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Mauro Carvalho Chehabe53dd082007-09-15 07:38:47 -03001 Kernel Parameters
2 ~~~~~~~~~~~~~~~~~
Linus Torvalds1da177e2005-04-16 15:20:36 -07003
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.
Chuck Ebbertc99c1082007-07-27 10:46:20 +100033 AGP AGP (Accelerated Graphics Port) is enabled.
Linus Torvalds1da177e2005-04-16 15:20:36 -070034 ALSA ALSA sound support is enabled.
35 APIC APIC support is enabled.
36 APM Advanced Power Management support is enabled.
Haavard Skinnemoene7ba1762007-10-10 14:58:29 +020037 AVR32 AVR32 architecture is enabled.
Linus Torvalds1da177e2005-04-16 15:20:36 -070038 AX25 Appropriate AX.25 support is enabled.
Robin Getz0ae53642007-10-09 17:24:49 +080039 BLACKFIN Blackfin architecture is enabled.
Randy Dunlapa9913042005-10-23 12:57:11 -070040 DRM Direct Rendering Management support is enabled.
Linus Torvalds1da177e2005-04-16 15:20:36 -070041 EDD BIOS Enhanced Disk Drive Services (EDD) is enabled
42 EFI EFI Partitioning (GPT) is enabled
43 EIDE EIDE/ATAPI support is enabled.
44 FB The frame buffer device is enabled.
45 HW Appropriate hardware is enabled.
Linus Torvalds1da177e2005-04-16 15:20:36 -070046 IA-64 IA-64 architecture is enabled.
47 IOSCHED More than one I/O scheduler is enabled.
Adrian Bunk41e2e8b2005-07-12 13:58:33 -070048 IP_PNP IP DHCP, BOOTP, or RARP is enabled.
Linus Torvalds1da177e2005-04-16 15:20:36 -070049 ISAPNP ISA PnP code is enabled.
50 ISDN Appropriate ISDN support is enabled.
51 JOY Appropriate joystick support is enabled.
Kristen Carlson Accardi11ef6972006-09-28 11:29:01 -070052 LIBATA Libata driver is enabled
Linus Torvalds1da177e2005-04-16 15:20:36 -070053 LP Printer support is enabled.
54 LOOP Loopback device support is enabled.
55 M68k M68k architecture is enabled.
56 These options have more detailed description inside of
57 Documentation/m68k/kernel-options.txt.
58 MCA MCA bus support is enabled.
59 MDA MDA console support is enabled.
60 MOUSE Appropriate mouse support is enabled.
Matthew Wilcox309e57d2006-03-05 22:33:34 -070061 MSI Message Signaled Interrupts (PCI).
Randy Dunlapc8facbb2007-07-31 00:37:40 -070062 MTD MTD (Memory Technology Device) support is enabled.
Linus Torvalds1da177e2005-04-16 15:20:36 -070063 NET Appropriate network support is enabled.
64 NUMA NUMA support is enabled.
john stultz734efb42006-06-26 00:25:05 -070065 GENERIC_TIME The generic timeofday code is enabled.
Linus Torvalds1da177e2005-04-16 15:20:36 -070066 NFS Appropriate NFS support is enabled.
67 OSS OSS sound support is enabled.
Randy Dunlapc8facbb2007-07-31 00:37:40 -070068 PV_OPS A paravirtualized kernel is enabled.
69 PARIDE The ParIDE (parallel port IDE) subsystem is enabled.
Linus Torvalds1da177e2005-04-16 15:20:36 -070070 PARISC The PA-RISC architecture is enabled.
71 PCI PCI bus support is enabled.
Randy Dunlap7f785762007-10-05 13:17:58 -070072 PCIE PCI Express support is enabled.
Linus Torvalds1da177e2005-04-16 15:20:36 -070073 PCMCIA The PCMCIA subsystem is enabled.
74 PNP Plug & Play support is enabled.
75 PPC PowerPC architecture is enabled.
76 PPT Parallel port support is enabled.
77 PS2 Appropriate PS/2 support is enabled.
78 RAM RAM disk support is enabled.
James Morris20510f22007-10-16 23:31:32 -070079 ROOTPLUG The example Root Plug LSM is enabled.
Linus Torvalds1da177e2005-04-16 15:20:36 -070080 S390 S390 architecture is enabled.
81 SCSI Appropriate SCSI support is enabled.
82 A lot of drivers has their options described inside of
83 Documentation/scsi/.
James Morris20510f22007-10-16 23:31:32 -070084 SECURITY Different security models are enabled.
Linus Torvalds1da177e2005-04-16 15:20:36 -070085 SELINUX SELinux support is enabled.
86 SERIAL Serial support is enabled.
Paul Mundte523d932007-02-28 18:30:01 +090087 SH SuperH architecture is enabled.
Linus Torvalds1da177e2005-04-16 15:20:36 -070088 SMP The kernel is an SMP kernel.
89 SPARC Sparc architecture is enabled.
Randy Dunlapa9913042005-10-23 12:57:11 -070090 SWSUSP Software suspend is enabled.
Linus Torvalds1da177e2005-04-16 15:20:36 -070091 TS Appropriate touchscreen support is enabled.
92 USB USB support is enabled.
93 USBHID USB Human Interface Device support is enabled.
94 V4L Video For Linux support is enabled.
95 VGA The VGA console has been enabled.
96 VT Virtual terminal support is enabled.
97 WDT Watchdog support is enabled.
98 XT IBM PC/XT MFM hard disk support is enabled.
Alan Coxcd4f0ef2007-07-31 00:37:59 -070099 X86-32 X86-32, aka i386 architecture is enabled.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700100 X86-64 X86-64 architecture is enabled.
101 More X86-64 boot options can be found in
102 Documentation/x86_64/boot-options.txt .
103
104In addition, the following text indicates that the option:
105
106 BUGS= Relates to possible processor bugs on the said processor.
107 KNL Is a kernel start-up parameter.
108 BOOT Is a boot loader parameter.
109
110Parameters denoted with BOOT are actually interpreted by the boot
111loader, and have no meaning to the kernel directly.
112Do not modify the syntax of boot loader parameters without extreme
113need or coordination with <Documentation/i386/boot.txt>.
114
Karsten Weiss55588702007-02-13 13:26:21 +0100115There are also arch-specific kernel-parameters not documented here.
116See for example <Documentation/x86_64/boot-options.txt>.
117
Linus Torvalds1da177e2005-04-16 15:20:36 -0700118Note that ALL kernel parameters listed below are CASE SENSITIVE, and that
119a trailing = on the name of any parameter states that that parameter will
120be entered as an environment variable, whereas its absence indicates that
121it will appear as a kernel argument readable via /proc/cmdline by programs
122running once the system is up.
123
jens m. noedler9c4751f2006-09-29 02:00:27 -0700124The number of kernel parameters is not limited, but the length of the
125complete command line (parameters including spaces etc.) is limited to
126a fixed number of characters. This limit depends on the architecture
127and is between 256 and 4096 characters. It is defined in the file
128./include/asm/setup.h as COMMAND_LINE_SIZE.
129
130
Bernhard Walle03d926f2007-03-06 02:29:44 -0800131 acpi= [HW,ACPI,X86-64,i386]
132 Advanced Configuration and Power Interface
Randy Dunlapa9913042005-10-23 12:57:11 -0700133 Format: { force | off | ht | strict | noirq }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700134 force -- enable ACPI if default was off
135 off -- disable ACPI if default was on
136 noirq -- do not use ACPI for IRQ routing
137 ht -- run only enough ACPI to enable Hyper Threading
Randy Dunlapa9913042005-10-23 12:57:11 -0700138 strict -- Be less tolerant of platforms that are not
Linus Torvalds1da177e2005-04-16 15:20:36 -0700139 strictly ACPI specification compliant.
140
Randy Dunlap53471122008-03-12 18:10:51 -0400141 See also Documentation/power/pm.txt, pci=noacpi
Linus Torvalds1da177e2005-04-16 15:20:36 -0700142
Len Browna1fdcc02007-03-11 03:26:14 -0400143 acpi_apic_instance= [ACPI, IOAPIC]
144 Format: <int>
145 2: use 2nd APIC table, if available
146 1,0: use 1st APIC table
Len Brown4e381a42007-03-30 14:16:10 -0400147 default: 0
Len Browna1fdcc02007-03-11 03:26:14 -0400148
Linus Torvalds1da177e2005-04-16 15:20:36 -0700149 acpi_sleep= [HW,ACPI] Sleep options
Rafael J. Wysockid8f3de02008-06-12 23:24:06 +0200150 Format: { s3_bios, s3_mode, s3_beep, old_ordering }
Pavel Machek23b168d2008-02-05 19:27:12 +0100151 See Documentation/power/video.txt for s3_bios and s3_mode.
152 s3_beep is for debugging; it makes the PC's speaker beep
153 as soon as the kernel's real-mode entry point is called.
Rafael J. Wysockid8f3de02008-06-12 23:24:06 +0200154 old_ordering causes the ACPI 1.0 ordering of the _PTS
155 control method, wrt putting devices into low power
156 states, to be enforced (the ACPI 2.0 ordering of _PTS is
157 used by default).
Randy Dunlapa9913042005-10-23 12:57:11 -0700158
Linus Torvalds1da177e2005-04-16 15:20:36 -0700159 acpi_sci= [HW,ACPI] ACPI System Control Interrupt trigger mode
Randy Dunlapa9913042005-10-23 12:57:11 -0700160 Format: { level | edge | high | low }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700161
Randy Dunlapa9913042005-10-23 12:57:11 -0700162 acpi_irq_balance [HW,ACPI]
163 ACPI will balance active IRQs
164 default in APIC mode
Linus Torvalds1da177e2005-04-16 15:20:36 -0700165
Randy Dunlapa9913042005-10-23 12:57:11 -0700166 acpi_irq_nobalance [HW,ACPI]
167 ACPI will not move active IRQs (default)
168 default in PIC mode
Linus Torvalds1da177e2005-04-16 15:20:36 -0700169
Randy Dunlapa9913042005-10-23 12:57:11 -0700170 acpi_irq_pci= [HW,ACPI] If irq_balance, clear listed IRQs for
171 use by PCI
Linus Torvalds1da177e2005-04-16 15:20:36 -0700172 Format: <irq>,<irq>...
173
Randy Dunlapa9913042005-10-23 12:57:11 -0700174 acpi_irq_isa= [HW,ACPI] If irq_balance, mark listed IRQs used by ISA
Linus Torvalds1da177e2005-04-16 15:20:36 -0700175 Format: <irq>,<irq>...
176
Len Brown67effe82007-07-26 00:50:06 -0400177 acpi_no_auto_ssdt [HW,ACPI] Disable automatic loading of SSDT
178
Len Browna1f9e652006-01-25 23:47:36 -0500179 acpi_os_name= [HW,ACPI] Tell ACPI BIOS the name of the OS
180 Format: To spoof as Windows 98: ="Microsoft Windows"
181
Len Brownae00d812007-05-29 18:43:33 -0400182 acpi_osi= [HW,ACPI] Modify list of supported OS interface strings
183 acpi_osi="string1" # add string1 -- only one string
184 acpi_osi="!string2" # remove built-in string2
185 acpi_osi= # disable all strings
Linus Torvalds1da177e2005-04-16 15:20:36 -0700186
187 acpi_serialize [HW,ACPI] force serialization of AML methods
188
189 acpi_skip_timer_override [HW,ACPI]
190 Recognize and ignore IRQ0/pin2 Interrupt Override.
191 For broken nForce2 BIOS resulting in XT-PIC timer.
Andi Kleenfa18f472006-11-14 16:57:46 +0100192 acpi_use_timer_override [HW,ACPI}
193 Use timer override. For some broken Nvidia NF5 boards
194 that require a timer override, but don't have
195 HPET
Linus Torvalds1da177e2005-04-16 15:20:36 -0700196
Zhang Ruif9891062007-04-24 13:53:22 +0800197 acpi.debug_layer= [HW,ACPI]
Linus Torvalds1da177e2005-04-16 15:20:36 -0700198 Format: <int>
Randy Dunlapa9913042005-10-23 12:57:11 -0700199 Each bit of the <int> indicates an ACPI debug layer,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700200 1: enable, 0: disable. It is useful for boot time
201 debugging. After system has booted up, it can be set
Zhang Ruif9891062007-04-24 13:53:22 +0800202 via /sys/module/acpi/parameters/debug_layer.
203 CONFIG_ACPI_DEBUG must be enabled for this to produce any output.
204 Available bits (add the numbers together) to enable debug output
205 for specific parts of the ACPI subsystem:
206 0x01 utilities 0x02 hardware 0x04 events 0x08 tables
207 0x10 namespace 0x20 parser 0x40 dispatcher
208 0x80 executer 0x100 resources 0x200 acpica debugger
209 0x400 os services 0x800 acpica disassembler.
210 The number can be in decimal or prefixed with 0x in hex.
211 Warning: Many of these options can produce a lot of
212 output and make your system unusable. Be very careful.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700213
Zhang Ruif9891062007-04-24 13:53:22 +0800214 acpi.debug_level= [HW,ACPI]
Linus Torvalds1da177e2005-04-16 15:20:36 -0700215 Format: <int>
Randy Dunlapa9913042005-10-23 12:57:11 -0700216 Each bit of the <int> indicates an ACPI debug level,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700217 1: enable, 0: disable. It is useful for boot time
218 debugging. After system has booted up, it can be set
Zhang Ruif9891062007-04-24 13:53:22 +0800219 via /sys/module/acpi/parameters/debug_level.
220 CONFIG_ACPI_DEBUG must be enabled for this to produce any output.
221 Available bits (add the numbers together) to enable different
222 debug output levels of the ACPI subsystem:
223 0x01 error 0x02 warn 0x04 init 0x08 debug object
224 0x10 info 0x20 init names 0x40 parse 0x80 load
225 0x100 dispatch 0x200 execute 0x400 names 0x800 operation region
226 0x1000 bfield 0x2000 tables 0x4000 values 0x8000 objects
227 0x10000 resources 0x20000 user requests 0x40000 package.
228 The number can be in decimal or prefixed with 0x in hex.
229 Warning: Many of these options can produce a lot of
230 output and make your system unusable. Be very careful.
231
Alan Coxcd4f0ef2007-07-31 00:37:59 -0700232 acpi_pm_good [X86-32,X86-64]
john stultz5d0cf412006-06-26 00:25:12 -0700233 Override the pmtimer bug detection: force the kernel
234 to assume that this machine's pmtimer latches its value
235 and always returns good values.
236
Chuck Ebbertc99c1082007-07-27 10:46:20 +1000237 agp= [AGP]
238 { off | try_unsupported }
239 off: disable AGP support
240 try_unsupported: try to drive unsupported chipsets
241 (may crash computer or cause data corruption)
242
Chuck Ebbert66759a02005-09-12 18:49:25 +0200243 enable_timer_pin_1 [i386,x86-64]
244 Enable PIN 1 of APIC timer
Randy Dunlapa9913042005-10-23 12:57:11 -0700245 Can be useful to work around chipset bugs
246 (in particular on some ATI chipsets).
Chuck Ebbert66759a02005-09-12 18:49:25 +0200247 The kernel tries to set a reasonable default.
248
249 disable_timer_pin_1 [i386,x86-64]
250 Disable PIN 1 of APIC timer
251 Can be useful to work around chipset bugs.
252
Linus Torvalds1da177e2005-04-16 15:20:36 -0700253 ad1848= [HW,OSS]
254 Format: <io>,<irq>,<dma>,<dma2>,<type>
255
Linus Torvalds1da177e2005-04-16 15:20:36 -0700256 advansys= [HW,SCSI]
257 See header of drivers/scsi/advansys.c.
258
259 advwdt= [HW,WDT] Advantech WDT
260 Format: <iostart>,<iostop>
261
262 aedsp16= [HW,OSS] Audio Excel DSP 16
263 Format: <io>,<irq>,<dma>,<mss_io>,<mpu_io>,<mpu_irq>
264 See also header of sound/oss/aedsp16.c.
Randy Dunlapa9913042005-10-23 12:57:11 -0700265
Linus Torvalds1da177e2005-04-16 15:20:36 -0700266 aha152x= [HW,SCSI]
267 See Documentation/scsi/aha152x.txt.
268
269 aha1542= [HW,SCSI]
270 Format: <portbase>[,<buson>,<busoff>[,<dmaspeed>]]
271
272 aic7xxx= [HW,SCSI]
273 See Documentation/scsi/aic7xxx.txt.
274
275 aic79xx= [HW,SCSI]
276 See Documentation/scsi/aic79xx.txt.
277
Joerg Roedel54b4cbd2008-06-26 21:28:10 +0200278 amd_iommu= [HW,X86-84]
279 Pass parameters to the AMD IOMMU driver in the system.
280 Possible values are:
Joerg Roedel54b4cbd2008-06-26 21:28:10 +0200281 isolate - enable device isolation (each device, as far
282 as possible, will get its own protection
283 domain)
284 amd_iommu_size= [HW,X86-64]
285 Define the size of the aperture for the AMD IOMMU
286 driver. Possible values are:
287 '32M', '64M' (default), '128M', '256M', '512M', '1G'
288
Linus Torvalds1da177e2005-04-16 15:20:36 -0700289 amijoy.map= [HW,JOY] Amiga joystick support
290 Map of devices attached to JOY0DAT and JOY1DAT
291 Format: <a>,<b>
292 See also Documentation/kernel/input/joystick.txt
293
294 analog.map= [HW,JOY] Analog joystick and gamepad support
295 Specifies type or capabilities of an analog joystick
296 connected to one of 16 gameports
297 Format: <type1>,<type2>,..<type16>
298
Randy Dunlapa9913042005-10-23 12:57:11 -0700299 apc= [HW,SPARC]
300 Power management functions (SPARCstation-4/5 + deriv.)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700301 Format: noidle
302 Disable APC CPU standby support. SPARCstation-Fox does
303 not play well with APC CPU idle - disable it if you have
304 APC and your system crashes randomly.
305
Randy Dunlapc8facbb2007-07-31 00:37:40 -0700306 apic= [APIC,i386] Advanced Programmable Interrupt Controller
307 Change the output verbosity whilst booting
Linus Torvalds1da177e2005-04-16 15:20:36 -0700308 Format: { quiet (default) | verbose | debug }
309 Change the amount of debugging information output
310 when initialising the APIC and IO-APIC components.
Randy Dunlapa9913042005-10-23 12:57:11 -0700311
Linus Torvalds1da177e2005-04-16 15:20:36 -0700312 apm= [APM] Advanced Power Management
Pavel Machek71f77052008-07-04 09:59:43 -0700313 See header of arch/x86/kernel/apm_32.c.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700314
Linus Torvalds1da177e2005-04-16 15:20:36 -0700315 arcrimi= [HW,NET] ARCnet - "RIM I" (entirely mem-mapped) cards
316 Format: <io>,<irq>,<nodeID>
317
318 ataflop= [HW,M68k]
319
320 atarimouse= [HW,MOUSE] Atari Mouse
321
322 atascsi= [HW,SCSI] Atari SCSI
323
324 atkbd.extra= [HW] Enable extra LEDs and keys on IBM RapidAccess,
325 EzKey and similar keyboards
326
327 atkbd.reset= [HW] Reset keyboard during initialization
328
Randy Dunlapa9913042005-10-23 12:57:11 -0700329 atkbd.set= [HW] Select keyboard code set
330 Format: <int> (2 = AT (default), 3 = PS/2)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700331
332 atkbd.scroll= [HW] Enable scroll wheel on MS Office and similar
333 keyboards
334
335 atkbd.softraw= [HW] Choose between synthetic and real raw mode
336 Format: <bool> (0 = real, 1 = synthetic (default))
Randy Dunlapa9913042005-10-23 12:57:11 -0700337
338 atkbd.softrepeat= [HW]
339 Use software keyboard repeat
Linus Torvalds1da177e2005-04-16 15:20:36 -0700340
341 autotest [IA64]
342
Linus Torvalds1da177e2005-04-16 15:20:36 -0700343 baycom_epp= [HW,AX25]
344 Format: <io>,<mode>
Randy Dunlapa9913042005-10-23 12:57:11 -0700345
Linus Torvalds1da177e2005-04-16 15:20:36 -0700346 baycom_par= [HW,AX25] BayCom Parallel Port AX.25 Modem
347 Format: <io>,<mode>
348 See header of drivers/net/hamradio/baycom_par.c.
349
Randy Dunlapa9913042005-10-23 12:57:11 -0700350 baycom_ser_fdx= [HW,AX25]
351 BayCom Serial Port AX.25 Modem (Full Duplex Mode)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700352 Format: <io>,<irq>,<mode>[,<baud>]
353 See header of drivers/net/hamradio/baycom_ser_fdx.c.
354
Randy Dunlapa9913042005-10-23 12:57:11 -0700355 baycom_ser_hdx= [HW,AX25]
356 BayCom Serial Port AX.25 Modem (Half Duplex Mode)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700357 Format: <io>,<irq>,<mode>
358 See header of drivers/net/hamradio/baycom_ser_hdx.c.
359
Randy Dunlapbfe8df32007-10-16 01:23:46 -0700360 boot_delay= Milliseconds to delay each printk during boot.
361 Values larger than 10 seconds (10000) are changed to
362 no delay (0).
363 Format: integer
364
Linus Torvalds1da177e2005-04-16 15:20:36 -0700365 bttv.card= [HW,V4L] bttv (bt848 + bt878 based grabber cards)
Randy Dunlapa9913042005-10-23 12:57:11 -0700366 bttv.radio= Most important insmod options are available as
367 kernel args too.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700368 bttv.pll= See Documentation/video4linux/bttv/Insmod-options
369 bttv.tuner= and Documentation/video4linux/bttv/CARDLIST
370
371 BusLogic= [HW,SCSI]
372 See drivers/scsi/BusLogic.c, comment before function
373 BusLogic_ParseDriverOptions().
374
375 c101= [NET] Moxa C101 synchronous serial card
376
Alan Coxcd4f0ef2007-07-31 00:37:59 -0700377 cachesize= [BUGS=X86-32] Override level 2 CPU cache size detection.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700378 Sometimes CPU hardware bugs make them report the cache
379 size incorrectly. The kernel will attempt work arounds
380 to fix known problems, but for some CPUs it is not
381 possible to determine what the correct size should be.
382 This option provides an override for these situations.
383
Ahmed S. Darwish076c54c2008-03-06 18:09:10 +0200384 security= [SECURITY] Choose a security module to enable at boot.
385 If this boot parameter is not specified, only the first
386 security module asking for security registration will be
387 loaded. An invalid security module name will be treated
388 as if no module has been chosen.
389
James Morris20510f22007-10-16 23:31:32 -0700390 capability.disable=
391 [SECURITY] Disable capabilities. This would normally
392 be used only if an alternative security model is to be
393 configured. Potentially dangerous and should only be
394 used if you are entirely sure of the consequences.
395
Sebastian Ott14ff56b2008-01-26 14:10:37 +0100396 ccw_timeout_log [S390]
397 See Documentation/s390/CommonIO for details.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700398
Paul Menage8bab8dd2008-04-04 14:29:57 -0700399 cgroup_disable= [KNL] Disable a particular controller
400 Format: {name of the controller(s) to disable}
401 {Currently supported controllers - "memory"}
402
Linus Torvalds1da177e2005-04-16 15:20:36 -0700403 checkreqprot [SELINUX] Set initial checkreqprot flag value.
404 Format: { "0" | "1" }
405 See security/selinux/Kconfig help text.
Randy Dunlapa9913042005-10-23 12:57:11 -0700406 0 -- check protection applied by kernel (includes
407 any implied execute protection).
Linus Torvalds1da177e2005-04-16 15:20:36 -0700408 1 -- check protection requested by application.
409 Default value is set via a kernel config option.
Randy Dunlapa9913042005-10-23 12:57:11 -0700410 Value can be changed at runtime via
411 /selinux/checkreqprot.
412
Sebastian Ott661ca0d2008-01-26 14:10:36 +0100413 cio_ignore= [S390]
414 See Documentation/s390/CommonIO for details.
415
Alan Coxcd4f0ef2007-07-31 00:37:59 -0700416 clock= [BUGS=X86-32, HW] gettimeofday clocksource override.
john stultz734efb42006-06-26 00:25:05 -0700417 [Deprecated]
Matt LaPlante3f6dee92006-10-03 22:45:33 +0200418 Forces specified clocksource (if available) to be used
john stultz734efb42006-06-26 00:25:05 -0700419 when calculating gettimeofday(). If specified
Matt LaPlante3f6dee92006-10-03 22:45:33 +0200420 clocksource is not available, it defaults to PIT.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700421 Format: { pit | tsc | cyclone | pmtmr }
422
Randy Dunlap3d6ac982007-05-23 13:58:16 -0700423 clocksource= [GENERIC_TIME] Override the default clocksource
424 Format: <string>
425 Override the default clocksource and use the clocksource
426 with the name specified.
427 Some clocksource names to choose from, depending on
428 the platform:
429 [all] jiffies (this is the base, fallback clocksource)
430 [ACPI] acpi_pm
431 [ARM] imx_timer1,OSTS,netx_timer,mpu_timer2,
432 pxa_timer,timer3,32k_counter,timer0_1
433 [AVR32] avr32
Alan Coxcd4f0ef2007-07-31 00:37:59 -0700434 [X86-32] pit,hpet,tsc,vmi-timer;
Randy Dunlap3d6ac982007-05-23 13:58:16 -0700435 scx200_hrt on Geode; cyclone on IBM x440
436 [MIPS] MIPS
437 [PARISC] cr16
438 [S390] tod
439 [SH] SuperH
440 [SPARC64] tick
441 [X86-64] hpet,tsc
442
Andi Kleenac72e782008-01-30 13:33:21 +0100443 clearcpuid=BITNUM [X86]
444 Disable CPUID feature X for the kernel. See
445 include/asm-x86/cpufeature.h for the valid bit numbers.
446 Note the Linux specific bits are not necessarily
447 stable over kernel options, but the vendor specific
448 ones should be.
449 Also note that user programs calling CPUID directly
450 or using the feature without checking anything
451 will still see it. This just prevents it from
452 being used by the kernel or shown in /proc/cpuinfo.
453 Also note the kernel might malfunction if you disable
454 some critical bits.
455
Arjan van de Vena25bd942008-01-30 13:33:08 +0100456 code_bytes [IA32/X86_64] How many bytes of object code to print
457 in an oops report.
Chuck Ebbert86c41832007-02-13 13:26:25 +0100458 Range: 0 - 8192
459 Default: 64
460
Andi Kleenf9262c12006-03-08 17:57:25 -0800461 disable_8254_timer
462 enable_8254_timer
463 [IA32/X86_64] Disable/Enable interrupt 0 timer routing
464 over the 8254 in addition to over the IO-APIC. The
465 kernel tries to set a sensible default.
466
Thomas Gleixnerb17530b2007-10-19 20:35:02 +0200467 hpet= [X86-32,HPET] option to control HPET usage
468 Format: { enable (default) | disable | force }
469 disable: disable HPET and use PIT instead
Carlos Corbachod79a5f82007-10-19 18:51:27 +0100470 force: allow force enabled of undocumented chips (ICH4,
471 VIA, nVidia)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700472
Linus Torvalds1da177e2005-04-16 15:20:36 -0700473 com20020= [HW,NET] ARCnet - COM20020 chipset
Randy Dunlapa9913042005-10-23 12:57:11 -0700474 Format:
475 <io>[,<irq>[,<nodeID>[,<backplane>[,<ckp>[,<timeout>]]]]]
Linus Torvalds1da177e2005-04-16 15:20:36 -0700476
477 com90io= [HW,NET] ARCnet - COM90xx chipset (IO-mapped buffers)
478 Format: <io>[,<irq>]
479
Randy Dunlapa9913042005-10-23 12:57:11 -0700480 com90xx= [HW,NET]
481 ARCnet - COM90xx chipset (memory-mapped buffers)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700482 Format: <io>[,<irq>[,<memstart>]]
483
484 condev= [HW,S390] console device
485 conmode=
Randy Dunlapa9913042005-10-23 12:57:11 -0700486
Linus Torvalds1da177e2005-04-16 15:20:36 -0700487 console= [KNL] Output console device and options.
488
489 tty<n> Use the virtual console device <n>.
490
491 ttyS<n>[,options]
Randy Dunlapf1a1c2d2006-03-25 03:08:17 -0800492 ttyUSB0[,options]
Linus Torvalds1da177e2005-04-16 15:20:36 -0700493 Use the specified serial port. The options are of
Randy Dunlapf1a1c2d2006-03-25 03:08:17 -0800494 the form "bbbbpnf", where "bbbb" is the baud rate,
495 "p" is parity ("n", "o", or "e"), "n" is number of
496 bits, and "f" is flow control ("r" for RTS or
497 omit it). Default is "9600n8".
Linus Torvalds1da177e2005-04-16 15:20:36 -0700498
Randy Dunlapf1a1c2d2006-03-25 03:08:17 -0800499 See Documentation/serial-console.txt for more
500 information. See
501 Documentation/networking/netconsole.txt for an
502 alternative.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700503
Yinghai Lu18a8bd92007-07-15 23:37:59 -0700504 uart[8250],io,<addr>[,options]
505 uart[8250],mmio,<addr>[,options]
Linus Torvalds1da177e2005-04-16 15:20:36 -0700506 Start an early, polled-mode console on the 8250/16550
507 UART at the specified I/O port or MMIO address,
508 switching to the matching ttyS device later. The
509 options are the same as for ttyS, above.
510
Samuel Thibaultf7511d52008-04-30 00:54:51 -0700511 If the device connected to the port is not a TTY but a braille
512 device, prepend "brl," before the device type, for instance
513 console=brl,ttyS0
514 For now, only VisioBraille is supported.
515
Yinghai Lu18a8bd92007-07-15 23:37:59 -0700516 earlycon= [KNL] Output early console device and options.
517 uart[8250],io,<addr>[,options]
518 uart[8250],mmio,<addr>[,options]
519 Start an early, polled-mode console on the 8250/16550
520 UART at the specified I/O port or MMIO address.
521 The options are the same as for ttyS, above.
522
Andres Salomon8f4ce8c2007-10-18 03:04:50 -0700523 no_console_suspend
524 [HW] Never suspend the console
525 Disable suspending of consoles during suspend and
526 hibernate operations. Once disabled, debugging
527 messages can reach various consoles while the rest
528 of the system is being put to sleep (ie, while
529 debugging driver suspend/resume hooks). This may
530 not work reliably with all consoles, but is known
531 to work with serial and VGA consoles.
532
Linus Torvalds1da177e2005-04-16 15:20:36 -0700533 cpcihp_generic= [HW,PCI] Generic port I/O CompactPCI driver
Randy Dunlapa9913042005-10-23 12:57:11 -0700534 Format:
535 <first_slot>,<last_slot>,<port>,<enum_bit>[,<debug>]
Linus Torvalds1da177e2005-04-16 15:20:36 -0700536
Eric W. Biedermandc009d92005-06-25 14:57:52 -0700537 crashkernel=nn[KMG]@ss[KMG]
538 [KNL] Reserve a chunk of physical memory to
539 hold a kernel to switch to with kexec on panic.
540
Bernhard Wallefb391592007-10-18 23:41:02 -0700541 crashkernel=range1:size1[,range2:size2,...][@offset]
542 [KNL] Same as above, but depends on the memory
543 in the running system. The syntax of range is
544 start-[end] where start and end are both
545 a memory unit (amount[KMG]). See also
546 Documentation/kdump/kdump.txt for a example.
547
Linus Torvalds1da177e2005-04-16 15:20:36 -0700548 cs4232= [HW,OSS]
549 Format: <io>,<irq>,<dma>,<dma2>,<mpuio>,<mpuirq>
550
551 cs89x0_dma= [HW,NET]
552 Format: <dma>
553
554 cs89x0_media= [HW,NET]
555 Format: { rj45 | aui | bnc }
Randy Dunlapa9913042005-10-23 12:57:11 -0700556
Randy Dunlapa9913042005-10-23 12:57:11 -0700557 dasd= [HW,NET]
Linus Torvalds1da177e2005-04-16 15:20:36 -0700558 See header of drivers/s390/block/dasd_devmap.c.
559
560 db9.dev[2|3]= [HW,JOY] Multisystem joystick support via parallel port
561 (one device per port)
562 Format: <port#>,<type>
563 See also Documentation/input/joystick-parport.txt
564
565 debug [KNL] Enable kernel debugging (events log level).
566
Ingo Molnarcae2ed92006-07-03 00:24:48 -0700567 debug_locks_verbose=
568 [KNL] verbose self-tests
569 Format=<0|1>
570 Print debugging info while doing the locking API
571 self-tests.
572 We default to 0 (no extra messages), setting it to
573 1 will print _a lot_ more information - normally
574 only useful to kernel developers.
575
Thomas Gleixner3ac7fe52008-04-30 00:55:01 -0700576 debug_objects [KNL] Enable object debugging
577
Thomas Gleixnerd3af01f2008-07-15 15:04:56 +0200578 debugpat [X86] Enable PAT debugging
579
Robert P. J. Day2d27a962008-02-03 15:18:45 +0200580 decnet.addr= [HW,NET]
Linus Torvalds1da177e2005-04-16 15:20:36 -0700581 Format: <area>[,<node>]
582 See also Documentation/networking/decnet.txt.
583
Samuel Thibaultecb77fa2008-01-03 16:17:54 +0000584 vt.default_blu= [VT]
Antonino A. Daplas55ff9782007-05-08 00:38:53 -0700585 Format: <blue0>,<blue1>,<blue2>,...,<blue15>
586 Change the default blue palette of the console.
587 This is a 16-member array composed of values
588 ranging from 0-255.
589
Samuel Thibaultecb77fa2008-01-03 16:17:54 +0000590 vt.default_grn= [VT]
Antonino A. Daplas55ff9782007-05-08 00:38:53 -0700591 Format: <green0>,<green1>,<green2>,...,<green15>
592 Change the default green palette of the console.
593 This is a 16-member array composed of values
594 ranging from 0-255.
595
Samuel Thibaultecb77fa2008-01-03 16:17:54 +0000596 vt.default_red= [VT]
Antonino A. Daplas55ff9782007-05-08 00:38:53 -0700597 Format: <red0>,<red1>,<red2>,...,<red15>
598 Change the default red palette of the console.
599 This is a 16-member array composed of values
600 ranging from 0-255.
601
Samuel Thibaultecb77fa2008-01-03 16:17:54 +0000602 vt.default_utf8=
603 [VT]
Antonino A. Daplas55ff9782007-05-08 00:38:53 -0700604 Format=<0|1>
605 Set system-wide default UTF-8 mode for all tty's.
Samuel Thibaultecb77fa2008-01-03 16:17:54 +0000606 Default is 1, i.e. UTF-8 mode is enabled for all
607 newly opened terminals.
Antonino A. Daplas55ff9782007-05-08 00:38:53 -0700608
Linus Torvalds1da177e2005-04-16 15:20:36 -0700609 dhash_entries= [KNL]
610 Set number of hash buckets for dentry cache.
Randy Dunlapa9913042005-10-23 12:57:11 -0700611
Linus Torvalds1da177e2005-04-16 15:20:36 -0700612 digi= [HW,SERIAL]
613 IO parameters + enable/disable command.
614
615 digiepca= [HW,SERIAL]
616 See drivers/char/README.epca and
617 Documentation/digiepca.txt.
618
Yinghai Lu95ffa242008-04-29 03:52:33 -0700619 disable_mtrr_cleanup [X86]
620 enable_mtrr_cleanup [X86]
621 The kernel tries to adjust MTRR layout from continuous
622 to discrete, to make X server driver able to add WB
623 entry later. This parameter enables/disables that.
624
625 mtrr_chunk_size=nn[KMG] [X86]
626 used for mtrr cleanup. It is largest continous chunk
627 that could hold holes aka. UC entries.
628
629 mtrr_gran_size=nn[KMG] [X86]
Yinghai Lu12031a62008-05-02 02:40:22 -0700630 Used for mtrr cleanup. It is granularity of mtrr block.
631 Default is 1.
632 Large value could prevent small alignment from
633 using up MTRRs.
634
635 mtrr_spare_reg_nr=n [X86]
636 Format: <integer>
637 Range: 0,7 : spare reg number
638 Default : 1
639 Used for mtrr cleanup. It is spare mtrr entries number.
640 Set to 2 or more if your graphical card needs more.
Yinghai Lu95ffa242008-04-29 03:52:33 -0700641
Yinghai Lu093af8d2008-01-30 13:33:32 +0100642 disable_mtrr_trim [X86, Intel and AMD only]
Jesse Barnes99fc8d42008-01-30 13:33:18 +0100643 By default the kernel will trim any uncacheable
644 memory out of your available memory pool based on
645 MTRR settings. This parameter disables that behavior,
646 possibly causing your machine to run very slowly.
647
Linus Torvalds1da177e2005-04-16 15:20:36 -0700648 dmasound= [HW,OSS] Sound subsystem buffers
649
650 dscc4.setup= [NET]
651
652 dtc3181e= [HW,SCSI]
653
Robin Getz0ae53642007-10-09 17:24:49 +0800654 earlyprintk= [X86-32,X86-64,SH,BLACKFIN]
Linus Torvalds1da177e2005-04-16 15:20:36 -0700655 earlyprintk=vga
656 earlyprintk=serial[,ttySn[,baudrate]]
657
Randy Dunlapa9913042005-10-23 12:57:11 -0700658 Append ",keep" to not disable it when the real console
Linus Torvalds1da177e2005-04-16 15:20:36 -0700659 takes over.
660
661 Only vga or serial at a time, not both.
662
663 Currently only ttyS0 and ttyS1 are supported.
664
665 Interaction with the standard serial driver is not
666 very good.
667
668 The VGA output is eventually overwritten by the real
669 console.
670
671 eata= [HW,SCSI]
672
Linus Torvalds1da177e2005-04-16 15:20:36 -0700673 edd= [EDD]
Tim Gardner8c4dd602008-04-29 01:02:45 -0700674 Format: {"off" | "on" | "skip[mbr]"}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700675
Linus Torvalds1da177e2005-04-16 15:20:36 -0700676 eisa_irq_edge= [PARISC,HW]
677 See header of drivers/parisc/eisa.c.
678
Alan Coxcd4f0ef2007-07-31 00:37:59 -0700679 elanfreq= [X86-32]
Linus Torvalds1da177e2005-04-16 15:20:36 -0700680 See comment before function elanfreq_setup() in
Pavel Machek71f77052008-07-04 09:59:43 -0700681 arch/x86/kernel/cpu/cpufreq/elanfreq.c.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700682
683 elevator= [IOSCHED]
Randy Dunlap16ab3ad2006-01-14 13:21:20 -0800684 Format: {"anticipatory" | "cfq" | "deadline" | "noop"}
Randy Dunlapa9913042005-10-23 12:57:11 -0700685 See Documentation/block/as-iosched.txt and
686 Documentation/block/deadline-iosched.txt for details.
687
Alan Coxcd4f0ef2007-07-31 00:37:59 -0700688 elfcorehdr= [X86-32, X86_64]
Randy Dunlapa9913042005-10-23 12:57:11 -0700689 Specifies physical address of start of kernel core
Vivek Goyalaac04b32006-01-09 20:51:47 -0800690 image elf header. Generally kexec loader will
691 pass this option to capture kernel.
692 See Documentation/kdump/kdump.txt for details.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700693
694 enforcing [SELINUX] Set initial enforcing status.
695 Format: {"0" | "1"}
696 See security/selinux/Kconfig help text.
697 0 -- permissive (log only, no denials).
698 1 -- enforcing (deny and log).
699 Default value is 0.
700 Value can be changed at runtime via /selinux/enforce.
701
Linus Torvalds1da177e2005-04-16 15:20:36 -0700702 es1371= [HW,OSS]
703 Format: <spdif>,[<nomix>,[<amplifier>]]
704 See also header of sound/oss/es1371.c.
Randy Dunlapa9913042005-10-23 12:57:11 -0700705
Linus Torvalds1da177e2005-04-16 15:20:36 -0700706 ether= [HW,NET] Ethernet cards parameters
707 This option is obsoleted by the "netdev=" option, which
708 has equivalent usage. See its documentation for details.
709
710 eurwdt= [HW,WDT] Eurotech CPU-1220/1410 onboard watchdog.
711 Format: <io>[,<irq>]
712
Akinobu Mitade1ba092006-12-08 02:39:42 -0800713 failslab=
714 fail_page_alloc=
715 fail_make_request=[KNL]
716 General fault injection mechanism.
717 Format: <interval>,<probability>,<space>,<times>
718 See also /Documentation/fault-injection/.
719
Linus Torvalds1da177e2005-04-16 15:20:36 -0700720 fd_mcs= [HW,SCSI]
721 See header of drivers/scsi/fd_mcs.c.
722
723 fdomain= [HW,SCSI]
724 See header of drivers/scsi/fdomain.c.
725
726 floppy= [HW]
727 See Documentation/floppy.txt.
728
Alex Chiangf13ae302008-05-08 14:03:23 -0600729 force_pal_cache_flush
730 [IA-64] Avoid check_sal_cache_flush which may hang on
731 buggy SAL_CACHE_FLUSH implementations. Using this
732 parameter will force ia64_sal_cache_flush to call
733 ia64_pal_cache_flush instead of SAL_CACHE_FLUSH.
734
Linus Torvalds1da177e2005-04-16 15:20:36 -0700735 gamecon.map[2|3]=
736 [HW,JOY] Multisystem joystick and NES/SNES/PSX pad
737 support via parallel port (up to 5 devices per port)
738 Format: <port#>,<pad1>,<pad2>,<pad3>,<pad4>,<pad5>
739 See also Documentation/input/joystick-parport.txt
740
741 gamma= [HW,DRM]
742
Yinghai Luaaf23042008-01-30 13:33:09 +0100743 gart_fix_e820= [X86_64] disable the fix e820 for K8 GART
744 Format: off | on
745 default: on
746
Linus Torvalds1da177e2005-04-16 15:20:36 -0700747 gdth= [HW,SCSI]
748 See header of drivers/scsi/gdth.c.
749
750 gpt [EFI] Forces disk with valid GPT signature but
751 invalid Protective MBR to be treated as GPT.
752
Linus Torvalds1da177e2005-04-16 15:20:36 -0700753 gvp11= [HW,SCSI]
754
755 hashdist= [KNL,NUMA] Large hashes allocated during boot
756 are distributed across NUMA nodes. Defaults on
757 for IA-64, off otherwise.
Randy Dunlapa9913042005-10-23 12:57:11 -0700758 Format: 0 | 1 (for off | on)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700759
760 hcl= [IA-64] SGI's Hardware Graph compatibility layer
761
762 hd= [EIDE] (E)IDE hard drive subsystem geometry
763 Format: <cyl>,<head>,<sect>
764
Linus Torvalds1da177e2005-04-16 15:20:36 -0700765 highmem=nn[KMG] [KNL,BOOT] forces the highmem zone to have an exact
766 size of <nn>. This works even on boxes that have no
767 highmem otherwise. This also works to reduce highmem
768 size on bigger boxes.
769
Thomas Gleixner54cdfdb2007-02-16 01:28:11 -0800770 highres= [KNL] Enable/disable high resolution timer mode.
771 Valid parameters: "on", "off"
772 Default: "on"
773
Linus Torvalds1da177e2005-04-16 15:20:36 -0700774 hisax= [HW,ISDN]
775 See Documentation/isdn/README.HiSax.
776
Andi Kleenb4718e62008-07-23 21:27:51 -0700777 hugepages= [HW,X86-32,IA-64] HugeTLB pages to allocate at boot.
778 hugepagesz= [HW,IA-64,PPC,X86-64] The size of the HugeTLB pages.
779 On x86 this option can be specified multiple times
780 interleaved with hugepages= to reserve huge pages
781 of different sizes. Valid pages sizes on x86-64
782 are 2M (when the CPU supports "pse") and 1G (when the
783 CPU supports the "pdpe1gb" cpuinfo flag)
784 Note that 1GB pages can only be allocated at boot time
785 using hugepages= and not freed afterwards.
Nick Piggine11bfbf2008-07-23 21:27:52 -0700786 default_hugepagesz=
787 [same as hugepagesz=] The size of the default
788 HugeTLB page size. This is the size represented by
789 the legacy /proc/ hugepages APIs, used for SHM, and
790 default size when mounting hugetlbfs filesystems.
791 Defaults to the default architecture's huge page size
792 if not specified.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700793
Linus Torvalds1da177e2005-04-16 15:20:36 -0700794 i8042.direct [HW] Put keyboard port into non-translated mode
Matt LaPlante84eb8d02006-10-03 22:53:09 +0200795 i8042.dumbkbd [HW] Pretend that controller can only read data from
796 keyboard and cannot control its state
Linus Torvalds1da177e2005-04-16 15:20:36 -0700797 (Don't attempt to blink the leds)
798 i8042.noaux [HW] Don't check for auxiliary (== mouse) port
Dmitry Torokhov945ef0d2005-09-04 01:42:00 -0500799 i8042.nokbd [HW] Don't check/create keyboard port
Jiri Kosina75d08c72008-03-13 16:13:59 -0400800 i8042.noloop [HW] Disable the AUX Loopback command while probing
801 for the AUX port
Linus Torvalds1da177e2005-04-16 15:20:36 -0700802 i8042.nomux [HW] Don't check presence of an active multiplexing
803 controller
804 i8042.nopnp [HW] Don't use ACPIPnP / PnPBIOS to discover KBD/AUX
805 controllers
806 i8042.panicblink=
807 [HW] Frequency with which keyboard LEDs should blink
808 when kernel panics (default is 0.5 sec)
809 i8042.reset [HW] Reset the controller during init and cleanup
810 i8042.unlock [HW] Unlock (ignore) the keylock
811
812 i810= [HW,DRM]
813
Dmitry Torokhove70c9d52005-06-25 14:54:25 -0700814 i8k.ignore_dmi [HW] Continue probing hardware even if DMI data
815 indicates that the driver is running on unsupported
816 hardware.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700817 i8k.force [HW] Activate i8k driver even if SMM BIOS signature
818 does not match list of supported models.
819 i8k.power_status
820 [HW] Report power status in /proc/i8k
821 (disabled by default)
822 i8k.restricted [HW] Allow controlling fans only if SYS_ADMIN
823 capability is set.
824
825 ibmmcascsi= [HW,MCA,SCSI] IBM MicroChannel SCSI adapter
826 See Documentation/mca.txt.
827
828 icn= [HW,ISDN]
829 Format: <io>[,<membase>[,<icn_id>[,<icn_id2>]]]
830
831 ide= [HW] (E)IDE subsystem
Greg Kroah-Hartmana594eeb2008-04-18 00:46:20 +0200832 Format: ide=nodma or ide=doubler
Randy Dunlap1c10e932008-03-07 21:53:50 +0100833 See Documentation/ide/ide.txt.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700834
Linus Torvalds1da177e2005-04-16 15:20:36 -0700835 idebus= [HW] (E)IDE subsystem - VLB/PCI bus speed
Randy Dunlap1c10e932008-03-07 21:53:50 +0100836 See Documentation/ide/ide.txt.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700837
Andi Kleenf039b752007-05-02 19:27:12 +0200838 idle= [X86]
Zhao Yakuida5e09a2008-06-24 18:01:09 +0800839 Format: idle=poll or idle=mwait, idle=halt, idle=nomwait
Andi Kleenf039b752007-05-02 19:27:12 +0200840 Poll forces a polling idle loop that can slightly improves the performance
841 of waking up a idle CPU, but will use a lot of power and make the system
842 run hot. Not recommended.
843 idle=mwait. On systems which support MONITOR/MWAIT but the kernel chose
844 to not use it because it doesn't save as much power as a normal idle
845 loop use the MONITOR/MWAIT idle loop anyways. Performance should be the same
846 as idle=poll.
Zhao Yakuic1e3b372008-06-24 17:58:53 +0800847 idle=halt. Halt is forced to be used for CPU idle.
848 In such case C2/C3 won't be used again.
Zhao Yakuida5e09a2008-06-24 18:01:09 +0800849 idle=nomwait. Disable mwait for CPU C-states
Randy Dunlapa9913042005-10-23 12:57:11 -0700850
Denis Cheng594765a2008-02-06 02:57:49 +0100851 ide-pci-generic.all-generic-ide [HW] (E)IDE subsystem
852 Claim all unknown PCI IDE storage controllers.
853
Ingo Molnar792908222006-12-06 20:40:51 -0800854 ignore_loglevel [KNL]
855 Ignore loglevel setting - this will print /all/
856 kernel messages to the console. Useful for debugging.
857
Linus Torvalds1da177e2005-04-16 15:20:36 -0700858 ihash_entries= [KNL]
859 Set number of hash buckets for inode cache.
860
861 in2000= [HW,SCSI]
862 See header of drivers/scsi/in2000.c.
863
864 init= [KNL]
865 Format: <full_path>
866 Run specified binary instead of /sbin/init as init
867 process.
868
869 initcall_debug [KNL] Trace initcalls as they are executed. Useful
870 for working out where the kernel is dying during
871 startup.
872
873 initrd= [BOOT] Specify the location of the initial ramdisk
874
875 inport.irq= [HW] Inport (ATI XL and Microsoft) busmouse driver
876 Format: <irq>
877
878 inttest= [IA64]
879
Pavel Machekb552da82008-03-19 15:58:11 +0100880 iommu= [x86]
881 off
882 force
883 noforce
884 biomerge
885 panic
886 nopanic
887 merge
888 nomerge
889 forcesac
890 soft
891
892
Keshavamurthy, Anil Sba395922007-10-21 16:41:49 -0700893 intel_iommu= [DMAR] Intel IOMMU driver (DMAR) option
894 off
895 Disable intel iommu driver.
896 igfx_off [Default Off]
897 By default, gfx is mapped as normal device. If a gfx
898 device has a dedicated DMAR unit, the DMAR unit is
899 bypassed by not enabling DMAR with this option. In
900 this case, gfx device will use physical address for
901 DMA.
Keshavamurthy, Anil S7d3b03c2007-10-21 16:41:53 -0700902 forcedac [x86_64]
903 With this option iommu will not optimize to look
904 for io virtual address below 32 bit forcing dual
905 address cycle on pci bus for cards supporting greater
906 than 32 bit addressing. The default is to look
907 for translation below 32 bit and if not available
908 then look in the higher range.
mark gross5e0d2a62008-03-04 15:22:08 -0800909 strict [Default Off]
910 With this option on every unmap_single operation will
911 result in a hardware IOTLB flush operation as opposed
912 to batching them for performance.
Keshavamurthy, Anil Sba395922007-10-21 16:41:49 -0700913
Rene Hermanb02aae92008-01-30 13:30:05 +0100914 io_delay= [X86-32,X86-64] I/O delay method
Ingo Molnar6e7c4022008-01-30 13:30:05 +0100915 0x80
916 Standard port 0x80 based delay
917 0xed
918 Alternate port 0xed based delay (needed on some systems)
Rene Hermanb02aae92008-01-30 13:30:05 +0100919 udelay
Ingo Molnar6e7c4022008-01-30 13:30:05 +0100920 Simple two microseconds delay
921 none
922 No delay
Rene Hermanb02aae92008-01-30 13:30:05 +0100923
Linus Torvalds1da177e2005-04-16 15:20:36 -0700924 io7= [HW] IO7 for Marvel based alpha systems
925 See comment before marvel_specify_io7 in
926 arch/alpha/kernel/core_marvel.c.
927
928 ip= [IP_PNP]
J. Bruce Fields6ded55d2008-04-07 15:59:03 -0400929 See Documentation/filesystems/nfsroot.txt.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700930
931 ip2= [HW] Set IO/IRQ pairs for up to 4 IntelliPort boards
Randy Dunlapc8facbb2007-07-31 00:37:40 -0700932 See comment before ip2_setup() in
933 drivers/char/ip2/ip2base.c.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700934
935 ips= [HW,SCSI] Adaptec / IBM ServeRAID controller
936 See header of drivers/scsi/ips.c.
937
Simon Horman72c4a132006-09-13 19:57:18 -0700938 ports= [IP_VS_FTP] IPVS ftp helper module
939 Default is 21.
940 Up to 8 (IP_VS_APP_MAX_PORTS) ports
941 may be specified.
942 Format: <port>,<port>....
943
Alan Cox200803d2005-06-28 20:45:18 -0700944 irqfixup [HW]
945 When an interrupt is not handled search all handlers
946 for it. Intended to get systems with badly broken
947 firmware running.
948
949 irqpoll [HW]
950 When an interrupt is not handled search all handlers
951 for it. Also check all handlers each timer
952 interrupt. Intended to get systems with badly broken
953 firmware running.
954
Linus Torvalds1da177e2005-04-16 15:20:36 -0700955 isapnp= [ISAPNP]
Randy Dunlapa9913042005-10-23 12:57:11 -0700956 Format: <RDP>,<reset>,<pci_scan>,<verbosity>
Linus Torvalds1da177e2005-04-16 15:20:36 -0700957
958 isolcpus= [KNL,SMP] Isolate CPUs from the general scheduler.
Derek Fults22f2e282006-12-06 20:37:11 -0800959 Format:
960 <cpu number>,...,<cpu number>
961 or
962 <cpu number>-<cpu number> (must be a positive range in ascending order)
963 or a mixture
964 <cpu number>,...,<cpu number>-<cpu number>
Linus Torvalds1da177e2005-04-16 15:20:36 -0700965 This option can be used to specify one or more CPUs
966 to isolate from the general SMP balancing and scheduling
967 algorithms. The only way to move a process onto or off
968 an "isolated" CPU is via the CPU affinity syscalls.
969 <cpu number> begins at 0 and the maximum value is
970 "number of CPUs in system - 1".
971
972 This option is the preferred way to isolate CPUs. The
Randy Dunlapa9913042005-10-23 12:57:11 -0700973 alternative -- manually setting the CPU mask of all
974 tasks in the system -- can cause problems and
975 suboptimal load balancer performance.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700976
Randy Dunlapa9913042005-10-23 12:57:11 -0700977 iucv= [HW,NET]
Linus Torvalds1da177e2005-04-16 15:20:36 -0700978
979 js= [HW,JOY] Analog joystick
980 See Documentation/input/joystick.txt.
981
Alan Coxcd4f0ef2007-07-31 00:37:59 -0700982 kernelcore=nn[KMG] [KNL,X86-32,IA-64,PPC,X86-64] This parameter
Mel Gormaned7ed362007-07-17 04:03:14 -0700983 specifies the amount of memory usable by the kernel
984 for non-movable allocations. The requested amount is
985 spread evenly throughout all nodes in the system. The
986 remaining memory in each node is used for Movable
987 pages. In the event, a node is too small to have both
988 kernelcore and Movable pages, kernelcore pages will
989 take priority and other nodes will have a larger number
990 of kernelcore pages. The Movable zone is used for the
991 allocation of pages that may be reclaimed or moved
992 by the page migration subsystem. This means that
993 HugeTLB pages may not be allocated from this zone.
994 Note that allocations like PTEs-from-HighMem still
995 use the HighMem zone if it exists, and the Normal
996 zone if it does not.
997
Alan Coxcd4f0ef2007-07-31 00:37:59 -0700998 movablecore=nn[KMG] [KNL,X86-32,IA-64,PPC,X86-64] This parameter
Mel Gorman7e63efe2007-07-17 04:03:15 -0700999 is similar to kernelcore except it specifies the
1000 amount of memory used for migratable allocations.
1001 If both kernelcore and movablecore is specified,
1002 then kernelcore will be at *least* the specified
1003 value but may be more. If movablecore on its own
1004 is specified, the administrator must be careful
1005 that the amount of memory usable for all allocations
1006 is not too small.
1007
Linus Torvalds1da177e2005-04-16 15:20:36 -07001008 keepinitrd [HW,ARM]
1009
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001010 kstack=N [X86-32,X86-64] Print N words from the kernel stack
Linus Torvalds1da177e2005-04-16 15:20:36 -07001011 in oops dumps.
1012
Jason Wessel6cdf6e02008-04-17 20:05:38 +02001013 kgdboc= [HW] kgdb over consoles.
1014 Requires a tty driver that supports console polling.
1015 (only serial suported for now)
1016 Format: <serial_device>[,baud]
1017
Linus Torvalds1da177e2005-04-16 15:20:36 -07001018 l2cr= [PPC]
1019
Robert Brosea78bfbf2008-03-29 07:20:23 +11001020 l3cr= [PPC]
1021
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001022 lapic [X86-32,APIC] Enable the local APIC even if BIOS
Randy Dunlapa9913042005-10-23 12:57:11 -07001023 disabled it.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001024
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001025 lapic_timer_c2_ok [X86-32,x86-64,APIC] trust the local apic timer in
Thomas Gleixnere585bef2007-03-23 16:08:01 +01001026 C2 power state.
1027
FD Camifcb71f62008-01-06 19:08:56 +01001028 libata.dma= [LIBATA] DMA control
1029 libata.dma=0 Disable all PATA and SATA DMA
1030 libata.dma=1 PATA and SATA Disk DMA only
1031 libata.dma=2 ATAPI (CDROM) DMA only
1032 libata.dma=4 Compact Flash DMA only
1033 Combinations also work, so libata.dma=3 enables DMA
1034 for disks and CDROMs, but not CFs.
1035
Dave Jones78e70c22007-09-27 11:50:13 -04001036 libata.noacpi [LIBATA] Disables use of ACPI in libata suspend/resume
1037 when set.
1038 Format: <int>
1039
Tejun Heo33267322008-02-13 09:15:09 +09001040 libata.force= [LIBATA] Force configurations. The format is comma
1041 separated list of "[ID:]VAL" where ID is
1042 PORT[:DEVICE]. PORT and DEVICE are decimal numbers
1043 matching port, link or device. Basically, it matches
1044 the ATA ID string printed on console by libata. If
1045 the whole ID part is omitted, the last PORT and DEVICE
1046 values are used. If ID hasn't been specified yet, the
1047 configuration applies to all ports, links and devices.
1048
1049 If only DEVICE is omitted, the parameter applies to
1050 the port and all links and devices behind it. DEVICE
1051 number of 0 either selects the first device or the
1052 first fan-out link behind PMP device. It does not
1053 select the host link. DEVICE number of 15 selects the
1054 host link and device attached to it.
1055
1056 The VAL specifies the configuration to force. As long
1057 as there's no ambiguity shortcut notation is allowed.
1058 For example, both 1.5 and 1.5G would work for 1.5Gbps.
1059 The following configurations can be forced.
1060
1061 * Cable type: 40c, 80c, short40c, unk, ign or sata.
1062 Any ID with matching PORT is used.
1063
1064 * SATA link speed limit: 1.5Gbps or 3.0Gbps.
1065
1066 * Transfer mode: pio[0-7], mwdma[0-4] and udma[0-7].
1067 udma[/][16,25,33,44,66,100,133] notation is also
1068 allowed.
1069
1070 * [no]ncq: Turn on or off NCQ.
1071
1072 If there are multiple matching configurations changing
1073 the same attribute, the last one is used.
1074
Linus Torvalds1da177e2005-04-16 15:20:36 -07001075 load_ramdisk= [RAM] List of ramdisks to load from floppy
1076 See Documentation/ramdisk.txt.
1077
Randy Dunlapa6b25b62006-01-14 13:21:19 -08001078 lockd.nlm_grace_period=P [NFS] Assign grace period.
1079 Format: <integer>
Linus Torvalds1da177e2005-04-16 15:20:36 -07001080
Randy Dunlapa6b25b62006-01-14 13:21:19 -08001081 lockd.nlm_tcpport=N [NFS] Assign TCP port.
1082 Format: <integer>
1083
1084 lockd.nlm_timeout=T [NFS] Assign timeout value.
1085 Format: <integer>
1086
1087 lockd.nlm_udpport=M [NFS] Assign UDP port.
1088 Format: <integer>
Linus Torvalds1da177e2005-04-16 15:20:36 -07001089
1090 logibm.irq= [HW,MOUSE] Logitech Bus Mouse Driver
1091 Format: <irq>
1092
1093 loglevel= All Kernel Messages with a loglevel smaller than the
1094 console loglevel will be printed to the console. It can
1095 also be changed with klogd or other programs. The
1096 loglevels are defined as follows:
1097
1098 0 (KERN_EMERG) system is unusable
1099 1 (KERN_ALERT) action must be taken immediately
1100 2 (KERN_CRIT) critical conditions
1101 3 (KERN_ERR) error conditions
1102 4 (KERN_WARNING) warning conditions
1103 5 (KERN_NOTICE) normal but significant condition
1104 6 (KERN_INFO) informational
1105 7 (KERN_DEBUG) debug-level messages
1106
1107 log_buf_len=n Sets the size of the printk ring buffer, in bytes.
Randy Dunlapa9913042005-10-23 12:57:11 -07001108 Format: { n | nk | nM }
1109 n must be a power of two. The default size
1110 is set in the kernel config file.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001111
Randy Dunlapaccaa242007-10-16 01:29:37 -07001112 logo.nologo [FB] Disables display of the built-in Linux logo.
1113 This may be used to provide more screen space for
1114 kernel log messages and is useful when debugging
1115 kernel boot problems.
1116
Linus Torvalds1da177e2005-04-16 15:20:36 -07001117 lp=0 [LP] Specify parallel ports to use, e.g,
1118 lp=port[,port...] lp=none,parport0 (lp0 not configured, lp1 uses
1119 lp=reset first parallel port). 'lp=0' disables the
1120 lp=auto printer driver. 'lp=reset' (which can be
1121 specified in addition to the ports) causes
1122 attached printers to be reset. Using
1123 lp=port1,port2,... specifies the parallel ports
1124 to associate lp devices with, starting with
1125 lp0. A port specification may be 'none' to skip
1126 that lp device, or a parport name such as
1127 'parport0'. Specifying 'lp=auto' instead of a
1128 port specification list means that device IDs
1129 from each port should be examined, to see if
1130 an IEEE 1284-compliant printer is attached; if
1131 so, the driver will manage that printer.
1132 See also header of drivers/char/lp.c.
1133
1134 lpj=n [KNL]
1135 Sets loops_per_jiffy to given constant, thus avoiding
1136 time-consuming boot-time autodetection (up to 250 ms per
1137 CPU). 0 enables autodetection (default). To determine
1138 the correct value for your kernel, boot with normal
1139 autodetection and see what value is printed. Note that
1140 on SMP systems the preset will be applied to all CPUs,
1141 which is likely to cause problems if your CPUs need
1142 significantly divergent settings. An incorrect value
1143 will cause delays in the kernel to be wrong, leading to
1144 unpredictable I/O errors and other breakage. Although
1145 unlikely, in the extreme case this might damage your
1146 hardware.
1147
1148 ltpc= [NET]
1149 Format: <io>,<irq>,<dma>
1150
Randy Dunlapa9913042005-10-23 12:57:11 -07001151 mac5380= [HW,SCSI] Format:
1152 <can_queue>,<cmd_per_lun>,<sg_tablesize>,<hostid>,<use_tags>
Linus Torvalds1da177e2005-04-16 15:20:36 -07001153
Randy Dunlapa9913042005-10-23 12:57:11 -07001154 machvec= [IA64] Force the use of a particular machine-vector
1155 (machvec) in a generic kernel.
1156 Example: machvec=hpzx1_swiotlb
Linus Torvalds1da177e2005-04-16 15:20:36 -07001157
Randy Dunlapa9913042005-10-23 12:57:11 -07001158 max_loop= [LOOP] Maximum number of loopback devices that can
Linus Torvalds1da177e2005-04-16 15:20:36 -07001159 be mounted
1160 Format: <1-256>
1161
1162 maxcpus= [SMP] Maximum number of processors that an SMP kernel
Len Brown61ec7562007-08-16 03:34:22 -04001163 should make use of. maxcpus=n : n >= 0 limits the
1164 kernel to using 'n' processors. n=0 is a special case,
1165 it is equivalent to "nosmp", which also disables
1166 the IO APIC.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001167
Bob Picco2b2c3752005-06-29 18:00:00 -07001168 max_addr=[KMG] [KNL,BOOT,ia64] All physical memory greater than or
1169 equal to this physical address is ignored.
1170
Randy Dunlapa9913042005-10-23 12:57:11 -07001171 max_luns= [SCSI] Maximum number of LUNs to probe.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001172 Should be between 1 and 2^32-1.
1173
1174 max_report_luns=
Randy Dunlapa9913042005-10-23 12:57:11 -07001175 [SCSI] Maximum number of LUNs received.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001176 Should be between 1 and 16384.
1177
Linus Torvalds1da177e2005-04-16 15:20:36 -07001178 mcatest= [IA-64]
1179
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001180 mce [X86-32] Machine Check Exception
Linus Torvalds1da177e2005-04-16 15:20:36 -07001181
Andi Kleen909dd322007-10-17 18:04:38 +02001182 mce=option [X86-64] See Documentation/x86_64/boot-options.txt
1183
Linus Torvalds1da177e2005-04-16 15:20:36 -07001184 md= [HW] RAID subsystems devices and level
1185 See Documentation/md.txt.
Randy Dunlapa9913042005-10-23 12:57:11 -07001186
Linus Torvalds1da177e2005-04-16 15:20:36 -07001187 mdacon= [MDA]
1188 Format: <first>,<last>
1189 Specifies range of consoles to be captured by the MDA.
Randy Dunlapa9913042005-10-23 12:57:11 -07001190
Linus Torvalds1da177e2005-04-16 15:20:36 -07001191 mem=nn[KMG] [KNL,BOOT] Force usage of a specific amount of memory
1192 Amount of memory to be used when the kernel is not able
1193 to see the whole system memory or for test.
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001194 [X86-32] Use together with memmap= to avoid physical
Linus Torvalds1da177e2005-04-16 15:20:36 -07001195 address space collisions. Without memmap= PCI devices
1196 could be placed at addresses belonging to unused RAM.
1197
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001198 mem=nopentium [BUGS=X86-32] Disable usage of 4MB pages for kernel
Linus Torvalds1da177e2005-04-16 15:20:36 -07001199 memory.
1200
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001201 memmap=exactmap [KNL,X86-32,X86_64] Enable setting of an exact
Linus Torvalds1da177e2005-04-16 15:20:36 -07001202 E820 memory map, as specified by the user.
1203 Such memmap=exactmap lines can be constructed based on
1204 BIOS output or other requirements. See the memmap=nn@ss
1205 option description.
1206
1207 memmap=nn[KMG]@ss[KMG]
1208 [KNL] Force usage of a specific region of memory
1209 Region of memory to be used, from ss to ss+nn.
1210
1211 memmap=nn[KMG]#ss[KMG]
1212 [KNL,ACPI] Mark specific memory as ACPI data.
1213 Region of memory to be used, from ss to ss+nn.
1214
1215 memmap=nn[KMG]$ss[KMG]
1216 [KNL,ACPI] Mark specific memory as reserved.
1217 Region of memory to be used, from ss to ss+nn.
Pavel Machek13128482008-03-24 12:29:43 -07001218 Example: Exclude memory from 0x18690000-0x1869ffff
1219 memmap=64K$0x18690000
1220 or
1221 memmap=0x10000$0x18690000
Linus Torvalds1da177e2005-04-16 15:20:36 -07001222
Yinghai Lucaadbdc2008-07-15 00:03:44 -07001223 memtest= [KNL,X86] Enable memtest
Yinghai Luc64df702008-03-21 18:56:19 -07001224 Format: <integer>
1225 range: 0,4 : pattern number
1226 default : 0 <disable>
1227
Linus Torvalds1da177e2005-04-16 15:20:36 -07001228 meye.*= [HW] Set MotionEye Camera parameters
1229 See Documentation/video4linux/meye.txt.
1230
Andres Salomon8f368812007-10-12 23:04:06 +02001231 mfgpt_irq= [IA-32] Specify the IRQ to use for the
1232 Multi-Function General Purpose Timers on AMD Geode
1233 platforms.
1234
Willy Tarreaue6c4dc62008-01-30 13:33:33 +01001235 mfgptfix [X86-32] Fix MFGPT timers on AMD Geode platforms when
1236 the BIOS has incorrectly applied a workaround. TinyBIOS
1237 version 0.98 is known to be affected, 0.99 fixes the
1238 problem by letting the user disable the workaround.
1239
Linus Torvalds1da177e2005-04-16 15:20:36 -07001240 mga= [HW,DRM]
1241
Mel Gorman6b74ab92008-07-23 21:26:49 -07001242 mminit_loglevel=
1243 [KNL] When CONFIG_DEBUG_MEMORY_INIT is set, this
1244 parameter allows control of the logging verbosity for
1245 the additional memory initialisation checks. A value
1246 of 0 disables mminit logging and a level of 4 will
1247 log everything. Information is printed at KERN_DEBUG
1248 so loglevel=8 may also need to be specified.
1249
Linus Torvalds1da177e2005-04-16 15:20:36 -07001250 mousedev.tap_time=
1251 [MOUSE] Maximum time between finger touching and
1252 leaving touchpad surface for touch to be considered
1253 a tap and be reported as a left button click (for
1254 touchpads working in absolute mode only).
1255 Format: <msecs>
1256 mousedev.xres= [MOUSE] Horizontal screen resolution, used for devices
1257 reporting absolute coordinates, such as tablets
1258 mousedev.yres= [MOUSE] Vertical screen resolution, used for devices
1259 reporting absolute coordinates, such as tablets
1260
1261 mpu401= [HW,OSS]
1262 Format: <io>,<irq>
1263
1264 MTD_Partition= [MTD]
1265 Format: <name>,<region-number>,<size>,<offset>
1266
Randy Dunlapa9913042005-10-23 12:57:11 -07001267 MTD_Region= [MTD] Format:
1268 <name>,<region-number>[,<base>,<size>,<buswidth>,<altbuswidth>]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001269
1270 mtdparts= [MTD]
Randy Dunlapc8facbb2007-07-31 00:37:40 -07001271 See drivers/mtd/cmdlinepart.c.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001272
Ben Dooks9db829f2008-07-03 11:24:29 +01001273 mtdset= [ARM]
1274 ARM/S3C2412 JIVE boot control
1275
1276 See arch/arm/mach-s3c2412/mach-jive.c
1277
Linus Torvalds1da177e2005-04-16 15:20:36 -07001278 mtouchusb.raw_coordinates=
Randy Dunlapa9913042005-10-23 12:57:11 -07001279 [HW] Make the MicroTouch USB driver use raw coordinates
1280 ('y', default) or cooked coordinates ('n')
Linus Torvalds1da177e2005-04-16 15:20:36 -07001281
1282 n2= [NET] SDL Inc. RISCom/N2 synchronous serial card
1283
1284 NCR_D700= [HW,SCSI]
1285 See header of drivers/scsi/NCR_D700.c.
1286
1287 ncr5380= [HW,SCSI]
1288
1289 ncr53c400= [HW,SCSI]
1290
1291 ncr53c400a= [HW,SCSI]
1292
1293 ncr53c406a= [HW,SCSI]
1294
1295 ncr53c8xx= [HW,SCSI]
1296
1297 netdev= [NET] Network devices parameters
1298 Format: <irq>,<io>,<mem_start>,<mem_end>,<name>
1299 Note that mem_start is often overloaded to mean
1300 something different and driver-specific.
Randy Dunlapa9913042005-10-23 12:57:11 -07001301 This usage is only documented in each driver source
1302 file if at all.
1303
Krzysztof Piotr Oledzki58401572008-07-21 10:01:34 -07001304 nf_conntrack.acct=
1305 [NETFILTER] Enable connection tracking flow accounting
1306 0 to disable accounting
1307 1 to enable accounting
1308 Default value depends on CONFIG_NF_CT_ACCT that is
1309 going to be removed in 2.6.29.
1310
Linus Torvalds1da177e2005-04-16 15:20:36 -07001311 nfsaddrs= [NFS]
J. Bruce Fields6ded55d2008-04-07 15:59:03 -04001312 See Documentation/filesystems/nfsroot.txt.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001313
1314 nfsroot= [NFS] nfs root filesystem for disk-less boxes.
J. Bruce Fields6ded55d2008-04-07 15:59:03 -04001315 See Documentation/filesystems/nfsroot.txt.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001316
Trond Myklebusta72b4422006-01-03 09:55:41 +01001317 nfs.callback_tcpport=
1318 [NFS] set the TCP port on which the NFSv4 callback
1319 channel should listen.
1320
Trond Myklebust58df0952006-01-03 09:55:57 +01001321 nfs.idmap_cache_timeout=
1322 [NFS] set the maximum lifetime for idmapper cache
1323 entries.
1324
Trond Myklebustf43bf0b2007-10-09 12:01:04 -04001325 nfs.enable_ino64=
1326 [NFS] enable 64-bit inode numbers.
1327 If zero, the NFS client will fake up a 32-bit inode
1328 number for the readdir() and stat() syscalls instead
1329 of returning the full 64-bit number.
1330 The default is to return 64-bit inode numbers.
1331
Haavard Skinnemoene7ba1762007-10-10 14:58:29 +02001332 nmi_debug= [KNL,AVR32] Specify one or more actions to take
1333 when a NMI is triggered.
1334 Format: [state][,regs][,debounce][,die]
1335
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001336 nmi_watchdog= [KNL,BUGS=X86-32] Debugging features for SMP kernels
Linus Torvalds1da177e2005-04-16 15:20:36 -07001337
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001338 no387 [BUGS=X86-32] Tells the kernel to use the 387 maths
Linus Torvalds1da177e2005-04-16 15:20:36 -07001339 emulation library even if a 387 maths coprocessor
1340 is present.
1341
Christoph Lameterc1aee212007-05-31 00:40:47 -07001342 noaliencache [MM, NUMA, SLAB] Disables the allocation of alien
1343 caches in the slab allocator. Saves per-node memory,
1344 but will impact performance.
Paul Menage3395ee02006-12-06 20:32:16 -08001345
Randy Dunlapa9913042005-10-23 12:57:11 -07001346 noalign [KNL,ARM]
1347
Linus Torvalds1da177e2005-04-16 15:20:36 -07001348 noapic [SMP,APIC] Tells the kernel to not make use of any
1349 IOAPICs that may be present in the system.
1350
Linus Torvalds1da177e2005-04-16 15:20:36 -07001351 nobats [PPC] Do not use BATs for mapping kernel lowmem
1352 on "Classic" PPC cores.
1353
1354 nocache [ARM]
Randy Dunlapa9913042005-10-23 12:57:11 -07001355
Shailabh Nagar163ecdf2006-07-30 03:03:11 -07001356 nodelayacct [KNL] Disable per-task delay accounting
1357
Linus Torvalds1da177e2005-04-16 15:20:36 -07001358 nodisconnect [HW,SCSI,M68K] Disables SCSI disconnects.
1359
Huang, Ying8b2cb7a2008-01-30 13:32:11 +01001360 noefi [X86-32,X86-64] Disable EFI runtime services support.
1361
Linus Torvalds1da177e2005-04-16 15:20:36 -07001362 noexec [IA-64]
1363
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001364 noexec [X86-32,X86-64]
Jiri Slabyf5a1b192008-04-12 10:28:25 +02001365 On X86-32 available only on PAE configured kernels.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001366 noexec=on: enable non-executable mappings (default)
Jiri Slabyf5a1b192008-04-12 10:28:25 +02001367 noexec=off: disable non-executable mappings
1368
1369 noexec32 [X86-64]
1370 This affects only 32-bit executables.
1371 noexec32=on: enable non-executable mappings (default)
1372 read doesn't imply executable mappings
1373 noexec32=off: disable non-executable mappings
1374 read implies executable mappings
Linus Torvalds1da177e2005-04-16 15:20:36 -07001375
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001376 nofxsr [BUGS=X86-32] Disables x86 floating point extended
Chuck Ebbert4f886512006-03-23 02:59:34 -08001377 register save and restore. The kernel will only save
1378 legacy floating-point registers on task switch.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001379
Andi Kleen191679f2008-01-30 13:33:21 +01001380 noclflush [BUGS=X86] Don't use the CLFLUSH instruction
1381
Linus Torvalds1da177e2005-04-16 15:20:36 -07001382 nohlt [BUGS=ARM]
Randy Dunlapa9913042005-10-23 12:57:11 -07001383
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001384 no-hlt [BUGS=X86-32] Tells the kernel that the hlt
Linus Torvalds1da177e2005-04-16 15:20:36 -07001385 instruction doesn't work correctly and not to
1386 use it.
1387
1388 nohalt [IA-64] Tells the kernel not to use the power saving
1389 function PAL_HALT_LIGHT when idle. This increases
1390 power-consumption. On the positive side, it reduces
1391 interrupt wake-up latency, which may improve performance
1392 in certain environments such as networked servers or
1393 real-time systems.
1394
Thomas Gleixner79bf2bb2007-02-16 01:28:03 -08001395 nohz= [KNL] Boottime enable/disable dynamic ticks
1396 Valid arguments: on, off
1397 Default: on
1398
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001399 noirqbalance [X86-32,SMP,KNL] Disable kernel irq balancing
Zachary Amsden8542b202006-12-07 02:14:09 +01001400
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001401 noirqdebug [X86-32] Disables the code which attempts to detect and
Linus Torvalds1da177e2005-04-16 15:20:36 -07001402 disable unhandled interrupt sources.
1403
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001404 no_timer_check [X86-32,X86_64,APIC] Disables the code which tests for
Zachary Amsden8542b202006-12-07 02:14:09 +01001405 broken timer IRQ sources.
1406
Linus Torvalds1da177e2005-04-16 15:20:36 -07001407 noisapnp [ISAPNP] Disables ISA PnP code.
1408
1409 noinitrd [RAM] Tells the kernel not to load any configured
1410 initial RAM disk.
1411
1412 nointroute [IA-64]
1413
Tony Luck0aa366f2007-07-20 11:22:30 -07001414 nojitter [IA64] Disables jitter checking for ITC timers.
1415
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001416 nolapic [X86-32,APIC] Do not enable or use the local APIC.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001417
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001418 nolapic_timer [X86-32,APIC] Do not use the local APIC timer.
Thomas Gleixnerad62ca22007-03-22 00:11:21 -08001419
Linus Torvalds1da177e2005-04-16 15:20:36 -07001420 noltlbs [PPC] Do not use large page/tlb entries for kernel
1421 lowmem mapping on PPC40x.
1422
Horms312f1f02006-02-22 09:57:55 +09001423 nomca [IA-64] Disable machine check abort handling
1424
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001425 nomce [X86-32] Machine Check Exception
Hormsabe37e52006-04-01 01:36:09 +02001426
Andres Salomon83d73842007-10-12 23:04:06 +02001427 nomfgpt [X86-32] Disable Multi-Function General Purpose
1428 Timer usage (for AMD Geode machines).
1429
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001430 noreplace-paravirt [X86-32,PV_OPS] Don't patch paravirt_ops
Jeremy Fitzhardinge959b4fd2007-05-02 19:27:16 +02001431
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001432 noreplace-smp [X86-32,SMP] Don't replace SMP instructions
Jeremy Fitzhardingeb7fb4af2007-05-02 19:27:13 +02001433 with UP alternatives
1434
Linus Torvalds1da177e2005-04-16 15:20:36 -07001435 noresidual [PPC] Don't use residual data on PReP machines.
1436
Randy Dunlapa9913042005-10-23 12:57:11 -07001437 noresume [SWSUSP] Disables resume and restores original swap
1438 space.
1439
Linus Torvalds1da177e2005-04-16 15:20:36 -07001440 no-scroll [VGA] Disables scrollback.
1441 This is required for the Braillex ib80-piezo Braille
1442 reader made by F.H. Papenmeier (Germany).
1443
1444 nosbagart [IA-64]
1445
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001446 nosep [BUGS=X86-32] Disables x86 SYSENTER/SYSEXIT support.
Chuck Ebbert4f886512006-03-23 02:59:34 -08001447
Len Brown61ec7562007-08-16 03:34:22 -04001448 nosmp [SMP] Tells an SMP kernel to act as a UP kernel,
1449 and disable the IO APIC. legacy for "maxcpus=0".
Linus Torvalds1da177e2005-04-16 15:20:36 -07001450
Dave Jones97842212007-07-15 23:41:05 -07001451 nosoftlockup [KNL] Disable the soft-lockup detector.
1452
Linus Torvalds1da177e2005-04-16 15:20:36 -07001453 nosync [HW,M68K] Disables sync negotiation for all devices.
1454
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001455 notsc [BUGS=X86-32] Disable Time Stamp Counter
Linus Torvalds1da177e2005-04-16 15:20:36 -07001456
1457 nousb [USB] Disable the USB subsystem
1458
1459 nowb [ARM]
Randy Dunlapa9913042005-10-23 12:57:11 -07001460
Fenghua Yua6c75b862008-03-14 13:57:08 -07001461 nptcg= [IA64] Override max number of concurrent global TLB
1462 purges which is reported from either PAL_VM_SUMMARY or
1463 SAL PALO.
1464
KAMEZAWA Hiroyukif0c0b2b2007-07-15 23:38:01 -07001465 numa_zonelist_order= [KNL, BOOT] Select zonelist order for NUMA.
1466 one of ['zone', 'node', 'default'] can be specified
1467 This can be set from sysctl after boot.
1468 See Documentation/sysctl/vm.txt for details.
1469
Dave Jonesa61c2d72006-01-07 23:18:19 +00001470 nr_uarts= [SERIAL] maximum number of UARTs to be registered.
1471
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07001472 olpc_ec_timeout= [OLPC] ms delay when issuing EC commands
1473 Rather than timing out after 20 ms if an EC
1474 command is not properly ACKed, override the length
1475 of the timeout. We have interrupts disabled while
1476 waiting for the ACK, so if this is set too high
1477 interrupts *may* be lost!
1478
Linus Torvalds1da177e2005-04-16 15:20:36 -07001479 opl3= [HW,OSS]
1480 Format: <io>
1481
Linus Torvalds1da177e2005-04-16 15:20:36 -07001482 oprofile.timer= [HW]
1483 Use timer interrupt instead of performance counters
1484
Linus Torvalds1da177e2005-04-16 15:20:36 -07001485 osst= [HW,SCSI] SCSI Tape Driver
1486 Format: <buffer_size>,<write_threshold>
1487 See also Documentation/scsi/st.txt.
1488
1489 panic= [KNL] Kernel behaviour on panic
1490 Format: <timeout>
1491
1492 parkbd.port= [HW] Parallel port number the keyboard adapter is
1493 connected to, default is 0.
1494 Format: <parport#>
1495 parkbd.mode= [HW] Parallel port keyboard adapter mode of operation,
1496 0 for XT, 1 for AT (default is AT).
Randy Dunlapa9913042005-10-23 12:57:11 -07001497 Format: <mode>
Linus Torvalds1da177e2005-04-16 15:20:36 -07001498
Randy Dunlapa9913042005-10-23 12:57:11 -07001499 parport= [HW,PPT] Specify parallel ports. 0 disables.
1500 Format: { 0 | auto | 0xBBB[,IRQ[,DMA]] }
1501 Use 'auto' to force the driver to use any
1502 IRQ/DMA settings detected (the default is to
1503 ignore detected IRQ/DMA settings because of
1504 possible conflicts). You can specify the base
1505 address, IRQ, and DMA settings; IRQ and DMA
1506 should be numbers, or 'auto' (for using detected
1507 settings on that particular port), or 'nofifo'
1508 (to avoid using a FIFO even if it is detected).
1509 Parallel ports are assigned in the order they
1510 are specified on the command line, starting
1511 with parport0.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001512
Randy Dunlapa9913042005-10-23 12:57:11 -07001513 parport_init_mode= [HW,PPT]
1514 Configure VIA parallel port to operate in
1515 a specific mode. This is necessary on Pegasos
1516 computer where firmware has no options for setting
1517 up parallel port mode and sets it to spp.
1518 Currently this function knows 686a and 8231 chips.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001519 Format: [spp|ps2|epp|ecp|ecpepp]
1520
Randy Dunlapa9913042005-10-23 12:57:11 -07001521 pas2= [HW,OSS] Format:
1522 <io>,<irq>,<dma>,<dma16>,<sb_io>,<sb_irq>,<sb_dma>,<sb_dma16>
1523
Linus Torvalds1da177e2005-04-16 15:20:36 -07001524 pas16= [HW,SCSI]
1525 See header of drivers/scsi/pas16.c.
1526
Andrew Mortondd287792006-03-23 03:00:57 -08001527 pause_on_oops=
1528 Halt all CPUs after the first oops has been printed for
1529 the specified number of seconds. This is to be used if
1530 your oopses keep scrolling off the screen.
1531
Linus Torvalds1da177e2005-04-16 15:20:36 -07001532 pcbit= [HW,ISDN]
1533
1534 pcd. [PARIDE]
1535 See header of drivers/block/paride/pcd.c.
1536 See also Documentation/paride.txt.
1537
Randy Dunlapa9913042005-10-23 12:57:11 -07001538 pci=option[,option...] [PCI] various PCI subsystem options:
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001539 off [X86-32] don't probe for the PCI bus
1540 bios [X86-32] force use of PCI BIOS, don't access
Randy Dunlapa9913042005-10-23 12:57:11 -07001541 the hardware directly. Use this if your machine
1542 has a non-standard PCI host bridge.
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001543 nobios [X86-32] disallow use of PCI BIOS, only direct
Randy Dunlapa9913042005-10-23 12:57:11 -07001544 hardware access methods are allowed. Use this
1545 if you experience crashes upon bootup and you
1546 suspect they are caused by the BIOS.
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001547 conf1 [X86-32] Force use of PCI Configuration
Randy Dunlapa9913042005-10-23 12:57:11 -07001548 Mechanism 1.
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001549 conf2 [X86-32] Force use of PCI Configuration
Randy Dunlapa9913042005-10-23 12:57:11 -07001550 Mechanism 2.
Randy Dunlap7f785762007-10-05 13:17:58 -07001551 noaer [PCIE] If the PCIEAER kernel config parameter is
1552 enabled, this kernel boot option can be used to
1553 disable the use of PCIE advanced error reporting.
Jeff Garzik32a2eea2007-10-11 16:57:27 -04001554 nodomains [PCI] Disable support for multiple PCI
1555 root domains (aka PCI segments, in ACPI-speak).
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001556 nommconf [X86-32,X86_64] Disable use of MMCONFIG for PCI
Bjorn Helgaas61be6d62006-02-15 15:17:43 -08001557 Configuration
Matthew Wilcox309e57d2006-03-05 22:33:34 -07001558 nomsi [MSI] If the PCI_MSI kernel config parameter is
1559 enabled, this kernel boot option can be used to
1560 disable the use of MSI interrupts system-wide.
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001561 biosirq [X86-32] Use PCI BIOS calls to get the interrupt
Randy Dunlapa9913042005-10-23 12:57:11 -07001562 routing table. These calls are known to be buggy
1563 on several machines and they hang the machine
1564 when used, but on other computers it's the only
1565 way to get the interrupt routing table. Try
1566 this option if the kernel is unable to allocate
1567 IRQs or discover secondary PCI buses on your
1568 motherboard.
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001569 rom [X86-32] Assign address space to expansion ROMs.
Randy Dunlapa9913042005-10-23 12:57:11 -07001570 Use with caution as certain devices share
1571 address decoders between ROMs and other
1572 resources.
Gary Hadebb71ad82008-05-12 13:57:46 -07001573 norom [X86-32,X86_64] Do not assign address space to
1574 expansion ROMs that do not already have
1575 BIOS assigned address ranges.
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001576 irqmask=0xMMMM [X86-32] Set a bit mask of IRQs allowed to be
Randy Dunlapa9913042005-10-23 12:57:11 -07001577 assigned automatically to PCI devices. You can
1578 make the kernel exclude IRQs of your ISA cards
1579 this way.
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001580 pirqaddr=0xAAAAA [X86-32] Specify the physical address
Randy Dunlapa9913042005-10-23 12:57:11 -07001581 of the PIRQ table (normally generated
1582 by the BIOS) if it is outside the
1583 F0000h-100000h range.
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001584 lastbus=N [X86-32] Scan all buses thru bus #N. Can be
Randy Dunlapa9913042005-10-23 12:57:11 -07001585 useful if the kernel is unable to find your
1586 secondary buses and you want to tell it
1587 explicitly which ones they are.
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001588 assign-busses [X86-32] Always assign all PCI bus
Randy Dunlapa9913042005-10-23 12:57:11 -07001589 numbers ourselves, overriding
1590 whatever the firmware may have done.
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001591 usepirqmask [X86-32] Honor the possible IRQ mask stored
Randy Dunlapa9913042005-10-23 12:57:11 -07001592 in the BIOS $PIR table. This is needed on
1593 some systems with broken BIOSes, notably
1594 some HP Pavilion N5400 and Omnibook XE3
1595 notebooks. This will have no effect if ACPI
1596 IRQ routing is enabled.
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001597 noacpi [X86-32] Do not use ACPI for IRQ routing
Randy Dunlapa9913042005-10-23 12:57:11 -07001598 or for PCI scanning.
Gary Hade62f420f2007-10-03 15:56:51 -07001599 use_crs [X86-32] Use _CRS for PCI resource
1600 allocation.
Randy Dunlapa9913042005-10-23 12:57:11 -07001601 routeirq Do IRQ routing for all PCI devices.
1602 This is normally done in pci_enable_device(),
1603 so this option is a temporary workaround
1604 for broken drivers that don't call it.
Yinghai Lu13a6ddb2008-03-27 01:31:18 -07001605 skip_isa_align [X86] do not align io start addr, so can
1606 handle more pci cards
Randy Dunlapa9913042005-10-23 12:57:11 -07001607 firmware [ARM] Do not re-enumerate the bus but instead
1608 just use the configuration from the
1609 bootloader. This is currently used on
1610 IXP2000 systems where the bus has to be
1611 configured a certain way for adjunct CPUs.
Andi Kleen0637a702006-09-26 10:52:41 +02001612 noearly [X86] Don't do any early type 1 scanning.
1613 This might help on some broken boards which
1614 machine check when some devices' config space
1615 is read. But various workarounds are disabled
1616 and some IOMMU drivers will not work.
Matt Domsch6b4b78f2006-09-29 15:23:23 -05001617 bfsort Sort PCI devices into breadth-first order.
1618 This sorting is done to get a device
1619 order compatible with older (<= 2.4) kernels.
1620 nobfsort Don't sort PCI devices into breadth-first order.
Atsushi Nemoto4516a612007-02-05 16:36:06 -08001621 cbiosize=nn[KMG] The fixed amount of bus space which is
1622 reserved for the CardBus bridge's IO window.
1623 The default value is 256 bytes.
1624 cbmemsize=nn[KMG] The fixed amount of bus space which is
1625 reserved for the CardBus bridge's memory
1626 window. The default value is 64 megabytes.
Matt Domsch6b4b78f2006-09-29 15:23:23 -05001627
Linus Torvalds1da177e2005-04-16 15:20:36 -07001628 pcmv= [HW,PCMCIA] BadgePAD 4
1629
1630 pd. [PARIDE]
1631 See Documentation/paride.txt.
1632
1633 pdcchassis= [PARISC,HW] Disable/Enable PDC Chassis Status codes at
1634 boot time.
1635 Format: { 0 | 1 }
1636 See arch/parisc/kernel/pdc_chassis.c
1637
1638 pf. [PARIDE]
1639 See Documentation/paride.txt.
1640
1641 pg. [PARIDE]
1642 See Documentation/paride.txt.
1643
1644 pirq= [SMP,APIC] Manual mp-table setup
1645 See Documentation/i386/IO-APIC.txt.
1646
1647 plip= [PPT,NET] Parallel port network link
1648 Format: { parport<nr> | timid | 0 }
1649 See also Documentation/parport.txt.
1650
Thomas Gleixnerde32a242008-07-12 05:33:30 +02001651 pmtmr= [X86] Manual setup of pmtmr I/O Port.
1652 Override pmtimer IOPort with a hex value.
1653 e.g. pmtmr=0x508
1654
Linus Torvalds1da177e2005-04-16 15:20:36 -07001655 pnpacpi= [ACPI]
1656 { off }
1657
1658 pnpbios= [ISAPNP]
1659 { on | off | curr | res | no-curr | no-res }
1660
1661 pnp_reserve_irq=
1662 [ISAPNP] Exclude IRQs for the autoconfiguration
1663
1664 pnp_reserve_dma=
1665 [ISAPNP] Exclude DMAs for the autoconfiguration
1666
1667 pnp_reserve_io= [ISAPNP] Exclude I/O ports for the autoconfiguration
Randy Dunlapa9913042005-10-23 12:57:11 -07001668 Ranges are in pairs (I/O port base and size).
Linus Torvalds1da177e2005-04-16 15:20:36 -07001669
1670 pnp_reserve_mem=
Randy Dunlapa9913042005-10-23 12:57:11 -07001671 [ISAPNP] Exclude memory regions for the
1672 autoconfiguration.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001673 Ranges are in pairs (memory base and size).
1674
Ingo Molnar45807a12007-07-15 23:40:10 -07001675 print-fatal-signals=
1676 [KNL] debug: print fatal signals
1677 print-fatal-signals=1: print segfault info to
1678 the kernel console.
1679 default: off.
1680
Randy Dunlape84845c2007-07-15 23:40:25 -07001681 printk.time= Show timing data prefixed to each printk message line
1682 Format: <bool> (1/Y/y=enable, 0/N/n=disable)
1683
Linus Torvalds1da177e2005-04-16 15:20:36 -07001684 profile= [KNL] Enable kernel profiling via /proc/profile
Randy Dunlapa9913042005-10-23 12:57:11 -07001685 Format: [schedule,]<number>
1686 Param: "schedule" - profile schedule points.
1687 Param: <number> - step/bucket size as a power of 2 for
1688 statistical time based profiling.
Mel Gormanb3da2a72007-10-24 18:23:50 +02001689 Param: "sleep" - profile D-state sleeping (millisecs).
1690 Requires CONFIG_SCHEDSTATS
Dave Jonesc0fe2e62007-10-20 03:08:22 +02001691 Param: "kvm" - profile VM exits.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001692
Randy Dunlapa9913042005-10-23 12:57:11 -07001693 processor.max_cstate= [HW,ACPI]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001694 Limit processor to maximum C-state
1695 max_cstate=9 overrides any DMI blacklist limit.
1696
Len Brown41c0d862005-12-28 12:43:51 -05001697 processor.nocst [HW,ACPI]
1698 Ignore the _CST method to determine C-states,
1699 instead using the legacy FADT method
1700
Linus Torvalds1da177e2005-04-16 15:20:36 -07001701 prompt_ramdisk= [RAM] List of RAM disks to prompt for floppy disk
1702 before loading.
1703 See Documentation/ramdisk.txt.
1704
Randy Dunlapa9913042005-10-23 12:57:11 -07001705 psmouse.proto= [HW,MOUSE] Highest PS2 mouse protocol extension to
1706 probe for; one of (bare|imps|exps|lifebook|any).
Linus Torvalds1da177e2005-04-16 15:20:36 -07001707 psmouse.rate= [HW,MOUSE] Set desired mouse report rate, in reports
1708 per second.
Randy Dunlapa9913042005-10-23 12:57:11 -07001709 psmouse.resetafter= [HW,MOUSE]
1710 Try to reset the device after so many bad packets
Linus Torvalds1da177e2005-04-16 15:20:36 -07001711 (0 = never).
1712 psmouse.resolution=
1713 [HW,MOUSE] Set desired mouse resolution, in dpi.
1714 psmouse.smartscroll=
Randy Dunlapa9913042005-10-23 12:57:11 -07001715 [HW,MOUSE] Controls Logitech smartscroll autorepeat.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001716 0 = disabled, 1 = enabled (default).
1717
1718 pss= [HW,OSS] Personal Sound System (ECHO ESC614)
Randy Dunlapa9913042005-10-23 12:57:11 -07001719 Format:
1720 <io>,<mss_io>,<mss_irq>,<mss_dma>,<mpu_io>,<mpu_irq>
Linus Torvalds1da177e2005-04-16 15:20:36 -07001721
1722 pt. [PARIDE]
1723 See Documentation/paride.txt.
1724
Kay Sieversdc8c8582007-08-15 12:25:38 +02001725 pty.legacy_count=
1726 [KNL] Number of legacy pty's. Overwrites compiled-in
1727 default number.
1728
Randy Dunlap7d2c5022006-09-29 02:01:02 -07001729 quiet [KNL] Disable most log messages
Randy Dunlapa9913042005-10-23 12:57:11 -07001730
Linus Torvalds1da177e2005-04-16 15:20:36 -07001731 r128= [HW,DRM]
1732
1733 raid= [HW,RAID]
1734 See Documentation/md.txt.
1735
Randy Dunlapa9913042005-10-23 12:57:11 -07001736 ramdisk_blocksize= [RAM]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001737 See Documentation/ramdisk.txt.
Randy Dunlapa9913042005-10-23 12:57:11 -07001738
Linus Torvalds1da177e2005-04-16 15:20:36 -07001739 ramdisk_size= [RAM] Sizes of RAM disks in kilobytes
Linus Torvalds1da177e2005-04-16 15:20:36 -07001740 See Documentation/ramdisk.txt.
1741
Robert P. J. Day24aaef82008-02-03 15:20:26 +02001742 rcupdate.blimit= [KNL,BOOT]
1743 Set maximum number of finished RCU callbacks to process
1744 in one batch.
Dipankar Sarma21a1ea92006-03-07 21:55:33 -08001745
Robert P. J. Day24aaef82008-02-03 15:20:26 +02001746 rcupdate.qhimark= [KNL,BOOT]
1747 Set threshold of queued
Dipankar Sarma21a1ea92006-03-07 21:55:33 -08001748 RCU callbacks over which batch limiting is disabled.
1749
Robert P. J. Day24aaef82008-02-03 15:20:26 +02001750 rcupdate.qlowmark= [KNL,BOOT]
1751 Set threshold of queued RCU callbacks below which
1752 batch limiting is re-enabled.
Dipankar Sarma21a1ea92006-03-07 21:55:33 -08001753
Olof Johanssonffdfc402005-09-06 15:17:19 -07001754 rdinit= [KNL]
1755 Format: <full_path>
1756 Run specified binary instead of /init from the ramdisk,
1757 used for early userspace startup. See initrd.
1758
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001759 reboot= [BUGS=X86-32,BUGS=ARM,BUGS=IA-64] Rebooting mode
Linus Torvalds1da177e2005-04-16 15:20:36 -07001760 Format: <reboot_mode>[,<reboot_mode2>[,...]]
Mauro Carvalho Chehabe53dd082007-09-15 07:38:47 -03001761 See arch/*/kernel/reboot.c or arch/*/kernel/process.c
Linus Torvalds1da177e2005-04-16 15:20:36 -07001762
Paul Jackson46b6d942008-07-04 10:00:09 -07001763 relax_domain_level=
1764 [KNL, SMP] Set scheduler's default relax_domain_level.
1765 See Documentation/cpusets.txt.
1766
Linus Torvalds1da177e2005-04-16 15:20:36 -07001767 reserve= [KNL,BUGS] Force the kernel to ignore some iomem area
1768
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001769 reservetop= [X86-32]
Zachary Amsden461a9af2006-09-25 23:32:25 -07001770 Format: nn[KMG]
1771 Reserves a hole at the top of the kernel virtual
1772 address space.
1773
Vivek Goyal7e962872006-09-27 01:50:44 -07001774 reset_devices [KNL] Force drivers to reset the underlying device
1775 during initialization.
1776
Randy Dunlapa9913042005-10-23 12:57:11 -07001777 resume= [SWSUSP]
1778 Specify the partition device for software suspend
Linus Torvalds1da177e2005-04-16 15:20:36 -07001779
Rafael J. Wysockiecbd0da2006-12-06 20:34:13 -08001780 resume_offset= [SWSUSP]
1781 Specify the offset from the beginning of the partition
1782 given by "resume=" at which the swap header is located,
1783 in <PAGE_SIZE> units (needed only for swap files).
1784 See Documentation/power/swsusp-and-swap-files.txt
1785
Michael Neuling0a7b35cb2007-02-10 01:44:33 -08001786 retain_initrd [RAM] Keep initrd memory after extraction
1787
Linus Torvalds1da177e2005-04-16 15:20:36 -07001788 rhash_entries= [KNL,NET]
1789 Set number of hash buckets for route cache
1790
1791 riscom8= [HW,SERIAL]
1792 Format: <io_board1>[,<io_board2>[,...<io_boardN>]]
1793
1794 ro [KNL] Mount root device read-only on boot
1795
1796 root= [KNL] Root filesystem
1797
1798 rootdelay= [KNL] Delay (in seconds) to pause before attempting to
1799 mount the root filesystem
1800
1801 rootflags= [KNL] Set root filesystem mount option string
1802
1803 rootfstype= [KNL] Set root filesystem type
1804
Pierre Ossmancc1ed752007-07-15 23:40:35 -07001805 rootwait [KNL] Wait (indefinitely) for root device to show up.
1806 Useful for devices that are detected asynchronously
1807 (e.g. USB and MMC devices).
1808
James Morris20510f22007-10-16 23:31:32 -07001809 root_plug.vendor_id=
1810 [ROOTPLUG] Override the default vendor ID
1811
1812 root_plug.product_id=
1813 [ROOTPLUG] Override the default product ID
1814
1815 root_plug.debug=
1816 [ROOTPLUG] Enable debugging output
1817
Linus Torvalds1da177e2005-04-16 15:20:36 -07001818 rw [KNL] Mount root device read-write on boot
1819
1820 S [KNL] Run init in single mode
1821
1822 sa1100ir [NET]
1823 See drivers/net/irda/sa1100_ir.c.
1824
Linus Torvalds1da177e2005-04-16 15:20:36 -07001825 sbni= [NET] Granch SBNI12 leased line adapter
Randy Dunlapa9913042005-10-23 12:57:11 -07001826
Linus Torvalds1da177e2005-04-16 15:20:36 -07001827 sc1200wdt= [HW,WDT] SC1200 WDT (watchdog) driver
1828 Format: <io>[,<timeout>[,<isapnp>]]
1829
1830 scsi_debug_*= [SCSI]
1831 See drivers/scsi/scsi_debug.c.
1832
1833 scsi_default_dev_flags=
1834 [SCSI] SCSI default device flags
1835 Format: <integer>
1836
1837 scsi_dev_flags= [SCSI] Black/white list entry for vendor and model
1838 Format: <vendor>:<model>:<flags>
1839 (flags are integer value)
1840
Randy Dunlap6af66322007-11-14 16:52:25 -08001841 scsi_logging_level= [SCSI] a bit mask of logging levels
1842 See drivers/scsi/scsi_logging.h for bits. Also
1843 settable via sysctl at dev.scsi.logging_level
1844 (/proc/sys/dev/scsi/logging_level).
1845 There is also a nice 'scsi_logging_level' script in the
1846 S390-tools package, available for download at
1847 http://www-128.ibm.com/developerworks/linux/linux390/s390-tools-1.5.4.html
Linus Torvalds1da177e2005-04-16 15:20:36 -07001848
Matthew Wilcox3e082a92006-09-28 15:19:20 -06001849 scsi_mod.scan= [SCSI] sync (default) scans SCSI busses as they are
1850 discovered. async scans them in kernel threads,
1851 allowing boot to proceed. none ignores them, expecting
1852 user space to do the scan.
1853
Linus Torvalds1da177e2005-04-16 15:20:36 -07001854 selinux [SELINUX] Disable or enable SELinux at boot time.
1855 Format: { "0" | "1" }
1856 See security/selinux/Kconfig help text.
1857 0 -- disable.
1858 1 -- enable.
1859 Default value is set via kernel config option.
1860 If enabled at boot time, /selinux/disable can be used
1861 later to disable prior to initial policy load.
1862
James Morris4e5ab4c2006-06-09 00:33:33 -07001863 selinux_compat_net =
1864 [SELINUX] Set initial selinux_compat_net flag value.
Mauro Carvalho Chehabe53dd082007-09-15 07:38:47 -03001865 Format: { "0" | "1" }
1866 0 -- use new secmark-based packet controls
1867 1 -- use legacy packet controls
1868 Default value is 0 (preferred).
1869 Value can be changed at runtime via
1870 /selinux/compat_net.
James Morris4e5ab4c2006-06-09 00:33:33 -07001871
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001872 serialnumber [BUGS=X86-32]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001873
Linus Torvalds1da177e2005-04-16 15:20:36 -07001874 shapers= [NET]
1875 Maximal number of shapers.
Randy Dunlapa9913042005-10-23 12:57:11 -07001876
Linus Torvalds1da177e2005-04-16 15:20:36 -07001877 sim710= [SCSI,HW]
1878 See header of drivers/scsi/sim710.c.
1879
1880 simeth= [IA-64]
1881 simscsi=
Randy Dunlapa9913042005-10-23 12:57:11 -07001882
Linus Torvalds1da177e2005-04-16 15:20:36 -07001883 slram= [HW,MTD]
1884
Christoph Lameterf0630ff2007-07-15 23:38:14 -07001885 slub_debug[=options[,slabs]] [MM, SLUB]
1886 Enabling slub_debug allows one to determine the
1887 culprit if slab objects become corrupted. Enabling
1888 slub_debug can create guard zones around objects and
1889 may poison objects when not in use. Also tracks the
1890 last alloc / free. For more information see
1891 Documentation/vm/slub.txt.
Christoph Lameterc1aee212007-05-31 00:40:47 -07001892
1893 slub_max_order= [MM, SLUB]
Christoph Lameterf0630ff2007-07-15 23:38:14 -07001894 Determines the maximum allowed order for slabs.
1895 A high setting may cause OOMs due to memory
1896 fragmentation. For more information see
1897 Documentation/vm/slub.txt.
Christoph Lameterc1aee212007-05-31 00:40:47 -07001898
1899 slub_min_objects= [MM, SLUB]
Christoph Lameterf0630ff2007-07-15 23:38:14 -07001900 The minimum number of objects per slab. SLUB will
1901 increase the slab order up to slub_max_order to
1902 generate a sufficiently large slab able to contain
1903 the number of objects indicated. The higher the number
1904 of objects the smaller the overhead of tracking slabs
1905 and the less frequently locks need to be acquired.
Christoph Lameterc1aee212007-05-31 00:40:47 -07001906 For more information see Documentation/vm/slub.txt.
1907
1908 slub_min_order= [MM, SLUB]
1909 Determines the mininum page order for slabs. Must be
Christoph Lameterf0630ff2007-07-15 23:38:14 -07001910 lower than slub_max_order.
Christoph Lameterc1aee212007-05-31 00:40:47 -07001911 For more information see Documentation/vm/slub.txt.
1912
1913 slub_nomerge [MM, SLUB]
Christoph Lameterf0630ff2007-07-15 23:38:14 -07001914 Disable merging of slabs with similar size. May be
Christoph Lameterc1aee212007-05-31 00:40:47 -07001915 necessary if there is some reason to distinguish
Christoph Lameterf0630ff2007-07-15 23:38:14 -07001916 allocs to different slabs. Debug options disable
1917 merging on their own.
Christoph Lameterc1aee212007-05-31 00:40:47 -07001918 For more information see Documentation/vm/slub.txt.
1919
Linus Torvalds1da177e2005-04-16 15:20:36 -07001920 smart2= [HW]
1921 Format: <io1>[,<io2>[,...,<io8>]]
1922
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001923 smp-alt-once [X86-32,SMP] On a hotplug CPU system, only
Jeremy Fitzhardingeb7fb4af2007-05-02 19:27:13 +02001924 attempt to substitute SMP alternatives once at boot.
1925
Bjorn Helgaasd0d4f692007-05-08 00:36:05 -07001926 smsc-ircc2.nopnp [HW] Don't use PNP to discover SMC devices
1927 smsc-ircc2.ircc_cfg= [HW] Device configuration I/O port
1928 smsc-ircc2.ircc_sir= [HW] SIR base I/O port
1929 smsc-ircc2.ircc_fir= [HW] FIR base I/O port
1930 smsc-ircc2.ircc_irq= [HW] IRQ line
1931 smsc-ircc2.ircc_dma= [HW] DMA channel
1932 smsc-ircc2.ircc_transceiver= [HW] Transceiver type:
1933 0: Toshiba Satellite 1800 (GP data pin select)
1934 1: Fast pin select (default)
1935 2: ATC IRMode
1936
Linus Torvalds1da177e2005-04-16 15:20:36 -07001937 snd-ad1816a= [HW,ALSA]
1938
1939 snd-ad1848= [HW,ALSA]
1940
1941 snd-ali5451= [HW,ALSA]
1942
1943 snd-als100= [HW,ALSA]
1944
1945 snd-als4000= [HW,ALSA]
1946
1947 snd-azt2320= [HW,ALSA]
1948
1949 snd-cmi8330= [HW,ALSA]
1950
1951 snd-cmipci= [HW,ALSA]
1952
1953 snd-cs4231= [HW,ALSA]
1954
1955 snd-cs4232= [HW,ALSA]
1956
1957 snd-cs4236= [HW,ALSA]
1958
1959 snd-cs4281= [HW,ALSA]
1960
1961 snd-cs46xx= [HW,ALSA]
1962
1963 snd-dt019x= [HW,ALSA]
1964
1965 snd-dummy= [HW,ALSA]
1966
1967 snd-emu10k1= [HW,ALSA]
1968
1969 snd-ens1370= [HW,ALSA]
1970
1971 snd-ens1371= [HW,ALSA]
1972
1973 snd-es968= [HW,ALSA]
1974
1975 snd-es1688= [HW,ALSA]
1976
1977 snd-es18xx= [HW,ALSA]
1978
1979 snd-es1938= [HW,ALSA]
1980
1981 snd-es1968= [HW,ALSA]
1982
1983 snd-fm801= [HW,ALSA]
1984
1985 snd-gusclassic= [HW,ALSA]
1986
1987 snd-gusextreme= [HW,ALSA]
1988
1989 snd-gusmax= [HW,ALSA]
1990
1991 snd-hdsp= [HW,ALSA]
1992
1993 snd-ice1712= [HW,ALSA]
1994
1995 snd-intel8x0= [HW,ALSA]
1996
1997 snd-interwave= [HW,ALSA]
1998
1999 snd-interwave-stb=
2000 [HW,ALSA]
2001
2002 snd-korg1212= [HW,ALSA]
2003
2004 snd-maestro3= [HW,ALSA]
2005
2006 snd-mpu401= [HW,ALSA]
2007
2008 snd-mtpav= [HW,ALSA]
2009
2010 snd-nm256= [HW,ALSA]
2011
2012 snd-opl3sa2= [HW,ALSA]
2013
2014 snd-opti92x-ad1848=
2015 [HW,ALSA]
2016
2017 snd-opti92x-cs4231=
2018 [HW,ALSA]
2019
2020 snd-opti93x= [HW,ALSA]
2021
2022 snd-pmac= [HW,ALSA]
2023
2024 snd-rme32= [HW,ALSA]
2025
2026 snd-rme96= [HW,ALSA]
2027
2028 snd-rme9652= [HW,ALSA]
2029
2030 snd-sb8= [HW,ALSA]
2031
2032 snd-sb16= [HW,ALSA]
2033
2034 snd-sbawe= [HW,ALSA]
2035
2036 snd-serial= [HW,ALSA]
2037
2038 snd-sgalaxy= [HW,ALSA]
2039
2040 snd-sonicvibes= [HW,ALSA]
2041
2042 snd-sun-amd7930=
2043 [HW,ALSA]
2044
2045 snd-sun-cs4231= [HW,ALSA]
2046
2047 snd-trident= [HW,ALSA]
2048
2049 snd-usb-audio= [HW,ALSA,USB]
2050
2051 snd-via82xx= [HW,ALSA]
2052
2053 snd-virmidi= [HW,ALSA]
2054
2055 snd-wavefront= [HW,ALSA]
2056
2057 snd-ymfpci= [HW,ALSA]
Randy Dunlapa9913042005-10-23 12:57:11 -07002058
Ingo Molnar9c44bc02008-05-12 21:21:04 +02002059 softlockup_panic=
2060 [KNL] Should the soft-lockup detector generate panics.
2061
Linus Torvalds1da177e2005-04-16 15:20:36 -07002062 sonypi.*= [HW] Sony Programmable I/O Control Device driver
2063 See Documentation/sonypi.txt
2064
2065 specialix= [HW,SERIAL] Specialix multi-serial port adapter
2066 See Documentation/specialix.txt.
2067
2068 spia_io_base= [HW,MTD]
2069 spia_fio_base=
2070 spia_pedr=
2071 spia_peddr=
2072
2073 sscape= [HW,OSS]
2074 Format: <io>,<irq>,<dma>,<mpu_io>,<mpu_irq>
Randy Dunlapa9913042005-10-23 12:57:11 -07002075
Linus Torvalds1da177e2005-04-16 15:20:36 -07002076 st= [HW,SCSI] SCSI tape parameters (buffers, etc.)
2077 See Documentation/scsi/st.txt.
2078
Linus Torvalds1da177e2005-04-16 15:20:36 -07002079 sti= [PARISC,HW]
2080 Format: <num>
2081 Set the STI (builtin display/keyboard on the HP-PARISC
2082 machines) console (graphic card) which should be used
2083 as the initial boot-console.
2084 See also comment in drivers/video/console/sticore.c.
2085
2086 sti_font= [HW]
2087 See comment in drivers/video/console/sticore.c.
2088
2089 stifb= [HW]
2090 Format: bpp:<bpp1>[:<bpp2>[:<bpp3>...]]
2091
Greg Banks42a7fc42007-03-06 01:42:23 -08002092 sunrpc.pool_mode=
2093 [NFS]
2094 Control how the NFS server code allocates CPUs to
2095 service thread pools. Depending on how many NICs
2096 you have and where their interrupts are bound, this
2097 option will affect which CPUs will do NFS serving.
2098 Note: this parameter cannot be changed while the
2099 NFS server is running.
2100
2101 auto the server chooses an appropriate mode
2102 automatically using heuristics
2103 global a single global pool contains all CPUs
2104 percpu one pool for each CPU
2105 pernode one pool for each NUMA node (equivalent
2106 to global on non-NUMA machines)
2107
Linus Torvalds1da177e2005-04-16 15:20:36 -07002108 swiotlb= [IA-64] Number of I/O TLB slabs
Randy Dunlapa9913042005-10-23 12:57:11 -07002109
Linus Torvalds1da177e2005-04-16 15:20:36 -07002110 switches= [HW,M68k]
2111
2112 sym53c416= [HW,SCSI]
2113 See header of drivers/scsi/sym53c416.c.
2114
Ingo Molnar5d6f6472006-12-13 00:34:36 -08002115 sysrq_always_enabled
2116 [KNL]
2117 Ignore sysrq setting - this boot parameter will
2118 neutralize any effect of /proc/sys/kernel/sysrq.
2119 Useful for debugging.
2120
Linus Torvalds1da177e2005-04-16 15:20:36 -07002121 t128= [HW,SCSI]
2122 See header of drivers/scsi/t128.c.
2123
2124 tdfx= [HW,DRM]
2125
2126 thash_entries= [KNL,NET]
2127 Set number of hash buckets for TCP connection
2128
Len Brownf8707ec2007-08-12 00:12:54 -04002129 thermal.act= [HW,ACPI]
2130 -1: disable all active trip points in all thermal zones
2131 <degrees C>: override all lowest active trip points
2132
Len Brownc52a7412007-08-14 15:49:32 -04002133 thermal.crt= [HW,ACPI]
2134 -1: disable all critical trip points in all thermal zones
2135 <degrees C>: lower all critical trip points
2136
Len Brownf5487142007-08-12 00:12:44 -04002137 thermal.nocrt= [HW,ACPI]
2138 Set to disable actions on ACPI thermal zone
2139 critical and hot trip points.
2140
Len Brown72b33ef2007-08-12 00:12:17 -04002141 thermal.off= [HW,ACPI]
2142 1: disable ACPI thermal control
2143
Len Browna70cdc52007-08-12 00:12:35 -04002144 thermal.psv= [HW,ACPI]
2145 -1: disable all passive trip points
2146 <degrees C>: override all passive trip points to this value
2147
Len Brown730ff342007-08-12 00:12:26 -04002148 thermal.tzp= [HW,ACPI]
2149 Specify global default ACPI thermal zone polling rate
2150 <deci-seconds>: poll all this frequency
2151 0: no polling (default)
2152
Linus Torvalds1da177e2005-04-16 15:20:36 -07002153 tipar.timeout= [HW,PPT]
2154 Set communications timeout in tenths of a second
2155 (default 15).
2156
2157 tipar.delay= [HW,PPT]
2158 Set inter-bit delay in microseconds (default 10).
2159
Linus Torvalds1da177e2005-04-16 15:20:36 -07002160 tmscsim= [HW,SCSI]
2161 See comment before function dc390_setup() in
2162 drivers/scsi/tmscsim.c.
2163
2164 tp720= [HW,PS2]
2165
2166 trix= [HW,OSS] MediaTrix AudioTrix Pro
Randy Dunlapa9913042005-10-23 12:57:11 -07002167 Format:
2168 <io>,<irq>,<dma>,<dma2>,<sb_io>,<sb_irq>,<sb_dma>,<mpu_io>,<mpu_irq>
2169
Randy Dunlapa9913042005-10-23 12:57:11 -07002170 turbografx.map[2|3]= [HW,JOY]
2171 TurboGraFX parallel port interface
2172 Format:
2173 <port#>,<js1>,<js2>,<js3>,<js4>,<js5>,<js6>,<js7>
Linus Torvalds1da177e2005-04-16 15:20:36 -07002174 See also Documentation/input/joystick-parport.txt
2175
2176 u14-34f= [HW,SCSI] UltraStor 14F/34F SCSI host adapter
2177 See header of drivers/scsi/u14-34f.c.
2178
2179 uart401= [HW,OSS]
2180 Format: <io>,<irq>
2181
2182 uart6850= [HW,OSS]
2183 Format: <io>,<irq>
2184
Alan Stern5f8364b2006-12-05 16:29:55 -05002185 uhci-hcd.ignore_oc=
2186 [USB] Ignore overcurrent events (default N).
2187 Some badly-designed motherboards generate lots of
2188 bogus events, for ports that aren't wired to
2189 anything. Set this parameter to avoid log spamming.
2190 Note that genuine overcurrent events won't be
2191 reported either.
2192
Simon Arlotte3a61b02008-07-19 23:32:54 +01002193 unknown_nmi_panic
2194 [X86-32,X86-64]
2195 Set unknown_nmi_panic=1 early on boot.
2196
Alan Sternb5e795f2007-02-20 15:00:53 -05002197 usbcore.autosuspend=
2198 [USB] The autosuspend time delay (in seconds) used
2199 for newly-detected USB devices (default 2). This
2200 is the time required before an idle device will be
2201 autosuspended. Devices for which the delay is set
Alan Sterneaafbc32007-03-13 16:39:15 -04002202 to a negative value won't be autosuspended at all.
Alan Sternb5e795f2007-02-20 15:00:53 -05002203
Linus Torvalds1da177e2005-04-16 15:20:36 -07002204 usbhid.mousepoll=
2205 [USBHID] The interval which mice are to be polled at.
Randy Dunlapa9913042005-10-23 12:57:11 -07002206
Paul Jackson200001e2008-06-25 05:44:46 -07002207 add_efi_memmap [EFI; x86-32,X86-64] Include EFI memory map in
2208 kernel's map of available physical RAM.
2209
Alan Coxcd4f0ef2007-07-31 00:37:59 -07002210 vdso= [X86-32,SH,x86-64]
Jeremy Fitzhardinge1dbf527c2007-05-02 19:27:12 +02002211 vdso=2: enable compat VDSO (default with COMPAT_VDSO)
Ingo Molnare6e54942006-06-27 02:53:50 -07002212 vdso=1: enable VDSO (default)
2213 vdso=0: disable VDSO mapping
2214
Roland McGrathaf65d642008-01-30 13:30:43 +01002215 vdso32= [X86-32,X86-64]
2216 vdso32=2: enable compat VDSO (default with COMPAT_VDSO)
2217 vdso32=1: enable 32-bit VDSO (default)
2218 vdso32=0: disable 32-bit VDSO mapping
2219
Yasuaki Ishimatsud080d392007-07-17 21:22:55 +09002220 vector= [IA-64,SMP]
2221 vector=percpu: enable percpu vector domain
2222
Linus Torvalds1da177e2005-04-16 15:20:36 -07002223 video= [FB] Frame buffer configuration
2224 See Documentation/fb/modedb.txt.
2225
Alan Coxcd4f0ef2007-07-31 00:37:59 -07002226 vga= [BOOT,X86-32] Select a particular video mode
Randy Dunlapa9913042005-10-23 12:57:11 -07002227 See Documentation/i386/boot.txt and
2228 Documentation/svga.txt.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002229 Use vga=ask for menu.
2230 This is actually a boot loader parameter; the value is
2231 passed to the kernel using a special protocol.
2232
Randy Dunlapa9913042005-10-23 12:57:11 -07002233 vmalloc=nn[KMG] [KNL,BOOT] Forces the vmalloc area to have an exact
Linus Torvalds1da177e2005-04-16 15:20:36 -07002234 size of <nn>. This can be used to increase the
2235 minimum size (128MB on x86). It can also be used to
2236 decrease the size and leave more room for directly
2237 mapped kernel RAM.
2238
Peter Oberparleiter585c3042006-06-29 15:08:25 +02002239 vmhalt= [KNL,S390] Perform z/VM CP command after system halt.
2240 Format: <command>
Linus Torvalds1da177e2005-04-16 15:20:36 -07002241
Peter Oberparleiter585c3042006-06-29 15:08:25 +02002242 vmpanic= [KNL,S390] Perform z/VM CP command after kernel panic.
2243 Format: <command>
2244
2245 vmpoff= [KNL,S390] Perform z/VM CP command after power off.
2246 Format: <command>
Randy Dunlapa9913042005-10-23 12:57:11 -07002247
Linus Torvalds1da177e2005-04-16 15:20:36 -07002248 waveartist= [HW,OSS]
2249 Format: <io>,<irq>,<dma>,<dma2>
Randy Dunlapa9913042005-10-23 12:57:11 -07002250
Linus Torvalds1da177e2005-04-16 15:20:36 -07002251 wd33c93= [HW,SCSI]
2252 See header of drivers/scsi/wd33c93.c.
2253
2254 wd7000= [HW,SCSI]
2255 See header of drivers/scsi/wd7000.c.
2256
2257 wdt= [WDT] Watchdog
Gabriel C8dfe9c22007-08-10 13:01:00 -07002258 See Documentation/watchdog/wdt.txt.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002259
2260 xd= [HW,XT] Original XT pre-IDE (RLL encoded) disks.
2261 xd_geo= See header of drivers/block/xd.c.
2262
2263 xirc2ps_cs= [NET,PCMCIA]
Randy Dunlapa9913042005-10-23 12:57:11 -07002264 Format:
2265 <irq>,<irq_mask>,<io>,<full_duplex>,<do_sound>,<lockup_hack>[,<irq2>[,<irq3>[,<irq4>]]]
Linus Torvalds1da177e2005-04-16 15:20:36 -07002266
Andi Kleena62eaf12006-02-16 23:41:58 +01002267 norandmaps Don't use address space randomization
2268 Equivalent to echo 0 > /proc/sys/kernel/randomize_va_space
2269
Randy Dunlapa9913042005-10-23 12:57:11 -07002270______________________________________________________________________
Linus Torvalds1da177e2005-04-16 15:20:36 -07002271
2272TODO:
2273
2274 Add documentation for ALSA options.
2275 Add more DRM drivers.