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Stefan Richter0ee9d712006-04-01 01:42:29 +02001 Kernel Parameters
Linus Torvalds1da177e2005-04-16 15:20:36 -07002 ~~~~~~~~~~~~~~~~~
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
Stefan Richtera901ebb2006-04-01 01:43:18 +020020This 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
Stefan Richter6585fa82006-04-01 01:44:30 +020027The 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:
Linus Torvalds1da177e2005-04-16 15:20:36 -070031
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.
Randy Dunlapa9913042005-10-23 12:57:11 -070038 DRM Direct Rendering Management support is enabled.
Linus Torvalds1da177e2005-04-16 15:20:36 -070039 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.
Adrian Bunk41e2e8b2005-07-12 13:58:33 -070047 IP_PNP IP DHCP, BOOTP, or RARP is enabled.
Linus Torvalds1da177e2005-04-16 15:20:36 -070048 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.
Matthew Wilcox309e57d2006-03-05 22:33:34 -070059 MSI Message Signaled Interrupts (PCI).
Linus Torvalds1da177e2005-04-16 15:20:36 -070060 MTD MTD support is enabled.
61 NET Appropriate network support is enabled.
62 NUMA NUMA support is enabled.
john stultz734efb42006-06-26 00:25:05 -070063 GENERIC_TIME The generic timeofday code is enabled.
Linus Torvalds1da177e2005-04-16 15:20:36 -070064 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.
Randy Dunlapa9913042005-10-23 12:57:11 -070083 SWSUSP Software suspend is enabled.
Linus Torvalds1da177e2005-04-16 15:20:36 -070084 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
jens m. noedler9c4751f2006-09-29 02:00:27 -0700113The 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
Linus Torvalds1da177e2005-04-16 15:20:36 -0700120 53c7xx= [HW,SCSI] Amiga SCSI controllers
121 See header of drivers/scsi/53c7xx.c.
122 See also Documentation/scsi/ncr53c7xx.txt.
123
Randy Dunlapa9913042005-10-23 12:57:11 -0700124 acpi= [HW,ACPI] Advanced Configuration and Power Interface
125 Format: { force | off | ht | strict | noirq }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700126 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
Randy Dunlapa9913042005-10-23 12:57:11 -0700130 strict -- Be less tolerant of platforms that are not
Linus Torvalds1da177e2005-04-16 15:20:36 -0700131 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
Randy Dunlapa9913042005-10-23 12:57:11 -0700138
Linus Torvalds1da177e2005-04-16 15:20:36 -0700139 acpi_sci= [HW,ACPI] ACPI System Control Interrupt trigger mode
Randy Dunlapa9913042005-10-23 12:57:11 -0700140 Format: { level | edge | high | low }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700141
Randy Dunlapa9913042005-10-23 12:57:11 -0700142 acpi_irq_balance [HW,ACPI]
143 ACPI will balance active IRQs
144 default in APIC mode
Linus Torvalds1da177e2005-04-16 15:20:36 -0700145
Randy Dunlapa9913042005-10-23 12:57:11 -0700146 acpi_irq_nobalance [HW,ACPI]
147 ACPI will not move active IRQs (default)
148 default in PIC mode
Linus Torvalds1da177e2005-04-16 15:20:36 -0700149
Randy Dunlapa9913042005-10-23 12:57:11 -0700150 acpi_irq_pci= [HW,ACPI] If irq_balance, clear listed IRQs for
151 use by PCI
Linus Torvalds1da177e2005-04-16 15:20:36 -0700152 Format: <irq>,<irq>...
153
Randy Dunlapa9913042005-10-23 12:57:11 -0700154 acpi_irq_isa= [HW,ACPI] If irq_balance, mark listed IRQs used by ISA
Linus Torvalds1da177e2005-04-16 15:20:36 -0700155 Format: <irq>,<irq>...
156
Len Browna1f9e652006-01-25 23:47:36 -0500157 acpi_os_name= [HW,ACPI] Tell ACPI BIOS the name of the OS
158 Format: To spoof as Windows 98: ="Microsoft Windows"
159
Linus Torvalds1da177e2005-04-16 15:20:36 -0700160 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.
Andi Kleenfa18f472006-11-14 16:57:46 +0100167 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
Linus Torvalds1da177e2005-04-16 15:20:36 -0700171
172 acpi_dbg_layer= [HW,ACPI]
173 Format: <int>
Randy Dunlapa9913042005-10-23 12:57:11 -0700174 Each bit of the <int> indicates an ACPI debug layer,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700175 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>
Randy Dunlapa9913042005-10-23 12:57:11 -0700181 Each bit of the <int> indicates an ACPI debug level,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700182 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
Luming Yu30e332f2005-08-12 00:31:00 -0400188 acpi_generic_hotkey [HW,ACPI]
189 Allow consolidated generic hotkey driver to
Randy Dunlapa9913042005-10-23 12:57:11 -0700190 override platform specific driver.
Luming Yu30e332f2005-08-12 00:31:00 -0400191 See also Documentation/acpi-hotkey.txt.
192
john stultz5d0cf412006-06-26 00:25:12 -0700193 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
Chuck Ebbert66759a02005-09-12 18:49:25 +0200198 enable_timer_pin_1 [i386,x86-64]
199 Enable PIN 1 of APIC timer
Randy Dunlapa9913042005-10-23 12:57:11 -0700200 Can be useful to work around chipset bugs
201 (in particular on some ATI chipsets).
Chuck Ebbert66759a02005-09-12 18:49:25 +0200202 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
Linus Torvalds1da177e2005-04-16 15:20:36 -0700208 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>
Randy Dunlapa9913042005-10-23 12:57:11 -0700217
Linus Torvalds1da177e2005-04-16 15:20:36 -0700218 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.
Randy Dunlapa9913042005-10-23 12:57:11 -0700227
Linus Torvalds1da177e2005-04-16 15:20:36 -0700228 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
Linus Torvalds1da177e2005-04-16 15:20:36 -0700240 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
Randy Dunlapa9913042005-10-23 12:57:11 -0700250 apc= [HW,SPARC]
251 Power management functions (SPARCstation-4/5 + deriv.)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700252 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
Randy Dunlapa9913042005-10-23 12:57:11 -0700257 apic= [APIC,i386] Change the output verbosity whilst booting
Linus Torvalds1da177e2005-04-16 15:20:36 -0700258 Format: { quiet (default) | verbose | debug }
259 Change the amount of debugging information output
260 when initialising the APIC and IO-APIC components.
Randy Dunlapa9913042005-10-23 12:57:11 -0700261
Linus Torvalds1da177e2005-04-16 15:20:36 -0700262 apm= [APM] Advanced Power Management
263 See header of arch/i386/kernel/apm.c.
264
265 applicom= [HW]
266 Format: <mem>,<irq>
Randy Dunlapa9913042005-10-23 12:57:11 -0700267
Linus Torvalds1da177e2005-04-16 15:20:36 -0700268 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
Randy Dunlapa9913042005-10-23 12:57:11 -0700282 atkbd.set= [HW] Select keyboard code set
283 Format: <int> (2 = AT (default), 3 = PS/2)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700284
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))
Randy Dunlapa9913042005-10-23 12:57:11 -0700290
291 atkbd.softrepeat= [HW]
292 Use software keyboard repeat
Linus Torvalds1da177e2005-04-16 15:20:36 -0700293
294 autotest [IA64]
295
Linus Torvalds1da177e2005-04-16 15:20:36 -0700296 aztcd= [HW,CD] Aztech CD268 CDROM driver
297 Format: <io>,0x79 (?)
298
299 baycom_epp= [HW,AX25]
300 Format: <io>,<mode>
Randy Dunlapa9913042005-10-23 12:57:11 -0700301
Linus Torvalds1da177e2005-04-16 15:20:36 -0700302 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
Randy Dunlapa9913042005-10-23 12:57:11 -0700306 baycom_ser_fdx= [HW,AX25]
307 BayCom Serial Port AX.25 Modem (Full Duplex Mode)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700308 Format: <io>,<irq>,<mode>[,<baud>]
309 See header of drivers/net/hamradio/baycom_ser_fdx.c.
310
Randy Dunlapa9913042005-10-23 12:57:11 -0700311 baycom_ser_hdx= [HW,AX25]
312 BayCom Serial Port AX.25 Modem (Half Duplex Mode)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700313 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)
Randy Dunlapa9913042005-10-23 12:57:11 -0700323 bttv.radio= Most important insmod options are available as
324 kernel args too.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700325 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.
Randy Dunlapa9913042005-10-23 12:57:11 -0700350 0 -- check protection applied by kernel (includes
351 any implied execute protection).
Linus Torvalds1da177e2005-04-16 15:20:36 -0700352 1 -- check protection requested by application.
353 Default value is set via a kernel config option.
Randy Dunlapa9913042005-10-23 12:57:11 -0700354 Value can be changed at runtime via
355 /selinux/checkreqprot.
356
john stultz734efb42006-06-26 00:25:05 -0700357 clock= [BUGS=IA-32, HW] gettimeofday clocksource override.
358 [Deprecated]
Matt LaPlante3f6dee92006-10-03 22:45:33 +0200359 Forces specified clocksource (if available) to be used
john stultz734efb42006-06-26 00:25:05 -0700360 when calculating gettimeofday(). If specified
Matt LaPlante3f6dee92006-10-03 22:45:33 +0200361 clocksource is not available, it defaults to PIT.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700362 Format: { pit | tsc | cyclone | pmtmr }
363
Andi Kleenf9262c12006-03-08 17:57:25 -0800364 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
Linus Torvalds1da177e2005-04-16 15:20:36 -0700370 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
Randy Dunlapa9913042005-10-23 12:57:11 -0700377 Format:
378 <io>[,<irq>[,<nodeID>[,<backplane>[,<ckp>[,<timeout>]]]]]
Linus Torvalds1da177e2005-04-16 15:20:36 -0700379
380 com90io= [HW,NET] ARCnet - COM90xx chipset (IO-mapped buffers)
381 Format: <io>[,<irq>]
382
Randy Dunlapa9913042005-10-23 12:57:11 -0700383 com90xx= [HW,NET]
384 ARCnet - COM90xx chipset (memory-mapped buffers)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700385 Format: <io>[,<irq>[,<memstart>]]
386
387 condev= [HW,S390] console device
388 conmode=
Randy Dunlapa9913042005-10-23 12:57:11 -0700389
Linus Torvalds1da177e2005-04-16 15:20:36 -0700390 console= [KNL] Output console device and options.
391
392 tty<n> Use the virtual console device <n>.
393
394 ttyS<n>[,options]
Randy Dunlapf1a1c2d2006-03-25 03:08:17 -0800395 ttyUSB0[,options]
Linus Torvalds1da177e2005-04-16 15:20:36 -0700396 Use the specified serial port. The options are of
Randy Dunlapf1a1c2d2006-03-25 03:08:17 -0800397 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".
Linus Torvalds1da177e2005-04-16 15:20:36 -0700401
Randy Dunlapf1a1c2d2006-03-25 03:08:17 -0800402 See Documentation/serial-console.txt for more
403 information. See
404 Documentation/networking/netconsole.txt for an
405 alternative.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700406
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
Randy Dunlapa9913042005-10-23 12:57:11 -0700415 Format:
416 <first_slot>,<last_slot>,<port>,<enum_bit>[,<debug>]
Linus Torvalds1da177e2005-04-16 15:20:36 -0700417
418 cpia_pp= [HW,PPT]
419 Format: { parport<nr> | auto | none }
420
Eric W. Biedermandc009d92005-06-25 14:57:52 -0700421 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
Linus Torvalds1da177e2005-04-16 15:20:36 -0700425 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 }
Randy Dunlapa9913042005-10-23 12:57:11 -0700433
Linus Torvalds1da177e2005-04-16 15:20:36 -0700434 cyclades= [HW,SERIAL] Cyclades multi-serial port adapter.
Randy Dunlapa9913042005-10-23 12:57:11 -0700435
436 dasd= [HW,NET]
Linus Torvalds1da177e2005-04-16 15:20:36 -0700437 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
Ingo Molnarcae2ed92006-07-03 00:24:48 -0700446 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
Linus Torvalds1da177e2005-04-16 15:20:36 -0700455 decnet= [HW,NET]
456 Format: <area>[,<node>]
457 See also Documentation/networking/decnet.txt.
458
Linus Torvalds1da177e2005-04-16 15:20:36 -0700459 dhash_entries= [KNL]
460 Set number of hash buckets for dentry cache.
Randy Dunlapa9913042005-10-23 12:57:11 -0700461
Linus Torvalds1da177e2005-04-16 15:20:36 -0700462 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
Randy Dunlapa9913042005-10-23 12:57:11 -0700479 earlyprintk= [IA-32,X86-64]
Linus Torvalds1da177e2005-04-16 15:20:36 -0700480 earlyprintk=vga
481 earlyprintk=serial[,ttySn[,baudrate]]
482
Randy Dunlapa9913042005-10-23 12:57:11 -0700483 Append ",keep" to not disable it when the real console
Linus Torvalds1da177e2005-04-16 15:20:36 -0700484 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
Len Brown53f11d42005-12-05 16:46:36 -0500498 ec_intr= [HW,ACPI] ACPI Embedded Controller interrupt mode
499 Format: <int>
500 0: polling mode
501 non-0: interrupt mode (default)
502
Linus Torvalds1da177e2005-04-16 15:20:36 -0700503 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
Randy Dunlapa9913042005-10-23 12:57:11 -0700511 eicon= [HW,ISDN]
Linus Torvalds1da177e2005-04-16 15:20:36 -0700512 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]
Randy Dunlap16ab3ad2006-01-14 13:21:20 -0800522 Format: {"anticipatory" | "cfq" | "deadline" | "noop"}
Randy Dunlapa9913042005-10-23 12:57:11 -0700523 See Documentation/block/as-iosched.txt and
524 Documentation/block/deadline-iosched.txt for details.
525
Vivek Goyalaac04b32006-01-09 20:51:47 -0800526 elfcorehdr= [IA-32, X86_64]
Randy Dunlapa9913042005-10-23 12:57:11 -0700527 Specifies physical address of start of kernel core
Vivek Goyalaac04b32006-01-09 20:51:47 -0800528 image elf header. Generally kexec loader will
529 pass this option to capture kernel.
530 See Documentation/kdump/kdump.txt for details.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700531
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
Linus Torvalds1da177e2005-04-16 15:20:36 -0700540 es1371= [HW,OSS]
541 Format: <spdif>,[<nomix>,[<amplifier>]]
542 See also header of sound/oss/es1371.c.
Randy Dunlapa9913042005-10-23 12:57:11 -0700543
Linus Torvalds1da177e2005-04-16 15:20:36 -0700544 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
Linus Torvalds1da177e2005-04-16 15:20:36 -0700560 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
Linus Torvalds1da177e2005-04-16 15:20:36 -0700577 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.
Randy Dunlapa9913042005-10-23 12:57:11 -0700582 Format: 0 | 1 (for off | on)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700583
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
Matt LaPlante84eb8d02006-10-03 22:53:09 +0200605 i8042.dumbkbd [HW] Pretend that controller can only read data from
606 keyboard and cannot control its state
Linus Torvalds1da177e2005-04-16 15:20:36 -0700607 (Don't attempt to blink the leds)
608 i8042.noaux [HW] Don't check for auxiliary (== mouse) port
Dmitry Torokhov945ef0d2005-09-04 01:42:00 -0500609 i8042.nokbd [HW] Don't check/create keyboard port
Linus Torvalds1da177e2005-04-16 15:20:36 -0700610 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
Dmitry Torokhove70c9d52005-06-25 14:54:25 -0700622 i8k.ignore_dmi [HW] Continue probing hardware even if DMI data
623 indicates that the driver is running on unsupported
624 hardware.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700625 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.
Randy Dunlapa9913042005-10-23 12:57:11 -0700646
Linus Torvalds1da177e2005-04-16 15:20:36 -0700647 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
Randy Dunlapa9913042005-10-23 12:57:11 -0700652
Linus Torvalds1da177e2005-04-16 15:20:36 -0700653 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
Jesse Barnes2bd0fa32005-12-13 03:05:03 -0500673 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
Linus Torvalds1da177e2005-04-16 15:20:36 -0700681 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
Simon Horman72c4a132006-09-13 19:57:18 -0700696 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
Alan Cox200803d2005-06-28 20:45:18 -0700702 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
Linus Torvalds1da177e2005-04-16 15:20:36 -0700713 isapnp= [ISAPNP]
Randy Dunlapa9913042005-10-23 12:57:11 -0700714 Format: <RDP>,<reset>,<pci_scan>,<verbosity>
Linus Torvalds1da177e2005-04-16 15:20:36 -0700715
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
Randy Dunlapa9913042005-10-23 12:57:11 -0700726 alternative -- manually setting the CPU mask of all
727 tasks in the system -- can cause problems and
728 suboptimal load balancer performance.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700729
730 isp16= [HW,CD]
731 Format: <io>,<irq>,<dma>,<setup>
732
Randy Dunlapa9913042005-10-23 12:57:11 -0700733 iucv= [HW,NET]
Linus Torvalds1da177e2005-04-16 15:20:36 -0700734
735 js= [HW,JOY] Analog joystick
736 See Documentation/input/joystick.txt.
737
738 keepinitrd [HW,ARM]
739
Randy Dunlapa9913042005-10-23 12:57:11 -0700740 kstack=N [IA-32,X86-64] Print N words from the kernel stack
Linus Torvalds1da177e2005-04-16 15:20:36 -0700741 in oops dumps.
742
743 l2cr= [PPC]
744
Randy Dunlapa9913042005-10-23 12:57:11 -0700745 lapic [IA-32,APIC] Enable the local APIC even if BIOS
746 disabled it.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700747
748 lasi= [HW,SCSI] PARISC LASI driver for the 53c700 chip
749 Format: addr:<io>,irq:<irq>
750
Randy Dunlapa9913042005-10-23 12:57:11 -0700751 llsc*= [IA64] See function print_params() in
752 arch/ia64/sn/kernel/llsc4.c.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700753
754 load_ramdisk= [RAM] List of ramdisks to load from floppy
755 See Documentation/ramdisk.txt.
756
Randy Dunlapa6b25b62006-01-14 13:21:19 -0800757 lockd.nlm_grace_period=P [NFS] Assign grace period.
758 Format: <integer>
Linus Torvalds1da177e2005-04-16 15:20:36 -0700759
Randy Dunlapa6b25b62006-01-14 13:21:19 -0800760 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>
Linus Torvalds1da177e2005-04-16 15:20:36 -0700768
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.
Randy Dunlapa9913042005-10-23 12:57:11 -0700787 Format: { n | nk | nM }
788 n must be a power of two. The default size
789 is set in the kernel config file.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700790
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
Randy Dunlapa9913042005-10-23 12:57:11 -0700825 mac5380= [HW,SCSI] Format:
826 <can_queue>,<cmd_per_lun>,<sg_tablesize>,<hostid>,<use_tags>
Linus Torvalds1da177e2005-04-16 15:20:36 -0700827
Randy Dunlapa9913042005-10-23 12:57:11 -0700828 mac53c9x= [HW,SCSI] Format:
829 <num_esps>,<disconnect>,<nosync>,<can_queue>,<cmd_per_lun>,<sg_tablesize>,<hostid>,<use_tags>
Linus Torvalds1da177e2005-04-16 15:20:36 -0700830
Randy Dunlapa9913042005-10-23 12:57:11 -0700831 machvec= [IA64] Force the use of a particular machine-vector
832 (machvec) in a generic kernel.
833 Example: machvec=hpzx1_swiotlb
Linus Torvalds1da177e2005-04-16 15:20:36 -0700834
Randy Dunlapa9913042005-10-23 12:57:11 -0700835 max_loop= [LOOP] Maximum number of loopback devices that can
Linus Torvalds1da177e2005-04-16 15:20:36 -0700836 be mounted
837 Format: <1-256>
838
839 maxcpus= [SMP] Maximum number of processors that an SMP kernel
840 should make use of
841
Bob Picco2b2c3752005-06-29 18:00:00 -0700842 max_addr=[KMG] [KNL,BOOT,ia64] All physical memory greater than or
843 equal to this physical address is ignored.
844
Randy Dunlapa9913042005-10-23 12:57:11 -0700845 max_luns= [SCSI] Maximum number of LUNs to probe.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700846 Should be between 1 and 2^32-1.
847
848 max_report_luns=
Randy Dunlapa9913042005-10-23 12:57:11 -0700849 [SCSI] Maximum number of LUNs received.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700850 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.
Randy Dunlapa9913042005-10-23 12:57:11 -0700865
Linus Torvalds1da177e2005-04-16 15:20:36 -0700866 mdacon= [MDA]
867 Format: <first>,<last>
868 Specifies range of consoles to be captured by the MDA.
Randy Dunlapa9913042005-10-23 12:57:11 -0700869
Linus Torvalds1da177e2005-04-16 15:20:36 -0700870 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
akpm@osdl.org69cda7b2006-01-09 20:51:46 -0800880 memmap=exactmap [KNL,IA-32,X86_64] Enable setting of an exact
Linus Torvalds1da177e2005-04-16 15:20:36 -0700881 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
akpm@osdl.org198e2f12006-01-12 01:05:30 -0800903 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
Linus Torvalds1da177e2005-04-16 15:20:36 -0700946 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
Randy Dunlapa9913042005-10-23 12:57:11 -0700963 MTD_Region= [MTD] Format:
964 <name>,<region-number>[,<base>,<size>,<buswidth>,<altbuswidth>]
Linus Torvalds1da177e2005-04-16 15:20:36 -0700965
966 mtdparts= [MTD]
967 See drivers/mtd/cmdline.c.
968
969 mtouchusb.raw_coordinates=
Randy Dunlapa9913042005-10-23 12:57:11 -0700970 [HW] Make the MicroTouch USB driver use raw coordinates
971 ('y', default) or cooked coordinates ('n')
Linus Torvalds1da177e2005-04-16 15:20:36 -0700972
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.
Randy Dunlapa9913042005-10-23 12:57:11 -0700992 This usage is only documented in each driver source
993 file if at all.
994
Linus Torvalds1da177e2005-04-16 15:20:36 -0700995 nfsaddrs= [NFS]
996 See Documentation/nfsroot.txt.
997
998 nfsroot= [NFS] nfs root filesystem for disk-less boxes.
999 See Documentation/nfsroot.txt.
1000
Trond Myklebusta72b4422006-01-03 09:55:41 +01001001 nfs.callback_tcpport=
1002 [NFS] set the TCP port on which the NFSv4 callback
1003 channel should listen.
1004
Trond Myklebust58df0952006-01-03 09:55:57 +01001005 nfs.idmap_cache_timeout=
1006 [NFS] set the maximum lifetime for idmapper cache
1007 entries.
1008
Linus Torvalds1da177e2005-04-16 15:20:36 -07001009 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
Randy Dunlapa9913042005-10-23 12:57:11 -07001015 noalign [KNL,ARM]
1016
Linus Torvalds1da177e2005-04-16 15:20:36 -07001017 noapic [SMP,APIC] Tells the kernel to not make use of any
1018 IOAPICs that may be present in the system.
1019
1020 noasync [HW,M68K] Disables async and sync negotiation for
1021 all devices.
1022
1023 nobats [PPC] Do not use BATs for mapping kernel lowmem
1024 on "Classic" PPC cores.
1025
1026 nocache [ARM]
Randy Dunlapa9913042005-10-23 12:57:11 -07001027
Shailabh Nagar163ecdf2006-07-30 03:03:11 -07001028 nodelayacct [KNL] Disable per-task delay accounting
1029
Linus Torvalds1da177e2005-04-16 15:20:36 -07001030 nodisconnect [HW,SCSI,M68K] Disables SCSI disconnects.
1031
1032 noexec [IA-64]
1033
Randy Dunlapa9913042005-10-23 12:57:11 -07001034 noexec [IA-32,X86-64]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001035 noexec=on: enable non-executable mappings (default)
1036 noexec=off: disable nn-executable mappings
1037
Chuck Ebbert4f886512006-03-23 02:59:34 -08001038 nofxsr [BUGS=IA-32] Disables x86 floating point extended
1039 register save and restore. The kernel will only save
1040 legacy floating-point registers on task switch.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001041
1042 nohlt [BUGS=ARM]
Randy Dunlapa9913042005-10-23 12:57:11 -07001043
Linus Torvalds1da177e2005-04-16 15:20:36 -07001044 no-hlt [BUGS=IA-32] Tells the kernel that the hlt
1045 instruction doesn't work correctly and not to
1046 use it.
1047
1048 nohalt [IA-64] Tells the kernel not to use the power saving
1049 function PAL_HALT_LIGHT when idle. This increases
1050 power-consumption. On the positive side, it reduces
1051 interrupt wake-up latency, which may improve performance
1052 in certain environments such as networked servers or
1053 real-time systems.
1054
1055 noirqdebug [IA-32] Disables the code which attempts to detect and
1056 disable unhandled interrupt sources.
1057
1058 noisapnp [ISAPNP] Disables ISA PnP code.
1059
1060 noinitrd [RAM] Tells the kernel not to load any configured
1061 initial RAM disk.
1062
1063 nointroute [IA-64]
1064
1065 nolapic [IA-32,APIC] Do not enable or use the local APIC.
1066
1067 noltlbs [PPC] Do not use large page/tlb entries for kernel
1068 lowmem mapping on PPC40x.
1069
Horms312f1f02006-02-22 09:57:55 +09001070 nomca [IA-64] Disable machine check abort handling
1071
Hormsabe37e52006-04-01 01:36:09 +02001072 nomce [IA-32] Machine Check Exception
1073
Linus Torvalds1da177e2005-04-16 15:20:36 -07001074 noresidual [PPC] Don't use residual data on PReP machines.
1075
Randy Dunlapa9913042005-10-23 12:57:11 -07001076 noresume [SWSUSP] Disables resume and restores original swap
1077 space.
1078
Linus Torvalds1da177e2005-04-16 15:20:36 -07001079 no-scroll [VGA] Disables scrollback.
1080 This is required for the Braillex ib80-piezo Braille
1081 reader made by F.H. Papenmeier (Germany).
1082
1083 nosbagart [IA-64]
1084
Chuck Ebbert4f886512006-03-23 02:59:34 -08001085 nosep [BUGS=IA-32] Disables x86 SYSENTER/SYSEXIT support.
1086
Linus Torvalds1da177e2005-04-16 15:20:36 -07001087 nosmp [SMP] Tells an SMP kernel to act as a UP kernel.
1088
1089 nosync [HW,M68K] Disables sync negotiation for all devices.
1090
1091 notsc [BUGS=IA-32] Disable Time Stamp Counter
1092
1093 nousb [USB] Disable the USB subsystem
1094
1095 nowb [ARM]
Randy Dunlapa9913042005-10-23 12:57:11 -07001096
Dave Jonesa61c2d72006-01-07 23:18:19 +00001097 nr_uarts= [SERIAL] maximum number of UARTs to be registered.
1098
Linus Torvalds1da177e2005-04-16 15:20:36 -07001099 opl3= [HW,OSS]
1100 Format: <io>
1101
Randy Dunlapa9913042005-10-23 12:57:11 -07001102 opl3sa2= [HW,OSS] Format:
1103 <io>,<irq>,<dma>,<dma2>,<mss_io>,<mpu_io>,<ymode>,<loopback>[,<isapnp>,<multiple]
1104
Linus Torvalds1da177e2005-04-16 15:20:36 -07001105 oprofile.timer= [HW]
1106 Use timer interrupt instead of performance counters
1107
1108 optcd= [HW,CD]
1109 Format: <io>
1110
1111 osst= [HW,SCSI] SCSI Tape Driver
1112 Format: <buffer_size>,<write_threshold>
1113 See also Documentation/scsi/st.txt.
1114
1115 panic= [KNL] Kernel behaviour on panic
1116 Format: <timeout>
1117
1118 parkbd.port= [HW] Parallel port number the keyboard adapter is
1119 connected to, default is 0.
1120 Format: <parport#>
1121 parkbd.mode= [HW] Parallel port keyboard adapter mode of operation,
1122 0 for XT, 1 for AT (default is AT).
Randy Dunlapa9913042005-10-23 12:57:11 -07001123 Format: <mode>
Linus Torvalds1da177e2005-04-16 15:20:36 -07001124
Randy Dunlapa9913042005-10-23 12:57:11 -07001125 parport= [HW,PPT] Specify parallel ports. 0 disables.
1126 Format: { 0 | auto | 0xBBB[,IRQ[,DMA]] }
1127 Use 'auto' to force the driver to use any
1128 IRQ/DMA settings detected (the default is to
1129 ignore detected IRQ/DMA settings because of
1130 possible conflicts). You can specify the base
1131 address, IRQ, and DMA settings; IRQ and DMA
1132 should be numbers, or 'auto' (for using detected
1133 settings on that particular port), or 'nofifo'
1134 (to avoid using a FIFO even if it is detected).
1135 Parallel ports are assigned in the order they
1136 are specified on the command line, starting
1137 with parport0.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001138
Randy Dunlapa9913042005-10-23 12:57:11 -07001139 parport_init_mode= [HW,PPT]
1140 Configure VIA parallel port to operate in
1141 a specific mode. This is necessary on Pegasos
1142 computer where firmware has no options for setting
1143 up parallel port mode and sets it to spp.
1144 Currently this function knows 686a and 8231 chips.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001145 Format: [spp|ps2|epp|ecp|ecpepp]
1146
Randy Dunlapa9913042005-10-23 12:57:11 -07001147 pas2= [HW,OSS] Format:
1148 <io>,<irq>,<dma>,<dma16>,<sb_io>,<sb_irq>,<sb_dma>,<sb_dma16>
1149
Linus Torvalds1da177e2005-04-16 15:20:36 -07001150 pas16= [HW,SCSI]
1151 See header of drivers/scsi/pas16.c.
1152
Andrew Mortondd287792006-03-23 03:00:57 -08001153 pause_on_oops=
1154 Halt all CPUs after the first oops has been printed for
1155 the specified number of seconds. This is to be used if
1156 your oopses keep scrolling off the screen.
1157
Linus Torvalds1da177e2005-04-16 15:20:36 -07001158 pcbit= [HW,ISDN]
1159
1160 pcd. [PARIDE]
1161 See header of drivers/block/paride/pcd.c.
1162 See also Documentation/paride.txt.
1163
Randy Dunlapa9913042005-10-23 12:57:11 -07001164 pci=option[,option...] [PCI] various PCI subsystem options:
1165 off [IA-32] don't probe for the PCI bus
1166 bios [IA-32] force use of PCI BIOS, don't access
1167 the hardware directly. Use this if your machine
1168 has a non-standard PCI host bridge.
1169 nobios [IA-32] disallow use of PCI BIOS, only direct
1170 hardware access methods are allowed. Use this
1171 if you experience crashes upon bootup and you
1172 suspect they are caused by the BIOS.
1173 conf1 [IA-32] Force use of PCI Configuration
1174 Mechanism 1.
1175 conf2 [IA-32] Force use of PCI Configuration
1176 Mechanism 2.
Bjorn Helgaas61be6d62006-02-15 15:17:43 -08001177 nommconf [IA-32,X86_64] Disable use of MMCONFIG for PCI
1178 Configuration
Matthew Wilcox309e57d2006-03-05 22:33:34 -07001179 nomsi [MSI] If the PCI_MSI kernel config parameter is
1180 enabled, this kernel boot option can be used to
1181 disable the use of MSI interrupts system-wide.
Randy Dunlapa9913042005-10-23 12:57:11 -07001182 nosort [IA-32] Don't sort PCI devices according to
1183 order given by the PCI BIOS. This sorting is
1184 done to get a device order compatible with
1185 older kernels.
1186 biosirq [IA-32] Use PCI BIOS calls to get the interrupt
1187 routing table. These calls are known to be buggy
1188 on several machines and they hang the machine
1189 when used, but on other computers it's the only
1190 way to get the interrupt routing table. Try
1191 this option if the kernel is unable to allocate
1192 IRQs or discover secondary PCI buses on your
1193 motherboard.
1194 rom [IA-32] Assign address space to expansion ROMs.
1195 Use with caution as certain devices share
1196 address decoders between ROMs and other
1197 resources.
1198 irqmask=0xMMMM [IA-32] Set a bit mask of IRQs allowed to be
1199 assigned automatically to PCI devices. You can
1200 make the kernel exclude IRQs of your ISA cards
1201 this way.
jayalk@intworks.biz120bb422005-03-21 20:20:42 -08001202 pirqaddr=0xAAAAA [IA-32] Specify the physical address
Randy Dunlapa9913042005-10-23 12:57:11 -07001203 of the PIRQ table (normally generated
1204 by the BIOS) if it is outside the
1205 F0000h-100000h range.
1206 lastbus=N [IA-32] Scan all buses thru bus #N. Can be
1207 useful if the kernel is unable to find your
1208 secondary buses and you want to tell it
1209 explicitly which ones they are.
1210 assign-busses [IA-32] Always assign all PCI bus
1211 numbers ourselves, overriding
1212 whatever the firmware may have done.
1213 usepirqmask [IA-32] Honor the possible IRQ mask stored
1214 in the BIOS $PIR table. This is needed on
1215 some systems with broken BIOSes, notably
1216 some HP Pavilion N5400 and Omnibook XE3
1217 notebooks. This will have no effect if ACPI
1218 IRQ routing is enabled.
1219 noacpi [IA-32] Do not use ACPI for IRQ routing
1220 or for PCI scanning.
1221 routeirq Do IRQ routing for all PCI devices.
1222 This is normally done in pci_enable_device(),
1223 so this option is a temporary workaround
1224 for broken drivers that don't call it.
1225 firmware [ARM] Do not re-enumerate the bus but instead
1226 just use the configuration from the
1227 bootloader. This is currently used on
1228 IXP2000 systems where the bus has to be
1229 configured a certain way for adjunct CPUs.
Andi Kleen0637a702006-09-26 10:52:41 +02001230 noearly [X86] Don't do any early type 1 scanning.
1231 This might help on some broken boards which
1232 machine check when some devices' config space
1233 is read. But various workarounds are disabled
1234 and some IOMMU drivers will not work.
Matt Domsch6b4b78f2006-09-29 15:23:23 -05001235 bfsort Sort PCI devices into breadth-first order.
1236 This sorting is done to get a device
1237 order compatible with older (<= 2.4) kernels.
1238 nobfsort Don't sort PCI devices into breadth-first order.
1239
Linus Torvalds1da177e2005-04-16 15:20:36 -07001240 pcmv= [HW,PCMCIA] BadgePAD 4
1241
1242 pd. [PARIDE]
1243 See Documentation/paride.txt.
1244
1245 pdcchassis= [PARISC,HW] Disable/Enable PDC Chassis Status codes at
1246 boot time.
1247 Format: { 0 | 1 }
1248 See arch/parisc/kernel/pdc_chassis.c
1249
1250 pf. [PARIDE]
1251 See Documentation/paride.txt.
1252
1253 pg. [PARIDE]
1254 See Documentation/paride.txt.
1255
1256 pirq= [SMP,APIC] Manual mp-table setup
1257 See Documentation/i386/IO-APIC.txt.
1258
1259 plip= [PPT,NET] Parallel port network link
1260 Format: { parport<nr> | timid | 0 }
1261 See also Documentation/parport.txt.
1262
1263 pnpacpi= [ACPI]
1264 { off }
1265
1266 pnpbios= [ISAPNP]
1267 { on | off | curr | res | no-curr | no-res }
1268
1269 pnp_reserve_irq=
1270 [ISAPNP] Exclude IRQs for the autoconfiguration
1271
1272 pnp_reserve_dma=
1273 [ISAPNP] Exclude DMAs for the autoconfiguration
1274
1275 pnp_reserve_io= [ISAPNP] Exclude I/O ports for the autoconfiguration
Randy Dunlapa9913042005-10-23 12:57:11 -07001276 Ranges are in pairs (I/O port base and size).
Linus Torvalds1da177e2005-04-16 15:20:36 -07001277
1278 pnp_reserve_mem=
Randy Dunlapa9913042005-10-23 12:57:11 -07001279 [ISAPNP] Exclude memory regions for the
1280 autoconfiguration.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001281 Ranges are in pairs (memory base and size).
1282
1283 profile= [KNL] Enable kernel profiling via /proc/profile
Randy Dunlapa9913042005-10-23 12:57:11 -07001284 Format: [schedule,]<number>
1285 Param: "schedule" - profile schedule points.
1286 Param: <number> - step/bucket size as a power of 2 for
1287 statistical time based profiling.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001288
Randy Dunlapa9913042005-10-23 12:57:11 -07001289 processor.max_cstate= [HW,ACPI]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001290 Limit processor to maximum C-state
1291 max_cstate=9 overrides any DMI blacklist limit.
1292
Len Brown41c0d862005-12-28 12:43:51 -05001293 processor.nocst [HW,ACPI]
1294 Ignore the _CST method to determine C-states,
1295 instead using the legacy FADT method
1296
Linus Torvalds1da177e2005-04-16 15:20:36 -07001297 prompt_ramdisk= [RAM] List of RAM disks to prompt for floppy disk
1298 before loading.
1299 See Documentation/ramdisk.txt.
1300
Randy Dunlapa9913042005-10-23 12:57:11 -07001301 psmouse.proto= [HW,MOUSE] Highest PS2 mouse protocol extension to
1302 probe for; one of (bare|imps|exps|lifebook|any).
Linus Torvalds1da177e2005-04-16 15:20:36 -07001303 psmouse.rate= [HW,MOUSE] Set desired mouse report rate, in reports
1304 per second.
Randy Dunlapa9913042005-10-23 12:57:11 -07001305 psmouse.resetafter= [HW,MOUSE]
1306 Try to reset the device after so many bad packets
Linus Torvalds1da177e2005-04-16 15:20:36 -07001307 (0 = never).
1308 psmouse.resolution=
1309 [HW,MOUSE] Set desired mouse resolution, in dpi.
1310 psmouse.smartscroll=
Randy Dunlapa9913042005-10-23 12:57:11 -07001311 [HW,MOUSE] Controls Logitech smartscroll autorepeat.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001312 0 = disabled, 1 = enabled (default).
1313
1314 pss= [HW,OSS] Personal Sound System (ECHO ESC614)
Randy Dunlapa9913042005-10-23 12:57:11 -07001315 Format:
1316 <io>,<mss_io>,<mss_irq>,<mss_dma>,<mpu_io>,<mpu_irq>
Linus Torvalds1da177e2005-04-16 15:20:36 -07001317
1318 pt. [PARIDE]
1319 See Documentation/paride.txt.
1320
Randy Dunlap7d2c5022006-09-29 02:01:02 -07001321 quiet [KNL] Disable most log messages
Randy Dunlapa9913042005-10-23 12:57:11 -07001322
Linus Torvalds1da177e2005-04-16 15:20:36 -07001323 r128= [HW,DRM]
1324
1325 raid= [HW,RAID]
1326 See Documentation/md.txt.
1327
1328 ramdisk= [RAM] Sizes of RAM disks in kilobytes [deprecated]
1329 See Documentation/ramdisk.txt.
1330
Randy Dunlapa9913042005-10-23 12:57:11 -07001331 ramdisk_blocksize= [RAM]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001332 See Documentation/ramdisk.txt.
Randy Dunlapa9913042005-10-23 12:57:11 -07001333
Linus Torvalds1da177e2005-04-16 15:20:36 -07001334 ramdisk_size= [RAM] Sizes of RAM disks in kilobytes
1335 New name for the ramdisk parameter.
1336 See Documentation/ramdisk.txt.
1337
Dipankar Sarma21a1ea92006-03-07 21:55:33 -08001338 rcu.blimit= [KNL,BOOT] Set maximum number of finished
1339 RCU callbacks to process in one batch.
1340
1341 rcu.qhimark= [KNL,BOOT] Set threshold of queued
1342 RCU callbacks over which batch limiting is disabled.
1343
1344 rcu.qlowmark= [KNL,BOOT] Set threshold of queued
1345 RCU callbacks below which batch limiting is re-enabled.
1346
Olof Johanssonffdfc402005-09-06 15:17:19 -07001347 rdinit= [KNL]
1348 Format: <full_path>
1349 Run specified binary instead of /init from the ramdisk,
1350 used for early userspace startup. See initrd.
1351
Linus Torvalds1da177e2005-04-16 15:20:36 -07001352 reboot= [BUGS=IA-32,BUGS=ARM,BUGS=IA-64] Rebooting mode
1353 Format: <reboot_mode>[,<reboot_mode2>[,...]]
Michael Opdenackerf3e299f2006-10-03 23:19:24 +02001354 See arch/*/kernel/reboot.c or arch/*/kernel/process.c
Linus Torvalds1da177e2005-04-16 15:20:36 -07001355
1356 reserve= [KNL,BUGS] Force the kernel to ignore some iomem area
1357
Zachary Amsden461a9af2006-09-25 23:32:25 -07001358 reservetop= [IA-32]
1359 Format: nn[KMG]
1360 Reserves a hole at the top of the kernel virtual
1361 address space.
1362
Vivek Goyal7e962872006-09-27 01:50:44 -07001363 reset_devices [KNL] Force drivers to reset the underlying device
1364 during initialization.
1365
Randy Dunlapa9913042005-10-23 12:57:11 -07001366 resume= [SWSUSP]
1367 Specify the partition device for software suspend
Linus Torvalds1da177e2005-04-16 15:20:36 -07001368
1369 rhash_entries= [KNL,NET]
1370 Set number of hash buckets for route cache
1371
1372 riscom8= [HW,SERIAL]
1373 Format: <io_board1>[,<io_board2>[,...<io_boardN>]]
1374
1375 ro [KNL] Mount root device read-only on boot
1376
1377 root= [KNL] Root filesystem
1378
1379 rootdelay= [KNL] Delay (in seconds) to pause before attempting to
1380 mount the root filesystem
1381
1382 rootflags= [KNL] Set root filesystem mount option string
1383
1384 rootfstype= [KNL] Set root filesystem type
1385
1386 rw [KNL] Mount root device read-write on boot
1387
1388 S [KNL] Run init in single mode
1389
1390 sa1100ir [NET]
1391 See drivers/net/irda/sa1100_ir.c.
1392
1393 sb= [HW,OSS]
1394 Format: <io>,<irq>,<dma>,<dma2>
1395
1396 sbni= [NET] Granch SBNI12 leased line adapter
Randy Dunlapa9913042005-10-23 12:57:11 -07001397
Linus Torvalds1da177e2005-04-16 15:20:36 -07001398 sbpcd= [HW,CD] Soundblaster CD adapter
1399 Format: <io>,<type>
1400 See a comment before function sbpcd_setup() in
1401 drivers/cdrom/sbpcd.c.
1402
1403 sc1200wdt= [HW,WDT] SC1200 WDT (watchdog) driver
1404 Format: <io>[,<timeout>[,<isapnp>]]
1405
1406 scsi_debug_*= [SCSI]
1407 See drivers/scsi/scsi_debug.c.
1408
1409 scsi_default_dev_flags=
1410 [SCSI] SCSI default device flags
1411 Format: <integer>
1412
1413 scsi_dev_flags= [SCSI] Black/white list entry for vendor and model
1414 Format: <vendor>:<model>:<flags>
1415 (flags are integer value)
1416
1417 scsi_logging= [SCSI]
1418
Matthew Wilcox3e082a92006-09-28 15:19:20 -06001419 scsi_mod.scan= [SCSI] sync (default) scans SCSI busses as they are
1420 discovered. async scans them in kernel threads,
1421 allowing boot to proceed. none ignores them, expecting
1422 user space to do the scan.
1423
Linus Torvalds1da177e2005-04-16 15:20:36 -07001424 selinux [SELINUX] Disable or enable SELinux at boot time.
1425 Format: { "0" | "1" }
1426 See security/selinux/Kconfig help text.
1427 0 -- disable.
1428 1 -- enable.
1429 Default value is set via kernel config option.
1430 If enabled at boot time, /selinux/disable can be used
1431 later to disable prior to initial policy load.
1432
James Morris4e5ab4c2006-06-09 00:33:33 -07001433 selinux_compat_net =
1434 [SELINUX] Set initial selinux_compat_net flag value.
1435 Format: { "0" | "1" }
1436 0 -- use new secmark-based packet controls
1437 1 -- use legacy packet controls
1438 Default value is 0 (preferred).
1439 Value can be changed at runtime via
1440 /selinux/compat_net.
1441
Linus Torvalds1da177e2005-04-16 15:20:36 -07001442 serialnumber [BUGS=IA-32]
1443
Randy Dunlapa9913042005-10-23 12:57:11 -07001444 sg_def_reserved_size= [SCSI]
1445
Linus Torvalds1da177e2005-04-16 15:20:36 -07001446 shapers= [NET]
1447 Maximal number of shapers.
Randy Dunlapa9913042005-10-23 12:57:11 -07001448
Linus Torvalds1da177e2005-04-16 15:20:36 -07001449 sim710= [SCSI,HW]
1450 See header of drivers/scsi/sim710.c.
1451
1452 simeth= [IA-64]
1453 simscsi=
Randy Dunlapa9913042005-10-23 12:57:11 -07001454
Linus Torvalds1da177e2005-04-16 15:20:36 -07001455 sjcd= [HW,CD]
1456 Format: <io>,<irq>,<dma>
1457 See header of drivers/cdrom/sjcd.c.
1458
1459 slram= [HW,MTD]
1460
1461 smart2= [HW]
1462 Format: <io1>[,<io2>[,...,<io8>]]
1463
1464 snd-ad1816a= [HW,ALSA]
1465
1466 snd-ad1848= [HW,ALSA]
1467
1468 snd-ali5451= [HW,ALSA]
1469
1470 snd-als100= [HW,ALSA]
1471
1472 snd-als4000= [HW,ALSA]
1473
1474 snd-azt2320= [HW,ALSA]
1475
1476 snd-cmi8330= [HW,ALSA]
1477
1478 snd-cmipci= [HW,ALSA]
1479
1480 snd-cs4231= [HW,ALSA]
1481
1482 snd-cs4232= [HW,ALSA]
1483
1484 snd-cs4236= [HW,ALSA]
1485
1486 snd-cs4281= [HW,ALSA]
1487
1488 snd-cs46xx= [HW,ALSA]
1489
1490 snd-dt019x= [HW,ALSA]
1491
1492 snd-dummy= [HW,ALSA]
1493
1494 snd-emu10k1= [HW,ALSA]
1495
1496 snd-ens1370= [HW,ALSA]
1497
1498 snd-ens1371= [HW,ALSA]
1499
1500 snd-es968= [HW,ALSA]
1501
1502 snd-es1688= [HW,ALSA]
1503
1504 snd-es18xx= [HW,ALSA]
1505
1506 snd-es1938= [HW,ALSA]
1507
1508 snd-es1968= [HW,ALSA]
1509
1510 snd-fm801= [HW,ALSA]
1511
1512 snd-gusclassic= [HW,ALSA]
1513
1514 snd-gusextreme= [HW,ALSA]
1515
1516 snd-gusmax= [HW,ALSA]
1517
1518 snd-hdsp= [HW,ALSA]
1519
1520 snd-ice1712= [HW,ALSA]
1521
1522 snd-intel8x0= [HW,ALSA]
1523
1524 snd-interwave= [HW,ALSA]
1525
1526 snd-interwave-stb=
1527 [HW,ALSA]
1528
1529 snd-korg1212= [HW,ALSA]
1530
1531 snd-maestro3= [HW,ALSA]
1532
1533 snd-mpu401= [HW,ALSA]
1534
1535 snd-mtpav= [HW,ALSA]
1536
1537 snd-nm256= [HW,ALSA]
1538
1539 snd-opl3sa2= [HW,ALSA]
1540
1541 snd-opti92x-ad1848=
1542 [HW,ALSA]
1543
1544 snd-opti92x-cs4231=
1545 [HW,ALSA]
1546
1547 snd-opti93x= [HW,ALSA]
1548
1549 snd-pmac= [HW,ALSA]
1550
1551 snd-rme32= [HW,ALSA]
1552
1553 snd-rme96= [HW,ALSA]
1554
1555 snd-rme9652= [HW,ALSA]
1556
1557 snd-sb8= [HW,ALSA]
1558
1559 snd-sb16= [HW,ALSA]
1560
1561 snd-sbawe= [HW,ALSA]
1562
1563 snd-serial= [HW,ALSA]
1564
1565 snd-sgalaxy= [HW,ALSA]
1566
1567 snd-sonicvibes= [HW,ALSA]
1568
1569 snd-sun-amd7930=
1570 [HW,ALSA]
1571
1572 snd-sun-cs4231= [HW,ALSA]
1573
1574 snd-trident= [HW,ALSA]
1575
1576 snd-usb-audio= [HW,ALSA,USB]
1577
1578 snd-via82xx= [HW,ALSA]
1579
1580 snd-virmidi= [HW,ALSA]
1581
1582 snd-wavefront= [HW,ALSA]
1583
1584 snd-ymfpci= [HW,ALSA]
Randy Dunlapa9913042005-10-23 12:57:11 -07001585
Linus Torvalds1da177e2005-04-16 15:20:36 -07001586 sonycd535= [HW,CD]
1587 Format: <io>[,<irq>]
1588
1589 sonypi.*= [HW] Sony Programmable I/O Control Device driver
1590 See Documentation/sonypi.txt
1591
1592 specialix= [HW,SERIAL] Specialix multi-serial port adapter
1593 See Documentation/specialix.txt.
1594
1595 spia_io_base= [HW,MTD]
1596 spia_fio_base=
1597 spia_pedr=
1598 spia_peddr=
1599
1600 sscape= [HW,OSS]
1601 Format: <io>,<irq>,<dma>,<mpu_io>,<mpu_irq>
Randy Dunlapa9913042005-10-23 12:57:11 -07001602
Linus Torvalds1da177e2005-04-16 15:20:36 -07001603 st= [HW,SCSI] SCSI tape parameters (buffers, etc.)
1604 See Documentation/scsi/st.txt.
1605
1606 st0x= [HW,SCSI]
1607 See header of drivers/scsi/seagate.c.
1608
1609 sti= [PARISC,HW]
1610 Format: <num>
1611 Set the STI (builtin display/keyboard on the HP-PARISC
1612 machines) console (graphic card) which should be used
1613 as the initial boot-console.
1614 See also comment in drivers/video/console/sticore.c.
1615
1616 sti_font= [HW]
1617 See comment in drivers/video/console/sticore.c.
1618
1619 stifb= [HW]
1620 Format: bpp:<bpp1>[:<bpp2>[:<bpp3>...]]
1621
Linus Torvalds1da177e2005-04-16 15:20:36 -07001622 swiotlb= [IA-64] Number of I/O TLB slabs
Randy Dunlapa9913042005-10-23 12:57:11 -07001623
Linus Torvalds1da177e2005-04-16 15:20:36 -07001624 switches= [HW,M68k]
1625
1626 sym53c416= [HW,SCSI]
1627 See header of drivers/scsi/sym53c416.c.
1628
1629 t128= [HW,SCSI]
1630 See header of drivers/scsi/t128.c.
1631
1632 tdfx= [HW,DRM]
1633
1634 thash_entries= [KNL,NET]
1635 Set number of hash buckets for TCP connection
1636
1637 time Show timing data prefixed to each printk message line
1638
john stultz734efb42006-06-26 00:25:05 -07001639 clocksource= [GENERIC_TIME] Override the default clocksource
1640 Override the default clocksource and use the clocksource
1641 with the name specified.
1642
Linus Torvalds1da177e2005-04-16 15:20:36 -07001643 tipar.timeout= [HW,PPT]
1644 Set communications timeout in tenths of a second
1645 (default 15).
1646
1647 tipar.delay= [HW,PPT]
1648 Set inter-bit delay in microseconds (default 10).
1649
1650 tmc8xx= [HW,SCSI]
1651 See header of drivers/scsi/seagate.c.
1652
1653 tmscsim= [HW,SCSI]
1654 See comment before function dc390_setup() in
1655 drivers/scsi/tmscsim.c.
1656
1657 tp720= [HW,PS2]
1658
1659 trix= [HW,OSS] MediaTrix AudioTrix Pro
Randy Dunlapa9913042005-10-23 12:57:11 -07001660 Format:
1661 <io>,<irq>,<dma>,<dma2>,<sb_io>,<sb_irq>,<sb_dma>,<mpu_io>,<mpu_irq>
1662
Linus Torvalds1da177e2005-04-16 15:20:36 -07001663 tsdev.xres= [TS] Horizontal screen resolution.
1664 tsdev.yres= [TS] Vertical screen resolution.
1665
Randy Dunlapa9913042005-10-23 12:57:11 -07001666 turbografx.map[2|3]= [HW,JOY]
1667 TurboGraFX parallel port interface
1668 Format:
1669 <port#>,<js1>,<js2>,<js3>,<js4>,<js5>,<js6>,<js7>
Linus Torvalds1da177e2005-04-16 15:20:36 -07001670 See also Documentation/input/joystick-parport.txt
1671
1672 u14-34f= [HW,SCSI] UltraStor 14F/34F SCSI host adapter
1673 See header of drivers/scsi/u14-34f.c.
1674
1675 uart401= [HW,OSS]
1676 Format: <io>,<irq>
1677
1678 uart6850= [HW,OSS]
1679 Format: <io>,<irq>
1680
Linus Torvalds1da177e2005-04-16 15:20:36 -07001681 usbhid.mousepoll=
1682 [USBHID] The interval which mice are to be polled at.
Randy Dunlapa9913042005-10-23 12:57:11 -07001683
Ingo Molnare6e54942006-06-27 02:53:50 -07001684 vdso= [IA-32]
1685 vdso=1: enable VDSO (default)
1686 vdso=0: disable VDSO mapping
1687
Linus Torvalds1da177e2005-04-16 15:20:36 -07001688 video= [FB] Frame buffer configuration
1689 See Documentation/fb/modedb.txt.
1690
1691 vga= [BOOT,IA-32] Select a particular video mode
Randy Dunlapa9913042005-10-23 12:57:11 -07001692 See Documentation/i386/boot.txt and
1693 Documentation/svga.txt.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001694 Use vga=ask for menu.
1695 This is actually a boot loader parameter; the value is
1696 passed to the kernel using a special protocol.
1697
Randy Dunlapa9913042005-10-23 12:57:11 -07001698 vmalloc=nn[KMG] [KNL,BOOT] Forces the vmalloc area to have an exact
Linus Torvalds1da177e2005-04-16 15:20:36 -07001699 size of <nn>. This can be used to increase the
1700 minimum size (128MB on x86). It can also be used to
1701 decrease the size and leave more room for directly
1702 mapped kernel RAM.
1703
Peter Oberparleiter585c3042006-06-29 15:08:25 +02001704 vmhalt= [KNL,S390] Perform z/VM CP command after system halt.
1705 Format: <command>
Linus Torvalds1da177e2005-04-16 15:20:36 -07001706
Peter Oberparleiter585c3042006-06-29 15:08:25 +02001707 vmpanic= [KNL,S390] Perform z/VM CP command after kernel panic.
1708 Format: <command>
1709
1710 vmpoff= [KNL,S390] Perform z/VM CP command after power off.
1711 Format: <command>
Randy Dunlapa9913042005-10-23 12:57:11 -07001712
Linus Torvalds1da177e2005-04-16 15:20:36 -07001713 waveartist= [HW,OSS]
1714 Format: <io>,<irq>,<dma>,<dma2>
Randy Dunlapa9913042005-10-23 12:57:11 -07001715
Linus Torvalds1da177e2005-04-16 15:20:36 -07001716 wd33c93= [HW,SCSI]
1717 See header of drivers/scsi/wd33c93.c.
1718
1719 wd7000= [HW,SCSI]
1720 See header of drivers/scsi/wd7000.c.
1721
1722 wdt= [WDT] Watchdog
1723 See Documentation/watchdog/watchdog.txt.
1724
1725 xd= [HW,XT] Original XT pre-IDE (RLL encoded) disks.
1726 xd_geo= See header of drivers/block/xd.c.
1727
1728 xirc2ps_cs= [NET,PCMCIA]
Randy Dunlapa9913042005-10-23 12:57:11 -07001729 Format:
1730 <irq>,<irq_mask>,<io>,<full_duplex>,<do_sound>,<lockup_hack>[,<irq2>[,<irq3>[,<irq4>]]]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001731
Andi Kleena62eaf12006-02-16 23:41:58 +01001732 norandmaps Don't use address space randomization
1733 Equivalent to echo 0 > /proc/sys/kernel/randomize_va_space
1734
Linus Torvalds1da177e2005-04-16 15:20:36 -07001735
Randy Dunlapa9913042005-10-23 12:57:11 -07001736______________________________________________________________________
Linus Torvalds1da177e2005-04-16 15:20:36 -07001737
1738TODO:
1739
1740 Add documentation for ALSA options.
1741 Add more DRM drivers.