Next: 2.2.4.0.4 IDE Disk/CD-ROM Driver
Up: 2.2.4 Specifying boot time
Previous: 2.2.4.0.2 The `root=' Argument
Contents
Other parameters that can be passed to the kernel include:
- rootflags=
- allows you to give options pertaining to the mounting
of the root filesystem
- rootfstype=
- allows you to give a comma separated list of fs types
that will be tried for a match when trying to mount the root filesystem
- ro
- tells the kernel to mount the root filesystem as `readonly'
- rw
- tells the kernel to mount the root filesystem as read/write
- nfsroot=
- tells the kernel which machine, what directory and what
NFS options to use for the root filesystem, root=/dev/nfs is required
- ip= or nfsaddrs=
- sets up the various network interface addresses
that are required to communicate over the network
- ramdisk_start=
- allow a kernel image to reside on a floppy disk
along with a compressed ramdisk image
- load_ramdisk=
- tells the kernel whether it is to try to load a ramdisk
image or not
- prompt_ramdisk=
- tells the kernel whether or not to give you a prompt
asking you to insert the floppy containing the ramdisk image
- ramdisk_size=
- override the default of 4096 (4MB) to a bigger or
smaller size with this boot argument
- ramdisk_blocksize=
- tuned for better memory management behaviour
- noinitrd
- determines what happens to the initrd data after the kernel
has booted
- cachesize=
- override level 2 CPU cache size detection (in kB)
- mem=
- to specify the amount of installed memory (or a value less
than that if you wanted to limit the amount of memory available to
linux)
- memfrac=
- memory is broken down into zones, the two (or three) integers
supplied here determine how much memory in each zone should be kept
free
- swap=
- tune some of the virtual memory (VM) parameters that are related
to swapping to disk
- buff=
- allows the user to tune some of the parameters related to
buffer memory management
- acpi=
- currently this only accepts `off' to disable the ACPI subsystem
- console=
- to be able to use another device like a serial port (or
even a printer!) to be the console when no video device is present
- debug
- the kernel communicates important (and not-so important) messages
to the operator via the printk() function
- decnet=
- supply two comma separated integers here to give your area
and node respectively.
- devfs=
- if you are using devfs, instead of the standard static devices
in /dev/ then you can supply the words only or mount with this argument
- gpt
- if you are using EFI GUID Partition Table handling, you can
use this to override problems associated with an invalid PMBR
- idle=
- setting this to `poll' causes the idle loop in the kernel
to poll on the need reschedule flag instead of waiting for an interrupt
to happen
- init=
- if for example, your init program got corrupted and thus stopped
you from being able to boot, you could simply use the boot prompt
init=/bin/sh which would drop you directly into a shell at boot, allowing
you to replace the corrupted program
- isapnp=
- takes the form of: isapnp=read_port,reset,skip_pci_scan,verbose
- isapnp_reserve_dma=
- takes the form of: isapnp_reserve_dma=n1,n2,n3,...nN
where n1 ... nN are the DMA channel numbers to not use for PnP
- isapnp_reserve_io=
- takes the form of: isapnp_reserve_irq=io1,size1,io2,size2,...ioN,sizeN
where ioX,sizeX are I/O start and length pairs of regions in I/O space
that are not to be used by PnP
- isapnp_reserve_irq=
- takes the form of: isapnp_reserve_irq=n1,n2,n3,...nN
where n1 ... nN are the interrupt numbers to not use for PnP
- isapnp_reserve_mem=
- takes the form of: isapnp_reserve_mem=mem1,size1,mem2,size2,...memN,sizeN
where ioX,sizeX are I/O start and length pairs of regions in memory
space that are not to be used by PnP
- kbd-reset
- forces a reset at initialization time
- lockd.udpport= and lockd.tcpport
- tell the kernel to use the given
port numbers for NFS lockd operation (for either UDP or TCP operation).
- maxcpus=
- number given with this argument limits the maximum number
of CPUs activated in SMP mode
- max_scsi_luns=
- allows you to set the maximum number of probed
LUNs
- mca-pentium
- prevent lock up on the test to detect the type of math
chip coupling on microchannel machines
- md=
- tell the kernel the multiple device layout
- nmi_watchdog=
- hecks 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
- no387
- causes Linux to ignore the math coprocessor even if you have
one
- no-hlt
- run an infinite loop when there is nothing else to do, and
to not halt your CPU when there is no activity
- no-scroll
- disables scrolling features that make it difficult to
use Braille terminals
- noapic
- do not use some of the advanced features of the interrupt
controller on multi processor machines
- noht
- disable hyper-threading on intel processors that have this
feature
- noisapnp
- if ISA PnP is built into the kernel, this will disable
it
- nomce
- disable the ability in some newer processors to self-monitor
and detect inconsistencies and create Machine Check Exception and
halt the system
- nosmp
- If software suspend is enabled, and a suspend to disk file
has been specified, using this argument will give a normal boot and
the suspend data will be ignored
- notsc
- tell the kernel to not use the Time Stamp Counter for anything,
even if the CPU has one
- nofxsr
- tell the kernel to not use any speed-up tricks involving
the floating point unit, even if the processor supports them
- panic=
- automatically reset after a kernel panic so that the machine
comes back on line
- pci=
- argument (not avail. in v2.0 kernels) can be used to change
the behaviour of PCI bus device probing and device behaviour.
- pirq=
- tells a SMP kernel information on the PCI slot versus IRQ
settings for SMP motherboards which are unknown (or known to be blacklisted)
- profile=
- kernel developers can profile how and where the kernel
is spending its CPU cycles in an effort to maximize efficiency and
performance
- quiet
- only important and system critical kernel messages are printed
to the console. Normal messages about hardware detection at boot are
suppressed
- raid=
- accepts noautodetect at the moment. See also md=
- reboot=
- controls the type of reboot that Linux will do when it resets
the computer
- reserve=
- used to protect I/O port regions from probes
- resume=
- If you are using software suspend, then this will allow
you to specify the file name of the suspend to disk data that you
want the machine to resume from.
- scsi_logging=
- turns on logging of all SCSI events (error, scan,
mlqueue, mlcomplete, llqueue, llcomplete, hlqueue, hlcomplete)
- st=
- boot time configuration of the SCSI tape driver
- video=
- argument (not avail. in v2.0 kernels) is used when the frame
buffer device abstraction layer is built into the kernel
- vga=
- not really a boot argument, allows the setup code to use the
video BIOS to change the default display mode before actually booting
the Linux kernel
Next: 2.2.4.0.4 IDE Disk/CD-ROM Driver
Up: 2.2.4 Specifying boot time
Previous: 2.2.4.0.2 The `root=' Argument
Contents
