| blob | b2361667839fd8850c385d1ba0a1f5cea1878751 |
1 Kernel Parameters
2 ~~~~~~~~~~~~~~~~~
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 AX25 Appropriate AX.25 support is enabled.
38 BLACKFIN Blackfin architecture is enabled.
39 DRM Direct Rendering Management support is enabled.
40 EDD BIOS Enhanced Disk Drive Services (EDD) is enabled
41 EFI EFI Partitioning (GPT) is enabled
42 EIDE EIDE/ATAPI support is enabled.
43 FB The frame buffer device is enabled.
44 HW Appropriate hardware is enabled.
45 IA-64 IA-64 architecture is enabled.
46 IOSCHED More than one I/O scheduler is enabled.
47 IP_PNP IP DHCP, BOOTP, or RARP is enabled.
48 ISAPNP ISA PnP code is enabled.
49 ISDN Appropriate ISDN support is enabled.
50 JOY Appropriate joystick support is enabled.
51 LIBATA Libata driver is enabled
52 LP Printer support is enabled.
53 LOOP Loopback device support is enabled.
54 M68k M68k architecture is enabled.
55 These options have more detailed description inside of
56 Documentation/m68k/kernel-options.txt.
57 MCA MCA bus support is enabled.
58 MDA MDA console support is enabled.
59 MOUSE Appropriate mouse support is enabled.
60 MSI Message Signaled Interrupts (PCI).
61 MTD MTD (Memory Technology Device) support is enabled.
62 NET Appropriate network support is enabled.
63 NUMA NUMA support is enabled.
64 GENERIC_TIME The generic timeofday code is enabled.
65 NFS Appropriate NFS support is enabled.
66 OSS OSS sound support is enabled.
67 PV_OPS A paravirtualized kernel is enabled.
68 PARIDE The ParIDE (parallel port IDE) subsystem is enabled.
69 PARISC The PA-RISC architecture is enabled.
70 PCI PCI bus support is enabled.
71 PCIE PCI Express support is enabled.
72 PCMCIA The PCMCIA subsystem is enabled.
73 PNP Plug & Play support is enabled.
74 PPC PowerPC architecture is enabled.
75 PPT Parallel port support is enabled.
76 PS2 Appropriate PS/2 support is enabled.
77 RAM RAM disk support is enabled.
78 ROOTPLUG The example Root Plug LSM is enabled.
79 S390 S390 architecture is enabled.
80 SCSI Appropriate SCSI support is enabled.
81 A lot of drivers has their options described inside of
82 Documentation/scsi/.
83 SECURITY Different security models are enabled.
84 SELINUX SELinux support is enabled.
85 SERIAL Serial support is enabled.
86 SH SuperH architecture is enabled.
87 SMP The kernel is an SMP kernel.
88 SPARC Sparc architecture is enabled.
89 SWSUSP Software suspend is enabled.
90 TS Appropriate touchscreen support is enabled.
91 USB USB support is enabled.
92 USBHID USB Human Interface Device support is enabled.
93 V4L Video For Linux support is enabled.
94 VGA The VGA console has been enabled.
95 VT Virtual terminal support is enabled.
96 WDT Watchdog support is enabled.
97 XT IBM PC/XT MFM hard disk support is enabled.
98 X86-32 X86-32, aka i386 architecture is enabled.
99 X86-64 X86-64 architecture is enabled.
100 More X86-64 boot options can be found in
101 Documentation/x86_64/boot-options.txt .
103 In addition, the following text indicates that the option:
105 BUGS= Relates to possible processor bugs on the said processor.
106 KNL Is a kernel start-up parameter.
107 BOOT Is a boot loader parameter.
109 Parameters denoted with BOOT are actually interpreted by the boot
110 loader, and have no meaning to the kernel directly.
111 Do not modify the syntax of boot loader parameters without extreme
112 need or coordination with <Documentation/i386/boot.txt>.
114 There are also arch-specific kernel-parameters not documented here.
115 See for example <Documentation/x86_64/boot-options.txt>.
117 Note that ALL kernel parameters listed below are CASE SENSITIVE, and that
118 a trailing = on the name of any parameter states that that parameter will
119 be entered as an environment variable, whereas its absence indicates that
120 it will appear as a kernel argument readable via /proc/cmdline by programs
121 running once the system is up.
123 The number of kernel parameters is not limited, but the length of the
124 complete command line (parameters including spaces etc.) is limited to
125 a fixed number of characters. This limit depends on the architecture
126 and is between 256 and 4096 characters. It is defined in the file
127 ./include/asm/setup.h as COMMAND_LINE_SIZE.
130 acpi= [HW,ACPI,X86-64,i386]
131 Advanced Configuration and Power Interface
132 Format: { force | off | ht | strict | noirq }
133 force -- enable ACPI if default was off
134 off -- disable ACPI if default was on
135 noirq -- do not use ACPI for IRQ routing
136 ht -- run only enough ACPI to enable Hyper Threading
137 strict -- Be less tolerant of platforms that are not
138 strictly ACPI specification compliant.
140 See also Documentation/pm.txt, pci=noacpi
142 acpi_apic_instance= [ACPI, IOAPIC]
143 Format: <int>
144 2: use 2nd APIC table, if available
145 1,0: use 1st APIC table
146 default: 0
148 acpi_sleep= [HW,ACPI] Sleep options
149 Format: { s3_bios, s3_mode }
150 See Documentation/power/video.txt
152 acpi_sci= [HW,ACPI] ACPI System Control Interrupt trigger mode
153 Format: { level | edge | high | low }
155 acpi_irq_balance [HW,ACPI]
156 ACPI will balance active IRQs
157 default in APIC mode
159 acpi_irq_nobalance [HW,ACPI]
160 ACPI will not move active IRQs (default)
161 default in PIC mode
163 acpi_irq_pci= [HW,ACPI] If irq_balance, clear listed IRQs for
164 use by PCI
165 Format: <irq>,<irq>...
167 acpi_irq_isa= [HW,ACPI] If irq_balance, mark listed IRQs used by ISA
168 Format: <irq>,<irq>...
170 acpi_no_auto_ssdt [HW,ACPI] Disable automatic loading of SSDT
172 acpi_os_name= [HW,ACPI] Tell ACPI BIOS the name of the OS
173 Format: To spoof as Windows 98: ="Microsoft Windows"
175 acpi_osi= [HW,ACPI] Modify list of supported OS interface strings
176 acpi_osi="string1" # add string1 -- only one string
177 acpi_osi="!string2" # remove built-in string2
178 acpi_osi= # disable all strings
180 acpi_serialize [HW,ACPI] force serialization of AML methods
182 acpi_skip_timer_override [HW,ACPI]
183 Recognize and ignore IRQ0/pin2 Interrupt Override.
184 For broken nForce2 BIOS resulting in XT-PIC timer.
185 acpi_use_timer_override [HW,ACPI}
186 Use timer override. For some broken Nvidia NF5 boards
187 that require a timer override, but don't have
188 HPET
190 acpi.debug_layer= [HW,ACPI]
191 Format: <int>
192 Each bit of the <int> indicates an ACPI debug layer,
193 1: enable, 0: disable. It is useful for boot time
194 debugging. After system has booted up, it can be set
195 via /sys/module/acpi/parameters/debug_layer.
196 CONFIG_ACPI_DEBUG must be enabled for this to produce any output.
197 Available bits (add the numbers together) to enable debug output
198 for specific parts of the ACPI subsystem:
199 0x01 utilities 0x02 hardware 0x04 events 0x08 tables
200 0x10 namespace 0x20 parser 0x40 dispatcher
201 0x80 executer 0x100 resources 0x200 acpica debugger
202 0x400 os services 0x800 acpica disassembler.
203 The number can be in decimal or prefixed with 0x in hex.
204 Warning: Many of these options can produce a lot of
205 output and make your system unusable. Be very careful.
207 acpi.debug_level= [HW,ACPI]
208 Format: <int>
209 Each bit of the <int> indicates an ACPI debug level,
210 1: enable, 0: disable. It is useful for boot time
211 debugging. After system has booted up, it can be set
212 via /sys/module/acpi/parameters/debug_level.
213 CONFIG_ACPI_DEBUG must be enabled for this to produce any output.
214 Available bits (add the numbers together) to enable different
215 debug output levels of the ACPI subsystem:
216 0x01 error 0x02 warn 0x04 init 0x08 debug object
217 0x10 info 0x20 init names 0x40 parse 0x80 load
218 0x100 dispatch 0x200 execute 0x400 names 0x800 operation region
219 0x1000 bfield 0x2000 tables 0x4000 values 0x8000 objects
220 0x10000 resources 0x20000 user requests 0x40000 package.
221 The number can be in decimal or prefixed with 0x in hex.
222 Warning: Many of these options can produce a lot of
223 output and make your system unusable. Be very careful.
225 acpi_pm_good [X86-32,X86-64]
226 Override the pmtimer bug detection: force the kernel
227 to assume that this machine's pmtimer latches its value
228 and always returns good values.
230 agp= [AGP]
231 { off | try_unsupported }
232 off: disable AGP support
233 try_unsupported: try to drive unsupported chipsets
234 (may crash computer or cause data corruption)
236 enable_timer_pin_1 [i386,x86-64]
237 Enable PIN 1 of APIC timer
238 Can be useful to work around chipset bugs
239 (in particular on some ATI chipsets).
240 The kernel tries to set a reasonable default.
242 disable_timer_pin_1 [i386,x86-64]
243 Disable PIN 1 of APIC timer
244 Can be useful to work around chipset bugs.
246 ad1848= [HW,OSS]
247 Format: <io>,<irq>,<dma>,<dma2>,<type>
249 advansys= [HW,SCSI]
250 See header of drivers/scsi/advansys.c.
252 advwdt= [HW,WDT] Advantech WDT
253 Format: <iostart>,<iostop>
255 aedsp16= [HW,OSS] Audio Excel DSP 16
256 Format: <io>,<irq>,<dma>,<mss_io>,<mpu_io>,<mpu_irq>
257 See also header of sound/oss/aedsp16.c.
259 aha152x= [HW,SCSI]
260 See Documentation/scsi/aha152x.txt.
262 aha1542= [HW,SCSI]
263 Format: <portbase>[,<buson>,<busoff>[,<dmaspeed>]]
265 aic7xxx= [HW,SCSI]
266 See Documentation/scsi/aic7xxx.txt.
268 aic79xx= [HW,SCSI]
269 See Documentation/scsi/aic79xx.txt.
271 amijoy.map= [HW,JOY] Amiga joystick support
272 Map of devices attached to JOY0DAT and JOY1DAT
273 Format: <a>,<b>
274 See also Documentation/kernel/input/joystick.txt
276 analog.map= [HW,JOY] Analog joystick and gamepad support
277 Specifies type or capabilities of an analog joystick
278 connected to one of 16 gameports
279 Format: <type1>,<type2>,..<type16>
281 apc= [HW,SPARC]
282 Power management functions (SPARCstation-4/5 + deriv.)
283 Format: noidle
284 Disable APC CPU standby support. SPARCstation-Fox does
285 not play well with APC CPU idle - disable it if you have
286 APC and your system crashes randomly.
288 apic= [APIC,i386] Advanced Programmable Interrupt Controller
289 Change the output verbosity whilst booting
290 Format: { quiet (default) | verbose | debug }
291 Change the amount of debugging information output
292 when initialising the APIC and IO-APIC components.
294 apm= [APM] Advanced Power Management
295 See header of arch/i386/kernel/apm.c.
297 arcrimi= [HW,NET] ARCnet - "RIM I" (entirely mem-mapped) cards
298 Format: <io>,<irq>,<nodeID>
300 ataflop= [HW,M68k]
302 atarimouse= [HW,MOUSE] Atari Mouse
304 atascsi= [HW,SCSI] Atari SCSI
306 atkbd.extra= [HW] Enable extra LEDs and keys on IBM RapidAccess,
307 EzKey and similar keyboards
309 atkbd.reset= [HW] Reset keyboard during initialization
311 atkbd.set= [HW] Select keyboard code set
312 Format: <int> (2 = AT (default), 3 = PS/2)
314 atkbd.scroll= [HW] Enable scroll wheel on MS Office and similar
315 keyboards
317 atkbd.softraw= [HW] Choose between synthetic and real raw mode
318 Format: <bool> (0 = real, 1 = synthetic (default))
320 atkbd.softrepeat= [HW]
321 Use software keyboard repeat
323 autotest [IA64]
325 baycom_epp= [HW,AX25]
326 Format: <io>,<mode>
328 baycom_par= [HW,AX25] BayCom Parallel Port AX.25 Modem
329 Format: <io>,<mode>
330 See header of drivers/net/hamradio/baycom_par.c.
332 baycom_ser_fdx= [HW,AX25]
333 BayCom Serial Port AX.25 Modem (Full Duplex Mode)
334 Format: <io>,<irq>,<mode>[,<baud>]
335 See header of drivers/net/hamradio/baycom_ser_fdx.c.
337 baycom_ser_hdx= [HW,AX25]
338 BayCom Serial Port AX.25 Modem (Half Duplex Mode)
339 Format: <io>,<irq>,<mode>
340 See header of drivers/net/hamradio/baycom_ser_hdx.c.
342 boot_delay= Milliseconds to delay each printk during boot.
343 Values larger than 10 seconds (10000) are changed to
344 no delay (0).
345 Format: integer
347 bttv.card= [HW,V4L] bttv (bt848 + bt878 based grabber cards)
348 bttv.radio= Most important insmod options are available as
349 kernel args too.
350 bttv.pll= See Documentation/video4linux/bttv/Insmod-options
351 bttv.tuner= and Documentation/video4linux/bttv/CARDLIST
353 BusLogic= [HW,SCSI]
354 See drivers/scsi/BusLogic.c, comment before function
355 BusLogic_ParseDriverOptions().
357 c101= [NET] Moxa C101 synchronous serial card
359 cachesize= [BUGS=X86-32] Override level 2 CPU cache size detection.
360 Sometimes CPU hardware bugs make them report the cache
361 size incorrectly. The kernel will attempt work arounds
362 to fix known problems, but for some CPUs it is not
363 possible to determine what the correct size should be.
364 This option provides an override for these situations.
366 capability.disable=
367 [SECURITY] Disable capabilities. This would normally
368 be used only if an alternative security model is to be
369 configured. Potentially dangerous and should only be
370 used if you are entirely sure of the consequences.
372 chandev= [HW,NET] Generic channel device initialisation
374 checkreqprot [SELINUX] Set initial checkreqprot flag value.
375 Format: { "0" | "1" }
376 See security/selinux/Kconfig help text.
377 0 -- check protection applied by kernel (includes
378 any implied execute protection).
379 1 -- check protection requested by application.
380 Default value is set via a kernel config option.
381 Value can be changed at runtime via
382 /selinux/checkreqprot.
384 clock= [BUGS=X86-32, HW] gettimeofday clocksource override.
385 [Deprecated]
386 Forces specified clocksource (if available) to be used
387 when calculating gettimeofday(). If specified
388 clocksource is not available, it defaults to PIT.
389 Format: { pit | tsc | cyclone | pmtmr }
391 clocksource= [GENERIC_TIME] Override the default clocksource
392 Format: <string>
393 Override the default clocksource and use the clocksource
394 with the name specified.
395 Some clocksource names to choose from, depending on
396 the platform:
397 [all] jiffies (this is the base, fallback clocksource)
398 [ACPI] acpi_pm
399 [ARM] imx_timer1,OSTS,netx_timer,mpu_timer2,
400 pxa_timer,timer3,32k_counter,timer0_1
401 [AVR32] avr32
402 [X86-32] pit,hpet,tsc,vmi-timer;
403 scx200_hrt on Geode; cyclone on IBM x440
404 [MIPS] MIPS
405 [PARISC] cr16
406 [S390] tod
407 [SH] SuperH
408 [SPARC64] tick
409 [X86-64] hpet,tsc
411 code_bytes [IA32] How many bytes of object code to print in an
412 oops report.
413 Range: 0 - 8192
414 Default: 64
416 disable_8254_timer
417 enable_8254_timer
418 [IA32/X86_64] Disable/Enable interrupt 0 timer routing
419 over the 8254 in addition to over the IO-APIC. The
420 kernel tries to set a sensible default.
422 hpet= [X86-32,HPET] option to control HPET usage
423 Format: { enable (default) | disable | force }
424 disable: disable HPET and use PIT instead
425 force: allow force enabled of undocumented chips (ICH4, VIA)
427 com20020= [HW,NET] ARCnet - COM20020 chipset
428 Format:
429 <io>[,<irq>[,<nodeID>[,<backplane>[,<ckp>[,<timeout>]]]]]
431 com90io= [HW,NET] ARCnet - COM90xx chipset (IO-mapped buffers)
432 Format: <io>[,<irq>]
434 com90xx= [HW,NET]
435 ARCnet - COM90xx chipset (memory-mapped buffers)
436 Format: <io>[,<irq>[,<memstart>]]
438 condev= [HW,S390] console device
439 conmode=
441 console= [KNL] Output console device and options.
443 tty<n> Use the virtual console device <n>.
445 ttyS<n>[,options]
446 ttyUSB0[,options]
447 Use the specified serial port. The options are of
448 the form "bbbbpnf", where "bbbb" is the baud rate,
449 "p" is parity ("n", "o", or "e"), "n" is number of
450 bits, and "f" is flow control ("r" for RTS or
451 omit it). Default is "9600n8".
453 See Documentation/serial-console.txt for more
454 information. See
455 Documentation/networking/netconsole.txt for an
456 alternative.
458 uart[8250],io,<addr>[,options]
459 uart[8250],mmio,<addr>[,options]
460 Start an early, polled-mode console on the 8250/16550
461 UART at the specified I/O port or MMIO address,
462 switching to the matching ttyS device later. The
463 options are the same as for ttyS, above.
465 earlycon= [KNL] Output early console device and options.
466 uart[8250],io,<addr>[,options]
467 uart[8250],mmio,<addr>[,options]
468 Start an early, polled-mode console on the 8250/16550
469 UART at the specified I/O port or MMIO address.
470 The options are the same as for ttyS, above.
472 no_console_suspend
473 [HW] Never suspend the console
474 Disable suspending of consoles during suspend and
475 hibernate operations. Once disabled, debugging
476 messages can reach various consoles while the rest
477 of the system is being put to sleep (ie, while
478 debugging driver suspend/resume hooks). This may
479 not work reliably with all consoles, but is known
480 to work with serial and VGA consoles.
482 cpcihp_generic= [HW,PCI] Generic port I/O CompactPCI driver
483 Format:
484 <first_slot>,<last_slot>,<port>,<enum_bit>[,<debug>]
486 crashkernel=nn[KMG]@ss[KMG]
487 [KNL] Reserve a chunk of physical memory to
488 hold a kernel to switch to with kexec on panic.
490 crashkernel=range1:size1[,range2:size2,...][@offset]
491 [KNL] Same as above, but depends on the memory
492 in the running system. The syntax of range is
493 start-[end] where start and end are both
494 a memory unit (amount[KMG]). See also
495 Documentation/kdump/kdump.txt for a example.
497 cs4232= [HW,OSS]
498 Format: <io>,<irq>,<dma>,<dma2>,<mpuio>,<mpuirq>
500 cs89x0_dma= [HW,NET]
501 Format: <dma>
503 cs89x0_media= [HW,NET]
504 Format: { rj45 | aui | bnc }
506 dasd= [HW,NET]
507 See header of drivers/s390/block/dasd_devmap.c.
509 db9.dev[2|3]= [HW,JOY] Multisystem joystick support via parallel port
510 (one device per port)
511 Format: <port#>,<type>
512 See also Documentation/input/joystick-parport.txt
514 debug [KNL] Enable kernel debugging (events log level).
516 debug_locks_verbose=
517 [KNL] verbose self-tests
518 Format=<0|1>
519 Print debugging info while doing the locking API
520 self-tests.
521 We default to 0 (no extra messages), setting it to
522 1 will print _a lot_ more information - normally
523 only useful to kernel developers.
525 decnet= [HW,NET]
526 Format: <area>[,<node>]
527 See also Documentation/networking/decnet.txt.
529 default_blu= [VT]
530 Format: <blue0>,<blue1>,<blue2>,...,<blue15>
531 Change the default blue palette of the console.
532 This is a 16-member array composed of values
533 ranging from 0-255.
535 default_grn= [VT]
536 Format: <green0>,<green1>,<green2>,...,<green15>
537 Change the default green palette of the console.
538 This is a 16-member array composed of values
539 ranging from 0-255.
541 default_red= [VT]
542 Format: <red0>,<red1>,<red2>,...,<red15>
543 Change the default red palette of the console.
544 This is a 16-member array composed of values
545 ranging from 0-255.
547 default_utf8= [VT]
548 Format=<0|1>
549 Set system-wide default UTF-8 mode for all tty's.
550 Default is 0 and by setting to 1, it enables UTF-8
551 mode for all newly opened or allocated terminals.
553 dhash_entries= [KNL]
554 Set number of hash buckets for dentry cache.
556 digi= [HW,SERIAL]
557 IO parameters + enable/disable command.
559 digiepca= [HW,SERIAL]
560 See drivers/char/README.epca and
561 Documentation/digiepca.txt.
563 dmasound= [HW,OSS] Sound subsystem buffers
565 dscc4.setup= [NET]
567 dtc3181e= [HW,SCSI]
569 earlyprintk= [X86-32,X86-64,SH,BLACKFIN]
570 earlyprintk=vga
571 earlyprintk=serial[,ttySn[,baudrate]]
573 Append ",keep" to not disable it when the real console
574 takes over.
576 Only vga or serial at a time, not both.
578 Currently only ttyS0 and ttyS1 are supported.
580 Interaction with the standard serial driver is not
581 very good.
583 The VGA output is eventually overwritten by the real
584 console.
586 eata= [HW,SCSI]
588 ec_intr= [HW,ACPI] ACPI Embedded Controller interrupt mode
589 Format: <int>
590 0: polling mode
591 non-0: interrupt mode (default)
593 edd= [EDD]
594 Format: {"of[f]" | "sk[ipmbr]"}
595 See comment in arch/i386/boot/edd.S
597 eisa_irq_edge= [PARISC,HW]
598 See header of drivers/parisc/eisa.c.
600 elanfreq= [X86-32]
601 See comment before function elanfreq_setup() in
602 arch/i386/kernel/cpu/cpufreq/elanfreq.c.
604 elevator= [IOSCHED]
605 Format: {"anticipatory" | "cfq" | "deadline" | "noop"}
606 See Documentation/block/as-iosched.txt and
607 Documentation/block/deadline-iosched.txt for details.
609 elfcorehdr= [X86-32, X86_64]
610 Specifies physical address of start of kernel core
611 image elf header. Generally kexec loader will
612 pass this option to capture kernel.
613 See Documentation/kdump/kdump.txt for details.
615 enforcing [SELINUX] Set initial enforcing status.
616 Format: {"0" | "1"}
617 See security/selinux/Kconfig help text.
618 0 -- permissive (log only, no denials).
619 1 -- enforcing (deny and log).
620 Default value is 0.
621 Value can be changed at runtime via /selinux/enforce.
623 es1371= [HW,OSS]
624 Format: <spdif>,[<nomix>,[<amplifier>]]
625 See also header of sound/oss/es1371.c.
627 ether= [HW,NET] Ethernet cards parameters
628 This option is obsoleted by the "netdev=" option, which
629 has equivalent usage. See its documentation for details.
631 eurwdt= [HW,WDT] Eurotech CPU-1220/1410 onboard watchdog.
632 Format: <io>[,<irq>]
634 failslab=
635 fail_page_alloc=
636 fail_make_request=[KNL]
637 General fault injection mechanism.
638 Format: <interval>,<probability>,<space>,<times>
639 See also /Documentation/fault-injection/.
641 fd_mcs= [HW,SCSI]
642 See header of drivers/scsi/fd_mcs.c.
644 fdomain= [HW,SCSI]
645 See header of drivers/scsi/fdomain.c.
647 floppy= [HW]
648 See Documentation/floppy.txt.
650 gamecon.map[2|3]=
651 [HW,JOY] Multisystem joystick and NES/SNES/PSX pad
652 support via parallel port (up to 5 devices per port)
653 Format: <port#>,<pad1>,<pad2>,<pad3>,<pad4>,<pad5>
654 See also Documentation/input/joystick-parport.txt
656 gamma= [HW,DRM]
658 gdth= [HW,SCSI]
659 See header of drivers/scsi/gdth.c.
661 gpt [EFI] Forces disk with valid GPT signature but
662 invalid Protective MBR to be treated as GPT.
664 gvp11= [HW,SCSI]
666 hashdist= [KNL,NUMA] Large hashes allocated during boot
667 are distributed across NUMA nodes. Defaults on
668 for IA-64, off otherwise.
669 Format: 0 | 1 (for off | on)
671 hcl= [IA-64] SGI's Hardware Graph compatibility layer
673 hd= [EIDE] (E)IDE hard drive subsystem geometry
674 Format: <cyl>,<head>,<sect>
676 hd?= [HW] (E)IDE subsystem
677 hd?lun= See Documentation/ide.txt.
679 highmem=nn[KMG] [KNL,BOOT] forces the highmem zone to have an exact
680 size of <nn>. This works even on boxes that have no
681 highmem otherwise. This also works to reduce highmem
682 size on bigger boxes.
684 highres= [KNL] Enable/disable high resolution timer mode.
685 Valid parameters: "on", "off"
686 Default: "on"
688 hisax= [HW,ISDN]
689 See Documentation/isdn/README.HiSax.
691 hugepages= [HW,X86-32,IA-64] Maximal number of HugeTLB pages.
693 i8042.direct [HW] Put keyboard port into non-translated mode
694 i8042.dumbkbd [HW] Pretend that controller can only read data from
695 keyboard and cannot control its state
696 (Don't attempt to blink the leds)
697 i8042.noaux [HW] Don't check for auxiliary (== mouse) port
698 i8042.nokbd [HW] Don't check/create keyboard port
699 i8042.nomux [HW] Don't check presence of an active multiplexing
700 controller
701 i8042.nopnp [HW] Don't use ACPIPnP / PnPBIOS to discover KBD/AUX
702 controllers
703 i8042.panicblink=
704 [HW] Frequency with which keyboard LEDs should blink
705 when kernel panics (default is 0.5 sec)
706 i8042.reset [HW] Reset the controller during init and cleanup
707 i8042.unlock [HW] Unlock (ignore) the keylock
709 i810= [HW,DRM]
711 i8k.ignore_dmi [HW] Continue probing hardware even if DMI data
712 indicates that the driver is running on unsupported
713 hardware.
714 i8k.force [HW] Activate i8k driver even if SMM BIOS signature
715 does not match list of supported models.
716 i8k.power_status
717 [HW] Report power status in /proc/i8k
718 (disabled by default)
719 i8k.restricted [HW] Allow controlling fans only if SYS_ADMIN
720 capability is set.
722 ibmmcascsi= [HW,MCA,SCSI] IBM MicroChannel SCSI adapter
723 See Documentation/mca.txt.
725 icn= [HW,ISDN]
726 Format: <io>[,<membase>[,<icn_id>[,<icn_id2>]]]
728 ide= [HW] (E)IDE subsystem
729 Format: ide=nodma or ide=doubler or ide=reverse
730 See Documentation/ide.txt.
732 ide?= [HW] (E)IDE subsystem
733 Format: ide?=noprobe or chipset specific parameters.
734 See Documentation/ide.txt.
736 idebus= [HW] (E)IDE subsystem - VLB/PCI bus speed
737 See Documentation/ide.txt.
739 idle= [X86]
740 Format: idle=poll or idle=mwait
741 Poll forces a polling idle loop that can slightly improves the performance
742 of waking up a idle CPU, but will use a lot of power and make the system
743 run hot. Not recommended.
744 idle=mwait. On systems which support MONITOR/MWAIT but the kernel chose
745 to not use it because it doesn't save as much power as a normal idle
746 loop use the MONITOR/MWAIT idle loop anyways. Performance should be the same
747 as idle=poll.
749 ignore_loglevel [KNL]
750 Ignore loglevel setting - this will print /all/
751 kernel messages to the console. Useful for debugging.
753 ihash_entries= [KNL]
754 Set number of hash buckets for inode cache.
756 in2000= [HW,SCSI]
757 See header of drivers/scsi/in2000.c.
759 init= [KNL]
760 Format: <full_path>
761 Run specified binary instead of /sbin/init as init
762 process.
764 initcall_debug [KNL] Trace initcalls as they are executed. Useful
765 for working out where the kernel is dying during
766 startup.
768 initrd= [BOOT] Specify the location of the initial ramdisk
770 inport.irq= [HW] Inport (ATI XL and Microsoft) busmouse driver
771 Format: <irq>
773 inttest= [IA64]
775 intel_iommu= [DMAR] Intel IOMMU driver (DMAR) option
776 off
777 Disable intel iommu driver.
778 igfx_off [Default Off]
779 By default, gfx is mapped as normal device. If a gfx
780 device has a dedicated DMAR unit, the DMAR unit is
781 bypassed by not enabling DMAR with this option. In
782 this case, gfx device will use physical address for
783 DMA.
784 forcedac [x86_64]
785 With this option iommu will not optimize to look
786 for io virtual address below 32 bit forcing dual
787 address cycle on pci bus for cards supporting greater
788 than 32 bit addressing. The default is to look
789 for translation below 32 bit and if not available
790 then look in the higher range.
792 io7= [HW] IO7 for Marvel based alpha systems
793 See comment before marvel_specify_io7 in
794 arch/alpha/kernel/core_marvel.c.
796 ip= [IP_PNP]
797 See Documentation/nfsroot.txt.
799 ip2= [HW] Set IO/IRQ pairs for up to 4 IntelliPort boards
800 See comment before ip2_setup() in
801 drivers/char/ip2/ip2base.c.
803 ips= [HW,SCSI] Adaptec / IBM ServeRAID controller
804 See header of drivers/scsi/ips.c.
806 ports= [IP_VS_FTP] IPVS ftp helper module
807 Default is 21.
808 Up to 8 (IP_VS_APP_MAX_PORTS) ports
809 may be specified.
810 Format: <port>,<port>....
812 irqfixup [HW]
813 When an interrupt is not handled search all handlers
814 for it. Intended to get systems with badly broken
815 firmware running.
817 irqpoll [HW]
818 When an interrupt is not handled search all handlers
819 for it. Also check all handlers each timer
820 interrupt. Intended to get systems with badly broken
821 firmware running.
823 isapnp= [ISAPNP]
824 Format: <RDP>,<reset>,<pci_scan>,<verbosity>
826 isolcpus= [KNL,SMP] Isolate CPUs from the general scheduler.
827 Format:
828 <cpu number>,...,<cpu number>
829 or
830 <cpu number>-<cpu number> (must be a positive range in ascending order)
831 or a mixture
832 <cpu number>,...,<cpu number>-<cpu number>
833 This option can be used to specify one or more CPUs
834 to isolate from the general SMP balancing and scheduling
835 algorithms. The only way to move a process onto or off
836 an "isolated" CPU is via the CPU affinity syscalls.
837 <cpu number> begins at 0 and the maximum value is
838 "number of CPUs in system - 1".
840 This option is the preferred way to isolate CPUs. The
841 alternative -- manually setting the CPU mask of all
842 tasks in the system -- can cause problems and
843 suboptimal load balancer performance.
845 iucv= [HW,NET]
847 js= [HW,JOY] Analog joystick
848 See Documentation/input/joystick.txt.
850 kernelcore=nn[KMG] [KNL,X86-32,IA-64,PPC,X86-64] This parameter
851 specifies the amount of memory usable by the kernel
852 for non-movable allocations. The requested amount is
853 spread evenly throughout all nodes in the system. The
854 remaining memory in each node is used for Movable
855 pages. In the event, a node is too small to have both
856 kernelcore and Movable pages, kernelcore pages will
857 take priority and other nodes will have a larger number
858 of kernelcore pages. The Movable zone is used for the
859 allocation of pages that may be reclaimed or moved
860 by the page migration subsystem. This means that
861 HugeTLB pages may not be allocated from this zone.
862 Note that allocations like PTEs-from-HighMem still
863 use the HighMem zone if it exists, and the Normal
864 zone if it does not.
866 movablecore=nn[KMG] [KNL,X86-32,IA-64,PPC,X86-64] This parameter
867 is similar to kernelcore except it specifies the
868 amount of memory used for migratable allocations.
869 If both kernelcore and movablecore is specified,
870 then kernelcore will be at *least* the specified
871 value but may be more. If movablecore on its own
872 is specified, the administrator must be careful
873 that the amount of memory usable for all allocations
874 is not too small.
876 keepinitrd [HW,ARM]
878 kstack=N [X86-32,X86-64] Print N words from the kernel stack
879 in oops dumps.
881 l2cr= [PPC]
883 lapic [X86-32,APIC] Enable the local APIC even if BIOS
884 disabled it.
886 lapic_timer_c2_ok [X86-32,x86-64,APIC] trust the local apic timer in
887 C2 power state.
889 libata.noacpi [LIBATA] Disables use of ACPI in libata suspend/resume
890 when set.
891 Format: <int>
893 load_ramdisk= [RAM] List of ramdisks to load from floppy
894 See Documentation/ramdisk.txt.
896 lockd.nlm_grace_period=P [NFS] Assign grace period.
897 Format: <integer>
899 lockd.nlm_tcpport=N [NFS] Assign TCP port.
900 Format: <integer>
902 lockd.nlm_timeout=T [NFS] Assign timeout value.
903 Format: <integer>
905 lockd.nlm_udpport=M [NFS] Assign UDP port.
906 Format: <integer>
908 logibm.irq= [HW,MOUSE] Logitech Bus Mouse Driver
909 Format: <irq>
911 loglevel= All Kernel Messages with a loglevel smaller than the
912 console loglevel will be printed to the console. It can
913 also be changed with klogd or other programs. The
914 loglevels are defined as follows:
916 0 (KERN_EMERG) system is unusable
917 1 (KERN_ALERT) action must be taken immediately
918 2 (KERN_CRIT) critical conditions
919 3 (KERN_ERR) error conditions
920 4 (KERN_WARNING) warning conditions
921 5 (KERN_NOTICE) normal but significant condition
922 6 (KERN_INFO) informational
923 7 (KERN_DEBUG) debug-level messages
925 log_buf_len=n Sets the size of the printk ring buffer, in bytes.
926 Format: { n | nk | nM }
927 n must be a power of two. The default size
928 is set in the kernel config file.
930 logo.nologo [FB] Disables display of the built-in Linux logo.
931 This may be used to provide more screen space for
932 kernel log messages and is useful when debugging
933 kernel boot problems.
935 lp=0 [LP] Specify parallel ports to use, e.g,
936 lp=port[,port...] lp=none,parport0 (lp0 not configured, lp1 uses
937 lp=reset first parallel port). 'lp=0' disables the
938 lp=auto printer driver. 'lp=reset' (which can be
939 specified in addition to the ports) causes
940 attached printers to be reset. Using
941 lp=port1,port2,... specifies the parallel ports
942 to associate lp devices with, starting with
943 lp0. A port specification may be 'none' to skip
944 that lp device, or a parport name such as
945 'parport0'. Specifying 'lp=auto' instead of a
946 port specification list means that device IDs
947 from each port should be examined, to see if
948 an IEEE 1284-compliant printer is attached; if
949 so, the driver will manage that printer.
950 See also header of drivers/char/lp.c.
952 lpj=n [KNL]
953 Sets loops_per_jiffy to given constant, thus avoiding
954 time-consuming boot-time autodetection (up to 250 ms per
955 CPU). 0 enables autodetection (default). To determine
956 the correct value for your kernel, boot with normal
957 autodetection and see what value is printed. Note that
958 on SMP systems the preset will be applied to all CPUs,
959 which is likely to cause problems if your CPUs need
960 significantly divergent settings. An incorrect value
961 will cause delays in the kernel to be wrong, leading to
962 unpredictable I/O errors and other breakage. Although
963 unlikely, in the extreme case this might damage your
964 hardware.
966 ltpc= [NET]
967 Format: <io>,<irq>,<dma>
969 mac5380= [HW,SCSI] Format:
970 <can_queue>,<cmd_per_lun>,<sg_tablesize>,<hostid>,<use_tags>
972 mac53c9x= [HW,SCSI] Format:
973 <num_esps>,<disconnect>,<nosync>,<can_queue>,<cmd_per_lun>,<sg_tablesize>,<hostid>,<use_tags>
975 machvec= [IA64] Force the use of a particular machine-vector
976 (machvec) in a generic kernel.
977 Example: machvec=hpzx1_swiotlb
979 max_loop= [LOOP] Maximum number of loopback devices that can
980 be mounted
981 Format: <1-256>
983 maxcpus= [SMP] Maximum number of processors that an SMP kernel
984 should make use of. maxcpus=n : n >= 0 limits the
985 kernel to using 'n' processors. n=0 is a special case,
986 it is equivalent to "nosmp", which also disables
987 the IO APIC.
989 max_addr=[KMG] [KNL,BOOT,ia64] All physical memory greater than or
990 equal to this physical address is ignored.
992 max_luns= [SCSI] Maximum number of LUNs to probe.
993 Should be between 1 and 2^32-1.
995 max_report_luns=
996 [SCSI] Maximum number of LUNs received.
997 Should be between 1 and 16384.
999 mca-pentium [BUGS=X86-32]
1001 mcatest= [IA-64]
1003 mce [X86-32] Machine Check Exception
1005 mce=option [X86-64] See Documentation/x86_64/boot-options.txt
1007 md= [HW] RAID subsystems devices and level
1008 See Documentation/md.txt.
1010 mdacon= [MDA]
1011 Format: <first>,<last>
1012 Specifies range of consoles to be captured by the MDA.
1014 mem=nn[KMG] [KNL,BOOT] Force usage of a specific amount of memory
1015 Amount of memory to be used when the kernel is not able
1016 to see the whole system memory or for test.
1017 [X86-32] Use together with memmap= to avoid physical
1018 address space collisions. Without memmap= PCI devices
1019 could be placed at addresses belonging to unused RAM.
1021 mem=nopentium [BUGS=X86-32] Disable usage of 4MB pages for kernel
1022 memory.
1024 memmap=exactmap [KNL,X86-32,X86_64] Enable setting of an exact
1025 E820 memory map, as specified by the user.
1026 Such memmap=exactmap lines can be constructed based on
1027 BIOS output or other requirements. See the memmap=nn@ss
1028 option description.
1030 memmap=nn[KMG]@ss[KMG]
1031 [KNL] Force usage of a specific region of memory
1032 Region of memory to be used, from ss to ss+nn.
1034 memmap=nn[KMG]#ss[KMG]
1035 [KNL,ACPI] Mark specific memory as ACPI data.
1036 Region of memory to be used, from ss to ss+nn.
1038 memmap=nn[KMG]$ss[KMG]
1039 [KNL,ACPI] Mark specific memory as reserved.
1040 Region of memory to be used, from ss to ss+nn.
1042 meye.*= [HW] Set MotionEye Camera parameters
1043 See Documentation/video4linux/meye.txt.
1045 mfgpt_irq= [IA-32] Specify the IRQ to use for the
1046 Multi-Function General Purpose Timers on AMD Geode
1047 platforms.
1049 mga= [HW,DRM]
1051 mousedev.tap_time=
1052 [MOUSE] Maximum time between finger touching and
1053 leaving touchpad surface for touch to be considered
1054 a tap and be reported as a left button click (for
1055 touchpads working in absolute mode only).
1056 Format: <msecs>
1057 mousedev.xres= [MOUSE] Horizontal screen resolution, used for devices
1058 reporting absolute coordinates, such as tablets
1059 mousedev.yres= [MOUSE] Vertical screen resolution, used for devices
1060 reporting absolute coordinates, such as tablets
1062 mpu401= [HW,OSS]
1063 Format: <io>,<irq>
1065 MTD_Partition= [MTD]
1066 Format: <name>,<region-number>,<size>,<offset>
1068 MTD_Region= [MTD] Format:
1069 <name>,<region-number>[,<base>,<size>,<buswidth>,<altbuswidth>]
1071 mtdparts= [MTD]
1072 See drivers/mtd/cmdlinepart.c.
1074 mtouchusb.raw_coordinates=
1075 [HW] Make the MicroTouch USB driver use raw coordinates
1076 ('y', default) or cooked coordinates ('n')
1078 n2= [NET] SDL Inc. RISCom/N2 synchronous serial card
1080 NCR_D700= [HW,SCSI]
1081 See header of drivers/scsi/NCR_D700.c.
1083 ncr5380= [HW,SCSI]
1085 ncr53c400= [HW,SCSI]
1087 ncr53c400a= [HW,SCSI]
1089 ncr53c406a= [HW,SCSI]
1091 ncr53c8xx= [HW,SCSI]
1093 netdev= [NET] Network devices parameters
1094 Format: <irq>,<io>,<mem_start>,<mem_end>,<name>
1095 Note that mem_start is often overloaded to mean
1096 something different and driver-specific.
1097 This usage is only documented in each driver source
1098 file if at all.
1100 nfsaddrs= [NFS]
1101 See Documentation/nfsroot.txt.
1103 nfsroot= [NFS] nfs root filesystem for disk-less boxes.
1104 See Documentation/nfsroot.txt.
1106 nfs.callback_tcpport=
1107 [NFS] set the TCP port on which the NFSv4 callback
1108 channel should listen.
1110 nfs.idmap_cache_timeout=
1111 [NFS] set the maximum lifetime for idmapper cache
1112 entries.
1114 nfs.enable_ino64=
1115 [NFS] enable 64-bit inode numbers.
1116 If zero, the NFS client will fake up a 32-bit inode
1117 number for the readdir() and stat() syscalls instead
1118 of returning the full 64-bit number.
1119 The default is to return 64-bit inode numbers.
1121 nmi_watchdog= [KNL,BUGS=X86-32] Debugging features for SMP kernels
1123 no387 [BUGS=X86-32] Tells the kernel to use the 387 maths
1124 emulation library even if a 387 maths coprocessor
1125 is present.
1127 noaliencache [MM, NUMA, SLAB] Disables the allocation of alien
1128 caches in the slab allocator. Saves per-node memory,
1129 but will impact performance.
1131 noalign [KNL,ARM]
1133 noapic [SMP,APIC] Tells the kernel to not make use of any
1134 IOAPICs that may be present in the system.
1136 nobats [PPC] Do not use BATs for mapping kernel lowmem
1137 on "Classic" PPC cores.
1139 nocache [ARM]
1141 nodelayacct [KNL] Disable per-task delay accounting
1143 nodisconnect [HW,SCSI,M68K] Disables SCSI disconnects.
1145 noexec [IA-64]
1147 noexec [X86-32,X86-64]
1148 noexec=on: enable non-executable mappings (default)
1149 noexec=off: disable nn-executable mappings
1151 nofxsr [BUGS=X86-32] Disables x86 floating point extended
1152 register save and restore. The kernel will only save
1153 legacy floating-point registers on task switch.
1155 nohlt [BUGS=ARM]
1157 no-hlt [BUGS=X86-32] Tells the kernel that the hlt
1158 instruction doesn't work correctly and not to
1159 use it.
1161 nohalt [IA-64] Tells the kernel not to use the power saving
1162 function PAL_HALT_LIGHT when idle. This increases
1163 power-consumption. On the positive side, it reduces
1164 interrupt wake-up latency, which may improve performance
1165 in certain environments such as networked servers or
1166 real-time systems.
1168 nohz= [KNL] Boottime enable/disable dynamic ticks
1169 Valid arguments: on, off
1170 Default: on
1172 noirqbalance [X86-32,SMP,KNL] Disable kernel irq balancing
1174 noirqdebug [X86-32] Disables the code which attempts to detect and
1175 disable unhandled interrupt sources.
1177 no_timer_check [X86-32,X86_64,APIC] Disables the code which tests for
1178 broken timer IRQ sources.
1180 noisapnp [ISAPNP] Disables ISA PnP code.
1182 noinitrd [RAM] Tells the kernel not to load any configured
1183 initial RAM disk.
1185 nointroute [IA-64]
1187 nojitter [IA64] Disables jitter checking for ITC timers.
1189 nolapic [X86-32,APIC] Do not enable or use the local APIC.
1191 nolapic_timer [X86-32,APIC] Do not use the local APIC timer.
1193 noltlbs [PPC] Do not use large page/tlb entries for kernel
1194 lowmem mapping on PPC40x.
1196 nomca [IA-64] Disable machine check abort handling
1198 nomce [X86-32] Machine Check Exception
1200 nomfgpt [X86-32] Disable Multi-Function General Purpose
1201 Timer usage (for AMD Geode machines).
1203 noreplace-paravirt [X86-32,PV_OPS] Don't patch paravirt_ops
1205 noreplace-smp [X86-32,SMP] Don't replace SMP instructions
1206 with UP alternatives
1208 noresidual [PPC] Don't use residual data on PReP machines.
1210 noresume [SWSUSP] Disables resume and restores original swap
1211 space.
1213 no-scroll [VGA] Disables scrollback.
1214 This is required for the Braillex ib80-piezo Braille
1215 reader made by F.H. Papenmeier (Germany).
1217 nosbagart [IA-64]
1219 nosep [BUGS=X86-32] Disables x86 SYSENTER/SYSEXIT support.
1221 nosmp [SMP] Tells an SMP kernel to act as a UP kernel,
1222 and disable the IO APIC. legacy for "maxcpus=0".
1224 nosoftlockup [KNL] Disable the soft-lockup detector.
1226 nosync [HW,M68K] Disables sync negotiation for all devices.
1228 notsc [BUGS=X86-32] Disable Time Stamp Counter
1230 nousb [USB] Disable the USB subsystem
1232 nowb [ARM]
1234 numa_zonelist_order= [KNL, BOOT] Select zonelist order for NUMA.
1235 one of ['zone', 'node', 'default'] can be specified
1236 This can be set from sysctl after boot.
1237 See Documentation/sysctl/vm.txt for details.
1239 nr_uarts= [SERIAL] maximum number of UARTs to be registered.
1241 opl3= [HW,OSS]
1242 Format: <io>
1244 oprofile.timer= [HW]
1245 Use timer interrupt instead of performance counters
1247 osst= [HW,SCSI] SCSI Tape Driver
1248 Format: <buffer_size>,<write_threshold>
1249 See also Documentation/scsi/st.txt.
1251 panic= [KNL] Kernel behaviour on panic
1252 Format: <timeout>
1254 parkbd.port= [HW] Parallel port number the keyboard adapter is
1255 connected to, default is 0.
1256 Format: <parport#>
1257 parkbd.mode= [HW] Parallel port keyboard adapter mode of operation,
1258 0 for XT, 1 for AT (default is AT).
1259 Format: <mode>
1261 parport= [HW,PPT] Specify parallel ports. 0 disables.
1262 Format: { 0 | auto | 0xBBB[,IRQ[,DMA]] }
1263 Use 'auto' to force the driver to use any
1264 IRQ/DMA settings detected (the default is to
1265 ignore detected IRQ/DMA settings because of
1266 possible conflicts). You can specify the base
1267 address, IRQ, and DMA settings; IRQ and DMA
1268 should be numbers, or 'auto' (for using detected
1269 settings on that particular port), or 'nofifo'
1270 (to avoid using a FIFO even if it is detected).
1271 Parallel ports are assigned in the order they
1272 are specified on the command line, starting
1273 with parport0.
1275 parport_init_mode= [HW,PPT]
1276 Configure VIA parallel port to operate in
1277 a specific mode. This is necessary on Pegasos
1278 computer where firmware has no options for setting
1279 up parallel port mode and sets it to spp.
1280 Currently this function knows 686a and 8231 chips.
1281 Format: [spp|ps2|epp|ecp|ecpepp]
1283 pas2= [HW,OSS] Format:
1284 <io>,<irq>,<dma>,<dma16>,<sb_io>,<sb_irq>,<sb_dma>,<sb_dma16>
1286 pas16= [HW,SCSI]
1287 See header of drivers/scsi/pas16.c.
1289 pause_on_oops=
1290 Halt all CPUs after the first oops has been printed for
1291 the specified number of seconds. This is to be used if
1292 your oopses keep scrolling off the screen.
1294 pcbit= [HW,ISDN]
1296 pcd. [PARIDE]
1297 See header of drivers/block/paride/pcd.c.
1298 See also Documentation/paride.txt.
1300 pci=option[,option...] [PCI] various PCI subsystem options:
1301 off [X86-32] don't probe for the PCI bus
1302 bios [X86-32] force use of PCI BIOS, don't access
1303 the hardware directly. Use this if your machine
1304 has a non-standard PCI host bridge.
1305 nobios [X86-32] disallow use of PCI BIOS, only direct
1306 hardware access methods are allowed. Use this
1307 if you experience crashes upon bootup and you
1308 suspect they are caused by the BIOS.
1309 conf1 [X86-32] Force use of PCI Configuration
1310 Mechanism 1.
1311 conf2 [X86-32] Force use of PCI Configuration
1312 Mechanism 2.
1313 noaer [PCIE] If the PCIEAER kernel config parameter is
1314 enabled, this kernel boot option can be used to
1315 disable the use of PCIE advanced error reporting.
1316 nodomains [PCI] Disable support for multiple PCI
1317 root domains (aka PCI segments, in ACPI-speak).
1318 nommconf [X86-32,X86_64] Disable use of MMCONFIG for PCI
1319 Configuration
1320 nomsi [MSI] If the PCI_MSI kernel config parameter is
1321 enabled, this kernel boot option can be used to
1322 disable the use of MSI interrupts system-wide.
1323 nosort [X86-32] Don't sort PCI devices according to
1324 order given by the PCI BIOS. This sorting is
1325 done to get a device order compatible with
1326 older kernels.
1327 biosirq [X86-32] Use PCI BIOS calls to get the interrupt
1328 routing table. These calls are known to be buggy
1329 on several machines and they hang the machine
1330 when used, but on other computers it's the only
1331 way to get the interrupt routing table. Try
1332 this option if the kernel is unable to allocate
1333 IRQs or discover secondary PCI buses on your
1334 motherboard.
1335 rom [X86-32] Assign address space to expansion ROMs.
1336 Use with caution as certain devices share
1337 address decoders between ROMs and other
1338 resources.
1339 irqmask=0xMMMM [X86-32] Set a bit mask of IRQs allowed to be
1340 assigned automatically to PCI devices. You can
1341 make the kernel exclude IRQs of your ISA cards
1342 this way.
1343 pirqaddr=0xAAAAA [X86-32] Specify the physical address
1344 of the PIRQ table (normally generated
1345 by the BIOS) if it is outside the
1346 F0000h-100000h range.
1347 lastbus=N [X86-32] Scan all buses thru bus #N. Can be
1348 useful if the kernel is unable to find your
1349 secondary buses and you want to tell it
1350 explicitly which ones they are.
1351 assign-busses [X86-32] Always assign all PCI bus
1352 numbers ourselves, overriding
1353 whatever the firmware may have done.
1354 usepirqmask [X86-32] Honor the possible IRQ mask stored
1355 in the BIOS $PIR table. This is needed on
1356 some systems with broken BIOSes, notably
1357 some HP Pavilion N5400 and Omnibook XE3
1358 notebooks. This will have no effect if ACPI
1359 IRQ routing is enabled.
1360 noacpi [X86-32] Do not use ACPI for IRQ routing
1361 or for PCI scanning.
1362 use_crs [X86-32] Use _CRS for PCI resource
1363 allocation.
1364 routeirq Do IRQ routing for all PCI devices.
1365 This is normally done in pci_enable_device(),
1366 so this option is a temporary workaround
1367 for broken drivers that don't call it.
1368 firmware [ARM] Do not re-enumerate the bus but instead
1369 just use the configuration from the
1370 bootloader. This is currently used on
1371 IXP2000 systems where the bus has to be
1372 configured a certain way for adjunct CPUs.
1373 noearly [X86] Don't do any early type 1 scanning.
1374 This might help on some broken boards which
1375 machine check when some devices' config space
1376 is read. But various workarounds are disabled
1377 and some IOMMU drivers will not work.
1378 bfsort Sort PCI devices into breadth-first order.
1379 This sorting is done to get a device
1380 order compatible with older (<= 2.4) kernels.
1381 nobfsort Don't sort PCI devices into breadth-first order.
1382 cbiosize=nn[KMG] The fixed amount of bus space which is
1383 reserved for the CardBus bridge's IO window.
1384 The default value is 256 bytes.
1385 cbmemsize=nn[KMG] The fixed amount of bus space which is
1386 reserved for the CardBus bridge's memory
1387 window. The default value is 64 megabytes.
1389 pcmv= [HW,PCMCIA] BadgePAD 4
1391 pd. [PARIDE]
1392 See Documentation/paride.txt.
1394 pdcchassis= [PARISC,HW] Disable/Enable PDC Chassis Status codes at
1395 boot time.
1396 Format: { 0 | 1 }
1397 See arch/parisc/kernel/pdc_chassis.c
1399 pf. [PARIDE]
1400 See Documentation/paride.txt.
1402 pg. [PARIDE]
1403 See Documentation/paride.txt.
1405 pirq= [SMP,APIC] Manual mp-table setup
1406 See Documentation/i386/IO-APIC.txt.
1408 plip= [PPT,NET] Parallel port network link
1409 Format: { parport<nr> | timid | 0 }
1410 See also Documentation/parport.txt.
1412 pnpacpi= [ACPI]
1413 { off }
1415 pnpbios= [ISAPNP]
1416 { on | off | curr | res | no-curr | no-res }
1418 pnp_reserve_irq=
1419 [ISAPNP] Exclude IRQs for the autoconfiguration
1421 pnp_reserve_dma=
1422 [ISAPNP] Exclude DMAs for the autoconfiguration
1424 pnp_reserve_io= [ISAPNP] Exclude I/O ports for the autoconfiguration
1425 Ranges are in pairs (I/O port base and size).
1427 pnp_reserve_mem=
1428 [ISAPNP] Exclude memory regions for the
1429 autoconfiguration.
1430 Ranges are in pairs (memory base and size).
1432 print-fatal-signals=
1433 [KNL] debug: print fatal signals
1434 print-fatal-signals=1: print segfault info to
1435 the kernel console.
1436 default: off.
1438 printk.time= Show timing data prefixed to each printk message line
1439 Format: <bool> (1/Y/y=enable, 0/N/n=disable)
1441 profile= [KNL] Enable kernel profiling via /proc/profile
1442 Format: [schedule,]<number>
1443 Param: "schedule" - profile schedule points.
1444 Param: <number> - step/bucket size as a power of 2 for
1445 statistical time based profiling.
1446 Param: "sleep" - profile D-state sleeping (millisecs)
1447 Param: "kvm" - profile VM exits.
1449 processor.max_cstate= [HW,ACPI]
1450 Limit processor to maximum C-state
1451 max_cstate=9 overrides any DMI blacklist limit.
1453 processor.nocst [HW,ACPI]
1454 Ignore the _CST method to determine C-states,
1455 instead using the legacy FADT method
1457 prompt_ramdisk= [RAM] List of RAM disks to prompt for floppy disk
1458 before loading.
1459 See Documentation/ramdisk.txt.
1461 psmouse.proto= [HW,MOUSE] Highest PS2 mouse protocol extension to
1462 probe for; one of (bare|imps|exps|lifebook|any).
1463 psmouse.rate= [HW,MOUSE] Set desired mouse report rate, in reports
1464 per second.
1465 psmouse.resetafter= [HW,MOUSE]
1466 Try to reset the device after so many bad packets
1467 (0 = never).
1468 psmouse.resolution=
1469 [HW,MOUSE] Set desired mouse resolution, in dpi.
1470 psmouse.smartscroll=
1471 [HW,MOUSE] Controls Logitech smartscroll autorepeat.
1472 0 = disabled, 1 = enabled (default).
1474 pss= [HW,OSS] Personal Sound System (ECHO ESC614)
1475 Format:
1476 <io>,<mss_io>,<mss_irq>,<mss_dma>,<mpu_io>,<mpu_irq>
1478 pt. [PARIDE]
1479 See Documentation/paride.txt.
1481 pty.legacy_count=
1482 [KNL] Number of legacy pty's. Overwrites compiled-in
1483 default number.
1485 quiet [KNL] Disable most log messages
1487 r128= [HW,DRM]
1489 raid= [HW,RAID]
1490 See Documentation/md.txt.
1492 ramdisk_blocksize= [RAM]
1493 See Documentation/ramdisk.txt.
1495 ramdisk_size= [RAM] Sizes of RAM disks in kilobytes
1496 See Documentation/ramdisk.txt.
1498 rcu.blimit= [KNL,BOOT] Set maximum number of finished
1499 RCU callbacks to process in one batch.
1501 rcu.qhimark= [KNL,BOOT] Set threshold of queued
1502 RCU callbacks over which batch limiting is disabled.
1504 rcu.qlowmark= [KNL,BOOT] Set threshold of queued
1505 RCU callbacks below which batch limiting is re-enabled.
1507 rdinit= [KNL]
1508 Format: <full_path>
1509 Run specified binary instead of /init from the ramdisk,
1510 used for early userspace startup. See initrd.
1512 reboot= [BUGS=X86-32,BUGS=ARM,BUGS=IA-64] Rebooting mode
1513 Format: <reboot_mode>[,<reboot_mode2>[,...]]
1514 See arch/*/kernel/reboot.c or arch/*/kernel/process.c
1516 reserve= [KNL,BUGS] Force the kernel to ignore some iomem area
1518 reservetop= [X86-32]
1519 Format: nn[KMG]
1520 Reserves a hole at the top of the kernel virtual
1521 address space.
1523 reset_devices [KNL] Force drivers to reset the underlying device
1524 during initialization.
1526 resume= [SWSUSP]
1527 Specify the partition device for software suspend
1529 resume_offset= [SWSUSP]
1530 Specify the offset from the beginning of the partition
1531 given by "resume=" at which the swap header is located,
1532 in <PAGE_SIZE> units (needed only for swap files).
1533 See Documentation/power/swsusp-and-swap-files.txt
1535 retain_initrd [RAM] Keep initrd memory after extraction
1537 rhash_entries= [KNL,NET]
1538 Set number of hash buckets for route cache
1540 riscom8= [HW,SERIAL]
1541 Format: <io_board1>[,<io_board2>[,...<io_boardN>]]
1543 ro [KNL] Mount root device read-only on boot
1545 root= [KNL] Root filesystem
1547 rootdelay= [KNL] Delay (in seconds) to pause before attempting to
1548 mount the root filesystem
1550 rootflags= [KNL] Set root filesystem mount option string
1552 rootfstype= [KNL] Set root filesystem type
1554 rootwait [KNL] Wait (indefinitely) for root device to show up.
1555 Useful for devices that are detected asynchronously
1556 (e.g. USB and MMC devices).
1558 root_plug.vendor_id=
1559 [ROOTPLUG] Override the default vendor ID
1561 root_plug.product_id=
1562 [ROOTPLUG] Override the default product ID
1564 root_plug.debug=
1565 [ROOTPLUG] Enable debugging output
1567 rw [KNL] Mount root device read-write on boot
1569 S [KNL] Run init in single mode
1571 sa1100ir [NET]
1572 See drivers/net/irda/sa1100_ir.c.
1574 sbni= [NET] Granch SBNI12 leased line adapter
1576 sc1200wdt= [HW,WDT] SC1200 WDT (watchdog) driver
1577 Format: <io>[,<timeout>[,<isapnp>]]
1579 scsi_debug_*= [SCSI]
1580 See drivers/scsi/scsi_debug.c.
1582 scsi_default_dev_flags=
1583 [SCSI] SCSI default device flags
1584 Format: <integer>
1586 scsi_dev_flags= [SCSI] Black/white list entry for vendor and model
1587 Format: <vendor>:<model>:<flags>
1588 (flags are integer value)
1590 scsi_logging= [SCSI]
1592 scsi_mod.scan= [SCSI] sync (default) scans SCSI busses as they are
1593 discovered. async scans them in kernel threads,
1594 allowing boot to proceed. none ignores them, expecting
1595 user space to do the scan.
1597 selinux [SELINUX] Disable or enable SELinux at boot time.
1598 Format: { "0" | "1" }
1599 See security/selinux/Kconfig help text.
1600 0 -- disable.
1601 1 -- enable.
1602 Default value is set via kernel config option.
1603 If enabled at boot time, /selinux/disable can be used
1604 later to disable prior to initial policy load.
1606 selinux_compat_net =
1607 [SELINUX] Set initial selinux_compat_net flag value.
1608 Format: { "0" | "1" }
1609 0 -- use new secmark-based packet controls
1610 1 -- use legacy packet controls
1611 Default value is 0 (preferred).
1612 Value can be changed at runtime via
1613 /selinux/compat_net.
1615 serialnumber [BUGS=X86-32]
1617 shapers= [NET]
1618 Maximal number of shapers.
1620 sim710= [SCSI,HW]
1621 See header of drivers/scsi/sim710.c.
1623 simeth= [IA-64]
1624 simscsi=
1626 slram= [HW,MTD]
1628 slub_debug[=options[,slabs]] [MM, SLUB]
1629 Enabling slub_debug allows one to determine the
1630 culprit if slab objects become corrupted. Enabling
1631 slub_debug can create guard zones around objects and
1632 may poison objects when not in use. Also tracks the
1633 last alloc / free. For more information see
1634 Documentation/vm/slub.txt.
1636 slub_max_order= [MM, SLUB]
1637 Determines the maximum allowed order for slabs.
1638 A high setting may cause OOMs due to memory
1639 fragmentation. For more information see
1640 Documentation/vm/slub.txt.
1642 slub_min_objects= [MM, SLUB]
1643 The minimum number of objects per slab. SLUB will
1644 increase the slab order up to slub_max_order to
1645 generate a sufficiently large slab able to contain
1646 the number of objects indicated. The higher the number
1647 of objects the smaller the overhead of tracking slabs
1648 and the less frequently locks need to be acquired.
1649 For more information see Documentation/vm/slub.txt.
1651 slub_min_order= [MM, SLUB]
1652 Determines the mininum page order for slabs. Must be
1653 lower than slub_max_order.
1654 For more information see Documentation/vm/slub.txt.
1656 slub_nomerge [MM, SLUB]
1657 Disable merging of slabs with similar size. May be
1658 necessary if there is some reason to distinguish
1659 allocs to different slabs. Debug options disable
1660 merging on their own.
1661 For more information see Documentation/vm/slub.txt.
1663 smart2= [HW]
1664 Format: <io1>[,<io2>[,...,<io8>]]
1666 smp-alt-once [X86-32,SMP] On a hotplug CPU system, only
1667 attempt to substitute SMP alternatives once at boot.
1669 smsc-ircc2.nopnp [HW] Don't use PNP to discover SMC devices
1670 smsc-ircc2.ircc_cfg= [HW] Device configuration I/O port
1671 smsc-ircc2.ircc_sir= [HW] SIR base I/O port
1672 smsc-ircc2.ircc_fir= [HW] FIR base I/O port
1673 smsc-ircc2.ircc_irq= [HW] IRQ line
1674 smsc-ircc2.ircc_dma= [HW] DMA channel
1675 smsc-ircc2.ircc_transceiver= [HW] Transceiver type:
1676 0: Toshiba Satellite 1800 (GP data pin select)
1677 1: Fast pin select (default)
1678 2: ATC IRMode
1680 snd-ad1816a= [HW,ALSA]
1682 snd-ad1848= [HW,ALSA]
1684 snd-ali5451= [HW,ALSA]
1686 snd-als100= [HW,ALSA]
1688 snd-als4000= [HW,ALSA]
1690 snd-azt2320= [HW,ALSA]
1692 snd-cmi8330= [HW,ALSA]
1694 snd-cmipci= [HW,ALSA]
1696 snd-cs4231= [HW,ALSA]
1698 snd-cs4232= [HW,ALSA]
1700 snd-cs4236= [HW,ALSA]
1702 snd-cs4281= [HW,ALSA]
1704 snd-cs46xx= [HW,ALSA]
1706 snd-dt019x= [HW,ALSA]
1708 snd-dummy= [HW,ALSA]
1710 snd-emu10k1= [HW,ALSA]
1712 snd-ens1370= [HW,ALSA]
1714 snd-ens1371= [HW,ALSA]
1716 snd-es968= [HW,ALSA]
1718 snd-es1688= [HW,ALSA]
1720 snd-es18xx= [HW,ALSA]
1722 snd-es1938= [HW,ALSA]
1724 snd-es1968= [HW,ALSA]
1726 snd-fm801= [HW,ALSA]
1728 snd-gusclassic= [HW,ALSA]
1730 snd-gusextreme= [HW,ALSA]
1732 snd-gusmax= [HW,ALSA]
1734 snd-hdsp= [HW,ALSA]
1736 snd-ice1712= [HW,ALSA]
1738 snd-intel8x0= [HW,ALSA]
1740 snd-interwave= [HW,ALSA]
1742 snd-interwave-stb=
1743 [HW,ALSA]
1745 snd-korg1212= [HW,ALSA]
1747 snd-maestro3= [HW,ALSA]
1749 snd-mpu401= [HW,ALSA]
1751 snd-mtpav= [HW,ALSA]
1753 snd-nm256= [HW,ALSA]
1755 snd-opl3sa2= [HW,ALSA]
1757 snd-opti92x-ad1848=
1758 [HW,ALSA]
1760 snd-opti92x-cs4231=
1761 [HW,ALSA]
1763 snd-opti93x= [HW,ALSA]
1765 snd-pmac= [HW,ALSA]
1767 snd-rme32= [HW,ALSA]
1769 snd-rme96= [HW,ALSA]
1771 snd-rme9652= [HW,ALSA]
1773 snd-sb8= [HW,ALSA]
1775 snd-sb16= [HW,ALSA]
1777 snd-sbawe= [HW,ALSA]
1779 snd-serial= [HW,ALSA]
1781 snd-sgalaxy= [HW,ALSA]
1783 snd-sonicvibes= [HW,ALSA]
1785 snd-sun-amd7930=
1786 [HW,ALSA]
1788 snd-sun-cs4231= [HW,ALSA]
1790 snd-trident= [HW,ALSA]
1792 snd-usb-audio= [HW,ALSA,USB]
1794 snd-via82xx= [HW,ALSA]
1796 snd-virmidi= [HW,ALSA]
1798 snd-wavefront= [HW,ALSA]
1800 snd-ymfpci= [HW,ALSA]
1802 sonypi.*= [HW] Sony Programmable I/O Control Device driver
1803 See Documentation/sonypi.txt
1805 specialix= [HW,SERIAL] Specialix multi-serial port adapter
1806 See Documentation/specialix.txt.
1808 spia_io_base= [HW,MTD]
1809 spia_fio_base=
1810 spia_pedr=
1811 spia_peddr=
1813 sscape= [HW,OSS]
1814 Format: <io>,<irq>,<dma>,<mpu_io>,<mpu_irq>
1816 st= [HW,SCSI] SCSI tape parameters (buffers, etc.)
1817 See Documentation/scsi/st.txt.
1819 st0x= [HW,SCSI]
1820 See header of drivers/scsi/seagate.c.
1822 sti= [PARISC,HW]
1823 Format: <num>
1824 Set the STI (builtin display/keyboard on the HP-PARISC
1825 machines) console (graphic card) which should be used
1826 as the initial boot-console.
1827 See also comment in drivers/video/console/sticore.c.
1829 sti_font= [HW]
1830 See comment in drivers/video/console/sticore.c.
1832 stifb= [HW]
1833 Format: bpp:<bpp1>[:<bpp2>[:<bpp3>...]]
1835 sunrpc.pool_mode=
1836 [NFS]
1837 Control how the NFS server code allocates CPUs to
1838 service thread pools. Depending on how many NICs
1839 you have and where their interrupts are bound, this
1840 option will affect which CPUs will do NFS serving.
1841 Note: this parameter cannot be changed while the
1842 NFS server is running.
1844 auto the server chooses an appropriate mode
1845 automatically using heuristics
1846 global a single global pool contains all CPUs
1847 percpu one pool for each CPU
1848 pernode one pool for each NUMA node (equivalent
1849 to global on non-NUMA machines)
1851 swiotlb= [IA-64] Number of I/O TLB slabs
1853 switches= [HW,M68k]
1855 sym53c416= [HW,SCSI]
1856 See header of drivers/scsi/sym53c416.c.
1858 sysrq_always_enabled
1859 [KNL]
1860 Ignore sysrq setting - this boot parameter will
1861 neutralize any effect of /proc/sys/kernel/sysrq.
1862 Useful for debugging.
1864 t128= [HW,SCSI]
1865 See header of drivers/scsi/t128.c.
1867 tdfx= [HW,DRM]
1869 thash_entries= [KNL,NET]
1870 Set number of hash buckets for TCP connection
1872 thermal.act= [HW,ACPI]
1873 -1: disable all active trip points in all thermal zones
1874 <degrees C>: override all lowest active trip points
1876 thermal.crt= [HW,ACPI]
1877 -1: disable all critical trip points in all thermal zones
1878 <degrees C>: lower all critical trip points
1880 thermal.nocrt= [HW,ACPI]
1881 Set to disable actions on ACPI thermal zone
1882 critical and hot trip points.
1884 thermal.off= [HW,ACPI]
1885 1: disable ACPI thermal control
1887 thermal.psv= [HW,ACPI]
1888 -1: disable all passive trip points
1889 <degrees C>: override all passive trip points to this value
1891 thermal.tzp= [HW,ACPI]
1892 Specify global default ACPI thermal zone polling rate
1893 <deci-seconds>: poll all this frequency
1894 0: no polling (default)
1896 time Show timing data prefixed to each printk message line
1897 [deprecated, see 'printk.time']
1899 tipar.timeout= [HW,PPT]
1900 Set communications timeout in tenths of a second
1901 (default 15).
1903 tipar.delay= [HW,PPT]
1904 Set inter-bit delay in microseconds (default 10).
1906 tmc8xx= [HW,SCSI]
1907 See header of drivers/scsi/seagate.c.
1909 tmscsim= [HW,SCSI]
1910 See comment before function dc390_setup() in
1911 drivers/scsi/tmscsim.c.
1913 tp720= [HW,PS2]
1915 trix= [HW,OSS] MediaTrix AudioTrix Pro
1916 Format:
1917 <io>,<irq>,<dma>,<dma2>,<sb_io>,<sb_irq>,<sb_dma>,<mpu_io>,<mpu_irq>
1919 turbografx.map[2|3]= [HW,JOY]
1920 TurboGraFX parallel port interface
1921 Format:
1922 <port#>,<js1>,<js2>,<js3>,<js4>,<js5>,<js6>,<js7>
1923 See also Documentation/input/joystick-parport.txt
1925 u14-34f= [HW,SCSI] UltraStor 14F/34F SCSI host adapter
1926 See header of drivers/scsi/u14-34f.c.
1928 uart401= [HW,OSS]
1929 Format: <io>,<irq>
1931 uart6850= [HW,OSS]
1932 Format: <io>,<irq>
1934 uhci-hcd.ignore_oc=
1935 [USB] Ignore overcurrent events (default N).
1936 Some badly-designed motherboards generate lots of
1937 bogus events, for ports that aren't wired to
1938 anything. Set this parameter to avoid log spamming.
1939 Note that genuine overcurrent events won't be
1940 reported either.
1942 usbcore.autosuspend=
1943 [USB] The autosuspend time delay (in seconds) used
1944 for newly-detected USB devices (default 2). This
1945 is the time required before an idle device will be
1946 autosuspended. Devices for which the delay is set
1947 to a negative value won't be autosuspended at all.
1949 usbhid.mousepoll=
1950 [USBHID] The interval which mice are to be polled at.
1952 vdso= [X86-32,SH,x86-64]
1953 vdso=2: enable compat VDSO (default with COMPAT_VDSO)
1954 vdso=1: enable VDSO (default)
1955 vdso=0: disable VDSO mapping
1957 vector= [IA-64,SMP]
1958 vector=percpu: enable percpu vector domain
1960 video= [FB] Frame buffer configuration
1961 See Documentation/fb/modedb.txt.
1963 vga= [BOOT,X86-32] Select a particular video mode
1964 See Documentation/i386/boot.txt and
1965 Documentation/svga.txt.
1966 Use vga=ask for menu.
1967 This is actually a boot loader parameter; the value is
1968 passed to the kernel using a special protocol.
1970 vmalloc=nn[KMG] [KNL,BOOT] Forces the vmalloc area to have an exact
1971 size of <nn>. This can be used to increase the
1972 minimum size (128MB on x86). It can also be used to
1973 decrease the size and leave more room for directly
1974 mapped kernel RAM.
1976 vmhalt= [KNL,S390] Perform z/VM CP command after system halt.
1977 Format: <command>
1979 vmpanic= [KNL,S390] Perform z/VM CP command after kernel panic.
1980 Format: <command>
1982 vmpoff= [KNL,S390] Perform z/VM CP command after power off.
1983 Format: <command>
1985 waveartist= [HW,OSS]
1986 Format: <io>,<irq>,<dma>,<dma2>
1988 wd33c93= [HW,SCSI]
1989 See header of drivers/scsi/wd33c93.c.
1991 wd7000= [HW,SCSI]
1992 See header of drivers/scsi/wd7000.c.
1994 wdt= [WDT] Watchdog
1995 See Documentation/watchdog/wdt.txt.
1997 xd= [HW,XT] Original XT pre-IDE (RLL encoded) disks.
1998 xd_geo= See header of drivers/block/xd.c.
2000 xirc2ps_cs= [NET,PCMCIA]
2001 Format:
2002 <irq>,<irq_mask>,<io>,<full_duplex>,<do_sound>,<lockup_hack>[,<irq2>[,<irq3>[,<irq4>]]]
2004 norandmaps Don't use address space randomization
2005 Equivalent to echo 0 > /proc/sys/kernel/randomize_va_space
2007 ______________________________________________________________________
2009 TODO:
2011 Add documentation for ALSA options.
2012 Add more DRM drivers.