Specifications

specified amount. The fault_level is only for raid−1 and sets the maximum fault number to the specified
number. (Currently unsupported due to lack of boot support for raid1.) The dev0−devN are a comma
separated list of the devices that make up the individual md device: e.g.
/dev/hda1,/dev/hdc1,/dev/sda1
See also raid=.
The `nmi_watchdog=' Argument
Supplying a non−zero integer will enable the non maskable interrupt watchdog (assuming IO APIC support is
compiled in). This checks to see if the interrupt count is increasing (indicating normal system activity) and if
it is not then it assumes that a processor is stuck and forces an error dump of diagnostic information.
The `no387' Argument
Some i387 coprocessor chips have bugs that show up when used in 32 bit protected mode. For example, some
of the early ULSI−387 chips would cause solid lockups while performing floating point calculations,
apparently due to a bug in the FRSAV/FRRESTOR instructions. Using the `no387' boot argument causes
Linux to ignore the math coprocessor even if you have one. Of course you must then have your kernel
compiled with math emulation support! This may also be useful if you have one of those really old 386
machines that could use an 80287 FPU, as Linux can't use an 80287.
The `no−hlt' Argument
The i386 (and successors thereof) family of CPUs have a `hlt' instruction which tells the CPU that nothing is
going to happen until an external device (keyboard, modem, disk, etc.) calls upon the CPU to do a task. This
allows the CPU to enter a `low−power' mode where it sits like a zombie until an external device wakes it up
(usually via an interrupt). Some of the early i486DX−100 chips had a problem with the `hlt' instruction, in that
they couldn't reliably return to operating mode after this instruction was used. Using the `no−hlt' instruction
tells Linux to just run an infinite loop when there is nothing else to do, and to not halt your CPU when there is
no activity. This allows people with these broken chips to use Linux, although they would be well advised to
seek a replacement through a warranty where possible.
The `no−scroll' Argument
Using this argument at boot disables scrolling features that make it difficult to use Braille terminals.
The `noapic' Argument
Using this option tells a SMP kernel to not use some of the advanced features of the interrupt controller on
multi processor machines. Use of this option may be required when a device (such as those using ne2k−pci or
3c59xi drivers) stops generating interrupts (i.e. cat /proc/interrupts shows the same interrupt
count.) See linux/Documentation/IO−APIC.txt for more information.
The `noht' Argument
This will disable hyper−threading on intel processors that have this feature.
The Linux BootPrompt−HowTo
The `nmi_watchdog=' Argument 15