MTD MTD (Memory Technology Device) support is enabled.
NET Appropriate network support is enabled.
NUMA NUMA support is enabled.
- GENERIC_TIME The generic timeofday code is enabled.
NFS Appropriate NFS support is enabled.
OSS OSS sound support is enabled.
PV_OPS A paravirtualized kernel is enabled.
RAM RAM disk support is enabled.
S390 S390 architecture is enabled.
SCSI Appropriate SCSI support is enabled.
- A lot of drivers has their options described inside of
- Documentation/scsi/.
+ A lot of drivers have their options described inside
+ the Documentation/scsi/ sub-directory.
SECURITY Different security models are enabled.
SELINUX SELinux support is enabled.
+ APPARMOR AppArmor support is enabled.
SERIAL Serial support is enabled.
SH SuperH architecture is enabled.
SMP The kernel is an SMP kernel.
More X86-64 boot options can be found in
Documentation/x86/x86_64/boot-options.txt .
X86 Either 32bit or 64bit x86 (same as X86-32+X86-64)
+ XEN Xen support is enabled
In addition, the following text indicates that the option:
add_efi_memmap [EFI; X86] Include EFI memory map in
kernel's map of available physical RAM.
- advansys= [HW,SCSI]
- See header of drivers/scsi/advansys.c.
-
agp= [AGP]
{ off | try_unsupported }
off: disable AGP support
try_unsupported: try to drive unsupported chipsets
(may crash computer or cause data corruption)
- aha152x= [HW,SCSI]
- See Documentation/scsi/aha152x.txt.
-
- aha1542= [HW,SCSI]
- Format: <portbase>[,<buson>,<busoff>[,<dmaspeed>]]
-
- aic7xxx= [HW,SCSI]
- See Documentation/scsi/aic7xxx.txt.
-
- aic79xx= [HW,SCSI]
- See Documentation/scsi/aic79xx.txt.
-
ALSA [HW,ALSA]
See Documentation/sound/alsa/alsa-parameters.txt
atarimouse= [HW,MOUSE] Atari Mouse
- atascsi= [HW,SCSI] Atari SCSI
-
atkbd.extra= [HW] Enable extra LEDs and keys on IBM RapidAccess,
EzKey and similar keyboards
bttv.pll= See Documentation/video4linux/bttv/Insmod-options
bttv.tuner= and Documentation/video4linux/bttv/CARDLIST
- BusLogic= [HW,SCSI]
- See drivers/scsi/BusLogic.c, comment before function
- BusLogic_ParseDriverOptions().
-
c101= [NET] Moxa C101 synchronous serial card
cachesize= [BUGS=X86-32] Override level 2 CPU cache size detection.
clocksource is not available, it defaults to PIT.
Format: { pit | tsc | cyclone | pmtmr }
- clocksource= [GENERIC_TIME] Override the default clocksource
+ clocksource= Override the default clocksource
Format: <string>
Override the default clocksource and use the clocksource
with the name specified.
[ARM] imx_timer1,OSTS,netx_timer,mpu_timer2,
pxa_timer,timer3,32k_counter,timer0_1
[AVR32] avr32
- [X86-32] pit,hpet,tsc,vmi-timer;
+ [X86-32] pit,hpet,tsc;
scx200_hrt on Geode; cyclone on IBM x440
[MIPS] MIPS
[PARISC] cr16
dscc4.setup= [NET]
- dtc3181e= [HW,SCSI]
-
dynamic_printk Enables pr_debug()/dev_dbg() calls if
CONFIG_DYNAMIC_PRINTK_DEBUG has been enabled.
These can also be switched on/off via
earlycon= [KNL] Output early console device and options.
uart[8250],io,<addr>[,options]
uart[8250],mmio,<addr>[,options]
+ uart[8250],mmio32,<addr>[,options]
Start an early, polled-mode console on the 8250/16550
UART at the specified I/O port or MMIO address.
+ MMIO inter-register address stride is either 8bit (mmio)
+ or 32bit (mmio32).
The options are the same as for ttyS, above.
earlyprintk= [X86,SH,BLACKFIN]
This is desgined to be used in conjunction with
the boot argument: earlyprintk=vga
- eata= [HW,SCSI]
-
edd= [EDD]
Format: {"off" | "on" | "skip[mbr]"}
Format: <interval>,<probability>,<space>,<times>
See also /Documentation/fault-injection/.
- fd_mcs= [HW,SCSI]
- See header of drivers/scsi/fd_mcs.c.
-
- fdomain= [HW,SCSI]
- See header of drivers/scsi/fdomain.c.
-
floppy= [HW]
See Documentation/blockdev/floppy.txt.
When zero, profiling data is discarded and associated
debugfs files are removed at module unload time.
- gdth= [HW,SCSI]
- See header of drivers/scsi/gdth.c.
-
gpt [EFI] Forces disk with valid GPT signature but
invalid Protective MBR to be treated as GPT.
- gvp11= [HW,SCSI]
-
hashdist= [KNL,NUMA] Large hashes allocated during boot
are distributed across NUMA nodes. Defaults on
for 64bit NUMA, off otherwise.
controller
i8042.nopnp [HW] Don't use ACPIPnP / PnPBIOS to discover KBD/AUX
controllers
- i8042.panicblink=
- [HW] Frequency with which keyboard LEDs should blink
- when kernel panics (default is 0.5 sec)
i8042.reset [HW] Reset the controller during init and cleanup
i8042.unlock [HW] Unlock (ignore) the keylock
i8k.restricted [HW] Allow controlling fans only if SYS_ADMIN
capability is set.
- ibmmcascsi= [HW,MCA,SCSI] IBM MicroChannel SCSI adapter
- See Documentation/mca.txt.
-
icn= [HW,ISDN]
Format: <io>[,<membase>[,<icn_id>[,<icn_id2>]]]
programs exec'd, files mmap'd for exec, and all files
opened for read by uid=0.
- in2000= [HW,SCSI]
- See header of drivers/scsi/in2000.c.
-
init= [KNL]
Format: <full_path>
Run specified binary instead of /sbin/init as init
result in a hardware IOTLB flush operation as opposed
to batching them for performance.
+ intremap= [X86-64, Intel-IOMMU]
+ Format: { on (default) | off | nosid }
+ on enable Interrupt Remapping (default)
+ off disable Interrupt Remapping
+ nosid disable Source ID checking
+
inttest= [IA64]
iomem= Disable strict checking of access to MMIO memory
See comment before ip2_setup() in
drivers/char/ip2/ip2base.c.
- ips= [HW,SCSI] Adaptec / IBM ServeRAID controller
- See header of drivers/scsi/ips.c.
-
irqfixup [HW]
When an interrupt is not handled search all handlers
for it. Intended to get systems with badly broken
kgdboc= [KGDB,HW] kgdb over consoles.
Requires a tty driver that supports console polling,
or a supported polling keyboard driver (non-usb).
- Serial only format: <serial_device>[,baud]
- keyboard only format: kbd
- keyboard and serial format: kbd,<serial_device>[,baud]
+ Serial only format: <serial_device>[,baud]
+ keyboard only format: kbd
+ keyboard and serial format: kbd,<serial_device>[,baud]
+ Optional Kernel mode setting:
+ kms, kbd format: kms,kbd
+ kms, kbd and serial format: kms,kbd,<ser_dev>[,baud]
kgdbwait [KGDB] Stop kernel execution and enter the
kernel debugger at the earliest opportunity.
ltpc= [NET]
Format: <io>,<irq>,<dma>
- mac5380= [HW,SCSI] Format:
- <can_queue>,<cmd_per_lun>,<sg_tablesize>,<hostid>,<use_tags>
-
machvec= [IA64] Force the use of a particular machine-vector
(machvec) in a generic kernel.
Example: machvec=hpzx1_swiotlb
be mounted
Format: <1-256>
- max_luns= [SCSI] Maximum number of LUNs to probe.
- Should be between 1 and 2^32-1.
-
- max_report_luns=
- [SCSI] Maximum number of LUNs received.
- Should be between 1 and 16384.
-
mcatest= [IA-64]
mce [X86-32] Machine Check Exception
n2= [NET] SDL Inc. RISCom/N2 synchronous serial card
- NCR_D700= [HW,SCSI]
- See header of drivers/scsi/NCR_D700.c.
-
- ncr5380= [HW,SCSI]
-
- ncr53c400= [HW,SCSI]
-
- ncr53c400a= [HW,SCSI]
-
- ncr53c406a= [HW,SCSI]
-
- ncr53c8xx= [HW,SCSI]
-
netdev= [NET] Network devices parameters
Format: <irq>,<io>,<mem_start>,<mem_end>,<name>
Note that mem_start is often overloaded to mean
[NETFILTER] Enable connection tracking flow accounting
0 to disable accounting
1 to enable accounting
- Default value depends on CONFIG_NF_CT_ACCT that is
- going to be removed in 2.6.29.
+ Default value is 0.
nfsaddrs= [NFS]
See Documentation/filesystems/nfs/nfsroot.txt.
nointremap [X86-64, Intel-IOMMU] Do not enable interrupt
remapping.
+ [Deprecated - use intremap=off]
nointroute [IA-64]
nousb [USB] Disable the USB subsystem
+ nowatchdog [KNL] Disable the lockup detector.
+
nowb [ARM]
nox2apic [X86-64,APIC] Do not enable x2APIC mode.
OSS [HW,OSS]
See Documentation/sound/oss/oss-parameters.txt
- osst= [HW,SCSI] SCSI Tape Driver
- Format: <buffer_size>,<write_threshold>
- See also Documentation/scsi/st.txt.
-
panic= [KNL] Kernel behaviour on panic
Format: <timeout>
Currently this function knows 686a and 8231 chips.
Format: [spp|ps2|epp|ecp|ecpepp]
- pas16= [HW,SCSI]
- See header of drivers/scsi/pas16.c.
-
pause_on_oops=
Halt all CPUs after the first oops has been printed for
the specified number of seconds. This is to be used if
norom [X86] Do not assign address space to
expansion ROMs that do not already have
BIOS assigned address ranges.
+ nobar [X86] Do not assign address space to the
+ BARs that weren't assigned by the BIOS.
irqmask=0xMMMM [X86] 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
force Enable ASPM even on devices that claim not to support it.
WARNING: Forcing ASPM on may cause system lockups.
+ pcie_ports= [PCIE] PCIe ports handling:
+ auto Ask the BIOS whether or not to use native PCIe services
+ associated with PCIe ports (PME, hot-plug, AER). Use
+ them only if that is allowed by the BIOS.
+ native Use native PCIe services associated with PCIe ports
+ unconditionally.
+ compat Treat PCIe ports as PCI-to-PCI bridges, disable the PCIe
+ ports driver.
+
pcie_pme= [PCIE,PM] Native PCIe PME signaling options:
- Format: {auto|force}[,nomsi]
- auto Use native PCIe PME signaling if the BIOS allows the
- kernel to control PCIe config registers of root ports.
- force Use native PCIe PME signaling even if the BIOS refuses
- to allow the kernel to control the relevant PCIe config
- registers.
nomsi Do not use MSI for native PCIe PME signaling (this makes
- all PCIe root ports use INTx for everything).
+ all PCIe root ports use INTx for all services).
pcmv= [HW,PCMCIA] BadgePAD 4
Reserves a hole at the top of the kernel virtual
address space.
+ reservelow= [X86]
+ Format: nn[K]
+ Set the amount of memory to reserve for BIOS at
+ the bottom of the address space.
+
reset_devices [KNL] Force drivers to reset the underlying device
during initialization.
in <PAGE_SIZE> units (needed only for swap files).
See Documentation/power/swsusp-and-swap-files.txt
+ hibernate= [HIBERNATION]
+ noresume Don't check if there's a hibernation image
+ present during boot.
+ nocompress Don't compress/decompress hibernation images.
+
retain_initrd [RAM] Keep initrd memory after extraction
rhash_entries= [KNL,NET]
sched_debug [KNL] Enables verbose scheduler debug messages.
- scsi_debug_*= [SCSI]
- See drivers/scsi/scsi_debug.c.
-
- scsi_default_dev_flags=
- [SCSI] SCSI default device flags
- Format: <integer>
-
- scsi_dev_flags= [SCSI] Black/white list entry for vendor and model
- Format: <vendor>:<model>:<flags>
- (flags are integer value)
-
- scsi_logging_level= [SCSI] a bit mask of logging levels
- See drivers/scsi/scsi_logging.h for bits. Also
- settable via sysctl at dev.scsi.logging_level
- (/proc/sys/dev/scsi/logging_level).
- There is also a nice 'scsi_logging_level' script in the
- S390-tools package, available for download at
- http://www-128.ibm.com/developerworks/linux/linux390/s390-tools-1.5.4.html
-
- scsi_mod.scan= [SCSI] sync (default) scans SCSI busses as they are
- discovered. async scans them in kernel threads,
- allowing boot to proceed. none ignores them, expecting
- user space to do the scan.
-
security= [SECURITY] Choose a security module to enable at boot.
If this boot parameter is not specified, only the first
security module asking for security registration will be
If enabled at boot time, /selinux/disable can be used
later to disable prior to initial policy load.
+ apparmor= [APPARMOR] Disable or enable AppArmor at boot time
+ Format: { "0" | "1" }
+ See security/apparmor/Kconfig help text
+ 0 -- disable.
+ 1 -- enable.
+ Default value is set via kernel config option.
+
serialnumber [BUGS=X86-32]
shapers= [NET]
The parameter means the number of CPUs to show,
for example 1 means boot CPU only.
- sim710= [SCSI,HW]
- See header of drivers/scsi/sim710.c.
-
simeth= [IA-64]
simscsi=
spia_pedr=
spia_peddr=
- st= [HW,SCSI] SCSI tape parameters (buffers, etc.)
- See Documentation/scsi/st.txt.
-
stacktrace [FTRACE]
Enabled the stack tracer on boot up.
switches= [HW,M68k]
- sym53c416= [HW,SCSI]
- See header of drivers/scsi/sym53c416.c.
-
sysrq_always_enabled
[KNL]
Ignore sysrq setting - this boot parameter will
neutralize any effect of /proc/sys/kernel/sysrq.
Useful for debugging.
- t128= [HW,SCSI]
- See header of drivers/scsi/t128.c.
-
tdfx= [HW,DRM]
test_suspend= [SUSPEND]
<deci-seconds>: poll all this frequency
0: no polling (default)
- tmscsim= [HW,SCSI]
- See comment before function dc390_setup() in
- drivers/scsi/tmscsim.c.
-
topology= [S390]
Format: {off | on}
Specify if the kernel should make use of the cpu
disables clocksource verification at runtime.
Used to enable high-resolution timer mode on older
hardware, and in virtualized environment.
+ [x86] noirqtime: Do not use TSC to do irq accounting.
+ Used to run time disable IRQ_TIME_ACCOUNTING on any
+ platforms where RDTSC is slow and this accounting
+ can add overhead.
turbografx.map[2|3]= [HW,JOY]
TurboGraFX parallel port interface
<port#>,<js1>,<js2>,<js3>,<js4>,<js5>,<js6>,<js7>
See also Documentation/input/joystick-parport.txt
- u14-34f= [HW,SCSI] UltraStor 14F/34F SCSI host adapter
- See header of drivers/scsi/u14-34f.c.
-
uhash_entries= [KNL,NET]
Set number of hash buckets for UDP/UDP-Lite connections
overridden by individual drivers. 0 will hide
cursors, 1 will display them.
- wd33c93= [HW,SCSI]
- See header of drivers/scsi/wd33c93.c.
-
- wd7000= [HW,SCSI]
- See header of drivers/scsi/wd7000.c.
-
watchdog timers [HW,WDT] For information on watchdog timers,
see Documentation/watchdog/watchdog-parameters.txt
or other driver-specific files in the
xd= [HW,XT] Original XT pre-IDE (RLL encoded) disks.
xd_geo= See header of drivers/block/xd.c.
+ xen_emul_unplug= [HW,X86,XEN]
+ Unplug Xen emulated devices
+ Format: [unplug0,][unplug1]
+ ide-disks -- unplug primary master IDE devices
+ aux-ide-disks -- unplug non-primary-master IDE devices
+ nics -- unplug network devices
+ all -- unplug all emulated devices (NICs and IDE disks)
+ unnecessary -- unplugging emulated devices is
+ unnecessary even if the host did not respond to
+ the unplug protocol
+ never -- do not unplug even if version check succeeds
+
xirc2ps_cs= [NET,PCMCIA]
Format:
<irq>,<irq_mask>,<io>,<full_duplex>,<do_sound>,<lockup_hack>[,<irq2>[,<irq3>[,<irq4>]]]