]> bbs.cooldavid.org Git - net-next-2.6.git/blame - Documentation/kernel-parameters.txt
[PATCH] PCI: the scheduled removal of PCI_LEGACY_PROC
[net-next-2.6.git] / Documentation / kernel-parameters.txt
CommitLineData
1da177e4
LT
1February 2003 Kernel Parameters v2.5.59
2 ~~~~~~~~~~~~~~~~~
3
4The 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
7case insensitive manner), and with descriptions where known.
8
9Module parameters for loadable modules are specified only as the
10parameter name with optional '=' and value as appropriate, such as:
11
12 modprobe usbcore blinkenlights=1
13
14Module parameters for modules that are built into the kernel image
15are specified on the kernel command line with the module name plus
16'.' plus parameter name, with '=' and value if appropriate, such as:
17
18 usbcore.blinkenlights=1
19
a9913044 20The text in square brackets at the beginning of the description states the
1da177e4
LT
21restrictions on the kernel for the said kernel parameter to be valid. The
22restrictions referred to are that the relevant option is valid if:
23
24 ACPI ACPI support is enabled.
25 ALSA ALSA sound support is enabled.
26 APIC APIC support is enabled.
27 APM Advanced Power Management support is enabled.
28 AX25 Appropriate AX.25 support is enabled.
29 CD Appropriate CD support is enabled.
a9913044
RD
30 DEVFS devfs support is enabled.
31 DRM Direct Rendering Management support is enabled.
1da177e4
LT
32 EDD BIOS Enhanced Disk Drive Services (EDD) is enabled
33 EFI EFI Partitioning (GPT) is enabled
34 EIDE EIDE/ATAPI support is enabled.
35 FB The frame buffer device is enabled.
36 HW Appropriate hardware is enabled.
37 IA-32 IA-32 aka i386 architecture is enabled.
38 IA-64 IA-64 architecture is enabled.
39 IOSCHED More than one I/O scheduler is enabled.
41e2e8be 40 IP_PNP IP DHCP, BOOTP, or RARP is enabled.
1da177e4
LT
41 ISAPNP ISA PnP code is enabled.
42 ISDN Appropriate ISDN support is enabled.
43 JOY Appropriate joystick support is enabled.
44 LP Printer support is enabled.
45 LOOP Loopback device support is enabled.
46 M68k M68k architecture is enabled.
47 These options have more detailed description inside of
48 Documentation/m68k/kernel-options.txt.
49 MCA MCA bus support is enabled.
50 MDA MDA console support is enabled.
51 MOUSE Appropriate mouse support is enabled.
52 MTD MTD support is enabled.
53 NET Appropriate network support is enabled.
54 NUMA NUMA support is enabled.
55 NFS Appropriate NFS support is enabled.
56 OSS OSS sound support is enabled.
57 PARIDE The ParIDE subsystem is enabled.
58 PARISC The PA-RISC architecture is enabled.
59 PCI PCI bus support is enabled.
60 PCMCIA The PCMCIA subsystem is enabled.
61 PNP Plug & Play support is enabled.
62 PPC PowerPC architecture is enabled.
63 PPT Parallel port support is enabled.
64 PS2 Appropriate PS/2 support is enabled.
65 RAM RAM disk support is enabled.
66 S390 S390 architecture is enabled.
67 SCSI Appropriate SCSI support is enabled.
68 A lot of drivers has their options described inside of
69 Documentation/scsi/.
70 SELINUX SELinux support is enabled.
71 SERIAL Serial support is enabled.
72 SMP The kernel is an SMP kernel.
73 SPARC Sparc architecture is enabled.
a9913044 74 SWSUSP Software suspend is enabled.
1da177e4
LT
75 TS Appropriate touchscreen support is enabled.
76 USB USB support is enabled.
77 USBHID USB Human Interface Device support is enabled.
78 V4L Video For Linux support is enabled.
79 VGA The VGA console has been enabled.
80 VT Virtual terminal support is enabled.
81 WDT Watchdog support is enabled.
82 XT IBM PC/XT MFM hard disk support is enabled.
83 X86-64 X86-64 architecture is enabled.
84 More X86-64 boot options can be found in
85 Documentation/x86_64/boot-options.txt .
86
87In addition, the following text indicates that the option:
88
89 BUGS= Relates to possible processor bugs on the said processor.
90 KNL Is a kernel start-up parameter.
91 BOOT Is a boot loader parameter.
92
93Parameters denoted with BOOT are actually interpreted by the boot
94loader, and have no meaning to the kernel directly.
95Do not modify the syntax of boot loader parameters without extreme
96need or coordination with <Documentation/i386/boot.txt>.
97
98Note that ALL kernel parameters listed below are CASE SENSITIVE, and that
99a trailing = on the name of any parameter states that that parameter will
100be entered as an environment variable, whereas its absence indicates that
101it will appear as a kernel argument readable via /proc/cmdline by programs
102running once the system is up.
103
104 53c7xx= [HW,SCSI] Amiga SCSI controllers
105 See header of drivers/scsi/53c7xx.c.
106 See also Documentation/scsi/ncr53c7xx.txt.
107
a9913044
RD
108 acpi= [HW,ACPI] Advanced Configuration and Power Interface
109 Format: { force | off | ht | strict | noirq }
1da177e4
LT
110 force -- enable ACPI if default was off
111 off -- disable ACPI if default was on
112 noirq -- do not use ACPI for IRQ routing
113 ht -- run only enough ACPI to enable Hyper Threading
a9913044 114 strict -- Be less tolerant of platforms that are not
1da177e4
LT
115 strictly ACPI specification compliant.
116
117 See also Documentation/pm.txt, pci=noacpi
118
119 acpi_sleep= [HW,ACPI] Sleep options
120 Format: { s3_bios, s3_mode }
121 See Documentation/power/video.txt
a9913044 122
1da177e4 123 acpi_sci= [HW,ACPI] ACPI System Control Interrupt trigger mode
a9913044 124 Format: { level | edge | high | low }
1da177e4 125
a9913044
RD
126 acpi_irq_balance [HW,ACPI]
127 ACPI will balance active IRQs
128 default in APIC mode
1da177e4 129
a9913044
RD
130 acpi_irq_nobalance [HW,ACPI]
131 ACPI will not move active IRQs (default)
132 default in PIC mode
1da177e4 133
a9913044
RD
134 acpi_irq_pci= [HW,ACPI] If irq_balance, clear listed IRQs for
135 use by PCI
1da177e4
LT
136 Format: <irq>,<irq>...
137
a9913044 138 acpi_irq_isa= [HW,ACPI] If irq_balance, mark listed IRQs used by ISA
1da177e4
LT
139 Format: <irq>,<irq>...
140
141 acpi_osi= [HW,ACPI] empty param disables _OSI
142
143 acpi_serialize [HW,ACPI] force serialization of AML methods
144
145 acpi_skip_timer_override [HW,ACPI]
146 Recognize and ignore IRQ0/pin2 Interrupt Override.
147 For broken nForce2 BIOS resulting in XT-PIC timer.
148
149 acpi_dbg_layer= [HW,ACPI]
150 Format: <int>
a9913044 151 Each bit of the <int> indicates an ACPI debug layer,
1da177e4
LT
152 1: enable, 0: disable. It is useful for boot time
153 debugging. After system has booted up, it can be set
154 via /proc/acpi/debug_layer.
155
156 acpi_dbg_level= [HW,ACPI]
157 Format: <int>
a9913044 158 Each bit of the <int> indicates an ACPI debug level,
1da177e4
LT
159 1: enable, 0: disable. It is useful for boot time
160 debugging. After system has booted up, it can be set
161 via /proc/acpi/debug_level.
162
163 acpi_fake_ecdt [HW,ACPI] Workaround failure due to BIOS lacking ECDT
164
30e332f3
LY
165 acpi_generic_hotkey [HW,ACPI]
166 Allow consolidated generic hotkey driver to
a9913044 167 override platform specific driver.
30e332f3
LY
168 See also Documentation/acpi-hotkey.txt.
169
66759a01
CE
170 enable_timer_pin_1 [i386,x86-64]
171 Enable PIN 1 of APIC timer
a9913044
RD
172 Can be useful to work around chipset bugs
173 (in particular on some ATI chipsets).
66759a01
CE
174 The kernel tries to set a reasonable default.
175
176 disable_timer_pin_1 [i386,x86-64]
177 Disable PIN 1 of APIC timer
178 Can be useful to work around chipset bugs.
179
1da177e4
LT
180 ad1816= [HW,OSS]
181 Format: <io>,<irq>,<dma>,<dma2>
182 See also Documentation/sound/oss/AD1816.
183
184 ad1848= [HW,OSS]
185 Format: <io>,<irq>,<dma>,<dma2>,<type>
186
187 adlib= [HW,OSS]
188 Format: <io>
a9913044 189
1da177e4
LT
190 advansys= [HW,SCSI]
191 See header of drivers/scsi/advansys.c.
192
193 advwdt= [HW,WDT] Advantech WDT
194 Format: <iostart>,<iostop>
195
196 aedsp16= [HW,OSS] Audio Excel DSP 16
197 Format: <io>,<irq>,<dma>,<mss_io>,<mpu_io>,<mpu_irq>
198 See also header of sound/oss/aedsp16.c.
a9913044 199
1da177e4
LT
200 aha152x= [HW,SCSI]
201 See Documentation/scsi/aha152x.txt.
202
203 aha1542= [HW,SCSI]
204 Format: <portbase>[,<buson>,<busoff>[,<dmaspeed>]]
205
206 aic7xxx= [HW,SCSI]
207 See Documentation/scsi/aic7xxx.txt.
208
209 aic79xx= [HW,SCSI]
210 See Documentation/scsi/aic79xx.txt.
211
1da177e4
LT
212 amijoy.map= [HW,JOY] Amiga joystick support
213 Map of devices attached to JOY0DAT and JOY1DAT
214 Format: <a>,<b>
215 See also Documentation/kernel/input/joystick.txt
216
217 analog.map= [HW,JOY] Analog joystick and gamepad support
218 Specifies type or capabilities of an analog joystick
219 connected to one of 16 gameports
220 Format: <type1>,<type2>,..<type16>
221
a9913044
RD
222 apc= [HW,SPARC]
223 Power management functions (SPARCstation-4/5 + deriv.)
1da177e4
LT
224 Format: noidle
225 Disable APC CPU standby support. SPARCstation-Fox does
226 not play well with APC CPU idle - disable it if you have
227 APC and your system crashes randomly.
228
a9913044 229 apic= [APIC,i386] Change the output verbosity whilst booting
1da177e4
LT
230 Format: { quiet (default) | verbose | debug }
231 Change the amount of debugging information output
232 when initialising the APIC and IO-APIC components.
a9913044 233
1da177e4
LT
234 apm= [APM] Advanced Power Management
235 See header of arch/i386/kernel/apm.c.
236
237 applicom= [HW]
238 Format: <mem>,<irq>
a9913044 239
1da177e4
LT
240 arcrimi= [HW,NET] ARCnet - "RIM I" (entirely mem-mapped) cards
241 Format: <io>,<irq>,<nodeID>
242
243 ataflop= [HW,M68k]
244
245 atarimouse= [HW,MOUSE] Atari Mouse
246
247 atascsi= [HW,SCSI] Atari SCSI
248
249 atkbd.extra= [HW] Enable extra LEDs and keys on IBM RapidAccess,
250 EzKey and similar keyboards
251
252 atkbd.reset= [HW] Reset keyboard during initialization
253
a9913044
RD
254 atkbd.set= [HW] Select keyboard code set
255 Format: <int> (2 = AT (default), 3 = PS/2)
1da177e4
LT
256
257 atkbd.scroll= [HW] Enable scroll wheel on MS Office and similar
258 keyboards
259
260 atkbd.softraw= [HW] Choose between synthetic and real raw mode
261 Format: <bool> (0 = real, 1 = synthetic (default))
a9913044
RD
262
263 atkbd.softrepeat= [HW]
264 Use software keyboard repeat
1da177e4
LT
265
266 autotest [IA64]
267
268 awe= [HW,OSS] AWE32/SB32/AWE64 wave table synth
269 Format: <io>,<memsize>,<isapnp>
a9913044 270
1da177e4
LT
271 aztcd= [HW,CD] Aztech CD268 CDROM driver
272 Format: <io>,0x79 (?)
273
274 baycom_epp= [HW,AX25]
275 Format: <io>,<mode>
a9913044 276
1da177e4
LT
277 baycom_par= [HW,AX25] BayCom Parallel Port AX.25 Modem
278 Format: <io>,<mode>
279 See header of drivers/net/hamradio/baycom_par.c.
280
a9913044
RD
281 baycom_ser_fdx= [HW,AX25]
282 BayCom Serial Port AX.25 Modem (Full Duplex Mode)
1da177e4
LT
283 Format: <io>,<irq>,<mode>[,<baud>]
284 See header of drivers/net/hamradio/baycom_ser_fdx.c.
285
a9913044
RD
286 baycom_ser_hdx= [HW,AX25]
287 BayCom Serial Port AX.25 Modem (Half Duplex Mode)
1da177e4
LT
288 Format: <io>,<irq>,<mode>
289 See header of drivers/net/hamradio/baycom_ser_hdx.c.
290
291 blkmtd_device= [HW,MTD]
292 blkmtd_erasesz=
293 blkmtd_ro=
294 blkmtd_bs=
295 blkmtd_count=
296
297 bttv.card= [HW,V4L] bttv (bt848 + bt878 based grabber cards)
a9913044
RD
298 bttv.radio= Most important insmod options are available as
299 kernel args too.
1da177e4
LT
300 bttv.pll= See Documentation/video4linux/bttv/Insmod-options
301 bttv.tuner= and Documentation/video4linux/bttv/CARDLIST
302
303 BusLogic= [HW,SCSI]
304 See drivers/scsi/BusLogic.c, comment before function
305 BusLogic_ParseDriverOptions().
306
307 c101= [NET] Moxa C101 synchronous serial card
308
309 cachesize= [BUGS=IA-32] Override level 2 CPU cache size detection.
310 Sometimes CPU hardware bugs make them report the cache
311 size incorrectly. The kernel will attempt work arounds
312 to fix known problems, but for some CPUs it is not
313 possible to determine what the correct size should be.
314 This option provides an override for these situations.
315
316 cdu31a= [HW,CD]
317 Format: <io>,<irq>[,PAS]
318 See header of drivers/cdrom/cdu31a.c.
319
320 chandev= [HW,NET] Generic channel device initialisation
321
322 checkreqprot [SELINUX] Set initial checkreqprot flag value.
323 Format: { "0" | "1" }
324 See security/selinux/Kconfig help text.
a9913044
RD
325 0 -- check protection applied by kernel (includes
326 any implied execute protection).
1da177e4
LT
327 1 -- check protection requested by application.
328 Default value is set via a kernel config option.
a9913044
RD
329 Value can be changed at runtime via
330 /selinux/checkreqprot.
331
332 clock= [BUGS=IA-32,HW] gettimeofday timesource override.
1da177e4 333 Forces specified timesource (if avaliable) to be used
a9913044
RD
334 when calculating gettimeofday(). If specicified
335 timesource is not avalible, it defaults to PIT.
1da177e4
LT
336 Format: { pit | tsc | cyclone | pmtmr }
337
f9262c12
AK
338 disable_8254_timer
339 enable_8254_timer
340 [IA32/X86_64] Disable/Enable interrupt 0 timer routing
341 over the 8254 in addition to over the IO-APIC. The
342 kernel tries to set a sensible default.
343
1da177e4
LT
344 hpet= [IA-32,HPET] option to disable HPET and use PIT.
345 Format: disable
346
347 cm206= [HW,CD]
348 Format: { auto | [<io>,][<irq>] }
349
350 com20020= [HW,NET] ARCnet - COM20020 chipset
a9913044
RD
351 Format:
352 <io>[,<irq>[,<nodeID>[,<backplane>[,<ckp>[,<timeout>]]]]]
1da177e4
LT
353
354 com90io= [HW,NET] ARCnet - COM90xx chipset (IO-mapped buffers)
355 Format: <io>[,<irq>]
356
a9913044
RD
357 com90xx= [HW,NET]
358 ARCnet - COM90xx chipset (memory-mapped buffers)
1da177e4
LT
359 Format: <io>[,<irq>[,<memstart>]]
360
361 condev= [HW,S390] console device
362 conmode=
a9913044 363
1da177e4
LT
364 console= [KNL] Output console device and options.
365
366 tty<n> Use the virtual console device <n>.
367
368 ttyS<n>[,options]
369 Use the specified serial port. The options are of
370 the form "bbbbpn", where "bbbb" is the baud rate,
371 "p" is parity ("n", "o", or "e"), and "n" is bits.
372 Default is "9600n8".
373
374 See also Documentation/serial-console.txt.
375
376 uart,io,<addr>[,options]
377 uart,mmio,<addr>[,options]
378 Start an early, polled-mode console on the 8250/16550
379 UART at the specified I/O port or MMIO address,
380 switching to the matching ttyS device later. The
381 options are the same as for ttyS, above.
382
383 cpcihp_generic= [HW,PCI] Generic port I/O CompactPCI driver
a9913044
RD
384 Format:
385 <first_slot>,<last_slot>,<port>,<enum_bit>[,<debug>]
1da177e4
LT
386
387 cpia_pp= [HW,PPT]
388 Format: { parport<nr> | auto | none }
389
dc009d92
EB
390 crashkernel=nn[KMG]@ss[KMG]
391 [KNL] Reserve a chunk of physical memory to
392 hold a kernel to switch to with kexec on panic.
393
1da177e4
LT
394 cs4232= [HW,OSS]
395 Format: <io>,<irq>,<dma>,<dma2>,<mpuio>,<mpuirq>
396
397 cs89x0_dma= [HW,NET]
398 Format: <dma>
399
400 cs89x0_media= [HW,NET]
401 Format: { rj45 | aui | bnc }
a9913044 402
1da177e4 403 cyclades= [HW,SERIAL] Cyclades multi-serial port adapter.
a9913044
RD
404
405 dasd= [HW,NET]
1da177e4
LT
406 See header of drivers/s390/block/dasd_devmap.c.
407
408 db9.dev[2|3]= [HW,JOY] Multisystem joystick support via parallel port
409 (one device per port)
410 Format: <port#>,<type>
411 See also Documentation/input/joystick-parport.txt
412
413 debug [KNL] Enable kernel debugging (events log level).
414
415 decnet= [HW,NET]
416 Format: <area>[,<node>]
417 See also Documentation/networking/decnet.txt.
418
419 devfs= [DEVFS]
420 See Documentation/filesystems/devfs/boot-options.
421
422 dhash_entries= [KNL]
423 Set number of hash buckets for dentry cache.
a9913044 424
1da177e4
LT
425 digi= [HW,SERIAL]
426 IO parameters + enable/disable command.
427
428 digiepca= [HW,SERIAL]
429 See drivers/char/README.epca and
430 Documentation/digiepca.txt.
431
432 dmascc= [HW,AX25,SERIAL] AX.25 Z80SCC driver with DMA
433 support available.
434 Format: <io_dev0>[,<io_dev1>[,..<io_dev32>]]
435
436 dmasound= [HW,OSS] Sound subsystem buffers
437
438 dscc4.setup= [NET]
439
440 dtc3181e= [HW,SCSI]
441
a9913044 442 earlyprintk= [IA-32,X86-64]
1da177e4
LT
443 earlyprintk=vga
444 earlyprintk=serial[,ttySn[,baudrate]]
445
a9913044 446 Append ",keep" to not disable it when the real console
1da177e4
LT
447 takes over.
448
449 Only vga or serial at a time, not both.
450
451 Currently only ttyS0 and ttyS1 are supported.
452
453 Interaction with the standard serial driver is not
454 very good.
455
456 The VGA output is eventually overwritten by the real
457 console.
458
459 eata= [HW,SCSI]
460
53f11d4f
LB
461 ec_intr= [HW,ACPI] ACPI Embedded Controller interrupt mode
462 Format: <int>
463 0: polling mode
464 non-0: interrupt mode (default)
465
1da177e4
LT
466 eda= [HW,PS2]
467
468 edb= [HW,PS2]
469
470 edd= [EDD]
471 Format: {"of[f]" | "sk[ipmbr]"}
472 See comment in arch/i386/boot/edd.S
473
a9913044 474 eicon= [HW,ISDN]
1da177e4
LT
475 Format: <id>,<membase>,<irq>
476
477 eisa_irq_edge= [PARISC,HW]
478 See header of drivers/parisc/eisa.c.
479
480 elanfreq= [IA-32]
481 See comment before function elanfreq_setup() in
482 arch/i386/kernel/cpu/cpufreq/elanfreq.c.
483
484 elevator= [IOSCHED]
16ab3adf 485 Format: {"anticipatory" | "cfq" | "deadline" | "noop"}
a9913044
RD
486 See Documentation/block/as-iosched.txt and
487 Documentation/block/deadline-iosched.txt for details.
488
aac04b32 489 elfcorehdr= [IA-32, X86_64]
a9913044 490 Specifies physical address of start of kernel core
aac04b32
VG
491 image elf header. Generally kexec loader will
492 pass this option to capture kernel.
493 See Documentation/kdump/kdump.txt for details.
1da177e4
LT
494
495 enforcing [SELINUX] Set initial enforcing status.
496 Format: {"0" | "1"}
497 See security/selinux/Kconfig help text.
498 0 -- permissive (log only, no denials).
499 1 -- enforcing (deny and log).
500 Default value is 0.
501 Value can be changed at runtime via /selinux/enforce.
502
503 es1370= [HW,OSS]
504 Format: <lineout>[,<micbias>]
505 See also header of sound/oss/es1370.c.
506
507 es1371= [HW,OSS]
508 Format: <spdif>,[<nomix>,[<amplifier>]]
509 See also header of sound/oss/es1371.c.
a9913044 510
1da177e4
LT
511 ether= [HW,NET] Ethernet cards parameters
512 This option is obsoleted by the "netdev=" option, which
513 has equivalent usage. See its documentation for details.
514
515 eurwdt= [HW,WDT] Eurotech CPU-1220/1410 onboard watchdog.
516 Format: <io>[,<irq>]
517
518 fd_mcs= [HW,SCSI]
519 See header of drivers/scsi/fd_mcs.c.
520
521 fdomain= [HW,SCSI]
522 See header of drivers/scsi/fdomain.c.
523
524 floppy= [HW]
525 See Documentation/floppy.txt.
526
527 ftape= [HW] Floppy Tape subsystem debugging options.
528 See Documentation/ftape.txt.
529
530 gamecon.map[2|3]=
531 [HW,JOY] Multisystem joystick and NES/SNES/PSX pad
532 support via parallel port (up to 5 devices per port)
533 Format: <port#>,<pad1>,<pad2>,<pad3>,<pad4>,<pad5>
534 See also Documentation/input/joystick-parport.txt
535
536 gamma= [HW,DRM]
537
538 gdth= [HW,SCSI]
539 See header of drivers/scsi/gdth.c.
540
541 gpt [EFI] Forces disk with valid GPT signature but
542 invalid Protective MBR to be treated as GPT.
543
544 gscd= [HW,CD]
545 Format: <io>
546
547 gt96100eth= [NET] MIPS GT96100 Advanced Communication Controller
548
549 gus= [HW,OSS]
550 Format: <io>,<irq>,<dma>,<dma16>
a9913044 551
1da177e4
LT
552 gvp11= [HW,SCSI]
553
554 hashdist= [KNL,NUMA] Large hashes allocated during boot
555 are distributed across NUMA nodes. Defaults on
556 for IA-64, off otherwise.
a9913044 557 Format: 0 | 1 (for off | on)
1da177e4
LT
558
559 hcl= [IA-64] SGI's Hardware Graph compatibility layer
560
561 hd= [EIDE] (E)IDE hard drive subsystem geometry
562 Format: <cyl>,<head>,<sect>
563
564 hd?= [HW] (E)IDE subsystem
565 hd?lun= See Documentation/ide.txt.
566
567 highmem=nn[KMG] [KNL,BOOT] forces the highmem zone to have an exact
568 size of <nn>. This works even on boxes that have no
569 highmem otherwise. This also works to reduce highmem
570 size on bigger boxes.
571
572 hisax= [HW,ISDN]
573 See Documentation/isdn/README.HiSax.
574
575 hugepages= [HW,IA-32,IA-64] Maximal number of HugeTLB pages.
576
577 noirqbalance [IA-32,SMP,KNL] Disable kernel irq balancing
578
579 i8042.direct [HW] Put keyboard port into non-translated mode
580 i8042.dumbkbd [HW] Pretend that controlled can only read data from
581 keyboard and can not control its state
582 (Don't attempt to blink the leds)
583 i8042.noaux [HW] Don't check for auxiliary (== mouse) port
945ef0d4 584 i8042.nokbd [HW] Don't check/create keyboard port
1da177e4
LT
585 i8042.nomux [HW] Don't check presence of an active multiplexing
586 controller
587 i8042.nopnp [HW] Don't use ACPIPnP / PnPBIOS to discover KBD/AUX
588 controllers
589 i8042.panicblink=
590 [HW] Frequency with which keyboard LEDs should blink
591 when kernel panics (default is 0.5 sec)
592 i8042.reset [HW] Reset the controller during init and cleanup
593 i8042.unlock [HW] Unlock (ignore) the keylock
594
595 i810= [HW,DRM]
596
e70c9d5e
DT
597 i8k.ignore_dmi [HW] Continue probing hardware even if DMI data
598 indicates that the driver is running on unsupported
599 hardware.
1da177e4
LT
600 i8k.force [HW] Activate i8k driver even if SMM BIOS signature
601 does not match list of supported models.
602 i8k.power_status
603 [HW] Report power status in /proc/i8k
604 (disabled by default)
605 i8k.restricted [HW] Allow controlling fans only if SYS_ADMIN
606 capability is set.
607
608 ibmmcascsi= [HW,MCA,SCSI] IBM MicroChannel SCSI adapter
609 See Documentation/mca.txt.
610
611 icn= [HW,ISDN]
612 Format: <io>[,<membase>[,<icn_id>[,<icn_id2>]]]
613
614 ide= [HW] (E)IDE subsystem
615 Format: ide=nodma or ide=doubler or ide=reverse
616 See Documentation/ide.txt.
617
618 ide?= [HW] (E)IDE subsystem
619 Format: ide?=noprobe or chipset specific parameters.
620 See Documentation/ide.txt.
a9913044 621
1da177e4
LT
622 idebus= [HW] (E)IDE subsystem - VLB/PCI bus speed
623 See Documentation/ide.txt.
624
625 idle= [HW]
626 Format: idle=poll or idle=halt
a9913044 627
1da177e4
LT
628 ihash_entries= [KNL]
629 Set number of hash buckets for inode cache.
630
631 in2000= [HW,SCSI]
632 See header of drivers/scsi/in2000.c.
633
634 init= [KNL]
635 Format: <full_path>
636 Run specified binary instead of /sbin/init as init
637 process.
638
639 initcall_debug [KNL] Trace initcalls as they are executed. Useful
640 for working out where the kernel is dying during
641 startup.
642
643 initrd= [BOOT] Specify the location of the initial ramdisk
644
645 inport.irq= [HW] Inport (ATI XL and Microsoft) busmouse driver
646 Format: <irq>
647
2bd0fa3b
JB
648 combined_mode= [HW] control which driver uses IDE ports in combined
649 mode: legacy IDE driver, libata, or both
650 (in the libata case, libata.atapi_enabled=1 may be
651 useful as well). Note that using the ide or libata
652 options may affect your device naming (e.g. by
653 changing hdc to sdb).
654 Format: combined (default), ide, or libata
655
1da177e4
LT
656 inttest= [IA64]
657
658 io7= [HW] IO7 for Marvel based alpha systems
659 See comment before marvel_specify_io7 in
660 arch/alpha/kernel/core_marvel.c.
661
662 ip= [IP_PNP]
663 See Documentation/nfsroot.txt.
664
665 ip2= [HW] Set IO/IRQ pairs for up to 4 IntelliPort boards
666 See comment before ip2_setup() in drivers/char/ip2.c.
667
668 ips= [HW,SCSI] Adaptec / IBM ServeRAID controller
669 See header of drivers/scsi/ips.c.
670
200803df
AC
671 irqfixup [HW]
672 When an interrupt is not handled search all handlers
673 for it. Intended to get systems with badly broken
674 firmware running.
675
676 irqpoll [HW]
677 When an interrupt is not handled search all handlers
678 for it. Also check all handlers each timer
679 interrupt. Intended to get systems with badly broken
680 firmware running.
681
1da177e4 682 isapnp= [ISAPNP]
a9913044 683 Format: <RDP>,<reset>,<pci_scan>,<verbosity>
1da177e4
LT
684
685 isolcpus= [KNL,SMP] Isolate CPUs from the general scheduler.
686 Format: <cpu number>,...,<cpu number>
687 This option can be used to specify one or more CPUs
688 to isolate from the general SMP balancing and scheduling
689 algorithms. The only way to move a process onto or off
690 an "isolated" CPU is via the CPU affinity syscalls.
691 <cpu number> begins at 0 and the maximum value is
692 "number of CPUs in system - 1".
693
694 This option is the preferred way to isolate CPUs. The
a9913044
RD
695 alternative -- manually setting the CPU mask of all
696 tasks in the system -- can cause problems and
697 suboptimal load balancer performance.
1da177e4
LT
698
699 isp16= [HW,CD]
700 Format: <io>,<irq>,<dma>,<setup>
701
a9913044 702 iucv= [HW,NET]
1da177e4
LT
703
704 js= [HW,JOY] Analog joystick
705 See Documentation/input/joystick.txt.
706
707 keepinitrd [HW,ARM]
708
a9913044 709 kstack=N [IA-32,X86-64] Print N words from the kernel stack
1da177e4
LT
710 in oops dumps.
711
712 l2cr= [PPC]
713
a9913044
RD
714 lapic [IA-32,APIC] Enable the local APIC even if BIOS
715 disabled it.
1da177e4
LT
716
717 lasi= [HW,SCSI] PARISC LASI driver for the 53c700 chip
718 Format: addr:<io>,irq:<irq>
719
a9913044
RD
720 llsc*= [IA64] See function print_params() in
721 arch/ia64/sn/kernel/llsc4.c.
1da177e4
LT
722
723 load_ramdisk= [RAM] List of ramdisks to load from floppy
724 See Documentation/ramdisk.txt.
725
a6b25b67
RD
726 lockd.nlm_grace_period=P [NFS] Assign grace period.
727 Format: <integer>
1da177e4 728
a6b25b67
RD
729 lockd.nlm_tcpport=N [NFS] Assign TCP port.
730 Format: <integer>
731
732 lockd.nlm_timeout=T [NFS] Assign timeout value.
733 Format: <integer>
734
735 lockd.nlm_udpport=M [NFS] Assign UDP port.
736 Format: <integer>
1da177e4
LT
737
738 logibm.irq= [HW,MOUSE] Logitech Bus Mouse Driver
739 Format: <irq>
740
741 loglevel= All Kernel Messages with a loglevel smaller than the
742 console loglevel will be printed to the console. It can
743 also be changed with klogd or other programs. The
744 loglevels are defined as follows:
745
746 0 (KERN_EMERG) system is unusable
747 1 (KERN_ALERT) action must be taken immediately
748 2 (KERN_CRIT) critical conditions
749 3 (KERN_ERR) error conditions
750 4 (KERN_WARNING) warning conditions
751 5 (KERN_NOTICE) normal but significant condition
752 6 (KERN_INFO) informational
753 7 (KERN_DEBUG) debug-level messages
754
755 log_buf_len=n Sets the size of the printk ring buffer, in bytes.
a9913044
RD
756 Format: { n | nk | nM }
757 n must be a power of two. The default size
758 is set in the kernel config file.
1da177e4
LT
759
760 lp=0 [LP] Specify parallel ports to use, e.g,
761 lp=port[,port...] lp=none,parport0 (lp0 not configured, lp1 uses
762 lp=reset first parallel port). 'lp=0' disables the
763 lp=auto printer driver. 'lp=reset' (which can be
764 specified in addition to the ports) causes
765 attached printers to be reset. Using
766 lp=port1,port2,... specifies the parallel ports
767 to associate lp devices with, starting with
768 lp0. A port specification may be 'none' to skip
769 that lp device, or a parport name such as
770 'parport0'. Specifying 'lp=auto' instead of a
771 port specification list means that device IDs
772 from each port should be examined, to see if
773 an IEEE 1284-compliant printer is attached; if
774 so, the driver will manage that printer.
775 See also header of drivers/char/lp.c.
776
777 lpj=n [KNL]
778 Sets loops_per_jiffy to given constant, thus avoiding
779 time-consuming boot-time autodetection (up to 250 ms per
780 CPU). 0 enables autodetection (default). To determine
781 the correct value for your kernel, boot with normal
782 autodetection and see what value is printed. Note that
783 on SMP systems the preset will be applied to all CPUs,
784 which is likely to cause problems if your CPUs need
785 significantly divergent settings. An incorrect value
786 will cause delays in the kernel to be wrong, leading to
787 unpredictable I/O errors and other breakage. Although
788 unlikely, in the extreme case this might damage your
789 hardware.
790
791 ltpc= [NET]
792 Format: <io>,<irq>,<dma>
793
a9913044
RD
794 mac5380= [HW,SCSI] Format:
795 <can_queue>,<cmd_per_lun>,<sg_tablesize>,<hostid>,<use_tags>
1da177e4 796
a9913044
RD
797 mac53c9x= [HW,SCSI] Format:
798 <num_esps>,<disconnect>,<nosync>,<can_queue>,<cmd_per_lun>,<sg_tablesize>,<hostid>,<use_tags>
1da177e4 799
a9913044
RD
800 machvec= [IA64] Force the use of a particular machine-vector
801 (machvec) in a generic kernel.
802 Example: machvec=hpzx1_swiotlb
1da177e4 803
a9913044
RD
804 mad16= [HW,OSS] Format:
805 <io>,<irq>,<dma>,<dma16>,<mpu_io>,<mpu_irq>,<joystick>
1da177e4
LT
806
807 maui= [HW,OSS]
808 Format: <io>,<irq>
a9913044
RD
809
810 max_loop= [LOOP] Maximum number of loopback devices that can
1da177e4
LT
811 be mounted
812 Format: <1-256>
813
814 maxcpus= [SMP] Maximum number of processors that an SMP kernel
815 should make use of
816
2b2c3750
BP
817 max_addr=[KMG] [KNL,BOOT,ia64] All physical memory greater than or
818 equal to this physical address is ignored.
819
a9913044 820 max_luns= [SCSI] Maximum number of LUNs to probe.
1da177e4
LT
821 Should be between 1 and 2^32-1.
822
823 max_report_luns=
a9913044 824 [SCSI] Maximum number of LUNs received.
1da177e4
LT
825 Should be between 1 and 16384.
826
827 mca-pentium [BUGS=IA-32]
828
829 mcatest= [IA-64]
830
831 mcd= [HW,CD]
832 Format: <port>,<irq>,<mitsumi_bug_93_wait>
833
834 mcdx= [HW,CD]
835
836 mce [IA-32] Machine Check Exception
837
838 md= [HW] RAID subsystems devices and level
839 See Documentation/md.txt.
a9913044 840
1da177e4
LT
841 mdacon= [MDA]
842 Format: <first>,<last>
843 Specifies range of consoles to be captured by the MDA.
a9913044 844
1da177e4
LT
845 mem=nn[KMG] [KNL,BOOT] Force usage of a specific amount of memory
846 Amount of memory to be used when the kernel is not able
847 to see the whole system memory or for test.
848 [IA-32] Use together with memmap= to avoid physical
849 address space collisions. Without memmap= PCI devices
850 could be placed at addresses belonging to unused RAM.
851
852 mem=nopentium [BUGS=IA-32] Disable usage of 4MB pages for kernel
853 memory.
854
69cda7b1 855 memmap=exactmap [KNL,IA-32,X86_64] Enable setting of an exact
1da177e4
LT
856 E820 memory map, as specified by the user.
857 Such memmap=exactmap lines can be constructed based on
858 BIOS output or other requirements. See the memmap=nn@ss
859 option description.
860
861 memmap=nn[KMG]@ss[KMG]
862 [KNL] Force usage of a specific region of memory
863 Region of memory to be used, from ss to ss+nn.
864
865 memmap=nn[KMG]#ss[KMG]
866 [KNL,ACPI] Mark specific memory as ACPI data.
867 Region of memory to be used, from ss to ss+nn.
868
869 memmap=nn[KMG]$ss[KMG]
870 [KNL,ACPI] Mark specific memory as reserved.
871 Region of memory to be used, from ss to ss+nn.
872
873 meye.*= [HW] Set MotionEye Camera parameters
874 See Documentation/video4linux/meye.txt.
875
876 mga= [HW,DRM]
877
198e2f18
AM
878 migration_cost=
879 [KNL,SMP] debug: override scheduler migration costs
880 Format: <level-1-usecs>,<level-2-usecs>,...
881 This debugging option can be used to override the
882 default scheduler migration cost matrix. The numbers
883 are indexed by 'CPU domain distance'.
884 E.g. migration_cost=1000,2000,3000 on an SMT NUMA
885 box will set up an intra-core migration cost of
886 1 msec, an inter-core migration cost of 2 msecs,
887 and an inter-node migration cost of 3 msecs.
888
889 WARNING: using the wrong values here can break
890 scheduler performance, so it's only for scheduler
891 development purposes, not production environments.
892
893 migration_debug=
894 [KNL,SMP] migration cost auto-detect verbosity
895 Format=<0|1|2>
896 If a system's migration matrix reported at bootup
897 seems erroneous then this option can be used to
898 increase verbosity of the detection process.
899 We default to 0 (no extra messages), 1 will print
900 some more information, and 2 will be really
901 verbose (probably only useful if you also have a
902 serial console attached to the system).
903
904 migration_factor=
905 [KNL,SMP] multiply/divide migration costs by a factor
906 Format=<percent>
907 This debug option can be used to proportionally
908 increase or decrease the auto-detected migration
909 costs for all entries of the migration matrix.
910 E.g. migration_factor=150 will increase migration
911 costs by 50%. (and thus the scheduler will be less
912 eager migrating cache-hot tasks)
913 migration_factor=80 will decrease migration costs
914 by 20%. (thus the scheduler will be more eager to
915 migrate tasks)
916
917 WARNING: using the wrong values here can break
918 scheduler performance, so it's only for scheduler
919 development purposes, not production environments.
920
1da177e4
LT
921 mousedev.tap_time=
922 [MOUSE] Maximum time between finger touching and
923 leaving touchpad surface for touch to be considered
924 a tap and be reported as a left button click (for
925 touchpads working in absolute mode only).
926 Format: <msecs>
927 mousedev.xres= [MOUSE] Horizontal screen resolution, used for devices
928 reporting absolute coordinates, such as tablets
929 mousedev.yres= [MOUSE] Vertical screen resolution, used for devices
930 reporting absolute coordinates, such as tablets
931
932 mpu401= [HW,OSS]
933 Format: <io>,<irq>
934
935 MTD_Partition= [MTD]
936 Format: <name>,<region-number>,<size>,<offset>
937
a9913044
RD
938 MTD_Region= [MTD] Format:
939 <name>,<region-number>[,<base>,<size>,<buswidth>,<altbuswidth>]
1da177e4
LT
940
941 mtdparts= [MTD]
942 See drivers/mtd/cmdline.c.
943
944 mtouchusb.raw_coordinates=
a9913044
RD
945 [HW] Make the MicroTouch USB driver use raw coordinates
946 ('y', default) or cooked coordinates ('n')
1da177e4
LT
947
948 n2= [NET] SDL Inc. RISCom/N2 synchronous serial card
949
950 NCR_D700= [HW,SCSI]
951 See header of drivers/scsi/NCR_D700.c.
952
953 ncr5380= [HW,SCSI]
954
955 ncr53c400= [HW,SCSI]
956
957 ncr53c400a= [HW,SCSI]
958
959 ncr53c406a= [HW,SCSI]
960
961 ncr53c8xx= [HW,SCSI]
962
963 netdev= [NET] Network devices parameters
964 Format: <irq>,<io>,<mem_start>,<mem_end>,<name>
965 Note that mem_start is often overloaded to mean
966 something different and driver-specific.
a9913044
RD
967 This usage is only documented in each driver source
968 file if at all.
969
1da177e4
LT
970 nfsaddrs= [NFS]
971 See Documentation/nfsroot.txt.
972
973 nfsroot= [NFS] nfs root filesystem for disk-less boxes.
974 See Documentation/nfsroot.txt.
975
a72b4422
TM
976 nfs.callback_tcpport=
977 [NFS] set the TCP port on which the NFSv4 callback
978 channel should listen.
979
58df095b
TM
980 nfs.idmap_cache_timeout=
981 [NFS] set the maximum lifetime for idmapper cache
982 entries.
983
1da177e4
LT
984 nmi_watchdog= [KNL,BUGS=IA-32] Debugging features for SMP kernels
985
986 no387 [BUGS=IA-32] Tells the kernel to use the 387 maths
987 emulation library even if a 387 maths coprocessor
988 is present.
989
a9913044
RD
990 noalign [KNL,ARM]
991
1da177e4
LT
992 noapic [SMP,APIC] Tells the kernel to not make use of any
993 IOAPICs that may be present in the system.
994
995 noasync [HW,M68K] Disables async and sync negotiation for
996 all devices.
997
998 nobats [PPC] Do not use BATs for mapping kernel lowmem
999 on "Classic" PPC cores.
1000
1001 nocache [ARM]
a9913044 1002
1da177e4
LT
1003 nodisconnect [HW,SCSI,M68K] Disables SCSI disconnects.
1004
1005 noexec [IA-64]
1006
a9913044 1007 noexec [IA-32,X86-64]
1da177e4
LT
1008 noexec=on: enable non-executable mappings (default)
1009 noexec=off: disable nn-executable mappings
1010
4f886511
CE
1011 nofxsr [BUGS=IA-32] Disables x86 floating point extended
1012 register save and restore. The kernel will only save
1013 legacy floating-point registers on task switch.
1da177e4
LT
1014
1015 nohlt [BUGS=ARM]
a9913044 1016
1da177e4
LT
1017 no-hlt [BUGS=IA-32] Tells the kernel that the hlt
1018 instruction doesn't work correctly and not to
1019 use it.
1020
1021 nohalt [IA-64] Tells the kernel not to use the power saving
1022 function PAL_HALT_LIGHT when idle. This increases
1023 power-consumption. On the positive side, it reduces
1024 interrupt wake-up latency, which may improve performance
1025 in certain environments such as networked servers or
1026 real-time systems.
1027
1028 noirqdebug [IA-32] Disables the code which attempts to detect and
1029 disable unhandled interrupt sources.
1030
1031 noisapnp [ISAPNP] Disables ISA PnP code.
1032
1033 noinitrd [RAM] Tells the kernel not to load any configured
1034 initial RAM disk.
1035
1036 nointroute [IA-64]
1037
1038 nolapic [IA-32,APIC] Do not enable or use the local APIC.
1039
1040 noltlbs [PPC] Do not use large page/tlb entries for kernel
1041 lowmem mapping on PPC40x.
1042
1043 nomce [IA-32] Machine Check Exception
1044
312f1f01
H
1045 nomca [IA-64] Disable machine check abort handling
1046
1da177e4
LT
1047 noresidual [PPC] Don't use residual data on PReP machines.
1048
a9913044
RD
1049 noresume [SWSUSP] Disables resume and restores original swap
1050 space.
1051
1da177e4
LT
1052 no-scroll [VGA] Disables scrollback.
1053 This is required for the Braillex ib80-piezo Braille
1054 reader made by F.H. Papenmeier (Germany).
1055
1056 nosbagart [IA-64]
1057
4f886511
CE
1058 nosep [BUGS=IA-32] Disables x86 SYSENTER/SYSEXIT support.
1059
1da177e4
LT
1060 nosmp [SMP] Tells an SMP kernel to act as a UP kernel.
1061
1062 nosync [HW,M68K] Disables sync negotiation for all devices.
1063
1064 notsc [BUGS=IA-32] Disable Time Stamp Counter
1065
1066 nousb [USB] Disable the USB subsystem
1067
1068 nowb [ARM]
a9913044 1069
a61c2d78
DJ
1070 nr_uarts= [SERIAL] maximum number of UARTs to be registered.
1071
1da177e4
LT
1072 opl3= [HW,OSS]
1073 Format: <io>
1074
1075 opl3sa= [HW,OSS]
1076 Format: <io>,<irq>,<dma>,<dma2>,<mpu_io>,<mpu_irq>
1077
a9913044
RD
1078 opl3sa2= [HW,OSS] Format:
1079 <io>,<irq>,<dma>,<dma2>,<mss_io>,<mpu_io>,<ymode>,<loopback>[,<isapnp>,<multiple]
1080
1da177e4
LT
1081 oprofile.timer= [HW]
1082 Use timer interrupt instead of performance counters
1083
1084 optcd= [HW,CD]
1085 Format: <io>
1086
1087 osst= [HW,SCSI] SCSI Tape Driver
1088 Format: <buffer_size>,<write_threshold>
1089 See also Documentation/scsi/st.txt.
1090
1091 panic= [KNL] Kernel behaviour on panic
1092 Format: <timeout>
1093
1094 parkbd.port= [HW] Parallel port number the keyboard adapter is
1095 connected to, default is 0.
1096 Format: <parport#>
1097 parkbd.mode= [HW] Parallel port keyboard adapter mode of operation,
1098 0 for XT, 1 for AT (default is AT).
a9913044
RD
1099 Format: <mode>
1100
1101 parport= [HW,PPT] Specify parallel ports. 0 disables.
1102 Format: { 0 | auto | 0xBBB[,IRQ[,DMA]] }
1103 Use 'auto' to force the driver to use any
1104 IRQ/DMA settings detected (the default is to
1105 ignore detected IRQ/DMA settings because of
1106 possible conflicts). You can specify the base
1107 address, IRQ, and DMA settings; IRQ and DMA
1108 should be numbers, or 'auto' (for using detected
1109 settings on that particular port), or 'nofifo'
1110 (to avoid using a FIFO even if it is detected).
1111 Parallel ports are assigned in the order they
1112 are specified on the command line, starting
1113 with parport0.
1114
1115 parport_init_mode= [HW,PPT]
1116 Configure VIA parallel port to operate in
1117 a specific mode. This is necessary on Pegasos
1118 computer where firmware has no options for setting
1119 up parallel port mode and sets it to spp.
1120 Currently this function knows 686a and 8231 chips.
1da177e4
LT
1121 Format: [spp|ps2|epp|ecp|ecpepp]
1122
a9913044
RD
1123 pas2= [HW,OSS] Format:
1124 <io>,<irq>,<dma>,<dma16>,<sb_io>,<sb_irq>,<sb_dma>,<sb_dma16>
1125
1da177e4
LT
1126 pas16= [HW,SCSI]
1127 See header of drivers/scsi/pas16.c.
1128
dd287796
AM
1129 pause_on_oops=
1130 Halt all CPUs after the first oops has been printed for
1131 the specified number of seconds. This is to be used if
1132 your oopses keep scrolling off the screen.
1133
1da177e4
LT
1134 pcbit= [HW,ISDN]
1135
1136 pcd. [PARIDE]
1137 See header of drivers/block/paride/pcd.c.
1138 See also Documentation/paride.txt.
1139
a9913044
RD
1140 pci=option[,option...] [PCI] various PCI subsystem options:
1141 off [IA-32] don't probe for the PCI bus
1142 bios [IA-32] force use of PCI BIOS, don't access
1143 the hardware directly. Use this if your machine
1144 has a non-standard PCI host bridge.
1145 nobios [IA-32] disallow use of PCI BIOS, only direct
1146 hardware access methods are allowed. Use this
1147 if you experience crashes upon bootup and you
1148 suspect they are caused by the BIOS.
1149 conf1 [IA-32] Force use of PCI Configuration
1150 Mechanism 1.
1151 conf2 [IA-32] Force use of PCI Configuration
1152 Mechanism 2.
61be6d66
BH
1153 nommconf [IA-32,X86_64] Disable use of MMCONFIG for PCI
1154 Configuration
a9913044
RD
1155 nosort [IA-32] Don't sort PCI devices according to
1156 order given by the PCI BIOS. This sorting is
1157 done to get a device order compatible with
1158 older kernels.
1159 biosirq [IA-32] Use PCI BIOS calls to get the interrupt
1160 routing table. These calls are known to be buggy
1161 on several machines and they hang the machine
1162 when used, but on other computers it's the only
1163 way to get the interrupt routing table. Try
1164 this option if the kernel is unable to allocate
1165 IRQs or discover secondary PCI buses on your
1166 motherboard.
1167 rom [IA-32] Assign address space to expansion ROMs.
1168 Use with caution as certain devices share
1169 address decoders between ROMs and other
1170 resources.
1171 irqmask=0xMMMM [IA-32] Set a bit mask of IRQs allowed to be
1172 assigned automatically to PCI devices. You can
1173 make the kernel exclude IRQs of your ISA cards
1174 this way.
120bb424 1175 pirqaddr=0xAAAAA [IA-32] Specify the physical address
a9913044
RD
1176 of the PIRQ table (normally generated
1177 by the BIOS) if it is outside the
1178 F0000h-100000h range.
1179 lastbus=N [IA-32] Scan all buses thru bus #N. Can be
1180 useful if the kernel is unable to find your
1181 secondary buses and you want to tell it
1182 explicitly which ones they are.
1183 assign-busses [IA-32] Always assign all PCI bus
1184 numbers ourselves, overriding
1185 whatever the firmware may have done.
1186 usepirqmask [IA-32] Honor the possible IRQ mask stored
1187 in the BIOS $PIR table. This is needed on
1188 some systems with broken BIOSes, notably
1189 some HP Pavilion N5400 and Omnibook XE3
1190 notebooks. This will have no effect if ACPI
1191 IRQ routing is enabled.
1192 noacpi [IA-32] Do not use ACPI for IRQ routing
1193 or for PCI scanning.
1194 routeirq Do IRQ routing for all PCI devices.
1195 This is normally done in pci_enable_device(),
1196 so this option is a temporary workaround
1197 for broken drivers that don't call it.
1198 firmware [ARM] Do not re-enumerate the bus but instead
1199 just use the configuration from the
1200 bootloader. This is currently used on
1201 IXP2000 systems where the bus has to be
1202 configured a certain way for adjunct CPUs.
1da177e4
LT
1203
1204 pcmv= [HW,PCMCIA] BadgePAD 4
1205
1206 pd. [PARIDE]
1207 See Documentation/paride.txt.
1208
1209 pdcchassis= [PARISC,HW] Disable/Enable PDC Chassis Status codes at
1210 boot time.
1211 Format: { 0 | 1 }
1212 See arch/parisc/kernel/pdc_chassis.c
1213
1214 pf. [PARIDE]
1215 See Documentation/paride.txt.
1216
1217 pg. [PARIDE]
1218 See Documentation/paride.txt.
1219
1220 pirq= [SMP,APIC] Manual mp-table setup
1221 See Documentation/i386/IO-APIC.txt.
1222
1223 plip= [PPT,NET] Parallel port network link
1224 Format: { parport<nr> | timid | 0 }
1225 See also Documentation/parport.txt.
1226
1227 pnpacpi= [ACPI]
1228 { off }
1229
1230 pnpbios= [ISAPNP]
1231 { on | off | curr | res | no-curr | no-res }
1232
1233 pnp_reserve_irq=
1234 [ISAPNP] Exclude IRQs for the autoconfiguration
1235
1236 pnp_reserve_dma=
1237 [ISAPNP] Exclude DMAs for the autoconfiguration
1238
1239 pnp_reserve_io= [ISAPNP] Exclude I/O ports for the autoconfiguration
a9913044 1240 Ranges are in pairs (I/O port base and size).
1da177e4
LT
1241
1242 pnp_reserve_mem=
a9913044
RD
1243 [ISAPNP] Exclude memory regions for the
1244 autoconfiguration.
1da177e4
LT
1245 Ranges are in pairs (memory base and size).
1246
1247 profile= [KNL] Enable kernel profiling via /proc/profile
a9913044
RD
1248 Format: [schedule,]<number>
1249 Param: "schedule" - profile schedule points.
1250 Param: <number> - step/bucket size as a power of 2 for
1251 statistical time based profiling.
1da177e4 1252
a9913044 1253 processor.max_cstate= [HW,ACPI]
1da177e4
LT
1254 Limit processor to maximum C-state
1255 max_cstate=9 overrides any DMI blacklist limit.
1256
41c0d868
LB
1257 processor.nocst [HW,ACPI]
1258 Ignore the _CST method to determine C-states,
1259 instead using the legacy FADT method
1260
1da177e4
LT
1261 prompt_ramdisk= [RAM] List of RAM disks to prompt for floppy disk
1262 before loading.
1263 See Documentation/ramdisk.txt.
1264
a9913044
RD
1265 psmouse.proto= [HW,MOUSE] Highest PS2 mouse protocol extension to
1266 probe for; one of (bare|imps|exps|lifebook|any).
1da177e4
LT
1267 psmouse.rate= [HW,MOUSE] Set desired mouse report rate, in reports
1268 per second.
a9913044
RD
1269 psmouse.resetafter= [HW,MOUSE]
1270 Try to reset the device after so many bad packets
1da177e4
LT
1271 (0 = never).
1272 psmouse.resolution=
1273 [HW,MOUSE] Set desired mouse resolution, in dpi.
1274 psmouse.smartscroll=
a9913044 1275 [HW,MOUSE] Controls Logitech smartscroll autorepeat.
1da177e4
LT
1276 0 = disabled, 1 = enabled (default).
1277
1278 pss= [HW,OSS] Personal Sound System (ECHO ESC614)
a9913044
RD
1279 Format:
1280 <io>,<mss_io>,<mss_irq>,<mss_dma>,<mpu_io>,<mpu_irq>
1da177e4
LT
1281
1282 pt. [PARIDE]
1283 See Documentation/paride.txt.
1284
1285 quiet= [KNL] Disable log messages
a9913044 1286
1da177e4
LT
1287 r128= [HW,DRM]
1288
1289 raid= [HW,RAID]
1290 See Documentation/md.txt.
1291
1292 ramdisk= [RAM] Sizes of RAM disks in kilobytes [deprecated]
1293 See Documentation/ramdisk.txt.
1294
a9913044 1295 ramdisk_blocksize= [RAM]
1da177e4 1296 See Documentation/ramdisk.txt.
a9913044 1297
1da177e4
LT
1298 ramdisk_size= [RAM] Sizes of RAM disks in kilobytes
1299 New name for the ramdisk parameter.
1300 See Documentation/ramdisk.txt.
1301
21a1ea9e
DS
1302 rcu.blimit= [KNL,BOOT] Set maximum number of finished
1303 RCU callbacks to process in one batch.
1304
1305 rcu.qhimark= [KNL,BOOT] Set threshold of queued
1306 RCU callbacks over which batch limiting is disabled.
1307
1308 rcu.qlowmark= [KNL,BOOT] Set threshold of queued
1309 RCU callbacks below which batch limiting is re-enabled.
1310
1311 rcu.rsinterval= [KNL,BOOT,SMP] Set the number of additional
1312 RCU callbacks to queued before forcing reschedule
1313 on all cpus.
1314
ffdfc409
OJ
1315 rdinit= [KNL]
1316 Format: <full_path>
1317 Run specified binary instead of /init from the ramdisk,
1318 used for early userspace startup. See initrd.
1319
1da177e4
LT
1320 reboot= [BUGS=IA-32,BUGS=ARM,BUGS=IA-64] Rebooting mode
1321 Format: <reboot_mode>[,<reboot_mode2>[,...]]
1322 See arch/*/kernel/reboot.c.
1323
1324 reserve= [KNL,BUGS] Force the kernel to ignore some iomem area
1325
a9913044
RD
1326 resume= [SWSUSP]
1327 Specify the partition device for software suspend
1da177e4
LT
1328
1329 rhash_entries= [KNL,NET]
1330 Set number of hash buckets for route cache
1331
1332 riscom8= [HW,SERIAL]
1333 Format: <io_board1>[,<io_board2>[,...<io_boardN>]]
1334
1335 ro [KNL] Mount root device read-only on boot
1336
1337 root= [KNL] Root filesystem
1338
1339 rootdelay= [KNL] Delay (in seconds) to pause before attempting to
1340 mount the root filesystem
1341
1342 rootflags= [KNL] Set root filesystem mount option string
1343
1344 rootfstype= [KNL] Set root filesystem type
1345
1346 rw [KNL] Mount root device read-write on boot
1347
1348 S [KNL] Run init in single mode
1349
1350 sa1100ir [NET]
1351 See drivers/net/irda/sa1100_ir.c.
1352
1353 sb= [HW,OSS]
1354 Format: <io>,<irq>,<dma>,<dma2>
1355
1356 sbni= [NET] Granch SBNI12 leased line adapter
a9913044 1357
1da177e4
LT
1358 sbpcd= [HW,CD] Soundblaster CD adapter
1359 Format: <io>,<type>
1360 See a comment before function sbpcd_setup() in
1361 drivers/cdrom/sbpcd.c.
1362
1363 sc1200wdt= [HW,WDT] SC1200 WDT (watchdog) driver
1364 Format: <io>[,<timeout>[,<isapnp>]]
1365
1366 scsi_debug_*= [SCSI]
1367 See drivers/scsi/scsi_debug.c.
1368
1369 scsi_default_dev_flags=
1370 [SCSI] SCSI default device flags
1371 Format: <integer>
1372
1373 scsi_dev_flags= [SCSI] Black/white list entry for vendor and model
1374 Format: <vendor>:<model>:<flags>
1375 (flags are integer value)
1376
1377 scsi_logging= [SCSI]
1378
1379 selinux [SELINUX] Disable or enable SELinux at boot time.
1380 Format: { "0" | "1" }
1381 See security/selinux/Kconfig help text.
1382 0 -- disable.
1383 1 -- enable.
1384 Default value is set via kernel config option.
1385 If enabled at boot time, /selinux/disable can be used
1386 later to disable prior to initial policy load.
1387
1388 serialnumber [BUGS=IA-32]
1389
a9913044
RD
1390 sg_def_reserved_size= [SCSI]
1391
1da177e4
LT
1392 sgalaxy= [HW,OSS]
1393 Format: <io>,<irq>,<dma>,<dma2>,<sgbase>
1394
1395 shapers= [NET]
1396 Maximal number of shapers.
a9913044 1397
1da177e4
LT
1398 sim710= [SCSI,HW]
1399 See header of drivers/scsi/sim710.c.
1400
1401 simeth= [IA-64]
1402 simscsi=
a9913044 1403
1da177e4
LT
1404 sjcd= [HW,CD]
1405 Format: <io>,<irq>,<dma>
1406 See header of drivers/cdrom/sjcd.c.
1407
1408 slram= [HW,MTD]
1409
1410 smart2= [HW]
1411 Format: <io1>[,<io2>[,...,<io8>]]
1412
1413 snd-ad1816a= [HW,ALSA]
1414
1415 snd-ad1848= [HW,ALSA]
1416
1417 snd-ali5451= [HW,ALSA]
1418
1419 snd-als100= [HW,ALSA]
1420
1421 snd-als4000= [HW,ALSA]
1422
1423 snd-azt2320= [HW,ALSA]
1424
1425 snd-cmi8330= [HW,ALSA]
1426
1427 snd-cmipci= [HW,ALSA]
1428
1429 snd-cs4231= [HW,ALSA]
1430
1431 snd-cs4232= [HW,ALSA]
1432
1433 snd-cs4236= [HW,ALSA]
1434
1435 snd-cs4281= [HW,ALSA]
1436
1437 snd-cs46xx= [HW,ALSA]
1438
1439 snd-dt019x= [HW,ALSA]
1440
1441 snd-dummy= [HW,ALSA]
1442
1443 snd-emu10k1= [HW,ALSA]
1444
1445 snd-ens1370= [HW,ALSA]
1446
1447 snd-ens1371= [HW,ALSA]
1448
1449 snd-es968= [HW,ALSA]
1450
1451 snd-es1688= [HW,ALSA]
1452
1453 snd-es18xx= [HW,ALSA]
1454
1455 snd-es1938= [HW,ALSA]
1456
1457 snd-es1968= [HW,ALSA]
1458
1459 snd-fm801= [HW,ALSA]
1460
1461 snd-gusclassic= [HW,ALSA]
1462
1463 snd-gusextreme= [HW,ALSA]
1464
1465 snd-gusmax= [HW,ALSA]
1466
1467 snd-hdsp= [HW,ALSA]
1468
1469 snd-ice1712= [HW,ALSA]
1470
1471 snd-intel8x0= [HW,ALSA]
1472
1473 snd-interwave= [HW,ALSA]
1474
1475 snd-interwave-stb=
1476 [HW,ALSA]
1477
1478 snd-korg1212= [HW,ALSA]
1479
1480 snd-maestro3= [HW,ALSA]
1481
1482 snd-mpu401= [HW,ALSA]
1483
1484 snd-mtpav= [HW,ALSA]
1485
1486 snd-nm256= [HW,ALSA]
1487
1488 snd-opl3sa2= [HW,ALSA]
1489
1490 snd-opti92x-ad1848=
1491 [HW,ALSA]
1492
1493 snd-opti92x-cs4231=
1494 [HW,ALSA]
1495
1496 snd-opti93x= [HW,ALSA]
1497
1498 snd-pmac= [HW,ALSA]
1499
1500 snd-rme32= [HW,ALSA]
1501
1502 snd-rme96= [HW,ALSA]
1503
1504 snd-rme9652= [HW,ALSA]
1505
1506 snd-sb8= [HW,ALSA]
1507
1508 snd-sb16= [HW,ALSA]
1509
1510 snd-sbawe= [HW,ALSA]
1511
1512 snd-serial= [HW,ALSA]
1513
1514 snd-sgalaxy= [HW,ALSA]
1515
1516 snd-sonicvibes= [HW,ALSA]
1517
1518 snd-sun-amd7930=
1519 [HW,ALSA]
1520
1521 snd-sun-cs4231= [HW,ALSA]
1522
1523 snd-trident= [HW,ALSA]
1524
1525 snd-usb-audio= [HW,ALSA,USB]
1526
1527 snd-via82xx= [HW,ALSA]
1528
1529 snd-virmidi= [HW,ALSA]
1530
1531 snd-wavefront= [HW,ALSA]
1532
1533 snd-ymfpci= [HW,ALSA]
a9913044 1534
1da177e4
LT
1535 sonicvibes= [HW,OSS]
1536 Format: <reverb>
a9913044 1537
1da177e4
LT
1538 sonycd535= [HW,CD]
1539 Format: <io>[,<irq>]
1540
1541 sonypi.*= [HW] Sony Programmable I/O Control Device driver
1542 See Documentation/sonypi.txt
1543
1544 specialix= [HW,SERIAL] Specialix multi-serial port adapter
1545 See Documentation/specialix.txt.
1546
1547 spia_io_base= [HW,MTD]
1548 spia_fio_base=
1549 spia_pedr=
1550 spia_peddr=
1551
1552 sscape= [HW,OSS]
1553 Format: <io>,<irq>,<dma>,<mpu_io>,<mpu_irq>
a9913044 1554
1da177e4
LT
1555 st= [HW,SCSI] SCSI tape parameters (buffers, etc.)
1556 See Documentation/scsi/st.txt.
1557
1558 st0x= [HW,SCSI]
1559 See header of drivers/scsi/seagate.c.
1560
1561 sti= [PARISC,HW]
1562 Format: <num>
1563 Set the STI (builtin display/keyboard on the HP-PARISC
1564 machines) console (graphic card) which should be used
1565 as the initial boot-console.
1566 See also comment in drivers/video/console/sticore.c.
1567
1568 sti_font= [HW]
1569 See comment in drivers/video/console/sticore.c.
1570
1571 stifb= [HW]
1572 Format: bpp:<bpp1>[:<bpp2>[:<bpp3>...]]
1573
1da177e4 1574 swiotlb= [IA-64] Number of I/O TLB slabs
a9913044 1575
1da177e4
LT
1576 switches= [HW,M68k]
1577
1578 sym53c416= [HW,SCSI]
1579 See header of drivers/scsi/sym53c416.c.
1580
1581 t128= [HW,SCSI]
1582 See header of drivers/scsi/t128.c.
1583
1584 tdfx= [HW,DRM]
1585
1586 thash_entries= [KNL,NET]
1587 Set number of hash buckets for TCP connection
1588
1589 time Show timing data prefixed to each printk message line
1590
1591 tipar.timeout= [HW,PPT]
1592 Set communications timeout in tenths of a second
1593 (default 15).
1594
1595 tipar.delay= [HW,PPT]
1596 Set inter-bit delay in microseconds (default 10).
1597
1598 tmc8xx= [HW,SCSI]
1599 See header of drivers/scsi/seagate.c.
1600
1601 tmscsim= [HW,SCSI]
1602 See comment before function dc390_setup() in
1603 drivers/scsi/tmscsim.c.
1604
1605 tp720= [HW,PS2]
1606
1607 trix= [HW,OSS] MediaTrix AudioTrix Pro
a9913044
RD
1608 Format:
1609 <io>,<irq>,<dma>,<dma2>,<sb_io>,<sb_irq>,<sb_dma>,<mpu_io>,<mpu_irq>
1610
1da177e4
LT
1611 tsdev.xres= [TS] Horizontal screen resolution.
1612 tsdev.yres= [TS] Vertical screen resolution.
1613
a9913044
RD
1614 turbografx.map[2|3]= [HW,JOY]
1615 TurboGraFX parallel port interface
1616 Format:
1617 <port#>,<js1>,<js2>,<js3>,<js4>,<js5>,<js6>,<js7>
1da177e4
LT
1618 See also Documentation/input/joystick-parport.txt
1619
1620 u14-34f= [HW,SCSI] UltraStor 14F/34F SCSI host adapter
1621 See header of drivers/scsi/u14-34f.c.
1622
1623 uart401= [HW,OSS]
1624 Format: <io>,<irq>
1625
1626 uart6850= [HW,OSS]
1627 Format: <io>,<irq>
1628
1da177e4
LT
1629 usbhid.mousepoll=
1630 [USBHID] The interval which mice are to be polled at.
a9913044 1631
1da177e4
LT
1632 video= [FB] Frame buffer configuration
1633 See Documentation/fb/modedb.txt.
1634
1635 vga= [BOOT,IA-32] Select a particular video mode
a9913044
RD
1636 See Documentation/i386/boot.txt and
1637 Documentation/svga.txt.
1da177e4
LT
1638 Use vga=ask for menu.
1639 This is actually a boot loader parameter; the value is
1640 passed to the kernel using a special protocol.
1641
a9913044 1642 vmalloc=nn[KMG] [KNL,BOOT] Forces the vmalloc area to have an exact
1da177e4
LT
1643 size of <nn>. This can be used to increase the
1644 minimum size (128MB on x86). It can also be used to
1645 decrease the size and leave more room for directly
1646 mapped kernel RAM.
1647
1648 vmhalt= [KNL,S390]
1649
a9913044
RD
1650 vmpoff= [KNL,S390]
1651
1da177e4
LT
1652 waveartist= [HW,OSS]
1653 Format: <io>,<irq>,<dma>,<dma2>
a9913044 1654
1da177e4
LT
1655 wd33c93= [HW,SCSI]
1656 See header of drivers/scsi/wd33c93.c.
1657
1658 wd7000= [HW,SCSI]
1659 See header of drivers/scsi/wd7000.c.
1660
1661 wdt= [WDT] Watchdog
1662 See Documentation/watchdog/watchdog.txt.
1663
1664 xd= [HW,XT] Original XT pre-IDE (RLL encoded) disks.
1665 xd_geo= See header of drivers/block/xd.c.
1666
1667 xirc2ps_cs= [NET,PCMCIA]
a9913044
RD
1668 Format:
1669 <irq>,<irq_mask>,<io>,<full_duplex>,<do_sound>,<lockup_hack>[,<irq2>[,<irq3>[,<irq4>]]]
1da177e4 1670
a62eaf15
AK
1671 norandmaps Don't use address space randomization
1672 Equivalent to echo 0 > /proc/sys/kernel/randomize_va_space
1673
1da177e4 1674
a9913044 1675______________________________________________________________________
1da177e4
LT
1676Changelog:
1677
a9913044 16782000-06-?? Mr. Unknown
1da177e4 1679 The last known update (for 2.4.0) - the changelog was not kept before.
1da177e4 1680
a9913044
RD
16812002-11-24 Petr Baudis <pasky@ucw.cz>
1682 Randy Dunlap <randy.dunlap@verizon.net>
1da177e4
LT
1683 Update for 2.5.49, description for most of the options introduced,
1684 references to other documentation (C files, READMEs, ..), added S390,
1685 PPC, SPARC, MTD, ALSA and OSS category. Minor corrections and
1686 reformatting.
a9913044
RD
1687
16882005-10-19 Randy Dunlap <rdunlap@xenotime.net>
1689 Lots of typos, whitespace, some reformatting.
1da177e4
LT
1690
1691TODO:
1692
1693 Add documentation for ALSA options.
1694 Add more DRM drivers.