Hack 8 Run Knoppix on a Laptop

With laptops sales on the rise, it is increasingly common that your desktop machine is actually a laptop. Knoppix provides cheat codes and other options so it can boot on laptop hardware.

If any type of hardware will make you resort to cheat codes and kernel-parameter voodoo to boot Knoppix, laptops will. Laptop manufacturers often resort to using special proprietary hardware that often has little to no support in the Linux kernel. Some laptops don't even include an internal IDE CD-ROM drive, and instead have an external PCMCIA, USB, or IEE1394 CD-ROM. On Knoppix, support for the CD-ROM after the BIOS boots is pretty important! Laptops also rely on power management features that can be iffy at times. None of these issues should scare you away from trying Knoppix on a laptop. Many of these problems can be solved or at least worked around using cheat codes.

Knoppix is one of the best distributions when it comes to getting laptops working out of the box. I recommend taking a Knoppix CD with you when shopping for laptops; it is one of the best ways to see how well Linux will run on that machine. Convincing the clerk at Best Buy to let you boot with Knoppix will be your real challenge.

1.9.1 Laptop Display Tweaks

The specifics of tweaking display settings have been covered already in [Hack #6]. Some of those cheat codes are particularly useful when setting up a laptop or desktop LCD display. Laptops use LCDs that have an ideal resolution even if they can display other resolutions. The fb cheat code is useful in these cases, because on some displays, running the console below the maximum resolution results in the text still being displayed with black bands around it. To display a framebuffer console on a laptop that has an ideal resolution of 1024 768, boot Knoppix with:

fb1024x768

In some cases, Knoppix may not detect the laptop's video card or may detect it incorrectly. If forcing Knoppix to use a particular module with the xmodule cheat code doesn't work, but the console displays fine, boot with xmodule=fbdev to use the same framebuffer support for X that you use in the console.

1.9.2 Special-Purpose Cheat Codes

There are many other special-purpose cheat codes to boot Knoppix on difficult hardware. Here are some bits of voodoo that have worked for other laptops. For some notebooks that use proprietary PCMCIA CD-ROM drives, the cheat code ide2=0x180 nopcmcia has been known to work by bypassing PCMCIA support in favor of direct BIOS support for the drive. If the PS/2 mouse on the laptop does not work, boot with pci=irqmask=0x0e98 to specify a specific PCI address.

For the worst cases, you might have to disable parts of the hardware to get the laptop to at least be partially usable. The cheat codes outlined in [Hack #7] can help, particularly noapic, nofirewire, or noscsi. On some lines of Dell laptops, passing nosmp has made the difference in being able to boot. For a time on my Fujitsu laptop, I needed to boot Knoppix with ide0=ata66 ide1=ata66 to work around a bug in my IDE chipset. If the power management support for your laptop is unstable—for instance the laptop goes to sleep, but you can't wake it back up—you might want to disable power management completely with noapm and acpi=off.