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Mauro Carvalho Chehabe53dd082007-09-15 07:38:47 -03001 Kernel Parameters
2 ~~~~~~~~~~~~~~~~~
Linus Torvalds1da177e2005-04-16 15:20:36 -07003
4The following is a consolidated list of the kernel parameters as implemented
5(mostly) by the __setup() macro and sorted into English Dictionary order
6(defined as ignoring all punctuation and sorting digits before letters in a
7case insensitive manner), and with descriptions where known.
8
9Module parameters for loadable modules are specified only as the
10parameter name with optional '=' and value as appropriate, such as:
11
12 modprobe usbcore blinkenlights=1
13
14Module parameters for modules that are built into the kernel image
15are specified on the kernel command line with the module name plus
16'.' plus parameter name, with '=' and value if appropriate, such as:
17
18 usbcore.blinkenlights=1
19
Stefan Richtera901ebb2006-04-01 01:43:18 +020020This document may not be entirely up to date and comprehensive. The command
21"modinfo -p ${modulename}" shows a current list of all parameters of a loadable
22module. Loadable modules, after being loaded into the running kernel, also
23reveal their parameters in /sys/module/${modulename}/parameters/. Some of these
24parameters may be changed at runtime by the command
25"echo -n ${value} > /sys/module/${modulename}/parameters/${parm}".
26
Stefan Richter6585fa82006-04-01 01:44:30 +020027The parameters listed below are only valid if certain kernel build options were
28enabled and if respective hardware is present. The text in square brackets at
29the beginning of each description states the restrictions within which a
30parameter is applicable:
Linus Torvalds1da177e2005-04-16 15:20:36 -070031
32 ACPI ACPI support is enabled.
Chuck Ebbertc99c1082007-07-27 10:46:20 +100033 AGP AGP (Accelerated Graphics Port) is enabled.
Linus Torvalds1da177e2005-04-16 15:20:36 -070034 ALSA ALSA sound support is enabled.
35 APIC APIC support is enabled.
36 APM Advanced Power Management support is enabled.
Haavard Skinnemoene7ba1762007-10-10 14:58:29 +020037 AVR32 AVR32 architecture is enabled.
Linus Torvalds1da177e2005-04-16 15:20:36 -070038 AX25 Appropriate AX.25 support is enabled.
Robin Getz0ae53642007-10-09 17:24:49 +080039 BLACKFIN Blackfin architecture is enabled.
Randy Dunlapa9913042005-10-23 12:57:11 -070040 DRM Direct Rendering Management support is enabled.
Linus Torvalds1da177e2005-04-16 15:20:36 -070041 EDD BIOS Enhanced Disk Drive Services (EDD) is enabled
42 EFI EFI Partitioning (GPT) is enabled
43 EIDE EIDE/ATAPI support is enabled.
44 FB The frame buffer device is enabled.
45 HW Appropriate hardware is enabled.
Linus Torvalds1da177e2005-04-16 15:20:36 -070046 IA-64 IA-64 architecture is enabled.
47 IOSCHED More than one I/O scheduler is enabled.
Adrian Bunk41e2e8b2005-07-12 13:58:33 -070048 IP_PNP IP DHCP, BOOTP, or RARP is enabled.
Linus Torvalds1da177e2005-04-16 15:20:36 -070049 ISAPNP ISA PnP code is enabled.
50 ISDN Appropriate ISDN support is enabled.
51 JOY Appropriate joystick support is enabled.
Kristen Carlson Accardi11ef6972006-09-28 11:29:01 -070052 LIBATA Libata driver is enabled
Linus Torvalds1da177e2005-04-16 15:20:36 -070053 LP Printer support is enabled.
54 LOOP Loopback device support is enabled.
55 M68k M68k architecture is enabled.
56 These options have more detailed description inside of
57 Documentation/m68k/kernel-options.txt.
58 MCA MCA bus support is enabled.
59 MDA MDA console support is enabled.
60 MOUSE Appropriate mouse support is enabled.
Matthew Wilcox309e57d2006-03-05 22:33:34 -070061 MSI Message Signaled Interrupts (PCI).
Randy Dunlapc8facbb2007-07-31 00:37:40 -070062 MTD MTD (Memory Technology Device) support is enabled.
Linus Torvalds1da177e2005-04-16 15:20:36 -070063 NET Appropriate network support is enabled.
64 NUMA NUMA support is enabled.
john stultz734efb42006-06-26 00:25:05 -070065 GENERIC_TIME The generic timeofday code is enabled.
Linus Torvalds1da177e2005-04-16 15:20:36 -070066 NFS Appropriate NFS support is enabled.
67 OSS OSS sound support is enabled.
Randy Dunlapc8facbb2007-07-31 00:37:40 -070068 PV_OPS A paravirtualized kernel is enabled.
69 PARIDE The ParIDE (parallel port IDE) subsystem is enabled.
Linus Torvalds1da177e2005-04-16 15:20:36 -070070 PARISC The PA-RISC architecture is enabled.
71 PCI PCI bus support is enabled.
Randy Dunlap7f785762007-10-05 13:17:58 -070072 PCIE PCI Express support is enabled.
Linus Torvalds1da177e2005-04-16 15:20:36 -070073 PCMCIA The PCMCIA subsystem is enabled.
74 PNP Plug & Play support is enabled.
75 PPC PowerPC architecture is enabled.
76 PPT Parallel port support is enabled.
77 PS2 Appropriate PS/2 support is enabled.
78 RAM RAM disk support is enabled.
James Morris20510f22007-10-16 23:31:32 -070079 ROOTPLUG The example Root Plug LSM is enabled.
Linus Torvalds1da177e2005-04-16 15:20:36 -070080 S390 S390 architecture is enabled.
81 SCSI Appropriate SCSI support is enabled.
82 A lot of drivers has their options described inside of
83 Documentation/scsi/.
James Morris20510f22007-10-16 23:31:32 -070084 SECURITY Different security models are enabled.
Linus Torvalds1da177e2005-04-16 15:20:36 -070085 SELINUX SELinux support is enabled.
86 SERIAL Serial support is enabled.
Paul Mundte523d932007-02-28 18:30:01 +090087 SH SuperH architecture is enabled.
Linus Torvalds1da177e2005-04-16 15:20:36 -070088 SMP The kernel is an SMP kernel.
89 SPARC Sparc architecture is enabled.
Randy Dunlapa9913042005-10-23 12:57:11 -070090 SWSUSP Software suspend is enabled.
Linus Torvalds1da177e2005-04-16 15:20:36 -070091 TS Appropriate touchscreen support is enabled.
92 USB USB support is enabled.
93 USBHID USB Human Interface Device support is enabled.
94 V4L Video For Linux support is enabled.
95 VGA The VGA console has been enabled.
96 VT Virtual terminal support is enabled.
97 WDT Watchdog support is enabled.
98 XT IBM PC/XT MFM hard disk support is enabled.
Alan Coxcd4f0ef2007-07-31 00:37:59 -070099 X86-32 X86-32, aka i386 architecture is enabled.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700100 X86-64 X86-64 architecture is enabled.
101 More X86-64 boot options can be found in
102 Documentation/x86_64/boot-options.txt .
103
104In addition, the following text indicates that the option:
105
106 BUGS= Relates to possible processor bugs on the said processor.
107 KNL Is a kernel start-up parameter.
108 BOOT Is a boot loader parameter.
109
110Parameters denoted with BOOT are actually interpreted by the boot
111loader, and have no meaning to the kernel directly.
112Do not modify the syntax of boot loader parameters without extreme
113need or coordination with <Documentation/i386/boot.txt>.
114
Karsten Weiss55588702007-02-13 13:26:21 +0100115There are also arch-specific kernel-parameters not documented here.
116See for example <Documentation/x86_64/boot-options.txt>.
117
Linus Torvalds1da177e2005-04-16 15:20:36 -0700118Note that ALL kernel parameters listed below are CASE SENSITIVE, and that
119a trailing = on the name of any parameter states that that parameter will
120be entered as an environment variable, whereas its absence indicates that
121it will appear as a kernel argument readable via /proc/cmdline by programs
122running once the system is up.
123
jens m. noedler9c4751f2006-09-29 02:00:27 -0700124The number of kernel parameters is not limited, but the length of the
125complete command line (parameters including spaces etc.) is limited to
126a fixed number of characters. This limit depends on the architecture
127and is between 256 and 4096 characters. It is defined in the file
128./include/asm/setup.h as COMMAND_LINE_SIZE.
129
130
Bernhard Walle03d926f2007-03-06 02:29:44 -0800131 acpi= [HW,ACPI,X86-64,i386]
132 Advanced Configuration and Power Interface
Randy Dunlapa9913042005-10-23 12:57:11 -0700133 Format: { force | off | ht | strict | noirq }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700134 force -- enable ACPI if default was off
135 off -- disable ACPI if default was on
136 noirq -- do not use ACPI for IRQ routing
137 ht -- run only enough ACPI to enable Hyper Threading
Randy Dunlapa9913042005-10-23 12:57:11 -0700138 strict -- Be less tolerant of platforms that are not
Linus Torvalds1da177e2005-04-16 15:20:36 -0700139 strictly ACPI specification compliant.
140
Randy Dunlap53471122008-03-12 18:10:51 -0400141 See also Documentation/power/pm.txt, pci=noacpi
Linus Torvalds1da177e2005-04-16 15:20:36 -0700142
Len Browna1fdcc02007-03-11 03:26:14 -0400143 acpi_apic_instance= [ACPI, IOAPIC]
144 Format: <int>
145 2: use 2nd APIC table, if available
146 1,0: use 1st APIC table
Len Brown4e381a42007-03-30 14:16:10 -0400147 default: 0
Len Browna1fdcc02007-03-11 03:26:14 -0400148
Linus Torvalds1da177e2005-04-16 15:20:36 -0700149 acpi_sleep= [HW,ACPI] Sleep options
Pavel Machek23b168d2008-02-05 19:27:12 +0100150 Format: { s3_bios, s3_mode, s3_beep }
151 See Documentation/power/video.txt for s3_bios and s3_mode.
152 s3_beep is for debugging; it makes the PC's speaker beep
153 as soon as the kernel's real-mode entry point is called.
Randy Dunlapa9913042005-10-23 12:57:11 -0700154
Linus Torvalds1da177e2005-04-16 15:20:36 -0700155 acpi_sci= [HW,ACPI] ACPI System Control Interrupt trigger mode
Randy Dunlapa9913042005-10-23 12:57:11 -0700156 Format: { level | edge | high | low }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700157
Randy Dunlapa9913042005-10-23 12:57:11 -0700158 acpi_irq_balance [HW,ACPI]
159 ACPI will balance active IRQs
160 default in APIC mode
Linus Torvalds1da177e2005-04-16 15:20:36 -0700161
Randy Dunlapa9913042005-10-23 12:57:11 -0700162 acpi_irq_nobalance [HW,ACPI]
163 ACPI will not move active IRQs (default)
164 default in PIC mode
Linus Torvalds1da177e2005-04-16 15:20:36 -0700165
Randy Dunlapa9913042005-10-23 12:57:11 -0700166 acpi_irq_pci= [HW,ACPI] If irq_balance, clear listed IRQs for
167 use by PCI
Linus Torvalds1da177e2005-04-16 15:20:36 -0700168 Format: <irq>,<irq>...
169
Randy Dunlapa9913042005-10-23 12:57:11 -0700170 acpi_irq_isa= [HW,ACPI] If irq_balance, mark listed IRQs used by ISA
Linus Torvalds1da177e2005-04-16 15:20:36 -0700171 Format: <irq>,<irq>...
172
Len Brown67effe82007-07-26 00:50:06 -0400173 acpi_no_auto_ssdt [HW,ACPI] Disable automatic loading of SSDT
174
Len Browna1f9e652006-01-25 23:47:36 -0500175 acpi_os_name= [HW,ACPI] Tell ACPI BIOS the name of the OS
176 Format: To spoof as Windows 98: ="Microsoft Windows"
177
Len Brownae00d812007-05-29 18:43:33 -0400178 acpi_osi= [HW,ACPI] Modify list of supported OS interface strings
179 acpi_osi="string1" # add string1 -- only one string
180 acpi_osi="!string2" # remove built-in string2
181 acpi_osi= # disable all strings
Linus Torvalds1da177e2005-04-16 15:20:36 -0700182
183 acpi_serialize [HW,ACPI] force serialization of AML methods
184
185 acpi_skip_timer_override [HW,ACPI]
186 Recognize and ignore IRQ0/pin2 Interrupt Override.
187 For broken nForce2 BIOS resulting in XT-PIC timer.
Andi Kleenfa18f472006-11-14 16:57:46 +0100188 acpi_use_timer_override [HW,ACPI}
189 Use timer override. For some broken Nvidia NF5 boards
190 that require a timer override, but don't have
191 HPET
Linus Torvalds1da177e2005-04-16 15:20:36 -0700192
Zhang Ruif9891062007-04-24 13:53:22 +0800193 acpi.debug_layer= [HW,ACPI]
Linus Torvalds1da177e2005-04-16 15:20:36 -0700194 Format: <int>
Randy Dunlapa9913042005-10-23 12:57:11 -0700195 Each bit of the <int> indicates an ACPI debug layer,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700196 1: enable, 0: disable. It is useful for boot time
197 debugging. After system has booted up, it can be set
Zhang Ruif9891062007-04-24 13:53:22 +0800198 via /sys/module/acpi/parameters/debug_layer.
199 CONFIG_ACPI_DEBUG must be enabled for this to produce any output.
200 Available bits (add the numbers together) to enable debug output
201 for specific parts of the ACPI subsystem:
202 0x01 utilities 0x02 hardware 0x04 events 0x08 tables
203 0x10 namespace 0x20 parser 0x40 dispatcher
204 0x80 executer 0x100 resources 0x200 acpica debugger
205 0x400 os services 0x800 acpica disassembler.
206 The number can be in decimal or prefixed with 0x in hex.
207 Warning: Many of these options can produce a lot of
208 output and make your system unusable. Be very careful.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700209
Zhang Ruif9891062007-04-24 13:53:22 +0800210 acpi.debug_level= [HW,ACPI]
Linus Torvalds1da177e2005-04-16 15:20:36 -0700211 Format: <int>
Randy Dunlapa9913042005-10-23 12:57:11 -0700212 Each bit of the <int> indicates an ACPI debug level,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700213 1: enable, 0: disable. It is useful for boot time
214 debugging. After system has booted up, it can be set
Zhang Ruif9891062007-04-24 13:53:22 +0800215 via /sys/module/acpi/parameters/debug_level.
216 CONFIG_ACPI_DEBUG must be enabled for this to produce any output.
217 Available bits (add the numbers together) to enable different
218 debug output levels of the ACPI subsystem:
219 0x01 error 0x02 warn 0x04 init 0x08 debug object
220 0x10 info 0x20 init names 0x40 parse 0x80 load
221 0x100 dispatch 0x200 execute 0x400 names 0x800 operation region
222 0x1000 bfield 0x2000 tables 0x4000 values 0x8000 objects
223 0x10000 resources 0x20000 user requests 0x40000 package.
224 The number can be in decimal or prefixed with 0x in hex.
225 Warning: Many of these options can produce a lot of
226 output and make your system unusable. Be very careful.
227
Alan Coxcd4f0ef2007-07-31 00:37:59 -0700228 acpi_pm_good [X86-32,X86-64]
john stultz5d0cf412006-06-26 00:25:12 -0700229 Override the pmtimer bug detection: force the kernel
230 to assume that this machine's pmtimer latches its value
231 and always returns good values.
232
Chuck Ebbertc99c1082007-07-27 10:46:20 +1000233 agp= [AGP]
234 { off | try_unsupported }
235 off: disable AGP support
236 try_unsupported: try to drive unsupported chipsets
237 (may crash computer or cause data corruption)
238
Chuck Ebbert66759a02005-09-12 18:49:25 +0200239 enable_timer_pin_1 [i386,x86-64]
240 Enable PIN 1 of APIC timer
Randy Dunlapa9913042005-10-23 12:57:11 -0700241 Can be useful to work around chipset bugs
242 (in particular on some ATI chipsets).
Chuck Ebbert66759a02005-09-12 18:49:25 +0200243 The kernel tries to set a reasonable default.
244
245 disable_timer_pin_1 [i386,x86-64]
246 Disable PIN 1 of APIC timer
247 Can be useful to work around chipset bugs.
248
Linus Torvalds1da177e2005-04-16 15:20:36 -0700249 ad1848= [HW,OSS]
250 Format: <io>,<irq>,<dma>,<dma2>,<type>
251
Linus Torvalds1da177e2005-04-16 15:20:36 -0700252 advansys= [HW,SCSI]
253 See header of drivers/scsi/advansys.c.
254
255 advwdt= [HW,WDT] Advantech WDT
256 Format: <iostart>,<iostop>
257
258 aedsp16= [HW,OSS] Audio Excel DSP 16
259 Format: <io>,<irq>,<dma>,<mss_io>,<mpu_io>,<mpu_irq>
260 See also header of sound/oss/aedsp16.c.
Randy Dunlapa9913042005-10-23 12:57:11 -0700261
Linus Torvalds1da177e2005-04-16 15:20:36 -0700262 aha152x= [HW,SCSI]
263 See Documentation/scsi/aha152x.txt.
264
265 aha1542= [HW,SCSI]
266 Format: <portbase>[,<buson>,<busoff>[,<dmaspeed>]]
267
268 aic7xxx= [HW,SCSI]
269 See Documentation/scsi/aic7xxx.txt.
270
271 aic79xx= [HW,SCSI]
272 See Documentation/scsi/aic79xx.txt.
273
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
Samuel Thibaultf7511d52008-04-30 00:54:51 -0700499 If the device connected to the port is not a TTY but a braille
500 device, prepend "brl," before the device type, for instance
501 console=brl,ttyS0
502 For now, only VisioBraille is supported.
503
Yinghai Lu18a8bd92007-07-15 23:37:59 -0700504 earlycon= [KNL] Output early console device and options.
505 uart[8250],io,<addr>[,options]
506 uart[8250],mmio,<addr>[,options]
507 Start an early, polled-mode console on the 8250/16550
508 UART at the specified I/O port or MMIO address.
509 The options are the same as for ttyS, above.
510
Andres Salomon8f4ce8c2007-10-18 03:04:50 -0700511 no_console_suspend
512 [HW] Never suspend the console
513 Disable suspending of consoles during suspend and
514 hibernate operations. Once disabled, debugging
515 messages can reach various consoles while the rest
516 of the system is being put to sleep (ie, while
517 debugging driver suspend/resume hooks). This may
518 not work reliably with all consoles, but is known
519 to work with serial and VGA consoles.
520
Linus Torvalds1da177e2005-04-16 15:20:36 -0700521 cpcihp_generic= [HW,PCI] Generic port I/O CompactPCI driver
Randy Dunlapa9913042005-10-23 12:57:11 -0700522 Format:
523 <first_slot>,<last_slot>,<port>,<enum_bit>[,<debug>]
Linus Torvalds1da177e2005-04-16 15:20:36 -0700524
Eric W. Biedermandc009d92005-06-25 14:57:52 -0700525 crashkernel=nn[KMG]@ss[KMG]
526 [KNL] Reserve a chunk of physical memory to
527 hold a kernel to switch to with kexec on panic.
528
Bernhard Wallefb391592007-10-18 23:41:02 -0700529 crashkernel=range1:size1[,range2:size2,...][@offset]
530 [KNL] Same as above, but depends on the memory
531 in the running system. The syntax of range is
532 start-[end] where start and end are both
533 a memory unit (amount[KMG]). See also
534 Documentation/kdump/kdump.txt for a example.
535
Linus Torvalds1da177e2005-04-16 15:20:36 -0700536 cs4232= [HW,OSS]
537 Format: <io>,<irq>,<dma>,<dma2>,<mpuio>,<mpuirq>
538
539 cs89x0_dma= [HW,NET]
540 Format: <dma>
541
542 cs89x0_media= [HW,NET]
543 Format: { rj45 | aui | bnc }
Randy Dunlapa9913042005-10-23 12:57:11 -0700544
Randy Dunlapa9913042005-10-23 12:57:11 -0700545 dasd= [HW,NET]
Linus Torvalds1da177e2005-04-16 15:20:36 -0700546 See header of drivers/s390/block/dasd_devmap.c.
547
548 db9.dev[2|3]= [HW,JOY] Multisystem joystick support via parallel port
549 (one device per port)
550 Format: <port#>,<type>
551 See also Documentation/input/joystick-parport.txt
552
553 debug [KNL] Enable kernel debugging (events log level).
554
Ingo Molnarcae2ed92006-07-03 00:24:48 -0700555 debug_locks_verbose=
556 [KNL] verbose self-tests
557 Format=<0|1>
558 Print debugging info while doing the locking API
559 self-tests.
560 We default to 0 (no extra messages), setting it to
561 1 will print _a lot_ more information - normally
562 only useful to kernel developers.
563
Thomas Gleixner3ac7fe52008-04-30 00:55:01 -0700564 debug_objects [KNL] Enable object debugging
565
Robert P. J. Day2d27a962008-02-03 15:18:45 +0200566 decnet.addr= [HW,NET]
Linus Torvalds1da177e2005-04-16 15:20:36 -0700567 Format: <area>[,<node>]
568 See also Documentation/networking/decnet.txt.
569
Samuel Thibaultecb77fa2008-01-03 16:17:54 +0000570 vt.default_blu= [VT]
Antonino A. Daplas55ff9782007-05-08 00:38:53 -0700571 Format: <blue0>,<blue1>,<blue2>,...,<blue15>
572 Change the default blue palette of the console.
573 This is a 16-member array composed of values
574 ranging from 0-255.
575
Samuel Thibaultecb77fa2008-01-03 16:17:54 +0000576 vt.default_grn= [VT]
Antonino A. Daplas55ff9782007-05-08 00:38:53 -0700577 Format: <green0>,<green1>,<green2>,...,<green15>
578 Change the default green palette of the console.
579 This is a 16-member array composed of values
580 ranging from 0-255.
581
Samuel Thibaultecb77fa2008-01-03 16:17:54 +0000582 vt.default_red= [VT]
Antonino A. Daplas55ff9782007-05-08 00:38:53 -0700583 Format: <red0>,<red1>,<red2>,...,<red15>
584 Change the default red palette of the console.
585 This is a 16-member array composed of values
586 ranging from 0-255.
587
Samuel Thibaultecb77fa2008-01-03 16:17:54 +0000588 vt.default_utf8=
589 [VT]
Antonino A. Daplas55ff9782007-05-08 00:38:53 -0700590 Format=<0|1>
591 Set system-wide default UTF-8 mode for all tty's.
Samuel Thibaultecb77fa2008-01-03 16:17:54 +0000592 Default is 1, i.e. UTF-8 mode is enabled for all
593 newly opened terminals.
Antonino A. Daplas55ff9782007-05-08 00:38:53 -0700594
Linus Torvalds1da177e2005-04-16 15:20:36 -0700595 dhash_entries= [KNL]
596 Set number of hash buckets for dentry cache.
Randy Dunlapa9913042005-10-23 12:57:11 -0700597
Linus Torvalds1da177e2005-04-16 15:20:36 -0700598 digi= [HW,SERIAL]
599 IO parameters + enable/disable command.
600
601 digiepca= [HW,SERIAL]
602 See drivers/char/README.epca and
603 Documentation/digiepca.txt.
604
Yinghai Lu093af8d2008-01-30 13:33:32 +0100605 disable_mtrr_trim [X86, Intel and AMD only]
Jesse Barnes99fc8d42008-01-30 13:33:18 +0100606 By default the kernel will trim any uncacheable
607 memory out of your available memory pool based on
608 MTRR settings. This parameter disables that behavior,
609 possibly causing your machine to run very slowly.
610
Linus Torvalds1da177e2005-04-16 15:20:36 -0700611 dmasound= [HW,OSS] Sound subsystem buffers
612
613 dscc4.setup= [NET]
614
615 dtc3181e= [HW,SCSI]
616
Robin Getz0ae53642007-10-09 17:24:49 +0800617 earlyprintk= [X86-32,X86-64,SH,BLACKFIN]
Linus Torvalds1da177e2005-04-16 15:20:36 -0700618 earlyprintk=vga
619 earlyprintk=serial[,ttySn[,baudrate]]
620
Randy Dunlapa9913042005-10-23 12:57:11 -0700621 Append ",keep" to not disable it when the real console
Linus Torvalds1da177e2005-04-16 15:20:36 -0700622 takes over.
623
624 Only vga or serial at a time, not both.
625
626 Currently only ttyS0 and ttyS1 are supported.
627
628 Interaction with the standard serial driver is not
629 very good.
630
631 The VGA output is eventually overwritten by the real
632 console.
633
634 eata= [HW,SCSI]
635
Linus Torvalds1da177e2005-04-16 15:20:36 -0700636 edd= [EDD]
Tim Gardner8c4dd602008-04-29 01:02:45 -0700637 Format: {"off" | "on" | "skip[mbr]"}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700638
Linus Torvalds1da177e2005-04-16 15:20:36 -0700639 eisa_irq_edge= [PARISC,HW]
640 See header of drivers/parisc/eisa.c.
641
Alan Coxcd4f0ef2007-07-31 00:37:59 -0700642 elanfreq= [X86-32]
Linus Torvalds1da177e2005-04-16 15:20:36 -0700643 See comment before function elanfreq_setup() in
644 arch/i386/kernel/cpu/cpufreq/elanfreq.c.
645
646 elevator= [IOSCHED]
Randy Dunlap16ab3ad2006-01-14 13:21:20 -0800647 Format: {"anticipatory" | "cfq" | "deadline" | "noop"}
Randy Dunlapa9913042005-10-23 12:57:11 -0700648 See Documentation/block/as-iosched.txt and
649 Documentation/block/deadline-iosched.txt for details.
650
Alan Coxcd4f0ef2007-07-31 00:37:59 -0700651 elfcorehdr= [X86-32, X86_64]
Randy Dunlapa9913042005-10-23 12:57:11 -0700652 Specifies physical address of start of kernel core
Vivek Goyalaac04b32006-01-09 20:51:47 -0800653 image elf header. Generally kexec loader will
654 pass this option to capture kernel.
655 See Documentation/kdump/kdump.txt for details.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700656
657 enforcing [SELINUX] Set initial enforcing status.
658 Format: {"0" | "1"}
659 See security/selinux/Kconfig help text.
660 0 -- permissive (log only, no denials).
661 1 -- enforcing (deny and log).
662 Default value is 0.
663 Value can be changed at runtime via /selinux/enforce.
664
Linus Torvalds1da177e2005-04-16 15:20:36 -0700665 es1371= [HW,OSS]
666 Format: <spdif>,[<nomix>,[<amplifier>]]
667 See also header of sound/oss/es1371.c.
Randy Dunlapa9913042005-10-23 12:57:11 -0700668
Linus Torvalds1da177e2005-04-16 15:20:36 -0700669 ether= [HW,NET] Ethernet cards parameters
670 This option is obsoleted by the "netdev=" option, which
671 has equivalent usage. See its documentation for details.
672
673 eurwdt= [HW,WDT] Eurotech CPU-1220/1410 onboard watchdog.
674 Format: <io>[,<irq>]
675
Akinobu Mitade1ba092006-12-08 02:39:42 -0800676 failslab=
677 fail_page_alloc=
678 fail_make_request=[KNL]
679 General fault injection mechanism.
680 Format: <interval>,<probability>,<space>,<times>
681 See also /Documentation/fault-injection/.
682
Linus Torvalds1da177e2005-04-16 15:20:36 -0700683 fd_mcs= [HW,SCSI]
684 See header of drivers/scsi/fd_mcs.c.
685
686 fdomain= [HW,SCSI]
687 See header of drivers/scsi/fdomain.c.
688
689 floppy= [HW]
690 See Documentation/floppy.txt.
691
Alex Chiangf13ae302008-05-08 14:03:23 -0600692 force_pal_cache_flush
693 [IA-64] Avoid check_sal_cache_flush which may hang on
694 buggy SAL_CACHE_FLUSH implementations. Using this
695 parameter will force ia64_sal_cache_flush to call
696 ia64_pal_cache_flush instead of SAL_CACHE_FLUSH.
697
Linus Torvalds1da177e2005-04-16 15:20:36 -0700698 gamecon.map[2|3]=
699 [HW,JOY] Multisystem joystick and NES/SNES/PSX pad
700 support via parallel port (up to 5 devices per port)
701 Format: <port#>,<pad1>,<pad2>,<pad3>,<pad4>,<pad5>
702 See also Documentation/input/joystick-parport.txt
703
704 gamma= [HW,DRM]
705
Yinghai Luaaf23042008-01-30 13:33:09 +0100706 gart_fix_e820= [X86_64] disable the fix e820 for K8 GART
707 Format: off | on
708 default: on
709
Linus Torvalds1da177e2005-04-16 15:20:36 -0700710 gdth= [HW,SCSI]
711 See header of drivers/scsi/gdth.c.
712
713 gpt [EFI] Forces disk with valid GPT signature but
714 invalid Protective MBR to be treated as GPT.
715
Linus Torvalds1da177e2005-04-16 15:20:36 -0700716 gvp11= [HW,SCSI]
717
718 hashdist= [KNL,NUMA] Large hashes allocated during boot
719 are distributed across NUMA nodes. Defaults on
720 for IA-64, off otherwise.
Randy Dunlapa9913042005-10-23 12:57:11 -0700721 Format: 0 | 1 (for off | on)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700722
723 hcl= [IA-64] SGI's Hardware Graph compatibility layer
724
725 hd= [EIDE] (E)IDE hard drive subsystem geometry
726 Format: <cyl>,<head>,<sect>
727
728 hd?= [HW] (E)IDE subsystem
Randy Dunlap1c10e932008-03-07 21:53:50 +0100729 hd?lun= See Documentation/ide/ide.txt.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700730
731 highmem=nn[KMG] [KNL,BOOT] forces the highmem zone to have an exact
732 size of <nn>. This works even on boxes that have no
733 highmem otherwise. This also works to reduce highmem
734 size on bigger boxes.
735
Thomas Gleixner54cdfdb2007-02-16 01:28:11 -0800736 highres= [KNL] Enable/disable high resolution timer mode.
737 Valid parameters: "on", "off"
738 Default: "on"
739
Linus Torvalds1da177e2005-04-16 15:20:36 -0700740 hisax= [HW,ISDN]
741 See Documentation/isdn/README.HiSax.
742
Alan Coxcd4f0ef2007-07-31 00:37:59 -0700743 hugepages= [HW,X86-32,IA-64] Maximal number of HugeTLB pages.
Jon Tollefson4ec161c2008-01-04 09:59:50 +1100744 hugepagesz= [HW,IA-64,PPC] The size of the HugeTLB pages.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700745
Linus Torvalds1da177e2005-04-16 15:20:36 -0700746 i8042.direct [HW] Put keyboard port into non-translated mode
Matt LaPlante84eb8d02006-10-03 22:53:09 +0200747 i8042.dumbkbd [HW] Pretend that controller can only read data from
748 keyboard and cannot control its state
Linus Torvalds1da177e2005-04-16 15:20:36 -0700749 (Don't attempt to blink the leds)
750 i8042.noaux [HW] Don't check for auxiliary (== mouse) port
Dmitry Torokhov945ef0d2005-09-04 01:42:00 -0500751 i8042.nokbd [HW] Don't check/create keyboard port
Jiri Kosina75d08c72008-03-13 16:13:59 -0400752 i8042.noloop [HW] Disable the AUX Loopback command while probing
753 for the AUX port
Linus Torvalds1da177e2005-04-16 15:20:36 -0700754 i8042.nomux [HW] Don't check presence of an active multiplexing
755 controller
756 i8042.nopnp [HW] Don't use ACPIPnP / PnPBIOS to discover KBD/AUX
757 controllers
758 i8042.panicblink=
759 [HW] Frequency with which keyboard LEDs should blink
760 when kernel panics (default is 0.5 sec)
761 i8042.reset [HW] Reset the controller during init and cleanup
762 i8042.unlock [HW] Unlock (ignore) the keylock
763
764 i810= [HW,DRM]
765
Dmitry Torokhove70c9d52005-06-25 14:54:25 -0700766 i8k.ignore_dmi [HW] Continue probing hardware even if DMI data
767 indicates that the driver is running on unsupported
768 hardware.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700769 i8k.force [HW] Activate i8k driver even if SMM BIOS signature
770 does not match list of supported models.
771 i8k.power_status
772 [HW] Report power status in /proc/i8k
773 (disabled by default)
774 i8k.restricted [HW] Allow controlling fans only if SYS_ADMIN
775 capability is set.
776
777 ibmmcascsi= [HW,MCA,SCSI] IBM MicroChannel SCSI adapter
778 See Documentation/mca.txt.
779
780 icn= [HW,ISDN]
781 Format: <io>[,<membase>[,<icn_id>[,<icn_id2>]]]
782
783 ide= [HW] (E)IDE subsystem
Greg Kroah-Hartmana594eeb2008-04-18 00:46:20 +0200784 Format: ide=nodma or ide=doubler
Randy Dunlap1c10e932008-03-07 21:53:50 +0100785 See Documentation/ide/ide.txt.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700786
Linus Torvalds1da177e2005-04-16 15:20:36 -0700787 idebus= [HW] (E)IDE subsystem - VLB/PCI bus speed
Randy Dunlap1c10e932008-03-07 21:53:50 +0100788 See Documentation/ide/ide.txt.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700789
Andi Kleenf039b752007-05-02 19:27:12 +0200790 idle= [X86]
791 Format: idle=poll or idle=mwait
792 Poll forces a polling idle loop that can slightly improves the performance
793 of waking up a idle CPU, but will use a lot of power and make the system
794 run hot. Not recommended.
795 idle=mwait. On systems which support MONITOR/MWAIT but the kernel chose
796 to not use it because it doesn't save as much power as a normal idle
797 loop use the MONITOR/MWAIT idle loop anyways. Performance should be the same
798 as idle=poll.
Randy Dunlapa9913042005-10-23 12:57:11 -0700799
Denis Cheng594765a2008-02-06 02:57:49 +0100800 ide-pci-generic.all-generic-ide [HW] (E)IDE subsystem
801 Claim all unknown PCI IDE storage controllers.
802
Ingo Molnar792908222006-12-06 20:40:51 -0800803 ignore_loglevel [KNL]
804 Ignore loglevel setting - this will print /all/
805 kernel messages to the console. Useful for debugging.
806
Linus Torvalds1da177e2005-04-16 15:20:36 -0700807 ihash_entries= [KNL]
808 Set number of hash buckets for inode cache.
809
810 in2000= [HW,SCSI]
811 See header of drivers/scsi/in2000.c.
812
813 init= [KNL]
814 Format: <full_path>
815 Run specified binary instead of /sbin/init as init
816 process.
817
818 initcall_debug [KNL] Trace initcalls as they are executed. Useful
819 for working out where the kernel is dying during
820 startup.
821
822 initrd= [BOOT] Specify the location of the initial ramdisk
823
824 inport.irq= [HW] Inport (ATI XL and Microsoft) busmouse driver
825 Format: <irq>
826
827 inttest= [IA64]
828
Pavel Machekb552da82008-03-19 15:58:11 +0100829 iommu= [x86]
830 off
831 force
832 noforce
833 biomerge
834 panic
835 nopanic
836 merge
837 nomerge
838 forcesac
839 soft
840
841
Keshavamurthy, Anil Sba395922007-10-21 16:41:49 -0700842 intel_iommu= [DMAR] Intel IOMMU driver (DMAR) option
843 off
844 Disable intel iommu driver.
845 igfx_off [Default Off]
846 By default, gfx is mapped as normal device. If a gfx
847 device has a dedicated DMAR unit, the DMAR unit is
848 bypassed by not enabling DMAR with this option. In
849 this case, gfx device will use physical address for
850 DMA.
Keshavamurthy, Anil S7d3b03c2007-10-21 16:41:53 -0700851 forcedac [x86_64]
852 With this option iommu will not optimize to look
853 for io virtual address below 32 bit forcing dual
854 address cycle on pci bus for cards supporting greater
855 than 32 bit addressing. The default is to look
856 for translation below 32 bit and if not available
857 then look in the higher range.
mark gross5e0d2a62008-03-04 15:22:08 -0800858 strict [Default Off]
859 With this option on every unmap_single operation will
860 result in a hardware IOTLB flush operation as opposed
861 to batching them for performance.
Keshavamurthy, Anil Sba395922007-10-21 16:41:49 -0700862
Rene Hermanb02aae92008-01-30 13:30:05 +0100863 io_delay= [X86-32,X86-64] I/O delay method
Ingo Molnar6e7c4022008-01-30 13:30:05 +0100864 0x80
865 Standard port 0x80 based delay
866 0xed
867 Alternate port 0xed based delay (needed on some systems)
Rene Hermanb02aae92008-01-30 13:30:05 +0100868 udelay
Ingo Molnar6e7c4022008-01-30 13:30:05 +0100869 Simple two microseconds delay
870 none
871 No delay
Rene Hermanb02aae92008-01-30 13:30:05 +0100872
Linus Torvalds1da177e2005-04-16 15:20:36 -0700873 io7= [HW] IO7 for Marvel based alpha systems
874 See comment before marvel_specify_io7 in
875 arch/alpha/kernel/core_marvel.c.
876
877 ip= [IP_PNP]
J. Bruce Fields6ded55d2008-04-07 15:59:03 -0400878 See Documentation/filesystems/nfsroot.txt.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700879
880 ip2= [HW] Set IO/IRQ pairs for up to 4 IntelliPort boards
Randy Dunlapc8facbb2007-07-31 00:37:40 -0700881 See comment before ip2_setup() in
882 drivers/char/ip2/ip2base.c.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700883
884 ips= [HW,SCSI] Adaptec / IBM ServeRAID controller
885 See header of drivers/scsi/ips.c.
886
Simon Horman72c4a132006-09-13 19:57:18 -0700887 ports= [IP_VS_FTP] IPVS ftp helper module
888 Default is 21.
889 Up to 8 (IP_VS_APP_MAX_PORTS) ports
890 may be specified.
891 Format: <port>,<port>....
892
Alan Cox200803d2005-06-28 20:45:18 -0700893 irqfixup [HW]
894 When an interrupt is not handled search all handlers
895 for it. Intended to get systems with badly broken
896 firmware running.
897
898 irqpoll [HW]
899 When an interrupt is not handled search all handlers
900 for it. Also check all handlers each timer
901 interrupt. Intended to get systems with badly broken
902 firmware running.
903
Linus Torvalds1da177e2005-04-16 15:20:36 -0700904 isapnp= [ISAPNP]
Randy Dunlapa9913042005-10-23 12:57:11 -0700905 Format: <RDP>,<reset>,<pci_scan>,<verbosity>
Linus Torvalds1da177e2005-04-16 15:20:36 -0700906
907 isolcpus= [KNL,SMP] Isolate CPUs from the general scheduler.
Derek Fults22f2e282006-12-06 20:37:11 -0800908 Format:
909 <cpu number>,...,<cpu number>
910 or
911 <cpu number>-<cpu number> (must be a positive range in ascending order)
912 or a mixture
913 <cpu number>,...,<cpu number>-<cpu number>
Linus Torvalds1da177e2005-04-16 15:20:36 -0700914 This option can be used to specify one or more CPUs
915 to isolate from the general SMP balancing and scheduling
916 algorithms. The only way to move a process onto or off
917 an "isolated" CPU is via the CPU affinity syscalls.
918 <cpu number> begins at 0 and the maximum value is
919 "number of CPUs in system - 1".
920
921 This option is the preferred way to isolate CPUs. The
Randy Dunlapa9913042005-10-23 12:57:11 -0700922 alternative -- manually setting the CPU mask of all
923 tasks in the system -- can cause problems and
924 suboptimal load balancer performance.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700925
Randy Dunlapa9913042005-10-23 12:57:11 -0700926 iucv= [HW,NET]
Linus Torvalds1da177e2005-04-16 15:20:36 -0700927
928 js= [HW,JOY] Analog joystick
929 See Documentation/input/joystick.txt.
930
Alan Coxcd4f0ef2007-07-31 00:37:59 -0700931 kernelcore=nn[KMG] [KNL,X86-32,IA-64,PPC,X86-64] This parameter
Mel Gormaned7ed362007-07-17 04:03:14 -0700932 specifies the amount of memory usable by the kernel
933 for non-movable allocations. The requested amount is
934 spread evenly throughout all nodes in the system. The
935 remaining memory in each node is used for Movable
936 pages. In the event, a node is too small to have both
937 kernelcore and Movable pages, kernelcore pages will
938 take priority and other nodes will have a larger number
939 of kernelcore pages. The Movable zone is used for the
940 allocation of pages that may be reclaimed or moved
941 by the page migration subsystem. This means that
942 HugeTLB pages may not be allocated from this zone.
943 Note that allocations like PTEs-from-HighMem still
944 use the HighMem zone if it exists, and the Normal
945 zone if it does not.
946
Alan Coxcd4f0ef2007-07-31 00:37:59 -0700947 movablecore=nn[KMG] [KNL,X86-32,IA-64,PPC,X86-64] This parameter
Mel Gorman7e63efe2007-07-17 04:03:15 -0700948 is similar to kernelcore except it specifies the
949 amount of memory used for migratable allocations.
950 If both kernelcore and movablecore is specified,
951 then kernelcore will be at *least* the specified
952 value but may be more. If movablecore on its own
953 is specified, the administrator must be careful
954 that the amount of memory usable for all allocations
955 is not too small.
956
Linus Torvalds1da177e2005-04-16 15:20:36 -0700957 keepinitrd [HW,ARM]
958
Alan Coxcd4f0ef2007-07-31 00:37:59 -0700959 kstack=N [X86-32,X86-64] Print N words from the kernel stack
Linus Torvalds1da177e2005-04-16 15:20:36 -0700960 in oops dumps.
961
Jason Wessel6cdf6e02008-04-17 20:05:38 +0200962 kgdboc= [HW] kgdb over consoles.
963 Requires a tty driver that supports console polling.
964 (only serial suported for now)
965 Format: <serial_device>[,baud]
966
Linus Torvalds1da177e2005-04-16 15:20:36 -0700967 l2cr= [PPC]
968
Robert Brosea78bfbf2008-03-29 07:20:23 +1100969 l3cr= [PPC]
970
Alan Coxcd4f0ef2007-07-31 00:37:59 -0700971 lapic [X86-32,APIC] Enable the local APIC even if BIOS
Randy Dunlapa9913042005-10-23 12:57:11 -0700972 disabled it.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700973
Alan Coxcd4f0ef2007-07-31 00:37:59 -0700974 lapic_timer_c2_ok [X86-32,x86-64,APIC] trust the local apic timer in
Thomas Gleixnere585bef2007-03-23 16:08:01 +0100975 C2 power state.
976
FD Camifcb71f62008-01-06 19:08:56 +0100977 libata.dma= [LIBATA] DMA control
978 libata.dma=0 Disable all PATA and SATA DMA
979 libata.dma=1 PATA and SATA Disk DMA only
980 libata.dma=2 ATAPI (CDROM) DMA only
981 libata.dma=4 Compact Flash DMA only
982 Combinations also work, so libata.dma=3 enables DMA
983 for disks and CDROMs, but not CFs.
984
Dave Jones78e70c22007-09-27 11:50:13 -0400985 libata.noacpi [LIBATA] Disables use of ACPI in libata suspend/resume
986 when set.
987 Format: <int>
988
Tejun Heo33267322008-02-13 09:15:09 +0900989 libata.force= [LIBATA] Force configurations. The format is comma
990 separated list of "[ID:]VAL" where ID is
991 PORT[:DEVICE]. PORT and DEVICE are decimal numbers
992 matching port, link or device. Basically, it matches
993 the ATA ID string printed on console by libata. If
994 the whole ID part is omitted, the last PORT and DEVICE
995 values are used. If ID hasn't been specified yet, the
996 configuration applies to all ports, links and devices.
997
998 If only DEVICE is omitted, the parameter applies to
999 the port and all links and devices behind it. DEVICE
1000 number of 0 either selects the first device or the
1001 first fan-out link behind PMP device. It does not
1002 select the host link. DEVICE number of 15 selects the
1003 host link and device attached to it.
1004
1005 The VAL specifies the configuration to force. As long
1006 as there's no ambiguity shortcut notation is allowed.
1007 For example, both 1.5 and 1.5G would work for 1.5Gbps.
1008 The following configurations can be forced.
1009
1010 * Cable type: 40c, 80c, short40c, unk, ign or sata.
1011 Any ID with matching PORT is used.
1012
1013 * SATA link speed limit: 1.5Gbps or 3.0Gbps.
1014
1015 * Transfer mode: pio[0-7], mwdma[0-4] and udma[0-7].
1016 udma[/][16,25,33,44,66,100,133] notation is also
1017 allowed.
1018
1019 * [no]ncq: Turn on or off NCQ.
1020
1021 If there are multiple matching configurations changing
1022 the same attribute, the last one is used.
1023
Linus Torvalds1da177e2005-04-16 15:20:36 -07001024 load_ramdisk= [RAM] List of ramdisks to load from floppy
1025 See Documentation/ramdisk.txt.
1026
Randy Dunlapa6b25b62006-01-14 13:21:19 -08001027 lockd.nlm_grace_period=P [NFS] Assign grace period.
1028 Format: <integer>
Linus Torvalds1da177e2005-04-16 15:20:36 -07001029
Randy Dunlapa6b25b62006-01-14 13:21:19 -08001030 lockd.nlm_tcpport=N [NFS] Assign TCP port.
1031 Format: <integer>
1032
1033 lockd.nlm_timeout=T [NFS] Assign timeout value.
1034 Format: <integer>
1035
1036 lockd.nlm_udpport=M [NFS] Assign UDP port.
1037 Format: <integer>
Linus Torvalds1da177e2005-04-16 15:20:36 -07001038
1039 logibm.irq= [HW,MOUSE] Logitech Bus Mouse Driver
1040 Format: <irq>
1041
1042 loglevel= All Kernel Messages with a loglevel smaller than the
1043 console loglevel will be printed to the console. It can
1044 also be changed with klogd or other programs. The
1045 loglevels are defined as follows:
1046
1047 0 (KERN_EMERG) system is unusable
1048 1 (KERN_ALERT) action must be taken immediately
1049 2 (KERN_CRIT) critical conditions
1050 3 (KERN_ERR) error conditions
1051 4 (KERN_WARNING) warning conditions
1052 5 (KERN_NOTICE) normal but significant condition
1053 6 (KERN_INFO) informational
1054 7 (KERN_DEBUG) debug-level messages
1055
1056 log_buf_len=n Sets the size of the printk ring buffer, in bytes.
Randy Dunlapa9913042005-10-23 12:57:11 -07001057 Format: { n | nk | nM }
1058 n must be a power of two. The default size
1059 is set in the kernel config file.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001060
Randy Dunlapaccaa242007-10-16 01:29:37 -07001061 logo.nologo [FB] Disables display of the built-in Linux logo.
1062 This may be used to provide more screen space for
1063 kernel log messages and is useful when debugging
1064 kernel boot problems.
1065
Linus Torvalds1da177e2005-04-16 15:20:36 -07001066 lp=0 [LP] Specify parallel ports to use, e.g,
1067 lp=port[,port...] lp=none,parport0 (lp0 not configured, lp1 uses
1068 lp=reset first parallel port). 'lp=0' disables the
1069 lp=auto printer driver. 'lp=reset' (which can be
1070 specified in addition to the ports) causes
1071 attached printers to be reset. Using
1072 lp=port1,port2,... specifies the parallel ports
1073 to associate lp devices with, starting with
1074 lp0. A port specification may be 'none' to skip
1075 that lp device, or a parport name such as
1076 'parport0'. Specifying 'lp=auto' instead of a
1077 port specification list means that device IDs
1078 from each port should be examined, to see if
1079 an IEEE 1284-compliant printer is attached; if
1080 so, the driver will manage that printer.
1081 See also header of drivers/char/lp.c.
1082
1083 lpj=n [KNL]
1084 Sets loops_per_jiffy to given constant, thus avoiding
1085 time-consuming boot-time autodetection (up to 250 ms per
1086 CPU). 0 enables autodetection (default). To determine
1087 the correct value for your kernel, boot with normal
1088 autodetection and see what value is printed. Note that
1089 on SMP systems the preset will be applied to all CPUs,
1090 which is likely to cause problems if your CPUs need
1091 significantly divergent settings. An incorrect value
1092 will cause delays in the kernel to be wrong, leading to
1093 unpredictable I/O errors and other breakage. Although
1094 unlikely, in the extreme case this might damage your
1095 hardware.
1096
1097 ltpc= [NET]
1098 Format: <io>,<irq>,<dma>
1099
Randy Dunlapa9913042005-10-23 12:57:11 -07001100 mac5380= [HW,SCSI] Format:
1101 <can_queue>,<cmd_per_lun>,<sg_tablesize>,<hostid>,<use_tags>
Linus Torvalds1da177e2005-04-16 15:20:36 -07001102
Randy Dunlapa9913042005-10-23 12:57:11 -07001103 machvec= [IA64] Force the use of a particular machine-vector
1104 (machvec) in a generic kernel.
1105 Example: machvec=hpzx1_swiotlb
Linus Torvalds1da177e2005-04-16 15:20:36 -07001106
Randy Dunlapa9913042005-10-23 12:57:11 -07001107 max_loop= [LOOP] Maximum number of loopback devices that can
Linus Torvalds1da177e2005-04-16 15:20:36 -07001108 be mounted
1109 Format: <1-256>
1110
1111 maxcpus= [SMP] Maximum number of processors that an SMP kernel
Len Brown61ec7562007-08-16 03:34:22 -04001112 should make use of. maxcpus=n : n >= 0 limits the
1113 kernel to using 'n' processors. n=0 is a special case,
1114 it is equivalent to "nosmp", which also disables
1115 the IO APIC.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001116
Bob Picco2b2c3752005-06-29 18:00:00 -07001117 max_addr=[KMG] [KNL,BOOT,ia64] All physical memory greater than or
1118 equal to this physical address is ignored.
1119
Randy Dunlapa9913042005-10-23 12:57:11 -07001120 max_luns= [SCSI] Maximum number of LUNs to probe.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001121 Should be between 1 and 2^32-1.
1122
1123 max_report_luns=
Randy Dunlapa9913042005-10-23 12:57:11 -07001124 [SCSI] Maximum number of LUNs received.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001125 Should be between 1 and 16384.
1126
Linus Torvalds1da177e2005-04-16 15:20:36 -07001127 mcatest= [IA-64]
1128
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001129 mce [X86-32] Machine Check Exception
Linus Torvalds1da177e2005-04-16 15:20:36 -07001130
Andi Kleen909dd322007-10-17 18:04:38 +02001131 mce=option [X86-64] See Documentation/x86_64/boot-options.txt
1132
Linus Torvalds1da177e2005-04-16 15:20:36 -07001133 md= [HW] RAID subsystems devices and level
1134 See Documentation/md.txt.
Randy Dunlapa9913042005-10-23 12:57:11 -07001135
Linus Torvalds1da177e2005-04-16 15:20:36 -07001136 mdacon= [MDA]
1137 Format: <first>,<last>
1138 Specifies range of consoles to be captured by the MDA.
Randy Dunlapa9913042005-10-23 12:57:11 -07001139
Linus Torvalds1da177e2005-04-16 15:20:36 -07001140 mem=nn[KMG] [KNL,BOOT] Force usage of a specific amount of memory
1141 Amount of memory to be used when the kernel is not able
1142 to see the whole system memory or for test.
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001143 [X86-32] Use together with memmap= to avoid physical
Linus Torvalds1da177e2005-04-16 15:20:36 -07001144 address space collisions. Without memmap= PCI devices
1145 could be placed at addresses belonging to unused RAM.
1146
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001147 mem=nopentium [BUGS=X86-32] Disable usage of 4MB pages for kernel
Linus Torvalds1da177e2005-04-16 15:20:36 -07001148 memory.
1149
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001150 memmap=exactmap [KNL,X86-32,X86_64] Enable setting of an exact
Linus Torvalds1da177e2005-04-16 15:20:36 -07001151 E820 memory map, as specified by the user.
1152 Such memmap=exactmap lines can be constructed based on
1153 BIOS output or other requirements. See the memmap=nn@ss
1154 option description.
1155
1156 memmap=nn[KMG]@ss[KMG]
1157 [KNL] Force usage of a specific region of memory
1158 Region of memory to be used, from ss to ss+nn.
1159
1160 memmap=nn[KMG]#ss[KMG]
1161 [KNL,ACPI] Mark specific memory as ACPI data.
1162 Region of memory to be used, from ss to ss+nn.
1163
1164 memmap=nn[KMG]$ss[KMG]
1165 [KNL,ACPI] Mark specific memory as reserved.
1166 Region of memory to be used, from ss to ss+nn.
Pavel Machek13128482008-03-24 12:29:43 -07001167 Example: Exclude memory from 0x18690000-0x1869ffff
1168 memmap=64K$0x18690000
1169 or
1170 memmap=0x10000$0x18690000
Linus Torvalds1da177e2005-04-16 15:20:36 -07001171
Yinghai Luc64df702008-03-21 18:56:19 -07001172 memtest= [KNL,X86_64] Enable memtest
1173 Format: <integer>
1174 range: 0,4 : pattern number
1175 default : 0 <disable>
1176
Linus Torvalds1da177e2005-04-16 15:20:36 -07001177 meye.*= [HW] Set MotionEye Camera parameters
1178 See Documentation/video4linux/meye.txt.
1179
Andres Salomon8f368812007-10-12 23:04:06 +02001180 mfgpt_irq= [IA-32] Specify the IRQ to use for the
1181 Multi-Function General Purpose Timers on AMD Geode
1182 platforms.
1183
Willy Tarreaue6c4dc62008-01-30 13:33:33 +01001184 mfgptfix [X86-32] Fix MFGPT timers on AMD Geode platforms when
1185 the BIOS has incorrectly applied a workaround. TinyBIOS
1186 version 0.98 is known to be affected, 0.99 fixes the
1187 problem by letting the user disable the workaround.
1188
Linus Torvalds1da177e2005-04-16 15:20:36 -07001189 mga= [HW,DRM]
1190
1191 mousedev.tap_time=
1192 [MOUSE] Maximum time between finger touching and
1193 leaving touchpad surface for touch to be considered
1194 a tap and be reported as a left button click (for
1195 touchpads working in absolute mode only).
1196 Format: <msecs>
1197 mousedev.xres= [MOUSE] Horizontal screen resolution, used for devices
1198 reporting absolute coordinates, such as tablets
1199 mousedev.yres= [MOUSE] Vertical screen resolution, used for devices
1200 reporting absolute coordinates, such as tablets
1201
1202 mpu401= [HW,OSS]
1203 Format: <io>,<irq>
1204
1205 MTD_Partition= [MTD]
1206 Format: <name>,<region-number>,<size>,<offset>
1207
Randy Dunlapa9913042005-10-23 12:57:11 -07001208 MTD_Region= [MTD] Format:
1209 <name>,<region-number>[,<base>,<size>,<buswidth>,<altbuswidth>]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001210
1211 mtdparts= [MTD]
Randy Dunlapc8facbb2007-07-31 00:37:40 -07001212 See drivers/mtd/cmdlinepart.c.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001213
1214 mtouchusb.raw_coordinates=
Randy Dunlapa9913042005-10-23 12:57:11 -07001215 [HW] Make the MicroTouch USB driver use raw coordinates
1216 ('y', default) or cooked coordinates ('n')
Linus Torvalds1da177e2005-04-16 15:20:36 -07001217
1218 n2= [NET] SDL Inc. RISCom/N2 synchronous serial card
1219
1220 NCR_D700= [HW,SCSI]
1221 See header of drivers/scsi/NCR_D700.c.
1222
1223 ncr5380= [HW,SCSI]
1224
1225 ncr53c400= [HW,SCSI]
1226
1227 ncr53c400a= [HW,SCSI]
1228
1229 ncr53c406a= [HW,SCSI]
1230
1231 ncr53c8xx= [HW,SCSI]
1232
1233 netdev= [NET] Network devices parameters
1234 Format: <irq>,<io>,<mem_start>,<mem_end>,<name>
1235 Note that mem_start is often overloaded to mean
1236 something different and driver-specific.
Randy Dunlapa9913042005-10-23 12:57:11 -07001237 This usage is only documented in each driver source
1238 file if at all.
1239
Linus Torvalds1da177e2005-04-16 15:20:36 -07001240 nfsaddrs= [NFS]
J. Bruce Fields6ded55d2008-04-07 15:59:03 -04001241 See Documentation/filesystems/nfsroot.txt.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001242
1243 nfsroot= [NFS] nfs root filesystem for disk-less boxes.
J. Bruce Fields6ded55d2008-04-07 15:59:03 -04001244 See Documentation/filesystems/nfsroot.txt.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001245
Trond Myklebusta72b4422006-01-03 09:55:41 +01001246 nfs.callback_tcpport=
1247 [NFS] set the TCP port on which the NFSv4 callback
1248 channel should listen.
1249
Trond Myklebust58df0952006-01-03 09:55:57 +01001250 nfs.idmap_cache_timeout=
1251 [NFS] set the maximum lifetime for idmapper cache
1252 entries.
1253
Trond Myklebustf43bf0b2007-10-09 12:01:04 -04001254 nfs.enable_ino64=
1255 [NFS] enable 64-bit inode numbers.
1256 If zero, the NFS client will fake up a 32-bit inode
1257 number for the readdir() and stat() syscalls instead
1258 of returning the full 64-bit number.
1259 The default is to return 64-bit inode numbers.
1260
Haavard Skinnemoene7ba1762007-10-10 14:58:29 +02001261 nmi_debug= [KNL,AVR32] Specify one or more actions to take
1262 when a NMI is triggered.
1263 Format: [state][,regs][,debounce][,die]
1264
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001265 nmi_watchdog= [KNL,BUGS=X86-32] Debugging features for SMP kernels
Linus Torvalds1da177e2005-04-16 15:20:36 -07001266
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001267 no387 [BUGS=X86-32] Tells the kernel to use the 387 maths
Linus Torvalds1da177e2005-04-16 15:20:36 -07001268 emulation library even if a 387 maths coprocessor
1269 is present.
1270
Christoph Lameterc1aee212007-05-31 00:40:47 -07001271 noaliencache [MM, NUMA, SLAB] Disables the allocation of alien
1272 caches in the slab allocator. Saves per-node memory,
1273 but will impact performance.
Paul Menage3395ee02006-12-06 20:32:16 -08001274
Randy Dunlapa9913042005-10-23 12:57:11 -07001275 noalign [KNL,ARM]
1276
Linus Torvalds1da177e2005-04-16 15:20:36 -07001277 noapic [SMP,APIC] Tells the kernel to not make use of any
1278 IOAPICs that may be present in the system.
1279
Linus Torvalds1da177e2005-04-16 15:20:36 -07001280 nobats [PPC] Do not use BATs for mapping kernel lowmem
1281 on "Classic" PPC cores.
1282
1283 nocache [ARM]
Randy Dunlapa9913042005-10-23 12:57:11 -07001284
Shailabh Nagar163ecdf2006-07-30 03:03:11 -07001285 nodelayacct [KNL] Disable per-task delay accounting
1286
Linus Torvalds1da177e2005-04-16 15:20:36 -07001287 nodisconnect [HW,SCSI,M68K] Disables SCSI disconnects.
1288
Huang, Ying8b2cb7a2008-01-30 13:32:11 +01001289 noefi [X86-32,X86-64] Disable EFI runtime services support.
1290
Linus Torvalds1da177e2005-04-16 15:20:36 -07001291 noexec [IA-64]
1292
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001293 noexec [X86-32,X86-64]
Jiri Slabyf5a1b192008-04-12 10:28:25 +02001294 On X86-32 available only on PAE configured kernels.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001295 noexec=on: enable non-executable mappings (default)
Jiri Slabyf5a1b192008-04-12 10:28:25 +02001296 noexec=off: disable non-executable mappings
1297
1298 noexec32 [X86-64]
1299 This affects only 32-bit executables.
1300 noexec32=on: enable non-executable mappings (default)
1301 read doesn't imply executable mappings
1302 noexec32=off: disable non-executable mappings
1303 read implies executable mappings
Linus Torvalds1da177e2005-04-16 15:20:36 -07001304
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001305 nofxsr [BUGS=X86-32] Disables x86 floating point extended
Chuck Ebbert4f886512006-03-23 02:59:34 -08001306 register save and restore. The kernel will only save
1307 legacy floating-point registers on task switch.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001308
Andi Kleen191679f2008-01-30 13:33:21 +01001309 noclflush [BUGS=X86] Don't use the CLFLUSH instruction
1310
Linus Torvalds1da177e2005-04-16 15:20:36 -07001311 nohlt [BUGS=ARM]
Randy Dunlapa9913042005-10-23 12:57:11 -07001312
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001313 no-hlt [BUGS=X86-32] Tells the kernel that the hlt
Linus Torvalds1da177e2005-04-16 15:20:36 -07001314 instruction doesn't work correctly and not to
1315 use it.
1316
1317 nohalt [IA-64] Tells the kernel not to use the power saving
1318 function PAL_HALT_LIGHT when idle. This increases
1319 power-consumption. On the positive side, it reduces
1320 interrupt wake-up latency, which may improve performance
1321 in certain environments such as networked servers or
1322 real-time systems.
1323
Thomas Gleixner79bf2bb2007-02-16 01:28:03 -08001324 nohz= [KNL] Boottime enable/disable dynamic ticks
1325 Valid arguments: on, off
1326 Default: on
1327
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001328 noirqbalance [X86-32,SMP,KNL] Disable kernel irq balancing
Zachary Amsden8542b202006-12-07 02:14:09 +01001329
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001330 noirqdebug [X86-32] Disables the code which attempts to detect and
Linus Torvalds1da177e2005-04-16 15:20:36 -07001331 disable unhandled interrupt sources.
1332
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001333 no_timer_check [X86-32,X86_64,APIC] Disables the code which tests for
Zachary Amsden8542b202006-12-07 02:14:09 +01001334 broken timer IRQ sources.
1335
Linus Torvalds1da177e2005-04-16 15:20:36 -07001336 noisapnp [ISAPNP] Disables ISA PnP code.
1337
1338 noinitrd [RAM] Tells the kernel not to load any configured
1339 initial RAM disk.
1340
1341 nointroute [IA-64]
1342
Tony Luck0aa366f2007-07-20 11:22:30 -07001343 nojitter [IA64] Disables jitter checking for ITC timers.
1344
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001345 nolapic [X86-32,APIC] Do not enable or use the local APIC.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001346
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001347 nolapic_timer [X86-32,APIC] Do not use the local APIC timer.
Thomas Gleixnerad62ca22007-03-22 00:11:21 -08001348
Linus Torvalds1da177e2005-04-16 15:20:36 -07001349 noltlbs [PPC] Do not use large page/tlb entries for kernel
1350 lowmem mapping on PPC40x.
1351
Horms312f1f02006-02-22 09:57:55 +09001352 nomca [IA-64] Disable machine check abort handling
1353
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001354 nomce [X86-32] Machine Check Exception
Hormsabe37e52006-04-01 01:36:09 +02001355
Andres Salomon83d73842007-10-12 23:04:06 +02001356 nomfgpt [X86-32] Disable Multi-Function General Purpose
1357 Timer usage (for AMD Geode machines).
1358
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001359 noreplace-paravirt [X86-32,PV_OPS] Don't patch paravirt_ops
Jeremy Fitzhardinge959b4fd2007-05-02 19:27:16 +02001360
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001361 noreplace-smp [X86-32,SMP] Don't replace SMP instructions
Jeremy Fitzhardingeb7fb4af2007-05-02 19:27:13 +02001362 with UP alternatives
1363
Linus Torvalds1da177e2005-04-16 15:20:36 -07001364 noresidual [PPC] Don't use residual data on PReP machines.
1365
Randy Dunlapa9913042005-10-23 12:57:11 -07001366 noresume [SWSUSP] Disables resume and restores original swap
1367 space.
1368
Linus Torvalds1da177e2005-04-16 15:20:36 -07001369 no-scroll [VGA] Disables scrollback.
1370 This is required for the Braillex ib80-piezo Braille
1371 reader made by F.H. Papenmeier (Germany).
1372
1373 nosbagart [IA-64]
1374
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001375 nosep [BUGS=X86-32] Disables x86 SYSENTER/SYSEXIT support.
Chuck Ebbert4f886512006-03-23 02:59:34 -08001376
Len Brown61ec7562007-08-16 03:34:22 -04001377 nosmp [SMP] Tells an SMP kernel to act as a UP kernel,
1378 and disable the IO APIC. legacy for "maxcpus=0".
Linus Torvalds1da177e2005-04-16 15:20:36 -07001379
Dave Jones97842212007-07-15 23:41:05 -07001380 nosoftlockup [KNL] Disable the soft-lockup detector.
1381
Linus Torvalds1da177e2005-04-16 15:20:36 -07001382 nosync [HW,M68K] Disables sync negotiation for all devices.
1383
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001384 notsc [BUGS=X86-32] Disable Time Stamp Counter
Linus Torvalds1da177e2005-04-16 15:20:36 -07001385
1386 nousb [USB] Disable the USB subsystem
1387
1388 nowb [ARM]
Randy Dunlapa9913042005-10-23 12:57:11 -07001389
Fenghua Yua6c75b862008-03-14 13:57:08 -07001390 nptcg= [IA64] Override max number of concurrent global TLB
1391 purges which is reported from either PAL_VM_SUMMARY or
1392 SAL PALO.
1393
KAMEZAWA Hiroyukif0c0b2b2007-07-15 23:38:01 -07001394 numa_zonelist_order= [KNL, BOOT] Select zonelist order for NUMA.
1395 one of ['zone', 'node', 'default'] can be specified
1396 This can be set from sysctl after boot.
1397 See Documentation/sysctl/vm.txt for details.
1398
Dave Jonesa61c2d72006-01-07 23:18:19 +00001399 nr_uarts= [SERIAL] maximum number of UARTs to be registered.
1400
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07001401 olpc_ec_timeout= [OLPC] ms delay when issuing EC commands
1402 Rather than timing out after 20 ms if an EC
1403 command is not properly ACKed, override the length
1404 of the timeout. We have interrupts disabled while
1405 waiting for the ACK, so if this is set too high
1406 interrupts *may* be lost!
1407
Linus Torvalds1da177e2005-04-16 15:20:36 -07001408 opl3= [HW,OSS]
1409 Format: <io>
1410
Linus Torvalds1da177e2005-04-16 15:20:36 -07001411 oprofile.timer= [HW]
1412 Use timer interrupt instead of performance counters
1413
Linus Torvalds1da177e2005-04-16 15:20:36 -07001414 osst= [HW,SCSI] SCSI Tape Driver
1415 Format: <buffer_size>,<write_threshold>
1416 See also Documentation/scsi/st.txt.
1417
1418 panic= [KNL] Kernel behaviour on panic
1419 Format: <timeout>
1420
1421 parkbd.port= [HW] Parallel port number the keyboard adapter is
1422 connected to, default is 0.
1423 Format: <parport#>
1424 parkbd.mode= [HW] Parallel port keyboard adapter mode of operation,
1425 0 for XT, 1 for AT (default is AT).
Randy Dunlapa9913042005-10-23 12:57:11 -07001426 Format: <mode>
Linus Torvalds1da177e2005-04-16 15:20:36 -07001427
Randy Dunlapa9913042005-10-23 12:57:11 -07001428 parport= [HW,PPT] Specify parallel ports. 0 disables.
1429 Format: { 0 | auto | 0xBBB[,IRQ[,DMA]] }
1430 Use 'auto' to force the driver to use any
1431 IRQ/DMA settings detected (the default is to
1432 ignore detected IRQ/DMA settings because of
1433 possible conflicts). You can specify the base
1434 address, IRQ, and DMA settings; IRQ and DMA
1435 should be numbers, or 'auto' (for using detected
1436 settings on that particular port), or 'nofifo'
1437 (to avoid using a FIFO even if it is detected).
1438 Parallel ports are assigned in the order they
1439 are specified on the command line, starting
1440 with parport0.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001441
Randy Dunlapa9913042005-10-23 12:57:11 -07001442 parport_init_mode= [HW,PPT]
1443 Configure VIA parallel port to operate in
1444 a specific mode. This is necessary on Pegasos
1445 computer where firmware has no options for setting
1446 up parallel port mode and sets it to spp.
1447 Currently this function knows 686a and 8231 chips.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001448 Format: [spp|ps2|epp|ecp|ecpepp]
1449
Randy Dunlapa9913042005-10-23 12:57:11 -07001450 pas2= [HW,OSS] Format:
1451 <io>,<irq>,<dma>,<dma16>,<sb_io>,<sb_irq>,<sb_dma>,<sb_dma16>
1452
Linus Torvalds1da177e2005-04-16 15:20:36 -07001453 pas16= [HW,SCSI]
1454 See header of drivers/scsi/pas16.c.
1455
Andrew Mortondd287792006-03-23 03:00:57 -08001456 pause_on_oops=
1457 Halt all CPUs after the first oops has been printed for
1458 the specified number of seconds. This is to be used if
1459 your oopses keep scrolling off the screen.
1460
Linus Torvalds1da177e2005-04-16 15:20:36 -07001461 pcbit= [HW,ISDN]
1462
1463 pcd. [PARIDE]
1464 See header of drivers/block/paride/pcd.c.
1465 See also Documentation/paride.txt.
1466
Randy Dunlapa9913042005-10-23 12:57:11 -07001467 pci=option[,option...] [PCI] various PCI subsystem options:
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001468 off [X86-32] don't probe for the PCI bus
1469 bios [X86-32] force use of PCI BIOS, don't access
Randy Dunlapa9913042005-10-23 12:57:11 -07001470 the hardware directly. Use this if your machine
1471 has a non-standard PCI host bridge.
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001472 nobios [X86-32] disallow use of PCI BIOS, only direct
Randy Dunlapa9913042005-10-23 12:57:11 -07001473 hardware access methods are allowed. Use this
1474 if you experience crashes upon bootup and you
1475 suspect they are caused by the BIOS.
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001476 conf1 [X86-32] Force use of PCI Configuration
Randy Dunlapa9913042005-10-23 12:57:11 -07001477 Mechanism 1.
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001478 conf2 [X86-32] Force use of PCI Configuration
Randy Dunlapa9913042005-10-23 12:57:11 -07001479 Mechanism 2.
Randy Dunlap7f785762007-10-05 13:17:58 -07001480 noaer [PCIE] If the PCIEAER kernel config parameter is
1481 enabled, this kernel boot option can be used to
1482 disable the use of PCIE advanced error reporting.
Jeff Garzik32a2eea2007-10-11 16:57:27 -04001483 nodomains [PCI] Disable support for multiple PCI
1484 root domains (aka PCI segments, in ACPI-speak).
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001485 nommconf [X86-32,X86_64] Disable use of MMCONFIG for PCI
Bjorn Helgaas61be6d62006-02-15 15:17:43 -08001486 Configuration
Matthew Wilcox309e57d2006-03-05 22:33:34 -07001487 nomsi [MSI] If the PCI_MSI kernel config parameter is
1488 enabled, this kernel boot option can be used to
1489 disable the use of MSI interrupts system-wide.
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001490 biosirq [X86-32] Use PCI BIOS calls to get the interrupt
Randy Dunlapa9913042005-10-23 12:57:11 -07001491 routing table. These calls are known to be buggy
1492 on several machines and they hang the machine
1493 when used, but on other computers it's the only
1494 way to get the interrupt routing table. Try
1495 this option if the kernel is unable to allocate
1496 IRQs or discover secondary PCI buses on your
1497 motherboard.
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001498 rom [X86-32] Assign address space to expansion ROMs.
Randy Dunlapa9913042005-10-23 12:57:11 -07001499 Use with caution as certain devices share
1500 address decoders between ROMs and other
1501 resources.
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001502 irqmask=0xMMMM [X86-32] Set a bit mask of IRQs allowed to be
Randy Dunlapa9913042005-10-23 12:57:11 -07001503 assigned automatically to PCI devices. You can
1504 make the kernel exclude IRQs of your ISA cards
1505 this way.
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001506 pirqaddr=0xAAAAA [X86-32] Specify the physical address
Randy Dunlapa9913042005-10-23 12:57:11 -07001507 of the PIRQ table (normally generated
1508 by the BIOS) if it is outside the
1509 F0000h-100000h range.
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001510 lastbus=N [X86-32] Scan all buses thru bus #N. Can be
Randy Dunlapa9913042005-10-23 12:57:11 -07001511 useful if the kernel is unable to find your
1512 secondary buses and you want to tell it
1513 explicitly which ones they are.
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001514 assign-busses [X86-32] Always assign all PCI bus
Randy Dunlapa9913042005-10-23 12:57:11 -07001515 numbers ourselves, overriding
1516 whatever the firmware may have done.
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001517 usepirqmask [X86-32] Honor the possible IRQ mask stored
Randy Dunlapa9913042005-10-23 12:57:11 -07001518 in the BIOS $PIR table. This is needed on
1519 some systems with broken BIOSes, notably
1520 some HP Pavilion N5400 and Omnibook XE3
1521 notebooks. This will have no effect if ACPI
1522 IRQ routing is enabled.
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001523 noacpi [X86-32] Do not use ACPI for IRQ routing
Randy Dunlapa9913042005-10-23 12:57:11 -07001524 or for PCI scanning.
Gary Hade62f420f2007-10-03 15:56:51 -07001525 use_crs [X86-32] Use _CRS for PCI resource
1526 allocation.
Randy Dunlapa9913042005-10-23 12:57:11 -07001527 routeirq Do IRQ routing for all PCI devices.
1528 This is normally done in pci_enable_device(),
1529 so this option is a temporary workaround
1530 for broken drivers that don't call it.
Yinghai Lu13a6ddb2008-03-27 01:31:18 -07001531 skip_isa_align [X86] do not align io start addr, so can
1532 handle more pci cards
Randy Dunlapa9913042005-10-23 12:57:11 -07001533 firmware [ARM] Do not re-enumerate the bus but instead
1534 just use the configuration from the
1535 bootloader. This is currently used on
1536 IXP2000 systems where the bus has to be
1537 configured a certain way for adjunct CPUs.
Andi Kleen0637a702006-09-26 10:52:41 +02001538 noearly [X86] Don't do any early type 1 scanning.
1539 This might help on some broken boards which
1540 machine check when some devices' config space
1541 is read. But various workarounds are disabled
1542 and some IOMMU drivers will not work.
Matt Domsch6b4b78f2006-09-29 15:23:23 -05001543 bfsort Sort PCI devices into breadth-first order.
1544 This sorting is done to get a device
1545 order compatible with older (<= 2.4) kernels.
1546 nobfsort Don't sort PCI devices into breadth-first order.
Atsushi Nemoto4516a612007-02-05 16:36:06 -08001547 cbiosize=nn[KMG] The fixed amount of bus space which is
1548 reserved for the CardBus bridge's IO window.
1549 The default value is 256 bytes.
1550 cbmemsize=nn[KMG] The fixed amount of bus space which is
1551 reserved for the CardBus bridge's memory
1552 window. The default value is 64 megabytes.
Matt Domsch6b4b78f2006-09-29 15:23:23 -05001553
Linus Torvalds1da177e2005-04-16 15:20:36 -07001554 pcmv= [HW,PCMCIA] BadgePAD 4
1555
1556 pd. [PARIDE]
1557 See Documentation/paride.txt.
1558
1559 pdcchassis= [PARISC,HW] Disable/Enable PDC Chassis Status codes at
1560 boot time.
1561 Format: { 0 | 1 }
1562 See arch/parisc/kernel/pdc_chassis.c
1563
1564 pf. [PARIDE]
1565 See Documentation/paride.txt.
1566
1567 pg. [PARIDE]
1568 See Documentation/paride.txt.
1569
1570 pirq= [SMP,APIC] Manual mp-table setup
1571 See Documentation/i386/IO-APIC.txt.
1572
1573 plip= [PPT,NET] Parallel port network link
1574 Format: { parport<nr> | timid | 0 }
1575 See also Documentation/parport.txt.
1576
1577 pnpacpi= [ACPI]
1578 { off }
1579
1580 pnpbios= [ISAPNP]
1581 { on | off | curr | res | no-curr | no-res }
1582
1583 pnp_reserve_irq=
1584 [ISAPNP] Exclude IRQs for the autoconfiguration
1585
1586 pnp_reserve_dma=
1587 [ISAPNP] Exclude DMAs for the autoconfiguration
1588
1589 pnp_reserve_io= [ISAPNP] Exclude I/O ports for the autoconfiguration
Randy Dunlapa9913042005-10-23 12:57:11 -07001590 Ranges are in pairs (I/O port base and size).
Linus Torvalds1da177e2005-04-16 15:20:36 -07001591
1592 pnp_reserve_mem=
Randy Dunlapa9913042005-10-23 12:57:11 -07001593 [ISAPNP] Exclude memory regions for the
1594 autoconfiguration.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001595 Ranges are in pairs (memory base and size).
1596
Ingo Molnar45807a12007-07-15 23:40:10 -07001597 print-fatal-signals=
1598 [KNL] debug: print fatal signals
1599 print-fatal-signals=1: print segfault info to
1600 the kernel console.
1601 default: off.
1602
Randy Dunlape84845c2007-07-15 23:40:25 -07001603 printk.time= Show timing data prefixed to each printk message line
1604 Format: <bool> (1/Y/y=enable, 0/N/n=disable)
1605
Linus Torvalds1da177e2005-04-16 15:20:36 -07001606 profile= [KNL] Enable kernel profiling via /proc/profile
Randy Dunlapa9913042005-10-23 12:57:11 -07001607 Format: [schedule,]<number>
1608 Param: "schedule" - profile schedule points.
1609 Param: <number> - step/bucket size as a power of 2 for
1610 statistical time based profiling.
Mel Gormanb3da2a72007-10-24 18:23:50 +02001611 Param: "sleep" - profile D-state sleeping (millisecs).
1612 Requires CONFIG_SCHEDSTATS
Dave Jonesc0fe2e62007-10-20 03:08:22 +02001613 Param: "kvm" - profile VM exits.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001614
Randy Dunlapa9913042005-10-23 12:57:11 -07001615 processor.max_cstate= [HW,ACPI]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001616 Limit processor to maximum C-state
1617 max_cstate=9 overrides any DMI blacklist limit.
1618
Len Brown41c0d862005-12-28 12:43:51 -05001619 processor.nocst [HW,ACPI]
1620 Ignore the _CST method to determine C-states,
1621 instead using the legacy FADT method
1622
Linus Torvalds1da177e2005-04-16 15:20:36 -07001623 prompt_ramdisk= [RAM] List of RAM disks to prompt for floppy disk
1624 before loading.
1625 See Documentation/ramdisk.txt.
1626
Randy Dunlapa9913042005-10-23 12:57:11 -07001627 psmouse.proto= [HW,MOUSE] Highest PS2 mouse protocol extension to
1628 probe for; one of (bare|imps|exps|lifebook|any).
Linus Torvalds1da177e2005-04-16 15:20:36 -07001629 psmouse.rate= [HW,MOUSE] Set desired mouse report rate, in reports
1630 per second.
Randy Dunlapa9913042005-10-23 12:57:11 -07001631 psmouse.resetafter= [HW,MOUSE]
1632 Try to reset the device after so many bad packets
Linus Torvalds1da177e2005-04-16 15:20:36 -07001633 (0 = never).
1634 psmouse.resolution=
1635 [HW,MOUSE] Set desired mouse resolution, in dpi.
1636 psmouse.smartscroll=
Randy Dunlapa9913042005-10-23 12:57:11 -07001637 [HW,MOUSE] Controls Logitech smartscroll autorepeat.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001638 0 = disabled, 1 = enabled (default).
1639
1640 pss= [HW,OSS] Personal Sound System (ECHO ESC614)
Randy Dunlapa9913042005-10-23 12:57:11 -07001641 Format:
1642 <io>,<mss_io>,<mss_irq>,<mss_dma>,<mpu_io>,<mpu_irq>
Linus Torvalds1da177e2005-04-16 15:20:36 -07001643
1644 pt. [PARIDE]
1645 See Documentation/paride.txt.
1646
Kay Sieversdc8c8582007-08-15 12:25:38 +02001647 pty.legacy_count=
1648 [KNL] Number of legacy pty's. Overwrites compiled-in
1649 default number.
1650
Randy Dunlap7d2c5022006-09-29 02:01:02 -07001651 quiet [KNL] Disable most log messages
Randy Dunlapa9913042005-10-23 12:57:11 -07001652
Linus Torvalds1da177e2005-04-16 15:20:36 -07001653 r128= [HW,DRM]
1654
1655 raid= [HW,RAID]
1656 See Documentation/md.txt.
1657
Randy Dunlapa9913042005-10-23 12:57:11 -07001658 ramdisk_blocksize= [RAM]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001659 See Documentation/ramdisk.txt.
Randy Dunlapa9913042005-10-23 12:57:11 -07001660
Linus Torvalds1da177e2005-04-16 15:20:36 -07001661 ramdisk_size= [RAM] Sizes of RAM disks in kilobytes
Linus Torvalds1da177e2005-04-16 15:20:36 -07001662 See Documentation/ramdisk.txt.
1663
Robert P. J. Day24aaef82008-02-03 15:20:26 +02001664 rcupdate.blimit= [KNL,BOOT]
1665 Set maximum number of finished RCU callbacks to process
1666 in one batch.
Dipankar Sarma21a1ea92006-03-07 21:55:33 -08001667
Robert P. J. Day24aaef82008-02-03 15:20:26 +02001668 rcupdate.qhimark= [KNL,BOOT]
1669 Set threshold of queued
Dipankar Sarma21a1ea92006-03-07 21:55:33 -08001670 RCU callbacks over which batch limiting is disabled.
1671
Robert P. J. Day24aaef82008-02-03 15:20:26 +02001672 rcupdate.qlowmark= [KNL,BOOT]
1673 Set threshold of queued RCU callbacks below which
1674 batch limiting is re-enabled.
Dipankar Sarma21a1ea92006-03-07 21:55:33 -08001675
Olof Johanssonffdfc402005-09-06 15:17:19 -07001676 rdinit= [KNL]
1677 Format: <full_path>
1678 Run specified binary instead of /init from the ramdisk,
1679 used for early userspace startup. See initrd.
1680
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001681 reboot= [BUGS=X86-32,BUGS=ARM,BUGS=IA-64] Rebooting mode
Linus Torvalds1da177e2005-04-16 15:20:36 -07001682 Format: <reboot_mode>[,<reboot_mode2>[,...]]
Mauro Carvalho Chehabe53dd082007-09-15 07:38:47 -03001683 See arch/*/kernel/reboot.c or arch/*/kernel/process.c
Linus Torvalds1da177e2005-04-16 15:20:36 -07001684
1685 reserve= [KNL,BUGS] Force the kernel to ignore some iomem area
1686
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001687 reservetop= [X86-32]
Zachary Amsden461a9af2006-09-25 23:32:25 -07001688 Format: nn[KMG]
1689 Reserves a hole at the top of the kernel virtual
1690 address space.
1691
Vivek Goyal7e962872006-09-27 01:50:44 -07001692 reset_devices [KNL] Force drivers to reset the underlying device
1693 during initialization.
1694
Randy Dunlapa9913042005-10-23 12:57:11 -07001695 resume= [SWSUSP]
1696 Specify the partition device for software suspend
Linus Torvalds1da177e2005-04-16 15:20:36 -07001697
Rafael J. Wysockiecbd0da2006-12-06 20:34:13 -08001698 resume_offset= [SWSUSP]
1699 Specify the offset from the beginning of the partition
1700 given by "resume=" at which the swap header is located,
1701 in <PAGE_SIZE> units (needed only for swap files).
1702 See Documentation/power/swsusp-and-swap-files.txt
1703
Michael Neuling0a7b35c2007-02-10 01:44:33 -08001704 retain_initrd [RAM] Keep initrd memory after extraction
1705
Linus Torvalds1da177e2005-04-16 15:20:36 -07001706 rhash_entries= [KNL,NET]
1707 Set number of hash buckets for route cache
1708
1709 riscom8= [HW,SERIAL]
1710 Format: <io_board1>[,<io_board2>[,...<io_boardN>]]
1711
1712 ro [KNL] Mount root device read-only on boot
1713
1714 root= [KNL] Root filesystem
1715
1716 rootdelay= [KNL] Delay (in seconds) to pause before attempting to
1717 mount the root filesystem
1718
1719 rootflags= [KNL] Set root filesystem mount option string
1720
1721 rootfstype= [KNL] Set root filesystem type
1722
Pierre Ossmancc1ed752007-07-15 23:40:35 -07001723 rootwait [KNL] Wait (indefinitely) for root device to show up.
1724 Useful for devices that are detected asynchronously
1725 (e.g. USB and MMC devices).
1726
James Morris20510f22007-10-16 23:31:32 -07001727 root_plug.vendor_id=
1728 [ROOTPLUG] Override the default vendor ID
1729
1730 root_plug.product_id=
1731 [ROOTPLUG] Override the default product ID
1732
1733 root_plug.debug=
1734 [ROOTPLUG] Enable debugging output
1735
Linus Torvalds1da177e2005-04-16 15:20:36 -07001736 rw [KNL] Mount root device read-write on boot
1737
1738 S [KNL] Run init in single mode
1739
1740 sa1100ir [NET]
1741 See drivers/net/irda/sa1100_ir.c.
1742
Linus Torvalds1da177e2005-04-16 15:20:36 -07001743 sbni= [NET] Granch SBNI12 leased line adapter
Randy Dunlapa9913042005-10-23 12:57:11 -07001744
Linus Torvalds1da177e2005-04-16 15:20:36 -07001745 sc1200wdt= [HW,WDT] SC1200 WDT (watchdog) driver
1746 Format: <io>[,<timeout>[,<isapnp>]]
1747
1748 scsi_debug_*= [SCSI]
1749 See drivers/scsi/scsi_debug.c.
1750
1751 scsi_default_dev_flags=
1752 [SCSI] SCSI default device flags
1753 Format: <integer>
1754
1755 scsi_dev_flags= [SCSI] Black/white list entry for vendor and model
1756 Format: <vendor>:<model>:<flags>
1757 (flags are integer value)
1758
Randy Dunlap6af66322007-11-14 16:52:25 -08001759 scsi_logging_level= [SCSI] a bit mask of logging levels
1760 See drivers/scsi/scsi_logging.h for bits. Also
1761 settable via sysctl at dev.scsi.logging_level
1762 (/proc/sys/dev/scsi/logging_level).
1763 There is also a nice 'scsi_logging_level' script in the
1764 S390-tools package, available for download at
1765 http://www-128.ibm.com/developerworks/linux/linux390/s390-tools-1.5.4.html
Linus Torvalds1da177e2005-04-16 15:20:36 -07001766
Matthew Wilcox3e082a92006-09-28 15:19:20 -06001767 scsi_mod.scan= [SCSI] sync (default) scans SCSI busses as they are
1768 discovered. async scans them in kernel threads,
1769 allowing boot to proceed. none ignores them, expecting
1770 user space to do the scan.
1771
Linus Torvalds1da177e2005-04-16 15:20:36 -07001772 selinux [SELINUX] Disable or enable SELinux at boot time.
1773 Format: { "0" | "1" }
1774 See security/selinux/Kconfig help text.
1775 0 -- disable.
1776 1 -- enable.
1777 Default value is set via kernel config option.
1778 If enabled at boot time, /selinux/disable can be used
1779 later to disable prior to initial policy load.
1780
James Morris4e5ab4c2006-06-09 00:33:33 -07001781 selinux_compat_net =
1782 [SELINUX] Set initial selinux_compat_net flag value.
Mauro Carvalho Chehabe53dd082007-09-15 07:38:47 -03001783 Format: { "0" | "1" }
1784 0 -- use new secmark-based packet controls
1785 1 -- use legacy packet controls
1786 Default value is 0 (preferred).
1787 Value can be changed at runtime via
1788 /selinux/compat_net.
James Morris4e5ab4c2006-06-09 00:33:33 -07001789
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001790 serialnumber [BUGS=X86-32]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001791
Linus Torvalds1da177e2005-04-16 15:20:36 -07001792 shapers= [NET]
1793 Maximal number of shapers.
Randy Dunlapa9913042005-10-23 12:57:11 -07001794
Linus Torvalds1da177e2005-04-16 15:20:36 -07001795 sim710= [SCSI,HW]
1796 See header of drivers/scsi/sim710.c.
1797
1798 simeth= [IA-64]
1799 simscsi=
Randy Dunlapa9913042005-10-23 12:57:11 -07001800
Linus Torvalds1da177e2005-04-16 15:20:36 -07001801 slram= [HW,MTD]
1802
Christoph Lameterf0630ff2007-07-15 23:38:14 -07001803 slub_debug[=options[,slabs]] [MM, SLUB]
1804 Enabling slub_debug allows one to determine the
1805 culprit if slab objects become corrupted. Enabling
1806 slub_debug can create guard zones around objects and
1807 may poison objects when not in use. Also tracks the
1808 last alloc / free. For more information see
1809 Documentation/vm/slub.txt.
Christoph Lameterc1aee212007-05-31 00:40:47 -07001810
1811 slub_max_order= [MM, SLUB]
Christoph Lameterf0630ff2007-07-15 23:38:14 -07001812 Determines the maximum allowed order for slabs.
1813 A high setting may cause OOMs due to memory
1814 fragmentation. For more information see
1815 Documentation/vm/slub.txt.
Christoph Lameterc1aee212007-05-31 00:40:47 -07001816
1817 slub_min_objects= [MM, SLUB]
Christoph Lameterf0630ff2007-07-15 23:38:14 -07001818 The minimum number of objects per slab. SLUB will
1819 increase the slab order up to slub_max_order to
1820 generate a sufficiently large slab able to contain
1821 the number of objects indicated. The higher the number
1822 of objects the smaller the overhead of tracking slabs
1823 and the less frequently locks need to be acquired.
Christoph Lameterc1aee212007-05-31 00:40:47 -07001824 For more information see Documentation/vm/slub.txt.
1825
1826 slub_min_order= [MM, SLUB]
1827 Determines the mininum page order for slabs. Must be
Christoph Lameterf0630ff2007-07-15 23:38:14 -07001828 lower than slub_max_order.
Christoph Lameterc1aee212007-05-31 00:40:47 -07001829 For more information see Documentation/vm/slub.txt.
1830
1831 slub_nomerge [MM, SLUB]
Christoph Lameterf0630ff2007-07-15 23:38:14 -07001832 Disable merging of slabs with similar size. May be
Christoph Lameterc1aee212007-05-31 00:40:47 -07001833 necessary if there is some reason to distinguish
Christoph Lameterf0630ff2007-07-15 23:38:14 -07001834 allocs to different slabs. Debug options disable
1835 merging on their own.
Christoph Lameterc1aee212007-05-31 00:40:47 -07001836 For more information see Documentation/vm/slub.txt.
1837
Linus Torvalds1da177e2005-04-16 15:20:36 -07001838 smart2= [HW]
1839 Format: <io1>[,<io2>[,...,<io8>]]
1840
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001841 smp-alt-once [X86-32,SMP] On a hotplug CPU system, only
Jeremy Fitzhardingeb7fb4af2007-05-02 19:27:13 +02001842 attempt to substitute SMP alternatives once at boot.
1843
Bjorn Helgaasd0d4f692007-05-08 00:36:05 -07001844 smsc-ircc2.nopnp [HW] Don't use PNP to discover SMC devices
1845 smsc-ircc2.ircc_cfg= [HW] Device configuration I/O port
1846 smsc-ircc2.ircc_sir= [HW] SIR base I/O port
1847 smsc-ircc2.ircc_fir= [HW] FIR base I/O port
1848 smsc-ircc2.ircc_irq= [HW] IRQ line
1849 smsc-ircc2.ircc_dma= [HW] DMA channel
1850 smsc-ircc2.ircc_transceiver= [HW] Transceiver type:
1851 0: Toshiba Satellite 1800 (GP data pin select)
1852 1: Fast pin select (default)
1853 2: ATC IRMode
1854
Linus Torvalds1da177e2005-04-16 15:20:36 -07001855 snd-ad1816a= [HW,ALSA]
1856
1857 snd-ad1848= [HW,ALSA]
1858
1859 snd-ali5451= [HW,ALSA]
1860
1861 snd-als100= [HW,ALSA]
1862
1863 snd-als4000= [HW,ALSA]
1864
1865 snd-azt2320= [HW,ALSA]
1866
1867 snd-cmi8330= [HW,ALSA]
1868
1869 snd-cmipci= [HW,ALSA]
1870
1871 snd-cs4231= [HW,ALSA]
1872
1873 snd-cs4232= [HW,ALSA]
1874
1875 snd-cs4236= [HW,ALSA]
1876
1877 snd-cs4281= [HW,ALSA]
1878
1879 snd-cs46xx= [HW,ALSA]
1880
1881 snd-dt019x= [HW,ALSA]
1882
1883 snd-dummy= [HW,ALSA]
1884
1885 snd-emu10k1= [HW,ALSA]
1886
1887 snd-ens1370= [HW,ALSA]
1888
1889 snd-ens1371= [HW,ALSA]
1890
1891 snd-es968= [HW,ALSA]
1892
1893 snd-es1688= [HW,ALSA]
1894
1895 snd-es18xx= [HW,ALSA]
1896
1897 snd-es1938= [HW,ALSA]
1898
1899 snd-es1968= [HW,ALSA]
1900
1901 snd-fm801= [HW,ALSA]
1902
1903 snd-gusclassic= [HW,ALSA]
1904
1905 snd-gusextreme= [HW,ALSA]
1906
1907 snd-gusmax= [HW,ALSA]
1908
1909 snd-hdsp= [HW,ALSA]
1910
1911 snd-ice1712= [HW,ALSA]
1912
1913 snd-intel8x0= [HW,ALSA]
1914
1915 snd-interwave= [HW,ALSA]
1916
1917 snd-interwave-stb=
1918 [HW,ALSA]
1919
1920 snd-korg1212= [HW,ALSA]
1921
1922 snd-maestro3= [HW,ALSA]
1923
1924 snd-mpu401= [HW,ALSA]
1925
1926 snd-mtpav= [HW,ALSA]
1927
1928 snd-nm256= [HW,ALSA]
1929
1930 snd-opl3sa2= [HW,ALSA]
1931
1932 snd-opti92x-ad1848=
1933 [HW,ALSA]
1934
1935 snd-opti92x-cs4231=
1936 [HW,ALSA]
1937
1938 snd-opti93x= [HW,ALSA]
1939
1940 snd-pmac= [HW,ALSA]
1941
1942 snd-rme32= [HW,ALSA]
1943
1944 snd-rme96= [HW,ALSA]
1945
1946 snd-rme9652= [HW,ALSA]
1947
1948 snd-sb8= [HW,ALSA]
1949
1950 snd-sb16= [HW,ALSA]
1951
1952 snd-sbawe= [HW,ALSA]
1953
1954 snd-serial= [HW,ALSA]
1955
1956 snd-sgalaxy= [HW,ALSA]
1957
1958 snd-sonicvibes= [HW,ALSA]
1959
1960 snd-sun-amd7930=
1961 [HW,ALSA]
1962
1963 snd-sun-cs4231= [HW,ALSA]
1964
1965 snd-trident= [HW,ALSA]
1966
1967 snd-usb-audio= [HW,ALSA,USB]
1968
1969 snd-via82xx= [HW,ALSA]
1970
1971 snd-virmidi= [HW,ALSA]
1972
1973 snd-wavefront= [HW,ALSA]
1974
1975 snd-ymfpci= [HW,ALSA]
Randy Dunlapa9913042005-10-23 12:57:11 -07001976
Linus Torvalds1da177e2005-04-16 15:20:36 -07001977 sonypi.*= [HW] Sony Programmable I/O Control Device driver
1978 See Documentation/sonypi.txt
1979
1980 specialix= [HW,SERIAL] Specialix multi-serial port adapter
1981 See Documentation/specialix.txt.
1982
1983 spia_io_base= [HW,MTD]
1984 spia_fio_base=
1985 spia_pedr=
1986 spia_peddr=
1987
1988 sscape= [HW,OSS]
1989 Format: <io>,<irq>,<dma>,<mpu_io>,<mpu_irq>
Randy Dunlapa9913042005-10-23 12:57:11 -07001990
Linus Torvalds1da177e2005-04-16 15:20:36 -07001991 st= [HW,SCSI] SCSI tape parameters (buffers, etc.)
1992 See Documentation/scsi/st.txt.
1993
Linus Torvalds1da177e2005-04-16 15:20:36 -07001994 sti= [PARISC,HW]
1995 Format: <num>
1996 Set the STI (builtin display/keyboard on the HP-PARISC
1997 machines) console (graphic card) which should be used
1998 as the initial boot-console.
1999 See also comment in drivers/video/console/sticore.c.
2000
2001 sti_font= [HW]
2002 See comment in drivers/video/console/sticore.c.
2003
2004 stifb= [HW]
2005 Format: bpp:<bpp1>[:<bpp2>[:<bpp3>...]]
2006
Greg Banks42a7fc42007-03-06 01:42:23 -08002007 sunrpc.pool_mode=
2008 [NFS]
2009 Control how the NFS server code allocates CPUs to
2010 service thread pools. Depending on how many NICs
2011 you have and where their interrupts are bound, this
2012 option will affect which CPUs will do NFS serving.
2013 Note: this parameter cannot be changed while the
2014 NFS server is running.
2015
2016 auto the server chooses an appropriate mode
2017 automatically using heuristics
2018 global a single global pool contains all CPUs
2019 percpu one pool for each CPU
2020 pernode one pool for each NUMA node (equivalent
2021 to global on non-NUMA machines)
2022
Linus Torvalds1da177e2005-04-16 15:20:36 -07002023 swiotlb= [IA-64] Number of I/O TLB slabs
Randy Dunlapa9913042005-10-23 12:57:11 -07002024
Linus Torvalds1da177e2005-04-16 15:20:36 -07002025 switches= [HW,M68k]
2026
2027 sym53c416= [HW,SCSI]
2028 See header of drivers/scsi/sym53c416.c.
2029
Ingo Molnar5d6f6472006-12-13 00:34:36 -08002030 sysrq_always_enabled
2031 [KNL]
2032 Ignore sysrq setting - this boot parameter will
2033 neutralize any effect of /proc/sys/kernel/sysrq.
2034 Useful for debugging.
2035
Linus Torvalds1da177e2005-04-16 15:20:36 -07002036 t128= [HW,SCSI]
2037 See header of drivers/scsi/t128.c.
2038
2039 tdfx= [HW,DRM]
2040
2041 thash_entries= [KNL,NET]
2042 Set number of hash buckets for TCP connection
2043
Len Brownf8707ec2007-08-12 00:12:54 -04002044 thermal.act= [HW,ACPI]
2045 -1: disable all active trip points in all thermal zones
2046 <degrees C>: override all lowest active trip points
2047
Len Brownc52a7412007-08-14 15:49:32 -04002048 thermal.crt= [HW,ACPI]
2049 -1: disable all critical trip points in all thermal zones
2050 <degrees C>: lower all critical trip points
2051
Len Brownf5487142007-08-12 00:12:44 -04002052 thermal.nocrt= [HW,ACPI]
2053 Set to disable actions on ACPI thermal zone
2054 critical and hot trip points.
2055
Len Brown72b33ef2007-08-12 00:12:17 -04002056 thermal.off= [HW,ACPI]
2057 1: disable ACPI thermal control
2058
Len Browna70cdc52007-08-12 00:12:35 -04002059 thermal.psv= [HW,ACPI]
2060 -1: disable all passive trip points
2061 <degrees C>: override all passive trip points to this value
2062
Len Brown730ff342007-08-12 00:12:26 -04002063 thermal.tzp= [HW,ACPI]
2064 Specify global default ACPI thermal zone polling rate
2065 <deci-seconds>: poll all this frequency
2066 0: no polling (default)
2067
Linus Torvalds1da177e2005-04-16 15:20:36 -07002068 tipar.timeout= [HW,PPT]
2069 Set communications timeout in tenths of a second
2070 (default 15).
2071
2072 tipar.delay= [HW,PPT]
2073 Set inter-bit delay in microseconds (default 10).
2074
Linus Torvalds1da177e2005-04-16 15:20:36 -07002075 tmscsim= [HW,SCSI]
2076 See comment before function dc390_setup() in
2077 drivers/scsi/tmscsim.c.
2078
2079 tp720= [HW,PS2]
2080
2081 trix= [HW,OSS] MediaTrix AudioTrix Pro
Randy Dunlapa9913042005-10-23 12:57:11 -07002082 Format:
2083 <io>,<irq>,<dma>,<dma2>,<sb_io>,<sb_irq>,<sb_dma>,<mpu_io>,<mpu_irq>
2084
Randy Dunlapa9913042005-10-23 12:57:11 -07002085 turbografx.map[2|3]= [HW,JOY]
2086 TurboGraFX parallel port interface
2087 Format:
2088 <port#>,<js1>,<js2>,<js3>,<js4>,<js5>,<js6>,<js7>
Linus Torvalds1da177e2005-04-16 15:20:36 -07002089 See also Documentation/input/joystick-parport.txt
2090
2091 u14-34f= [HW,SCSI] UltraStor 14F/34F SCSI host adapter
2092 See header of drivers/scsi/u14-34f.c.
2093
2094 uart401= [HW,OSS]
2095 Format: <io>,<irq>
2096
2097 uart6850= [HW,OSS]
2098 Format: <io>,<irq>
2099
Alan Stern5f8364b2006-12-05 16:29:55 -05002100 uhci-hcd.ignore_oc=
2101 [USB] Ignore overcurrent events (default N).
2102 Some badly-designed motherboards generate lots of
2103 bogus events, for ports that aren't wired to
2104 anything. Set this parameter to avoid log spamming.
2105 Note that genuine overcurrent events won't be
2106 reported either.
2107
Alan Sternb5e795f2007-02-20 15:00:53 -05002108 usbcore.autosuspend=
2109 [USB] The autosuspend time delay (in seconds) used
2110 for newly-detected USB devices (default 2). This
2111 is the time required before an idle device will be
2112 autosuspended. Devices for which the delay is set
Alan Sterneaafbc32007-03-13 16:39:15 -04002113 to a negative value won't be autosuspended at all.
Alan Sternb5e795f2007-02-20 15:00:53 -05002114
Linus Torvalds1da177e2005-04-16 15:20:36 -07002115 usbhid.mousepoll=
2116 [USBHID] The interval which mice are to be polled at.
Randy Dunlapa9913042005-10-23 12:57:11 -07002117
Alan Coxcd4f0ef2007-07-31 00:37:59 -07002118 vdso= [X86-32,SH,x86-64]
Jeremy Fitzhardinge1dbf527c2007-05-02 19:27:12 +02002119 vdso=2: enable compat VDSO (default with COMPAT_VDSO)
Ingo Molnare6e54942006-06-27 02:53:50 -07002120 vdso=1: enable VDSO (default)
2121 vdso=0: disable VDSO mapping
2122
Roland McGrathaf65d642008-01-30 13:30:43 +01002123 vdso32= [X86-32,X86-64]
2124 vdso32=2: enable compat VDSO (default with COMPAT_VDSO)
2125 vdso32=1: enable 32-bit VDSO (default)
2126 vdso32=0: disable 32-bit VDSO mapping
2127
Yasuaki Ishimatsud080d392007-07-17 21:22:55 +09002128 vector= [IA-64,SMP]
2129 vector=percpu: enable percpu vector domain
2130
Linus Torvalds1da177e2005-04-16 15:20:36 -07002131 video= [FB] Frame buffer configuration
2132 See Documentation/fb/modedb.txt.
2133
Alan Coxcd4f0ef2007-07-31 00:37:59 -07002134 vga= [BOOT,X86-32] Select a particular video mode
Randy Dunlapa9913042005-10-23 12:57:11 -07002135 See Documentation/i386/boot.txt and
2136 Documentation/svga.txt.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002137 Use vga=ask for menu.
2138 This is actually a boot loader parameter; the value is
2139 passed to the kernel using a special protocol.
2140
Randy Dunlapa9913042005-10-23 12:57:11 -07002141 vmalloc=nn[KMG] [KNL,BOOT] Forces the vmalloc area to have an exact
Linus Torvalds1da177e2005-04-16 15:20:36 -07002142 size of <nn>. This can be used to increase the
2143 minimum size (128MB on x86). It can also be used to
2144 decrease the size and leave more room for directly
2145 mapped kernel RAM.
2146
Peter Oberparleiter585c3042006-06-29 15:08:25 +02002147 vmhalt= [KNL,S390] Perform z/VM CP command after system halt.
2148 Format: <command>
Linus Torvalds1da177e2005-04-16 15:20:36 -07002149
Peter Oberparleiter585c3042006-06-29 15:08:25 +02002150 vmpanic= [KNL,S390] Perform z/VM CP command after kernel panic.
2151 Format: <command>
2152
2153 vmpoff= [KNL,S390] Perform z/VM CP command after power off.
2154 Format: <command>
Randy Dunlapa9913042005-10-23 12:57:11 -07002155
Linus Torvalds1da177e2005-04-16 15:20:36 -07002156 waveartist= [HW,OSS]
2157 Format: <io>,<irq>,<dma>,<dma2>
Randy Dunlapa9913042005-10-23 12:57:11 -07002158
Linus Torvalds1da177e2005-04-16 15:20:36 -07002159 wd33c93= [HW,SCSI]
2160 See header of drivers/scsi/wd33c93.c.
2161
2162 wd7000= [HW,SCSI]
2163 See header of drivers/scsi/wd7000.c.
2164
2165 wdt= [WDT] Watchdog
Gabriel C8dfe9c22007-08-10 13:01:00 -07002166 See Documentation/watchdog/wdt.txt.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002167
2168 xd= [HW,XT] Original XT pre-IDE (RLL encoded) disks.
2169 xd_geo= See header of drivers/block/xd.c.
2170
2171 xirc2ps_cs= [NET,PCMCIA]
Randy Dunlapa9913042005-10-23 12:57:11 -07002172 Format:
2173 <irq>,<irq_mask>,<io>,<full_duplex>,<do_sound>,<lockup_hack>[,<irq2>[,<irq3>[,<irq4>]]]
Linus Torvalds1da177e2005-04-16 15:20:36 -07002174
Andi Kleena62eaf12006-02-16 23:41:58 +01002175 norandmaps Don't use address space randomization
2176 Equivalent to echo 0 > /proc/sys/kernel/randomize_va_space
2177
Randy Dunlapa9913042005-10-23 12:57:11 -07002178______________________________________________________________________
Linus Torvalds1da177e2005-04-16 15:20:36 -07002179
2180TODO:
2181
2182 Add documentation for ALSA options.
2183 Add more DRM drivers.