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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
Alan Coxcd4f0ef2007-07-31 00:37:59 -0700401 clock= [BUGS=X86-32, HW] gettimeofday clocksource override.
john stultz734efb42006-06-26 00:25:05 -0700402 [Deprecated]
Matt LaPlante3f6dee92006-10-03 22:45:33 +0200403 Forces specified clocksource (if available) to be used
john stultz734efb42006-06-26 00:25:05 -0700404 when calculating gettimeofday(). If specified
Matt LaPlante3f6dee92006-10-03 22:45:33 +0200405 clocksource is not available, it defaults to PIT.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700406 Format: { pit | tsc | cyclone | pmtmr }
407
Randy Dunlap3d6ac982007-05-23 13:58:16 -0700408 clocksource= [GENERIC_TIME] Override the default clocksource
409 Format: <string>
410 Override the default clocksource and use the clocksource
411 with the name specified.
412 Some clocksource names to choose from, depending on
413 the platform:
414 [all] jiffies (this is the base, fallback clocksource)
415 [ACPI] acpi_pm
416 [ARM] imx_timer1,OSTS,netx_timer,mpu_timer2,
417 pxa_timer,timer3,32k_counter,timer0_1
418 [AVR32] avr32
Alan Coxcd4f0ef2007-07-31 00:37:59 -0700419 [X86-32] pit,hpet,tsc,vmi-timer;
Randy Dunlap3d6ac982007-05-23 13:58:16 -0700420 scx200_hrt on Geode; cyclone on IBM x440
421 [MIPS] MIPS
422 [PARISC] cr16
423 [S390] tod
424 [SH] SuperH
425 [SPARC64] tick
426 [X86-64] hpet,tsc
427
Andi Kleenac72e782008-01-30 13:33:21 +0100428 clearcpuid=BITNUM [X86]
429 Disable CPUID feature X for the kernel. See
430 include/asm-x86/cpufeature.h for the valid bit numbers.
431 Note the Linux specific bits are not necessarily
432 stable over kernel options, but the vendor specific
433 ones should be.
434 Also note that user programs calling CPUID directly
435 or using the feature without checking anything
436 will still see it. This just prevents it from
437 being used by the kernel or shown in /proc/cpuinfo.
438 Also note the kernel might malfunction if you disable
439 some critical bits.
440
Arjan van de Vena25bd942008-01-30 13:33:08 +0100441 code_bytes [IA32/X86_64] How many bytes of object code to print
442 in an oops report.
Chuck Ebbert86c41832007-02-13 13:26:25 +0100443 Range: 0 - 8192
444 Default: 64
445
Andi Kleenf9262c12006-03-08 17:57:25 -0800446 disable_8254_timer
447 enable_8254_timer
448 [IA32/X86_64] Disable/Enable interrupt 0 timer routing
449 over the 8254 in addition to over the IO-APIC. The
450 kernel tries to set a sensible default.
451
Thomas Gleixnerb17530b2007-10-19 20:35:02 +0200452 hpet= [X86-32,HPET] option to control HPET usage
453 Format: { enable (default) | disable | force }
454 disable: disable HPET and use PIT instead
Carlos Corbachod79a5f82007-10-19 18:51:27 +0100455 force: allow force enabled of undocumented chips (ICH4,
456 VIA, nVidia)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700457
Linus Torvalds1da177e2005-04-16 15:20:36 -0700458 com20020= [HW,NET] ARCnet - COM20020 chipset
Randy Dunlapa9913042005-10-23 12:57:11 -0700459 Format:
460 <io>[,<irq>[,<nodeID>[,<backplane>[,<ckp>[,<timeout>]]]]]
Linus Torvalds1da177e2005-04-16 15:20:36 -0700461
462 com90io= [HW,NET] ARCnet - COM90xx chipset (IO-mapped buffers)
463 Format: <io>[,<irq>]
464
Randy Dunlapa9913042005-10-23 12:57:11 -0700465 com90xx= [HW,NET]
466 ARCnet - COM90xx chipset (memory-mapped buffers)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700467 Format: <io>[,<irq>[,<memstart>]]
468
469 condev= [HW,S390] console device
470 conmode=
Randy Dunlapa9913042005-10-23 12:57:11 -0700471
Linus Torvalds1da177e2005-04-16 15:20:36 -0700472 console= [KNL] Output console device and options.
473
474 tty<n> Use the virtual console device <n>.
475
476 ttyS<n>[,options]
Randy Dunlapf1a1c2d2006-03-25 03:08:17 -0800477 ttyUSB0[,options]
Linus Torvalds1da177e2005-04-16 15:20:36 -0700478 Use the specified serial port. The options are of
Randy Dunlapf1a1c2d2006-03-25 03:08:17 -0800479 the form "bbbbpnf", where "bbbb" is the baud rate,
480 "p" is parity ("n", "o", or "e"), "n" is number of
481 bits, and "f" is flow control ("r" for RTS or
482 omit it). Default is "9600n8".
Linus Torvalds1da177e2005-04-16 15:20:36 -0700483
Randy Dunlapf1a1c2d2006-03-25 03:08:17 -0800484 See Documentation/serial-console.txt for more
485 information. See
486 Documentation/networking/netconsole.txt for an
487 alternative.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700488
Yinghai Lu18a8bd92007-07-15 23:37:59 -0700489 uart[8250],io,<addr>[,options]
490 uart[8250],mmio,<addr>[,options]
Linus Torvalds1da177e2005-04-16 15:20:36 -0700491 Start an early, polled-mode console on the 8250/16550
492 UART at the specified I/O port or MMIO address,
493 switching to the matching ttyS device later. The
494 options are the same as for ttyS, above.
495
Samuel Thibaultf7511d52008-04-30 00:54:51 -0700496 If the device connected to the port is not a TTY but a braille
497 device, prepend "brl," before the device type, for instance
498 console=brl,ttyS0
499 For now, only VisioBraille is supported.
500
Yinghai Lu18a8bd92007-07-15 23:37:59 -0700501 earlycon= [KNL] Output early console device and options.
502 uart[8250],io,<addr>[,options]
503 uart[8250],mmio,<addr>[,options]
504 Start an early, polled-mode console on the 8250/16550
505 UART at the specified I/O port or MMIO address.
506 The options are the same as for ttyS, above.
507
Andres Salomon8f4ce8c2007-10-18 03:04:50 -0700508 no_console_suspend
509 [HW] Never suspend the console
510 Disable suspending of consoles during suspend and
511 hibernate operations. Once disabled, debugging
512 messages can reach various consoles while the rest
513 of the system is being put to sleep (ie, while
514 debugging driver suspend/resume hooks). This may
515 not work reliably with all consoles, but is known
516 to work with serial and VGA consoles.
517
Linus Torvalds1da177e2005-04-16 15:20:36 -0700518 cpcihp_generic= [HW,PCI] Generic port I/O CompactPCI driver
Randy Dunlapa9913042005-10-23 12:57:11 -0700519 Format:
520 <first_slot>,<last_slot>,<port>,<enum_bit>[,<debug>]
Linus Torvalds1da177e2005-04-16 15:20:36 -0700521
Eric W. Biedermandc009d92005-06-25 14:57:52 -0700522 crashkernel=nn[KMG]@ss[KMG]
523 [KNL] Reserve a chunk of physical memory to
524 hold a kernel to switch to with kexec on panic.
525
Bernhard Wallefb391592007-10-18 23:41:02 -0700526 crashkernel=range1:size1[,range2:size2,...][@offset]
527 [KNL] Same as above, but depends on the memory
528 in the running system. The syntax of range is
529 start-[end] where start and end are both
530 a memory unit (amount[KMG]). See also
531 Documentation/kdump/kdump.txt for a example.
532
Linus Torvalds1da177e2005-04-16 15:20:36 -0700533 cs4232= [HW,OSS]
534 Format: <io>,<irq>,<dma>,<dma2>,<mpuio>,<mpuirq>
535
536 cs89x0_dma= [HW,NET]
537 Format: <dma>
538
539 cs89x0_media= [HW,NET]
540 Format: { rj45 | aui | bnc }
Randy Dunlapa9913042005-10-23 12:57:11 -0700541
Randy Dunlapa9913042005-10-23 12:57:11 -0700542 dasd= [HW,NET]
Linus Torvalds1da177e2005-04-16 15:20:36 -0700543 See header of drivers/s390/block/dasd_devmap.c.
544
545 db9.dev[2|3]= [HW,JOY] Multisystem joystick support via parallel port
546 (one device per port)
547 Format: <port#>,<type>
548 See also Documentation/input/joystick-parport.txt
549
550 debug [KNL] Enable kernel debugging (events log level).
551
Ingo Molnarcae2ed92006-07-03 00:24:48 -0700552 debug_locks_verbose=
553 [KNL] verbose self-tests
554 Format=<0|1>
555 Print debugging info while doing the locking API
556 self-tests.
557 We default to 0 (no extra messages), setting it to
558 1 will print _a lot_ more information - normally
559 only useful to kernel developers.
560
Thomas Gleixner3ac7fe52008-04-30 00:55:01 -0700561 debug_objects [KNL] Enable object debugging
562
Robert P. J. Day2d27a962008-02-03 15:18:45 +0200563 decnet.addr= [HW,NET]
Linus Torvalds1da177e2005-04-16 15:20:36 -0700564 Format: <area>[,<node>]
565 See also Documentation/networking/decnet.txt.
566
Samuel Thibaultecb77fa2008-01-03 16:17:54 +0000567 vt.default_blu= [VT]
Antonino A. Daplas55ff9782007-05-08 00:38:53 -0700568 Format: <blue0>,<blue1>,<blue2>,...,<blue15>
569 Change the default blue palette of the console.
570 This is a 16-member array composed of values
571 ranging from 0-255.
572
Samuel Thibaultecb77fa2008-01-03 16:17:54 +0000573 vt.default_grn= [VT]
Antonino A. Daplas55ff9782007-05-08 00:38:53 -0700574 Format: <green0>,<green1>,<green2>,...,<green15>
575 Change the default green palette of the console.
576 This is a 16-member array composed of values
577 ranging from 0-255.
578
Samuel Thibaultecb77fa2008-01-03 16:17:54 +0000579 vt.default_red= [VT]
Antonino A. Daplas55ff9782007-05-08 00:38:53 -0700580 Format: <red0>,<red1>,<red2>,...,<red15>
581 Change the default red palette of the console.
582 This is a 16-member array composed of values
583 ranging from 0-255.
584
Samuel Thibaultecb77fa2008-01-03 16:17:54 +0000585 vt.default_utf8=
586 [VT]
Antonino A. Daplas55ff9782007-05-08 00:38:53 -0700587 Format=<0|1>
588 Set system-wide default UTF-8 mode for all tty's.
Samuel Thibaultecb77fa2008-01-03 16:17:54 +0000589 Default is 1, i.e. UTF-8 mode is enabled for all
590 newly opened terminals.
Antonino A. Daplas55ff9782007-05-08 00:38:53 -0700591
Linus Torvalds1da177e2005-04-16 15:20:36 -0700592 dhash_entries= [KNL]
593 Set number of hash buckets for dentry cache.
Randy Dunlapa9913042005-10-23 12:57:11 -0700594
Linus Torvalds1da177e2005-04-16 15:20:36 -0700595 digi= [HW,SERIAL]
596 IO parameters + enable/disable command.
597
598 digiepca= [HW,SERIAL]
599 See drivers/char/README.epca and
600 Documentation/digiepca.txt.
601
Yinghai Lu95ffa242008-04-29 03:52:33 -0700602 disable_mtrr_cleanup [X86]
603 enable_mtrr_cleanup [X86]
604 The kernel tries to adjust MTRR layout from continuous
605 to discrete, to make X server driver able to add WB
606 entry later. This parameter enables/disables that.
607
608 mtrr_chunk_size=nn[KMG] [X86]
609 used for mtrr cleanup. It is largest continous chunk
610 that could hold holes aka. UC entries.
611
612 mtrr_gran_size=nn[KMG] [X86]
Yinghai Lu12031a62008-05-02 02:40:22 -0700613 Used for mtrr cleanup. It is granularity of mtrr block.
614 Default is 1.
615 Large value could prevent small alignment from
616 using up MTRRs.
617
618 mtrr_spare_reg_nr=n [X86]
619 Format: <integer>
620 Range: 0,7 : spare reg number
621 Default : 1
622 Used for mtrr cleanup. It is spare mtrr entries number.
623 Set to 2 or more if your graphical card needs more.
Yinghai Lu95ffa242008-04-29 03:52:33 -0700624
Yinghai Lu093af8d2008-01-30 13:33:32 +0100625 disable_mtrr_trim [X86, Intel and AMD only]
Jesse Barnes99fc8d42008-01-30 13:33:18 +0100626 By default the kernel will trim any uncacheable
627 memory out of your available memory pool based on
628 MTRR settings. This parameter disables that behavior,
629 possibly causing your machine to run very slowly.
630
Linus Torvalds1da177e2005-04-16 15:20:36 -0700631 dmasound= [HW,OSS] Sound subsystem buffers
632
633 dscc4.setup= [NET]
634
635 dtc3181e= [HW,SCSI]
636
Robin Getz0ae53642007-10-09 17:24:49 +0800637 earlyprintk= [X86-32,X86-64,SH,BLACKFIN]
Linus Torvalds1da177e2005-04-16 15:20:36 -0700638 earlyprintk=vga
639 earlyprintk=serial[,ttySn[,baudrate]]
640
Randy Dunlapa9913042005-10-23 12:57:11 -0700641 Append ",keep" to not disable it when the real console
Linus Torvalds1da177e2005-04-16 15:20:36 -0700642 takes over.
643
644 Only vga or serial at a time, not both.
645
646 Currently only ttyS0 and ttyS1 are supported.
647
648 Interaction with the standard serial driver is not
649 very good.
650
651 The VGA output is eventually overwritten by the real
652 console.
653
654 eata= [HW,SCSI]
655
Linus Torvalds1da177e2005-04-16 15:20:36 -0700656 edd= [EDD]
Tim Gardner8c4dd602008-04-29 01:02:45 -0700657 Format: {"off" | "on" | "skip[mbr]"}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700658
Linus Torvalds1da177e2005-04-16 15:20:36 -0700659 eisa_irq_edge= [PARISC,HW]
660 See header of drivers/parisc/eisa.c.
661
Alan Coxcd4f0ef2007-07-31 00:37:59 -0700662 elanfreq= [X86-32]
Linus Torvalds1da177e2005-04-16 15:20:36 -0700663 See comment before function elanfreq_setup() in
664 arch/i386/kernel/cpu/cpufreq/elanfreq.c.
665
666 elevator= [IOSCHED]
Randy Dunlap16ab3ad2006-01-14 13:21:20 -0800667 Format: {"anticipatory" | "cfq" | "deadline" | "noop"}
Randy Dunlapa9913042005-10-23 12:57:11 -0700668 See Documentation/block/as-iosched.txt and
669 Documentation/block/deadline-iosched.txt for details.
670
Alan Coxcd4f0ef2007-07-31 00:37:59 -0700671 elfcorehdr= [X86-32, X86_64]
Randy Dunlapa9913042005-10-23 12:57:11 -0700672 Specifies physical address of start of kernel core
Vivek Goyalaac04b32006-01-09 20:51:47 -0800673 image elf header. Generally kexec loader will
674 pass this option to capture kernel.
675 See Documentation/kdump/kdump.txt for details.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700676
677 enforcing [SELINUX] Set initial enforcing status.
678 Format: {"0" | "1"}
679 See security/selinux/Kconfig help text.
680 0 -- permissive (log only, no denials).
681 1 -- enforcing (deny and log).
682 Default value is 0.
683 Value can be changed at runtime via /selinux/enforce.
684
Linus Torvalds1da177e2005-04-16 15:20:36 -0700685 es1371= [HW,OSS]
686 Format: <spdif>,[<nomix>,[<amplifier>]]
687 See also header of sound/oss/es1371.c.
Randy Dunlapa9913042005-10-23 12:57:11 -0700688
Linus Torvalds1da177e2005-04-16 15:20:36 -0700689 ether= [HW,NET] Ethernet cards parameters
690 This option is obsoleted by the "netdev=" option, which
691 has equivalent usage. See its documentation for details.
692
693 eurwdt= [HW,WDT] Eurotech CPU-1220/1410 onboard watchdog.
694 Format: <io>[,<irq>]
695
Akinobu Mitade1ba092006-12-08 02:39:42 -0800696 failslab=
697 fail_page_alloc=
698 fail_make_request=[KNL]
699 General fault injection mechanism.
700 Format: <interval>,<probability>,<space>,<times>
701 See also /Documentation/fault-injection/.
702
Linus Torvalds1da177e2005-04-16 15:20:36 -0700703 fd_mcs= [HW,SCSI]
704 See header of drivers/scsi/fd_mcs.c.
705
706 fdomain= [HW,SCSI]
707 See header of drivers/scsi/fdomain.c.
708
709 floppy= [HW]
710 See Documentation/floppy.txt.
711
Alex Chiangf13ae302008-05-08 14:03:23 -0600712 force_pal_cache_flush
713 [IA-64] Avoid check_sal_cache_flush which may hang on
714 buggy SAL_CACHE_FLUSH implementations. Using this
715 parameter will force ia64_sal_cache_flush to call
716 ia64_pal_cache_flush instead of SAL_CACHE_FLUSH.
717
Linus Torvalds1da177e2005-04-16 15:20:36 -0700718 gamecon.map[2|3]=
719 [HW,JOY] Multisystem joystick and NES/SNES/PSX pad
720 support via parallel port (up to 5 devices per port)
721 Format: <port#>,<pad1>,<pad2>,<pad3>,<pad4>,<pad5>
722 See also Documentation/input/joystick-parport.txt
723
724 gamma= [HW,DRM]
725
Yinghai Luaaf23042008-01-30 13:33:09 +0100726 gart_fix_e820= [X86_64] disable the fix e820 for K8 GART
727 Format: off | on
728 default: on
729
Linus Torvalds1da177e2005-04-16 15:20:36 -0700730 gdth= [HW,SCSI]
731 See header of drivers/scsi/gdth.c.
732
733 gpt [EFI] Forces disk with valid GPT signature but
734 invalid Protective MBR to be treated as GPT.
735
Linus Torvalds1da177e2005-04-16 15:20:36 -0700736 gvp11= [HW,SCSI]
737
738 hashdist= [KNL,NUMA] Large hashes allocated during boot
739 are distributed across NUMA nodes. Defaults on
740 for IA-64, off otherwise.
Randy Dunlapa9913042005-10-23 12:57:11 -0700741 Format: 0 | 1 (for off | on)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700742
743 hcl= [IA-64] SGI's Hardware Graph compatibility layer
744
745 hd= [EIDE] (E)IDE hard drive subsystem geometry
746 Format: <cyl>,<head>,<sect>
747
748 hd?= [HW] (E)IDE subsystem
Randy Dunlap1c10e932008-03-07 21:53:50 +0100749 hd?lun= See Documentation/ide/ide.txt.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700750
751 highmem=nn[KMG] [KNL,BOOT] forces the highmem zone to have an exact
752 size of <nn>. This works even on boxes that have no
753 highmem otherwise. This also works to reduce highmem
754 size on bigger boxes.
755
Thomas Gleixner54cdfdb2007-02-16 01:28:11 -0800756 highres= [KNL] Enable/disable high resolution timer mode.
757 Valid parameters: "on", "off"
758 Default: "on"
759
Linus Torvalds1da177e2005-04-16 15:20:36 -0700760 hisax= [HW,ISDN]
761 See Documentation/isdn/README.HiSax.
762
Alan Coxcd4f0ef2007-07-31 00:37:59 -0700763 hugepages= [HW,X86-32,IA-64] Maximal number of HugeTLB pages.
Jon Tollefson4ec161c2008-01-04 09:59:50 +1100764 hugepagesz= [HW,IA-64,PPC] The size of the HugeTLB pages.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700765
Linus Torvalds1da177e2005-04-16 15:20:36 -0700766 i8042.direct [HW] Put keyboard port into non-translated mode
Matt LaPlante84eb8d02006-10-03 22:53:09 +0200767 i8042.dumbkbd [HW] Pretend that controller can only read data from
768 keyboard and cannot control its state
Linus Torvalds1da177e2005-04-16 15:20:36 -0700769 (Don't attempt to blink the leds)
770 i8042.noaux [HW] Don't check for auxiliary (== mouse) port
Dmitry Torokhov945ef0d2005-09-04 01:42:00 -0500771 i8042.nokbd [HW] Don't check/create keyboard port
Jiri Kosina75d08c72008-03-13 16:13:59 -0400772 i8042.noloop [HW] Disable the AUX Loopback command while probing
773 for the AUX port
Linus Torvalds1da177e2005-04-16 15:20:36 -0700774 i8042.nomux [HW] Don't check presence of an active multiplexing
775 controller
776 i8042.nopnp [HW] Don't use ACPIPnP / PnPBIOS to discover KBD/AUX
777 controllers
778 i8042.panicblink=
779 [HW] Frequency with which keyboard LEDs should blink
780 when kernel panics (default is 0.5 sec)
781 i8042.reset [HW] Reset the controller during init and cleanup
782 i8042.unlock [HW] Unlock (ignore) the keylock
783
784 i810= [HW,DRM]
785
Dmitry Torokhove70c9d52005-06-25 14:54:25 -0700786 i8k.ignore_dmi [HW] Continue probing hardware even if DMI data
787 indicates that the driver is running on unsupported
788 hardware.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700789 i8k.force [HW] Activate i8k driver even if SMM BIOS signature
790 does not match list of supported models.
791 i8k.power_status
792 [HW] Report power status in /proc/i8k
793 (disabled by default)
794 i8k.restricted [HW] Allow controlling fans only if SYS_ADMIN
795 capability is set.
796
797 ibmmcascsi= [HW,MCA,SCSI] IBM MicroChannel SCSI adapter
798 See Documentation/mca.txt.
799
800 icn= [HW,ISDN]
801 Format: <io>[,<membase>[,<icn_id>[,<icn_id2>]]]
802
803 ide= [HW] (E)IDE subsystem
Greg Kroah-Hartmana594eeb2008-04-18 00:46:20 +0200804 Format: ide=nodma or ide=doubler
Randy Dunlap1c10e932008-03-07 21:53:50 +0100805 See Documentation/ide/ide.txt.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700806
Linus Torvalds1da177e2005-04-16 15:20:36 -0700807 idebus= [HW] (E)IDE subsystem - VLB/PCI bus speed
Randy Dunlap1c10e932008-03-07 21:53:50 +0100808 See Documentation/ide/ide.txt.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700809
Andi Kleenf039b752007-05-02 19:27:12 +0200810 idle= [X86]
811 Format: idle=poll or idle=mwait
812 Poll forces a polling idle loop that can slightly improves the performance
813 of waking up a idle CPU, but will use a lot of power and make the system
814 run hot. Not recommended.
815 idle=mwait. On systems which support MONITOR/MWAIT but the kernel chose
816 to not use it because it doesn't save as much power as a normal idle
817 loop use the MONITOR/MWAIT idle loop anyways. Performance should be the same
818 as idle=poll.
Randy Dunlapa9913042005-10-23 12:57:11 -0700819
Denis Cheng594765a2008-02-06 02:57:49 +0100820 ide-pci-generic.all-generic-ide [HW] (E)IDE subsystem
821 Claim all unknown PCI IDE storage controllers.
822
Ingo Molnar792908222006-12-06 20:40:51 -0800823 ignore_loglevel [KNL]
824 Ignore loglevel setting - this will print /all/
825 kernel messages to the console. Useful for debugging.
826
Linus Torvalds1da177e2005-04-16 15:20:36 -0700827 ihash_entries= [KNL]
828 Set number of hash buckets for inode cache.
829
830 in2000= [HW,SCSI]
831 See header of drivers/scsi/in2000.c.
832
833 init= [KNL]
834 Format: <full_path>
835 Run specified binary instead of /sbin/init as init
836 process.
837
838 initcall_debug [KNL] Trace initcalls as they are executed. Useful
839 for working out where the kernel is dying during
840 startup.
841
842 initrd= [BOOT] Specify the location of the initial ramdisk
843
844 inport.irq= [HW] Inport (ATI XL and Microsoft) busmouse driver
845 Format: <irq>
846
847 inttest= [IA64]
848
Pavel Machekb552da82008-03-19 15:58:11 +0100849 iommu= [x86]
850 off
851 force
852 noforce
853 biomerge
854 panic
855 nopanic
856 merge
857 nomerge
858 forcesac
859 soft
860
861
Keshavamurthy, Anil Sba395922007-10-21 16:41:49 -0700862 intel_iommu= [DMAR] Intel IOMMU driver (DMAR) option
863 off
864 Disable intel iommu driver.
865 igfx_off [Default Off]
866 By default, gfx is mapped as normal device. If a gfx
867 device has a dedicated DMAR unit, the DMAR unit is
868 bypassed by not enabling DMAR with this option. In
869 this case, gfx device will use physical address for
870 DMA.
Keshavamurthy, Anil S7d3b03c2007-10-21 16:41:53 -0700871 forcedac [x86_64]
872 With this option iommu will not optimize to look
873 for io virtual address below 32 bit forcing dual
874 address cycle on pci bus for cards supporting greater
875 than 32 bit addressing. The default is to look
876 for translation below 32 bit and if not available
877 then look in the higher range.
mark gross5e0d2a62008-03-04 15:22:08 -0800878 strict [Default Off]
879 With this option on every unmap_single operation will
880 result in a hardware IOTLB flush operation as opposed
881 to batching them for performance.
Keshavamurthy, Anil Sba395922007-10-21 16:41:49 -0700882
Rene Hermanb02aae92008-01-30 13:30:05 +0100883 io_delay= [X86-32,X86-64] I/O delay method
Ingo Molnar6e7c4022008-01-30 13:30:05 +0100884 0x80
885 Standard port 0x80 based delay
886 0xed
887 Alternate port 0xed based delay (needed on some systems)
Rene Hermanb02aae92008-01-30 13:30:05 +0100888 udelay
Ingo Molnar6e7c4022008-01-30 13:30:05 +0100889 Simple two microseconds delay
890 none
891 No delay
Rene Hermanb02aae92008-01-30 13:30:05 +0100892
Linus Torvalds1da177e2005-04-16 15:20:36 -0700893 io7= [HW] IO7 for Marvel based alpha systems
894 See comment before marvel_specify_io7 in
895 arch/alpha/kernel/core_marvel.c.
896
897 ip= [IP_PNP]
J. Bruce Fields6ded55d2008-04-07 15:59:03 -0400898 See Documentation/filesystems/nfsroot.txt.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700899
900 ip2= [HW] Set IO/IRQ pairs for up to 4 IntelliPort boards
Randy Dunlapc8facbb2007-07-31 00:37:40 -0700901 See comment before ip2_setup() in
902 drivers/char/ip2/ip2base.c.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700903
904 ips= [HW,SCSI] Adaptec / IBM ServeRAID controller
905 See header of drivers/scsi/ips.c.
906
Simon Horman72c4a132006-09-13 19:57:18 -0700907 ports= [IP_VS_FTP] IPVS ftp helper module
908 Default is 21.
909 Up to 8 (IP_VS_APP_MAX_PORTS) ports
910 may be specified.
911 Format: <port>,<port>....
912
Alan Cox200803d2005-06-28 20:45:18 -0700913 irqfixup [HW]
914 When an interrupt is not handled search all handlers
915 for it. Intended to get systems with badly broken
916 firmware running.
917
918 irqpoll [HW]
919 When an interrupt is not handled search all handlers
920 for it. Also check all handlers each timer
921 interrupt. Intended to get systems with badly broken
922 firmware running.
923
Linus Torvalds1da177e2005-04-16 15:20:36 -0700924 isapnp= [ISAPNP]
Randy Dunlapa9913042005-10-23 12:57:11 -0700925 Format: <RDP>,<reset>,<pci_scan>,<verbosity>
Linus Torvalds1da177e2005-04-16 15:20:36 -0700926
927 isolcpus= [KNL,SMP] Isolate CPUs from the general scheduler.
Derek Fults22f2e282006-12-06 20:37:11 -0800928 Format:
929 <cpu number>,...,<cpu number>
930 or
931 <cpu number>-<cpu number> (must be a positive range in ascending order)
932 or a mixture
933 <cpu number>,...,<cpu number>-<cpu number>
Linus Torvalds1da177e2005-04-16 15:20:36 -0700934 This option can be used to specify one or more CPUs
935 to isolate from the general SMP balancing and scheduling
936 algorithms. The only way to move a process onto or off
937 an "isolated" CPU is via the CPU affinity syscalls.
938 <cpu number> begins at 0 and the maximum value is
939 "number of CPUs in system - 1".
940
941 This option is the preferred way to isolate CPUs. The
Randy Dunlapa9913042005-10-23 12:57:11 -0700942 alternative -- manually setting the CPU mask of all
943 tasks in the system -- can cause problems and
944 suboptimal load balancer performance.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700945
Randy Dunlapa9913042005-10-23 12:57:11 -0700946 iucv= [HW,NET]
Linus Torvalds1da177e2005-04-16 15:20:36 -0700947
948 js= [HW,JOY] Analog joystick
949 See Documentation/input/joystick.txt.
950
Alan Coxcd4f0ef2007-07-31 00:37:59 -0700951 kernelcore=nn[KMG] [KNL,X86-32,IA-64,PPC,X86-64] This parameter
Mel Gormaned7ed362007-07-17 04:03:14 -0700952 specifies the amount of memory usable by the kernel
953 for non-movable allocations. The requested amount is
954 spread evenly throughout all nodes in the system. The
955 remaining memory in each node is used for Movable
956 pages. In the event, a node is too small to have both
957 kernelcore and Movable pages, kernelcore pages will
958 take priority and other nodes will have a larger number
959 of kernelcore pages. The Movable zone is used for the
960 allocation of pages that may be reclaimed or moved
961 by the page migration subsystem. This means that
962 HugeTLB pages may not be allocated from this zone.
963 Note that allocations like PTEs-from-HighMem still
964 use the HighMem zone if it exists, and the Normal
965 zone if it does not.
966
Alan Coxcd4f0ef2007-07-31 00:37:59 -0700967 movablecore=nn[KMG] [KNL,X86-32,IA-64,PPC,X86-64] This parameter
Mel Gorman7e63efe2007-07-17 04:03:15 -0700968 is similar to kernelcore except it specifies the
969 amount of memory used for migratable allocations.
970 If both kernelcore and movablecore is specified,
971 then kernelcore will be at *least* the specified
972 value but may be more. If movablecore on its own
973 is specified, the administrator must be careful
974 that the amount of memory usable for all allocations
975 is not too small.
976
Linus Torvalds1da177e2005-04-16 15:20:36 -0700977 keepinitrd [HW,ARM]
978
Alan Coxcd4f0ef2007-07-31 00:37:59 -0700979 kstack=N [X86-32,X86-64] Print N words from the kernel stack
Linus Torvalds1da177e2005-04-16 15:20:36 -0700980 in oops dumps.
981
Jason Wessel6cdf6e02008-04-17 20:05:38 +0200982 kgdboc= [HW] kgdb over consoles.
983 Requires a tty driver that supports console polling.
984 (only serial suported for now)
985 Format: <serial_device>[,baud]
986
Linus Torvalds1da177e2005-04-16 15:20:36 -0700987 l2cr= [PPC]
988
Robert Brosea78bfbf2008-03-29 07:20:23 +1100989 l3cr= [PPC]
990
Alan Coxcd4f0ef2007-07-31 00:37:59 -0700991 lapic [X86-32,APIC] Enable the local APIC even if BIOS
Randy Dunlapa9913042005-10-23 12:57:11 -0700992 disabled it.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700993
Alan Coxcd4f0ef2007-07-31 00:37:59 -0700994 lapic_timer_c2_ok [X86-32,x86-64,APIC] trust the local apic timer in
Thomas Gleixnere585bef2007-03-23 16:08:01 +0100995 C2 power state.
996
FD Camifcb71f62008-01-06 19:08:56 +0100997 libata.dma= [LIBATA] DMA control
998 libata.dma=0 Disable all PATA and SATA DMA
999 libata.dma=1 PATA and SATA Disk DMA only
1000 libata.dma=2 ATAPI (CDROM) DMA only
1001 libata.dma=4 Compact Flash DMA only
1002 Combinations also work, so libata.dma=3 enables DMA
1003 for disks and CDROMs, but not CFs.
1004
Dave Jones78e70c22007-09-27 11:50:13 -04001005 libata.noacpi [LIBATA] Disables use of ACPI in libata suspend/resume
1006 when set.
1007 Format: <int>
1008
Tejun Heo33267322008-02-13 09:15:09 +09001009 libata.force= [LIBATA] Force configurations. The format is comma
1010 separated list of "[ID:]VAL" where ID is
1011 PORT[:DEVICE]. PORT and DEVICE are decimal numbers
1012 matching port, link or device. Basically, it matches
1013 the ATA ID string printed on console by libata. If
1014 the whole ID part is omitted, the last PORT and DEVICE
1015 values are used. If ID hasn't been specified yet, the
1016 configuration applies to all ports, links and devices.
1017
1018 If only DEVICE is omitted, the parameter applies to
1019 the port and all links and devices behind it. DEVICE
1020 number of 0 either selects the first device or the
1021 first fan-out link behind PMP device. It does not
1022 select the host link. DEVICE number of 15 selects the
1023 host link and device attached to it.
1024
1025 The VAL specifies the configuration to force. As long
1026 as there's no ambiguity shortcut notation is allowed.
1027 For example, both 1.5 and 1.5G would work for 1.5Gbps.
1028 The following configurations can be forced.
1029
1030 * Cable type: 40c, 80c, short40c, unk, ign or sata.
1031 Any ID with matching PORT is used.
1032
1033 * SATA link speed limit: 1.5Gbps or 3.0Gbps.
1034
1035 * Transfer mode: pio[0-7], mwdma[0-4] and udma[0-7].
1036 udma[/][16,25,33,44,66,100,133] notation is also
1037 allowed.
1038
1039 * [no]ncq: Turn on or off NCQ.
1040
1041 If there are multiple matching configurations changing
1042 the same attribute, the last one is used.
1043
Linus Torvalds1da177e2005-04-16 15:20:36 -07001044 load_ramdisk= [RAM] List of ramdisks to load from floppy
1045 See Documentation/ramdisk.txt.
1046
Randy Dunlapa6b25b62006-01-14 13:21:19 -08001047 lockd.nlm_grace_period=P [NFS] Assign grace period.
1048 Format: <integer>
Linus Torvalds1da177e2005-04-16 15:20:36 -07001049
Randy Dunlapa6b25b62006-01-14 13:21:19 -08001050 lockd.nlm_tcpport=N [NFS] Assign TCP port.
1051 Format: <integer>
1052
1053 lockd.nlm_timeout=T [NFS] Assign timeout value.
1054 Format: <integer>
1055
1056 lockd.nlm_udpport=M [NFS] Assign UDP port.
1057 Format: <integer>
Linus Torvalds1da177e2005-04-16 15:20:36 -07001058
1059 logibm.irq= [HW,MOUSE] Logitech Bus Mouse Driver
1060 Format: <irq>
1061
1062 loglevel= All Kernel Messages with a loglevel smaller than the
1063 console loglevel will be printed to the console. It can
1064 also be changed with klogd or other programs. The
1065 loglevels are defined as follows:
1066
1067 0 (KERN_EMERG) system is unusable
1068 1 (KERN_ALERT) action must be taken immediately
1069 2 (KERN_CRIT) critical conditions
1070 3 (KERN_ERR) error conditions
1071 4 (KERN_WARNING) warning conditions
1072 5 (KERN_NOTICE) normal but significant condition
1073 6 (KERN_INFO) informational
1074 7 (KERN_DEBUG) debug-level messages
1075
1076 log_buf_len=n Sets the size of the printk ring buffer, in bytes.
Randy Dunlapa9913042005-10-23 12:57:11 -07001077 Format: { n | nk | nM }
1078 n must be a power of two. The default size
1079 is set in the kernel config file.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001080
Randy Dunlapaccaa242007-10-16 01:29:37 -07001081 logo.nologo [FB] Disables display of the built-in Linux logo.
1082 This may be used to provide more screen space for
1083 kernel log messages and is useful when debugging
1084 kernel boot problems.
1085
Linus Torvalds1da177e2005-04-16 15:20:36 -07001086 lp=0 [LP] Specify parallel ports to use, e.g,
1087 lp=port[,port...] lp=none,parport0 (lp0 not configured, lp1 uses
1088 lp=reset first parallel port). 'lp=0' disables the
1089 lp=auto printer driver. 'lp=reset' (which can be
1090 specified in addition to the ports) causes
1091 attached printers to be reset. Using
1092 lp=port1,port2,... specifies the parallel ports
1093 to associate lp devices with, starting with
1094 lp0. A port specification may be 'none' to skip
1095 that lp device, or a parport name such as
1096 'parport0'. Specifying 'lp=auto' instead of a
1097 port specification list means that device IDs
1098 from each port should be examined, to see if
1099 an IEEE 1284-compliant printer is attached; if
1100 so, the driver will manage that printer.
1101 See also header of drivers/char/lp.c.
1102
1103 lpj=n [KNL]
1104 Sets loops_per_jiffy to given constant, thus avoiding
1105 time-consuming boot-time autodetection (up to 250 ms per
1106 CPU). 0 enables autodetection (default). To determine
1107 the correct value for your kernel, boot with normal
1108 autodetection and see what value is printed. Note that
1109 on SMP systems the preset will be applied to all CPUs,
1110 which is likely to cause problems if your CPUs need
1111 significantly divergent settings. An incorrect value
1112 will cause delays in the kernel to be wrong, leading to
1113 unpredictable I/O errors and other breakage. Although
1114 unlikely, in the extreme case this might damage your
1115 hardware.
1116
1117 ltpc= [NET]
1118 Format: <io>,<irq>,<dma>
1119
Randy Dunlapa9913042005-10-23 12:57:11 -07001120 mac5380= [HW,SCSI] Format:
1121 <can_queue>,<cmd_per_lun>,<sg_tablesize>,<hostid>,<use_tags>
Linus Torvalds1da177e2005-04-16 15:20:36 -07001122
Randy Dunlapa9913042005-10-23 12:57:11 -07001123 machvec= [IA64] Force the use of a particular machine-vector
1124 (machvec) in a generic kernel.
1125 Example: machvec=hpzx1_swiotlb
Linus Torvalds1da177e2005-04-16 15:20:36 -07001126
Randy Dunlapa9913042005-10-23 12:57:11 -07001127 max_loop= [LOOP] Maximum number of loopback devices that can
Linus Torvalds1da177e2005-04-16 15:20:36 -07001128 be mounted
1129 Format: <1-256>
1130
1131 maxcpus= [SMP] Maximum number of processors that an SMP kernel
Len Brown61ec7562007-08-16 03:34:22 -04001132 should make use of. maxcpus=n : n >= 0 limits the
1133 kernel to using 'n' processors. n=0 is a special case,
1134 it is equivalent to "nosmp", which also disables
1135 the IO APIC.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001136
Bob Picco2b2c3752005-06-29 18:00:00 -07001137 max_addr=[KMG] [KNL,BOOT,ia64] All physical memory greater than or
1138 equal to this physical address is ignored.
1139
Randy Dunlapa9913042005-10-23 12:57:11 -07001140 max_luns= [SCSI] Maximum number of LUNs to probe.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001141 Should be between 1 and 2^32-1.
1142
1143 max_report_luns=
Randy Dunlapa9913042005-10-23 12:57:11 -07001144 [SCSI] Maximum number of LUNs received.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001145 Should be between 1 and 16384.
1146
Linus Torvalds1da177e2005-04-16 15:20:36 -07001147 mcatest= [IA-64]
1148
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001149 mce [X86-32] Machine Check Exception
Linus Torvalds1da177e2005-04-16 15:20:36 -07001150
Andi Kleen909dd322007-10-17 18:04:38 +02001151 mce=option [X86-64] See Documentation/x86_64/boot-options.txt
1152
Linus Torvalds1da177e2005-04-16 15:20:36 -07001153 md= [HW] RAID subsystems devices and level
1154 See Documentation/md.txt.
Randy Dunlapa9913042005-10-23 12:57:11 -07001155
Linus Torvalds1da177e2005-04-16 15:20:36 -07001156 mdacon= [MDA]
1157 Format: <first>,<last>
1158 Specifies range of consoles to be captured by the MDA.
Randy Dunlapa9913042005-10-23 12:57:11 -07001159
Linus Torvalds1da177e2005-04-16 15:20:36 -07001160 mem=nn[KMG] [KNL,BOOT] Force usage of a specific amount of memory
1161 Amount of memory to be used when the kernel is not able
1162 to see the whole system memory or for test.
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001163 [X86-32] Use together with memmap= to avoid physical
Linus Torvalds1da177e2005-04-16 15:20:36 -07001164 address space collisions. Without memmap= PCI devices
1165 could be placed at addresses belonging to unused RAM.
1166
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001167 mem=nopentium [BUGS=X86-32] Disable usage of 4MB pages for kernel
Linus Torvalds1da177e2005-04-16 15:20:36 -07001168 memory.
1169
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001170 memmap=exactmap [KNL,X86-32,X86_64] Enable setting of an exact
Linus Torvalds1da177e2005-04-16 15:20:36 -07001171 E820 memory map, as specified by the user.
1172 Such memmap=exactmap lines can be constructed based on
1173 BIOS output or other requirements. See the memmap=nn@ss
1174 option description.
1175
1176 memmap=nn[KMG]@ss[KMG]
1177 [KNL] Force usage of a specific region of memory
1178 Region of memory to be used, from ss to ss+nn.
1179
1180 memmap=nn[KMG]#ss[KMG]
1181 [KNL,ACPI] Mark specific memory as ACPI data.
1182 Region of memory to be used, from ss to ss+nn.
1183
1184 memmap=nn[KMG]$ss[KMG]
1185 [KNL,ACPI] Mark specific memory as reserved.
1186 Region of memory to be used, from ss to ss+nn.
Pavel Machek13128482008-03-24 12:29:43 -07001187 Example: Exclude memory from 0x18690000-0x1869ffff
1188 memmap=64K$0x18690000
1189 or
1190 memmap=0x10000$0x18690000
Linus Torvalds1da177e2005-04-16 15:20:36 -07001191
Yinghai Luc64df702008-03-21 18:56:19 -07001192 memtest= [KNL,X86_64] Enable memtest
1193 Format: <integer>
1194 range: 0,4 : pattern number
1195 default : 0 <disable>
1196
Linus Torvalds1da177e2005-04-16 15:20:36 -07001197 meye.*= [HW] Set MotionEye Camera parameters
1198 See Documentation/video4linux/meye.txt.
1199
Andres Salomon8f368812007-10-12 23:04:06 +02001200 mfgpt_irq= [IA-32] Specify the IRQ to use for the
1201 Multi-Function General Purpose Timers on AMD Geode
1202 platforms.
1203
Willy Tarreaue6c4dc62008-01-30 13:33:33 +01001204 mfgptfix [X86-32] Fix MFGPT timers on AMD Geode platforms when
1205 the BIOS has incorrectly applied a workaround. TinyBIOS
1206 version 0.98 is known to be affected, 0.99 fixes the
1207 problem by letting the user disable the workaround.
1208
Linus Torvalds1da177e2005-04-16 15:20:36 -07001209 mga= [HW,DRM]
1210
1211 mousedev.tap_time=
1212 [MOUSE] Maximum time between finger touching and
1213 leaving touchpad surface for touch to be considered
1214 a tap and be reported as a left button click (for
1215 touchpads working in absolute mode only).
1216 Format: <msecs>
1217 mousedev.xres= [MOUSE] Horizontal screen resolution, used for devices
1218 reporting absolute coordinates, such as tablets
1219 mousedev.yres= [MOUSE] Vertical screen resolution, used for devices
1220 reporting absolute coordinates, such as tablets
1221
1222 mpu401= [HW,OSS]
1223 Format: <io>,<irq>
1224
1225 MTD_Partition= [MTD]
1226 Format: <name>,<region-number>,<size>,<offset>
1227
Randy Dunlapa9913042005-10-23 12:57:11 -07001228 MTD_Region= [MTD] Format:
1229 <name>,<region-number>[,<base>,<size>,<buswidth>,<altbuswidth>]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001230
1231 mtdparts= [MTD]
Randy Dunlapc8facbb2007-07-31 00:37:40 -07001232 See drivers/mtd/cmdlinepart.c.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001233
1234 mtouchusb.raw_coordinates=
Randy Dunlapa9913042005-10-23 12:57:11 -07001235 [HW] Make the MicroTouch USB driver use raw coordinates
1236 ('y', default) or cooked coordinates ('n')
Linus Torvalds1da177e2005-04-16 15:20:36 -07001237
1238 n2= [NET] SDL Inc. RISCom/N2 synchronous serial card
1239
1240 NCR_D700= [HW,SCSI]
1241 See header of drivers/scsi/NCR_D700.c.
1242
1243 ncr5380= [HW,SCSI]
1244
1245 ncr53c400= [HW,SCSI]
1246
1247 ncr53c400a= [HW,SCSI]
1248
1249 ncr53c406a= [HW,SCSI]
1250
1251 ncr53c8xx= [HW,SCSI]
1252
1253 netdev= [NET] Network devices parameters
1254 Format: <irq>,<io>,<mem_start>,<mem_end>,<name>
1255 Note that mem_start is often overloaded to mean
1256 something different and driver-specific.
Randy Dunlapa9913042005-10-23 12:57:11 -07001257 This usage is only documented in each driver source
1258 file if at all.
1259
Linus Torvalds1da177e2005-04-16 15:20:36 -07001260 nfsaddrs= [NFS]
J. Bruce Fields6ded55d2008-04-07 15:59:03 -04001261 See Documentation/filesystems/nfsroot.txt.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001262
1263 nfsroot= [NFS] nfs root filesystem for disk-less boxes.
J. Bruce Fields6ded55d2008-04-07 15:59:03 -04001264 See Documentation/filesystems/nfsroot.txt.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001265
Trond Myklebusta72b4422006-01-03 09:55:41 +01001266 nfs.callback_tcpport=
1267 [NFS] set the TCP port on which the NFSv4 callback
1268 channel should listen.
1269
Trond Myklebust58df0952006-01-03 09:55:57 +01001270 nfs.idmap_cache_timeout=
1271 [NFS] set the maximum lifetime for idmapper cache
1272 entries.
1273
Trond Myklebustf43bf0b2007-10-09 12:01:04 -04001274 nfs.enable_ino64=
1275 [NFS] enable 64-bit inode numbers.
1276 If zero, the NFS client will fake up a 32-bit inode
1277 number for the readdir() and stat() syscalls instead
1278 of returning the full 64-bit number.
1279 The default is to return 64-bit inode numbers.
1280
Haavard Skinnemoene7ba1762007-10-10 14:58:29 +02001281 nmi_debug= [KNL,AVR32] Specify one or more actions to take
1282 when a NMI is triggered.
1283 Format: [state][,regs][,debounce][,die]
1284
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001285 nmi_watchdog= [KNL,BUGS=X86-32] Debugging features for SMP kernels
Linus Torvalds1da177e2005-04-16 15:20:36 -07001286
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001287 no387 [BUGS=X86-32] Tells the kernel to use the 387 maths
Linus Torvalds1da177e2005-04-16 15:20:36 -07001288 emulation library even if a 387 maths coprocessor
1289 is present.
1290
Christoph Lameterc1aee212007-05-31 00:40:47 -07001291 noaliencache [MM, NUMA, SLAB] Disables the allocation of alien
1292 caches in the slab allocator. Saves per-node memory,
1293 but will impact performance.
Paul Menage3395ee02006-12-06 20:32:16 -08001294
Randy Dunlapa9913042005-10-23 12:57:11 -07001295 noalign [KNL,ARM]
1296
Linus Torvalds1da177e2005-04-16 15:20:36 -07001297 noapic [SMP,APIC] Tells the kernel to not make use of any
1298 IOAPICs that may be present in the system.
1299
Linus Torvalds1da177e2005-04-16 15:20:36 -07001300 nobats [PPC] Do not use BATs for mapping kernel lowmem
1301 on "Classic" PPC cores.
1302
1303 nocache [ARM]
Randy Dunlapa9913042005-10-23 12:57:11 -07001304
Shailabh Nagar163ecdf2006-07-30 03:03:11 -07001305 nodelayacct [KNL] Disable per-task delay accounting
1306
Linus Torvalds1da177e2005-04-16 15:20:36 -07001307 nodisconnect [HW,SCSI,M68K] Disables SCSI disconnects.
1308
Huang, Ying8b2cb7a2008-01-30 13:32:11 +01001309 noefi [X86-32,X86-64] Disable EFI runtime services support.
1310
Linus Torvalds1da177e2005-04-16 15:20:36 -07001311 noexec [IA-64]
1312
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001313 noexec [X86-32,X86-64]
Jiri Slabyf5a1b192008-04-12 10:28:25 +02001314 On X86-32 available only on PAE configured kernels.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001315 noexec=on: enable non-executable mappings (default)
Jiri Slabyf5a1b192008-04-12 10:28:25 +02001316 noexec=off: disable non-executable mappings
1317
1318 noexec32 [X86-64]
1319 This affects only 32-bit executables.
1320 noexec32=on: enable non-executable mappings (default)
1321 read doesn't imply executable mappings
1322 noexec32=off: disable non-executable mappings
1323 read implies executable mappings
Linus Torvalds1da177e2005-04-16 15:20:36 -07001324
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001325 nofxsr [BUGS=X86-32] Disables x86 floating point extended
Chuck Ebbert4f886512006-03-23 02:59:34 -08001326 register save and restore. The kernel will only save
1327 legacy floating-point registers on task switch.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001328
Andi Kleen191679f2008-01-30 13:33:21 +01001329 noclflush [BUGS=X86] Don't use the CLFLUSH instruction
1330
Linus Torvalds1da177e2005-04-16 15:20:36 -07001331 nohlt [BUGS=ARM]
Randy Dunlapa9913042005-10-23 12:57:11 -07001332
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001333 no-hlt [BUGS=X86-32] Tells the kernel that the hlt
Linus Torvalds1da177e2005-04-16 15:20:36 -07001334 instruction doesn't work correctly and not to
1335 use it.
1336
1337 nohalt [IA-64] Tells the kernel not to use the power saving
1338 function PAL_HALT_LIGHT when idle. This increases
1339 power-consumption. On the positive side, it reduces
1340 interrupt wake-up latency, which may improve performance
1341 in certain environments such as networked servers or
1342 real-time systems.
1343
Thomas Gleixner79bf2bb2007-02-16 01:28:03 -08001344 nohz= [KNL] Boottime enable/disable dynamic ticks
1345 Valid arguments: on, off
1346 Default: on
1347
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001348 noirqbalance [X86-32,SMP,KNL] Disable kernel irq balancing
Zachary Amsden8542b202006-12-07 02:14:09 +01001349
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001350 noirqdebug [X86-32] Disables the code which attempts to detect and
Linus Torvalds1da177e2005-04-16 15:20:36 -07001351 disable unhandled interrupt sources.
1352
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001353 no_timer_check [X86-32,X86_64,APIC] Disables the code which tests for
Zachary Amsden8542b202006-12-07 02:14:09 +01001354 broken timer IRQ sources.
1355
Linus Torvalds1da177e2005-04-16 15:20:36 -07001356 noisapnp [ISAPNP] Disables ISA PnP code.
1357
1358 noinitrd [RAM] Tells the kernel not to load any configured
1359 initial RAM disk.
1360
1361 nointroute [IA-64]
1362
Tony Luck0aa366f2007-07-20 11:22:30 -07001363 nojitter [IA64] Disables jitter checking for ITC timers.
1364
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001365 nolapic [X86-32,APIC] Do not enable or use the local APIC.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001366
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001367 nolapic_timer [X86-32,APIC] Do not use the local APIC timer.
Thomas Gleixnerad62ca22007-03-22 00:11:21 -08001368
Linus Torvalds1da177e2005-04-16 15:20:36 -07001369 noltlbs [PPC] Do not use large page/tlb entries for kernel
1370 lowmem mapping on PPC40x.
1371
Horms312f1f02006-02-22 09:57:55 +09001372 nomca [IA-64] Disable machine check abort handling
1373
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001374 nomce [X86-32] Machine Check Exception
Hormsabe37e52006-04-01 01:36:09 +02001375
Andres Salomon83d73842007-10-12 23:04:06 +02001376 nomfgpt [X86-32] Disable Multi-Function General Purpose
1377 Timer usage (for AMD Geode machines).
1378
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001379 noreplace-paravirt [X86-32,PV_OPS] Don't patch paravirt_ops
Jeremy Fitzhardinge959b4fd2007-05-02 19:27:16 +02001380
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001381 noreplace-smp [X86-32,SMP] Don't replace SMP instructions
Jeremy Fitzhardingeb7fb4af2007-05-02 19:27:13 +02001382 with UP alternatives
1383
Linus Torvalds1da177e2005-04-16 15:20:36 -07001384 noresidual [PPC] Don't use residual data on PReP machines.
1385
Randy Dunlapa9913042005-10-23 12:57:11 -07001386 noresume [SWSUSP] Disables resume and restores original swap
1387 space.
1388
Linus Torvalds1da177e2005-04-16 15:20:36 -07001389 no-scroll [VGA] Disables scrollback.
1390 This is required for the Braillex ib80-piezo Braille
1391 reader made by F.H. Papenmeier (Germany).
1392
1393 nosbagart [IA-64]
1394
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001395 nosep [BUGS=X86-32] Disables x86 SYSENTER/SYSEXIT support.
Chuck Ebbert4f886512006-03-23 02:59:34 -08001396
Len Brown61ec7562007-08-16 03:34:22 -04001397 nosmp [SMP] Tells an SMP kernel to act as a UP kernel,
1398 and disable the IO APIC. legacy for "maxcpus=0".
Linus Torvalds1da177e2005-04-16 15:20:36 -07001399
Dave Jones97842212007-07-15 23:41:05 -07001400 nosoftlockup [KNL] Disable the soft-lockup detector.
1401
Linus Torvalds1da177e2005-04-16 15:20:36 -07001402 nosync [HW,M68K] Disables sync negotiation for all devices.
1403
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001404 notsc [BUGS=X86-32] Disable Time Stamp Counter
Linus Torvalds1da177e2005-04-16 15:20:36 -07001405
1406 nousb [USB] Disable the USB subsystem
1407
1408 nowb [ARM]
Randy Dunlapa9913042005-10-23 12:57:11 -07001409
Fenghua Yua6c75b862008-03-14 13:57:08 -07001410 nptcg= [IA64] Override max number of concurrent global TLB
1411 purges which is reported from either PAL_VM_SUMMARY or
1412 SAL PALO.
1413
KAMEZAWA Hiroyukif0c0b2b2007-07-15 23:38:01 -07001414 numa_zonelist_order= [KNL, BOOT] Select zonelist order for NUMA.
1415 one of ['zone', 'node', 'default'] can be specified
1416 This can be set from sysctl after boot.
1417 See Documentation/sysctl/vm.txt for details.
1418
Dave Jonesa61c2d72006-01-07 23:18:19 +00001419 nr_uarts= [SERIAL] maximum number of UARTs to be registered.
1420
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07001421 olpc_ec_timeout= [OLPC] ms delay when issuing EC commands
1422 Rather than timing out after 20 ms if an EC
1423 command is not properly ACKed, override the length
1424 of the timeout. We have interrupts disabled while
1425 waiting for the ACK, so if this is set too high
1426 interrupts *may* be lost!
1427
Linus Torvalds1da177e2005-04-16 15:20:36 -07001428 opl3= [HW,OSS]
1429 Format: <io>
1430
Linus Torvalds1da177e2005-04-16 15:20:36 -07001431 oprofile.timer= [HW]
1432 Use timer interrupt instead of performance counters
1433
Linus Torvalds1da177e2005-04-16 15:20:36 -07001434 osst= [HW,SCSI] SCSI Tape Driver
1435 Format: <buffer_size>,<write_threshold>
1436 See also Documentation/scsi/st.txt.
1437
1438 panic= [KNL] Kernel behaviour on panic
1439 Format: <timeout>
1440
1441 parkbd.port= [HW] Parallel port number the keyboard adapter is
1442 connected to, default is 0.
1443 Format: <parport#>
1444 parkbd.mode= [HW] Parallel port keyboard adapter mode of operation,
1445 0 for XT, 1 for AT (default is AT).
Randy Dunlapa9913042005-10-23 12:57:11 -07001446 Format: <mode>
Linus Torvalds1da177e2005-04-16 15:20:36 -07001447
Randy Dunlapa9913042005-10-23 12:57:11 -07001448 parport= [HW,PPT] Specify parallel ports. 0 disables.
1449 Format: { 0 | auto | 0xBBB[,IRQ[,DMA]] }
1450 Use 'auto' to force the driver to use any
1451 IRQ/DMA settings detected (the default is to
1452 ignore detected IRQ/DMA settings because of
1453 possible conflicts). You can specify the base
1454 address, IRQ, and DMA settings; IRQ and DMA
1455 should be numbers, or 'auto' (for using detected
1456 settings on that particular port), or 'nofifo'
1457 (to avoid using a FIFO even if it is detected).
1458 Parallel ports are assigned in the order they
1459 are specified on the command line, starting
1460 with parport0.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001461
Randy Dunlapa9913042005-10-23 12:57:11 -07001462 parport_init_mode= [HW,PPT]
1463 Configure VIA parallel port to operate in
1464 a specific mode. This is necessary on Pegasos
1465 computer where firmware has no options for setting
1466 up parallel port mode and sets it to spp.
1467 Currently this function knows 686a and 8231 chips.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001468 Format: [spp|ps2|epp|ecp|ecpepp]
1469
Randy Dunlapa9913042005-10-23 12:57:11 -07001470 pas2= [HW,OSS] Format:
1471 <io>,<irq>,<dma>,<dma16>,<sb_io>,<sb_irq>,<sb_dma>,<sb_dma16>
1472
Linus Torvalds1da177e2005-04-16 15:20:36 -07001473 pas16= [HW,SCSI]
1474 See header of drivers/scsi/pas16.c.
1475
Andrew Mortondd287792006-03-23 03:00:57 -08001476 pause_on_oops=
1477 Halt all CPUs after the first oops has been printed for
1478 the specified number of seconds. This is to be used if
1479 your oopses keep scrolling off the screen.
1480
Linus Torvalds1da177e2005-04-16 15:20:36 -07001481 pcbit= [HW,ISDN]
1482
1483 pcd. [PARIDE]
1484 See header of drivers/block/paride/pcd.c.
1485 See also Documentation/paride.txt.
1486
Randy Dunlapa9913042005-10-23 12:57:11 -07001487 pci=option[,option...] [PCI] various PCI subsystem options:
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001488 off [X86-32] don't probe for the PCI bus
1489 bios [X86-32] force use of PCI BIOS, don't access
Randy Dunlapa9913042005-10-23 12:57:11 -07001490 the hardware directly. Use this if your machine
1491 has a non-standard PCI host bridge.
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001492 nobios [X86-32] disallow use of PCI BIOS, only direct
Randy Dunlapa9913042005-10-23 12:57:11 -07001493 hardware access methods are allowed. Use this
1494 if you experience crashes upon bootup and you
1495 suspect they are caused by the BIOS.
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001496 conf1 [X86-32] Force use of PCI Configuration
Randy Dunlapa9913042005-10-23 12:57:11 -07001497 Mechanism 1.
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001498 conf2 [X86-32] Force use of PCI Configuration
Randy Dunlapa9913042005-10-23 12:57:11 -07001499 Mechanism 2.
Randy Dunlap7f785762007-10-05 13:17:58 -07001500 noaer [PCIE] If the PCIEAER kernel config parameter is
1501 enabled, this kernel boot option can be used to
1502 disable the use of PCIE advanced error reporting.
Jeff Garzik32a2eea2007-10-11 16:57:27 -04001503 nodomains [PCI] Disable support for multiple PCI
1504 root domains (aka PCI segments, in ACPI-speak).
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001505 nommconf [X86-32,X86_64] Disable use of MMCONFIG for PCI
Bjorn Helgaas61be6d62006-02-15 15:17:43 -08001506 Configuration
Matthew Wilcox309e57d2006-03-05 22:33:34 -07001507 nomsi [MSI] If the PCI_MSI kernel config parameter is
1508 enabled, this kernel boot option can be used to
1509 disable the use of MSI interrupts system-wide.
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001510 biosirq [X86-32] Use PCI BIOS calls to get the interrupt
Randy Dunlapa9913042005-10-23 12:57:11 -07001511 routing table. These calls are known to be buggy
1512 on several machines and they hang the machine
1513 when used, but on other computers it's the only
1514 way to get the interrupt routing table. Try
1515 this option if the kernel is unable to allocate
1516 IRQs or discover secondary PCI buses on your
1517 motherboard.
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001518 rom [X86-32] Assign address space to expansion ROMs.
Randy Dunlapa9913042005-10-23 12:57:11 -07001519 Use with caution as certain devices share
1520 address decoders between ROMs and other
1521 resources.
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001522 irqmask=0xMMMM [X86-32] Set a bit mask of IRQs allowed to be
Randy Dunlapa9913042005-10-23 12:57:11 -07001523 assigned automatically to PCI devices. You can
1524 make the kernel exclude IRQs of your ISA cards
1525 this way.
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001526 pirqaddr=0xAAAAA [X86-32] Specify the physical address
Randy Dunlapa9913042005-10-23 12:57:11 -07001527 of the PIRQ table (normally generated
1528 by the BIOS) if it is outside the
1529 F0000h-100000h range.
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001530 lastbus=N [X86-32] Scan all buses thru bus #N. Can be
Randy Dunlapa9913042005-10-23 12:57:11 -07001531 useful if the kernel is unable to find your
1532 secondary buses and you want to tell it
1533 explicitly which ones they are.
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001534 assign-busses [X86-32] Always assign all PCI bus
Randy Dunlapa9913042005-10-23 12:57:11 -07001535 numbers ourselves, overriding
1536 whatever the firmware may have done.
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001537 usepirqmask [X86-32] Honor the possible IRQ mask stored
Randy Dunlapa9913042005-10-23 12:57:11 -07001538 in the BIOS $PIR table. This is needed on
1539 some systems with broken BIOSes, notably
1540 some HP Pavilion N5400 and Omnibook XE3
1541 notebooks. This will have no effect if ACPI
1542 IRQ routing is enabled.
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001543 noacpi [X86-32] Do not use ACPI for IRQ routing
Randy Dunlapa9913042005-10-23 12:57:11 -07001544 or for PCI scanning.
Gary Hade62f420f2007-10-03 15:56:51 -07001545 use_crs [X86-32] Use _CRS for PCI resource
1546 allocation.
Randy Dunlapa9913042005-10-23 12:57:11 -07001547 routeirq Do IRQ routing for all PCI devices.
1548 This is normally done in pci_enable_device(),
1549 so this option is a temporary workaround
1550 for broken drivers that don't call it.
Yinghai Lu13a6ddb2008-03-27 01:31:18 -07001551 skip_isa_align [X86] do not align io start addr, so can
1552 handle more pci cards
Randy Dunlapa9913042005-10-23 12:57:11 -07001553 firmware [ARM] Do not re-enumerate the bus but instead
1554 just use the configuration from the
1555 bootloader. This is currently used on
1556 IXP2000 systems where the bus has to be
1557 configured a certain way for adjunct CPUs.
Andi Kleen0637a702006-09-26 10:52:41 +02001558 noearly [X86] Don't do any early type 1 scanning.
1559 This might help on some broken boards which
1560 machine check when some devices' config space
1561 is read. But various workarounds are disabled
1562 and some IOMMU drivers will not work.
Matt Domsch6b4b78f2006-09-29 15:23:23 -05001563 bfsort Sort PCI devices into breadth-first order.
1564 This sorting is done to get a device
1565 order compatible with older (<= 2.4) kernels.
1566 nobfsort Don't sort PCI devices into breadth-first order.
Atsushi Nemoto4516a612007-02-05 16:36:06 -08001567 cbiosize=nn[KMG] The fixed amount of bus space which is
1568 reserved for the CardBus bridge's IO window.
1569 The default value is 256 bytes.
1570 cbmemsize=nn[KMG] The fixed amount of bus space which is
1571 reserved for the CardBus bridge's memory
1572 window. The default value is 64 megabytes.
Matt Domsch6b4b78f2006-09-29 15:23:23 -05001573
Linus Torvalds1da177e2005-04-16 15:20:36 -07001574 pcmv= [HW,PCMCIA] BadgePAD 4
1575
1576 pd. [PARIDE]
1577 See Documentation/paride.txt.
1578
1579 pdcchassis= [PARISC,HW] Disable/Enable PDC Chassis Status codes at
1580 boot time.
1581 Format: { 0 | 1 }
1582 See arch/parisc/kernel/pdc_chassis.c
1583
1584 pf. [PARIDE]
1585 See Documentation/paride.txt.
1586
1587 pg. [PARIDE]
1588 See Documentation/paride.txt.
1589
1590 pirq= [SMP,APIC] Manual mp-table setup
1591 See Documentation/i386/IO-APIC.txt.
1592
1593 plip= [PPT,NET] Parallel port network link
1594 Format: { parport<nr> | timid | 0 }
1595 See also Documentation/parport.txt.
1596
1597 pnpacpi= [ACPI]
1598 { off }
1599
1600 pnpbios= [ISAPNP]
1601 { on | off | curr | res | no-curr | no-res }
1602
1603 pnp_reserve_irq=
1604 [ISAPNP] Exclude IRQs for the autoconfiguration
1605
1606 pnp_reserve_dma=
1607 [ISAPNP] Exclude DMAs for the autoconfiguration
1608
1609 pnp_reserve_io= [ISAPNP] Exclude I/O ports for the autoconfiguration
Randy Dunlapa9913042005-10-23 12:57:11 -07001610 Ranges are in pairs (I/O port base and size).
Linus Torvalds1da177e2005-04-16 15:20:36 -07001611
1612 pnp_reserve_mem=
Randy Dunlapa9913042005-10-23 12:57:11 -07001613 [ISAPNP] Exclude memory regions for the
1614 autoconfiguration.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001615 Ranges are in pairs (memory base and size).
1616
Ingo Molnar45807a12007-07-15 23:40:10 -07001617 print-fatal-signals=
1618 [KNL] debug: print fatal signals
1619 print-fatal-signals=1: print segfault info to
1620 the kernel console.
1621 default: off.
1622
Randy Dunlape84845c2007-07-15 23:40:25 -07001623 printk.time= Show timing data prefixed to each printk message line
1624 Format: <bool> (1/Y/y=enable, 0/N/n=disable)
1625
Linus Torvalds1da177e2005-04-16 15:20:36 -07001626 profile= [KNL] Enable kernel profiling via /proc/profile
Randy Dunlapa9913042005-10-23 12:57:11 -07001627 Format: [schedule,]<number>
1628 Param: "schedule" - profile schedule points.
1629 Param: <number> - step/bucket size as a power of 2 for
1630 statistical time based profiling.
Mel Gormanb3da2a72007-10-24 18:23:50 +02001631 Param: "sleep" - profile D-state sleeping (millisecs).
1632 Requires CONFIG_SCHEDSTATS
Dave Jonesc0fe2e62007-10-20 03:08:22 +02001633 Param: "kvm" - profile VM exits.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001634
Randy Dunlapa9913042005-10-23 12:57:11 -07001635 processor.max_cstate= [HW,ACPI]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001636 Limit processor to maximum C-state
1637 max_cstate=9 overrides any DMI blacklist limit.
1638
Len Brown41c0d862005-12-28 12:43:51 -05001639 processor.nocst [HW,ACPI]
1640 Ignore the _CST method to determine C-states,
1641 instead using the legacy FADT method
1642
Linus Torvalds1da177e2005-04-16 15:20:36 -07001643 prompt_ramdisk= [RAM] List of RAM disks to prompt for floppy disk
1644 before loading.
1645 See Documentation/ramdisk.txt.
1646
Randy Dunlapa9913042005-10-23 12:57:11 -07001647 psmouse.proto= [HW,MOUSE] Highest PS2 mouse protocol extension to
1648 probe for; one of (bare|imps|exps|lifebook|any).
Linus Torvalds1da177e2005-04-16 15:20:36 -07001649 psmouse.rate= [HW,MOUSE] Set desired mouse report rate, in reports
1650 per second.
Randy Dunlapa9913042005-10-23 12:57:11 -07001651 psmouse.resetafter= [HW,MOUSE]
1652 Try to reset the device after so many bad packets
Linus Torvalds1da177e2005-04-16 15:20:36 -07001653 (0 = never).
1654 psmouse.resolution=
1655 [HW,MOUSE] Set desired mouse resolution, in dpi.
1656 psmouse.smartscroll=
Randy Dunlapa9913042005-10-23 12:57:11 -07001657 [HW,MOUSE] Controls Logitech smartscroll autorepeat.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001658 0 = disabled, 1 = enabled (default).
1659
1660 pss= [HW,OSS] Personal Sound System (ECHO ESC614)
Randy Dunlapa9913042005-10-23 12:57:11 -07001661 Format:
1662 <io>,<mss_io>,<mss_irq>,<mss_dma>,<mpu_io>,<mpu_irq>
Linus Torvalds1da177e2005-04-16 15:20:36 -07001663
1664 pt. [PARIDE]
1665 See Documentation/paride.txt.
1666
Kay Sieversdc8c8582007-08-15 12:25:38 +02001667 pty.legacy_count=
1668 [KNL] Number of legacy pty's. Overwrites compiled-in
1669 default number.
1670
Randy Dunlap7d2c5022006-09-29 02:01:02 -07001671 quiet [KNL] Disable most log messages
Randy Dunlapa9913042005-10-23 12:57:11 -07001672
Linus Torvalds1da177e2005-04-16 15:20:36 -07001673 r128= [HW,DRM]
1674
1675 raid= [HW,RAID]
1676 See Documentation/md.txt.
1677
Randy Dunlapa9913042005-10-23 12:57:11 -07001678 ramdisk_blocksize= [RAM]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001679 See Documentation/ramdisk.txt.
Randy Dunlapa9913042005-10-23 12:57:11 -07001680
Linus Torvalds1da177e2005-04-16 15:20:36 -07001681 ramdisk_size= [RAM] Sizes of RAM disks in kilobytes
Linus Torvalds1da177e2005-04-16 15:20:36 -07001682 See Documentation/ramdisk.txt.
1683
Robert P. J. Day24aaef82008-02-03 15:20:26 +02001684 rcupdate.blimit= [KNL,BOOT]
1685 Set maximum number of finished RCU callbacks to process
1686 in one batch.
Dipankar Sarma21a1ea92006-03-07 21:55:33 -08001687
Robert P. J. Day24aaef82008-02-03 15:20:26 +02001688 rcupdate.qhimark= [KNL,BOOT]
1689 Set threshold of queued
Dipankar Sarma21a1ea92006-03-07 21:55:33 -08001690 RCU callbacks over which batch limiting is disabled.
1691
Robert P. J. Day24aaef82008-02-03 15:20:26 +02001692 rcupdate.qlowmark= [KNL,BOOT]
1693 Set threshold of queued RCU callbacks below which
1694 batch limiting is re-enabled.
Dipankar Sarma21a1ea92006-03-07 21:55:33 -08001695
Olof Johanssonffdfc402005-09-06 15:17:19 -07001696 rdinit= [KNL]
1697 Format: <full_path>
1698 Run specified binary instead of /init from the ramdisk,
1699 used for early userspace startup. See initrd.
1700
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001701 reboot= [BUGS=X86-32,BUGS=ARM,BUGS=IA-64] Rebooting mode
Linus Torvalds1da177e2005-04-16 15:20:36 -07001702 Format: <reboot_mode>[,<reboot_mode2>[,...]]
Mauro Carvalho Chehabe53dd082007-09-15 07:38:47 -03001703 See arch/*/kernel/reboot.c or arch/*/kernel/process.c
Linus Torvalds1da177e2005-04-16 15:20:36 -07001704
1705 reserve= [KNL,BUGS] Force the kernel to ignore some iomem area
1706
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001707 reservetop= [X86-32]
Zachary Amsden461a9af2006-09-25 23:32:25 -07001708 Format: nn[KMG]
1709 Reserves a hole at the top of the kernel virtual
1710 address space.
1711
Vivek Goyal7e962872006-09-27 01:50:44 -07001712 reset_devices [KNL] Force drivers to reset the underlying device
1713 during initialization.
1714
Randy Dunlapa9913042005-10-23 12:57:11 -07001715 resume= [SWSUSP]
1716 Specify the partition device for software suspend
Linus Torvalds1da177e2005-04-16 15:20:36 -07001717
Rafael J. Wysockiecbd0da2006-12-06 20:34:13 -08001718 resume_offset= [SWSUSP]
1719 Specify the offset from the beginning of the partition
1720 given by "resume=" at which the swap header is located,
1721 in <PAGE_SIZE> units (needed only for swap files).
1722 See Documentation/power/swsusp-and-swap-files.txt
1723
Michael Neuling0a7b35c2007-02-10 01:44:33 -08001724 retain_initrd [RAM] Keep initrd memory after extraction
1725
Linus Torvalds1da177e2005-04-16 15:20:36 -07001726 rhash_entries= [KNL,NET]
1727 Set number of hash buckets for route cache
1728
1729 riscom8= [HW,SERIAL]
1730 Format: <io_board1>[,<io_board2>[,...<io_boardN>]]
1731
1732 ro [KNL] Mount root device read-only on boot
1733
1734 root= [KNL] Root filesystem
1735
1736 rootdelay= [KNL] Delay (in seconds) to pause before attempting to
1737 mount the root filesystem
1738
1739 rootflags= [KNL] Set root filesystem mount option string
1740
1741 rootfstype= [KNL] Set root filesystem type
1742
Pierre Ossmancc1ed752007-07-15 23:40:35 -07001743 rootwait [KNL] Wait (indefinitely) for root device to show up.
1744 Useful for devices that are detected asynchronously
1745 (e.g. USB and MMC devices).
1746
James Morris20510f22007-10-16 23:31:32 -07001747 root_plug.vendor_id=
1748 [ROOTPLUG] Override the default vendor ID
1749
1750 root_plug.product_id=
1751 [ROOTPLUG] Override the default product ID
1752
1753 root_plug.debug=
1754 [ROOTPLUG] Enable debugging output
1755
Linus Torvalds1da177e2005-04-16 15:20:36 -07001756 rw [KNL] Mount root device read-write on boot
1757
1758 S [KNL] Run init in single mode
1759
1760 sa1100ir [NET]
1761 See drivers/net/irda/sa1100_ir.c.
1762
Linus Torvalds1da177e2005-04-16 15:20:36 -07001763 sbni= [NET] Granch SBNI12 leased line adapter
Randy Dunlapa9913042005-10-23 12:57:11 -07001764
Linus Torvalds1da177e2005-04-16 15:20:36 -07001765 sc1200wdt= [HW,WDT] SC1200 WDT (watchdog) driver
1766 Format: <io>[,<timeout>[,<isapnp>]]
1767
1768 scsi_debug_*= [SCSI]
1769 See drivers/scsi/scsi_debug.c.
1770
1771 scsi_default_dev_flags=
1772 [SCSI] SCSI default device flags
1773 Format: <integer>
1774
1775 scsi_dev_flags= [SCSI] Black/white list entry for vendor and model
1776 Format: <vendor>:<model>:<flags>
1777 (flags are integer value)
1778
Randy Dunlap6af66322007-11-14 16:52:25 -08001779 scsi_logging_level= [SCSI] a bit mask of logging levels
1780 See drivers/scsi/scsi_logging.h for bits. Also
1781 settable via sysctl at dev.scsi.logging_level
1782 (/proc/sys/dev/scsi/logging_level).
1783 There is also a nice 'scsi_logging_level' script in the
1784 S390-tools package, available for download at
1785 http://www-128.ibm.com/developerworks/linux/linux390/s390-tools-1.5.4.html
Linus Torvalds1da177e2005-04-16 15:20:36 -07001786
Matthew Wilcox3e082a92006-09-28 15:19:20 -06001787 scsi_mod.scan= [SCSI] sync (default) scans SCSI busses as they are
1788 discovered. async scans them in kernel threads,
1789 allowing boot to proceed. none ignores them, expecting
1790 user space to do the scan.
1791
Linus Torvalds1da177e2005-04-16 15:20:36 -07001792 selinux [SELINUX] Disable or enable SELinux at boot time.
1793 Format: { "0" | "1" }
1794 See security/selinux/Kconfig help text.
1795 0 -- disable.
1796 1 -- enable.
1797 Default value is set via kernel config option.
1798 If enabled at boot time, /selinux/disable can be used
1799 later to disable prior to initial policy load.
1800
James Morris4e5ab4c2006-06-09 00:33:33 -07001801 selinux_compat_net =
1802 [SELINUX] Set initial selinux_compat_net flag value.
Mauro Carvalho Chehabe53dd082007-09-15 07:38:47 -03001803 Format: { "0" | "1" }
1804 0 -- use new secmark-based packet controls
1805 1 -- use legacy packet controls
1806 Default value is 0 (preferred).
1807 Value can be changed at runtime via
1808 /selinux/compat_net.
James Morris4e5ab4c2006-06-09 00:33:33 -07001809
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001810 serialnumber [BUGS=X86-32]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001811
Linus Torvalds1da177e2005-04-16 15:20:36 -07001812 shapers= [NET]
1813 Maximal number of shapers.
Randy Dunlapa9913042005-10-23 12:57:11 -07001814
Linus Torvalds1da177e2005-04-16 15:20:36 -07001815 sim710= [SCSI,HW]
1816 See header of drivers/scsi/sim710.c.
1817
1818 simeth= [IA-64]
1819 simscsi=
Randy Dunlapa9913042005-10-23 12:57:11 -07001820
Linus Torvalds1da177e2005-04-16 15:20:36 -07001821 slram= [HW,MTD]
1822
Christoph Lameterf0630ff2007-07-15 23:38:14 -07001823 slub_debug[=options[,slabs]] [MM, SLUB]
1824 Enabling slub_debug allows one to determine the
1825 culprit if slab objects become corrupted. Enabling
1826 slub_debug can create guard zones around objects and
1827 may poison objects when not in use. Also tracks the
1828 last alloc / free. For more information see
1829 Documentation/vm/slub.txt.
Christoph Lameterc1aee212007-05-31 00:40:47 -07001830
1831 slub_max_order= [MM, SLUB]
Christoph Lameterf0630ff2007-07-15 23:38:14 -07001832 Determines the maximum allowed order for slabs.
1833 A high setting may cause OOMs due to memory
1834 fragmentation. For more information see
1835 Documentation/vm/slub.txt.
Christoph Lameterc1aee212007-05-31 00:40:47 -07001836
1837 slub_min_objects= [MM, SLUB]
Christoph Lameterf0630ff2007-07-15 23:38:14 -07001838 The minimum number of objects per slab. SLUB will
1839 increase the slab order up to slub_max_order to
1840 generate a sufficiently large slab able to contain
1841 the number of objects indicated. The higher the number
1842 of objects the smaller the overhead of tracking slabs
1843 and the less frequently locks need to be acquired.
Christoph Lameterc1aee212007-05-31 00:40:47 -07001844 For more information see Documentation/vm/slub.txt.
1845
1846 slub_min_order= [MM, SLUB]
1847 Determines the mininum page order for slabs. Must be
Christoph Lameterf0630ff2007-07-15 23:38:14 -07001848 lower than slub_max_order.
Christoph Lameterc1aee212007-05-31 00:40:47 -07001849 For more information see Documentation/vm/slub.txt.
1850
1851 slub_nomerge [MM, SLUB]
Christoph Lameterf0630ff2007-07-15 23:38:14 -07001852 Disable merging of slabs with similar size. May be
Christoph Lameterc1aee212007-05-31 00:40:47 -07001853 necessary if there is some reason to distinguish
Christoph Lameterf0630ff2007-07-15 23:38:14 -07001854 allocs to different slabs. Debug options disable
1855 merging on their own.
Christoph Lameterc1aee212007-05-31 00:40:47 -07001856 For more information see Documentation/vm/slub.txt.
1857
Linus Torvalds1da177e2005-04-16 15:20:36 -07001858 smart2= [HW]
1859 Format: <io1>[,<io2>[,...,<io8>]]
1860
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001861 smp-alt-once [X86-32,SMP] On a hotplug CPU system, only
Jeremy Fitzhardingeb7fb4af2007-05-02 19:27:13 +02001862 attempt to substitute SMP alternatives once at boot.
1863
Bjorn Helgaasd0d4f692007-05-08 00:36:05 -07001864 smsc-ircc2.nopnp [HW] Don't use PNP to discover SMC devices
1865 smsc-ircc2.ircc_cfg= [HW] Device configuration I/O port
1866 smsc-ircc2.ircc_sir= [HW] SIR base I/O port
1867 smsc-ircc2.ircc_fir= [HW] FIR base I/O port
1868 smsc-ircc2.ircc_irq= [HW] IRQ line
1869 smsc-ircc2.ircc_dma= [HW] DMA channel
1870 smsc-ircc2.ircc_transceiver= [HW] Transceiver type:
1871 0: Toshiba Satellite 1800 (GP data pin select)
1872 1: Fast pin select (default)
1873 2: ATC IRMode
1874
Linus Torvalds1da177e2005-04-16 15:20:36 -07001875 snd-ad1816a= [HW,ALSA]
1876
1877 snd-ad1848= [HW,ALSA]
1878
1879 snd-ali5451= [HW,ALSA]
1880
1881 snd-als100= [HW,ALSA]
1882
1883 snd-als4000= [HW,ALSA]
1884
1885 snd-azt2320= [HW,ALSA]
1886
1887 snd-cmi8330= [HW,ALSA]
1888
1889 snd-cmipci= [HW,ALSA]
1890
1891 snd-cs4231= [HW,ALSA]
1892
1893 snd-cs4232= [HW,ALSA]
1894
1895 snd-cs4236= [HW,ALSA]
1896
1897 snd-cs4281= [HW,ALSA]
1898
1899 snd-cs46xx= [HW,ALSA]
1900
1901 snd-dt019x= [HW,ALSA]
1902
1903 snd-dummy= [HW,ALSA]
1904
1905 snd-emu10k1= [HW,ALSA]
1906
1907 snd-ens1370= [HW,ALSA]
1908
1909 snd-ens1371= [HW,ALSA]
1910
1911 snd-es968= [HW,ALSA]
1912
1913 snd-es1688= [HW,ALSA]
1914
1915 snd-es18xx= [HW,ALSA]
1916
1917 snd-es1938= [HW,ALSA]
1918
1919 snd-es1968= [HW,ALSA]
1920
1921 snd-fm801= [HW,ALSA]
1922
1923 snd-gusclassic= [HW,ALSA]
1924
1925 snd-gusextreme= [HW,ALSA]
1926
1927 snd-gusmax= [HW,ALSA]
1928
1929 snd-hdsp= [HW,ALSA]
1930
1931 snd-ice1712= [HW,ALSA]
1932
1933 snd-intel8x0= [HW,ALSA]
1934
1935 snd-interwave= [HW,ALSA]
1936
1937 snd-interwave-stb=
1938 [HW,ALSA]
1939
1940 snd-korg1212= [HW,ALSA]
1941
1942 snd-maestro3= [HW,ALSA]
1943
1944 snd-mpu401= [HW,ALSA]
1945
1946 snd-mtpav= [HW,ALSA]
1947
1948 snd-nm256= [HW,ALSA]
1949
1950 snd-opl3sa2= [HW,ALSA]
1951
1952 snd-opti92x-ad1848=
1953 [HW,ALSA]
1954
1955 snd-opti92x-cs4231=
1956 [HW,ALSA]
1957
1958 snd-opti93x= [HW,ALSA]
1959
1960 snd-pmac= [HW,ALSA]
1961
1962 snd-rme32= [HW,ALSA]
1963
1964 snd-rme96= [HW,ALSA]
1965
1966 snd-rme9652= [HW,ALSA]
1967
1968 snd-sb8= [HW,ALSA]
1969
1970 snd-sb16= [HW,ALSA]
1971
1972 snd-sbawe= [HW,ALSA]
1973
1974 snd-serial= [HW,ALSA]
1975
1976 snd-sgalaxy= [HW,ALSA]
1977
1978 snd-sonicvibes= [HW,ALSA]
1979
1980 snd-sun-amd7930=
1981 [HW,ALSA]
1982
1983 snd-sun-cs4231= [HW,ALSA]
1984
1985 snd-trident= [HW,ALSA]
1986
1987 snd-usb-audio= [HW,ALSA,USB]
1988
1989 snd-via82xx= [HW,ALSA]
1990
1991 snd-virmidi= [HW,ALSA]
1992
1993 snd-wavefront= [HW,ALSA]
1994
1995 snd-ymfpci= [HW,ALSA]
Randy Dunlapa9913042005-10-23 12:57:11 -07001996
Linus Torvalds1da177e2005-04-16 15:20:36 -07001997 sonypi.*= [HW] Sony Programmable I/O Control Device driver
1998 See Documentation/sonypi.txt
1999
2000 specialix= [HW,SERIAL] Specialix multi-serial port adapter
2001 See Documentation/specialix.txt.
2002
2003 spia_io_base= [HW,MTD]
2004 spia_fio_base=
2005 spia_pedr=
2006 spia_peddr=
2007
2008 sscape= [HW,OSS]
2009 Format: <io>,<irq>,<dma>,<mpu_io>,<mpu_irq>
Randy Dunlapa9913042005-10-23 12:57:11 -07002010
Linus Torvalds1da177e2005-04-16 15:20:36 -07002011 st= [HW,SCSI] SCSI tape parameters (buffers, etc.)
2012 See Documentation/scsi/st.txt.
2013
Linus Torvalds1da177e2005-04-16 15:20:36 -07002014 sti= [PARISC,HW]
2015 Format: <num>
2016 Set the STI (builtin display/keyboard on the HP-PARISC
2017 machines) console (graphic card) which should be used
2018 as the initial boot-console.
2019 See also comment in drivers/video/console/sticore.c.
2020
2021 sti_font= [HW]
2022 See comment in drivers/video/console/sticore.c.
2023
2024 stifb= [HW]
2025 Format: bpp:<bpp1>[:<bpp2>[:<bpp3>...]]
2026
Greg Banks42a7fc42007-03-06 01:42:23 -08002027 sunrpc.pool_mode=
2028 [NFS]
2029 Control how the NFS server code allocates CPUs to
2030 service thread pools. Depending on how many NICs
2031 you have and where their interrupts are bound, this
2032 option will affect which CPUs will do NFS serving.
2033 Note: this parameter cannot be changed while the
2034 NFS server is running.
2035
2036 auto the server chooses an appropriate mode
2037 automatically using heuristics
2038 global a single global pool contains all CPUs
2039 percpu one pool for each CPU
2040 pernode one pool for each NUMA node (equivalent
2041 to global on non-NUMA machines)
2042
Linus Torvalds1da177e2005-04-16 15:20:36 -07002043 swiotlb= [IA-64] Number of I/O TLB slabs
Randy Dunlapa9913042005-10-23 12:57:11 -07002044
Linus Torvalds1da177e2005-04-16 15:20:36 -07002045 switches= [HW,M68k]
2046
2047 sym53c416= [HW,SCSI]
2048 See header of drivers/scsi/sym53c416.c.
2049
Ingo Molnar5d6f6472006-12-13 00:34:36 -08002050 sysrq_always_enabled
2051 [KNL]
2052 Ignore sysrq setting - this boot parameter will
2053 neutralize any effect of /proc/sys/kernel/sysrq.
2054 Useful for debugging.
2055
Linus Torvalds1da177e2005-04-16 15:20:36 -07002056 t128= [HW,SCSI]
2057 See header of drivers/scsi/t128.c.
2058
2059 tdfx= [HW,DRM]
2060
2061 thash_entries= [KNL,NET]
2062 Set number of hash buckets for TCP connection
2063
Len Brownf8707ec2007-08-12 00:12:54 -04002064 thermal.act= [HW,ACPI]
2065 -1: disable all active trip points in all thermal zones
2066 <degrees C>: override all lowest active trip points
2067
Len Brownc52a7412007-08-14 15:49:32 -04002068 thermal.crt= [HW,ACPI]
2069 -1: disable all critical trip points in all thermal zones
2070 <degrees C>: lower all critical trip points
2071
Len Brownf5487142007-08-12 00:12:44 -04002072 thermal.nocrt= [HW,ACPI]
2073 Set to disable actions on ACPI thermal zone
2074 critical and hot trip points.
2075
Len Brown72b33ef2007-08-12 00:12:17 -04002076 thermal.off= [HW,ACPI]
2077 1: disable ACPI thermal control
2078
Len Browna70cdc52007-08-12 00:12:35 -04002079 thermal.psv= [HW,ACPI]
2080 -1: disable all passive trip points
2081 <degrees C>: override all passive trip points to this value
2082
Len Brown730ff342007-08-12 00:12:26 -04002083 thermal.tzp= [HW,ACPI]
2084 Specify global default ACPI thermal zone polling rate
2085 <deci-seconds>: poll all this frequency
2086 0: no polling (default)
2087
Linus Torvalds1da177e2005-04-16 15:20:36 -07002088 tipar.timeout= [HW,PPT]
2089 Set communications timeout in tenths of a second
2090 (default 15).
2091
2092 tipar.delay= [HW,PPT]
2093 Set inter-bit delay in microseconds (default 10).
2094
Linus Torvalds1da177e2005-04-16 15:20:36 -07002095 tmscsim= [HW,SCSI]
2096 See comment before function dc390_setup() in
2097 drivers/scsi/tmscsim.c.
2098
2099 tp720= [HW,PS2]
2100
2101 trix= [HW,OSS] MediaTrix AudioTrix Pro
Randy Dunlapa9913042005-10-23 12:57:11 -07002102 Format:
2103 <io>,<irq>,<dma>,<dma2>,<sb_io>,<sb_irq>,<sb_dma>,<mpu_io>,<mpu_irq>
2104
Randy Dunlapa9913042005-10-23 12:57:11 -07002105 turbografx.map[2|3]= [HW,JOY]
2106 TurboGraFX parallel port interface
2107 Format:
2108 <port#>,<js1>,<js2>,<js3>,<js4>,<js5>,<js6>,<js7>
Linus Torvalds1da177e2005-04-16 15:20:36 -07002109 See also Documentation/input/joystick-parport.txt
2110
2111 u14-34f= [HW,SCSI] UltraStor 14F/34F SCSI host adapter
2112 See header of drivers/scsi/u14-34f.c.
2113
2114 uart401= [HW,OSS]
2115 Format: <io>,<irq>
2116
2117 uart6850= [HW,OSS]
2118 Format: <io>,<irq>
2119
Alan Stern5f8364b2006-12-05 16:29:55 -05002120 uhci-hcd.ignore_oc=
2121 [USB] Ignore overcurrent events (default N).
2122 Some badly-designed motherboards generate lots of
2123 bogus events, for ports that aren't wired to
2124 anything. Set this parameter to avoid log spamming.
2125 Note that genuine overcurrent events won't be
2126 reported either.
2127
Alan Sternb5e795f2007-02-20 15:00:53 -05002128 usbcore.autosuspend=
2129 [USB] The autosuspend time delay (in seconds) used
2130 for newly-detected USB devices (default 2). This
2131 is the time required before an idle device will be
2132 autosuspended. Devices for which the delay is set
Alan Sterneaafbc32007-03-13 16:39:15 -04002133 to a negative value won't be autosuspended at all.
Alan Sternb5e795f2007-02-20 15:00:53 -05002134
Linus Torvalds1da177e2005-04-16 15:20:36 -07002135 usbhid.mousepoll=
2136 [USBHID] The interval which mice are to be polled at.
Randy Dunlapa9913042005-10-23 12:57:11 -07002137
Alan Coxcd4f0ef2007-07-31 00:37:59 -07002138 vdso= [X86-32,SH,x86-64]
Jeremy Fitzhardinge1dbf5272007-05-02 19:27:12 +02002139 vdso=2: enable compat VDSO (default with COMPAT_VDSO)
Ingo Molnare6e54942006-06-27 02:53:50 -07002140 vdso=1: enable VDSO (default)
2141 vdso=0: disable VDSO mapping
2142
Roland McGrathaf65d642008-01-30 13:30:43 +01002143 vdso32= [X86-32,X86-64]
2144 vdso32=2: enable compat VDSO (default with COMPAT_VDSO)
2145 vdso32=1: enable 32-bit VDSO (default)
2146 vdso32=0: disable 32-bit VDSO mapping
2147
Yasuaki Ishimatsud080d392007-07-17 21:22:55 +09002148 vector= [IA-64,SMP]
2149 vector=percpu: enable percpu vector domain
2150
Linus Torvalds1da177e2005-04-16 15:20:36 -07002151 video= [FB] Frame buffer configuration
2152 See Documentation/fb/modedb.txt.
2153
Alan Coxcd4f0ef2007-07-31 00:37:59 -07002154 vga= [BOOT,X86-32] Select a particular video mode
Randy Dunlapa9913042005-10-23 12:57:11 -07002155 See Documentation/i386/boot.txt and
2156 Documentation/svga.txt.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002157 Use vga=ask for menu.
2158 This is actually a boot loader parameter; the value is
2159 passed to the kernel using a special protocol.
2160
Randy Dunlapa9913042005-10-23 12:57:11 -07002161 vmalloc=nn[KMG] [KNL,BOOT] Forces the vmalloc area to have an exact
Linus Torvalds1da177e2005-04-16 15:20:36 -07002162 size of <nn>. This can be used to increase the
2163 minimum size (128MB on x86). It can also be used to
2164 decrease the size and leave more room for directly
2165 mapped kernel RAM.
2166
Peter Oberparleiter585c3042006-06-29 15:08:25 +02002167 vmhalt= [KNL,S390] Perform z/VM CP command after system halt.
2168 Format: <command>
Linus Torvalds1da177e2005-04-16 15:20:36 -07002169
Peter Oberparleiter585c3042006-06-29 15:08:25 +02002170 vmpanic= [KNL,S390] Perform z/VM CP command after kernel panic.
2171 Format: <command>
2172
2173 vmpoff= [KNL,S390] Perform z/VM CP command after power off.
2174 Format: <command>
Randy Dunlapa9913042005-10-23 12:57:11 -07002175
Linus Torvalds1da177e2005-04-16 15:20:36 -07002176 waveartist= [HW,OSS]
2177 Format: <io>,<irq>,<dma>,<dma2>
Randy Dunlapa9913042005-10-23 12:57:11 -07002178
Linus Torvalds1da177e2005-04-16 15:20:36 -07002179 wd33c93= [HW,SCSI]
2180 See header of drivers/scsi/wd33c93.c.
2181
2182 wd7000= [HW,SCSI]
2183 See header of drivers/scsi/wd7000.c.
2184
2185 wdt= [WDT] Watchdog
Gabriel C8dfe9c22007-08-10 13:01:00 -07002186 See Documentation/watchdog/wdt.txt.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002187
2188 xd= [HW,XT] Original XT pre-IDE (RLL encoded) disks.
2189 xd_geo= See header of drivers/block/xd.c.
2190
2191 xirc2ps_cs= [NET,PCMCIA]
Randy Dunlapa9913042005-10-23 12:57:11 -07002192 Format:
2193 <irq>,<irq_mask>,<io>,<full_duplex>,<do_sound>,<lockup_hack>[,<irq2>[,<irq3>[,<irq4>]]]
Linus Torvalds1da177e2005-04-16 15:20:36 -07002194
Andi Kleena62eaf12006-02-16 23:41:58 +01002195 norandmaps Don't use address space randomization
2196 Equivalent to echo 0 > /proc/sys/kernel/randomize_va_space
2197
Randy Dunlapa9913042005-10-23 12:57:11 -07002198______________________________________________________________________
Linus Torvalds1da177e2005-04-16 15:20:36 -07002199
2200TODO:
2201
2202 Add documentation for ALSA options.
2203 Add more DRM drivers.