July 2000 Kernel Parameters v2.4.0
~~~~~~~~~~~~~~~~~
The following is a consolidated list of the kernel parameters as implemented
by the __setup() macro and sorted into English Dictionary order (defined
as ignoring all punctuation and sorting digits before letters in a case
insensitive manner), and with descriptions where known.
The text in square brackets at the beginning of the description state the
restrictions on the kernel for the said kernel parameter to be valid. The
restrictions referred to are that the relevant option is valid if:
ACPI ACPI support is enabled.
APIC APIC support is enabled.
APM Advanced Power Management support is enabled.
AX25 Appropriate AX.25 support is enabled.
CD Appropriate CD support is enabled.
DEVFS devfs support is enabled.
DRM Direct Rendering Management support is enabled.
EFI EFI Partitioning (GPT) is enabled
EIDE EIDE/ATAPI support is enabled.
FB The frame buffer device is enabled.
HW Appropriate hardware is enabled.
IA-32 IA-32 aka i386 architecture is enabled.
IA-64 IA-64 architecture is enabled.
IP_PNP IP DCHP, BOOTP, or RARP is enabled.
ISAPNP ISA PnP code is enabled.
ISDN Appropriate ISDN support is enabled.
JOY Appropriate joystick support is enabled.
LP Printer support is enabled.
LOOP Loopback device support is enabled.
M68k M68k architecture is enabled.
MCA MCA bus support is enabled.
MDA MDA console support is enabled.
MOUSE Appropriate mouse support is enabled.
NET Appropriate network support is enabled.
NFS Appropriate NFS support is enabled.
PARIDE The ParIDE subsystem is enabled.
PCI PCI bus support is enabled.
PCMCIA The PCMCIA subsystem is enabled.
PNP Plug & Play support is enabled.
PPT Parallel port support is enabled.
PS2 Appropriate PS/2 support is enabled.
RAM RAM disk support is enabled.
SCSI Appropriate SCSI support is enabled.
SERIAL Serial support is enabled.
SMP The kernel is an SMP kernel.
SOUND Appropriate sound system support is enabled.
V4L Video For Linux support is enabled.
VGA The VGA console has been enabled.
VT Virtual terminal support is enabled.
XT IBM PC/XT MFM hard disk support is enabled.
In addition, the following text indicates that the option:
BUGS= Relates to possible processor bugs on the said processor.
KNL Is a kernel start-up parameter.
BOOT Is a boot loader parameter.
Parameters denoted with BOOT are actually interpreted by the boot
loader, and have no meaning to the kernel directly.
Note that ALL kernel parameters listed below are CASE SENSITIVE, and that
a trailing = on the name of any parameter states that that parameter will
be entered as an environment variable, whereas its absence indicates that
it will appear as a kernel argument readable via /proc/cmdline by programs
running once the system is up.
53c7xx= [HW,SCSI] Amiga SCSI controllers.
acpi= [HW,ACPI] Advanced Configuration and Power Interface
force Force ACPI on, even if blacklisted platform
off Disable ACPI
ht Limit ACPI to boot-time LAPIC enumeration for HT,
disabling the run-time AML interpreter.
strict Be less tolerant of platforms that are not
strictly ACPI specification compliant.
acpi_sci= [HW,ACPI] ACPI System Control Interrupt trigger mode
Format: { level | edge | high | low }
acpi_irq_balance ACPI will balance active IRQs
acpi_irq_nobalance ACPI will not move active IRQs
acpi_irq_pci= If irq_balance, Clear listed IRQs for use by PCI
acpi_irq_isa= If irq_balance, Mark listed IRQs used by ISA
acpi_osi= [HW,ACPI] empty param disables _OSI
acpi_serialize [HW,ACPI] force serialization of AML methods
ad1816= [HW,SOUND]
ad1848= [HW,SOUND]
adb_buttons= [HW,MOUSE]
adlib= [HW,SOUND]
advansys= [HW,SCSI]
aedsp16= [HW,SOUND]
aha152x= [HW,SCSI]
aha1542= [HW,SCSI]
aic7xxx= [HW,SCSI]
AM53C974= [HW,SCSI]
amijoy= [HW,JOY] Amiga joystick support
apm= [APM] Advanced Power Management.
applicom= [HW]
arcrimi= [HW,NET]
ataflop= [HW,M68k]
atarimouse= [HW,MOUSE] Atari Mouse.
atascsi= [HW,SCSI] Atari SCSI.
awe= [HW,SOUND]
aztcd= [HW,CD] Aztec CD driver.
baycom_epp= [HW,AX25]
baycom_par= [HW,AX25] BayCom Parallel Port AX.25 Modem.
baycom_ser_fdx= [HW,AX25] BayCom Serial Port AX.25 Modem in Full
Duplex Mode.
baycom_ser_hdx= [HW,AX25] BayCom Serial Port AX.25 Modem in Half
Duplex Mode.
bmouse= [HW,MOUSE,PS2] Bus mouse.
bttv.card= [HW,V4L] bttv (bt848 + bt878 based grabber cards), most
bttv.radio= important insmod options are available as kernel args too.
bttv.pll= see Documentation/video4linux/bttv/Insmod-options
bttv.tuner= and Documentation/video4linux/bttv/CARDLIST
BusLogic= [HW,SCSI]
cdu31a= [HW,CD]
chandev= [HW,NET]
cm206= [HW,CD]
com20020= [HW,NET]
com90io= [HW,NET]
com90xx= [HW,NET]
condev= [HW]
console= [KNL] output console + comm spec (speed, control,
parity).
cpia_pp= [HW,PPT]
cs4232= [HW,SOUND]
cs89x0_dma= [HW,NET]
ctc= [HW,NET]
cyclades= [HW,SERIAL] Cyclades multi-serial port adapter.
dasd= [HW,NET]
db9= [HW,JOY]
db9_2= [HW,JOY]
db9_3= [HW,JOY]
debug [KNL] Enable kernel debugging (events log level).
decnet= [HW,NET]
devfs= [DEVFS]
digi= [HW,SERIAL] io parameters + enable/disable command.
digiepca= [HW,SERIAL]
dmascc= [HW,AX25,SERIAL] AX.25 Z80SCC driver with DMA
support available.
dmasound= [HW,SOUND] (sound subsystem buffers).
dtc3181e= [HW,SCSI]
eata= [HW,SCSI]
eda= [HW,PS2]
edb= [HW,PS2]
eicon= [HW,ISDN]
es1370= [HW,SOUND]
es1371= [HW,SOUND]
ether= [HW,NET] Ethernet cards parameters (irq,
base_io_addr, mem_start, mem_end, name.
(mem_start is often overloaded to mean something
different and driver-specific).
fd_mcs= [HW,SCSI]
fdomain= [HW,SCSI]
floppy= [HW]
ftape= [HW] Floppy Tape subsystem debugging options.
gamma= [HW,DRM]
gc= [HW,JOY]
gc_2= [HW,JOY]
gc_3= [HW,JOY]
gdth= [HW,SCSI]
gpt [EFI] Forces disk with valid GPT signature but
invalid Protective MBR to be treated as GPT.
gscd= [HW,CD]
gus= [HW,SOUND]
gvp11= [HW,SCSI]
hd= [EIDE] (E)IDE hard drive subsystem geometry
(Cyl/heads/sectors) or tune parameters.
hfmodem= [HW,AX25]
hisax= [HW,ISDN]
i810= [HW,DRM]
ibmmcascsi= [HW,MCA,SCSI] IBM MicroChannel SCSI adapter.
icn= [HW,ISDN]
ide?= [HW] (E)IDE subsystem : config (iomem/irq), tuning or
debugging (serialize,reset,no{dma,tune,probe}) or
chipset specific parameters.
idebus= [HW] (E)IDE subsystem : VLB/PCI bus speed.
idle= [HW]
in2000= [HW,SCSI]
init= [KNL]
initrd= [BOOT] Specify the location of the initial ramdisk.
ip= [IP_PNP]
isapnp= [ISAPNP] Specify RDP, reset, pci_scan and verbosity.
isapnp_reserve_irq= [ISAPNP] Exclude IRQs for the autoconfiguration.
isapnp_reserve_dma= [ISAPNP] Exclude DMAs for the autoconfiguration.
isapnp_reserve_io= [ISAPNP] Exclude I/O ports for the autoconfiguration.
Ranges are in pairs (I/O port base and size).
isapnp_reserve_mem= [ISAPNP] Exclude memory regions for the autoconfiguration.
Ranges are in pairs (memory base and size).
isp16= [HW,CD]
iucv= [HW,NET]
js= [HW,JOY] Analog joystick
kbd-reset [VT]
keepinitrd [HW, ARM]
lapic [IA-32,APIC] Enable the local APIC even if BIOS disabled it.
load_ramdisk= [RAM] List of ramdisks to load from floppy.
lockd.udpport= [NFS]
lockd.tcpport= [NFS]
logi_busmouse= [HW, MOUSE]
lp=0 [LP] Specify parallel ports to use, e.g,
lp=port[,port...] lp=none,parport0 (lp0 not configured, lp1 uses
lp=reset first parallel port). 'lp=0' disables the
lp=auto printer driver. 'lp=reset' (which can be
specified in addition to the ports) causes
attached printers to be reset. Using
lp=port1,port2,... specifies the parallel ports
to associate lp devices with, starting with
lp0. A port specification may be 'none' to skip
that lp device, or a parport name such as
'parport0'. Specifying 'lp=auto' instead of a
port specification list means that device IDs
from each port should be examined, to see if
an IEEE 1284-compliant printer is attached; if
so, the driver will manage that printer.
ltpc= [HW]
mac5380= [HW,SCSI]
mac53c9x= [HW,SCSI]
mad16= [HW,SOUND]
maui= [HW,SOUND]
max_loop=[0-255] [LOOP] Set the maximum number of loopback devices
that can be mounted.
maxcpus= [SMP] States the maximum number of processors that
an SMP kernel should make use of.
max_scsi_luns= [SCSI]
mca-pentium [BUGS=IA-32]
mcd= [HW,CD]
mcdx= [HW,CD]
md= [HW] RAID subsystems devices and level.
mdisk= [HW]
mdacon= [MDA]
megaraid= [HW,SCSI]
mem=exactmap [KNL,BOOT,IA-32] enable setting of an exact
e820 memory map, as specified by the user.
Such mem=exactmap lines can be constructed
based on BIOS output or other requirements.
mem=nn[KMG] [KNL,BOOT] force use of a specific amount of
memory; to be used when the kernel is not able
to see the whole system memory or for test.
mem=nn[KMG]@ss[KMG]
[KNL,BOOT] Force usage of a specific region of memory
Region of memory to be used, from ss to ss+nn.
mem=nn[KMG]#ss[KMG]
[KNL,BOOT,ACPI] Mark specific memory as ACPI data.
Region of memory to be used, from ss to ss+nn.
mem=nn[KMG]$ss[KMG]
[KNL,BOOT,ACPI] Mark specific memory as reserved.
Region of memory to be used, from ss to ss+nn.
memfrac= [KNL]
mga= [HW,DRM]
mpu401= [HW,SOUND]
msmouse= [HW,MOUSE] Microsoft Mouse.
ncr5380= [HW,SCSI]
ncr53c400= [HW,SCSI]
ncr53c400a= [HW,SCSI]
ncr53c406a= [HW,SCSI]
ncr53c8xx= [HW,SCSI]
netdev= [NET] Ethernet cards parameters (irq,
base_io_addr, mem_start, mem_end, name.
(mem_start is often overloaded to mean something
different and driver-specific).
(cf: ether=)
nfsaddrs= [NFS]
nfsroot= [NFS] nfs root filesystem for disk-less boxes.
nmi_watchdog= [KNL,BUGS=IA-32] debugging features for SMP kernels.
no387 [BUGS=IA-32] Tells the kernel to use the 387 maths
emulation library even if a 387 maths coprocessor
is present.
noalign [KNL,ARM]
noapic [SMP,APIC] Tells the kernel not to make use of any
APIC that may be present on the system.
noasync [HW, M68K] Disables async and sync negotiation for
all devices.
nocache [ARM]
nodisconnect [HW,SCSI, M68K] Disables SCSI disconnects.
nohlt [BUGS=ARM]
no-hlt [BUGS=IA-32] Tells the kernel that the hlt
instruction doesn't work correctly and not to
use it.
noisapnp [ISAPNP] Disables ISA PnP code.
noinitrd [RAM] Tells the kernel not to load any configured
initial RAM disk.
nointroute [IA-64]
nolapic [IA-32,APIC] Do not enable or use the local APIC.
no-scroll [VGA]
nosmp [SMP] Tells an SMP kernel to act as a UP kernel.
nosync [HW, M68K] Disables sync negotiation for all devices.
notsc [BUGS=IA-32] Disable Time Stamp Counter
nowb [ARM]
opl3= [HW,SOUND]
opl3sa= [HW,SOUND]
opl3sa2= [HW,SOUND]
optcd= [HW,CD]
panic= [KNL] kernel behaviour on panic.
parport=0 [HW,PPT] Specify parallel ports. 0 disables.
parport=auto Use 'auto' to force the driver to use
parport=0xBBB[,IRQ[,DMA]] any IRQ/DMA settings detected (the
default is to ignore detected IRQ/DMA
settings because of possible
conflicts). You can specify the base
address, IRQ, and DMA settings; IRQ and
DMA should be numbers, or 'auto' (for
using detected settings on that
particular port), or 'nofifo' (to avoid
using a FIFO even if it is detected).
Parallel ports are assigned in the
order they are specified on the command
line, starting with parport0.
pas2= [HW,SOUND]
pas16= [HW,SCSI]
pcbit= [HW,ISDN]
pcd. [PARIDE]
pci=option[,option...] [PCI] various PCI subsystem options:
off [IA-32] don't probe for the PCI bus
bios [IA-32] force use of PCI BIOS, don't access
the hardware directly. Use this if your machine
has a non-standard PCI host bridge.
nobios [IA-32] disallow use of PCI BIOS, only direct
hardware access methods are allowed. Use this
if you experience crashes upon bootup and you
suspect they are caused by the BIOS.
conf1 [IA-32] Force use of PCI Configuration Mechanism 1.
conf2 [IA-32] Force use of PCI Configuration Mechanism 2.
nosort [IA-32] Don't sort PCI devices according to
order given by the PCI BIOS. This sorting is done
to get a device order compatible with older kernels.
biosirq [IA-32] Use PCI BIOS calls to get the interrupt
routing table. These calls are known to be buggy
on several machines and they hang the machine when used,
but on other computers it's the only way to get the
interrupt routing table. Try this option if the kernel
is unable to allocate IRQs or discover secondary PCI
buses on your motherboard.
rom [IA-32] Assign address space to expansion ROMs.
Use with caution as certain devices share address
decoders between ROMs and other resources.
irqmask=0xMMMM [IA-32] Set a bit mask of IRQs allowed to be assigned
automatically to PCI devices. You can make the kernel
exclude IRQs of your ISA cards this way.
lastbus=N [IA-32] Scan all buses till bus #N. Can be useful
if the kernel is unable to find your secondary buses
and you want to tell it explicitly which ones they are.
assign-busses [IA-32] Always assign all PCI bus
numbers ourselves, overriding
whatever the firmware may have
done.
pd. [PARIDE]
pf. [PARIDE]
pg. [PARIDE]
pirq= [SMP,APIC] mp-table.
plip= [PPT,NET] Parallel port network link.
profile= [KNL] enable kernel profiling via /proc/profile
(param: profile step/bucket size as a power of 2)
prompt_ramdisk= [RAM] List of RAM disks to prompt for floppy disk
before loading.
pss= [HW,SOUND]
pt. [PARIDE]
quiet= [KNL] Disable log messages.
r128= [HW,DRM]
raid= [HW,RAID]
ramdisk= [RAM] Sizes of RAM disks in kilobytes [deprecated].
ramdisk_blocksize=
[RAM]
ramdisk_size= [RAM] New name for the ramdisk parameter.
ramdisk_start= [RAM] Starting block of RAM disk image (so you can
place it after the kernel image on a boot floppy).
reboot= [BUGS=IA-32]
reserve= [KNL,BUGS] force the kernel to ignore some iomem area.
riscom8= [HW,SERIAL]
ro [KNL] Mount root device read-only on boot.
root= [KNL] root filesystem.
rootflags= [KNL] set root filesystem mount option string
rootfstype= [KNL] set root filesystem type
rw [KNL] Mount root device read-write on boot.
S [KNL] run init in single mode.
sb= [HW,SOUND]
sbpcd= [HW,CD] Soundblaster CD adapter.
scsi_logging= [SCSI]
scsihosts= [SCSI]
sg_def_reserved_size=
[SCSI]
sgalaxy= [HW,SOUND]
sim710= [SCSI,HW]
sjcd= [HW,CD]
smart2= [HW]
sonicvibes= [HW,SOUND]
sonycd535= [HW,CD]
sound= [SOUND]
soundmodem= [HW,AX25,SOUND] Use sound card as packet radio modem.
specialix= [HW,SERIAL] Specialix multi-serial port adapter.
sscape= [HW,SOUND]
st= [HW,SCSI] SCSI tape parameters (buffers, etc.).
st0x= [HW,SCSI]
stram_swap= [HW]
swiotlb= [IA-64] Number of I/O TLB slabs.
switches= [HW, M68K]
sym53c416= [HW,SCSI]
sym53c8xx= [HW,SCSI]
t128= [HW,SCSI]
tdfx= [HW,DRM]
tgfx= [HW,JOY]
tgfx_2= [HW,JOY]
tgfx_3= [HW,JOY]
tmc8xx= [HW,SCSI]
tmscsim= [HW,SCSI]
tp720= [HW,PS2]
trix= [HW,SOUND]
u14-34f= [HW,SCSI]
uart401= [HW,SOUND]
uart6850= [HW,SOUND]
usbfix [BUGS=IA-64]
video= [FB] frame buffer configuration.
vga= [BOOT] on ix386, select a particular video mode
(use vga=ask for menu). This is actually a
boot loader parameter; the value is passed to
the kernel using a special protocol. See
linux/Documentation/i386/boot.txt for information.
vmhalt= [KNL,S390]
vmpoff= [KNL,S390]
waveartist= [HW,SOUND]
wd33c93= [HW,SCSI]
wd7000= [HW,SCSI]
wdt= [HW]
xd= [HW,XT] Original XT pre-IDE (RLL encoded) disks.
xd_geo= [HW,XT]
Download Driver Pack
After your driver has been downloaded, follow these simple steps to install it.
Expand the archive file (if the download file is in zip or rar format).
If the expanded file has an .exe extension, double click it and follow the installation instructions.
Otherwise, open Device Manager by right-clicking the Start menu and selecting Device Manager.
Find the device and model you want to update in the device list.
Double-click on it to open the Properties dialog box.
From the Properties dialog box, select the Driver tab.
Click the Update Driver button, then follow the instructions.
Very important: You must reboot your system to ensure that any driver updates have taken effect.
For more help, visit our Driver Support section for step-by-step videos on how to install drivers for every file type.