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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.
David Brownell77437fd2008-07-23 21:28:33 -070090 SWSUSP Software suspend (hibernation) is enabled.
91 SUSPEND System suspend states are enabled.
Linus Torvalds1da177e2005-04-16 15:20:36 -070092 TS Appropriate touchscreen support is enabled.
93 USB USB support is enabled.
94 USBHID USB Human Interface Device support is enabled.
95 V4L Video For Linux support is enabled.
96 VGA The VGA console has been enabled.
97 VT Virtual terminal support is enabled.
98 WDT Watchdog support is enabled.
99 XT IBM PC/XT MFM hard disk support is enabled.
Alan Coxcd4f0ef2007-07-31 00:37:59 -0700100 X86-32 X86-32, aka i386 architecture is enabled.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700101 X86-64 X86-64 architecture is enabled.
102 More X86-64 boot options can be found in
103 Documentation/x86_64/boot-options.txt .
104
105In addition, the following text indicates that the option:
106
107 BUGS= Relates to possible processor bugs on the said processor.
108 KNL Is a kernel start-up parameter.
109 BOOT Is a boot loader parameter.
110
111Parameters denoted with BOOT are actually interpreted by the boot
112loader, and have no meaning to the kernel directly.
113Do not modify the syntax of boot loader parameters without extreme
114need or coordination with <Documentation/i386/boot.txt>.
115
Karsten Weiss55588702007-02-13 13:26:21 +0100116There are also arch-specific kernel-parameters not documented here.
117See for example <Documentation/x86_64/boot-options.txt>.
118
Linus Torvalds1da177e2005-04-16 15:20:36 -0700119Note that ALL kernel parameters listed below are CASE SENSITIVE, and that
120a trailing = on the name of any parameter states that that parameter will
121be entered as an environment variable, whereas its absence indicates that
122it will appear as a kernel argument readable via /proc/cmdline by programs
123running once the system is up.
124
jens m. noedler9c4751f2006-09-29 02:00:27 -0700125The number of kernel parameters is not limited, but the length of the
126complete command line (parameters including spaces etc.) is limited to
127a fixed number of characters. This limit depends on the architecture
128and is between 256 and 4096 characters. It is defined in the file
129./include/asm/setup.h as COMMAND_LINE_SIZE.
130
131
Bernhard Walle03d926f2007-03-06 02:29:44 -0800132 acpi= [HW,ACPI,X86-64,i386]
133 Advanced Configuration and Power Interface
Randy Dunlapa9913042005-10-23 12:57:11 -0700134 Format: { force | off | ht | strict | noirq }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700135 force -- enable ACPI if default was off
136 off -- disable ACPI if default was on
137 noirq -- do not use ACPI for IRQ routing
138 ht -- run only enough ACPI to enable Hyper Threading
Randy Dunlapa9913042005-10-23 12:57:11 -0700139 strict -- Be less tolerant of platforms that are not
Linus Torvalds1da177e2005-04-16 15:20:36 -0700140 strictly ACPI specification compliant.
141
Randy Dunlap53471122008-03-12 18:10:51 -0400142 See also Documentation/power/pm.txt, pci=noacpi
Linus Torvalds1da177e2005-04-16 15:20:36 -0700143
Len Browna1fdcc02007-03-11 03:26:14 -0400144 acpi_apic_instance= [ACPI, IOAPIC]
145 Format: <int>
146 2: use 2nd APIC table, if available
147 1,0: use 1st APIC table
Len Brown4e381a42007-03-30 14:16:10 -0400148 default: 0
Len Browna1fdcc02007-03-11 03:26:14 -0400149
Linus Torvalds1da177e2005-04-16 15:20:36 -0700150 acpi_sleep= [HW,ACPI] Sleep options
Rafael J. Wysockid8f3de02008-06-12 23:24:06 +0200151 Format: { s3_bios, s3_mode, s3_beep, old_ordering }
Pavel Machek23b168d2008-02-05 19:27:12 +0100152 See Documentation/power/video.txt for s3_bios and s3_mode.
153 s3_beep is for debugging; it makes the PC's speaker beep
154 as soon as the kernel's real-mode entry point is called.
Rafael J. Wysockid8f3de02008-06-12 23:24:06 +0200155 old_ordering causes the ACPI 1.0 ordering of the _PTS
156 control method, wrt putting devices into low power
157 states, to be enforced (the ACPI 2.0 ordering of _PTS is
158 used by default).
Randy Dunlapa9913042005-10-23 12:57:11 -0700159
Linus Torvalds1da177e2005-04-16 15:20:36 -0700160 acpi_sci= [HW,ACPI] ACPI System Control Interrupt trigger mode
Randy Dunlapa9913042005-10-23 12:57:11 -0700161 Format: { level | edge | high | low }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700162
Randy Dunlapa9913042005-10-23 12:57:11 -0700163 acpi_irq_balance [HW,ACPI]
164 ACPI will balance active IRQs
165 default in APIC mode
Linus Torvalds1da177e2005-04-16 15:20:36 -0700166
Randy Dunlapa9913042005-10-23 12:57:11 -0700167 acpi_irq_nobalance [HW,ACPI]
168 ACPI will not move active IRQs (default)
169 default in PIC mode
Linus Torvalds1da177e2005-04-16 15:20:36 -0700170
Randy Dunlapa9913042005-10-23 12:57:11 -0700171 acpi_irq_pci= [HW,ACPI] If irq_balance, clear listed IRQs for
172 use by PCI
Linus Torvalds1da177e2005-04-16 15:20:36 -0700173 Format: <irq>,<irq>...
174
Randy Dunlapa9913042005-10-23 12:57:11 -0700175 acpi_irq_isa= [HW,ACPI] If irq_balance, mark listed IRQs used by ISA
Linus Torvalds1da177e2005-04-16 15:20:36 -0700176 Format: <irq>,<irq>...
177
Len Brown67effe82007-07-26 00:50:06 -0400178 acpi_no_auto_ssdt [HW,ACPI] Disable automatic loading of SSDT
179
Len Browna1f9e652006-01-25 23:47:36 -0500180 acpi_os_name= [HW,ACPI] Tell ACPI BIOS the name of the OS
181 Format: To spoof as Windows 98: ="Microsoft Windows"
182
Len Brownae00d812007-05-29 18:43:33 -0400183 acpi_osi= [HW,ACPI] Modify list of supported OS interface strings
184 acpi_osi="string1" # add string1 -- only one string
185 acpi_osi="!string2" # remove built-in string2
186 acpi_osi= # disable all strings
Linus Torvalds1da177e2005-04-16 15:20:36 -0700187
188 acpi_serialize [HW,ACPI] force serialization of AML methods
189
190 acpi_skip_timer_override [HW,ACPI]
191 Recognize and ignore IRQ0/pin2 Interrupt Override.
192 For broken nForce2 BIOS resulting in XT-PIC timer.
Andi Kleenfa18f472006-11-14 16:57:46 +0100193 acpi_use_timer_override [HW,ACPI}
194 Use timer override. For some broken Nvidia NF5 boards
195 that require a timer override, but don't have
196 HPET
Linus Torvalds1da177e2005-04-16 15:20:36 -0700197
Zhang Ruif9891062007-04-24 13:53:22 +0800198 acpi.debug_layer= [HW,ACPI]
Linus Torvalds1da177e2005-04-16 15:20:36 -0700199 Format: <int>
Randy Dunlapa9913042005-10-23 12:57:11 -0700200 Each bit of the <int> indicates an ACPI debug layer,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700201 1: enable, 0: disable. It is useful for boot time
202 debugging. After system has booted up, it can be set
Zhang Ruif9891062007-04-24 13:53:22 +0800203 via /sys/module/acpi/parameters/debug_layer.
204 CONFIG_ACPI_DEBUG must be enabled for this to produce any output.
205 Available bits (add the numbers together) to enable debug output
206 for specific parts of the ACPI subsystem:
207 0x01 utilities 0x02 hardware 0x04 events 0x08 tables
208 0x10 namespace 0x20 parser 0x40 dispatcher
209 0x80 executer 0x100 resources 0x200 acpica debugger
210 0x400 os services 0x800 acpica disassembler.
211 The number can be in decimal or prefixed with 0x in hex.
212 Warning: Many of these options can produce a lot of
213 output and make your system unusable. Be very careful.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700214
Zhang Ruif9891062007-04-24 13:53:22 +0800215 acpi.debug_level= [HW,ACPI]
Linus Torvalds1da177e2005-04-16 15:20:36 -0700216 Format: <int>
Randy Dunlapa9913042005-10-23 12:57:11 -0700217 Each bit of the <int> indicates an ACPI debug level,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700218 1: enable, 0: disable. It is useful for boot time
219 debugging. After system has booted up, it can be set
Zhang Ruif9891062007-04-24 13:53:22 +0800220 via /sys/module/acpi/parameters/debug_level.
221 CONFIG_ACPI_DEBUG must be enabled for this to produce any output.
222 Available bits (add the numbers together) to enable different
223 debug output levels of the ACPI subsystem:
224 0x01 error 0x02 warn 0x04 init 0x08 debug object
225 0x10 info 0x20 init names 0x40 parse 0x80 load
226 0x100 dispatch 0x200 execute 0x400 names 0x800 operation region
227 0x1000 bfield 0x2000 tables 0x4000 values 0x8000 objects
228 0x10000 resources 0x20000 user requests 0x40000 package.
229 The number can be in decimal or prefixed with 0x in hex.
230 Warning: Many of these options can produce a lot of
231 output and make your system unusable. Be very careful.
232
Alan Coxcd4f0ef2007-07-31 00:37:59 -0700233 acpi_pm_good [X86-32,X86-64]
john stultz5d0cf412006-06-26 00:25:12 -0700234 Override the pmtimer bug detection: force the kernel
235 to assume that this machine's pmtimer latches its value
236 and always returns good values.
237
Chuck Ebbertc99c1082007-07-27 10:46:20 +1000238 agp= [AGP]
239 { off | try_unsupported }
240 off: disable AGP support
241 try_unsupported: try to drive unsupported chipsets
242 (may crash computer or cause data corruption)
243
Chuck Ebbert66759a02005-09-12 18:49:25 +0200244 enable_timer_pin_1 [i386,x86-64]
245 Enable PIN 1 of APIC timer
Randy Dunlapa9913042005-10-23 12:57:11 -0700246 Can be useful to work around chipset bugs
247 (in particular on some ATI chipsets).
Chuck Ebbert66759a02005-09-12 18:49:25 +0200248 The kernel tries to set a reasonable default.
249
250 disable_timer_pin_1 [i386,x86-64]
251 Disable PIN 1 of APIC timer
252 Can be useful to work around chipset bugs.
253
Linus Torvalds1da177e2005-04-16 15:20:36 -0700254 ad1848= [HW,OSS]
255 Format: <io>,<irq>,<dma>,<dma2>,<type>
256
Linus Torvalds1da177e2005-04-16 15:20:36 -0700257 advansys= [HW,SCSI]
258 See header of drivers/scsi/advansys.c.
259
260 advwdt= [HW,WDT] Advantech WDT
261 Format: <iostart>,<iostop>
262
263 aedsp16= [HW,OSS] Audio Excel DSP 16
264 Format: <io>,<irq>,<dma>,<mss_io>,<mpu_io>,<mpu_irq>
265 See also header of sound/oss/aedsp16.c.
Randy Dunlapa9913042005-10-23 12:57:11 -0700266
Linus Torvalds1da177e2005-04-16 15:20:36 -0700267 aha152x= [HW,SCSI]
268 See Documentation/scsi/aha152x.txt.
269
270 aha1542= [HW,SCSI]
271 Format: <portbase>[,<buson>,<busoff>[,<dmaspeed>]]
272
273 aic7xxx= [HW,SCSI]
274 See Documentation/scsi/aic7xxx.txt.
275
276 aic79xx= [HW,SCSI]
277 See Documentation/scsi/aic79xx.txt.
278
Joerg Roedel54b4cbd2008-06-26 21:28:10 +0200279 amd_iommu= [HW,X86-84]
280 Pass parameters to the AMD IOMMU driver in the system.
281 Possible values are:
Joerg Roedel54b4cbd2008-06-26 21:28:10 +0200282 isolate - enable device isolation (each device, as far
283 as possible, will get its own protection
284 domain)
285 amd_iommu_size= [HW,X86-64]
286 Define the size of the aperture for the AMD IOMMU
287 driver. Possible values are:
288 '32M', '64M' (default), '128M', '256M', '512M', '1G'
289
Linus Torvalds1da177e2005-04-16 15:20:36 -0700290 amijoy.map= [HW,JOY] Amiga joystick support
291 Map of devices attached to JOY0DAT and JOY1DAT
292 Format: <a>,<b>
293 See also Documentation/kernel/input/joystick.txt
294
295 analog.map= [HW,JOY] Analog joystick and gamepad support
296 Specifies type or capabilities of an analog joystick
297 connected to one of 16 gameports
298 Format: <type1>,<type2>,..<type16>
299
Randy Dunlapa9913042005-10-23 12:57:11 -0700300 apc= [HW,SPARC]
301 Power management functions (SPARCstation-4/5 + deriv.)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700302 Format: noidle
303 Disable APC CPU standby support. SPARCstation-Fox does
304 not play well with APC CPU idle - disable it if you have
305 APC and your system crashes randomly.
306
Randy Dunlapc8facbb2007-07-31 00:37:40 -0700307 apic= [APIC,i386] Advanced Programmable Interrupt Controller
308 Change the output verbosity whilst booting
Linus Torvalds1da177e2005-04-16 15:20:36 -0700309 Format: { quiet (default) | verbose | debug }
310 Change the amount of debugging information output
311 when initialising the APIC and IO-APIC components.
Randy Dunlapa9913042005-10-23 12:57:11 -0700312
Linus Torvalds1da177e2005-04-16 15:20:36 -0700313 apm= [APM] Advanced Power Management
Pavel Machek71f77052008-07-04 09:59:43 -0700314 See header of arch/x86/kernel/apm_32.c.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700315
Linus Torvalds1da177e2005-04-16 15:20:36 -0700316 arcrimi= [HW,NET] ARCnet - "RIM I" (entirely mem-mapped) cards
317 Format: <io>,<irq>,<nodeID>
318
319 ataflop= [HW,M68k]
320
321 atarimouse= [HW,MOUSE] Atari Mouse
322
323 atascsi= [HW,SCSI] Atari SCSI
324
325 atkbd.extra= [HW] Enable extra LEDs and keys on IBM RapidAccess,
326 EzKey and similar keyboards
327
328 atkbd.reset= [HW] Reset keyboard during initialization
329
Randy Dunlapa9913042005-10-23 12:57:11 -0700330 atkbd.set= [HW] Select keyboard code set
331 Format: <int> (2 = AT (default), 3 = PS/2)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700332
333 atkbd.scroll= [HW] Enable scroll wheel on MS Office and similar
334 keyboards
335
336 atkbd.softraw= [HW] Choose between synthetic and real raw mode
337 Format: <bool> (0 = real, 1 = synthetic (default))
Randy Dunlapa9913042005-10-23 12:57:11 -0700338
339 atkbd.softrepeat= [HW]
340 Use software keyboard repeat
Linus Torvalds1da177e2005-04-16 15:20:36 -0700341
342 autotest [IA64]
343
Linus Torvalds1da177e2005-04-16 15:20:36 -0700344 baycom_epp= [HW,AX25]
345 Format: <io>,<mode>
Randy Dunlapa9913042005-10-23 12:57:11 -0700346
Linus Torvalds1da177e2005-04-16 15:20:36 -0700347 baycom_par= [HW,AX25] BayCom Parallel Port AX.25 Modem
348 Format: <io>,<mode>
349 See header of drivers/net/hamradio/baycom_par.c.
350
Randy Dunlapa9913042005-10-23 12:57:11 -0700351 baycom_ser_fdx= [HW,AX25]
352 BayCom Serial Port AX.25 Modem (Full Duplex Mode)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700353 Format: <io>,<irq>,<mode>[,<baud>]
354 See header of drivers/net/hamradio/baycom_ser_fdx.c.
355
Randy Dunlapa9913042005-10-23 12:57:11 -0700356 baycom_ser_hdx= [HW,AX25]
357 BayCom Serial Port AX.25 Modem (Half Duplex Mode)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700358 Format: <io>,<irq>,<mode>
359 See header of drivers/net/hamradio/baycom_ser_hdx.c.
360
Randy Dunlapbfe8df32007-10-16 01:23:46 -0700361 boot_delay= Milliseconds to delay each printk during boot.
362 Values larger than 10 seconds (10000) are changed to
363 no delay (0).
364 Format: integer
365
Linus Torvalds1da177e2005-04-16 15:20:36 -0700366 bttv.card= [HW,V4L] bttv (bt848 + bt878 based grabber cards)
Randy Dunlapa9913042005-10-23 12:57:11 -0700367 bttv.radio= Most important insmod options are available as
368 kernel args too.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700369 bttv.pll= See Documentation/video4linux/bttv/Insmod-options
370 bttv.tuner= and Documentation/video4linux/bttv/CARDLIST
371
372 BusLogic= [HW,SCSI]
373 See drivers/scsi/BusLogic.c, comment before function
374 BusLogic_ParseDriverOptions().
375
376 c101= [NET] Moxa C101 synchronous serial card
377
Alan Coxcd4f0ef2007-07-31 00:37:59 -0700378 cachesize= [BUGS=X86-32] Override level 2 CPU cache size detection.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700379 Sometimes CPU hardware bugs make them report the cache
380 size incorrectly. The kernel will attempt work arounds
381 to fix known problems, but for some CPUs it is not
382 possible to determine what the correct size should be.
383 This option provides an override for these situations.
384
Ahmed S. Darwish076c54c2008-03-06 18:09:10 +0200385 security= [SECURITY] Choose a security module to enable at boot.
386 If this boot parameter is not specified, only the first
387 security module asking for security registration will be
388 loaded. An invalid security module name will be treated
389 as if no module has been chosen.
390
James Morris20510f22007-10-16 23:31:32 -0700391 capability.disable=
392 [SECURITY] Disable capabilities. This would normally
393 be used only if an alternative security model is to be
394 configured. Potentially dangerous and should only be
395 used if you are entirely sure of the consequences.
396
Sebastian Ott14ff56b2008-01-26 14:10:37 +0100397 ccw_timeout_log [S390]
398 See Documentation/s390/CommonIO for details.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700399
Paul Menage8bab8dd2008-04-04 14:29:57 -0700400 cgroup_disable= [KNL] Disable a particular controller
401 Format: {name of the controller(s) to disable}
402 {Currently supported controllers - "memory"}
403
Linus Torvalds1da177e2005-04-16 15:20:36 -0700404 checkreqprot [SELINUX] Set initial checkreqprot flag value.
405 Format: { "0" | "1" }
406 See security/selinux/Kconfig help text.
Randy Dunlapa9913042005-10-23 12:57:11 -0700407 0 -- check protection applied by kernel (includes
408 any implied execute protection).
Linus Torvalds1da177e2005-04-16 15:20:36 -0700409 1 -- check protection requested by application.
410 Default value is set via a kernel config option.
Randy Dunlapa9913042005-10-23 12:57:11 -0700411 Value can be changed at runtime via
412 /selinux/checkreqprot.
413
Sebastian Ott661ca0d2008-01-26 14:10:36 +0100414 cio_ignore= [S390]
415 See Documentation/s390/CommonIO for details.
416
Alan Coxcd4f0ef2007-07-31 00:37:59 -0700417 clock= [BUGS=X86-32, HW] gettimeofday clocksource override.
john stultz734efb42006-06-26 00:25:05 -0700418 [Deprecated]
Matt LaPlante3f6dee92006-10-03 22:45:33 +0200419 Forces specified clocksource (if available) to be used
john stultz734efb42006-06-26 00:25:05 -0700420 when calculating gettimeofday(). If specified
Matt LaPlante3f6dee92006-10-03 22:45:33 +0200421 clocksource is not available, it defaults to PIT.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700422 Format: { pit | tsc | cyclone | pmtmr }
423
Randy Dunlap3d6ac982007-05-23 13:58:16 -0700424 clocksource= [GENERIC_TIME] Override the default clocksource
425 Format: <string>
426 Override the default clocksource and use the clocksource
427 with the name specified.
428 Some clocksource names to choose from, depending on
429 the platform:
430 [all] jiffies (this is the base, fallback clocksource)
431 [ACPI] acpi_pm
432 [ARM] imx_timer1,OSTS,netx_timer,mpu_timer2,
433 pxa_timer,timer3,32k_counter,timer0_1
434 [AVR32] avr32
Alan Coxcd4f0ef2007-07-31 00:37:59 -0700435 [X86-32] pit,hpet,tsc,vmi-timer;
Randy Dunlap3d6ac982007-05-23 13:58:16 -0700436 scx200_hrt on Geode; cyclone on IBM x440
437 [MIPS] MIPS
438 [PARISC] cr16
439 [S390] tod
440 [SH] SuperH
441 [SPARC64] tick
442 [X86-64] hpet,tsc
443
Andi Kleenac72e782008-01-30 13:33:21 +0100444 clearcpuid=BITNUM [X86]
445 Disable CPUID feature X for the kernel. See
446 include/asm-x86/cpufeature.h for the valid bit numbers.
447 Note the Linux specific bits are not necessarily
448 stable over kernel options, but the vendor specific
449 ones should be.
450 Also note that user programs calling CPUID directly
451 or using the feature without checking anything
452 will still see it. This just prevents it from
453 being used by the kernel or shown in /proc/cpuinfo.
454 Also note the kernel might malfunction if you disable
455 some critical bits.
456
Arjan van de Vena25bd942008-01-30 13:33:08 +0100457 code_bytes [IA32/X86_64] How many bytes of object code to print
458 in an oops report.
Chuck Ebbert86c41832007-02-13 13:26:25 +0100459 Range: 0 - 8192
460 Default: 64
461
Andi Kleenf9262c12006-03-08 17:57:25 -0800462 disable_8254_timer
463 enable_8254_timer
464 [IA32/X86_64] Disable/Enable interrupt 0 timer routing
465 over the 8254 in addition to over the IO-APIC. The
466 kernel tries to set a sensible default.
467
Thomas Gleixnerb17530b2007-10-19 20:35:02 +0200468 hpet= [X86-32,HPET] option to control HPET usage
469 Format: { enable (default) | disable | force }
470 disable: disable HPET and use PIT instead
Carlos Corbachod79a5f82007-10-19 18:51:27 +0100471 force: allow force enabled of undocumented chips (ICH4,
472 VIA, nVidia)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700473
Linus Torvalds1da177e2005-04-16 15:20:36 -0700474 com20020= [HW,NET] ARCnet - COM20020 chipset
Randy Dunlapa9913042005-10-23 12:57:11 -0700475 Format:
476 <io>[,<irq>[,<nodeID>[,<backplane>[,<ckp>[,<timeout>]]]]]
Linus Torvalds1da177e2005-04-16 15:20:36 -0700477
478 com90io= [HW,NET] ARCnet - COM90xx chipset (IO-mapped buffers)
479 Format: <io>[,<irq>]
480
Randy Dunlapa9913042005-10-23 12:57:11 -0700481 com90xx= [HW,NET]
482 ARCnet - COM90xx chipset (memory-mapped buffers)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700483 Format: <io>[,<irq>[,<memstart>]]
484
485 condev= [HW,S390] console device
486 conmode=
Randy Dunlapa9913042005-10-23 12:57:11 -0700487
Linus Torvalds1da177e2005-04-16 15:20:36 -0700488 console= [KNL] Output console device and options.
489
490 tty<n> Use the virtual console device <n>.
491
492 ttyS<n>[,options]
Randy Dunlapf1a1c2d2006-03-25 03:08:17 -0800493 ttyUSB0[,options]
Linus Torvalds1da177e2005-04-16 15:20:36 -0700494 Use the specified serial port. The options are of
Randy Dunlapf1a1c2d2006-03-25 03:08:17 -0800495 the form "bbbbpnf", where "bbbb" is the baud rate,
496 "p" is parity ("n", "o", or "e"), "n" is number of
497 bits, and "f" is flow control ("r" for RTS or
498 omit it). Default is "9600n8".
Linus Torvalds1da177e2005-04-16 15:20:36 -0700499
Randy Dunlapf1a1c2d2006-03-25 03:08:17 -0800500 See Documentation/serial-console.txt for more
501 information. See
502 Documentation/networking/netconsole.txt for an
503 alternative.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700504
Yinghai Lu18a8bd92007-07-15 23:37:59 -0700505 uart[8250],io,<addr>[,options]
506 uart[8250],mmio,<addr>[,options]
Linus Torvalds1da177e2005-04-16 15:20:36 -0700507 Start an early, polled-mode console on the 8250/16550
508 UART at the specified I/O port or MMIO address,
509 switching to the matching ttyS device later. The
510 options are the same as for ttyS, above.
511
Samuel Thibaultf7511d52008-04-30 00:54:51 -0700512 If the device connected to the port is not a TTY but a braille
513 device, prepend "brl," before the device type, for instance
514 console=brl,ttyS0
515 For now, only VisioBraille is supported.
516
Yinghai Lu18a8bd92007-07-15 23:37:59 -0700517 earlycon= [KNL] Output early console device and options.
518 uart[8250],io,<addr>[,options]
519 uart[8250],mmio,<addr>[,options]
520 Start an early, polled-mode console on the 8250/16550
521 UART at the specified I/O port or MMIO address.
522 The options are the same as for ttyS, above.
523
Andres Salomon8f4ce8c2007-10-18 03:04:50 -0700524 no_console_suspend
525 [HW] Never suspend the console
526 Disable suspending of consoles during suspend and
527 hibernate operations. Once disabled, debugging
528 messages can reach various consoles while the rest
529 of the system is being put to sleep (ie, while
530 debugging driver suspend/resume hooks). This may
531 not work reliably with all consoles, but is known
532 to work with serial and VGA consoles.
533
Linus Torvalds1da177e2005-04-16 15:20:36 -0700534 cpcihp_generic= [HW,PCI] Generic port I/O CompactPCI driver
Randy Dunlapa9913042005-10-23 12:57:11 -0700535 Format:
536 <first_slot>,<last_slot>,<port>,<enum_bit>[,<debug>]
Linus Torvalds1da177e2005-04-16 15:20:36 -0700537
Eric W. Biedermandc009d92005-06-25 14:57:52 -0700538 crashkernel=nn[KMG]@ss[KMG]
539 [KNL] Reserve a chunk of physical memory to
540 hold a kernel to switch to with kexec on panic.
541
Bernhard Wallefb391592007-10-18 23:41:02 -0700542 crashkernel=range1:size1[,range2:size2,...][@offset]
543 [KNL] Same as above, but depends on the memory
544 in the running system. The syntax of range is
545 start-[end] where start and end are both
546 a memory unit (amount[KMG]). See also
547 Documentation/kdump/kdump.txt for a example.
548
Linus Torvalds1da177e2005-04-16 15:20:36 -0700549 cs4232= [HW,OSS]
550 Format: <io>,<irq>,<dma>,<dma2>,<mpuio>,<mpuirq>
551
552 cs89x0_dma= [HW,NET]
553 Format: <dma>
554
555 cs89x0_media= [HW,NET]
556 Format: { rj45 | aui | bnc }
Randy Dunlapa9913042005-10-23 12:57:11 -0700557
Randy Dunlapa9913042005-10-23 12:57:11 -0700558 dasd= [HW,NET]
Linus Torvalds1da177e2005-04-16 15:20:36 -0700559 See header of drivers/s390/block/dasd_devmap.c.
560
561 db9.dev[2|3]= [HW,JOY] Multisystem joystick support via parallel port
562 (one device per port)
563 Format: <port#>,<type>
564 See also Documentation/input/joystick-parport.txt
565
566 debug [KNL] Enable kernel debugging (events log level).
567
Ingo Molnarcae2ed92006-07-03 00:24:48 -0700568 debug_locks_verbose=
569 [KNL] verbose self-tests
570 Format=<0|1>
571 Print debugging info while doing the locking API
572 self-tests.
573 We default to 0 (no extra messages), setting it to
574 1 will print _a lot_ more information - normally
575 only useful to kernel developers.
576
Thomas Gleixner3ac7fe52008-04-30 00:55:01 -0700577 debug_objects [KNL] Enable object debugging
578
Thomas Gleixnerd3af01f2008-07-15 15:04:56 +0200579 debugpat [X86] Enable PAT debugging
580
Robert P. J. Day2d27a962008-02-03 15:18:45 +0200581 decnet.addr= [HW,NET]
Linus Torvalds1da177e2005-04-16 15:20:36 -0700582 Format: <area>[,<node>]
583 See also Documentation/networking/decnet.txt.
584
Samuel Thibaultecb77fa2008-01-03 16:17:54 +0000585 vt.default_blu= [VT]
Antonino A. Daplas55ff9782007-05-08 00:38:53 -0700586 Format: <blue0>,<blue1>,<blue2>,...,<blue15>
587 Change the default blue 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_grn= [VT]
Antonino A. Daplas55ff9782007-05-08 00:38:53 -0700592 Format: <green0>,<green1>,<green2>,...,<green15>
593 Change the default green 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_red= [VT]
Antonino A. Daplas55ff9782007-05-08 00:38:53 -0700598 Format: <red0>,<red1>,<red2>,...,<red15>
599 Change the default red palette of the console.
600 This is a 16-member array composed of values
601 ranging from 0-255.
602
Samuel Thibaultecb77fa2008-01-03 16:17:54 +0000603 vt.default_utf8=
604 [VT]
Antonino A. Daplas55ff9782007-05-08 00:38:53 -0700605 Format=<0|1>
606 Set system-wide default UTF-8 mode for all tty's.
Samuel Thibaultecb77fa2008-01-03 16:17:54 +0000607 Default is 1, i.e. UTF-8 mode is enabled for all
608 newly opened terminals.
Antonino A. Daplas55ff9782007-05-08 00:38:53 -0700609
Linus Torvalds1da177e2005-04-16 15:20:36 -0700610 dhash_entries= [KNL]
611 Set number of hash buckets for dentry cache.
Randy Dunlapa9913042005-10-23 12:57:11 -0700612
Linus Torvalds1da177e2005-04-16 15:20:36 -0700613 digi= [HW,SERIAL]
614 IO parameters + enable/disable command.
615
616 digiepca= [HW,SERIAL]
617 See drivers/char/README.epca and
618 Documentation/digiepca.txt.
619
Yinghai Lu95ffa242008-04-29 03:52:33 -0700620 disable_mtrr_cleanup [X86]
621 enable_mtrr_cleanup [X86]
622 The kernel tries to adjust MTRR layout from continuous
623 to discrete, to make X server driver able to add WB
624 entry later. This parameter enables/disables that.
625
626 mtrr_chunk_size=nn[KMG] [X86]
627 used for mtrr cleanup. It is largest continous chunk
628 that could hold holes aka. UC entries.
629
630 mtrr_gran_size=nn[KMG] [X86]
Yinghai Lu12031a62008-05-02 02:40:22 -0700631 Used for mtrr cleanup. It is granularity of mtrr block.
632 Default is 1.
633 Large value could prevent small alignment from
634 using up MTRRs.
635
636 mtrr_spare_reg_nr=n [X86]
637 Format: <integer>
638 Range: 0,7 : spare reg number
639 Default : 1
640 Used for mtrr cleanup. It is spare mtrr entries number.
641 Set to 2 or more if your graphical card needs more.
Yinghai Lu95ffa242008-04-29 03:52:33 -0700642
Yinghai Lu093af8d2008-01-30 13:33:32 +0100643 disable_mtrr_trim [X86, Intel and AMD only]
Jesse Barnes99fc8d42008-01-30 13:33:18 +0100644 By default the kernel will trim any uncacheable
645 memory out of your available memory pool based on
646 MTRR settings. This parameter disables that behavior,
647 possibly causing your machine to run very slowly.
648
Linus Torvalds1da177e2005-04-16 15:20:36 -0700649 dmasound= [HW,OSS] Sound subsystem buffers
650
651 dscc4.setup= [NET]
652
653 dtc3181e= [HW,SCSI]
654
Robin Getz0ae53642007-10-09 17:24:49 +0800655 earlyprintk= [X86-32,X86-64,SH,BLACKFIN]
Linus Torvalds1da177e2005-04-16 15:20:36 -0700656 earlyprintk=vga
657 earlyprintk=serial[,ttySn[,baudrate]]
658
Randy Dunlapa9913042005-10-23 12:57:11 -0700659 Append ",keep" to not disable it when the real console
Linus Torvalds1da177e2005-04-16 15:20:36 -0700660 takes over.
661
662 Only vga or serial at a time, not both.
663
664 Currently only ttyS0 and ttyS1 are supported.
665
666 Interaction with the standard serial driver is not
667 very good.
668
669 The VGA output is eventually overwritten by the real
670 console.
671
672 eata= [HW,SCSI]
673
Linus Torvalds1da177e2005-04-16 15:20:36 -0700674 edd= [EDD]
Tim Gardner8c4dd602008-04-29 01:02:45 -0700675 Format: {"off" | "on" | "skip[mbr]"}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700676
Linus Torvalds1da177e2005-04-16 15:20:36 -0700677 eisa_irq_edge= [PARISC,HW]
678 See header of drivers/parisc/eisa.c.
679
Alan Coxcd4f0ef2007-07-31 00:37:59 -0700680 elanfreq= [X86-32]
Linus Torvalds1da177e2005-04-16 15:20:36 -0700681 See comment before function elanfreq_setup() in
Pavel Machek71f77052008-07-04 09:59:43 -0700682 arch/x86/kernel/cpu/cpufreq/elanfreq.c.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700683
684 elevator= [IOSCHED]
Randy Dunlap16ab3ad2006-01-14 13:21:20 -0800685 Format: {"anticipatory" | "cfq" | "deadline" | "noop"}
Randy Dunlapa9913042005-10-23 12:57:11 -0700686 See Documentation/block/as-iosched.txt and
687 Documentation/block/deadline-iosched.txt for details.
688
Alan Coxcd4f0ef2007-07-31 00:37:59 -0700689 elfcorehdr= [X86-32, X86_64]
Randy Dunlapa9913042005-10-23 12:57:11 -0700690 Specifies physical address of start of kernel core
Vivek Goyalaac04b32006-01-09 20:51:47 -0800691 image elf header. Generally kexec loader will
692 pass this option to capture kernel.
693 See Documentation/kdump/kdump.txt for details.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700694
695 enforcing [SELINUX] Set initial enforcing status.
696 Format: {"0" | "1"}
697 See security/selinux/Kconfig help text.
698 0 -- permissive (log only, no denials).
699 1 -- enforcing (deny and log).
700 Default value is 0.
701 Value can be changed at runtime via /selinux/enforce.
702
Linus Torvalds1da177e2005-04-16 15:20:36 -0700703 es1371= [HW,OSS]
704 Format: <spdif>,[<nomix>,[<amplifier>]]
705 See also header of sound/oss/es1371.c.
Randy Dunlapa9913042005-10-23 12:57:11 -0700706
Linus Torvalds1da177e2005-04-16 15:20:36 -0700707 ether= [HW,NET] Ethernet cards parameters
708 This option is obsoleted by the "netdev=" option, which
709 has equivalent usage. See its documentation for details.
710
711 eurwdt= [HW,WDT] Eurotech CPU-1220/1410 onboard watchdog.
712 Format: <io>[,<irq>]
713
Akinobu Mitade1ba092006-12-08 02:39:42 -0800714 failslab=
715 fail_page_alloc=
716 fail_make_request=[KNL]
717 General fault injection mechanism.
718 Format: <interval>,<probability>,<space>,<times>
719 See also /Documentation/fault-injection/.
720
Linus Torvalds1da177e2005-04-16 15:20:36 -0700721 fd_mcs= [HW,SCSI]
722 See header of drivers/scsi/fd_mcs.c.
723
724 fdomain= [HW,SCSI]
725 See header of drivers/scsi/fdomain.c.
726
727 floppy= [HW]
728 See Documentation/floppy.txt.
729
Alex Chiangf13ae302008-05-08 14:03:23 -0600730 force_pal_cache_flush
731 [IA-64] Avoid check_sal_cache_flush which may hang on
732 buggy SAL_CACHE_FLUSH implementations. Using this
733 parameter will force ia64_sal_cache_flush to call
734 ia64_pal_cache_flush instead of SAL_CACHE_FLUSH.
735
Linus Torvalds1da177e2005-04-16 15:20:36 -0700736 gamecon.map[2|3]=
737 [HW,JOY] Multisystem joystick and NES/SNES/PSX pad
738 support via parallel port (up to 5 devices per port)
739 Format: <port#>,<pad1>,<pad2>,<pad3>,<pad4>,<pad5>
740 See also Documentation/input/joystick-parport.txt
741
742 gamma= [HW,DRM]
743
Yinghai Luaaf23042008-01-30 13:33:09 +0100744 gart_fix_e820= [X86_64] disable the fix e820 for K8 GART
745 Format: off | on
746 default: on
747
Linus Torvalds1da177e2005-04-16 15:20:36 -0700748 gdth= [HW,SCSI]
749 See header of drivers/scsi/gdth.c.
750
751 gpt [EFI] Forces disk with valid GPT signature but
752 invalid Protective MBR to be treated as GPT.
753
Linus Torvalds1da177e2005-04-16 15:20:36 -0700754 gvp11= [HW,SCSI]
755
756 hashdist= [KNL,NUMA] Large hashes allocated during boot
757 are distributed across NUMA nodes. Defaults on
758 for IA-64, off otherwise.
Randy Dunlapa9913042005-10-23 12:57:11 -0700759 Format: 0 | 1 (for off | on)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700760
761 hcl= [IA-64] SGI's Hardware Graph compatibility layer
762
763 hd= [EIDE] (E)IDE hard drive subsystem geometry
764 Format: <cyl>,<head>,<sect>
765
Linus Torvalds1da177e2005-04-16 15:20:36 -0700766 highmem=nn[KMG] [KNL,BOOT] forces the highmem zone to have an exact
767 size of <nn>. This works even on boxes that have no
768 highmem otherwise. This also works to reduce highmem
769 size on bigger boxes.
770
Thomas Gleixner54cdfdb2007-02-16 01:28:11 -0800771 highres= [KNL] Enable/disable high resolution timer mode.
772 Valid parameters: "on", "off"
773 Default: "on"
774
Linus Torvalds1da177e2005-04-16 15:20:36 -0700775 hisax= [HW,ISDN]
776 See Documentation/isdn/README.HiSax.
777
Andi Kleenb4718e62008-07-23 21:27:51 -0700778 hugepages= [HW,X86-32,IA-64] HugeTLB pages to allocate at boot.
779 hugepagesz= [HW,IA-64,PPC,X86-64] The size of the HugeTLB pages.
Jon Tollefson0d9ea752008-07-23 21:27:56 -0700780 On x86-64 and powerpc, this option can be specified
781 multiple times interleaved with hugepages= to reserve
782 huge pages of different sizes. Valid pages sizes on
783 x86-64 are 2M (when the CPU supports "pse") and 1G
784 (when the CPU supports the "pdpe1gb" cpuinfo flag)
Andi Kleenb4718e62008-07-23 21:27:51 -0700785 Note that 1GB pages can only be allocated at boot time
786 using hugepages= and not freed afterwards.
Nick Piggine11bfbf2008-07-23 21:27:52 -0700787 default_hugepagesz=
788 [same as hugepagesz=] The size of the default
789 HugeTLB page size. This is the size represented by
790 the legacy /proc/ hugepages APIs, used for SHM, and
791 default size when mounting hugetlbfs filesystems.
792 Defaults to the default architecture's huge page size
793 if not specified.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700794
Linus Torvalds1da177e2005-04-16 15:20:36 -0700795 i8042.direct [HW] Put keyboard port into non-translated mode
Matt LaPlante84eb8d02006-10-03 22:53:09 +0200796 i8042.dumbkbd [HW] Pretend that controller can only read data from
797 keyboard and cannot control its state
Linus Torvalds1da177e2005-04-16 15:20:36 -0700798 (Don't attempt to blink the leds)
799 i8042.noaux [HW] Don't check for auxiliary (== mouse) port
Dmitry Torokhov945ef0d2005-09-04 01:42:00 -0500800 i8042.nokbd [HW] Don't check/create keyboard port
Jiri Kosina75d08c72008-03-13 16:13:59 -0400801 i8042.noloop [HW] Disable the AUX Loopback command while probing
802 for the AUX port
Linus Torvalds1da177e2005-04-16 15:20:36 -0700803 i8042.nomux [HW] Don't check presence of an active multiplexing
804 controller
805 i8042.nopnp [HW] Don't use ACPIPnP / PnPBIOS to discover KBD/AUX
806 controllers
807 i8042.panicblink=
808 [HW] Frequency with which keyboard LEDs should blink
809 when kernel panics (default is 0.5 sec)
810 i8042.reset [HW] Reset the controller during init and cleanup
811 i8042.unlock [HW] Unlock (ignore) the keylock
812
813 i810= [HW,DRM]
814
Dmitry Torokhove70c9d52005-06-25 14:54:25 -0700815 i8k.ignore_dmi [HW] Continue probing hardware even if DMI data
816 indicates that the driver is running on unsupported
817 hardware.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700818 i8k.force [HW] Activate i8k driver even if SMM BIOS signature
819 does not match list of supported models.
820 i8k.power_status
821 [HW] Report power status in /proc/i8k
822 (disabled by default)
823 i8k.restricted [HW] Allow controlling fans only if SYS_ADMIN
824 capability is set.
825
826 ibmmcascsi= [HW,MCA,SCSI] IBM MicroChannel SCSI adapter
827 See Documentation/mca.txt.
828
829 icn= [HW,ISDN]
830 Format: <io>[,<membase>[,<icn_id>[,<icn_id2>]]]
831
832 ide= [HW] (E)IDE subsystem
Greg Kroah-Hartmana594eeb2008-04-18 00:46:20 +0200833 Format: ide=nodma or ide=doubler
Randy Dunlap1c10e932008-03-07 21:53:50 +0100834 See Documentation/ide/ide.txt.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700835
Linus Torvalds1da177e2005-04-16 15:20:36 -0700836 idebus= [HW] (E)IDE subsystem - VLB/PCI bus speed
Randy Dunlap1c10e932008-03-07 21:53:50 +0100837 See Documentation/ide/ide.txt.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700838
Andi Kleenf039b752007-05-02 19:27:12 +0200839 idle= [X86]
Zhao Yakuida5e09a2008-06-24 18:01:09 +0800840 Format: idle=poll or idle=mwait, idle=halt, idle=nomwait
Andi Kleenf039b752007-05-02 19:27:12 +0200841 Poll forces a polling idle loop that can slightly improves the performance
842 of waking up a idle CPU, but will use a lot of power and make the system
843 run hot. Not recommended.
844 idle=mwait. On systems which support MONITOR/MWAIT but the kernel chose
845 to not use it because it doesn't save as much power as a normal idle
846 loop use the MONITOR/MWAIT idle loop anyways. Performance should be the same
847 as idle=poll.
Zhao Yakuic1e3b372008-06-24 17:58:53 +0800848 idle=halt. Halt is forced to be used for CPU idle.
849 In such case C2/C3 won't be used again.
Zhao Yakuida5e09a2008-06-24 18:01:09 +0800850 idle=nomwait. Disable mwait for CPU C-states
Randy Dunlapa9913042005-10-23 12:57:11 -0700851
Denis Cheng594765a2008-02-06 02:57:49 +0100852 ide-pci-generic.all-generic-ide [HW] (E)IDE subsystem
853 Claim all unknown PCI IDE storage controllers.
854
Ingo Molnar792908222006-12-06 20:40:51 -0800855 ignore_loglevel [KNL]
856 Ignore loglevel setting - this will print /all/
857 kernel messages to the console. Useful for debugging.
858
Linus Torvalds1da177e2005-04-16 15:20:36 -0700859 ihash_entries= [KNL]
860 Set number of hash buckets for inode cache.
861
862 in2000= [HW,SCSI]
863 See header of drivers/scsi/in2000.c.
864
865 init= [KNL]
866 Format: <full_path>
867 Run specified binary instead of /sbin/init as init
868 process.
869
870 initcall_debug [KNL] Trace initcalls as they are executed. Useful
871 for working out where the kernel is dying during
872 startup.
873
874 initrd= [BOOT] Specify the location of the initial ramdisk
875
876 inport.irq= [HW] Inport (ATI XL and Microsoft) busmouse driver
877 Format: <irq>
878
879 inttest= [IA64]
880
Pavel Machekb552da82008-03-19 15:58:11 +0100881 iommu= [x86]
882 off
883 force
884 noforce
885 biomerge
886 panic
887 nopanic
888 merge
889 nomerge
890 forcesac
891 soft
892
893
Keshavamurthy, Anil Sba395922007-10-21 16:41:49 -0700894 intel_iommu= [DMAR] Intel IOMMU driver (DMAR) option
895 off
896 Disable intel iommu driver.
897 igfx_off [Default Off]
898 By default, gfx is mapped as normal device. If a gfx
899 device has a dedicated DMAR unit, the DMAR unit is
900 bypassed by not enabling DMAR with this option. In
901 this case, gfx device will use physical address for
902 DMA.
Keshavamurthy, Anil S7d3b03c2007-10-21 16:41:53 -0700903 forcedac [x86_64]
904 With this option iommu will not optimize to look
905 for io virtual address below 32 bit forcing dual
906 address cycle on pci bus for cards supporting greater
907 than 32 bit addressing. The default is to look
908 for translation below 32 bit and if not available
909 then look in the higher range.
mark gross5e0d2a62008-03-04 15:22:08 -0800910 strict [Default Off]
911 With this option on every unmap_single operation will
912 result in a hardware IOTLB flush operation as opposed
913 to batching them for performance.
Keshavamurthy, Anil Sba395922007-10-21 16:41:49 -0700914
Rene Hermanb02aae92008-01-30 13:30:05 +0100915 io_delay= [X86-32,X86-64] I/O delay method
Ingo Molnar6e7c4022008-01-30 13:30:05 +0100916 0x80
917 Standard port 0x80 based delay
918 0xed
919 Alternate port 0xed based delay (needed on some systems)
Rene Hermanb02aae92008-01-30 13:30:05 +0100920 udelay
Ingo Molnar6e7c4022008-01-30 13:30:05 +0100921 Simple two microseconds delay
922 none
923 No delay
Rene Hermanb02aae92008-01-30 13:30:05 +0100924
Linus Torvalds1da177e2005-04-16 15:20:36 -0700925 io7= [HW] IO7 for Marvel based alpha systems
926 See comment before marvel_specify_io7 in
927 arch/alpha/kernel/core_marvel.c.
928
929 ip= [IP_PNP]
J. Bruce Fields6ded55d2008-04-07 15:59:03 -0400930 See Documentation/filesystems/nfsroot.txt.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700931
932 ip2= [HW] Set IO/IRQ pairs for up to 4 IntelliPort boards
Randy Dunlapc8facbb2007-07-31 00:37:40 -0700933 See comment before ip2_setup() in
934 drivers/char/ip2/ip2base.c.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700935
936 ips= [HW,SCSI] Adaptec / IBM ServeRAID controller
937 See header of drivers/scsi/ips.c.
938
Simon Horman72c4a132006-09-13 19:57:18 -0700939 ports= [IP_VS_FTP] IPVS ftp helper module
940 Default is 21.
941 Up to 8 (IP_VS_APP_MAX_PORTS) ports
942 may be specified.
943 Format: <port>,<port>....
944
Alan Cox200803d2005-06-28 20:45:18 -0700945 irqfixup [HW]
946 When an interrupt is not handled search all handlers
947 for it. Intended to get systems with badly broken
948 firmware running.
949
950 irqpoll [HW]
951 When an interrupt is not handled search all handlers
952 for it. Also check all handlers each timer
953 interrupt. Intended to get systems with badly broken
954 firmware running.
955
Linus Torvalds1da177e2005-04-16 15:20:36 -0700956 isapnp= [ISAPNP]
Randy Dunlapa9913042005-10-23 12:57:11 -0700957 Format: <RDP>,<reset>,<pci_scan>,<verbosity>
Linus Torvalds1da177e2005-04-16 15:20:36 -0700958
959 isolcpus= [KNL,SMP] Isolate CPUs from the general scheduler.
Derek Fults22f2e282006-12-06 20:37:11 -0800960 Format:
961 <cpu number>,...,<cpu number>
962 or
963 <cpu number>-<cpu number> (must be a positive range in ascending order)
964 or a mixture
965 <cpu number>,...,<cpu number>-<cpu number>
Linus Torvalds1da177e2005-04-16 15:20:36 -0700966 This option can be used to specify one or more CPUs
967 to isolate from the general SMP balancing and scheduling
968 algorithms. The only way to move a process onto or off
969 an "isolated" CPU is via the CPU affinity syscalls.
970 <cpu number> begins at 0 and the maximum value is
971 "number of CPUs in system - 1".
972
973 This option is the preferred way to isolate CPUs. The
Randy Dunlapa9913042005-10-23 12:57:11 -0700974 alternative -- manually setting the CPU mask of all
975 tasks in the system -- can cause problems and
976 suboptimal load balancer performance.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700977
Randy Dunlapa9913042005-10-23 12:57:11 -0700978 iucv= [HW,NET]
Linus Torvalds1da177e2005-04-16 15:20:36 -0700979
980 js= [HW,JOY] Analog joystick
981 See Documentation/input/joystick.txt.
982
Alan Coxcd4f0ef2007-07-31 00:37:59 -0700983 kernelcore=nn[KMG] [KNL,X86-32,IA-64,PPC,X86-64] This parameter
Mel Gormaned7ed362007-07-17 04:03:14 -0700984 specifies the amount of memory usable by the kernel
985 for non-movable allocations. The requested amount is
986 spread evenly throughout all nodes in the system. The
987 remaining memory in each node is used for Movable
988 pages. In the event, a node is too small to have both
989 kernelcore and Movable pages, kernelcore pages will
990 take priority and other nodes will have a larger number
991 of kernelcore pages. The Movable zone is used for the
992 allocation of pages that may be reclaimed or moved
993 by the page migration subsystem. This means that
994 HugeTLB pages may not be allocated from this zone.
995 Note that allocations like PTEs-from-HighMem still
996 use the HighMem zone if it exists, and the Normal
997 zone if it does not.
998
Alan Coxcd4f0ef2007-07-31 00:37:59 -0700999 movablecore=nn[KMG] [KNL,X86-32,IA-64,PPC,X86-64] This parameter
Mel Gorman7e63efe2007-07-17 04:03:15 -07001000 is similar to kernelcore except it specifies the
1001 amount of memory used for migratable allocations.
1002 If both kernelcore and movablecore is specified,
1003 then kernelcore will be at *least* the specified
1004 value but may be more. If movablecore on its own
1005 is specified, the administrator must be careful
1006 that the amount of memory usable for all allocations
1007 is not too small.
1008
Linus Torvalds1da177e2005-04-16 15:20:36 -07001009 keepinitrd [HW,ARM]
1010
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001011 kstack=N [X86-32,X86-64] Print N words from the kernel stack
Linus Torvalds1da177e2005-04-16 15:20:36 -07001012 in oops dumps.
1013
Jason Wessel6cdf6e02008-04-17 20:05:38 +02001014 kgdboc= [HW] kgdb over consoles.
1015 Requires a tty driver that supports console polling.
1016 (only serial suported for now)
1017 Format: <serial_device>[,baud]
1018
Linus Torvalds1da177e2005-04-16 15:20:36 -07001019 l2cr= [PPC]
1020
Robert Brosea78bfbf2008-03-29 07:20:23 +11001021 l3cr= [PPC]
1022
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001023 lapic [X86-32,APIC] Enable the local APIC even if BIOS
Randy Dunlapa9913042005-10-23 12:57:11 -07001024 disabled it.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001025
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001026 lapic_timer_c2_ok [X86-32,x86-64,APIC] trust the local apic timer in
Thomas Gleixnere585bef2007-03-23 16:08:01 +01001027 C2 power state.
1028
FD Camifcb71f62008-01-06 19:08:56 +01001029 libata.dma= [LIBATA] DMA control
1030 libata.dma=0 Disable all PATA and SATA DMA
1031 libata.dma=1 PATA and SATA Disk DMA only
1032 libata.dma=2 ATAPI (CDROM) DMA only
1033 libata.dma=4 Compact Flash DMA only
1034 Combinations also work, so libata.dma=3 enables DMA
1035 for disks and CDROMs, but not CFs.
1036
Dave Jones78e70c22007-09-27 11:50:13 -04001037 libata.noacpi [LIBATA] Disables use of ACPI in libata suspend/resume
1038 when set.
1039 Format: <int>
1040
Tejun Heo33267322008-02-13 09:15:09 +09001041 libata.force= [LIBATA] Force configurations. The format is comma
1042 separated list of "[ID:]VAL" where ID is
1043 PORT[:DEVICE]. PORT and DEVICE are decimal numbers
1044 matching port, link or device. Basically, it matches
1045 the ATA ID string printed on console by libata. If
1046 the whole ID part is omitted, the last PORT and DEVICE
1047 values are used. If ID hasn't been specified yet, the
1048 configuration applies to all ports, links and devices.
1049
1050 If only DEVICE is omitted, the parameter applies to
1051 the port and all links and devices behind it. DEVICE
1052 number of 0 either selects the first device or the
1053 first fan-out link behind PMP device. It does not
1054 select the host link. DEVICE number of 15 selects the
1055 host link and device attached to it.
1056
1057 The VAL specifies the configuration to force. As long
1058 as there's no ambiguity shortcut notation is allowed.
1059 For example, both 1.5 and 1.5G would work for 1.5Gbps.
1060 The following configurations can be forced.
1061
1062 * Cable type: 40c, 80c, short40c, unk, ign or sata.
1063 Any ID with matching PORT is used.
1064
1065 * SATA link speed limit: 1.5Gbps or 3.0Gbps.
1066
1067 * Transfer mode: pio[0-7], mwdma[0-4] and udma[0-7].
1068 udma[/][16,25,33,44,66,100,133] notation is also
1069 allowed.
1070
1071 * [no]ncq: Turn on or off NCQ.
1072
1073 If there are multiple matching configurations changing
1074 the same attribute, the last one is used.
1075
Linus Torvalds1da177e2005-04-16 15:20:36 -07001076 load_ramdisk= [RAM] List of ramdisks to load from floppy
1077 See Documentation/ramdisk.txt.
1078
Randy Dunlapa6b25b62006-01-14 13:21:19 -08001079 lockd.nlm_grace_period=P [NFS] Assign grace period.
1080 Format: <integer>
Linus Torvalds1da177e2005-04-16 15:20:36 -07001081
Randy Dunlapa6b25b62006-01-14 13:21:19 -08001082 lockd.nlm_tcpport=N [NFS] Assign TCP port.
1083 Format: <integer>
1084
1085 lockd.nlm_timeout=T [NFS] Assign timeout value.
1086 Format: <integer>
1087
1088 lockd.nlm_udpport=M [NFS] Assign UDP port.
1089 Format: <integer>
Linus Torvalds1da177e2005-04-16 15:20:36 -07001090
1091 logibm.irq= [HW,MOUSE] Logitech Bus Mouse Driver
1092 Format: <irq>
1093
1094 loglevel= All Kernel Messages with a loglevel smaller than the
1095 console loglevel will be printed to the console. It can
1096 also be changed with klogd or other programs. The
1097 loglevels are defined as follows:
1098
1099 0 (KERN_EMERG) system is unusable
1100 1 (KERN_ALERT) action must be taken immediately
1101 2 (KERN_CRIT) critical conditions
1102 3 (KERN_ERR) error conditions
1103 4 (KERN_WARNING) warning conditions
1104 5 (KERN_NOTICE) normal but significant condition
1105 6 (KERN_INFO) informational
1106 7 (KERN_DEBUG) debug-level messages
1107
1108 log_buf_len=n Sets the size of the printk ring buffer, in bytes.
Randy Dunlapa9913042005-10-23 12:57:11 -07001109 Format: { n | nk | nM }
1110 n must be a power of two. The default size
1111 is set in the kernel config file.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001112
Randy Dunlapaccaa242007-10-16 01:29:37 -07001113 logo.nologo [FB] Disables display of the built-in Linux logo.
1114 This may be used to provide more screen space for
1115 kernel log messages and is useful when debugging
1116 kernel boot problems.
1117
Linus Torvalds1da177e2005-04-16 15:20:36 -07001118 lp=0 [LP] Specify parallel ports to use, e.g,
1119 lp=port[,port...] lp=none,parport0 (lp0 not configured, lp1 uses
1120 lp=reset first parallel port). 'lp=0' disables the
1121 lp=auto printer driver. 'lp=reset' (which can be
1122 specified in addition to the ports) causes
1123 attached printers to be reset. Using
1124 lp=port1,port2,... specifies the parallel ports
1125 to associate lp devices with, starting with
1126 lp0. A port specification may be 'none' to skip
1127 that lp device, or a parport name such as
1128 'parport0'. Specifying 'lp=auto' instead of a
1129 port specification list means that device IDs
1130 from each port should be examined, to see if
1131 an IEEE 1284-compliant printer is attached; if
1132 so, the driver will manage that printer.
1133 See also header of drivers/char/lp.c.
1134
1135 lpj=n [KNL]
1136 Sets loops_per_jiffy to given constant, thus avoiding
1137 time-consuming boot-time autodetection (up to 250 ms per
1138 CPU). 0 enables autodetection (default). To determine
1139 the correct value for your kernel, boot with normal
1140 autodetection and see what value is printed. Note that
1141 on SMP systems the preset will be applied to all CPUs,
1142 which is likely to cause problems if your CPUs need
1143 significantly divergent settings. An incorrect value
1144 will cause delays in the kernel to be wrong, leading to
1145 unpredictable I/O errors and other breakage. Although
1146 unlikely, in the extreme case this might damage your
1147 hardware.
1148
1149 ltpc= [NET]
1150 Format: <io>,<irq>,<dma>
1151
Randy Dunlapa9913042005-10-23 12:57:11 -07001152 mac5380= [HW,SCSI] Format:
1153 <can_queue>,<cmd_per_lun>,<sg_tablesize>,<hostid>,<use_tags>
Linus Torvalds1da177e2005-04-16 15:20:36 -07001154
Randy Dunlapa9913042005-10-23 12:57:11 -07001155 machvec= [IA64] Force the use of a particular machine-vector
1156 (machvec) in a generic kernel.
1157 Example: machvec=hpzx1_swiotlb
Linus Torvalds1da177e2005-04-16 15:20:36 -07001158
Randy Dunlapa9913042005-10-23 12:57:11 -07001159 max_loop= [LOOP] Maximum number of loopback devices that can
Linus Torvalds1da177e2005-04-16 15:20:36 -07001160 be mounted
1161 Format: <1-256>
1162
1163 maxcpus= [SMP] Maximum number of processors that an SMP kernel
Len Brown61ec7562007-08-16 03:34:22 -04001164 should make use of. maxcpus=n : n >= 0 limits the
1165 kernel to using 'n' processors. n=0 is a special case,
1166 it is equivalent to "nosmp", which also disables
1167 the IO APIC.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001168
Bob Picco2b2c3752005-06-29 18:00:00 -07001169 max_addr=[KMG] [KNL,BOOT,ia64] All physical memory greater than or
1170 equal to this physical address is ignored.
1171
Randy Dunlapa9913042005-10-23 12:57:11 -07001172 max_luns= [SCSI] Maximum number of LUNs to probe.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001173 Should be between 1 and 2^32-1.
1174
1175 max_report_luns=
Randy Dunlapa9913042005-10-23 12:57:11 -07001176 [SCSI] Maximum number of LUNs received.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001177 Should be between 1 and 16384.
1178
Linus Torvalds1da177e2005-04-16 15:20:36 -07001179 mcatest= [IA-64]
1180
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001181 mce [X86-32] Machine Check Exception
Linus Torvalds1da177e2005-04-16 15:20:36 -07001182
Andi Kleen909dd322007-10-17 18:04:38 +02001183 mce=option [X86-64] See Documentation/x86_64/boot-options.txt
1184
Linus Torvalds1da177e2005-04-16 15:20:36 -07001185 md= [HW] RAID subsystems devices and level
1186 See Documentation/md.txt.
Randy Dunlapa9913042005-10-23 12:57:11 -07001187
Linus Torvalds1da177e2005-04-16 15:20:36 -07001188 mdacon= [MDA]
1189 Format: <first>,<last>
1190 Specifies range of consoles to be captured by the MDA.
Randy Dunlapa9913042005-10-23 12:57:11 -07001191
Linus Torvalds1da177e2005-04-16 15:20:36 -07001192 mem=nn[KMG] [KNL,BOOT] Force usage of a specific amount of memory
1193 Amount of memory to be used when the kernel is not able
1194 to see the whole system memory or for test.
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001195 [X86-32] Use together with memmap= to avoid physical
Linus Torvalds1da177e2005-04-16 15:20:36 -07001196 address space collisions. Without memmap= PCI devices
1197 could be placed at addresses belonging to unused RAM.
1198
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001199 mem=nopentium [BUGS=X86-32] Disable usage of 4MB pages for kernel
Linus Torvalds1da177e2005-04-16 15:20:36 -07001200 memory.
1201
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001202 memmap=exactmap [KNL,X86-32,X86_64] Enable setting of an exact
Linus Torvalds1da177e2005-04-16 15:20:36 -07001203 E820 memory map, as specified by the user.
1204 Such memmap=exactmap lines can be constructed based on
1205 BIOS output or other requirements. See the memmap=nn@ss
1206 option description.
1207
1208 memmap=nn[KMG]@ss[KMG]
1209 [KNL] Force usage of a specific region of memory
1210 Region of memory to be used, from ss to ss+nn.
1211
1212 memmap=nn[KMG]#ss[KMG]
1213 [KNL,ACPI] Mark specific memory as ACPI data.
1214 Region of memory to be used, from ss to ss+nn.
1215
1216 memmap=nn[KMG]$ss[KMG]
1217 [KNL,ACPI] Mark specific memory as reserved.
1218 Region of memory to be used, from ss to ss+nn.
Pavel Machek13128482008-03-24 12:29:43 -07001219 Example: Exclude memory from 0x18690000-0x1869ffff
1220 memmap=64K$0x18690000
1221 or
1222 memmap=0x10000$0x18690000
Linus Torvalds1da177e2005-04-16 15:20:36 -07001223
Yinghai Lucaadbdc2008-07-15 00:03:44 -07001224 memtest= [KNL,X86] Enable memtest
Yinghai Luc64df702008-03-21 18:56:19 -07001225 Format: <integer>
1226 range: 0,4 : pattern number
1227 default : 0 <disable>
1228
Linus Torvalds1da177e2005-04-16 15:20:36 -07001229 meye.*= [HW] Set MotionEye Camera parameters
1230 See Documentation/video4linux/meye.txt.
1231
Andres Salomon8f368812007-10-12 23:04:06 +02001232 mfgpt_irq= [IA-32] Specify the IRQ to use for the
1233 Multi-Function General Purpose Timers on AMD Geode
1234 platforms.
1235
Willy Tarreaue6c4dc62008-01-30 13:33:33 +01001236 mfgptfix [X86-32] Fix MFGPT timers on AMD Geode platforms when
1237 the BIOS has incorrectly applied a workaround. TinyBIOS
1238 version 0.98 is known to be affected, 0.99 fixes the
1239 problem by letting the user disable the workaround.
1240
Linus Torvalds1da177e2005-04-16 15:20:36 -07001241 mga= [HW,DRM]
1242
Mel Gorman6b74ab92008-07-23 21:26:49 -07001243 mminit_loglevel=
1244 [KNL] When CONFIG_DEBUG_MEMORY_INIT is set, this
1245 parameter allows control of the logging verbosity for
1246 the additional memory initialisation checks. A value
1247 of 0 disables mminit logging and a level of 4 will
1248 log everything. Information is printed at KERN_DEBUG
1249 so loglevel=8 may also need to be specified.
1250
Linus Torvalds1da177e2005-04-16 15:20:36 -07001251 mousedev.tap_time=
1252 [MOUSE] Maximum time between finger touching and
1253 leaving touchpad surface for touch to be considered
1254 a tap and be reported as a left button click (for
1255 touchpads working in absolute mode only).
1256 Format: <msecs>
1257 mousedev.xres= [MOUSE] Horizontal screen resolution, used for devices
1258 reporting absolute coordinates, such as tablets
1259 mousedev.yres= [MOUSE] Vertical screen resolution, used for devices
1260 reporting absolute coordinates, such as tablets
1261
1262 mpu401= [HW,OSS]
1263 Format: <io>,<irq>
1264
1265 MTD_Partition= [MTD]
1266 Format: <name>,<region-number>,<size>,<offset>
1267
Randy Dunlapa9913042005-10-23 12:57:11 -07001268 MTD_Region= [MTD] Format:
1269 <name>,<region-number>[,<base>,<size>,<buswidth>,<altbuswidth>]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001270
1271 mtdparts= [MTD]
Randy Dunlapc8facbb2007-07-31 00:37:40 -07001272 See drivers/mtd/cmdlinepart.c.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001273
Ben Dooks9db829f2008-07-03 11:24:29 +01001274 mtdset= [ARM]
1275 ARM/S3C2412 JIVE boot control
1276
1277 See arch/arm/mach-s3c2412/mach-jive.c
1278
Linus Torvalds1da177e2005-04-16 15:20:36 -07001279 mtouchusb.raw_coordinates=
Randy Dunlapa9913042005-10-23 12:57:11 -07001280 [HW] Make the MicroTouch USB driver use raw coordinates
1281 ('y', default) or cooked coordinates ('n')
Linus Torvalds1da177e2005-04-16 15:20:36 -07001282
1283 n2= [NET] SDL Inc. RISCom/N2 synchronous serial card
1284
1285 NCR_D700= [HW,SCSI]
1286 See header of drivers/scsi/NCR_D700.c.
1287
1288 ncr5380= [HW,SCSI]
1289
1290 ncr53c400= [HW,SCSI]
1291
1292 ncr53c400a= [HW,SCSI]
1293
1294 ncr53c406a= [HW,SCSI]
1295
1296 ncr53c8xx= [HW,SCSI]
1297
1298 netdev= [NET] Network devices parameters
1299 Format: <irq>,<io>,<mem_start>,<mem_end>,<name>
1300 Note that mem_start is often overloaded to mean
1301 something different and driver-specific.
Randy Dunlapa9913042005-10-23 12:57:11 -07001302 This usage is only documented in each driver source
1303 file if at all.
1304
Krzysztof Piotr Oledzki58401572008-07-21 10:01:34 -07001305 nf_conntrack.acct=
1306 [NETFILTER] Enable connection tracking flow accounting
1307 0 to disable accounting
1308 1 to enable accounting
1309 Default value depends on CONFIG_NF_CT_ACCT that is
1310 going to be removed in 2.6.29.
1311
Linus Torvalds1da177e2005-04-16 15:20:36 -07001312 nfsaddrs= [NFS]
J. Bruce Fields6ded55d2008-04-07 15:59:03 -04001313 See Documentation/filesystems/nfsroot.txt.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001314
1315 nfsroot= [NFS] nfs root filesystem for disk-less boxes.
J. Bruce Fields6ded55d2008-04-07 15:59:03 -04001316 See Documentation/filesystems/nfsroot.txt.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001317
Trond Myklebusta72b4422006-01-03 09:55:41 +01001318 nfs.callback_tcpport=
1319 [NFS] set the TCP port on which the NFSv4 callback
1320 channel should listen.
1321
Trond Myklebust58df0952006-01-03 09:55:57 +01001322 nfs.idmap_cache_timeout=
1323 [NFS] set the maximum lifetime for idmapper cache
1324 entries.
1325
Trond Myklebustf43bf0b2007-10-09 12:01:04 -04001326 nfs.enable_ino64=
1327 [NFS] enable 64-bit inode numbers.
1328 If zero, the NFS client will fake up a 32-bit inode
1329 number for the readdir() and stat() syscalls instead
1330 of returning the full 64-bit number.
1331 The default is to return 64-bit inode numbers.
1332
Haavard Skinnemoene7ba1762007-10-10 14:58:29 +02001333 nmi_debug= [KNL,AVR32] Specify one or more actions to take
1334 when a NMI is triggered.
1335 Format: [state][,regs][,debounce][,die]
1336
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001337 nmi_watchdog= [KNL,BUGS=X86-32] Debugging features for SMP kernels
Linus Torvalds1da177e2005-04-16 15:20:36 -07001338
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001339 no387 [BUGS=X86-32] Tells the kernel to use the 387 maths
Linus Torvalds1da177e2005-04-16 15:20:36 -07001340 emulation library even if a 387 maths coprocessor
1341 is present.
1342
Christoph Lameterc1aee212007-05-31 00:40:47 -07001343 noaliencache [MM, NUMA, SLAB] Disables the allocation of alien
1344 caches in the slab allocator. Saves per-node memory,
1345 but will impact performance.
Paul Menage3395ee02006-12-06 20:32:16 -08001346
Randy Dunlapa9913042005-10-23 12:57:11 -07001347 noalign [KNL,ARM]
1348
Linus Torvalds1da177e2005-04-16 15:20:36 -07001349 noapic [SMP,APIC] Tells the kernel to not make use of any
1350 IOAPICs that may be present in the system.
1351
Linus Torvalds1da177e2005-04-16 15:20:36 -07001352 nobats [PPC] Do not use BATs for mapping kernel lowmem
1353 on "Classic" PPC cores.
1354
1355 nocache [ARM]
Randy Dunlapa9913042005-10-23 12:57:11 -07001356
Shailabh Nagar163ecdf2006-07-30 03:03:11 -07001357 nodelayacct [KNL] Disable per-task delay accounting
1358
Linus Torvalds1da177e2005-04-16 15:20:36 -07001359 nodisconnect [HW,SCSI,M68K] Disables SCSI disconnects.
1360
Huang, Ying8b2cb7a2008-01-30 13:32:11 +01001361 noefi [X86-32,X86-64] Disable EFI runtime services support.
1362
Linus Torvalds1da177e2005-04-16 15:20:36 -07001363 noexec [IA-64]
1364
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001365 noexec [X86-32,X86-64]
Jiri Slabyf5a1b192008-04-12 10:28:25 +02001366 On X86-32 available only on PAE configured kernels.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001367 noexec=on: enable non-executable mappings (default)
Jiri Slabyf5a1b192008-04-12 10:28:25 +02001368 noexec=off: disable non-executable mappings
1369
1370 noexec32 [X86-64]
1371 This affects only 32-bit executables.
1372 noexec32=on: enable non-executable mappings (default)
1373 read doesn't imply executable mappings
1374 noexec32=off: disable non-executable mappings
1375 read implies executable mappings
Linus Torvalds1da177e2005-04-16 15:20:36 -07001376
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001377 nofxsr [BUGS=X86-32] Disables x86 floating point extended
Chuck Ebbert4f886512006-03-23 02:59:34 -08001378 register save and restore. The kernel will only save
1379 legacy floating-point registers on task switch.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001380
Andi Kleen191679f2008-01-30 13:33:21 +01001381 noclflush [BUGS=X86] Don't use the CLFLUSH instruction
1382
Linus Torvalds1da177e2005-04-16 15:20:36 -07001383 nohlt [BUGS=ARM]
Randy Dunlapa9913042005-10-23 12:57:11 -07001384
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001385 no-hlt [BUGS=X86-32] Tells the kernel that the hlt
Linus Torvalds1da177e2005-04-16 15:20:36 -07001386 instruction doesn't work correctly and not to
1387 use it.
1388
1389 nohalt [IA-64] Tells the kernel not to use the power saving
1390 function PAL_HALT_LIGHT when idle. This increases
1391 power-consumption. On the positive side, it reduces
1392 interrupt wake-up latency, which may improve performance
1393 in certain environments such as networked servers or
1394 real-time systems.
1395
Thomas Gleixner79bf2bb2007-02-16 01:28:03 -08001396 nohz= [KNL] Boottime enable/disable dynamic ticks
1397 Valid arguments: on, off
1398 Default: on
1399
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001400 noirqbalance [X86-32,SMP,KNL] Disable kernel irq balancing
Zachary Amsden8542b202006-12-07 02:14:09 +01001401
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001402 noirqdebug [X86-32] Disables the code which attempts to detect and
Linus Torvalds1da177e2005-04-16 15:20:36 -07001403 disable unhandled interrupt sources.
1404
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001405 no_timer_check [X86-32,X86_64,APIC] Disables the code which tests for
Zachary Amsden8542b202006-12-07 02:14:09 +01001406 broken timer IRQ sources.
1407
Linus Torvalds1da177e2005-04-16 15:20:36 -07001408 noisapnp [ISAPNP] Disables ISA PnP code.
1409
1410 noinitrd [RAM] Tells the kernel not to load any configured
1411 initial RAM disk.
1412
1413 nointroute [IA-64]
1414
Tony Luck0aa366f2007-07-20 11:22:30 -07001415 nojitter [IA64] Disables jitter checking for ITC timers.
1416
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001417 nolapic [X86-32,APIC] Do not enable or use the local APIC.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001418
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001419 nolapic_timer [X86-32,APIC] Do not use the local APIC timer.
Thomas Gleixnerad62ca22007-03-22 00:11:21 -08001420
Linus Torvalds1da177e2005-04-16 15:20:36 -07001421 noltlbs [PPC] Do not use large page/tlb entries for kernel
1422 lowmem mapping on PPC40x.
1423
Horms312f1f02006-02-22 09:57:55 +09001424 nomca [IA-64] Disable machine check abort handling
1425
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001426 nomce [X86-32] Machine Check Exception
Hormsabe37e52006-04-01 01:36:09 +02001427
Andres Salomon83d73842007-10-12 23:04:06 +02001428 nomfgpt [X86-32] Disable Multi-Function General Purpose
1429 Timer usage (for AMD Geode machines).
1430
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001431 noreplace-paravirt [X86-32,PV_OPS] Don't patch paravirt_ops
Jeremy Fitzhardinge959b4fd2007-05-02 19:27:16 +02001432
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001433 noreplace-smp [X86-32,SMP] Don't replace SMP instructions
Jeremy Fitzhardingeb7fb4af2007-05-02 19:27:13 +02001434 with UP alternatives
1435
Linus Torvalds1da177e2005-04-16 15:20:36 -07001436 noresidual [PPC] Don't use residual data on PReP machines.
1437
Randy Dunlapa9913042005-10-23 12:57:11 -07001438 noresume [SWSUSP] Disables resume and restores original swap
1439 space.
1440
Linus Torvalds1da177e2005-04-16 15:20:36 -07001441 no-scroll [VGA] Disables scrollback.
1442 This is required for the Braillex ib80-piezo Braille
1443 reader made by F.H. Papenmeier (Germany).
1444
1445 nosbagart [IA-64]
1446
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001447 nosep [BUGS=X86-32] Disables x86 SYSENTER/SYSEXIT support.
Chuck Ebbert4f886512006-03-23 02:59:34 -08001448
Len Brown61ec7562007-08-16 03:34:22 -04001449 nosmp [SMP] Tells an SMP kernel to act as a UP kernel,
1450 and disable the IO APIC. legacy for "maxcpus=0".
Linus Torvalds1da177e2005-04-16 15:20:36 -07001451
Dave Jones97842212007-07-15 23:41:05 -07001452 nosoftlockup [KNL] Disable the soft-lockup detector.
1453
Linus Torvalds1da177e2005-04-16 15:20:36 -07001454 nosync [HW,M68K] Disables sync negotiation for all devices.
1455
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001456 notsc [BUGS=X86-32] Disable Time Stamp Counter
Linus Torvalds1da177e2005-04-16 15:20:36 -07001457
1458 nousb [USB] Disable the USB subsystem
1459
1460 nowb [ARM]
Randy Dunlapa9913042005-10-23 12:57:11 -07001461
Fenghua Yua6c75b862008-03-14 13:57:08 -07001462 nptcg= [IA64] Override max number of concurrent global TLB
1463 purges which is reported from either PAL_VM_SUMMARY or
1464 SAL PALO.
1465
KAMEZAWA Hiroyukif0c0b2b2007-07-15 23:38:01 -07001466 numa_zonelist_order= [KNL, BOOT] Select zonelist order for NUMA.
1467 one of ['zone', 'node', 'default'] can be specified
1468 This can be set from sysctl after boot.
1469 See Documentation/sysctl/vm.txt for details.
1470
Dave Jonesa61c2d72006-01-07 23:18:19 +00001471 nr_uarts= [SERIAL] maximum number of UARTs to be registered.
1472
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07001473 olpc_ec_timeout= [OLPC] ms delay when issuing EC commands
1474 Rather than timing out after 20 ms if an EC
1475 command is not properly ACKed, override the length
1476 of the timeout. We have interrupts disabled while
1477 waiting for the ACK, so if this is set too high
1478 interrupts *may* be lost!
1479
Linus Torvalds1da177e2005-04-16 15:20:36 -07001480 opl3= [HW,OSS]
1481 Format: <io>
1482
Linus Torvalds1da177e2005-04-16 15:20:36 -07001483 oprofile.timer= [HW]
1484 Use timer interrupt instead of performance counters
1485
Linus Torvalds1da177e2005-04-16 15:20:36 -07001486 osst= [HW,SCSI] SCSI Tape Driver
1487 Format: <buffer_size>,<write_threshold>
1488 See also Documentation/scsi/st.txt.
1489
1490 panic= [KNL] Kernel behaviour on panic
1491 Format: <timeout>
1492
1493 parkbd.port= [HW] Parallel port number the keyboard adapter is
1494 connected to, default is 0.
1495 Format: <parport#>
1496 parkbd.mode= [HW] Parallel port keyboard adapter mode of operation,
1497 0 for XT, 1 for AT (default is AT).
Randy Dunlapa9913042005-10-23 12:57:11 -07001498 Format: <mode>
Linus Torvalds1da177e2005-04-16 15:20:36 -07001499
Randy Dunlapa9913042005-10-23 12:57:11 -07001500 parport= [HW,PPT] Specify parallel ports. 0 disables.
1501 Format: { 0 | auto | 0xBBB[,IRQ[,DMA]] }
1502 Use 'auto' to force the driver to use any
1503 IRQ/DMA settings detected (the default is to
1504 ignore detected IRQ/DMA settings because of
1505 possible conflicts). You can specify the base
1506 address, IRQ, and DMA settings; IRQ and DMA
1507 should be numbers, or 'auto' (for using detected
1508 settings on that particular port), or 'nofifo'
1509 (to avoid using a FIFO even if it is detected).
1510 Parallel ports are assigned in the order they
1511 are specified on the command line, starting
1512 with parport0.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001513
Randy Dunlapa9913042005-10-23 12:57:11 -07001514 parport_init_mode= [HW,PPT]
1515 Configure VIA parallel port to operate in
1516 a specific mode. This is necessary on Pegasos
1517 computer where firmware has no options for setting
1518 up parallel port mode and sets it to spp.
1519 Currently this function knows 686a and 8231 chips.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001520 Format: [spp|ps2|epp|ecp|ecpepp]
1521
Randy Dunlapa9913042005-10-23 12:57:11 -07001522 pas2= [HW,OSS] Format:
1523 <io>,<irq>,<dma>,<dma16>,<sb_io>,<sb_irq>,<sb_dma>,<sb_dma16>
1524
Linus Torvalds1da177e2005-04-16 15:20:36 -07001525 pas16= [HW,SCSI]
1526 See header of drivers/scsi/pas16.c.
1527
Andrew Mortondd287792006-03-23 03:00:57 -08001528 pause_on_oops=
1529 Halt all CPUs after the first oops has been printed for
1530 the specified number of seconds. This is to be used if
1531 your oopses keep scrolling off the screen.
1532
Linus Torvalds1da177e2005-04-16 15:20:36 -07001533 pcbit= [HW,ISDN]
1534
1535 pcd. [PARIDE]
1536 See header of drivers/block/paride/pcd.c.
1537 See also Documentation/paride.txt.
1538
Randy Dunlapa9913042005-10-23 12:57:11 -07001539 pci=option[,option...] [PCI] various PCI subsystem options:
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001540 off [X86-32] don't probe for the PCI bus
1541 bios [X86-32] force use of PCI BIOS, don't access
Randy Dunlapa9913042005-10-23 12:57:11 -07001542 the hardware directly. Use this if your machine
1543 has a non-standard PCI host bridge.
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001544 nobios [X86-32] disallow use of PCI BIOS, only direct
Randy Dunlapa9913042005-10-23 12:57:11 -07001545 hardware access methods are allowed. Use this
1546 if you experience crashes upon bootup and you
1547 suspect they are caused by the BIOS.
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001548 conf1 [X86-32] Force use of PCI Configuration
Randy Dunlapa9913042005-10-23 12:57:11 -07001549 Mechanism 1.
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001550 conf2 [X86-32] Force use of PCI Configuration
Randy Dunlapa9913042005-10-23 12:57:11 -07001551 Mechanism 2.
Randy Dunlap7f785762007-10-05 13:17:58 -07001552 noaer [PCIE] If the PCIEAER kernel config parameter is
1553 enabled, this kernel boot option can be used to
1554 disable the use of PCIE advanced error reporting.
Jeff Garzik32a2eea2007-10-11 16:57:27 -04001555 nodomains [PCI] Disable support for multiple PCI
1556 root domains (aka PCI segments, in ACPI-speak).
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001557 nommconf [X86-32,X86_64] Disable use of MMCONFIG for PCI
Bjorn Helgaas61be6d62006-02-15 15:17:43 -08001558 Configuration
Matthew Wilcox309e57d2006-03-05 22:33:34 -07001559 nomsi [MSI] If the PCI_MSI kernel config parameter is
1560 enabled, this kernel boot option can be used to
1561 disable the use of MSI interrupts system-wide.
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001562 biosirq [X86-32] Use PCI BIOS calls to get the interrupt
Randy Dunlapa9913042005-10-23 12:57:11 -07001563 routing table. These calls are known to be buggy
1564 on several machines and they hang the machine
1565 when used, but on other computers it's the only
1566 way to get the interrupt routing table. Try
1567 this option if the kernel is unable to allocate
1568 IRQs or discover secondary PCI buses on your
1569 motherboard.
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001570 rom [X86-32] Assign address space to expansion ROMs.
Randy Dunlapa9913042005-10-23 12:57:11 -07001571 Use with caution as certain devices share
1572 address decoders between ROMs and other
1573 resources.
Gary Hadebb71ad82008-05-12 13:57:46 -07001574 norom [X86-32,X86_64] Do not assign address space to
1575 expansion ROMs that do not already have
1576 BIOS assigned address ranges.
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001577 irqmask=0xMMMM [X86-32] Set a bit mask of IRQs allowed to be
Randy Dunlapa9913042005-10-23 12:57:11 -07001578 assigned automatically to PCI devices. You can
1579 make the kernel exclude IRQs of your ISA cards
1580 this way.
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001581 pirqaddr=0xAAAAA [X86-32] Specify the physical address
Randy Dunlapa9913042005-10-23 12:57:11 -07001582 of the PIRQ table (normally generated
1583 by the BIOS) if it is outside the
1584 F0000h-100000h range.
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001585 lastbus=N [X86-32] Scan all buses thru bus #N. Can be
Randy Dunlapa9913042005-10-23 12:57:11 -07001586 useful if the kernel is unable to find your
1587 secondary buses and you want to tell it
1588 explicitly which ones they are.
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001589 assign-busses [X86-32] Always assign all PCI bus
Randy Dunlapa9913042005-10-23 12:57:11 -07001590 numbers ourselves, overriding
1591 whatever the firmware may have done.
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001592 usepirqmask [X86-32] Honor the possible IRQ mask stored
Randy Dunlapa9913042005-10-23 12:57:11 -07001593 in the BIOS $PIR table. This is needed on
1594 some systems with broken BIOSes, notably
1595 some HP Pavilion N5400 and Omnibook XE3
1596 notebooks. This will have no effect if ACPI
1597 IRQ routing is enabled.
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001598 noacpi [X86-32] Do not use ACPI for IRQ routing
Randy Dunlapa9913042005-10-23 12:57:11 -07001599 or for PCI scanning.
Gary Hade62f420f2007-10-03 15:56:51 -07001600 use_crs [X86-32] Use _CRS for PCI resource
1601 allocation.
Randy Dunlapa9913042005-10-23 12:57:11 -07001602 routeirq Do IRQ routing for all PCI devices.
1603 This is normally done in pci_enable_device(),
1604 so this option is a temporary workaround
1605 for broken drivers that don't call it.
Yinghai Lu13a6ddb2008-03-27 01:31:18 -07001606 skip_isa_align [X86] do not align io start addr, so can
1607 handle more pci cards
Randy Dunlapa9913042005-10-23 12:57:11 -07001608 firmware [ARM] Do not re-enumerate the bus but instead
1609 just use the configuration from the
1610 bootloader. This is currently used on
1611 IXP2000 systems where the bus has to be
1612 configured a certain way for adjunct CPUs.
Andi Kleen0637a702006-09-26 10:52:41 +02001613 noearly [X86] Don't do any early type 1 scanning.
1614 This might help on some broken boards which
1615 machine check when some devices' config space
1616 is read. But various workarounds are disabled
1617 and some IOMMU drivers will not work.
Matt Domsch6b4b78f2006-09-29 15:23:23 -05001618 bfsort Sort PCI devices into breadth-first order.
1619 This sorting is done to get a device
1620 order compatible with older (<= 2.4) kernels.
1621 nobfsort Don't sort PCI devices into breadth-first order.
Atsushi Nemoto4516a612007-02-05 16:36:06 -08001622 cbiosize=nn[KMG] The fixed amount of bus space which is
1623 reserved for the CardBus bridge's IO window.
1624 The default value is 256 bytes.
1625 cbmemsize=nn[KMG] The fixed amount of bus space which is
1626 reserved for the CardBus bridge's memory
1627 window. The default value is 64 megabytes.
Matt Domsch6b4b78f2006-09-29 15:23:23 -05001628
Linus Torvalds1da177e2005-04-16 15:20:36 -07001629 pcmv= [HW,PCMCIA] BadgePAD 4
1630
1631 pd. [PARIDE]
1632 See Documentation/paride.txt.
1633
1634 pdcchassis= [PARISC,HW] Disable/Enable PDC Chassis Status codes at
1635 boot time.
1636 Format: { 0 | 1 }
1637 See arch/parisc/kernel/pdc_chassis.c
1638
1639 pf. [PARIDE]
1640 See Documentation/paride.txt.
1641
1642 pg. [PARIDE]
1643 See Documentation/paride.txt.
1644
1645 pirq= [SMP,APIC] Manual mp-table setup
1646 See Documentation/i386/IO-APIC.txt.
1647
1648 plip= [PPT,NET] Parallel port network link
1649 Format: { parport<nr> | timid | 0 }
1650 See also Documentation/parport.txt.
1651
Thomas Gleixnerde32a242008-07-12 05:33:30 +02001652 pmtmr= [X86] Manual setup of pmtmr I/O Port.
1653 Override pmtimer IOPort with a hex value.
1654 e.g. pmtmr=0x508
1655
Linus Torvalds1da177e2005-04-16 15:20:36 -07001656 pnpacpi= [ACPI]
1657 { off }
1658
1659 pnpbios= [ISAPNP]
1660 { on | off | curr | res | no-curr | no-res }
1661
1662 pnp_reserve_irq=
1663 [ISAPNP] Exclude IRQs for the autoconfiguration
1664
1665 pnp_reserve_dma=
1666 [ISAPNP] Exclude DMAs for the autoconfiguration
1667
1668 pnp_reserve_io= [ISAPNP] Exclude I/O ports for the autoconfiguration
Randy Dunlapa9913042005-10-23 12:57:11 -07001669 Ranges are in pairs (I/O port base and size).
Linus Torvalds1da177e2005-04-16 15:20:36 -07001670
1671 pnp_reserve_mem=
Randy Dunlapa9913042005-10-23 12:57:11 -07001672 [ISAPNP] Exclude memory regions for the
1673 autoconfiguration.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001674 Ranges are in pairs (memory base and size).
1675
Ingo Molnar45807a12007-07-15 23:40:10 -07001676 print-fatal-signals=
1677 [KNL] debug: print fatal signals
1678 print-fatal-signals=1: print segfault info to
1679 the kernel console.
1680 default: off.
1681
Randy Dunlape84845c2007-07-15 23:40:25 -07001682 printk.time= Show timing data prefixed to each printk message line
1683 Format: <bool> (1/Y/y=enable, 0/N/n=disable)
1684
Linus Torvalds1da177e2005-04-16 15:20:36 -07001685 profile= [KNL] Enable kernel profiling via /proc/profile
Randy Dunlapa9913042005-10-23 12:57:11 -07001686 Format: [schedule,]<number>
1687 Param: "schedule" - profile schedule points.
1688 Param: <number> - step/bucket size as a power of 2 for
1689 statistical time based profiling.
Mel Gormanb3da2a72007-10-24 18:23:50 +02001690 Param: "sleep" - profile D-state sleeping (millisecs).
1691 Requires CONFIG_SCHEDSTATS
Dave Jonesc0fe2e62007-10-20 03:08:22 +02001692 Param: "kvm" - profile VM exits.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001693
Randy Dunlapa9913042005-10-23 12:57:11 -07001694 processor.max_cstate= [HW,ACPI]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001695 Limit processor to maximum C-state
1696 max_cstate=9 overrides any DMI blacklist limit.
1697
Len Brown41c0d862005-12-28 12:43:51 -05001698 processor.nocst [HW,ACPI]
1699 Ignore the _CST method to determine C-states,
1700 instead using the legacy FADT method
1701
Linus Torvalds1da177e2005-04-16 15:20:36 -07001702 prompt_ramdisk= [RAM] List of RAM disks to prompt for floppy disk
1703 before loading.
1704 See Documentation/ramdisk.txt.
1705
Randy Dunlapa9913042005-10-23 12:57:11 -07001706 psmouse.proto= [HW,MOUSE] Highest PS2 mouse protocol extension to
1707 probe for; one of (bare|imps|exps|lifebook|any).
Linus Torvalds1da177e2005-04-16 15:20:36 -07001708 psmouse.rate= [HW,MOUSE] Set desired mouse report rate, in reports
1709 per second.
Randy Dunlapa9913042005-10-23 12:57:11 -07001710 psmouse.resetafter= [HW,MOUSE]
1711 Try to reset the device after so many bad packets
Linus Torvalds1da177e2005-04-16 15:20:36 -07001712 (0 = never).
1713 psmouse.resolution=
1714 [HW,MOUSE] Set desired mouse resolution, in dpi.
1715 psmouse.smartscroll=
Randy Dunlapa9913042005-10-23 12:57:11 -07001716 [HW,MOUSE] Controls Logitech smartscroll autorepeat.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001717 0 = disabled, 1 = enabled (default).
1718
1719 pss= [HW,OSS] Personal Sound System (ECHO ESC614)
Randy Dunlapa9913042005-10-23 12:57:11 -07001720 Format:
1721 <io>,<mss_io>,<mss_irq>,<mss_dma>,<mpu_io>,<mpu_irq>
Linus Torvalds1da177e2005-04-16 15:20:36 -07001722
1723 pt. [PARIDE]
1724 See Documentation/paride.txt.
1725
Kay Sieversdc8c8582007-08-15 12:25:38 +02001726 pty.legacy_count=
1727 [KNL] Number of legacy pty's. Overwrites compiled-in
1728 default number.
1729
Randy Dunlap7d2c5022006-09-29 02:01:02 -07001730 quiet [KNL] Disable most log messages
Randy Dunlapa9913042005-10-23 12:57:11 -07001731
Linus Torvalds1da177e2005-04-16 15:20:36 -07001732 r128= [HW,DRM]
1733
1734 raid= [HW,RAID]
1735 See Documentation/md.txt.
1736
Randy Dunlapa9913042005-10-23 12:57:11 -07001737 ramdisk_blocksize= [RAM]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001738 See Documentation/ramdisk.txt.
Randy Dunlapa9913042005-10-23 12:57:11 -07001739
Linus Torvalds1da177e2005-04-16 15:20:36 -07001740 ramdisk_size= [RAM] Sizes of RAM disks in kilobytes
Linus Torvalds1da177e2005-04-16 15:20:36 -07001741 See Documentation/ramdisk.txt.
1742
Robert P. J. Day24aaef82008-02-03 15:20:26 +02001743 rcupdate.blimit= [KNL,BOOT]
1744 Set maximum number of finished RCU callbacks to process
1745 in one batch.
Dipankar Sarma21a1ea92006-03-07 21:55:33 -08001746
Robert P. J. Day24aaef82008-02-03 15:20:26 +02001747 rcupdate.qhimark= [KNL,BOOT]
1748 Set threshold of queued
Dipankar Sarma21a1ea92006-03-07 21:55:33 -08001749 RCU callbacks over which batch limiting is disabled.
1750
Robert P. J. Day24aaef82008-02-03 15:20:26 +02001751 rcupdate.qlowmark= [KNL,BOOT]
1752 Set threshold of queued RCU callbacks below which
1753 batch limiting is re-enabled.
Dipankar Sarma21a1ea92006-03-07 21:55:33 -08001754
Olof Johanssonffdfc402005-09-06 15:17:19 -07001755 rdinit= [KNL]
1756 Format: <full_path>
1757 Run specified binary instead of /init from the ramdisk,
1758 used for early userspace startup. See initrd.
1759
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001760 reboot= [BUGS=X86-32,BUGS=ARM,BUGS=IA-64] Rebooting mode
Linus Torvalds1da177e2005-04-16 15:20:36 -07001761 Format: <reboot_mode>[,<reboot_mode2>[,...]]
Mauro Carvalho Chehabe53dd082007-09-15 07:38:47 -03001762 See arch/*/kernel/reboot.c or arch/*/kernel/process.c
Linus Torvalds1da177e2005-04-16 15:20:36 -07001763
Paul Jackson46b6d942008-07-04 10:00:09 -07001764 relax_domain_level=
1765 [KNL, SMP] Set scheduler's default relax_domain_level.
1766 See Documentation/cpusets.txt.
1767
Linus Torvalds1da177e2005-04-16 15:20:36 -07001768 reserve= [KNL,BUGS] Force the kernel to ignore some iomem area
1769
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001770 reservetop= [X86-32]
Zachary Amsden461a9af2006-09-25 23:32:25 -07001771 Format: nn[KMG]
1772 Reserves a hole at the top of the kernel virtual
1773 address space.
1774
Vivek Goyal7e962872006-09-27 01:50:44 -07001775 reset_devices [KNL] Force drivers to reset the underlying device
1776 during initialization.
1777
Randy Dunlapa9913042005-10-23 12:57:11 -07001778 resume= [SWSUSP]
1779 Specify the partition device for software suspend
Linus Torvalds1da177e2005-04-16 15:20:36 -07001780
Rafael J. Wysockiecbd0da2006-12-06 20:34:13 -08001781 resume_offset= [SWSUSP]
1782 Specify the offset from the beginning of the partition
1783 given by "resume=" at which the swap header is located,
1784 in <PAGE_SIZE> units (needed only for swap files).
1785 See Documentation/power/swsusp-and-swap-files.txt
1786
Michael Neuling0a7b35cb2007-02-10 01:44:33 -08001787 retain_initrd [RAM] Keep initrd memory after extraction
1788
Linus Torvalds1da177e2005-04-16 15:20:36 -07001789 rhash_entries= [KNL,NET]
1790 Set number of hash buckets for route cache
1791
1792 riscom8= [HW,SERIAL]
1793 Format: <io_board1>[,<io_board2>[,...<io_boardN>]]
1794
1795 ro [KNL] Mount root device read-only on boot
1796
1797 root= [KNL] Root filesystem
1798
1799 rootdelay= [KNL] Delay (in seconds) to pause before attempting to
1800 mount the root filesystem
1801
1802 rootflags= [KNL] Set root filesystem mount option string
1803
1804 rootfstype= [KNL] Set root filesystem type
1805
Pierre Ossmancc1ed752007-07-15 23:40:35 -07001806 rootwait [KNL] Wait (indefinitely) for root device to show up.
1807 Useful for devices that are detected asynchronously
1808 (e.g. USB and MMC devices).
1809
James Morris20510f22007-10-16 23:31:32 -07001810 root_plug.vendor_id=
1811 [ROOTPLUG] Override the default vendor ID
1812
1813 root_plug.product_id=
1814 [ROOTPLUG] Override the default product ID
1815
1816 root_plug.debug=
1817 [ROOTPLUG] Enable debugging output
1818
Linus Torvalds1da177e2005-04-16 15:20:36 -07001819 rw [KNL] Mount root device read-write on boot
1820
1821 S [KNL] Run init in single mode
1822
1823 sa1100ir [NET]
1824 See drivers/net/irda/sa1100_ir.c.
1825
Linus Torvalds1da177e2005-04-16 15:20:36 -07001826 sbni= [NET] Granch SBNI12 leased line adapter
Randy Dunlapa9913042005-10-23 12:57:11 -07001827
Linus Torvalds1da177e2005-04-16 15:20:36 -07001828 sc1200wdt= [HW,WDT] SC1200 WDT (watchdog) driver
1829 Format: <io>[,<timeout>[,<isapnp>]]
1830
1831 scsi_debug_*= [SCSI]
1832 See drivers/scsi/scsi_debug.c.
1833
1834 scsi_default_dev_flags=
1835 [SCSI] SCSI default device flags
1836 Format: <integer>
1837
1838 scsi_dev_flags= [SCSI] Black/white list entry for vendor and model
1839 Format: <vendor>:<model>:<flags>
1840 (flags are integer value)
1841
Randy Dunlap6af66322007-11-14 16:52:25 -08001842 scsi_logging_level= [SCSI] a bit mask of logging levels
1843 See drivers/scsi/scsi_logging.h for bits. Also
1844 settable via sysctl at dev.scsi.logging_level
1845 (/proc/sys/dev/scsi/logging_level).
1846 There is also a nice 'scsi_logging_level' script in the
1847 S390-tools package, available for download at
1848 http://www-128.ibm.com/developerworks/linux/linux390/s390-tools-1.5.4.html
Linus Torvalds1da177e2005-04-16 15:20:36 -07001849
Matthew Wilcox3e082a92006-09-28 15:19:20 -06001850 scsi_mod.scan= [SCSI] sync (default) scans SCSI busses as they are
1851 discovered. async scans them in kernel threads,
1852 allowing boot to proceed. none ignores them, expecting
1853 user space to do the scan.
1854
Linus Torvalds1da177e2005-04-16 15:20:36 -07001855 selinux [SELINUX] Disable or enable SELinux at boot time.
1856 Format: { "0" | "1" }
1857 See security/selinux/Kconfig help text.
1858 0 -- disable.
1859 1 -- enable.
1860 Default value is set via kernel config option.
1861 If enabled at boot time, /selinux/disable can be used
1862 later to disable prior to initial policy load.
1863
James Morris4e5ab4c2006-06-09 00:33:33 -07001864 selinux_compat_net =
1865 [SELINUX] Set initial selinux_compat_net flag value.
Mauro Carvalho Chehabe53dd082007-09-15 07:38:47 -03001866 Format: { "0" | "1" }
1867 0 -- use new secmark-based packet controls
1868 1 -- use legacy packet controls
1869 Default value is 0 (preferred).
1870 Value can be changed at runtime via
1871 /selinux/compat_net.
James Morris4e5ab4c2006-06-09 00:33:33 -07001872
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001873 serialnumber [BUGS=X86-32]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001874
Linus Torvalds1da177e2005-04-16 15:20:36 -07001875 shapers= [NET]
1876 Maximal number of shapers.
Randy Dunlapa9913042005-10-23 12:57:11 -07001877
Linus Torvalds1da177e2005-04-16 15:20:36 -07001878 sim710= [SCSI,HW]
1879 See header of drivers/scsi/sim710.c.
1880
1881 simeth= [IA-64]
1882 simscsi=
Randy Dunlapa9913042005-10-23 12:57:11 -07001883
Linus Torvalds1da177e2005-04-16 15:20:36 -07001884 slram= [HW,MTD]
1885
Christoph Lameterf0630ff2007-07-15 23:38:14 -07001886 slub_debug[=options[,slabs]] [MM, SLUB]
1887 Enabling slub_debug allows one to determine the
1888 culprit if slab objects become corrupted. Enabling
1889 slub_debug can create guard zones around objects and
1890 may poison objects when not in use. Also tracks the
1891 last alloc / free. For more information see
1892 Documentation/vm/slub.txt.
Christoph Lameterc1aee212007-05-31 00:40:47 -07001893
1894 slub_max_order= [MM, SLUB]
Christoph Lameterf0630ff2007-07-15 23:38:14 -07001895 Determines the maximum allowed order for slabs.
1896 A high setting may cause OOMs due to memory
1897 fragmentation. For more information see
1898 Documentation/vm/slub.txt.
Christoph Lameterc1aee212007-05-31 00:40:47 -07001899
1900 slub_min_objects= [MM, SLUB]
Christoph Lameterf0630ff2007-07-15 23:38:14 -07001901 The minimum number of objects per slab. SLUB will
1902 increase the slab order up to slub_max_order to
1903 generate a sufficiently large slab able to contain
1904 the number of objects indicated. The higher the number
1905 of objects the smaller the overhead of tracking slabs
1906 and the less frequently locks need to be acquired.
Christoph Lameterc1aee212007-05-31 00:40:47 -07001907 For more information see Documentation/vm/slub.txt.
1908
1909 slub_min_order= [MM, SLUB]
1910 Determines the mininum page order for slabs. Must be
Christoph Lameterf0630ff2007-07-15 23:38:14 -07001911 lower than slub_max_order.
Christoph Lameterc1aee212007-05-31 00:40:47 -07001912 For more information see Documentation/vm/slub.txt.
1913
1914 slub_nomerge [MM, SLUB]
Christoph Lameterf0630ff2007-07-15 23:38:14 -07001915 Disable merging of slabs with similar size. May be
Christoph Lameterc1aee212007-05-31 00:40:47 -07001916 necessary if there is some reason to distinguish
Christoph Lameterf0630ff2007-07-15 23:38:14 -07001917 allocs to different slabs. Debug options disable
1918 merging on their own.
Christoph Lameterc1aee212007-05-31 00:40:47 -07001919 For more information see Documentation/vm/slub.txt.
1920
Linus Torvalds1da177e2005-04-16 15:20:36 -07001921 smart2= [HW]
1922 Format: <io1>[,<io2>[,...,<io8>]]
1923
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001924 smp-alt-once [X86-32,SMP] On a hotplug CPU system, only
Jeremy Fitzhardingeb7fb4af2007-05-02 19:27:13 +02001925 attempt to substitute SMP alternatives once at boot.
1926
Bjorn Helgaasd0d4f692007-05-08 00:36:05 -07001927 smsc-ircc2.nopnp [HW] Don't use PNP to discover SMC devices
1928 smsc-ircc2.ircc_cfg= [HW] Device configuration I/O port
1929 smsc-ircc2.ircc_sir= [HW] SIR base I/O port
1930 smsc-ircc2.ircc_fir= [HW] FIR base I/O port
1931 smsc-ircc2.ircc_irq= [HW] IRQ line
1932 smsc-ircc2.ircc_dma= [HW] DMA channel
1933 smsc-ircc2.ircc_transceiver= [HW] Transceiver type:
1934 0: Toshiba Satellite 1800 (GP data pin select)
1935 1: Fast pin select (default)
1936 2: ATC IRMode
1937
Linus Torvalds1da177e2005-04-16 15:20:36 -07001938 snd-ad1816a= [HW,ALSA]
1939
1940 snd-ad1848= [HW,ALSA]
1941
1942 snd-ali5451= [HW,ALSA]
1943
1944 snd-als100= [HW,ALSA]
1945
1946 snd-als4000= [HW,ALSA]
1947
1948 snd-azt2320= [HW,ALSA]
1949
1950 snd-cmi8330= [HW,ALSA]
1951
1952 snd-cmipci= [HW,ALSA]
1953
1954 snd-cs4231= [HW,ALSA]
1955
1956 snd-cs4232= [HW,ALSA]
1957
1958 snd-cs4236= [HW,ALSA]
1959
1960 snd-cs4281= [HW,ALSA]
1961
1962 snd-cs46xx= [HW,ALSA]
1963
1964 snd-dt019x= [HW,ALSA]
1965
1966 snd-dummy= [HW,ALSA]
1967
1968 snd-emu10k1= [HW,ALSA]
1969
1970 snd-ens1370= [HW,ALSA]
1971
1972 snd-ens1371= [HW,ALSA]
1973
1974 snd-es968= [HW,ALSA]
1975
1976 snd-es1688= [HW,ALSA]
1977
1978 snd-es18xx= [HW,ALSA]
1979
1980 snd-es1938= [HW,ALSA]
1981
1982 snd-es1968= [HW,ALSA]
1983
1984 snd-fm801= [HW,ALSA]
1985
1986 snd-gusclassic= [HW,ALSA]
1987
1988 snd-gusextreme= [HW,ALSA]
1989
1990 snd-gusmax= [HW,ALSA]
1991
1992 snd-hdsp= [HW,ALSA]
1993
1994 snd-ice1712= [HW,ALSA]
1995
1996 snd-intel8x0= [HW,ALSA]
1997
1998 snd-interwave= [HW,ALSA]
1999
2000 snd-interwave-stb=
2001 [HW,ALSA]
2002
2003 snd-korg1212= [HW,ALSA]
2004
2005 snd-maestro3= [HW,ALSA]
2006
2007 snd-mpu401= [HW,ALSA]
2008
2009 snd-mtpav= [HW,ALSA]
2010
2011 snd-nm256= [HW,ALSA]
2012
2013 snd-opl3sa2= [HW,ALSA]
2014
2015 snd-opti92x-ad1848=
2016 [HW,ALSA]
2017
2018 snd-opti92x-cs4231=
2019 [HW,ALSA]
2020
2021 snd-opti93x= [HW,ALSA]
2022
2023 snd-pmac= [HW,ALSA]
2024
2025 snd-rme32= [HW,ALSA]
2026
2027 snd-rme96= [HW,ALSA]
2028
2029 snd-rme9652= [HW,ALSA]
2030
2031 snd-sb8= [HW,ALSA]
2032
2033 snd-sb16= [HW,ALSA]
2034
2035 snd-sbawe= [HW,ALSA]
2036
2037 snd-serial= [HW,ALSA]
2038
2039 snd-sgalaxy= [HW,ALSA]
2040
2041 snd-sonicvibes= [HW,ALSA]
2042
2043 snd-sun-amd7930=
2044 [HW,ALSA]
2045
2046 snd-sun-cs4231= [HW,ALSA]
2047
2048 snd-trident= [HW,ALSA]
2049
2050 snd-usb-audio= [HW,ALSA,USB]
2051
2052 snd-via82xx= [HW,ALSA]
2053
2054 snd-virmidi= [HW,ALSA]
2055
2056 snd-wavefront= [HW,ALSA]
2057
2058 snd-ymfpci= [HW,ALSA]
Randy Dunlapa9913042005-10-23 12:57:11 -07002059
Ingo Molnar9c44bc02008-05-12 21:21:04 +02002060 softlockup_panic=
2061 [KNL] Should the soft-lockup detector generate panics.
2062
Linus Torvalds1da177e2005-04-16 15:20:36 -07002063 sonypi.*= [HW] Sony Programmable I/O Control Device driver
2064 See Documentation/sonypi.txt
2065
2066 specialix= [HW,SERIAL] Specialix multi-serial port adapter
2067 See Documentation/specialix.txt.
2068
2069 spia_io_base= [HW,MTD]
2070 spia_fio_base=
2071 spia_pedr=
2072 spia_peddr=
2073
2074 sscape= [HW,OSS]
2075 Format: <io>,<irq>,<dma>,<mpu_io>,<mpu_irq>
Randy Dunlapa9913042005-10-23 12:57:11 -07002076
Linus Torvalds1da177e2005-04-16 15:20:36 -07002077 st= [HW,SCSI] SCSI tape parameters (buffers, etc.)
2078 See Documentation/scsi/st.txt.
2079
Linus Torvalds1da177e2005-04-16 15:20:36 -07002080 sti= [PARISC,HW]
2081 Format: <num>
2082 Set the STI (builtin display/keyboard on the HP-PARISC
2083 machines) console (graphic card) which should be used
2084 as the initial boot-console.
2085 See also comment in drivers/video/console/sticore.c.
2086
2087 sti_font= [HW]
2088 See comment in drivers/video/console/sticore.c.
2089
2090 stifb= [HW]
2091 Format: bpp:<bpp1>[:<bpp2>[:<bpp3>...]]
2092
Greg Banks42a7fc42007-03-06 01:42:23 -08002093 sunrpc.pool_mode=
2094 [NFS]
2095 Control how the NFS server code allocates CPUs to
2096 service thread pools. Depending on how many NICs
2097 you have and where their interrupts are bound, this
2098 option will affect which CPUs will do NFS serving.
2099 Note: this parameter cannot be changed while the
2100 NFS server is running.
2101
2102 auto the server chooses an appropriate mode
2103 automatically using heuristics
2104 global a single global pool contains all CPUs
2105 percpu one pool for each CPU
2106 pernode one pool for each NUMA node (equivalent
2107 to global on non-NUMA machines)
2108
Linus Torvalds1da177e2005-04-16 15:20:36 -07002109 swiotlb= [IA-64] Number of I/O TLB slabs
Randy Dunlapa9913042005-10-23 12:57:11 -07002110
Linus Torvalds1da177e2005-04-16 15:20:36 -07002111 switches= [HW,M68k]
2112
2113 sym53c416= [HW,SCSI]
2114 See header of drivers/scsi/sym53c416.c.
2115
Ingo Molnar5d6f6472006-12-13 00:34:36 -08002116 sysrq_always_enabled
2117 [KNL]
2118 Ignore sysrq setting - this boot parameter will
2119 neutralize any effect of /proc/sys/kernel/sysrq.
2120 Useful for debugging.
2121
Linus Torvalds1da177e2005-04-16 15:20:36 -07002122 t128= [HW,SCSI]
2123 See header of drivers/scsi/t128.c.
2124
2125 tdfx= [HW,DRM]
2126
David Brownell77437fd2008-07-23 21:28:33 -07002127 test_suspend= [SUSPEND]
2128 Specify "mem" (for Suspend-to-RAM) or "standby" (for
2129 standby suspend) as the system sleep state to briefly
2130 enter during system startup. The system is woken from
2131 this state using a wakeup-capable RTC alarm.
2132
Linus Torvalds1da177e2005-04-16 15:20:36 -07002133 thash_entries= [KNL,NET]
2134 Set number of hash buckets for TCP connection
2135
Len Brownf8707ec2007-08-12 00:12:54 -04002136 thermal.act= [HW,ACPI]
2137 -1: disable all active trip points in all thermal zones
2138 <degrees C>: override all lowest active trip points
2139
Len Brownc52a7412007-08-14 15:49:32 -04002140 thermal.crt= [HW,ACPI]
2141 -1: disable all critical trip points in all thermal zones
2142 <degrees C>: lower all critical trip points
2143
Len Brownf5487142007-08-12 00:12:44 -04002144 thermal.nocrt= [HW,ACPI]
2145 Set to disable actions on ACPI thermal zone
2146 critical and hot trip points.
2147
Len Brown72b33ef2007-08-12 00:12:17 -04002148 thermal.off= [HW,ACPI]
2149 1: disable ACPI thermal control
2150
Len Browna70cdc52007-08-12 00:12:35 -04002151 thermal.psv= [HW,ACPI]
2152 -1: disable all passive trip points
2153 <degrees C>: override all passive trip points to this value
2154
Len Brown730ff342007-08-12 00:12:26 -04002155 thermal.tzp= [HW,ACPI]
2156 Specify global default ACPI thermal zone polling rate
2157 <deci-seconds>: poll all this frequency
2158 0: no polling (default)
2159
Linus Torvalds1da177e2005-04-16 15:20:36 -07002160 tipar.timeout= [HW,PPT]
2161 Set communications timeout in tenths of a second
2162 (default 15).
2163
2164 tipar.delay= [HW,PPT]
2165 Set inter-bit delay in microseconds (default 10).
2166
Linus Torvalds1da177e2005-04-16 15:20:36 -07002167 tmscsim= [HW,SCSI]
2168 See comment before function dc390_setup() in
2169 drivers/scsi/tmscsim.c.
2170
2171 tp720= [HW,PS2]
2172
2173 trix= [HW,OSS] MediaTrix AudioTrix Pro
Randy Dunlapa9913042005-10-23 12:57:11 -07002174 Format:
2175 <io>,<irq>,<dma>,<dma2>,<sb_io>,<sb_irq>,<sb_dma>,<mpu_io>,<mpu_irq>
2176
Randy Dunlapa9913042005-10-23 12:57:11 -07002177 turbografx.map[2|3]= [HW,JOY]
2178 TurboGraFX parallel port interface
2179 Format:
2180 <port#>,<js1>,<js2>,<js3>,<js4>,<js5>,<js6>,<js7>
Linus Torvalds1da177e2005-04-16 15:20:36 -07002181 See also Documentation/input/joystick-parport.txt
2182
2183 u14-34f= [HW,SCSI] UltraStor 14F/34F SCSI host adapter
2184 See header of drivers/scsi/u14-34f.c.
2185
2186 uart401= [HW,OSS]
2187 Format: <io>,<irq>
2188
2189 uart6850= [HW,OSS]
2190 Format: <io>,<irq>
2191
Alan Stern5f8364b2006-12-05 16:29:55 -05002192 uhci-hcd.ignore_oc=
2193 [USB] Ignore overcurrent events (default N).
2194 Some badly-designed motherboards generate lots of
2195 bogus events, for ports that aren't wired to
2196 anything. Set this parameter to avoid log spamming.
2197 Note that genuine overcurrent events won't be
2198 reported either.
2199
Simon Arlotte3a61b02008-07-19 23:32:54 +01002200 unknown_nmi_panic
2201 [X86-32,X86-64]
2202 Set unknown_nmi_panic=1 early on boot.
2203
Alan Sternb5e795f2007-02-20 15:00:53 -05002204 usbcore.autosuspend=
2205 [USB] The autosuspend time delay (in seconds) used
2206 for newly-detected USB devices (default 2). This
2207 is the time required before an idle device will be
2208 autosuspended. Devices for which the delay is set
Alan Sterneaafbc32007-03-13 16:39:15 -04002209 to a negative value won't be autosuspended at all.
Alan Sternb5e795f2007-02-20 15:00:53 -05002210
Linus Torvalds1da177e2005-04-16 15:20:36 -07002211 usbhid.mousepoll=
2212 [USBHID] The interval which mice are to be polled at.
Randy Dunlapa9913042005-10-23 12:57:11 -07002213
Paul Jackson200001e2008-06-25 05:44:46 -07002214 add_efi_memmap [EFI; x86-32,X86-64] Include EFI memory map in
2215 kernel's map of available physical RAM.
2216
Alan Coxcd4f0ef2007-07-31 00:37:59 -07002217 vdso= [X86-32,SH,x86-64]
Jeremy Fitzhardinge1dbf527c2007-05-02 19:27:12 +02002218 vdso=2: enable compat VDSO (default with COMPAT_VDSO)
Ingo Molnare6e54942006-06-27 02:53:50 -07002219 vdso=1: enable VDSO (default)
2220 vdso=0: disable VDSO mapping
2221
Roland McGrathaf65d642008-01-30 13:30:43 +01002222 vdso32= [X86-32,X86-64]
2223 vdso32=2: enable compat VDSO (default with COMPAT_VDSO)
2224 vdso32=1: enable 32-bit VDSO (default)
2225 vdso32=0: disable 32-bit VDSO mapping
2226
Yasuaki Ishimatsud080d392007-07-17 21:22:55 +09002227 vector= [IA-64,SMP]
2228 vector=percpu: enable percpu vector domain
2229
Linus Torvalds1da177e2005-04-16 15:20:36 -07002230 video= [FB] Frame buffer configuration
2231 See Documentation/fb/modedb.txt.
2232
Alan Coxcd4f0ef2007-07-31 00:37:59 -07002233 vga= [BOOT,X86-32] Select a particular video mode
Randy Dunlapa9913042005-10-23 12:57:11 -07002234 See Documentation/i386/boot.txt and
2235 Documentation/svga.txt.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002236 Use vga=ask for menu.
2237 This is actually a boot loader parameter; the value is
2238 passed to the kernel using a special protocol.
2239
Randy Dunlapa9913042005-10-23 12:57:11 -07002240 vmalloc=nn[KMG] [KNL,BOOT] Forces the vmalloc area to have an exact
Linus Torvalds1da177e2005-04-16 15:20:36 -07002241 size of <nn>. This can be used to increase the
2242 minimum size (128MB on x86). It can also be used to
2243 decrease the size and leave more room for directly
2244 mapped kernel RAM.
2245
Peter Oberparleiter585c3042006-06-29 15:08:25 +02002246 vmhalt= [KNL,S390] Perform z/VM CP command after system halt.
2247 Format: <command>
Linus Torvalds1da177e2005-04-16 15:20:36 -07002248
Peter Oberparleiter585c3042006-06-29 15:08:25 +02002249 vmpanic= [KNL,S390] Perform z/VM CP command after kernel panic.
2250 Format: <command>
2251
2252 vmpoff= [KNL,S390] Perform z/VM CP command after power off.
2253 Format: <command>
Randy Dunlapa9913042005-10-23 12:57:11 -07002254
Linus Torvalds1da177e2005-04-16 15:20:36 -07002255 waveartist= [HW,OSS]
2256 Format: <io>,<irq>,<dma>,<dma2>
Randy Dunlapa9913042005-10-23 12:57:11 -07002257
Linus Torvalds1da177e2005-04-16 15:20:36 -07002258 wd33c93= [HW,SCSI]
2259 See header of drivers/scsi/wd33c93.c.
2260
2261 wd7000= [HW,SCSI]
2262 See header of drivers/scsi/wd7000.c.
2263
2264 wdt= [WDT] Watchdog
Gabriel C8dfe9c22007-08-10 13:01:00 -07002265 See Documentation/watchdog/wdt.txt.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002266
2267 xd= [HW,XT] Original XT pre-IDE (RLL encoded) disks.
2268 xd_geo= See header of drivers/block/xd.c.
2269
2270 xirc2ps_cs= [NET,PCMCIA]
Randy Dunlapa9913042005-10-23 12:57:11 -07002271 Format:
2272 <irq>,<irq_mask>,<io>,<full_duplex>,<do_sound>,<lockup_hack>[,<irq2>[,<irq3>[,<irq4>]]]
Linus Torvalds1da177e2005-04-16 15:20:36 -07002273
Andi Kleena62eaf12006-02-16 23:41:58 +01002274 norandmaps Don't use address space randomization
2275 Equivalent to echo 0 > /proc/sys/kernel/randomize_va_space
2276
Randy Dunlapa9913042005-10-23 12:57:11 -07002277______________________________________________________________________
Linus Torvalds1da177e2005-04-16 15:20:36 -07002278
2279TODO:
2280
2281 Add documentation for ALSA options.
2282 Add more DRM drivers.