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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
Pavel Machek23b168d2008-02-05 19:27:12 +0100150 Format: { s3_bios, s3_mode, s3_beep }
151 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.
Randy Dunlapa9913042005-10-23 12:57:11 -0700154
Linus Torvalds1da177e2005-04-16 15:20:36 -0700155 acpi_sci= [HW,ACPI] ACPI System Control Interrupt trigger mode
Randy Dunlapa9913042005-10-23 12:57:11 -0700156 Format: { level | edge | high | low }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700157
Randy Dunlapa9913042005-10-23 12:57:11 -0700158 acpi_irq_balance [HW,ACPI]
159 ACPI will balance active IRQs
160 default in APIC mode
Linus Torvalds1da177e2005-04-16 15:20:36 -0700161
Randy Dunlapa9913042005-10-23 12:57:11 -0700162 acpi_irq_nobalance [HW,ACPI]
163 ACPI will not move active IRQs (default)
164 default in PIC mode
Linus Torvalds1da177e2005-04-16 15:20:36 -0700165
Randy Dunlapa9913042005-10-23 12:57:11 -0700166 acpi_irq_pci= [HW,ACPI] If irq_balance, clear listed IRQs for
167 use by PCI
Linus Torvalds1da177e2005-04-16 15:20:36 -0700168 Format: <irq>,<irq>...
169
Randy Dunlapa9913042005-10-23 12:57:11 -0700170 acpi_irq_isa= [HW,ACPI] If irq_balance, mark listed IRQs used by ISA
Linus Torvalds1da177e2005-04-16 15:20:36 -0700171 Format: <irq>,<irq>...
172
Len Brown67effe82007-07-26 00:50:06 -0400173 acpi_no_auto_ssdt [HW,ACPI] Disable automatic loading of SSDT
174
Len Browna1f9e652006-01-25 23:47:36 -0500175 acpi_os_name= [HW,ACPI] Tell ACPI BIOS the name of the OS
176 Format: To spoof as Windows 98: ="Microsoft Windows"
177
Len Brownae00d812007-05-29 18:43:33 -0400178 acpi_osi= [HW,ACPI] Modify list of supported OS interface strings
179 acpi_osi="string1" # add string1 -- only one string
180 acpi_osi="!string2" # remove built-in string2
181 acpi_osi= # disable all strings
Linus Torvalds1da177e2005-04-16 15:20:36 -0700182
183 acpi_serialize [HW,ACPI] force serialization of AML methods
184
185 acpi_skip_timer_override [HW,ACPI]
186 Recognize and ignore IRQ0/pin2 Interrupt Override.
187 For broken nForce2 BIOS resulting in XT-PIC timer.
Andi Kleenfa18f472006-11-14 16:57:46 +0100188 acpi_use_timer_override [HW,ACPI}
189 Use timer override. For some broken Nvidia NF5 boards
190 that require a timer override, but don't have
191 HPET
Linus Torvalds1da177e2005-04-16 15:20:36 -0700192
Zhang Ruif9891062007-04-24 13:53:22 +0800193 acpi.debug_layer= [HW,ACPI]
Linus Torvalds1da177e2005-04-16 15:20:36 -0700194 Format: <int>
Randy Dunlapa9913042005-10-23 12:57:11 -0700195 Each bit of the <int> indicates an ACPI debug layer,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700196 1: enable, 0: disable. It is useful for boot time
197 debugging. After system has booted up, it can be set
Zhang Ruif9891062007-04-24 13:53:22 +0800198 via /sys/module/acpi/parameters/debug_layer.
199 CONFIG_ACPI_DEBUG must be enabled for this to produce any output.
200 Available bits (add the numbers together) to enable debug output
201 for specific parts of the ACPI subsystem:
202 0x01 utilities 0x02 hardware 0x04 events 0x08 tables
203 0x10 namespace 0x20 parser 0x40 dispatcher
204 0x80 executer 0x100 resources 0x200 acpica debugger
205 0x400 os services 0x800 acpica disassembler.
206 The number can be in decimal or prefixed with 0x in hex.
207 Warning: Many of these options can produce a lot of
208 output and make your system unusable. Be very careful.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700209
Zhang Ruif9891062007-04-24 13:53:22 +0800210 acpi.debug_level= [HW,ACPI]
Linus Torvalds1da177e2005-04-16 15:20:36 -0700211 Format: <int>
Randy Dunlapa9913042005-10-23 12:57:11 -0700212 Each bit of the <int> indicates an ACPI debug level,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700213 1: enable, 0: disable. It is useful for boot time
214 debugging. After system has booted up, it can be set
Zhang Ruif9891062007-04-24 13:53:22 +0800215 via /sys/module/acpi/parameters/debug_level.
216 CONFIG_ACPI_DEBUG must be enabled for this to produce any output.
217 Available bits (add the numbers together) to enable different
218 debug output levels of the ACPI subsystem:
219 0x01 error 0x02 warn 0x04 init 0x08 debug object
220 0x10 info 0x20 init names 0x40 parse 0x80 load
221 0x100 dispatch 0x200 execute 0x400 names 0x800 operation region
222 0x1000 bfield 0x2000 tables 0x4000 values 0x8000 objects
223 0x10000 resources 0x20000 user requests 0x40000 package.
224 The number can be in decimal or prefixed with 0x in hex.
225 Warning: Many of these options can produce a lot of
226 output and make your system unusable. Be very careful.
227
Alan Coxcd4f0ef2007-07-31 00:37:59 -0700228 acpi_pm_good [X86-32,X86-64]
john stultz5d0cf412006-06-26 00:25:12 -0700229 Override the pmtimer bug detection: force the kernel
230 to assume that this machine's pmtimer latches its value
231 and always returns good values.
232
Chuck Ebbertc99c1082007-07-27 10:46:20 +1000233 agp= [AGP]
234 { off | try_unsupported }
235 off: disable AGP support
236 try_unsupported: try to drive unsupported chipsets
237 (may crash computer or cause data corruption)
238
Chuck Ebbert66759a02005-09-12 18:49:25 +0200239 enable_timer_pin_1 [i386,x86-64]
240 Enable PIN 1 of APIC timer
Randy Dunlapa9913042005-10-23 12:57:11 -0700241 Can be useful to work around chipset bugs
242 (in particular on some ATI chipsets).
Chuck Ebbert66759a02005-09-12 18:49:25 +0200243 The kernel tries to set a reasonable default.
244
245 disable_timer_pin_1 [i386,x86-64]
246 Disable PIN 1 of APIC timer
247 Can be useful to work around chipset bugs.
248
Linus Torvalds1da177e2005-04-16 15:20:36 -0700249 ad1848= [HW,OSS]
250 Format: <io>,<irq>,<dma>,<dma2>,<type>
251
Linus Torvalds1da177e2005-04-16 15:20:36 -0700252 advansys= [HW,SCSI]
253 See header of drivers/scsi/advansys.c.
254
255 advwdt= [HW,WDT] Advantech WDT
256 Format: <iostart>,<iostop>
257
258 aedsp16= [HW,OSS] Audio Excel DSP 16
259 Format: <io>,<irq>,<dma>,<mss_io>,<mpu_io>,<mpu_irq>
260 See also header of sound/oss/aedsp16.c.
Randy Dunlapa9913042005-10-23 12:57:11 -0700261
Linus Torvalds1da177e2005-04-16 15:20:36 -0700262 aha152x= [HW,SCSI]
263 See Documentation/scsi/aha152x.txt.
264
265 aha1542= [HW,SCSI]
266 Format: <portbase>[,<buson>,<busoff>[,<dmaspeed>]]
267
268 aic7xxx= [HW,SCSI]
269 See Documentation/scsi/aic7xxx.txt.
270
271 aic79xx= [HW,SCSI]
272 See Documentation/scsi/aic79xx.txt.
273
Joerg Roedel54b4cbd2008-06-26 21:28:10 +0200274 amd_iommu= [HW,X86-84]
275 Pass parameters to the AMD IOMMU driver in the system.
276 Possible values are:
277 off - disable the driver for AMD IOMMU
278 isolate - enable device isolation (each device, as far
279 as possible, will get its own protection
280 domain)
281 amd_iommu_size= [HW,X86-64]
282 Define the size of the aperture for the AMD IOMMU
283 driver. Possible values are:
284 '32M', '64M' (default), '128M', '256M', '512M', '1G'
285
Linus Torvalds1da177e2005-04-16 15:20:36 -0700286 amijoy.map= [HW,JOY] Amiga joystick support
287 Map of devices attached to JOY0DAT and JOY1DAT
288 Format: <a>,<b>
289 See also Documentation/kernel/input/joystick.txt
290
291 analog.map= [HW,JOY] Analog joystick and gamepad support
292 Specifies type or capabilities of an analog joystick
293 connected to one of 16 gameports
294 Format: <type1>,<type2>,..<type16>
295
Randy Dunlapa9913042005-10-23 12:57:11 -0700296 apc= [HW,SPARC]
297 Power management functions (SPARCstation-4/5 + deriv.)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700298 Format: noidle
299 Disable APC CPU standby support. SPARCstation-Fox does
300 not play well with APC CPU idle - disable it if you have
301 APC and your system crashes randomly.
302
Randy Dunlapc8facbb2007-07-31 00:37:40 -0700303 apic= [APIC,i386] Advanced Programmable Interrupt Controller
304 Change the output verbosity whilst booting
Linus Torvalds1da177e2005-04-16 15:20:36 -0700305 Format: { quiet (default) | verbose | debug }
306 Change the amount of debugging information output
307 when initialising the APIC and IO-APIC components.
Randy Dunlapa9913042005-10-23 12:57:11 -0700308
Linus Torvalds1da177e2005-04-16 15:20:36 -0700309 apm= [APM] Advanced Power Management
310 See header of arch/i386/kernel/apm.c.
311
Linus Torvalds1da177e2005-04-16 15:20:36 -0700312 arcrimi= [HW,NET] ARCnet - "RIM I" (entirely mem-mapped) cards
313 Format: <io>,<irq>,<nodeID>
314
315 ataflop= [HW,M68k]
316
317 atarimouse= [HW,MOUSE] Atari Mouse
318
319 atascsi= [HW,SCSI] Atari SCSI
320
321 atkbd.extra= [HW] Enable extra LEDs and keys on IBM RapidAccess,
322 EzKey and similar keyboards
323
324 atkbd.reset= [HW] Reset keyboard during initialization
325
Randy Dunlapa9913042005-10-23 12:57:11 -0700326 atkbd.set= [HW] Select keyboard code set
327 Format: <int> (2 = AT (default), 3 = PS/2)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700328
329 atkbd.scroll= [HW] Enable scroll wheel on MS Office and similar
330 keyboards
331
332 atkbd.softraw= [HW] Choose between synthetic and real raw mode
333 Format: <bool> (0 = real, 1 = synthetic (default))
Randy Dunlapa9913042005-10-23 12:57:11 -0700334
335 atkbd.softrepeat= [HW]
336 Use software keyboard repeat
Linus Torvalds1da177e2005-04-16 15:20:36 -0700337
338 autotest [IA64]
339
Linus Torvalds1da177e2005-04-16 15:20:36 -0700340 baycom_epp= [HW,AX25]
341 Format: <io>,<mode>
Randy Dunlapa9913042005-10-23 12:57:11 -0700342
Linus Torvalds1da177e2005-04-16 15:20:36 -0700343 baycom_par= [HW,AX25] BayCom Parallel Port AX.25 Modem
344 Format: <io>,<mode>
345 See header of drivers/net/hamradio/baycom_par.c.
346
Randy Dunlapa9913042005-10-23 12:57:11 -0700347 baycom_ser_fdx= [HW,AX25]
348 BayCom Serial Port AX.25 Modem (Full Duplex Mode)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700349 Format: <io>,<irq>,<mode>[,<baud>]
350 See header of drivers/net/hamradio/baycom_ser_fdx.c.
351
Randy Dunlapa9913042005-10-23 12:57:11 -0700352 baycom_ser_hdx= [HW,AX25]
353 BayCom Serial Port AX.25 Modem (Half Duplex Mode)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700354 Format: <io>,<irq>,<mode>
355 See header of drivers/net/hamradio/baycom_ser_hdx.c.
356
Randy Dunlapbfe8df32007-10-16 01:23:46 -0700357 boot_delay= Milliseconds to delay each printk during boot.
358 Values larger than 10 seconds (10000) are changed to
359 no delay (0).
360 Format: integer
361
Linus Torvalds1da177e2005-04-16 15:20:36 -0700362 bttv.card= [HW,V4L] bttv (bt848 + bt878 based grabber cards)
Randy Dunlapa9913042005-10-23 12:57:11 -0700363 bttv.radio= Most important insmod options are available as
364 kernel args too.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700365 bttv.pll= See Documentation/video4linux/bttv/Insmod-options
366 bttv.tuner= and Documentation/video4linux/bttv/CARDLIST
367
368 BusLogic= [HW,SCSI]
369 See drivers/scsi/BusLogic.c, comment before function
370 BusLogic_ParseDriverOptions().
371
372 c101= [NET] Moxa C101 synchronous serial card
373
Alan Coxcd4f0ef2007-07-31 00:37:59 -0700374 cachesize= [BUGS=X86-32] Override level 2 CPU cache size detection.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700375 Sometimes CPU hardware bugs make them report the cache
376 size incorrectly. The kernel will attempt work arounds
377 to fix known problems, but for some CPUs it is not
378 possible to determine what the correct size should be.
379 This option provides an override for these situations.
380
Ahmed S. Darwish076c54c2008-03-06 18:09:10 +0200381 security= [SECURITY] Choose a security module to enable at boot.
382 If this boot parameter is not specified, only the first
383 security module asking for security registration will be
384 loaded. An invalid security module name will be treated
385 as if no module has been chosen.
386
James Morris20510f22007-10-16 23:31:32 -0700387 capability.disable=
388 [SECURITY] Disable capabilities. This would normally
389 be used only if an alternative security model is to be
390 configured. Potentially dangerous and should only be
391 used if you are entirely sure of the consequences.
392
Sebastian Ott14ff56b2008-01-26 14:10:37 +0100393 ccw_timeout_log [S390]
394 See Documentation/s390/CommonIO for details.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700395
Paul Menage8bab8dd2008-04-04 14:29:57 -0700396 cgroup_disable= [KNL] Disable a particular controller
397 Format: {name of the controller(s) to disable}
398 {Currently supported controllers - "memory"}
399
Linus Torvalds1da177e2005-04-16 15:20:36 -0700400 checkreqprot [SELINUX] Set initial checkreqprot flag value.
401 Format: { "0" | "1" }
402 See security/selinux/Kconfig help text.
Randy Dunlapa9913042005-10-23 12:57:11 -0700403 0 -- check protection applied by kernel (includes
404 any implied execute protection).
Linus Torvalds1da177e2005-04-16 15:20:36 -0700405 1 -- check protection requested by application.
406 Default value is set via a kernel config option.
Randy Dunlapa9913042005-10-23 12:57:11 -0700407 Value can be changed at runtime via
408 /selinux/checkreqprot.
409
Sebastian Ott661ca0d2008-01-26 14:10:36 +0100410 cio_ignore= [S390]
411 See Documentation/s390/CommonIO for details.
412
Alan Coxcd4f0ef2007-07-31 00:37:59 -0700413 clock= [BUGS=X86-32, HW] gettimeofday clocksource override.
john stultz734efb42006-06-26 00:25:05 -0700414 [Deprecated]
Matt LaPlante3f6dee92006-10-03 22:45:33 +0200415 Forces specified clocksource (if available) to be used
john stultz734efb42006-06-26 00:25:05 -0700416 when calculating gettimeofday(). If specified
Matt LaPlante3f6dee92006-10-03 22:45:33 +0200417 clocksource is not available, it defaults to PIT.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700418 Format: { pit | tsc | cyclone | pmtmr }
419
Randy Dunlap3d6ac982007-05-23 13:58:16 -0700420 clocksource= [GENERIC_TIME] Override the default clocksource
421 Format: <string>
422 Override the default clocksource and use the clocksource
423 with the name specified.
424 Some clocksource names to choose from, depending on
425 the platform:
426 [all] jiffies (this is the base, fallback clocksource)
427 [ACPI] acpi_pm
428 [ARM] imx_timer1,OSTS,netx_timer,mpu_timer2,
429 pxa_timer,timer3,32k_counter,timer0_1
430 [AVR32] avr32
Alan Coxcd4f0ef2007-07-31 00:37:59 -0700431 [X86-32] pit,hpet,tsc,vmi-timer;
Randy Dunlap3d6ac982007-05-23 13:58:16 -0700432 scx200_hrt on Geode; cyclone on IBM x440
433 [MIPS] MIPS
434 [PARISC] cr16
435 [S390] tod
436 [SH] SuperH
437 [SPARC64] tick
438 [X86-64] hpet,tsc
439
Andi Kleenac72e782008-01-30 13:33:21 +0100440 clearcpuid=BITNUM [X86]
441 Disable CPUID feature X for the kernel. See
442 include/asm-x86/cpufeature.h for the valid bit numbers.
443 Note the Linux specific bits are not necessarily
444 stable over kernel options, but the vendor specific
445 ones should be.
446 Also note that user programs calling CPUID directly
447 or using the feature without checking anything
448 will still see it. This just prevents it from
449 being used by the kernel or shown in /proc/cpuinfo.
450 Also note the kernel might malfunction if you disable
451 some critical bits.
452
Arjan van de Vena25bd942008-01-30 13:33:08 +0100453 code_bytes [IA32/X86_64] How many bytes of object code to print
454 in an oops report.
Chuck Ebbert86c41832007-02-13 13:26:25 +0100455 Range: 0 - 8192
456 Default: 64
457
Andi Kleenf9262c12006-03-08 17:57:25 -0800458 disable_8254_timer
459 enable_8254_timer
460 [IA32/X86_64] Disable/Enable interrupt 0 timer routing
461 over the 8254 in addition to over the IO-APIC. The
462 kernel tries to set a sensible default.
463
Thomas Gleixnerb17530b2007-10-19 20:35:02 +0200464 hpet= [X86-32,HPET] option to control HPET usage
465 Format: { enable (default) | disable | force }
466 disable: disable HPET and use PIT instead
Carlos Corbachod79a5f82007-10-19 18:51:27 +0100467 force: allow force enabled of undocumented chips (ICH4,
468 VIA, nVidia)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700469
Linus Torvalds1da177e2005-04-16 15:20:36 -0700470 com20020= [HW,NET] ARCnet - COM20020 chipset
Randy Dunlapa9913042005-10-23 12:57:11 -0700471 Format:
472 <io>[,<irq>[,<nodeID>[,<backplane>[,<ckp>[,<timeout>]]]]]
Linus Torvalds1da177e2005-04-16 15:20:36 -0700473
474 com90io= [HW,NET] ARCnet - COM90xx chipset (IO-mapped buffers)
475 Format: <io>[,<irq>]
476
Randy Dunlapa9913042005-10-23 12:57:11 -0700477 com90xx= [HW,NET]
478 ARCnet - COM90xx chipset (memory-mapped buffers)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700479 Format: <io>[,<irq>[,<memstart>]]
480
481 condev= [HW,S390] console device
482 conmode=
Randy Dunlapa9913042005-10-23 12:57:11 -0700483
Linus Torvalds1da177e2005-04-16 15:20:36 -0700484 console= [KNL] Output console device and options.
485
486 tty<n> Use the virtual console device <n>.
487
488 ttyS<n>[,options]
Randy Dunlapf1a1c2d2006-03-25 03:08:17 -0800489 ttyUSB0[,options]
Linus Torvalds1da177e2005-04-16 15:20:36 -0700490 Use the specified serial port. The options are of
Randy Dunlapf1a1c2d2006-03-25 03:08:17 -0800491 the form "bbbbpnf", where "bbbb" is the baud rate,
492 "p" is parity ("n", "o", or "e"), "n" is number of
493 bits, and "f" is flow control ("r" for RTS or
494 omit it). Default is "9600n8".
Linus Torvalds1da177e2005-04-16 15:20:36 -0700495
Randy Dunlapf1a1c2d2006-03-25 03:08:17 -0800496 See Documentation/serial-console.txt for more
497 information. See
498 Documentation/networking/netconsole.txt for an
499 alternative.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700500
Yinghai Lu18a8bd92007-07-15 23:37:59 -0700501 uart[8250],io,<addr>[,options]
502 uart[8250],mmio,<addr>[,options]
Linus Torvalds1da177e2005-04-16 15:20:36 -0700503 Start an early, polled-mode console on the 8250/16550
504 UART at the specified I/O port or MMIO address,
505 switching to the matching ttyS device later. The
506 options are the same as for ttyS, above.
507
Samuel Thibaultf7511d52008-04-30 00:54:51 -0700508 If the device connected to the port is not a TTY but a braille
509 device, prepend "brl," before the device type, for instance
510 console=brl,ttyS0
511 For now, only VisioBraille is supported.
512
Yinghai Lu18a8bd92007-07-15 23:37:59 -0700513 earlycon= [KNL] Output early console device and options.
514 uart[8250],io,<addr>[,options]
515 uart[8250],mmio,<addr>[,options]
516 Start an early, polled-mode console on the 8250/16550
517 UART at the specified I/O port or MMIO address.
518 The options are the same as for ttyS, above.
519
Andres Salomon8f4ce8c2007-10-18 03:04:50 -0700520 no_console_suspend
521 [HW] Never suspend the console
522 Disable suspending of consoles during suspend and
523 hibernate operations. Once disabled, debugging
524 messages can reach various consoles while the rest
525 of the system is being put to sleep (ie, while
526 debugging driver suspend/resume hooks). This may
527 not work reliably with all consoles, but is known
528 to work with serial and VGA consoles.
529
Linus Torvalds1da177e2005-04-16 15:20:36 -0700530 cpcihp_generic= [HW,PCI] Generic port I/O CompactPCI driver
Randy Dunlapa9913042005-10-23 12:57:11 -0700531 Format:
532 <first_slot>,<last_slot>,<port>,<enum_bit>[,<debug>]
Linus Torvalds1da177e2005-04-16 15:20:36 -0700533
Eric W. Biedermandc009d92005-06-25 14:57:52 -0700534 crashkernel=nn[KMG]@ss[KMG]
535 [KNL] Reserve a chunk of physical memory to
536 hold a kernel to switch to with kexec on panic.
537
Bernhard Wallefb391592007-10-18 23:41:02 -0700538 crashkernel=range1:size1[,range2:size2,...][@offset]
539 [KNL] Same as above, but depends on the memory
540 in the running system. The syntax of range is
541 start-[end] where start and end are both
542 a memory unit (amount[KMG]). See also
543 Documentation/kdump/kdump.txt for a example.
544
Linus Torvalds1da177e2005-04-16 15:20:36 -0700545 cs4232= [HW,OSS]
546 Format: <io>,<irq>,<dma>,<dma2>,<mpuio>,<mpuirq>
547
548 cs89x0_dma= [HW,NET]
549 Format: <dma>
550
551 cs89x0_media= [HW,NET]
552 Format: { rj45 | aui | bnc }
Randy Dunlapa9913042005-10-23 12:57:11 -0700553
Randy Dunlapa9913042005-10-23 12:57:11 -0700554 dasd= [HW,NET]
Linus Torvalds1da177e2005-04-16 15:20:36 -0700555 See header of drivers/s390/block/dasd_devmap.c.
556
557 db9.dev[2|3]= [HW,JOY] Multisystem joystick support via parallel port
558 (one device per port)
559 Format: <port#>,<type>
560 See also Documentation/input/joystick-parport.txt
561
562 debug [KNL] Enable kernel debugging (events log level).
563
Ingo Molnarcae2ed92006-07-03 00:24:48 -0700564 debug_locks_verbose=
565 [KNL] verbose self-tests
566 Format=<0|1>
567 Print debugging info while doing the locking API
568 self-tests.
569 We default to 0 (no extra messages), setting it to
570 1 will print _a lot_ more information - normally
571 only useful to kernel developers.
572
Thomas Gleixner3ac7fe52008-04-30 00:55:01 -0700573 debug_objects [KNL] Enable object debugging
574
Robert P. J. Day2d27a962008-02-03 15:18:45 +0200575 decnet.addr= [HW,NET]
Linus Torvalds1da177e2005-04-16 15:20:36 -0700576 Format: <area>[,<node>]
577 See also Documentation/networking/decnet.txt.
578
Samuel Thibaultecb77fa2008-01-03 16:17:54 +0000579 vt.default_blu= [VT]
Antonino A. Daplas55ff9782007-05-08 00:38:53 -0700580 Format: <blue0>,<blue1>,<blue2>,...,<blue15>
581 Change the default blue palette of the console.
582 This is a 16-member array composed of values
583 ranging from 0-255.
584
Samuel Thibaultecb77fa2008-01-03 16:17:54 +0000585 vt.default_grn= [VT]
Antonino A. Daplas55ff9782007-05-08 00:38:53 -0700586 Format: <green0>,<green1>,<green2>,...,<green15>
587 Change the default green palette of the console.
588 This is a 16-member array composed of values
589 ranging from 0-255.
590
Samuel Thibaultecb77fa2008-01-03 16:17:54 +0000591 vt.default_red= [VT]
Antonino A. Daplas55ff9782007-05-08 00:38:53 -0700592 Format: <red0>,<red1>,<red2>,...,<red15>
593 Change the default red palette of the console.
594 This is a 16-member array composed of values
595 ranging from 0-255.
596
Samuel Thibaultecb77fa2008-01-03 16:17:54 +0000597 vt.default_utf8=
598 [VT]
Antonino A. Daplas55ff9782007-05-08 00:38:53 -0700599 Format=<0|1>
600 Set system-wide default UTF-8 mode for all tty's.
Samuel Thibaultecb77fa2008-01-03 16:17:54 +0000601 Default is 1, i.e. UTF-8 mode is enabled for all
602 newly opened terminals.
Antonino A. Daplas55ff9782007-05-08 00:38:53 -0700603
Linus Torvalds1da177e2005-04-16 15:20:36 -0700604 dhash_entries= [KNL]
605 Set number of hash buckets for dentry cache.
Randy Dunlapa9913042005-10-23 12:57:11 -0700606
Linus Torvalds1da177e2005-04-16 15:20:36 -0700607 digi= [HW,SERIAL]
608 IO parameters + enable/disable command.
609
610 digiepca= [HW,SERIAL]
611 See drivers/char/README.epca and
612 Documentation/digiepca.txt.
613
Yinghai Lu093af8d2008-01-30 13:33:32 +0100614 disable_mtrr_trim [X86, Intel and AMD only]
Jesse Barnes99fc8d42008-01-30 13:33:18 +0100615 By default the kernel will trim any uncacheable
616 memory out of your available memory pool based on
617 MTRR settings. This parameter disables that behavior,
618 possibly causing your machine to run very slowly.
619
Linus Torvalds1da177e2005-04-16 15:20:36 -0700620 dmasound= [HW,OSS] Sound subsystem buffers
621
622 dscc4.setup= [NET]
623
624 dtc3181e= [HW,SCSI]
625
Robin Getz0ae53642007-10-09 17:24:49 +0800626 earlyprintk= [X86-32,X86-64,SH,BLACKFIN]
Linus Torvalds1da177e2005-04-16 15:20:36 -0700627 earlyprintk=vga
628 earlyprintk=serial[,ttySn[,baudrate]]
629
Randy Dunlapa9913042005-10-23 12:57:11 -0700630 Append ",keep" to not disable it when the real console
Linus Torvalds1da177e2005-04-16 15:20:36 -0700631 takes over.
632
633 Only vga or serial at a time, not both.
634
635 Currently only ttyS0 and ttyS1 are supported.
636
637 Interaction with the standard serial driver is not
638 very good.
639
640 The VGA output is eventually overwritten by the real
641 console.
642
643 eata= [HW,SCSI]
644
Linus Torvalds1da177e2005-04-16 15:20:36 -0700645 edd= [EDD]
Tim Gardner8c4dd602008-04-29 01:02:45 -0700646 Format: {"off" | "on" | "skip[mbr]"}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700647
Linus Torvalds1da177e2005-04-16 15:20:36 -0700648 eisa_irq_edge= [PARISC,HW]
649 See header of drivers/parisc/eisa.c.
650
Alan Coxcd4f0ef2007-07-31 00:37:59 -0700651 elanfreq= [X86-32]
Linus Torvalds1da177e2005-04-16 15:20:36 -0700652 See comment before function elanfreq_setup() in
653 arch/i386/kernel/cpu/cpufreq/elanfreq.c.
654
655 elevator= [IOSCHED]
Randy Dunlap16ab3ad2006-01-14 13:21:20 -0800656 Format: {"anticipatory" | "cfq" | "deadline" | "noop"}
Randy Dunlapa9913042005-10-23 12:57:11 -0700657 See Documentation/block/as-iosched.txt and
658 Documentation/block/deadline-iosched.txt for details.
659
Alan Coxcd4f0ef2007-07-31 00:37:59 -0700660 elfcorehdr= [X86-32, X86_64]
Randy Dunlapa9913042005-10-23 12:57:11 -0700661 Specifies physical address of start of kernel core
Vivek Goyalaac04b32006-01-09 20:51:47 -0800662 image elf header. Generally kexec loader will
663 pass this option to capture kernel.
664 See Documentation/kdump/kdump.txt for details.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700665
666 enforcing [SELINUX] Set initial enforcing status.
667 Format: {"0" | "1"}
668 See security/selinux/Kconfig help text.
669 0 -- permissive (log only, no denials).
670 1 -- enforcing (deny and log).
671 Default value is 0.
672 Value can be changed at runtime via /selinux/enforce.
673
Linus Torvalds1da177e2005-04-16 15:20:36 -0700674 es1371= [HW,OSS]
675 Format: <spdif>,[<nomix>,[<amplifier>]]
676 See also header of sound/oss/es1371.c.
Randy Dunlapa9913042005-10-23 12:57:11 -0700677
Linus Torvalds1da177e2005-04-16 15:20:36 -0700678 ether= [HW,NET] Ethernet cards parameters
679 This option is obsoleted by the "netdev=" option, which
680 has equivalent usage. See its documentation for details.
681
682 eurwdt= [HW,WDT] Eurotech CPU-1220/1410 onboard watchdog.
683 Format: <io>[,<irq>]
684
Akinobu Mitade1ba092006-12-08 02:39:42 -0800685 failslab=
686 fail_page_alloc=
687 fail_make_request=[KNL]
688 General fault injection mechanism.
689 Format: <interval>,<probability>,<space>,<times>
690 See also /Documentation/fault-injection/.
691
Linus Torvalds1da177e2005-04-16 15:20:36 -0700692 fd_mcs= [HW,SCSI]
693 See header of drivers/scsi/fd_mcs.c.
694
695 fdomain= [HW,SCSI]
696 See header of drivers/scsi/fdomain.c.
697
698 floppy= [HW]
699 See Documentation/floppy.txt.
700
Alex Chiangf13ae302008-05-08 14:03:23 -0600701 force_pal_cache_flush
702 [IA-64] Avoid check_sal_cache_flush which may hang on
703 buggy SAL_CACHE_FLUSH implementations. Using this
704 parameter will force ia64_sal_cache_flush to call
705 ia64_pal_cache_flush instead of SAL_CACHE_FLUSH.
706
Linus Torvalds1da177e2005-04-16 15:20:36 -0700707 gamecon.map[2|3]=
708 [HW,JOY] Multisystem joystick and NES/SNES/PSX pad
709 support via parallel port (up to 5 devices per port)
710 Format: <port#>,<pad1>,<pad2>,<pad3>,<pad4>,<pad5>
711 See also Documentation/input/joystick-parport.txt
712
713 gamma= [HW,DRM]
714
Yinghai Luaaf23042008-01-30 13:33:09 +0100715 gart_fix_e820= [X86_64] disable the fix e820 for K8 GART
716 Format: off | on
717 default: on
718
Linus Torvalds1da177e2005-04-16 15:20:36 -0700719 gdth= [HW,SCSI]
720 See header of drivers/scsi/gdth.c.
721
722 gpt [EFI] Forces disk with valid GPT signature but
723 invalid Protective MBR to be treated as GPT.
724
Linus Torvalds1da177e2005-04-16 15:20:36 -0700725 gvp11= [HW,SCSI]
726
727 hashdist= [KNL,NUMA] Large hashes allocated during boot
728 are distributed across NUMA nodes. Defaults on
729 for IA-64, off otherwise.
Randy Dunlapa9913042005-10-23 12:57:11 -0700730 Format: 0 | 1 (for off | on)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700731
732 hcl= [IA-64] SGI's Hardware Graph compatibility layer
733
734 hd= [EIDE] (E)IDE hard drive subsystem geometry
735 Format: <cyl>,<head>,<sect>
736
737 hd?= [HW] (E)IDE subsystem
Randy Dunlap1c10e932008-03-07 21:53:50 +0100738 hd?lun= See Documentation/ide/ide.txt.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700739
740 highmem=nn[KMG] [KNL,BOOT] forces the highmem zone to have an exact
741 size of <nn>. This works even on boxes that have no
742 highmem otherwise. This also works to reduce highmem
743 size on bigger boxes.
744
Thomas Gleixner54cdfdb2007-02-16 01:28:11 -0800745 highres= [KNL] Enable/disable high resolution timer mode.
746 Valid parameters: "on", "off"
747 Default: "on"
748
Linus Torvalds1da177e2005-04-16 15:20:36 -0700749 hisax= [HW,ISDN]
750 See Documentation/isdn/README.HiSax.
751
Alan Coxcd4f0ef2007-07-31 00:37:59 -0700752 hugepages= [HW,X86-32,IA-64] Maximal number of HugeTLB pages.
Jon Tollefson4ec161c2008-01-04 09:59:50 +1100753 hugepagesz= [HW,IA-64,PPC] The size of the HugeTLB pages.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700754
Linus Torvalds1da177e2005-04-16 15:20:36 -0700755 i8042.direct [HW] Put keyboard port into non-translated mode
Matt LaPlante84eb8d02006-10-03 22:53:09 +0200756 i8042.dumbkbd [HW] Pretend that controller can only read data from
757 keyboard and cannot control its state
Linus Torvalds1da177e2005-04-16 15:20:36 -0700758 (Don't attempt to blink the leds)
759 i8042.noaux [HW] Don't check for auxiliary (== mouse) port
Dmitry Torokhov945ef0d2005-09-04 01:42:00 -0500760 i8042.nokbd [HW] Don't check/create keyboard port
Jiri Kosina75d08c72008-03-13 16:13:59 -0400761 i8042.noloop [HW] Disable the AUX Loopback command while probing
762 for the AUX port
Linus Torvalds1da177e2005-04-16 15:20:36 -0700763 i8042.nomux [HW] Don't check presence of an active multiplexing
764 controller
765 i8042.nopnp [HW] Don't use ACPIPnP / PnPBIOS to discover KBD/AUX
766 controllers
767 i8042.panicblink=
768 [HW] Frequency with which keyboard LEDs should blink
769 when kernel panics (default is 0.5 sec)
770 i8042.reset [HW] Reset the controller during init and cleanup
771 i8042.unlock [HW] Unlock (ignore) the keylock
772
773 i810= [HW,DRM]
774
Dmitry Torokhove70c9d52005-06-25 14:54:25 -0700775 i8k.ignore_dmi [HW] Continue probing hardware even if DMI data
776 indicates that the driver is running on unsupported
777 hardware.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700778 i8k.force [HW] Activate i8k driver even if SMM BIOS signature
779 does not match list of supported models.
780 i8k.power_status
781 [HW] Report power status in /proc/i8k
782 (disabled by default)
783 i8k.restricted [HW] Allow controlling fans only if SYS_ADMIN
784 capability is set.
785
786 ibmmcascsi= [HW,MCA,SCSI] IBM MicroChannel SCSI adapter
787 See Documentation/mca.txt.
788
789 icn= [HW,ISDN]
790 Format: <io>[,<membase>[,<icn_id>[,<icn_id2>]]]
791
792 ide= [HW] (E)IDE subsystem
Greg Kroah-Hartmana594eeb2008-04-18 00:46:20 +0200793 Format: ide=nodma or ide=doubler
Randy Dunlap1c10e932008-03-07 21:53:50 +0100794 See Documentation/ide/ide.txt.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700795
Linus Torvalds1da177e2005-04-16 15:20:36 -0700796 idebus= [HW] (E)IDE subsystem - VLB/PCI bus speed
Randy Dunlap1c10e932008-03-07 21:53:50 +0100797 See Documentation/ide/ide.txt.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700798
Andi Kleenf039b752007-05-02 19:27:12 +0200799 idle= [X86]
800 Format: idle=poll or idle=mwait
801 Poll forces a polling idle loop that can slightly improves the performance
802 of waking up a idle CPU, but will use a lot of power and make the system
803 run hot. Not recommended.
804 idle=mwait. On systems which support MONITOR/MWAIT but the kernel chose
805 to not use it because it doesn't save as much power as a normal idle
806 loop use the MONITOR/MWAIT idle loop anyways. Performance should be the same
807 as idle=poll.
Randy Dunlapa9913042005-10-23 12:57:11 -0700808
Denis Cheng594765a2008-02-06 02:57:49 +0100809 ide-pci-generic.all-generic-ide [HW] (E)IDE subsystem
810 Claim all unknown PCI IDE storage controllers.
811
Ingo Molnar792908222006-12-06 20:40:51 -0800812 ignore_loglevel [KNL]
813 Ignore loglevel setting - this will print /all/
814 kernel messages to the console. Useful for debugging.
815
Linus Torvalds1da177e2005-04-16 15:20:36 -0700816 ihash_entries= [KNL]
817 Set number of hash buckets for inode cache.
818
819 in2000= [HW,SCSI]
820 See header of drivers/scsi/in2000.c.
821
822 init= [KNL]
823 Format: <full_path>
824 Run specified binary instead of /sbin/init as init
825 process.
826
827 initcall_debug [KNL] Trace initcalls as they are executed. Useful
828 for working out where the kernel is dying during
829 startup.
830
831 initrd= [BOOT] Specify the location of the initial ramdisk
832
833 inport.irq= [HW] Inport (ATI XL and Microsoft) busmouse driver
834 Format: <irq>
835
836 inttest= [IA64]
837
Pavel Machekb552da82008-03-19 15:58:11 +0100838 iommu= [x86]
839 off
840 force
841 noforce
842 biomerge
843 panic
844 nopanic
845 merge
846 nomerge
847 forcesac
848 soft
849
850
Keshavamurthy, Anil Sba395922007-10-21 16:41:49 -0700851 intel_iommu= [DMAR] Intel IOMMU driver (DMAR) option
852 off
853 Disable intel iommu driver.
854 igfx_off [Default Off]
855 By default, gfx is mapped as normal device. If a gfx
856 device has a dedicated DMAR unit, the DMAR unit is
857 bypassed by not enabling DMAR with this option. In
858 this case, gfx device will use physical address for
859 DMA.
Keshavamurthy, Anil S7d3b03c2007-10-21 16:41:53 -0700860 forcedac [x86_64]
861 With this option iommu will not optimize to look
862 for io virtual address below 32 bit forcing dual
863 address cycle on pci bus for cards supporting greater
864 than 32 bit addressing. The default is to look
865 for translation below 32 bit and if not available
866 then look in the higher range.
mark gross5e0d2a62008-03-04 15:22:08 -0800867 strict [Default Off]
868 With this option on every unmap_single operation will
869 result in a hardware IOTLB flush operation as opposed
870 to batching them for performance.
Keshavamurthy, Anil Sba395922007-10-21 16:41:49 -0700871
Rene Hermanb02aae92008-01-30 13:30:05 +0100872 io_delay= [X86-32,X86-64] I/O delay method
Ingo Molnar6e7c4022008-01-30 13:30:05 +0100873 0x80
874 Standard port 0x80 based delay
875 0xed
876 Alternate port 0xed based delay (needed on some systems)
Rene Hermanb02aae92008-01-30 13:30:05 +0100877 udelay
Ingo Molnar6e7c4022008-01-30 13:30:05 +0100878 Simple two microseconds delay
879 none
880 No delay
Rene Hermanb02aae92008-01-30 13:30:05 +0100881
Linus Torvalds1da177e2005-04-16 15:20:36 -0700882 io7= [HW] IO7 for Marvel based alpha systems
883 See comment before marvel_specify_io7 in
884 arch/alpha/kernel/core_marvel.c.
885
886 ip= [IP_PNP]
J. Bruce Fields6ded55d2008-04-07 15:59:03 -0400887 See Documentation/filesystems/nfsroot.txt.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700888
889 ip2= [HW] Set IO/IRQ pairs for up to 4 IntelliPort boards
Randy Dunlapc8facbb2007-07-31 00:37:40 -0700890 See comment before ip2_setup() in
891 drivers/char/ip2/ip2base.c.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700892
893 ips= [HW,SCSI] Adaptec / IBM ServeRAID controller
894 See header of drivers/scsi/ips.c.
895
Simon Horman72c4a132006-09-13 19:57:18 -0700896 ports= [IP_VS_FTP] IPVS ftp helper module
897 Default is 21.
898 Up to 8 (IP_VS_APP_MAX_PORTS) ports
899 may be specified.
900 Format: <port>,<port>....
901
Alan Cox200803d2005-06-28 20:45:18 -0700902 irqfixup [HW]
903 When an interrupt is not handled search all handlers
904 for it. Intended to get systems with badly broken
905 firmware running.
906
907 irqpoll [HW]
908 When an interrupt is not handled search all handlers
909 for it. Also check all handlers each timer
910 interrupt. Intended to get systems with badly broken
911 firmware running.
912
Linus Torvalds1da177e2005-04-16 15:20:36 -0700913 isapnp= [ISAPNP]
Randy Dunlapa9913042005-10-23 12:57:11 -0700914 Format: <RDP>,<reset>,<pci_scan>,<verbosity>
Linus Torvalds1da177e2005-04-16 15:20:36 -0700915
916 isolcpus= [KNL,SMP] Isolate CPUs from the general scheduler.
Derek Fults22f2e282006-12-06 20:37:11 -0800917 Format:
918 <cpu number>,...,<cpu number>
919 or
920 <cpu number>-<cpu number> (must be a positive range in ascending order)
921 or a mixture
922 <cpu number>,...,<cpu number>-<cpu number>
Linus Torvalds1da177e2005-04-16 15:20:36 -0700923 This option can be used to specify one or more CPUs
924 to isolate from the general SMP balancing and scheduling
925 algorithms. The only way to move a process onto or off
926 an "isolated" CPU is via the CPU affinity syscalls.
927 <cpu number> begins at 0 and the maximum value is
928 "number of CPUs in system - 1".
929
930 This option is the preferred way to isolate CPUs. The
Randy Dunlapa9913042005-10-23 12:57:11 -0700931 alternative -- manually setting the CPU mask of all
932 tasks in the system -- can cause problems and
933 suboptimal load balancer performance.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700934
Randy Dunlapa9913042005-10-23 12:57:11 -0700935 iucv= [HW,NET]
Linus Torvalds1da177e2005-04-16 15:20:36 -0700936
937 js= [HW,JOY] Analog joystick
938 See Documentation/input/joystick.txt.
939
Alan Coxcd4f0ef2007-07-31 00:37:59 -0700940 kernelcore=nn[KMG] [KNL,X86-32,IA-64,PPC,X86-64] This parameter
Mel Gormaned7ed362007-07-17 04:03:14 -0700941 specifies the amount of memory usable by the kernel
942 for non-movable allocations. The requested amount is
943 spread evenly throughout all nodes in the system. The
944 remaining memory in each node is used for Movable
945 pages. In the event, a node is too small to have both
946 kernelcore and Movable pages, kernelcore pages will
947 take priority and other nodes will have a larger number
948 of kernelcore pages. The Movable zone is used for the
949 allocation of pages that may be reclaimed or moved
950 by the page migration subsystem. This means that
951 HugeTLB pages may not be allocated from this zone.
952 Note that allocations like PTEs-from-HighMem still
953 use the HighMem zone if it exists, and the Normal
954 zone if it does not.
955
Alan Coxcd4f0ef2007-07-31 00:37:59 -0700956 movablecore=nn[KMG] [KNL,X86-32,IA-64,PPC,X86-64] This parameter
Mel Gorman7e63efe2007-07-17 04:03:15 -0700957 is similar to kernelcore except it specifies the
958 amount of memory used for migratable allocations.
959 If both kernelcore and movablecore is specified,
960 then kernelcore will be at *least* the specified
961 value but may be more. If movablecore on its own
962 is specified, the administrator must be careful
963 that the amount of memory usable for all allocations
964 is not too small.
965
Linus Torvalds1da177e2005-04-16 15:20:36 -0700966 keepinitrd [HW,ARM]
967
Alan Coxcd4f0ef2007-07-31 00:37:59 -0700968 kstack=N [X86-32,X86-64] Print N words from the kernel stack
Linus Torvalds1da177e2005-04-16 15:20:36 -0700969 in oops dumps.
970
Jason Wessel6cdf6e02008-04-17 20:05:38 +0200971 kgdboc= [HW] kgdb over consoles.
972 Requires a tty driver that supports console polling.
973 (only serial suported for now)
974 Format: <serial_device>[,baud]
975
Linus Torvalds1da177e2005-04-16 15:20:36 -0700976 l2cr= [PPC]
977
Robert Brosea78bfbf2008-03-29 07:20:23 +1100978 l3cr= [PPC]
979
Alan Coxcd4f0ef2007-07-31 00:37:59 -0700980 lapic [X86-32,APIC] Enable the local APIC even if BIOS
Randy Dunlapa9913042005-10-23 12:57:11 -0700981 disabled it.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700982
Alan Coxcd4f0ef2007-07-31 00:37:59 -0700983 lapic_timer_c2_ok [X86-32,x86-64,APIC] trust the local apic timer in
Thomas Gleixnere585bef2007-03-23 16:08:01 +0100984 C2 power state.
985
FD Camifcb71f62008-01-06 19:08:56 +0100986 libata.dma= [LIBATA] DMA control
987 libata.dma=0 Disable all PATA and SATA DMA
988 libata.dma=1 PATA and SATA Disk DMA only
989 libata.dma=2 ATAPI (CDROM) DMA only
990 libata.dma=4 Compact Flash DMA only
991 Combinations also work, so libata.dma=3 enables DMA
992 for disks and CDROMs, but not CFs.
993
Dave Jones78e70c22007-09-27 11:50:13 -0400994 libata.noacpi [LIBATA] Disables use of ACPI in libata suspend/resume
995 when set.
996 Format: <int>
997
Tejun Heo33267322008-02-13 09:15:09 +0900998 libata.force= [LIBATA] Force configurations. The format is comma
999 separated list of "[ID:]VAL" where ID is
1000 PORT[:DEVICE]. PORT and DEVICE are decimal numbers
1001 matching port, link or device. Basically, it matches
1002 the ATA ID string printed on console by libata. If
1003 the whole ID part is omitted, the last PORT and DEVICE
1004 values are used. If ID hasn't been specified yet, the
1005 configuration applies to all ports, links and devices.
1006
1007 If only DEVICE is omitted, the parameter applies to
1008 the port and all links and devices behind it. DEVICE
1009 number of 0 either selects the first device or the
1010 first fan-out link behind PMP device. It does not
1011 select the host link. DEVICE number of 15 selects the
1012 host link and device attached to it.
1013
1014 The VAL specifies the configuration to force. As long
1015 as there's no ambiguity shortcut notation is allowed.
1016 For example, both 1.5 and 1.5G would work for 1.5Gbps.
1017 The following configurations can be forced.
1018
1019 * Cable type: 40c, 80c, short40c, unk, ign or sata.
1020 Any ID with matching PORT is used.
1021
1022 * SATA link speed limit: 1.5Gbps or 3.0Gbps.
1023
1024 * Transfer mode: pio[0-7], mwdma[0-4] and udma[0-7].
1025 udma[/][16,25,33,44,66,100,133] notation is also
1026 allowed.
1027
1028 * [no]ncq: Turn on or off NCQ.
1029
1030 If there are multiple matching configurations changing
1031 the same attribute, the last one is used.
1032
Linus Torvalds1da177e2005-04-16 15:20:36 -07001033 load_ramdisk= [RAM] List of ramdisks to load from floppy
1034 See Documentation/ramdisk.txt.
1035
Randy Dunlapa6b25b62006-01-14 13:21:19 -08001036 lockd.nlm_grace_period=P [NFS] Assign grace period.
1037 Format: <integer>
Linus Torvalds1da177e2005-04-16 15:20:36 -07001038
Randy Dunlapa6b25b62006-01-14 13:21:19 -08001039 lockd.nlm_tcpport=N [NFS] Assign TCP port.
1040 Format: <integer>
1041
1042 lockd.nlm_timeout=T [NFS] Assign timeout value.
1043 Format: <integer>
1044
1045 lockd.nlm_udpport=M [NFS] Assign UDP port.
1046 Format: <integer>
Linus Torvalds1da177e2005-04-16 15:20:36 -07001047
1048 logibm.irq= [HW,MOUSE] Logitech Bus Mouse Driver
1049 Format: <irq>
1050
1051 loglevel= All Kernel Messages with a loglevel smaller than the
1052 console loglevel will be printed to the console. It can
1053 also be changed with klogd or other programs. The
1054 loglevels are defined as follows:
1055
1056 0 (KERN_EMERG) system is unusable
1057 1 (KERN_ALERT) action must be taken immediately
1058 2 (KERN_CRIT) critical conditions
1059 3 (KERN_ERR) error conditions
1060 4 (KERN_WARNING) warning conditions
1061 5 (KERN_NOTICE) normal but significant condition
1062 6 (KERN_INFO) informational
1063 7 (KERN_DEBUG) debug-level messages
1064
1065 log_buf_len=n Sets the size of the printk ring buffer, in bytes.
Randy Dunlapa9913042005-10-23 12:57:11 -07001066 Format: { n | nk | nM }
1067 n must be a power of two. The default size
1068 is set in the kernel config file.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001069
Randy Dunlapaccaa242007-10-16 01:29:37 -07001070 logo.nologo [FB] Disables display of the built-in Linux logo.
1071 This may be used to provide more screen space for
1072 kernel log messages and is useful when debugging
1073 kernel boot problems.
1074
Linus Torvalds1da177e2005-04-16 15:20:36 -07001075 lp=0 [LP] Specify parallel ports to use, e.g,
1076 lp=port[,port...] lp=none,parport0 (lp0 not configured, lp1 uses
1077 lp=reset first parallel port). 'lp=0' disables the
1078 lp=auto printer driver. 'lp=reset' (which can be
1079 specified in addition to the ports) causes
1080 attached printers to be reset. Using
1081 lp=port1,port2,... specifies the parallel ports
1082 to associate lp devices with, starting with
1083 lp0. A port specification may be 'none' to skip
1084 that lp device, or a parport name such as
1085 'parport0'. Specifying 'lp=auto' instead of a
1086 port specification list means that device IDs
1087 from each port should be examined, to see if
1088 an IEEE 1284-compliant printer is attached; if
1089 so, the driver will manage that printer.
1090 See also header of drivers/char/lp.c.
1091
1092 lpj=n [KNL]
1093 Sets loops_per_jiffy to given constant, thus avoiding
1094 time-consuming boot-time autodetection (up to 250 ms per
1095 CPU). 0 enables autodetection (default). To determine
1096 the correct value for your kernel, boot with normal
1097 autodetection and see what value is printed. Note that
1098 on SMP systems the preset will be applied to all CPUs,
1099 which is likely to cause problems if your CPUs need
1100 significantly divergent settings. An incorrect value
1101 will cause delays in the kernel to be wrong, leading to
1102 unpredictable I/O errors and other breakage. Although
1103 unlikely, in the extreme case this might damage your
1104 hardware.
1105
1106 ltpc= [NET]
1107 Format: <io>,<irq>,<dma>
1108
Randy Dunlapa9913042005-10-23 12:57:11 -07001109 mac5380= [HW,SCSI] Format:
1110 <can_queue>,<cmd_per_lun>,<sg_tablesize>,<hostid>,<use_tags>
Linus Torvalds1da177e2005-04-16 15:20:36 -07001111
Randy Dunlapa9913042005-10-23 12:57:11 -07001112 machvec= [IA64] Force the use of a particular machine-vector
1113 (machvec) in a generic kernel.
1114 Example: machvec=hpzx1_swiotlb
Linus Torvalds1da177e2005-04-16 15:20:36 -07001115
Randy Dunlapa9913042005-10-23 12:57:11 -07001116 max_loop= [LOOP] Maximum number of loopback devices that can
Linus Torvalds1da177e2005-04-16 15:20:36 -07001117 be mounted
1118 Format: <1-256>
1119
1120 maxcpus= [SMP] Maximum number of processors that an SMP kernel
Len Brown61ec7562007-08-16 03:34:22 -04001121 should make use of. maxcpus=n : n >= 0 limits the
1122 kernel to using 'n' processors. n=0 is a special case,
1123 it is equivalent to "nosmp", which also disables
1124 the IO APIC.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001125
Bob Picco2b2c3752005-06-29 18:00:00 -07001126 max_addr=[KMG] [KNL,BOOT,ia64] All physical memory greater than or
1127 equal to this physical address is ignored.
1128
Randy Dunlapa9913042005-10-23 12:57:11 -07001129 max_luns= [SCSI] Maximum number of LUNs to probe.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001130 Should be between 1 and 2^32-1.
1131
1132 max_report_luns=
Randy Dunlapa9913042005-10-23 12:57:11 -07001133 [SCSI] Maximum number of LUNs received.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001134 Should be between 1 and 16384.
1135
Linus Torvalds1da177e2005-04-16 15:20:36 -07001136 mcatest= [IA-64]
1137
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001138 mce [X86-32] Machine Check Exception
Linus Torvalds1da177e2005-04-16 15:20:36 -07001139
Andi Kleen909dd322007-10-17 18:04:38 +02001140 mce=option [X86-64] See Documentation/x86_64/boot-options.txt
1141
Linus Torvalds1da177e2005-04-16 15:20:36 -07001142 md= [HW] RAID subsystems devices and level
1143 See Documentation/md.txt.
Randy Dunlapa9913042005-10-23 12:57:11 -07001144
Linus Torvalds1da177e2005-04-16 15:20:36 -07001145 mdacon= [MDA]
1146 Format: <first>,<last>
1147 Specifies range of consoles to be captured by the MDA.
Randy Dunlapa9913042005-10-23 12:57:11 -07001148
Linus Torvalds1da177e2005-04-16 15:20:36 -07001149 mem=nn[KMG] [KNL,BOOT] Force usage of a specific amount of memory
1150 Amount of memory to be used when the kernel is not able
1151 to see the whole system memory or for test.
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001152 [X86-32] Use together with memmap= to avoid physical
Linus Torvalds1da177e2005-04-16 15:20:36 -07001153 address space collisions. Without memmap= PCI devices
1154 could be placed at addresses belonging to unused RAM.
1155
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001156 mem=nopentium [BUGS=X86-32] Disable usage of 4MB pages for kernel
Linus Torvalds1da177e2005-04-16 15:20:36 -07001157 memory.
1158
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001159 memmap=exactmap [KNL,X86-32,X86_64] Enable setting of an exact
Linus Torvalds1da177e2005-04-16 15:20:36 -07001160 E820 memory map, as specified by the user.
1161 Such memmap=exactmap lines can be constructed based on
1162 BIOS output or other requirements. See the memmap=nn@ss
1163 option description.
1164
1165 memmap=nn[KMG]@ss[KMG]
1166 [KNL] Force usage of a specific region of memory
1167 Region of memory to be used, from ss to ss+nn.
1168
1169 memmap=nn[KMG]#ss[KMG]
1170 [KNL,ACPI] Mark specific memory as ACPI data.
1171 Region of memory to be used, from ss to ss+nn.
1172
1173 memmap=nn[KMG]$ss[KMG]
1174 [KNL,ACPI] Mark specific memory as reserved.
1175 Region of memory to be used, from ss to ss+nn.
Pavel Machek13128482008-03-24 12:29:43 -07001176 Example: Exclude memory from 0x18690000-0x1869ffff
1177 memmap=64K$0x18690000
1178 or
1179 memmap=0x10000$0x18690000
Linus Torvalds1da177e2005-04-16 15:20:36 -07001180
Yinghai Luc64df702008-03-21 18:56:19 -07001181 memtest= [KNL,X86_64] Enable memtest
1182 Format: <integer>
1183 range: 0,4 : pattern number
1184 default : 0 <disable>
1185
Linus Torvalds1da177e2005-04-16 15:20:36 -07001186 meye.*= [HW] Set MotionEye Camera parameters
1187 See Documentation/video4linux/meye.txt.
1188
Andres Salomon8f368812007-10-12 23:04:06 +02001189 mfgpt_irq= [IA-32] Specify the IRQ to use for the
1190 Multi-Function General Purpose Timers on AMD Geode
1191 platforms.
1192
Willy Tarreaue6c4dc62008-01-30 13:33:33 +01001193 mfgptfix [X86-32] Fix MFGPT timers on AMD Geode platforms when
1194 the BIOS has incorrectly applied a workaround. TinyBIOS
1195 version 0.98 is known to be affected, 0.99 fixes the
1196 problem by letting the user disable the workaround.
1197
Linus Torvalds1da177e2005-04-16 15:20:36 -07001198 mga= [HW,DRM]
1199
1200 mousedev.tap_time=
1201 [MOUSE] Maximum time between finger touching and
1202 leaving touchpad surface for touch to be considered
1203 a tap and be reported as a left button click (for
1204 touchpads working in absolute mode only).
1205 Format: <msecs>
1206 mousedev.xres= [MOUSE] Horizontal screen resolution, used for devices
1207 reporting absolute coordinates, such as tablets
1208 mousedev.yres= [MOUSE] Vertical screen resolution, used for devices
1209 reporting absolute coordinates, such as tablets
1210
1211 mpu401= [HW,OSS]
1212 Format: <io>,<irq>
1213
1214 MTD_Partition= [MTD]
1215 Format: <name>,<region-number>,<size>,<offset>
1216
Randy Dunlapa9913042005-10-23 12:57:11 -07001217 MTD_Region= [MTD] Format:
1218 <name>,<region-number>[,<base>,<size>,<buswidth>,<altbuswidth>]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001219
1220 mtdparts= [MTD]
Randy Dunlapc8facbb2007-07-31 00:37:40 -07001221 See drivers/mtd/cmdlinepart.c.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001222
1223 mtouchusb.raw_coordinates=
Randy Dunlapa9913042005-10-23 12:57:11 -07001224 [HW] Make the MicroTouch USB driver use raw coordinates
1225 ('y', default) or cooked coordinates ('n')
Linus Torvalds1da177e2005-04-16 15:20:36 -07001226
1227 n2= [NET] SDL Inc. RISCom/N2 synchronous serial card
1228
1229 NCR_D700= [HW,SCSI]
1230 See header of drivers/scsi/NCR_D700.c.
1231
1232 ncr5380= [HW,SCSI]
1233
1234 ncr53c400= [HW,SCSI]
1235
1236 ncr53c400a= [HW,SCSI]
1237
1238 ncr53c406a= [HW,SCSI]
1239
1240 ncr53c8xx= [HW,SCSI]
1241
1242 netdev= [NET] Network devices parameters
1243 Format: <irq>,<io>,<mem_start>,<mem_end>,<name>
1244 Note that mem_start is often overloaded to mean
1245 something different and driver-specific.
Randy Dunlapa9913042005-10-23 12:57:11 -07001246 This usage is only documented in each driver source
1247 file if at all.
1248
Linus Torvalds1da177e2005-04-16 15:20:36 -07001249 nfsaddrs= [NFS]
J. Bruce Fields6ded55d2008-04-07 15:59:03 -04001250 See Documentation/filesystems/nfsroot.txt.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001251
1252 nfsroot= [NFS] nfs root filesystem for disk-less boxes.
J. Bruce Fields6ded55d2008-04-07 15:59:03 -04001253 See Documentation/filesystems/nfsroot.txt.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001254
Trond Myklebusta72b4422006-01-03 09:55:41 +01001255 nfs.callback_tcpport=
1256 [NFS] set the TCP port on which the NFSv4 callback
1257 channel should listen.
1258
Trond Myklebust58df0952006-01-03 09:55:57 +01001259 nfs.idmap_cache_timeout=
1260 [NFS] set the maximum lifetime for idmapper cache
1261 entries.
1262
Trond Myklebustf43bf0b2007-10-09 12:01:04 -04001263 nfs.enable_ino64=
1264 [NFS] enable 64-bit inode numbers.
1265 If zero, the NFS client will fake up a 32-bit inode
1266 number for the readdir() and stat() syscalls instead
1267 of returning the full 64-bit number.
1268 The default is to return 64-bit inode numbers.
1269
Haavard Skinnemoene7ba1762007-10-10 14:58:29 +02001270 nmi_debug= [KNL,AVR32] Specify one or more actions to take
1271 when a NMI is triggered.
1272 Format: [state][,regs][,debounce][,die]
1273
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001274 nmi_watchdog= [KNL,BUGS=X86-32] Debugging features for SMP kernels
Linus Torvalds1da177e2005-04-16 15:20:36 -07001275
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001276 no387 [BUGS=X86-32] Tells the kernel to use the 387 maths
Linus Torvalds1da177e2005-04-16 15:20:36 -07001277 emulation library even if a 387 maths coprocessor
1278 is present.
1279
Christoph Lameterc1aee212007-05-31 00:40:47 -07001280 noaliencache [MM, NUMA, SLAB] Disables the allocation of alien
1281 caches in the slab allocator. Saves per-node memory,
1282 but will impact performance.
Paul Menage3395ee02006-12-06 20:32:16 -08001283
Randy Dunlapa9913042005-10-23 12:57:11 -07001284 noalign [KNL,ARM]
1285
Linus Torvalds1da177e2005-04-16 15:20:36 -07001286 noapic [SMP,APIC] Tells the kernel to not make use of any
1287 IOAPICs that may be present in the system.
1288
Linus Torvalds1da177e2005-04-16 15:20:36 -07001289 nobats [PPC] Do not use BATs for mapping kernel lowmem
1290 on "Classic" PPC cores.
1291
1292 nocache [ARM]
Randy Dunlapa9913042005-10-23 12:57:11 -07001293
Shailabh Nagar163ecdf2006-07-30 03:03:11 -07001294 nodelayacct [KNL] Disable per-task delay accounting
1295
Linus Torvalds1da177e2005-04-16 15:20:36 -07001296 nodisconnect [HW,SCSI,M68K] Disables SCSI disconnects.
1297
Huang, Ying8b2cb7a2008-01-30 13:32:11 +01001298 noefi [X86-32,X86-64] Disable EFI runtime services support.
1299
Linus Torvalds1da177e2005-04-16 15:20:36 -07001300 noexec [IA-64]
1301
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001302 noexec [X86-32,X86-64]
Jiri Slabyf5a1b192008-04-12 10:28:25 +02001303 On X86-32 available only on PAE configured kernels.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001304 noexec=on: enable non-executable mappings (default)
Jiri Slabyf5a1b192008-04-12 10:28:25 +02001305 noexec=off: disable non-executable mappings
1306
1307 noexec32 [X86-64]
1308 This affects only 32-bit executables.
1309 noexec32=on: enable non-executable mappings (default)
1310 read doesn't imply executable mappings
1311 noexec32=off: disable non-executable mappings
1312 read implies executable mappings
Linus Torvalds1da177e2005-04-16 15:20:36 -07001313
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001314 nofxsr [BUGS=X86-32] Disables x86 floating point extended
Chuck Ebbert4f886512006-03-23 02:59:34 -08001315 register save and restore. The kernel will only save
1316 legacy floating-point registers on task switch.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001317
Andi Kleen191679f2008-01-30 13:33:21 +01001318 noclflush [BUGS=X86] Don't use the CLFLUSH instruction
1319
Linus Torvalds1da177e2005-04-16 15:20:36 -07001320 nohlt [BUGS=ARM]
Randy Dunlapa9913042005-10-23 12:57:11 -07001321
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001322 no-hlt [BUGS=X86-32] Tells the kernel that the hlt
Linus Torvalds1da177e2005-04-16 15:20:36 -07001323 instruction doesn't work correctly and not to
1324 use it.
1325
1326 nohalt [IA-64] Tells the kernel not to use the power saving
1327 function PAL_HALT_LIGHT when idle. This increases
1328 power-consumption. On the positive side, it reduces
1329 interrupt wake-up latency, which may improve performance
1330 in certain environments such as networked servers or
1331 real-time systems.
1332
Thomas Gleixner79bf2bb2007-02-16 01:28:03 -08001333 nohz= [KNL] Boottime enable/disable dynamic ticks
1334 Valid arguments: on, off
1335 Default: on
1336
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001337 noirqbalance [X86-32,SMP,KNL] Disable kernel irq balancing
Zachary Amsden8542b202006-12-07 02:14:09 +01001338
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001339 noirqdebug [X86-32] Disables the code which attempts to detect and
Linus Torvalds1da177e2005-04-16 15:20:36 -07001340 disable unhandled interrupt sources.
1341
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001342 no_timer_check [X86-32,X86_64,APIC] Disables the code which tests for
Zachary Amsden8542b202006-12-07 02:14:09 +01001343 broken timer IRQ sources.
1344
Linus Torvalds1da177e2005-04-16 15:20:36 -07001345 noisapnp [ISAPNP] Disables ISA PnP code.
1346
1347 noinitrd [RAM] Tells the kernel not to load any configured
1348 initial RAM disk.
1349
1350 nointroute [IA-64]
1351
Tony Luck0aa366f2007-07-20 11:22:30 -07001352 nojitter [IA64] Disables jitter checking for ITC timers.
1353
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001354 nolapic [X86-32,APIC] Do not enable or use the local APIC.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001355
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001356 nolapic_timer [X86-32,APIC] Do not use the local APIC timer.
Thomas Gleixnerad62ca22007-03-22 00:11:21 -08001357
Linus Torvalds1da177e2005-04-16 15:20:36 -07001358 noltlbs [PPC] Do not use large page/tlb entries for kernel
1359 lowmem mapping on PPC40x.
1360
Horms312f1f02006-02-22 09:57:55 +09001361 nomca [IA-64] Disable machine check abort handling
1362
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001363 nomce [X86-32] Machine Check Exception
Hormsabe37e52006-04-01 01:36:09 +02001364
Andres Salomon83d73842007-10-12 23:04:06 +02001365 nomfgpt [X86-32] Disable Multi-Function General Purpose
1366 Timer usage (for AMD Geode machines).
1367
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001368 noreplace-paravirt [X86-32,PV_OPS] Don't patch paravirt_ops
Jeremy Fitzhardinge959b4fd2007-05-02 19:27:16 +02001369
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001370 noreplace-smp [X86-32,SMP] Don't replace SMP instructions
Jeremy Fitzhardingeb7fb4af2007-05-02 19:27:13 +02001371 with UP alternatives
1372
Linus Torvalds1da177e2005-04-16 15:20:36 -07001373 noresidual [PPC] Don't use residual data on PReP machines.
1374
Randy Dunlapa9913042005-10-23 12:57:11 -07001375 noresume [SWSUSP] Disables resume and restores original swap
1376 space.
1377
Linus Torvalds1da177e2005-04-16 15:20:36 -07001378 no-scroll [VGA] Disables scrollback.
1379 This is required for the Braillex ib80-piezo Braille
1380 reader made by F.H. Papenmeier (Germany).
1381
1382 nosbagart [IA-64]
1383
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001384 nosep [BUGS=X86-32] Disables x86 SYSENTER/SYSEXIT support.
Chuck Ebbert4f886512006-03-23 02:59:34 -08001385
Len Brown61ec7562007-08-16 03:34:22 -04001386 nosmp [SMP] Tells an SMP kernel to act as a UP kernel,
1387 and disable the IO APIC. legacy for "maxcpus=0".
Linus Torvalds1da177e2005-04-16 15:20:36 -07001388
Dave Jones97842212007-07-15 23:41:05 -07001389 nosoftlockup [KNL] Disable the soft-lockup detector.
1390
Linus Torvalds1da177e2005-04-16 15:20:36 -07001391 nosync [HW,M68K] Disables sync negotiation for all devices.
1392
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001393 notsc [BUGS=X86-32] Disable Time Stamp Counter
Linus Torvalds1da177e2005-04-16 15:20:36 -07001394
1395 nousb [USB] Disable the USB subsystem
1396
1397 nowb [ARM]
Randy Dunlapa9913042005-10-23 12:57:11 -07001398
Fenghua Yua6c75b862008-03-14 13:57:08 -07001399 nptcg= [IA64] Override max number of concurrent global TLB
1400 purges which is reported from either PAL_VM_SUMMARY or
1401 SAL PALO.
1402
KAMEZAWA Hiroyukif0c0b2b2007-07-15 23:38:01 -07001403 numa_zonelist_order= [KNL, BOOT] Select zonelist order for NUMA.
1404 one of ['zone', 'node', 'default'] can be specified
1405 This can be set from sysctl after boot.
1406 See Documentation/sysctl/vm.txt for details.
1407
Dave Jonesa61c2d72006-01-07 23:18:19 +00001408 nr_uarts= [SERIAL] maximum number of UARTs to be registered.
1409
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07001410 olpc_ec_timeout= [OLPC] ms delay when issuing EC commands
1411 Rather than timing out after 20 ms if an EC
1412 command is not properly ACKed, override the length
1413 of the timeout. We have interrupts disabled while
1414 waiting for the ACK, so if this is set too high
1415 interrupts *may* be lost!
1416
Linus Torvalds1da177e2005-04-16 15:20:36 -07001417 opl3= [HW,OSS]
1418 Format: <io>
1419
Linus Torvalds1da177e2005-04-16 15:20:36 -07001420 oprofile.timer= [HW]
1421 Use timer interrupt instead of performance counters
1422
Linus Torvalds1da177e2005-04-16 15:20:36 -07001423 osst= [HW,SCSI] SCSI Tape Driver
1424 Format: <buffer_size>,<write_threshold>
1425 See also Documentation/scsi/st.txt.
1426
1427 panic= [KNL] Kernel behaviour on panic
1428 Format: <timeout>
1429
1430 parkbd.port= [HW] Parallel port number the keyboard adapter is
1431 connected to, default is 0.
1432 Format: <parport#>
1433 parkbd.mode= [HW] Parallel port keyboard adapter mode of operation,
1434 0 for XT, 1 for AT (default is AT).
Randy Dunlapa9913042005-10-23 12:57:11 -07001435 Format: <mode>
Linus Torvalds1da177e2005-04-16 15:20:36 -07001436
Randy Dunlapa9913042005-10-23 12:57:11 -07001437 parport= [HW,PPT] Specify parallel ports. 0 disables.
1438 Format: { 0 | auto | 0xBBB[,IRQ[,DMA]] }
1439 Use 'auto' to force the driver to use any
1440 IRQ/DMA settings detected (the default is to
1441 ignore detected IRQ/DMA settings because of
1442 possible conflicts). You can specify the base
1443 address, IRQ, and DMA settings; IRQ and DMA
1444 should be numbers, or 'auto' (for using detected
1445 settings on that particular port), or 'nofifo'
1446 (to avoid using a FIFO even if it is detected).
1447 Parallel ports are assigned in the order they
1448 are specified on the command line, starting
1449 with parport0.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001450
Randy Dunlapa9913042005-10-23 12:57:11 -07001451 parport_init_mode= [HW,PPT]
1452 Configure VIA parallel port to operate in
1453 a specific mode. This is necessary on Pegasos
1454 computer where firmware has no options for setting
1455 up parallel port mode and sets it to spp.
1456 Currently this function knows 686a and 8231 chips.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001457 Format: [spp|ps2|epp|ecp|ecpepp]
1458
Randy Dunlapa9913042005-10-23 12:57:11 -07001459 pas2= [HW,OSS] Format:
1460 <io>,<irq>,<dma>,<dma16>,<sb_io>,<sb_irq>,<sb_dma>,<sb_dma16>
1461
Linus Torvalds1da177e2005-04-16 15:20:36 -07001462 pas16= [HW,SCSI]
1463 See header of drivers/scsi/pas16.c.
1464
Andrew Mortondd287792006-03-23 03:00:57 -08001465 pause_on_oops=
1466 Halt all CPUs after the first oops has been printed for
1467 the specified number of seconds. This is to be used if
1468 your oopses keep scrolling off the screen.
1469
Linus Torvalds1da177e2005-04-16 15:20:36 -07001470 pcbit= [HW,ISDN]
1471
1472 pcd. [PARIDE]
1473 See header of drivers/block/paride/pcd.c.
1474 See also Documentation/paride.txt.
1475
Randy Dunlapa9913042005-10-23 12:57:11 -07001476 pci=option[,option...] [PCI] various PCI subsystem options:
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001477 off [X86-32] don't probe for the PCI bus
1478 bios [X86-32] force use of PCI BIOS, don't access
Randy Dunlapa9913042005-10-23 12:57:11 -07001479 the hardware directly. Use this if your machine
1480 has a non-standard PCI host bridge.
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001481 nobios [X86-32] disallow use of PCI BIOS, only direct
Randy Dunlapa9913042005-10-23 12:57:11 -07001482 hardware access methods are allowed. Use this
1483 if you experience crashes upon bootup and you
1484 suspect they are caused by the BIOS.
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001485 conf1 [X86-32] Force use of PCI Configuration
Randy Dunlapa9913042005-10-23 12:57:11 -07001486 Mechanism 1.
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001487 conf2 [X86-32] Force use of PCI Configuration
Randy Dunlapa9913042005-10-23 12:57:11 -07001488 Mechanism 2.
Randy Dunlap7f785762007-10-05 13:17:58 -07001489 noaer [PCIE] If the PCIEAER kernel config parameter is
1490 enabled, this kernel boot option can be used to
1491 disable the use of PCIE advanced error reporting.
Jeff Garzik32a2eea2007-10-11 16:57:27 -04001492 nodomains [PCI] Disable support for multiple PCI
1493 root domains (aka PCI segments, in ACPI-speak).
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001494 nommconf [X86-32,X86_64] Disable use of MMCONFIG for PCI
Bjorn Helgaas61be6d62006-02-15 15:17:43 -08001495 Configuration
Matthew Wilcox309e57d2006-03-05 22:33:34 -07001496 nomsi [MSI] If the PCI_MSI kernel config parameter is
1497 enabled, this kernel boot option can be used to
1498 disable the use of MSI interrupts system-wide.
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001499 biosirq [X86-32] Use PCI BIOS calls to get the interrupt
Randy Dunlapa9913042005-10-23 12:57:11 -07001500 routing table. These calls are known to be buggy
1501 on several machines and they hang the machine
1502 when used, but on other computers it's the only
1503 way to get the interrupt routing table. Try
1504 this option if the kernel is unable to allocate
1505 IRQs or discover secondary PCI buses on your
1506 motherboard.
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001507 rom [X86-32] Assign address space to expansion ROMs.
Randy Dunlapa9913042005-10-23 12:57:11 -07001508 Use with caution as certain devices share
1509 address decoders between ROMs and other
1510 resources.
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001511 irqmask=0xMMMM [X86-32] Set a bit mask of IRQs allowed to be
Randy Dunlapa9913042005-10-23 12:57:11 -07001512 assigned automatically to PCI devices. You can
1513 make the kernel exclude IRQs of your ISA cards
1514 this way.
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001515 pirqaddr=0xAAAAA [X86-32] Specify the physical address
Randy Dunlapa9913042005-10-23 12:57:11 -07001516 of the PIRQ table (normally generated
1517 by the BIOS) if it is outside the
1518 F0000h-100000h range.
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001519 lastbus=N [X86-32] Scan all buses thru bus #N. Can be
Randy Dunlapa9913042005-10-23 12:57:11 -07001520 useful if the kernel is unable to find your
1521 secondary buses and you want to tell it
1522 explicitly which ones they are.
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001523 assign-busses [X86-32] Always assign all PCI bus
Randy Dunlapa9913042005-10-23 12:57:11 -07001524 numbers ourselves, overriding
1525 whatever the firmware may have done.
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001526 usepirqmask [X86-32] Honor the possible IRQ mask stored
Randy Dunlapa9913042005-10-23 12:57:11 -07001527 in the BIOS $PIR table. This is needed on
1528 some systems with broken BIOSes, notably
1529 some HP Pavilion N5400 and Omnibook XE3
1530 notebooks. This will have no effect if ACPI
1531 IRQ routing is enabled.
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001532 noacpi [X86-32] Do not use ACPI for IRQ routing
Randy Dunlapa9913042005-10-23 12:57:11 -07001533 or for PCI scanning.
Gary Hade62f420f2007-10-03 15:56:51 -07001534 use_crs [X86-32] Use _CRS for PCI resource
1535 allocation.
Randy Dunlapa9913042005-10-23 12:57:11 -07001536 routeirq Do IRQ routing for all PCI devices.
1537 This is normally done in pci_enable_device(),
1538 so this option is a temporary workaround
1539 for broken drivers that don't call it.
Yinghai Lu13a6ddb2008-03-27 01:31:18 -07001540 skip_isa_align [X86] do not align io start addr, so can
1541 handle more pci cards
Randy Dunlapa9913042005-10-23 12:57:11 -07001542 firmware [ARM] Do not re-enumerate the bus but instead
1543 just use the configuration from the
1544 bootloader. This is currently used on
1545 IXP2000 systems where the bus has to be
1546 configured a certain way for adjunct CPUs.
Andi Kleen0637a702006-09-26 10:52:41 +02001547 noearly [X86] Don't do any early type 1 scanning.
1548 This might help on some broken boards which
1549 machine check when some devices' config space
1550 is read. But various workarounds are disabled
1551 and some IOMMU drivers will not work.
Matt Domsch6b4b78f2006-09-29 15:23:23 -05001552 bfsort Sort PCI devices into breadth-first order.
1553 This sorting is done to get a device
1554 order compatible with older (<= 2.4) kernels.
1555 nobfsort Don't sort PCI devices into breadth-first order.
Atsushi Nemoto4516a612007-02-05 16:36:06 -08001556 cbiosize=nn[KMG] The fixed amount of bus space which is
1557 reserved for the CardBus bridge's IO window.
1558 The default value is 256 bytes.
1559 cbmemsize=nn[KMG] The fixed amount of bus space which is
1560 reserved for the CardBus bridge's memory
1561 window. The default value is 64 megabytes.
Matt Domsch6b4b78f2006-09-29 15:23:23 -05001562
Linus Torvalds1da177e2005-04-16 15:20:36 -07001563 pcmv= [HW,PCMCIA] BadgePAD 4
1564
1565 pd. [PARIDE]
1566 See Documentation/paride.txt.
1567
1568 pdcchassis= [PARISC,HW] Disable/Enable PDC Chassis Status codes at
1569 boot time.
1570 Format: { 0 | 1 }
1571 See arch/parisc/kernel/pdc_chassis.c
1572
1573 pf. [PARIDE]
1574 See Documentation/paride.txt.
1575
1576 pg. [PARIDE]
1577 See Documentation/paride.txt.
1578
1579 pirq= [SMP,APIC] Manual mp-table setup
1580 See Documentation/i386/IO-APIC.txt.
1581
1582 plip= [PPT,NET] Parallel port network link
1583 Format: { parport<nr> | timid | 0 }
1584 See also Documentation/parport.txt.
1585
1586 pnpacpi= [ACPI]
1587 { off }
1588
1589 pnpbios= [ISAPNP]
1590 { on | off | curr | res | no-curr | no-res }
1591
1592 pnp_reserve_irq=
1593 [ISAPNP] Exclude IRQs for the autoconfiguration
1594
1595 pnp_reserve_dma=
1596 [ISAPNP] Exclude DMAs for the autoconfiguration
1597
1598 pnp_reserve_io= [ISAPNP] Exclude I/O ports for the autoconfiguration
Randy Dunlapa9913042005-10-23 12:57:11 -07001599 Ranges are in pairs (I/O port base and size).
Linus Torvalds1da177e2005-04-16 15:20:36 -07001600
1601 pnp_reserve_mem=
Randy Dunlapa9913042005-10-23 12:57:11 -07001602 [ISAPNP] Exclude memory regions for the
1603 autoconfiguration.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001604 Ranges are in pairs (memory base and size).
1605
Ingo Molnar45807a12007-07-15 23:40:10 -07001606 print-fatal-signals=
1607 [KNL] debug: print fatal signals
1608 print-fatal-signals=1: print segfault info to
1609 the kernel console.
1610 default: off.
1611
Randy Dunlape84845c2007-07-15 23:40:25 -07001612 printk.time= Show timing data prefixed to each printk message line
1613 Format: <bool> (1/Y/y=enable, 0/N/n=disable)
1614
Linus Torvalds1da177e2005-04-16 15:20:36 -07001615 profile= [KNL] Enable kernel profiling via /proc/profile
Randy Dunlapa9913042005-10-23 12:57:11 -07001616 Format: [schedule,]<number>
1617 Param: "schedule" - profile schedule points.
1618 Param: <number> - step/bucket size as a power of 2 for
1619 statistical time based profiling.
Mel Gormanb3da2a72007-10-24 18:23:50 +02001620 Param: "sleep" - profile D-state sleeping (millisecs).
1621 Requires CONFIG_SCHEDSTATS
Dave Jonesc0fe2e62007-10-20 03:08:22 +02001622 Param: "kvm" - profile VM exits.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001623
Randy Dunlapa9913042005-10-23 12:57:11 -07001624 processor.max_cstate= [HW,ACPI]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001625 Limit processor to maximum C-state
1626 max_cstate=9 overrides any DMI blacklist limit.
1627
Len Brown41c0d862005-12-28 12:43:51 -05001628 processor.nocst [HW,ACPI]
1629 Ignore the _CST method to determine C-states,
1630 instead using the legacy FADT method
1631
Linus Torvalds1da177e2005-04-16 15:20:36 -07001632 prompt_ramdisk= [RAM] List of RAM disks to prompt for floppy disk
1633 before loading.
1634 See Documentation/ramdisk.txt.
1635
Randy Dunlapa9913042005-10-23 12:57:11 -07001636 psmouse.proto= [HW,MOUSE] Highest PS2 mouse protocol extension to
1637 probe for; one of (bare|imps|exps|lifebook|any).
Linus Torvalds1da177e2005-04-16 15:20:36 -07001638 psmouse.rate= [HW,MOUSE] Set desired mouse report rate, in reports
1639 per second.
Randy Dunlapa9913042005-10-23 12:57:11 -07001640 psmouse.resetafter= [HW,MOUSE]
1641 Try to reset the device after so many bad packets
Linus Torvalds1da177e2005-04-16 15:20:36 -07001642 (0 = never).
1643 psmouse.resolution=
1644 [HW,MOUSE] Set desired mouse resolution, in dpi.
1645 psmouse.smartscroll=
Randy Dunlapa9913042005-10-23 12:57:11 -07001646 [HW,MOUSE] Controls Logitech smartscroll autorepeat.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001647 0 = disabled, 1 = enabled (default).
1648
1649 pss= [HW,OSS] Personal Sound System (ECHO ESC614)
Randy Dunlapa9913042005-10-23 12:57:11 -07001650 Format:
1651 <io>,<mss_io>,<mss_irq>,<mss_dma>,<mpu_io>,<mpu_irq>
Linus Torvalds1da177e2005-04-16 15:20:36 -07001652
1653 pt. [PARIDE]
1654 See Documentation/paride.txt.
1655
Kay Sieversdc8c8582007-08-15 12:25:38 +02001656 pty.legacy_count=
1657 [KNL] Number of legacy pty's. Overwrites compiled-in
1658 default number.
1659
Randy Dunlap7d2c5022006-09-29 02:01:02 -07001660 quiet [KNL] Disable most log messages
Randy Dunlapa9913042005-10-23 12:57:11 -07001661
Linus Torvalds1da177e2005-04-16 15:20:36 -07001662 r128= [HW,DRM]
1663
1664 raid= [HW,RAID]
1665 See Documentation/md.txt.
1666
Randy Dunlapa9913042005-10-23 12:57:11 -07001667 ramdisk_blocksize= [RAM]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001668 See Documentation/ramdisk.txt.
Randy Dunlapa9913042005-10-23 12:57:11 -07001669
Linus Torvalds1da177e2005-04-16 15:20:36 -07001670 ramdisk_size= [RAM] Sizes of RAM disks in kilobytes
Linus Torvalds1da177e2005-04-16 15:20:36 -07001671 See Documentation/ramdisk.txt.
1672
Robert P. J. Day24aaef82008-02-03 15:20:26 +02001673 rcupdate.blimit= [KNL,BOOT]
1674 Set maximum number of finished RCU callbacks to process
1675 in one batch.
Dipankar Sarma21a1ea92006-03-07 21:55:33 -08001676
Robert P. J. Day24aaef82008-02-03 15:20:26 +02001677 rcupdate.qhimark= [KNL,BOOT]
1678 Set threshold of queued
Dipankar Sarma21a1ea92006-03-07 21:55:33 -08001679 RCU callbacks over which batch limiting is disabled.
1680
Robert P. J. Day24aaef82008-02-03 15:20:26 +02001681 rcupdate.qlowmark= [KNL,BOOT]
1682 Set threshold of queued RCU callbacks below which
1683 batch limiting is re-enabled.
Dipankar Sarma21a1ea92006-03-07 21:55:33 -08001684
Olof Johanssonffdfc402005-09-06 15:17:19 -07001685 rdinit= [KNL]
1686 Format: <full_path>
1687 Run specified binary instead of /init from the ramdisk,
1688 used for early userspace startup. See initrd.
1689
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001690 reboot= [BUGS=X86-32,BUGS=ARM,BUGS=IA-64] Rebooting mode
Linus Torvalds1da177e2005-04-16 15:20:36 -07001691 Format: <reboot_mode>[,<reboot_mode2>[,...]]
Mauro Carvalho Chehabe53dd082007-09-15 07:38:47 -03001692 See arch/*/kernel/reboot.c or arch/*/kernel/process.c
Linus Torvalds1da177e2005-04-16 15:20:36 -07001693
1694 reserve= [KNL,BUGS] Force the kernel to ignore some iomem area
1695
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001696 reservetop= [X86-32]
Zachary Amsden461a9af2006-09-25 23:32:25 -07001697 Format: nn[KMG]
1698 Reserves a hole at the top of the kernel virtual
1699 address space.
1700
Vivek Goyal7e962872006-09-27 01:50:44 -07001701 reset_devices [KNL] Force drivers to reset the underlying device
1702 during initialization.
1703
Randy Dunlapa9913042005-10-23 12:57:11 -07001704 resume= [SWSUSP]
1705 Specify the partition device for software suspend
Linus Torvalds1da177e2005-04-16 15:20:36 -07001706
Rafael J. Wysockiecbd0da2006-12-06 20:34:13 -08001707 resume_offset= [SWSUSP]
1708 Specify the offset from the beginning of the partition
1709 given by "resume=" at which the swap header is located,
1710 in <PAGE_SIZE> units (needed only for swap files).
1711 See Documentation/power/swsusp-and-swap-files.txt
1712
Michael Neuling0a7b35cb2007-02-10 01:44:33 -08001713 retain_initrd [RAM] Keep initrd memory after extraction
1714
Linus Torvalds1da177e2005-04-16 15:20:36 -07001715 rhash_entries= [KNL,NET]
1716 Set number of hash buckets for route cache
1717
1718 riscom8= [HW,SERIAL]
1719 Format: <io_board1>[,<io_board2>[,...<io_boardN>]]
1720
1721 ro [KNL] Mount root device read-only on boot
1722
1723 root= [KNL] Root filesystem
1724
1725 rootdelay= [KNL] Delay (in seconds) to pause before attempting to
1726 mount the root filesystem
1727
1728 rootflags= [KNL] Set root filesystem mount option string
1729
1730 rootfstype= [KNL] Set root filesystem type
1731
Pierre Ossmancc1ed752007-07-15 23:40:35 -07001732 rootwait [KNL] Wait (indefinitely) for root device to show up.
1733 Useful for devices that are detected asynchronously
1734 (e.g. USB and MMC devices).
1735
James Morris20510f22007-10-16 23:31:32 -07001736 root_plug.vendor_id=
1737 [ROOTPLUG] Override the default vendor ID
1738
1739 root_plug.product_id=
1740 [ROOTPLUG] Override the default product ID
1741
1742 root_plug.debug=
1743 [ROOTPLUG] Enable debugging output
1744
Linus Torvalds1da177e2005-04-16 15:20:36 -07001745 rw [KNL] Mount root device read-write on boot
1746
1747 S [KNL] Run init in single mode
1748
1749 sa1100ir [NET]
1750 See drivers/net/irda/sa1100_ir.c.
1751
Linus Torvalds1da177e2005-04-16 15:20:36 -07001752 sbni= [NET] Granch SBNI12 leased line adapter
Randy Dunlapa9913042005-10-23 12:57:11 -07001753
Linus Torvalds1da177e2005-04-16 15:20:36 -07001754 sc1200wdt= [HW,WDT] SC1200 WDT (watchdog) driver
1755 Format: <io>[,<timeout>[,<isapnp>]]
1756
1757 scsi_debug_*= [SCSI]
1758 See drivers/scsi/scsi_debug.c.
1759
1760 scsi_default_dev_flags=
1761 [SCSI] SCSI default device flags
1762 Format: <integer>
1763
1764 scsi_dev_flags= [SCSI] Black/white list entry for vendor and model
1765 Format: <vendor>:<model>:<flags>
1766 (flags are integer value)
1767
Randy Dunlap6af66322007-11-14 16:52:25 -08001768 scsi_logging_level= [SCSI] a bit mask of logging levels
1769 See drivers/scsi/scsi_logging.h for bits. Also
1770 settable via sysctl at dev.scsi.logging_level
1771 (/proc/sys/dev/scsi/logging_level).
1772 There is also a nice 'scsi_logging_level' script in the
1773 S390-tools package, available for download at
1774 http://www-128.ibm.com/developerworks/linux/linux390/s390-tools-1.5.4.html
Linus Torvalds1da177e2005-04-16 15:20:36 -07001775
Matthew Wilcox3e082a92006-09-28 15:19:20 -06001776 scsi_mod.scan= [SCSI] sync (default) scans SCSI busses as they are
1777 discovered. async scans them in kernel threads,
1778 allowing boot to proceed. none ignores them, expecting
1779 user space to do the scan.
1780
Linus Torvalds1da177e2005-04-16 15:20:36 -07001781 selinux [SELINUX] Disable or enable SELinux at boot time.
1782 Format: { "0" | "1" }
1783 See security/selinux/Kconfig help text.
1784 0 -- disable.
1785 1 -- enable.
1786 Default value is set via kernel config option.
1787 If enabled at boot time, /selinux/disable can be used
1788 later to disable prior to initial policy load.
1789
James Morris4e5ab4c2006-06-09 00:33:33 -07001790 selinux_compat_net =
1791 [SELINUX] Set initial selinux_compat_net flag value.
Mauro Carvalho Chehabe53dd082007-09-15 07:38:47 -03001792 Format: { "0" | "1" }
1793 0 -- use new secmark-based packet controls
1794 1 -- use legacy packet controls
1795 Default value is 0 (preferred).
1796 Value can be changed at runtime via
1797 /selinux/compat_net.
James Morris4e5ab4c2006-06-09 00:33:33 -07001798
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001799 serialnumber [BUGS=X86-32]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001800
Linus Torvalds1da177e2005-04-16 15:20:36 -07001801 shapers= [NET]
1802 Maximal number of shapers.
Randy Dunlapa9913042005-10-23 12:57:11 -07001803
Linus Torvalds1da177e2005-04-16 15:20:36 -07001804 sim710= [SCSI,HW]
1805 See header of drivers/scsi/sim710.c.
1806
1807 simeth= [IA-64]
1808 simscsi=
Randy Dunlapa9913042005-10-23 12:57:11 -07001809
Linus Torvalds1da177e2005-04-16 15:20:36 -07001810 slram= [HW,MTD]
1811
Christoph Lameterf0630ff2007-07-15 23:38:14 -07001812 slub_debug[=options[,slabs]] [MM, SLUB]
1813 Enabling slub_debug allows one to determine the
1814 culprit if slab objects become corrupted. Enabling
1815 slub_debug can create guard zones around objects and
1816 may poison objects when not in use. Also tracks the
1817 last alloc / free. For more information see
1818 Documentation/vm/slub.txt.
Christoph Lameterc1aee212007-05-31 00:40:47 -07001819
1820 slub_max_order= [MM, SLUB]
Christoph Lameterf0630ff2007-07-15 23:38:14 -07001821 Determines the maximum allowed order for slabs.
1822 A high setting may cause OOMs due to memory
1823 fragmentation. For more information see
1824 Documentation/vm/slub.txt.
Christoph Lameterc1aee212007-05-31 00:40:47 -07001825
1826 slub_min_objects= [MM, SLUB]
Christoph Lameterf0630ff2007-07-15 23:38:14 -07001827 The minimum number of objects per slab. SLUB will
1828 increase the slab order up to slub_max_order to
1829 generate a sufficiently large slab able to contain
1830 the number of objects indicated. The higher the number
1831 of objects the smaller the overhead of tracking slabs
1832 and the less frequently locks need to be acquired.
Christoph Lameterc1aee212007-05-31 00:40:47 -07001833 For more information see Documentation/vm/slub.txt.
1834
1835 slub_min_order= [MM, SLUB]
1836 Determines the mininum page order for slabs. Must be
Christoph Lameterf0630ff2007-07-15 23:38:14 -07001837 lower than slub_max_order.
Christoph Lameterc1aee212007-05-31 00:40:47 -07001838 For more information see Documentation/vm/slub.txt.
1839
1840 slub_nomerge [MM, SLUB]
Christoph Lameterf0630ff2007-07-15 23:38:14 -07001841 Disable merging of slabs with similar size. May be
Christoph Lameterc1aee212007-05-31 00:40:47 -07001842 necessary if there is some reason to distinguish
Christoph Lameterf0630ff2007-07-15 23:38:14 -07001843 allocs to different slabs. Debug options disable
1844 merging on their own.
Christoph Lameterc1aee212007-05-31 00:40:47 -07001845 For more information see Documentation/vm/slub.txt.
1846
Linus Torvalds1da177e2005-04-16 15:20:36 -07001847 smart2= [HW]
1848 Format: <io1>[,<io2>[,...,<io8>]]
1849
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001850 smp-alt-once [X86-32,SMP] On a hotplug CPU system, only
Jeremy Fitzhardingeb7fb4af2007-05-02 19:27:13 +02001851 attempt to substitute SMP alternatives once at boot.
1852
Bjorn Helgaasd0d4f692007-05-08 00:36:05 -07001853 smsc-ircc2.nopnp [HW] Don't use PNP to discover SMC devices
1854 smsc-ircc2.ircc_cfg= [HW] Device configuration I/O port
1855 smsc-ircc2.ircc_sir= [HW] SIR base I/O port
1856 smsc-ircc2.ircc_fir= [HW] FIR base I/O port
1857 smsc-ircc2.ircc_irq= [HW] IRQ line
1858 smsc-ircc2.ircc_dma= [HW] DMA channel
1859 smsc-ircc2.ircc_transceiver= [HW] Transceiver type:
1860 0: Toshiba Satellite 1800 (GP data pin select)
1861 1: Fast pin select (default)
1862 2: ATC IRMode
1863
Linus Torvalds1da177e2005-04-16 15:20:36 -07001864 snd-ad1816a= [HW,ALSA]
1865
1866 snd-ad1848= [HW,ALSA]
1867
1868 snd-ali5451= [HW,ALSA]
1869
1870 snd-als100= [HW,ALSA]
1871
1872 snd-als4000= [HW,ALSA]
1873
1874 snd-azt2320= [HW,ALSA]
1875
1876 snd-cmi8330= [HW,ALSA]
1877
1878 snd-cmipci= [HW,ALSA]
1879
1880 snd-cs4231= [HW,ALSA]
1881
1882 snd-cs4232= [HW,ALSA]
1883
1884 snd-cs4236= [HW,ALSA]
1885
1886 snd-cs4281= [HW,ALSA]
1887
1888 snd-cs46xx= [HW,ALSA]
1889
1890 snd-dt019x= [HW,ALSA]
1891
1892 snd-dummy= [HW,ALSA]
1893
1894 snd-emu10k1= [HW,ALSA]
1895
1896 snd-ens1370= [HW,ALSA]
1897
1898 snd-ens1371= [HW,ALSA]
1899
1900 snd-es968= [HW,ALSA]
1901
1902 snd-es1688= [HW,ALSA]
1903
1904 snd-es18xx= [HW,ALSA]
1905
1906 snd-es1938= [HW,ALSA]
1907
1908 snd-es1968= [HW,ALSA]
1909
1910 snd-fm801= [HW,ALSA]
1911
1912 snd-gusclassic= [HW,ALSA]
1913
1914 snd-gusextreme= [HW,ALSA]
1915
1916 snd-gusmax= [HW,ALSA]
1917
1918 snd-hdsp= [HW,ALSA]
1919
1920 snd-ice1712= [HW,ALSA]
1921
1922 snd-intel8x0= [HW,ALSA]
1923
1924 snd-interwave= [HW,ALSA]
1925
1926 snd-interwave-stb=
1927 [HW,ALSA]
1928
1929 snd-korg1212= [HW,ALSA]
1930
1931 snd-maestro3= [HW,ALSA]
1932
1933 snd-mpu401= [HW,ALSA]
1934
1935 snd-mtpav= [HW,ALSA]
1936
1937 snd-nm256= [HW,ALSA]
1938
1939 snd-opl3sa2= [HW,ALSA]
1940
1941 snd-opti92x-ad1848=
1942 [HW,ALSA]
1943
1944 snd-opti92x-cs4231=
1945 [HW,ALSA]
1946
1947 snd-opti93x= [HW,ALSA]
1948
1949 snd-pmac= [HW,ALSA]
1950
1951 snd-rme32= [HW,ALSA]
1952
1953 snd-rme96= [HW,ALSA]
1954
1955 snd-rme9652= [HW,ALSA]
1956
1957 snd-sb8= [HW,ALSA]
1958
1959 snd-sb16= [HW,ALSA]
1960
1961 snd-sbawe= [HW,ALSA]
1962
1963 snd-serial= [HW,ALSA]
1964
1965 snd-sgalaxy= [HW,ALSA]
1966
1967 snd-sonicvibes= [HW,ALSA]
1968
1969 snd-sun-amd7930=
1970 [HW,ALSA]
1971
1972 snd-sun-cs4231= [HW,ALSA]
1973
1974 snd-trident= [HW,ALSA]
1975
1976 snd-usb-audio= [HW,ALSA,USB]
1977
1978 snd-via82xx= [HW,ALSA]
1979
1980 snd-virmidi= [HW,ALSA]
1981
1982 snd-wavefront= [HW,ALSA]
1983
1984 snd-ymfpci= [HW,ALSA]
Randy Dunlapa9913042005-10-23 12:57:11 -07001985
Linus Torvalds1da177e2005-04-16 15:20:36 -07001986 sonypi.*= [HW] Sony Programmable I/O Control Device driver
1987 See Documentation/sonypi.txt
1988
1989 specialix= [HW,SERIAL] Specialix multi-serial port adapter
1990 See Documentation/specialix.txt.
1991
1992 spia_io_base= [HW,MTD]
1993 spia_fio_base=
1994 spia_pedr=
1995 spia_peddr=
1996
1997 sscape= [HW,OSS]
1998 Format: <io>,<irq>,<dma>,<mpu_io>,<mpu_irq>
Randy Dunlapa9913042005-10-23 12:57:11 -07001999
Linus Torvalds1da177e2005-04-16 15:20:36 -07002000 st= [HW,SCSI] SCSI tape parameters (buffers, etc.)
2001 See Documentation/scsi/st.txt.
2002
Linus Torvalds1da177e2005-04-16 15:20:36 -07002003 sti= [PARISC,HW]
2004 Format: <num>
2005 Set the STI (builtin display/keyboard on the HP-PARISC
2006 machines) console (graphic card) which should be used
2007 as the initial boot-console.
2008 See also comment in drivers/video/console/sticore.c.
2009
2010 sti_font= [HW]
2011 See comment in drivers/video/console/sticore.c.
2012
2013 stifb= [HW]
2014 Format: bpp:<bpp1>[:<bpp2>[:<bpp3>...]]
2015
Greg Banks42a7fc42007-03-06 01:42:23 -08002016 sunrpc.pool_mode=
2017 [NFS]
2018 Control how the NFS server code allocates CPUs to
2019 service thread pools. Depending on how many NICs
2020 you have and where their interrupts are bound, this
2021 option will affect which CPUs will do NFS serving.
2022 Note: this parameter cannot be changed while the
2023 NFS server is running.
2024
2025 auto the server chooses an appropriate mode
2026 automatically using heuristics
2027 global a single global pool contains all CPUs
2028 percpu one pool for each CPU
2029 pernode one pool for each NUMA node (equivalent
2030 to global on non-NUMA machines)
2031
Linus Torvalds1da177e2005-04-16 15:20:36 -07002032 swiotlb= [IA-64] Number of I/O TLB slabs
Randy Dunlapa9913042005-10-23 12:57:11 -07002033
Linus Torvalds1da177e2005-04-16 15:20:36 -07002034 switches= [HW,M68k]
2035
2036 sym53c416= [HW,SCSI]
2037 See header of drivers/scsi/sym53c416.c.
2038
Ingo Molnar5d6f6472006-12-13 00:34:36 -08002039 sysrq_always_enabled
2040 [KNL]
2041 Ignore sysrq setting - this boot parameter will
2042 neutralize any effect of /proc/sys/kernel/sysrq.
2043 Useful for debugging.
2044
Linus Torvalds1da177e2005-04-16 15:20:36 -07002045 t128= [HW,SCSI]
2046 See header of drivers/scsi/t128.c.
2047
2048 tdfx= [HW,DRM]
2049
2050 thash_entries= [KNL,NET]
2051 Set number of hash buckets for TCP connection
2052
Len Brownf8707ec2007-08-12 00:12:54 -04002053 thermal.act= [HW,ACPI]
2054 -1: disable all active trip points in all thermal zones
2055 <degrees C>: override all lowest active trip points
2056
Len Brownc52a7412007-08-14 15:49:32 -04002057 thermal.crt= [HW,ACPI]
2058 -1: disable all critical trip points in all thermal zones
2059 <degrees C>: lower all critical trip points
2060
Len Brownf5487142007-08-12 00:12:44 -04002061 thermal.nocrt= [HW,ACPI]
2062 Set to disable actions on ACPI thermal zone
2063 critical and hot trip points.
2064
Len Brown72b33ef2007-08-12 00:12:17 -04002065 thermal.off= [HW,ACPI]
2066 1: disable ACPI thermal control
2067
Len Browna70cdc52007-08-12 00:12:35 -04002068 thermal.psv= [HW,ACPI]
2069 -1: disable all passive trip points
2070 <degrees C>: override all passive trip points to this value
2071
Len Brown730ff342007-08-12 00:12:26 -04002072 thermal.tzp= [HW,ACPI]
2073 Specify global default ACPI thermal zone polling rate
2074 <deci-seconds>: poll all this frequency
2075 0: no polling (default)
2076
Linus Torvalds1da177e2005-04-16 15:20:36 -07002077 tipar.timeout= [HW,PPT]
2078 Set communications timeout in tenths of a second
2079 (default 15).
2080
2081 tipar.delay= [HW,PPT]
2082 Set inter-bit delay in microseconds (default 10).
2083
Linus Torvalds1da177e2005-04-16 15:20:36 -07002084 tmscsim= [HW,SCSI]
2085 See comment before function dc390_setup() in
2086 drivers/scsi/tmscsim.c.
2087
2088 tp720= [HW,PS2]
2089
2090 trix= [HW,OSS] MediaTrix AudioTrix Pro
Randy Dunlapa9913042005-10-23 12:57:11 -07002091 Format:
2092 <io>,<irq>,<dma>,<dma2>,<sb_io>,<sb_irq>,<sb_dma>,<mpu_io>,<mpu_irq>
2093
Randy Dunlapa9913042005-10-23 12:57:11 -07002094 turbografx.map[2|3]= [HW,JOY]
2095 TurboGraFX parallel port interface
2096 Format:
2097 <port#>,<js1>,<js2>,<js3>,<js4>,<js5>,<js6>,<js7>
Linus Torvalds1da177e2005-04-16 15:20:36 -07002098 See also Documentation/input/joystick-parport.txt
2099
2100 u14-34f= [HW,SCSI] UltraStor 14F/34F SCSI host adapter
2101 See header of drivers/scsi/u14-34f.c.
2102
2103 uart401= [HW,OSS]
2104 Format: <io>,<irq>
2105
2106 uart6850= [HW,OSS]
2107 Format: <io>,<irq>
2108
Alan Stern5f8364b2006-12-05 16:29:55 -05002109 uhci-hcd.ignore_oc=
2110 [USB] Ignore overcurrent events (default N).
2111 Some badly-designed motherboards generate lots of
2112 bogus events, for ports that aren't wired to
2113 anything. Set this parameter to avoid log spamming.
2114 Note that genuine overcurrent events won't be
2115 reported either.
2116
Alan Sternb5e795f2007-02-20 15:00:53 -05002117 usbcore.autosuspend=
2118 [USB] The autosuspend time delay (in seconds) used
2119 for newly-detected USB devices (default 2). This
2120 is the time required before an idle device will be
2121 autosuspended. Devices for which the delay is set
Alan Sterneaafbc32007-03-13 16:39:15 -04002122 to a negative value won't be autosuspended at all.
Alan Sternb5e795f2007-02-20 15:00:53 -05002123
Linus Torvalds1da177e2005-04-16 15:20:36 -07002124 usbhid.mousepoll=
2125 [USBHID] The interval which mice are to be polled at.
Randy Dunlapa9913042005-10-23 12:57:11 -07002126
Alan Coxcd4f0ef2007-07-31 00:37:59 -07002127 vdso= [X86-32,SH,x86-64]
Jeremy Fitzhardinge1dbf527c2007-05-02 19:27:12 +02002128 vdso=2: enable compat VDSO (default with COMPAT_VDSO)
Ingo Molnare6e54942006-06-27 02:53:50 -07002129 vdso=1: enable VDSO (default)
2130 vdso=0: disable VDSO mapping
2131
Roland McGrathaf65d642008-01-30 13:30:43 +01002132 vdso32= [X86-32,X86-64]
2133 vdso32=2: enable compat VDSO (default with COMPAT_VDSO)
2134 vdso32=1: enable 32-bit VDSO (default)
2135 vdso32=0: disable 32-bit VDSO mapping
2136
Yasuaki Ishimatsud080d392007-07-17 21:22:55 +09002137 vector= [IA-64,SMP]
2138 vector=percpu: enable percpu vector domain
2139
Linus Torvalds1da177e2005-04-16 15:20:36 -07002140 video= [FB] Frame buffer configuration
2141 See Documentation/fb/modedb.txt.
2142
Alan Coxcd4f0ef2007-07-31 00:37:59 -07002143 vga= [BOOT,X86-32] Select a particular video mode
Randy Dunlapa9913042005-10-23 12:57:11 -07002144 See Documentation/i386/boot.txt and
2145 Documentation/svga.txt.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002146 Use vga=ask for menu.
2147 This is actually a boot loader parameter; the value is
2148 passed to the kernel using a special protocol.
2149
Randy Dunlapa9913042005-10-23 12:57:11 -07002150 vmalloc=nn[KMG] [KNL,BOOT] Forces the vmalloc area to have an exact
Linus Torvalds1da177e2005-04-16 15:20:36 -07002151 size of <nn>. This can be used to increase the
2152 minimum size (128MB on x86). It can also be used to
2153 decrease the size and leave more room for directly
2154 mapped kernel RAM.
2155
Peter Oberparleiter585c3042006-06-29 15:08:25 +02002156 vmhalt= [KNL,S390] Perform z/VM CP command after system halt.
2157 Format: <command>
Linus Torvalds1da177e2005-04-16 15:20:36 -07002158
Peter Oberparleiter585c3042006-06-29 15:08:25 +02002159 vmpanic= [KNL,S390] Perform z/VM CP command after kernel panic.
2160 Format: <command>
2161
2162 vmpoff= [KNL,S390] Perform z/VM CP command after power off.
2163 Format: <command>
Randy Dunlapa9913042005-10-23 12:57:11 -07002164
Linus Torvalds1da177e2005-04-16 15:20:36 -07002165 waveartist= [HW,OSS]
2166 Format: <io>,<irq>,<dma>,<dma2>
Randy Dunlapa9913042005-10-23 12:57:11 -07002167
Linus Torvalds1da177e2005-04-16 15:20:36 -07002168 wd33c93= [HW,SCSI]
2169 See header of drivers/scsi/wd33c93.c.
2170
2171 wd7000= [HW,SCSI]
2172 See header of drivers/scsi/wd7000.c.
2173
2174 wdt= [WDT] Watchdog
Gabriel C8dfe9c22007-08-10 13:01:00 -07002175 See Documentation/watchdog/wdt.txt.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002176
2177 xd= [HW,XT] Original XT pre-IDE (RLL encoded) disks.
2178 xd_geo= See header of drivers/block/xd.c.
2179
2180 xirc2ps_cs= [NET,PCMCIA]
Randy Dunlapa9913042005-10-23 12:57:11 -07002181 Format:
2182 <irq>,<irq_mask>,<io>,<full_duplex>,<do_sound>,<lockup_hack>[,<irq2>[,<irq3>[,<irq4>]]]
Linus Torvalds1da177e2005-04-16 15:20:36 -07002183
Andi Kleena62eaf12006-02-16 23:41:58 +01002184 norandmaps Don't use address space randomization
2185 Equivalent to echo 0 > /proc/sys/kernel/randomize_va_space
2186
Randy Dunlapa9913042005-10-23 12:57:11 -07002187______________________________________________________________________
Linus Torvalds1da177e2005-04-16 15:20:36 -07002188
2189TODO:
2190
2191 Add documentation for ALSA options.
2192 Add more DRM drivers.