blob: 3ce193f8656514519d9d9f1db03f24a5722c3011 [file] [log] [blame]
Mauro Carvalho Chehabe53dd082007-09-15 07:38:47 -03001 Kernel Parameters
2 ~~~~~~~~~~~~~~~~~
Linus Torvalds1da177e2005-04-16 15:20:36 -07003
4The following is a consolidated list of the kernel parameters as implemented
5(mostly) by the __setup() macro and sorted into English Dictionary order
6(defined as ignoring all punctuation and sorting digits before letters in a
7case insensitive manner), and with descriptions where known.
8
9Module parameters for loadable modules are specified only as the
10parameter name with optional '=' and value as appropriate, such as:
11
12 modprobe usbcore blinkenlights=1
13
14Module parameters for modules that are built into the kernel image
15are specified on the kernel command line with the module name plus
16'.' plus parameter name, with '=' and value if appropriate, such as:
17
18 usbcore.blinkenlights=1
19
Stefan Richtera901ebb2006-04-01 01:43:18 +020020This document may not be entirely up to date and comprehensive. The command
21"modinfo -p ${modulename}" shows a current list of all parameters of a loadable
22module. Loadable modules, after being loaded into the running kernel, also
23reveal their parameters in /sys/module/${modulename}/parameters/. Some of these
24parameters may be changed at runtime by the command
25"echo -n ${value} > /sys/module/${modulename}/parameters/${parm}".
26
Stefan Richter6585fa82006-04-01 01:44:30 +020027The parameters listed below are only valid if certain kernel build options were
28enabled and if respective hardware is present. The text in square brackets at
29the beginning of each description states the restrictions within which a
30parameter is applicable:
Linus Torvalds1da177e2005-04-16 15:20:36 -070031
32 ACPI ACPI support is enabled.
Chuck Ebbertc99c1082007-07-27 10:46:20 +100033 AGP AGP (Accelerated Graphics Port) is enabled.
Linus Torvalds1da177e2005-04-16 15:20:36 -070034 ALSA ALSA sound support is enabled.
35 APIC APIC support is enabled.
36 APM Advanced Power Management support is enabled.
Haavard Skinnemoene7ba1762007-10-10 14:58:29 +020037 AVR32 AVR32 architecture is enabled.
Linus Torvalds1da177e2005-04-16 15:20:36 -070038 AX25 Appropriate AX.25 support is enabled.
Robin Getz0ae53642007-10-09 17:24:49 +080039 BLACKFIN Blackfin architecture is enabled.
Randy Dunlapa9913042005-10-23 12:57:11 -070040 DRM Direct Rendering Management support is enabled.
Linus Torvalds1da177e2005-04-16 15:20:36 -070041 EDD BIOS Enhanced Disk Drive Services (EDD) is enabled
42 EFI EFI Partitioning (GPT) is enabled
43 EIDE EIDE/ATAPI support is enabled.
44 FB The frame buffer device is enabled.
45 HW Appropriate hardware is enabled.
Linus Torvalds1da177e2005-04-16 15:20:36 -070046 IA-64 IA-64 architecture is enabled.
47 IOSCHED More than one I/O scheduler is enabled.
Adrian Bunk41e2e8b2005-07-12 13:58:33 -070048 IP_PNP IP DHCP, BOOTP, or RARP is enabled.
Linus Torvalds1da177e2005-04-16 15:20:36 -070049 ISAPNP ISA PnP code is enabled.
50 ISDN Appropriate ISDN support is enabled.
51 JOY Appropriate joystick support is enabled.
Kristen Carlson Accardi11ef6972006-09-28 11:29:01 -070052 LIBATA Libata driver is enabled
Linus Torvalds1da177e2005-04-16 15:20:36 -070053 LP Printer support is enabled.
54 LOOP Loopback device support is enabled.
55 M68k M68k architecture is enabled.
56 These options have more detailed description inside of
57 Documentation/m68k/kernel-options.txt.
58 MCA MCA bus support is enabled.
59 MDA MDA console support is enabled.
60 MOUSE Appropriate mouse support is enabled.
Matthew Wilcox309e57d2006-03-05 22:33:34 -070061 MSI Message Signaled Interrupts (PCI).
Randy Dunlapc8facbb2007-07-31 00:37:40 -070062 MTD MTD (Memory Technology Device) support is enabled.
Linus Torvalds1da177e2005-04-16 15:20:36 -070063 NET Appropriate network support is enabled.
64 NUMA NUMA support is enabled.
john stultz734efb42006-06-26 00:25:05 -070065 GENERIC_TIME The generic timeofday code is enabled.
Linus Torvalds1da177e2005-04-16 15:20:36 -070066 NFS Appropriate NFS support is enabled.
67 OSS OSS sound support is enabled.
Randy Dunlapc8facbb2007-07-31 00:37:40 -070068 PV_OPS A paravirtualized kernel is enabled.
69 PARIDE The ParIDE (parallel port IDE) subsystem is enabled.
Linus Torvalds1da177e2005-04-16 15:20:36 -070070 PARISC The PA-RISC architecture is enabled.
71 PCI PCI bus support is enabled.
Randy Dunlap7f785762007-10-05 13:17:58 -070072 PCIE PCI Express support is enabled.
Linus Torvalds1da177e2005-04-16 15:20:36 -070073 PCMCIA The PCMCIA subsystem is enabled.
74 PNP Plug & Play support is enabled.
75 PPC PowerPC architecture is enabled.
76 PPT Parallel port support is enabled.
77 PS2 Appropriate PS/2 support is enabled.
78 RAM RAM disk support is enabled.
James Morris20510f22007-10-16 23:31:32 -070079 ROOTPLUG The example Root Plug LSM is enabled.
Linus Torvalds1da177e2005-04-16 15:20:36 -070080 S390 S390 architecture is enabled.
81 SCSI Appropriate SCSI support is enabled.
82 A lot of drivers has their options described inside of
83 Documentation/scsi/.
James Morris20510f22007-10-16 23:31:32 -070084 SECURITY Different security models are enabled.
Linus Torvalds1da177e2005-04-16 15:20:36 -070085 SELINUX SELinux support is enabled.
86 SERIAL Serial support is enabled.
Paul Mundte523d932007-02-28 18:30:01 +090087 SH SuperH architecture is enabled.
Linus Torvalds1da177e2005-04-16 15:20:36 -070088 SMP The kernel is an SMP kernel.
89 SPARC Sparc architecture is enabled.
Randy Dunlapa9913042005-10-23 12:57:11 -070090 SWSUSP Software suspend is enabled.
Linus Torvalds1da177e2005-04-16 15:20:36 -070091 TS Appropriate touchscreen support is enabled.
92 USB USB support is enabled.
93 USBHID USB Human Interface Device support is enabled.
94 V4L Video For Linux support is enabled.
95 VGA The VGA console has been enabled.
96 VT Virtual terminal support is enabled.
97 WDT Watchdog support is enabled.
98 XT IBM PC/XT MFM hard disk support is enabled.
Alan Coxcd4f0ef2007-07-31 00:37:59 -070099 X86-32 X86-32, aka i386 architecture is enabled.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700100 X86-64 X86-64 architecture is enabled.
101 More X86-64 boot options can be found in
102 Documentation/x86_64/boot-options.txt .
103
104In addition, the following text indicates that the option:
105
106 BUGS= Relates to possible processor bugs on the said processor.
107 KNL Is a kernel start-up parameter.
108 BOOT Is a boot loader parameter.
109
110Parameters denoted with BOOT are actually interpreted by the boot
111loader, and have no meaning to the kernel directly.
112Do not modify the syntax of boot loader parameters without extreme
113need or coordination with <Documentation/i386/boot.txt>.
114
Karsten Weiss55588702007-02-13 13:26:21 +0100115There are also arch-specific kernel-parameters not documented here.
116See for example <Documentation/x86_64/boot-options.txt>.
117
Linus Torvalds1da177e2005-04-16 15:20:36 -0700118Note that ALL kernel parameters listed below are CASE SENSITIVE, and that
119a trailing = on the name of any parameter states that that parameter will
120be entered as an environment variable, whereas its absence indicates that
121it will appear as a kernel argument readable via /proc/cmdline by programs
122running once the system is up.
123
jens m. noedler9c4751f2006-09-29 02:00:27 -0700124The number of kernel parameters is not limited, but the length of the
125complete command line (parameters including spaces etc.) is limited to
126a fixed number of characters. This limit depends on the architecture
127and is between 256 and 4096 characters. It is defined in the file
128./include/asm/setup.h as COMMAND_LINE_SIZE.
129
130
Bernhard Walle03d926f2007-03-06 02:29:44 -0800131 acpi= [HW,ACPI,X86-64,i386]
132 Advanced Configuration and Power Interface
Randy Dunlapa9913042005-10-23 12:57:11 -0700133 Format: { force | off | ht | strict | noirq }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700134 force -- enable ACPI if default was off
135 off -- disable ACPI if default was on
136 noirq -- do not use ACPI for IRQ routing
137 ht -- run only enough ACPI to enable Hyper Threading
Randy Dunlapa9913042005-10-23 12:57:11 -0700138 strict -- Be less tolerant of platforms that are not
Linus Torvalds1da177e2005-04-16 15:20:36 -0700139 strictly ACPI specification compliant.
140
Randy Dunlap53471122008-03-12 18:10:51 -0400141 See also Documentation/power/pm.txt, pci=noacpi
Linus Torvalds1da177e2005-04-16 15:20:36 -0700142
Len Browna1fdcc02007-03-11 03:26:14 -0400143 acpi_apic_instance= [ACPI, IOAPIC]
144 Format: <int>
145 2: use 2nd APIC table, if available
146 1,0: use 1st APIC table
Len Brown4e381a42007-03-30 14:16:10 -0400147 default: 0
Len Browna1fdcc02007-03-11 03:26:14 -0400148
Linus Torvalds1da177e2005-04-16 15:20:36 -0700149 acpi_sleep= [HW,ACPI] Sleep options
Pavel Machek23b168d2008-02-05 19:27:12 +0100150 Format: { s3_bios, s3_mode, s3_beep }
151 See Documentation/power/video.txt for s3_bios and s3_mode.
152 s3_beep is for debugging; it makes the PC's speaker beep
153 as soon as the kernel's real-mode entry point is called.
Randy Dunlapa9913042005-10-23 12:57:11 -0700154
Linus Torvalds1da177e2005-04-16 15:20:36 -0700155 acpi_sci= [HW,ACPI] ACPI System Control Interrupt trigger mode
Randy Dunlapa9913042005-10-23 12:57:11 -0700156 Format: { level | edge | high | low }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700157
Randy Dunlapa9913042005-10-23 12:57:11 -0700158 acpi_irq_balance [HW,ACPI]
159 ACPI will balance active IRQs
160 default in APIC mode
Linus Torvalds1da177e2005-04-16 15:20:36 -0700161
Randy Dunlapa9913042005-10-23 12:57:11 -0700162 acpi_irq_nobalance [HW,ACPI]
163 ACPI will not move active IRQs (default)
164 default in PIC mode
Linus Torvalds1da177e2005-04-16 15:20:36 -0700165
Randy Dunlapa9913042005-10-23 12:57:11 -0700166 acpi_irq_pci= [HW,ACPI] If irq_balance, clear listed IRQs for
167 use by PCI
Linus Torvalds1da177e2005-04-16 15:20:36 -0700168 Format: <irq>,<irq>...
169
Randy Dunlapa9913042005-10-23 12:57:11 -0700170 acpi_irq_isa= [HW,ACPI] If irq_balance, mark listed IRQs used by ISA
Linus Torvalds1da177e2005-04-16 15:20:36 -0700171 Format: <irq>,<irq>...
172
Len Brown67effe82007-07-26 00:50:06 -0400173 acpi_no_auto_ssdt [HW,ACPI] Disable automatic loading of SSDT
174
Len Browna1f9e652006-01-25 23:47:36 -0500175 acpi_os_name= [HW,ACPI] Tell ACPI BIOS the name of the OS
176 Format: To spoof as Windows 98: ="Microsoft Windows"
177
Len Brownae00d812007-05-29 18:43:33 -0400178 acpi_osi= [HW,ACPI] Modify list of supported OS interface strings
179 acpi_osi="string1" # add string1 -- only one string
180 acpi_osi="!string2" # remove built-in string2
181 acpi_osi= # disable all strings
Linus Torvalds1da177e2005-04-16 15:20:36 -0700182
183 acpi_serialize [HW,ACPI] force serialization of AML methods
184
185 acpi_skip_timer_override [HW,ACPI]
186 Recognize and ignore IRQ0/pin2 Interrupt Override.
187 For broken nForce2 BIOS resulting in XT-PIC timer.
Andi Kleenfa18f472006-11-14 16:57:46 +0100188 acpi_use_timer_override [HW,ACPI}
189 Use timer override. For some broken Nvidia NF5 boards
190 that require a timer override, but don't have
191 HPET
Linus Torvalds1da177e2005-04-16 15:20:36 -0700192
Zhang Ruif9891062007-04-24 13:53:22 +0800193 acpi.debug_layer= [HW,ACPI]
Linus Torvalds1da177e2005-04-16 15:20:36 -0700194 Format: <int>
Randy Dunlapa9913042005-10-23 12:57:11 -0700195 Each bit of the <int> indicates an ACPI debug layer,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700196 1: enable, 0: disable. It is useful for boot time
197 debugging. After system has booted up, it can be set
Zhang Ruif9891062007-04-24 13:53:22 +0800198 via /sys/module/acpi/parameters/debug_layer.
199 CONFIG_ACPI_DEBUG must be enabled for this to produce any output.
200 Available bits (add the numbers together) to enable debug output
201 for specific parts of the ACPI subsystem:
202 0x01 utilities 0x02 hardware 0x04 events 0x08 tables
203 0x10 namespace 0x20 parser 0x40 dispatcher
204 0x80 executer 0x100 resources 0x200 acpica debugger
205 0x400 os services 0x800 acpica disassembler.
206 The number can be in decimal or prefixed with 0x in hex.
207 Warning: Many of these options can produce a lot of
208 output and make your system unusable. Be very careful.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700209
Zhang Ruif9891062007-04-24 13:53:22 +0800210 acpi.debug_level= [HW,ACPI]
Linus Torvalds1da177e2005-04-16 15:20:36 -0700211 Format: <int>
Randy Dunlapa9913042005-10-23 12:57:11 -0700212 Each bit of the <int> indicates an ACPI debug level,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700213 1: enable, 0: disable. It is useful for boot time
214 debugging. After system has booted up, it can be set
Zhang Ruif9891062007-04-24 13:53:22 +0800215 via /sys/module/acpi/parameters/debug_level.
216 CONFIG_ACPI_DEBUG must be enabled for this to produce any output.
217 Available bits (add the numbers together) to enable different
218 debug output levels of the ACPI subsystem:
219 0x01 error 0x02 warn 0x04 init 0x08 debug object
220 0x10 info 0x20 init names 0x40 parse 0x80 load
221 0x100 dispatch 0x200 execute 0x400 names 0x800 operation region
222 0x1000 bfield 0x2000 tables 0x4000 values 0x8000 objects
223 0x10000 resources 0x20000 user requests 0x40000 package.
224 The number can be in decimal or prefixed with 0x in hex.
225 Warning: Many of these options can produce a lot of
226 output and make your system unusable. Be very careful.
227
Alan Coxcd4f0ef2007-07-31 00:37:59 -0700228 acpi_pm_good [X86-32,X86-64]
john stultz5d0cf412006-06-26 00:25:12 -0700229 Override the pmtimer bug detection: force the kernel
230 to assume that this machine's pmtimer latches its value
231 and always returns good values.
232
Chuck Ebbertc99c1082007-07-27 10:46:20 +1000233 agp= [AGP]
234 { off | try_unsupported }
235 off: disable AGP support
236 try_unsupported: try to drive unsupported chipsets
237 (may crash computer or cause data corruption)
238
Chuck Ebbert66759a02005-09-12 18:49:25 +0200239 enable_timer_pin_1 [i386,x86-64]
240 Enable PIN 1 of APIC timer
Randy Dunlapa9913042005-10-23 12:57:11 -0700241 Can be useful to work around chipset bugs
242 (in particular on some ATI chipsets).
Chuck Ebbert66759a02005-09-12 18:49:25 +0200243 The kernel tries to set a reasonable default.
244
245 disable_timer_pin_1 [i386,x86-64]
246 Disable PIN 1 of APIC timer
247 Can be useful to work around chipset bugs.
248
Linus Torvalds1da177e2005-04-16 15:20:36 -0700249 ad1848= [HW,OSS]
250 Format: <io>,<irq>,<dma>,<dma2>,<type>
251
Linus Torvalds1da177e2005-04-16 15:20:36 -0700252 advansys= [HW,SCSI]
253 See header of drivers/scsi/advansys.c.
254
255 advwdt= [HW,WDT] Advantech WDT
256 Format: <iostart>,<iostop>
257
258 aedsp16= [HW,OSS] Audio Excel DSP 16
259 Format: <io>,<irq>,<dma>,<mss_io>,<mpu_io>,<mpu_irq>
260 See also header of sound/oss/aedsp16.c.
Randy Dunlapa9913042005-10-23 12:57:11 -0700261
Linus Torvalds1da177e2005-04-16 15:20:36 -0700262 aha152x= [HW,SCSI]
263 See Documentation/scsi/aha152x.txt.
264
265 aha1542= [HW,SCSI]
266 Format: <portbase>[,<buson>,<busoff>[,<dmaspeed>]]
267
268 aic7xxx= [HW,SCSI]
269 See Documentation/scsi/aic7xxx.txt.
270
271 aic79xx= [HW,SCSI]
272 See Documentation/scsi/aic79xx.txt.
273
Linus Torvalds1da177e2005-04-16 15:20:36 -0700274 amijoy.map= [HW,JOY] Amiga joystick support
275 Map of devices attached to JOY0DAT and JOY1DAT
276 Format: <a>,<b>
277 See also Documentation/kernel/input/joystick.txt
278
279 analog.map= [HW,JOY] Analog joystick and gamepad support
280 Specifies type or capabilities of an analog joystick
281 connected to one of 16 gameports
282 Format: <type1>,<type2>,..<type16>
283
Randy Dunlapa9913042005-10-23 12:57:11 -0700284 apc= [HW,SPARC]
285 Power management functions (SPARCstation-4/5 + deriv.)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700286 Format: noidle
287 Disable APC CPU standby support. SPARCstation-Fox does
288 not play well with APC CPU idle - disable it if you have
289 APC and your system crashes randomly.
290
Randy Dunlapc8facbb2007-07-31 00:37:40 -0700291 apic= [APIC,i386] Advanced Programmable Interrupt Controller
292 Change the output verbosity whilst booting
Linus Torvalds1da177e2005-04-16 15:20:36 -0700293 Format: { quiet (default) | verbose | debug }
294 Change the amount of debugging information output
295 when initialising the APIC and IO-APIC components.
Randy Dunlapa9913042005-10-23 12:57:11 -0700296
Linus Torvalds1da177e2005-04-16 15:20:36 -0700297 apm= [APM] Advanced Power Management
298 See header of arch/i386/kernel/apm.c.
299
Linus Torvalds1da177e2005-04-16 15:20:36 -0700300 arcrimi= [HW,NET] ARCnet - "RIM I" (entirely mem-mapped) cards
301 Format: <io>,<irq>,<nodeID>
302
303 ataflop= [HW,M68k]
304
305 atarimouse= [HW,MOUSE] Atari Mouse
306
307 atascsi= [HW,SCSI] Atari SCSI
308
309 atkbd.extra= [HW] Enable extra LEDs and keys on IBM RapidAccess,
310 EzKey and similar keyboards
311
312 atkbd.reset= [HW] Reset keyboard during initialization
313
Randy Dunlapa9913042005-10-23 12:57:11 -0700314 atkbd.set= [HW] Select keyboard code set
315 Format: <int> (2 = AT (default), 3 = PS/2)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700316
317 atkbd.scroll= [HW] Enable scroll wheel on MS Office and similar
318 keyboards
319
320 atkbd.softraw= [HW] Choose between synthetic and real raw mode
321 Format: <bool> (0 = real, 1 = synthetic (default))
Randy Dunlapa9913042005-10-23 12:57:11 -0700322
323 atkbd.softrepeat= [HW]
324 Use software keyboard repeat
Linus Torvalds1da177e2005-04-16 15:20:36 -0700325
326 autotest [IA64]
327
Linus Torvalds1da177e2005-04-16 15:20:36 -0700328 baycom_epp= [HW,AX25]
329 Format: <io>,<mode>
Randy Dunlapa9913042005-10-23 12:57:11 -0700330
Linus Torvalds1da177e2005-04-16 15:20:36 -0700331 baycom_par= [HW,AX25] BayCom Parallel Port AX.25 Modem
332 Format: <io>,<mode>
333 See header of drivers/net/hamradio/baycom_par.c.
334
Randy Dunlapa9913042005-10-23 12:57:11 -0700335 baycom_ser_fdx= [HW,AX25]
336 BayCom Serial Port AX.25 Modem (Full Duplex Mode)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700337 Format: <io>,<irq>,<mode>[,<baud>]
338 See header of drivers/net/hamradio/baycom_ser_fdx.c.
339
Randy Dunlapa9913042005-10-23 12:57:11 -0700340 baycom_ser_hdx= [HW,AX25]
341 BayCom Serial Port AX.25 Modem (Half Duplex Mode)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700342 Format: <io>,<irq>,<mode>
343 See header of drivers/net/hamradio/baycom_ser_hdx.c.
344
Randy Dunlapbfe8df32007-10-16 01:23:46 -0700345 boot_delay= Milliseconds to delay each printk during boot.
346 Values larger than 10 seconds (10000) are changed to
347 no delay (0).
348 Format: integer
349
Linus Torvalds1da177e2005-04-16 15:20:36 -0700350 bttv.card= [HW,V4L] bttv (bt848 + bt878 based grabber cards)
Randy Dunlapa9913042005-10-23 12:57:11 -0700351 bttv.radio= Most important insmod options are available as
352 kernel args too.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700353 bttv.pll= See Documentation/video4linux/bttv/Insmod-options
354 bttv.tuner= and Documentation/video4linux/bttv/CARDLIST
355
356 BusLogic= [HW,SCSI]
357 See drivers/scsi/BusLogic.c, comment before function
358 BusLogic_ParseDriverOptions().
359
360 c101= [NET] Moxa C101 synchronous serial card
361
Alan Coxcd4f0ef2007-07-31 00:37:59 -0700362 cachesize= [BUGS=X86-32] Override level 2 CPU cache size detection.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700363 Sometimes CPU hardware bugs make them report the cache
364 size incorrectly. The kernel will attempt work arounds
365 to fix known problems, but for some CPUs it is not
366 possible to determine what the correct size should be.
367 This option provides an override for these situations.
368
Ahmed S. Darwish076c54c2008-03-06 18:09:10 +0200369 security= [SECURITY] Choose a security module to enable at boot.
370 If this boot parameter is not specified, only the first
371 security module asking for security registration will be
372 loaded. An invalid security module name will be treated
373 as if no module has been chosen.
374
James Morris20510f22007-10-16 23:31:32 -0700375 capability.disable=
376 [SECURITY] Disable capabilities. This would normally
377 be used only if an alternative security model is to be
378 configured. Potentially dangerous and should only be
379 used if you are entirely sure of the consequences.
380
Sebastian Ott14ff56b2008-01-26 14:10:37 +0100381 ccw_timeout_log [S390]
382 See Documentation/s390/CommonIO for details.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700383
Paul Menage8bab8dd2008-04-04 14:29:57 -0700384 cgroup_disable= [KNL] Disable a particular controller
385 Format: {name of the controller(s) to disable}
386 {Currently supported controllers - "memory"}
387
Linus Torvalds1da177e2005-04-16 15:20:36 -0700388 checkreqprot [SELINUX] Set initial checkreqprot flag value.
389 Format: { "0" | "1" }
390 See security/selinux/Kconfig help text.
Randy Dunlapa9913042005-10-23 12:57:11 -0700391 0 -- check protection applied by kernel (includes
392 any implied execute protection).
Linus Torvalds1da177e2005-04-16 15:20:36 -0700393 1 -- check protection requested by application.
394 Default value is set via a kernel config option.
Randy Dunlapa9913042005-10-23 12:57:11 -0700395 Value can be changed at runtime via
396 /selinux/checkreqprot.
397
Sebastian Ott661ca0d2008-01-26 14:10:36 +0100398 cio_ignore= [S390]
399 See Documentation/s390/CommonIO for details.
400
401 cio_msg= [S390]
402 See Documentation/s390/CommonIO for details.
403
Alan Coxcd4f0ef2007-07-31 00:37:59 -0700404 clock= [BUGS=X86-32, HW] gettimeofday clocksource override.
john stultz734efb42006-06-26 00:25:05 -0700405 [Deprecated]
Matt LaPlante3f6dee92006-10-03 22:45:33 +0200406 Forces specified clocksource (if available) to be used
john stultz734efb42006-06-26 00:25:05 -0700407 when calculating gettimeofday(). If specified
Matt LaPlante3f6dee92006-10-03 22:45:33 +0200408 clocksource is not available, it defaults to PIT.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700409 Format: { pit | tsc | cyclone | pmtmr }
410
Randy Dunlap3d6ac982007-05-23 13:58:16 -0700411 clocksource= [GENERIC_TIME] Override the default clocksource
412 Format: <string>
413 Override the default clocksource and use the clocksource
414 with the name specified.
415 Some clocksource names to choose from, depending on
416 the platform:
417 [all] jiffies (this is the base, fallback clocksource)
418 [ACPI] acpi_pm
419 [ARM] imx_timer1,OSTS,netx_timer,mpu_timer2,
420 pxa_timer,timer3,32k_counter,timer0_1
421 [AVR32] avr32
Alan Coxcd4f0ef2007-07-31 00:37:59 -0700422 [X86-32] pit,hpet,tsc,vmi-timer;
Randy Dunlap3d6ac982007-05-23 13:58:16 -0700423 scx200_hrt on Geode; cyclone on IBM x440
424 [MIPS] MIPS
425 [PARISC] cr16
426 [S390] tod
427 [SH] SuperH
428 [SPARC64] tick
429 [X86-64] hpet,tsc
430
Andi Kleenac72e782008-01-30 13:33:21 +0100431 clearcpuid=BITNUM [X86]
432 Disable CPUID feature X for the kernel. See
433 include/asm-x86/cpufeature.h for the valid bit numbers.
434 Note the Linux specific bits are not necessarily
435 stable over kernel options, but the vendor specific
436 ones should be.
437 Also note that user programs calling CPUID directly
438 or using the feature without checking anything
439 will still see it. This just prevents it from
440 being used by the kernel or shown in /proc/cpuinfo.
441 Also note the kernel might malfunction if you disable
442 some critical bits.
443
Arjan van de Vena25bd942008-01-30 13:33:08 +0100444 code_bytes [IA32/X86_64] How many bytes of object code to print
445 in an oops report.
Chuck Ebbert86c41832007-02-13 13:26:25 +0100446 Range: 0 - 8192
447 Default: 64
448
Andi Kleenf9262c12006-03-08 17:57:25 -0800449 disable_8254_timer
450 enable_8254_timer
451 [IA32/X86_64] Disable/Enable interrupt 0 timer routing
452 over the 8254 in addition to over the IO-APIC. The
453 kernel tries to set a sensible default.
454
Thomas Gleixnerb17530b2007-10-19 20:35:02 +0200455 hpet= [X86-32,HPET] option to control HPET usage
456 Format: { enable (default) | disable | force }
457 disable: disable HPET and use PIT instead
Carlos Corbachod79a5f82007-10-19 18:51:27 +0100458 force: allow force enabled of undocumented chips (ICH4,
459 VIA, nVidia)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700460
Linus Torvalds1da177e2005-04-16 15:20:36 -0700461 com20020= [HW,NET] ARCnet - COM20020 chipset
Randy Dunlapa9913042005-10-23 12:57:11 -0700462 Format:
463 <io>[,<irq>[,<nodeID>[,<backplane>[,<ckp>[,<timeout>]]]]]
Linus Torvalds1da177e2005-04-16 15:20:36 -0700464
465 com90io= [HW,NET] ARCnet - COM90xx chipset (IO-mapped buffers)
466 Format: <io>[,<irq>]
467
Randy Dunlapa9913042005-10-23 12:57:11 -0700468 com90xx= [HW,NET]
469 ARCnet - COM90xx chipset (memory-mapped buffers)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700470 Format: <io>[,<irq>[,<memstart>]]
471
472 condev= [HW,S390] console device
473 conmode=
Randy Dunlapa9913042005-10-23 12:57:11 -0700474
Linus Torvalds1da177e2005-04-16 15:20:36 -0700475 console= [KNL] Output console device and options.
476
477 tty<n> Use the virtual console device <n>.
478
479 ttyS<n>[,options]
Randy Dunlapf1a1c2d2006-03-25 03:08:17 -0800480 ttyUSB0[,options]
Linus Torvalds1da177e2005-04-16 15:20:36 -0700481 Use the specified serial port. The options are of
Randy Dunlapf1a1c2d2006-03-25 03:08:17 -0800482 the form "bbbbpnf", where "bbbb" is the baud rate,
483 "p" is parity ("n", "o", or "e"), "n" is number of
484 bits, and "f" is flow control ("r" for RTS or
485 omit it). Default is "9600n8".
Linus Torvalds1da177e2005-04-16 15:20:36 -0700486
Randy Dunlapf1a1c2d2006-03-25 03:08:17 -0800487 See Documentation/serial-console.txt for more
488 information. See
489 Documentation/networking/netconsole.txt for an
490 alternative.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700491
Yinghai Lu18a8bd92007-07-15 23:37:59 -0700492 uart[8250],io,<addr>[,options]
493 uart[8250],mmio,<addr>[,options]
Linus Torvalds1da177e2005-04-16 15:20:36 -0700494 Start an early, polled-mode console on the 8250/16550
495 UART at the specified I/O port or MMIO address,
496 switching to the matching ttyS device later. The
497 options are the same as for ttyS, above.
498
Yinghai Lu18a8bd92007-07-15 23:37:59 -0700499 earlycon= [KNL] Output early console device and options.
500 uart[8250],io,<addr>[,options]
501 uart[8250],mmio,<addr>[,options]
502 Start an early, polled-mode console on the 8250/16550
503 UART at the specified I/O port or MMIO address.
504 The options are the same as for ttyS, above.
505
Andres Salomon8f4ce8c2007-10-18 03:04:50 -0700506 no_console_suspend
507 [HW] Never suspend the console
508 Disable suspending of consoles during suspend and
509 hibernate operations. Once disabled, debugging
510 messages can reach various consoles while the rest
511 of the system is being put to sleep (ie, while
512 debugging driver suspend/resume hooks). This may
513 not work reliably with all consoles, but is known
514 to work with serial and VGA consoles.
515
Linus Torvalds1da177e2005-04-16 15:20:36 -0700516 cpcihp_generic= [HW,PCI] Generic port I/O CompactPCI driver
Randy Dunlapa9913042005-10-23 12:57:11 -0700517 Format:
518 <first_slot>,<last_slot>,<port>,<enum_bit>[,<debug>]
Linus Torvalds1da177e2005-04-16 15:20:36 -0700519
Eric W. Biedermandc009d92005-06-25 14:57:52 -0700520 crashkernel=nn[KMG]@ss[KMG]
521 [KNL] Reserve a chunk of physical memory to
522 hold a kernel to switch to with kexec on panic.
523
Bernhard Wallefb391592007-10-18 23:41:02 -0700524 crashkernel=range1:size1[,range2:size2,...][@offset]
525 [KNL] Same as above, but depends on the memory
526 in the running system. The syntax of range is
527 start-[end] where start and end are both
528 a memory unit (amount[KMG]). See also
529 Documentation/kdump/kdump.txt for a example.
530
Linus Torvalds1da177e2005-04-16 15:20:36 -0700531 cs4232= [HW,OSS]
532 Format: <io>,<irq>,<dma>,<dma2>,<mpuio>,<mpuirq>
533
534 cs89x0_dma= [HW,NET]
535 Format: <dma>
536
537 cs89x0_media= [HW,NET]
538 Format: { rj45 | aui | bnc }
Randy Dunlapa9913042005-10-23 12:57:11 -0700539
Randy Dunlapa9913042005-10-23 12:57:11 -0700540 dasd= [HW,NET]
Linus Torvalds1da177e2005-04-16 15:20:36 -0700541 See header of drivers/s390/block/dasd_devmap.c.
542
543 db9.dev[2|3]= [HW,JOY] Multisystem joystick support via parallel port
544 (one device per port)
545 Format: <port#>,<type>
546 See also Documentation/input/joystick-parport.txt
547
548 debug [KNL] Enable kernel debugging (events log level).
549
Ingo Molnarcae2ed92006-07-03 00:24:48 -0700550 debug_locks_verbose=
551 [KNL] verbose self-tests
552 Format=<0|1>
553 Print debugging info while doing the locking API
554 self-tests.
555 We default to 0 (no extra messages), setting it to
556 1 will print _a lot_ more information - normally
557 only useful to kernel developers.
558
Robert P. J. Day2d27a962008-02-03 15:18:45 +0200559 decnet.addr= [HW,NET]
Linus Torvalds1da177e2005-04-16 15:20:36 -0700560 Format: <area>[,<node>]
561 See also Documentation/networking/decnet.txt.
562
Samuel Thibaultecb77fa2008-01-03 16:17:54 +0000563 vt.default_blu= [VT]
Antonino A. Daplas55ff9782007-05-08 00:38:53 -0700564 Format: <blue0>,<blue1>,<blue2>,...,<blue15>
565 Change the default blue palette of the console.
566 This is a 16-member array composed of values
567 ranging from 0-255.
568
Samuel Thibaultecb77fa2008-01-03 16:17:54 +0000569 vt.default_grn= [VT]
Antonino A. Daplas55ff9782007-05-08 00:38:53 -0700570 Format: <green0>,<green1>,<green2>,...,<green15>
571 Change the default green palette of the console.
572 This is a 16-member array composed of values
573 ranging from 0-255.
574
Samuel Thibaultecb77fa2008-01-03 16:17:54 +0000575 vt.default_red= [VT]
Antonino A. Daplas55ff9782007-05-08 00:38:53 -0700576 Format: <red0>,<red1>,<red2>,...,<red15>
577 Change the default red palette of the console.
578 This is a 16-member array composed of values
579 ranging from 0-255.
580
Samuel Thibaultecb77fa2008-01-03 16:17:54 +0000581 vt.default_utf8=
582 [VT]
Antonino A. Daplas55ff9782007-05-08 00:38:53 -0700583 Format=<0|1>
584 Set system-wide default UTF-8 mode for all tty's.
Samuel Thibaultecb77fa2008-01-03 16:17:54 +0000585 Default is 1, i.e. UTF-8 mode is enabled for all
586 newly opened terminals.
Antonino A. Daplas55ff9782007-05-08 00:38:53 -0700587
Linus Torvalds1da177e2005-04-16 15:20:36 -0700588 dhash_entries= [KNL]
589 Set number of hash buckets for dentry cache.
Randy Dunlapa9913042005-10-23 12:57:11 -0700590
Linus Torvalds1da177e2005-04-16 15:20:36 -0700591 digi= [HW,SERIAL]
592 IO parameters + enable/disable command.
593
594 digiepca= [HW,SERIAL]
595 See drivers/char/README.epca and
596 Documentation/digiepca.txt.
597
Yinghai Lu093af8d2008-01-30 13:33:32 +0100598 disable_mtrr_trim [X86, Intel and AMD only]
Jesse Barnes99fc8d42008-01-30 13:33:18 +0100599 By default the kernel will trim any uncacheable
600 memory out of your available memory pool based on
601 MTRR settings. This parameter disables that behavior,
602 possibly causing your machine to run very slowly.
603
Linus Torvalds1da177e2005-04-16 15:20:36 -0700604 dmasound= [HW,OSS] Sound subsystem buffers
605
606 dscc4.setup= [NET]
607
608 dtc3181e= [HW,SCSI]
609
Robin Getz0ae53642007-10-09 17:24:49 +0800610 earlyprintk= [X86-32,X86-64,SH,BLACKFIN]
Linus Torvalds1da177e2005-04-16 15:20:36 -0700611 earlyprintk=vga
612 earlyprintk=serial[,ttySn[,baudrate]]
613
Randy Dunlapa9913042005-10-23 12:57:11 -0700614 Append ",keep" to not disable it when the real console
Linus Torvalds1da177e2005-04-16 15:20:36 -0700615 takes over.
616
617 Only vga or serial at a time, not both.
618
619 Currently only ttyS0 and ttyS1 are supported.
620
621 Interaction with the standard serial driver is not
622 very good.
623
624 The VGA output is eventually overwritten by the real
625 console.
626
627 eata= [HW,SCSI]
628
Linus Torvalds1da177e2005-04-16 15:20:36 -0700629 edd= [EDD]
Tim Gardner8c4dd602008-04-29 01:02:45 -0700630 Format: {"off" | "on" | "skip[mbr]"}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700631
Linus Torvalds1da177e2005-04-16 15:20:36 -0700632 eisa_irq_edge= [PARISC,HW]
633 See header of drivers/parisc/eisa.c.
634
Alan Coxcd4f0ef2007-07-31 00:37:59 -0700635 elanfreq= [X86-32]
Linus Torvalds1da177e2005-04-16 15:20:36 -0700636 See comment before function elanfreq_setup() in
637 arch/i386/kernel/cpu/cpufreq/elanfreq.c.
638
639 elevator= [IOSCHED]
Randy Dunlap16ab3ad2006-01-14 13:21:20 -0800640 Format: {"anticipatory" | "cfq" | "deadline" | "noop"}
Randy Dunlapa9913042005-10-23 12:57:11 -0700641 See Documentation/block/as-iosched.txt and
642 Documentation/block/deadline-iosched.txt for details.
643
Alan Coxcd4f0ef2007-07-31 00:37:59 -0700644 elfcorehdr= [X86-32, X86_64]
Randy Dunlapa9913042005-10-23 12:57:11 -0700645 Specifies physical address of start of kernel core
Vivek Goyalaac04b32006-01-09 20:51:47 -0800646 image elf header. Generally kexec loader will
647 pass this option to capture kernel.
648 See Documentation/kdump/kdump.txt for details.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700649
650 enforcing [SELINUX] Set initial enforcing status.
651 Format: {"0" | "1"}
652 See security/selinux/Kconfig help text.
653 0 -- permissive (log only, no denials).
654 1 -- enforcing (deny and log).
655 Default value is 0.
656 Value can be changed at runtime via /selinux/enforce.
657
Linus Torvalds1da177e2005-04-16 15:20:36 -0700658 es1371= [HW,OSS]
659 Format: <spdif>,[<nomix>,[<amplifier>]]
660 See also header of sound/oss/es1371.c.
Randy Dunlapa9913042005-10-23 12:57:11 -0700661
Linus Torvalds1da177e2005-04-16 15:20:36 -0700662 ether= [HW,NET] Ethernet cards parameters
663 This option is obsoleted by the "netdev=" option, which
664 has equivalent usage. See its documentation for details.
665
666 eurwdt= [HW,WDT] Eurotech CPU-1220/1410 onboard watchdog.
667 Format: <io>[,<irq>]
668
Akinobu Mitade1ba092006-12-08 02:39:42 -0800669 failslab=
670 fail_page_alloc=
671 fail_make_request=[KNL]
672 General fault injection mechanism.
673 Format: <interval>,<probability>,<space>,<times>
674 See also /Documentation/fault-injection/.
675
Linus Torvalds1da177e2005-04-16 15:20:36 -0700676 fd_mcs= [HW,SCSI]
677 See header of drivers/scsi/fd_mcs.c.
678
679 fdomain= [HW,SCSI]
680 See header of drivers/scsi/fdomain.c.
681
682 floppy= [HW]
683 See Documentation/floppy.txt.
684
Linus Torvalds1da177e2005-04-16 15:20:36 -0700685 gamecon.map[2|3]=
686 [HW,JOY] Multisystem joystick and NES/SNES/PSX pad
687 support via parallel port (up to 5 devices per port)
688 Format: <port#>,<pad1>,<pad2>,<pad3>,<pad4>,<pad5>
689 See also Documentation/input/joystick-parport.txt
690
691 gamma= [HW,DRM]
692
Yinghai Luaaf23042008-01-30 13:33:09 +0100693 gart_fix_e820= [X86_64] disable the fix e820 for K8 GART
694 Format: off | on
695 default: on
696
Linus Torvalds1da177e2005-04-16 15:20:36 -0700697 gdth= [HW,SCSI]
698 See header of drivers/scsi/gdth.c.
699
700 gpt [EFI] Forces disk with valid GPT signature but
701 invalid Protective MBR to be treated as GPT.
702
Linus Torvalds1da177e2005-04-16 15:20:36 -0700703 gvp11= [HW,SCSI]
704
705 hashdist= [KNL,NUMA] Large hashes allocated during boot
706 are distributed across NUMA nodes. Defaults on
707 for IA-64, off otherwise.
Randy Dunlapa9913042005-10-23 12:57:11 -0700708 Format: 0 | 1 (for off | on)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700709
710 hcl= [IA-64] SGI's Hardware Graph compatibility layer
711
712 hd= [EIDE] (E)IDE hard drive subsystem geometry
713 Format: <cyl>,<head>,<sect>
714
715 hd?= [HW] (E)IDE subsystem
Randy Dunlap1c10e932008-03-07 21:53:50 +0100716 hd?lun= See Documentation/ide/ide.txt.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700717
718 highmem=nn[KMG] [KNL,BOOT] forces the highmem zone to have an exact
719 size of <nn>. This works even on boxes that have no
720 highmem otherwise. This also works to reduce highmem
721 size on bigger boxes.
722
Thomas Gleixner54cdfdb2007-02-16 01:28:11 -0800723 highres= [KNL] Enable/disable high resolution timer mode.
724 Valid parameters: "on", "off"
725 Default: "on"
726
Linus Torvalds1da177e2005-04-16 15:20:36 -0700727 hisax= [HW,ISDN]
728 See Documentation/isdn/README.HiSax.
729
Alan Coxcd4f0ef2007-07-31 00:37:59 -0700730 hugepages= [HW,X86-32,IA-64] Maximal number of HugeTLB pages.
Jon Tollefson4ec161c2008-01-04 09:59:50 +1100731 hugepagesz= [HW,IA-64,PPC] The size of the HugeTLB pages.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700732
Linus Torvalds1da177e2005-04-16 15:20:36 -0700733 i8042.direct [HW] Put keyboard port into non-translated mode
Matt LaPlante84eb8d02006-10-03 22:53:09 +0200734 i8042.dumbkbd [HW] Pretend that controller can only read data from
735 keyboard and cannot control its state
Linus Torvalds1da177e2005-04-16 15:20:36 -0700736 (Don't attempt to blink the leds)
737 i8042.noaux [HW] Don't check for auxiliary (== mouse) port
Dmitry Torokhov945ef0d2005-09-04 01:42:00 -0500738 i8042.nokbd [HW] Don't check/create keyboard port
Jiri Kosina75d08c72008-03-13 16:13:59 -0400739 i8042.noloop [HW] Disable the AUX Loopback command while probing
740 for the AUX port
Linus Torvalds1da177e2005-04-16 15:20:36 -0700741 i8042.nomux [HW] Don't check presence of an active multiplexing
742 controller
743 i8042.nopnp [HW] Don't use ACPIPnP / PnPBIOS to discover KBD/AUX
744 controllers
745 i8042.panicblink=
746 [HW] Frequency with which keyboard LEDs should blink
747 when kernel panics (default is 0.5 sec)
748 i8042.reset [HW] Reset the controller during init and cleanup
749 i8042.unlock [HW] Unlock (ignore) the keylock
750
751 i810= [HW,DRM]
752
Dmitry Torokhove70c9d52005-06-25 14:54:25 -0700753 i8k.ignore_dmi [HW] Continue probing hardware even if DMI data
754 indicates that the driver is running on unsupported
755 hardware.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700756 i8k.force [HW] Activate i8k driver even if SMM BIOS signature
757 does not match list of supported models.
758 i8k.power_status
759 [HW] Report power status in /proc/i8k
760 (disabled by default)
761 i8k.restricted [HW] Allow controlling fans only if SYS_ADMIN
762 capability is set.
763
764 ibmmcascsi= [HW,MCA,SCSI] IBM MicroChannel SCSI adapter
765 See Documentation/mca.txt.
766
767 icn= [HW,ISDN]
768 Format: <io>[,<membase>[,<icn_id>[,<icn_id2>]]]
769
770 ide= [HW] (E)IDE subsystem
Greg Kroah-Hartmana594eeb2008-04-18 00:46:20 +0200771 Format: ide=nodma or ide=doubler
Randy Dunlap1c10e932008-03-07 21:53:50 +0100772 See Documentation/ide/ide.txt.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700773
Linus Torvalds1da177e2005-04-16 15:20:36 -0700774 idebus= [HW] (E)IDE subsystem - VLB/PCI bus speed
Randy Dunlap1c10e932008-03-07 21:53:50 +0100775 See Documentation/ide/ide.txt.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700776
Andi Kleenf039b752007-05-02 19:27:12 +0200777 idle= [X86]
778 Format: idle=poll or idle=mwait
779 Poll forces a polling idle loop that can slightly improves the performance
780 of waking up a idle CPU, but will use a lot of power and make the system
781 run hot. Not recommended.
782 idle=mwait. On systems which support MONITOR/MWAIT but the kernel chose
783 to not use it because it doesn't save as much power as a normal idle
784 loop use the MONITOR/MWAIT idle loop anyways. Performance should be the same
785 as idle=poll.
Randy Dunlapa9913042005-10-23 12:57:11 -0700786
Denis Cheng594765a2008-02-06 02:57:49 +0100787 ide-pci-generic.all-generic-ide [HW] (E)IDE subsystem
788 Claim all unknown PCI IDE storage controllers.
789
Ingo Molnar792908222006-12-06 20:40:51 -0800790 ignore_loglevel [KNL]
791 Ignore loglevel setting - this will print /all/
792 kernel messages to the console. Useful for debugging.
793
Linus Torvalds1da177e2005-04-16 15:20:36 -0700794 ihash_entries= [KNL]
795 Set number of hash buckets for inode cache.
796
797 in2000= [HW,SCSI]
798 See header of drivers/scsi/in2000.c.
799
800 init= [KNL]
801 Format: <full_path>
802 Run specified binary instead of /sbin/init as init
803 process.
804
805 initcall_debug [KNL] Trace initcalls as they are executed. Useful
806 for working out where the kernel is dying during
807 startup.
808
809 initrd= [BOOT] Specify the location of the initial ramdisk
810
811 inport.irq= [HW] Inport (ATI XL and Microsoft) busmouse driver
812 Format: <irq>
813
814 inttest= [IA64]
815
Pavel Machekb552da82008-03-19 15:58:11 +0100816 iommu= [x86]
817 off
818 force
819 noforce
820 biomerge
821 panic
822 nopanic
823 merge
824 nomerge
825 forcesac
826 soft
827
828
Keshavamurthy, Anil Sba395922007-10-21 16:41:49 -0700829 intel_iommu= [DMAR] Intel IOMMU driver (DMAR) option
830 off
831 Disable intel iommu driver.
832 igfx_off [Default Off]
833 By default, gfx is mapped as normal device. If a gfx
834 device has a dedicated DMAR unit, the DMAR unit is
835 bypassed by not enabling DMAR with this option. In
836 this case, gfx device will use physical address for
837 DMA.
Keshavamurthy, Anil S7d3b03c2007-10-21 16:41:53 -0700838 forcedac [x86_64]
839 With this option iommu will not optimize to look
840 for io virtual address below 32 bit forcing dual
841 address cycle on pci bus for cards supporting greater
842 than 32 bit addressing. The default is to look
843 for translation below 32 bit and if not available
844 then look in the higher range.
mark gross5e0d2a62008-03-04 15:22:08 -0800845 strict [Default Off]
846 With this option on every unmap_single operation will
847 result in a hardware IOTLB flush operation as opposed
848 to batching them for performance.
Keshavamurthy, Anil Sba395922007-10-21 16:41:49 -0700849
Rene Hermanb02aae92008-01-30 13:30:05 +0100850 io_delay= [X86-32,X86-64] I/O delay method
Ingo Molnar6e7c4022008-01-30 13:30:05 +0100851 0x80
852 Standard port 0x80 based delay
853 0xed
854 Alternate port 0xed based delay (needed on some systems)
Rene Hermanb02aae92008-01-30 13:30:05 +0100855 udelay
Ingo Molnar6e7c4022008-01-30 13:30:05 +0100856 Simple two microseconds delay
857 none
858 No delay
Rene Hermanb02aae92008-01-30 13:30:05 +0100859
Linus Torvalds1da177e2005-04-16 15:20:36 -0700860 io7= [HW] IO7 for Marvel based alpha systems
861 See comment before marvel_specify_io7 in
862 arch/alpha/kernel/core_marvel.c.
863
864 ip= [IP_PNP]
J. Bruce Fields6ded55d2008-04-07 15:59:03 -0400865 See Documentation/filesystems/nfsroot.txt.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700866
867 ip2= [HW] Set IO/IRQ pairs for up to 4 IntelliPort boards
Randy Dunlapc8facbb2007-07-31 00:37:40 -0700868 See comment before ip2_setup() in
869 drivers/char/ip2/ip2base.c.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700870
871 ips= [HW,SCSI] Adaptec / IBM ServeRAID controller
872 See header of drivers/scsi/ips.c.
873
Simon Horman72c4a132006-09-13 19:57:18 -0700874 ports= [IP_VS_FTP] IPVS ftp helper module
875 Default is 21.
876 Up to 8 (IP_VS_APP_MAX_PORTS) ports
877 may be specified.
878 Format: <port>,<port>....
879
Alan Cox200803d2005-06-28 20:45:18 -0700880 irqfixup [HW]
881 When an interrupt is not handled search all handlers
882 for it. Intended to get systems with badly broken
883 firmware running.
884
885 irqpoll [HW]
886 When an interrupt is not handled search all handlers
887 for it. Also check all handlers each timer
888 interrupt. Intended to get systems with badly broken
889 firmware running.
890
Linus Torvalds1da177e2005-04-16 15:20:36 -0700891 isapnp= [ISAPNP]
Randy Dunlapa9913042005-10-23 12:57:11 -0700892 Format: <RDP>,<reset>,<pci_scan>,<verbosity>
Linus Torvalds1da177e2005-04-16 15:20:36 -0700893
894 isolcpus= [KNL,SMP] Isolate CPUs from the general scheduler.
Derek Fults22f2e282006-12-06 20:37:11 -0800895 Format:
896 <cpu number>,...,<cpu number>
897 or
898 <cpu number>-<cpu number> (must be a positive range in ascending order)
899 or a mixture
900 <cpu number>,...,<cpu number>-<cpu number>
Linus Torvalds1da177e2005-04-16 15:20:36 -0700901 This option can be used to specify one or more CPUs
902 to isolate from the general SMP balancing and scheduling
903 algorithms. The only way to move a process onto or off
904 an "isolated" CPU is via the CPU affinity syscalls.
905 <cpu number> begins at 0 and the maximum value is
906 "number of CPUs in system - 1".
907
908 This option is the preferred way to isolate CPUs. The
Randy Dunlapa9913042005-10-23 12:57:11 -0700909 alternative -- manually setting the CPU mask of all
910 tasks in the system -- can cause problems and
911 suboptimal load balancer performance.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700912
Randy Dunlapa9913042005-10-23 12:57:11 -0700913 iucv= [HW,NET]
Linus Torvalds1da177e2005-04-16 15:20:36 -0700914
915 js= [HW,JOY] Analog joystick
916 See Documentation/input/joystick.txt.
917
Alan Coxcd4f0ef2007-07-31 00:37:59 -0700918 kernelcore=nn[KMG] [KNL,X86-32,IA-64,PPC,X86-64] This parameter
Mel Gormaned7ed362007-07-17 04:03:14 -0700919 specifies the amount of memory usable by the kernel
920 for non-movable allocations. The requested amount is
921 spread evenly throughout all nodes in the system. The
922 remaining memory in each node is used for Movable
923 pages. In the event, a node is too small to have both
924 kernelcore and Movable pages, kernelcore pages will
925 take priority and other nodes will have a larger number
926 of kernelcore pages. The Movable zone is used for the
927 allocation of pages that may be reclaimed or moved
928 by the page migration subsystem. This means that
929 HugeTLB pages may not be allocated from this zone.
930 Note that allocations like PTEs-from-HighMem still
931 use the HighMem zone if it exists, and the Normal
932 zone if it does not.
933
Alan Coxcd4f0ef2007-07-31 00:37:59 -0700934 movablecore=nn[KMG] [KNL,X86-32,IA-64,PPC,X86-64] This parameter
Mel Gorman7e63efe2007-07-17 04:03:15 -0700935 is similar to kernelcore except it specifies the
936 amount of memory used for migratable allocations.
937 If both kernelcore and movablecore is specified,
938 then kernelcore will be at *least* the specified
939 value but may be more. If movablecore on its own
940 is specified, the administrator must be careful
941 that the amount of memory usable for all allocations
942 is not too small.
943
Linus Torvalds1da177e2005-04-16 15:20:36 -0700944 keepinitrd [HW,ARM]
945
Alan Coxcd4f0ef2007-07-31 00:37:59 -0700946 kstack=N [X86-32,X86-64] Print N words from the kernel stack
Linus Torvalds1da177e2005-04-16 15:20:36 -0700947 in oops dumps.
948
Jason Wessel6cdf6e02008-04-17 20:05:38 +0200949 kgdboc= [HW] kgdb over consoles.
950 Requires a tty driver that supports console polling.
951 (only serial suported for now)
952 Format: <serial_device>[,baud]
953
Linus Torvalds1da177e2005-04-16 15:20:36 -0700954 l2cr= [PPC]
955
Robert Brosea78bfbf2008-03-29 07:20:23 +1100956 l3cr= [PPC]
957
Alan Coxcd4f0ef2007-07-31 00:37:59 -0700958 lapic [X86-32,APIC] Enable the local APIC even if BIOS
Randy Dunlapa9913042005-10-23 12:57:11 -0700959 disabled it.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700960
Alan Coxcd4f0ef2007-07-31 00:37:59 -0700961 lapic_timer_c2_ok [X86-32,x86-64,APIC] trust the local apic timer in
Thomas Gleixnere585bef2007-03-23 16:08:01 +0100962 C2 power state.
963
FD Camifcb71f62008-01-06 19:08:56 +0100964 libata.dma= [LIBATA] DMA control
965 libata.dma=0 Disable all PATA and SATA DMA
966 libata.dma=1 PATA and SATA Disk DMA only
967 libata.dma=2 ATAPI (CDROM) DMA only
968 libata.dma=4 Compact Flash DMA only
969 Combinations also work, so libata.dma=3 enables DMA
970 for disks and CDROMs, but not CFs.
971
Dave Jones78e70c22007-09-27 11:50:13 -0400972 libata.noacpi [LIBATA] Disables use of ACPI in libata suspend/resume
973 when set.
974 Format: <int>
975
Tejun Heo33267322008-02-13 09:15:09 +0900976 libata.force= [LIBATA] Force configurations. The format is comma
977 separated list of "[ID:]VAL" where ID is
978 PORT[:DEVICE]. PORT and DEVICE are decimal numbers
979 matching port, link or device. Basically, it matches
980 the ATA ID string printed on console by libata. If
981 the whole ID part is omitted, the last PORT and DEVICE
982 values are used. If ID hasn't been specified yet, the
983 configuration applies to all ports, links and devices.
984
985 If only DEVICE is omitted, the parameter applies to
986 the port and all links and devices behind it. DEVICE
987 number of 0 either selects the first device or the
988 first fan-out link behind PMP device. It does not
989 select the host link. DEVICE number of 15 selects the
990 host link and device attached to it.
991
992 The VAL specifies the configuration to force. As long
993 as there's no ambiguity shortcut notation is allowed.
994 For example, both 1.5 and 1.5G would work for 1.5Gbps.
995 The following configurations can be forced.
996
997 * Cable type: 40c, 80c, short40c, unk, ign or sata.
998 Any ID with matching PORT is used.
999
1000 * SATA link speed limit: 1.5Gbps or 3.0Gbps.
1001
1002 * Transfer mode: pio[0-7], mwdma[0-4] and udma[0-7].
1003 udma[/][16,25,33,44,66,100,133] notation is also
1004 allowed.
1005
1006 * [no]ncq: Turn on or off NCQ.
1007
1008 If there are multiple matching configurations changing
1009 the same attribute, the last one is used.
1010
Linus Torvalds1da177e2005-04-16 15:20:36 -07001011 load_ramdisk= [RAM] List of ramdisks to load from floppy
1012 See Documentation/ramdisk.txt.
1013
Randy Dunlapa6b25b62006-01-14 13:21:19 -08001014 lockd.nlm_grace_period=P [NFS] Assign grace period.
1015 Format: <integer>
Linus Torvalds1da177e2005-04-16 15:20:36 -07001016
Randy Dunlapa6b25b62006-01-14 13:21:19 -08001017 lockd.nlm_tcpport=N [NFS] Assign TCP port.
1018 Format: <integer>
1019
1020 lockd.nlm_timeout=T [NFS] Assign timeout value.
1021 Format: <integer>
1022
1023 lockd.nlm_udpport=M [NFS] Assign UDP port.
1024 Format: <integer>
Linus Torvalds1da177e2005-04-16 15:20:36 -07001025
1026 logibm.irq= [HW,MOUSE] Logitech Bus Mouse Driver
1027 Format: <irq>
1028
1029 loglevel= All Kernel Messages with a loglevel smaller than the
1030 console loglevel will be printed to the console. It can
1031 also be changed with klogd or other programs. The
1032 loglevels are defined as follows:
1033
1034 0 (KERN_EMERG) system is unusable
1035 1 (KERN_ALERT) action must be taken immediately
1036 2 (KERN_CRIT) critical conditions
1037 3 (KERN_ERR) error conditions
1038 4 (KERN_WARNING) warning conditions
1039 5 (KERN_NOTICE) normal but significant condition
1040 6 (KERN_INFO) informational
1041 7 (KERN_DEBUG) debug-level messages
1042
1043 log_buf_len=n Sets the size of the printk ring buffer, in bytes.
Randy Dunlapa9913042005-10-23 12:57:11 -07001044 Format: { n | nk | nM }
1045 n must be a power of two. The default size
1046 is set in the kernel config file.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001047
Randy Dunlapaccaa242007-10-16 01:29:37 -07001048 logo.nologo [FB] Disables display of the built-in Linux logo.
1049 This may be used to provide more screen space for
1050 kernel log messages and is useful when debugging
1051 kernel boot problems.
1052
Linus Torvalds1da177e2005-04-16 15:20:36 -07001053 lp=0 [LP] Specify parallel ports to use, e.g,
1054 lp=port[,port...] lp=none,parport0 (lp0 not configured, lp1 uses
1055 lp=reset first parallel port). 'lp=0' disables the
1056 lp=auto printer driver. 'lp=reset' (which can be
1057 specified in addition to the ports) causes
1058 attached printers to be reset. Using
1059 lp=port1,port2,... specifies the parallel ports
1060 to associate lp devices with, starting with
1061 lp0. A port specification may be 'none' to skip
1062 that lp device, or a parport name such as
1063 'parport0'. Specifying 'lp=auto' instead of a
1064 port specification list means that device IDs
1065 from each port should be examined, to see if
1066 an IEEE 1284-compliant printer is attached; if
1067 so, the driver will manage that printer.
1068 See also header of drivers/char/lp.c.
1069
1070 lpj=n [KNL]
1071 Sets loops_per_jiffy to given constant, thus avoiding
1072 time-consuming boot-time autodetection (up to 250 ms per
1073 CPU). 0 enables autodetection (default). To determine
1074 the correct value for your kernel, boot with normal
1075 autodetection and see what value is printed. Note that
1076 on SMP systems the preset will be applied to all CPUs,
1077 which is likely to cause problems if your CPUs need
1078 significantly divergent settings. An incorrect value
1079 will cause delays in the kernel to be wrong, leading to
1080 unpredictable I/O errors and other breakage. Although
1081 unlikely, in the extreme case this might damage your
1082 hardware.
1083
1084 ltpc= [NET]
1085 Format: <io>,<irq>,<dma>
1086
Randy Dunlapa9913042005-10-23 12:57:11 -07001087 mac5380= [HW,SCSI] Format:
1088 <can_queue>,<cmd_per_lun>,<sg_tablesize>,<hostid>,<use_tags>
Linus Torvalds1da177e2005-04-16 15:20:36 -07001089
Randy Dunlapa9913042005-10-23 12:57:11 -07001090 mac53c9x= [HW,SCSI] Format:
1091 <num_esps>,<disconnect>,<nosync>,<can_queue>,<cmd_per_lun>,<sg_tablesize>,<hostid>,<use_tags>
Linus Torvalds1da177e2005-04-16 15:20:36 -07001092
Randy Dunlapa9913042005-10-23 12:57:11 -07001093 machvec= [IA64] Force the use of a particular machine-vector
1094 (machvec) in a generic kernel.
1095 Example: machvec=hpzx1_swiotlb
Linus Torvalds1da177e2005-04-16 15:20:36 -07001096
Randy Dunlapa9913042005-10-23 12:57:11 -07001097 max_loop= [LOOP] Maximum number of loopback devices that can
Linus Torvalds1da177e2005-04-16 15:20:36 -07001098 be mounted
1099 Format: <1-256>
1100
1101 maxcpus= [SMP] Maximum number of processors that an SMP kernel
Len Brown61ec7562007-08-16 03:34:22 -04001102 should make use of. maxcpus=n : n >= 0 limits the
1103 kernel to using 'n' processors. n=0 is a special case,
1104 it is equivalent to "nosmp", which also disables
1105 the IO APIC.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001106
Bob Picco2b2c3752005-06-29 18:00:00 -07001107 max_addr=[KMG] [KNL,BOOT,ia64] All physical memory greater than or
1108 equal to this physical address is ignored.
1109
Randy Dunlapa9913042005-10-23 12:57:11 -07001110 max_luns= [SCSI] Maximum number of LUNs to probe.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001111 Should be between 1 and 2^32-1.
1112
1113 max_report_luns=
Randy Dunlapa9913042005-10-23 12:57:11 -07001114 [SCSI] Maximum number of LUNs received.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001115 Should be between 1 and 16384.
1116
Linus Torvalds1da177e2005-04-16 15:20:36 -07001117 mcatest= [IA-64]
1118
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001119 mce [X86-32] Machine Check Exception
Linus Torvalds1da177e2005-04-16 15:20:36 -07001120
Andi Kleen909dd322007-10-17 18:04:38 +02001121 mce=option [X86-64] See Documentation/x86_64/boot-options.txt
1122
Linus Torvalds1da177e2005-04-16 15:20:36 -07001123 md= [HW] RAID subsystems devices and level
1124 See Documentation/md.txt.
Randy Dunlapa9913042005-10-23 12:57:11 -07001125
Linus Torvalds1da177e2005-04-16 15:20:36 -07001126 mdacon= [MDA]
1127 Format: <first>,<last>
1128 Specifies range of consoles to be captured by the MDA.
Randy Dunlapa9913042005-10-23 12:57:11 -07001129
Linus Torvalds1da177e2005-04-16 15:20:36 -07001130 mem=nn[KMG] [KNL,BOOT] Force usage of a specific amount of memory
1131 Amount of memory to be used when the kernel is not able
1132 to see the whole system memory or for test.
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001133 [X86-32] Use together with memmap= to avoid physical
Linus Torvalds1da177e2005-04-16 15:20:36 -07001134 address space collisions. Without memmap= PCI devices
1135 could be placed at addresses belonging to unused RAM.
1136
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001137 mem=nopentium [BUGS=X86-32] Disable usage of 4MB pages for kernel
Linus Torvalds1da177e2005-04-16 15:20:36 -07001138 memory.
1139
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001140 memmap=exactmap [KNL,X86-32,X86_64] Enable setting of an exact
Linus Torvalds1da177e2005-04-16 15:20:36 -07001141 E820 memory map, as specified by the user.
1142 Such memmap=exactmap lines can be constructed based on
1143 BIOS output or other requirements. See the memmap=nn@ss
1144 option description.
1145
1146 memmap=nn[KMG]@ss[KMG]
1147 [KNL] Force usage of a specific region of memory
1148 Region of memory to be used, from ss to ss+nn.
1149
1150 memmap=nn[KMG]#ss[KMG]
1151 [KNL,ACPI] Mark specific memory as ACPI data.
1152 Region of memory to be used, from ss to ss+nn.
1153
1154 memmap=nn[KMG]$ss[KMG]
1155 [KNL,ACPI] Mark specific memory as reserved.
1156 Region of memory to be used, from ss to ss+nn.
Pavel Machek13128482008-03-24 12:29:43 -07001157 Example: Exclude memory from 0x18690000-0x1869ffff
1158 memmap=64K$0x18690000
1159 or
1160 memmap=0x10000$0x18690000
Linus Torvalds1da177e2005-04-16 15:20:36 -07001161
Yinghai Luc64df702008-03-21 18:56:19 -07001162 memtest= [KNL,X86_64] Enable memtest
1163 Format: <integer>
1164 range: 0,4 : pattern number
1165 default : 0 <disable>
1166
Linus Torvalds1da177e2005-04-16 15:20:36 -07001167 meye.*= [HW] Set MotionEye Camera parameters
1168 See Documentation/video4linux/meye.txt.
1169
Andres Salomon8f368812007-10-12 23:04:06 +02001170 mfgpt_irq= [IA-32] Specify the IRQ to use for the
1171 Multi-Function General Purpose Timers on AMD Geode
1172 platforms.
1173
Willy Tarreaue6c4dc62008-01-30 13:33:33 +01001174 mfgptfix [X86-32] Fix MFGPT timers on AMD Geode platforms when
1175 the BIOS has incorrectly applied a workaround. TinyBIOS
1176 version 0.98 is known to be affected, 0.99 fixes the
1177 problem by letting the user disable the workaround.
1178
Linus Torvalds1da177e2005-04-16 15:20:36 -07001179 mga= [HW,DRM]
1180
1181 mousedev.tap_time=
1182 [MOUSE] Maximum time between finger touching and
1183 leaving touchpad surface for touch to be considered
1184 a tap and be reported as a left button click (for
1185 touchpads working in absolute mode only).
1186 Format: <msecs>
1187 mousedev.xres= [MOUSE] Horizontal screen resolution, used for devices
1188 reporting absolute coordinates, such as tablets
1189 mousedev.yres= [MOUSE] Vertical screen resolution, used for devices
1190 reporting absolute coordinates, such as tablets
1191
1192 mpu401= [HW,OSS]
1193 Format: <io>,<irq>
1194
1195 MTD_Partition= [MTD]
1196 Format: <name>,<region-number>,<size>,<offset>
1197
Randy Dunlapa9913042005-10-23 12:57:11 -07001198 MTD_Region= [MTD] Format:
1199 <name>,<region-number>[,<base>,<size>,<buswidth>,<altbuswidth>]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001200
1201 mtdparts= [MTD]
Randy Dunlapc8facbb2007-07-31 00:37:40 -07001202 See drivers/mtd/cmdlinepart.c.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001203
1204 mtouchusb.raw_coordinates=
Randy Dunlapa9913042005-10-23 12:57:11 -07001205 [HW] Make the MicroTouch USB driver use raw coordinates
1206 ('y', default) or cooked coordinates ('n')
Linus Torvalds1da177e2005-04-16 15:20:36 -07001207
1208 n2= [NET] SDL Inc. RISCom/N2 synchronous serial card
1209
1210 NCR_D700= [HW,SCSI]
1211 See header of drivers/scsi/NCR_D700.c.
1212
1213 ncr5380= [HW,SCSI]
1214
1215 ncr53c400= [HW,SCSI]
1216
1217 ncr53c400a= [HW,SCSI]
1218
1219 ncr53c406a= [HW,SCSI]
1220
1221 ncr53c8xx= [HW,SCSI]
1222
1223 netdev= [NET] Network devices parameters
1224 Format: <irq>,<io>,<mem_start>,<mem_end>,<name>
1225 Note that mem_start is often overloaded to mean
1226 something different and driver-specific.
Randy Dunlapa9913042005-10-23 12:57:11 -07001227 This usage is only documented in each driver source
1228 file if at all.
1229
Linus Torvalds1da177e2005-04-16 15:20:36 -07001230 nfsaddrs= [NFS]
J. Bruce Fields6ded55d2008-04-07 15:59:03 -04001231 See Documentation/filesystems/nfsroot.txt.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001232
1233 nfsroot= [NFS] nfs root filesystem for disk-less boxes.
J. Bruce Fields6ded55d2008-04-07 15:59:03 -04001234 See Documentation/filesystems/nfsroot.txt.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001235
Trond Myklebusta72b4422006-01-03 09:55:41 +01001236 nfs.callback_tcpport=
1237 [NFS] set the TCP port on which the NFSv4 callback
1238 channel should listen.
1239
Trond Myklebust58df0952006-01-03 09:55:57 +01001240 nfs.idmap_cache_timeout=
1241 [NFS] set the maximum lifetime for idmapper cache
1242 entries.
1243
Trond Myklebustf43bf0b2007-10-09 12:01:04 -04001244 nfs.enable_ino64=
1245 [NFS] enable 64-bit inode numbers.
1246 If zero, the NFS client will fake up a 32-bit inode
1247 number for the readdir() and stat() syscalls instead
1248 of returning the full 64-bit number.
1249 The default is to return 64-bit inode numbers.
1250
Haavard Skinnemoene7ba1762007-10-10 14:58:29 +02001251 nmi_debug= [KNL,AVR32] Specify one or more actions to take
1252 when a NMI is triggered.
1253 Format: [state][,regs][,debounce][,die]
1254
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001255 nmi_watchdog= [KNL,BUGS=X86-32] Debugging features for SMP kernels
Linus Torvalds1da177e2005-04-16 15:20:36 -07001256
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001257 no387 [BUGS=X86-32] Tells the kernel to use the 387 maths
Linus Torvalds1da177e2005-04-16 15:20:36 -07001258 emulation library even if a 387 maths coprocessor
1259 is present.
1260
Christoph Lameterc1aee212007-05-31 00:40:47 -07001261 noaliencache [MM, NUMA, SLAB] Disables the allocation of alien
1262 caches in the slab allocator. Saves per-node memory,
1263 but will impact performance.
Paul Menage3395ee02006-12-06 20:32:16 -08001264
Randy Dunlapa9913042005-10-23 12:57:11 -07001265 noalign [KNL,ARM]
1266
Linus Torvalds1da177e2005-04-16 15:20:36 -07001267 noapic [SMP,APIC] Tells the kernel to not make use of any
1268 IOAPICs that may be present in the system.
1269
Linus Torvalds1da177e2005-04-16 15:20:36 -07001270 nobats [PPC] Do not use BATs for mapping kernel lowmem
1271 on "Classic" PPC cores.
1272
1273 nocache [ARM]
Randy Dunlapa9913042005-10-23 12:57:11 -07001274
Shailabh Nagar163ecdf2006-07-30 03:03:11 -07001275 nodelayacct [KNL] Disable per-task delay accounting
1276
Linus Torvalds1da177e2005-04-16 15:20:36 -07001277 nodisconnect [HW,SCSI,M68K] Disables SCSI disconnects.
1278
Huang, Ying8b2cb7a2008-01-30 13:32:11 +01001279 noefi [X86-32,X86-64] Disable EFI runtime services support.
1280
Linus Torvalds1da177e2005-04-16 15:20:36 -07001281 noexec [IA-64]
1282
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001283 noexec [X86-32,X86-64]
Jiri Slabyf5a1b192008-04-12 10:28:25 +02001284 On X86-32 available only on PAE configured kernels.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001285 noexec=on: enable non-executable mappings (default)
Jiri Slabyf5a1b192008-04-12 10:28:25 +02001286 noexec=off: disable non-executable mappings
1287
1288 noexec32 [X86-64]
1289 This affects only 32-bit executables.
1290 noexec32=on: enable non-executable mappings (default)
1291 read doesn't imply executable mappings
1292 noexec32=off: disable non-executable mappings
1293 read implies executable mappings
Linus Torvalds1da177e2005-04-16 15:20:36 -07001294
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001295 nofxsr [BUGS=X86-32] Disables x86 floating point extended
Chuck Ebbert4f886512006-03-23 02:59:34 -08001296 register save and restore. The kernel will only save
1297 legacy floating-point registers on task switch.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001298
Andi Kleen191679f2008-01-30 13:33:21 +01001299 noclflush [BUGS=X86] Don't use the CLFLUSH instruction
1300
Linus Torvalds1da177e2005-04-16 15:20:36 -07001301 nohlt [BUGS=ARM]
Randy Dunlapa9913042005-10-23 12:57:11 -07001302
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001303 no-hlt [BUGS=X86-32] Tells the kernel that the hlt
Linus Torvalds1da177e2005-04-16 15:20:36 -07001304 instruction doesn't work correctly and not to
1305 use it.
1306
1307 nohalt [IA-64] Tells the kernel not to use the power saving
1308 function PAL_HALT_LIGHT when idle. This increases
1309 power-consumption. On the positive side, it reduces
1310 interrupt wake-up latency, which may improve performance
1311 in certain environments such as networked servers or
1312 real-time systems.
1313
Thomas Gleixner79bf2bb2007-02-16 01:28:03 -08001314 nohz= [KNL] Boottime enable/disable dynamic ticks
1315 Valid arguments: on, off
1316 Default: on
1317
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001318 noirqbalance [X86-32,SMP,KNL] Disable kernel irq balancing
Zachary Amsden8542b202006-12-07 02:14:09 +01001319
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001320 noirqdebug [X86-32] Disables the code which attempts to detect and
Linus Torvalds1da177e2005-04-16 15:20:36 -07001321 disable unhandled interrupt sources.
1322
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001323 no_timer_check [X86-32,X86_64,APIC] Disables the code which tests for
Zachary Amsden8542b202006-12-07 02:14:09 +01001324 broken timer IRQ sources.
1325
Linus Torvalds1da177e2005-04-16 15:20:36 -07001326 noisapnp [ISAPNP] Disables ISA PnP code.
1327
1328 noinitrd [RAM] Tells the kernel not to load any configured
1329 initial RAM disk.
1330
1331 nointroute [IA-64]
1332
Tony Luck0aa366f2007-07-20 11:22:30 -07001333 nojitter [IA64] Disables jitter checking for ITC timers.
1334
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001335 nolapic [X86-32,APIC] Do not enable or use the local APIC.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001336
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001337 nolapic_timer [X86-32,APIC] Do not use the local APIC timer.
Thomas Gleixnerad62ca22007-03-22 00:11:21 -08001338
Linus Torvalds1da177e2005-04-16 15:20:36 -07001339 noltlbs [PPC] Do not use large page/tlb entries for kernel
1340 lowmem mapping on PPC40x.
1341
Horms312f1f02006-02-22 09:57:55 +09001342 nomca [IA-64] Disable machine check abort handling
1343
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001344 nomce [X86-32] Machine Check Exception
Hormsabe37e52006-04-01 01:36:09 +02001345
Andres Salomon83d73842007-10-12 23:04:06 +02001346 nomfgpt [X86-32] Disable Multi-Function General Purpose
1347 Timer usage (for AMD Geode machines).
1348
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001349 noreplace-paravirt [X86-32,PV_OPS] Don't patch paravirt_ops
Jeremy Fitzhardinge959b4fd2007-05-02 19:27:16 +02001350
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001351 noreplace-smp [X86-32,SMP] Don't replace SMP instructions
Jeremy Fitzhardingeb7fb4af2007-05-02 19:27:13 +02001352 with UP alternatives
1353
Linus Torvalds1da177e2005-04-16 15:20:36 -07001354 noresidual [PPC] Don't use residual data on PReP machines.
1355
Randy Dunlapa9913042005-10-23 12:57:11 -07001356 noresume [SWSUSP] Disables resume and restores original swap
1357 space.
1358
Linus Torvalds1da177e2005-04-16 15:20:36 -07001359 no-scroll [VGA] Disables scrollback.
1360 This is required for the Braillex ib80-piezo Braille
1361 reader made by F.H. Papenmeier (Germany).
1362
1363 nosbagart [IA-64]
1364
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001365 nosep [BUGS=X86-32] Disables x86 SYSENTER/SYSEXIT support.
Chuck Ebbert4f886512006-03-23 02:59:34 -08001366
Len Brown61ec7562007-08-16 03:34:22 -04001367 nosmp [SMP] Tells an SMP kernel to act as a UP kernel,
1368 and disable the IO APIC. legacy for "maxcpus=0".
Linus Torvalds1da177e2005-04-16 15:20:36 -07001369
Dave Jones97842212007-07-15 23:41:05 -07001370 nosoftlockup [KNL] Disable the soft-lockup detector.
1371
Linus Torvalds1da177e2005-04-16 15:20:36 -07001372 nosync [HW,M68K] Disables sync negotiation for all devices.
1373
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001374 notsc [BUGS=X86-32] Disable Time Stamp Counter
Linus Torvalds1da177e2005-04-16 15:20:36 -07001375
1376 nousb [USB] Disable the USB subsystem
1377
1378 nowb [ARM]
Randy Dunlapa9913042005-10-23 12:57:11 -07001379
Fenghua Yua6c75b862008-03-14 13:57:08 -07001380 nptcg= [IA64] Override max number of concurrent global TLB
1381 purges which is reported from either PAL_VM_SUMMARY or
1382 SAL PALO.
1383
KAMEZAWA Hiroyukif0c0b2b2007-07-15 23:38:01 -07001384 numa_zonelist_order= [KNL, BOOT] Select zonelist order for NUMA.
1385 one of ['zone', 'node', 'default'] can be specified
1386 This can be set from sysctl after boot.
1387 See Documentation/sysctl/vm.txt for details.
1388
Dave Jonesa61c2d72006-01-07 23:18:19 +00001389 nr_uarts= [SERIAL] maximum number of UARTs to be registered.
1390
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07001391 olpc_ec_timeout= [OLPC] ms delay when issuing EC commands
1392 Rather than timing out after 20 ms if an EC
1393 command is not properly ACKed, override the length
1394 of the timeout. We have interrupts disabled while
1395 waiting for the ACK, so if this is set too high
1396 interrupts *may* be lost!
1397
Linus Torvalds1da177e2005-04-16 15:20:36 -07001398 opl3= [HW,OSS]
1399 Format: <io>
1400
Linus Torvalds1da177e2005-04-16 15:20:36 -07001401 oprofile.timer= [HW]
1402 Use timer interrupt instead of performance counters
1403
Linus Torvalds1da177e2005-04-16 15:20:36 -07001404 osst= [HW,SCSI] SCSI Tape Driver
1405 Format: <buffer_size>,<write_threshold>
1406 See also Documentation/scsi/st.txt.
1407
1408 panic= [KNL] Kernel behaviour on panic
1409 Format: <timeout>
1410
1411 parkbd.port= [HW] Parallel port number the keyboard adapter is
1412 connected to, default is 0.
1413 Format: <parport#>
1414 parkbd.mode= [HW] Parallel port keyboard adapter mode of operation,
1415 0 for XT, 1 for AT (default is AT).
Randy Dunlapa9913042005-10-23 12:57:11 -07001416 Format: <mode>
Linus Torvalds1da177e2005-04-16 15:20:36 -07001417
Randy Dunlapa9913042005-10-23 12:57:11 -07001418 parport= [HW,PPT] Specify parallel ports. 0 disables.
1419 Format: { 0 | auto | 0xBBB[,IRQ[,DMA]] }
1420 Use 'auto' to force the driver to use any
1421 IRQ/DMA settings detected (the default is to
1422 ignore detected IRQ/DMA settings because of
1423 possible conflicts). You can specify the base
1424 address, IRQ, and DMA settings; IRQ and DMA
1425 should be numbers, or 'auto' (for using detected
1426 settings on that particular port), or 'nofifo'
1427 (to avoid using a FIFO even if it is detected).
1428 Parallel ports are assigned in the order they
1429 are specified on the command line, starting
1430 with parport0.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001431
Randy Dunlapa9913042005-10-23 12:57:11 -07001432 parport_init_mode= [HW,PPT]
1433 Configure VIA parallel port to operate in
1434 a specific mode. This is necessary on Pegasos
1435 computer where firmware has no options for setting
1436 up parallel port mode and sets it to spp.
1437 Currently this function knows 686a and 8231 chips.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001438 Format: [spp|ps2|epp|ecp|ecpepp]
1439
Randy Dunlapa9913042005-10-23 12:57:11 -07001440 pas2= [HW,OSS] Format:
1441 <io>,<irq>,<dma>,<dma16>,<sb_io>,<sb_irq>,<sb_dma>,<sb_dma16>
1442
Linus Torvalds1da177e2005-04-16 15:20:36 -07001443 pas16= [HW,SCSI]
1444 See header of drivers/scsi/pas16.c.
1445
Andrew Mortondd287792006-03-23 03:00:57 -08001446 pause_on_oops=
1447 Halt all CPUs after the first oops has been printed for
1448 the specified number of seconds. This is to be used if
1449 your oopses keep scrolling off the screen.
1450
Linus Torvalds1da177e2005-04-16 15:20:36 -07001451 pcbit= [HW,ISDN]
1452
1453 pcd. [PARIDE]
1454 See header of drivers/block/paride/pcd.c.
1455 See also Documentation/paride.txt.
1456
Randy Dunlapa9913042005-10-23 12:57:11 -07001457 pci=option[,option...] [PCI] various PCI subsystem options:
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001458 off [X86-32] don't probe for the PCI bus
1459 bios [X86-32] force use of PCI BIOS, don't access
Randy Dunlapa9913042005-10-23 12:57:11 -07001460 the hardware directly. Use this if your machine
1461 has a non-standard PCI host bridge.
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001462 nobios [X86-32] disallow use of PCI BIOS, only direct
Randy Dunlapa9913042005-10-23 12:57:11 -07001463 hardware access methods are allowed. Use this
1464 if you experience crashes upon bootup and you
1465 suspect they are caused by the BIOS.
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001466 conf1 [X86-32] Force use of PCI Configuration
Randy Dunlapa9913042005-10-23 12:57:11 -07001467 Mechanism 1.
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001468 conf2 [X86-32] Force use of PCI Configuration
Randy Dunlapa9913042005-10-23 12:57:11 -07001469 Mechanism 2.
Randy Dunlap7f785762007-10-05 13:17:58 -07001470 noaer [PCIE] If the PCIEAER kernel config parameter is
1471 enabled, this kernel boot option can be used to
1472 disable the use of PCIE advanced error reporting.
Jeff Garzik32a2eea2007-10-11 16:57:27 -04001473 nodomains [PCI] Disable support for multiple PCI
1474 root domains (aka PCI segments, in ACPI-speak).
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001475 nommconf [X86-32,X86_64] Disable use of MMCONFIG for PCI
Bjorn Helgaas61be6d62006-02-15 15:17:43 -08001476 Configuration
Matthew Wilcox309e57d2006-03-05 22:33:34 -07001477 nomsi [MSI] If the PCI_MSI kernel config parameter is
1478 enabled, this kernel boot option can be used to
1479 disable the use of MSI interrupts system-wide.
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001480 biosirq [X86-32] Use PCI BIOS calls to get the interrupt
Randy Dunlapa9913042005-10-23 12:57:11 -07001481 routing table. These calls are known to be buggy
1482 on several machines and they hang the machine
1483 when used, but on other computers it's the only
1484 way to get the interrupt routing table. Try
1485 this option if the kernel is unable to allocate
1486 IRQs or discover secondary PCI buses on your
1487 motherboard.
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001488 rom [X86-32] Assign address space to expansion ROMs.
Randy Dunlapa9913042005-10-23 12:57:11 -07001489 Use with caution as certain devices share
1490 address decoders between ROMs and other
1491 resources.
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001492 irqmask=0xMMMM [X86-32] Set a bit mask of IRQs allowed to be
Randy Dunlapa9913042005-10-23 12:57:11 -07001493 assigned automatically to PCI devices. You can
1494 make the kernel exclude IRQs of your ISA cards
1495 this way.
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001496 pirqaddr=0xAAAAA [X86-32] Specify the physical address
Randy Dunlapa9913042005-10-23 12:57:11 -07001497 of the PIRQ table (normally generated
1498 by the BIOS) if it is outside the
1499 F0000h-100000h range.
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001500 lastbus=N [X86-32] Scan all buses thru bus #N. Can be
Randy Dunlapa9913042005-10-23 12:57:11 -07001501 useful if the kernel is unable to find your
1502 secondary buses and you want to tell it
1503 explicitly which ones they are.
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001504 assign-busses [X86-32] Always assign all PCI bus
Randy Dunlapa9913042005-10-23 12:57:11 -07001505 numbers ourselves, overriding
1506 whatever the firmware may have done.
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001507 usepirqmask [X86-32] Honor the possible IRQ mask stored
Randy Dunlapa9913042005-10-23 12:57:11 -07001508 in the BIOS $PIR table. This is needed on
1509 some systems with broken BIOSes, notably
1510 some HP Pavilion N5400 and Omnibook XE3
1511 notebooks. This will have no effect if ACPI
1512 IRQ routing is enabled.
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001513 noacpi [X86-32] Do not use ACPI for IRQ routing
Randy Dunlapa9913042005-10-23 12:57:11 -07001514 or for PCI scanning.
Gary Hade62f420f2007-10-03 15:56:51 -07001515 use_crs [X86-32] Use _CRS for PCI resource
1516 allocation.
Randy Dunlapa9913042005-10-23 12:57:11 -07001517 routeirq Do IRQ routing for all PCI devices.
1518 This is normally done in pci_enable_device(),
1519 so this option is a temporary workaround
1520 for broken drivers that don't call it.
1521 firmware [ARM] Do not re-enumerate the bus but instead
1522 just use the configuration from the
1523 bootloader. This is currently used on
1524 IXP2000 systems where the bus has to be
1525 configured a certain way for adjunct CPUs.
Andi Kleen0637a702006-09-26 10:52:41 +02001526 noearly [X86] Don't do any early type 1 scanning.
1527 This might help on some broken boards which
1528 machine check when some devices' config space
1529 is read. But various workarounds are disabled
1530 and some IOMMU drivers will not work.
Matt Domsch6b4b78f2006-09-29 15:23:23 -05001531 bfsort Sort PCI devices into breadth-first order.
1532 This sorting is done to get a device
1533 order compatible with older (<= 2.4) kernels.
1534 nobfsort Don't sort PCI devices into breadth-first order.
Atsushi Nemoto4516a612007-02-05 16:36:06 -08001535 cbiosize=nn[KMG] The fixed amount of bus space which is
1536 reserved for the CardBus bridge's IO window.
1537 The default value is 256 bytes.
1538 cbmemsize=nn[KMG] The fixed amount of bus space which is
1539 reserved for the CardBus bridge's memory
1540 window. The default value is 64 megabytes.
Matt Domsch6b4b78f2006-09-29 15:23:23 -05001541
Linus Torvalds1da177e2005-04-16 15:20:36 -07001542 pcmv= [HW,PCMCIA] BadgePAD 4
1543
1544 pd. [PARIDE]
1545 See Documentation/paride.txt.
1546
1547 pdcchassis= [PARISC,HW] Disable/Enable PDC Chassis Status codes at
1548 boot time.
1549 Format: { 0 | 1 }
1550 See arch/parisc/kernel/pdc_chassis.c
1551
1552 pf. [PARIDE]
1553 See Documentation/paride.txt.
1554
1555 pg. [PARIDE]
1556 See Documentation/paride.txt.
1557
1558 pirq= [SMP,APIC] Manual mp-table setup
1559 See Documentation/i386/IO-APIC.txt.
1560
1561 plip= [PPT,NET] Parallel port network link
1562 Format: { parport<nr> | timid | 0 }
1563 See also Documentation/parport.txt.
1564
1565 pnpacpi= [ACPI]
1566 { off }
1567
1568 pnpbios= [ISAPNP]
1569 { on | off | curr | res | no-curr | no-res }
1570
1571 pnp_reserve_irq=
1572 [ISAPNP] Exclude IRQs for the autoconfiguration
1573
1574 pnp_reserve_dma=
1575 [ISAPNP] Exclude DMAs for the autoconfiguration
1576
1577 pnp_reserve_io= [ISAPNP] Exclude I/O ports for the autoconfiguration
Randy Dunlapa9913042005-10-23 12:57:11 -07001578 Ranges are in pairs (I/O port base and size).
Linus Torvalds1da177e2005-04-16 15:20:36 -07001579
1580 pnp_reserve_mem=
Randy Dunlapa9913042005-10-23 12:57:11 -07001581 [ISAPNP] Exclude memory regions for the
1582 autoconfiguration.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001583 Ranges are in pairs (memory base and size).
1584
Ingo Molnar45807a12007-07-15 23:40:10 -07001585 print-fatal-signals=
1586 [KNL] debug: print fatal signals
1587 print-fatal-signals=1: print segfault info to
1588 the kernel console.
1589 default: off.
1590
Randy Dunlape84845c2007-07-15 23:40:25 -07001591 printk.time= Show timing data prefixed to each printk message line
1592 Format: <bool> (1/Y/y=enable, 0/N/n=disable)
1593
Linus Torvalds1da177e2005-04-16 15:20:36 -07001594 profile= [KNL] Enable kernel profiling via /proc/profile
Randy Dunlapa9913042005-10-23 12:57:11 -07001595 Format: [schedule,]<number>
1596 Param: "schedule" - profile schedule points.
1597 Param: <number> - step/bucket size as a power of 2 for
1598 statistical time based profiling.
Mel Gormanb3da2a72007-10-24 18:23:50 +02001599 Param: "sleep" - profile D-state sleeping (millisecs).
1600 Requires CONFIG_SCHEDSTATS
Dave Jonesc0fe2e62007-10-20 03:08:22 +02001601 Param: "kvm" - profile VM exits.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001602
Randy Dunlapa9913042005-10-23 12:57:11 -07001603 processor.max_cstate= [HW,ACPI]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001604 Limit processor to maximum C-state
1605 max_cstate=9 overrides any DMI blacklist limit.
1606
Len Brown41c0d862005-12-28 12:43:51 -05001607 processor.nocst [HW,ACPI]
1608 Ignore the _CST method to determine C-states,
1609 instead using the legacy FADT method
1610
Linus Torvalds1da177e2005-04-16 15:20:36 -07001611 prompt_ramdisk= [RAM] List of RAM disks to prompt for floppy disk
1612 before loading.
1613 See Documentation/ramdisk.txt.
1614
Randy Dunlapa9913042005-10-23 12:57:11 -07001615 psmouse.proto= [HW,MOUSE] Highest PS2 mouse protocol extension to
1616 probe for; one of (bare|imps|exps|lifebook|any).
Linus Torvalds1da177e2005-04-16 15:20:36 -07001617 psmouse.rate= [HW,MOUSE] Set desired mouse report rate, in reports
1618 per second.
Randy Dunlapa9913042005-10-23 12:57:11 -07001619 psmouse.resetafter= [HW,MOUSE]
1620 Try to reset the device after so many bad packets
Linus Torvalds1da177e2005-04-16 15:20:36 -07001621 (0 = never).
1622 psmouse.resolution=
1623 [HW,MOUSE] Set desired mouse resolution, in dpi.
1624 psmouse.smartscroll=
Randy Dunlapa9913042005-10-23 12:57:11 -07001625 [HW,MOUSE] Controls Logitech smartscroll autorepeat.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001626 0 = disabled, 1 = enabled (default).
1627
1628 pss= [HW,OSS] Personal Sound System (ECHO ESC614)
Randy Dunlapa9913042005-10-23 12:57:11 -07001629 Format:
1630 <io>,<mss_io>,<mss_irq>,<mss_dma>,<mpu_io>,<mpu_irq>
Linus Torvalds1da177e2005-04-16 15:20:36 -07001631
1632 pt. [PARIDE]
1633 See Documentation/paride.txt.
1634
Kay Sieversdc8c8582007-08-15 12:25:38 +02001635 pty.legacy_count=
1636 [KNL] Number of legacy pty's. Overwrites compiled-in
1637 default number.
1638
Randy Dunlap7d2c5022006-09-29 02:01:02 -07001639 quiet [KNL] Disable most log messages
Randy Dunlapa9913042005-10-23 12:57:11 -07001640
Linus Torvalds1da177e2005-04-16 15:20:36 -07001641 r128= [HW,DRM]
1642
1643 raid= [HW,RAID]
1644 See Documentation/md.txt.
1645
Randy Dunlapa9913042005-10-23 12:57:11 -07001646 ramdisk_blocksize= [RAM]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001647 See Documentation/ramdisk.txt.
Randy Dunlapa9913042005-10-23 12:57:11 -07001648
Linus Torvalds1da177e2005-04-16 15:20:36 -07001649 ramdisk_size= [RAM] Sizes of RAM disks in kilobytes
Linus Torvalds1da177e2005-04-16 15:20:36 -07001650 See Documentation/ramdisk.txt.
1651
Robert P. J. Day24aaef82008-02-03 15:20:26 +02001652 rcupdate.blimit= [KNL,BOOT]
1653 Set maximum number of finished RCU callbacks to process
1654 in one batch.
Dipankar Sarma21a1ea92006-03-07 21:55:33 -08001655
Robert P. J. Day24aaef82008-02-03 15:20:26 +02001656 rcupdate.qhimark= [KNL,BOOT]
1657 Set threshold of queued
Dipankar Sarma21a1ea92006-03-07 21:55:33 -08001658 RCU callbacks over which batch limiting is disabled.
1659
Robert P. J. Day24aaef82008-02-03 15:20:26 +02001660 rcupdate.qlowmark= [KNL,BOOT]
1661 Set threshold of queued RCU callbacks below which
1662 batch limiting is re-enabled.
Dipankar Sarma21a1ea92006-03-07 21:55:33 -08001663
Olof Johanssonffdfc402005-09-06 15:17:19 -07001664 rdinit= [KNL]
1665 Format: <full_path>
1666 Run specified binary instead of /init from the ramdisk,
1667 used for early userspace startup. See initrd.
1668
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001669 reboot= [BUGS=X86-32,BUGS=ARM,BUGS=IA-64] Rebooting mode
Linus Torvalds1da177e2005-04-16 15:20:36 -07001670 Format: <reboot_mode>[,<reboot_mode2>[,...]]
Mauro Carvalho Chehabe53dd082007-09-15 07:38:47 -03001671 See arch/*/kernel/reboot.c or arch/*/kernel/process.c
Linus Torvalds1da177e2005-04-16 15:20:36 -07001672
1673 reserve= [KNL,BUGS] Force the kernel to ignore some iomem area
1674
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001675 reservetop= [X86-32]
Zachary Amsden461a9af2006-09-25 23:32:25 -07001676 Format: nn[KMG]
1677 Reserves a hole at the top of the kernel virtual
1678 address space.
1679
Vivek Goyal7e962872006-09-27 01:50:44 -07001680 reset_devices [KNL] Force drivers to reset the underlying device
1681 during initialization.
1682
Randy Dunlapa9913042005-10-23 12:57:11 -07001683 resume= [SWSUSP]
1684 Specify the partition device for software suspend
Linus Torvalds1da177e2005-04-16 15:20:36 -07001685
Rafael J. Wysockiecbd0da2006-12-06 20:34:13 -08001686 resume_offset= [SWSUSP]
1687 Specify the offset from the beginning of the partition
1688 given by "resume=" at which the swap header is located,
1689 in <PAGE_SIZE> units (needed only for swap files).
1690 See Documentation/power/swsusp-and-swap-files.txt
1691
Michael Neuling0a7b35cb2007-02-10 01:44:33 -08001692 retain_initrd [RAM] Keep initrd memory after extraction
1693
Linus Torvalds1da177e2005-04-16 15:20:36 -07001694 rhash_entries= [KNL,NET]
1695 Set number of hash buckets for route cache
1696
1697 riscom8= [HW,SERIAL]
1698 Format: <io_board1>[,<io_board2>[,...<io_boardN>]]
1699
1700 ro [KNL] Mount root device read-only on boot
1701
1702 root= [KNL] Root filesystem
1703
1704 rootdelay= [KNL] Delay (in seconds) to pause before attempting to
1705 mount the root filesystem
1706
1707 rootflags= [KNL] Set root filesystem mount option string
1708
1709 rootfstype= [KNL] Set root filesystem type
1710
Pierre Ossmancc1ed752007-07-15 23:40:35 -07001711 rootwait [KNL] Wait (indefinitely) for root device to show up.
1712 Useful for devices that are detected asynchronously
1713 (e.g. USB and MMC devices).
1714
James Morris20510f22007-10-16 23:31:32 -07001715 root_plug.vendor_id=
1716 [ROOTPLUG] Override the default vendor ID
1717
1718 root_plug.product_id=
1719 [ROOTPLUG] Override the default product ID
1720
1721 root_plug.debug=
1722 [ROOTPLUG] Enable debugging output
1723
Linus Torvalds1da177e2005-04-16 15:20:36 -07001724 rw [KNL] Mount root device read-write on boot
1725
1726 S [KNL] Run init in single mode
1727
1728 sa1100ir [NET]
1729 See drivers/net/irda/sa1100_ir.c.
1730
Linus Torvalds1da177e2005-04-16 15:20:36 -07001731 sbni= [NET] Granch SBNI12 leased line adapter
Randy Dunlapa9913042005-10-23 12:57:11 -07001732
Linus Torvalds1da177e2005-04-16 15:20:36 -07001733 sc1200wdt= [HW,WDT] SC1200 WDT (watchdog) driver
1734 Format: <io>[,<timeout>[,<isapnp>]]
1735
1736 scsi_debug_*= [SCSI]
1737 See drivers/scsi/scsi_debug.c.
1738
1739 scsi_default_dev_flags=
1740 [SCSI] SCSI default device flags
1741 Format: <integer>
1742
1743 scsi_dev_flags= [SCSI] Black/white list entry for vendor and model
1744 Format: <vendor>:<model>:<flags>
1745 (flags are integer value)
1746
Randy Dunlap6af66322007-11-14 16:52:25 -08001747 scsi_logging_level= [SCSI] a bit mask of logging levels
1748 See drivers/scsi/scsi_logging.h for bits. Also
1749 settable via sysctl at dev.scsi.logging_level
1750 (/proc/sys/dev/scsi/logging_level).
1751 There is also a nice 'scsi_logging_level' script in the
1752 S390-tools package, available for download at
1753 http://www-128.ibm.com/developerworks/linux/linux390/s390-tools-1.5.4.html
Linus Torvalds1da177e2005-04-16 15:20:36 -07001754
Matthew Wilcox3e082a92006-09-28 15:19:20 -06001755 scsi_mod.scan= [SCSI] sync (default) scans SCSI busses as they are
1756 discovered. async scans them in kernel threads,
1757 allowing boot to proceed. none ignores them, expecting
1758 user space to do the scan.
1759
Linus Torvalds1da177e2005-04-16 15:20:36 -07001760 selinux [SELINUX] Disable or enable SELinux at boot time.
1761 Format: { "0" | "1" }
1762 See security/selinux/Kconfig help text.
1763 0 -- disable.
1764 1 -- enable.
1765 Default value is set via kernel config option.
1766 If enabled at boot time, /selinux/disable can be used
1767 later to disable prior to initial policy load.
1768
James Morris4e5ab4c2006-06-09 00:33:33 -07001769 selinux_compat_net =
1770 [SELINUX] Set initial selinux_compat_net flag value.
Mauro Carvalho Chehabe53dd082007-09-15 07:38:47 -03001771 Format: { "0" | "1" }
1772 0 -- use new secmark-based packet controls
1773 1 -- use legacy packet controls
1774 Default value is 0 (preferred).
1775 Value can be changed at runtime via
1776 /selinux/compat_net.
James Morris4e5ab4c2006-06-09 00:33:33 -07001777
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001778 serialnumber [BUGS=X86-32]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001779
Linus Torvalds1da177e2005-04-16 15:20:36 -07001780 shapers= [NET]
1781 Maximal number of shapers.
Randy Dunlapa9913042005-10-23 12:57:11 -07001782
Linus Torvalds1da177e2005-04-16 15:20:36 -07001783 sim710= [SCSI,HW]
1784 See header of drivers/scsi/sim710.c.
1785
1786 simeth= [IA-64]
1787 simscsi=
Randy Dunlapa9913042005-10-23 12:57:11 -07001788
Linus Torvalds1da177e2005-04-16 15:20:36 -07001789 slram= [HW,MTD]
1790
Christoph Lameterf0630ff2007-07-15 23:38:14 -07001791 slub_debug[=options[,slabs]] [MM, SLUB]
1792 Enabling slub_debug allows one to determine the
1793 culprit if slab objects become corrupted. Enabling
1794 slub_debug can create guard zones around objects and
1795 may poison objects when not in use. Also tracks the
1796 last alloc / free. For more information see
1797 Documentation/vm/slub.txt.
Christoph Lameterc1aee212007-05-31 00:40:47 -07001798
1799 slub_max_order= [MM, SLUB]
Christoph Lameterf0630ff2007-07-15 23:38:14 -07001800 Determines the maximum allowed order for slabs.
1801 A high setting may cause OOMs due to memory
1802 fragmentation. For more information see
1803 Documentation/vm/slub.txt.
Christoph Lameterc1aee212007-05-31 00:40:47 -07001804
1805 slub_min_objects= [MM, SLUB]
Christoph Lameterf0630ff2007-07-15 23:38:14 -07001806 The minimum number of objects per slab. SLUB will
1807 increase the slab order up to slub_max_order to
1808 generate a sufficiently large slab able to contain
1809 the number of objects indicated. The higher the number
1810 of objects the smaller the overhead of tracking slabs
1811 and the less frequently locks need to be acquired.
Christoph Lameterc1aee212007-05-31 00:40:47 -07001812 For more information see Documentation/vm/slub.txt.
1813
1814 slub_min_order= [MM, SLUB]
1815 Determines the mininum page order for slabs. Must be
Christoph Lameterf0630ff2007-07-15 23:38:14 -07001816 lower than slub_max_order.
Christoph Lameterc1aee212007-05-31 00:40:47 -07001817 For more information see Documentation/vm/slub.txt.
1818
1819 slub_nomerge [MM, SLUB]
Christoph Lameterf0630ff2007-07-15 23:38:14 -07001820 Disable merging of slabs with similar size. May be
Christoph Lameterc1aee212007-05-31 00:40:47 -07001821 necessary if there is some reason to distinguish
Christoph Lameterf0630ff2007-07-15 23:38:14 -07001822 allocs to different slabs. Debug options disable
1823 merging on their own.
Christoph Lameterc1aee212007-05-31 00:40:47 -07001824 For more information see Documentation/vm/slub.txt.
1825
Linus Torvalds1da177e2005-04-16 15:20:36 -07001826 smart2= [HW]
1827 Format: <io1>[,<io2>[,...,<io8>]]
1828
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001829 smp-alt-once [X86-32,SMP] On a hotplug CPU system, only
Jeremy Fitzhardingeb7fb4af2007-05-02 19:27:13 +02001830 attempt to substitute SMP alternatives once at boot.
1831
Bjorn Helgaasd0d4f692007-05-08 00:36:05 -07001832 smsc-ircc2.nopnp [HW] Don't use PNP to discover SMC devices
1833 smsc-ircc2.ircc_cfg= [HW] Device configuration I/O port
1834 smsc-ircc2.ircc_sir= [HW] SIR base I/O port
1835 smsc-ircc2.ircc_fir= [HW] FIR base I/O port
1836 smsc-ircc2.ircc_irq= [HW] IRQ line
1837 smsc-ircc2.ircc_dma= [HW] DMA channel
1838 smsc-ircc2.ircc_transceiver= [HW] Transceiver type:
1839 0: Toshiba Satellite 1800 (GP data pin select)
1840 1: Fast pin select (default)
1841 2: ATC IRMode
1842
Linus Torvalds1da177e2005-04-16 15:20:36 -07001843 snd-ad1816a= [HW,ALSA]
1844
1845 snd-ad1848= [HW,ALSA]
1846
1847 snd-ali5451= [HW,ALSA]
1848
1849 snd-als100= [HW,ALSA]
1850
1851 snd-als4000= [HW,ALSA]
1852
1853 snd-azt2320= [HW,ALSA]
1854
1855 snd-cmi8330= [HW,ALSA]
1856
1857 snd-cmipci= [HW,ALSA]
1858
1859 snd-cs4231= [HW,ALSA]
1860
1861 snd-cs4232= [HW,ALSA]
1862
1863 snd-cs4236= [HW,ALSA]
1864
1865 snd-cs4281= [HW,ALSA]
1866
1867 snd-cs46xx= [HW,ALSA]
1868
1869 snd-dt019x= [HW,ALSA]
1870
1871 snd-dummy= [HW,ALSA]
1872
1873 snd-emu10k1= [HW,ALSA]
1874
1875 snd-ens1370= [HW,ALSA]
1876
1877 snd-ens1371= [HW,ALSA]
1878
1879 snd-es968= [HW,ALSA]
1880
1881 snd-es1688= [HW,ALSA]
1882
1883 snd-es18xx= [HW,ALSA]
1884
1885 snd-es1938= [HW,ALSA]
1886
1887 snd-es1968= [HW,ALSA]
1888
1889 snd-fm801= [HW,ALSA]
1890
1891 snd-gusclassic= [HW,ALSA]
1892
1893 snd-gusextreme= [HW,ALSA]
1894
1895 snd-gusmax= [HW,ALSA]
1896
1897 snd-hdsp= [HW,ALSA]
1898
1899 snd-ice1712= [HW,ALSA]
1900
1901 snd-intel8x0= [HW,ALSA]
1902
1903 snd-interwave= [HW,ALSA]
1904
1905 snd-interwave-stb=
1906 [HW,ALSA]
1907
1908 snd-korg1212= [HW,ALSA]
1909
1910 snd-maestro3= [HW,ALSA]
1911
1912 snd-mpu401= [HW,ALSA]
1913
1914 snd-mtpav= [HW,ALSA]
1915
1916 snd-nm256= [HW,ALSA]
1917
1918 snd-opl3sa2= [HW,ALSA]
1919
1920 snd-opti92x-ad1848=
1921 [HW,ALSA]
1922
1923 snd-opti92x-cs4231=
1924 [HW,ALSA]
1925
1926 snd-opti93x= [HW,ALSA]
1927
1928 snd-pmac= [HW,ALSA]
1929
1930 snd-rme32= [HW,ALSA]
1931
1932 snd-rme96= [HW,ALSA]
1933
1934 snd-rme9652= [HW,ALSA]
1935
1936 snd-sb8= [HW,ALSA]
1937
1938 snd-sb16= [HW,ALSA]
1939
1940 snd-sbawe= [HW,ALSA]
1941
1942 snd-serial= [HW,ALSA]
1943
1944 snd-sgalaxy= [HW,ALSA]
1945
1946 snd-sonicvibes= [HW,ALSA]
1947
1948 snd-sun-amd7930=
1949 [HW,ALSA]
1950
1951 snd-sun-cs4231= [HW,ALSA]
1952
1953 snd-trident= [HW,ALSA]
1954
1955 snd-usb-audio= [HW,ALSA,USB]
1956
1957 snd-via82xx= [HW,ALSA]
1958
1959 snd-virmidi= [HW,ALSA]
1960
1961 snd-wavefront= [HW,ALSA]
1962
1963 snd-ymfpci= [HW,ALSA]
Randy Dunlapa9913042005-10-23 12:57:11 -07001964
Linus Torvalds1da177e2005-04-16 15:20:36 -07001965 sonypi.*= [HW] Sony Programmable I/O Control Device driver
1966 See Documentation/sonypi.txt
1967
1968 specialix= [HW,SERIAL] Specialix multi-serial port adapter
1969 See Documentation/specialix.txt.
1970
1971 spia_io_base= [HW,MTD]
1972 spia_fio_base=
1973 spia_pedr=
1974 spia_peddr=
1975
1976 sscape= [HW,OSS]
1977 Format: <io>,<irq>,<dma>,<mpu_io>,<mpu_irq>
Randy Dunlapa9913042005-10-23 12:57:11 -07001978
Linus Torvalds1da177e2005-04-16 15:20:36 -07001979 st= [HW,SCSI] SCSI tape parameters (buffers, etc.)
1980 See Documentation/scsi/st.txt.
1981
Linus Torvalds1da177e2005-04-16 15:20:36 -07001982 sti= [PARISC,HW]
1983 Format: <num>
1984 Set the STI (builtin display/keyboard on the HP-PARISC
1985 machines) console (graphic card) which should be used
1986 as the initial boot-console.
1987 See also comment in drivers/video/console/sticore.c.
1988
1989 sti_font= [HW]
1990 See comment in drivers/video/console/sticore.c.
1991
1992 stifb= [HW]
1993 Format: bpp:<bpp1>[:<bpp2>[:<bpp3>...]]
1994
Greg Banks42a7fc42007-03-06 01:42:23 -08001995 sunrpc.pool_mode=
1996 [NFS]
1997 Control how the NFS server code allocates CPUs to
1998 service thread pools. Depending on how many NICs
1999 you have and where their interrupts are bound, this
2000 option will affect which CPUs will do NFS serving.
2001 Note: this parameter cannot be changed while the
2002 NFS server is running.
2003
2004 auto the server chooses an appropriate mode
2005 automatically using heuristics
2006 global a single global pool contains all CPUs
2007 percpu one pool for each CPU
2008 pernode one pool for each NUMA node (equivalent
2009 to global on non-NUMA machines)
2010
Linus Torvalds1da177e2005-04-16 15:20:36 -07002011 swiotlb= [IA-64] Number of I/O TLB slabs
Randy Dunlapa9913042005-10-23 12:57:11 -07002012
Linus Torvalds1da177e2005-04-16 15:20:36 -07002013 switches= [HW,M68k]
2014
2015 sym53c416= [HW,SCSI]
2016 See header of drivers/scsi/sym53c416.c.
2017
Ingo Molnar5d6f6472006-12-13 00:34:36 -08002018 sysrq_always_enabled
2019 [KNL]
2020 Ignore sysrq setting - this boot parameter will
2021 neutralize any effect of /proc/sys/kernel/sysrq.
2022 Useful for debugging.
2023
Linus Torvalds1da177e2005-04-16 15:20:36 -07002024 t128= [HW,SCSI]
2025 See header of drivers/scsi/t128.c.
2026
2027 tdfx= [HW,DRM]
2028
2029 thash_entries= [KNL,NET]
2030 Set number of hash buckets for TCP connection
2031
Len Brownf8707ec2007-08-12 00:12:54 -04002032 thermal.act= [HW,ACPI]
2033 -1: disable all active trip points in all thermal zones
2034 <degrees C>: override all lowest active trip points
2035
Len Brownc52a7412007-08-14 15:49:32 -04002036 thermal.crt= [HW,ACPI]
2037 -1: disable all critical trip points in all thermal zones
2038 <degrees C>: lower all critical trip points
2039
Len Brownf5487142007-08-12 00:12:44 -04002040 thermal.nocrt= [HW,ACPI]
2041 Set to disable actions on ACPI thermal zone
2042 critical and hot trip points.
2043
Len Brown72b33ef2007-08-12 00:12:17 -04002044 thermal.off= [HW,ACPI]
2045 1: disable ACPI thermal control
2046
Len Browna70cdc52007-08-12 00:12:35 -04002047 thermal.psv= [HW,ACPI]
2048 -1: disable all passive trip points
2049 <degrees C>: override all passive trip points to this value
2050
Len Brown730ff342007-08-12 00:12:26 -04002051 thermal.tzp= [HW,ACPI]
2052 Specify global default ACPI thermal zone polling rate
2053 <deci-seconds>: poll all this frequency
2054 0: no polling (default)
2055
Linus Torvalds1da177e2005-04-16 15:20:36 -07002056 tipar.timeout= [HW,PPT]
2057 Set communications timeout in tenths of a second
2058 (default 15).
2059
2060 tipar.delay= [HW,PPT]
2061 Set inter-bit delay in microseconds (default 10).
2062
Linus Torvalds1da177e2005-04-16 15:20:36 -07002063 tmscsim= [HW,SCSI]
2064 See comment before function dc390_setup() in
2065 drivers/scsi/tmscsim.c.
2066
2067 tp720= [HW,PS2]
2068
2069 trix= [HW,OSS] MediaTrix AudioTrix Pro
Randy Dunlapa9913042005-10-23 12:57:11 -07002070 Format:
2071 <io>,<irq>,<dma>,<dma2>,<sb_io>,<sb_irq>,<sb_dma>,<mpu_io>,<mpu_irq>
2072
Randy Dunlapa9913042005-10-23 12:57:11 -07002073 turbografx.map[2|3]= [HW,JOY]
2074 TurboGraFX parallel port interface
2075 Format:
2076 <port#>,<js1>,<js2>,<js3>,<js4>,<js5>,<js6>,<js7>
Linus Torvalds1da177e2005-04-16 15:20:36 -07002077 See also Documentation/input/joystick-parport.txt
2078
2079 u14-34f= [HW,SCSI] UltraStor 14F/34F SCSI host adapter
2080 See header of drivers/scsi/u14-34f.c.
2081
2082 uart401= [HW,OSS]
2083 Format: <io>,<irq>
2084
2085 uart6850= [HW,OSS]
2086 Format: <io>,<irq>
2087
Alan Stern5f8364b2006-12-05 16:29:55 -05002088 uhci-hcd.ignore_oc=
2089 [USB] Ignore overcurrent events (default N).
2090 Some badly-designed motherboards generate lots of
2091 bogus events, for ports that aren't wired to
2092 anything. Set this parameter to avoid log spamming.
2093 Note that genuine overcurrent events won't be
2094 reported either.
2095
Alan Sternb5e795f2007-02-20 15:00:53 -05002096 usbcore.autosuspend=
2097 [USB] The autosuspend time delay (in seconds) used
2098 for newly-detected USB devices (default 2). This
2099 is the time required before an idle device will be
2100 autosuspended. Devices for which the delay is set
Alan Sterneaafbc32007-03-13 16:39:15 -04002101 to a negative value won't be autosuspended at all.
Alan Sternb5e795f2007-02-20 15:00:53 -05002102
Linus Torvalds1da177e2005-04-16 15:20:36 -07002103 usbhid.mousepoll=
2104 [USBHID] The interval which mice are to be polled at.
Randy Dunlapa9913042005-10-23 12:57:11 -07002105
Alan Coxcd4f0ef2007-07-31 00:37:59 -07002106 vdso= [X86-32,SH,x86-64]
Jeremy Fitzhardinge1dbf527c2007-05-02 19:27:12 +02002107 vdso=2: enable compat VDSO (default with COMPAT_VDSO)
Ingo Molnare6e54942006-06-27 02:53:50 -07002108 vdso=1: enable VDSO (default)
2109 vdso=0: disable VDSO mapping
2110
Roland McGrathaf65d642008-01-30 13:30:43 +01002111 vdso32= [X86-32,X86-64]
2112 vdso32=2: enable compat VDSO (default with COMPAT_VDSO)
2113 vdso32=1: enable 32-bit VDSO (default)
2114 vdso32=0: disable 32-bit VDSO mapping
2115
Yasuaki Ishimatsud080d392007-07-17 21:22:55 +09002116 vector= [IA-64,SMP]
2117 vector=percpu: enable percpu vector domain
2118
Linus Torvalds1da177e2005-04-16 15:20:36 -07002119 video= [FB] Frame buffer configuration
2120 See Documentation/fb/modedb.txt.
2121
Alan Coxcd4f0ef2007-07-31 00:37:59 -07002122 vga= [BOOT,X86-32] Select a particular video mode
Randy Dunlapa9913042005-10-23 12:57:11 -07002123 See Documentation/i386/boot.txt and
2124 Documentation/svga.txt.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002125 Use vga=ask for menu.
2126 This is actually a boot loader parameter; the value is
2127 passed to the kernel using a special protocol.
2128
Randy Dunlapa9913042005-10-23 12:57:11 -07002129 vmalloc=nn[KMG] [KNL,BOOT] Forces the vmalloc area to have an exact
Linus Torvalds1da177e2005-04-16 15:20:36 -07002130 size of <nn>. This can be used to increase the
2131 minimum size (128MB on x86). It can also be used to
2132 decrease the size and leave more room for directly
2133 mapped kernel RAM.
2134
Peter Oberparleiter585c3042006-06-29 15:08:25 +02002135 vmhalt= [KNL,S390] Perform z/VM CP command after system halt.
2136 Format: <command>
Linus Torvalds1da177e2005-04-16 15:20:36 -07002137
Peter Oberparleiter585c3042006-06-29 15:08:25 +02002138 vmpanic= [KNL,S390] Perform z/VM CP command after kernel panic.
2139 Format: <command>
2140
2141 vmpoff= [KNL,S390] Perform z/VM CP command after power off.
2142 Format: <command>
Randy Dunlapa9913042005-10-23 12:57:11 -07002143
Linus Torvalds1da177e2005-04-16 15:20:36 -07002144 waveartist= [HW,OSS]
2145 Format: <io>,<irq>,<dma>,<dma2>
Randy Dunlapa9913042005-10-23 12:57:11 -07002146
Linus Torvalds1da177e2005-04-16 15:20:36 -07002147 wd33c93= [HW,SCSI]
2148 See header of drivers/scsi/wd33c93.c.
2149
2150 wd7000= [HW,SCSI]
2151 See header of drivers/scsi/wd7000.c.
2152
2153 wdt= [WDT] Watchdog
Gabriel C8dfe9c22007-08-10 13:01:00 -07002154 See Documentation/watchdog/wdt.txt.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002155
2156 xd= [HW,XT] Original XT pre-IDE (RLL encoded) disks.
2157 xd_geo= See header of drivers/block/xd.c.
2158
2159 xirc2ps_cs= [NET,PCMCIA]
Randy Dunlapa9913042005-10-23 12:57:11 -07002160 Format:
2161 <irq>,<irq_mask>,<io>,<full_duplex>,<do_sound>,<lockup_hack>[,<irq2>[,<irq3>[,<irq4>]]]
Linus Torvalds1da177e2005-04-16 15:20:36 -07002162
Andi Kleena62eaf12006-02-16 23:41:58 +01002163 norandmaps Don't use address space randomization
2164 Equivalent to echo 0 > /proc/sys/kernel/randomize_va_space
2165
Randy Dunlapa9913042005-10-23 12:57:11 -07002166______________________________________________________________________
Linus Torvalds1da177e2005-04-16 15:20:36 -07002167
2168TODO:
2169
2170 Add documentation for ALSA options.
2171 Add more DRM drivers.