings from being executed.

noapic

This disables the Advanced Programmable Interrupt Controller that is present on newer motherboards. It has been known to cause some problems on older hardware.

nodetect

This disables all of the autodetection done by the CD, including device autodetection and DHCP probing. This is useful for doing debugging of a failing CD or driver.

nodhcp

This disables DHCP probing on detected network cards. This is useful on networks with only static addresses.

nodmraid

Disables support for device-mapper RAID, such as that used for on-board IDE/SATA RAID controllers.

nofirewire

This disables the loading of Firewire modules. This should only be necessary if your Firewire hardware is causing a problem with booting the CD.

nogpm

This disables gpm console mouse support.

nohotplug

This disables the loading of the hotplug and coldplug init scripts at boot. This is useful for doing debugging of a failing CD or driver.

nokeymap

This disables the keymap selection used to select non-US keyboard layouts.

nolapic

This disables the local APIC on Uniprocessor kernels.

nosata

This disables the loading of Serial ATA modules. This is used if your system is having problems with the SATA subsystem.

nosmp

This disables SMP, or Symmetric Multiprocessing, on SMP-enabled kernels. This is useful for debugging SMP-related issues with certain drivers and motherboards.

nosound

This disables sound support and volume setting. This is useful for systems where sound support causes problems.

nousb

This disables the autoloading of USB modules. This is useful for debugging USB issues.

slowusb

This adds some extra pauses into the boot process for slow USB CDROMs, like in the IBM BladeCenter.

Volume/Device Management:

dolvm

This enables support for Linux's Logical Volume Management.

Other options:

debug

Enables debugging code. This might get messy, as it displays a lot of data to the screen.

docache

This caches the entire runtime portion of the CD into RAM, which allows you to umount /mnt/cdrom and mount another CDROM. This option requires that you have at least twice as much available RAM as the size of the CD.

doload=X

This causes the initial ramdisk to load any module listed, as well as dependencies. Replace X with the module name.
Multiple modules can be specified by a comma-separated list.

dosshd

Starts sshd on boot, which is useful for unattended installs.

passwd=foo

Sets whatever follows the equals as the root password, which is required for dosshd since we scramble the root password.

noload=X

This causes the initial ramdisk to skip the loading of a specific module that may be causing a problem. Syntax matches that of doload.

nonfs

Disables the starting of portmap/nfsmount on boot.

nox

This causes an X-enabled LiveCD to not automatically start X, but rather, to drop to the command line instead.

scandelay

This causes the CD to pause for 10 seconds during certain portions the boot process to allow for devices that are slow to initialize to be ready for use.

scandelay=X

This allows you to specify a given delay, in seconds, to be added to certain portions of the boot process to allow for devices that are slow to initialize to be ready for use. Replace X with the number of seconds to pause.