| blob | c4178778e7fd01d65b99b2279aecad0727701770 |
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,
426 VIA, nVidia)
428 com20020= [HW,NET] ARCnet - COM20020 chipset
429 Format:
430 <io>[,<irq>[,<nodeID>[,<backplane>[,<ckp>[,<timeout>]]]]]
432 com90io= [HW,NET] ARCnet - COM90xx chipset (IO-mapped buffers)
433 Format: <io>[,<irq>]
435 com90xx= [HW,NET]
436 ARCnet - COM90xx chipset (memory-mapped buffers)
437 Format: <io>[,<irq>[,<memstart>]]
439 condev= [HW,S390] console device
440 conmode=
442 console= [KNL] Output console device and options.
444 tty<n> Use the virtual console device <n>.
446 ttyS<n>[,options]
447 ttyUSB0[,options]
448 Use the specified serial port. The options are of
449 the form "bbbbpnf", where "bbbb" is the baud rate,
450 "p" is parity ("n", "o", or "e"), "n" is number of
451 bits, and "f" is flow control ("r" for RTS or
452 omit it). Default is "9600n8".
454 See Documentation/serial-console.txt for more
455 information. See
456 Documentation/networking/netconsole.txt for an
457 alternative.
459 uart[8250],io,<addr>[,options]
460 uart[8250],mmio,<addr>[,options]
461 Start an early, polled-mode console on the 8250/16550
462 UART at the specified I/O port or MMIO address,
463 switching to the matching ttyS device later. The
464 options are the same as for ttyS, above.
466 earlycon= [KNL] Output early console device and options.
467 uart[8250],io,<addr>[,options]
468 uart[8250],mmio,<addr>[,options]
469 Start an early, polled-mode console on the 8250/16550
470 UART at the specified I/O port or MMIO address.
471 The options are the same as for ttyS, above.
473 no_console_suspend
474 [HW] Never suspend the console
475 Disable suspending of consoles during suspend and
476 hibernate operations. Once disabled, debugging
477 messages can reach various consoles while the rest
478 of the system is being put to sleep (ie, while
479 debugging driver suspend/resume hooks). This may
480 not work reliably with all consoles, but is known
481 to work with serial and VGA consoles.
483 cpcihp_generic= [HW,PCI] Generic port I/O CompactPCI driver
484 Format:
485 <first_slot>,<last_slot>,<port>,<enum_bit>[,<debug>]
487 crashkernel=nn[KMG]@ss[KMG]
488 [KNL] Reserve a chunk of physical memory to
489 hold a kernel to switch to with kexec on panic.
491 crashkernel=range1:size1[,range2:size2,...][@offset]
492 [KNL] Same as above, but depends on the memory
493 in the running system. The syntax of range is
494 start-[end] where start and end are both
495 a memory unit (amount[KMG]). See also
496 Documentation/kdump/kdump.txt for a example.
498 cs4232= [HW,OSS]
499 Format: <io>,<irq>,<dma>,<dma2>,<mpuio>,<mpuirq>
501 cs89x0_dma= [HW,NET]
502 Format: <dma>
504 cs89x0_media= [HW,NET]
505 Format: { rj45 | aui | bnc }
507 dasd= [HW,NET]
508 See header of drivers/s390/block/dasd_devmap.c.
510 db9.dev[2|3]= [HW,JOY] Multisystem joystick support via parallel port
511 (one device per port)
512 Format: <port#>,<type>
513 See also Documentation/input/joystick-parport.txt
515 debug [KNL] Enable kernel debugging (events log level).
517 debug_locks_verbose=
518 [KNL] verbose self-tests
519 Format=<0|1>
520 Print debugging info while doing the locking API
521 self-tests.
522 We default to 0 (no extra messages), setting it to
523 1 will print _a lot_ more information - normally
524 only useful to kernel developers.
526 decnet= [HW,NET]
527 Format: <area>[,<node>]
528 See also Documentation/networking/decnet.txt.
530 vt.default_blu= [VT]
531 Format: <blue0>,<blue1>,<blue2>,...,<blue15>
532 Change the default blue palette of the console.
533 This is a 16-member array composed of values
534 ranging from 0-255.
536 vt.default_grn= [VT]
537 Format: <green0>,<green1>,<green2>,...,<green15>
538 Change the default green palette of the console.
539 This is a 16-member array composed of values
540 ranging from 0-255.
542 vt.default_red= [VT]
543 Format: <red0>,<red1>,<red2>,...,<red15>
544 Change the default red palette of the console.
545 This is a 16-member array composed of values
546 ranging from 0-255.
548 vt.default_utf8=
549 [VT]
550 Format=<0|1>
551 Set system-wide default UTF-8 mode for all tty's.
552 Default is 1, i.e. UTF-8 mode is enabled for all
553 newly opened terminals.
555 dhash_entries= [KNL]
556 Set number of hash buckets for dentry cache.
558 digi= [HW,SERIAL]
559 IO parameters + enable/disable command.
561 digiepca= [HW,SERIAL]
562 See drivers/char/README.epca and
563 Documentation/digiepca.txt.
565 dmasound= [HW,OSS] Sound subsystem buffers
567 dscc4.setup= [NET]
569 dtc3181e= [HW,SCSI]
571 earlyprintk= [X86-32,X86-64,SH,BLACKFIN]
572 earlyprintk=vga
573 earlyprintk=serial[,ttySn[,baudrate]]
575 Append ",keep" to not disable it when the real console
576 takes over.
578 Only vga or serial at a time, not both.
580 Currently only ttyS0 and ttyS1 are supported.
582 Interaction with the standard serial driver is not
583 very good.
585 The VGA output is eventually overwritten by the real
586 console.
588 eata= [HW,SCSI]
590 edd= [EDD]
591 Format: {"of[f]" | "sk[ipmbr]"}
592 See comment in arch/i386/boot/edd.S
594 eisa_irq_edge= [PARISC,HW]
595 See header of drivers/parisc/eisa.c.
597 elanfreq= [X86-32]
598 See comment before function elanfreq_setup() in
599 arch/i386/kernel/cpu/cpufreq/elanfreq.c.
601 elevator= [IOSCHED]
602 Format: {"anticipatory" | "cfq" | "deadline" | "noop"}
603 See Documentation/block/as-iosched.txt and
604 Documentation/block/deadline-iosched.txt for details.
606 elfcorehdr= [X86-32, X86_64]
607 Specifies physical address of start of kernel core
608 image elf header. Generally kexec loader will
609 pass this option to capture kernel.
610 See Documentation/kdump/kdump.txt for details.
612 enforcing [SELINUX] Set initial enforcing status.
613 Format: {"0" | "1"}
614 See security/selinux/Kconfig help text.
615 0 -- permissive (log only, no denials).
616 1 -- enforcing (deny and log).
617 Default value is 0.
618 Value can be changed at runtime via /selinux/enforce.
620 es1371= [HW,OSS]
621 Format: <spdif>,[<nomix>,[<amplifier>]]
622 See also header of sound/oss/es1371.c.
624 ether= [HW,NET] Ethernet cards parameters
625 This option is obsoleted by the "netdev=" option, which
626 has equivalent usage. See its documentation for details.
628 eurwdt= [HW,WDT] Eurotech CPU-1220/1410 onboard watchdog.
629 Format: <io>[,<irq>]
631 failslab=
632 fail_page_alloc=
633 fail_make_request=[KNL]
634 General fault injection mechanism.
635 Format: <interval>,<probability>,<space>,<times>
636 See also /Documentation/fault-injection/.
638 fd_mcs= [HW,SCSI]
639 See header of drivers/scsi/fd_mcs.c.
641 fdomain= [HW,SCSI]
642 See header of drivers/scsi/fdomain.c.
644 floppy= [HW]
645 See Documentation/floppy.txt.
647 gamecon.map[2|3]=
648 [HW,JOY] Multisystem joystick and NES/SNES/PSX pad
649 support via parallel port (up to 5 devices per port)
650 Format: <port#>,<pad1>,<pad2>,<pad3>,<pad4>,<pad5>
651 See also Documentation/input/joystick-parport.txt
653 gamma= [HW,DRM]
655 gdth= [HW,SCSI]
656 See header of drivers/scsi/gdth.c.
658 gpt [EFI] Forces disk with valid GPT signature but
659 invalid Protective MBR to be treated as GPT.
661 gvp11= [HW,SCSI]
663 hashdist= [KNL,NUMA] Large hashes allocated during boot
664 are distributed across NUMA nodes. Defaults on
665 for IA-64, off otherwise.
666 Format: 0 | 1 (for off | on)
668 hcl= [IA-64] SGI's Hardware Graph compatibility layer
670 hd= [EIDE] (E)IDE hard drive subsystem geometry
671 Format: <cyl>,<head>,<sect>
673 hd?= [HW] (E)IDE subsystem
674 hd?lun= See Documentation/ide.txt.
676 highmem=nn[KMG] [KNL,BOOT] forces the highmem zone to have an exact
677 size of <nn>. This works even on boxes that have no
678 highmem otherwise. This also works to reduce highmem
679 size on bigger boxes.
681 highres= [KNL] Enable/disable high resolution timer mode.
682 Valid parameters: "on", "off"
683 Default: "on"
685 hisax= [HW,ISDN]
686 See Documentation/isdn/README.HiSax.
688 hugepages= [HW,X86-32,IA-64] Maximal number of HugeTLB pages.
690 i8042.direct [HW] Put keyboard port into non-translated mode
691 i8042.dumbkbd [HW] Pretend that controller can only read data from
692 keyboard and cannot control its state
693 (Don't attempt to blink the leds)
694 i8042.noaux [HW] Don't check for auxiliary (== mouse) port
695 i8042.nokbd [HW] Don't check/create keyboard port
696 i8042.nomux [HW] Don't check presence of an active multiplexing
697 controller
698 i8042.nopnp [HW] Don't use ACPIPnP / PnPBIOS to discover KBD/AUX
699 controllers
700 i8042.panicblink=
701 [HW] Frequency with which keyboard LEDs should blink
702 when kernel panics (default is 0.5 sec)
703 i8042.reset [HW] Reset the controller during init and cleanup
704 i8042.unlock [HW] Unlock (ignore) the keylock
706 i810= [HW,DRM]
708 i8k.ignore_dmi [HW] Continue probing hardware even if DMI data
709 indicates that the driver is running on unsupported
710 hardware.
711 i8k.force [HW] Activate i8k driver even if SMM BIOS signature
712 does not match list of supported models.
713 i8k.power_status
714 [HW] Report power status in /proc/i8k
715 (disabled by default)
716 i8k.restricted [HW] Allow controlling fans only if SYS_ADMIN
717 capability is set.
719 ibmmcascsi= [HW,MCA,SCSI] IBM MicroChannel SCSI adapter
720 See Documentation/mca.txt.
722 icn= [HW,ISDN]
723 Format: <io>[,<membase>[,<icn_id>[,<icn_id2>]]]
725 ide= [HW] (E)IDE subsystem
726 Format: ide=nodma or ide=doubler or ide=reverse
727 See Documentation/ide.txt.
729 ide?= [HW] (E)IDE subsystem
730 Format: ide?=noprobe or chipset specific parameters.
731 See Documentation/ide.txt.
733 idebus= [HW] (E)IDE subsystem - VLB/PCI bus speed
734 See Documentation/ide.txt.
736 idle= [X86]
737 Format: idle=poll or idle=mwait
738 Poll forces a polling idle loop that can slightly improves the performance
739 of waking up a idle CPU, but will use a lot of power and make the system
740 run hot. Not recommended.
741 idle=mwait. On systems which support MONITOR/MWAIT but the kernel chose
742 to not use it because it doesn't save as much power as a normal idle
743 loop use the MONITOR/MWAIT idle loop anyways. Performance should be the same
744 as idle=poll.
746 ignore_loglevel [KNL]
747 Ignore loglevel setting - this will print /all/
748 kernel messages to the console. Useful for debugging.
750 ihash_entries= [KNL]
751 Set number of hash buckets for inode cache.
753 in2000= [HW,SCSI]
754 See header of drivers/scsi/in2000.c.
756 init= [KNL]
757 Format: <full_path>
758 Run specified binary instead of /sbin/init as init
759 process.
761 initcall_debug [KNL] Trace initcalls as they are executed. Useful
762 for working out where the kernel is dying during
763 startup.
765 initrd= [BOOT] Specify the location of the initial ramdisk
767 inport.irq= [HW] Inport (ATI XL and Microsoft) busmouse driver
768 Format: <irq>
770 inttest= [IA64]
772 intel_iommu= [DMAR] Intel IOMMU driver (DMAR) option
773 off
774 Disable intel iommu driver.
775 igfx_off [Default Off]
776 By default, gfx is mapped as normal device. If a gfx
777 device has a dedicated DMAR unit, the DMAR unit is
778 bypassed by not enabling DMAR with this option. In
779 this case, gfx device will use physical address for
780 DMA.
781 forcedac [x86_64]
782 With this option iommu will not optimize to look
783 for io virtual address below 32 bit forcing dual
784 address cycle on pci bus for cards supporting greater
785 than 32 bit addressing. The default is to look
786 for translation below 32 bit and if not available
787 then look in the higher range.
789 io7= [HW] IO7 for Marvel based alpha systems
790 See comment before marvel_specify_io7 in
791 arch/alpha/kernel/core_marvel.c.
793 ip= [IP_PNP]
794 See Documentation/nfsroot.txt.
796 ip2= [HW] Set IO/IRQ pairs for up to 4 IntelliPort boards
797 See comment before ip2_setup() in
798 drivers/char/ip2/ip2base.c.
800 ips= [HW,SCSI] Adaptec / IBM ServeRAID controller
801 See header of drivers/scsi/ips.c.
803 ports= [IP_VS_FTP] IPVS ftp helper module
804 Default is 21.
805 Up to 8 (IP_VS_APP_MAX_PORTS) ports
806 may be specified.
807 Format: <port>,<port>....
809 irqfixup [HW]
810 When an interrupt is not handled search all handlers
811 for it. Intended to get systems with badly broken
812 firmware running.
814 irqpoll [HW]
815 When an interrupt is not handled search all handlers
816 for it. Also check all handlers each timer
817 interrupt. Intended to get systems with badly broken
818 firmware running.
820 isapnp= [ISAPNP]
821 Format: <RDP>,<reset>,<pci_scan>,<verbosity>
823 isolcpus= [KNL,SMP] Isolate CPUs from the general scheduler.
824 Format:
825 <cpu number>,...,<cpu number>
826 or
827 <cpu number>-<cpu number> (must be a positive range in ascending order)
828 or a mixture
829 <cpu number>,...,<cpu number>-<cpu number>
830 This option can be used to specify one or more CPUs
831 to isolate from the general SMP balancing and scheduling
832 algorithms. The only way to move a process onto or off
833 an "isolated" CPU is via the CPU affinity syscalls.
834 <cpu number> begins at 0 and the maximum value is
835 "number of CPUs in system - 1".
837 This option is the preferred way to isolate CPUs. The
838 alternative -- manually setting the CPU mask of all
839 tasks in the system -- can cause problems and
840 suboptimal load balancer performance.
842 iucv= [HW,NET]
844 js= [HW,JOY] Analog joystick
845 See Documentation/input/joystick.txt.
847 kernelcore=nn[KMG] [KNL,X86-32,IA-64,PPC,X86-64] This parameter
848 specifies the amount of memory usable by the kernel
849 for non-movable allocations. The requested amount is
850 spread evenly throughout all nodes in the system. The
851 remaining memory in each node is used for Movable
852 pages. In the event, a node is too small to have both
853 kernelcore and Movable pages, kernelcore pages will
854 take priority and other nodes will have a larger number
855 of kernelcore pages. The Movable zone is used for the
856 allocation of pages that may be reclaimed or moved
857 by the page migration subsystem. This means that
858 HugeTLB pages may not be allocated from this zone.
859 Note that allocations like PTEs-from-HighMem still
860 use the HighMem zone if it exists, and the Normal
861 zone if it does not.
863 movablecore=nn[KMG] [KNL,X86-32,IA-64,PPC,X86-64] This parameter
864 is similar to kernelcore except it specifies the
865 amount of memory used for migratable allocations.
866 If both kernelcore and movablecore is specified,
867 then kernelcore will be at *least* the specified
868 value but may be more. If movablecore on its own
869 is specified, the administrator must be careful
870 that the amount of memory usable for all allocations
871 is not too small.
873 keepinitrd [HW,ARM]
875 kstack=N [X86-32,X86-64] Print N words from the kernel stack
876 in oops dumps.
878 l2cr= [PPC]
880 lapic [X86-32,APIC] Enable the local APIC even if BIOS
881 disabled it.
883 lapic_timer_c2_ok [X86-32,x86-64,APIC] trust the local apic timer in
884 C2 power state.
886 libata.dma= [LIBATA] DMA control
887 libata.dma=0 Disable all PATA and SATA DMA
888 libata.dma=1 PATA and SATA Disk DMA only
889 libata.dma=2 ATAPI (CDROM) DMA only
890 libata.dma=4 Compact Flash DMA only
891 Combinations also work, so libata.dma=3 enables DMA
892 for disks and CDROMs, but not CFs.
894 libata.noacpi [LIBATA] Disables use of ACPI in libata suspend/resume
895 when set.
896 Format: <int>
898 load_ramdisk= [RAM] List of ramdisks to load from floppy
899 See Documentation/ramdisk.txt.
901 lockd.nlm_grace_period=P [NFS] Assign grace period.
902 Format: <integer>
904 lockd.nlm_tcpport=N [NFS] Assign TCP port.
905 Format: <integer>
907 lockd.nlm_timeout=T [NFS] Assign timeout value.
908 Format: <integer>
910 lockd.nlm_udpport=M [NFS] Assign UDP port.
911 Format: <integer>
913 logibm.irq= [HW,MOUSE] Logitech Bus Mouse Driver
914 Format: <irq>
916 loglevel= All Kernel Messages with a loglevel smaller than the
917 console loglevel will be printed to the console. It can
918 also be changed with klogd or other programs. The
919 loglevels are defined as follows:
921 0 (KERN_EMERG) system is unusable
922 1 (KERN_ALERT) action must be taken immediately
923 2 (KERN_CRIT) critical conditions
924 3 (KERN_ERR) error conditions
925 4 (KERN_WARNING) warning conditions
926 5 (KERN_NOTICE) normal but significant condition
927 6 (KERN_INFO) informational
928 7 (KERN_DEBUG) debug-level messages
930 log_buf_len=n Sets the size of the printk ring buffer, in bytes.
931 Format: { n | nk | nM }
932 n must be a power of two. The default size
933 is set in the kernel config file.
935 logo.nologo [FB] Disables display of the built-in Linux logo.
936 This may be used to provide more screen space for
937 kernel log messages and is useful when debugging
938 kernel boot problems.
940 lp=0 [LP] Specify parallel ports to use, e.g,
941 lp=port[,port...] lp=none,parport0 (lp0 not configured, lp1 uses
942 lp=reset first parallel port). 'lp=0' disables the
943 lp=auto printer driver. 'lp=reset' (which can be
944 specified in addition to the ports) causes
945 attached printers to be reset. Using
946 lp=port1,port2,... specifies the parallel ports
947 to associate lp devices with, starting with
948 lp0. A port specification may be 'none' to skip
949 that lp device, or a parport name such as
950 'parport0'. Specifying 'lp=auto' instead of a
951 port specification list means that device IDs
952 from each port should be examined, to see if
953 an IEEE 1284-compliant printer is attached; if
954 so, the driver will manage that printer.
955 See also header of drivers/char/lp.c.
957 lpj=n [KNL]
958 Sets loops_per_jiffy to given constant, thus avoiding
959 time-consuming boot-time autodetection (up to 250 ms per
960 CPU). 0 enables autodetection (default). To determine
961 the correct value for your kernel, boot with normal
962 autodetection and see what value is printed. Note that
963 on SMP systems the preset will be applied to all CPUs,
964 which is likely to cause problems if your CPUs need
965 significantly divergent settings. An incorrect value
966 will cause delays in the kernel to be wrong, leading to
967 unpredictable I/O errors and other breakage. Although
968 unlikely, in the extreme case this might damage your
969 hardware.
971 ltpc= [NET]
972 Format: <io>,<irq>,<dma>
974 mac5380= [HW,SCSI] Format:
975 <can_queue>,<cmd_per_lun>,<sg_tablesize>,<hostid>,<use_tags>
977 mac53c9x= [HW,SCSI] Format:
978 <num_esps>,<disconnect>,<nosync>,<can_queue>,<cmd_per_lun>,<sg_tablesize>,<hostid>,<use_tags>
980 machvec= [IA64] Force the use of a particular machine-vector
981 (machvec) in a generic kernel.
982 Example: machvec=hpzx1_swiotlb
984 max_loop= [LOOP] Maximum number of loopback devices that can
985 be mounted
986 Format: <1-256>
988 maxcpus= [SMP] Maximum number of processors that an SMP kernel
989 should make use of. maxcpus=n : n >= 0 limits the
990 kernel to using 'n' processors. n=0 is a special case,
991 it is equivalent to "nosmp", which also disables
992 the IO APIC.
994 max_addr=[KMG] [KNL,BOOT,ia64] All physical memory greater than or
995 equal to this physical address is ignored.
997 max_luns= [SCSI] Maximum number of LUNs to probe.
998 Should be between 1 and 2^32-1.
1000 max_report_luns=
1001 [SCSI] Maximum number of LUNs received.
1002 Should be between 1 and 16384.
1004 mca-pentium [BUGS=X86-32]
1006 mcatest= [IA-64]
1008 mce [X86-32] Machine Check Exception
1010 mce=option [X86-64] See Documentation/x86_64/boot-options.txt
1012 md= [HW] RAID subsystems devices and level
1013 See Documentation/md.txt.
1015 mdacon= [MDA]
1016 Format: <first>,<last>
1017 Specifies range of consoles to be captured by the MDA.
1019 mem=nn[KMG] [KNL,BOOT] Force usage of a specific amount of memory
1020 Amount of memory to be used when the kernel is not able
1021 to see the whole system memory or for test.
1022 [X86-32] Use together with memmap= to avoid physical
1023 address space collisions. Without memmap= PCI devices
1024 could be placed at addresses belonging to unused RAM.
1026 mem=nopentium [BUGS=X86-32] Disable usage of 4MB pages for kernel
1027 memory.
1029 memmap=exactmap [KNL,X86-32,X86_64] Enable setting of an exact
1030 E820 memory map, as specified by the user.
1031 Such memmap=exactmap lines can be constructed based on
1032 BIOS output or other requirements. See the memmap=nn@ss
1033 option description.
1035 memmap=nn[KMG]@ss[KMG]
1036 [KNL] Force usage of a specific region of memory
1037 Region of memory to be used, from ss to ss+nn.
1039 memmap=nn[KMG]#ss[KMG]
1040 [KNL,ACPI] Mark specific memory as ACPI data.
1041 Region of memory to be used, from ss to ss+nn.
1043 memmap=nn[KMG]$ss[KMG]
1044 [KNL,ACPI] Mark specific memory as reserved.
1045 Region of memory to be used, from ss to ss+nn.
1047 meye.*= [HW] Set MotionEye Camera parameters
1048 See Documentation/video4linux/meye.txt.
1050 mfgpt_irq= [IA-32] Specify the IRQ to use for the
1051 Multi-Function General Purpose Timers on AMD Geode
1052 platforms.
1054 mga= [HW,DRM]
1056 mousedev.tap_time=
1057 [MOUSE] Maximum time between finger touching and
1058 leaving touchpad surface for touch to be considered
1059 a tap and be reported as a left button click (for
1060 touchpads working in absolute mode only).
1061 Format: <msecs>
1062 mousedev.xres= [MOUSE] Horizontal screen resolution, used for devices
1063 reporting absolute coordinates, such as tablets
1064 mousedev.yres= [MOUSE] Vertical screen resolution, used for devices
1065 reporting absolute coordinates, such as tablets
1067 mpu401= [HW,OSS]
1068 Format: <io>,<irq>
1070 MTD_Partition= [MTD]
1071 Format: <name>,<region-number>,<size>,<offset>
1073 MTD_Region= [MTD] Format:
1074 <name>,<region-number>[,<base>,<size>,<buswidth>,<altbuswidth>]
1076 mtdparts= [MTD]
1077 See drivers/mtd/cmdlinepart.c.
1079 mtouchusb.raw_coordinates=
1080 [HW] Make the MicroTouch USB driver use raw coordinates
1081 ('y', default) or cooked coordinates ('n')
1083 n2= [NET] SDL Inc. RISCom/N2 synchronous serial card
1085 NCR_D700= [HW,SCSI]
1086 See header of drivers/scsi/NCR_D700.c.
1088 ncr5380= [HW,SCSI]
1090 ncr53c400= [HW,SCSI]
1092 ncr53c400a= [HW,SCSI]
1094 ncr53c406a= [HW,SCSI]
1096 ncr53c8xx= [HW,SCSI]
1098 netdev= [NET] Network devices parameters
1099 Format: <irq>,<io>,<mem_start>,<mem_end>,<name>
1100 Note that mem_start is often overloaded to mean
1101 something different and driver-specific.
1102 This usage is only documented in each driver source
1103 file if at all.
1105 nfsaddrs= [NFS]
1106 See Documentation/nfsroot.txt.
1108 nfsroot= [NFS] nfs root filesystem for disk-less boxes.
1109 See Documentation/nfsroot.txt.
1111 nfs.callback_tcpport=
1112 [NFS] set the TCP port on which the NFSv4 callback
1113 channel should listen.
1115 nfs.idmap_cache_timeout=
1116 [NFS] set the maximum lifetime for idmapper cache
1117 entries.
1119 nfs.enable_ino64=
1120 [NFS] enable 64-bit inode numbers.
1121 If zero, the NFS client will fake up a 32-bit inode
1122 number for the readdir() and stat() syscalls instead
1123 of returning the full 64-bit number.
1124 The default is to return 64-bit inode numbers.
1126 nmi_watchdog= [KNL,BUGS=X86-32] Debugging features for SMP kernels
1128 no387 [BUGS=X86-32] Tells the kernel to use the 387 maths
1129 emulation library even if a 387 maths coprocessor
1130 is present.
1132 noaliencache [MM, NUMA, SLAB] Disables the allocation of alien
1133 caches in the slab allocator. Saves per-node memory,
1134 but will impact performance.
1136 noalign [KNL,ARM]
1138 noapic [SMP,APIC] Tells the kernel to not make use of any
1139 IOAPICs that may be present in the system.
1141 nobats [PPC] Do not use BATs for mapping kernel lowmem
1142 on "Classic" PPC cores.
1144 nocache [ARM]
1146 nodelayacct [KNL] Disable per-task delay accounting
1148 nodisconnect [HW,SCSI,M68K] Disables SCSI disconnects.
1150 noexec [IA-64]
1152 noexec [X86-32,X86-64]
1153 noexec=on: enable non-executable mappings (default)
1154 noexec=off: disable nn-executable mappings
1156 nofxsr [BUGS=X86-32] Disables x86 floating point extended
1157 register save and restore. The kernel will only save
1158 legacy floating-point registers on task switch.
1160 nohlt [BUGS=ARM]
1162 no-hlt [BUGS=X86-32] Tells the kernel that the hlt
1163 instruction doesn't work correctly and not to
1164 use it.
1166 nohalt [IA-64] Tells the kernel not to use the power saving
1167 function PAL_HALT_LIGHT when idle. This increases
1168 power-consumption. On the positive side, it reduces
1169 interrupt wake-up latency, which may improve performance
1170 in certain environments such as networked servers or
1171 real-time systems.
1173 nohz= [KNL] Boottime enable/disable dynamic ticks
1174 Valid arguments: on, off
1175 Default: on
1177 noirqbalance [X86-32,SMP,KNL] Disable kernel irq balancing
1179 noirqdebug [X86-32] Disables the code which attempts to detect and
1180 disable unhandled interrupt sources.
1182 no_timer_check [X86-32,X86_64,APIC] Disables the code which tests for
1183 broken timer IRQ sources.
1185 noisapnp [ISAPNP] Disables ISA PnP code.
1187 noinitrd [RAM] Tells the kernel not to load any configured
1188 initial RAM disk.
1190 nointroute [IA-64]
1192 nojitter [IA64] Disables jitter checking for ITC timers.
1194 nolapic [X86-32,APIC] Do not enable or use the local APIC.
1196 nolapic_timer [X86-32,APIC] Do not use the local APIC timer.
1198 noltlbs [PPC] Do not use large page/tlb entries for kernel
1199 lowmem mapping on PPC40x.
1201 nomca [IA-64] Disable machine check abort handling
1203 nomce [X86-32] Machine Check Exception
1205 nomfgpt [X86-32] Disable Multi-Function General Purpose
1206 Timer usage (for AMD Geode machines).
1208 noreplace-paravirt [X86-32,PV_OPS] Don't patch paravirt_ops
1210 noreplace-smp [X86-32,SMP] Don't replace SMP instructions
1211 with UP alternatives
1213 noresidual [PPC] Don't use residual data on PReP machines.
1215 noresume [SWSUSP] Disables resume and restores original swap
1216 space.
1218 no-scroll [VGA] Disables scrollback.
1219 This is required for the Braillex ib80-piezo Braille
1220 reader made by F.H. Papenmeier (Germany).
1222 nosbagart [IA-64]
1224 nosep [BUGS=X86-32] Disables x86 SYSENTER/SYSEXIT support.
1226 nosmp [SMP] Tells an SMP kernel to act as a UP kernel,
1227 and disable the IO APIC. legacy for "maxcpus=0".
1229 nosoftlockup [KNL] Disable the soft-lockup detector.
1231 nosync [HW,M68K] Disables sync negotiation for all devices.
1233 notsc [BUGS=X86-32] Disable Time Stamp Counter
1235 nousb [USB] Disable the USB subsystem
1237 nowb [ARM]
1239 numa_zonelist_order= [KNL, BOOT] Select zonelist order for NUMA.
1240 one of ['zone', 'node', 'default'] can be specified
1241 This can be set from sysctl after boot.
1242 See Documentation/sysctl/vm.txt for details.
1244 nr_uarts= [SERIAL] maximum number of UARTs to be registered.
1246 opl3= [HW,OSS]
1247 Format: <io>
1249 oprofile.timer= [HW]
1250 Use timer interrupt instead of performance counters
1252 osst= [HW,SCSI] SCSI Tape Driver
1253 Format: <buffer_size>,<write_threshold>
1254 See also Documentation/scsi/st.txt.
1256 panic= [KNL] Kernel behaviour on panic
1257 Format: <timeout>
1259 parkbd.port= [HW] Parallel port number the keyboard adapter is
1260 connected to, default is 0.
1261 Format: <parport#>
1262 parkbd.mode= [HW] Parallel port keyboard adapter mode of operation,
1263 0 for XT, 1 for AT (default is AT).
1264 Format: <mode>
1266 parport= [HW,PPT] Specify parallel ports. 0 disables.
1267 Format: { 0 | auto | 0xBBB[,IRQ[,DMA]] }
1268 Use 'auto' to force the driver to use any
1269 IRQ/DMA settings detected (the default is to
1270 ignore detected IRQ/DMA settings because of
1271 possible conflicts). You can specify the base
1272 address, IRQ, and DMA settings; IRQ and DMA
1273 should be numbers, or 'auto' (for using detected
1274 settings on that particular port), or 'nofifo'
1275 (to avoid using a FIFO even if it is detected).
1276 Parallel ports are assigned in the order they
1277 are specified on the command line, starting
1278 with parport0.
1280 parport_init_mode= [HW,PPT]
1281 Configure VIA parallel port to operate in
1282 a specific mode. This is necessary on Pegasos
1283 computer where firmware has no options for setting
1284 up parallel port mode and sets it to spp.
1285 Currently this function knows 686a and 8231 chips.
1286 Format: [spp|ps2|epp|ecp|ecpepp]
1288 pas2= [HW,OSS] Format:
1289 <io>,<irq>,<dma>,<dma16>,<sb_io>,<sb_irq>,<sb_dma>,<sb_dma16>
1291 pas16= [HW,SCSI]
1292 See header of drivers/scsi/pas16.c.
1294 pause_on_oops=
1295 Halt all CPUs after the first oops has been printed for
1296 the specified number of seconds. This is to be used if
1297 your oopses keep scrolling off the screen.
1299 pcbit= [HW,ISDN]
1301 pcd. [PARIDE]
1302 See header of drivers/block/paride/pcd.c.
1303 See also Documentation/paride.txt.
1305 pci=option[,option...] [PCI] various PCI subsystem options:
1306 off [X86-32] don't probe for the PCI bus
1307 bios [X86-32] force use of PCI BIOS, don't access
1308 the hardware directly. Use this if your machine
1309 has a non-standard PCI host bridge.
1310 nobios [X86-32] disallow use of PCI BIOS, only direct
1311 hardware access methods are allowed. Use this
1312 if you experience crashes upon bootup and you
1313 suspect they are caused by the BIOS.
1314 conf1 [X86-32] Force use of PCI Configuration
1315 Mechanism 1.
1316 conf2 [X86-32] Force use of PCI Configuration
1317 Mechanism 2.
1318 noaer [PCIE] If the PCIEAER kernel config parameter is
1319 enabled, this kernel boot option can be used to
1320 disable the use of PCIE advanced error reporting.
1321 nodomains [PCI] Disable support for multiple PCI
1322 root domains (aka PCI segments, in ACPI-speak).
1323 nommconf [X86-32,X86_64] Disable use of MMCONFIG for PCI
1324 Configuration
1325 nomsi [MSI] If the PCI_MSI kernel config parameter is
1326 enabled, this kernel boot option can be used to
1327 disable the use of MSI interrupts system-wide.
1328 nosort [X86-32] Don't sort PCI devices according to
1329 order given by the PCI BIOS. This sorting is
1330 done to get a device order compatible with
1331 older kernels.
1332 biosirq [X86-32] Use PCI BIOS calls to get the interrupt
1333 routing table. These calls are known to be buggy
1334 on several machines and they hang the machine
1335 when used, but on other computers it's the only
1336 way to get the interrupt routing table. Try
1337 this option if the kernel is unable to allocate
1338 IRQs or discover secondary PCI buses on your
1339 motherboard.
1340 rom [X86-32] Assign address space to expansion ROMs.
1341 Use with caution as certain devices share
1342 address decoders between ROMs and other
1343 resources.
1344 irqmask=0xMMMM [X86-32] Set a bit mask of IRQs allowed to be
1345 assigned automatically to PCI devices. You can
1346 make the kernel exclude IRQs of your ISA cards
1347 this way.
1348 pirqaddr=0xAAAAA [X86-32] Specify the physical address
1349 of the PIRQ table (normally generated
1350 by the BIOS) if it is outside the
1351 F0000h-100000h range.
1352 lastbus=N [X86-32] Scan all buses thru bus #N. Can be
1353 useful if the kernel is unable to find your
1354 secondary buses and you want to tell it
1355 explicitly which ones they are.
1356 assign-busses [X86-32] Always assign all PCI bus
1357 numbers ourselves, overriding
1358 whatever the firmware may have done.
1359 usepirqmask [X86-32] Honor the possible IRQ mask stored
1360 in the BIOS $PIR table. This is needed on
1361 some systems with broken BIOSes, notably
1362 some HP Pavilion N5400 and Omnibook XE3
1363 notebooks. This will have no effect if ACPI
1364 IRQ routing is enabled.
1365 noacpi [X86-32] Do not use ACPI for IRQ routing
1366 or for PCI scanning.
1367 use_crs [X86-32] Use _CRS for PCI resource
1368 allocation.
1369 routeirq Do IRQ routing for all PCI devices.
1370 This is normally done in pci_enable_device(),
1371 so this option is a temporary workaround
1372 for broken drivers that don't call it.
1373 firmware [ARM] Do not re-enumerate the bus but instead
1374 just use the configuration from the
1375 bootloader. This is currently used on
1376 IXP2000 systems where the bus has to be
1377 configured a certain way for adjunct CPUs.
1378 noearly [X86] Don't do any early type 1 scanning.
1379 This might help on some broken boards which
1380 machine check when some devices' config space
1381 is read. But various workarounds are disabled
1382 and some IOMMU drivers will not work.
1383 bfsort Sort PCI devices into breadth-first order.
1384 This sorting is done to get a device
1385 order compatible with older (<= 2.4) kernels.
1386 nobfsort Don't sort PCI devices into breadth-first order.
1387 cbiosize=nn[KMG] The fixed amount of bus space which is
1388 reserved for the CardBus bridge's IO window.
1389 The default value is 256 bytes.
1390 cbmemsize=nn[KMG] The fixed amount of bus space which is
1391 reserved for the CardBus bridge's memory
1392 window. The default value is 64 megabytes.
1394 pcmv= [HW,PCMCIA] BadgePAD 4
1396 pd. [PARIDE]
1397 See Documentation/paride.txt.
1399 pdcchassis= [PARISC,HW] Disable/Enable PDC Chassis Status codes at
1400 boot time.
1401 Format: { 0 | 1 }
1402 See arch/parisc/kernel/pdc_chassis.c
1404 pf. [PARIDE]
1405 See Documentation/paride.txt.
1407 pg. [PARIDE]
1408 See Documentation/paride.txt.
1410 pirq= [SMP,APIC] Manual mp-table setup
1411 See Documentation/i386/IO-APIC.txt.
1413 plip= [PPT,NET] Parallel port network link
1414 Format: { parport<nr> | timid | 0 }
1415 See also Documentation/parport.txt.
1417 pnpacpi= [ACPI]
1418 { off }
1420 pnpbios= [ISAPNP]
1421 { on | off | curr | res | no-curr | no-res }
1423 pnp_reserve_irq=
1424 [ISAPNP] Exclude IRQs for the autoconfiguration
1426 pnp_reserve_dma=
1427 [ISAPNP] Exclude DMAs for the autoconfiguration
1429 pnp_reserve_io= [ISAPNP] Exclude I/O ports for the autoconfiguration
1430 Ranges are in pairs (I/O port base and size).
1432 pnp_reserve_mem=
1433 [ISAPNP] Exclude memory regions for the
1434 autoconfiguration.
1435 Ranges are in pairs (memory base and size).
1437 print-fatal-signals=
1438 [KNL] debug: print fatal signals
1439 print-fatal-signals=1: print segfault info to
1440 the kernel console.
1441 default: off.
1443 printk.time= Show timing data prefixed to each printk message line
1444 Format: <bool> (1/Y/y=enable, 0/N/n=disable)
1446 profile= [KNL] Enable kernel profiling via /proc/profile
1447 Format: [schedule,]<number>
1448 Param: "schedule" - profile schedule points.
1449 Param: <number> - step/bucket size as a power of 2 for
1450 statistical time based profiling.
1451 Param: "sleep" - profile D-state sleeping (millisecs).
1452 Requires CONFIG_SCHEDSTATS
1453 Param: "kvm" - profile VM exits.
1455 processor.max_cstate= [HW,ACPI]
1456 Limit processor to maximum C-state
1457 max_cstate=9 overrides any DMI blacklist limit.
1459 processor.nocst [HW,ACPI]
1460 Ignore the _CST method to determine C-states,
1461 instead using the legacy FADT method
1463 prompt_ramdisk= [RAM] List of RAM disks to prompt for floppy disk
1464 before loading.
1465 See Documentation/ramdisk.txt.
1467 psmouse.proto= [HW,MOUSE] Highest PS2 mouse protocol extension to
1468 probe for; one of (bare|imps|exps|lifebook|any).
1469 psmouse.rate= [HW,MOUSE] Set desired mouse report rate, in reports
1470 per second.
1471 psmouse.resetafter= [HW,MOUSE]
1472 Try to reset the device after so many bad packets
1473 (0 = never).
1474 psmouse.resolution=
1475 [HW,MOUSE] Set desired mouse resolution, in dpi.
1476 psmouse.smartscroll=
1477 [HW,MOUSE] Controls Logitech smartscroll autorepeat.
1478 0 = disabled, 1 = enabled (default).
1480 pss= [HW,OSS] Personal Sound System (ECHO ESC614)
1481 Format:
1482 <io>,<mss_io>,<mss_irq>,<mss_dma>,<mpu_io>,<mpu_irq>
1484 pt. [PARIDE]
1485 See Documentation/paride.txt.
1487 pty.legacy_count=
1488 [KNL] Number of legacy pty's. Overwrites compiled-in
1489 default number.
1491 quiet [KNL] Disable most log messages
1493 r128= [HW,DRM]
1495 raid= [HW,RAID]
1496 See Documentation/md.txt.
1498 ramdisk_blocksize= [RAM]
1499 See Documentation/ramdisk.txt.
1501 ramdisk_size= [RAM] Sizes of RAM disks in kilobytes
1502 See Documentation/ramdisk.txt.
1504 rcu.blimit= [KNL,BOOT] Set maximum number of finished
1505 RCU callbacks to process in one batch.
1507 rcu.qhimark= [KNL,BOOT] Set threshold of queued
1508 RCU callbacks over which batch limiting is disabled.
1510 rcu.qlowmark= [KNL,BOOT] Set threshold of queued
1511 RCU callbacks below which batch limiting is re-enabled.
1513 rdinit= [KNL]
1514 Format: <full_path>
1515 Run specified binary instead of /init from the ramdisk,
1516 used for early userspace startup. See initrd.
1518 reboot= [BUGS=X86-32,BUGS=ARM,BUGS=IA-64] Rebooting mode
1519 Format: <reboot_mode>[,<reboot_mode2>[,...]]
1520 See arch/*/kernel/reboot.c or arch/*/kernel/process.c
1522 reserve= [KNL,BUGS] Force the kernel to ignore some iomem area
1524 reservetop= [X86-32]
1525 Format: nn[KMG]
1526 Reserves a hole at the top of the kernel virtual
1527 address space.
1529 reset_devices [KNL] Force drivers to reset the underlying device
1530 during initialization.
1532 resume= [SWSUSP]
1533 Specify the partition device for software suspend
1535 resume_offset= [SWSUSP]
1536 Specify the offset from the beginning of the partition
1537 given by "resume=" at which the swap header is located,
1538 in <PAGE_SIZE> units (needed only for swap files).
1539 See Documentation/power/swsusp-and-swap-files.txt
1541 retain_initrd [RAM] Keep initrd memory after extraction
1543 rhash_entries= [KNL,NET]
1544 Set number of hash buckets for route cache
1546 riscom8= [HW,SERIAL]
1547 Format: <io_board1>[,<io_board2>[,...<io_boardN>]]
1549 ro [KNL] Mount root device read-only on boot
1551 root= [KNL] Root filesystem
1553 rootdelay= [KNL] Delay (in seconds) to pause before attempting to
1554 mount the root filesystem
1556 rootflags= [KNL] Set root filesystem mount option string
1558 rootfstype= [KNL] Set root filesystem type
1560 rootwait [KNL] Wait (indefinitely) for root device to show up.
1561 Useful for devices that are detected asynchronously
1562 (e.g. USB and MMC devices).
1564 root_plug.vendor_id=
1565 [ROOTPLUG] Override the default vendor ID
1567 root_plug.product_id=
1568 [ROOTPLUG] Override the default product ID
1570 root_plug.debug=
1571 [ROOTPLUG] Enable debugging output
1573 rw [KNL] Mount root device read-write on boot
1575 S [KNL] Run init in single mode
1577 sa1100ir [NET]
1578 See drivers/net/irda/sa1100_ir.c.
1580 sbni= [NET] Granch SBNI12 leased line adapter
1582 sc1200wdt= [HW,WDT] SC1200 WDT (watchdog) driver
1583 Format: <io>[,<timeout>[,<isapnp>]]
1585 scsi_debug_*= [SCSI]
1586 See drivers/scsi/scsi_debug.c.
1588 scsi_default_dev_flags=
1589 [SCSI] SCSI default device flags
1590 Format: <integer>
1592 scsi_dev_flags= [SCSI] Black/white list entry for vendor and model
1593 Format: <vendor>:<model>:<flags>
1594 (flags are integer value)
1596 scsi_logging= [SCSI]
1598 scsi_mod.scan= [SCSI] sync (default) scans SCSI busses as they are
1599 discovered. async scans them in kernel threads,
1600 allowing boot to proceed. none ignores them, expecting
1601 user space to do the scan.
1603 selinux [SELINUX] Disable or enable SELinux at boot time.
1604 Format: { "0" | "1" }
1605 See security/selinux/Kconfig help text.
1606 0 -- disable.
1607 1 -- enable.
1608 Default value is set via kernel config option.
1609 If enabled at boot time, /selinux/disable can be used
1610 later to disable prior to initial policy load.
1612 selinux_compat_net =
1613 [SELINUX] Set initial selinux_compat_net flag value.
1614 Format: { "0" | "1" }
1615 0 -- use new secmark-based packet controls
1616 1 -- use legacy packet controls
1617 Default value is 0 (preferred).
1618 Value can be changed at runtime via
1619 /selinux/compat_net.
1621 serialnumber [BUGS=X86-32]
1623 shapers= [NET]
1624 Maximal number of shapers.
1626 sim710= [SCSI,HW]
1627 See header of drivers/scsi/sim710.c.
1629 simeth= [IA-64]
1630 simscsi=
1632 slram= [HW,MTD]
1634 slub_debug[=options[,slabs]] [MM, SLUB]
1635 Enabling slub_debug allows one to determine the
1636 culprit if slab objects become corrupted. Enabling
1637 slub_debug can create guard zones around objects and
1638 may poison objects when not in use. Also tracks the
1639 last alloc / free. For more information see
1640 Documentation/vm/slub.txt.
1642 slub_max_order= [MM, SLUB]
1643 Determines the maximum allowed order for slabs.
1644 A high setting may cause OOMs due to memory
1645 fragmentation. For more information see
1646 Documentation/vm/slub.txt.
1648 slub_min_objects= [MM, SLUB]
1649 The minimum number of objects per slab. SLUB will
1650 increase the slab order up to slub_max_order to
1651 generate a sufficiently large slab able to contain
1652 the number of objects indicated. The higher the number
1653 of objects the smaller the overhead of tracking slabs
1654 and the less frequently locks need to be acquired.
1655 For more information see Documentation/vm/slub.txt.
1657 slub_min_order= [MM, SLUB]
1658 Determines the mininum page order for slabs. Must be
1659 lower than slub_max_order.
1660 For more information see Documentation/vm/slub.txt.
1662 slub_nomerge [MM, SLUB]
1663 Disable merging of slabs with similar size. May be
1664 necessary if there is some reason to distinguish
1665 allocs to different slabs. Debug options disable
1666 merging on their own.
1667 For more information see Documentation/vm/slub.txt.
1669 smart2= [HW]
1670 Format: <io1>[,<io2>[,...,<io8>]]
1672 smp-alt-once [X86-32,SMP] On a hotplug CPU system, only
1673 attempt to substitute SMP alternatives once at boot.
1675 smsc-ircc2.nopnp [HW] Don't use PNP to discover SMC devices
1676 smsc-ircc2.ircc_cfg= [HW] Device configuration I/O port
1677 smsc-ircc2.ircc_sir= [HW] SIR base I/O port
1678 smsc-ircc2.ircc_fir= [HW] FIR base I/O port
1679 smsc-ircc2.ircc_irq= [HW] IRQ line
1680 smsc-ircc2.ircc_dma= [HW] DMA channel
1681 smsc-ircc2.ircc_transceiver= [HW] Transceiver type:
1682 0: Toshiba Satellite 1800 (GP data pin select)
1683 1: Fast pin select (default)
1684 2: ATC IRMode
1686 snd-ad1816a= [HW,ALSA]
1688 snd-ad1848= [HW,ALSA]
1690 snd-ali5451= [HW,ALSA]
1692 snd-als100= [HW,ALSA]
1694 snd-als4000= [HW,ALSA]
1696 snd-azt2320= [HW,ALSA]
1698 snd-cmi8330= [HW,ALSA]
1700 snd-cmipci= [HW,ALSA]
1702 snd-cs4231= [HW,ALSA]
1704 snd-cs4232= [HW,ALSA]
1706 snd-cs4236= [HW,ALSA]
1708 snd-cs4281= [HW,ALSA]
1710 snd-cs46xx= [HW,ALSA]
1712 snd-dt019x= [HW,ALSA]
1714 snd-dummy= [HW,ALSA]
1716 snd-emu10k1= [HW,ALSA]
1718 snd-ens1370= [HW,ALSA]
1720 snd-ens1371= [HW,ALSA]
1722 snd-es968= [HW,ALSA]
1724 snd-es1688= [HW,ALSA]
1726 snd-es18xx= [HW,ALSA]
1728 snd-es1938= [HW,ALSA]
1730 snd-es1968= [HW,ALSA]
1732 snd-fm801= [HW,ALSA]
1734 snd-gusclassic= [HW,ALSA]
1736 snd-gusextreme= [HW,ALSA]
1738 snd-gusmax= [HW,ALSA]
1740 snd-hdsp= [HW,ALSA]
1742 snd-ice1712= [HW,ALSA]
1744 snd-intel8x0= [HW,ALSA]
1746 snd-interwave= [HW,ALSA]
1748 snd-interwave-stb=
1749 [HW,ALSA]
1751 snd-korg1212= [HW,ALSA]
1753 snd-maestro3= [HW,ALSA]
1755 snd-mpu401= [HW,ALSA]
1757 snd-mtpav= [HW,ALSA]
1759 snd-nm256= [HW,ALSA]
1761 snd-opl3sa2= [HW,ALSA]
1763 snd-opti92x-ad1848=
1764 [HW,ALSA]
1766 snd-opti92x-cs4231=
1767 [HW,ALSA]
1769 snd-opti93x= [HW,ALSA]
1771 snd-pmac= [HW,ALSA]
1773 snd-rme32= [HW,ALSA]
1775 snd-rme96= [HW,ALSA]
1777 snd-rme9652= [HW,ALSA]
1779 snd-sb8= [HW,ALSA]
1781 snd-sb16= [HW,ALSA]
1783 snd-sbawe= [HW,ALSA]
1785 snd-serial= [HW,ALSA]
1787 snd-sgalaxy= [HW,ALSA]
1789 snd-sonicvibes= [HW,ALSA]
1791 snd-sun-amd7930=
1792 [HW,ALSA]
1794 snd-sun-cs4231= [HW,ALSA]
1796 snd-trident= [HW,ALSA]
1798 snd-usb-audio= [HW,ALSA,USB]
1800 snd-via82xx= [HW,ALSA]
1802 snd-virmidi= [HW,ALSA]
1804 snd-wavefront= [HW,ALSA]
1806 snd-ymfpci= [HW,ALSA]
1808 sonypi.*= [HW] Sony Programmable I/O Control Device driver
1809 See Documentation/sonypi.txt
1811 specialix= [HW,SERIAL] Specialix multi-serial port adapter
1812 See Documentation/specialix.txt.
1814 spia_io_base= [HW,MTD]
1815 spia_fio_base=
1816 spia_pedr=
1817 spia_peddr=
1819 sscape= [HW,OSS]
1820 Format: <io>,<irq>,<dma>,<mpu_io>,<mpu_irq>
1822 st= [HW,SCSI] SCSI tape parameters (buffers, etc.)
1823 See Documentation/scsi/st.txt.
1825 st0x= [HW,SCSI]
1826 See header of drivers/scsi/seagate.c.
1828 sti= [PARISC,HW]
1829 Format: <num>
1830 Set the STI (builtin display/keyboard on the HP-PARISC
1831 machines) console (graphic card) which should be used
1832 as the initial boot-console.
1833 See also comment in drivers/video/console/sticore.c.
1835 sti_font= [HW]
1836 See comment in drivers/video/console/sticore.c.
1838 stifb= [HW]
1839 Format: bpp:<bpp1>[:<bpp2>[:<bpp3>...]]
1841 sunrpc.pool_mode=
1842 [NFS]
1843 Control how the NFS server code allocates CPUs to
1844 service thread pools. Depending on how many NICs
1845 you have and where their interrupts are bound, this
1846 option will affect which CPUs will do NFS serving.
1847 Note: this parameter cannot be changed while the
1848 NFS server is running.
1850 auto the server chooses an appropriate mode
1851 automatically using heuristics
1852 global a single global pool contains all CPUs
1853 percpu one pool for each CPU
1854 pernode one pool for each NUMA node (equivalent
1855 to global on non-NUMA machines)
1857 swiotlb= [IA-64] Number of I/O TLB slabs
1859 switches= [HW,M68k]
1861 sym53c416= [HW,SCSI]
1862 See header of drivers/scsi/sym53c416.c.
1864 sysrq_always_enabled
1865 [KNL]
1866 Ignore sysrq setting - this boot parameter will
1867 neutralize any effect of /proc/sys/kernel/sysrq.
1868 Useful for debugging.
1870 t128= [HW,SCSI]
1871 See header of drivers/scsi/t128.c.
1873 tdfx= [HW,DRM]
1875 thash_entries= [KNL,NET]
1876 Set number of hash buckets for TCP connection
1878 thermal.act= [HW,ACPI]
1879 -1: disable all active trip points in all thermal zones
1880 <degrees C>: override all lowest active trip points
1882 thermal.crt= [HW,ACPI]
1883 -1: disable all critical trip points in all thermal zones
1884 <degrees C>: lower all critical trip points
1886 thermal.nocrt= [HW,ACPI]
1887 Set to disable actions on ACPI thermal zone
1888 critical and hot trip points.
1890 thermal.off= [HW,ACPI]
1891 1: disable ACPI thermal control
1893 thermal.psv= [HW,ACPI]
1894 -1: disable all passive trip points
1895 <degrees C>: override all passive trip points to this value
1897 thermal.tzp= [HW,ACPI]
1898 Specify global default ACPI thermal zone polling rate
1899 <deci-seconds>: poll all this frequency
1900 0: no polling (default)
1902 time Show timing data prefixed to each printk message line
1903 [deprecated, see 'printk.time']
1905 tipar.timeout= [HW,PPT]
1906 Set communications timeout in tenths of a second
1907 (default 15).
1909 tipar.delay= [HW,PPT]
1910 Set inter-bit delay in microseconds (default 10).
1912 tmc8xx= [HW,SCSI]
1913 See header of drivers/scsi/seagate.c.
1915 tmscsim= [HW,SCSI]
1916 See comment before function dc390_setup() in
1917 drivers/scsi/tmscsim.c.
1919 tp720= [HW,PS2]
1921 trix= [HW,OSS] MediaTrix AudioTrix Pro
1922 Format:
1923 <io>,<irq>,<dma>,<dma2>,<sb_io>,<sb_irq>,<sb_dma>,<mpu_io>,<mpu_irq>
1925 turbografx.map[2|3]= [HW,JOY]
1926 TurboGraFX parallel port interface
1927 Format:
1928 <port#>,<js1>,<js2>,<js3>,<js4>,<js5>,<js6>,<js7>
1929 See also Documentation/input/joystick-parport.txt
1931 u14-34f= [HW,SCSI] UltraStor 14F/34F SCSI host adapter
1932 See header of drivers/scsi/u14-34f.c.
1934 uart401= [HW,OSS]
1935 Format: <io>,<irq>
1937 uart6850= [HW,OSS]
1938 Format: <io>,<irq>
1940 uhci-hcd.ignore_oc=
1941 [USB] Ignore overcurrent events (default N).
1942 Some badly-designed motherboards generate lots of
1943 bogus events, for ports that aren't wired to
1944 anything. Set this parameter to avoid log spamming.
1945 Note that genuine overcurrent events won't be
1946 reported either.
1948 usbcore.autosuspend=
1949 [USB] The autosuspend time delay (in seconds) used
1950 for newly-detected USB devices (default 2). This
1951 is the time required before an idle device will be
1952 autosuspended. Devices for which the delay is set
1953 to a negative value won't be autosuspended at all.
1955 usbhid.mousepoll=
1956 [USBHID] The interval which mice are to be polled at.
1958 vdso= [X86-32,SH,x86-64]
1959 vdso=2: enable compat VDSO (default with COMPAT_VDSO)
1960 vdso=1: enable VDSO (default)
1961 vdso=0: disable VDSO mapping
1963 vector= [IA-64,SMP]
1964 vector=percpu: enable percpu vector domain
1966 video= [FB] Frame buffer configuration
1967 See Documentation/fb/modedb.txt.
1969 vga= [BOOT,X86-32] Select a particular video mode
1970 See Documentation/i386/boot.txt and
1971 Documentation/svga.txt.
1972 Use vga=ask for menu.
1973 This is actually a boot loader parameter; the value is
1974 passed to the kernel using a special protocol.
1976 vmalloc=nn[KMG] [KNL,BOOT] Forces the vmalloc area to have an exact
1977 size of <nn>. This can be used to increase the
1978 minimum size (128MB on x86). It can also be used to
1979 decrease the size and leave more room for directly
1980 mapped kernel RAM.
1982 vmhalt= [KNL,S390] Perform z/VM CP command after system halt.
1983 Format: <command>
1985 vmpanic= [KNL,S390] Perform z/VM CP command after kernel panic.
1986 Format: <command>
1988 vmpoff= [KNL,S390] Perform z/VM CP command after power off.
1989 Format: <command>
1991 waveartist= [HW,OSS]
1992 Format: <io>,<irq>,<dma>,<dma2>
1994 wd33c93= [HW,SCSI]
1995 See header of drivers/scsi/wd33c93.c.
1997 wd7000= [HW,SCSI]
1998 See header of drivers/scsi/wd7000.c.
2000 wdt= [WDT] Watchdog
2001 See Documentation/watchdog/wdt.txt.
2003 xd= [HW,XT] Original XT pre-IDE (RLL encoded) disks.
2004 xd_geo= See header of drivers/block/xd.c.
2006 xirc2ps_cs= [NET,PCMCIA]
2007 Format:
2008 <irq>,<irq_mask>,<io>,<full_duplex>,<do_sound>,<lockup_hack>[,<irq2>[,<irq3>[,<irq4>]]]
2010 norandmaps Don't use address space randomization
2011 Equivalent to echo 0 > /proc/sys/kernel/randomize_va_space
2013 ______________________________________________________________________
2015 TODO:
2017 Add documentation for ALSA options.
2018 Add more DRM drivers.