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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
2bd0fa3b
JB
636 combined_mode= [HW] control which driver uses IDE ports in combined
637 mode: legacy IDE driver, libata, or both
638 (in the libata case, libata.atapi_enabled=1 may be
639 useful as well). Note that using the ide or libata
640 options may affect your device naming (e.g. by
641 changing hdc to sdb).
642 Format: combined (default), ide, or libata
643
1da177e4
LT
644 inttest= [IA64]
645
646 io7= [HW] IO7 for Marvel based alpha systems
647 See comment before marvel_specify_io7 in
648 arch/alpha/kernel/core_marvel.c.
649
650 ip= [IP_PNP]
651 See Documentation/nfsroot.txt.
652
653 ip2= [HW] Set IO/IRQ pairs for up to 4 IntelliPort boards
654 See comment before ip2_setup() in drivers/char/ip2.c.
655
656 ips= [HW,SCSI] Adaptec / IBM ServeRAID controller
657 See header of drivers/scsi/ips.c.
658
200803df
AC
659 irqfixup [HW]
660 When an interrupt is not handled search all handlers
661 for it. Intended to get systems with badly broken
662 firmware running.
663
664 irqpoll [HW]
665 When an interrupt is not handled search all handlers
666 for it. Also check all handlers each timer
667 interrupt. Intended to get systems with badly broken
668 firmware running.
669
1da177e4 670 isapnp= [ISAPNP]
a9913044 671 Format: <RDP>,<reset>,<pci_scan>,<verbosity>
1da177e4
LT
672
673 isolcpus= [KNL,SMP] Isolate CPUs from the general scheduler.
674 Format: <cpu number>,...,<cpu number>
675 This option can be used to specify one or more CPUs
676 to isolate from the general SMP balancing and scheduling
677 algorithms. The only way to move a process onto or off
678 an "isolated" CPU is via the CPU affinity syscalls.
679 <cpu number> begins at 0 and the maximum value is
680 "number of CPUs in system - 1".
681
682 This option is the preferred way to isolate CPUs. The
a9913044
RD
683 alternative -- manually setting the CPU mask of all
684 tasks in the system -- can cause problems and
685 suboptimal load balancer performance.
1da177e4
LT
686
687 isp16= [HW,CD]
688 Format: <io>,<irq>,<dma>,<setup>
689
a9913044 690 iucv= [HW,NET]
1da177e4
LT
691
692 js= [HW,JOY] Analog joystick
693 See Documentation/input/joystick.txt.
694
695 keepinitrd [HW,ARM]
696
a9913044 697 kstack=N [IA-32,X86-64] Print N words from the kernel stack
1da177e4
LT
698 in oops dumps.
699
700 l2cr= [PPC]
701
a9913044
RD
702 lapic [IA-32,APIC] Enable the local APIC even if BIOS
703 disabled it.
1da177e4
LT
704
705 lasi= [HW,SCSI] PARISC LASI driver for the 53c700 chip
706 Format: addr:<io>,irq:<irq>
707
a9913044
RD
708 llsc*= [IA64] See function print_params() in
709 arch/ia64/sn/kernel/llsc4.c.
1da177e4
LT
710
711 load_ramdisk= [RAM] List of ramdisks to load from floppy
712 See Documentation/ramdisk.txt.
713
714 lockd.udpport= [NFS]
715
716 lockd.tcpport= [NFS]
717
718 logibm.irq= [HW,MOUSE] Logitech Bus Mouse Driver
719 Format: <irq>
720
721 loglevel= All Kernel Messages with a loglevel smaller than the
722 console loglevel will be printed to the console. It can
723 also be changed with klogd or other programs. The
724 loglevels are defined as follows:
725
726 0 (KERN_EMERG) system is unusable
727 1 (KERN_ALERT) action must be taken immediately
728 2 (KERN_CRIT) critical conditions
729 3 (KERN_ERR) error conditions
730 4 (KERN_WARNING) warning conditions
731 5 (KERN_NOTICE) normal but significant condition
732 6 (KERN_INFO) informational
733 7 (KERN_DEBUG) debug-level messages
734
735 log_buf_len=n Sets the size of the printk ring buffer, in bytes.
a9913044
RD
736 Format: { n | nk | nM }
737 n must be a power of two. The default size
738 is set in the kernel config file.
1da177e4
LT
739
740 lp=0 [LP] Specify parallel ports to use, e.g,
741 lp=port[,port...] lp=none,parport0 (lp0 not configured, lp1 uses
742 lp=reset first parallel port). 'lp=0' disables the
743 lp=auto printer driver. 'lp=reset' (which can be
744 specified in addition to the ports) causes
745 attached printers to be reset. Using
746 lp=port1,port2,... specifies the parallel ports
747 to associate lp devices with, starting with
748 lp0. A port specification may be 'none' to skip
749 that lp device, or a parport name such as
750 'parport0'. Specifying 'lp=auto' instead of a
751 port specification list means that device IDs
752 from each port should be examined, to see if
753 an IEEE 1284-compliant printer is attached; if
754 so, the driver will manage that printer.
755 See also header of drivers/char/lp.c.
756
757 lpj=n [KNL]
758 Sets loops_per_jiffy to given constant, thus avoiding
759 time-consuming boot-time autodetection (up to 250 ms per
760 CPU). 0 enables autodetection (default). To determine
761 the correct value for your kernel, boot with normal
762 autodetection and see what value is printed. Note that
763 on SMP systems the preset will be applied to all CPUs,
764 which is likely to cause problems if your CPUs need
765 significantly divergent settings. An incorrect value
766 will cause delays in the kernel to be wrong, leading to
767 unpredictable I/O errors and other breakage. Although
768 unlikely, in the extreme case this might damage your
769 hardware.
770
771 ltpc= [NET]
772 Format: <io>,<irq>,<dma>
773
a9913044
RD
774 mac5380= [HW,SCSI] Format:
775 <can_queue>,<cmd_per_lun>,<sg_tablesize>,<hostid>,<use_tags>
1da177e4 776
a9913044
RD
777 mac53c9x= [HW,SCSI] Format:
778 <num_esps>,<disconnect>,<nosync>,<can_queue>,<cmd_per_lun>,<sg_tablesize>,<hostid>,<use_tags>
1da177e4 779
a9913044
RD
780 machvec= [IA64] Force the use of a particular machine-vector
781 (machvec) in a generic kernel.
782 Example: machvec=hpzx1_swiotlb
1da177e4 783
a9913044
RD
784 mad16= [HW,OSS] Format:
785 <io>,<irq>,<dma>,<dma16>,<mpu_io>,<mpu_irq>,<joystick>
1da177e4
LT
786
787 maui= [HW,OSS]
788 Format: <io>,<irq>
a9913044
RD
789
790 max_loop= [LOOP] Maximum number of loopback devices that can
1da177e4
LT
791 be mounted
792 Format: <1-256>
793
794 maxcpus= [SMP] Maximum number of processors that an SMP kernel
795 should make use of
796
2b2c3750
BP
797 max_addr=[KMG] [KNL,BOOT,ia64] All physical memory greater than or
798 equal to this physical address is ignored.
799
a9913044 800 max_luns= [SCSI] Maximum number of LUNs to probe.
1da177e4
LT
801 Should be between 1 and 2^32-1.
802
803 max_report_luns=
a9913044 804 [SCSI] Maximum number of LUNs received.
1da177e4
LT
805 Should be between 1 and 16384.
806
807 mca-pentium [BUGS=IA-32]
808
809 mcatest= [IA-64]
810
811 mcd= [HW,CD]
812 Format: <port>,<irq>,<mitsumi_bug_93_wait>
813
814 mcdx= [HW,CD]
815
816 mce [IA-32] Machine Check Exception
817
818 md= [HW] RAID subsystems devices and level
819 See Documentation/md.txt.
a9913044 820
1da177e4
LT
821 mdacon= [MDA]
822 Format: <first>,<last>
823 Specifies range of consoles to be captured by the MDA.
a9913044 824
1da177e4
LT
825 mem=nn[KMG] [KNL,BOOT] Force usage of a specific amount of memory
826 Amount of memory to be used when the kernel is not able
827 to see the whole system memory or for test.
828 [IA-32] Use together with memmap= to avoid physical
829 address space collisions. Without memmap= PCI devices
830 could be placed at addresses belonging to unused RAM.
831
832 mem=nopentium [BUGS=IA-32] Disable usage of 4MB pages for kernel
833 memory.
834
835 memmap=exactmap [KNL,IA-32] Enable setting of an exact
836 E820 memory map, as specified by the user.
837 Such memmap=exactmap lines can be constructed based on
838 BIOS output or other requirements. See the memmap=nn@ss
839 option description.
840
841 memmap=nn[KMG]@ss[KMG]
842 [KNL] Force usage of a specific region of memory
843 Region of memory to be used, from ss to ss+nn.
844
845 memmap=nn[KMG]#ss[KMG]
846 [KNL,ACPI] Mark specific memory as ACPI data.
847 Region of memory to be used, from ss to ss+nn.
848
849 memmap=nn[KMG]$ss[KMG]
850 [KNL,ACPI] Mark specific memory as reserved.
851 Region of memory to be used, from ss to ss+nn.
852
853 meye.*= [HW] Set MotionEye Camera parameters
854 See Documentation/video4linux/meye.txt.
855
856 mga= [HW,DRM]
857
858 mousedev.tap_time=
859 [MOUSE] Maximum time between finger touching and
860 leaving touchpad surface for touch to be considered
861 a tap and be reported as a left button click (for
862 touchpads working in absolute mode only).
863 Format: <msecs>
864 mousedev.xres= [MOUSE] Horizontal screen resolution, used for devices
865 reporting absolute coordinates, such as tablets
866 mousedev.yres= [MOUSE] Vertical screen resolution, used for devices
867 reporting absolute coordinates, such as tablets
868
869 mpu401= [HW,OSS]
870 Format: <io>,<irq>
871
872 MTD_Partition= [MTD]
873 Format: <name>,<region-number>,<size>,<offset>
874
a9913044
RD
875 MTD_Region= [MTD] Format:
876 <name>,<region-number>[,<base>,<size>,<buswidth>,<altbuswidth>]
1da177e4
LT
877
878 mtdparts= [MTD]
879 See drivers/mtd/cmdline.c.
880
881 mtouchusb.raw_coordinates=
a9913044
RD
882 [HW] Make the MicroTouch USB driver use raw coordinates
883 ('y', default) or cooked coordinates ('n')
1da177e4
LT
884
885 n2= [NET] SDL Inc. RISCom/N2 synchronous serial card
886
887 NCR_D700= [HW,SCSI]
888 See header of drivers/scsi/NCR_D700.c.
889
890 ncr5380= [HW,SCSI]
891
892 ncr53c400= [HW,SCSI]
893
894 ncr53c400a= [HW,SCSI]
895
896 ncr53c406a= [HW,SCSI]
897
898 ncr53c8xx= [HW,SCSI]
899
900 netdev= [NET] Network devices parameters
901 Format: <irq>,<io>,<mem_start>,<mem_end>,<name>
902 Note that mem_start is often overloaded to mean
903 something different and driver-specific.
a9913044
RD
904 This usage is only documented in each driver source
905 file if at all.
906
1da177e4
LT
907 nfsaddrs= [NFS]
908 See Documentation/nfsroot.txt.
909
910 nfsroot= [NFS] nfs root filesystem for disk-less boxes.
911 See Documentation/nfsroot.txt.
912
a72b4422
TM
913 nfs.callback_tcpport=
914 [NFS] set the TCP port on which the NFSv4 callback
915 channel should listen.
916
1da177e4
LT
917 nmi_watchdog= [KNL,BUGS=IA-32] Debugging features for SMP kernels
918
919 no387 [BUGS=IA-32] Tells the kernel to use the 387 maths
920 emulation library even if a 387 maths coprocessor
921 is present.
922
a9913044
RD
923 noalign [KNL,ARM]
924
1da177e4
LT
925 noapic [SMP,APIC] Tells the kernel to not make use of any
926 IOAPICs that may be present in the system.
927
928 noasync [HW,M68K] Disables async and sync negotiation for
929 all devices.
930
931 nobats [PPC] Do not use BATs for mapping kernel lowmem
932 on "Classic" PPC cores.
933
934 nocache [ARM]
a9913044 935
1da177e4
LT
936 nodisconnect [HW,SCSI,M68K] Disables SCSI disconnects.
937
938 noexec [IA-64]
939
a9913044 940 noexec [IA-32,X86-64]
1da177e4
LT
941 noexec=on: enable non-executable mappings (default)
942 noexec=off: disable nn-executable mappings
943
944 nofxsr [BUGS=IA-32]
945
946 nohlt [BUGS=ARM]
a9913044 947
1da177e4
LT
948 no-hlt [BUGS=IA-32] Tells the kernel that the hlt
949 instruction doesn't work correctly and not to
950 use it.
951
952 nohalt [IA-64] Tells the kernel not to use the power saving
953 function PAL_HALT_LIGHT when idle. This increases
954 power-consumption. On the positive side, it reduces
955 interrupt wake-up latency, which may improve performance
956 in certain environments such as networked servers or
957 real-time systems.
958
959 noirqdebug [IA-32] Disables the code which attempts to detect and
960 disable unhandled interrupt sources.
961
962 noisapnp [ISAPNP] Disables ISA PnP code.
963
964 noinitrd [RAM] Tells the kernel not to load any configured
965 initial RAM disk.
966
967 nointroute [IA-64]
968
969 nolapic [IA-32,APIC] Do not enable or use the local APIC.
970
971 noltlbs [PPC] Do not use large page/tlb entries for kernel
972 lowmem mapping on PPC40x.
973
974 nomce [IA-32] Machine Check Exception
975
976 noresidual [PPC] Don't use residual data on PReP machines.
977
a9913044
RD
978 noresume [SWSUSP] Disables resume and restores original swap
979 space.
980
1da177e4
LT
981 no-scroll [VGA] Disables scrollback.
982 This is required for the Braillex ib80-piezo Braille
983 reader made by F.H. Papenmeier (Germany).
984
985 nosbagart [IA-64]
986
987 nosmp [SMP] Tells an SMP kernel to act as a UP kernel.
988
989 nosync [HW,M68K] Disables sync negotiation for all devices.
990
991 notsc [BUGS=IA-32] Disable Time Stamp Counter
992
993 nousb [USB] Disable the USB subsystem
994
995 nowb [ARM]
a9913044 996
1da177e4
LT
997 opl3= [HW,OSS]
998 Format: <io>
999
1000 opl3sa= [HW,OSS]
1001 Format: <io>,<irq>,<dma>,<dma2>,<mpu_io>,<mpu_irq>
1002
a9913044
RD
1003 opl3sa2= [HW,OSS] Format:
1004 <io>,<irq>,<dma>,<dma2>,<mss_io>,<mpu_io>,<ymode>,<loopback>[,<isapnp>,<multiple]
1005
1da177e4
LT
1006 oprofile.timer= [HW]
1007 Use timer interrupt instead of performance counters
1008
1009 optcd= [HW,CD]
1010 Format: <io>
1011
1012 osst= [HW,SCSI] SCSI Tape Driver
1013 Format: <buffer_size>,<write_threshold>
1014 See also Documentation/scsi/st.txt.
1015
1016 panic= [KNL] Kernel behaviour on panic
1017 Format: <timeout>
1018
1019 parkbd.port= [HW] Parallel port number the keyboard adapter is
1020 connected to, default is 0.
1021 Format: <parport#>
1022 parkbd.mode= [HW] Parallel port keyboard adapter mode of operation,
1023 0 for XT, 1 for AT (default is AT).
a9913044
RD
1024 Format: <mode>
1025
1026 parport= [HW,PPT] Specify parallel ports. 0 disables.
1027 Format: { 0 | auto | 0xBBB[,IRQ[,DMA]] }
1028 Use 'auto' to force the driver to use any
1029 IRQ/DMA settings detected (the default is to
1030 ignore detected IRQ/DMA settings because of
1031 possible conflicts). You can specify the base
1032 address, IRQ, and DMA settings; IRQ and DMA
1033 should be numbers, or 'auto' (for using detected
1034 settings on that particular port), or 'nofifo'
1035 (to avoid using a FIFO even if it is detected).
1036 Parallel ports are assigned in the order they
1037 are specified on the command line, starting
1038 with parport0.
1039
1040 parport_init_mode= [HW,PPT]
1041 Configure VIA parallel port to operate in
1042 a specific mode. This is necessary on Pegasos
1043 computer where firmware has no options for setting
1044 up parallel port mode and sets it to spp.
1045 Currently this function knows 686a and 8231 chips.
1da177e4
LT
1046 Format: [spp|ps2|epp|ecp|ecpepp]
1047
a9913044
RD
1048 pas2= [HW,OSS] Format:
1049 <io>,<irq>,<dma>,<dma16>,<sb_io>,<sb_irq>,<sb_dma>,<sb_dma16>
1050
1da177e4
LT
1051 pas16= [HW,SCSI]
1052 See header of drivers/scsi/pas16.c.
1053
1054 pcbit= [HW,ISDN]
1055
1056 pcd. [PARIDE]
1057 See header of drivers/block/paride/pcd.c.
1058 See also Documentation/paride.txt.
1059
a9913044
RD
1060 pci=option[,option...] [PCI] various PCI subsystem options:
1061 off [IA-32] don't probe for the PCI bus
1062 bios [IA-32] force use of PCI BIOS, don't access
1063 the hardware directly. Use this if your machine
1064 has a non-standard PCI host bridge.
1065 nobios [IA-32] disallow use of PCI BIOS, only direct
1066 hardware access methods are allowed. Use this
1067 if you experience crashes upon bootup and you
1068 suspect they are caused by the BIOS.
1069 conf1 [IA-32] Force use of PCI Configuration
1070 Mechanism 1.
1071 conf2 [IA-32] Force use of PCI Configuration
1072 Mechanism 2.
1073 nosort [IA-32] Don't sort PCI devices according to
1074 order given by the PCI BIOS. This sorting is
1075 done to get a device order compatible with
1076 older kernels.
1077 biosirq [IA-32] Use PCI BIOS calls to get the interrupt
1078 routing table. These calls are known to be buggy
1079 on several machines and they hang the machine
1080 when used, but on other computers it's the only
1081 way to get the interrupt routing table. Try
1082 this option if the kernel is unable to allocate
1083 IRQs or discover secondary PCI buses on your
1084 motherboard.
1085 rom [IA-32] Assign address space to expansion ROMs.
1086 Use with caution as certain devices share
1087 address decoders between ROMs and other
1088 resources.
1089 irqmask=0xMMMM [IA-32] Set a bit mask of IRQs allowed to be
1090 assigned automatically to PCI devices. You can
1091 make the kernel exclude IRQs of your ISA cards
1092 this way.
120bb424 1093 pirqaddr=0xAAAAA [IA-32] Specify the physical address
a9913044
RD
1094 of the PIRQ table (normally generated
1095 by the BIOS) if it is outside the
1096 F0000h-100000h range.
1097 lastbus=N [IA-32] Scan all buses thru bus #N. Can be
1098 useful if the kernel is unable to find your
1099 secondary buses and you want to tell it
1100 explicitly which ones they are.
1101 assign-busses [IA-32] Always assign all PCI bus
1102 numbers ourselves, overriding
1103 whatever the firmware may have done.
1104 usepirqmask [IA-32] Honor the possible IRQ mask stored
1105 in the BIOS $PIR table. This is needed on
1106 some systems with broken BIOSes, notably
1107 some HP Pavilion N5400 and Omnibook XE3
1108 notebooks. This will have no effect if ACPI
1109 IRQ routing is enabled.
1110 noacpi [IA-32] Do not use ACPI for IRQ routing
1111 or for PCI scanning.
1112 routeirq Do IRQ routing for all PCI devices.
1113 This is normally done in pci_enable_device(),
1114 so this option is a temporary workaround
1115 for broken drivers that don't call it.
1116 firmware [ARM] Do not re-enumerate the bus but instead
1117 just use the configuration from the
1118 bootloader. This is currently used on
1119 IXP2000 systems where the bus has to be
1120 configured a certain way for adjunct CPUs.
1da177e4
LT
1121
1122 pcmv= [HW,PCMCIA] BadgePAD 4
1123
1124 pd. [PARIDE]
1125 See Documentation/paride.txt.
1126
1127 pdcchassis= [PARISC,HW] Disable/Enable PDC Chassis Status codes at
1128 boot time.
1129 Format: { 0 | 1 }
1130 See arch/parisc/kernel/pdc_chassis.c
1131
1132 pf. [PARIDE]
1133 See Documentation/paride.txt.
1134
1135 pg. [PARIDE]
1136 See Documentation/paride.txt.
1137
1138 pirq= [SMP,APIC] Manual mp-table setup
1139 See Documentation/i386/IO-APIC.txt.
1140
1141 plip= [PPT,NET] Parallel port network link
1142 Format: { parport<nr> | timid | 0 }
1143 See also Documentation/parport.txt.
1144
1145 pnpacpi= [ACPI]
1146 { off }
1147
1148 pnpbios= [ISAPNP]
1149 { on | off | curr | res | no-curr | no-res }
1150
1151 pnp_reserve_irq=
1152 [ISAPNP] Exclude IRQs for the autoconfiguration
1153
1154 pnp_reserve_dma=
1155 [ISAPNP] Exclude DMAs for the autoconfiguration
1156
1157 pnp_reserve_io= [ISAPNP] Exclude I/O ports for the autoconfiguration
a9913044 1158 Ranges are in pairs (I/O port base and size).
1da177e4
LT
1159
1160 pnp_reserve_mem=
a9913044
RD
1161 [ISAPNP] Exclude memory regions for the
1162 autoconfiguration.
1da177e4
LT
1163 Ranges are in pairs (memory base and size).
1164
1165 profile= [KNL] Enable kernel profiling via /proc/profile
a9913044
RD
1166 Format: [schedule,]<number>
1167 Param: "schedule" - profile schedule points.
1168 Param: <number> - step/bucket size as a power of 2 for
1169 statistical time based profiling.
1da177e4 1170
a9913044 1171 processor.max_cstate= [HW,ACPI]
1da177e4
LT
1172 Limit processor to maximum C-state
1173 max_cstate=9 overrides any DMI blacklist limit.
1174
1175 prompt_ramdisk= [RAM] List of RAM disks to prompt for floppy disk
1176 before loading.
1177 See Documentation/ramdisk.txt.
1178
a9913044
RD
1179 psmouse.proto= [HW,MOUSE] Highest PS2 mouse protocol extension to
1180 probe for; one of (bare|imps|exps|lifebook|any).
1da177e4
LT
1181 psmouse.rate= [HW,MOUSE] Set desired mouse report rate, in reports
1182 per second.
a9913044
RD
1183 psmouse.resetafter= [HW,MOUSE]
1184 Try to reset the device after so many bad packets
1da177e4
LT
1185 (0 = never).
1186 psmouse.resolution=
1187 [HW,MOUSE] Set desired mouse resolution, in dpi.
1188 psmouse.smartscroll=
a9913044 1189 [HW,MOUSE] Controls Logitech smartscroll autorepeat.
1da177e4
LT
1190 0 = disabled, 1 = enabled (default).
1191
1192 pss= [HW,OSS] Personal Sound System (ECHO ESC614)
a9913044
RD
1193 Format:
1194 <io>,<mss_io>,<mss_irq>,<mss_dma>,<mpu_io>,<mpu_irq>
1da177e4
LT
1195
1196 pt. [PARIDE]
1197 See Documentation/paride.txt.
1198
1199 quiet= [KNL] Disable log messages
a9913044 1200
1da177e4
LT
1201 r128= [HW,DRM]
1202
1203 raid= [HW,RAID]
1204 See Documentation/md.txt.
1205
1206 ramdisk= [RAM] Sizes of RAM disks in kilobytes [deprecated]
1207 See Documentation/ramdisk.txt.
1208
a9913044 1209 ramdisk_blocksize= [RAM]
1da177e4 1210 See Documentation/ramdisk.txt.
a9913044 1211
1da177e4
LT
1212 ramdisk_size= [RAM] Sizes of RAM disks in kilobytes
1213 New name for the ramdisk parameter.
1214 See Documentation/ramdisk.txt.
1215
ffdfc409
OJ
1216 rdinit= [KNL]
1217 Format: <full_path>
1218 Run specified binary instead of /init from the ramdisk,
1219 used for early userspace startup. See initrd.
1220
1da177e4
LT
1221 reboot= [BUGS=IA-32,BUGS=ARM,BUGS=IA-64] Rebooting mode
1222 Format: <reboot_mode>[,<reboot_mode2>[,...]]
1223 See arch/*/kernel/reboot.c.
1224
1225 reserve= [KNL,BUGS] Force the kernel to ignore some iomem area
1226
a9913044
RD
1227 resume= [SWSUSP]
1228 Specify the partition device for software suspend
1da177e4
LT
1229
1230 rhash_entries= [KNL,NET]
1231 Set number of hash buckets for route cache
1232
1233 riscom8= [HW,SERIAL]
1234 Format: <io_board1>[,<io_board2>[,...<io_boardN>]]
1235
1236 ro [KNL] Mount root device read-only on boot
1237
1238 root= [KNL] Root filesystem
1239
1240 rootdelay= [KNL] Delay (in seconds) to pause before attempting to
1241 mount the root filesystem
1242
1243 rootflags= [KNL] Set root filesystem mount option string
1244
1245 rootfstype= [KNL] Set root filesystem type
1246
1247 rw [KNL] Mount root device read-write on boot
1248
1249 S [KNL] Run init in single mode
1250
1251 sa1100ir [NET]
1252 See drivers/net/irda/sa1100_ir.c.
1253
1254 sb= [HW,OSS]
1255 Format: <io>,<irq>,<dma>,<dma2>
1256
1257 sbni= [NET] Granch SBNI12 leased line adapter
a9913044 1258
1da177e4
LT
1259 sbpcd= [HW,CD] Soundblaster CD adapter
1260 Format: <io>,<type>
1261 See a comment before function sbpcd_setup() in
1262 drivers/cdrom/sbpcd.c.
1263
1264 sc1200wdt= [HW,WDT] SC1200 WDT (watchdog) driver
1265 Format: <io>[,<timeout>[,<isapnp>]]
1266
1267 scsi_debug_*= [SCSI]
1268 See drivers/scsi/scsi_debug.c.
1269
1270 scsi_default_dev_flags=
1271 [SCSI] SCSI default device flags
1272 Format: <integer>
1273
1274 scsi_dev_flags= [SCSI] Black/white list entry for vendor and model
1275 Format: <vendor>:<model>:<flags>
1276 (flags are integer value)
1277
1278 scsi_logging= [SCSI]
1279
1280 selinux [SELINUX] Disable or enable SELinux at boot time.
1281 Format: { "0" | "1" }
1282 See security/selinux/Kconfig help text.
1283 0 -- disable.
1284 1 -- enable.
1285 Default value is set via kernel config option.
1286 If enabled at boot time, /selinux/disable can be used
1287 later to disable prior to initial policy load.
1288
1289 serialnumber [BUGS=IA-32]
1290
a9913044
RD
1291 sg_def_reserved_size= [SCSI]
1292
1da177e4
LT
1293 sgalaxy= [HW,OSS]
1294 Format: <io>,<irq>,<dma>,<dma2>,<sgbase>
1295
1296 shapers= [NET]
1297 Maximal number of shapers.
a9913044 1298
1da177e4
LT
1299 sim710= [SCSI,HW]
1300 See header of drivers/scsi/sim710.c.
1301
1302 simeth= [IA-64]
1303 simscsi=
a9913044 1304
1da177e4
LT
1305 sjcd= [HW,CD]
1306 Format: <io>,<irq>,<dma>
1307 See header of drivers/cdrom/sjcd.c.
1308
1309 slram= [HW,MTD]
1310
1311 smart2= [HW]
1312 Format: <io1>[,<io2>[,...,<io8>]]
1313
1314 snd-ad1816a= [HW,ALSA]
1315
1316 snd-ad1848= [HW,ALSA]
1317
1318 snd-ali5451= [HW,ALSA]
1319
1320 snd-als100= [HW,ALSA]
1321
1322 snd-als4000= [HW,ALSA]
1323
1324 snd-azt2320= [HW,ALSA]
1325
1326 snd-cmi8330= [HW,ALSA]
1327
1328 snd-cmipci= [HW,ALSA]
1329
1330 snd-cs4231= [HW,ALSA]
1331
1332 snd-cs4232= [HW,ALSA]
1333
1334 snd-cs4236= [HW,ALSA]
1335
1336 snd-cs4281= [HW,ALSA]
1337
1338 snd-cs46xx= [HW,ALSA]
1339
1340 snd-dt019x= [HW,ALSA]
1341
1342 snd-dummy= [HW,ALSA]
1343
1344 snd-emu10k1= [HW,ALSA]
1345
1346 snd-ens1370= [HW,ALSA]
1347
1348 snd-ens1371= [HW,ALSA]
1349
1350 snd-es968= [HW,ALSA]
1351
1352 snd-es1688= [HW,ALSA]
1353
1354 snd-es18xx= [HW,ALSA]
1355
1356 snd-es1938= [HW,ALSA]
1357
1358 snd-es1968= [HW,ALSA]
1359
1360 snd-fm801= [HW,ALSA]
1361
1362 snd-gusclassic= [HW,ALSA]
1363
1364 snd-gusextreme= [HW,ALSA]
1365
1366 snd-gusmax= [HW,ALSA]
1367
1368 snd-hdsp= [HW,ALSA]
1369
1370 snd-ice1712= [HW,ALSA]
1371
1372 snd-intel8x0= [HW,ALSA]
1373
1374 snd-interwave= [HW,ALSA]
1375
1376 snd-interwave-stb=
1377 [HW,ALSA]
1378
1379 snd-korg1212= [HW,ALSA]
1380
1381 snd-maestro3= [HW,ALSA]
1382
1383 snd-mpu401= [HW,ALSA]
1384
1385 snd-mtpav= [HW,ALSA]
1386
1387 snd-nm256= [HW,ALSA]
1388
1389 snd-opl3sa2= [HW,ALSA]
1390
1391 snd-opti92x-ad1848=
1392 [HW,ALSA]
1393
1394 snd-opti92x-cs4231=
1395 [HW,ALSA]
1396
1397 snd-opti93x= [HW,ALSA]
1398
1399 snd-pmac= [HW,ALSA]
1400
1401 snd-rme32= [HW,ALSA]
1402
1403 snd-rme96= [HW,ALSA]
1404
1405 snd-rme9652= [HW,ALSA]
1406
1407 snd-sb8= [HW,ALSA]
1408
1409 snd-sb16= [HW,ALSA]
1410
1411 snd-sbawe= [HW,ALSA]
1412
1413 snd-serial= [HW,ALSA]
1414
1415 snd-sgalaxy= [HW,ALSA]
1416
1417 snd-sonicvibes= [HW,ALSA]
1418
1419 snd-sun-amd7930=
1420 [HW,ALSA]
1421
1422 snd-sun-cs4231= [HW,ALSA]
1423
1424 snd-trident= [HW,ALSA]
1425
1426 snd-usb-audio= [HW,ALSA,USB]
1427
1428 snd-via82xx= [HW,ALSA]
1429
1430 snd-virmidi= [HW,ALSA]
1431
1432 snd-wavefront= [HW,ALSA]
1433
1434 snd-ymfpci= [HW,ALSA]
a9913044 1435
1da177e4
LT
1436 sonicvibes= [HW,OSS]
1437 Format: <reverb>
a9913044 1438
1da177e4
LT
1439 sonycd535= [HW,CD]
1440 Format: <io>[,<irq>]
1441
1442 sonypi.*= [HW] Sony Programmable I/O Control Device driver
1443 See Documentation/sonypi.txt
1444
1445 specialix= [HW,SERIAL] Specialix multi-serial port adapter
1446 See Documentation/specialix.txt.
1447
1448 spia_io_base= [HW,MTD]
1449 spia_fio_base=
1450 spia_pedr=
1451 spia_peddr=
1452
1453 sscape= [HW,OSS]
1454 Format: <io>,<irq>,<dma>,<mpu_io>,<mpu_irq>
a9913044 1455
1da177e4
LT
1456 st= [HW,SCSI] SCSI tape parameters (buffers, etc.)
1457 See Documentation/scsi/st.txt.
1458
1459 st0x= [HW,SCSI]
1460 See header of drivers/scsi/seagate.c.
1461
1462 sti= [PARISC,HW]
1463 Format: <num>
1464 Set the STI (builtin display/keyboard on the HP-PARISC
1465 machines) console (graphic card) which should be used
1466 as the initial boot-console.
1467 See also comment in drivers/video/console/sticore.c.
1468
1469 sti_font= [HW]
1470 See comment in drivers/video/console/sticore.c.
1471
1472 stifb= [HW]
1473 Format: bpp:<bpp1>[:<bpp2>[:<bpp3>...]]
1474
1da177e4 1475 swiotlb= [IA-64] Number of I/O TLB slabs
a9913044 1476
1da177e4
LT
1477 switches= [HW,M68k]
1478
1479 sym53c416= [HW,SCSI]
1480 See header of drivers/scsi/sym53c416.c.
1481
1482 t128= [HW,SCSI]
1483 See header of drivers/scsi/t128.c.
1484
1485 tdfx= [HW,DRM]
1486
1487 thash_entries= [KNL,NET]
1488 Set number of hash buckets for TCP connection
1489
1490 time Show timing data prefixed to each printk message line
1491
1492 tipar.timeout= [HW,PPT]
1493 Set communications timeout in tenths of a second
1494 (default 15).
1495
1496 tipar.delay= [HW,PPT]
1497 Set inter-bit delay in microseconds (default 10).
1498
1499 tmc8xx= [HW,SCSI]
1500 See header of drivers/scsi/seagate.c.
1501
1502 tmscsim= [HW,SCSI]
1503 See comment before function dc390_setup() in
1504 drivers/scsi/tmscsim.c.
1505
1506 tp720= [HW,PS2]
1507
1508 trix= [HW,OSS] MediaTrix AudioTrix Pro
a9913044
RD
1509 Format:
1510 <io>,<irq>,<dma>,<dma2>,<sb_io>,<sb_irq>,<sb_dma>,<mpu_io>,<mpu_irq>
1511
1da177e4
LT
1512 tsdev.xres= [TS] Horizontal screen resolution.
1513 tsdev.yres= [TS] Vertical screen resolution.
1514
a9913044
RD
1515 turbografx.map[2|3]= [HW,JOY]
1516 TurboGraFX parallel port interface
1517 Format:
1518 <port#>,<js1>,<js2>,<js3>,<js4>,<js5>,<js6>,<js7>
1da177e4
LT
1519 See also Documentation/input/joystick-parport.txt
1520
1521 u14-34f= [HW,SCSI] UltraStor 14F/34F SCSI host adapter
1522 See header of drivers/scsi/u14-34f.c.
1523
1524 uart401= [HW,OSS]
1525 Format: <io>,<irq>
1526
1527 uart6850= [HW,OSS]
1528 Format: <io>,<irq>
1529
1da177e4
LT
1530 usbhid.mousepoll=
1531 [USBHID] The interval which mice are to be polled at.
a9913044 1532
1da177e4
LT
1533 video= [FB] Frame buffer configuration
1534 See Documentation/fb/modedb.txt.
1535
1536 vga= [BOOT,IA-32] Select a particular video mode
a9913044
RD
1537 See Documentation/i386/boot.txt and
1538 Documentation/svga.txt.
1da177e4
LT
1539 Use vga=ask for menu.
1540 This is actually a boot loader parameter; the value is
1541 passed to the kernel using a special protocol.
1542
a9913044 1543 vmalloc=nn[KMG] [KNL,BOOT] Forces the vmalloc area to have an exact
1da177e4
LT
1544 size of <nn>. This can be used to increase the
1545 minimum size (128MB on x86). It can also be used to
1546 decrease the size and leave more room for directly
1547 mapped kernel RAM.
1548
1549 vmhalt= [KNL,S390]
1550
a9913044
RD
1551 vmpoff= [KNL,S390]
1552
1da177e4
LT
1553 waveartist= [HW,OSS]
1554 Format: <io>,<irq>,<dma>,<dma2>
a9913044 1555
1da177e4
LT
1556 wd33c93= [HW,SCSI]
1557 See header of drivers/scsi/wd33c93.c.
1558
1559 wd7000= [HW,SCSI]
1560 See header of drivers/scsi/wd7000.c.
1561
1562 wdt= [WDT] Watchdog
1563 See Documentation/watchdog/watchdog.txt.
1564
1565 xd= [HW,XT] Original XT pre-IDE (RLL encoded) disks.
1566 xd_geo= See header of drivers/block/xd.c.
1567
1568 xirc2ps_cs= [NET,PCMCIA]
a9913044
RD
1569 Format:
1570 <irq>,<irq_mask>,<io>,<full_duplex>,<do_sound>,<lockup_hack>[,<irq2>[,<irq3>[,<irq4>]]]
1da177e4
LT
1571
1572
a9913044 1573______________________________________________________________________
1da177e4
LT
1574Changelog:
1575
a9913044 15762000-06-?? Mr. Unknown
1da177e4 1577 The last known update (for 2.4.0) - the changelog was not kept before.
1da177e4 1578
a9913044
RD
15792002-11-24 Petr Baudis <pasky@ucw.cz>
1580 Randy Dunlap <randy.dunlap@verizon.net>
1da177e4
LT
1581 Update for 2.5.49, description for most of the options introduced,
1582 references to other documentation (C files, READMEs, ..), added S390,
1583 PPC, SPARC, MTD, ALSA and OSS category. Minor corrections and
1584 reformatting.
a9913044
RD
1585
15862005-10-19 Randy Dunlap <rdunlap@xenotime.net>
1587 Lots of typos, whitespace, some reformatting.
1da177e4
LT
1588
1589TODO:
1590
1591 Add documentation for ALSA options.
1592 Add more DRM drivers.