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 bttv.card= [HW,V4L] bttv (bt848 + bt878 based grabber cards)
369 bttv.radio= Most important insmod options are available as
371 bttv.pll= See Documentation/video4linux/bttv/Insmod-options
372 bttv.tuner= and Documentation/video4linux/bttv/CARDLIST
375 See drivers/scsi/BusLogic.c, comment before function
376 BusLogic_ParseDriverOptions().
378 c101= [NET] Moxa C101 synchronous serial card
380 cachesize= [BUGS=X86-32] Override level 2 CPU cache size detection.
381 Sometimes CPU hardware bugs make them report the cache
382 size incorrectly. The kernel will attempt work arounds
383 to fix known problems, but for some CPUs it is not
384 possible to determine what the correct size should be.
385 This option provides an override for these situations.
387 security= [SECURITY] Choose a security module to enable at boot.
388 If this boot parameter is not specified, only the first
389 security module asking for security registration will be
390 loaded. An invalid security module name will be treated
391 as if no module has been chosen.
394 [SECURITY] Disable capabilities. This would normally
395 be used only if an alternative security model is to be
396 configured. Potentially dangerous and should only be
397 used if you are entirely sure of the consequences.
399 ccw_timeout_log [S390]
400 See Documentation/s390/CommonIO for details.
402 cgroup_disable= [KNL] Disable a particular controller
403 Format: {name of the controller(s) to disable}
404 {Currently supported controllers - "memory"}
406 checkreqprot [SELINUX] Set initial checkreqprot flag value.
407 Format: { "0" | "1" }
408 See security/selinux/Kconfig help text.
409 0 -- check protection applied by kernel (includes
410 any implied execute protection).
411 1 -- check protection requested by application.
412 Default value is set via a kernel config option.
413 Value can be changed at runtime via
414 /selinux/checkreqprot.
417 See Documentation/s390/CommonIO for details.
419 clock= [BUGS=X86-32, HW] gettimeofday clocksource override.
421 Forces specified clocksource (if available) to be used
422 when calculating gettimeofday(). If specified
423 clocksource is not available, it defaults to PIT.
424 Format: { pit | tsc | cyclone | pmtmr }
426 clocksource= [GENERIC_TIME] Override the default clocksource
428 Override the default clocksource and use the clocksource
429 with the name specified.
430 Some clocksource names to choose from, depending on
432 [all] jiffies (this is the base, fallback clocksource)
434 [ARM] imx_timer1,OSTS,netx_timer,mpu_timer2,
435 pxa_timer,timer3,32k_counter,timer0_1
437 [X86-32] pit,hpet,tsc,vmi-timer;
438 scx200_hrt on Geode; cyclone on IBM x440
446 clearcpuid=BITNUM [X86]
447 Disable CPUID feature X for the kernel. See
448 include/asm-x86/cpufeature.h for the valid bit numbers.
449 Note the Linux specific bits are not necessarily
450 stable over kernel options, but the vendor specific
452 Also note that user programs calling CPUID directly
453 or using the feature without checking anything
454 will still see it. This just prevents it from
455 being used by the kernel or shown in /proc/cpuinfo.
456 Also note the kernel might malfunction if you disable
459 code_bytes [IA32/X86_64] How many bytes of object code to print
466 [IA32/X86_64] Disable/Enable interrupt 0 timer routing
467 over the 8254 in addition to over the IO-APIC. The
468 kernel tries to set a sensible default.
470 hpet= [X86-32,HPET] option to control HPET usage
471 Format: { enable (default) | disable | force }
472 disable: disable HPET and use PIT instead
473 force: allow force enabled of undocumented chips (ICH4,
476 com20020= [HW,NET] ARCnet - COM20020 chipset
478 <io>[,<irq>[,<nodeID>[,<backplane>[,<ckp>[,<timeout>]]]]]
480 com90io= [HW,NET] ARCnet - COM90xx chipset (IO-mapped buffers)
484 ARCnet - COM90xx chipset (memory-mapped buffers)
485 Format: <io>[,<irq>[,<memstart>]]
487 condev= [HW,S390] console device
490 console= [KNL] Output console device and options.
492 tty<n> Use the virtual console device <n>.
496 Use the specified serial port. The options are of
497 the form "bbbbpnf", where "bbbb" is the baud rate,
498 "p" is parity ("n", "o", or "e"), "n" is number of
499 bits, and "f" is flow control ("r" for RTS or
500 omit it). Default is "9600n8".
502 See Documentation/serial-console.txt for more
504 Documentation/networking/netconsole.txt for an
507 uart[8250],io,<addr>[,options]
508 uart[8250],mmio,<addr>[,options]
509 Start an early, polled-mode console on the 8250/16550
510 UART at the specified I/O port or MMIO address,
511 switching to the matching ttyS device later. The
512 options are the same as for ttyS, above.
514 If the device connected to the port is not a TTY but a braille
515 device, prepend "brl," before the device type, for instance
517 For now, only VisioBraille is supported.
519 earlycon= [KNL] Output early console device and options.
520 uart[8250],io,<addr>[,options]
521 uart[8250],mmio,<addr>[,options]
522 Start an early, polled-mode console on the 8250/16550
523 UART at the specified I/O port or MMIO address.
524 The options are the same as for ttyS, above.
527 [HW] Never suspend the console
528 Disable suspending of consoles during suspend and
529 hibernate operations. Once disabled, debugging
530 messages can reach various consoles while the rest
531 of the system is being put to sleep (ie, while
532 debugging driver suspend/resume hooks). This may
533 not work reliably with all consoles, but is known
534 to work with serial and VGA consoles.
536 cpcihp_generic= [HW,PCI] Generic port I/O CompactPCI driver
538 <first_slot>,<last_slot>,<port>,<enum_bit>[,<debug>]
540 crashkernel=nn[KMG]@ss[KMG]
541 [KNL] Reserve a chunk of physical memory to
542 hold a kernel to switch to with kexec on panic.
544 crashkernel=range1:size1[,range2:size2,...][@offset]
545 [KNL] Same as above, but depends on the memory
546 in the running system. The syntax of range is
547 start-[end] where start and end are both
548 a memory unit (amount[KMG]). See also
549 Documentation/kdump/kdump.txt for a example.
552 Format: <io>,<irq>,<dma>,<dma2>,<mpuio>,<mpuirq>
557 cs89x0_media= [HW,NET]
558 Format: { rj45 | aui | bnc }
561 See header of drivers/s390/block/dasd_devmap.c.
563 db9.dev[2|3]= [HW,JOY] Multisystem joystick support via parallel port
564 (one device per port)
565 Format: <port#>,<type>
566 See also Documentation/input/joystick-parport.txt
568 debug [KNL] Enable kernel debugging (events log level).
571 [KNL] verbose self-tests
573 Print debugging info while doing the locking API
575 We default to 0 (no extra messages), setting it to
576 1 will print _a lot_ more information - normally
577 only useful to kernel developers.
579 debug_objects [KNL] Enable object debugging
581 debugpat [X86] Enable PAT debugging
583 decnet.addr= [HW,NET]
584 Format: <area>[,<node>]
585 See also Documentation/networking/decnet.txt.
588 Format: <blue0>,<blue1>,<blue2>,...,<blue15>
589 Change the default blue palette of the console.
590 This is a 16-member array composed of values
594 Format: <green0>,<green1>,<green2>,...,<green15>
595 Change the default green palette of the console.
596 This is a 16-member array composed of values
600 Format: <red0>,<red1>,<red2>,...,<red15>
601 Change the default red palette of the console.
602 This is a 16-member array composed of values
608 Set system-wide default UTF-8 mode for all tty's.
609 Default is 1, i.e. UTF-8 mode is enabled for all
610 newly opened terminals.
613 Set number of hash buckets for dentry cache.
616 IO parameters + enable/disable command.
618 digiepca= [HW,SERIAL]
619 See drivers/char/README.epca and
620 Documentation/digiepca.txt.
622 disable_mtrr_cleanup [X86]
623 enable_mtrr_cleanup [X86]
624 The kernel tries to adjust MTRR layout from continuous
625 to discrete, to make X server driver able to add WB
626 entry later. This parameter enables/disables that.
628 mtrr_chunk_size=nn[KMG] [X86]
629 used for mtrr cleanup. It is largest continous chunk
630 that could hold holes aka. UC entries.
632 mtrr_gran_size=nn[KMG] [X86]
633 Used for mtrr cleanup. It is granularity of mtrr block.
635 Large value could prevent small alignment from
638 mtrr_spare_reg_nr=n [X86]
640 Range: 0,7 : spare reg number
642 Used for mtrr cleanup. It is spare mtrr entries number.
643 Set to 2 or more if your graphical card needs more.
645 disable_mtrr_trim [X86, Intel and AMD only]
646 By default the kernel will trim any uncacheable
647 memory out of your available memory pool based on
648 MTRR settings. This parameter disables that behavior,
649 possibly causing your machine to run very slowly.
651 dmasound= [HW,OSS] Sound subsystem buffers
657 earlyprintk= [X86-32,X86-64,SH,BLACKFIN]
659 earlyprintk=serial[,ttySn[,baudrate]]
661 Append ",keep" to not disable it when the real console
664 Only vga or serial at a time, not both.
666 Currently only ttyS0 and ttyS1 are supported.
668 Interaction with the standard serial driver is not
671 The VGA output is eventually overwritten by the real
677 Format: {"off" | "on" | "skip[mbr]"}
679 eisa_irq_edge= [PARISC,HW]
680 See header of drivers/parisc/eisa.c.
683 See comment before function elanfreq_setup() in
684 arch/x86/kernel/cpu/cpufreq/elanfreq.c.
687 Format: {"anticipatory" | "cfq" | "deadline" | "noop"}
688 See Documentation/block/as-iosched.txt and
689 Documentation/block/deadline-iosched.txt for details.
691 elfcorehdr= [X86-32, X86_64]
692 Specifies physical address of start of kernel core
693 image elf header. Generally kexec loader will
694 pass this option to capture kernel.
695 See Documentation/kdump/kdump.txt for details.
697 enforcing [SELINUX] Set initial enforcing status.
699 See security/selinux/Kconfig help text.
700 0 -- permissive (log only, no denials).
701 1 -- enforcing (deny and log).
703 Value can be changed at runtime via /selinux/enforce.
706 Format: <spdif>,[<nomix>,[<amplifier>]]
707 See also header of sound/oss/es1371.c.
709 ether= [HW,NET] Ethernet cards parameters
710 This option is obsoleted by the "netdev=" option, which
711 has equivalent usage. See its documentation for details.
713 eurwdt= [HW,WDT] Eurotech CPU-1220/1410 onboard watchdog.
718 fail_make_request=[KNL]
719 General fault injection mechanism.
720 Format: <interval>,<probability>,<space>,<times>
721 See also /Documentation/fault-injection/.
724 See header of drivers/scsi/fd_mcs.c.
727 See header of drivers/scsi/fdomain.c.
730 See Documentation/floppy.txt.
732 force_pal_cache_flush
733 [IA-64] Avoid check_sal_cache_flush which may hang on
734 buggy SAL_CACHE_FLUSH implementations. Using this
735 parameter will force ia64_sal_cache_flush to call
736 ia64_pal_cache_flush instead of SAL_CACHE_FLUSH.
739 [HW,JOY] Multisystem joystick and NES/SNES/PSX pad
740 support via parallel port (up to 5 devices per port)
741 Format: <port#>,<pad1>,<pad2>,<pad3>,<pad4>,<pad5>
742 See also Documentation/input/joystick-parport.txt
746 gart_fix_e820= [X86_64] disable the fix e820 for K8 GART
751 See header of drivers/scsi/gdth.c.
753 gpt [EFI] Forces disk with valid GPT signature but
754 invalid Protective MBR to be treated as GPT.
758 hashdist= [KNL,NUMA] Large hashes allocated during boot
759 are distributed across NUMA nodes. Defaults on
760 for IA-64, off otherwise.
761 Format: 0 | 1 (for off | on)
763 hcl= [IA-64] SGI's Hardware Graph compatibility layer
765 hd= [EIDE] (E)IDE hard drive subsystem geometry
766 Format: <cyl>,<head>,<sect>
768 highmem=nn[KMG] [KNL,BOOT] forces the highmem zone to have an exact
769 size of <nn>. This works even on boxes that have no
770 highmem otherwise. This also works to reduce highmem
771 size on bigger boxes.
773 highres= [KNL] Enable/disable high resolution timer mode.
774 Valid parameters: "on", "off"
778 See Documentation/isdn/README.HiSax.
780 hugepages= [HW,X86-32,IA-64] HugeTLB pages to allocate at boot.
781 hugepagesz= [HW,IA-64,PPC,X86-64] The size of the HugeTLB pages.
782 On x86-64 and powerpc, this option can be specified
783 multiple times interleaved with hugepages= to reserve
784 huge pages of different sizes. Valid pages sizes on
785 x86-64 are 2M (when the CPU supports "pse") and 1G
786 (when the CPU supports the "pdpe1gb" cpuinfo flag)
787 Note that 1GB pages can only be allocated at boot time
788 using hugepages= and not freed afterwards.
790 [same as hugepagesz=] The size of the default
791 HugeTLB page size. This is the size represented by
792 the legacy /proc/ hugepages APIs, used for SHM, and
793 default size when mounting hugetlbfs filesystems.
794 Defaults to the default architecture's huge page size
797 i8042.direct [HW] Put keyboard port into non-translated mode
798 i8042.dumbkbd [HW] Pretend that controller can only read data from
799 keyboard and cannot control its state
800 (Don't attempt to blink the leds)
801 i8042.noaux [HW] Don't check for auxiliary (== mouse) port
802 i8042.nokbd [HW] Don't check/create keyboard port
803 i8042.noloop [HW] Disable the AUX Loopback command while probing
805 i8042.nomux [HW] Don't check presence of an active multiplexing
807 i8042.nopnp [HW] Don't use ACPIPnP / PnPBIOS to discover KBD/AUX
810 [HW] Frequency with which keyboard LEDs should blink
811 when kernel panics (default is 0.5 sec)
812 i8042.reset [HW] Reset the controller during init and cleanup
813 i8042.unlock [HW] Unlock (ignore) the keylock
817 i8k.ignore_dmi [HW] Continue probing hardware even if DMI data
818 indicates that the driver is running on unsupported
820 i8k.force [HW] Activate i8k driver even if SMM BIOS signature
821 does not match list of supported models.
823 [HW] Report power status in /proc/i8k
824 (disabled by default)
825 i8k.restricted [HW] Allow controlling fans only if SYS_ADMIN
828 ibmmcascsi= [HW,MCA,SCSI] IBM MicroChannel SCSI adapter
829 See Documentation/mca.txt.
832 Format: <io>[,<membase>[,<icn_id>[,<icn_id2>]]]
834 ide= [HW] (E)IDE subsystem
835 Format: ide=nodma or ide=doubler
836 See Documentation/ide/ide.txt.
838 idebus= [HW] (E)IDE subsystem - VLB/PCI bus speed
839 See Documentation/ide/ide.txt.
842 Format: idle=poll or idle=mwait, idle=halt, idle=nomwait
843 Poll forces a polling idle loop that can slightly improves the performance
844 of waking up a idle CPU, but will use a lot of power and make the system
845 run hot. Not recommended.
846 idle=mwait. On systems which support MONITOR/MWAIT but the kernel chose
847 to not use it because it doesn't save as much power as a normal idle
848 loop use the MONITOR/MWAIT idle loop anyways. Performance should be the same
850 idle=halt. Halt is forced to be used for CPU idle.
851 In such case C2/C3 won't be used again.
852 idle=nomwait. Disable mwait for CPU C-states
854 ide-pci-generic.all-generic-ide [HW] (E)IDE subsystem
855 Claim all unknown PCI IDE storage controllers.
857 ignore_loglevel [KNL]
858 Ignore loglevel setting - this will print /all/
859 kernel messages to the console. Useful for debugging.
862 Set number of hash buckets for inode cache.
865 See header of drivers/scsi/in2000.c.
869 Run specified binary instead of /sbin/init as init
872 initcall_debug [KNL] Trace initcalls as they are executed. Useful
873 for working out where the kernel is dying during
876 initrd= [BOOT] Specify the location of the initial ramdisk
878 inport.irq= [HW] Inport (ATI XL and Microsoft) busmouse driver
896 intel_iommu= [DMAR] Intel IOMMU driver (DMAR) option
898 Disable intel iommu driver.
899 igfx_off [Default Off]
900 By default, gfx is mapped as normal device. If a gfx
901 device has a dedicated DMAR unit, the DMAR unit is
902 bypassed by not enabling DMAR with this option. In
903 this case, gfx device will use physical address for
906 With this option iommu will not optimize to look
907 for io virtual address below 32 bit forcing dual
908 address cycle on pci bus for cards supporting greater
909 than 32 bit addressing. The default is to look
910 for translation below 32 bit and if not available
911 then look in the higher range.
913 With this option on every unmap_single operation will
914 result in a hardware IOTLB flush operation as opposed
915 to batching them for performance.
917 io_delay= [X86-32,X86-64] I/O delay method
919 Standard port 0x80 based delay
921 Alternate port 0xed based delay (needed on some systems)
923 Simple two microseconds delay
927 io7= [HW] IO7 for Marvel based alpha systems
928 See comment before marvel_specify_io7 in
929 arch/alpha/kernel/core_marvel.c.
932 See Documentation/filesystems/nfsroot.txt.
934 ip2= [HW] Set IO/IRQ pairs for up to 4 IntelliPort boards
935 See comment before ip2_setup() in
936 drivers/char/ip2/ip2base.c.
938 ips= [HW,SCSI] Adaptec / IBM ServeRAID controller
939 See header of drivers/scsi/ips.c.
941 ports= [IP_VS_FTP] IPVS ftp helper module
943 Up to 8 (IP_VS_APP_MAX_PORTS) ports
945 Format: <port>,<port>....
948 When an interrupt is not handled search all handlers
949 for it. Intended to get systems with badly broken
953 When an interrupt is not handled search all handlers
954 for it. Also check all handlers each timer
955 interrupt. Intended to get systems with badly broken
959 Format: <RDP>,<reset>,<pci_scan>,<verbosity>
961 isolcpus= [KNL,SMP] Isolate CPUs from the general scheduler.
963 <cpu number>,...,<cpu number>
965 <cpu number>-<cpu number> (must be a positive range in ascending order)
967 <cpu number>,...,<cpu number>-<cpu number>
968 This option can be used to specify one or more CPUs
969 to isolate from the general SMP balancing and scheduling
970 algorithms. The only way to move a process onto or off
971 an "isolated" CPU is via the CPU affinity syscalls.
972 <cpu number> begins at 0 and the maximum value is
973 "number of CPUs in system - 1".
975 This option is the preferred way to isolate CPUs. The
976 alternative -- manually setting the CPU mask of all
977 tasks in the system -- can cause problems and
978 suboptimal load balancer performance.
982 js= [HW,JOY] Analog joystick
983 See Documentation/input/joystick.txt.
985 kernelcore=nn[KMG] [KNL,X86-32,IA-64,PPC,X86-64] This parameter
986 specifies the amount of memory usable by the kernel
987 for non-movable allocations. The requested amount is
988 spread evenly throughout all nodes in the system. The
989 remaining memory in each node is used for Movable
990 pages. In the event, a node is too small to have both
991 kernelcore and Movable pages, kernelcore pages will
992 take priority and other nodes will have a larger number
993 of kernelcore pages. The Movable zone is used for the
994 allocation of pages that may be reclaimed or moved
995 by the page migration subsystem. This means that
996 HugeTLB pages may not be allocated from this zone.
997 Note that allocations like PTEs-from-HighMem still
998 use the HighMem zone if it exists, and the Normal
1001 movablecore=nn[KMG] [KNL,X86-32,IA-64,PPC,X86-64] This parameter
1002 is similar to kernelcore except it specifies the
1003 amount of memory used for migratable allocations.
1004 If both kernelcore and movablecore is specified,
1005 then kernelcore will be at *least* the specified
1006 value but may be more. If movablecore on its own
1007 is specified, the administrator must be careful
1008 that the amount of memory usable for all allocations
1013 kstack=N [X86-32,X86-64] Print N words from the kernel stack
1016 kgdboc= [HW] kgdb over consoles.
1017 Requires a tty driver that supports console polling.
1018 (only serial suported for now)
1019 Format: <serial_device>[,baud]
1025 lapic [X86-32,APIC] Enable the local APIC even if BIOS
1028 lapic_timer_c2_ok [X86-32,x86-64,APIC] trust the local apic timer in
1031 libata.dma= [LIBATA] DMA control
1032 libata.dma=0 Disable all PATA and SATA DMA
1033 libata.dma=1 PATA and SATA Disk DMA only
1034 libata.dma=2 ATAPI (CDROM) DMA only
1035 libata.dma=4 Compact Flash DMA only
1036 Combinations also work, so libata.dma=3 enables DMA
1037 for disks and CDROMs, but not CFs.
1039 libata.noacpi [LIBATA] Disables use of ACPI in libata suspend/resume
1043 libata.force= [LIBATA] Force configurations. The format is comma
1044 separated list of "[ID:]VAL" where ID is
1045 PORT[:DEVICE]. PORT and DEVICE are decimal numbers
1046 matching port, link or device. Basically, it matches
1047 the ATA ID string printed on console by libata. If
1048 the whole ID part is omitted, the last PORT and DEVICE
1049 values are used. If ID hasn't been specified yet, the
1050 configuration applies to all ports, links and devices.
1052 If only DEVICE is omitted, the parameter applies to
1053 the port and all links and devices behind it. DEVICE
1054 number of 0 either selects the first device or the
1055 first fan-out link behind PMP device. It does not
1056 select the host link. DEVICE number of 15 selects the
1057 host link and device attached to it.
1059 The VAL specifies the configuration to force. As long
1060 as there's no ambiguity shortcut notation is allowed.
1061 For example, both 1.5 and 1.5G would work for 1.5Gbps.
1062 The following configurations can be forced.
1064 * Cable type: 40c, 80c, short40c, unk, ign or sata.
1065 Any ID with matching PORT is used.
1067 * SATA link speed limit: 1.5Gbps or 3.0Gbps.
1069 * Transfer mode: pio[0-7], mwdma[0-4] and udma[0-7].
1070 udma[/][16,25,33,44,66,100,133] notation is also
1073 * [no]ncq: Turn on or off NCQ.
1075 If there are multiple matching configurations changing
1076 the same attribute, the last one is used.
1078 load_ramdisk= [RAM] List of ramdisks to load from floppy
1079 See Documentation/ramdisk.txt.
1081 lockd.nlm_grace_period=P [NFS] Assign grace period.
1084 lockd.nlm_tcpport=N [NFS] Assign TCP port.
1087 lockd.nlm_timeout=T [NFS] Assign timeout value.
1090 lockd.nlm_udpport=M [NFS] Assign UDP port.
1093 logibm.irq= [HW,MOUSE] Logitech Bus Mouse Driver
1096 loglevel= All Kernel Messages with a loglevel smaller than the
1097 console loglevel will be printed to the console. It can
1098 also be changed with klogd or other programs. The
1099 loglevels are defined as follows:
1101 0 (KERN_EMERG) system is unusable
1102 1 (KERN_ALERT) action must be taken immediately
1103 2 (KERN_CRIT) critical conditions
1104 3 (KERN_ERR) error conditions
1105 4 (KERN_WARNING) warning conditions
1106 5 (KERN_NOTICE) normal but significant condition
1107 6 (KERN_INFO) informational
1108 7 (KERN_DEBUG) debug-level messages
1110 log_buf_len=n Sets the size of the printk ring buffer, in bytes.
1111 Format: { n | nk | nM }
1112 n must be a power of two. The default size
1113 is set in the kernel config file.
1115 logo.nologo [FB] Disables display of the built-in Linux logo.
1116 This may be used to provide more screen space for
1117 kernel log messages and is useful when debugging
1118 kernel boot problems.
1120 lp=0 [LP] Specify parallel ports to use, e.g,
1121 lp=port[,port...] lp=none,parport0 (lp0 not configured, lp1 uses
1122 lp=reset first parallel port). 'lp=0' disables the
1123 lp=auto printer driver. 'lp=reset' (which can be
1124 specified in addition to the ports) causes
1125 attached printers to be reset. Using
1126 lp=port1,port2,... specifies the parallel ports
1127 to associate lp devices with, starting with
1128 lp0. A port specification may be 'none' to skip
1129 that lp device, or a parport name such as
1130 'parport0'. Specifying 'lp=auto' instead of a
1131 port specification list means that device IDs
1132 from each port should be examined, to see if
1133 an IEEE 1284-compliant printer is attached; if
1134 so, the driver will manage that printer.
1135 See also header of drivers/char/lp.c.
1138 Sets loops_per_jiffy to given constant, thus avoiding
1139 time-consuming boot-time autodetection (up to 250 ms per
1140 CPU). 0 enables autodetection (default). To determine
1141 the correct value for your kernel, boot with normal
1142 autodetection and see what value is printed. Note that
1143 on SMP systems the preset will be applied to all CPUs,
1144 which is likely to cause problems if your CPUs need
1145 significantly divergent settings. An incorrect value
1146 will cause delays in the kernel to be wrong, leading to
1147 unpredictable I/O errors and other breakage. Although
1148 unlikely, in the extreme case this might damage your
1152 Format: <io>,<irq>,<dma>
1154 mac5380= [HW,SCSI] Format:
1155 <can_queue>,<cmd_per_lun>,<sg_tablesize>,<hostid>,<use_tags>
1157 machvec= [IA64] Force the use of a particular machine-vector
1158 (machvec) in a generic kernel.
1159 Example: machvec=hpzx1_swiotlb
1161 max_loop= [LOOP] Maximum number of loopback devices that can
1165 maxcpus= [SMP] Maximum number of processors that an SMP kernel
1166 should make use of. maxcpus=n : n >= 0 limits the
1167 kernel to using 'n' processors. n=0 is a special case,
1168 it is equivalent to "nosmp", which also disables
1171 max_addr=[KMG] [KNL,BOOT,ia64] All physical memory greater than or
1172 equal to this physical address is ignored.
1174 max_luns= [SCSI] Maximum number of LUNs to probe.
1175 Should be between 1 and 2^32-1.
1178 [SCSI] Maximum number of LUNs received.
1179 Should be between 1 and 16384.
1183 mce [X86-32] Machine Check Exception
1185 mce=option [X86-64] See Documentation/x86_64/boot-options.txt
1187 md= [HW] RAID subsystems devices and level
1188 See Documentation/md.txt.
1191 Format: <first>,<last>
1192 Specifies range of consoles to be captured by the MDA.
1194 mem=nn[KMG] [KNL,BOOT] Force usage of a specific amount of memory
1195 Amount of memory to be used when the kernel is not able
1196 to see the whole system memory or for test.
1197 [X86-32] Use together with memmap= to avoid physical
1198 address space collisions. Without memmap= PCI devices
1199 could be placed at addresses belonging to unused RAM.
1201 mem=nopentium [BUGS=X86-32] Disable usage of 4MB pages for kernel
1204 memmap=exactmap [KNL,X86-32,X86_64] Enable setting of an exact
1205 E820 memory map, as specified by the user.
1206 Such memmap=exactmap lines can be constructed based on
1207 BIOS output or other requirements. See the memmap=nn@ss
1210 memmap=nn[KMG]@ss[KMG]
1211 [KNL] Force usage of a specific region of memory
1212 Region of memory to be used, from ss to ss+nn.
1214 memmap=nn[KMG]#ss[KMG]
1215 [KNL,ACPI] Mark specific memory as ACPI data.
1216 Region of memory to be used, from ss to ss+nn.
1218 memmap=nn[KMG]$ss[KMG]
1219 [KNL,ACPI] Mark specific memory as reserved.
1220 Region of memory to be used, from ss to ss+nn.
1221 Example: Exclude memory from 0x18690000-0x1869ffff
1222 memmap=64K$0x18690000
1224 memmap=0x10000$0x18690000
1226 memtest= [KNL,X86] Enable memtest
1228 range: 0,4 : pattern number
1229 default : 0 <disable>
1231 meye.*= [HW] Set MotionEye Camera parameters
1232 See Documentation/video4linux/meye.txt.
1234 mfgpt_irq= [IA-32] Specify the IRQ to use for the
1235 Multi-Function General Purpose Timers on AMD Geode
1238 mfgptfix [X86-32] Fix MFGPT timers on AMD Geode platforms when
1239 the BIOS has incorrectly applied a workaround. TinyBIOS
1240 version 0.98 is known to be affected, 0.99 fixes the
1241 problem by letting the user disable the workaround.
1246 [KNL] When CONFIG_DEBUG_MEMORY_INIT is set, this
1247 parameter allows control of the logging verbosity for
1248 the additional memory initialisation checks. A value
1249 of 0 disables mminit logging and a level of 4 will
1250 log everything. Information is printed at KERN_DEBUG
1251 so loglevel=8 may also need to be specified.
1254 [MOUSE] Maximum time between finger touching and
1255 leaving touchpad surface for touch to be considered
1256 a tap and be reported as a left button click (for
1257 touchpads working in absolute mode only).
1259 mousedev.xres= [MOUSE] Horizontal screen resolution, used for devices
1260 reporting absolute coordinates, such as tablets
1261 mousedev.yres= [MOUSE] Vertical screen resolution, used for devices
1262 reporting absolute coordinates, such as tablets
1267 MTD_Partition= [MTD]
1268 Format: <name>,<region-number>,<size>,<offset>
1270 MTD_Region= [MTD] Format:
1271 <name>,<region-number>[,<base>,<size>,<buswidth>,<altbuswidth>]
1274 See drivers/mtd/cmdlinepart.c.
1277 ARM/S3C2412 JIVE boot control
1279 See arch/arm/mach-s3c2412/mach-jive.c
1281 mtouchusb.raw_coordinates=
1282 [HW] Make the MicroTouch USB driver use raw coordinates
1283 ('y', default) or cooked coordinates ('n')
1285 n2= [NET] SDL Inc. RISCom/N2 synchronous serial card
1288 See header of drivers/scsi/NCR_D700.c.
1292 ncr53c400= [HW,SCSI]
1294 ncr53c400a= [HW,SCSI]
1296 ncr53c406a= [HW,SCSI]
1298 ncr53c8xx= [HW,SCSI]
1300 netdev= [NET] Network devices parameters
1301 Format: <irq>,<io>,<mem_start>,<mem_end>,<name>
1302 Note that mem_start is often overloaded to mean
1303 something different and driver-specific.
1304 This usage is only documented in each driver source
1308 [NETFILTER] Enable connection tracking flow accounting
1309 0 to disable accounting
1310 1 to enable accounting
1311 Default value depends on CONFIG_NF_CT_ACCT that is
1312 going to be removed in 2.6.29.
1315 See Documentation/filesystems/nfsroot.txt.
1317 nfsroot= [NFS] nfs root filesystem for disk-less boxes.
1318 See Documentation/filesystems/nfsroot.txt.
1320 nfs.callback_tcpport=
1321 [NFS] set the TCP port on which the NFSv4 callback
1322 channel should listen.
1324 nfs.idmap_cache_timeout=
1325 [NFS] set the maximum lifetime for idmapper cache
1329 [NFS] enable 64-bit inode numbers.
1330 If zero, the NFS client will fake up a 32-bit inode
1331 number for the readdir() and stat() syscalls instead
1332 of returning the full 64-bit number.
1333 The default is to return 64-bit inode numbers.
1335 nmi_debug= [KNL,AVR32] Specify one or more actions to take
1336 when a NMI is triggered.
1337 Format: [state][,regs][,debounce][,die]
1339 nmi_watchdog= [KNL,BUGS=X86-32] Debugging features for SMP kernels
1341 no387 [BUGS=X86-32] Tells the kernel to use the 387 maths
1342 emulation library even if a 387 maths coprocessor
1345 noaliencache [MM, NUMA, SLAB] Disables the allocation of alien
1346 caches in the slab allocator. Saves per-node memory,
1347 but will impact performance.
1351 noapic [SMP,APIC] Tells the kernel to not make use of any
1352 IOAPICs that may be present in the system.
1354 nobats [PPC] Do not use BATs for mapping kernel lowmem
1355 on "Classic" PPC cores.
1359 nodelayacct [KNL] Disable per-task delay accounting
1361 nodisconnect [HW,SCSI,M68K] Disables SCSI disconnects.
1363 noefi [X86-32,X86-64] Disable EFI runtime services support.
1367 noexec [X86-32,X86-64]
1368 On X86-32 available only on PAE configured kernels.
1369 noexec=on: enable non-executable mappings (default)
1370 noexec=off: disable non-executable mappings
1373 This affects only 32-bit executables.
1374 noexec32=on: enable non-executable mappings (default)
1375 read doesn't imply executable mappings
1376 noexec32=off: disable non-executable mappings
1377 read implies executable mappings
1379 nofxsr [BUGS=X86-32] Disables x86 floating point extended
1380 register save and restore. The kernel will only save
1381 legacy floating-point registers on task switch.
1383 noclflush [BUGS=X86] Don't use the CLFLUSH instruction
1387 no-hlt [BUGS=X86-32] Tells the kernel that the hlt
1388 instruction doesn't work correctly and not to
1391 nohalt [IA-64] Tells the kernel not to use the power saving
1392 function PAL_HALT_LIGHT when idle. This increases
1393 power-consumption. On the positive side, it reduces
1394 interrupt wake-up latency, which may improve performance
1395 in certain environments such as networked servers or
1398 nohz= [KNL] Boottime enable/disable dynamic ticks
1399 Valid arguments: on, off
1402 noirqbalance [X86-32,SMP,KNL] Disable kernel irq balancing
1404 noirqdebug [X86-32] Disables the code which attempts to detect and
1405 disable unhandled interrupt sources.
1407 no_timer_check [X86-32,X86_64,APIC] Disables the code which tests for
1408 broken timer IRQ sources.
1410 noisapnp [ISAPNP] Disables ISA PnP code.
1412 noinitrd [RAM] Tells the kernel not to load any configured
1417 nojitter [IA64] Disables jitter checking for ITC timers.
1419 nolapic [X86-32,APIC] Do not enable or use the local APIC.
1421 nolapic_timer [X86-32,APIC] Do not use the local APIC timer.
1423 nox2apic [X86-64,APIC] Do not enable x2APIC mode.
1425 x2apic_phys [X86-64,APIC] Use x2apic physical mode instead of
1426 default x2apic cluster mode on platforms
1429 noltlbs [PPC] Do not use large page/tlb entries for kernel
1430 lowmem mapping on PPC40x.
1432 nomca [IA-64] Disable machine check abort handling
1434 nomce [X86-32] Machine Check Exception
1436 nomfgpt [X86-32] Disable Multi-Function General Purpose
1437 Timer usage (for AMD Geode machines).
1439 noreplace-paravirt [X86-32,PV_OPS] Don't patch paravirt_ops
1441 noreplace-smp [X86-32,SMP] Don't replace SMP instructions
1442 with UP alternatives
1444 noresidual [PPC] Don't use residual data on PReP machines.
1446 noresume [SWSUSP] Disables resume and restores original swap
1449 no-scroll [VGA] Disables scrollback.
1450 This is required for the Braillex ib80-piezo Braille
1451 reader made by F.H. Papenmeier (Germany).
1455 nosep [BUGS=X86-32] Disables x86 SYSENTER/SYSEXIT support.
1457 nosmp [SMP] Tells an SMP kernel to act as a UP kernel,
1458 and disable the IO APIC. legacy for "maxcpus=0".
1460 nosoftlockup [KNL] Disable the soft-lockup detector.
1462 nosync [HW,M68K] Disables sync negotiation for all devices.
1464 notsc [BUGS=X86-32] Disable Time Stamp Counter
1466 nousb [USB] Disable the USB subsystem
1470 nptcg= [IA64] Override max number of concurrent global TLB
1471 purges which is reported from either PAL_VM_SUMMARY or
1474 numa_zonelist_order= [KNL, BOOT] Select zonelist order for NUMA.
1475 one of ['zone', 'node', 'default'] can be specified
1476 This can be set from sysctl after boot.
1477 See Documentation/sysctl/vm.txt for details.
1479 nr_uarts= [SERIAL] maximum number of UARTs to be registered.
1481 olpc_ec_timeout= [OLPC] ms delay when issuing EC commands
1482 Rather than timing out after 20 ms if an EC
1483 command is not properly ACKed, override the length
1484 of the timeout. We have interrupts disabled while
1485 waiting for the ACK, so if this is set too high
1486 interrupts *may* be lost!
1491 oprofile.timer= [HW]
1492 Use timer interrupt instead of performance counters
1494 osst= [HW,SCSI] SCSI Tape Driver
1495 Format: <buffer_size>,<write_threshold>
1496 See also Documentation/scsi/st.txt.
1498 panic= [KNL] Kernel behaviour on panic
1501 parkbd.port= [HW] Parallel port number the keyboard adapter is
1502 connected to, default is 0.
1504 parkbd.mode= [HW] Parallel port keyboard adapter mode of operation,
1505 0 for XT, 1 for AT (default is AT).
1508 parport= [HW,PPT] Specify parallel ports. 0 disables.
1509 Format: { 0 | auto | 0xBBB[,IRQ[,DMA]] }
1510 Use 'auto' to force the driver to use any
1511 IRQ/DMA settings detected (the default is to
1512 ignore detected IRQ/DMA settings because of
1513 possible conflicts). You can specify the base
1514 address, IRQ, and DMA settings; IRQ and DMA
1515 should be numbers, or 'auto' (for using detected
1516 settings on that particular port), or 'nofifo'
1517 (to avoid using a FIFO even if it is detected).
1518 Parallel ports are assigned in the order they
1519 are specified on the command line, starting
1522 parport_init_mode= [HW,PPT]
1523 Configure VIA parallel port to operate in
1524 a specific mode. This is necessary on Pegasos
1525 computer where firmware has no options for setting
1526 up parallel port mode and sets it to spp.
1527 Currently this function knows 686a and 8231 chips.
1528 Format: [spp|ps2|epp|ecp|ecpepp]
1530 pas2= [HW,OSS] Format:
1531 <io>,<irq>,<dma>,<dma16>,<sb_io>,<sb_irq>,<sb_dma>,<sb_dma16>
1534 See header of drivers/scsi/pas16.c.
1537 Halt all CPUs after the first oops has been printed for
1538 the specified number of seconds. This is to be used if
1539 your oopses keep scrolling off the screen.
1544 See header of drivers/block/paride/pcd.c.
1545 See also Documentation/paride.txt.
1547 pci=option[,option...] [PCI] various PCI subsystem options:
1548 off [X86-32] don't probe for the PCI bus
1549 bios [X86-32] force use of PCI BIOS, don't access
1550 the hardware directly. Use this if your machine
1551 has a non-standard PCI host bridge.
1552 nobios [X86-32] disallow use of PCI BIOS, only direct
1553 hardware access methods are allowed. Use this
1554 if you experience crashes upon bootup and you
1555 suspect they are caused by the BIOS.
1556 conf1 [X86-32] Force use of PCI Configuration
1558 conf2 [X86-32] Force use of PCI Configuration
1560 noaer [PCIE] If the PCIEAER kernel config parameter is
1561 enabled, this kernel boot option can be used to
1562 disable the use of PCIE advanced error reporting.
1563 nodomains [PCI] Disable support for multiple PCI
1564 root domains (aka PCI segments, in ACPI-speak).
1565 nommconf [X86-32,X86_64] Disable use of MMCONFIG for PCI
1567 nomsi [MSI] If the PCI_MSI kernel config parameter is
1568 enabled, this kernel boot option can be used to
1569 disable the use of MSI interrupts system-wide.
1570 biosirq [X86-32] Use PCI BIOS calls to get the interrupt
1571 routing table. These calls are known to be buggy
1572 on several machines and they hang the machine
1573 when used, but on other computers it's the only
1574 way to get the interrupt routing table. Try
1575 this option if the kernel is unable to allocate
1576 IRQs or discover secondary PCI buses on your
1578 rom [X86-32] Assign address space to expansion ROMs.
1579 Use with caution as certain devices share
1580 address decoders between ROMs and other
1582 norom [X86-32,X86_64] Do not assign address space to
1583 expansion ROMs that do not already have
1584 BIOS assigned address ranges.
1585 irqmask=0xMMMM [X86-32] Set a bit mask of IRQs allowed to be
1586 assigned automatically to PCI devices. You can
1587 make the kernel exclude IRQs of your ISA cards
1589 pirqaddr=0xAAAAA [X86-32] Specify the physical address
1590 of the PIRQ table (normally generated
1591 by the BIOS) if it is outside the
1592 F0000h-100000h range.
1593 lastbus=N [X86-32] Scan all buses thru bus #N. Can be
1594 useful if the kernel is unable to find your
1595 secondary buses and you want to tell it
1596 explicitly which ones they are.
1597 assign-busses [X86-32] Always assign all PCI bus
1598 numbers ourselves, overriding
1599 whatever the firmware may have done.
1600 usepirqmask [X86-32] Honor the possible IRQ mask stored
1601 in the BIOS $PIR table. This is needed on
1602 some systems with broken BIOSes, notably
1603 some HP Pavilion N5400 and Omnibook XE3
1604 notebooks. This will have no effect if ACPI
1605 IRQ routing is enabled.
1606 noacpi [X86-32] Do not use ACPI for IRQ routing
1607 or for PCI scanning.
1608 use_crs [X86-32] Use _CRS for PCI resource
1610 routeirq Do IRQ routing for all PCI devices.
1611 This is normally done in pci_enable_device(),
1612 so this option is a temporary workaround
1613 for broken drivers that don't call it.
1614 skip_isa_align [X86] do not align io start addr, so can
1615 handle more pci cards
1616 firmware [ARM] Do not re-enumerate the bus but instead
1617 just use the configuration from the
1618 bootloader. This is currently used on
1619 IXP2000 systems where the bus has to be
1620 configured a certain way for adjunct CPUs.
1621 noearly [X86] Don't do any early type 1 scanning.
1622 This might help on some broken boards which
1623 machine check when some devices' config space
1624 is read. But various workarounds are disabled
1625 and some IOMMU drivers will not work.
1626 bfsort Sort PCI devices into breadth-first order.
1627 This sorting is done to get a device
1628 order compatible with older (<= 2.4) kernels.
1629 nobfsort Don't sort PCI devices into breadth-first order.
1630 cbiosize=nn[KMG] The fixed amount of bus space which is
1631 reserved for the CardBus bridge's IO window.
1632 The default value is 256 bytes.
1633 cbmemsize=nn[KMG] The fixed amount of bus space which is
1634 reserved for the CardBus bridge's memory
1635 window. The default value is 64 megabytes.
1637 pcmv= [HW,PCMCIA] BadgePAD 4
1640 See Documentation/paride.txt.
1642 pdcchassis= [PARISC,HW] Disable/Enable PDC Chassis Status codes at
1645 See arch/parisc/kernel/pdc_chassis.c
1648 See Documentation/paride.txt.
1651 See Documentation/paride.txt.
1653 pirq= [SMP,APIC] Manual mp-table setup
1654 See Documentation/i386/IO-APIC.txt.
1656 plip= [PPT,NET] Parallel port network link
1657 Format: { parport<nr> | timid | 0 }
1658 See also Documentation/parport.txt.
1660 pmtmr= [X86] Manual setup of pmtmr I/O Port.
1661 Override pmtimer IOPort with a hex value.
1668 { on | off | curr | res | no-curr | no-res }
1671 [ISAPNP] Exclude IRQs for the autoconfiguration
1674 [ISAPNP] Exclude DMAs for the autoconfiguration
1676 pnp_reserve_io= [ISAPNP] Exclude I/O ports for the autoconfiguration
1677 Ranges are in pairs (I/O port base and size).
1680 [ISAPNP] Exclude memory regions for the
1682 Ranges are in pairs (memory base and size).
1684 print-fatal-signals=
1685 [KNL] debug: print fatal signals
1686 print-fatal-signals=1: print segfault info to
1690 printk.time= Show timing data prefixed to each printk message line
1691 Format: <bool> (1/Y/y=enable, 0/N/n=disable)
1693 profile= [KNL] Enable kernel profiling via /proc/profile
1694 Format: [schedule,]<number>
1695 Param: "schedule" - profile schedule points.
1696 Param: <number> - step/bucket size as a power of 2 for
1697 statistical time based profiling.
1698 Param: "sleep" - profile D-state sleeping (millisecs).
1699 Requires CONFIG_SCHEDSTATS
1700 Param: "kvm" - profile VM exits.
1702 processor.max_cstate= [HW,ACPI]
1703 Limit processor to maximum C-state
1704 max_cstate=9 overrides any DMI blacklist limit.
1706 processor.nocst [HW,ACPI]
1707 Ignore the _CST method to determine C-states,
1708 instead using the legacy FADT method
1710 prompt_ramdisk= [RAM] List of RAM disks to prompt for floppy disk
1712 See Documentation/ramdisk.txt.
1714 psmouse.proto= [HW,MOUSE] Highest PS2 mouse protocol extension to
1715 probe for; one of (bare|imps|exps|lifebook|any).
1716 psmouse.rate= [HW,MOUSE] Set desired mouse report rate, in reports
1718 psmouse.resetafter= [HW,MOUSE]
1719 Try to reset the device after so many bad packets
1722 [HW,MOUSE] Set desired mouse resolution, in dpi.
1723 psmouse.smartscroll=
1724 [HW,MOUSE] Controls Logitech smartscroll autorepeat.
1725 0 = disabled, 1 = enabled (default).
1727 pss= [HW,OSS] Personal Sound System (ECHO ESC614)
1729 <io>,<mss_io>,<mss_irq>,<mss_dma>,<mpu_io>,<mpu_irq>
1732 See Documentation/paride.txt.
1735 [KNL] Number of legacy pty's. Overwrites compiled-in
1738 quiet [KNL] Disable most log messages
1743 See Documentation/md.txt.
1745 ramdisk_blocksize= [RAM]
1746 See Documentation/ramdisk.txt.
1748 ramdisk_size= [RAM] Sizes of RAM disks in kilobytes
1749 See Documentation/ramdisk.txt.
1751 rcupdate.blimit= [KNL,BOOT]
1752 Set maximum number of finished RCU callbacks to process
1755 rcupdate.qhimark= [KNL,BOOT]
1756 Set threshold of queued
1757 RCU callbacks over which batch limiting is disabled.
1759 rcupdate.qlowmark= [KNL,BOOT]
1760 Set threshold of queued RCU callbacks below which
1761 batch limiting is re-enabled.
1765 Run specified binary instead of /init from the ramdisk,
1766 used for early userspace startup. See initrd.
1768 reboot= [BUGS=X86-32,BUGS=ARM,BUGS=IA-64] Rebooting mode
1769 Format: <reboot_mode>[,<reboot_mode2>[,...]]
1770 See arch/*/kernel/reboot.c or arch/*/kernel/process.c
1773 [KNL, SMP] Set scheduler's default relax_domain_level.
1774 See Documentation/cpusets.txt.
1776 reserve= [KNL,BUGS] Force the kernel to ignore some iomem area
1778 reservetop= [X86-32]
1780 Reserves a hole at the top of the kernel virtual
1783 reset_devices [KNL] Force drivers to reset the underlying device
1784 during initialization.
1787 Specify the partition device for software suspend
1789 resume_offset= [SWSUSP]
1790 Specify the offset from the beginning of the partition
1791 given by "resume=" at which the swap header is located,
1792 in <PAGE_SIZE> units (needed only for swap files).
1793 See Documentation/power/swsusp-and-swap-files.txt
1795 retain_initrd [RAM] Keep initrd memory after extraction
1797 rhash_entries= [KNL,NET]
1798 Set number of hash buckets for route cache
1800 riscom8= [HW,SERIAL]
1801 Format: <io_board1>[,<io_board2>[,...<io_boardN>]]
1803 ro [KNL] Mount root device read-only on boot
1805 root= [KNL] Root filesystem
1807 rootdelay= [KNL] Delay (in seconds) to pause before attempting to
1808 mount the root filesystem
1810 rootflags= [KNL] Set root filesystem mount option string
1812 rootfstype= [KNL] Set root filesystem type
1814 rootwait [KNL] Wait (indefinitely) for root device to show up.
1815 Useful for devices that are detected asynchronously
1816 (e.g. USB and MMC devices).
1818 root_plug.vendor_id=
1819 [ROOTPLUG] Override the default vendor ID
1821 root_plug.product_id=
1822 [ROOTPLUG] Override the default product ID
1825 [ROOTPLUG] Enable debugging output
1827 rw [KNL] Mount root device read-write on boot
1829 S [KNL] Run init in single mode
1832 See drivers/net/irda/sa1100_ir.c.
1834 sbni= [NET] Granch SBNI12 leased line adapter
1836 sc1200wdt= [HW,WDT] SC1200 WDT (watchdog) driver
1837 Format: <io>[,<timeout>[,<isapnp>]]
1839 scsi_debug_*= [SCSI]
1840 See drivers/scsi/scsi_debug.c.
1842 scsi_default_dev_flags=
1843 [SCSI] SCSI default device flags
1846 scsi_dev_flags= [SCSI] Black/white list entry for vendor and model
1847 Format: <vendor>:<model>:<flags>
1848 (flags are integer value)
1850 scsi_logging_level= [SCSI] a bit mask of logging levels
1851 See drivers/scsi/scsi_logging.h for bits. Also
1852 settable via sysctl at dev.scsi.logging_level
1853 (/proc/sys/dev/scsi/logging_level).
1854 There is also a nice 'scsi_logging_level' script in the
1855 S390-tools package, available for download at
1856 http://www-128.ibm.com/developerworks/linux/linux390/s390-tools-1.5.4.html
1858 scsi_mod.scan= [SCSI] sync (default) scans SCSI busses as they are
1859 discovered. async scans them in kernel threads,
1860 allowing boot to proceed. none ignores them, expecting
1861 user space to do the scan.
1863 selinux [SELINUX] Disable or enable SELinux at boot time.
1864 Format: { "0" | "1" }
1865 See security/selinux/Kconfig help text.
1868 Default value is set via kernel config option.
1869 If enabled at boot time, /selinux/disable can be used
1870 later to disable prior to initial policy load.
1872 selinux_compat_net =
1873 [SELINUX] Set initial selinux_compat_net flag value.
1874 Format: { "0" | "1" }
1875 0 -- use new secmark-based packet controls
1876 1 -- use legacy packet controls
1877 Default value is 0 (preferred).
1878 Value can be changed at runtime via
1879 /selinux/compat_net.
1881 serialnumber [BUGS=X86-32]
1884 Maximal number of shapers.
1887 See header of drivers/scsi/sim710.c.
1894 slub_debug[=options[,slabs]] [MM, SLUB]
1895 Enabling slub_debug allows one to determine the
1896 culprit if slab objects become corrupted. Enabling
1897 slub_debug can create guard zones around objects and
1898 may poison objects when not in use. Also tracks the
1899 last alloc / free. For more information see
1900 Documentation/vm/slub.txt.
1902 slub_max_order= [MM, SLUB]
1903 Determines the maximum allowed order for slabs.
1904 A high setting may cause OOMs due to memory
1905 fragmentation. For more information see
1906 Documentation/vm/slub.txt.
1908 slub_min_objects= [MM, SLUB]
1909 The minimum number of objects per slab. SLUB will
1910 increase the slab order up to slub_max_order to
1911 generate a sufficiently large slab able to contain
1912 the number of objects indicated. The higher the number
1913 of objects the smaller the overhead of tracking slabs
1914 and the less frequently locks need to be acquired.
1915 For more information see Documentation/vm/slub.txt.
1917 slub_min_order= [MM, SLUB]
1918 Determines the mininum page order for slabs. Must be
1919 lower than slub_max_order.
1920 For more information see Documentation/vm/slub.txt.
1922 slub_nomerge [MM, SLUB]
1923 Disable merging of slabs with similar size. May be
1924 necessary if there is some reason to distinguish
1925 allocs to different slabs. Debug options disable
1926 merging on their own.
1927 For more information see Documentation/vm/slub.txt.
1930 Format: <io1>[,<io2>[,...,<io8>]]
1932 smp-alt-once [X86-32,SMP] On a hotplug CPU system, only
1933 attempt to substitute SMP alternatives once at boot.
1935 smsc-ircc2.nopnp [HW] Don't use PNP to discover SMC devices
1936 smsc-ircc2.ircc_cfg= [HW] Device configuration I/O port
1937 smsc-ircc2.ircc_sir= [HW] SIR base I/O port
1938 smsc-ircc2.ircc_fir= [HW] FIR base I/O port
1939 smsc-ircc2.ircc_irq= [HW] IRQ line
1940 smsc-ircc2.ircc_dma= [HW] DMA channel
1941 smsc-ircc2.ircc_transceiver= [HW] Transceiver type:
1942 0: Toshiba Satellite 1800 (GP data pin select)
1943 1: Fast pin select (default)
1946 snd-ad1816a= [HW,ALSA]
1948 snd-ad1848= [HW,ALSA]
1950 snd-ali5451= [HW,ALSA]
1952 snd-als100= [HW,ALSA]
1954 snd-als4000= [HW,ALSA]
1956 snd-azt2320= [HW,ALSA]
1958 snd-cmi8330= [HW,ALSA]
1960 snd-cmipci= [HW,ALSA]
1962 snd-cs4231= [HW,ALSA]
1964 snd-cs4232= [HW,ALSA]
1966 snd-cs4236= [HW,ALSA]
1968 snd-cs4281= [HW,ALSA]
1970 snd-cs46xx= [HW,ALSA]
1972 snd-dt019x= [HW,ALSA]
1974 snd-dummy= [HW,ALSA]
1976 snd-emu10k1= [HW,ALSA]
1978 snd-ens1370= [HW,ALSA]
1980 snd-ens1371= [HW,ALSA]
1982 snd-es968= [HW,ALSA]
1984 snd-es1688= [HW,ALSA]
1986 snd-es18xx= [HW,ALSA]
1988 snd-es1938= [HW,ALSA]
1990 snd-es1968= [HW,ALSA]
1992 snd-fm801= [HW,ALSA]
1994 snd-gusclassic= [HW,ALSA]
1996 snd-gusextreme= [HW,ALSA]
1998 snd-gusmax= [HW,ALSA]
2002 snd-ice1712= [HW,ALSA]
2004 snd-intel8x0= [HW,ALSA]
2006 snd-interwave= [HW,ALSA]
2011 snd-korg1212= [HW,ALSA]
2013 snd-maestro3= [HW,ALSA]
2015 snd-mpu401= [HW,ALSA]
2017 snd-mtpav= [HW,ALSA]
2019 snd-nm256= [HW,ALSA]
2021 snd-opl3sa2= [HW,ALSA]
2029 snd-opti93x= [HW,ALSA]
2033 snd-rme32= [HW,ALSA]
2035 snd-rme96= [HW,ALSA]
2037 snd-rme9652= [HW,ALSA]
2043 snd-sbawe= [HW,ALSA]
2045 snd-serial= [HW,ALSA]
2047 snd-sgalaxy= [HW,ALSA]
2049 snd-sonicvibes= [HW,ALSA]
2054 snd-sun-cs4231= [HW,ALSA]
2056 snd-trident= [HW,ALSA]
2058 snd-usb-audio= [HW,ALSA,USB]
2060 snd-via82xx= [HW,ALSA]
2062 snd-virmidi= [HW,ALSA]
2064 snd-wavefront= [HW,ALSA]
2066 snd-ymfpci= [HW,ALSA]
2069 [KNL] Should the soft-lockup detector generate panics.
2071 sonypi.*= [HW] Sony Programmable I/O Control Device driver
2072 See Documentation/sonypi.txt
2074 specialix= [HW,SERIAL] Specialix multi-serial port adapter
2075 See Documentation/specialix.txt.
2077 spia_io_base= [HW,MTD]
2083 Format: <io>,<irq>,<dma>,<mpu_io>,<mpu_irq>
2085 st= [HW,SCSI] SCSI tape parameters (buffers, etc.)
2086 See Documentation/scsi/st.txt.
2090 Set the STI (builtin display/keyboard on the HP-PARISC
2091 machines) console (graphic card) which should be used
2092 as the initial boot-console.
2093 See also comment in drivers/video/console/sticore.c.
2096 See comment in drivers/video/console/sticore.c.
2099 Format: bpp:<bpp1>[:<bpp2>[:<bpp3>...]]
2103 Control how the NFS server code allocates CPUs to
2104 service thread pools. Depending on how many NICs
2105 you have and where their interrupts are bound, this
2106 option will affect which CPUs will do NFS serving.
2107 Note: this parameter cannot be changed while the
2108 NFS server is running.
2110 auto the server chooses an appropriate mode
2111 automatically using heuristics
2112 global a single global pool contains all CPUs
2113 percpu one pool for each CPU
2114 pernode one pool for each NUMA node (equivalent
2115 to global on non-NUMA machines)
2117 swiotlb= [IA-64] Number of I/O TLB slabs
2121 sym53c416= [HW,SCSI]
2122 See header of drivers/scsi/sym53c416.c.
2124 sysrq_always_enabled
2126 Ignore sysrq setting - this boot parameter will
2127 neutralize any effect of /proc/sys/kernel/sysrq.
2128 Useful for debugging.
2131 See header of drivers/scsi/t128.c.
2135 test_suspend= [SUSPEND]
2136 Specify "mem" (for Suspend-to-RAM) or "standby" (for
2137 standby suspend) as the system sleep state to briefly
2138 enter during system startup. The system is woken from
2139 this state using a wakeup-capable RTC alarm.
2141 thash_entries= [KNL,NET]
2142 Set number of hash buckets for TCP connection
2144 thermal.act= [HW,ACPI]
2145 -1: disable all active trip points in all thermal zones
2146 <degrees C>: override all lowest active trip points
2148 thermal.crt= [HW,ACPI]
2149 -1: disable all critical trip points in all thermal zones
2150 <degrees C>: lower all critical trip points
2152 thermal.nocrt= [HW,ACPI]
2153 Set to disable actions on ACPI thermal zone
2154 critical and hot trip points.
2156 thermal.off= [HW,ACPI]
2157 1: disable ACPI thermal control
2159 thermal.psv= [HW,ACPI]
2160 -1: disable all passive trip points
2161 <degrees C>: override all passive trip points to this value
2163 thermal.tzp= [HW,ACPI]
2164 Specify global default ACPI thermal zone polling rate
2165 <deci-seconds>: poll all this frequency
2166 0: no polling (default)
2169 See comment before function dc390_setup() in
2170 drivers/scsi/tmscsim.c.
2174 trix= [HW,OSS] MediaTrix AudioTrix Pro
2176 <io>,<irq>,<dma>,<dma2>,<sb_io>,<sb_irq>,<sb_dma>,<mpu_io>,<mpu_irq>
2178 turbografx.map[2|3]= [HW,JOY]
2179 TurboGraFX parallel port interface
2181 <port#>,<js1>,<js2>,<js3>,<js4>,<js5>,<js6>,<js7>
2182 See also Documentation/input/joystick-parport.txt
2184 u14-34f= [HW,SCSI] UltraStor 14F/34F SCSI host adapter
2185 See header of drivers/scsi/u14-34f.c.
2194 [USB] Ignore overcurrent events (default N).
2195 Some badly-designed motherboards generate lots of
2196 bogus events, for ports that aren't wired to
2197 anything. Set this parameter to avoid log spamming.
2198 Note that genuine overcurrent events won't be
2203 Set unknown_nmi_panic=1 early on boot.
2205 usbcore.autosuspend=
2206 [USB] The autosuspend time delay (in seconds) used
2207 for newly-detected USB devices (default 2). This
2208 is the time required before an idle device will be
2209 autosuspended. Devices for which the delay is set
2210 to a negative value won't be autosuspended at all.
2213 [USBHID] The interval which mice are to be polled at.
2215 add_efi_memmap [EFI; x86-32,X86-64] Include EFI memory map in
2216 kernel's map of available physical RAM.
2218 vdso= [X86-32,SH,x86-64]
2219 vdso=2: enable compat VDSO (default with COMPAT_VDSO)
2220 vdso=1: enable VDSO (default)
2221 vdso=0: disable VDSO mapping
2223 vdso32= [X86-32,X86-64]
2224 vdso32=2: enable compat VDSO (default with COMPAT_VDSO)
2225 vdso32=1: enable 32-bit VDSO (default)
2226 vdso32=0: disable 32-bit VDSO mapping
2229 vector=percpu: enable percpu vector domain
2231 video= [FB] Frame buffer configuration
2232 See Documentation/fb/modedb.txt.
2234 vga= [BOOT,X86-32] Select a particular video mode
2235 See Documentation/i386/boot.txt and
2236 Documentation/svga.txt.
2237 Use vga=ask for menu.
2238 This is actually a boot loader parameter; the value is
2239 passed to the kernel using a special protocol.
2241 vmalloc=nn[KMG] [KNL,BOOT] Forces the vmalloc area to have an exact
2242 size of <nn>. This can be used to increase the
2243 minimum size (128MB on x86). It can also be used to
2244 decrease the size and leave more room for directly
2247 vmhalt= [KNL,S390] Perform z/VM CP command after system halt.
2250 vmpanic= [KNL,S390] Perform z/VM CP command after kernel panic.
2253 vmpoff= [KNL,S390] Perform z/VM CP command after power off.
2256 waveartist= [HW,OSS]
2257 Format: <io>,<irq>,<dma>,<dma2>
2260 See header of drivers/scsi/wd33c93.c.
2263 See header of drivers/scsi/wd7000.c.
2266 See Documentation/watchdog/wdt.txt.
2268 xd= [HW,XT] Original XT pre-IDE (RLL encoded) disks.
2269 xd_geo= See header of drivers/block/xd.c.
2271 xirc2ps_cs= [NET,PCMCIA]
2273 <irq>,<irq_mask>,<io>,<full_duplex>,<do_sound>,<lockup_hack>[,<irq2>[,<irq3>[,<irq4>]]]
2275 norandmaps Don't use address space randomization
2276 Equivalent to echo 0 > /proc/sys/kernel/randomize_va_space
2278 ______________________________________________________________________
2282 Add documentation for ALSA options.
2283 Add more DRM drivers.
projects / linux-2.6 / blob