view Documentation/kernel-parameters.txt @ 884:c7c92f868aa1

linux/pci: reserve io/memory space for bridge

reserve io/memory space for bridge which will be used later
by PCI hotplug.

Signed-off-by: Isaku Yamahata <yamahata@valinux.co.jp>
author Keir Fraser <keir.fraser@citrix.com>
date Thu May 28 10:00:03 2009 +0100 (2009-05-28)
parents b998614e2e2a
line source
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 ALSA ALSA sound support is enabled.
34 APIC APIC support is enabled.
35 APM Advanced Power Management support is enabled.
36 AX25 Appropriate AX.25 support is enabled.
37 CD Appropriate CD support is enabled.
38 DRM Direct Rendering Management support is enabled.
39 EDD BIOS Enhanced Disk Drive Services (EDD) is enabled
40 EFI EFI Partitioning (GPT) is enabled
41 EIDE EIDE/ATAPI support is enabled.
42 FB The frame buffer device is enabled.
43 HW Appropriate hardware is enabled.
44 IA-32 IA-32 aka i386 architecture 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 LP Printer support is enabled.
52 LOOP Loopback device support is enabled.
53 M68k M68k architecture is enabled.
54 These options have more detailed description inside of
55 Documentation/m68k/kernel-options.txt.
56 MCA MCA bus support is enabled.
57 MDA MDA console support is enabled.
58 MOUSE Appropriate mouse support is enabled.
59 MSI Message Signaled Interrupts (PCI).
60 MTD MTD support is enabled.
61 NET Appropriate network support is enabled.
62 NUMA NUMA support is enabled.
63 GENERIC_TIME The generic timeofday code is enabled.
64 NFS Appropriate NFS support is enabled.
65 OSS OSS sound support is enabled.
66 PARIDE The ParIDE subsystem is enabled.
67 PARISC The PA-RISC architecture is enabled.
68 PCI PCI bus support is enabled.
69 PCMCIA The PCMCIA subsystem is enabled.
70 PNP Plug & Play support is enabled.
71 PPC PowerPC architecture is enabled.
72 PPT Parallel port support is enabled.
73 PS2 Appropriate PS/2 support is enabled.
74 RAM RAM disk support is enabled.
75 S390 S390 architecture is enabled.
76 SCSI Appropriate SCSI support is enabled.
77 A lot of drivers has their options described inside of
78 Documentation/scsi/.
79 SELINUX SELinux support is enabled.
80 SERIAL Serial support is enabled.
81 SMP The kernel is an SMP kernel.
82 SPARC Sparc architecture is enabled.
83 SWSUSP Software suspend is enabled.
84 TS Appropriate touchscreen support is enabled.
85 USB USB support is enabled.
86 USBHID USB Human Interface Device support is enabled.
87 V4L Video For Linux support is enabled.
88 VGA The VGA console has been enabled.
89 VT Virtual terminal support is enabled.
90 WDT Watchdog support is enabled.
91 XT IBM PC/XT MFM hard disk support is enabled.
92 X86-64 X86-64 architecture is enabled.
93 More X86-64 boot options can be found in
94 Documentation/x86_64/boot-options.txt .
96 In addition, the following text indicates that the option:
98 BUGS= Relates to possible processor bugs on the said processor.
99 KNL Is a kernel start-up parameter.
100 BOOT Is a boot loader parameter.
102 Parameters denoted with BOOT are actually interpreted by the boot
103 loader, and have no meaning to the kernel directly.
104 Do not modify the syntax of boot loader parameters without extreme
105 need or coordination with <Documentation/i386/boot.txt>.
107 Note that ALL kernel parameters listed below are CASE SENSITIVE, and that
108 a trailing = on the name of any parameter states that that parameter will
109 be entered as an environment variable, whereas its absence indicates that
110 it will appear as a kernel argument readable via /proc/cmdline by programs
111 running once the system is up.
113 53c7xx= [HW,SCSI] Amiga SCSI controllers
114 See header of drivers/scsi/53c7xx.c.
115 See also Documentation/scsi/ncr53c7xx.txt.
117 acpi= [HW,ACPI] Advanced Configuration and Power Interface
118 Format: { force | off | ht | strict | noirq }
119 force -- enable ACPI if default was off
120 off -- disable ACPI if default was on
121 noirq -- do not use ACPI for IRQ routing
122 ht -- run only enough ACPI to enable Hyper Threading
123 strict -- Be less tolerant of platforms that are not
124 strictly ACPI specification compliant.
126 See also Documentation/pm.txt, pci=noacpi
128 acpi_sleep= [HW,ACPI] Sleep options
129 Format: { s3_bios, s3_mode }
130 See Documentation/power/video.txt
132 acpi_sci= [HW,ACPI] ACPI System Control Interrupt trigger mode
133 Format: { level | edge | high | low }
135 acpi_irq_balance [HW,ACPI]
136 ACPI will balance active IRQs
137 default in APIC mode
139 acpi_irq_nobalance [HW,ACPI]
140 ACPI will not move active IRQs (default)
141 default in PIC mode
143 acpi_irq_pci= [HW,ACPI] If irq_balance, clear listed IRQs for
144 use by PCI
145 Format: <irq>,<irq>...
147 acpi_irq_isa= [HW,ACPI] If irq_balance, mark listed IRQs used by ISA
148 Format: <irq>,<irq>...
150 acpi_os_name= [HW,ACPI] Tell ACPI BIOS the name of the OS
151 Format: To spoof as Windows 98: ="Microsoft Windows"
153 acpi_osi= [HW,ACPI] empty param disables _OSI
155 acpi_serialize [HW,ACPI] force serialization of AML methods
157 acpi_skip_timer_override [HW,ACPI]
158 Recognize and ignore IRQ0/pin2 Interrupt Override.
159 For broken nForce2 BIOS resulting in XT-PIC timer.
161 acpi_dbg_layer= [HW,ACPI]
162 Format: <int>
163 Each bit of the <int> indicates an ACPI debug layer,
164 1: enable, 0: disable. It is useful for boot time
165 debugging. After system has booted up, it can be set
166 via /proc/acpi/debug_layer.
168 acpi_dbg_level= [HW,ACPI]
169 Format: <int>
170 Each bit of the <int> indicates an ACPI debug level,
171 1: enable, 0: disable. It is useful for boot time
172 debugging. After system has booted up, it can be set
173 via /proc/acpi/debug_level.
175 acpi_fake_ecdt [HW,ACPI] Workaround failure due to BIOS lacking ECDT
177 acpi_generic_hotkey [HW,ACPI]
178 Allow consolidated generic hotkey driver to
179 override platform specific driver.
180 See also Documentation/acpi-hotkey.txt.
182 acpi_pm_good [IA-32,X86-64]
183 Override the pmtimer bug detection: force the kernel
184 to assume that this machine's pmtimer latches its value
185 and always returns good values.
187 enable_timer_pin_1 [i386,x86-64]
188 Enable PIN 1 of APIC timer
189 Can be useful to work around chipset bugs
190 (in particular on some ATI chipsets).
191 The kernel tries to set a reasonable default.
193 disable_timer_pin_1 [i386,x86-64]
194 Disable PIN 1 of APIC timer
195 Can be useful to work around chipset bugs.
197 ad1816= [HW,OSS]
198 Format: <io>,<irq>,<dma>,<dma2>
199 See also Documentation/sound/oss/AD1816.
201 ad1848= [HW,OSS]
202 Format: <io>,<irq>,<dma>,<dma2>,<type>
204 adlib= [HW,OSS]
205 Format: <io>
207 advansys= [HW,SCSI]
208 See header of drivers/scsi/advansys.c.
210 advwdt= [HW,WDT] Advantech WDT
211 Format: <iostart>,<iostop>
213 aedsp16= [HW,OSS] Audio Excel DSP 16
214 Format: <io>,<irq>,<dma>,<mss_io>,<mpu_io>,<mpu_irq>
215 See also header of sound/oss/aedsp16.c.
217 aha152x= [HW,SCSI]
218 See Documentation/scsi/aha152x.txt.
220 aha1542= [HW,SCSI]
221 Format: <portbase>[,<buson>,<busoff>[,<dmaspeed>]]
223 aic7xxx= [HW,SCSI]
224 See Documentation/scsi/aic7xxx.txt.
226 aic79xx= [HW,SCSI]
227 See Documentation/scsi/aic79xx.txt.
229 amijoy.map= [HW,JOY] Amiga joystick support
230 Map of devices attached to JOY0DAT and JOY1DAT
231 Format: <a>,<b>
232 See also Documentation/kernel/input/joystick.txt
234 analog.map= [HW,JOY] Analog joystick and gamepad support
235 Specifies type or capabilities of an analog joystick
236 connected to one of 16 gameports
237 Format: <type1>,<type2>,..<type16>
239 apc= [HW,SPARC]
240 Power management functions (SPARCstation-4/5 + deriv.)
241 Format: noidle
242 Disable APC CPU standby support. SPARCstation-Fox does
243 not play well with APC CPU idle - disable it if you have
244 APC and your system crashes randomly.
246 apic= [APIC,i386] Change the output verbosity whilst booting
247 Format: { quiet (default) | verbose | debug }
248 Change the amount of debugging information output
249 when initialising the APIC and IO-APIC components.
251 apm= [APM] Advanced Power Management
252 See header of arch/i386/kernel/apm.c.
254 applicom= [HW]
255 Format: <mem>,<irq>
257 arcrimi= [HW,NET] ARCnet - "RIM I" (entirely mem-mapped) cards
258 Format: <io>,<irq>,<nodeID>
260 ataflop= [HW,M68k]
262 atarimouse= [HW,MOUSE] Atari Mouse
264 atascsi= [HW,SCSI] Atari SCSI
266 atkbd.extra= [HW] Enable extra LEDs and keys on IBM RapidAccess,
267 EzKey and similar keyboards
269 atkbd.reset= [HW] Reset keyboard during initialization
271 atkbd.set= [HW] Select keyboard code set
272 Format: <int> (2 = AT (default), 3 = PS/2)
274 atkbd.scroll= [HW] Enable scroll wheel on MS Office and similar
275 keyboards
277 atkbd.softraw= [HW] Choose between synthetic and real raw mode
278 Format: <bool> (0 = real, 1 = synthetic (default))
280 atkbd.softrepeat= [HW]
281 Use software keyboard repeat
283 autotest [IA64]
285 awe= [HW,OSS] AWE32/SB32/AWE64 wave table synth
286 Format: <io>,<memsize>,<isapnp>
288 aztcd= [HW,CD] Aztech CD268 CDROM driver
289 Format: <io>,0x79 (?)
291 baycom_epp= [HW,AX25]
292 Format: <io>,<mode>
294 baycom_par= [HW,AX25] BayCom Parallel Port AX.25 Modem
295 Format: <io>,<mode>
296 See header of drivers/net/hamradio/baycom_par.c.
298 baycom_ser_fdx= [HW,AX25]
299 BayCom Serial Port AX.25 Modem (Full Duplex Mode)
300 Format: <io>,<irq>,<mode>[,<baud>]
301 See header of drivers/net/hamradio/baycom_ser_fdx.c.
303 baycom_ser_hdx= [HW,AX25]
304 BayCom Serial Port AX.25 Modem (Half Duplex Mode)
305 Format: <io>,<irq>,<mode>
306 See header of drivers/net/hamradio/baycom_ser_hdx.c.
308 blkmtd_device= [HW,MTD]
309 blkmtd_erasesz=
310 blkmtd_ro=
311 blkmtd_bs=
312 blkmtd_count=
314 bttv.card= [HW,V4L] bttv (bt848 + bt878 based grabber cards)
315 bttv.radio= Most important insmod options are available as
316 kernel args too.
317 bttv.pll= See Documentation/video4linux/bttv/Insmod-options
318 bttv.tuner= and Documentation/video4linux/bttv/CARDLIST
320 BusLogic= [HW,SCSI]
321 See drivers/scsi/BusLogic.c, comment before function
322 BusLogic_ParseDriverOptions().
324 c101= [NET] Moxa C101 synchronous serial card
326 cachesize= [BUGS=IA-32] Override level 2 CPU cache size detection.
327 Sometimes CPU hardware bugs make them report the cache
328 size incorrectly. The kernel will attempt work arounds
329 to fix known problems, but for some CPUs it is not
330 possible to determine what the correct size should be.
331 This option provides an override for these situations.
333 cdu31a= [HW,CD]
334 Format: <io>,<irq>[,PAS]
335 See header of drivers/cdrom/cdu31a.c.
337 chandev= [HW,NET] Generic channel device initialisation
339 checkreqprot [SELINUX] Set initial checkreqprot flag value.
340 Format: { "0" | "1" }
341 See security/selinux/Kconfig help text.
342 0 -- check protection applied by kernel (includes
343 any implied execute protection).
344 1 -- check protection requested by application.
345 Default value is set via a kernel config option.
346 Value can be changed at runtime via
347 /selinux/checkreqprot.
349 clock= [BUGS=IA-32, HW] gettimeofday clocksource override.
350 [Deprecated]
351 Forces specified clocksource (if avaliable) to be used
352 when calculating gettimeofday(). If specified
353 clocksource is not avalible, it defaults to PIT.
354 Format: { pit | tsc | cyclone | pmtmr }
356 disable_8254_timer
357 enable_8254_timer
358 [IA32/X86_64] Disable/Enable interrupt 0 timer routing
359 over the 8254 in addition to over the IO-APIC. The
360 kernel tries to set a sensible default.
362 hpet= [IA-32,HPET] option to disable HPET and use PIT.
363 Format: disable
365 cm206= [HW,CD]
366 Format: { auto | [<io>,][<irq>] }
368 com20020= [HW,NET] ARCnet - COM20020 chipset
369 Format:
370 <io>[,<irq>[,<nodeID>[,<backplane>[,<ckp>[,<timeout>]]]]]
372 com90io= [HW,NET] ARCnet - COM90xx chipset (IO-mapped buffers)
373 Format: <io>[,<irq>]
375 com90xx= [HW,NET]
376 ARCnet - COM90xx chipset (memory-mapped buffers)
377 Format: <io>[,<irq>[,<memstart>]]
379 condev= [HW,S390] console device
380 conmode=
382 console= [KNL] Output console device and options.
384 tty<n> Use the virtual console device <n>.
386 ttyS<n>[,options]
387 ttyUSB0[,options]
388 Use the specified serial port. The options are of
389 the form "bbbbpnf", where "bbbb" is the baud rate,
390 "p" is parity ("n", "o", or "e"), "n" is number of
391 bits, and "f" is flow control ("r" for RTS or
392 omit it). Default is "9600n8".
394 See Documentation/serial-console.txt for more
395 information. See
396 Documentation/networking/netconsole.txt for an
397 alternative.
399 uart,io,<addr>[,options]
400 uart,mmio,<addr>[,options]
401 Start an early, polled-mode console on the 8250/16550
402 UART at the specified I/O port or MMIO address,
403 switching to the matching ttyS device later. The
404 options are the same as for ttyS, above.
406 cpcihp_generic= [HW,PCI] Generic port I/O CompactPCI driver
407 Format:
408 <first_slot>,<last_slot>,<port>,<enum_bit>[,<debug>]
410 cpia_pp= [HW,PPT]
411 Format: { parport<nr> | auto | none }
413 crashkernel=nn[KMG]@ss[KMG]
414 [KNL] Reserve a chunk of physical memory to
415 hold a kernel to switch to with kexec on panic.
417 cs4232= [HW,OSS]
418 Format: <io>,<irq>,<dma>,<dma2>,<mpuio>,<mpuirq>
420 cs89x0_dma= [HW,NET]
421 Format: <dma>
423 cs89x0_media= [HW,NET]
424 Format: { rj45 | aui | bnc }
426 cyclades= [HW,SERIAL] Cyclades multi-serial port adapter.
428 dasd= [HW,NET]
429 See header of drivers/s390/block/dasd_devmap.c.
431 db9.dev[2|3]= [HW,JOY] Multisystem joystick support via parallel port
432 (one device per port)
433 Format: <port#>,<type>
434 See also Documentation/input/joystick-parport.txt
436 debug [KNL] Enable kernel debugging (events log level).
438 debug_locks_verbose=
439 [KNL] verbose self-tests
440 Format=<0|1>
441 Print debugging info while doing the locking API
442 self-tests.
443 We default to 0 (no extra messages), setting it to
444 1 will print _a lot_ more information - normally
445 only useful to kernel developers.
447 decnet= [HW,NET]
448 Format: <area>[,<node>]
449 See also Documentation/networking/decnet.txt.
451 dhash_entries= [KNL]
452 Set number of hash buckets for dentry cache.
454 digi= [HW,SERIAL]
455 IO parameters + enable/disable command.
457 digiepca= [HW,SERIAL]
458 See drivers/char/README.epca and
459 Documentation/digiepca.txt.
461 dmascc= [HW,AX25,SERIAL] AX.25 Z80SCC driver with DMA
462 support available.
463 Format: <io_dev0>[,<io_dev1>[,..<io_dev32>]]
465 dmasound= [HW,OSS] Sound subsystem buffers
467 dscc4.setup= [NET]
469 dtc3181e= [HW,SCSI]
471 earlyprintk= [IA-32,X86-64]
472 earlyprintk=vga
473 earlyprintk=serial[,ttySn[,baudrate]]
475 Append ",keep" to not disable it when the real console
476 takes over.
478 Only vga or serial at a time, not both.
480 Currently only ttyS0 and ttyS1 are supported.
482 Interaction with the standard serial driver is not
483 very good.
485 The VGA output is eventually overwritten by the real
486 console.
488 eata= [HW,SCSI]
490 ec_intr= [HW,ACPI] ACPI Embedded Controller interrupt mode
491 Format: <int>
492 0: polling mode
493 non-0: interrupt mode (default)
495 eda= [HW,PS2]
497 edb= [HW,PS2]
499 edd= [EDD]
500 Format: {"of[f]" | "sk[ipmbr]"}
501 See comment in arch/i386/boot/edd.S
503 eicon= [HW,ISDN]
504 Format: <id>,<membase>,<irq>
506 eisa_irq_edge= [PARISC,HW]
507 See header of drivers/parisc/eisa.c.
509 elanfreq= [IA-32]
510 See comment before function elanfreq_setup() in
511 arch/i386/kernel/cpu/cpufreq/elanfreq.c.
513 elevator= [IOSCHED]
514 Format: {"anticipatory" | "cfq" | "deadline" | "noop"}
515 See Documentation/block/as-iosched.txt and
516 Documentation/block/deadline-iosched.txt for details.
518 elfcorehdr= [IA-32, X86_64]
519 Specifies physical address of start of kernel core
520 image elf header. Generally kexec loader will
521 pass this option to capture kernel.
522 See Documentation/kdump/kdump.txt for details.
524 enforcing [SELINUX] Set initial enforcing status.
525 Format: {"0" | "1"}
526 See security/selinux/Kconfig help text.
527 0 -- permissive (log only, no denials).
528 1 -- enforcing (deny and log).
529 Default value is 0.
530 Value can be changed at runtime via /selinux/enforce.
532 es1370= [HW,OSS]
533 Format: <lineout>[,<micbias>]
534 See also header of sound/oss/es1370.c.
536 es1371= [HW,OSS]
537 Format: <spdif>,[<nomix>,[<amplifier>]]
538 See also header of sound/oss/es1371.c.
540 ether= [HW,NET] Ethernet cards parameters
541 This option is obsoleted by the "netdev=" option, which
542 has equivalent usage. See its documentation for details.
544 eurwdt= [HW,WDT] Eurotech CPU-1220/1410 onboard watchdog.
545 Format: <io>[,<irq>]
547 fd_mcs= [HW,SCSI]
548 See header of drivers/scsi/fd_mcs.c.
550 fdomain= [HW,SCSI]
551 See header of drivers/scsi/fdomain.c.
553 floppy= [HW]
554 See Documentation/floppy.txt.
556 ftape= [HW] Floppy Tape subsystem debugging options.
557 See Documentation/ftape.txt.
559 gamecon.map[2|3]=
560 [HW,JOY] Multisystem joystick and NES/SNES/PSX pad
561 support via parallel port (up to 5 devices per port)
562 Format: <port#>,<pad1>,<pad2>,<pad3>,<pad4>,<pad5>
563 See also Documentation/input/joystick-parport.txt
565 gamma= [HW,DRM]
567 gdth= [HW,SCSI]
568 See header of drivers/scsi/gdth.c.
570 gpt [EFI] Forces disk with valid GPT signature but
571 invalid Protective MBR to be treated as GPT.
573 gscd= [HW,CD]
574 Format: <io>
576 gt96100eth= [NET] MIPS GT96100 Advanced Communication Controller
578 guestdev= [PCI,ACPI]
579 Format: {<device path>|<sbdf>}][,{<device path>|<sbdf>}[,...]]
580 Format of device path: <hid>[:<uid>]-<dev>.<func>[-<dev>.<func>[,...]][+iomul]
581 Format of sbdf: [<segment>:]<bus>:<dev>.<func>[+iomul]
582 Specifies PCI device for guest domain.
583 If PCI-PCI bridge is specified, all PCI devices
584 behind PCI-PCI bridge are reserved.
585 +iomul means that this PCI function will share
586 IO ports with other +iomul functions under same
587 switch. NOTE: if +iomul is specfied, all the functions
588 of the device will share IO ports.
590 guestiomuldev= [PCI]
591 Format: [sbd][,<sbd>][,...]
592 Format of sbdf: [<segment>:]<bus>:<dev>
593 Note: function shouldn't be specified.
594 Specifies PCI device for IO port multiplexing driver.
596 gus= [HW,OSS]
597 Format: <io>,<irq>,<dma>,<dma16>
599 gvp11= [HW,SCSI]
601 hashdist= [KNL,NUMA] Large hashes allocated during boot
602 are distributed across NUMA nodes. Defaults on
603 for IA-64, off otherwise.
604 Format: 0 | 1 (for off | on)
606 hcl= [IA-64] SGI's Hardware Graph compatibility layer
608 hd= [EIDE] (E)IDE hard drive subsystem geometry
609 Format: <cyl>,<head>,<sect>
611 hd?= [HW] (E)IDE subsystem
612 hd?lun= See Documentation/ide.txt.
614 highmem=nn[KMG] [KNL,BOOT] forces the highmem zone to have an exact
615 size of <nn>. This works even on boxes that have no
616 highmem otherwise. This also works to reduce highmem
617 size on bigger boxes.
619 hisax= [HW,ISDN]
620 See Documentation/isdn/README.HiSax.
622 hugepages= [HW,IA-32,IA-64] Maximal number of HugeTLB pages.
624 noirqbalance [IA-32,SMP,KNL] Disable kernel irq balancing
626 i8042.direct [HW] Put keyboard port into non-translated mode
627 i8042.dumbkbd [HW] Pretend that controlled can only read data from
628 keyboard and can not control its state
629 (Don't attempt to blink the leds)
630 i8042.noaux [HW] Don't check for auxiliary (== mouse) port
631 i8042.nokbd [HW] Don't check/create keyboard port
632 i8042.nomux [HW] Don't check presence of an active multiplexing
633 controller
634 i8042.nopnp [HW] Don't use ACPIPnP / PnPBIOS to discover KBD/AUX
635 controllers
636 i8042.panicblink=
637 [HW] Frequency with which keyboard LEDs should blink
638 when kernel panics (default is 0.5 sec)
639 i8042.reset [HW] Reset the controller during init and cleanup
640 i8042.unlock [HW] Unlock (ignore) the keylock
642 i810= [HW,DRM]
644 i8k.ignore_dmi [HW] Continue probing hardware even if DMI data
645 indicates that the driver is running on unsupported
646 hardware.
647 i8k.force [HW] Activate i8k driver even if SMM BIOS signature
648 does not match list of supported models.
649 i8k.power_status
650 [HW] Report power status in /proc/i8k
651 (disabled by default)
652 i8k.restricted [HW] Allow controlling fans only if SYS_ADMIN
653 capability is set.
655 ibmmcascsi= [HW,MCA,SCSI] IBM MicroChannel SCSI adapter
656 See Documentation/mca.txt.
658 icn= [HW,ISDN]
659 Format: <io>[,<membase>[,<icn_id>[,<icn_id2>]]]
661 ide= [HW] (E)IDE subsystem
662 Format: ide=nodma or ide=doubler or ide=reverse
663 See Documentation/ide.txt.
665 ide?= [HW] (E)IDE subsystem
666 Format: ide?=noprobe or chipset specific parameters.
667 See Documentation/ide.txt.
669 idebus= [HW] (E)IDE subsystem - VLB/PCI bus speed
670 See Documentation/ide.txt.
672 idle= [HW]
673 Format: idle=poll or idle=halt
675 ihash_entries= [KNL]
676 Set number of hash buckets for inode cache.
678 in2000= [HW,SCSI]
679 See header of drivers/scsi/in2000.c.
681 init= [KNL]
682 Format: <full_path>
683 Run specified binary instead of /sbin/init as init
684 process.
686 initcall_debug [KNL] Trace initcalls as they are executed. Useful
687 for working out where the kernel is dying during
688 startup.
690 initrd= [BOOT] Specify the location of the initial ramdisk
692 inport.irq= [HW] Inport (ATI XL and Microsoft) busmouse driver
693 Format: <irq>
695 combined_mode= [HW] control which driver uses IDE ports in combined
696 mode: legacy IDE driver, libata, or both
697 (in the libata case, libata.atapi_enabled=1 may be
698 useful as well). Note that using the ide or libata
699 options may affect your device naming (e.g. by
700 changing hdc to sdb).
701 Format: combined (default), ide, or libata
703 inttest= [IA64]
705 io7= [HW] IO7 for Marvel based alpha systems
706 See comment before marvel_specify_io7 in
707 arch/alpha/kernel/core_marvel.c.
709 ip= [IP_PNP]
710 See Documentation/nfsroot.txt.
712 ip2= [HW] Set IO/IRQ pairs for up to 4 IntelliPort boards
713 See comment before ip2_setup() in drivers/char/ip2.c.
715 ips= [HW,SCSI] Adaptec / IBM ServeRAID controller
716 See header of drivers/scsi/ips.c.
718 ports= [IP_VS_FTP] IPVS ftp helper module
719 Default is 21.
720 Up to 8 (IP_VS_APP_MAX_PORTS) ports
721 may be specified.
722 Format: <port>,<port>....
724 irqfixup [HW]
725 When an interrupt is not handled search all handlers
726 for it. Intended to get systems with badly broken
727 firmware running.
729 irqpoll [HW]
730 When an interrupt is not handled search all handlers
731 for it. Also check all handlers each timer
732 interrupt. Intended to get systems with badly broken
733 firmware running.
735 isapnp= [ISAPNP]
736 Format: <RDP>,<reset>,<pci_scan>,<verbosity>
738 isolcpus= [KNL,SMP] Isolate CPUs from the general scheduler.
739 Format: <cpu number>,...,<cpu number>
740 This option can be used to specify one or more CPUs
741 to isolate from the general SMP balancing and scheduling
742 algorithms. The only way to move a process onto or off
743 an "isolated" CPU is via the CPU affinity syscalls.
744 <cpu number> begins at 0 and the maximum value is
745 "number of CPUs in system - 1".
747 This option is the preferred way to isolate CPUs. The
748 alternative -- manually setting the CPU mask of all
749 tasks in the system -- can cause problems and
750 suboptimal load balancer performance.
752 isp16= [HW,CD]
753 Format: <io>,<irq>,<dma>,<setup>
755 iucv= [HW,NET]
757 js= [HW,JOY] Analog joystick
758 See Documentation/input/joystick.txt.
760 keepinitrd [HW,ARM]
762 kstack=N [IA-32,X86-64] Print N words from the kernel stack
763 in oops dumps.
765 l2cr= [PPC]
767 lapic [IA-32,APIC] Enable the local APIC even if BIOS
768 disabled it.
770 lasi= [HW,SCSI] PARISC LASI driver for the 53c700 chip
771 Format: addr:<io>,irq:<irq>
773 llsc*= [IA64] See function print_params() in
774 arch/ia64/sn/kernel/llsc4.c.
776 load_ramdisk= [RAM] List of ramdisks to load from floppy
777 See Documentation/ramdisk.txt.
779 lockd.nlm_grace_period=P [NFS] Assign grace period.
780 Format: <integer>
782 lockd.nlm_tcpport=N [NFS] Assign TCP port.
783 Format: <integer>
785 lockd.nlm_timeout=T [NFS] Assign timeout value.
786 Format: <integer>
788 lockd.nlm_udpport=M [NFS] Assign UDP port.
789 Format: <integer>
791 logibm.irq= [HW,MOUSE] Logitech Bus Mouse Driver
792 Format: <irq>
794 loglevel= All Kernel Messages with a loglevel smaller than the
795 console loglevel will be printed to the console. It can
796 also be changed with klogd or other programs. The
797 loglevels are defined as follows:
799 0 (KERN_EMERG) system is unusable
800 1 (KERN_ALERT) action must be taken immediately
801 2 (KERN_CRIT) critical conditions
802 3 (KERN_ERR) error conditions
803 4 (KERN_WARNING) warning conditions
804 5 (KERN_NOTICE) normal but significant condition
805 6 (KERN_INFO) informational
806 7 (KERN_DEBUG) debug-level messages
808 log_buf_len=n Sets the size of the printk ring buffer, in bytes.
809 Format: { n | nk | nM }
810 n must be a power of two. The default size
811 is set in the kernel config file.
813 lp=0 [LP] Specify parallel ports to use, e.g,
814 lp=port[,port...] lp=none,parport0 (lp0 not configured, lp1 uses
815 lp=reset first parallel port). 'lp=0' disables the
816 lp=auto printer driver. 'lp=reset' (which can be
817 specified in addition to the ports) causes
818 attached printers to be reset. Using
819 lp=port1,port2,... specifies the parallel ports
820 to associate lp devices with, starting with
821 lp0. A port specification may be 'none' to skip
822 that lp device, or a parport name such as
823 'parport0'. Specifying 'lp=auto' instead of a
824 port specification list means that device IDs
825 from each port should be examined, to see if
826 an IEEE 1284-compliant printer is attached; if
827 so, the driver will manage that printer.
828 See also header of drivers/char/lp.c.
830 lpj=n [KNL]
831 Sets loops_per_jiffy to given constant, thus avoiding
832 time-consuming boot-time autodetection (up to 250 ms per
833 CPU). 0 enables autodetection (default). To determine
834 the correct value for your kernel, boot with normal
835 autodetection and see what value is printed. Note that
836 on SMP systems the preset will be applied to all CPUs,
837 which is likely to cause problems if your CPUs need
838 significantly divergent settings. An incorrect value
839 will cause delays in the kernel to be wrong, leading to
840 unpredictable I/O errors and other breakage. Although
841 unlikely, in the extreme case this might damage your
842 hardware.
844 ltpc= [NET]
845 Format: <io>,<irq>,<dma>
847 mac5380= [HW,SCSI] Format:
848 <can_queue>,<cmd_per_lun>,<sg_tablesize>,<hostid>,<use_tags>
850 mac53c9x= [HW,SCSI] Format:
851 <num_esps>,<disconnect>,<nosync>,<can_queue>,<cmd_per_lun>,<sg_tablesize>,<hostid>,<use_tags>
853 machvec= [IA64] Force the use of a particular machine-vector
854 (machvec) in a generic kernel.
855 Example: machvec=hpzx1_swiotlb
857 mad16= [HW,OSS] Format:
858 <io>,<irq>,<dma>,<dma16>,<mpu_io>,<mpu_irq>,<joystick>
860 maui= [HW,OSS]
861 Format: <io>,<irq>
863 max_loop= [LOOP] Maximum number of loopback devices that can
864 be mounted
865 Format: <1-256>
867 maxcpus= [SMP] Maximum number of processors that an SMP kernel
868 should make use of
870 max_addr=[KMG] [KNL,BOOT,ia64] All physical memory greater than or
871 equal to this physical address is ignored.
873 max_luns= [SCSI] Maximum number of LUNs to probe.
874 Should be between 1 and 2^32-1.
876 max_report_luns=
877 [SCSI] Maximum number of LUNs received.
878 Should be between 1 and 16384.
880 mca-pentium [BUGS=IA-32]
882 mcatest= [IA-64]
884 mcd= [HW,CD]
885 Format: <port>,<irq>,<mitsumi_bug_93_wait>
887 mcdx= [HW,CD]
889 mce [IA-32] Machine Check Exception
891 md= [HW] RAID subsystems devices and level
892 See Documentation/md.txt.
894 mdacon= [MDA]
895 Format: <first>,<last>
896 Specifies range of consoles to be captured by the MDA.
898 mem=nn[KMG] [KNL,BOOT] Force usage of a specific amount of memory
899 Amount of memory to be used when the kernel is not able
900 to see the whole system memory or for test.
901 [IA-32] Use together with memmap= to avoid physical
902 address space collisions. Without memmap= PCI devices
903 could be placed at addresses belonging to unused RAM.
905 mem=nopentium [BUGS=IA-32] Disable usage of 4MB pages for kernel
906 memory.
908 memmap=exactmap [KNL,IA-32,X86_64] Enable setting of an exact
909 E820 memory map, as specified by the user.
910 Such memmap=exactmap lines can be constructed based on
911 BIOS output or other requirements. See the memmap=nn@ss
912 option description.
914 memmap=nn[KMG]@ss[KMG]
915 [KNL] Force usage of a specific region of memory
916 Region of memory to be used, from ss to ss+nn.
918 memmap=nn[KMG]#ss[KMG]
919 [KNL,ACPI] Mark specific memory as ACPI data.
920 Region of memory to be used, from ss to ss+nn.
922 memmap=nn[KMG]$ss[KMG]
923 [KNL,ACPI] Mark specific memory as reserved.
924 Region of memory to be used, from ss to ss+nn.
926 meye.*= [HW] Set MotionEye Camera parameters
927 See Documentation/video4linux/meye.txt.
929 mga= [HW,DRM]
931 migration_cost=
932 [KNL,SMP] debug: override scheduler migration costs
933 Format: <level-1-usecs>,<level-2-usecs>,...
934 This debugging option can be used to override the
935 default scheduler migration cost matrix. The numbers
936 are indexed by 'CPU domain distance'.
937 E.g. migration_cost=1000,2000,3000 on an SMT NUMA
938 box will set up an intra-core migration cost of
939 1 msec, an inter-core migration cost of 2 msecs,
940 and an inter-node migration cost of 3 msecs.
942 WARNING: using the wrong values here can break
943 scheduler performance, so it's only for scheduler
944 development purposes, not production environments.
946 migration_debug=
947 [KNL,SMP] migration cost auto-detect verbosity
948 Format=<0|1|2>
949 If a system's migration matrix reported at bootup
950 seems erroneous then this option can be used to
951 increase verbosity of the detection process.
952 We default to 0 (no extra messages), 1 will print
953 some more information, and 2 will be really
954 verbose (probably only useful if you also have a
955 serial console attached to the system).
957 migration_factor=
958 [KNL,SMP] multiply/divide migration costs by a factor
959 Format=<percent>
960 This debug option can be used to proportionally
961 increase or decrease the auto-detected migration
962 costs for all entries of the migration matrix.
963 E.g. migration_factor=150 will increase migration
964 costs by 50%. (and thus the scheduler will be less
965 eager migrating cache-hot tasks)
966 migration_factor=80 will decrease migration costs
967 by 20%. (thus the scheduler will be more eager to
968 migrate tasks)
970 WARNING: using the wrong values here can break
971 scheduler performance, so it's only for scheduler
972 development purposes, not production environments.
974 mousedev.tap_time=
975 [MOUSE] Maximum time between finger touching and
976 leaving touchpad surface for touch to be considered
977 a tap and be reported as a left button click (for
978 touchpads working in absolute mode only).
979 Format: <msecs>
980 mousedev.xres= [MOUSE] Horizontal screen resolution, used for devices
981 reporting absolute coordinates, such as tablets
982 mousedev.yres= [MOUSE] Vertical screen resolution, used for devices
983 reporting absolute coordinates, such as tablets
985 mpu401= [HW,OSS]
986 Format: <io>,<irq>
988 MTD_Partition= [MTD]
989 Format: <name>,<region-number>,<size>,<offset>
991 MTD_Region= [MTD] Format:
992 <name>,<region-number>[,<base>,<size>,<buswidth>,<altbuswidth>]
994 mtdparts= [MTD]
995 See drivers/mtd/cmdline.c.
997 mtouchusb.raw_coordinates=
998 [HW] Make the MicroTouch USB driver use raw coordinates
999 ('y', default) or cooked coordinates ('n')
1001 n2= [NET] SDL Inc. RISCom/N2 synchronous serial card
1003 NCR_D700= [HW,SCSI]
1004 See header of drivers/scsi/NCR_D700.c.
1006 ncr5380= [HW,SCSI]
1008 ncr53c400= [HW,SCSI]
1010 ncr53c400a= [HW,SCSI]
1012 ncr53c406a= [HW,SCSI]
1014 ncr53c8xx= [HW,SCSI]
1016 netdev= [NET] Network devices parameters
1017 Format: <irq>,<io>,<mem_start>,<mem_end>,<name>
1018 Note that mem_start is often overloaded to mean
1019 something different and driver-specific.
1020 This usage is only documented in each driver source
1021 file if at all.
1023 nfsaddrs= [NFS]
1024 See Documentation/nfsroot.txt.
1026 nfsroot= [NFS] nfs root filesystem for disk-less boxes.
1027 See Documentation/nfsroot.txt.
1029 nfs.callback_tcpport=
1030 [NFS] set the TCP port on which the NFSv4 callback
1031 channel should listen.
1033 nfs.idmap_cache_timeout=
1034 [NFS] set the maximum lifetime for idmapper cache
1035 entries.
1037 nmi_watchdog= [KNL,BUGS=IA-32] Debugging features for SMP kernels
1039 no387 [BUGS=IA-32] Tells the kernel to use the 387 maths
1040 emulation library even if a 387 maths coprocessor
1041 is present.
1043 noalign [KNL,ARM]
1045 noapic [SMP,APIC] Tells the kernel to not make use of any
1046 IOAPICs that may be present in the system.
1048 noasync [HW,M68K] Disables async and sync negotiation for
1049 all devices.
1051 nobats [PPC] Do not use BATs for mapping kernel lowmem
1052 on "Classic" PPC cores.
1054 nocache [ARM]
1056 nodelayacct [KNL] Disable per-task delay accounting
1058 nodisconnect [HW,SCSI,M68K] Disables SCSI disconnects.
1060 noexec [IA-64]
1062 noexec [IA-32,X86-64]
1063 noexec=on: enable non-executable mappings (default)
1064 noexec=off: disable nn-executable mappings
1066 nofxsr [BUGS=IA-32] Disables x86 floating point extended
1067 register save and restore. The kernel will only save
1068 legacy floating-point registers on task switch.
1070 nohlt [BUGS=ARM]
1072 no-hlt [BUGS=IA-32] Tells the kernel that the hlt
1073 instruction doesn't work correctly and not to
1074 use it.
1076 nohalt [IA-64] Tells the kernel not to use the power saving
1077 function PAL_HALT_LIGHT when idle. This increases
1078 power-consumption. On the positive side, it reduces
1079 interrupt wake-up latency, which may improve performance
1080 in certain environments such as networked servers or
1081 real-time systems.
1083 noirqdebug [IA-32] Disables the code which attempts to detect and
1084 disable unhandled interrupt sources.
1086 noisapnp [ISAPNP] Disables ISA PnP code.
1088 noinitrd [RAM] Tells the kernel not to load any configured
1089 initial RAM disk.
1091 nointroute [IA-64]
1093 nolapic [IA-32,APIC] Do not enable or use the local APIC.
1095 noltlbs [PPC] Do not use large page/tlb entries for kernel
1096 lowmem mapping on PPC40x.
1098 nomca [IA-64] Disable machine check abort handling
1100 nomce [IA-32] Machine Check Exception
1102 noresidual [PPC] Don't use residual data on PReP machines.
1104 noresume [SWSUSP] Disables resume and restores original swap
1105 space.
1107 no-scroll [VGA] Disables scrollback.
1108 This is required for the Braillex ib80-piezo Braille
1109 reader made by F.H. Papenmeier (Germany).
1111 nosbagart [IA-64]
1113 nosep [BUGS=IA-32] Disables x86 SYSENTER/SYSEXIT support.
1115 nosmp [SMP] Tells an SMP kernel to act as a UP kernel.
1117 nosync [HW,M68K] Disables sync negotiation for all devices.
1119 notsc [BUGS=IA-32] Disable Time Stamp Counter
1121 nousb [USB] Disable the USB subsystem
1123 nowb [ARM]
1125 nr_uarts= [SERIAL] maximum number of UARTs to be registered.
1127 opl3= [HW,OSS]
1128 Format: <io>
1130 opl3sa= [HW,OSS]
1131 Format: <io>,<irq>,<dma>,<dma2>,<mpu_io>,<mpu_irq>
1133 opl3sa2= [HW,OSS] Format:
1134 <io>,<irq>,<dma>,<dma2>,<mss_io>,<mpu_io>,<ymode>,<loopback>[,<isapnp>,<multiple]
1136 oprofile.timer= [HW]
1137 Use timer interrupt instead of performance counters
1139 optcd= [HW,CD]
1140 Format: <io>
1142 osst= [HW,SCSI] SCSI Tape Driver
1143 Format: <buffer_size>,<write_threshold>
1144 See also Documentation/scsi/st.txt.
1146 panic= [KNL] Kernel behaviour on panic
1147 Format: <timeout>
1149 parkbd.port= [HW] Parallel port number the keyboard adapter is
1150 connected to, default is 0.
1151 Format: <parport#>
1152 parkbd.mode= [HW] Parallel port keyboard adapter mode of operation,
1153 0 for XT, 1 for AT (default is AT).
1154 Format: <mode>
1156 parport= [HW,PPT] Specify parallel ports. 0 disables.
1157 Format: { 0 | auto | 0xBBB[,IRQ[,DMA]] }
1158 Use 'auto' to force the driver to use any
1159 IRQ/DMA settings detected (the default is to
1160 ignore detected IRQ/DMA settings because of
1161 possible conflicts). You can specify the base
1162 address, IRQ, and DMA settings; IRQ and DMA
1163 should be numbers, or 'auto' (for using detected
1164 settings on that particular port), or 'nofifo'
1165 (to avoid using a FIFO even if it is detected).
1166 Parallel ports are assigned in the order they
1167 are specified on the command line, starting
1168 with parport0.
1170 parport_init_mode= [HW,PPT]
1171 Configure VIA parallel port to operate in
1172 a specific mode. This is necessary on Pegasos
1173 computer where firmware has no options for setting
1174 up parallel port mode and sets it to spp.
1175 Currently this function knows 686a and 8231 chips.
1176 Format: [spp|ps2|epp|ecp|ecpepp]
1178 pas2= [HW,OSS] Format:
1179 <io>,<irq>,<dma>,<dma16>,<sb_io>,<sb_irq>,<sb_dma>,<sb_dma16>
1181 pas16= [HW,SCSI]
1182 See header of drivers/scsi/pas16.c.
1184 pause_on_oops=
1185 Halt all CPUs after the first oops has been printed for
1186 the specified number of seconds. This is to be used if
1187 your oopses keep scrolling off the screen.
1189 pcbit= [HW,ISDN]
1191 pcd. [PARIDE]
1192 See header of drivers/block/paride/pcd.c.
1193 See also Documentation/paride.txt.
1195 pci=option[,option...] [PCI] various PCI subsystem options:
1196 off [IA-32] don't probe for the PCI bus
1197 bios [IA-32] force use of PCI BIOS, don't access
1198 the hardware directly. Use this if your machine
1199 has a non-standard PCI host bridge.
1200 nobios [IA-32] disallow use of PCI BIOS, only direct
1201 hardware access methods are allowed. Use this
1202 if you experience crashes upon bootup and you
1203 suspect they are caused by the BIOS.
1204 conf1 [IA-32] Force use of PCI Configuration
1205 Mechanism 1.
1206 conf2 [IA-32] Force use of PCI Configuration
1207 Mechanism 2.
1208 nommconf [IA-32,X86_64] Disable use of MMCONFIG for PCI
1209 Configuration
1210 nomsi [MSI] If the PCI_MSI kernel config parameter is
1211 enabled, this kernel boot option can be used to
1212 disable the use of MSI interrupts system-wide.
1213 nosort [IA-32] Don't sort PCI devices according to
1214 order given by the PCI BIOS. This sorting is
1215 done to get a device order compatible with
1216 older kernels.
1217 biosirq [IA-32] Use PCI BIOS calls to get the interrupt
1218 routing table. These calls are known to be buggy
1219 on several machines and they hang the machine
1220 when used, but on other computers it's the only
1221 way to get the interrupt routing table. Try
1222 this option if the kernel is unable to allocate
1223 IRQs or discover secondary PCI buses on your
1224 motherboard.
1225 rom [IA-32] Assign address space to expansion ROMs.
1226 Use with caution as certain devices share
1227 address decoders between ROMs and other
1228 resources.
1229 irqmask=0xMMMM [IA-32] Set a bit mask of IRQs allowed to be
1230 assigned automatically to PCI devices. You can
1231 make the kernel exclude IRQs of your ISA cards
1232 this way.
1233 pirqaddr=0xAAAAA [IA-32] Specify the physical address
1234 of the PIRQ table (normally generated
1235 by the BIOS) if it is outside the
1236 F0000h-100000h range.
1237 lastbus=N [IA-32] Scan all buses thru bus #N. Can be
1238 useful if the kernel is unable to find your
1239 secondary buses and you want to tell it
1240 explicitly which ones they are.
1241 assign-busses [IA-32] Always assign all PCI bus
1242 numbers ourselves, overriding
1243 whatever the firmware may have done.
1244 usepirqmask [IA-32] Honor the possible IRQ mask stored
1245 in the BIOS $PIR table. This is needed on
1246 some systems with broken BIOSes, notably
1247 some HP Pavilion N5400 and Omnibook XE3
1248 notebooks. This will have no effect if ACPI
1249 IRQ routing is enabled.
1250 noacpi [IA-32] Do not use ACPI for IRQ routing
1251 or for PCI scanning.
1252 routeirq Do IRQ routing for all PCI devices.
1253 This is normally done in pci_enable_device(),
1254 so this option is a temporary workaround
1255 for broken drivers that don't call it.
1256 firmware [ARM] Do not re-enumerate the bus but instead
1257 just use the configuration from the
1258 bootloader. This is currently used on
1259 IXP2000 systems where the bus has to be
1260 configured a certain way for adjunct CPUs.
1262 pci_reserve= [PCI]
1263 Format: [<sbdf>[+IO<size>][+MEM<size>]][,<sbdf>...]
1264 Format of sbdf: [<segment>:]<bus>:<dev>.<func>
1265 Specifies the least reserved io size or memory size
1266 which is assigned to PCI bridge even when no child
1267 pci device exists. This is useful with PCI hotplug.
1269 pcmv= [HW,PCMCIA] BadgePAD 4
1271 pd. [PARIDE]
1272 See Documentation/paride.txt.
1274 pdcchassis= [PARISC,HW] Disable/Enable PDC Chassis Status codes at
1275 boot time.
1276 Format: { 0 | 1 }
1277 See arch/parisc/kernel/pdc_chassis.c
1279 pf. [PARIDE]
1280 See Documentation/paride.txt.
1282 pg. [PARIDE]
1283 See Documentation/paride.txt.
1285 pirq= [SMP,APIC] Manual mp-table setup
1286 See Documentation/i386/IO-APIC.txt.
1288 plip= [PPT,NET] Parallel port network link
1289 Format: { parport<nr> | timid | 0 }
1290 See also Documentation/parport.txt.
1292 pnpacpi= [ACPI]
1293 { off }
1295 pnpbios= [ISAPNP]
1296 { on | off | curr | res | no-curr | no-res }
1298 pnp_reserve_irq=
1299 [ISAPNP] Exclude IRQs for the autoconfiguration
1301 pnp_reserve_dma=
1302 [ISAPNP] Exclude DMAs for the autoconfiguration
1304 pnp_reserve_io= [ISAPNP] Exclude I/O ports for the autoconfiguration
1305 Ranges are in pairs (I/O port base and size).
1307 pnp_reserve_mem=
1308 [ISAPNP] Exclude memory regions for the
1309 autoconfiguration.
1310 Ranges are in pairs (memory base and size).
1312 profile= [KNL] Enable kernel profiling via /proc/profile
1313 Format: [schedule,]<number>
1314 Param: "schedule" - profile schedule points.
1315 Param: <number> - step/bucket size as a power of 2 for
1316 statistical time based profiling.
1318 processor.max_cstate= [HW,ACPI]
1319 Limit processor to maximum C-state
1320 max_cstate=9 overrides any DMI blacklist limit.
1322 processor.nocst [HW,ACPI]
1323 Ignore the _CST method to determine C-states,
1324 instead using the legacy FADT method
1326 prompt_ramdisk= [RAM] List of RAM disks to prompt for floppy disk
1327 before loading.
1328 See Documentation/ramdisk.txt.
1330 psmouse.proto= [HW,MOUSE] Highest PS2 mouse protocol extension to
1331 probe for; one of (bare|imps|exps|lifebook|any).
1332 psmouse.rate= [HW,MOUSE] Set desired mouse report rate, in reports
1333 per second.
1334 psmouse.resetafter= [HW,MOUSE]
1335 Try to reset the device after so many bad packets
1336 (0 = never).
1337 psmouse.resolution=
1338 [HW,MOUSE] Set desired mouse resolution, in dpi.
1339 psmouse.smartscroll=
1340 [HW,MOUSE] Controls Logitech smartscroll autorepeat.
1341 0 = disabled, 1 = enabled (default).
1343 pss= [HW,OSS] Personal Sound System (ECHO ESC614)
1344 Format:
1345 <io>,<mss_io>,<mss_irq>,<mss_dma>,<mpu_io>,<mpu_irq>
1347 pt. [PARIDE]
1348 See Documentation/paride.txt.
1350 quiet= [KNL] Disable log messages
1352 r128= [HW,DRM]
1354 raid= [HW,RAID]
1355 See Documentation/md.txt.
1357 ramdisk= [RAM] Sizes of RAM disks in kilobytes [deprecated]
1358 See Documentation/ramdisk.txt.
1360 ramdisk_blocksize= [RAM]
1361 See Documentation/ramdisk.txt.
1363 ramdisk_size= [RAM] Sizes of RAM disks in kilobytes
1364 New name for the ramdisk parameter.
1365 See Documentation/ramdisk.txt.
1367 rcu.blimit= [KNL,BOOT] Set maximum number of finished
1368 RCU callbacks to process in one batch.
1370 rcu.qhimark= [KNL,BOOT] Set threshold of queued
1371 RCU callbacks over which batch limiting is disabled.
1373 rcu.qlowmark= [KNL,BOOT] Set threshold of queued
1374 RCU callbacks below which batch limiting is re-enabled.
1376 rcu.rsinterval= [KNL,BOOT,SMP] Set the number of additional
1377 RCU callbacks to queued before forcing reschedule
1378 on all cpus.
1380 rdinit= [KNL]
1381 Format: <full_path>
1382 Run specified binary instead of /init from the ramdisk,
1383 used for early userspace startup. See initrd.
1385 reassign_resources
1386 [PCI,ACPI] Use guestdev parameter to reassign device's
1387 resources.
1389 reboot= [BUGS=IA-32,BUGS=ARM,BUGS=IA-64] Rebooting mode
1390 Format: <reboot_mode>[,<reboot_mode2>[,...]]
1391 See arch/*/kernel/reboot.c.
1393 reserve= [KNL,BUGS] Force the kernel to ignore some iomem area
1395 resume= [SWSUSP]
1396 Specify the partition device for software suspend
1398 rhash_entries= [KNL,NET]
1399 Set number of hash buckets for route cache
1401 riscom8= [HW,SERIAL]
1402 Format: <io_board1>[,<io_board2>[,...<io_boardN>]]
1404 ro [KNL] Mount root device read-only on boot
1406 root= [KNL] Root filesystem
1408 rootdelay= [KNL] Delay (in seconds) to pause before attempting to
1409 mount the root filesystem
1411 rootflags= [KNL] Set root filesystem mount option string
1413 rootfstype= [KNL] Set root filesystem type
1415 rw [KNL] Mount root device read-write on boot
1417 S [KNL] Run init in single mode
1419 sa1100ir [NET]
1420 See drivers/net/irda/sa1100_ir.c.
1422 sb= [HW,OSS]
1423 Format: <io>,<irq>,<dma>,<dma2>
1425 sbni= [NET] Granch SBNI12 leased line adapter
1427 sbpcd= [HW,CD] Soundblaster CD adapter
1428 Format: <io>,<type>
1429 See a comment before function sbpcd_setup() in
1430 drivers/cdrom/sbpcd.c.
1432 sc1200wdt= [HW,WDT] SC1200 WDT (watchdog) driver
1433 Format: <io>[,<timeout>[,<isapnp>]]
1435 scsi_debug_*= [SCSI]
1436 See drivers/scsi/scsi_debug.c.
1438 scsi_default_dev_flags=
1439 [SCSI] SCSI default device flags
1440 Format: <integer>
1442 scsi_dev_flags= [SCSI] Black/white list entry for vendor and model
1443 Format: <vendor>:<model>:<flags>
1444 (flags are integer value)
1446 scsi_logging= [SCSI]
1448 selinux [SELINUX] Disable or enable SELinux at boot time.
1449 Format: { "0" | "1" }
1450 See security/selinux/Kconfig help text.
1451 0 -- disable.
1452 1 -- enable.
1453 Default value is set via kernel config option.
1454 If enabled at boot time, /selinux/disable can be used
1455 later to disable prior to initial policy load.
1457 selinux_compat_net =
1458 [SELINUX] Set initial selinux_compat_net flag value.
1459 Format: { "0" | "1" }
1460 0 -- use new secmark-based packet controls
1461 1 -- use legacy packet controls
1462 Default value is 0 (preferred).
1463 Value can be changed at runtime via
1464 /selinux/compat_net.
1466 serialnumber [BUGS=IA-32]
1468 sg_def_reserved_size= [SCSI]
1470 sgalaxy= [HW,OSS]
1471 Format: <io>,<irq>,<dma>,<dma2>,<sgbase>
1473 shapers= [NET]
1474 Maximal number of shapers.
1476 sim710= [SCSI,HW]
1477 See header of drivers/scsi/sim710.c.
1479 simeth= [IA-64]
1480 simscsi=
1482 sjcd= [HW,CD]
1483 Format: <io>,<irq>,<dma>
1484 See header of drivers/cdrom/sjcd.c.
1486 slram= [HW,MTD]
1488 smart2= [HW]
1489 Format: <io1>[,<io2>[,...,<io8>]]
1491 snd-ad1816a= [HW,ALSA]
1493 snd-ad1848= [HW,ALSA]
1495 snd-ali5451= [HW,ALSA]
1497 snd-als100= [HW,ALSA]
1499 snd-als4000= [HW,ALSA]
1501 snd-azt2320= [HW,ALSA]
1503 snd-cmi8330= [HW,ALSA]
1505 snd-cmipci= [HW,ALSA]
1507 snd-cs4231= [HW,ALSA]
1509 snd-cs4232= [HW,ALSA]
1511 snd-cs4236= [HW,ALSA]
1513 snd-cs4281= [HW,ALSA]
1515 snd-cs46xx= [HW,ALSA]
1517 snd-dt019x= [HW,ALSA]
1519 snd-dummy= [HW,ALSA]
1521 snd-emu10k1= [HW,ALSA]
1523 snd-ens1370= [HW,ALSA]
1525 snd-ens1371= [HW,ALSA]
1527 snd-es968= [HW,ALSA]
1529 snd-es1688= [HW,ALSA]
1531 snd-es18xx= [HW,ALSA]
1533 snd-es1938= [HW,ALSA]
1535 snd-es1968= [HW,ALSA]
1537 snd-fm801= [HW,ALSA]
1539 snd-gusclassic= [HW,ALSA]
1541 snd-gusextreme= [HW,ALSA]
1543 snd-gusmax= [HW,ALSA]
1545 snd-hdsp= [HW,ALSA]
1547 snd-ice1712= [HW,ALSA]
1549 snd-intel8x0= [HW,ALSA]
1551 snd-interwave= [HW,ALSA]
1553 snd-interwave-stb=
1554 [HW,ALSA]
1556 snd-korg1212= [HW,ALSA]
1558 snd-maestro3= [HW,ALSA]
1560 snd-mpu401= [HW,ALSA]
1562 snd-mtpav= [HW,ALSA]
1564 snd-nm256= [HW,ALSA]
1566 snd-opl3sa2= [HW,ALSA]
1568 snd-opti92x-ad1848=
1569 [HW,ALSA]
1571 snd-opti92x-cs4231=
1572 [HW,ALSA]
1574 snd-opti93x= [HW,ALSA]
1576 snd-pmac= [HW,ALSA]
1578 snd-rme32= [HW,ALSA]
1580 snd-rme96= [HW,ALSA]
1582 snd-rme9652= [HW,ALSA]
1584 snd-sb8= [HW,ALSA]
1586 snd-sb16= [HW,ALSA]
1588 snd-sbawe= [HW,ALSA]
1590 snd-serial= [HW,ALSA]
1592 snd-sgalaxy= [HW,ALSA]
1594 snd-sonicvibes= [HW,ALSA]
1596 snd-sun-amd7930=
1597 [HW,ALSA]
1599 snd-sun-cs4231= [HW,ALSA]
1601 snd-trident= [HW,ALSA]
1603 snd-usb-audio= [HW,ALSA,USB]
1605 snd-via82xx= [HW,ALSA]
1607 snd-virmidi= [HW,ALSA]
1609 snd-wavefront= [HW,ALSA]
1611 snd-ymfpci= [HW,ALSA]
1613 sonicvibes= [HW,OSS]
1614 Format: <reverb>
1616 sonycd535= [HW,CD]
1617 Format: <io>[,<irq>]
1619 sonypi.*= [HW] Sony Programmable I/O Control Device driver
1620 See Documentation/sonypi.txt
1622 specialix= [HW,SERIAL] Specialix multi-serial port adapter
1623 See Documentation/specialix.txt.
1625 spia_io_base= [HW,MTD]
1626 spia_fio_base=
1627 spia_pedr=
1628 spia_peddr=
1630 sscape= [HW,OSS]
1631 Format: <io>,<irq>,<dma>,<mpu_io>,<mpu_irq>
1633 st= [HW,SCSI] SCSI tape parameters (buffers, etc.)
1634 See Documentation/scsi/st.txt.
1636 st0x= [HW,SCSI]
1637 See header of drivers/scsi/seagate.c.
1639 sti= [PARISC,HW]
1640 Format: <num>
1641 Set the STI (builtin display/keyboard on the HP-PARISC
1642 machines) console (graphic card) which should be used
1643 as the initial boot-console.
1644 See also comment in drivers/video/console/sticore.c.
1646 sti_font= [HW]
1647 See comment in drivers/video/console/sticore.c.
1649 stifb= [HW]
1650 Format: bpp:<bpp1>[:<bpp2>[:<bpp3>...]]
1652 swiotlb= [IA-64] Number of I/O TLB slabs
1654 switches= [HW,M68k]
1656 sym53c416= [HW,SCSI]
1657 See header of drivers/scsi/sym53c416.c.
1659 t128= [HW,SCSI]
1660 See header of drivers/scsi/t128.c.
1662 tdfx= [HW,DRM]
1664 thash_entries= [KNL,NET]
1665 Set number of hash buckets for TCP connection
1667 time Show timing data prefixed to each printk message line
1669 clocksource= [GENERIC_TIME] Override the default clocksource
1670 Override the default clocksource and use the clocksource
1671 with the name specified.
1673 tipar.timeout= [HW,PPT]
1674 Set communications timeout in tenths of a second
1675 (default 15).
1677 tipar.delay= [HW,PPT]
1678 Set inter-bit delay in microseconds (default 10).
1680 tmc8xx= [HW,SCSI]
1681 See header of drivers/scsi/seagate.c.
1683 tmscsim= [HW,SCSI]
1684 See comment before function dc390_setup() in
1685 drivers/scsi/tmscsim.c.
1687 tp720= [HW,PS2]
1689 trix= [HW,OSS] MediaTrix AudioTrix Pro
1690 Format:
1691 <io>,<irq>,<dma>,<dma2>,<sb_io>,<sb_irq>,<sb_dma>,<mpu_io>,<mpu_irq>
1693 tsdev.xres= [TS] Horizontal screen resolution.
1694 tsdev.yres= [TS] Vertical screen resolution.
1696 turbografx.map[2|3]= [HW,JOY]
1697 TurboGraFX parallel port interface
1698 Format:
1699 <port#>,<js1>,<js2>,<js3>,<js4>,<js5>,<js6>,<js7>
1700 See also Documentation/input/joystick-parport.txt
1702 u14-34f= [HW,SCSI] UltraStor 14F/34F SCSI host adapter
1703 See header of drivers/scsi/u14-34f.c.
1705 uart401= [HW,OSS]
1706 Format: <io>,<irq>
1708 uart6850= [HW,OSS]
1709 Format: <io>,<irq>
1711 usbhid.mousepoll=
1712 [USBHID] The interval which mice are to be polled at.
1714 vdso= [IA-32]
1715 vdso=1: enable VDSO (default)
1716 vdso=0: disable VDSO mapping
1718 video= [FB] Frame buffer configuration
1719 See Documentation/fb/modedb.txt.
1721 vga= [BOOT,IA-32] Select a particular video mode
1722 See Documentation/i386/boot.txt and
1723 Documentation/svga.txt.
1724 Use vga=ask for menu.
1725 This is actually a boot loader parameter; the value is
1726 passed to the kernel using a special protocol.
1728 vmalloc=nn[KMG] [KNL,BOOT] Forces the vmalloc area to have an exact
1729 size of <nn>. This can be used to increase the
1730 minimum size (128MB on x86). It can also be used to
1731 decrease the size and leave more room for directly
1732 mapped kernel RAM.
1734 vmhalt= [KNL,S390] Perform z/VM CP command after system halt.
1735 Format: <command>
1737 vmpanic= [KNL,S390] Perform z/VM CP command after kernel panic.
1738 Format: <command>
1740 vmpoff= [KNL,S390] Perform z/VM CP command after power off.
1741 Format: <command>
1743 waveartist= [HW,OSS]
1744 Format: <io>,<irq>,<dma>,<dma2>
1746 wd33c93= [HW,SCSI]
1747 See header of drivers/scsi/wd33c93.c.
1749 wd7000= [HW,SCSI]
1750 See header of drivers/scsi/wd7000.c.
1752 wdt= [WDT] Watchdog
1753 See Documentation/watchdog/watchdog.txt.
1755 xd= [HW,XT] Original XT pre-IDE (RLL encoded) disks.
1756 xd_geo= See header of drivers/block/xd.c.
1758 xirc2ps_cs= [NET,PCMCIA]
1759 Format:
1760 <irq>,<irq_mask>,<io>,<full_duplex>,<do_sound>,<lockup_hack>[,<irq2>[,<irq3>[,<irq4>]]]
1762 norandmaps Don't use address space randomization
1763 Equivalent to echo 0 > /proc/sys/kernel/randomize_va_space
1766 ______________________________________________________________________
1768 TODO:
1770 Add documentation for ALSA options.
1771 Add more DRM drivers.