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.
9 Module parameters for loadable modules are specified only as the
10 parameter name with optional '=' and value as appropriate, such as:
12 modprobe usbcore blinkenlights=1
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:
18 usbcore.blinkenlights=1
20 This document may not be entirely up to date and comprehensive. The command
21 "modinfo -p ${modulename}" shows a current list of all parameters of a loadable
22 module. Loadable modules, after being loaded into the running kernel, also
23 reveal their parameters in /sys/module/${modulename}/parameters/. Some of these
24 parameters may be changed at runtime by the command
25 "echo -n ${value} > /sys/module/${modulename}/parameters/${parm}".
27 The parameters listed below are only valid if certain kernel build options were
28 enabled and if respective hardware is present. The text in square brackets at
29 the beginning of each description states the restrictions within which a
30 parameter is applicable:
32 ACPI ACPI support is enabled.
33 AGP AGP (Accelerated Graphics Port) is enabled.
34 ALSA ALSA sound support is enabled.
35 APIC APIC support is enabled.
36 APM Advanced Power Management support is enabled.
37 AVR32 AVR32 architecture is enabled.
38 AX25 Appropriate AX.25 support is enabled.
39 BLACKFIN Blackfin architecture is enabled.
40 DRM Direct Rendering Management support is enabled.
41 EDD BIOS Enhanced Disk Drive Services (EDD) is enabled
42 EFI EFI Partitioning (GPT) is enabled
43 EIDE EIDE/ATAPI support is enabled.
44 FB The frame buffer device is enabled.
45 HW Appropriate hardware is enabled.
46 IA-64 IA-64 architecture is enabled.
47 IOSCHED More than one I/O scheduler is enabled.
48 IP_PNP IP DHCP, BOOTP, or RARP is enabled.
49 ISAPNP ISA PnP code is enabled.
50 ISDN Appropriate ISDN support is enabled.
51 JOY Appropriate joystick support is enabled.
52 LIBATA Libata driver is enabled
53 LP Printer support is enabled.
54 LOOP Loopback device support is enabled.
55 M68k M68k architecture is enabled.
56 These options have more detailed description inside of
57 Documentation/m68k/kernel-options.txt.
58 MCA MCA bus support is enabled.
59 MDA MDA console support is enabled.
60 MOUSE Appropriate mouse support is enabled.
61 MSI Message Signaled Interrupts (PCI).
62 MTD MTD (Memory Technology Device) support is enabled.
63 NET Appropriate network support is enabled.
64 NUMA NUMA support is enabled.
65 GENERIC_TIME The generic timeofday code is enabled.
66 NFS Appropriate NFS support is enabled.
67 OSS OSS sound support is enabled.
68 PV_OPS A paravirtualized kernel is enabled.
69 PARIDE The ParIDE (parallel port IDE) subsystem is enabled.
70 PARISC The PA-RISC architecture is enabled.
71 PCI PCI bus support is enabled.
72 PCIE PCI Express support is enabled.
73 PCMCIA The PCMCIA subsystem is enabled.
74 PNP Plug & Play support is enabled.
75 PPC PowerPC architecture is enabled.
76 PPT Parallel port support is enabled.
77 PS2 Appropriate PS/2 support is enabled.
78 RAM RAM disk support is enabled.
79 ROOTPLUG The example Root Plug LSM is enabled.
80 S390 S390 architecture is enabled.
81 SCSI Appropriate SCSI support is enabled.
82 A lot of drivers has their options described inside of
84 SECURITY Different security models are enabled.
85 SELINUX SELinux support is enabled.
86 SERIAL Serial support is enabled.
87 SH SuperH architecture is enabled.
88 SMP The kernel is an SMP kernel.
89 SPARC Sparc architecture is enabled.
90 SWSUSP Software suspend (hibernation) is enabled.
91 SUSPEND System suspend states are enabled.
92 TS Appropriate touchscreen support is enabled.
93 USB USB support is enabled.
94 USBHID USB Human Interface Device support is enabled.
95 V4L Video For Linux support is enabled.
96 VGA The VGA console has been enabled.
97 VT Virtual terminal support is enabled.
98 WDT Watchdog support is enabled.
99 XT IBM PC/XT MFM hard disk support is enabled.
100 X86-32 X86-32, aka i386 architecture is enabled.
101 X86-64 X86-64 architecture is enabled.
102 More X86-64 boot options can be found in
103 Documentation/x86_64/boot-options.txt .
105 In addition, the following text indicates that the option:
107 BUGS= Relates to possible processor bugs on the said processor.
108 KNL Is a kernel start-up parameter.
109 BOOT Is a boot loader parameter.
111 Parameters denoted with BOOT are actually interpreted by the boot
112 loader, and have no meaning to the kernel directly.
113 Do not modify the syntax of boot loader parameters without extreme
114 need or coordination with <Documentation/i386/boot.txt>.
116 There are also arch-specific kernel-parameters not documented here.
117 See for example <Documentation/x86_64/boot-options.txt>.
119 Note that ALL kernel parameters listed below are CASE SENSITIVE, and that
120 a trailing = on the name of any parameter states that that parameter will
121 be entered as an environment variable, whereas its absence indicates that
122 it will appear as a kernel argument readable via /proc/cmdline by programs
123 running once the system is up.
125 The number of kernel parameters is not limited, but the length of the
126 complete command line (parameters including spaces etc.) is limited to
127 a fixed number of characters. This limit depends on the architecture
128 and is between 256 and 4096 characters. It is defined in the file
129 ./include/asm/setup.h as COMMAND_LINE_SIZE.
132 acpi= [HW,ACPI,X86-64,i386]
133 Advanced Configuration and Power Interface
134 Format: { force | off | ht | strict | noirq }
135 force -- enable ACPI if default was off
136 off -- disable ACPI if default was on
137 noirq -- do not use ACPI for IRQ routing
138 ht -- run only enough ACPI to enable Hyper Threading
139 strict -- Be less tolerant of platforms that are not
140 strictly ACPI specification compliant.
142 See also Documentation/power/pm.txt, pci=noacpi
144 acpi_apic_instance= [ACPI, IOAPIC]
146 2: use 2nd APIC table, if available
147 1,0: use 1st APIC table
150 acpi_sleep= [HW,ACPI] Sleep options
151 Format: { s3_bios, s3_mode, s3_beep, s4_nohwsig, old_ordering }
152 See Documentation/power/video.txt for s3_bios and s3_mode.
153 s3_beep is for debugging; it makes the PC's speaker beep
154 as soon as the kernel's real-mode entry point is called.
155 s4_nohwsig prevents ACPI hardware signature from being
156 used during resume from hibernation.
157 old_ordering causes the ACPI 1.0 ordering of the _PTS
158 control method, wrt putting devices into low power
159 states, to be enforced (the ACPI 2.0 ordering of _PTS is
162 acpi_sci= [HW,ACPI] ACPI System Control Interrupt trigger mode
163 Format: { level | edge | high | low }
165 acpi_irq_balance [HW,ACPI]
166 ACPI will balance active IRQs
169 acpi_irq_nobalance [HW,ACPI]
170 ACPI will not move active IRQs (default)
173 acpi_irq_pci= [HW,ACPI] If irq_balance, clear listed IRQs for
175 Format: <irq>,<irq>...
177 acpi_irq_isa= [HW,ACPI] If irq_balance, mark listed IRQs used by ISA
178 Format: <irq>,<irq>...
180 acpi_no_auto_ssdt [HW,ACPI] Disable automatic loading of SSDT
182 acpi_os_name= [HW,ACPI] Tell ACPI BIOS the name of the OS
183 Format: To spoof as Windows 98: ="Microsoft Windows"
185 acpi_osi= [HW,ACPI] Modify list of supported OS interface strings
186 acpi_osi="string1" # add string1 -- only one string
187 acpi_osi="!string2" # remove built-in string2
188 acpi_osi= # disable all strings
190 acpi_serialize [HW,ACPI] force serialization of AML methods
192 acpi_skip_timer_override [HW,ACPI]
193 Recognize and ignore IRQ0/pin2 Interrupt Override.
194 For broken nForce2 BIOS resulting in XT-PIC timer.
195 acpi_use_timer_override [HW,ACPI}
196 Use timer override. For some broken Nvidia NF5 boards
197 that require a timer override, but don't have
200 acpi.debug_layer= [HW,ACPI]
202 Each bit of the <int> indicates an ACPI debug layer,
203 1: enable, 0: disable. It is useful for boot time
204 debugging. After system has booted up, it can be set
205 via /sys/module/acpi/parameters/debug_layer.
206 CONFIG_ACPI_DEBUG must be enabled for this to produce any output.
207 Available bits (add the numbers together) to enable debug output
208 for specific parts of the ACPI subsystem:
209 0x01 utilities 0x02 hardware 0x04 events 0x08 tables
210 0x10 namespace 0x20 parser 0x40 dispatcher
211 0x80 executer 0x100 resources 0x200 acpica debugger
212 0x400 os services 0x800 acpica disassembler.
213 The number can be in decimal or prefixed with 0x in hex.
214 Warning: Many of these options can produce a lot of
215 output and make your system unusable. Be very careful.
217 acpi.debug_level= [HW,ACPI]
219 Each bit of the <int> indicates an ACPI debug level,
220 1: enable, 0: disable. It is useful for boot time
221 debugging. After system has booted up, it can be set
222 via /sys/module/acpi/parameters/debug_level.
223 CONFIG_ACPI_DEBUG must be enabled for this to produce any output.
224 Available bits (add the numbers together) to enable different
225 debug output levels of the ACPI subsystem:
226 0x01 error 0x02 warn 0x04 init 0x08 debug object
227 0x10 info 0x20 init names 0x40 parse 0x80 load
228 0x100 dispatch 0x200 execute 0x400 names 0x800 operation region
229 0x1000 bfield 0x2000 tables 0x4000 values 0x8000 objects
230 0x10000 resources 0x20000 user requests 0x40000 package.
231 The number can be in decimal or prefixed with 0x in hex.
232 Warning: Many of these options can produce a lot of
233 output and make your system unusable. Be very careful.
235 acpi_pm_good [X86-32,X86-64]
236 Override the pmtimer bug detection: force the kernel
237 to assume that this machine's pmtimer latches its value
238 and always returns good values.
241 { off | try_unsupported }
242 off: disable AGP support
243 try_unsupported: try to drive unsupported chipsets
244 (may crash computer or cause data corruption)
246 enable_timer_pin_1 [i386,x86-64]
247 Enable PIN 1 of APIC timer
248 Can be useful to work around chipset bugs
249 (in particular on some ATI chipsets).
250 The kernel tries to set a reasonable default.
252 disable_timer_pin_1 [i386,x86-64]
253 Disable PIN 1 of APIC timer
254 Can be useful to work around chipset bugs.
257 Format: <io>,<irq>,<dma>,<dma2>,<type>
260 See header of drivers/scsi/advansys.c.
262 advwdt= [HW,WDT] Advantech WDT
263 Format: <iostart>,<iostop>
265 aedsp16= [HW,OSS] Audio Excel DSP 16
266 Format: <io>,<irq>,<dma>,<mss_io>,<mpu_io>,<mpu_irq>
267 See also header of sound/oss/aedsp16.c.
270 See Documentation/scsi/aha152x.txt.
273 Format: <portbase>[,<buson>,<busoff>[,<dmaspeed>]]
276 See Documentation/scsi/aic7xxx.txt.
279 See Documentation/scsi/aic79xx.txt.
281 amd_iommu= [HW,X86-84]
282 Pass parameters to the AMD IOMMU driver in the system.
284 isolate - enable device isolation (each device, as far
285 as possible, will get its own protection
287 amd_iommu_size= [HW,X86-64]
288 Define the size of the aperture for the AMD IOMMU
289 driver. Possible values are:
290 '32M', '64M' (default), '128M', '256M', '512M', '1G'
292 amijoy.map= [HW,JOY] Amiga joystick support
293 Map of devices attached to JOY0DAT and JOY1DAT
295 See also Documentation/kernel/input/joystick.txt
297 analog.map= [HW,JOY] Analog joystick and gamepad support
298 Specifies type or capabilities of an analog joystick
299 connected to one of 16 gameports
300 Format: <type1>,<type2>,..<type16>
303 Power management functions (SPARCstation-4/5 + deriv.)
305 Disable APC CPU standby support. SPARCstation-Fox does
306 not play well with APC CPU idle - disable it if you have
307 APC and your system crashes randomly.
309 apic= [APIC,i386] Advanced Programmable Interrupt Controller
310 Change the output verbosity whilst booting
311 Format: { quiet (default) | verbose | debug }
312 Change the amount of debugging information output
313 when initialising the APIC and IO-APIC components.
315 apm= [APM] Advanced Power Management
316 See header of arch/x86/kernel/apm_32.c.
318 arcrimi= [HW,NET] ARCnet - "RIM I" (entirely mem-mapped) cards
319 Format: <io>,<irq>,<nodeID>
323 atarimouse= [HW,MOUSE] Atari Mouse
325 atascsi= [HW,SCSI] Atari SCSI
327 atkbd.extra= [HW] Enable extra LEDs and keys on IBM RapidAccess,
328 EzKey and similar keyboards
330 atkbd.reset= [HW] Reset keyboard during initialization
332 atkbd.set= [HW] Select keyboard code set
333 Format: <int> (2 = AT (default), 3 = PS/2)
335 atkbd.scroll= [HW] Enable scroll wheel on MS Office and similar
338 atkbd.softraw= [HW] Choose between synthetic and real raw mode
339 Format: <bool> (0 = real, 1 = synthetic (default))
341 atkbd.softrepeat= [HW]
342 Use software keyboard repeat
346 baycom_epp= [HW,AX25]
349 baycom_par= [HW,AX25] BayCom Parallel Port AX.25 Modem
351 See header of drivers/net/hamradio/baycom_par.c.
353 baycom_ser_fdx= [HW,AX25]
354 BayCom Serial Port AX.25 Modem (Full Duplex Mode)
355 Format: <io>,<irq>,<mode>[,<baud>]
356 See header of drivers/net/hamradio/baycom_ser_fdx.c.
358 baycom_ser_hdx= [HW,AX25]
359 BayCom Serial Port AX.25 Modem (Half Duplex Mode)
360 Format: <io>,<irq>,<mode>
361 See header of drivers/net/hamradio/baycom_ser_hdx.c.
363 boot_delay= Milliseconds to delay each printk during boot.
364 Values larger than 10 seconds (10000) are changed to
368 bootmem_debug [KNL] Enable bootmem allocator debug messages.
370 bttv.card= [HW,V4L] bttv (bt848 + bt878 based grabber cards)
371 bttv.radio= Most important insmod options are available as
373 bttv.pll= See Documentation/video4linux/bttv/Insmod-options
374 bttv.tuner= and Documentation/video4linux/bttv/CARDLIST
377 See drivers/scsi/BusLogic.c, comment before function
378 BusLogic_ParseDriverOptions().
380 c101= [NET] Moxa C101 synchronous serial card
382 cachesize= [BUGS=X86-32] Override level 2 CPU cache size detection.
383 Sometimes CPU hardware bugs make them report the cache
384 size incorrectly. The kernel will attempt work arounds
385 to fix known problems, but for some CPUs it is not
386 possible to determine what the correct size should be.
387 This option provides an override for these situations.
389 security= [SECURITY] Choose a security module to enable at boot.
390 If this boot parameter is not specified, only the first
391 security module asking for security registration will be
392 loaded. An invalid security module name will be treated
393 as if no module has been chosen.
396 [SECURITY] Disable capabilities. This would normally
397 be used only if an alternative security model is to be
398 configured. Potentially dangerous and should only be
399 used if you are entirely sure of the consequences.
401 ccw_timeout_log [S390]
402 See Documentation/s390/CommonIO for details.
404 cgroup_disable= [KNL] Disable a particular controller
405 Format: {name of the controller(s) to disable}
406 {Currently supported controllers - "memory"}
408 checkreqprot [SELINUX] Set initial checkreqprot flag value.
409 Format: { "0" | "1" }
410 See security/selinux/Kconfig help text.
411 0 -- check protection applied by kernel (includes
412 any implied execute protection).
413 1 -- check protection requested by application.
414 Default value is set via a kernel config option.
415 Value can be changed at runtime via
416 /selinux/checkreqprot.
419 See Documentation/s390/CommonIO for details.
421 clock= [BUGS=X86-32, HW] gettimeofday clocksource override.
423 Forces specified clocksource (if available) to be used
424 when calculating gettimeofday(). If specified
425 clocksource is not available, it defaults to PIT.
426 Format: { pit | tsc | cyclone | pmtmr }
428 clocksource= [GENERIC_TIME] Override the default clocksource
430 Override the default clocksource and use the clocksource
431 with the name specified.
432 Some clocksource names to choose from, depending on
434 [all] jiffies (this is the base, fallback clocksource)
436 [ARM] imx_timer1,OSTS,netx_timer,mpu_timer2,
437 pxa_timer,timer3,32k_counter,timer0_1
439 [X86-32] pit,hpet,tsc,vmi-timer;
440 scx200_hrt on Geode; cyclone on IBM x440
448 clearcpuid=BITNUM [X86]
449 Disable CPUID feature X for the kernel. See
450 include/asm-x86/cpufeature.h for the valid bit numbers.
451 Note the Linux specific bits are not necessarily
452 stable over kernel options, but the vendor specific
454 Also note that user programs calling CPUID directly
455 or using the feature without checking anything
456 will still see it. This just prevents it from
457 being used by the kernel or shown in /proc/cpuinfo.
458 Also note the kernel might malfunction if you disable
461 code_bytes [IA32/X86_64] How many bytes of object code to print
466 hpet= [X86-32,HPET] option to control HPET usage
467 Format: { enable (default) | disable | force }
468 disable: disable HPET and use PIT instead
469 force: allow force enabled of undocumented chips (ICH4,
472 com20020= [HW,NET] ARCnet - COM20020 chipset
474 <io>[,<irq>[,<nodeID>[,<backplane>[,<ckp>[,<timeout>]]]]]
476 com90io= [HW,NET] ARCnet - COM90xx chipset (IO-mapped buffers)
480 ARCnet - COM90xx chipset (memory-mapped buffers)
481 Format: <io>[,<irq>[,<memstart>]]
483 condev= [HW,S390] console device
486 console= [KNL] Output console device and options.
488 tty<n> Use the virtual console device <n>.
492 Use the specified serial port. The options are of
493 the form "bbbbpnf", where "bbbb" is the baud rate,
494 "p" is parity ("n", "o", or "e"), "n" is number of
495 bits, and "f" is flow control ("r" for RTS or
496 omit it). Default is "9600n8".
498 See Documentation/serial-console.txt for more
500 Documentation/networking/netconsole.txt for an
503 uart[8250],io,<addr>[,options]
504 uart[8250],mmio,<addr>[,options]
505 Start an early, polled-mode console on the 8250/16550
506 UART at the specified I/O port or MMIO address,
507 switching to the matching ttyS device later. The
508 options are the same as for ttyS, above.
510 If the device connected to the port is not a TTY but a braille
511 device, prepend "brl," before the device type, for instance
513 For now, only VisioBraille is supported.
515 earlycon= [KNL] Output early console device and options.
516 uart[8250],io,<addr>[,options]
517 uart[8250],mmio,<addr>[,options]
518 Start an early, polled-mode console on the 8250/16550
519 UART at the specified I/O port or MMIO address.
520 The options are the same as for ttyS, above.
523 [HW] Never suspend the console
524 Disable suspending of consoles during suspend and
525 hibernate operations. Once disabled, debugging
526 messages can reach various consoles while the rest
527 of the system is being put to sleep (ie, while
528 debugging driver suspend/resume hooks). This may
529 not work reliably with all consoles, but is known
530 to work with serial and VGA consoles.
532 cpcihp_generic= [HW,PCI] Generic port I/O CompactPCI driver
534 <first_slot>,<last_slot>,<port>,<enum_bit>[,<debug>]
536 crashkernel=nn[KMG]@ss[KMG]
537 [KNL] Reserve a chunk of physical memory to
538 hold a kernel to switch to with kexec on panic.
540 crashkernel=range1:size1[,range2:size2,...][@offset]
541 [KNL] Same as above, but depends on the memory
542 in the running system. The syntax of range is
543 start-[end] where start and end are both
544 a memory unit (amount[KMG]). See also
545 Documentation/kdump/kdump.txt for a example.
548 Format: <io>,<irq>,<dma>,<dma2>,<mpuio>,<mpuirq>
553 cs89x0_media= [HW,NET]
554 Format: { rj45 | aui | bnc }
557 See header of drivers/s390/block/dasd_devmap.c.
559 db9.dev[2|3]= [HW,JOY] Multisystem joystick support via parallel port
560 (one device per port)
561 Format: <port#>,<type>
562 See also Documentation/input/joystick-parport.txt
564 debug [KNL] Enable kernel debugging (events log level).
567 [KNL] verbose self-tests
569 Print debugging info while doing the locking API
571 We default to 0 (no extra messages), setting it to
572 1 will print _a lot_ more information - normally
573 only useful to kernel developers.
575 debug_objects [KNL] Enable object debugging
577 debugpat [X86] Enable PAT debugging
579 decnet.addr= [HW,NET]
580 Format: <area>[,<node>]
581 See also Documentation/networking/decnet.txt.
584 Format: <blue0>,<blue1>,<blue2>,...,<blue15>
585 Change the default blue palette of the console.
586 This is a 16-member array composed of values
590 Format: <green0>,<green1>,<green2>,...,<green15>
591 Change the default green palette of the console.
592 This is a 16-member array composed of values
596 Format: <red0>,<red1>,<red2>,...,<red15>
597 Change the default red palette of the console.
598 This is a 16-member array composed of values
604 Set system-wide default UTF-8 mode for all tty's.
605 Default is 1, i.e. UTF-8 mode is enabled for all
606 newly opened terminals.
609 Set number of hash buckets for dentry cache.
612 IO parameters + enable/disable command.
614 digiepca= [HW,SERIAL]
615 See drivers/char/README.epca and
616 Documentation/digiepca.txt.
618 disable_mtrr_cleanup [X86]
619 enable_mtrr_cleanup [X86]
620 The kernel tries to adjust MTRR layout from continuous
621 to discrete, to make X server driver able to add WB
622 entry later. This parameter enables/disables that.
624 mtrr_chunk_size=nn[KMG] [X86]
625 used for mtrr cleanup. It is largest continous chunk
626 that could hold holes aka. UC entries.
628 mtrr_gran_size=nn[KMG] [X86]
629 Used for mtrr cleanup. It is granularity of mtrr block.
631 Large value could prevent small alignment from
634 mtrr_spare_reg_nr=n [X86]
636 Range: 0,7 : spare reg number
638 Used for mtrr cleanup. It is spare mtrr entries number.
639 Set to 2 or more if your graphical card needs more.
641 disable_mtrr_trim [X86, Intel and AMD only]
642 By default the kernel will trim any uncacheable
643 memory out of your available memory pool based on
644 MTRR settings. This parameter disables that behavior,
645 possibly causing your machine to run very slowly.
647 dmasound= [HW,OSS] Sound subsystem buffers
653 earlyprintk= [X86-32,X86-64,SH,BLACKFIN]
655 earlyprintk=serial[,ttySn[,baudrate]]
657 Append ",keep" to not disable it when the real console
660 Only vga or serial at a time, not both.
662 Currently only ttyS0 and ttyS1 are supported.
664 Interaction with the standard serial driver is not
667 The VGA output is eventually overwritten by the real
673 Format: {"off" | "on" | "skip[mbr]"}
675 eisa_irq_edge= [PARISC,HW]
676 See header of drivers/parisc/eisa.c.
679 See comment before function elanfreq_setup() in
680 arch/x86/kernel/cpu/cpufreq/elanfreq.c.
683 Format: {"anticipatory" | "cfq" | "deadline" | "noop"}
684 See Documentation/block/as-iosched.txt and
685 Documentation/block/deadline-iosched.txt for details.
687 elfcorehdr= [X86-32, X86_64]
688 Specifies physical address of start of kernel core
689 image elf header. Generally kexec loader will
690 pass this option to capture kernel.
691 See Documentation/kdump/kdump.txt for details.
693 enforcing [SELINUX] Set initial enforcing status.
695 See security/selinux/Kconfig help text.
696 0 -- permissive (log only, no denials).
697 1 -- enforcing (deny and log).
699 Value can be changed at runtime via /selinux/enforce.
702 Format: <spdif>,[<nomix>,[<amplifier>]]
703 See also header of sound/oss/es1371.c.
705 ether= [HW,NET] Ethernet cards parameters
706 This option is obsoleted by the "netdev=" option, which
707 has equivalent usage. See its documentation for details.
709 eurwdt= [HW,WDT] Eurotech CPU-1220/1410 onboard watchdog.
714 fail_make_request=[KNL]
715 General fault injection mechanism.
716 Format: <interval>,<probability>,<space>,<times>
717 See also /Documentation/fault-injection/.
720 See header of drivers/scsi/fd_mcs.c.
723 See header of drivers/scsi/fdomain.c.
726 See Documentation/floppy.txt.
728 force_pal_cache_flush
729 [IA-64] Avoid check_sal_cache_flush which may hang on
730 buggy SAL_CACHE_FLUSH implementations. Using this
731 parameter will force ia64_sal_cache_flush to call
732 ia64_pal_cache_flush instead of SAL_CACHE_FLUSH.
735 [HW,JOY] Multisystem joystick and NES/SNES/PSX pad
736 support via parallel port (up to 5 devices per port)
737 Format: <port#>,<pad1>,<pad2>,<pad3>,<pad4>,<pad5>
738 See also Documentation/input/joystick-parport.txt
742 gart_fix_e820= [X86_64] disable the fix e820 for K8 GART
747 See header of drivers/scsi/gdth.c.
749 gpt [EFI] Forces disk with valid GPT signature but
750 invalid Protective MBR to be treated as GPT.
754 hashdist= [KNL,NUMA] Large hashes allocated during boot
755 are distributed across NUMA nodes. Defaults on
756 for IA-64, off otherwise.
757 Format: 0 | 1 (for off | on)
759 hcl= [IA-64] SGI's Hardware Graph compatibility layer
761 hd= [EIDE] (E)IDE hard drive subsystem geometry
762 Format: <cyl>,<head>,<sect>
764 highmem=nn[KMG] [KNL,BOOT] forces the highmem zone to have an exact
765 size of <nn>. This works even on boxes that have no
766 highmem otherwise. This also works to reduce highmem
767 size on bigger boxes.
769 highres= [KNL] Enable/disable high resolution timer mode.
770 Valid parameters: "on", "off"
774 See Documentation/isdn/README.HiSax.
776 hugepages= [HW,X86-32,IA-64] HugeTLB pages to allocate at boot.
777 hugepagesz= [HW,IA-64,PPC,X86-64] The size of the HugeTLB pages.
778 On x86-64 and powerpc, this option can be specified
779 multiple times interleaved with hugepages= to reserve
780 huge pages of different sizes. Valid pages sizes on
781 x86-64 are 2M (when the CPU supports "pse") and 1G
782 (when the CPU supports the "pdpe1gb" cpuinfo flag)
783 Note that 1GB pages can only be allocated at boot time
784 using hugepages= and not freed afterwards.
786 [same as hugepagesz=] The size of the default
787 HugeTLB page size. This is the size represented by
788 the legacy /proc/ hugepages APIs, used for SHM, and
789 default size when mounting hugetlbfs filesystems.
790 Defaults to the default architecture's huge page size
793 i8042.direct [HW] Put keyboard port into non-translated mode
794 i8042.dumbkbd [HW] Pretend that controller can only read data from
795 keyboard and cannot control its state
796 (Don't attempt to blink the leds)
797 i8042.noaux [HW] Don't check for auxiliary (== mouse) port
798 i8042.nokbd [HW] Don't check/create keyboard port
799 i8042.noloop [HW] Disable the AUX Loopback command while probing
801 i8042.nomux [HW] Don't check presence of an active multiplexing
803 i8042.nopnp [HW] Don't use ACPIPnP / PnPBIOS to discover KBD/AUX
806 [HW] Frequency with which keyboard LEDs should blink
807 when kernel panics (default is 0.5 sec)
808 i8042.reset [HW] Reset the controller during init and cleanup
809 i8042.unlock [HW] Unlock (ignore) the keylock
813 i8k.ignore_dmi [HW] Continue probing hardware even if DMI data
814 indicates that the driver is running on unsupported
816 i8k.force [HW] Activate i8k driver even if SMM BIOS signature
817 does not match list of supported models.
819 [HW] Report power status in /proc/i8k
820 (disabled by default)
821 i8k.restricted [HW] Allow controlling fans only if SYS_ADMIN
824 ibmmcascsi= [HW,MCA,SCSI] IBM MicroChannel SCSI adapter
825 See Documentation/mca.txt.
828 Format: <io>[,<membase>[,<icn_id>[,<icn_id2>]]]
830 ide= [HW] (E)IDE subsystem
831 Format: ide=nodma or ide=doubler
832 See Documentation/ide/ide.txt.
834 idebus= [HW] (E)IDE subsystem - VLB/PCI bus speed
835 See Documentation/ide/ide.txt.
838 Format: idle=poll or idle=mwait, idle=halt, idle=nomwait
839 Poll forces a polling idle loop that can slightly improves the performance
840 of waking up a idle CPU, but will use a lot of power and make the system
841 run hot. Not recommended.
842 idle=mwait. On systems which support MONITOR/MWAIT but the kernel chose
843 to not use it because it doesn't save as much power as a normal idle
844 loop use the MONITOR/MWAIT idle loop anyways. Performance should be the same
846 idle=halt. Halt is forced to be used for CPU idle.
847 In such case C2/C3 won't be used again.
848 idle=nomwait. Disable mwait for CPU C-states
850 ide-pci-generic.all-generic-ide [HW] (E)IDE subsystem
851 Claim all unknown PCI IDE storage controllers.
853 ignore_loglevel [KNL]
854 Ignore loglevel setting - this will print /all/
855 kernel messages to the console. Useful for debugging.
858 Set number of hash buckets for inode cache.
861 See header of drivers/scsi/in2000.c.
865 Run specified binary instead of /sbin/init as init
868 initcall_debug [KNL] Trace initcalls as they are executed. Useful
869 for working out where the kernel is dying during
872 initrd= [BOOT] Specify the location of the initial ramdisk
874 inport.irq= [HW] Inport (ATI XL and Microsoft) busmouse driver
892 intel_iommu= [DMAR] Intel IOMMU driver (DMAR) option
894 Disable intel iommu driver.
895 igfx_off [Default Off]
896 By default, gfx is mapped as normal device. If a gfx
897 device has a dedicated DMAR unit, the DMAR unit is
898 bypassed by not enabling DMAR with this option. In
899 this case, gfx device will use physical address for
902 With this option iommu will not optimize to look
903 for io virtual address below 32 bit forcing dual
904 address cycle on pci bus for cards supporting greater
905 than 32 bit addressing. The default is to look
906 for translation below 32 bit and if not available
907 then look in the higher range.
909 With this option on every unmap_single operation will
910 result in a hardware IOTLB flush operation as opposed
911 to batching them for performance.
913 io_delay= [X86-32,X86-64] I/O delay method
915 Standard port 0x80 based delay
917 Alternate port 0xed based delay (needed on some systems)
919 Simple two microseconds delay
923 io7= [HW] IO7 for Marvel based alpha systems
924 See comment before marvel_specify_io7 in
925 arch/alpha/kernel/core_marvel.c.
928 See Documentation/filesystems/nfsroot.txt.
930 ip2= [HW] Set IO/IRQ pairs for up to 4 IntelliPort boards
931 See comment before ip2_setup() in
932 drivers/char/ip2/ip2base.c.
934 ips= [HW,SCSI] Adaptec / IBM ServeRAID controller
935 See header of drivers/scsi/ips.c.
937 ports= [IP_VS_FTP] IPVS ftp helper module
939 Up to 8 (IP_VS_APP_MAX_PORTS) ports
941 Format: <port>,<port>....
944 When an interrupt is not handled search all handlers
945 for it. Intended to get systems with badly broken
949 When an interrupt is not handled search all handlers
950 for it. Also check all handlers each timer
951 interrupt. Intended to get systems with badly broken
955 Format: <RDP>,<reset>,<pci_scan>,<verbosity>
957 isolcpus= [KNL,SMP] Isolate CPUs from the general scheduler.
959 <cpu number>,...,<cpu number>
961 <cpu number>-<cpu number> (must be a positive range in ascending order)
963 <cpu number>,...,<cpu number>-<cpu number>
964 This option can be used to specify one or more CPUs
965 to isolate from the general SMP balancing and scheduling
966 algorithms. The only way to move a process onto or off
967 an "isolated" CPU is via the CPU affinity syscalls.
968 <cpu number> begins at 0 and the maximum value is
969 "number of CPUs in system - 1".
971 This option is the preferred way to isolate CPUs. The
972 alternative -- manually setting the CPU mask of all
973 tasks in the system -- can cause problems and
974 suboptimal load balancer performance.
978 js= [HW,JOY] Analog joystick
979 See Documentation/input/joystick.txt.
981 kernelcore=nn[KMG] [KNL,X86-32,IA-64,PPC,X86-64] This parameter
982 specifies the amount of memory usable by the kernel
983 for non-movable allocations. The requested amount is
984 spread evenly throughout all nodes in the system. The
985 remaining memory in each node is used for Movable
986 pages. In the event, a node is too small to have both
987 kernelcore and Movable pages, kernelcore pages will
988 take priority and other nodes will have a larger number
989 of kernelcore pages. The Movable zone is used for the
990 allocation of pages that may be reclaimed or moved
991 by the page migration subsystem. This means that
992 HugeTLB pages may not be allocated from this zone.
993 Note that allocations like PTEs-from-HighMem still
994 use the HighMem zone if it exists, and the Normal
997 movablecore=nn[KMG] [KNL,X86-32,IA-64,PPC,X86-64] This parameter
998 is similar to kernelcore except it specifies the
999 amount of memory used for migratable allocations.
1000 If both kernelcore and movablecore is specified,
1001 then kernelcore will be at *least* the specified
1002 value but may be more. If movablecore on its own
1003 is specified, the administrator must be careful
1004 that the amount of memory usable for all allocations
1009 kstack=N [X86-32,X86-64] Print N words from the kernel stack
1012 kgdboc= [HW] kgdb over consoles.
1013 Requires a tty driver that supports console polling.
1014 (only serial suported for now)
1015 Format: <serial_device>[,baud]
1021 lapic [X86-32,APIC] Enable the local APIC even if BIOS
1024 lapic_timer_c2_ok [X86-32,x86-64,APIC] trust the local apic timer in
1027 libata.dma= [LIBATA] DMA control
1028 libata.dma=0 Disable all PATA and SATA DMA
1029 libata.dma=1 PATA and SATA Disk DMA only
1030 libata.dma=2 ATAPI (CDROM) DMA only
1031 libata.dma=4 Compact Flash DMA only
1032 Combinations also work, so libata.dma=3 enables DMA
1033 for disks and CDROMs, but not CFs.
1035 libata.noacpi [LIBATA] Disables use of ACPI in libata suspend/resume
1039 libata.force= [LIBATA] Force configurations. The format is comma
1040 separated list of "[ID:]VAL" where ID is
1041 PORT[:DEVICE]. PORT and DEVICE are decimal numbers
1042 matching port, link or device. Basically, it matches
1043 the ATA ID string printed on console by libata. If
1044 the whole ID part is omitted, the last PORT and DEVICE
1045 values are used. If ID hasn't been specified yet, the
1046 configuration applies to all ports, links and devices.
1048 If only DEVICE is omitted, the parameter applies to
1049 the port and all links and devices behind it. DEVICE
1050 number of 0 either selects the first device or the
1051 first fan-out link behind PMP device. It does not
1052 select the host link. DEVICE number of 15 selects the
1053 host link and device attached to it.
1055 The VAL specifies the configuration to force. As long
1056 as there's no ambiguity shortcut notation is allowed.
1057 For example, both 1.5 and 1.5G would work for 1.5Gbps.
1058 The following configurations can be forced.
1060 * Cable type: 40c, 80c, short40c, unk, ign or sata.
1061 Any ID with matching PORT is used.
1063 * SATA link speed limit: 1.5Gbps or 3.0Gbps.
1065 * Transfer mode: pio[0-7], mwdma[0-4] and udma[0-7].
1066 udma[/][16,25,33,44,66,100,133] notation is also
1069 * [no]ncq: Turn on or off NCQ.
1071 * nohrst, nosrst, norst: suppress hard, soft
1074 If there are multiple matching configurations changing
1075 the same attribute, the last one is used.
1077 load_ramdisk= [RAM] List of ramdisks to load from floppy
1078 See Documentation/ramdisk.txt.
1080 lockd.nlm_grace_period=P [NFS] Assign grace period.
1083 lockd.nlm_tcpport=N [NFS] Assign TCP port.
1086 lockd.nlm_timeout=T [NFS] Assign timeout value.
1089 lockd.nlm_udpport=M [NFS] Assign UDP port.
1092 logibm.irq= [HW,MOUSE] Logitech Bus Mouse Driver
1095 loglevel= All Kernel Messages with a loglevel smaller than the
1096 console loglevel will be printed to the console. It can
1097 also be changed with klogd or other programs. The
1098 loglevels are defined as follows:
1100 0 (KERN_EMERG) system is unusable
1101 1 (KERN_ALERT) action must be taken immediately
1102 2 (KERN_CRIT) critical conditions
1103 3 (KERN_ERR) error conditions
1104 4 (KERN_WARNING) warning conditions
1105 5 (KERN_NOTICE) normal but significant condition
1106 6 (KERN_INFO) informational
1107 7 (KERN_DEBUG) debug-level messages
1109 log_buf_len=n Sets the size of the printk ring buffer, in bytes.
1110 Format: { n | nk | nM }
1111 n must be a power of two. The default size
1112 is set in the kernel config file.
1114 logo.nologo [FB] Disables display of the built-in Linux logo.
1115 This may be used to provide more screen space for
1116 kernel log messages and is useful when debugging
1117 kernel boot problems.
1119 lp=0 [LP] Specify parallel ports to use, e.g,
1120 lp=port[,port...] lp=none,parport0 (lp0 not configured, lp1 uses
1121 lp=reset first parallel port). 'lp=0' disables the
1122 lp=auto printer driver. 'lp=reset' (which can be
1123 specified in addition to the ports) causes
1124 attached printers to be reset. Using
1125 lp=port1,port2,... specifies the parallel ports
1126 to associate lp devices with, starting with
1127 lp0. A port specification may be 'none' to skip
1128 that lp device, or a parport name such as
1129 'parport0'. Specifying 'lp=auto' instead of a
1130 port specification list means that device IDs
1131 from each port should be examined, to see if
1132 an IEEE 1284-compliant printer is attached; if
1133 so, the driver will manage that printer.
1134 See also header of drivers/char/lp.c.
1137 Sets loops_per_jiffy to given constant, thus avoiding
1138 time-consuming boot-time autodetection (up to 250 ms per
1139 CPU). 0 enables autodetection (default). To determine
1140 the correct value for your kernel, boot with normal
1141 autodetection and see what value is printed. Note that
1142 on SMP systems the preset will be applied to all CPUs,
1143 which is likely to cause problems if your CPUs need
1144 significantly divergent settings. An incorrect value
1145 will cause delays in the kernel to be wrong, leading to
1146 unpredictable I/O errors and other breakage. Although
1147 unlikely, in the extreme case this might damage your
1151 Format: <io>,<irq>,<dma>
1153 mac5380= [HW,SCSI] Format:
1154 <can_queue>,<cmd_per_lun>,<sg_tablesize>,<hostid>,<use_tags>
1156 machvec= [IA64] Force the use of a particular machine-vector
1157 (machvec) in a generic kernel.
1158 Example: machvec=hpzx1_swiotlb
1160 max_loop= [LOOP] Maximum number of loopback devices that can
1164 maxcpus= [SMP] Maximum number of processors that an SMP kernel
1165 should make use of. maxcpus=n : n >= 0 limits the
1166 kernel to using 'n' processors. n=0 is a special case,
1167 it is equivalent to "nosmp", which also disables
1170 max_addr=[KMG] [KNL,BOOT,ia64] All physical memory greater than or
1171 equal to this physical address is ignored.
1173 max_luns= [SCSI] Maximum number of LUNs to probe.
1174 Should be between 1 and 2^32-1.
1177 [SCSI] Maximum number of LUNs received.
1178 Should be between 1 and 16384.
1182 mce [X86-32] Machine Check Exception
1184 mce=option [X86-64] See Documentation/x86_64/boot-options.txt
1186 md= [HW] RAID subsystems devices and level
1187 See Documentation/md.txt.
1190 Format: <first>,<last>
1191 Specifies range of consoles to be captured by the MDA.
1193 mem=nn[KMG] [KNL,BOOT] Force usage of a specific amount of memory
1194 Amount of memory to be used when the kernel is not able
1195 to see the whole system memory or for test.
1196 [X86-32] Use together with memmap= to avoid physical
1197 address space collisions. Without memmap= PCI devices
1198 could be placed at addresses belonging to unused RAM.
1200 mem=nopentium [BUGS=X86-32] Disable usage of 4MB pages for kernel
1203 memmap=exactmap [KNL,X86-32,X86_64] Enable setting of an exact
1204 E820 memory map, as specified by the user.
1205 Such memmap=exactmap lines can be constructed based on
1206 BIOS output or other requirements. See the memmap=nn@ss
1209 memmap=nn[KMG]@ss[KMG]
1210 [KNL] Force usage of a specific region of memory
1211 Region of memory to be used, from ss to ss+nn.
1213 memmap=nn[KMG]#ss[KMG]
1214 [KNL,ACPI] Mark specific memory as ACPI data.
1215 Region of memory to be used, from ss to ss+nn.
1217 memmap=nn[KMG]$ss[KMG]
1218 [KNL,ACPI] Mark specific memory as reserved.
1219 Region of memory to be used, from ss to ss+nn.
1220 Example: Exclude memory from 0x18690000-0x1869ffff
1221 memmap=64K$0x18690000
1223 memmap=0x10000$0x18690000
1225 memtest= [KNL,X86] Enable memtest
1227 range: 0,4 : pattern number
1228 default : 0 <disable>
1230 meye.*= [HW] Set MotionEye Camera parameters
1231 See Documentation/video4linux/meye.txt.
1233 mfgpt_irq= [IA-32] Specify the IRQ to use for the
1234 Multi-Function General Purpose Timers on AMD Geode
1237 mfgptfix [X86-32] Fix MFGPT timers on AMD Geode platforms when
1238 the BIOS has incorrectly applied a workaround. TinyBIOS
1239 version 0.98 is known to be affected, 0.99 fixes the
1240 problem by letting the user disable the workaround.
1245 [KNL] When CONFIG_DEBUG_MEMORY_INIT is set, this
1246 parameter allows control of the logging verbosity for
1247 the additional memory initialisation checks. A value
1248 of 0 disables mminit logging and a level of 4 will
1249 log everything. Information is printed at KERN_DEBUG
1250 so loglevel=8 may also need to be specified.
1253 [MOUSE] Maximum time between finger touching and
1254 leaving touchpad surface for touch to be considered
1255 a tap and be reported as a left button click (for
1256 touchpads working in absolute mode only).
1258 mousedev.xres= [MOUSE] Horizontal screen resolution, used for devices
1259 reporting absolute coordinates, such as tablets
1260 mousedev.yres= [MOUSE] Vertical screen resolution, used for devices
1261 reporting absolute coordinates, such as tablets
1266 MTD_Partition= [MTD]
1267 Format: <name>,<region-number>,<size>,<offset>
1269 MTD_Region= [MTD] Format:
1270 <name>,<region-number>[,<base>,<size>,<buswidth>,<altbuswidth>]
1273 See drivers/mtd/cmdlinepart.c.
1276 ARM/S3C2412 JIVE boot control
1278 See arch/arm/mach-s3c2412/mach-jive.c
1280 mtouchusb.raw_coordinates=
1281 [HW] Make the MicroTouch USB driver use raw coordinates
1282 ('y', default) or cooked coordinates ('n')
1284 n2= [NET] SDL Inc. RISCom/N2 synchronous serial card
1287 See header of drivers/scsi/NCR_D700.c.
1291 ncr53c400= [HW,SCSI]
1293 ncr53c400a= [HW,SCSI]
1295 ncr53c406a= [HW,SCSI]
1297 ncr53c8xx= [HW,SCSI]
1299 netdev= [NET] Network devices parameters
1300 Format: <irq>,<io>,<mem_start>,<mem_end>,<name>
1301 Note that mem_start is often overloaded to mean
1302 something different and driver-specific.
1303 This usage is only documented in each driver source
1307 [NETFILTER] Enable connection tracking flow accounting
1308 0 to disable accounting
1309 1 to enable accounting
1310 Default value depends on CONFIG_NF_CT_ACCT that is
1311 going to be removed in 2.6.29.
1314 See Documentation/filesystems/nfsroot.txt.
1316 nfsroot= [NFS] nfs root filesystem for disk-less boxes.
1317 See Documentation/filesystems/nfsroot.txt.
1319 nfs.callback_tcpport=
1320 [NFS] set the TCP port on which the NFSv4 callback
1321 channel should listen.
1323 nfs.idmap_cache_timeout=
1324 [NFS] set the maximum lifetime for idmapper cache
1328 [NFS] enable 64-bit inode numbers.
1329 If zero, the NFS client will fake up a 32-bit inode
1330 number for the readdir() and stat() syscalls instead
1331 of returning the full 64-bit number.
1332 The default is to return 64-bit inode numbers.
1334 nmi_debug= [KNL,AVR32] Specify one or more actions to take
1335 when a NMI is triggered.
1336 Format: [state][,regs][,debounce][,die]
1338 nmi_watchdog= [KNL,BUGS=X86-32] Debugging features for SMP kernels
1340 no387 [BUGS=X86-32] Tells the kernel to use the 387 maths
1341 emulation library even if a 387 maths coprocessor
1344 noaliencache [MM, NUMA, SLAB] Disables the allocation of alien
1345 caches in the slab allocator. Saves per-node memory,
1346 but will impact performance.
1350 noapic [SMP,APIC] Tells the kernel to not make use of any
1351 IOAPICs that may be present in the system.
1353 nobats [PPC] Do not use BATs for mapping kernel lowmem
1354 on "Classic" PPC cores.
1358 nodelayacct [KNL] Disable per-task delay accounting
1360 nodisconnect [HW,SCSI,M68K] Disables SCSI disconnects.
1362 noefi [X86-32,X86-64] Disable EFI runtime services support.
1366 noexec [X86-32,X86-64]
1367 On X86-32 available only on PAE configured kernels.
1368 noexec=on: enable non-executable mappings (default)
1369 noexec=off: disable non-executable mappings
1372 This affects only 32-bit executables.
1373 noexec32=on: enable non-executable mappings (default)
1374 read doesn't imply executable mappings
1375 noexec32=off: disable non-executable mappings
1376 read implies executable mappings
1378 nofxsr [BUGS=X86-32] Disables x86 floating point extended
1379 register save and restore. The kernel will only save
1380 legacy floating-point registers on task switch.
1382 noclflush [BUGS=X86] Don't use the CLFLUSH instruction
1386 no-hlt [BUGS=X86-32] Tells the kernel that the hlt
1387 instruction doesn't work correctly and not to
1390 nohalt [IA-64] Tells the kernel not to use the power saving
1391 function PAL_HALT_LIGHT when idle. This increases
1392 power-consumption. On the positive side, it reduces
1393 interrupt wake-up latency, which may improve performance
1394 in certain environments such as networked servers or
1397 nohz= [KNL] Boottime enable/disable dynamic ticks
1398 Valid arguments: on, off
1401 noirqbalance [X86-32,SMP,KNL] Disable kernel irq balancing
1403 noirqdebug [X86-32] Disables the code which attempts to detect and
1404 disable unhandled interrupt sources.
1406 no_timer_check [X86-32,X86_64,APIC] Disables the code which tests for
1407 broken timer IRQ sources.
1409 noisapnp [ISAPNP] Disables ISA PnP code.
1411 noinitrd [RAM] Tells the kernel not to load any configured
1416 nojitter [IA64] Disables jitter checking for ITC timers.
1418 nolapic [X86-32,APIC] Do not enable or use the local APIC.
1420 nolapic_timer [X86-32,APIC] Do not use the local APIC timer.
1422 noltlbs [PPC] Do not use large page/tlb entries for kernel
1423 lowmem mapping on PPC40x.
1425 nomca [IA-64] Disable machine check abort handling
1427 nomce [X86-32] Machine Check Exception
1429 nomfgpt [X86-32] Disable Multi-Function General Purpose
1430 Timer usage (for AMD Geode machines).
1432 noreplace-paravirt [X86-32,PV_OPS] Don't patch paravirt_ops
1434 noreplace-smp [X86-32,SMP] Don't replace SMP instructions
1435 with UP alternatives
1437 noresidual [PPC] Don't use residual data on PReP machines.
1439 noresume [SWSUSP] Disables resume and restores original swap
1442 no-scroll [VGA] Disables scrollback.
1443 This is required for the Braillex ib80-piezo Braille
1444 reader made by F.H. Papenmeier (Germany).
1448 nosep [BUGS=X86-32] Disables x86 SYSENTER/SYSEXIT support.
1450 nosmp [SMP] Tells an SMP kernel to act as a UP kernel,
1451 and disable the IO APIC. legacy for "maxcpus=0".
1453 nosoftlockup [KNL] Disable the soft-lockup detector.
1455 nosync [HW,M68K] Disables sync negotiation for all devices.
1457 notsc [BUGS=X86-32] Disable Time Stamp Counter
1459 nousb [USB] Disable the USB subsystem
1463 nptcg= [IA64] Override max number of concurrent global TLB
1464 purges which is reported from either PAL_VM_SUMMARY or
1467 numa_zonelist_order= [KNL, BOOT] Select zonelist order for NUMA.
1468 one of ['zone', 'node', 'default'] can be specified
1469 This can be set from sysctl after boot.
1470 See Documentation/sysctl/vm.txt for details.
1472 nr_uarts= [SERIAL] maximum number of UARTs to be registered.
1474 olpc_ec_timeout= [OLPC] ms delay when issuing EC commands
1475 Rather than timing out after 20 ms if an EC
1476 command is not properly ACKed, override the length
1477 of the timeout. We have interrupts disabled while
1478 waiting for the ACK, so if this is set too high
1479 interrupts *may* be lost!
1484 oprofile.timer= [HW]
1485 Use timer interrupt instead of performance counters
1487 osst= [HW,SCSI] SCSI Tape Driver
1488 Format: <buffer_size>,<write_threshold>
1489 See also Documentation/scsi/st.txt.
1491 panic= [KNL] Kernel behaviour on panic
1494 parkbd.port= [HW] Parallel port number the keyboard adapter is
1495 connected to, default is 0.
1497 parkbd.mode= [HW] Parallel port keyboard adapter mode of operation,
1498 0 for XT, 1 for AT (default is AT).
1501 parport= [HW,PPT] Specify parallel ports. 0 disables.
1502 Format: { 0 | auto | 0xBBB[,IRQ[,DMA]] }
1503 Use 'auto' to force the driver to use any
1504 IRQ/DMA settings detected (the default is to
1505 ignore detected IRQ/DMA settings because of
1506 possible conflicts). You can specify the base
1507 address, IRQ, and DMA settings; IRQ and DMA
1508 should be numbers, or 'auto' (for using detected
1509 settings on that particular port), or 'nofifo'
1510 (to avoid using a FIFO even if it is detected).
1511 Parallel ports are assigned in the order they
1512 are specified on the command line, starting
1515 parport_init_mode= [HW,PPT]
1516 Configure VIA parallel port to operate in
1517 a specific mode. This is necessary on Pegasos
1518 computer where firmware has no options for setting
1519 up parallel port mode and sets it to spp.
1520 Currently this function knows 686a and 8231 chips.
1521 Format: [spp|ps2|epp|ecp|ecpepp]
1523 pas2= [HW,OSS] Format:
1524 <io>,<irq>,<dma>,<dma16>,<sb_io>,<sb_irq>,<sb_dma>,<sb_dma16>
1527 See header of drivers/scsi/pas16.c.
1530 Halt all CPUs after the first oops has been printed for
1531 the specified number of seconds. This is to be used if
1532 your oopses keep scrolling off the screen.
1537 See header of drivers/block/paride/pcd.c.
1538 See also Documentation/paride.txt.
1540 pci=option[,option...] [PCI] various PCI subsystem options:
1541 off [X86-32] don't probe for the PCI bus
1542 bios [X86-32] force use of PCI BIOS, don't access
1543 the hardware directly. Use this if your machine
1544 has a non-standard PCI host bridge.
1545 nobios [X86-32] disallow use of PCI BIOS, only direct
1546 hardware access methods are allowed. Use this
1547 if you experience crashes upon bootup and you
1548 suspect they are caused by the BIOS.
1549 conf1 [X86-32] Force use of PCI Configuration
1551 conf2 [X86-32] Force use of PCI Configuration
1553 noaer [PCIE] If the PCIEAER kernel config parameter is
1554 enabled, this kernel boot option can be used to
1555 disable the use of PCIE advanced error reporting.
1556 nodomains [PCI] Disable support for multiple PCI
1557 root domains (aka PCI segments, in ACPI-speak).
1558 nommconf [X86-32,X86_64] Disable use of MMCONFIG for PCI
1560 nomsi [MSI] If the PCI_MSI kernel config parameter is
1561 enabled, this kernel boot option can be used to
1562 disable the use of MSI interrupts system-wide.
1563 biosirq [X86-32] Use PCI BIOS calls to get the interrupt
1564 routing table. These calls are known to be buggy
1565 on several machines and they hang the machine
1566 when used, but on other computers it's the only
1567 way to get the interrupt routing table. Try
1568 this option if the kernel is unable to allocate
1569 IRQs or discover secondary PCI buses on your
1571 rom [X86-32] Assign address space to expansion ROMs.
1572 Use with caution as certain devices share
1573 address decoders between ROMs and other
1575 norom [X86-32,X86_64] Do not assign address space to
1576 expansion ROMs that do not already have
1577 BIOS assigned address ranges.
1578 irqmask=0xMMMM [X86-32] Set a bit mask of IRQs allowed to be
1579 assigned automatically to PCI devices. You can
1580 make the kernel exclude IRQs of your ISA cards
1582 pirqaddr=0xAAAAA [X86-32] Specify the physical address
1583 of the PIRQ table (normally generated
1584 by the BIOS) if it is outside the
1585 F0000h-100000h range.
1586 lastbus=N [X86-32] Scan all buses thru bus #N. Can be
1587 useful if the kernel is unable to find your
1588 secondary buses and you want to tell it
1589 explicitly which ones they are.
1590 assign-busses [X86-32] Always assign all PCI bus
1591 numbers ourselves, overriding
1592 whatever the firmware may have done.
1593 usepirqmask [X86-32] Honor the possible IRQ mask stored
1594 in the BIOS $PIR table. This is needed on
1595 some systems with broken BIOSes, notably
1596 some HP Pavilion N5400 and Omnibook XE3
1597 notebooks. This will have no effect if ACPI
1598 IRQ routing is enabled.
1599 noacpi [X86-32] Do not use ACPI for IRQ routing
1600 or for PCI scanning.
1601 use_crs [X86-32] Use _CRS for PCI resource
1603 routeirq Do IRQ routing for all PCI devices.
1604 This is normally done in pci_enable_device(),
1605 so this option is a temporary workaround
1606 for broken drivers that don't call it.
1607 skip_isa_align [X86] do not align io start addr, so can
1608 handle more pci cards
1609 firmware [ARM] Do not re-enumerate the bus but instead
1610 just use the configuration from the
1611 bootloader. This is currently used on
1612 IXP2000 systems where the bus has to be
1613 configured a certain way for adjunct CPUs.
1614 noearly [X86] Don't do any early type 1 scanning.
1615 This might help on some broken boards which
1616 machine check when some devices' config space
1617 is read. But various workarounds are disabled
1618 and some IOMMU drivers will not work.
1619 bfsort Sort PCI devices into breadth-first order.
1620 This sorting is done to get a device
1621 order compatible with older (<= 2.4) kernels.
1622 nobfsort Don't sort PCI devices into breadth-first order.
1623 cbiosize=nn[KMG] The fixed amount of bus space which is
1624 reserved for the CardBus bridge's IO window.
1625 The default value is 256 bytes.
1626 cbmemsize=nn[KMG] The fixed amount of bus space which is
1627 reserved for the CardBus bridge's memory
1628 window. The default value is 64 megabytes.
1630 pcmv= [HW,PCMCIA] BadgePAD 4
1633 See Documentation/paride.txt.
1635 pdcchassis= [PARISC,HW] Disable/Enable PDC Chassis Status codes at
1638 See arch/parisc/kernel/pdc_chassis.c
1641 See Documentation/paride.txt.
1644 See Documentation/paride.txt.
1646 pirq= [SMP,APIC] Manual mp-table setup
1647 See Documentation/i386/IO-APIC.txt.
1649 plip= [PPT,NET] Parallel port network link
1650 Format: { parport<nr> | timid | 0 }
1651 See also Documentation/parport.txt.
1653 pmtmr= [X86] Manual setup of pmtmr I/O Port.
1654 Override pmtimer IOPort with a hex value.
1661 { on | off | curr | res | no-curr | no-res }
1664 [ISAPNP] Exclude IRQs for the autoconfiguration
1667 [ISAPNP] Exclude DMAs for the autoconfiguration
1669 pnp_reserve_io= [ISAPNP] Exclude I/O ports for the autoconfiguration
1670 Ranges are in pairs (I/O port base and size).
1673 [ISAPNP] Exclude memory regions for the
1675 Ranges are in pairs (memory base and size).
1677 print-fatal-signals=
1678 [KNL] debug: print fatal signals
1679 print-fatal-signals=1: print segfault info to
1683 printk.time= Show timing data prefixed to each printk message line
1684 Format: <bool> (1/Y/y=enable, 0/N/n=disable)
1686 profile= [KNL] Enable kernel profiling via /proc/profile
1687 Format: [schedule,]<number>
1688 Param: "schedule" - profile schedule points.
1689 Param: <number> - step/bucket size as a power of 2 for
1690 statistical time based profiling.
1691 Param: "sleep" - profile D-state sleeping (millisecs).
1692 Requires CONFIG_SCHEDSTATS
1693 Param: "kvm" - profile VM exits.
1695 processor.max_cstate= [HW,ACPI]
1696 Limit processor to maximum C-state
1697 max_cstate=9 overrides any DMI blacklist limit.
1699 processor.nocst [HW,ACPI]
1700 Ignore the _CST method to determine C-states,
1701 instead using the legacy FADT method
1703 prompt_ramdisk= [RAM] List of RAM disks to prompt for floppy disk
1705 See Documentation/ramdisk.txt.
1707 psmouse.proto= [HW,MOUSE] Highest PS2 mouse protocol extension to
1708 probe for; one of (bare|imps|exps|lifebook|any).
1709 psmouse.rate= [HW,MOUSE] Set desired mouse report rate, in reports
1711 psmouse.resetafter= [HW,MOUSE]
1712 Try to reset the device after so many bad packets
1715 [HW,MOUSE] Set desired mouse resolution, in dpi.
1716 psmouse.smartscroll=
1717 [HW,MOUSE] Controls Logitech smartscroll autorepeat.
1718 0 = disabled, 1 = enabled (default).
1720 pss= [HW,OSS] Personal Sound System (ECHO ESC614)
1722 <io>,<mss_io>,<mss_irq>,<mss_dma>,<mpu_io>,<mpu_irq>
1725 See Documentation/paride.txt.
1728 [KNL] Number of legacy pty's. Overwrites compiled-in
1731 quiet [KNL] Disable most log messages
1736 See Documentation/md.txt.
1738 ramdisk_blocksize= [RAM]
1739 See Documentation/ramdisk.txt.
1741 ramdisk_size= [RAM] Sizes of RAM disks in kilobytes
1742 See Documentation/ramdisk.txt.
1744 rcupdate.blimit= [KNL,BOOT]
1745 Set maximum number of finished RCU callbacks to process
1748 rcupdate.qhimark= [KNL,BOOT]
1749 Set threshold of queued
1750 RCU callbacks over which batch limiting is disabled.
1752 rcupdate.qlowmark= [KNL,BOOT]
1753 Set threshold of queued RCU callbacks below which
1754 batch limiting is re-enabled.
1758 Run specified binary instead of /init from the ramdisk,
1759 used for early userspace startup. See initrd.
1761 reboot= [BUGS=X86-32,BUGS=ARM,BUGS=IA-64] Rebooting mode
1762 Format: <reboot_mode>[,<reboot_mode2>[,...]]
1763 See arch/*/kernel/reboot.c or arch/*/kernel/process.c
1766 [KNL, SMP] Set scheduler's default relax_domain_level.
1767 See Documentation/cpusets.txt.
1769 reserve= [KNL,BUGS] Force the kernel to ignore some iomem area
1771 reservetop= [X86-32]
1773 Reserves a hole at the top of the kernel virtual
1776 reset_devices [KNL] Force drivers to reset the underlying device
1777 during initialization.
1780 Specify the partition device for software suspend
1782 resume_offset= [SWSUSP]
1783 Specify the offset from the beginning of the partition
1784 given by "resume=" at which the swap header is located,
1785 in <PAGE_SIZE> units (needed only for swap files).
1786 See Documentation/power/swsusp-and-swap-files.txt
1788 retain_initrd [RAM] Keep initrd memory after extraction
1790 rhash_entries= [KNL,NET]
1791 Set number of hash buckets for route cache
1793 riscom8= [HW,SERIAL]
1794 Format: <io_board1>[,<io_board2>[,...<io_boardN>]]
1796 ro [KNL] Mount root device read-only on boot
1798 root= [KNL] Root filesystem
1800 rootdelay= [KNL] Delay (in seconds) to pause before attempting to
1801 mount the root filesystem
1803 rootflags= [KNL] Set root filesystem mount option string
1805 rootfstype= [KNL] Set root filesystem type
1807 rootwait [KNL] Wait (indefinitely) for root device to show up.
1808 Useful for devices that are detected asynchronously
1809 (e.g. USB and MMC devices).
1811 root_plug.vendor_id=
1812 [ROOTPLUG] Override the default vendor ID
1814 root_plug.product_id=
1815 [ROOTPLUG] Override the default product ID
1818 [ROOTPLUG] Enable debugging output
1820 rw [KNL] Mount root device read-write on boot
1822 S [KNL] Run init in single mode
1825 See drivers/net/irda/sa1100_ir.c.
1827 sbni= [NET] Granch SBNI12 leased line adapter
1829 sc1200wdt= [HW,WDT] SC1200 WDT (watchdog) driver
1830 Format: <io>[,<timeout>[,<isapnp>]]
1832 scsi_debug_*= [SCSI]
1833 See drivers/scsi/scsi_debug.c.
1835 scsi_default_dev_flags=
1836 [SCSI] SCSI default device flags
1839 scsi_dev_flags= [SCSI] Black/white list entry for vendor and model
1840 Format: <vendor>:<model>:<flags>
1841 (flags are integer value)
1843 scsi_logging_level= [SCSI] a bit mask of logging levels
1844 See drivers/scsi/scsi_logging.h for bits. Also
1845 settable via sysctl at dev.scsi.logging_level
1846 (/proc/sys/dev/scsi/logging_level).
1847 There is also a nice 'scsi_logging_level' script in the
1848 S390-tools package, available for download at
1849 http://www-128.ibm.com/developerworks/linux/linux390/s390-tools-1.5.4.html
1851 scsi_mod.scan= [SCSI] sync (default) scans SCSI busses as they are
1852 discovered. async scans them in kernel threads,
1853 allowing boot to proceed. none ignores them, expecting
1854 user space to do the scan.
1856 selinux [SELINUX] Disable or enable SELinux at boot time.
1857 Format: { "0" | "1" }
1858 See security/selinux/Kconfig help text.
1861 Default value is set via kernel config option.
1862 If enabled at boot time, /selinux/disable can be used
1863 later to disable prior to initial policy load.
1865 selinux_compat_net =
1866 [SELINUX] Set initial selinux_compat_net flag value.
1867 Format: { "0" | "1" }
1868 0 -- use new secmark-based packet controls
1869 1 -- use legacy packet controls
1870 Default value is 0 (preferred).
1871 Value can be changed at runtime via
1872 /selinux/compat_net.
1874 serialnumber [BUGS=X86-32]
1877 Maximal number of shapers.
1879 show_msr= [x86] show boot-time MSR settings
1880 Format: { <integer> }
1881 Show boot-time (BIOS-initialized) MSR settings.
1882 The parameter means the number of CPUs to show,
1883 for example 1 means boot CPU only.
1886 See header of drivers/scsi/sim710.c.
1893 slub_debug[=options[,slabs]] [MM, SLUB]
1894 Enabling slub_debug allows one to determine the
1895 culprit if slab objects become corrupted. Enabling
1896 slub_debug can create guard zones around objects and
1897 may poison objects when not in use. Also tracks the
1898 last alloc / free. For more information see
1899 Documentation/vm/slub.txt.
1901 slub_max_order= [MM, SLUB]
1902 Determines the maximum allowed order for slabs.
1903 A high setting may cause OOMs due to memory
1904 fragmentation. For more information see
1905 Documentation/vm/slub.txt.
1907 slub_min_objects= [MM, SLUB]
1908 The minimum number of objects per slab. SLUB will
1909 increase the slab order up to slub_max_order to
1910 generate a sufficiently large slab able to contain
1911 the number of objects indicated. The higher the number
1912 of objects the smaller the overhead of tracking slabs
1913 and the less frequently locks need to be acquired.
1914 For more information see Documentation/vm/slub.txt.
1916 slub_min_order= [MM, SLUB]
1917 Determines the mininum page order for slabs. Must be
1918 lower than slub_max_order.
1919 For more information see Documentation/vm/slub.txt.
1921 slub_nomerge [MM, SLUB]
1922 Disable merging of slabs with similar size. May be
1923 necessary if there is some reason to distinguish
1924 allocs to different slabs. Debug options disable
1925 merging on their own.
1926 For more information see Documentation/vm/slub.txt.
1929 Format: <io1>[,<io2>[,...,<io8>]]
1931 smp-alt-once [X86-32,SMP] On a hotplug CPU system, only
1932 attempt to substitute SMP alternatives once at boot.
1934 smsc-ircc2.nopnp [HW] Don't use PNP to discover SMC devices
1935 smsc-ircc2.ircc_cfg= [HW] Device configuration I/O port
1936 smsc-ircc2.ircc_sir= [HW] SIR base I/O port
1937 smsc-ircc2.ircc_fir= [HW] FIR base I/O port
1938 smsc-ircc2.ircc_irq= [HW] IRQ line
1939 smsc-ircc2.ircc_dma= [HW] DMA channel
1940 smsc-ircc2.ircc_transceiver= [HW] Transceiver type:
1941 0: Toshiba Satellite 1800 (GP data pin select)
1942 1: Fast pin select (default)
1945 snd-ad1816a= [HW,ALSA]
1947 snd-ad1848= [HW,ALSA]
1949 snd-ali5451= [HW,ALSA]
1951 snd-als100= [HW,ALSA]
1953 snd-als4000= [HW,ALSA]
1955 snd-azt2320= [HW,ALSA]
1957 snd-cmi8330= [HW,ALSA]
1959 snd-cmipci= [HW,ALSA]
1961 snd-cs4231= [HW,ALSA]
1963 snd-cs4232= [HW,ALSA]
1965 snd-cs4236= [HW,ALSA]
1967 snd-cs4281= [HW,ALSA]
1969 snd-cs46xx= [HW,ALSA]
1971 snd-dt019x= [HW,ALSA]
1973 snd-dummy= [HW,ALSA]
1975 snd-emu10k1= [HW,ALSA]
1977 snd-ens1370= [HW,ALSA]
1979 snd-ens1371= [HW,ALSA]
1981 snd-es968= [HW,ALSA]
1983 snd-es1688= [HW,ALSA]
1985 snd-es18xx= [HW,ALSA]
1987 snd-es1938= [HW,ALSA]
1989 snd-es1968= [HW,ALSA]
1991 snd-fm801= [HW,ALSA]
1993 snd-gusclassic= [HW,ALSA]
1995 snd-gusextreme= [HW,ALSA]
1997 snd-gusmax= [HW,ALSA]
2001 snd-ice1712= [HW,ALSA]
2003 snd-intel8x0= [HW,ALSA]
2005 snd-interwave= [HW,ALSA]
2010 snd-korg1212= [HW,ALSA]
2012 snd-maestro3= [HW,ALSA]
2014 snd-mpu401= [HW,ALSA]
2016 snd-mtpav= [HW,ALSA]
2018 snd-nm256= [HW,ALSA]
2020 snd-opl3sa2= [HW,ALSA]
2028 snd-opti93x= [HW,ALSA]
2032 snd-rme32= [HW,ALSA]
2034 snd-rme96= [HW,ALSA]
2036 snd-rme9652= [HW,ALSA]
2042 snd-sbawe= [HW,ALSA]
2044 snd-serial= [HW,ALSA]
2046 snd-sgalaxy= [HW,ALSA]
2048 snd-sonicvibes= [HW,ALSA]
2053 snd-sun-cs4231= [HW,ALSA]
2055 snd-trident= [HW,ALSA]
2057 snd-usb-audio= [HW,ALSA,USB]
2059 snd-via82xx= [HW,ALSA]
2061 snd-virmidi= [HW,ALSA]
2063 snd-wavefront= [HW,ALSA]
2065 snd-ymfpci= [HW,ALSA]
2068 [KNL] Should the soft-lockup detector generate panics.
2070 sonypi.*= [HW] Sony Programmable I/O Control Device driver
2071 See Documentation/sonypi.txt
2073 specialix= [HW,SERIAL] Specialix multi-serial port adapter
2074 See Documentation/specialix.txt.
2076 spia_io_base= [HW,MTD]
2082 Format: <io>,<irq>,<dma>,<mpu_io>,<mpu_irq>
2084 st= [HW,SCSI] SCSI tape parameters (buffers, etc.)
2085 See Documentation/scsi/st.txt.
2089 Set the STI (builtin display/keyboard on the HP-PARISC
2090 machines) console (graphic card) which should be used
2091 as the initial boot-console.
2092 See also comment in drivers/video/console/sticore.c.
2095 See comment in drivers/video/console/sticore.c.
2098 Format: bpp:<bpp1>[:<bpp2>[:<bpp3>...]]
2102 Control how the NFS server code allocates CPUs to
2103 service thread pools. Depending on how many NICs
2104 you have and where their interrupts are bound, this
2105 option will affect which CPUs will do NFS serving.
2106 Note: this parameter cannot be changed while the
2107 NFS server is running.
2109 auto the server chooses an appropriate mode
2110 automatically using heuristics
2111 global a single global pool contains all CPUs
2112 percpu one pool for each CPU
2113 pernode one pool for each NUMA node (equivalent
2114 to global on non-NUMA machines)
2116 swiotlb= [IA-64] Number of I/O TLB slabs
2120 sym53c416= [HW,SCSI]
2121 See header of drivers/scsi/sym53c416.c.
2123 sysrq_always_enabled
2125 Ignore sysrq setting - this boot parameter will
2126 neutralize any effect of /proc/sys/kernel/sysrq.
2127 Useful for debugging.
2130 See header of drivers/scsi/t128.c.
2134 test_suspend= [SUSPEND]
2135 Specify "mem" (for Suspend-to-RAM) or "standby" (for
2136 standby suspend) as the system sleep state to briefly
2137 enter during system startup. The system is woken from
2138 this state using a wakeup-capable RTC alarm.
2140 thash_entries= [KNL,NET]
2141 Set number of hash buckets for TCP connection
2143 thermal.act= [HW,ACPI]
2144 -1: disable all active trip points in all thermal zones
2145 <degrees C>: override all lowest active trip points
2147 thermal.crt= [HW,ACPI]
2148 -1: disable all critical trip points in all thermal zones
2149 <degrees C>: lower all critical trip points
2151 thermal.nocrt= [HW,ACPI]
2152 Set to disable actions on ACPI thermal zone
2153 critical and hot trip points.
2155 thermal.off= [HW,ACPI]
2156 1: disable ACPI thermal control
2158 thermal.psv= [HW,ACPI]
2159 -1: disable all passive trip points
2160 <degrees C>: override all passive trip points to this value
2162 thermal.tzp= [HW,ACPI]
2163 Specify global default ACPI thermal zone polling rate
2164 <deci-seconds>: poll all this frequency
2165 0: no polling (default)
2168 See comment before function dc390_setup() in
2169 drivers/scsi/tmscsim.c.
2173 trix= [HW,OSS] MediaTrix AudioTrix Pro
2175 <io>,<irq>,<dma>,<dma2>,<sb_io>,<sb_irq>,<sb_dma>,<mpu_io>,<mpu_irq>
2177 turbografx.map[2|3]= [HW,JOY]
2178 TurboGraFX parallel port interface
2180 <port#>,<js1>,<js2>,<js3>,<js4>,<js5>,<js6>,<js7>
2181 See also Documentation/input/joystick-parport.txt
2183 u14-34f= [HW,SCSI] UltraStor 14F/34F SCSI host adapter
2184 See header of drivers/scsi/u14-34f.c.
2193 [USB] Ignore overcurrent events (default N).
2194 Some badly-designed motherboards generate lots of
2195 bogus events, for ports that aren't wired to
2196 anything. Set this parameter to avoid log spamming.
2197 Note that genuine overcurrent events won't be
2202 Set unknown_nmi_panic=1 early on boot.
2204 usbcore.autosuspend=
2205 [USB] The autosuspend time delay (in seconds) used
2206 for newly-detected USB devices (default 2). This
2207 is the time required before an idle device will be
2208 autosuspended. Devices for which the delay is set
2209 to a negative value won't be autosuspended at all.
2212 [USBHID] The interval which mice are to be polled at.
2214 add_efi_memmap [EFI; x86-32,X86-64] Include EFI memory map in
2215 kernel's map of available physical RAM.
2217 vdso= [X86-32,SH,x86-64]
2218 vdso=2: enable compat VDSO (default with COMPAT_VDSO)
2219 vdso=1: enable VDSO (default)
2220 vdso=0: disable VDSO mapping
2222 vdso32= [X86-32,X86-64]
2223 vdso32=2: enable compat VDSO (default with COMPAT_VDSO)
2224 vdso32=1: enable 32-bit VDSO (default)
2225 vdso32=0: disable 32-bit VDSO mapping
2228 vector=percpu: enable percpu vector domain
2230 video= [FB] Frame buffer configuration
2231 See Documentation/fb/modedb.txt.
2233 vga= [BOOT,X86-32] Select a particular video mode
2234 See Documentation/i386/boot.txt and
2235 Documentation/svga.txt.
2236 Use vga=ask for menu.
2237 This is actually a boot loader parameter; the value is
2238 passed to the kernel using a special protocol.
2240 vmalloc=nn[KMG] [KNL,BOOT] Forces the vmalloc area to have an exact
2241 size of <nn>. This can be used to increase the
2242 minimum size (128MB on x86). It can also be used to
2243 decrease the size and leave more room for directly
2246 vmhalt= [KNL,S390] Perform z/VM CP command after system halt.
2249 vmpanic= [KNL,S390] Perform z/VM CP command after kernel panic.
2252 vmpoff= [KNL,S390] Perform z/VM CP command after power off.
2255 waveartist= [HW,OSS]
2256 Format: <io>,<irq>,<dma>,<dma2>
2259 See header of drivers/scsi/wd33c93.c.
2262 See header of drivers/scsi/wd7000.c.
2265 See Documentation/watchdog/wdt.txt.
2267 xd= [HW,XT] Original XT pre-IDE (RLL encoded) disks.
2268 xd_geo= See header of drivers/block/xd.c.
2270 xirc2ps_cs= [NET,PCMCIA]
2272 <irq>,<irq_mask>,<io>,<full_duplex>,<do_sound>,<lockup_hack>[,<irq2>[,<irq3>[,<irq4>]]]
2274 norandmaps Don't use address space randomization
2275 Equivalent to echo 0 > /proc/sys/kernel/randomize_va_space
2277 ______________________________________________________________________
2281 Add documentation for ALSA options.
2282 Add more DRM drivers.