[PATCH] swsusp: add resume_offset command line parameter
[GitHub/LineageOS/android_kernel_motorola_exynos9610.git] / Documentation / kernel-parameters.txt
CommitLineData
0ee9d71f 1 Kernel Parameters
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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
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20This document may not be entirely up to date and comprehensive. The command
21"modinfo -p ${modulename}" shows a current list of all parameters of a loadable
22module. Loadable modules, after being loaded into the running kernel, also
23reveal their parameters in /sys/module/${modulename}/parameters/. Some of these
24parameters may be changed at runtime by the command
25"echo -n ${value} > /sys/module/${modulename}/parameters/${parm}".
26
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27The parameters listed below are only valid if certain kernel build options were
28enabled and if respective hardware is present. The text in square brackets at
29the beginning of each description states the restrictions within which a
30parameter is applicable:
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31
32 ACPI ACPI support is enabled.
33 ALSA ALSA sound support is enabled.
34 APIC APIC support is enabled.
35 APM Advanced Power Management support is enabled.
36 AX25 Appropriate AX.25 support is enabled.
37 CD Appropriate CD support is enabled.
a9913044 38 DRM Direct Rendering Management support is enabled.
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39 EDD BIOS Enhanced Disk Drive Services (EDD) is enabled
40 EFI EFI Partitioning (GPT) is enabled
41 EIDE EIDE/ATAPI support is enabled.
42 FB The frame buffer device is enabled.
43 HW Appropriate hardware is enabled.
44 IA-32 IA-32 aka i386 architecture is enabled.
45 IA-64 IA-64 architecture is enabled.
46 IOSCHED More than one I/O scheduler is enabled.
41e2e8be 47 IP_PNP IP DHCP, BOOTP, or RARP is enabled.
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48 ISAPNP ISA PnP code is enabled.
49 ISDN Appropriate ISDN support is enabled.
50 JOY Appropriate joystick support is enabled.
51 LP Printer support is enabled.
52 LOOP Loopback device support is enabled.
53 M68k M68k architecture is enabled.
54 These options have more detailed description inside of
55 Documentation/m68k/kernel-options.txt.
56 MCA MCA bus support is enabled.
57 MDA MDA console support is enabled.
58 MOUSE Appropriate mouse support is enabled.
309e57df 59 MSI Message Signaled Interrupts (PCI).
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60 MTD MTD support is enabled.
61 NET Appropriate network support is enabled.
62 NUMA NUMA support is enabled.
734efb46 63 GENERIC_TIME The generic timeofday code is enabled.
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64 NFS Appropriate NFS support is enabled.
65 OSS OSS sound support is enabled.
66 PARIDE The ParIDE subsystem is enabled.
67 PARISC The PA-RISC architecture is enabled.
68 PCI PCI bus support is enabled.
69 PCMCIA The PCMCIA subsystem is enabled.
70 PNP Plug & Play support is enabled.
71 PPC PowerPC architecture is enabled.
72 PPT Parallel port support is enabled.
73 PS2 Appropriate PS/2 support is enabled.
74 RAM RAM disk support is enabled.
75 S390 S390 architecture is enabled.
76 SCSI Appropriate SCSI support is enabled.
77 A lot of drivers has their options described inside of
78 Documentation/scsi/.
79 SELINUX SELinux support is enabled.
80 SERIAL Serial support is enabled.
81 SMP The kernel is an SMP kernel.
82 SPARC Sparc architecture is enabled.
a9913044 83 SWSUSP Software suspend is enabled.
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84 TS Appropriate touchscreen support is enabled.
85 USB USB support is enabled.
86 USBHID USB Human Interface Device support is enabled.
87 V4L Video For Linux support is enabled.
88 VGA The VGA console has been enabled.
89 VT Virtual terminal support is enabled.
90 WDT Watchdog support is enabled.
91 XT IBM PC/XT MFM hard disk support is enabled.
92 X86-64 X86-64 architecture is enabled.
93 More X86-64 boot options can be found in
94 Documentation/x86_64/boot-options.txt .
95
96In addition, the following text indicates that the option:
97
98 BUGS= Relates to possible processor bugs on the said processor.
99 KNL Is a kernel start-up parameter.
100 BOOT Is a boot loader parameter.
101
102Parameters denoted with BOOT are actually interpreted by the boot
103loader, and have no meaning to the kernel directly.
104Do not modify the syntax of boot loader parameters without extreme
105need or coordination with <Documentation/i386/boot.txt>.
106
107Note that ALL kernel parameters listed below are CASE SENSITIVE, and that
108a trailing = on the name of any parameter states that that parameter will
109be entered as an environment variable, whereas its absence indicates that
110it will appear as a kernel argument readable via /proc/cmdline by programs
111running once the system is up.
112
9c4751fd 113The number of kernel parameters is not limited, but the length of the
114complete command line (parameters including spaces etc.) is limited to
115a fixed number of characters. This limit depends on the architecture
116and is between 256 and 4096 characters. It is defined in the file
117./include/asm/setup.h as COMMAND_LINE_SIZE.
118
119
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120 53c7xx= [HW,SCSI] Amiga SCSI controllers
121 See header of drivers/scsi/53c7xx.c.
122 See also Documentation/scsi/ncr53c7xx.txt.
123
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124 acpi= [HW,ACPI] Advanced Configuration and Power Interface
125 Format: { force | off | ht | strict | noirq }
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126 force -- enable ACPI if default was off
127 off -- disable ACPI if default was on
128 noirq -- do not use ACPI for IRQ routing
129 ht -- run only enough ACPI to enable Hyper Threading
a9913044 130 strict -- Be less tolerant of platforms that are not
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131 strictly ACPI specification compliant.
132
133 See also Documentation/pm.txt, pci=noacpi
134
135 acpi_sleep= [HW,ACPI] Sleep options
136 Format: { s3_bios, s3_mode }
137 See Documentation/power/video.txt
a9913044 138
1da177e4 139 acpi_sci= [HW,ACPI] ACPI System Control Interrupt trigger mode
a9913044 140 Format: { level | edge | high | low }
1da177e4 141
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142 acpi_irq_balance [HW,ACPI]
143 ACPI will balance active IRQs
144 default in APIC mode
1da177e4 145
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146 acpi_irq_nobalance [HW,ACPI]
147 ACPI will not move active IRQs (default)
148 default in PIC mode
1da177e4 149
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150 acpi_irq_pci= [HW,ACPI] If irq_balance, clear listed IRQs for
151 use by PCI
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152 Format: <irq>,<irq>...
153
a9913044 154 acpi_irq_isa= [HW,ACPI] If irq_balance, mark listed IRQs used by ISA
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155 Format: <irq>,<irq>...
156
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157 acpi_os_name= [HW,ACPI] Tell ACPI BIOS the name of the OS
158 Format: To spoof as Windows 98: ="Microsoft Windows"
159
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160 acpi_osi= [HW,ACPI] empty param disables _OSI
161
162 acpi_serialize [HW,ACPI] force serialization of AML methods
163
164 acpi_skip_timer_override [HW,ACPI]
165 Recognize and ignore IRQ0/pin2 Interrupt Override.
166 For broken nForce2 BIOS resulting in XT-PIC timer.
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167 acpi_use_timer_override [HW,ACPI}
168 Use timer override. For some broken Nvidia NF5 boards
169 that require a timer override, but don't have
170 HPET
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171
172 acpi_dbg_layer= [HW,ACPI]
173 Format: <int>
a9913044 174 Each bit of the <int> indicates an ACPI debug layer,
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175 1: enable, 0: disable. It is useful for boot time
176 debugging. After system has booted up, it can be set
177 via /proc/acpi/debug_layer.
178
179 acpi_dbg_level= [HW,ACPI]
180 Format: <int>
a9913044 181 Each bit of the <int> indicates an ACPI debug level,
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182 1: enable, 0: disable. It is useful for boot time
183 debugging. After system has booted up, it can be set
184 via /proc/acpi/debug_level.
185
186 acpi_fake_ecdt [HW,ACPI] Workaround failure due to BIOS lacking ECDT
187
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188 acpi_generic_hotkey [HW,ACPI]
189 Allow consolidated generic hotkey driver to
a9913044 190 override platform specific driver.
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191 See also Documentation/acpi-hotkey.txt.
192
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193 acpi_pm_good [IA-32,X86-64]
194 Override the pmtimer bug detection: force the kernel
195 to assume that this machine's pmtimer latches its value
196 and always returns good values.
197
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198 enable_timer_pin_1 [i386,x86-64]
199 Enable PIN 1 of APIC timer
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200 Can be useful to work around chipset bugs
201 (in particular on some ATI chipsets).
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202 The kernel tries to set a reasonable default.
203
204 disable_timer_pin_1 [i386,x86-64]
205 Disable PIN 1 of APIC timer
206 Can be useful to work around chipset bugs.
207
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208 ad1816= [HW,OSS]
209 Format: <io>,<irq>,<dma>,<dma2>
210 See also Documentation/sound/oss/AD1816.
211
212 ad1848= [HW,OSS]
213 Format: <io>,<irq>,<dma>,<dma2>,<type>
214
215 adlib= [HW,OSS]
216 Format: <io>
a9913044 217
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218 advansys= [HW,SCSI]
219 See header of drivers/scsi/advansys.c.
220
221 advwdt= [HW,WDT] Advantech WDT
222 Format: <iostart>,<iostop>
223
224 aedsp16= [HW,OSS] Audio Excel DSP 16
225 Format: <io>,<irq>,<dma>,<mss_io>,<mpu_io>,<mpu_irq>
226 See also header of sound/oss/aedsp16.c.
a9913044 227
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228 aha152x= [HW,SCSI]
229 See Documentation/scsi/aha152x.txt.
230
231 aha1542= [HW,SCSI]
232 Format: <portbase>[,<buson>,<busoff>[,<dmaspeed>]]
233
234 aic7xxx= [HW,SCSI]
235 See Documentation/scsi/aic7xxx.txt.
236
237 aic79xx= [HW,SCSI]
238 See Documentation/scsi/aic79xx.txt.
239
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240 amijoy.map= [HW,JOY] Amiga joystick support
241 Map of devices attached to JOY0DAT and JOY1DAT
242 Format: <a>,<b>
243 See also Documentation/kernel/input/joystick.txt
244
245 analog.map= [HW,JOY] Analog joystick and gamepad support
246 Specifies type or capabilities of an analog joystick
247 connected to one of 16 gameports
248 Format: <type1>,<type2>,..<type16>
249
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250 apc= [HW,SPARC]
251 Power management functions (SPARCstation-4/5 + deriv.)
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252 Format: noidle
253 Disable APC CPU standby support. SPARCstation-Fox does
254 not play well with APC CPU idle - disable it if you have
255 APC and your system crashes randomly.
256
a9913044 257 apic= [APIC,i386] Change the output verbosity whilst booting
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258 Format: { quiet (default) | verbose | debug }
259 Change the amount of debugging information output
260 when initialising the APIC and IO-APIC components.
a9913044 261
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262 apm= [APM] Advanced Power Management
263 See header of arch/i386/kernel/apm.c.
264
265 applicom= [HW]
266 Format: <mem>,<irq>
a9913044 267
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268 arcrimi= [HW,NET] ARCnet - "RIM I" (entirely mem-mapped) cards
269 Format: <io>,<irq>,<nodeID>
270
271 ataflop= [HW,M68k]
272
273 atarimouse= [HW,MOUSE] Atari Mouse
274
275 atascsi= [HW,SCSI] Atari SCSI
276
277 atkbd.extra= [HW] Enable extra LEDs and keys on IBM RapidAccess,
278 EzKey and similar keyboards
279
280 atkbd.reset= [HW] Reset keyboard during initialization
281
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282 atkbd.set= [HW] Select keyboard code set
283 Format: <int> (2 = AT (default), 3 = PS/2)
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284
285 atkbd.scroll= [HW] Enable scroll wheel on MS Office and similar
286 keyboards
287
288 atkbd.softraw= [HW] Choose between synthetic and real raw mode
289 Format: <bool> (0 = real, 1 = synthetic (default))
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290
291 atkbd.softrepeat= [HW]
292 Use software keyboard repeat
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293
294 autotest [IA64]
295
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296 aztcd= [HW,CD] Aztech CD268 CDROM driver
297 Format: <io>,0x79 (?)
298
299 baycom_epp= [HW,AX25]
300 Format: <io>,<mode>
a9913044 301
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302 baycom_par= [HW,AX25] BayCom Parallel Port AX.25 Modem
303 Format: <io>,<mode>
304 See header of drivers/net/hamradio/baycom_par.c.
305
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306 baycom_ser_fdx= [HW,AX25]
307 BayCom Serial Port AX.25 Modem (Full Duplex Mode)
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308 Format: <io>,<irq>,<mode>[,<baud>]
309 See header of drivers/net/hamradio/baycom_ser_fdx.c.
310
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311 baycom_ser_hdx= [HW,AX25]
312 BayCom Serial Port AX.25 Modem (Half Duplex Mode)
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313 Format: <io>,<irq>,<mode>
314 See header of drivers/net/hamradio/baycom_ser_hdx.c.
315
316 blkmtd_device= [HW,MTD]
317 blkmtd_erasesz=
318 blkmtd_ro=
319 blkmtd_bs=
320 blkmtd_count=
321
322 bttv.card= [HW,V4L] bttv (bt848 + bt878 based grabber cards)
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323 bttv.radio= Most important insmod options are available as
324 kernel args too.
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325 bttv.pll= See Documentation/video4linux/bttv/Insmod-options
326 bttv.tuner= and Documentation/video4linux/bttv/CARDLIST
327
328 BusLogic= [HW,SCSI]
329 See drivers/scsi/BusLogic.c, comment before function
330 BusLogic_ParseDriverOptions().
331
332 c101= [NET] Moxa C101 synchronous serial card
333
334 cachesize= [BUGS=IA-32] Override level 2 CPU cache size detection.
335 Sometimes CPU hardware bugs make them report the cache
336 size incorrectly. The kernel will attempt work arounds
337 to fix known problems, but for some CPUs it is not
338 possible to determine what the correct size should be.
339 This option provides an override for these situations.
340
341 cdu31a= [HW,CD]
342 Format: <io>,<irq>[,PAS]
343 See header of drivers/cdrom/cdu31a.c.
344
345 chandev= [HW,NET] Generic channel device initialisation
346
347 checkreqprot [SELINUX] Set initial checkreqprot flag value.
348 Format: { "0" | "1" }
349 See security/selinux/Kconfig help text.
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350 0 -- check protection applied by kernel (includes
351 any implied execute protection).
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352 1 -- check protection requested by application.
353 Default value is set via a kernel config option.
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354 Value can be changed at runtime via
355 /selinux/checkreqprot.
356
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357 clock= [BUGS=IA-32, HW] gettimeofday clocksource override.
358 [Deprecated]
3f6dee9b 359 Forces specified clocksource (if available) to be used
734efb46 360 when calculating gettimeofday(). If specified
3f6dee9b 361 clocksource is not available, it defaults to PIT.
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362 Format: { pit | tsc | cyclone | pmtmr }
363
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364 disable_8254_timer
365 enable_8254_timer
366 [IA32/X86_64] Disable/Enable interrupt 0 timer routing
367 over the 8254 in addition to over the IO-APIC. The
368 kernel tries to set a sensible default.
369
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370 hpet= [IA-32,HPET] option to disable HPET and use PIT.
371 Format: disable
372
373 cm206= [HW,CD]
374 Format: { auto | [<io>,][<irq>] }
375
376 com20020= [HW,NET] ARCnet - COM20020 chipset
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377 Format:
378 <io>[,<irq>[,<nodeID>[,<backplane>[,<ckp>[,<timeout>]]]]]
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379
380 com90io= [HW,NET] ARCnet - COM90xx chipset (IO-mapped buffers)
381 Format: <io>[,<irq>]
382
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383 com90xx= [HW,NET]
384 ARCnet - COM90xx chipset (memory-mapped buffers)
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385 Format: <io>[,<irq>[,<memstart>]]
386
387 condev= [HW,S390] console device
388 conmode=
a9913044 389
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390 console= [KNL] Output console device and options.
391
392 tty<n> Use the virtual console device <n>.
393
394 ttyS<n>[,options]
f1a1c2dc 395 ttyUSB0[,options]
1da177e4 396 Use the specified serial port. The options are of
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397 the form "bbbbpnf", where "bbbb" is the baud rate,
398 "p" is parity ("n", "o", or "e"), "n" is number of
399 bits, and "f" is flow control ("r" for RTS or
400 omit it). Default is "9600n8".
401
402 See Documentation/serial-console.txt for more
403 information. See
404 Documentation/networking/netconsole.txt for an
405 alternative.
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406
407 uart,io,<addr>[,options]
408 uart,mmio,<addr>[,options]
409 Start an early, polled-mode console on the 8250/16550
410 UART at the specified I/O port or MMIO address,
411 switching to the matching ttyS device later. The
412 options are the same as for ttyS, above.
413
414 cpcihp_generic= [HW,PCI] Generic port I/O CompactPCI driver
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415 Format:
416 <first_slot>,<last_slot>,<port>,<enum_bit>[,<debug>]
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417
418 cpia_pp= [HW,PPT]
419 Format: { parport<nr> | auto | none }
420
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421 crashkernel=nn[KMG]@ss[KMG]
422 [KNL] Reserve a chunk of physical memory to
423 hold a kernel to switch to with kexec on panic.
424
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425 cs4232= [HW,OSS]
426 Format: <io>,<irq>,<dma>,<dma2>,<mpuio>,<mpuirq>
427
428 cs89x0_dma= [HW,NET]
429 Format: <dma>
430
431 cs89x0_media= [HW,NET]
432 Format: { rj45 | aui | bnc }
a9913044 433
1da177e4 434 cyclades= [HW,SERIAL] Cyclades multi-serial port adapter.
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435
436 dasd= [HW,NET]
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437 See header of drivers/s390/block/dasd_devmap.c.
438
439 db9.dev[2|3]= [HW,JOY] Multisystem joystick support via parallel port
440 (one device per port)
441 Format: <port#>,<type>
442 See also Documentation/input/joystick-parport.txt
443
444 debug [KNL] Enable kernel debugging (events log level).
445
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446 debug_locks_verbose=
447 [KNL] verbose self-tests
448 Format=<0|1>
449 Print debugging info while doing the locking API
450 self-tests.
451 We default to 0 (no extra messages), setting it to
452 1 will print _a lot_ more information - normally
453 only useful to kernel developers.
454
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455 decnet= [HW,NET]
456 Format: <area>[,<node>]
457 See also Documentation/networking/decnet.txt.
458
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459 dhash_entries= [KNL]
460 Set number of hash buckets for dentry cache.
a9913044 461
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462 digi= [HW,SERIAL]
463 IO parameters + enable/disable command.
464
465 digiepca= [HW,SERIAL]
466 See drivers/char/README.epca and
467 Documentation/digiepca.txt.
468
469 dmascc= [HW,AX25,SERIAL] AX.25 Z80SCC driver with DMA
470 support available.
471 Format: <io_dev0>[,<io_dev1>[,..<io_dev32>]]
472
473 dmasound= [HW,OSS] Sound subsystem buffers
474
475 dscc4.setup= [NET]
476
477 dtc3181e= [HW,SCSI]
478
a9913044 479 earlyprintk= [IA-32,X86-64]
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480 earlyprintk=vga
481 earlyprintk=serial[,ttySn[,baudrate]]
482
a9913044 483 Append ",keep" to not disable it when the real console
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484 takes over.
485
486 Only vga or serial at a time, not both.
487
488 Currently only ttyS0 and ttyS1 are supported.
489
490 Interaction with the standard serial driver is not
491 very good.
492
493 The VGA output is eventually overwritten by the real
494 console.
495
496 eata= [HW,SCSI]
497
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498 ec_intr= [HW,ACPI] ACPI Embedded Controller interrupt mode
499 Format: <int>
500 0: polling mode
501 non-0: interrupt mode (default)
502
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503 eda= [HW,PS2]
504
505 edb= [HW,PS2]
506
507 edd= [EDD]
508 Format: {"of[f]" | "sk[ipmbr]"}
509 See comment in arch/i386/boot/edd.S
510
a9913044 511 eicon= [HW,ISDN]
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512 Format: <id>,<membase>,<irq>
513
514 eisa_irq_edge= [PARISC,HW]
515 See header of drivers/parisc/eisa.c.
516
517 elanfreq= [IA-32]
518 See comment before function elanfreq_setup() in
519 arch/i386/kernel/cpu/cpufreq/elanfreq.c.
520
521 elevator= [IOSCHED]
16ab3adf 522 Format: {"anticipatory" | "cfq" | "deadline" | "noop"}
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523 See Documentation/block/as-iosched.txt and
524 Documentation/block/deadline-iosched.txt for details.
525
aac04b32 526 elfcorehdr= [IA-32, X86_64]
a9913044 527 Specifies physical address of start of kernel core
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528 image elf header. Generally kexec loader will
529 pass this option to capture kernel.
530 See Documentation/kdump/kdump.txt for details.
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531
532 enforcing [SELINUX] Set initial enforcing status.
533 Format: {"0" | "1"}
534 See security/selinux/Kconfig help text.
535 0 -- permissive (log only, no denials).
536 1 -- enforcing (deny and log).
537 Default value is 0.
538 Value can be changed at runtime via /selinux/enforce.
539
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540 es1371= [HW,OSS]
541 Format: <spdif>,[<nomix>,[<amplifier>]]
542 See also header of sound/oss/es1371.c.
a9913044 543
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544 ether= [HW,NET] Ethernet cards parameters
545 This option is obsoleted by the "netdev=" option, which
546 has equivalent usage. See its documentation for details.
547
548 eurwdt= [HW,WDT] Eurotech CPU-1220/1410 onboard watchdog.
549 Format: <io>[,<irq>]
550
551 fd_mcs= [HW,SCSI]
552 See header of drivers/scsi/fd_mcs.c.
553
554 fdomain= [HW,SCSI]
555 See header of drivers/scsi/fdomain.c.
556
557 floppy= [HW]
558 See Documentation/floppy.txt.
559
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560 gamecon.map[2|3]=
561 [HW,JOY] Multisystem joystick and NES/SNES/PSX pad
562 support via parallel port (up to 5 devices per port)
563 Format: <port#>,<pad1>,<pad2>,<pad3>,<pad4>,<pad5>
564 See also Documentation/input/joystick-parport.txt
565
566 gamma= [HW,DRM]
567
568 gdth= [HW,SCSI]
569 See header of drivers/scsi/gdth.c.
570
571 gpt [EFI] Forces disk with valid GPT signature but
572 invalid Protective MBR to be treated as GPT.
573
574 gscd= [HW,CD]
575 Format: <io>
576
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577 gvp11= [HW,SCSI]
578
579 hashdist= [KNL,NUMA] Large hashes allocated during boot
580 are distributed across NUMA nodes. Defaults on
581 for IA-64, off otherwise.
a9913044 582 Format: 0 | 1 (for off | on)
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583
584 hcl= [IA-64] SGI's Hardware Graph compatibility layer
585
586 hd= [EIDE] (E)IDE hard drive subsystem geometry
587 Format: <cyl>,<head>,<sect>
588
589 hd?= [HW] (E)IDE subsystem
590 hd?lun= See Documentation/ide.txt.
591
592 highmem=nn[KMG] [KNL,BOOT] forces the highmem zone to have an exact
593 size of <nn>. This works even on boxes that have no
594 highmem otherwise. This also works to reduce highmem
595 size on bigger boxes.
596
597 hisax= [HW,ISDN]
598 See Documentation/isdn/README.HiSax.
599
600 hugepages= [HW,IA-32,IA-64] Maximal number of HugeTLB pages.
601
602 noirqbalance [IA-32,SMP,KNL] Disable kernel irq balancing
603
604 i8042.direct [HW] Put keyboard port into non-translated mode
84eb8d06
ML
605 i8042.dumbkbd [HW] Pretend that controller can only read data from
606 keyboard and cannot control its state
1da177e4
LT
607 (Don't attempt to blink the leds)
608 i8042.noaux [HW] Don't check for auxiliary (== mouse) port
945ef0d4 609 i8042.nokbd [HW] Don't check/create keyboard port
1da177e4
LT
610 i8042.nomux [HW] Don't check presence of an active multiplexing
611 controller
612 i8042.nopnp [HW] Don't use ACPIPnP / PnPBIOS to discover KBD/AUX
613 controllers
614 i8042.panicblink=
615 [HW] Frequency with which keyboard LEDs should blink
616 when kernel panics (default is 0.5 sec)
617 i8042.reset [HW] Reset the controller during init and cleanup
618 i8042.unlock [HW] Unlock (ignore) the keylock
619
620 i810= [HW,DRM]
621
e70c9d5e
DT
622 i8k.ignore_dmi [HW] Continue probing hardware even if DMI data
623 indicates that the driver is running on unsupported
624 hardware.
1da177e4
LT
625 i8k.force [HW] Activate i8k driver even if SMM BIOS signature
626 does not match list of supported models.
627 i8k.power_status
628 [HW] Report power status in /proc/i8k
629 (disabled by default)
630 i8k.restricted [HW] Allow controlling fans only if SYS_ADMIN
631 capability is set.
632
633 ibmmcascsi= [HW,MCA,SCSI] IBM MicroChannel SCSI adapter
634 See Documentation/mca.txt.
635
636 icn= [HW,ISDN]
637 Format: <io>[,<membase>[,<icn_id>[,<icn_id2>]]]
638
639 ide= [HW] (E)IDE subsystem
640 Format: ide=nodma or ide=doubler or ide=reverse
641 See Documentation/ide.txt.
642
643 ide?= [HW] (E)IDE subsystem
644 Format: ide?=noprobe or chipset specific parameters.
645 See Documentation/ide.txt.
a9913044 646
1da177e4
LT
647 idebus= [HW] (E)IDE subsystem - VLB/PCI bus speed
648 See Documentation/ide.txt.
649
650 idle= [HW]
651 Format: idle=poll or idle=halt
a9913044 652
1da177e4
LT
653 ihash_entries= [KNL]
654 Set number of hash buckets for inode cache.
655
656 in2000= [HW,SCSI]
657 See header of drivers/scsi/in2000.c.
658
659 init= [KNL]
660 Format: <full_path>
661 Run specified binary instead of /sbin/init as init
662 process.
663
664 initcall_debug [KNL] Trace initcalls as they are executed. Useful
665 for working out where the kernel is dying during
666 startup.
667
668 initrd= [BOOT] Specify the location of the initial ramdisk
669
670 inport.irq= [HW] Inport (ATI XL and Microsoft) busmouse driver
671 Format: <irq>
672
2bd0fa3b
JB
673 combined_mode= [HW] control which driver uses IDE ports in combined
674 mode: legacy IDE driver, libata, or both
675 (in the libata case, libata.atapi_enabled=1 may be
676 useful as well). Note that using the ide or libata
677 options may affect your device naming (e.g. by
678 changing hdc to sdb).
679 Format: combined (default), ide, or libata
680
1da177e4
LT
681 inttest= [IA64]
682
683 io7= [HW] IO7 for Marvel based alpha systems
684 See comment before marvel_specify_io7 in
685 arch/alpha/kernel/core_marvel.c.
686
687 ip= [IP_PNP]
688 See Documentation/nfsroot.txt.
689
690 ip2= [HW] Set IO/IRQ pairs for up to 4 IntelliPort boards
691 See comment before ip2_setup() in drivers/char/ip2.c.
692
693 ips= [HW,SCSI] Adaptec / IBM ServeRAID controller
694 See header of drivers/scsi/ips.c.
695
72c4a13a
SH
696 ports= [IP_VS_FTP] IPVS ftp helper module
697 Default is 21.
698 Up to 8 (IP_VS_APP_MAX_PORTS) ports
699 may be specified.
700 Format: <port>,<port>....
701
200803df
AC
702 irqfixup [HW]
703 When an interrupt is not handled search all handlers
704 for it. Intended to get systems with badly broken
705 firmware running.
706
707 irqpoll [HW]
708 When an interrupt is not handled search all handlers
709 for it. Also check all handlers each timer
710 interrupt. Intended to get systems with badly broken
711 firmware running.
712
1da177e4 713 isapnp= [ISAPNP]
a9913044 714 Format: <RDP>,<reset>,<pci_scan>,<verbosity>
1da177e4
LT
715
716 isolcpus= [KNL,SMP] Isolate CPUs from the general scheduler.
717 Format: <cpu number>,...,<cpu number>
718 This option can be used to specify one or more CPUs
719 to isolate from the general SMP balancing and scheduling
720 algorithms. The only way to move a process onto or off
721 an "isolated" CPU is via the CPU affinity syscalls.
722 <cpu number> begins at 0 and the maximum value is
723 "number of CPUs in system - 1".
724
725 This option is the preferred way to isolate CPUs. The
a9913044
RD
726 alternative -- manually setting the CPU mask of all
727 tasks in the system -- can cause problems and
728 suboptimal load balancer performance.
1da177e4
LT
729
730 isp16= [HW,CD]
731 Format: <io>,<irq>,<dma>,<setup>
732
a9913044 733 iucv= [HW,NET]
1da177e4
LT
734
735 js= [HW,JOY] Analog joystick
736 See Documentation/input/joystick.txt.
737
738 keepinitrd [HW,ARM]
739
a9913044 740 kstack=N [IA-32,X86-64] Print N words from the kernel stack
1da177e4
LT
741 in oops dumps.
742
743 l2cr= [PPC]
744
a9913044
RD
745 lapic [IA-32,APIC] Enable the local APIC even if BIOS
746 disabled it.
1da177e4
LT
747
748 lasi= [HW,SCSI] PARISC LASI driver for the 53c700 chip
749 Format: addr:<io>,irq:<irq>
750
a9913044
RD
751 llsc*= [IA64] See function print_params() in
752 arch/ia64/sn/kernel/llsc4.c.
1da177e4
LT
753
754 load_ramdisk= [RAM] List of ramdisks to load from floppy
755 See Documentation/ramdisk.txt.
756
a6b25b67
RD
757 lockd.nlm_grace_period=P [NFS] Assign grace period.
758 Format: <integer>
1da177e4 759
a6b25b67
RD
760 lockd.nlm_tcpport=N [NFS] Assign TCP port.
761 Format: <integer>
762
763 lockd.nlm_timeout=T [NFS] Assign timeout value.
764 Format: <integer>
765
766 lockd.nlm_udpport=M [NFS] Assign UDP port.
767 Format: <integer>
1da177e4
LT
768
769 logibm.irq= [HW,MOUSE] Logitech Bus Mouse Driver
770 Format: <irq>
771
772 loglevel= All Kernel Messages with a loglevel smaller than the
773 console loglevel will be printed to the console. It can
774 also be changed with klogd or other programs. The
775 loglevels are defined as follows:
776
777 0 (KERN_EMERG) system is unusable
778 1 (KERN_ALERT) action must be taken immediately
779 2 (KERN_CRIT) critical conditions
780 3 (KERN_ERR) error conditions
781 4 (KERN_WARNING) warning conditions
782 5 (KERN_NOTICE) normal but significant condition
783 6 (KERN_INFO) informational
784 7 (KERN_DEBUG) debug-level messages
785
786 log_buf_len=n Sets the size of the printk ring buffer, in bytes.
a9913044
RD
787 Format: { n | nk | nM }
788 n must be a power of two. The default size
789 is set in the kernel config file.
1da177e4
LT
790
791 lp=0 [LP] Specify parallel ports to use, e.g,
792 lp=port[,port...] lp=none,parport0 (lp0 not configured, lp1 uses
793 lp=reset first parallel port). 'lp=0' disables the
794 lp=auto printer driver. 'lp=reset' (which can be
795 specified in addition to the ports) causes
796 attached printers to be reset. Using
797 lp=port1,port2,... specifies the parallel ports
798 to associate lp devices with, starting with
799 lp0. A port specification may be 'none' to skip
800 that lp device, or a parport name such as
801 'parport0'. Specifying 'lp=auto' instead of a
802 port specification list means that device IDs
803 from each port should be examined, to see if
804 an IEEE 1284-compliant printer is attached; if
805 so, the driver will manage that printer.
806 See also header of drivers/char/lp.c.
807
808 lpj=n [KNL]
809 Sets loops_per_jiffy to given constant, thus avoiding
810 time-consuming boot-time autodetection (up to 250 ms per
811 CPU). 0 enables autodetection (default). To determine
812 the correct value for your kernel, boot with normal
813 autodetection and see what value is printed. Note that
814 on SMP systems the preset will be applied to all CPUs,
815 which is likely to cause problems if your CPUs need
816 significantly divergent settings. An incorrect value
817 will cause delays in the kernel to be wrong, leading to
818 unpredictable I/O errors and other breakage. Although
819 unlikely, in the extreme case this might damage your
820 hardware.
821
822 ltpc= [NET]
823 Format: <io>,<irq>,<dma>
824
a9913044
RD
825 mac5380= [HW,SCSI] Format:
826 <can_queue>,<cmd_per_lun>,<sg_tablesize>,<hostid>,<use_tags>
1da177e4 827
a9913044
RD
828 mac53c9x= [HW,SCSI] Format:
829 <num_esps>,<disconnect>,<nosync>,<can_queue>,<cmd_per_lun>,<sg_tablesize>,<hostid>,<use_tags>
1da177e4 830
a9913044
RD
831 machvec= [IA64] Force the use of a particular machine-vector
832 (machvec) in a generic kernel.
833 Example: machvec=hpzx1_swiotlb
1da177e4 834
a9913044 835 max_loop= [LOOP] Maximum number of loopback devices that can
1da177e4
LT
836 be mounted
837 Format: <1-256>
838
839 maxcpus= [SMP] Maximum number of processors that an SMP kernel
840 should make use of
841
2b2c3750
BP
842 max_addr=[KMG] [KNL,BOOT,ia64] All physical memory greater than or
843 equal to this physical address is ignored.
844
a9913044 845 max_luns= [SCSI] Maximum number of LUNs to probe.
1da177e4
LT
846 Should be between 1 and 2^32-1.
847
848 max_report_luns=
a9913044 849 [SCSI] Maximum number of LUNs received.
1da177e4
LT
850 Should be between 1 and 16384.
851
852 mca-pentium [BUGS=IA-32]
853
854 mcatest= [IA-64]
855
856 mcd= [HW,CD]
857 Format: <port>,<irq>,<mitsumi_bug_93_wait>
858
859 mcdx= [HW,CD]
860
861 mce [IA-32] Machine Check Exception
862
863 md= [HW] RAID subsystems devices and level
864 See Documentation/md.txt.
a9913044 865
1da177e4
LT
866 mdacon= [MDA]
867 Format: <first>,<last>
868 Specifies range of consoles to be captured by the MDA.
a9913044 869
1da177e4
LT
870 mem=nn[KMG] [KNL,BOOT] Force usage of a specific amount of memory
871 Amount of memory to be used when the kernel is not able
872 to see the whole system memory or for test.
873 [IA-32] Use together with memmap= to avoid physical
874 address space collisions. Without memmap= PCI devices
875 could be placed at addresses belonging to unused RAM.
876
877 mem=nopentium [BUGS=IA-32] Disable usage of 4MB pages for kernel
878 memory.
879
69cda7b1 880 memmap=exactmap [KNL,IA-32,X86_64] Enable setting of an exact
1da177e4
LT
881 E820 memory map, as specified by the user.
882 Such memmap=exactmap lines can be constructed based on
883 BIOS output or other requirements. See the memmap=nn@ss
884 option description.
885
886 memmap=nn[KMG]@ss[KMG]
887 [KNL] Force usage of a specific region of memory
888 Region of memory to be used, from ss to ss+nn.
889
890 memmap=nn[KMG]#ss[KMG]
891 [KNL,ACPI] Mark specific memory as ACPI data.
892 Region of memory to be used, from ss to ss+nn.
893
894 memmap=nn[KMG]$ss[KMG]
895 [KNL,ACPI] Mark specific memory as reserved.
896 Region of memory to be used, from ss to ss+nn.
897
898 meye.*= [HW] Set MotionEye Camera parameters
899 See Documentation/video4linux/meye.txt.
900
901 mga= [HW,DRM]
902
198e2f18 903 migration_cost=
904 [KNL,SMP] debug: override scheduler migration costs
905 Format: <level-1-usecs>,<level-2-usecs>,...
906 This debugging option can be used to override the
907 default scheduler migration cost matrix. The numbers
908 are indexed by 'CPU domain distance'.
909 E.g. migration_cost=1000,2000,3000 on an SMT NUMA
910 box will set up an intra-core migration cost of
911 1 msec, an inter-core migration cost of 2 msecs,
912 and an inter-node migration cost of 3 msecs.
913
914 WARNING: using the wrong values here can break
915 scheduler performance, so it's only for scheduler
916 development purposes, not production environments.
917
918 migration_debug=
919 [KNL,SMP] migration cost auto-detect verbosity
920 Format=<0|1|2>
921 If a system's migration matrix reported at bootup
922 seems erroneous then this option can be used to
923 increase verbosity of the detection process.
924 We default to 0 (no extra messages), 1 will print
925 some more information, and 2 will be really
926 verbose (probably only useful if you also have a
927 serial console attached to the system).
928
929 migration_factor=
930 [KNL,SMP] multiply/divide migration costs by a factor
931 Format=<percent>
932 This debug option can be used to proportionally
933 increase or decrease the auto-detected migration
934 costs for all entries of the migration matrix.
935 E.g. migration_factor=150 will increase migration
936 costs by 50%. (and thus the scheduler will be less
937 eager migrating cache-hot tasks)
938 migration_factor=80 will decrease migration costs
939 by 20%. (thus the scheduler will be more eager to
940 migrate tasks)
941
942 WARNING: using the wrong values here can break
943 scheduler performance, so it's only for scheduler
944 development purposes, not production environments.
945
1da177e4
LT
946 mousedev.tap_time=
947 [MOUSE] Maximum time between finger touching and
948 leaving touchpad surface for touch to be considered
949 a tap and be reported as a left button click (for
950 touchpads working in absolute mode only).
951 Format: <msecs>
952 mousedev.xres= [MOUSE] Horizontal screen resolution, used for devices
953 reporting absolute coordinates, such as tablets
954 mousedev.yres= [MOUSE] Vertical screen resolution, used for devices
955 reporting absolute coordinates, such as tablets
956
957 mpu401= [HW,OSS]
958 Format: <io>,<irq>
959
960 MTD_Partition= [MTD]
961 Format: <name>,<region-number>,<size>,<offset>
962
a9913044
RD
963 MTD_Region= [MTD] Format:
964 <name>,<region-number>[,<base>,<size>,<buswidth>,<altbuswidth>]
1da177e4
LT
965
966 mtdparts= [MTD]
967 See drivers/mtd/cmdline.c.
968
969 mtouchusb.raw_coordinates=
a9913044
RD
970 [HW] Make the MicroTouch USB driver use raw coordinates
971 ('y', default) or cooked coordinates ('n')
1da177e4
LT
972
973 n2= [NET] SDL Inc. RISCom/N2 synchronous serial card
974
975 NCR_D700= [HW,SCSI]
976 See header of drivers/scsi/NCR_D700.c.
977
978 ncr5380= [HW,SCSI]
979
980 ncr53c400= [HW,SCSI]
981
982 ncr53c400a= [HW,SCSI]
983
984 ncr53c406a= [HW,SCSI]
985
986 ncr53c8xx= [HW,SCSI]
987
988 netdev= [NET] Network devices parameters
989 Format: <irq>,<io>,<mem_start>,<mem_end>,<name>
990 Note that mem_start is often overloaded to mean
991 something different and driver-specific.
a9913044
RD
992 This usage is only documented in each driver source
993 file if at all.
994
1da177e4
LT
995 nfsaddrs= [NFS]
996 See Documentation/nfsroot.txt.
997
998 nfsroot= [NFS] nfs root filesystem for disk-less boxes.
999 See Documentation/nfsroot.txt.
1000
a72b4422
TM
1001 nfs.callback_tcpport=
1002 [NFS] set the TCP port on which the NFSv4 callback
1003 channel should listen.
1004
58df095b
TM
1005 nfs.idmap_cache_timeout=
1006 [NFS] set the maximum lifetime for idmapper cache
1007 entries.
1008
1da177e4
LT
1009 nmi_watchdog= [KNL,BUGS=IA-32] Debugging features for SMP kernels
1010
1011 no387 [BUGS=IA-32] Tells the kernel to use the 387 maths
1012 emulation library even if a 387 maths coprocessor
1013 is present.
1014
3395ee05
PM
1015 noaliencache [MM, NUMA] Disables the allcoation of alien caches in
1016 the slab allocator. Saves per-node memory, but will
1017 impact performance on real NUMA hardware.
1018
a9913044
RD
1019 noalign [KNL,ARM]
1020
1da177e4
LT
1021 noapic [SMP,APIC] Tells the kernel to not make use of any
1022 IOAPICs that may be present in the system.
1023
1024 noasync [HW,M68K] Disables async and sync negotiation for
1025 all devices.
1026
1027 nobats [PPC] Do not use BATs for mapping kernel lowmem
1028 on "Classic" PPC cores.
1029
1030 nocache [ARM]
a9913044 1031
163ecdff
SN
1032 nodelayacct [KNL] Disable per-task delay accounting
1033
1da177e4
LT
1034 nodisconnect [HW,SCSI,M68K] Disables SCSI disconnects.
1035
1036 noexec [IA-64]
1037
a9913044 1038 noexec [IA-32,X86-64]
1da177e4
LT
1039 noexec=on: enable non-executable mappings (default)
1040 noexec=off: disable nn-executable mappings
1041
4f886511
CE
1042 nofxsr [BUGS=IA-32] Disables x86 floating point extended
1043 register save and restore. The kernel will only save
1044 legacy floating-point registers on task switch.
1da177e4
LT
1045
1046 nohlt [BUGS=ARM]
a9913044 1047
1da177e4
LT
1048 no-hlt [BUGS=IA-32] Tells the kernel that the hlt
1049 instruction doesn't work correctly and not to
1050 use it.
1051
1052 nohalt [IA-64] Tells the kernel not to use the power saving
1053 function PAL_HALT_LIGHT when idle. This increases
1054 power-consumption. On the positive side, it reduces
1055 interrupt wake-up latency, which may improve performance
1056 in certain environments such as networked servers or
1057 real-time systems.
1058
1059 noirqdebug [IA-32] Disables the code which attempts to detect and
1060 disable unhandled interrupt sources.
1061
1062 noisapnp [ISAPNP] Disables ISA PnP code.
1063
1064 noinitrd [RAM] Tells the kernel not to load any configured
1065 initial RAM disk.
1066
1067 nointroute [IA-64]
1068
1069 nolapic [IA-32,APIC] Do not enable or use the local APIC.
1070
1071 noltlbs [PPC] Do not use large page/tlb entries for kernel
1072 lowmem mapping on PPC40x.
1073
312f1f01
H
1074 nomca [IA-64] Disable machine check abort handling
1075
abe37e5a
H
1076 nomce [IA-32] Machine Check Exception
1077
1da177e4
LT
1078 noresidual [PPC] Don't use residual data on PReP machines.
1079
a9913044
RD
1080 noresume [SWSUSP] Disables resume and restores original swap
1081 space.
1082
1da177e4
LT
1083 no-scroll [VGA] Disables scrollback.
1084 This is required for the Braillex ib80-piezo Braille
1085 reader made by F.H. Papenmeier (Germany).
1086
1087 nosbagart [IA-64]
1088
4f886511
CE
1089 nosep [BUGS=IA-32] Disables x86 SYSENTER/SYSEXIT support.
1090
1da177e4
LT
1091 nosmp [SMP] Tells an SMP kernel to act as a UP kernel.
1092
1093 nosync [HW,M68K] Disables sync negotiation for all devices.
1094
1095 notsc [BUGS=IA-32] Disable Time Stamp Counter
1096
1097 nousb [USB] Disable the USB subsystem
1098
1099 nowb [ARM]
a9913044 1100
a61c2d78
DJ
1101 nr_uarts= [SERIAL] maximum number of UARTs to be registered.
1102
1da177e4
LT
1103 opl3= [HW,OSS]
1104 Format: <io>
1105
a9913044
RD
1106 opl3sa2= [HW,OSS] Format:
1107 <io>,<irq>,<dma>,<dma2>,<mss_io>,<mpu_io>,<ymode>,<loopback>[,<isapnp>,<multiple]
1108
1da177e4
LT
1109 oprofile.timer= [HW]
1110 Use timer interrupt instead of performance counters
1111
1112 optcd= [HW,CD]
1113 Format: <io>
1114
1115 osst= [HW,SCSI] SCSI Tape Driver
1116 Format: <buffer_size>,<write_threshold>
1117 See also Documentation/scsi/st.txt.
1118
1119 panic= [KNL] Kernel behaviour on panic
1120 Format: <timeout>
1121
1122 parkbd.port= [HW] Parallel port number the keyboard adapter is
1123 connected to, default is 0.
1124 Format: <parport#>
1125 parkbd.mode= [HW] Parallel port keyboard adapter mode of operation,
1126 0 for XT, 1 for AT (default is AT).
a9913044
RD
1127 Format: <mode>
1128
1129 parport= [HW,PPT] Specify parallel ports. 0 disables.
1130 Format: { 0 | auto | 0xBBB[,IRQ[,DMA]] }
1131 Use 'auto' to force the driver to use any
1132 IRQ/DMA settings detected (the default is to
1133 ignore detected IRQ/DMA settings because of
1134 possible conflicts). You can specify the base
1135 address, IRQ, and DMA settings; IRQ and DMA
1136 should be numbers, or 'auto' (for using detected
1137 settings on that particular port), or 'nofifo'
1138 (to avoid using a FIFO even if it is detected).
1139 Parallel ports are assigned in the order they
1140 are specified on the command line, starting
1141 with parport0.
1142
1143 parport_init_mode= [HW,PPT]
1144 Configure VIA parallel port to operate in
1145 a specific mode. This is necessary on Pegasos
1146 computer where firmware has no options for setting
1147 up parallel port mode and sets it to spp.
1148 Currently this function knows 686a and 8231 chips.
1da177e4
LT
1149 Format: [spp|ps2|epp|ecp|ecpepp]
1150
a9913044
RD
1151 pas2= [HW,OSS] Format:
1152 <io>,<irq>,<dma>,<dma16>,<sb_io>,<sb_irq>,<sb_dma>,<sb_dma16>
1153
1da177e4
LT
1154 pas16= [HW,SCSI]
1155 See header of drivers/scsi/pas16.c.
1156
dd287796
AM
1157 pause_on_oops=
1158 Halt all CPUs after the first oops has been printed for
1159 the specified number of seconds. This is to be used if
1160 your oopses keep scrolling off the screen.
1161
1da177e4
LT
1162 pcbit= [HW,ISDN]
1163
1164 pcd. [PARIDE]
1165 See header of drivers/block/paride/pcd.c.
1166 See also Documentation/paride.txt.
1167
a9913044
RD
1168 pci=option[,option...] [PCI] various PCI subsystem options:
1169 off [IA-32] don't probe for the PCI bus
1170 bios [IA-32] force use of PCI BIOS, don't access
1171 the hardware directly. Use this if your machine
1172 has a non-standard PCI host bridge.
1173 nobios [IA-32] disallow use of PCI BIOS, only direct
1174 hardware access methods are allowed. Use this
1175 if you experience crashes upon bootup and you
1176 suspect they are caused by the BIOS.
1177 conf1 [IA-32] Force use of PCI Configuration
1178 Mechanism 1.
1179 conf2 [IA-32] Force use of PCI Configuration
1180 Mechanism 2.
61be6d66
BH
1181 nommconf [IA-32,X86_64] Disable use of MMCONFIG for PCI
1182 Configuration
309e57df
MW
1183 nomsi [MSI] If the PCI_MSI kernel config parameter is
1184 enabled, this kernel boot option can be used to
1185 disable the use of MSI interrupts system-wide.
a9913044
RD
1186 nosort [IA-32] Don't sort PCI devices according to
1187 order given by the PCI BIOS. This sorting is
1188 done to get a device order compatible with
1189 older kernels.
1190 biosirq [IA-32] Use PCI BIOS calls to get the interrupt
1191 routing table. These calls are known to be buggy
1192 on several machines and they hang the machine
1193 when used, but on other computers it's the only
1194 way to get the interrupt routing table. Try
1195 this option if the kernel is unable to allocate
1196 IRQs or discover secondary PCI buses on your
1197 motherboard.
1198 rom [IA-32] Assign address space to expansion ROMs.
1199 Use with caution as certain devices share
1200 address decoders between ROMs and other
1201 resources.
1202 irqmask=0xMMMM [IA-32] Set a bit mask of IRQs allowed to be
1203 assigned automatically to PCI devices. You can
1204 make the kernel exclude IRQs of your ISA cards
1205 this way.
120bb424 1206 pirqaddr=0xAAAAA [IA-32] Specify the physical address
a9913044
RD
1207 of the PIRQ table (normally generated
1208 by the BIOS) if it is outside the
1209 F0000h-100000h range.
1210 lastbus=N [IA-32] Scan all buses thru bus #N. Can be
1211 useful if the kernel is unable to find your
1212 secondary buses and you want to tell it
1213 explicitly which ones they are.
1214 assign-busses [IA-32] Always assign all PCI bus
1215 numbers ourselves, overriding
1216 whatever the firmware may have done.
1217 usepirqmask [IA-32] Honor the possible IRQ mask stored
1218 in the BIOS $PIR table. This is needed on
1219 some systems with broken BIOSes, notably
1220 some HP Pavilion N5400 and Omnibook XE3
1221 notebooks. This will have no effect if ACPI
1222 IRQ routing is enabled.
1223 noacpi [IA-32] Do not use ACPI for IRQ routing
1224 or for PCI scanning.
1225 routeirq Do IRQ routing for all PCI devices.
1226 This is normally done in pci_enable_device(),
1227 so this option is a temporary workaround
1228 for broken drivers that don't call it.
1229 firmware [ARM] Do not re-enumerate the bus but instead
1230 just use the configuration from the
1231 bootloader. This is currently used on
1232 IXP2000 systems where the bus has to be
1233 configured a certain way for adjunct CPUs.
0637a70a
AK
1234 noearly [X86] Don't do any early type 1 scanning.
1235 This might help on some broken boards which
1236 machine check when some devices' config space
1237 is read. But various workarounds are disabled
1238 and some IOMMU drivers will not work.
6b4b78fe
MD
1239 bfsort Sort PCI devices into breadth-first order.
1240 This sorting is done to get a device
1241 order compatible with older (<= 2.4) kernels.
1242 nobfsort Don't sort PCI devices into breadth-first order.
1243
1da177e4
LT
1244 pcmv= [HW,PCMCIA] BadgePAD 4
1245
1246 pd. [PARIDE]
1247 See Documentation/paride.txt.
1248
1249 pdcchassis= [PARISC,HW] Disable/Enable PDC Chassis Status codes at
1250 boot time.
1251 Format: { 0 | 1 }
1252 See arch/parisc/kernel/pdc_chassis.c
1253
1254 pf. [PARIDE]
1255 See Documentation/paride.txt.
1256
1257 pg. [PARIDE]
1258 See Documentation/paride.txt.
1259
1260 pirq= [SMP,APIC] Manual mp-table setup
1261 See Documentation/i386/IO-APIC.txt.
1262
1263 plip= [PPT,NET] Parallel port network link
1264 Format: { parport<nr> | timid | 0 }
1265 See also Documentation/parport.txt.
1266
1267 pnpacpi= [ACPI]
1268 { off }
1269
1270 pnpbios= [ISAPNP]
1271 { on | off | curr | res | no-curr | no-res }
1272
1273 pnp_reserve_irq=
1274 [ISAPNP] Exclude IRQs for the autoconfiguration
1275
1276 pnp_reserve_dma=
1277 [ISAPNP] Exclude DMAs for the autoconfiguration
1278
1279 pnp_reserve_io= [ISAPNP] Exclude I/O ports for the autoconfiguration
a9913044 1280 Ranges are in pairs (I/O port base and size).
1da177e4
LT
1281
1282 pnp_reserve_mem=
a9913044
RD
1283 [ISAPNP] Exclude memory regions for the
1284 autoconfiguration.
1da177e4
LT
1285 Ranges are in pairs (memory base and size).
1286
1287 profile= [KNL] Enable kernel profiling via /proc/profile
a9913044
RD
1288 Format: [schedule,]<number>
1289 Param: "schedule" - profile schedule points.
1290 Param: <number> - step/bucket size as a power of 2 for
1291 statistical time based profiling.
1da177e4 1292
a9913044 1293 processor.max_cstate= [HW,ACPI]
1da177e4
LT
1294 Limit processor to maximum C-state
1295 max_cstate=9 overrides any DMI blacklist limit.
1296
41c0d868
LB
1297 processor.nocst [HW,ACPI]
1298 Ignore the _CST method to determine C-states,
1299 instead using the legacy FADT method
1300
1da177e4
LT
1301 prompt_ramdisk= [RAM] List of RAM disks to prompt for floppy disk
1302 before loading.
1303 See Documentation/ramdisk.txt.
1304
a9913044
RD
1305 psmouse.proto= [HW,MOUSE] Highest PS2 mouse protocol extension to
1306 probe for; one of (bare|imps|exps|lifebook|any).
1da177e4
LT
1307 psmouse.rate= [HW,MOUSE] Set desired mouse report rate, in reports
1308 per second.
a9913044
RD
1309 psmouse.resetafter= [HW,MOUSE]
1310 Try to reset the device after so many bad packets
1da177e4
LT
1311 (0 = never).
1312 psmouse.resolution=
1313 [HW,MOUSE] Set desired mouse resolution, in dpi.
1314 psmouse.smartscroll=
a9913044 1315 [HW,MOUSE] Controls Logitech smartscroll autorepeat.
1da177e4
LT
1316 0 = disabled, 1 = enabled (default).
1317
1318 pss= [HW,OSS] Personal Sound System (ECHO ESC614)
a9913044
RD
1319 Format:
1320 <io>,<mss_io>,<mss_irq>,<mss_dma>,<mpu_io>,<mpu_irq>
1da177e4
LT
1321
1322 pt. [PARIDE]
1323 See Documentation/paride.txt.
1324
7d2c502f 1325 quiet [KNL] Disable most log messages
a9913044 1326
1da177e4
LT
1327 r128= [HW,DRM]
1328
1329 raid= [HW,RAID]
1330 See Documentation/md.txt.
1331
1332 ramdisk= [RAM] Sizes of RAM disks in kilobytes [deprecated]
1333 See Documentation/ramdisk.txt.
1334
a9913044 1335 ramdisk_blocksize= [RAM]
1da177e4 1336 See Documentation/ramdisk.txt.
a9913044 1337
1da177e4
LT
1338 ramdisk_size= [RAM] Sizes of RAM disks in kilobytes
1339 New name for the ramdisk parameter.
1340 See Documentation/ramdisk.txt.
1341
21a1ea9e
DS
1342 rcu.blimit= [KNL,BOOT] Set maximum number of finished
1343 RCU callbacks to process in one batch.
1344
1345 rcu.qhimark= [KNL,BOOT] Set threshold of queued
1346 RCU callbacks over which batch limiting is disabled.
1347
1348 rcu.qlowmark= [KNL,BOOT] Set threshold of queued
1349 RCU callbacks below which batch limiting is re-enabled.
1350
ffdfc409
OJ
1351 rdinit= [KNL]
1352 Format: <full_path>
1353 Run specified binary instead of /init from the ramdisk,
1354 used for early userspace startup. See initrd.
1355
1da177e4
LT
1356 reboot= [BUGS=IA-32,BUGS=ARM,BUGS=IA-64] Rebooting mode
1357 Format: <reboot_mode>[,<reboot_mode2>[,...]]
f3e299fe 1358 See arch/*/kernel/reboot.c or arch/*/kernel/process.c
1da177e4
LT
1359
1360 reserve= [KNL,BUGS] Force the kernel to ignore some iomem area
1361
461a9aff
ZA
1362 reservetop= [IA-32]
1363 Format: nn[KMG]
1364 Reserves a hole at the top of the kernel virtual
1365 address space.
1366
7e96287d
VG
1367 reset_devices [KNL] Force drivers to reset the underlying device
1368 during initialization.
1369
a9913044
RD
1370 resume= [SWSUSP]
1371 Specify the partition device for software suspend
1da177e4
LT
1372
1373 rhash_entries= [KNL,NET]
1374 Set number of hash buckets for route cache
1375
1376 riscom8= [HW,SERIAL]
1377 Format: <io_board1>[,<io_board2>[,...<io_boardN>]]
1378
1379 ro [KNL] Mount root device read-only on boot
1380
1381 root= [KNL] Root filesystem
1382
1383 rootdelay= [KNL] Delay (in seconds) to pause before attempting to
1384 mount the root filesystem
1385
1386 rootflags= [KNL] Set root filesystem mount option string
1387
1388 rootfstype= [KNL] Set root filesystem type
1389
1390 rw [KNL] Mount root device read-write on boot
1391
1392 S [KNL] Run init in single mode
1393
1394 sa1100ir [NET]
1395 See drivers/net/irda/sa1100_ir.c.
1396
1397 sb= [HW,OSS]
1398 Format: <io>,<irq>,<dma>,<dma2>
1399
1400 sbni= [NET] Granch SBNI12 leased line adapter
a9913044 1401
1da177e4
LT
1402 sbpcd= [HW,CD] Soundblaster CD adapter
1403 Format: <io>,<type>
1404 See a comment before function sbpcd_setup() in
1405 drivers/cdrom/sbpcd.c.
1406
1407 sc1200wdt= [HW,WDT] SC1200 WDT (watchdog) driver
1408 Format: <io>[,<timeout>[,<isapnp>]]
1409
1410 scsi_debug_*= [SCSI]
1411 See drivers/scsi/scsi_debug.c.
1412
1413 scsi_default_dev_flags=
1414 [SCSI] SCSI default device flags
1415 Format: <integer>
1416
1417 scsi_dev_flags= [SCSI] Black/white list entry for vendor and model
1418 Format: <vendor>:<model>:<flags>
1419 (flags are integer value)
1420
1421 scsi_logging= [SCSI]
1422
3e082a91
MW
1423 scsi_mod.scan= [SCSI] sync (default) scans SCSI busses as they are
1424 discovered. async scans them in kernel threads,
1425 allowing boot to proceed. none ignores them, expecting
1426 user space to do the scan.
1427
1da177e4
LT
1428 selinux [SELINUX] Disable or enable SELinux at boot time.
1429 Format: { "0" | "1" }
1430 See security/selinux/Kconfig help text.
1431 0 -- disable.
1432 1 -- enable.
1433 Default value is set via kernel config option.
1434 If enabled at boot time, /selinux/disable can be used
1435 later to disable prior to initial policy load.
1436
4e5ab4cb
JM
1437 selinux_compat_net =
1438 [SELINUX] Set initial selinux_compat_net flag value.
1439 Format: { "0" | "1" }
1440 0 -- use new secmark-based packet controls
1441 1 -- use legacy packet controls
1442 Default value is 0 (preferred).
1443 Value can be changed at runtime via
1444 /selinux/compat_net.
1445
1da177e4
LT
1446 serialnumber [BUGS=IA-32]
1447
a9913044
RD
1448 sg_def_reserved_size= [SCSI]
1449
1da177e4
LT
1450 shapers= [NET]
1451 Maximal number of shapers.
a9913044 1452
1da177e4
LT
1453 sim710= [SCSI,HW]
1454 See header of drivers/scsi/sim710.c.
1455
1456 simeth= [IA-64]
1457 simscsi=
a9913044 1458
1da177e4
LT
1459 sjcd= [HW,CD]
1460 Format: <io>,<irq>,<dma>
1461 See header of drivers/cdrom/sjcd.c.
1462
1463 slram= [HW,MTD]
1464
1465 smart2= [HW]
1466 Format: <io1>[,<io2>[,...,<io8>]]
1467
1468 snd-ad1816a= [HW,ALSA]
1469
1470 snd-ad1848= [HW,ALSA]
1471
1472 snd-ali5451= [HW,ALSA]
1473
1474 snd-als100= [HW,ALSA]
1475
1476 snd-als4000= [HW,ALSA]
1477
1478 snd-azt2320= [HW,ALSA]
1479
1480 snd-cmi8330= [HW,ALSA]
1481
1482 snd-cmipci= [HW,ALSA]
1483
1484 snd-cs4231= [HW,ALSA]
1485
1486 snd-cs4232= [HW,ALSA]
1487
1488 snd-cs4236= [HW,ALSA]
1489
1490 snd-cs4281= [HW,ALSA]
1491
1492 snd-cs46xx= [HW,ALSA]
1493
1494 snd-dt019x= [HW,ALSA]
1495
1496 snd-dummy= [HW,ALSA]
1497
1498 snd-emu10k1= [HW,ALSA]
1499
1500 snd-ens1370= [HW,ALSA]
1501
1502 snd-ens1371= [HW,ALSA]
1503
1504 snd-es968= [HW,ALSA]
1505
1506 snd-es1688= [HW,ALSA]
1507
1508 snd-es18xx= [HW,ALSA]
1509
1510 snd-es1938= [HW,ALSA]
1511
1512 snd-es1968= [HW,ALSA]
1513
1514 snd-fm801= [HW,ALSA]
1515
1516 snd-gusclassic= [HW,ALSA]
1517
1518 snd-gusextreme= [HW,ALSA]
1519
1520 snd-gusmax= [HW,ALSA]
1521
1522 snd-hdsp= [HW,ALSA]
1523
1524 snd-ice1712= [HW,ALSA]
1525
1526 snd-intel8x0= [HW,ALSA]
1527
1528 snd-interwave= [HW,ALSA]
1529
1530 snd-interwave-stb=
1531 [HW,ALSA]
1532
1533 snd-korg1212= [HW,ALSA]
1534
1535 snd-maestro3= [HW,ALSA]
1536
1537 snd-mpu401= [HW,ALSA]
1538
1539 snd-mtpav= [HW,ALSA]
1540
1541 snd-nm256= [HW,ALSA]
1542
1543 snd-opl3sa2= [HW,ALSA]
1544
1545 snd-opti92x-ad1848=
1546 [HW,ALSA]
1547
1548 snd-opti92x-cs4231=
1549 [HW,ALSA]
1550
1551 snd-opti93x= [HW,ALSA]
1552
1553 snd-pmac= [HW,ALSA]
1554
1555 snd-rme32= [HW,ALSA]
1556
1557 snd-rme96= [HW,ALSA]
1558
1559 snd-rme9652= [HW,ALSA]
1560
1561 snd-sb8= [HW,ALSA]
1562
1563 snd-sb16= [HW,ALSA]
1564
1565 snd-sbawe= [HW,ALSA]
1566
1567 snd-serial= [HW,ALSA]
1568
1569 snd-sgalaxy= [HW,ALSA]
1570
1571 snd-sonicvibes= [HW,ALSA]
1572
1573 snd-sun-amd7930=
1574 [HW,ALSA]
1575
1576 snd-sun-cs4231= [HW,ALSA]
1577
1578 snd-trident= [HW,ALSA]
1579
1580 snd-usb-audio= [HW,ALSA,USB]
1581
1582 snd-via82xx= [HW,ALSA]
1583
1584 snd-virmidi= [HW,ALSA]
1585
1586 snd-wavefront= [HW,ALSA]
1587
1588 snd-ymfpci= [HW,ALSA]
a9913044 1589
1da177e4
LT
1590 sonycd535= [HW,CD]
1591 Format: <io>[,<irq>]
1592
1593 sonypi.*= [HW] Sony Programmable I/O Control Device driver
1594 See Documentation/sonypi.txt
1595
1596 specialix= [HW,SERIAL] Specialix multi-serial port adapter
1597 See Documentation/specialix.txt.
1598
1599 spia_io_base= [HW,MTD]
1600 spia_fio_base=
1601 spia_pedr=
1602 spia_peddr=
1603
1604 sscape= [HW,OSS]
1605 Format: <io>,<irq>,<dma>,<mpu_io>,<mpu_irq>
a9913044 1606
1da177e4
LT
1607 st= [HW,SCSI] SCSI tape parameters (buffers, etc.)
1608 See Documentation/scsi/st.txt.
1609
1610 st0x= [HW,SCSI]
1611 See header of drivers/scsi/seagate.c.
1612
1613 sti= [PARISC,HW]
1614 Format: <num>
1615 Set the STI (builtin display/keyboard on the HP-PARISC
1616 machines) console (graphic card) which should be used
1617 as the initial boot-console.
1618 See also comment in drivers/video/console/sticore.c.
1619
1620 sti_font= [HW]
1621 See comment in drivers/video/console/sticore.c.
1622
1623 stifb= [HW]
1624 Format: bpp:<bpp1>[:<bpp2>[:<bpp3>...]]
1625
1da177e4 1626 swiotlb= [IA-64] Number of I/O TLB slabs
a9913044 1627
1da177e4
LT
1628 switches= [HW,M68k]
1629
1630 sym53c416= [HW,SCSI]
1631 See header of drivers/scsi/sym53c416.c.
1632
1633 t128= [HW,SCSI]
1634 See header of drivers/scsi/t128.c.
1635
1636 tdfx= [HW,DRM]
1637
1638 thash_entries= [KNL,NET]
1639 Set number of hash buckets for TCP connection
1640
1641 time Show timing data prefixed to each printk message line
1642
734efb46
JS
1643 clocksource= [GENERIC_TIME] Override the default clocksource
1644 Override the default clocksource and use the clocksource
1645 with the name specified.
1646
1da177e4
LT
1647 tipar.timeout= [HW,PPT]
1648 Set communications timeout in tenths of a second
1649 (default 15).
1650
1651 tipar.delay= [HW,PPT]
1652 Set inter-bit delay in microseconds (default 10).
1653
1654 tmc8xx= [HW,SCSI]
1655 See header of drivers/scsi/seagate.c.
1656
1657 tmscsim= [HW,SCSI]
1658 See comment before function dc390_setup() in
1659 drivers/scsi/tmscsim.c.
1660
1661 tp720= [HW,PS2]
1662
1663 trix= [HW,OSS] MediaTrix AudioTrix Pro
a9913044
RD
1664 Format:
1665 <io>,<irq>,<dma>,<dma2>,<sb_io>,<sb_irq>,<sb_dma>,<mpu_io>,<mpu_irq>
1666
1da177e4
LT
1667 tsdev.xres= [TS] Horizontal screen resolution.
1668 tsdev.yres= [TS] Vertical screen resolution.
1669
a9913044
RD
1670 turbografx.map[2|3]= [HW,JOY]
1671 TurboGraFX parallel port interface
1672 Format:
1673 <port#>,<js1>,<js2>,<js3>,<js4>,<js5>,<js6>,<js7>
1da177e4
LT
1674 See also Documentation/input/joystick-parport.txt
1675
1676 u14-34f= [HW,SCSI] UltraStor 14F/34F SCSI host adapter
1677 See header of drivers/scsi/u14-34f.c.
1678
1679 uart401= [HW,OSS]
1680 Format: <io>,<irq>
1681
1682 uart6850= [HW,OSS]
1683 Format: <io>,<irq>
1684
1da177e4
LT
1685 usbhid.mousepoll=
1686 [USBHID] The interval which mice are to be polled at.
a9913044 1687
e6e5494c
IM
1688 vdso= [IA-32]
1689 vdso=1: enable VDSO (default)
1690 vdso=0: disable VDSO mapping
1691
1da177e4
LT
1692 video= [FB] Frame buffer configuration
1693 See Documentation/fb/modedb.txt.
1694
1695 vga= [BOOT,IA-32] Select a particular video mode
a9913044
RD
1696 See Documentation/i386/boot.txt and
1697 Documentation/svga.txt.
1da177e4
LT
1698 Use vga=ask for menu.
1699 This is actually a boot loader parameter; the value is
1700 passed to the kernel using a special protocol.
1701
a9913044 1702 vmalloc=nn[KMG] [KNL,BOOT] Forces the vmalloc area to have an exact
1da177e4
LT
1703 size of <nn>. This can be used to increase the
1704 minimum size (128MB on x86). It can also be used to
1705 decrease the size and leave more room for directly
1706 mapped kernel RAM.
1707
585c3047
PO
1708 vmhalt= [KNL,S390] Perform z/VM CP command after system halt.
1709 Format: <command>
1da177e4 1710
585c3047
PO
1711 vmpanic= [KNL,S390] Perform z/VM CP command after kernel panic.
1712 Format: <command>
1713
1714 vmpoff= [KNL,S390] Perform z/VM CP command after power off.
1715 Format: <command>
a9913044 1716
1da177e4
LT
1717 waveartist= [HW,OSS]
1718 Format: <io>,<irq>,<dma>,<dma2>
a9913044 1719
1da177e4
LT
1720 wd33c93= [HW,SCSI]
1721 See header of drivers/scsi/wd33c93.c.
1722
1723 wd7000= [HW,SCSI]
1724 See header of drivers/scsi/wd7000.c.
1725
1726 wdt= [WDT] Watchdog
1727 See Documentation/watchdog/watchdog.txt.
1728
1729 xd= [HW,XT] Original XT pre-IDE (RLL encoded) disks.
1730 xd_geo= See header of drivers/block/xd.c.
1731
1732 xirc2ps_cs= [NET,PCMCIA]
a9913044
RD
1733 Format:
1734 <irq>,<irq_mask>,<io>,<full_duplex>,<do_sound>,<lockup_hack>[,<irq2>[,<irq3>[,<irq4>]]]
1da177e4 1735
a62eaf15
AK
1736 norandmaps Don't use address space randomization
1737 Equivalent to echo 0 > /proc/sys/kernel/randomize_va_space
1738
1da177e4 1739
a9913044 1740______________________________________________________________________
1da177e4
LT
1741
1742TODO:
1743
1744 Add documentation for ALSA options.
1745 Add more DRM drivers.