kernel-parameters.txt

	nfs.callback_tcpport=
			[NFS] set the TCP port on which the NFSv4 callback
			channel should listen.

	nfs.idmap_cache_timeout=
			[NFS] set the maximum lifetime for idmapper cache
			entries.

	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.

	noaliencache	[MM, NUMA] Disables the allcoation of alien caches in
			the slab allocator.  Saves per-node memory, but will
			impact performance on real NUMA hardware.

	noalign		[KNL,ARM]

	noapic		[SMP,APIC] Tells the kernel to not make use of any
			IOAPICs that may be present in the system.

	noasync		[HW,M68K] Disables async and sync negotiation for
			all devices.

	nobats		[PPC] Do not use BATs for mapping kernel lowmem
			on "Classic" PPC cores.

	nocache		[ARM]

	nodelayacct	[KNL] Disable per-task delay accounting

	nodisconnect	[HW,SCSI,M68K] Disables SCSI disconnects.

	noexec		[IA-64]

	noexec		[IA-32,X86-64]
			noexec=on: enable non-executable mappings (default)
			noexec=off: disable nn-executable mappings

	nofxsr		[BUGS=IA-32] Disables x86 floating point extended
			register save and restore. The kernel will only save
			legacy floating-point registers on task switch.

	nohlt		[BUGS=ARM]

	no-hlt		[BUGS=IA-32] Tells the kernel that the hlt
			instruction doesn't work correctly and not to
			use it.

	nohalt		[IA-64] Tells the kernel not to use the power saving
			function PAL_HALT_LIGHT when idle. This increases
			power-consumption. On the positive side, it reduces
			interrupt wake-up latency, which may improve performance
			in certain environments such as networked servers or
			real-time systems.

	noirqdebug	[IA-32] Disables the code which attempts to detect and
			disable unhandled interrupt sources.

	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.

	noltlbs		[PPC] Do not use large page/tlb entries for kernel
			lowmem mapping on PPC40x.

	nomca		[IA-64] Disable machine check abort handling

	nomce		[IA-32] Machine Check Exception

	noresidual	[PPC] Don't use residual data on PReP machines.

	noresume	[SWSUSP] Disables resume and restores original swap
			space.

	no-scroll	[VGA] Disables scrollback.
			This is required for the Braillex ib80-piezo Braille
			reader made by F.H. Papenmeier (Germany).

	nosbagart	[IA-64]

	nosep		[BUGS=IA-32] Disables x86 SYSENTER/SYSEXIT support.

	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

	nousb		[USB] Disable the USB subsystem

	nowb		[ARM]

	nr_uarts=	[SERIAL] maximum number of UARTs to be registered.

	opl3=		[HW,OSS]
			Format: <io>

	opl3sa2=	[HW,OSS] Format:
			<io>,<irq>,<dma>,<dma2>,<mss_io>,<mpu_io>,<ymode>,<loopback>[,<isapnp>,<multiple]

	oprofile.timer=	[HW]
			Use timer interrupt instead of performance counters

	optcd=		[HW,CD]
			Format: <io>

	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>

	parkbd.port=	[HW] Parallel port number the keyboard adapter is
			connected to, default is 0.
			Format: <parport#>
	parkbd.mode=	[HW] Parallel port keyboard adapter mode of operation,
			0 for XT, 1 for AT (default is AT).
			Format: <mode>

	parport=	[HW,PPT] Specify parallel ports. 0 disables.
			Format: { 0 | auto | 0xBBB[,IRQ[,DMA]] }
			Use 'auto' to force the driver to use 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.

	parport_init_mode=	[HW,PPT]
			Configure VIA parallel port to operate in
			a specific mode. This is necessary on Pegasos
			computer where firmware has no options for setting
			up parallel port mode and sets it to spp.
			Currently this function knows 686a and 8231 chips.
			Format: [spp|ps2|epp|ecp|ecpepp]

	pas2=		[HW,OSS] Format:
			<io>,<irq>,<dma>,<dma16>,<sb_io>,<sb_irq>,<sb_dma>,<sb_dma16>

	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
			your oopses keep scrolling off the screen.

	pcbit=		[HW,ISDN]

	pcd.		[PARIDE]
			See header of drivers/block/paride/pcd.c.
			See also Documentation/paride.txt.

	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.
		nommconf	[IA-32,X86_64] Disable use of MMCONFIG for PCI
				Configuration
		nomsi		[MSI] If the PCI_MSI kernel config parameter is
				enabled, this kernel boot option can be used to
				disable the use of MSI interrupts system-wide.
		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.
		pirqaddr=0xAAAAA	[IA-32] Specify the physical address
				of the PIRQ table (normally generated
				by the BIOS) if it is outside the
				F0000h-100000h range.
		lastbus=N	[IA-32] Scan all buses thru 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.
		usepirqmask	[IA-32] Honor the possible IRQ mask stored
				in the BIOS $PIR table. This is needed on
				some systems with broken BIOSes, notably
				some HP Pavilion N5400 and Omnibook XE3
				notebooks. This will have no effect if ACPI
				IRQ routing is enabled.
		noacpi		[IA-32] Do not use ACPI for IRQ routing
				or for PCI scanning.
		routeirq	Do IRQ routing for all PCI devices.
				This is normally done in pci_enable_device(),
				so this option is a temporary workaround
				for broken drivers that don't call it.
		firmware	[ARM] Do not re-enumerate the bus but instead
				just use the configuration from the
				bootloader. This is currently used on
				IXP2000 systems where the bus has to be
				configured a certain way for adjunct CPUs.
		noearly		[X86] Don't do any early type 1 scanning.
				This might help on some broken boards which
				machine check when some devices' config space
				is read. But various workarounds are disabled
				and some IOMMU drivers will not work.
		bfsort		Sort PCI devices into breadth-first order.
				This sorting is done to get a device
				order compatible with older (<= 2.4) kernels.
		nobfsort	Don't sort PCI devices into breadth-first order.

	pcmv=		[HW,PCMCIA] BadgePAD 4

	pd.		[PARIDE]
			See Documentation/paride.txt.

	pdcchassis=	[PARISC,HW] Disable/Enable PDC Chassis Status codes at
			boot time.
			Format: { 0 | 1 }
			See arch/parisc/kernel/pdc_chassis.c

	pf.		[PARIDE]
			See Documentation/paride.txt.

	pg.		[PARIDE]
			See Documentation/paride.txt.

	pirq=		[SMP,APIC] Manual mp-table setup
			See Documentation/i386/IO-APIC.txt.

	plip=		[PPT,NET] Parallel port network link
			Format: { parport<nr> | timid | 0 }
			See also Documentation/parport.txt.

	pnpacpi=	[ACPI]
			{ off }

	pnpbios=	[ISAPNP]
			{ on | off | curr | res | no-curr | no-res }

	pnp_reserve_irq=
			[ISAPNP] Exclude IRQs for the autoconfiguration

	pnp_reserve_dma=
			[ISAPNP] Exclude DMAs for the autoconfiguration

	pnp_reserve_io=	[ISAPNP] Exclude I/O ports for the autoconfiguration
			Ranges are in pairs (I/O port base and size).

	pnp_reserve_mem=
			[ISAPNP] Exclude memory regions for the
			autoconfiguration.
			Ranges are in pairs (memory base and size).

	profile=	[KNL] Enable kernel profiling via /proc/profile
			Format: [schedule,]<number>
			Param: "schedule" - profile schedule points.
			Param: <number> - step/bucket size as a power of 2 for
				statistical time based profiling.

	processor.max_cstate=	[HW,ACPI]
			Limit processor to maximum C-state
			max_cstate=9 overrides any DMI blacklist limit.

	processor.nocst	[HW,ACPI]
			Ignore the _CST method to determine C-states,
			instead using the legacy FADT method

	prompt_ramdisk=	[RAM] List of RAM disks to prompt for floppy disk
			before loading.
			See Documentation/ramdisk.txt.

	psmouse.proto=	[HW,MOUSE] Highest PS2 mouse protocol extension to
			probe for; one of (bare|imps|exps|lifebook|any).
	psmouse.rate=	[HW,MOUSE] Set desired mouse report rate, in reports
			per second.
	psmouse.resetafter=	[HW,MOUSE]
			Try to reset the device after so many bad packets
			(0 = never).
	psmouse.resolution=
			[HW,MOUSE] Set desired mouse resolution, in dpi.
	psmouse.smartscroll=
			[HW,MOUSE] Controls Logitech smartscroll autorepeat.
			0 = disabled, 1 = enabled (default).

	pss=		[HW,OSS] Personal Sound System (ECHO ESC614)
			Format:
			<io>,<mss_io>,<mss_irq>,<mss_dma>,<mpu_io>,<mpu_irq>

	pt.		[PARIDE]
			See Documentation/paride.txt.

	quiet		[KNL] Disable most log messages

	r128=		[HW,DRM]

	raid=		[HW,RAID]
			See Documentation/md.txt.

	ramdisk=	[RAM] Sizes of RAM disks in kilobytes [deprecated]
			See Documentation/ramdisk.txt.

	ramdisk_blocksize=	[RAM]
			See Documentation/ramdisk.txt.

	ramdisk_size=	[RAM] Sizes of RAM disks in kilobytes
			New name for the ramdisk parameter.
			See Documentation/ramdisk.txt.

	rcu.blimit=	[KNL,BOOT] Set maximum number of finished
			RCU callbacks to process in one batch.

	rcu.qhimark=	[KNL,BOOT] Set threshold of queued
			RCU callbacks over which batch limiting is disabled.

	rcu.qlowmark=	[KNL,BOOT] Set threshold of queued
			RCU callbacks below which batch limiting is re-enabled.

	rdinit=		[KNL]
			Format: <full_path>
			Run specified binary instead of /init from the ramdisk,
			used for early userspace startup. See initrd.

	reboot=		[BUGS=IA-32,BUGS=ARM,BUGS=IA-64] Rebooting mode
			Format: <reboot_mode>[,<reboot_mode2>[,...]]
			See arch/*/kernel/reboot.c or arch/*/kernel/process.c			

	reserve=	[KNL,BUGS] Force the kernel to ignore some iomem area

	reservetop=	[IA-32]
			Format: nn[KMG]
			Reserves a hole at the top of the kernel virtual
			address space.

	reset_devices	[KNL] Force drivers to reset the underlying device
			during initialization.

	resume=		[SWSUSP]
			Specify the partition device for software suspend

	resume_offset=	[SWSUSP]
			Specify the offset from the beginning of the partition
			given by "resume=" at which the swap header is located,
			in <PAGE_SIZE> units (needed only for swap files).
			See  Documentation/power/swsusp-and-swap-files.txt

	rhash_entries=	[KNL,NET]
			Set number of hash buckets for route cache

	riscom8=	[HW,SERIAL]
			Format: <io_board1>[,<io_board2>[,...<io_boardN>]]

	ro		[KNL] Mount root device read-only on boot

	root=		[KNL] Root filesystem

	rootdelay=	[KNL] Delay (in seconds) to pause before attempting to
			mount the 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

	sa1100ir	[NET]
			See drivers/net/irda/sa1100_ir.c.

	sb=		[HW,OSS]
			Format: <io>,<irq>,<dma>,<dma2>

	sbni=		[NET] Granch SBNI12 leased line adapter

	sbpcd=		[HW,CD] Soundblaster CD adapter
			Format: <io>,<type>
			See a comment before function sbpcd_setup() in
			drivers/cdrom/sbpcd.c.

	sc1200wdt=	[HW,WDT] SC1200 WDT (watchdog) driver
			Format: <io>[,<timeout>[,<isapnp>]]

	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=	[SCSI]

	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.

	selinux		[SELINUX] Disable or enable SELinux at boot time.
			Format: { "0" | "1" }
			See security/selinux/Kconfig help text.
			0 -- disable.
			1 -- enable.
			Default value is set via kernel config option.
			If enabled at boot time, /selinux/disable can be used
			later to disable prior to initial policy load.

	selinux_compat_net =
			[SELINUX] Set initial selinux_compat_net flag value.
                        Format: { "0" | "1" }
                        0 -- use new secmark-based packet controls
                        1 -- use legacy packet controls
                        Default value is 0 (preferred).
                        Value can be changed at runtime via
                        /selinux/compat_net.

	serialnumber	[BUGS=IA-32]

	sg_def_reserved_size=	[SCSI]

	shapers=	[NET]
			Maximal number of shapers.

	sim710=		[SCSI,HW]
			See header of drivers/scsi/sim710.c.

	simeth=		[IA-64]
	simscsi=

	sjcd=		[HW,CD]
			Format: <io>,<irq>,<dma>
			See header of drivers/cdrom/sjcd.c.

	slram=		[HW,MTD]

	smart2=		[HW]
			Format: <io1>[,<io2>[,...,<io8>]]

	snd-ad1816a=	[HW,ALSA]

	snd-ad1848=	[HW,ALSA]

	snd-ali5451=	[HW,ALSA]

	snd-als100=	[HW,ALSA]

	snd-als4000=	[HW,ALSA]

	snd-azt2320=	[HW,ALSA]

	snd-cmi8330=	[HW,ALSA]

	snd-cmipci=	[HW,ALSA]

	snd-cs4231=	[HW,ALSA]

	snd-cs4232=	[HW,ALSA]

	snd-cs4236=	[HW,ALSA]

	snd-cs4281=	[HW,ALSA]

	snd-cs46xx=	[HW,ALSA]

	snd-dt019x=	[HW,ALSA]

	snd-dummy=	[HW,ALSA]

	snd-emu10k1=	[HW,ALSA]

	snd-ens1370=	[HW,ALSA]

	snd-ens1371=	[HW,ALSA]

	snd-es968=	[HW,ALSA]

	snd-es1688=	[HW,ALSA]

	snd-es18xx=	[HW,ALSA]

	snd-es1938=	[HW,ALSA]

	snd-es1968=	[HW,ALSA]

	snd-fm801=	[HW,ALSA]

	snd-gusclassic=	[HW,ALSA]

	snd-gusextreme=	[HW,ALSA]

	snd-gusmax=	[HW,ALSA]

	snd-hdsp=	[HW,ALSA]

	snd-ice1712=	[HW,ALSA]

	snd-intel8x0=	[HW,ALSA]

	snd-interwave=	[HW,ALSA]

	snd-interwave-stb=
			[HW,ALSA]

	snd-korg1212=	[HW,ALSA]

	snd-maestro3=	[HW,ALSA]

	snd-mpu401=	[HW,ALSA]

	snd-mtpav=	[HW,ALSA]

	snd-nm256=	[HW,ALSA]

	snd-opl3sa2=	[HW,ALSA]

	snd-opti92x-ad1848=
			[HW,ALSA]

	snd-opti92x-cs4231=
			[HW,ALSA]

	snd-opti93x=	[HW,ALSA]

	snd-pmac=	[HW,ALSA]

	snd-rme32=	[HW,ALSA]

	snd-rme96=	[HW,ALSA]

	snd-rme9652=	[HW,ALSA]

	snd-sb8=	[HW,ALSA]

	snd-sb16=	[HW,ALSA]

	snd-sbawe=	[HW,ALSA]

	snd-serial=	[HW,ALSA]

	snd-sgalaxy=	[HW,ALSA]

	snd-sonicvibes=	[HW,ALSA]

	snd-sun-amd7930=
			[HW,ALSA]

	snd-sun-cs4231=	[HW,ALSA]

	snd-trident=	[HW,ALSA]

	snd-usb-audio=	[HW,ALSA,USB]

	snd-via82xx=	[HW,ALSA]

	snd-virmidi=	[HW,ALSA]

	snd-wavefront=	[HW,ALSA]

	snd-ymfpci=	[HW,ALSA]

	sonycd535=	[HW,CD]
			Format: <io>[,<irq>]

	sonypi.*=	[HW] Sony Programmable I/O Control Device driver
			See Documentation/sonypi.txt

	specialix=	[HW,SERIAL] Specialix multi-serial port adapter
			See Documentation/specialix.txt.

	spia_io_base=	[HW,MTD]
	spia_fio_base=
	spia_pedr=
	spia_peddr=

	sscape=		[HW,OSS]
			Format: <io>,<irq>,<dma>,<mpu_io>,<mpu_irq>

	st=		[HW,SCSI] SCSI tape parameters (buffers, etc.)
			See Documentation/scsi/st.txt.

	st0x=		[HW,SCSI]
			See header of drivers/scsi/seagate.c.

	sti=		[PARISC,HW]
			Format: <num>
			Set the STI (builtin display/keyboard on the HP-PARISC
			machines) console (graphic card) which should be used
			as the initial boot-console.
			See also comment in drivers/video/console/sticore.c.

	sti_font=	[HW]
			See comment in drivers/video/console/sticore.c.

	stifb=		[HW]
			Format: bpp:<bpp1>[:<bpp2>[:<bpp3>...]]

	swiotlb=	[IA-64] Number of I/O TLB slabs

	switches=	[HW,M68k]

	sym53c416=	[HW,SCSI]
			See header of drivers/scsi/sym53c416.c.

	t128=		[HW,SCSI]
			See header of drivers/scsi/t128.c.

	tdfx=		[HW,DRM]

	thash_entries=	[KNL,NET]
			Set number of hash buckets for TCP connection

	time		Show timing data prefixed to each printk message line

	clocksource=	[GENERIC_TIME] Override the default clocksource
			Override the default clocksource and use the clocksource
			with the name specified.

	tipar.timeout=	[HW,PPT]
			Set communications timeout in tenths of a second
			(default 15).

	tipar.delay=	[HW,PPT]
			Set inter-bit delay in microseconds (default 10).

	tmc8xx=		[HW,SCSI]
			See header of drivers/scsi/seagate.c.

	tmscsim=	[HW,SCSI]
			See comment before function dc390_setup() in
			drivers/scsi/tmscsim.c.

	tp720=		[HW,PS2]

	trix=		[HW,OSS] MediaTrix AudioTrix Pro
			Format:
			<io>,<irq>,<dma>,<dma2>,<sb_io>,<sb_irq>,<sb_dma>,<mpu_io>,<mpu_irq>

	tsdev.xres=	[TS] Horizontal screen resolution.
	tsdev.yres=	[TS] Vertical screen resolution.

	turbografx.map[2|3]=	[HW,JOY]
			TurboGraFX parallel port interface
			Format:
			<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.

	uart401=	[HW,OSS]
			Format: <io>,<irq>

	uart6850=	[HW,OSS]
			Format: <io>,<irq>

	usbhid.mousepoll=
			[USBHID] The interval which mice are to be polled at.

	vdso=		[IA-32]
			vdso=1: enable VDSO (default)
			vdso=0: disable VDSO mapping

	video=		[FB] Frame buffer configuration
			See Documentation/fb/modedb.txt.

	vga=		[BOOT,IA-32] Select a particular video mode
			See Documentation/i386/boot.txt and
			Documentation/svga.txt.
			Use vga=ask for menu.
			This is actually a boot loader parameter; the value is
			passed to the kernel using a special protocol.

	vmalloc=nn[KMG]	[KNL,BOOT] Forces the vmalloc area to have an exact
			size of <nn>. This can be used to increase the
			minimum size (128MB on x86). It can also be used to
			decrease the size and leave more room for directly
			mapped kernel RAM.

	vmhalt=		[KNL,S390] Perform z/VM CP command after system halt.
			Format: <command>

	vmpanic=	[KNL,S390] Perform z/VM CP command after kernel panic.
			Format: <command>

	vmpoff=		[KNL,S390] Perform z/VM CP command after power off.
			Format: <command>

	waveartist=	[HW,OSS]
			Format: <io>,<irq>,<dma>,<dma2>

	wd33c93=	[HW,SCSI]
			See header of drivers/scsi/wd33c93.c.

	wd7000=		[HW,SCSI]
			See header of drivers/scsi/wd7000.c.

	wdt=		[WDT] Watchdog
			See Documentation/watchdog/watchdog.txt.

	xd=		[HW,XT] Original XT pre-IDE (RLL encoded) disks.
	xd_geo=		See header of drivers/block/xd.c.

	xirc2ps_cs=	[NET,PCMCIA]
			Format:
			<irq>,<irq_mask>,<io>,<full_duplex>,<do_sound>,<lockup_hack>[,<irq2>[,<irq3>[,<irq4>]]]

	norandmaps	Don't use address space randomization
			Equivalent to echo 0 > /proc/sys/kernel/randomize_va_space


______________________________________________________________________

TODO:

	Add documentation for ALSA options.
	Add more DRM drivers.