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Based on kernel version 2.6.34. Page generated on 2010-05-31 16:03 EST.

1	                          Kernel Parameters
2	                          ~~~~~~~~~~~~~~~~~
3	
4	The following is a consolidated list of the kernel parameters as implemented
5	(mostly) by the __setup() macro and sorted into English Dictionary order
6	(defined as ignoring all punctuation and sorting digits before letters in a
7	case insensitive manner), and with descriptions where known.
8	
9	Module parameters for loadable modules are specified only as the
10	parameter name with optional '=' and value as appropriate, such as:
11	
12		modprobe usbcore blinkenlights=1
13	
14	Module parameters for modules that are built into the kernel image
15	are specified on the kernel command line with the module name plus
16	'.' plus parameter name, with '=' and value if appropriate, such as:
17	
18		usbcore.blinkenlights=1
19	
20	Hyphens (dashes) and underscores are equivalent in parameter names, so
21		log_buf_len=1M print-fatal-signals=1
22	can also be entered as
23		log-buf-len=1M print_fatal_signals=1
24	
25	
26	This document may not be entirely up to date and comprehensive. The command
27	"modinfo -p ${modulename}" shows a current list of all parameters of a loadable
28	module. Loadable modules, after being loaded into the running kernel, also
29	reveal their parameters in /sys/module/${modulename}/parameters/. Some of these
30	parameters may be changed at runtime by the command
31	"echo -n ${value} > /sys/module/${modulename}/parameters/${parm}".
32	
33	The parameters listed below are only valid if certain kernel build options were
34	enabled and if respective hardware is present. The text in square brackets at
35	the beginning of each description states the restrictions within which a
36	parameter is applicable:
37	
38		ACPI	ACPI support is enabled.
39		AGP	AGP (Accelerated Graphics Port) is enabled.
40		ALSA	ALSA sound support is enabled.
41		APIC	APIC support is enabled.
42		APM	Advanced Power Management support is enabled.
43		AVR32	AVR32 architecture is enabled.
44		AX25	Appropriate AX.25 support is enabled.
45		BLACKFIN Blackfin architecture is enabled.
46		DRM	Direct Rendering Management support is enabled.
47		EDD	BIOS Enhanced Disk Drive Services (EDD) is enabled
48		EFI	EFI Partitioning (GPT) is enabled
49		EIDE	EIDE/ATAPI support is enabled.
50		FB	The frame buffer device is enabled.
51		GCOV	GCOV profiling is enabled.
52		HW	Appropriate hardware is enabled.
53		IA-64	IA-64 architecture is enabled.
54		IMA     Integrity measurement architecture is enabled.
55		IOSCHED	More than one I/O scheduler is enabled.
56		IP_PNP	IP DHCP, BOOTP, or RARP is enabled.
57		IPV6	IPv6 support is enabled.
58		ISAPNP	ISA PnP code is enabled.
59		ISDN	Appropriate ISDN support is enabled.
60		JOY	Appropriate joystick support is enabled.
61		KVM	Kernel Virtual Machine support is enabled.
62		LIBATA  Libata driver is enabled
63		LP	Printer support is enabled.
64		LOOP	Loopback device support is enabled.
65		M68k	M68k architecture is enabled.
66				These options have more detailed description inside of
67				Documentation/m68k/kernel-options.txt.
68		MCA	MCA bus support is enabled.
69		MDA	MDA console support is enabled.
70		MOUSE	Appropriate mouse support is enabled.
71		MSI	Message Signaled Interrupts (PCI).
72		MTD	MTD (Memory Technology Device) support is enabled.
73		NET	Appropriate network support is enabled.
74		NUMA	NUMA support is enabled.
75		GENERIC_TIME The generic timeofday code is enabled.
76		NFS	Appropriate NFS support is enabled.
77		OSS	OSS sound support is enabled.
78		PV_OPS	A paravirtualized kernel is enabled.
79		PARIDE	The ParIDE (parallel port IDE) subsystem is enabled.
80		PARISC	The PA-RISC architecture is enabled.
81		PCI	PCI bus support is enabled.
82		PCIE	PCI Express support is enabled.
83		PCMCIA	The PCMCIA subsystem is enabled.
84		PNP	Plug & Play support is enabled.
85		PPC	PowerPC architecture is enabled.
86		PPT	Parallel port support is enabled.
87		PS2	Appropriate PS/2 support is enabled.
88		RAM	RAM disk support is enabled.
89		S390	S390 architecture is enabled.
90		SCSI	Appropriate SCSI support is enabled.
91				A lot of drivers has their options described inside of
92				Documentation/scsi/.
93		SECURITY Different security models are enabled.
94		SELINUX SELinux support is enabled.
95		SERIAL	Serial support is enabled.
96		SH	SuperH architecture is enabled.
97		SMP	The kernel is an SMP kernel.
98		SPARC	Sparc architecture is enabled.
99		SWSUSP	Software suspend (hibernation) is enabled.
100		SUSPEND	System suspend states are enabled.
101		FTRACE	Function tracing enabled.
102		TS	Appropriate touchscreen support is enabled.
103		UMS	USB Mass Storage support is enabled.
104		USB	USB support is enabled.
105		USBHID	USB Human Interface Device support is enabled.
106		V4L	Video For Linux support is enabled.
107		VGA	The VGA console has been enabled.
108		VT	Virtual terminal support is enabled.
109		WDT	Watchdog support is enabled.
110		XT	IBM PC/XT MFM hard disk support is enabled.
111		X86-32	X86-32, aka i386 architecture is enabled.
112		X86-64	X86-64 architecture is enabled.
113				More X86-64 boot options can be found in
114				Documentation/x86/x86_64/boot-options.txt .
115		X86	Either 32bit or 64bit x86 (same as X86-32+X86-64)
116	
117	In addition, the following text indicates that the option:
118	
119		BUGS=	Relates to possible processor bugs on the said processor.
120		KNL	Is a kernel start-up parameter.
121		BOOT	Is a boot loader parameter.
122	
123	Parameters denoted with BOOT are actually interpreted by the boot
124	loader, and have no meaning to the kernel directly.
125	Do not modify the syntax of boot loader parameters without extreme
126	need or coordination with <Documentation/x86/boot.txt>.
127	
128	There are also arch-specific kernel-parameters not documented here.
129	See for example <Documentation/x86/x86_64/boot-options.txt>.
130	
131	Note that ALL kernel parameters listed below are CASE SENSITIVE, and that
132	a trailing = on the name of any parameter states that that parameter will
133	be entered as an environment variable, whereas its absence indicates that
134	it will appear as a kernel argument readable via /proc/cmdline by programs
135	running once the system is up.
136	
137	The number of kernel parameters is not limited, but the length of the
138	complete command line (parameters including spaces etc.) is limited to
139	a fixed number of characters. This limit depends on the architecture
140	and is between 256 and 4096 characters. It is defined in the file
141	./include/asm/setup.h as COMMAND_LINE_SIZE.
142	
143	
144		acpi=		[HW,ACPI,X86]
145				Advanced Configuration and Power Interface
146				Format: { force | off | ht | strict | noirq | rsdt }
147				force -- enable ACPI if default was off
148				off -- disable ACPI if default was on
149				noirq -- do not use ACPI for IRQ routing
150				ht -- run only enough ACPI to enable Hyper Threading
151				strict -- Be less tolerant of platforms that are not
152					strictly ACPI specification compliant.
153				rsdt -- prefer RSDT over (default) XSDT
154	
155				See also Documentation/power/pm.txt, pci=noacpi
156	
157		acpi_apic_instance=	[ACPI, IOAPIC]
158				Format: <int>
159				2: use 2nd APIC table, if available
160				1,0: use 1st APIC table
161				default: 0
162	
163		acpi_backlight=	[HW,ACPI]
164				acpi_backlight=vendor
165				acpi_backlight=video
166				If set to vendor, prefer vendor specific driver
167				(e.g. thinkpad_acpi, sony_acpi, etc.) instead
168				of the ACPI video.ko driver.
169	
170		acpi.debug_layer=	[HW,ACPI,ACPI_DEBUG]
171		acpi.debug_level=	[HW,ACPI,ACPI_DEBUG]
172				Format: <int>
173				CONFIG_ACPI_DEBUG must be enabled to produce any ACPI
174				debug output.  Bits in debug_layer correspond to a
175				_COMPONENT in an ACPI source file, e.g.,
176				    #define _COMPONENT ACPI_PCI_COMPONENT
177				Bits in debug_level correspond to a level in
178				ACPI_DEBUG_PRINT statements, e.g.,
179				    ACPI_DEBUG_PRINT((ACPI_DB_INFO, ...
180				The debug_level mask defaults to "info".  See
181				Documentation/acpi/debug.txt for more information about
182				debug layers and levels.
183	
184				Enable processor driver info messages:
185				    acpi.debug_layer=0x20000000
186				Enable PCI/PCI interrupt routing info messages:
187				    acpi.debug_layer=0x400000
188				Enable AML "Debug" output, i.e., stores to the Debug
189				object while interpreting AML:
190				    acpi.debug_layer=0xffffffff acpi.debug_level=0x2
191				Enable all messages related to ACPI hardware:
192				    acpi.debug_layer=0x2 acpi.debug_level=0xffffffff
193	
194				Some values produce so much output that the system is
195				unusable.  The "log_buf_len" parameter may be useful
196				if you need to capture more output.
197	
198		acpi_display_output=	[HW,ACPI]
199				acpi_display_output=vendor
200				acpi_display_output=video
201				See above.
202	
203		acpi_irq_balance [HW,ACPI]
204				ACPI will balance active IRQs
205				default in APIC mode
206	
207		acpi_irq_nobalance [HW,ACPI]
208				ACPI will not move active IRQs (default)
209				default in PIC mode
210	
211		acpi_irq_isa=	[HW,ACPI] If irq_balance, mark listed IRQs used by ISA
212				Format: <irq>,<irq>...
213	
214		acpi_irq_pci=	[HW,ACPI] If irq_balance, clear listed IRQs for
215				use by PCI
216				Format: <irq>,<irq>...
217	
218		acpi_no_auto_ssdt	[HW,ACPI] Disable automatic loading of SSDT
219	
220		acpi_os_name=	[HW,ACPI] Tell ACPI BIOS the name of the OS
221				Format: To spoof as Windows 98: ="Microsoft Windows"
222	
223		acpi_osi=	[HW,ACPI] Modify list of supported OS interface strings
224				acpi_osi="string1"	# add string1 -- only one string
225				acpi_osi="!string2"	# remove built-in string2
226				acpi_osi=		# disable all strings
227	
228		acpi_pm_good	[X86]
229				Override the pmtimer bug detection: force the kernel
230				to assume that this machine's pmtimer latches its value
231				and always returns good values.
232	
233		acpi_sci=	[HW,ACPI] ACPI System Control Interrupt trigger mode
234				Format: { level | edge | high | low }
235	
236		acpi_serialize	[HW,ACPI] force serialization of AML methods
237	
238		acpi_skip_timer_override [HW,ACPI]
239				Recognize and ignore IRQ0/pin2 Interrupt Override.
240				For broken nForce2 BIOS resulting in XT-PIC timer.
241	
242		acpi_sleep=	[HW,ACPI] Sleep options
243				Format: { s3_bios, s3_mode, s3_beep, s4_nohwsig,
244					  old_ordering, s4_nonvs, sci_force_enable }
245				See Documentation/power/video.txt for information on
246				s3_bios and s3_mode.
247				s3_beep is for debugging; it makes the PC's speaker beep
248				as soon as the kernel's real-mode entry point is called.
249				s4_nohwsig prevents ACPI hardware signature from being
250				used during resume from hibernation.
251				old_ordering causes the ACPI 1.0 ordering of the _PTS
252				control method, with respect to putting devices into
253				low power states, to be enforced (the ACPI 2.0 ordering
254				of _PTS is used by default).
255				s4_nonvs prevents the kernel from saving/restoring the
256				ACPI NVS memory during hibernation.
257				sci_force_enable causes the kernel to set SCI_EN directly
258				on resume from S1/S3 (which is against the ACPI spec,
259				but some broken systems don't work without it).
260	
261		acpi_use_timer_override [HW,ACPI]
262				Use timer override. For some broken Nvidia NF5 boards
263				that require a timer override, but don't have HPET
264	
265		acpi_enforce_resources=	[ACPI]
266				{ strict | lax | no }
267				Check for resource conflicts between native drivers
268				and ACPI OperationRegions (SystemIO and SystemMemory
269				only). IO ports and memory declared in ACPI might be
270				used by the ACPI subsystem in arbitrary AML code and
271				can interfere with legacy drivers.
272				strict (default): access to resources claimed by ACPI
273				is denied; legacy drivers trying to access reserved
274				resources will fail to bind to device using them.
275				lax: access to resources claimed by ACPI is allowed;
276				legacy drivers trying to access reserved resources
277				will bind successfully but a warning message is logged.
278				no: ACPI OperationRegions are not marked as reserved,
279				no further checks are performed.
280	
281		ad1848=		[HW,OSS]
282				Format: <io>,<irq>,<dma>,<dma2>,<type>
283	
284		add_efi_memmap	[EFI; X86] Include EFI memory map in
285				kernel's map of available physical RAM.
286	
287		advansys=	[HW,SCSI]
288				See header of drivers/scsi/advansys.c.
289	
290		advwdt=		[HW,WDT] Advantech WDT
291				Format: <iostart>,<iostop>
292	
293		aedsp16=	[HW,OSS] Audio Excel DSP 16
294				Format: <io>,<irq>,<dma>,<mss_io>,<mpu_io>,<mpu_irq>
295				See also header of sound/oss/aedsp16.c.
296	
297		agp=		[AGP]
298				{ off | try_unsupported }
299				off: disable AGP support
300				try_unsupported: try to drive unsupported chipsets
301					(may crash computer or cause data corruption)
302	
303		aha152x=	[HW,SCSI]
304				See Documentation/scsi/aha152x.txt.
305	
306		aha1542=	[HW,SCSI]
307				Format: <portbase>[,<buson>,<busoff>[,<dmaspeed>]]
308	
309		aic7xxx=	[HW,SCSI]
310				See Documentation/scsi/aic7xxx.txt.
311	
312		aic79xx=	[HW,SCSI]
313				See Documentation/scsi/aic79xx.txt.
314	
315		alignment=	[KNL,ARM]
316				Allow the default userspace alignment fault handler
317				behaviour to be specified.  Bit 0 enables warnings,
318				bit 1 enables fixups, and bit 2 sends a segfault.
319	
320		amd_iommu=	[HW,X86-84]
321				Pass parameters to the AMD IOMMU driver in the system.
322				Possible values are:
323				fullflush - enable flushing of IO/TLB entries when
324					    they are unmapped. Otherwise they are
325					    flushed before they will be reused, which
326					    is a lot of faster
327	
328		amijoy.map=	[HW,JOY] Amiga joystick support
329				Map of devices attached to JOY0DAT and JOY1DAT
330				Format: <a>,<b>
331				See also Documentation/kernel/input/joystick.txt
332	
333		analog.map=	[HW,JOY] Analog joystick and gamepad support
334				Specifies type or capabilities of an analog joystick
335				connected to one of 16 gameports
336				Format: <type1>,<type2>,..<type16>
337	
338		apc=		[HW,SPARC]
339				Power management functions (SPARCstation-4/5 + deriv.)
340				Format: noidle
341				Disable APC CPU standby support. SPARCstation-Fox does
342				not play well with APC CPU idle - disable it if you have
343				APC and your system crashes randomly.
344	
345		apic=		[APIC,X86-32] Advanced Programmable Interrupt Controller
346				Change the output verbosity whilst booting
347				Format: { quiet (default) | verbose | debug }
348				Change the amount of debugging information output
349				when initialising the APIC and IO-APIC components.
350	
351		autoconf=	[IPV6]
352				See Documentation/networking/ipv6.txt.
353	
354		show_lapic=	[APIC,X86] Advanced Programmable Interrupt Controller
355				Limit apic dumping. The parameter defines the maximal
356				number of local apics being dumped. Also it is possible
357				to set it to "all" by meaning -- no limit here.
358				Format: { 1 (default) | 2 | ... | all }.
359				The parameter valid if only apic=debug or
360				apic=verbose is specified.
361				Example: apic=debug show_lapic=all
362	
363		apm=		[APM] Advanced Power Management
364				See header of arch/x86/kernel/apm_32.c.
365	
366		arcrimi=	[HW,NET] ARCnet - "RIM I" (entirely mem-mapped) cards
367				Format: <io>,<irq>,<nodeID>
368	
369		ataflop=	[HW,M68k]
370	
371		atarimouse=	[HW,MOUSE] Atari Mouse
372	
373		atascsi=	[HW,SCSI] Atari SCSI
374	
375		atkbd.extra=	[HW] Enable extra LEDs and keys on IBM RapidAccess,
376				EzKey and similar keyboards
377	
378		atkbd.reset=	[HW] Reset keyboard during initialization
379	
380		atkbd.set=	[HW] Select keyboard code set
381				Format: <int> (2 = AT (default), 3 = PS/2)
382	
383		atkbd.scroll=	[HW] Enable scroll wheel on MS Office and similar
384				keyboards
385	
386		atkbd.softraw=	[HW] Choose between synthetic and real raw mode
387				Format: <bool> (0 = real, 1 = synthetic (default))
388	
389		atkbd.softrepeat= [HW]
390				Use software keyboard repeat
391	
392		autotest	[IA64]
393	
394		baycom_epp=	[HW,AX25]
395				Format: <io>,<mode>
396	
397		baycom_par=	[HW,AX25] BayCom Parallel Port AX.25 Modem
398				Format: <io>,<mode>
399				See header of drivers/net/hamradio/baycom_par.c.
400	
401		baycom_ser_fdx=	[HW,AX25]
402				BayCom Serial Port AX.25 Modem (Full Duplex Mode)
403				Format: <io>,<irq>,<mode>[,<baud>]
404				See header of drivers/net/hamradio/baycom_ser_fdx.c.
405	
406		baycom_ser_hdx=	[HW,AX25]
407				BayCom Serial Port AX.25 Modem (Half Duplex Mode)
408				Format: <io>,<irq>,<mode>
409				See header of drivers/net/hamradio/baycom_ser_hdx.c.
410	
411		boot_delay=	Milliseconds to delay each printk during boot.
412				Values larger than 10 seconds (10000) are changed to
413				no delay (0).
414				Format: integer
415	
416		bootmem_debug	[KNL] Enable bootmem allocator debug messages.
417	
418		bttv.card=	[HW,V4L] bttv (bt848 + bt878 based grabber cards)
419		bttv.radio=	Most important insmod options are available as
420				kernel args too.
421		bttv.pll=	See Documentation/video4linux/bttv/Insmod-options
422		bttv.tuner=	and Documentation/video4linux/bttv/CARDLIST
423	
424		BusLogic=	[HW,SCSI]
425				See drivers/scsi/BusLogic.c, comment before function
426				BusLogic_ParseDriverOptions().
427	
428		c101=		[NET] Moxa C101 synchronous serial card
429	
430		cachesize=	[BUGS=X86-32] Override level 2 CPU cache size detection.
431				Sometimes CPU hardware bugs make them report the cache
432				size incorrectly. The kernel will attempt work arounds
433				to fix known problems, but for some CPUs it is not
434				possible to determine what the correct size should be.
435				This option provides an override for these situations.
436	
437		capability.disable=
438				[SECURITY] Disable capabilities.  This would normally
439				be used only if an alternative security model is to be
440				configured.  Potentially dangerous and should only be
441				used if you are entirely sure of the consequences.
442	
443		ccw_timeout_log [S390]
444				See Documentation/s390/CommonIO for details.
445	
446		cgroup_disable= [KNL] Disable a particular controller
447				Format: {name of the controller(s) to disable}
448					{Currently supported controllers - "memory"}
449	
450		checkreqprot	[SELINUX] Set initial checkreqprot flag value.
451				Format: { "0" | "1" }
452				See security/selinux/Kconfig help text.
453				0 -- check protection applied by kernel (includes
454					any implied execute protection).
455				1 -- check protection requested by application.
456				Default value is set via a kernel config option.
457				Value can be changed at runtime via
458					/selinux/checkreqprot.
459	
460		cio_ignore=	[S390]
461				See Documentation/s390/CommonIO for details.
462	
463		clock=		[BUGS=X86-32, HW] gettimeofday clocksource override.
464				[Deprecated]
465				Forces specified clocksource (if available) to be used
466				when calculating gettimeofday(). If specified
467				clocksource is not available, it defaults to PIT.
468				Format: { pit | tsc | cyclone | pmtmr }
469	
470		clocksource=	[GENERIC_TIME] Override the default clocksource
471				Format: <string>
472				Override the default clocksource and use the clocksource
473				with the name specified.
474				Some clocksource names to choose from, depending on
475				the platform:
476				[all] jiffies (this is the base, fallback clocksource)
477				[ACPI] acpi_pm
478				[ARM] imx_timer1,OSTS,netx_timer,mpu_timer2,
479					pxa_timer,timer3,32k_counter,timer0_1
480				[AVR32] avr32
481				[X86-32] pit,hpet,tsc,vmi-timer;
482					scx200_hrt on Geode; cyclone on IBM x440
483				[MIPS] MIPS
484				[PARISC] cr16
485				[S390] tod
486				[SH] SuperH
487				[SPARC64] tick
488				[X86-64] hpet,tsc
489	
490		clearcpuid=BITNUM [X86]
491				Disable CPUID feature X for the kernel. See
492				arch/x86/include/asm/cpufeature.h for the valid bit
493				numbers. Note the Linux specific bits are not necessarily
494				stable over kernel options, but the vendor specific
495				ones should be.
496				Also note that user programs calling CPUID directly
497				or using the feature without checking anything
498				will still see it. This just prevents it from
499				being used by the kernel or shown in /proc/cpuinfo.
500				Also note the kernel might malfunction if you disable
501				some critical bits.
502	
503		cmo_free_hint=	[PPC] Format: { yes | no }
504				Specify whether pages are marked as being inactive
505				when they are freed.  This is used in CMO environments
506				to determine OS memory pressure for page stealing by
507				a hypervisor.
508				Default: yes
509	
510		code_bytes	[X86] How many bytes of object code to print
511				in an oops report.
512				Range: 0 - 8192
513				Default: 64
514	
515		com20020=	[HW,NET] ARCnet - COM20020 chipset
516				Format:
517				<io>[,<irq>[,<nodeID>[,<backplane>[,<ckp>[,<timeout>]]]]]
518	
519		com90io=	[HW,NET] ARCnet - COM90xx chipset (IO-mapped buffers)
520				Format: <io>[,<irq>]
521	
522		com90xx=	[HW,NET]
523				ARCnet - COM90xx chipset (memory-mapped buffers)
524				Format: <io>[,<irq>[,<memstart>]]
525	
526		condev=		[HW,S390] console device
527		conmode=
528	
529		console=	[KNL] Output console device and options.
530	
531			tty<n>	Use the virtual console device <n>.
532	
533			ttyS<n>[,options]
534			ttyUSB0[,options]
535				Use the specified serial port.  The options are of
536				the form "bbbbpnf", where "bbbb" is the baud rate,
537				"p" is parity ("n", "o", or "e"), "n" is number of
538				bits, and "f" is flow control ("r" for RTS or
539				omit it).  Default is "9600n8".
540	
541				See Documentation/serial-console.txt for more
542				information.  See
543				Documentation/networking/netconsole.txt for an
544				alternative.
545	
546			uart[8250],io,<addr>[,options]
547			uart[8250],mmio,<addr>[,options]
548				Start an early, polled-mode console on the 8250/16550
549				UART at the specified I/O port or MMIO address,
550				switching to the matching ttyS device later.  The
551				options are the same as for ttyS, above.
552	
553	                If the device connected to the port is not a TTY but a braille
554	                device, prepend "brl," before the device type, for instance
555				console=brl,ttyS0
556			For now, only VisioBraille is supported.
557	
558		consoleblank=	[KNL] The console blank (screen saver) timeout in
559				seconds. Defaults to 10*60 = 10mins. A value of 0
560				disables the blank timer.
561	
562		coredump_filter=
563				[KNL] Change the default value for
564				/proc/<pid>/coredump_filter.
565				See also Documentation/filesystems/proc.txt.
566	
567		cpcihp_generic=	[HW,PCI] Generic port I/O CompactPCI driver
568				Format:
569				<first_slot>,<last_slot>,<port>,<enum_bit>[,<debug>]
570	
571		crashkernel=nn[KMG]@ss[KMG]
572				[KNL] Reserve a chunk of physical memory to
573				hold a kernel to switch to with kexec on panic.
574	
575		crashkernel=range1:size1[,range2:size2,...][@offset]
576				[KNL] Same as above, but depends on the memory
577				in the running system. The syntax of range is
578				start-[end] where start and end are both
579				a memory unit (amount[KMG]). See also
580				Documentation/kdump/kdump.txt for a example.
581	
582		cs89x0_dma=	[HW,NET]
583				Format: <dma>
584	
585		cs89x0_media=	[HW,NET]
586				Format: { rj45 | aui | bnc }
587	
588		dasd=		[HW,NET]
589				See header of drivers/s390/block/dasd_devmap.c.
590	
591		db9.dev[2|3]=	[HW,JOY] Multisystem joystick support via parallel port
592				(one device per port)
593				Format: <port#>,<type>
594				See also Documentation/input/joystick-parport.txt
595	
596		debug		[KNL] Enable kernel debugging (events log level).
597	
598		debug_locks_verbose=
599				[KNL] verbose self-tests
600				Format=<0|1>
601				Print debugging info while doing the locking API
602				self-tests.
603				We default to 0 (no extra messages), setting it to
604				1 will print _a lot_ more information - normally
605				only useful to kernel developers.
606	
607		debug_objects	[KNL] Enable object debugging
608	
609		no_debug_objects
610				[KNL] Disable object debugging
611	
612		debugpat	[X86] Enable PAT debugging
613	
614		decnet.addr=	[HW,NET]
615				Format: <area>[,<node>]
616				See also Documentation/networking/decnet.txt.
617	
618		default_hugepagesz=
619				[same as hugepagesz=] The size of the default
620				HugeTLB page size. This is the size represented by
621				the legacy /proc/ hugepages APIs, used for SHM, and
622				default size when mounting hugetlbfs filesystems.
623				Defaults to the default architecture's huge page size
624				if not specified.
625	
626		dhash_entries=	[KNL]
627				Set number of hash buckets for dentry cache.
628	
629		digi=		[HW,SERIAL]
630				IO parameters + enable/disable command.
631	
632		digiepca=	[HW,SERIAL]
633				See drivers/char/README.epca and
634				Documentation/serial/digiepca.txt.
635	
636		disable=	[IPV6]
637				See Documentation/networking/ipv6.txt.
638	
639		disable_ipv6=	[IPV6]
640				See Documentation/networking/ipv6.txt.
641	
642		disable_mtrr_cleanup [X86]
643				The kernel tries to adjust MTRR layout from continuous
644				to discrete, to make X server driver able to add WB
645				entry later. This parameter disables that.
646	
647		disable_mtrr_trim [X86, Intel and AMD only]
648				By default the kernel will trim any uncacheable
649				memory out of your available memory pool based on
650				MTRR settings.  This parameter disables that behavior,
651				possibly causing your machine to run very slowly.
652	
653		disable_timer_pin_1 [X86]
654				Disable PIN 1 of APIC timer
655				Can be useful to work around chipset bugs.
656	
657		dmasound=	[HW,OSS] Sound subsystem buffers
658	
659		dma_debug=off	If the kernel is compiled with DMA_API_DEBUG support,
660				this option disables the debugging code at boot.
661	
662		dma_debug_entries=<number>
663				This option allows to tune the number of preallocated
664				entries for DMA-API debugging code. One entry is
665				required per DMA-API allocation. Use this if the
666				DMA-API debugging code disables itself because the
667				architectural default is too low.
668	
669		dma_debug_driver=<driver_name>
670				With this option the DMA-API debugging driver
671				filter feature can be enabled at boot time. Just
672				pass the driver to filter for as the parameter.
673				The filter can be disabled or changed to another
674				driver later using sysfs.
675	
676		dscc4.setup=	[NET]
677	
678		dtc3181e=	[HW,SCSI]
679	
680		dynamic_printk	Enables pr_debug()/dev_dbg() calls if
681				CONFIG_DYNAMIC_PRINTK_DEBUG has been enabled.
682				These can also be switched on/off via
683				<debugfs>/dynamic_printk/modules
684	
685		earlycon=	[KNL] Output early console device and options.
686			uart[8250],io,<addr>[,options]
687			uart[8250],mmio,<addr>[,options]
688				Start an early, polled-mode console on the 8250/16550
689				UART at the specified I/O port or MMIO address.
690				The options are the same as for ttyS, above.
691	
692		earlyprintk=	[X86,SH,BLACKFIN]
693				earlyprintk=vga
694				earlyprintk=serial[,ttySn[,baudrate]]
695				earlyprintk=ttySn[,baudrate]
696				earlyprintk=dbgp[debugController#]
697	
698				Append ",keep" to not disable it when the real console
699				takes over.
700	
701				Only vga or serial or usb debug port at a time.
702	
703				Currently only ttyS0 and ttyS1 are supported.
704	
705				Interaction with the standard serial driver is not
706				very good.
707	
708				The VGA output is eventually overwritten by the real
709				console.
710	
711		eata=		[HW,SCSI]
712	
713		edd=		[EDD]
714				Format: {"off" | "on" | "skip[mbr]"}
715	
716		eisa_irq_edge=	[PARISC,HW]
717				See header of drivers/parisc/eisa.c.
718	
719		elanfreq=	[X86-32]
720				See comment before function elanfreq_setup() in
721				arch/x86/kernel/cpu/cpufreq/elanfreq.c.
722	
723		elevator=	[IOSCHED]
724				Format: {"anticipatory" | "cfq" | "deadline" | "noop"}
725				See Documentation/block/as-iosched.txt and
726				Documentation/block/deadline-iosched.txt for details.
727	
728		elfcorehdr=	[IA64,PPC,SH,X86]
729				Specifies physical address of start of kernel core
730				image elf header. Generally kexec loader will
731				pass this option to capture kernel.
732				See Documentation/kdump/kdump.txt for details.
733	
734		enable_mtrr_cleanup [X86]
735				The kernel tries to adjust MTRR layout from continuous
736				to discrete, to make X server driver able to add WB
737				entry later. This parameter enables that.
738	
739		enable_timer_pin_1 [X86]
740				Enable PIN 1 of APIC timer
741				Can be useful to work around chipset bugs
742				(in particular on some ATI chipsets).
743				The kernel tries to set a reasonable default.
744	
745		enforcing	[SELINUX] Set initial enforcing status.
746				Format: {"0" | "1"}
747				See security/selinux/Kconfig help text.
748				0 -- permissive (log only, no denials).
749				1 -- enforcing (deny and log).
750				Default value is 0.
751				Value can be changed at runtime via /selinux/enforce.
752	
753		ether=		[HW,NET] Ethernet cards parameters
754				This option is obsoleted by the "netdev=" option, which
755				has equivalent usage. See its documentation for details.
756	
757		eurwdt=		[HW,WDT] Eurotech CPU-1220/1410 onboard watchdog.
758				Format: <io>[,<irq>]
759	
760		failslab=
761		fail_page_alloc=
762		fail_make_request=[KNL]
763				General fault injection mechanism.
764				Format: <interval>,<probability>,<space>,<times>
765				See also /Documentation/fault-injection/.
766	
767		fd_mcs=		[HW,SCSI]
768				See header of drivers/scsi/fd_mcs.c.
769	
770		fdomain=	[HW,SCSI]
771				See header of drivers/scsi/fdomain.c.
772	
773		floppy=		[HW]
774				See Documentation/blockdev/floppy.txt.
775	
776		force_pal_cache_flush
777				[IA-64] Avoid check_sal_cache_flush which may hang on
778				buggy SAL_CACHE_FLUSH implementations. Using this
779				parameter will force ia64_sal_cache_flush to call
780				ia64_pal_cache_flush instead of SAL_CACHE_FLUSH.
781	
782		ftrace=[tracer]
783				[FTRACE] will set and start the specified tracer
784				as early as possible in order to facilitate early
785				boot debugging.
786	
787		ftrace_dump_on_oops
788				[FTRACE] will dump the trace buffers on oops.
789	
790		ftrace_filter=[function-list]
791				[FTRACE] Limit the functions traced by the function
792				tracer at boot up. function-list is a comma separated
793				list of functions. This list can be changed at run
794				time by the set_ftrace_filter file in the debugfs
795				tracing directory. 
796	
797		ftrace_notrace=[function-list]
798				[FTRACE] Do not trace the functions specified in
799				function-list. This list can be changed at run time
800				by the set_ftrace_notrace file in the debugfs
801				tracing directory.
802	
803		ftrace_graph_filter=[function-list]
804				[FTRACE] Limit the top level callers functions traced
805				by the function graph tracer at boot up.
806				function-list is a comma separated list of functions
807				that can be changed at run time by the
808				set_graph_function file in the debugfs tracing directory.
809	
810		gamecon.map[2|3]=
811				[HW,JOY] Multisystem joystick and NES/SNES/PSX pad
812				support via parallel port (up to 5 devices per port)
813				Format: <port#>,<pad1>,<pad2>,<pad3>,<pad4>,<pad5>
814				See also Documentation/input/joystick-parport.txt
815	
816		gamma=		[HW,DRM]
817	
818		gart_fix_e820=  [X86_64] disable the fix e820 for K8 GART
819				Format: off | on
820				default: on
821	
822		gcov_persist=	[GCOV] When non-zero (default), profiling data for
823				kernel modules is saved and remains accessible via
824				debugfs, even when the module is unloaded/reloaded.
825				When zero, profiling data is discarded and associated
826				debugfs files are removed at module unload time.
827	
828		gdth=		[HW,SCSI]
829				See header of drivers/scsi/gdth.c.
830	
831		gpt		[EFI] Forces disk with valid GPT signature but
832				invalid Protective MBR to be treated as GPT.
833	
834		gvp11=		[HW,SCSI]
835	
836		hashdist=	[KNL,NUMA] Large hashes allocated during boot
837				are distributed across NUMA nodes.  Defaults on
838				for 64bit NUMA, off otherwise.
839				Format: 0 | 1 (for off | on)
840	
841		hcl=		[IA-64] SGI's Hardware Graph compatibility layer
842	
843		hd=		[EIDE] (E)IDE hard drive subsystem geometry
844				Format: <cyl>,<head>,<sect>
845	
846		highmem=nn[KMG]	[KNL,BOOT] forces the highmem zone to have an exact
847				size of <nn>. This works even on boxes that have no
848				highmem otherwise. This also works to reduce highmem
849				size on bigger boxes.
850	
851		highres=	[KNL] Enable/disable high resolution timer mode.
852				Valid parameters: "on", "off"
853				Default: "on"
854	
855		hisax=		[HW,ISDN]
856				See Documentation/isdn/README.HiSax.
857	
858		hlt		[BUGS=ARM,SH]
859	
860		hpet=		[X86-32,HPET] option to control HPET usage
861				Format: { enable (default) | disable | force |
862					verbose }
863				disable: disable HPET and use PIT instead
864				force: allow force enabled of undocumented chips (ICH4,
865					VIA, nVidia)
866				verbose: show contents of HPET registers during setup
867	
868		hugepages=	[HW,X86-32,IA-64] HugeTLB pages to allocate at boot.
869		hugepagesz=	[HW,IA-64,PPC,X86-64] The size of the HugeTLB pages.
870				On x86-64 and powerpc, this option can be specified
871				multiple times interleaved with hugepages= to reserve
872				huge pages of different sizes. Valid pages sizes on
873				x86-64 are 2M (when the CPU supports "pse") and 1G
874				(when the CPU supports the "pdpe1gb" cpuinfo flag)
875				Note that 1GB pages can only be allocated at boot time
876				using hugepages= and not freed afterwards.
877	
878		hvc_iucv=	[S390] Number of z/VM IUCV hypervisor console (HVC)
879				       terminal devices. Valid values: 0..8
880		hvc_iucv_allow=	[S390] Comma-separated list of z/VM user IDs.
881				       If specified, z/VM IUCV HVC accepts connections
882				       from listed z/VM user IDs only.
883	
884		i2c_bus=	[HW] Override the default board specific I2C bus speed
885				     or register an additional I2C bus that is not
886				     registered from board initialization code.
887				     Format:
888				     <bus_id>,<clkrate>
889	
890		i8042.debug	[HW] Toggle i8042 debug mode
891		i8042.direct	[HW] Put keyboard port into non-translated mode
892		i8042.dumbkbd	[HW] Pretend that controller can only read data from
893				     keyboard and cannot control its state
894				     (Don't attempt to blink the leds)
895		i8042.noaux	[HW] Don't check for auxiliary (== mouse) port
896		i8042.nokbd	[HW] Don't check/create keyboard port
897		i8042.noloop	[HW] Disable the AUX Loopback command while probing
898				     for the AUX port
899		i8042.nomux	[HW] Don't check presence of an active multiplexing
900				     controller
901		i8042.nopnp	[HW] Don't use ACPIPnP / PnPBIOS to discover KBD/AUX
902				     controllers
903		i8042.panicblink=
904				[HW] Frequency with which keyboard LEDs should blink
905				     when kernel panics (default is 0.5 sec)
906		i8042.reset	[HW] Reset the controller during init and cleanup
907		i8042.unlock	[HW] Unlock (ignore) the keylock
908	
909		i810=		[HW,DRM]
910	
911		i8k.ignore_dmi	[HW] Continue probing hardware even if DMI data
912				indicates that the driver is running on unsupported
913				hardware.
914		i8k.force	[HW] Activate i8k driver even if SMM BIOS signature
915				does not match list of supported models.
916		i8k.power_status
917				[HW] Report power status in /proc/i8k
918				(disabled by default)
919		i8k.restricted	[HW] Allow controlling fans only if SYS_ADMIN
920				capability is set.
921	
922		ibmmcascsi=	[HW,MCA,SCSI] IBM MicroChannel SCSI adapter
923				See Documentation/mca.txt.
924	
925		icn=		[HW,ISDN]
926				Format: <io>[,<membase>[,<icn_id>[,<icn_id2>]]]
927	
928		ide-core.nodma=	[HW] (E)IDE subsystem
929				Format: =0.0 to prevent dma on hda, =0.1 hdb =1.0 hdc
930				.vlb_clock .pci_clock .noflush .nohpa .noprobe .nowerr
931				.cdrom .chs .ignore_cable are additional options
932				See Documentation/ide/ide.txt.
933	
934		ide-pci-generic.all-generic-ide [HW] (E)IDE subsystem
935				Claim all unknown PCI IDE storage controllers.
936	
937		idle=		[X86]
938				Format: idle=poll, idle=mwait, idle=halt, idle=nomwait
939				Poll forces a polling idle loop that can slightly
940				improve the performance of waking up a idle CPU, but
941				will use a lot of power and make the system run hot.
942				Not recommended.
943				idle=mwait: On systems which support MONITOR/MWAIT but
944				the kernel chose to not use it because it doesn't save
945				as much power as a normal idle loop, use the
946				MONITOR/MWAIT idle loop anyways. Performance should be
947				the same as idle=poll.
948				idle=halt: Halt is forced to be used for CPU idle.
949				In such case C2/C3 won't be used again.
950				idle=nomwait: Disable mwait for CPU C-states
951	
952		ignore_loglevel	[KNL]
953				Ignore loglevel setting - this will print /all/
954				kernel messages to the console. Useful for debugging.
955	
956		ihash_entries=	[KNL]
957				Set number of hash buckets for inode cache.
958	
959		ima_audit=	[IMA]
960				Format: { "0" | "1" }
961				0 -- integrity auditing messages. (Default)
962				1 -- enable informational integrity auditing messages.
963	
964		ima_hash=	[IMA]
965				Format: { "sha1" | "md5" }
966				default: "sha1"
967	
968		ima_tcb		[IMA]
969				Load a policy which meets the needs of the Trusted
970				Computing Base.  This means IMA will measure all
971				programs exec'd, files mmap'd for exec, and all files
972				opened for read by uid=0.
973	
974		in2000=		[HW,SCSI]
975				See header of drivers/scsi/in2000.c.
976	
977		init=		[KNL]
978				Format: <full_path>
979				Run specified binary instead of /sbin/init as init
980				process.
981	
982		initcall_debug	[KNL] Trace initcalls as they are executed.  Useful
983				for working out where the kernel is dying during
984				startup.
985	
986		initrd=		[BOOT] Specify the location of the initial ramdisk
987	
988		inport.irq=	[HW] Inport (ATI XL and Microsoft) busmouse driver
989				Format: <irq>
990	
991		intel_iommu=	[DMAR] Intel IOMMU driver (DMAR) option
992			on
993				Enable intel iommu driver.
994			off
995				Disable intel iommu driver.
996			igfx_off [Default Off]
997				By default, gfx is mapped as normal device. If a gfx
998				device has a dedicated DMAR unit, the DMAR unit is
999				bypassed by not enabling DMAR with this option. In
1000				this case, gfx device will use physical address for
1001				DMA.
1002			forcedac [x86_64]
1003				With this option iommu will not optimize to look
1004				for io virtual address below 32 bit forcing dual
1005				address cycle on pci bus for cards supporting greater
1006				than 32 bit addressing. The default is to look
1007				for translation below 32 bit and if not available
1008				then look in the higher range.
1009			strict [Default Off]
1010				With this option on every unmap_single operation will
1011				result in a hardware IOTLB flush operation as opposed
1012				to batching them for performance.
1013	
1014		inttest=	[IA64]
1015	
1016		iomem=		Disable strict checking of access to MMIO memory
1017			strict	regions from userspace.
1018			relaxed
1019	
1020		iommu=		[x86]
1021			off
1022			force
1023			noforce
1024			biomerge
1025			panic
1026			nopanic
1027			merge
1028			nomerge
1029			forcesac
1030			soft
1031			pt	[x86, IA64]
1032	
1033		io7=		[HW] IO7 for Marvel based alpha systems
1034				See comment before marvel_specify_io7 in
1035				arch/alpha/kernel/core_marvel.c.
1036	
1037		io_delay=	[X86] I/O delay method
1038			0x80
1039				Standard port 0x80 based delay
1040			0xed
1041				Alternate port 0xed based delay (needed on some systems)
1042			udelay
1043				Simple two microseconds delay
1044			none
1045				No delay
1046	
1047		ip=		[IP_PNP]
1048				See Documentation/filesystems/nfs/nfsroot.txt.
1049	
1050		ip2=		[HW] Set IO/IRQ pairs for up to 4 IntelliPort boards
1051				See comment before ip2_setup() in
1052				drivers/char/ip2/ip2base.c.
1053	
1054		ips=		[HW,SCSI] Adaptec / IBM ServeRAID controller
1055				See header of drivers/scsi/ips.c.
1056	
1057		irqfixup	[HW]
1058				When an interrupt is not handled search all handlers
1059				for it. Intended to get systems with badly broken
1060				firmware running.
1061	
1062		irqpoll		[HW]
1063				When an interrupt is not handled search all handlers
1064				for it. Also check all handlers each timer
1065				interrupt. Intended to get systems with badly broken
1066				firmware running.
1067	
1068		isapnp=		[ISAPNP]
1069				Format: <RDP>,<reset>,<pci_scan>,<verbosity>
1070	
1071		isolcpus=	[KNL,SMP] Isolate CPUs from the general scheduler.
1072				Format:
1073				<cpu number>,...,<cpu number>
1074				or
1075				<cpu number>-<cpu number>
1076				(must be a positive range in ascending order)
1077				or a mixture
1078				<cpu number>,...,<cpu number>-<cpu number>
1079	
1080				This option can be used to specify one or more CPUs
1081				to isolate from the general SMP balancing and scheduling
1082				algorithms. You can move a process onto or off an
1083				"isolated" CPU via the CPU affinity syscalls or cpuset.
1084				<cpu number> begins at 0 and the maximum value is
1085				"number of CPUs in system - 1".
1086	
1087				This option is the preferred way to isolate CPUs. The
1088				alternative -- manually setting the CPU mask of all
1089				tasks in the system -- can cause problems and
1090				suboptimal load balancer performance.
1091	
1092		iucv=		[HW,NET]
1093	
1094		js=		[HW,JOY] Analog joystick
1095				See Documentation/input/joystick.txt.
1096	
1097		keepinitrd	[HW,ARM]
1098	
1099		kernelcore=nn[KMG]	[KNL,X86,IA-64,PPC] This parameter
1100				specifies the amount of memory usable by the kernel
1101				for non-movable allocations.  The requested amount is
1102				spread evenly throughout all nodes in the system. The
1103				remaining memory in each node is used for Movable
1104				pages. In the event, a node is too small to have both
1105				kernelcore and Movable pages, kernelcore pages will
1106				take priority and other nodes will have a larger number
1107				of kernelcore pages.  The Movable zone is used for the
1108				allocation of pages that may be reclaimed or moved
1109				by the page migration subsystem.  This means that
1110				HugeTLB pages may not be allocated from this zone.
1111				Note that allocations like PTEs-from-HighMem still
1112				use the HighMem zone if it exists, and the Normal
1113				zone if it does not.
1114	
1115		kgdboc=		[HW] kgdb over consoles.
1116				Requires a tty driver that supports console polling.
1117				(only serial supported for now)
1118				Format: <serial_device>[,baud]
1119	
1120		kmac=		[MIPS] korina ethernet MAC address.
1121				Configure the RouterBoard 532 series on-chip
1122				Ethernet adapter MAC address.
1123	
1124		kmemleak=	[KNL] Boot-time kmemleak enable/disable
1125				Valid arguments: on, off
1126				Default: on
1127	
1128		kstack=N	[X86] Print N words from the kernel stack
1129				in oops dumps.
1130	
1131		kvm.ignore_msrs=[KVM] Ignore guest accesses to unhandled MSRs.
1132				Default is 0 (don't ignore, but inject #GP)
1133	
1134		kvm.oos_shadow=	[KVM] Disable out-of-sync shadow paging.
1135				Default is 1 (enabled)
1136	
1137		kvm-amd.nested=	[KVM,AMD] Allow nested virtualization in KVM/SVM.
1138				Default is 0 (off)
1139	
1140		kvm-amd.npt=	[KVM,AMD] Disable nested paging (virtualized MMU)
1141				for all guests.
1142				Default is 1 (enabled) if in 64bit or 32bit-PAE mode
1143	
1144		kvm-intel.bypass_guest_pf=
1145				[KVM,Intel] Disables bypassing of guest page faults
1146				on Intel chips. Default is 1 (enabled)
1147	
1148		kvm-intel.ept=	[KVM,Intel] Disable extended page tables
1149				(virtualized MMU) support on capable Intel chips.
1150				Default is 1 (enabled)
1151	
1152		kvm-intel.emulate_invalid_guest_state=
1153				[KVM,Intel] Enable emulation of invalid guest states
1154				Default is 0 (disabled)
1155	
1156		kvm-intel.flexpriority=
1157				[KVM,Intel] Disable FlexPriority feature (TPR shadow).
1158				Default is 1 (enabled)
1159	
1160		kvm-intel.unrestricted_guest=
1161				[KVM,Intel] Disable unrestricted guest feature
1162				(virtualized real and unpaged mode) on capable
1163				Intel chips. Default is 1 (enabled)
1164	
1165		kvm-intel.vpid=	[KVM,Intel] Disable Virtual Processor Identification
1166				feature (tagged TLBs) on capable Intel chips.
1167				Default is 1 (enabled)
1168	
1169		l2cr=		[PPC]
1170	
1171		l3cr=		[PPC]
1172	
1173		lapic		[X86-32,APIC] Enable the local APIC even if BIOS
1174				disabled it.
1175	
1176		lapic_timer_c2_ok	[X86,APIC] trust the local apic timer
1177				in C2 power state.
1178	
1179		libata.dma=	[LIBATA] DMA control
1180				libata.dma=0	  Disable all PATA and SATA DMA
1181				libata.dma=1	  PATA and SATA Disk DMA only
1182				libata.dma=2	  ATAPI (CDROM) DMA only
1183				libata.dma=4	  Compact Flash DMA only 
1184				Combinations also work, so libata.dma=3 enables DMA
1185				for disks and CDROMs, but not CFs.
1186		
1187		libata.ignore_hpa=	[LIBATA] Ignore HPA limit
1188				libata.ignore_hpa=0	  keep BIOS limits (default)
1189				libata.ignore_hpa=1	  ignore limits, using full disk
1190	
1191		libata.noacpi	[LIBATA] Disables use of ACPI in libata suspend/resume
1192				when set.
1193				Format: <int>
1194	
1195		libata.force=	[LIBATA] Force configurations.  The format is comma
1196				separated list of "[ID:]VAL" where ID is
1197				PORT[.DEVICE].  PORT and DEVICE are decimal numbers
1198				matching port, link or device.  Basically, it matches
1199				the ATA ID string printed on console by libata.  If
1200				the whole ID part is omitted, the last PORT and DEVICE
1201				values are used.  If ID hasn't been specified yet, the
1202				configuration applies to all ports, links and devices.
1203	
1204				If only DEVICE is omitted, the parameter applies to
1205				the port and all links and devices behind it.  DEVICE
1206				number of 0 either selects the first device or the
1207				first fan-out link behind PMP device.  It does not
1208				select the host link.  DEVICE number of 15 selects the
1209				host link and device attached to it.
1210	
1211				The VAL specifies the configuration to force.  As long
1212				as there's no ambiguity shortcut notation is allowed.
1213				For example, both 1.5 and 1.5G would work for 1.5Gbps.
1214				The following configurations can be forced.
1215	
1216				* Cable type: 40c, 80c, short40c, unk, ign or sata.
1217				  Any ID with matching PORT is used.
1218	
1219				* SATA link speed limit: 1.5Gbps or 3.0Gbps.
1220	
1221				* Transfer mode: pio[0-7], mwdma[0-4] and udma[0-7].
1222				  udma[/][16,25,33,44,66,100,133] notation is also
1223				  allowed.
1224	
1225				* [no]ncq: Turn on or off NCQ.
1226	
1227				* nohrst, nosrst, norst: suppress hard, soft
1228	                          and both resets.
1229	
1230				If there are multiple matching configurations changing
1231				the same attribute, the last one is used.
1232	
1233		lmb=debug	[KNL] Enable lmb debug messages.
1234	
1235		load_ramdisk=	[RAM] List of ramdisks to load from floppy
1236				See Documentation/blockdev/ramdisk.txt.
1237	
1238		lockd.nlm_grace_period=P  [NFS] Assign grace period.
1239				Format: <integer>
1240	
1241		lockd.nlm_tcpport=N	[NFS] Assign TCP port.
1242				Format: <integer>
1243	
1244		lockd.nlm_timeout=T	[NFS] Assign timeout value.
1245				Format: <integer>
1246	
1247		lockd.nlm_udpport=M	[NFS] Assign UDP port.
1248				Format: <integer>
1249	
1250		logibm.irq=	[HW,MOUSE] Logitech Bus Mouse Driver
1251				Format: <irq>
1252	
1253		loglevel=	All Kernel Messages with a loglevel smaller than the
1254				console loglevel will be printed to the console. It can
1255				also be changed with klogd or other programs. The
1256				loglevels are defined as follows:
1257	
1258				0 (KERN_EMERG)		system is unusable
1259				1 (KERN_ALERT)		action must be taken immediately
1260				2 (KERN_CRIT)		critical conditions
1261				3 (KERN_ERR)		error conditions
1262				4 (KERN_WARNING)	warning conditions
1263				5 (KERN_NOTICE)		normal but significant condition
1264				6 (KERN_INFO)		informational
1265				7 (KERN_DEBUG)		debug-level messages
1266	
1267		log_buf_len=n	Sets the size of the printk ring buffer, in bytes.
1268				Format: { n | nk | nM }
1269				n must be a power of two.  The default size
1270				is set in the kernel config file.
1271	
1272		logo.nologo	[FB] Disables display of the built-in Linux logo.
1273				This may be used to provide more screen space for
1274				kernel log messages and is useful when debugging
1275				kernel boot problems.
1276	
1277		lp=0		[LP]	Specify parallel ports to use, e.g,
1278		lp=port[,port...]	lp=none,parport0 (lp0 not configured, lp1 uses
1279		lp=reset		first parallel port). 'lp=0' disables the
1280		lp=auto			printer driver. 'lp=reset' (which can be
1281					specified in addition to the ports) causes
1282					attached printers to be reset. Using
1283					lp=port1,port2,... specifies the parallel ports
1284					to associate lp devices with, starting with
1285					lp0. A port specification may be 'none' to skip
1286					that lp device, or a parport name such as
1287					'parport0'. Specifying 'lp=auto' instead of a
1288					port specification list means that device IDs
1289					from each port should be examined, to see if
1290					an IEEE 1284-compliant printer is attached; if
1291					so, the driver will manage that printer.
1292					See also header of drivers/char/lp.c.
1293	
1294		lpj=n		[KNL]
1295				Sets loops_per_jiffy to given constant, thus avoiding
1296				time-consuming boot-time autodetection (up to 250 ms per
1297				CPU). 0 enables autodetection (default). To determine
1298				the correct value for your kernel, boot with normal
1299				autodetection and see what value is printed. Note that
1300				on SMP systems the preset will be applied to all CPUs,
1301				which is likely to cause problems if your CPUs need
1302				significantly divergent settings. An incorrect value
1303				will cause delays in the kernel to be wrong, leading to
1304				unpredictable I/O errors and other breakage. Although
1305				unlikely, in the extreme case this might damage your
1306				hardware.
1307	
1308		ltpc=		[NET]
1309				Format: <io>,<irq>,<dma>
1310	
1311		mac5380=	[HW,SCSI] Format:
1312				<can_queue>,<cmd_per_lun>,<sg_tablesize>,<hostid>,<use_tags>
1313	
1314		machvec=	[IA64] Force the use of a particular machine-vector
1315				(machvec) in a generic kernel.
1316				Example: machvec=hpzx1_swiotlb
1317	
1318		machtype=	[Loongson] Share the same kernel image file between different
1319				 yeeloong laptop.
1320				Example: machtype=lemote-yeeloong-2f-7inch
1321	
1322		max_addr=nn[KMG]	[KNL,BOOT,ia64] All physical memory greater
1323				than or equal to this physical address is ignored.
1324	
1325		maxcpus=	[SMP] Maximum number of processors that	an SMP kernel
1326				should make use of.  maxcpus=n : n >= 0 limits the
1327				kernel to using 'n' processors.  n=0 is a special case,
1328				it is equivalent to "nosmp", which also disables
1329				the IO APIC.
1330	
1331		max_loop=	[LOOP] Maximum number of loopback devices that can
1332				be mounted
1333				Format: <1-256>
1334	
1335		max_luns=	[SCSI] Maximum number of LUNs to probe.
1336				Should be between 1 and 2^32-1.
1337	
1338		max_report_luns=
1339				[SCSI] Maximum number of LUNs received.
1340				Should be between 1 and 16384.
1341	
1342		mcatest=	[IA-64]
1343	
1344		mce		[X86-32] Machine Check Exception
1345	
1346		mce=option	[X86-64] See Documentation/x86/x86_64/boot-options.txt
1347	
1348		md=		[HW] RAID subsystems devices and level
1349				See Documentation/md.txt.
1350	
1351		mdacon=		[MDA]
1352				Format: <first>,<last>
1353				Specifies range of consoles to be captured by the MDA.
1354	
1355		mem=nn[KMG]	[KNL,BOOT] Force usage of a specific amount of memory
1356				Amount of memory to be used when the kernel is not able
1357				to see the whole system memory or for test.
1358				[X86-32] Use together with memmap= to avoid physical
1359				address space collisions. Without memmap= PCI devices
1360				could be placed at addresses belonging to unused RAM.
1361	
1362		mem=nopentium	[BUGS=X86-32] Disable usage of 4MB pages for kernel
1363				memory.
1364	
1365		memchunk=nn[KMG]
1366				[KNL,SH] Allow user to override the default size for
1367				per-device physically contiguous DMA buffers.
1368	
1369		memmap=exactmap	[KNL,X86] Enable setting of an exact
1370				E820 memory map, as specified by the user.
1371				Such memmap=exactmap lines can be constructed based on
1372				BIOS output or other requirements. See the memmap=nn@ss
1373				option description.
1374	
1375		memmap=nn[KMG]@ss[KMG]
1376				[KNL] Force usage of a specific region of memory
1377				Region of memory to be used, from ss to ss+nn.
1378	
1379		memmap=nn[KMG]#ss[KMG]
1380				[KNL,ACPI] Mark specific memory as ACPI data.
1381				Region of memory to be used, from ss to ss+nn.
1382	
1383		memmap=nn[KMG]$ss[KMG]
1384				[KNL,ACPI] Mark specific memory as reserved.
1385				Region of memory to be used, from ss to ss+nn.
1386				Example: Exclude memory from 0x18690000-0x1869ffff
1387				         memmap=64K$0x18690000
1388				         or
1389				         memmap=0x10000$0x18690000
1390	
1391		memory_corruption_check=0/1 [X86]
1392				Some BIOSes seem to corrupt the first 64k of
1393				memory when doing things like suspend/resume.
1394				Setting this option will scan the memory
1395				looking for corruption.  Enabling this will
1396				both detect corruption and prevent the kernel
1397				from using the memory being corrupted.
1398				However, its intended as a diagnostic tool; if
1399				repeatable BIOS-originated corruption always
1400				affects the same memory, you can use memmap=
1401				to prevent the kernel from using that memory.
1402	
1403		memory_corruption_check_size=size [X86]
1404				By default it checks for corruption in the low
1405				64k, making this memory unavailable for normal
1406				use.  Use this parameter to scan for
1407				corruption in more or less memory.
1408	
1409		memory_corruption_check_period=seconds [X86]
1410				By default it checks for corruption every 60
1411				seconds.  Use this parameter to check at some
1412				other rate.  0 disables periodic checking.
1413	
1414		memtest=	[KNL,X86] Enable memtest
1415				Format: <integer>
1416				default : 0 <disable>
1417				Specifies the number of memtest passes to be
1418				performed. Each pass selects another test
1419				pattern from a given set of patterns. Memtest
1420				fills the memory with this pattern, validates
1421				memory contents and reserves bad memory
1422				regions that are detected.
1423	
1424		meye.*=		[HW] Set MotionEye Camera parameters
1425				See Documentation/video4linux/meye.txt.
1426	
1427		mfgpt_irq=	[IA-32] Specify the IRQ to use for the
1428				Multi-Function General Purpose Timers on AMD Geode
1429				platforms.
1430	
1431		mfgptfix	[X86-32] Fix MFGPT timers on AMD Geode platforms when
1432				the BIOS has incorrectly applied a workaround. TinyBIOS
1433				version 0.98 is known to be affected, 0.99 fixes the
1434				problem by letting the user disable the workaround.
1435	
1436		mga=		[HW,DRM]
1437	
1438		min_addr=nn[KMG]	[KNL,BOOT,ia64] All physical memory below this
1439				physical address is ignored.
1440	
1441		mini2440=	[ARM,HW,KNL]
1442				Format:[0..2][b][c][t]
1443				Default: "0tb"
1444				MINI2440 configuration specification:
1445				0 - The attached screen is the 3.5" TFT
1446				1 - The attached screen is the 7" TFT
1447				2 - The VGA Shield is attached (1024x768)
1448				Leaving out the screen size parameter will not load
1449				the TFT driver, and the framebuffer will be left
1450				unconfigured.
1451				b - Enable backlight. The TFT backlight pin will be
1452				linked to the kernel VESA blanking code and a GPIO
1453				LED. This parameter is not necessary when using the
1454				VGA shield.
1455				c - Enable the s3c camera interface.
1456				t - Reserved for enabling touchscreen support. The
1457				touchscreen support is not enabled in the mainstream
1458				kernel as of 2.6.30, a preliminary port can be found
1459				in the "bleeding edge" mini2440 support kernel at
1460				http://repo.or.cz/w/linux-2.6/mini2440.git
1461	
1462		mminit_loglevel=
1463				[KNL] When CONFIG_DEBUG_MEMORY_INIT is set, this
1464				parameter allows control of the logging verbosity for
1465				the additional memory initialisation checks. A value
1466				of 0 disables mminit logging and a level of 4 will
1467				log everything. Information is printed at KERN_DEBUG
1468				so loglevel=8 may also need to be specified.
1469	
1470		mousedev.tap_time=
1471				[MOUSE] Maximum time between finger touching and
1472				leaving touchpad surface for touch to be considered
1473				a tap and be reported as a left button click (for
1474				touchpads working in absolute mode only).
1475				Format: <msecs>
1476		mousedev.xres=	[MOUSE] Horizontal screen resolution, used for devices
1477				reporting absolute coordinates, such as tablets
1478		mousedev.yres=	[MOUSE] Vertical screen resolution, used for devices
1479				reporting absolute coordinates, such as tablets
1480	
1481		movablecore=nn[KMG]	[KNL,X86,IA-64,PPC] This parameter
1482				is similar to kernelcore except it specifies the
1483				amount of memory used for migratable allocations.
1484				If both kernelcore and movablecore is specified,
1485				then kernelcore will be at *least* the specified
1486				value but may be more. If movablecore on its own
1487				is specified, the administrator must be careful
1488				that the amount of memory usable for all allocations
1489				is not too small.
1490	
1491		mpu401=		[HW,OSS]
1492				Format: <io>,<irq>
1493	
1494		MTD_Partition=	[MTD]
1495				Format: <name>,<region-number>,<size>,<offset>
1496	
1497		MTD_Region=	[MTD] Format:
1498				<name>,<region-number>[,<base>,<size>,<buswidth>,<altbuswidth>]
1499	
1500		mtdparts=	[MTD]
1501				See drivers/mtd/cmdlinepart.c.
1502	
1503		onenand.bdry=	[HW,MTD] Flex-OneNAND Boundary Configuration
1504	
1505				Format: [die0_boundary][,die0_lock][,die1_boundary][,die1_lock]
1506	
1507				boundary - index of last SLC block on Flex-OneNAND.
1508					   The remaining blocks are configured as MLC blocks.
1509				lock	 - Configure if Flex-OneNAND boundary should be locked.
1510					   Once locked, the boundary cannot be changed.
1511					   1 indicates lock status, 0 indicates unlock status.
1512	
1513		mtdset=		[ARM]
1514				ARM/S3C2412 JIVE boot control
1515	
1516				See arch/arm/mach-s3c2412/mach-jive.c
1517	
1518		mtouchusb.raw_coordinates=
1519				[HW] Make the MicroTouch USB driver use raw coordinates
1520				('y', default) or cooked coordinates ('n')
1521	
1522		mtrr_chunk_size=nn[KMG] [X86]
1523				used for mtrr cleanup. It is largest continuous chunk
1524				that could hold holes aka. UC entries.
1525	
1526		mtrr_gran_size=nn[KMG] [X86]
1527				Used for mtrr cleanup. It is granularity of mtrr block.
1528				Default is 1.
1529				Large value could prevent small alignment from
1530				using up MTRRs.
1531	
1532		mtrr_spare_reg_nr=n [X86]
1533				Format: <integer>
1534				Range: 0,7 : spare reg number
1535				Default : 1
1536				Used for mtrr cleanup. It is spare mtrr entries number.
1537				Set to 2 or more if your graphical card needs more.
1538	
1539		n2=		[NET] SDL Inc. RISCom/N2 synchronous serial card
1540	
1541		NCR_D700=	[HW,SCSI]
1542				See header of drivers/scsi/NCR_D700.c.
1543	
1544		ncr5380=	[HW,SCSI]
1545	
1546		ncr53c400=	[HW,SCSI]
1547	
1548		ncr53c400a=	[HW,SCSI]
1549	
1550		ncr53c406a=	[HW,SCSI]
1551	
1552		ncr53c8xx=	[HW,SCSI]
1553	
1554		netdev=		[NET] Network devices parameters
1555				Format: <irq>,<io>,<mem_start>,<mem_end>,<name>
1556				Note that mem_start is often overloaded to mean
1557				something different and driver-specific.
1558				This usage is only documented in each driver source
1559				file if at all.
1560	
1561		nf_conntrack.acct=
1562				[NETFILTER] Enable connection tracking flow accounting
1563				0 to disable accounting
1564				1 to enable accounting
1565				Default value depends on CONFIG_NF_CT_ACCT that is
1566				going to be removed in 2.6.29.
1567	
1568		nfsaddrs=	[NFS]
1569				See Documentation/filesystems/nfs/nfsroot.txt.
1570	
1571		nfsroot=	[NFS] nfs root filesystem for disk-less boxes.
1572				See Documentation/filesystems/nfs/nfsroot.txt.
1573	
1574		nfs.callback_tcpport=
1575				[NFS] set the TCP port on which the NFSv4 callback
1576				channel should listen.
1577	
1578		nfs.cache_getent=
1579				[NFS] sets the pathname to the program which is used
1580				to update the NFS client cache entries.
1581	
1582		nfs.cache_getent_timeout=
1583				[NFS] sets the timeout after which an attempt to
1584				update a cache entry is deemed to have failed.
1585	
1586		nfs.idmap_cache_timeout=
1587				[NFS] set the maximum lifetime for idmapper cache
1588				entries.
1589	
1590		nfs.enable_ino64=
1591				[NFS] enable 64-bit inode numbers.
1592				If zero, the NFS client will fake up a 32-bit inode
1593				number for the readdir() and stat() syscalls instead
1594				of returning the full 64-bit number.
1595				The default is to return 64-bit inode numbers.
1596	
1597		nmi_debug=	[KNL,AVR32,SH] Specify one or more actions to take
1598				when a NMI is triggered.
1599				Format: [state][,regs][,debounce][,die]
1600	
1601		nmi_watchdog=	[KNL,BUGS=X86] Debugging features for SMP kernels
1602				Format: [panic,][num]
1603				Valid num: 0,1,2
1604				0 - turn nmi_watchdog off
1605				1 - use the IO-APIC timer for the NMI watchdog
1606				2 - use the local APIC for the NMI watchdog using
1607				a performance counter. Note: This will use one
1608				performance counter and the local APIC's performance
1609				vector.
1610				When panic is specified, panic when an NMI watchdog
1611				timeout occurs.
1612				This is useful when you use a panic=... timeout and
1613				need the box quickly up again.
1614				Instead of 1 and 2 it is possible to use the following
1615				symbolic names: lapic and ioapic
1616				Example: nmi_watchdog=2 or nmi_watchdog=panic,lapic
1617	
1618		netpoll.carrier_timeout=
1619				[NET] Specifies amount of time (in seconds) that
1620				netpoll should wait for a carrier. By default netpoll
1621				waits 4 seconds.
1622	
1623		no387		[BUGS=X86-32] Tells the kernel to use the 387 maths
1624				emulation library even if a 387 maths coprocessor
1625				is present.
1626	
1627		no_console_suspend
1628				[HW] Never suspend the console
1629				Disable suspending of consoles during suspend and
1630				hibernate operations.  Once disabled, debugging
1631				messages can reach various consoles while the rest
1632				of the system is being put to sleep (ie, while
1633				debugging driver suspend/resume hooks).  This may
1634				not work reliably with all consoles, but is known
1635				to work with serial and VGA consoles.
1636	
1637		noaliencache	[MM, NUMA, SLAB] Disables the allocation of alien
1638				caches in the slab allocator.  Saves per-node memory,
1639				but will impact performance.
1640	
1641		noalign		[KNL,ARM]
1642	
1643		noapic		[SMP,APIC] Tells the kernel to not make use of any
1644				IOAPICs that may be present in the system.
1645	
1646		nobats		[PPC] Do not use BATs for mapping kernel lowmem
1647				on "Classic" PPC cores.
1648	
1649		nocache		[ARM]
1650	
1651		noclflush	[BUGS=X86] Don't use the CLFLUSH instruction
1652	
1653		nodelayacct	[KNL] Disable per-task delay accounting
1654	
1655		nodisconnect	[HW,SCSI,M68K] Disables SCSI disconnects.
1656	
1657		nodsp		[SH] Disable hardware DSP at boot time.
1658	
1659		noefi		[X86] Disable EFI runtime services support.
1660	
1661		noexec		[IA-64]
1662	
1663		noexec		[X86]
1664				On X86-32 available only on PAE configured kernels.
1665				noexec=on: enable non-executable mappings (default)
1666				noexec=off: disable non-executable mappings
1667	
1668		noexec32	[X86-64]
1669				This affects only 32-bit executables.
1670				noexec32=on: enable non-executable mappings (default)
1671					read doesn't imply executable mappings
1672				noexec32=off: disable non-executable mappings
1673					read implies executable mappings
1674	
1675		nofpu		[SH] Disable hardware FPU at boot time.
1676	
1677		nofxsr		[BUGS=X86-32] Disables x86 floating point extended
1678				register save and restore. The kernel will only save
1679				legacy floating-point registers on task switch.
1680	
1681		noxsave		[BUGS=X86] Disables x86 extended register state save
1682				and restore using xsave. The kernel will fallback to
1683				enabling legacy floating-point and sse state.
1684	
1685		nohlt		[BUGS=ARM,SH] Tells the kernel that the sleep(SH) or
1686				wfi(ARM) instruction doesn't work correctly and not to
1687				use it. This is also useful when using JTAG debugger.
1688	
1689		no-hlt		[BUGS=X86-32] Tells the kernel that the hlt
1690				instruction doesn't work correctly and not to
1691				use it.
1692	
1693		no_file_caps	Tells the kernel not to honor file capabilities.  The
1694				only way then for a file to be executed with privilege
1695				is to be setuid root or executed by root.
1696	
1697		nohalt		[IA-64] Tells the kernel not to use the power saving
1698				function PAL_HALT_LIGHT when idle. This increases
1699				power-consumption. On the positive side, it reduces
1700				interrupt wake-up latency, which may improve performance
1701				in certain environments such as networked servers or
1702				real-time systems.
1703	
1704		nohz=		[KNL] Boottime enable/disable dynamic ticks
1705				Valid arguments: on, off
1706				Default: on
1707	
1708		noiotrap	[SH] Disables trapped I/O port accesses.
1709	
1710		noirqdebug	[X86-32] Disables the code which attempts to detect and
1711				disable unhandled interrupt sources.
1712	
1713		no_timer_check	[X86,APIC] Disables the code which tests for
1714				broken timer IRQ sources.
1715	
1716		noisapnp	[ISAPNP] Disables ISA PnP code.
1717	
1718		noinitrd	[RAM] Tells the kernel not to load any configured
1719				initial RAM disk.
1720	
1721		nointremap	[X86-64, Intel-IOMMU] Do not enable interrupt
1722				remapping.
1723	
1724		nointroute	[IA-64]
1725	
1726		nojitter	[IA64] Disables jitter checking for ITC timers.
1727	
1728		nolapic		[X86-32,APIC] Do not enable or use the local APIC.
1729	
1730		nolapic_timer	[X86-32,APIC] Do not use the local APIC timer.
1731	
1732		noltlbs		[PPC] Do not use large page/tlb entries for kernel
1733				lowmem mapping on PPC40x.
1734	
1735		nomca		[IA-64] Disable machine check abort handling
1736	
1737		nomce		[X86-32] Machine Check Exception
1738	
1739		nomfgpt		[X86-32] Disable Multi-Function General Purpose
1740				Timer usage (for AMD Geode machines).
1741	
1742		nopat		[X86] Disable PAT (page attribute table extension of
1743				pagetables) support.
1744	
1745		norandmaps	Don't use address space randomization.  Equivalent to
1746				echo 0 > /proc/sys/kernel/randomize_va_space
1747	
1748		noreplace-paravirt	[X86-32,PV_OPS] Don't patch paravirt_ops
1749	
1750		noreplace-smp	[X86-32,SMP] Don't replace SMP instructions
1751				with UP alternatives
1752	
1753		noresidual	[PPC] Don't use residual data on PReP machines.
1754	
1755		noresume	[SWSUSP] Disables resume and restores original swap
1756				space.
1757	
1758		no-scroll	[VGA] Disables scrollback.
1759				This is required for the Braillex ib80-piezo Braille
1760				reader made by F.H. Papenmeier (Germany).
1761	
1762		nosbagart	[IA-64]
1763	
1764		nosep		[BUGS=X86-32] Disables x86 SYSENTER/SYSEXIT support.
1765	
1766		nosmp		[SMP] Tells an SMP kernel to act as a UP kernel,
1767				and disable the IO APIC.  legacy for "maxcpus=0".
1768	
1769		nosoftlockup	[KNL] Disable the soft-lockup detector.
1770	
1771		noswapaccount	[KNL] Disable accounting of swap in memory resource
1772				controller. (See Documentation/cgroups/memory.txt)
1773	
1774		nosync		[HW,M68K] Disables sync negotiation for all devices.
1775	
1776		notsc		[BUGS=X86-32] Disable Time Stamp Counter
1777	
1778		nousb		[USB] Disable the USB subsystem
1779	
1780		nowb		[ARM]
1781	
1782		nox2apic	[X86-64,APIC] Do not enable x2APIC mode.
1783	
1784		nptcg=		[IA64] Override max number of concurrent global TLB
1785				purges which is reported from either PAL_VM_SUMMARY or
1786				SAL PALO.
1787	
1788		nr_cpus=	[SMP] Maximum number of processors that	an SMP kernel
1789				could support.  nr_cpus=n : n >= 1 limits the kernel to
1790				supporting 'n' processors. Later in runtime you can not
1791				use hotplug cpu feature to put more cpu back to online.
1792				just like you compile the kernel NR_CPUS=n
1793	
1794		nr_uarts=	[SERIAL] maximum number of UARTs to be registered.
1795	
1796		numa_zonelist_order= [KNL, BOOT] Select zonelist order for NUMA.
1797				one of ['zone', 'node', 'default'] can be specified
1798				This can be set from sysctl after boot.
1799				See Documentation/sysctl/vm.txt for details.
1800	
1801		ohci1394_dma=early	[HW] enable debugging via the ohci1394 driver.
1802				See Documentation/debugging-via-ohci1394.txt for more
1803				info.
1804	
1805		olpc_ec_timeout= [OLPC] ms delay when issuing EC commands
1806				Rather than timing out after 20 ms if an EC
1807				command is not properly ACKed, override the length
1808				of the timeout.  We have interrupts disabled while
1809				waiting for the ACK, so if this is set too high
1810				interrupts *may* be lost!
1811	
1812		omap_mux=	[OMAP] Override bootloader pin multiplexing.
1813				Format: <mux_mode0.mode_name=value>...
1814				For example, to override I2C bus2:
1815				omap_mux=i2c2_scl.i2c2_scl=0x100,i2c2_sda.i2c2_sda=0x100
1816	
1817		opl3=		[HW,OSS]
1818				Format: <io>
1819	
1820		oprofile.timer=	[HW]
1821				Use timer interrupt instead of performance counters
1822	
1823		oprofile.cpu_type=	Force an oprofile cpu type
1824				This might be useful if you have an older oprofile
1825				userland or if you want common events.
1826				Format: { arch_perfmon }
1827				arch_perfmon: [X86] Force use of architectural
1828					perfmon on Intel CPUs instead of the
1829					CPU specific event set.
1830	
1831		osst=		[HW,SCSI] SCSI Tape Driver
1832				Format: <buffer_size>,<write_threshold>
1833				See also Documentation/scsi/st.txt.
1834	
1835		panic=		[KNL] Kernel behaviour on panic
1836				Format: <timeout>
1837	
1838		parkbd.port=	[HW] Parallel port number the keyboard adapter is
1839				connected to, default is 0.
1840				Format: <parport#>
1841		parkbd.mode=	[HW] Parallel port keyboard adapter mode of operation,
1842				0 for XT, 1 for AT (default is AT).
1843				Format: <mode>
1844	
1845		parport=	[HW,PPT] Specify parallel ports. 0 disables.
1846				Format: { 0 | auto | 0xBBB[,IRQ[,DMA]] }
1847				Use 'auto' to force the driver to use any
1848				IRQ/DMA settings detected (the default is to
1849				ignore detected IRQ/DMA settings because of
1850				possible conflicts). You can specify the base
1851				address, IRQ, and DMA settings; IRQ and DMA
1852				should be numbers, or 'auto' (for using detected
1853				settings on that particular port), or 'nofifo'
1854				(to avoid using a FIFO even if it is detected).
1855				Parallel ports are assigned in the order they
1856				are specified on the command line, starting
1857				with parport0.
1858	
1859		parport_init_mode=	[HW,PPT]
1860				Configure VIA parallel port to operate in
1861				a specific mode. This is necessary on Pegasos
1862				computer where firmware has no options for setting
1863				up parallel port mode and sets it to spp.
1864				Currently this function knows 686a and 8231 chips.
1865				Format: [spp|ps2|epp|ecp|ecpepp]
1866	
1867		pas2=		[HW,OSS] Format:
1868				<io>,<irq>,<dma>,<dma16>,<sb_io>,<sb_irq>,<sb_dma>,<sb_dma16>
1869	
1870		pas16=		[HW,SCSI]
1871				See header of drivers/scsi/pas16.c.
1872	
1873		pause_on_oops=
1874				Halt all CPUs after the first oops has been printed for
1875				the specified number of seconds.  This is to be used if
1876				your oopses keep scrolling off the screen.
1877	
1878		pcbit=		[HW,ISDN]
1879	
1880		pcd.		[PARIDE]
1881				See header of drivers/block/paride/pcd.c.
1882				See also Documentation/blockdev/paride.txt.
1883	
1884		pci=option[,option...]	[PCI] various PCI subsystem options:
1885			earlydump	[X86] dump PCI config space before the kernel
1886				        changes anything
1887			off		[X86] don't probe for the PCI bus
1888			bios		[X86-32] force use of PCI BIOS, don't access
1889					the hardware directly. Use this if your machine
1890					has a non-standard PCI host bridge.
1891			nobios		[X86-32] disallow use of PCI BIOS, only direct
1892					hardware access methods are allowed. Use this
1893					if you experience crashes upon bootup and you
1894					suspect they are caused by the BIOS.
1895			conf1		[X86] Force use of PCI Configuration
1896					Mechanism 1.
1897			conf2		[X86] Force use of PCI Configuration
1898					Mechanism 2.
1899			noaer		[PCIE] If the PCIEAER kernel config parameter is
1900					enabled, this kernel boot option can be used to
1901					disable the use of PCIE advanced error reporting.
1902			nodomains	[PCI] Disable support for multiple PCI
1903					root domains (aka PCI segments, in ACPI-speak).
1904			nommconf	[X86] Disable use of MMCONFIG for PCI
1905					Configuration
1906			check_enable_amd_mmconf [X86] check for and enable
1907					properly configured MMIO access to PCI
1908					config space on AMD family 10h CPU
1909			nomsi		[MSI] If the PCI_MSI kernel config parameter is
1910					enabled, this kernel boot option can be used to
1911					disable the use of MSI interrupts system-wide.
1912			noioapicquirk	[APIC] Disable all boot interrupt quirks.
1913					Safety option to keep boot IRQs enabled. This
1914					should never be necessary.
1915			ioapicreroute	[APIC] Enable rerouting of boot IRQs to the
1916					primary IO-APIC for bridges that cannot disable
1917					boot IRQs. This fixes a source of spurious IRQs
1918					when the system masks IRQs.
1919			noioapicreroute	[APIC] Disable workaround that uses the
1920					boot IRQ equivalent of an IRQ that connects to
1921					a chipset where boot IRQs cannot be disabled.
1922					The opposite of ioapicreroute.
1923			biosirq		[X86-32] Use PCI BIOS calls to get the interrupt
1924					routing table. These calls are known to be buggy
1925					on several machines and they hang the machine
1926					when used, but on other computers it's the only
1927					way to get the interrupt routing table. Try
1928					this option if the kernel is unable to allocate
1929					IRQs or discover secondary PCI buses on your
1930					motherboard.
1931			rom		[X86] Assign address space to expansion ROMs.
1932					Use with caution as certain devices share
1933					address decoders between ROMs and other
1934					resources.
1935			norom		[X86] Do not assign address space to
1936					expansion ROMs that do not already have
1937					BIOS assigned address ranges.
1938			irqmask=0xMMMM	[X86] Set a bit mask of IRQs allowed to be
1939					assigned automatically to PCI devices. You can
1940					make the kernel exclude IRQs of your ISA cards
1941					this way.
1942			pirqaddr=0xAAAAA	[X86] Specify the physical address
1943					of the PIRQ table (normally generated
1944					by the BIOS) if it is outside the
1945					F0000h-100000h range.
1946			lastbus=N	[X86] Scan all buses thru bus #N. Can be
1947					useful if the kernel is unable to find your
1948					secondary buses and you want to tell it
1949					explicitly which ones they are.
1950			assign-busses	[X86] Always assign all PCI bus
1951					numbers ourselves, overriding
1952					whatever the firmware may have done.
1953			usepirqmask	[X86] Honor the possible IRQ mask stored
1954					in the BIOS $PIR table. This is needed on
1955					some systems with broken BIOSes, notably
1956					some HP Pavilion N5400 and Omnibook XE3
1957					notebooks. This will have no effect if ACPI
1958					IRQ routing is enabled.
1959			noacpi		[X86] Do not use ACPI for IRQ routing
1960					or for PCI scanning.
1961			use_crs		[X86] Use PCI host bridge window information
1962					from ACPI.  On BIOSes from 2008 or later, this
1963					is enabled by default.  If you need to use this,
1964					please report a bug.
1965			nocrs		[X86] Ignore PCI host bridge windows from ACPI.
1966				        If you need to use this, please report a bug.
1967			routeirq	Do IRQ routing for all PCI devices.
1968					This is normally done in pci_enable_device(),
1969					so this option is a temporary workaround
1970					for broken drivers that don't call it.
1971			skip_isa_align	[X86] do not align io start addr, so can
1972					handle more pci cards
1973			firmware	[ARM] Do not re-enumerate the bus but instead
1974					just use the configuration from the
1975					bootloader. This is currently used on
1976					IXP2000 systems where the bus has to be
1977					configured a certain way for adjunct CPUs.
1978			noearly		[X86] Don't do any early type 1 scanning.
1979					This might help on some broken boards which
1980					machine check when some devices' config space
1981					is read. But various workarounds are disabled
1982					and some IOMMU drivers will not work.
1983			bfsort		Sort PCI devices into breadth-first order.
1984					This sorting is done to get a device
1985					order compatible with older (<= 2.4) kernels.
1986			nobfsort	Don't sort PCI devices into breadth-first order.
1987			cbiosize=nn[KMG]	The fixed amount of bus space which is
1988					reserved for the CardBus bridge's IO window.
1989					The default value is 256 bytes.
1990			cbmemsize=nn[KMG]	The fixed amount of bus space which is
1991					reserved for the CardBus bridge's memory
1992					window. The default value is 64 megabytes.
1993			resource_alignment=
1994					Format:
1995					[<order of align>[AT]][<domain>:]<bus>:<slot>.<func>[; ..[DOT]]
1996					Specifies alignment and device to reassign
1997					aligned memory resources.
1998					If <order of align> is not specified,
1999					PAGE_SIZE is used as alignment.
2000					PCI-PCI bridge can be specified, if resource
2001					windows need to be expanded.
2002			ecrc=		Enable/disable PCIe ECRC (transaction layer
2003					end-to-end CRC checking).
2004					bios: Use BIOS/firmware settings. This is the
2005					the default.
2006					off: Turn ECRC off
2007					on: Turn ECRC on.
2008	
2009		pcie_aspm=	[PCIE] Forcibly enable or disable PCIe Active State Power
2010				Management.
2011			off	Disable ASPM.
2012			force	Enable ASPM even on devices that claim not to support it.
2013				WARNING: Forcing ASPM on may cause system lockups.
2014	
2015		pcie_pme=	[PCIE,PM] Native PCIe PME signaling options:
2016			off	Do not use native PCIe PME signaling.
2017			force	Use native PCIe PME signaling even if the BIOS refuses
2018				to allow the kernel to control the relevant PCIe config
2019				registers.
2020			nomsi	Do not use MSI for native PCIe PME signaling (this makes
2021				all PCIe root ports use INTx for everything).
2022	
2023		pcmv=		[HW,PCMCIA] BadgePAD 4
2024	
2025		pd.		[PARIDE]
2026				See Documentation/blockdev/paride.txt.
2027	
2028		pdcchassis=	[PARISC,HW] Disable/Enable PDC Chassis Status codes at
2029				boot time.
2030				Format: { 0 | 1 }
2031				See arch/parisc/kernel/pdc_chassis.c
2032	
2033		percpu_alloc=	Select which percpu first chunk allocator to use.
2034				Currently supported values are "embed" and "page".
2035				Archs may support subset or none of the	selections.
2036				See comments in mm/percpu.c for details on each
2037				allocator.  This parameter is primarily	for debugging
2038				and performance comparison.
2039	
2040		pf.		[PARIDE]
2041				See Documentation/blockdev/paride.txt.
2042	
2043		pg.		[PARIDE]
2044				See Documentation/blockdev/paride.txt.
2045	
2046		pirq=		[SMP,APIC] Manual mp-table setup
2047				See Documentation/x86/i386/IO-APIC.txt.
2048	
2049		plip=		[PPT,NET] Parallel port network link
2050				Format: { parport<nr> | timid | 0 }
2051				See also Documentation/parport.txt.
2052	
2053		pmtmr=		[X86] Manual setup of pmtmr I/O Port. 
2054				Override pmtimer IOPort with a hex value.
2055				e.g. pmtmr=0x508
2056	
2057		pnp.debug	[PNP]
2058				Enable PNP debug messages.  This depends on the
2059				CONFIG_PNP_DEBUG_MESSAGES option.
2060	
2061		pnpacpi=	[ACPI]
2062				{ off }
2063	
2064		pnpbios=	[ISAPNP]
2065				{ on | off | curr | res | no-curr | no-res }
2066	
2067		pnp_reserve_irq=
2068				[ISAPNP] Exclude IRQs for the autoconfiguration
2069	
2070		pnp_reserve_dma=
2071				[ISAPNP] Exclude DMAs for the autoconfiguration
2072	
2073		pnp_reserve_io=	[ISAPNP] Exclude I/O ports for the autoconfiguration
2074				Ranges are in pairs (I/O port base and size).
2075	
2076		pnp_reserve_mem=
2077				[ISAPNP] Exclude memory regions for the
2078				autoconfiguration.
2079				Ranges are in pairs (memory base and size).
2080	
2081		ports=		[IP_VS_FTP] IPVS ftp helper module
2082				Default is 21.
2083				Up to 8 (IP_VS_APP_MAX_PORTS) ports
2084				may be specified.
2085				Format: <port>,<port>....
2086	
2087		print-fatal-signals=
2088				[KNL] debug: print fatal signals
2089	
2090				If enabled, warn about various signal handling
2091				related application anomalies: too many signals,
2092				too many POSIX.1 timers, fatal signals causing a
2093				coredump - etc.
2094	
2095				If you hit the warning due to signal overflow,
2096				you might want to try "ulimit -i unlimited".
2097	
2098				default: off.
2099	
2100		printk.time=	Show timing data prefixed to each printk message line
2101				Format: <bool>  (1/Y/y=enable, 0/N/n=disable)
2102	
2103		processor.max_cstate=	[HW,ACPI]
2104				Limit processor to maximum C-state
2105				max_cstate=9 overrides any DMI blacklist limit.
2106	
2107		processor.nocst	[HW,ACPI]
2108				Ignore the _CST method to determine C-states,
2109				instead using the legacy FADT method
2110	
2111		profile=	[KNL] Enable kernel profiling via /proc/profile
2112				Format: [schedule,]<number>
2113				Param: "schedule" - profile schedule points.
2114				Param: <number> - step/bucket size as a power of 2 for
2115					statistical time based profiling.
2116				Param: "sleep" - profile D-state sleeping (millisecs).
2117					Requires CONFIG_SCHEDSTATS
2118				Param: "kvm" - profile VM exits.
2119	
2120		prompt_ramdisk=	[RAM] List of RAM disks to prompt for floppy disk
2121				before loading.
2122				See Documentation/blockdev/ramdisk.txt.
2123	
2124		psmouse.proto=	[HW,MOUSE] Highest PS2 mouse protocol extension to
2125				probe for; one of (bare|imps|exps|lifebook|any).
2126		psmouse.rate=	[HW,MOUSE] Set desired mouse report rate, in reports
2127				per second.
2128		psmouse.resetafter=	[HW,MOUSE]
2129				Try to reset the device after so many bad packets
2130				(0 = never).
2131		psmouse.resolution=
2132				[HW,MOUSE] Set desired mouse resolution, in dpi.
2133		psmouse.smartscroll=
2134				[HW,MOUSE] Controls Logitech smartscroll autorepeat.
2135				0 = disabled, 1 = enabled (default).
2136	
2137		pss=		[HW,OSS] Personal Sound System (ECHO ESC614)
2138				Format:
2139				<io>,<mss_io>,<mss_irq>,<mss_dma>,<mpu_io>,<mpu_irq>
2140	
2141		pt.		[PARIDE]
2142				See Documentation/blockdev/paride.txt.
2143	
2144		pty.legacy_count=
2145				[KNL] Number of legacy pty's. Overwrites compiled-in
2146				default number.
2147	
2148		quiet		[KNL] Disable most log messages
2149	
2150		r128=		[HW,DRM]
2151	
2152		raid=		[HW,RAID]
2153				See Documentation/md.txt.
2154	
2155		ramdisk_blocksize=	[RAM]
2156				See Documentation/blockdev/ramdisk.txt.
2157	
2158		ramdisk_size=	[RAM] Sizes of RAM disks in kilobytes
2159				See Documentation/blockdev/ramdisk.txt.
2160	
2161		rcupdate.blimit=	[KNL,BOOT]
2162				Set maximum number of finished RCU callbacks to process
2163				in one batch.
2164	
2165		rcupdate.qhimark=	[KNL,BOOT]
2166				Set threshold of queued
2167				RCU callbacks over which batch limiting is disabled.
2168	
2169		rcupdate.qlowmark=	[KNL,BOOT]
2170				Set threshold of queued RCU callbacks below which
2171				batch limiting is re-enabled.
2172	
2173		rdinit=		[KNL]
2174				Format: <full_path>
2175				Run specified binary instead of /init from the ramdisk,
2176				used for early userspace startup. See initrd.
2177	
2178		reboot=		[BUGS=X86-32,BUGS=ARM,BUGS=IA-64] Rebooting mode
2179				Format: <reboot_mode>[,<reboot_mode2>[,...]]
2180				See arch/*/kernel/reboot.c or arch/*/kernel/process.c
2181	
2182		relax_domain_level=
2183				[KNL, SMP] Set scheduler's default relax_domain_level.
2184				See Documentation/cgroups/cpusets.txt.
2185	
2186		reserve=	[KNL,BUGS] Force the kernel to ignore some iomem area
2187	
2188		reservetop=	[X86-32]
2189				Format: nn[KMG]
2190				Reserves a hole at the top of the kernel virtual
2191				address space.
2192	
2193		reset_devices	[KNL] Force drivers to reset the underlying device
2194				during initialization.
2195	
2196		resume=		[SWSUSP]
2197				Specify the partition device for software suspend
2198	
2199		resume_offset=	[SWSUSP]
2200				Specify the offset from the beginning of the partition
2201				given by "resume=" at which the swap header is located,
2202				in <PAGE_SIZE> units (needed only for swap files).
2203				See  Documentation/power/swsusp-and-swap-files.txt
2204	
2205		retain_initrd	[RAM] Keep initrd memory after extraction
2206	
2207		rhash_entries=	[KNL,NET]
2208				Set number of hash buckets for route cache
2209	
2210		riscom8=	[HW,SERIAL]
2211				Format: <io_board1>[,<io_board2>[,...<io_boardN>]]
2212	
2213		ro		[KNL] Mount root device read-only on boot
2214	
2215		root=		[KNL] Root filesystem
2216	
2217		rootdelay=	[KNL] Delay (in seconds) to pause before attempting to
2218				mount the root filesystem
2219	
2220		rootflags=	[KNL] Set root filesystem mount option string
2221	
2222		rootfstype=	[KNL] Set root filesystem type
2223	
2224		rootwait	[KNL] Wait (indefinitely) for root device to show up.
2225				Useful for devices that are detected asynchronously
2226				(e.g. USB and MMC devices).
2227	
2228		rw		[KNL] Mount root device read-write on boot
2229	
2230		S		[KNL] Run init in single mode
2231	
2232		sa1100ir	[NET]
2233				See drivers/net/irda/sa1100_ir.c.
2234	
2235		sbni=		[NET] Granch SBNI12 leased line adapter
2236	
2237		sched_debug	[KNL] Enables verbose scheduler debug messages.
2238	
2239		sc1200wdt=	[HW,WDT] SC1200 WDT (watchdog) driver
2240				Format: <io>[,<timeout>[,<isapnp>]]
2241	
2242		scsi_debug_*=	[SCSI]
2243				See drivers/scsi/scsi_debug.c.
2244	
2245		scsi_default_dev_flags=
2246				[SCSI] SCSI default device flags
2247				Format: <integer>
2248	
2249		scsi_dev_flags=	[SCSI] Black/white list entry for vendor and model
2250				Format: <vendor>:<model>:<flags>
2251				(flags are integer value)
2252	
2253		scsi_logging_level=	[SCSI] a bit mask of logging levels
2254				See drivers/scsi/scsi_logging.h for bits.  Also
2255				settable via sysctl at dev.scsi.logging_level
2256				(/proc/sys/dev/scsi/logging_level).
2257				There is also a nice 'scsi_logging_level' script in the
2258				S390-tools package, available for download at
2259				http://www-128.ibm.com/developerworks/linux/linux390/s390-tools-1.5.4.html
2260	
2261		scsi_mod.scan=	[SCSI] sync (default) scans SCSI busses as they are
2262				discovered.  async scans them in kernel threads,
2263				allowing boot to proceed.  none ignores them, expecting
2264				user space to do the scan.
2265	
2266		security=	[SECURITY] Choose a security module to enable at boot.
2267				If this boot parameter is not specified, only the first
2268				security module asking for security registration will be
2269				loaded. An invalid security module name will be treated
2270				as if no module has been chosen.
2271	
2272		selinux=	[SELINUX] Disable or enable SELinux at boot time.
2273				Format: { "0" | "1" }
2274				See security/selinux/Kconfig help text.
2275				0 -- disable.
2276				1 -- enable.
2277				Default value is set via kernel config option.
2278				If enabled at boot time, /selinux/disable can be used
2279				later to disable prior to initial policy load.
2280	
2281		serialnumber	[BUGS=X86-32]
2282	
2283		shapers=	[NET]
2284				Maximal number of shapers.
2285	
2286		show_msr=	[x86] show boot-time MSR settings
2287				Format: { <integer> }
2288				Show boot-time (BIOS-initialized) MSR settings.
2289				The parameter means the number of CPUs to show,
2290				for example 1 means boot CPU only.
2291	
2292		sim710=		[SCSI,HW]
2293				See header of drivers/scsi/sim710.c.
2294	
2295		simeth=		[IA-64]
2296		simscsi=
2297	
2298		slram=		[HW,MTD]
2299	
2300		slub_debug[=options[,slabs]]	[MM, SLUB]
2301				Enabling slub_debug allows one to determine the
2302				culprit if slab objects become corrupted. Enabling
2303				slub_debug can create guard zones around objects and
2304				may poison objects when not in use. Also tracks the
2305				last alloc / free. For more information see
2306				Documentation/vm/slub.txt.
2307	
2308		slub_max_order= [MM, SLUB]
2309				Determines the maximum allowed order for slabs.
2310				A high setting may cause OOMs due to memory
2311				fragmentation. For more information see
2312				Documentation/vm/slub.txt.
2313	
2314		slub_min_objects=	[MM, SLUB]
2315				The minimum number of objects per slab. SLUB will
2316				increase the slab order up to slub_max_order to
2317				generate a sufficiently large slab able to contain
2318				the number of objects indicated. The higher the number
2319				of objects the smaller the overhead of tracking slabs
2320				and the less frequently locks need to be acquired.
2321				For more information see Documentation/vm/slub.txt.
2322	
2323		slub_min_order=	[MM, SLUB]
2324				Determines the mininum page order for slabs. Must be
2325				lower than slub_max_order.
2326				For more information see Documentation/vm/slub.txt.
2327	
2328		slub_nomerge	[MM, SLUB]
2329				Disable merging of slabs with similar size. May be
2330				necessary if there is some reason to distinguish
2331				allocs to different slabs. Debug options disable
2332				merging on their own.
2333				For more information see Documentation/vm/slub.txt.
2334	
2335		smart2=		[HW]
2336				Format: <io1>[,<io2>[,...,<io8>]]
2337	
2338		smp-alt-once	[X86-32,SMP] On a hotplug CPU system, only
2339				attempt to substitute SMP alternatives once at boot.
2340	
2341		smsc-ircc2.nopnp	[HW] Don't use PNP to discover SMC devices
2342		smsc-ircc2.ircc_cfg=	[HW] Device configuration I/O port
2343		smsc-ircc2.ircc_sir=	[HW] SIR base I/O port
2344		smsc-ircc2.ircc_fir=	[HW] FIR base I/O port
2345		smsc-ircc2.ircc_irq=	[HW] IRQ line
2346		smsc-ircc2.ircc_dma=	[HW] DMA channel
2347		smsc-ircc2.ircc_transceiver= [HW] Transceiver type:
2348					0: Toshiba Satellite 1800 (GP data pin select)
2349					1: Fast pin select (default)
2350					2: ATC IRMode
2351	
2352		snd-ad1816a=	[HW,ALSA]
2353	
2354		snd-ad1848=	[HW,ALSA]
2355	
2356		snd-ali5451=	[HW,ALSA]
2357	
2358		snd-als100=	[HW,ALSA]
2359	
2360		snd-als4000=	[HW,ALSA]
2361	
2362		snd-azt2320=	[HW,ALSA]
2363	
2364		snd-cmi8330=	[HW,ALSA]
2365	
2366		snd-cmipci=	[HW,ALSA]
2367	
2368		snd-cs4231=	[HW,ALSA]
2369	
2370		snd-cs4232=	[HW,ALSA]
2371	
2372		snd-cs4236=	[HW,ALSA]
2373	
2374		snd-cs4281=	[HW,ALSA]
2375	
2376		snd-cs46xx=	[HW,ALSA]
2377	
2378		snd-dt019x=	[HW,ALSA]
2379	
2380		snd-dummy=	[HW,ALSA]
2381	
2382		snd-emu10k1=	[HW,ALSA]
2383	
2384		snd-ens1370=	[HW,ALSA]
2385	
2386		snd-ens1371=	[HW,ALSA]
2387	
2388		snd-es968=	[HW,ALSA]
2389	
2390		snd-es1688=	[HW,ALSA]
2391	
2392		snd-es18xx=	[HW,ALSA]
2393	
2394		snd-es1938=	[HW,ALSA]
2395	
2396		snd-es1968=	[HW,ALSA]
2397	
2398		snd-fm801=	[HW,ALSA]
2399	
2400		snd-gusclassic=	[HW,ALSA]
2401	
2402		snd-gusextreme=	[HW,ALSA]
2403	
2404		snd-gusmax=	[HW,ALSA]
2405	
2406		snd-hdsp=	[HW,ALSA]
2407	
2408		snd-ice1712=	[HW,ALSA]
2409	
2410		snd-intel8x0=	[HW,ALSA]
2411	
2412		snd-interwave=	[HW,ALSA]
2413	
2414		snd-interwave-stb=
2415				[HW,ALSA]
2416	
2417		snd-korg1212=	[HW,ALSA]
2418	
2419		snd-maestro3=	[HW,ALSA]
2420	
2421		snd-mpu401=	[HW,ALSA]
2422	
2423		snd-mtpav=	[HW,ALSA]
2424	
2425		snd-nm256=	[HW,ALSA]
2426	
2427		snd-opl3sa2=	[HW,ALSA]
2428	
2429		snd-opti92x-ad1848=
2430				[HW,ALSA]
2431	
2432		snd-opti92x-cs4231=
2433				[HW,ALSA]
2434	
2435		snd-opti93x=	[HW,ALSA]
2436	
2437		snd-pmac=	[HW,ALSA]
2438	
2439		snd-rme32=	[HW,ALSA]
2440	
2441		snd-rme96=	[HW,ALSA]
2442	
2443		snd-rme9652=	[HW,ALSA]
2444	
2445		snd-sb8=	[HW,ALSA]
2446	
2447		snd-sb16=	[HW,ALSA]
2448	
2449		snd-sbawe=	[HW,ALSA]
2450	
2451		snd-serial=	[HW,ALSA]
2452	
2453		snd-sgalaxy=	[HW,ALSA]
2454	
2455		snd-sonicvibes=	[HW,ALSA]
2456	
2457		snd-sun-amd7930=
2458				[HW,ALSA]
2459	
2460		snd-sun-cs4231=	[HW,ALSA]
2461	
2462		snd-trident=	[HW,ALSA]
2463	
2464		snd-usb-audio=	[HW,ALSA,USB]
2465	
2466		snd-via82xx=	[HW,ALSA]
2467	
2468		snd-virmidi=	[HW,ALSA]
2469	
2470		snd-wavefront=	[HW,ALSA]
2471	
2472		snd-ymfpci=	[HW,ALSA]
2473	
2474		softlockup_panic=
2475				[KNL] Should the soft-lockup detector generate panics.
2476	
2477		sonypi.*=	[HW] Sony Programmable I/O Control Device driver
2478				See Documentation/sonypi.txt
2479	
2480		specialix=	[HW,SERIAL] Specialix multi-serial port adapter
2481				See Documentation/serial/specialix.txt.
2482	
2483		spia_io_base=	[HW,MTD]
2484		spia_fio_base=
2485		spia_pedr=
2486		spia_peddr=
2487	
2488		sscape=		[HW,OSS]
2489				Format: <io>,<irq>,<dma>,<mpu_io>,<mpu_irq>
2490	
2491		st=		[HW,SCSI] SCSI tape parameters (buffers, etc.)
2492				See Documentation/scsi/st.txt.
2493	
2494		stacktrace	[FTRACE]
2495				Enabled the stack tracer on boot up.
2496	
2497		sti=		[PARISC,HW]
2498				Format: <num>
2499				Set the STI (builtin display/keyboard on the HP-PARISC
2500				machines) console (graphic card) which should be used
2501				as the initial boot-console.
2502				See also comment in drivers/video/console/sticore.c.
2503	
2504		sti_font=	[HW]
2505				See comment in drivers/video/console/sticore.c.
2506	
2507		stifb=		[HW]
2508				Format: bpp:<bpp1>[:<bpp2>[:<bpp3>...]]
2509	
2510		sunrpc.min_resvport=
2511		sunrpc.max_resvport=
2512				[NFS,SUNRPC]
2513				SunRPC servers often require that client requests
2514				originate from a privileged port (i.e. a port in the
2515				range 0 < portnr < 1024).
2516				An administrator who wishes to reserve some of these
2517				ports for other uses may adjust the range that the
2518				kernel's sunrpc client considers to be privileged
2519				using these two parameters to set the minimum and
2520				maximum port values.
2521	
2522		sunrpc.pool_mode=
2523				[NFS]
2524				Control how the NFS server code allocates CPUs to
2525				service thread pools.  Depending on how many NICs
2526				you have and where their interrupts are bound, this
2527				option will affect which CPUs will do NFS serving.
2528				Note: this parameter cannot be changed while the
2529				NFS server is running.
2530	
2531				auto	    the server chooses an appropriate mode
2532					    automatically using heuristics
2533				global	    a single global pool contains all CPUs
2534				percpu	    one pool for each CPU
2535				pernode	    one pool for each NUMA node (equivalent
2536					    to global on non-NUMA machines)
2537	
2538		sunrpc.tcp_slot_table_entries=
2539		sunrpc.udp_slot_table_entries=
2540				[NFS,SUNRPC]
2541				Sets the upper limit on the number of simultaneous
2542				RPC calls that can be sent from the client to a
2543				server. Increasing these values may allow you to
2544				improve throughput, but will also increase the
2545				amount of memory reserved for use by the client.
2546	
2547		swiotlb=	[IA-64] Number of I/O TLB slabs
2548	
2549		switches=	[HW,M68k]
2550	
2551		sym53c416=	[HW,SCSI]
2552				See header of drivers/scsi/sym53c416.c.
2553	
2554		sysrq_always_enabled
2555				[KNL]
2556				Ignore sysrq setting - this boot parameter will
2557				neutralize any effect of /proc/sys/kernel/sysrq.
2558				Useful for debugging.
2559	
2560		t128=		[HW,SCSI]
2561				See header of drivers/scsi/t128.c.
2562	
2563		tdfx=		[HW,DRM]
2564	
2565		test_suspend=	[SUSPEND]
2566				Specify "mem" (for Suspend-to-RAM) or "standby" (for
2567				standby suspend) as the system sleep state to briefly
2568				enter during system startup.  The system is woken from
2569				this state using a wakeup-capable RTC alarm.
2570	
2571		thash_entries=	[KNL,NET]
2572				Set number of hash buckets for TCP connection
2573	
2574		thermal.act=	[HW,ACPI]
2575				-1: disable all active trip points in all thermal zones
2576				<degrees C>: override all lowest active trip points
2577	
2578		thermal.crt=	[HW,ACPI]
2579				-1: disable all critical trip points in all thermal zones
2580				<degrees C>: override all critical trip points
2581	
2582		thermal.nocrt=	[HW,ACPI]
2583				Set to disable actions on ACPI thermal zone
2584				critical and hot trip points.
2585	
2586		thermal.off=	[HW,ACPI]
2587				1: disable ACPI thermal control
2588	
2589		thermal.psv=	[HW,ACPI]
2590				-1: disable all passive trip points
2591				<degrees C>: override all passive trip points to this
2592				value
2593	
2594		thermal.tzp=	[HW,ACPI]
2595				Specify global default ACPI thermal zone polling rate
2596				<deci-seconds>: poll all this frequency
2597				0: no polling (default)
2598	
2599		tmscsim=	[HW,SCSI]
2600				See comment before function dc390_setup() in
2601				drivers/scsi/tmscsim.c.
2602	
2603		topology=	[S390]
2604				Format: {off | on}
2605				Specify if the kernel should make use of the cpu
2606				topology informations if the hardware supports these.
2607				The scheduler will make use of these informations and
2608				e.g. base its process migration decisions on it.
2609				Default is off.
2610	
2611		tp720=		[HW,PS2]
2612	
2613		trace_buf_size=nn[KMG]
2614				[FTRACE] will set tracing buffer size.
2615	
2616		trace_event=[event-list]
2617				[FTRACE] Set and start specified trace events in order
2618				to facilitate early boot debugging.
2619				See also Documentation/trace/events.txt
2620	
2621		trix=		[HW,OSS] MediaTrix AudioTrix Pro
2622				Format:
2623				<io>,<irq>,<dma>,<dma2>,<sb_io>,<sb_irq>,<sb_dma>,<mpu_io>,<mpu_irq>
2624	
2625		tsc=		Disable clocksource-must-verify flag for TSC.
2626				Format: <string>
2627				[x86] reliable: mark tsc clocksource as reliable, this
2628				disables clocksource verification at runtime.
2629				Used to enable high-resolution timer mode on older
2630				hardware, and in virtualized environment.
2631	
2632		turbografx.map[2|3]=	[HW,JOY]
2633				TurboGraFX parallel port interface
2634				Format:
2635				<port#>,<js1>,<js2>,<js3>,<js4>,<js5>,<js6>,<js7>
2636				See also Documentation/input/joystick-parport.txt
2637	
2638		u14-34f=	[HW,SCSI] UltraStor 14F/34F SCSI host adapter
2639				See header of drivers/scsi/u14-34f.c.
2640	
2641		uart401=	[HW,OSS]
2642				Format: <io>,<irq>
2643	
2644		uart6850=	[HW,OSS]
2645				Format: <io>,<irq>
2646	
2647		uhash_entries=	[KNL,NET]
2648				Set number of hash buckets for UDP/UDP-Lite connections
2649	
2650		uhci-hcd.ignore_oc=
2651				[USB] Ignore overcurrent events (default N).
2652				Some badly-designed motherboards generate lots of
2653				bogus events, for ports that aren't wired to
2654				anything.  Set this parameter to avoid log spamming.
2655				Note that genuine overcurrent events won't be
2656				reported either.
2657	
2658		unknown_nmi_panic
2659				[X86]
2660				Set unknown_nmi_panic=1 early on boot.
2661	
2662		usbcore.autosuspend=
2663				[USB] The autosuspend time delay (in seconds) used
2664				for newly-detected USB devices (default 2).  This
2665				is the time required before an idle device will be
2666				autosuspended.  Devices for which the delay is set
2667				to a negative value won't be autosuspended at all.
2668	
2669		usbcore.usbfs_snoop=
2670				[USB] Set to log all usbfs traffic (default 0 = off).
2671	
2672		usbcore.blinkenlights=
2673				[USB] Set to cycle leds on hubs (default 0 = off).
2674	
2675		usbcore.old_scheme_first=
2676				[USB] Start with the old device initialization
2677				scheme (default 0 = off).
2678	
2679		usbcore.use_both_schemes=
2680				[USB] Try the other device initialization scheme
2681				if the first one fails (default 1 = enabled).
2682	
2683		usbcore.initial_descriptor_timeout=
2684				[USB] Specifies timeout for the initial 64-byte
2685	                        USB_REQ_GET_DESCRIPTOR request in milliseconds
2686				(default 5000 = 5.0 seconds).
2687	
2688		usbhid.mousepoll=
2689				[USBHID] The interval which mice are to be polled at.
2690	
2691		usb-storage.delay_use=
2692				[UMS] The delay in seconds before a new device is
2693				scanned for Logical Units (default 5).
2694	
2695		usb-storage.quirks=
2696				[UMS] A list of quirks entries to supplement or
2697				override the built-in unusual_devs list.  List
2698				entries are separated by commas.  Each entry has
2699				the form VID:PID:Flags where VID and PID are Vendor
2700				and Product ID values (4-digit hex numbers) and
2701				Flags is a set of characters, each corresponding
2702				to a common usb-storage quirk flag as follows:
2703					a = SANE_SENSE (collect more than 18 bytes
2704						of sense data);
2705					b = BAD_SENSE (don't collect more than 18
2706						bytes of sense data);
2707					c = FIX_CAPACITY (decrease the reported
2708						device capacity by one sector);
2709					h = CAPACITY_HEURISTICS (decrease the
2710						reported device capacity by one
2711						sector if the number is odd);
2712					i = IGNORE_DEVICE (don't bind to this
2713						device);
2714					l = NOT_LOCKABLE (don't try to lock and
2715						unlock ejectable media);
2716					m = MAX_SECTORS_64 (don't transfer more
2717						than 64 sectors = 32 KB at a time);
2718					o = CAPACITY_OK (accept the capacity
2719						reported by the device);
2720					r = IGNORE_RESIDUE (the device reports
2721						bogus residue values);
2722					s = SINGLE_LUN (the device has only one
2723						Logical Unit);
2724					w = NO_WP_DETECT (don't test whether the
2725						medium is write-protected).
2726				Example: quirks=0419:aaf5:rl,0421:0433:rc
2727	
2728		userpte=
2729				[X86] Flags controlling user PTE allocations.
2730	
2731					nohigh = do not allocate PTE pages in
2732						HIGHMEM regardless of setting
2733						of CONFIG_HIGHPTE.
2734	
2735		vdso=		[X86,SH]
2736				vdso=2: enable compat VDSO (default with COMPAT_VDSO)
2737				vdso=1: enable VDSO (default)
2738				vdso=0: disable VDSO mapping
2739	
2740		vdso32=		[X86]
2741				vdso32=2: enable compat VDSO (default with COMPAT_VDSO)
2742				vdso32=1: enable 32-bit VDSO (default)
2743				vdso32=0: disable 32-bit VDSO mapping
2744	
2745		vector=		[IA-64,SMP]
2746				vector=percpu: enable percpu vector domain
2747	
2748		video=		[FB] Frame buffer configuration
2749				See Documentation/fb/modedb.txt.
2750	
2751		vga=		[BOOT,X86-32] Select a particular video mode
2752				See Documentation/x86/boot.txt and
2753				Documentation/svga.txt.
2754				Use vga=ask for menu.
2755				This is actually a boot loader parameter; the value is
2756				passed to the kernel using a special protocol.
2757	
2758		vmalloc=nn[KMG]	[KNL,BOOT] Forces the vmalloc area to have an exact
2759				size of <nn>. This can be used to increase the
2760				minimum size (128MB on x86). It can also be used to
2761				decrease the size and leave more room for directly
2762				mapped kernel RAM.
2763	
2764		vmhalt=		[KNL,S390] Perform z/VM CP command after system halt.
2765				Format: <command>
2766	
2767		vmpanic=	[KNL,S390] Perform z/VM CP command after kernel panic.
2768				Format: <command>
2769	
2770		vmpoff=		[KNL,S390] Perform z/VM CP command after power off.
2771				Format: <command>
2772	
2773		vt.cur_default=	[VT] Default cursor shape.
2774				Format: 0xCCBBAA, where AA, BB, and CC are the same as
2775				the parameters of the <Esc>[?A;B;Cc escape sequence;
2776				see VGA-softcursor.txt. Default: 2 = underline.
2777	
2778		vt.default_blu=	[VT]
2779				Format: <blue0>,<blue1>,<blue2>,...,<blue15>
2780				Change the default blue palette of the console.
2781				This is a 16-member array composed of values
2782				ranging from 0-255.
2783	
2784		vt.default_grn=	[VT]
2785				Format: <green0>,<green1>,<green2>,...,<green15>
2786				Change the default green palette of the console.
2787				This is a 16-member array composed of values
2788				ranging from 0-255.
2789	
2790		vt.default_red=	[VT]
2791				Format: <red0>,<red1>,<red2>,...,<red15>
2792				Change the default red palette of the console.
2793				This is a 16-member array composed of values
2794				ranging from 0-255.
2795	
2796		vt.default_utf8=
2797				[VT]
2798				Format=<0|1>
2799				Set system-wide default UTF-8 mode for all tty's.
2800				Default is 1, i.e. UTF-8 mode is enabled for all
2801				newly opened terminals.
2802	
2803		vt.global_cursor_default=
2804				[VT]
2805				Format=<-1|0|1>
2806				Set system-wide default for whether a cursor
2807				is shown on new VTs. Default is -1,
2808				i.e. cursors will be created by default unless
2809				overridden by individual drivers. 0 will hide
2810				cursors, 1 will display them.
2811	
2812		waveartist=	[HW,OSS]
2813				Format: <io>,<irq>,<dma>,<dma2>
2814	
2815		wd33c93=	[HW,SCSI]
2816				See header of drivers/scsi/wd33c93.c.
2817	
2818		wd7000=		[HW,SCSI]
2819				See header of drivers/scsi/wd7000.c.
2820	
2821		wdt=		[WDT] Watchdog
2822				See Documentation/watchdog/wdt.txt.
2823	
2824		x2apic_phys	[X86-64,APIC] Use x2apic physical mode instead of
2825				default x2apic cluster mode on platforms
2826				supporting x2apic.
2827	
2828		x86_mrst_timer= [X86-32,APBT]
2829				Choose timer option for x86 Moorestown MID platform.
2830				Two valid options are apbt timer only and lapic timer
2831				plus one apbt timer for broadcast timer.
2832				x86_mrst_timer=apbt_only | lapic_and_apbt
2833	
2834		xd=		[HW,XT] Original XT pre-IDE (RLL encoded) disks.
2835		xd_geo=		See header of drivers/block/xd.c.
2836	
2837		xirc2ps_cs=	[NET,PCMCIA]
2838				Format:
2839				<irq>,<irq_mask>,<io>,<full_duplex>,<do_sound>,<lockup_hack>[,<irq2>[,<irq3>[,<irq4>]]]
2840	
2841	______________________________________________________________________
2842	
2843	TODO:
2844	
2845		Add documentation for ALSA options.
2846		Add more DRM drivers.
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