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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
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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.
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30 DEVFS devfs support is enabled.
31 DRM Direct Rendering Management support is enabled.
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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.
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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.
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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
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108 acpi= [HW,ACPI] Advanced Configuration and Power Interface
109 Format: { force | off | ht | strict | noirq }
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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
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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
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126 acpi_irq_balance [HW,ACPI]
127 ACPI will balance active IRQs
128 default in APIC mode
1da177e4 129
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130 acpi_irq_nobalance [HW,ACPI]
131 ACPI will not move active IRQs (default)
132 default in PIC mode
1da177e4 133
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134 acpi_irq_pci= [HW,ACPI] If irq_balance, clear listed IRQs for
135 use by PCI
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136 Format: <irq>,<irq>...
137
a9913044 138 acpi_irq_isa= [HW,ACPI] If irq_balance, mark listed IRQs used by ISA
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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,
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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,
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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
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165 acpi_generic_hotkey [HW,ACPI]
166 Allow consolidated generic hotkey driver to
a9913044 167 override platform specific driver.
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168 See also Documentation/acpi-hotkey.txt.
169
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170 enable_timer_pin_1 [i386,x86-64]
171 Enable PIN 1 of APIC timer
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172 Can be useful to work around chipset bugs
173 (in particular on some ATI chipsets).
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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
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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
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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
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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
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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
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222 apc= [HW,SPARC]
223 Power management functions (SPARCstation-4/5 + deriv.)
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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
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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
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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
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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
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254 atkbd.set= [HW] Select keyboard code set
255 Format: <int> (2 = AT (default), 3 = PS/2)
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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))
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262
263 atkbd.softrepeat= [HW]
264 Use software keyboard repeat
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265
266 autotest [IA64]
267
268 awe= [HW,OSS] AWE32/SB32/AWE64 wave table synth
269 Format: <io>,<memsize>,<isapnp>
a9913044 270
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271 aztcd= [HW,CD] Aztech CD268 CDROM driver
272 Format: <io>,0x79 (?)
273
274 baycom_epp= [HW,AX25]
275 Format: <io>,<mode>
a9913044 276
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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
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281 baycom_ser_fdx= [HW,AX25]
282 BayCom Serial Port AX.25 Modem (Full Duplex Mode)
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283 Format: <io>,<irq>,<mode>[,<baud>]
284 See header of drivers/net/hamradio/baycom_ser_fdx.c.
285
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286 baycom_ser_hdx= [HW,AX25]
287 BayCom Serial Port AX.25 Modem (Half Duplex Mode)
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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)
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298 bttv.radio= Most important insmod options are available as
299 kernel args too.
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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.
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325 0 -- check protection applied by kernel (includes
326 any implied execute protection).
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327 1 -- check protection requested by application.
328 Default value is set via a kernel config option.
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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
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334 when calculating gettimeofday(). If specicified
335 timesource is not avalible, it defaults to PIT.
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336 Format: { pit | tsc | cyclone | pmtmr }
337
338 hpet= [IA-32,HPET] option to disable HPET and use PIT.
339 Format: disable
340
341 cm206= [HW,CD]
342 Format: { auto | [<io>,][<irq>] }
343
344 com20020= [HW,NET] ARCnet - COM20020 chipset
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345 Format:
346 <io>[,<irq>[,<nodeID>[,<backplane>[,<ckp>[,<timeout>]]]]]
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347
348 com90io= [HW,NET] ARCnet - COM90xx chipset (IO-mapped buffers)
349 Format: <io>[,<irq>]
350
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351 com90xx= [HW,NET]
352 ARCnet - COM90xx chipset (memory-mapped buffers)
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353 Format: <io>[,<irq>[,<memstart>]]
354
355 condev= [HW,S390] console device
356 conmode=
a9913044 357
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358 console= [KNL] Output console device and options.
359
360 tty<n> Use the virtual console device <n>.
361
362 ttyS<n>[,options]
363 Use the specified serial port. The options are of
364 the form "bbbbpn", where "bbbb" is the baud rate,
365 "p" is parity ("n", "o", or "e"), and "n" is bits.
366 Default is "9600n8".
367
368 See also Documentation/serial-console.txt.
369
370 uart,io,<addr>[,options]
371 uart,mmio,<addr>[,options]
372 Start an early, polled-mode console on the 8250/16550
373 UART at the specified I/O port or MMIO address,
374 switching to the matching ttyS device later. The
375 options are the same as for ttyS, above.
376
377 cpcihp_generic= [HW,PCI] Generic port I/O CompactPCI driver
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378 Format:
379 <first_slot>,<last_slot>,<port>,<enum_bit>[,<debug>]
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380
381 cpia_pp= [HW,PPT]
382 Format: { parport<nr> | auto | none }
383
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384 crashkernel=nn[KMG]@ss[KMG]
385 [KNL] Reserve a chunk of physical memory to
386 hold a kernel to switch to with kexec on panic.
387
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388 cs4232= [HW,OSS]
389 Format: <io>,<irq>,<dma>,<dma2>,<mpuio>,<mpuirq>
390
391 cs89x0_dma= [HW,NET]
392 Format: <dma>
393
394 cs89x0_media= [HW,NET]
395 Format: { rj45 | aui | bnc }
a9913044 396
1da177e4 397 cyclades= [HW,SERIAL] Cyclades multi-serial port adapter.
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398
399 dasd= [HW,NET]
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400 See header of drivers/s390/block/dasd_devmap.c.
401
402 db9.dev[2|3]= [HW,JOY] Multisystem joystick support via parallel port
403 (one device per port)
404 Format: <port#>,<type>
405 See also Documentation/input/joystick-parport.txt
406
407 debug [KNL] Enable kernel debugging (events log level).
408
409 decnet= [HW,NET]
410 Format: <area>[,<node>]
411 See also Documentation/networking/decnet.txt.
412
413 devfs= [DEVFS]
414 See Documentation/filesystems/devfs/boot-options.
415
416 dhash_entries= [KNL]
417 Set number of hash buckets for dentry cache.
a9913044 418
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419 digi= [HW,SERIAL]
420 IO parameters + enable/disable command.
421
422 digiepca= [HW,SERIAL]
423 See drivers/char/README.epca and
424 Documentation/digiepca.txt.
425
426 dmascc= [HW,AX25,SERIAL] AX.25 Z80SCC driver with DMA
427 support available.
428 Format: <io_dev0>[,<io_dev1>[,..<io_dev32>]]
429
430 dmasound= [HW,OSS] Sound subsystem buffers
431
432 dscc4.setup= [NET]
433
434 dtc3181e= [HW,SCSI]
435
a9913044 436 earlyprintk= [IA-32,X86-64]
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437 earlyprintk=vga
438 earlyprintk=serial[,ttySn[,baudrate]]
439
a9913044 440 Append ",keep" to not disable it when the real console
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441 takes over.
442
443 Only vga or serial at a time, not both.
444
445 Currently only ttyS0 and ttyS1 are supported.
446
447 Interaction with the standard serial driver is not
448 very good.
449
450 The VGA output is eventually overwritten by the real
451 console.
452
453 eata= [HW,SCSI]
454
455 eda= [HW,PS2]
456
457 edb= [HW,PS2]
458
459 edd= [EDD]
460 Format: {"of[f]" | "sk[ipmbr]"}
461 See comment in arch/i386/boot/edd.S
462
a9913044 463 eicon= [HW,ISDN]
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464 Format: <id>,<membase>,<irq>
465
466 eisa_irq_edge= [PARISC,HW]
467 See header of drivers/parisc/eisa.c.
468
469 elanfreq= [IA-32]
470 See comment before function elanfreq_setup() in
471 arch/i386/kernel/cpu/cpufreq/elanfreq.c.
472
473 elevator= [IOSCHED]
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474 Format: {"as" | "cfq" | "deadline" | "noop"}
475 See Documentation/block/as-iosched.txt and
476 Documentation/block/deadline-iosched.txt for details.
477
2030eae5 478 elfcorehdr= [IA-32]
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479 Specifies physical address of start of kernel core
480 image elf header.
2030eae5 481 See Documentation/kdump.txt for details.
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482
483 enforcing [SELINUX] Set initial enforcing status.
484 Format: {"0" | "1"}
485 See security/selinux/Kconfig help text.
486 0 -- permissive (log only, no denials).
487 1 -- enforcing (deny and log).
488 Default value is 0.
489 Value can be changed at runtime via /selinux/enforce.
490
491 es1370= [HW,OSS]
492 Format: <lineout>[,<micbias>]
493 See also header of sound/oss/es1370.c.
494
495 es1371= [HW,OSS]
496 Format: <spdif>,[<nomix>,[<amplifier>]]
497 See also header of sound/oss/es1371.c.
a9913044 498
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499 ether= [HW,NET] Ethernet cards parameters
500 This option is obsoleted by the "netdev=" option, which
501 has equivalent usage. See its documentation for details.
502
503 eurwdt= [HW,WDT] Eurotech CPU-1220/1410 onboard watchdog.
504 Format: <io>[,<irq>]
505
506 fd_mcs= [HW,SCSI]
507 See header of drivers/scsi/fd_mcs.c.
508
509 fdomain= [HW,SCSI]
510 See header of drivers/scsi/fdomain.c.
511
512 floppy= [HW]
513 See Documentation/floppy.txt.
514
515 ftape= [HW] Floppy Tape subsystem debugging options.
516 See Documentation/ftape.txt.
517
518 gamecon.map[2|3]=
519 [HW,JOY] Multisystem joystick and NES/SNES/PSX pad
520 support via parallel port (up to 5 devices per port)
521 Format: <port#>,<pad1>,<pad2>,<pad3>,<pad4>,<pad5>
522 See also Documentation/input/joystick-parport.txt
523
524 gamma= [HW,DRM]
525
526 gdth= [HW,SCSI]
527 See header of drivers/scsi/gdth.c.
528
529 gpt [EFI] Forces disk with valid GPT signature but
530 invalid Protective MBR to be treated as GPT.
531
532 gscd= [HW,CD]
533 Format: <io>
534
535 gt96100eth= [NET] MIPS GT96100 Advanced Communication Controller
536
537 gus= [HW,OSS]
538 Format: <io>,<irq>,<dma>,<dma16>
a9913044 539
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540 gvp11= [HW,SCSI]
541
542 hashdist= [KNL,NUMA] Large hashes allocated during boot
543 are distributed across NUMA nodes. Defaults on
544 for IA-64, off otherwise.
a9913044 545 Format: 0 | 1 (for off | on)
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546
547 hcl= [IA-64] SGI's Hardware Graph compatibility layer
548
549 hd= [EIDE] (E)IDE hard drive subsystem geometry
550 Format: <cyl>,<head>,<sect>
551
552 hd?= [HW] (E)IDE subsystem
553 hd?lun= See Documentation/ide.txt.
554
555 highmem=nn[KMG] [KNL,BOOT] forces the highmem zone to have an exact
556 size of <nn>. This works even on boxes that have no
557 highmem otherwise. This also works to reduce highmem
558 size on bigger boxes.
559
560 hisax= [HW,ISDN]
561 See Documentation/isdn/README.HiSax.
562
563 hugepages= [HW,IA-32,IA-64] Maximal number of HugeTLB pages.
564
565 noirqbalance [IA-32,SMP,KNL] Disable kernel irq balancing
566
567 i8042.direct [HW] Put keyboard port into non-translated mode
568 i8042.dumbkbd [HW] Pretend that controlled can only read data from
569 keyboard and can not control its state
570 (Don't attempt to blink the leds)
571 i8042.noaux [HW] Don't check for auxiliary (== mouse) port
945ef0d4 572 i8042.nokbd [HW] Don't check/create keyboard port
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573 i8042.nomux [HW] Don't check presence of an active multiplexing
574 controller
575 i8042.nopnp [HW] Don't use ACPIPnP / PnPBIOS to discover KBD/AUX
576 controllers
577 i8042.panicblink=
578 [HW] Frequency with which keyboard LEDs should blink
579 when kernel panics (default is 0.5 sec)
580 i8042.reset [HW] Reset the controller during init and cleanup
581 i8042.unlock [HW] Unlock (ignore) the keylock
582
583 i810= [HW,DRM]
584
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585 i8k.ignore_dmi [HW] Continue probing hardware even if DMI data
586 indicates that the driver is running on unsupported
587 hardware.
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588 i8k.force [HW] Activate i8k driver even if SMM BIOS signature
589 does not match list of supported models.
590 i8k.power_status
591 [HW] Report power status in /proc/i8k
592 (disabled by default)
593 i8k.restricted [HW] Allow controlling fans only if SYS_ADMIN
594 capability is set.
595
596 ibmmcascsi= [HW,MCA,SCSI] IBM MicroChannel SCSI adapter
597 See Documentation/mca.txt.
598
599 icn= [HW,ISDN]
600 Format: <io>[,<membase>[,<icn_id>[,<icn_id2>]]]
601
602 ide= [HW] (E)IDE subsystem
603 Format: ide=nodma or ide=doubler or ide=reverse
604 See Documentation/ide.txt.
605
606 ide?= [HW] (E)IDE subsystem
607 Format: ide?=noprobe or chipset specific parameters.
608 See Documentation/ide.txt.
a9913044 609
1da177e4
LT
610 idebus= [HW] (E)IDE subsystem - VLB/PCI bus speed
611 See Documentation/ide.txt.
612
613 idle= [HW]
614 Format: idle=poll or idle=halt
a9913044 615
1da177e4
LT
616 ihash_entries= [KNL]
617 Set number of hash buckets for inode cache.
618
619 in2000= [HW,SCSI]
620 See header of drivers/scsi/in2000.c.
621
622 init= [KNL]
623 Format: <full_path>
624 Run specified binary instead of /sbin/init as init
625 process.
626
627 initcall_debug [KNL] Trace initcalls as they are executed. Useful
628 for working out where the kernel is dying during
629 startup.
630
631 initrd= [BOOT] Specify the location of the initial ramdisk
632
633 inport.irq= [HW] Inport (ATI XL and Microsoft) busmouse driver
634 Format: <irq>
635
636 inttest= [IA64]
637
638 io7= [HW] IO7 for Marvel based alpha systems
639 See comment before marvel_specify_io7 in
640 arch/alpha/kernel/core_marvel.c.
641
642 ip= [IP_PNP]
643 See Documentation/nfsroot.txt.
644
645 ip2= [HW] Set IO/IRQ pairs for up to 4 IntelliPort boards
646 See comment before ip2_setup() in drivers/char/ip2.c.
647
648 ips= [HW,SCSI] Adaptec / IBM ServeRAID controller
649 See header of drivers/scsi/ips.c.
650
200803df
AC
651 irqfixup [HW]
652 When an interrupt is not handled search all handlers
653 for it. Intended to get systems with badly broken
654 firmware running.
655
656 irqpoll [HW]
657 When an interrupt is not handled search all handlers
658 for it. Also check all handlers each timer
659 interrupt. Intended to get systems with badly broken
660 firmware running.
661
1da177e4 662 isapnp= [ISAPNP]
a9913044 663 Format: <RDP>,<reset>,<pci_scan>,<verbosity>
1da177e4
LT
664
665 isolcpus= [KNL,SMP] Isolate CPUs from the general scheduler.
666 Format: <cpu number>,...,<cpu number>
667 This option can be used to specify one or more CPUs
668 to isolate from the general SMP balancing and scheduling
669 algorithms. The only way to move a process onto or off
670 an "isolated" CPU is via the CPU affinity syscalls.
671 <cpu number> begins at 0 and the maximum value is
672 "number of CPUs in system - 1".
673
674 This option is the preferred way to isolate CPUs. The
a9913044
RD
675 alternative -- manually setting the CPU mask of all
676 tasks in the system -- can cause problems and
677 suboptimal load balancer performance.
1da177e4
LT
678
679 isp16= [HW,CD]
680 Format: <io>,<irq>,<dma>,<setup>
681
a9913044 682 iucv= [HW,NET]
1da177e4
LT
683
684 js= [HW,JOY] Analog joystick
685 See Documentation/input/joystick.txt.
686
687 keepinitrd [HW,ARM]
688
a9913044 689 kstack=N [IA-32,X86-64] Print N words from the kernel stack
1da177e4
LT
690 in oops dumps.
691
692 l2cr= [PPC]
693
a9913044
RD
694 lapic [IA-32,APIC] Enable the local APIC even if BIOS
695 disabled it.
1da177e4
LT
696
697 lasi= [HW,SCSI] PARISC LASI driver for the 53c700 chip
698 Format: addr:<io>,irq:<irq>
699
a9913044
RD
700 llsc*= [IA64] See function print_params() in
701 arch/ia64/sn/kernel/llsc4.c.
1da177e4
LT
702
703 load_ramdisk= [RAM] List of ramdisks to load from floppy
704 See Documentation/ramdisk.txt.
705
706 lockd.udpport= [NFS]
707
708 lockd.tcpport= [NFS]
709
710 logibm.irq= [HW,MOUSE] Logitech Bus Mouse Driver
711 Format: <irq>
712
713 loglevel= All Kernel Messages with a loglevel smaller than the
714 console loglevel will be printed to the console. It can
715 also be changed with klogd or other programs. The
716 loglevels are defined as follows:
717
718 0 (KERN_EMERG) system is unusable
719 1 (KERN_ALERT) action must be taken immediately
720 2 (KERN_CRIT) critical conditions
721 3 (KERN_ERR) error conditions
722 4 (KERN_WARNING) warning conditions
723 5 (KERN_NOTICE) normal but significant condition
724 6 (KERN_INFO) informational
725 7 (KERN_DEBUG) debug-level messages
726
727 log_buf_len=n Sets the size of the printk ring buffer, in bytes.
a9913044
RD
728 Format: { n | nk | nM }
729 n must be a power of two. The default size
730 is set in the kernel config file.
1da177e4
LT
731
732 lp=0 [LP] Specify parallel ports to use, e.g,
733 lp=port[,port...] lp=none,parport0 (lp0 not configured, lp1 uses
734 lp=reset first parallel port). 'lp=0' disables the
735 lp=auto printer driver. 'lp=reset' (which can be
736 specified in addition to the ports) causes
737 attached printers to be reset. Using
738 lp=port1,port2,... specifies the parallel ports
739 to associate lp devices with, starting with
740 lp0. A port specification may be 'none' to skip
741 that lp device, or a parport name such as
742 'parport0'. Specifying 'lp=auto' instead of a
743 port specification list means that device IDs
744 from each port should be examined, to see if
745 an IEEE 1284-compliant printer is attached; if
746 so, the driver will manage that printer.
747 See also header of drivers/char/lp.c.
748
749 lpj=n [KNL]
750 Sets loops_per_jiffy to given constant, thus avoiding
751 time-consuming boot-time autodetection (up to 250 ms per
752 CPU). 0 enables autodetection (default). To determine
753 the correct value for your kernel, boot with normal
754 autodetection and see what value is printed. Note that
755 on SMP systems the preset will be applied to all CPUs,
756 which is likely to cause problems if your CPUs need
757 significantly divergent settings. An incorrect value
758 will cause delays in the kernel to be wrong, leading to
759 unpredictable I/O errors and other breakage. Although
760 unlikely, in the extreme case this might damage your
761 hardware.
762
763 ltpc= [NET]
764 Format: <io>,<irq>,<dma>
765
a9913044
RD
766 mac5380= [HW,SCSI] Format:
767 <can_queue>,<cmd_per_lun>,<sg_tablesize>,<hostid>,<use_tags>
1da177e4 768
a9913044
RD
769 mac53c9x= [HW,SCSI] Format:
770 <num_esps>,<disconnect>,<nosync>,<can_queue>,<cmd_per_lun>,<sg_tablesize>,<hostid>,<use_tags>
1da177e4 771
a9913044
RD
772 machvec= [IA64] Force the use of a particular machine-vector
773 (machvec) in a generic kernel.
774 Example: machvec=hpzx1_swiotlb
1da177e4 775
a9913044
RD
776 mad16= [HW,OSS] Format:
777 <io>,<irq>,<dma>,<dma16>,<mpu_io>,<mpu_irq>,<joystick>
1da177e4
LT
778
779 maui= [HW,OSS]
780 Format: <io>,<irq>
a9913044
RD
781
782 max_loop= [LOOP] Maximum number of loopback devices that can
1da177e4
LT
783 be mounted
784 Format: <1-256>
785
786 maxcpus= [SMP] Maximum number of processors that an SMP kernel
787 should make use of
788
2b2c3750
BP
789 max_addr=[KMG] [KNL,BOOT,ia64] All physical memory greater than or
790 equal to this physical address is ignored.
791
a9913044 792 max_luns= [SCSI] Maximum number of LUNs to probe.
1da177e4
LT
793 Should be between 1 and 2^32-1.
794
795 max_report_luns=
a9913044 796 [SCSI] Maximum number of LUNs received.
1da177e4
LT
797 Should be between 1 and 16384.
798
799 mca-pentium [BUGS=IA-32]
800
801 mcatest= [IA-64]
802
803 mcd= [HW,CD]
804 Format: <port>,<irq>,<mitsumi_bug_93_wait>
805
806 mcdx= [HW,CD]
807
808 mce [IA-32] Machine Check Exception
809
810 md= [HW] RAID subsystems devices and level
811 See Documentation/md.txt.
a9913044 812
1da177e4
LT
813 mdacon= [MDA]
814 Format: <first>,<last>
815 Specifies range of consoles to be captured by the MDA.
a9913044 816
1da177e4
LT
817 mem=nn[KMG] [KNL,BOOT] Force usage of a specific amount of memory
818 Amount of memory to be used when the kernel is not able
819 to see the whole system memory or for test.
820 [IA-32] Use together with memmap= to avoid physical
821 address space collisions. Without memmap= PCI devices
822 could be placed at addresses belonging to unused RAM.
823
824 mem=nopentium [BUGS=IA-32] Disable usage of 4MB pages for kernel
825 memory.
826
827 memmap=exactmap [KNL,IA-32] Enable setting of an exact
828 E820 memory map, as specified by the user.
829 Such memmap=exactmap lines can be constructed based on
830 BIOS output or other requirements. See the memmap=nn@ss
831 option description.
832
833 memmap=nn[KMG]@ss[KMG]
834 [KNL] Force usage of a specific region of memory
835 Region of memory to be used, from ss to ss+nn.
836
837 memmap=nn[KMG]#ss[KMG]
838 [KNL,ACPI] Mark specific memory as ACPI data.
839 Region of memory to be used, from ss to ss+nn.
840
841 memmap=nn[KMG]$ss[KMG]
842 [KNL,ACPI] Mark specific memory as reserved.
843 Region of memory to be used, from ss to ss+nn.
844
845 meye.*= [HW] Set MotionEye Camera parameters
846 See Documentation/video4linux/meye.txt.
847
848 mga= [HW,DRM]
849
850 mousedev.tap_time=
851 [MOUSE] Maximum time between finger touching and
852 leaving touchpad surface for touch to be considered
853 a tap and be reported as a left button click (for
854 touchpads working in absolute mode only).
855 Format: <msecs>
856 mousedev.xres= [MOUSE] Horizontal screen resolution, used for devices
857 reporting absolute coordinates, such as tablets
858 mousedev.yres= [MOUSE] Vertical screen resolution, used for devices
859 reporting absolute coordinates, such as tablets
860
861 mpu401= [HW,OSS]
862 Format: <io>,<irq>
863
864 MTD_Partition= [MTD]
865 Format: <name>,<region-number>,<size>,<offset>
866
a9913044
RD
867 MTD_Region= [MTD] Format:
868 <name>,<region-number>[,<base>,<size>,<buswidth>,<altbuswidth>]
1da177e4
LT
869
870 mtdparts= [MTD]
871 See drivers/mtd/cmdline.c.
872
873 mtouchusb.raw_coordinates=
a9913044
RD
874 [HW] Make the MicroTouch USB driver use raw coordinates
875 ('y', default) or cooked coordinates ('n')
1da177e4
LT
876
877 n2= [NET] SDL Inc. RISCom/N2 synchronous serial card
878
879 NCR_D700= [HW,SCSI]
880 See header of drivers/scsi/NCR_D700.c.
881
882 ncr5380= [HW,SCSI]
883
884 ncr53c400= [HW,SCSI]
885
886 ncr53c400a= [HW,SCSI]
887
888 ncr53c406a= [HW,SCSI]
889
890 ncr53c8xx= [HW,SCSI]
891
892 netdev= [NET] Network devices parameters
893 Format: <irq>,<io>,<mem_start>,<mem_end>,<name>
894 Note that mem_start is often overloaded to mean
895 something different and driver-specific.
a9913044
RD
896 This usage is only documented in each driver source
897 file if at all.
898
1da177e4
LT
899 nfsaddrs= [NFS]
900 See Documentation/nfsroot.txt.
901
902 nfsroot= [NFS] nfs root filesystem for disk-less boxes.
903 See Documentation/nfsroot.txt.
904
905 nmi_watchdog= [KNL,BUGS=IA-32] Debugging features for SMP kernels
906
907 no387 [BUGS=IA-32] Tells the kernel to use the 387 maths
908 emulation library even if a 387 maths coprocessor
909 is present.
910
a9913044
RD
911 noalign [KNL,ARM]
912
1da177e4
LT
913 noapic [SMP,APIC] Tells the kernel to not make use of any
914 IOAPICs that may be present in the system.
915
916 noasync [HW,M68K] Disables async and sync negotiation for
917 all devices.
918
919 nobats [PPC] Do not use BATs for mapping kernel lowmem
920 on "Classic" PPC cores.
921
922 nocache [ARM]
a9913044 923
1da177e4
LT
924 nodisconnect [HW,SCSI,M68K] Disables SCSI disconnects.
925
926 noexec [IA-64]
927
a9913044 928 noexec [IA-32,X86-64]
1da177e4
LT
929 noexec=on: enable non-executable mappings (default)
930 noexec=off: disable nn-executable mappings
931
932 nofxsr [BUGS=IA-32]
933
934 nohlt [BUGS=ARM]
a9913044 935
1da177e4
LT
936 no-hlt [BUGS=IA-32] Tells the kernel that the hlt
937 instruction doesn't work correctly and not to
938 use it.
939
940 nohalt [IA-64] Tells the kernel not to use the power saving
941 function PAL_HALT_LIGHT when idle. This increases
942 power-consumption. On the positive side, it reduces
943 interrupt wake-up latency, which may improve performance
944 in certain environments such as networked servers or
945 real-time systems.
946
947 noirqdebug [IA-32] Disables the code which attempts to detect and
948 disable unhandled interrupt sources.
949
950 noisapnp [ISAPNP] Disables ISA PnP code.
951
952 noinitrd [RAM] Tells the kernel not to load any configured
953 initial RAM disk.
954
955 nointroute [IA-64]
956
957 nolapic [IA-32,APIC] Do not enable or use the local APIC.
958
959 noltlbs [PPC] Do not use large page/tlb entries for kernel
960 lowmem mapping on PPC40x.
961
962 nomce [IA-32] Machine Check Exception
963
964 noresidual [PPC] Don't use residual data on PReP machines.
965
a9913044
RD
966 noresume [SWSUSP] Disables resume and restores original swap
967 space.
968
1da177e4
LT
969 no-scroll [VGA] Disables scrollback.
970 This is required for the Braillex ib80-piezo Braille
971 reader made by F.H. Papenmeier (Germany).
972
973 nosbagart [IA-64]
974
975 nosmp [SMP] Tells an SMP kernel to act as a UP kernel.
976
977 nosync [HW,M68K] Disables sync negotiation for all devices.
978
979 notsc [BUGS=IA-32] Disable Time Stamp Counter
980
981 nousb [USB] Disable the USB subsystem
982
983 nowb [ARM]
a9913044 984
1da177e4
LT
985 opl3= [HW,OSS]
986 Format: <io>
987
988 opl3sa= [HW,OSS]
989 Format: <io>,<irq>,<dma>,<dma2>,<mpu_io>,<mpu_irq>
990
a9913044
RD
991 opl3sa2= [HW,OSS] Format:
992 <io>,<irq>,<dma>,<dma2>,<mss_io>,<mpu_io>,<ymode>,<loopback>[,<isapnp>,<multiple]
993
1da177e4
LT
994 oprofile.timer= [HW]
995 Use timer interrupt instead of performance counters
996
997 optcd= [HW,CD]
998 Format: <io>
999
1000 osst= [HW,SCSI] SCSI Tape Driver
1001 Format: <buffer_size>,<write_threshold>
1002 See also Documentation/scsi/st.txt.
1003
1004 panic= [KNL] Kernel behaviour on panic
1005 Format: <timeout>
1006
1007 parkbd.port= [HW] Parallel port number the keyboard adapter is
1008 connected to, default is 0.
1009 Format: <parport#>
1010 parkbd.mode= [HW] Parallel port keyboard adapter mode of operation,
1011 0 for XT, 1 for AT (default is AT).
a9913044
RD
1012 Format: <mode>
1013
1014 parport= [HW,PPT] Specify parallel ports. 0 disables.
1015 Format: { 0 | auto | 0xBBB[,IRQ[,DMA]] }
1016 Use 'auto' to force the driver to use any
1017 IRQ/DMA settings detected (the default is to
1018 ignore detected IRQ/DMA settings because of
1019 possible conflicts). You can specify the base
1020 address, IRQ, and DMA settings; IRQ and DMA
1021 should be numbers, or 'auto' (for using detected
1022 settings on that particular port), or 'nofifo'
1023 (to avoid using a FIFO even if it is detected).
1024 Parallel ports are assigned in the order they
1025 are specified on the command line, starting
1026 with parport0.
1027
1028 parport_init_mode= [HW,PPT]
1029 Configure VIA parallel port to operate in
1030 a specific mode. This is necessary on Pegasos
1031 computer where firmware has no options for setting
1032 up parallel port mode and sets it to spp.
1033 Currently this function knows 686a and 8231 chips.
1da177e4
LT
1034 Format: [spp|ps2|epp|ecp|ecpepp]
1035
a9913044
RD
1036 pas2= [HW,OSS] Format:
1037 <io>,<irq>,<dma>,<dma16>,<sb_io>,<sb_irq>,<sb_dma>,<sb_dma16>
1038
1da177e4
LT
1039 pas16= [HW,SCSI]
1040 See header of drivers/scsi/pas16.c.
1041
1042 pcbit= [HW,ISDN]
1043
1044 pcd. [PARIDE]
1045 See header of drivers/block/paride/pcd.c.
1046 See also Documentation/paride.txt.
1047
a9913044
RD
1048 pci=option[,option...] [PCI] various PCI subsystem options:
1049 off [IA-32] don't probe for the PCI bus
1050 bios [IA-32] force use of PCI BIOS, don't access
1051 the hardware directly. Use this if your machine
1052 has a non-standard PCI host bridge.
1053 nobios [IA-32] disallow use of PCI BIOS, only direct
1054 hardware access methods are allowed. Use this
1055 if you experience crashes upon bootup and you
1056 suspect they are caused by the BIOS.
1057 conf1 [IA-32] Force use of PCI Configuration
1058 Mechanism 1.
1059 conf2 [IA-32] Force use of PCI Configuration
1060 Mechanism 2.
1061 nosort [IA-32] Don't sort PCI devices according to
1062 order given by the PCI BIOS. This sorting is
1063 done to get a device order compatible with
1064 older kernels.
1065 biosirq [IA-32] Use PCI BIOS calls to get the interrupt
1066 routing table. These calls are known to be buggy
1067 on several machines and they hang the machine
1068 when used, but on other computers it's the only
1069 way to get the interrupt routing table. Try
1070 this option if the kernel is unable to allocate
1071 IRQs or discover secondary PCI buses on your
1072 motherboard.
1073 rom [IA-32] Assign address space to expansion ROMs.
1074 Use with caution as certain devices share
1075 address decoders between ROMs and other
1076 resources.
1077 irqmask=0xMMMM [IA-32] Set a bit mask of IRQs allowed to be
1078 assigned automatically to PCI devices. You can
1079 make the kernel exclude IRQs of your ISA cards
1080 this way.
120bb424 1081 pirqaddr=0xAAAAA [IA-32] Specify the physical address
a9913044
RD
1082 of the PIRQ table (normally generated
1083 by the BIOS) if it is outside the
1084 F0000h-100000h range.
1085 lastbus=N [IA-32] Scan all buses thru bus #N. Can be
1086 useful if the kernel is unable to find your
1087 secondary buses and you want to tell it
1088 explicitly which ones they are.
1089 assign-busses [IA-32] Always assign all PCI bus
1090 numbers ourselves, overriding
1091 whatever the firmware may have done.
1092 usepirqmask [IA-32] Honor the possible IRQ mask stored
1093 in the BIOS $PIR table. This is needed on
1094 some systems with broken BIOSes, notably
1095 some HP Pavilion N5400 and Omnibook XE3
1096 notebooks. This will have no effect if ACPI
1097 IRQ routing is enabled.
1098 noacpi [IA-32] Do not use ACPI for IRQ routing
1099 or for PCI scanning.
1100 routeirq Do IRQ routing for all PCI devices.
1101 This is normally done in pci_enable_device(),
1102 so this option is a temporary workaround
1103 for broken drivers that don't call it.
1104 firmware [ARM] Do not re-enumerate the bus but instead
1105 just use the configuration from the
1106 bootloader. This is currently used on
1107 IXP2000 systems where the bus has to be
1108 configured a certain way for adjunct CPUs.
1da177e4
LT
1109
1110 pcmv= [HW,PCMCIA] BadgePAD 4
1111
1112 pd. [PARIDE]
1113 See Documentation/paride.txt.
1114
1115 pdcchassis= [PARISC,HW] Disable/Enable PDC Chassis Status codes at
1116 boot time.
1117 Format: { 0 | 1 }
1118 See arch/parisc/kernel/pdc_chassis.c
1119
1120 pf. [PARIDE]
1121 See Documentation/paride.txt.
1122
1123 pg. [PARIDE]
1124 See Documentation/paride.txt.
1125
1126 pirq= [SMP,APIC] Manual mp-table setup
1127 See Documentation/i386/IO-APIC.txt.
1128
1129 plip= [PPT,NET] Parallel port network link
1130 Format: { parport<nr> | timid | 0 }
1131 See also Documentation/parport.txt.
1132
1133 pnpacpi= [ACPI]
1134 { off }
1135
1136 pnpbios= [ISAPNP]
1137 { on | off | curr | res | no-curr | no-res }
1138
1139 pnp_reserve_irq=
1140 [ISAPNP] Exclude IRQs for the autoconfiguration
1141
1142 pnp_reserve_dma=
1143 [ISAPNP] Exclude DMAs for the autoconfiguration
1144
1145 pnp_reserve_io= [ISAPNP] Exclude I/O ports for the autoconfiguration
a9913044 1146 Ranges are in pairs (I/O port base and size).
1da177e4
LT
1147
1148 pnp_reserve_mem=
a9913044
RD
1149 [ISAPNP] Exclude memory regions for the
1150 autoconfiguration.
1da177e4
LT
1151 Ranges are in pairs (memory base and size).
1152
1153 profile= [KNL] Enable kernel profiling via /proc/profile
a9913044
RD
1154 Format: [schedule,]<number>
1155 Param: "schedule" - profile schedule points.
1156 Param: <number> - step/bucket size as a power of 2 for
1157 statistical time based profiling.
1da177e4 1158
a9913044 1159 processor.max_cstate= [HW,ACPI]
1da177e4
LT
1160 Limit processor to maximum C-state
1161 max_cstate=9 overrides any DMI blacklist limit.
1162
1163 prompt_ramdisk= [RAM] List of RAM disks to prompt for floppy disk
1164 before loading.
1165 See Documentation/ramdisk.txt.
1166
a9913044
RD
1167 psmouse.proto= [HW,MOUSE] Highest PS2 mouse protocol extension to
1168 probe for; one of (bare|imps|exps|lifebook|any).
1da177e4
LT
1169 psmouse.rate= [HW,MOUSE] Set desired mouse report rate, in reports
1170 per second.
a9913044
RD
1171 psmouse.resetafter= [HW,MOUSE]
1172 Try to reset the device after so many bad packets
1da177e4
LT
1173 (0 = never).
1174 psmouse.resolution=
1175 [HW,MOUSE] Set desired mouse resolution, in dpi.
1176 psmouse.smartscroll=
a9913044 1177 [HW,MOUSE] Controls Logitech smartscroll autorepeat.
1da177e4
LT
1178 0 = disabled, 1 = enabled (default).
1179
1180 pss= [HW,OSS] Personal Sound System (ECHO ESC614)
a9913044
RD
1181 Format:
1182 <io>,<mss_io>,<mss_irq>,<mss_dma>,<mpu_io>,<mpu_irq>
1da177e4
LT
1183
1184 pt. [PARIDE]
1185 See Documentation/paride.txt.
1186
1187 quiet= [KNL] Disable log messages
a9913044 1188
1da177e4
LT
1189 r128= [HW,DRM]
1190
1191 raid= [HW,RAID]
1192 See Documentation/md.txt.
1193
1194 ramdisk= [RAM] Sizes of RAM disks in kilobytes [deprecated]
1195 See Documentation/ramdisk.txt.
1196
a9913044 1197 ramdisk_blocksize= [RAM]
1da177e4 1198 See Documentation/ramdisk.txt.
a9913044 1199
1da177e4
LT
1200 ramdisk_size= [RAM] Sizes of RAM disks in kilobytes
1201 New name for the ramdisk parameter.
1202 See Documentation/ramdisk.txt.
1203
ffdfc409
OJ
1204 rdinit= [KNL]
1205 Format: <full_path>
1206 Run specified binary instead of /init from the ramdisk,
1207 used for early userspace startup. See initrd.
1208
1da177e4
LT
1209 reboot= [BUGS=IA-32,BUGS=ARM,BUGS=IA-64] Rebooting mode
1210 Format: <reboot_mode>[,<reboot_mode2>[,...]]
1211 See arch/*/kernel/reboot.c.
1212
1213 reserve= [KNL,BUGS] Force the kernel to ignore some iomem area
1214
a9913044
RD
1215 resume= [SWSUSP]
1216 Specify the partition device for software suspend
1da177e4
LT
1217
1218 rhash_entries= [KNL,NET]
1219 Set number of hash buckets for route cache
1220
1221 riscom8= [HW,SERIAL]
1222 Format: <io_board1>[,<io_board2>[,...<io_boardN>]]
1223
1224 ro [KNL] Mount root device read-only on boot
1225
1226 root= [KNL] Root filesystem
1227
1228 rootdelay= [KNL] Delay (in seconds) to pause before attempting to
1229 mount the root filesystem
1230
1231 rootflags= [KNL] Set root filesystem mount option string
1232
1233 rootfstype= [KNL] Set root filesystem type
1234
1235 rw [KNL] Mount root device read-write on boot
1236
1237 S [KNL] Run init in single mode
1238
1239 sa1100ir [NET]
1240 See drivers/net/irda/sa1100_ir.c.
1241
1242 sb= [HW,OSS]
1243 Format: <io>,<irq>,<dma>,<dma2>
1244
1245 sbni= [NET] Granch SBNI12 leased line adapter
a9913044 1246
1da177e4
LT
1247 sbpcd= [HW,CD] Soundblaster CD adapter
1248 Format: <io>,<type>
1249 See a comment before function sbpcd_setup() in
1250 drivers/cdrom/sbpcd.c.
1251
1252 sc1200wdt= [HW,WDT] SC1200 WDT (watchdog) driver
1253 Format: <io>[,<timeout>[,<isapnp>]]
1254
1255 scsi_debug_*= [SCSI]
1256 See drivers/scsi/scsi_debug.c.
1257
1258 scsi_default_dev_flags=
1259 [SCSI] SCSI default device flags
1260 Format: <integer>
1261
1262 scsi_dev_flags= [SCSI] Black/white list entry for vendor and model
1263 Format: <vendor>:<model>:<flags>
1264 (flags are integer value)
1265
1266 scsi_logging= [SCSI]
1267
1268 selinux [SELINUX] Disable or enable SELinux at boot time.
1269 Format: { "0" | "1" }
1270 See security/selinux/Kconfig help text.
1271 0 -- disable.
1272 1 -- enable.
1273 Default value is set via kernel config option.
1274 If enabled at boot time, /selinux/disable can be used
1275 later to disable prior to initial policy load.
1276
1277 serialnumber [BUGS=IA-32]
1278
a9913044
RD
1279 sg_def_reserved_size= [SCSI]
1280
1da177e4
LT
1281 sgalaxy= [HW,OSS]
1282 Format: <io>,<irq>,<dma>,<dma2>,<sgbase>
1283
1284 shapers= [NET]
1285 Maximal number of shapers.
a9913044 1286
1da177e4
LT
1287 sim710= [SCSI,HW]
1288 See header of drivers/scsi/sim710.c.
1289
1290 simeth= [IA-64]
1291 simscsi=
a9913044 1292
1da177e4
LT
1293 sjcd= [HW,CD]
1294 Format: <io>,<irq>,<dma>
1295 See header of drivers/cdrom/sjcd.c.
1296
1297 slram= [HW,MTD]
1298
1299 smart2= [HW]
1300 Format: <io1>[,<io2>[,...,<io8>]]
1301
1302 snd-ad1816a= [HW,ALSA]
1303
1304 snd-ad1848= [HW,ALSA]
1305
1306 snd-ali5451= [HW,ALSA]
1307
1308 snd-als100= [HW,ALSA]
1309
1310 snd-als4000= [HW,ALSA]
1311
1312 snd-azt2320= [HW,ALSA]
1313
1314 snd-cmi8330= [HW,ALSA]
1315
1316 snd-cmipci= [HW,ALSA]
1317
1318 snd-cs4231= [HW,ALSA]
1319
1320 snd-cs4232= [HW,ALSA]
1321
1322 snd-cs4236= [HW,ALSA]
1323
1324 snd-cs4281= [HW,ALSA]
1325
1326 snd-cs46xx= [HW,ALSA]
1327
1328 snd-dt019x= [HW,ALSA]
1329
1330 snd-dummy= [HW,ALSA]
1331
1332 snd-emu10k1= [HW,ALSA]
1333
1334 snd-ens1370= [HW,ALSA]
1335
1336 snd-ens1371= [HW,ALSA]
1337
1338 snd-es968= [HW,ALSA]
1339
1340 snd-es1688= [HW,ALSA]
1341
1342 snd-es18xx= [HW,ALSA]
1343
1344 snd-es1938= [HW,ALSA]
1345
1346 snd-es1968= [HW,ALSA]
1347
1348 snd-fm801= [HW,ALSA]
1349
1350 snd-gusclassic= [HW,ALSA]
1351
1352 snd-gusextreme= [HW,ALSA]
1353
1354 snd-gusmax= [HW,ALSA]
1355
1356 snd-hdsp= [HW,ALSA]
1357
1358 snd-ice1712= [HW,ALSA]
1359
1360 snd-intel8x0= [HW,ALSA]
1361
1362 snd-interwave= [HW,ALSA]
1363
1364 snd-interwave-stb=
1365 [HW,ALSA]
1366
1367 snd-korg1212= [HW,ALSA]
1368
1369 snd-maestro3= [HW,ALSA]
1370
1371 snd-mpu401= [HW,ALSA]
1372
1373 snd-mtpav= [HW,ALSA]
1374
1375 snd-nm256= [HW,ALSA]
1376
1377 snd-opl3sa2= [HW,ALSA]
1378
1379 snd-opti92x-ad1848=
1380 [HW,ALSA]
1381
1382 snd-opti92x-cs4231=
1383 [HW,ALSA]
1384
1385 snd-opti93x= [HW,ALSA]
1386
1387 snd-pmac= [HW,ALSA]
1388
1389 snd-rme32= [HW,ALSA]
1390
1391 snd-rme96= [HW,ALSA]
1392
1393 snd-rme9652= [HW,ALSA]
1394
1395 snd-sb8= [HW,ALSA]
1396
1397 snd-sb16= [HW,ALSA]
1398
1399 snd-sbawe= [HW,ALSA]
1400
1401 snd-serial= [HW,ALSA]
1402
1403 snd-sgalaxy= [HW,ALSA]
1404
1405 snd-sonicvibes= [HW,ALSA]
1406
1407 snd-sun-amd7930=
1408 [HW,ALSA]
1409
1410 snd-sun-cs4231= [HW,ALSA]
1411
1412 snd-trident= [HW,ALSA]
1413
1414 snd-usb-audio= [HW,ALSA,USB]
1415
1416 snd-via82xx= [HW,ALSA]
1417
1418 snd-virmidi= [HW,ALSA]
1419
1420 snd-wavefront= [HW,ALSA]
1421
1422 snd-ymfpci= [HW,ALSA]
a9913044 1423
1da177e4
LT
1424 sonicvibes= [HW,OSS]
1425 Format: <reverb>
a9913044 1426
1da177e4
LT
1427 sonycd535= [HW,CD]
1428 Format: <io>[,<irq>]
1429
1430 sonypi.*= [HW] Sony Programmable I/O Control Device driver
1431 See Documentation/sonypi.txt
1432
1433 specialix= [HW,SERIAL] Specialix multi-serial port adapter
1434 See Documentation/specialix.txt.
1435
1436 spia_io_base= [HW,MTD]
1437 spia_fio_base=
1438 spia_pedr=
1439 spia_peddr=
1440
1441 sscape= [HW,OSS]
1442 Format: <io>,<irq>,<dma>,<mpu_io>,<mpu_irq>
a9913044 1443
1da177e4
LT
1444 st= [HW,SCSI] SCSI tape parameters (buffers, etc.)
1445 See Documentation/scsi/st.txt.
1446
1447 st0x= [HW,SCSI]
1448 See header of drivers/scsi/seagate.c.
1449
1450 sti= [PARISC,HW]
1451 Format: <num>
1452 Set the STI (builtin display/keyboard on the HP-PARISC
1453 machines) console (graphic card) which should be used
1454 as the initial boot-console.
1455 See also comment in drivers/video/console/sticore.c.
1456
1457 sti_font= [HW]
1458 See comment in drivers/video/console/sticore.c.
1459
1460 stifb= [HW]
1461 Format: bpp:<bpp1>[:<bpp2>[:<bpp3>...]]
1462
1da177e4 1463 swiotlb= [IA-64] Number of I/O TLB slabs
a9913044 1464
1da177e4
LT
1465 switches= [HW,M68k]
1466
1467 sym53c416= [HW,SCSI]
1468 See header of drivers/scsi/sym53c416.c.
1469
1470 t128= [HW,SCSI]
1471 See header of drivers/scsi/t128.c.
1472
1473 tdfx= [HW,DRM]
1474
1475 thash_entries= [KNL,NET]
1476 Set number of hash buckets for TCP connection
1477
1478 time Show timing data prefixed to each printk message line
1479
1480 tipar.timeout= [HW,PPT]
1481 Set communications timeout in tenths of a second
1482 (default 15).
1483
1484 tipar.delay= [HW,PPT]
1485 Set inter-bit delay in microseconds (default 10).
1486
1487 tmc8xx= [HW,SCSI]
1488 See header of drivers/scsi/seagate.c.
1489
1490 tmscsim= [HW,SCSI]
1491 See comment before function dc390_setup() in
1492 drivers/scsi/tmscsim.c.
1493
1494 tp720= [HW,PS2]
1495
1496 trix= [HW,OSS] MediaTrix AudioTrix Pro
a9913044
RD
1497 Format:
1498 <io>,<irq>,<dma>,<dma2>,<sb_io>,<sb_irq>,<sb_dma>,<mpu_io>,<mpu_irq>
1499
1da177e4
LT
1500 tsdev.xres= [TS] Horizontal screen resolution.
1501 tsdev.yres= [TS] Vertical screen resolution.
1502
a9913044
RD
1503 turbografx.map[2|3]= [HW,JOY]
1504 TurboGraFX parallel port interface
1505 Format:
1506 <port#>,<js1>,<js2>,<js3>,<js4>,<js5>,<js6>,<js7>
1da177e4
LT
1507 See also Documentation/input/joystick-parport.txt
1508
1509 u14-34f= [HW,SCSI] UltraStor 14F/34F SCSI host adapter
1510 See header of drivers/scsi/u14-34f.c.
1511
1512 uart401= [HW,OSS]
1513 Format: <io>,<irq>
1514
1515 uart6850= [HW,OSS]
1516 Format: <io>,<irq>
1517
1da177e4
LT
1518 usbhid.mousepoll=
1519 [USBHID] The interval which mice are to be polled at.
a9913044 1520
1da177e4
LT
1521 video= [FB] Frame buffer configuration
1522 See Documentation/fb/modedb.txt.
1523
1524 vga= [BOOT,IA-32] Select a particular video mode
a9913044
RD
1525 See Documentation/i386/boot.txt and
1526 Documentation/svga.txt.
1da177e4
LT
1527 Use vga=ask for menu.
1528 This is actually a boot loader parameter; the value is
1529 passed to the kernel using a special protocol.
1530
a9913044 1531 vmalloc=nn[KMG] [KNL,BOOT] Forces the vmalloc area to have an exact
1da177e4
LT
1532 size of <nn>. This can be used to increase the
1533 minimum size (128MB on x86). It can also be used to
1534 decrease the size and leave more room for directly
1535 mapped kernel RAM.
1536
1537 vmhalt= [KNL,S390]
1538
a9913044
RD
1539 vmpoff= [KNL,S390]
1540
1da177e4
LT
1541 waveartist= [HW,OSS]
1542 Format: <io>,<irq>,<dma>,<dma2>
a9913044 1543
1da177e4
LT
1544 wd33c93= [HW,SCSI]
1545 See header of drivers/scsi/wd33c93.c.
1546
1547 wd7000= [HW,SCSI]
1548 See header of drivers/scsi/wd7000.c.
1549
1550 wdt= [WDT] Watchdog
1551 See Documentation/watchdog/watchdog.txt.
1552
1553 xd= [HW,XT] Original XT pre-IDE (RLL encoded) disks.
1554 xd_geo= See header of drivers/block/xd.c.
1555
1556 xirc2ps_cs= [NET,PCMCIA]
a9913044
RD
1557 Format:
1558 <irq>,<irq_mask>,<io>,<full_duplex>,<do_sound>,<lockup_hack>[,<irq2>[,<irq3>[,<irq4>]]]
1da177e4
LT
1559
1560
a9913044 1561______________________________________________________________________
1da177e4
LT
1562Changelog:
1563
a9913044 15642000-06-?? Mr. Unknown
1da177e4 1565 The last known update (for 2.4.0) - the changelog was not kept before.
1da177e4 1566
a9913044
RD
15672002-11-24 Petr Baudis <pasky@ucw.cz>
1568 Randy Dunlap <randy.dunlap@verizon.net>
1da177e4
LT
1569 Update for 2.5.49, description for most of the options introduced,
1570 references to other documentation (C files, READMEs, ..), added S390,
1571 PPC, SPARC, MTD, ALSA and OSS category. Minor corrections and
1572 reformatting.
a9913044
RD
1573
15742005-10-19 Randy Dunlap <rdunlap@xenotime.net>
1575 Lots of typos, whitespace, some reformatting.
1da177e4
LT
1576
1577TODO:
1578
1579 Add documentation for ALSA options.
1580 Add more DRM drivers.