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Mauro Carvalho Chehabe53dd082007-09-15 07:38:47 -03001 Kernel Parameters
2 ~~~~~~~~~~~~~~~~~
Linus Torvalds1da177e2005-04-16 15:20:36 -07003
4The following is a consolidated list of the kernel parameters as implemented
5(mostly) by the __setup() macro and sorted into English Dictionary order
6(defined as ignoring all punctuation and sorting digits before letters in a
7case insensitive manner), and with descriptions where known.
8
9Module parameters for loadable modules are specified only as the
10parameter name with optional '=' and value as appropriate, such as:
11
12 modprobe usbcore blinkenlights=1
13
14Module parameters for modules that are built into the kernel image
15are specified on the kernel command line with the module name plus
16'.' plus parameter name, with '=' and value if appropriate, such as:
17
18 usbcore.blinkenlights=1
19
Stefan Richtera901ebb2006-04-01 01:43:18 +020020This document may not be entirely up to date and comprehensive. The command
21"modinfo -p ${modulename}" shows a current list of all parameters of a loadable
22module. Loadable modules, after being loaded into the running kernel, also
23reveal their parameters in /sys/module/${modulename}/parameters/. Some of these
24parameters may be changed at runtime by the command
25"echo -n ${value} > /sys/module/${modulename}/parameters/${parm}".
26
Stefan Richter6585fa82006-04-01 01:44:30 +020027The parameters listed below are only valid if certain kernel build options were
28enabled and if respective hardware is present. The text in square brackets at
29the beginning of each description states the restrictions within which a
30parameter is applicable:
Linus Torvalds1da177e2005-04-16 15:20:36 -070031
32 ACPI ACPI support is enabled.
Chuck Ebbertc99c1082007-07-27 10:46:20 +100033 AGP AGP (Accelerated Graphics Port) is enabled.
Linus Torvalds1da177e2005-04-16 15:20:36 -070034 ALSA ALSA sound support is enabled.
35 APIC APIC support is enabled.
36 APM Advanced Power Management support is enabled.
Haavard Skinnemoene7ba1762007-10-10 14:58:29 +020037 AVR32 AVR32 architecture is enabled.
Linus Torvalds1da177e2005-04-16 15:20:36 -070038 AX25 Appropriate AX.25 support is enabled.
Robin Getz0ae53642007-10-09 17:24:49 +080039 BLACKFIN Blackfin architecture is enabled.
Randy Dunlapa9913042005-10-23 12:57:11 -070040 DRM Direct Rendering Management support is enabled.
Linus Torvalds1da177e2005-04-16 15:20:36 -070041 EDD BIOS Enhanced Disk Drive Services (EDD) is enabled
42 EFI EFI Partitioning (GPT) is enabled
43 EIDE EIDE/ATAPI support is enabled.
44 FB The frame buffer device is enabled.
45 HW Appropriate hardware is enabled.
Linus Torvalds1da177e2005-04-16 15:20:36 -070046 IA-64 IA-64 architecture is enabled.
47 IOSCHED More than one I/O scheduler is enabled.
Adrian Bunk41e2e8b2005-07-12 13:58:33 -070048 IP_PNP IP DHCP, BOOTP, or RARP is enabled.
Linus Torvalds1da177e2005-04-16 15:20:36 -070049 ISAPNP ISA PnP code is enabled.
50 ISDN Appropriate ISDN support is enabled.
51 JOY Appropriate joystick support is enabled.
Kristen Carlson Accardi11ef6972006-09-28 11:29:01 -070052 LIBATA Libata driver is enabled
Linus Torvalds1da177e2005-04-16 15:20:36 -070053 LP Printer support is enabled.
54 LOOP Loopback device support is enabled.
55 M68k M68k architecture is enabled.
56 These options have more detailed description inside of
57 Documentation/m68k/kernel-options.txt.
58 MCA MCA bus support is enabled.
59 MDA MDA console support is enabled.
60 MOUSE Appropriate mouse support is enabled.
Matthew Wilcox309e57d2006-03-05 22:33:34 -070061 MSI Message Signaled Interrupts (PCI).
Randy Dunlapc8facbb2007-07-31 00:37:40 -070062 MTD MTD (Memory Technology Device) support is enabled.
Linus Torvalds1da177e2005-04-16 15:20:36 -070063 NET Appropriate network support is enabled.
64 NUMA NUMA support is enabled.
john stultz734efb42006-06-26 00:25:05 -070065 GENERIC_TIME The generic timeofday code is enabled.
Linus Torvalds1da177e2005-04-16 15:20:36 -070066 NFS Appropriate NFS support is enabled.
67 OSS OSS sound support is enabled.
Randy Dunlapc8facbb2007-07-31 00:37:40 -070068 PV_OPS A paravirtualized kernel is enabled.
69 PARIDE The ParIDE (parallel port IDE) subsystem is enabled.
Linus Torvalds1da177e2005-04-16 15:20:36 -070070 PARISC The PA-RISC architecture is enabled.
71 PCI PCI bus support is enabled.
Randy Dunlap7f785762007-10-05 13:17:58 -070072 PCIE PCI Express support is enabled.
Linus Torvalds1da177e2005-04-16 15:20:36 -070073 PCMCIA The PCMCIA subsystem is enabled.
74 PNP Plug & Play support is enabled.
75 PPC PowerPC architecture is enabled.
76 PPT Parallel port support is enabled.
77 PS2 Appropriate PS/2 support is enabled.
78 RAM RAM disk support is enabled.
James Morris20510f22007-10-16 23:31:32 -070079 ROOTPLUG The example Root Plug LSM is enabled.
Linus Torvalds1da177e2005-04-16 15:20:36 -070080 S390 S390 architecture is enabled.
81 SCSI Appropriate SCSI support is enabled.
82 A lot of drivers has their options described inside of
83 Documentation/scsi/.
James Morris20510f22007-10-16 23:31:32 -070084 SECURITY Different security models are enabled.
Linus Torvalds1da177e2005-04-16 15:20:36 -070085 SELINUX SELinux support is enabled.
86 SERIAL Serial support is enabled.
Paul Mundte523d932007-02-28 18:30:01 +090087 SH SuperH architecture is enabled.
Linus Torvalds1da177e2005-04-16 15:20:36 -070088 SMP The kernel is an SMP kernel.
89 SPARC Sparc architecture is enabled.
Randy Dunlapa9913042005-10-23 12:57:11 -070090 SWSUSP Software suspend is enabled.
Linus Torvalds1da177e2005-04-16 15:20:36 -070091 TS Appropriate touchscreen support is enabled.
92 USB USB support is enabled.
93 USBHID USB Human Interface Device support is enabled.
94 V4L Video For Linux support is enabled.
95 VGA The VGA console has been enabled.
96 VT Virtual terminal support is enabled.
97 WDT Watchdog support is enabled.
98 XT IBM PC/XT MFM hard disk support is enabled.
Alan Coxcd4f0ef2007-07-31 00:37:59 -070099 X86-32 X86-32, aka i386 architecture is enabled.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700100 X86-64 X86-64 architecture is enabled.
101 More X86-64 boot options can be found in
102 Documentation/x86_64/boot-options.txt .
103
104In addition, the following text indicates that the option:
105
106 BUGS= Relates to possible processor bugs on the said processor.
107 KNL Is a kernel start-up parameter.
108 BOOT Is a boot loader parameter.
109
110Parameters denoted with BOOT are actually interpreted by the boot
111loader, and have no meaning to the kernel directly.
112Do not modify the syntax of boot loader parameters without extreme
113need or coordination with <Documentation/i386/boot.txt>.
114
Karsten Weiss55588702007-02-13 13:26:21 +0100115There are also arch-specific kernel-parameters not documented here.
116See for example <Documentation/x86_64/boot-options.txt>.
117
Linus Torvalds1da177e2005-04-16 15:20:36 -0700118Note that ALL kernel parameters listed below are CASE SENSITIVE, and that
119a trailing = on the name of any parameter states that that parameter will
120be entered as an environment variable, whereas its absence indicates that
121it will appear as a kernel argument readable via /proc/cmdline by programs
122running once the system is up.
123
jens m. noedler9c4751f2006-09-29 02:00:27 -0700124The number of kernel parameters is not limited, but the length of the
125complete command line (parameters including spaces etc.) is limited to
126a fixed number of characters. This limit depends on the architecture
127and is between 256 and 4096 characters. It is defined in the file
128./include/asm/setup.h as COMMAND_LINE_SIZE.
129
130
Bernhard Walle03d926f2007-03-06 02:29:44 -0800131 acpi= [HW,ACPI,X86-64,i386]
132 Advanced Configuration and Power Interface
Randy Dunlapa9913042005-10-23 12:57:11 -0700133 Format: { force | off | ht | strict | noirq }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700134 force -- enable ACPI if default was off
135 off -- disable ACPI if default was on
136 noirq -- do not use ACPI for IRQ routing
137 ht -- run only enough ACPI to enable Hyper Threading
Randy Dunlapa9913042005-10-23 12:57:11 -0700138 strict -- Be less tolerant of platforms that are not
Linus Torvalds1da177e2005-04-16 15:20:36 -0700139 strictly ACPI specification compliant.
140
Randy Dunlap53471122008-03-12 18:10:51 -0400141 See also Documentation/power/pm.txt, pci=noacpi
Linus Torvalds1da177e2005-04-16 15:20:36 -0700142
Len Browna1fdcc02007-03-11 03:26:14 -0400143 acpi_apic_instance= [ACPI, IOAPIC]
144 Format: <int>
145 2: use 2nd APIC table, if available
146 1,0: use 1st APIC table
Len Brown4e381a42007-03-30 14:16:10 -0400147 default: 0
Len Browna1fdcc02007-03-11 03:26:14 -0400148
Linus Torvalds1da177e2005-04-16 15:20:36 -0700149 acpi_sleep= [HW,ACPI] Sleep options
Pavel Machek23b168d2008-02-05 19:27:12 +0100150 Format: { s3_bios, s3_mode, s3_beep }
151 See Documentation/power/video.txt for s3_bios and s3_mode.
152 s3_beep is for debugging; it makes the PC's speaker beep
153 as soon as the kernel's real-mode entry point is called.
Randy Dunlapa9913042005-10-23 12:57:11 -0700154
Linus Torvalds1da177e2005-04-16 15:20:36 -0700155 acpi_sci= [HW,ACPI] ACPI System Control Interrupt trigger mode
Randy Dunlapa9913042005-10-23 12:57:11 -0700156 Format: { level | edge | high | low }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700157
Randy Dunlapa9913042005-10-23 12:57:11 -0700158 acpi_irq_balance [HW,ACPI]
159 ACPI will balance active IRQs
160 default in APIC mode
Linus Torvalds1da177e2005-04-16 15:20:36 -0700161
Randy Dunlapa9913042005-10-23 12:57:11 -0700162 acpi_irq_nobalance [HW,ACPI]
163 ACPI will not move active IRQs (default)
164 default in PIC mode
Linus Torvalds1da177e2005-04-16 15:20:36 -0700165
Randy Dunlapa9913042005-10-23 12:57:11 -0700166 acpi_irq_pci= [HW,ACPI] If irq_balance, clear listed IRQs for
167 use by PCI
Linus Torvalds1da177e2005-04-16 15:20:36 -0700168 Format: <irq>,<irq>...
169
Randy Dunlapa9913042005-10-23 12:57:11 -0700170 acpi_irq_isa= [HW,ACPI] If irq_balance, mark listed IRQs used by ISA
Linus Torvalds1da177e2005-04-16 15:20:36 -0700171 Format: <irq>,<irq>...
172
Len Brown67effe82007-07-26 00:50:06 -0400173 acpi_no_auto_ssdt [HW,ACPI] Disable automatic loading of SSDT
174
Len Browna1f9e652006-01-25 23:47:36 -0500175 acpi_os_name= [HW,ACPI] Tell ACPI BIOS the name of the OS
176 Format: To spoof as Windows 98: ="Microsoft Windows"
177
Len Brownae00d812007-05-29 18:43:33 -0400178 acpi_osi= [HW,ACPI] Modify list of supported OS interface strings
179 acpi_osi="string1" # add string1 -- only one string
180 acpi_osi="!string2" # remove built-in string2
181 acpi_osi= # disable all strings
Linus Torvalds1da177e2005-04-16 15:20:36 -0700182
183 acpi_serialize [HW,ACPI] force serialization of AML methods
184
185 acpi_skip_timer_override [HW,ACPI]
186 Recognize and ignore IRQ0/pin2 Interrupt Override.
187 For broken nForce2 BIOS resulting in XT-PIC timer.
Andi Kleenfa18f472006-11-14 16:57:46 +0100188 acpi_use_timer_override [HW,ACPI}
189 Use timer override. For some broken Nvidia NF5 boards
190 that require a timer override, but don't have
191 HPET
Linus Torvalds1da177e2005-04-16 15:20:36 -0700192
Zhang Ruif9891062007-04-24 13:53:22 +0800193 acpi.debug_layer= [HW,ACPI]
Linus Torvalds1da177e2005-04-16 15:20:36 -0700194 Format: <int>
Randy Dunlapa9913042005-10-23 12:57:11 -0700195 Each bit of the <int> indicates an ACPI debug layer,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700196 1: enable, 0: disable. It is useful for boot time
197 debugging. After system has booted up, it can be set
Zhang Ruif9891062007-04-24 13:53:22 +0800198 via /sys/module/acpi/parameters/debug_layer.
199 CONFIG_ACPI_DEBUG must be enabled for this to produce any output.
200 Available bits (add the numbers together) to enable debug output
201 for specific parts of the ACPI subsystem:
202 0x01 utilities 0x02 hardware 0x04 events 0x08 tables
203 0x10 namespace 0x20 parser 0x40 dispatcher
204 0x80 executer 0x100 resources 0x200 acpica debugger
205 0x400 os services 0x800 acpica disassembler.
206 The number can be in decimal or prefixed with 0x in hex.
207 Warning: Many of these options can produce a lot of
208 output and make your system unusable. Be very careful.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700209
Zhang Ruif9891062007-04-24 13:53:22 +0800210 acpi.debug_level= [HW,ACPI]
Linus Torvalds1da177e2005-04-16 15:20:36 -0700211 Format: <int>
Randy Dunlapa9913042005-10-23 12:57:11 -0700212 Each bit of the <int> indicates an ACPI debug level,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700213 1: enable, 0: disable. It is useful for boot time
214 debugging. After system has booted up, it can be set
Zhang Ruif9891062007-04-24 13:53:22 +0800215 via /sys/module/acpi/parameters/debug_level.
216 CONFIG_ACPI_DEBUG must be enabled for this to produce any output.
217 Available bits (add the numbers together) to enable different
218 debug output levels of the ACPI subsystem:
219 0x01 error 0x02 warn 0x04 init 0x08 debug object
220 0x10 info 0x20 init names 0x40 parse 0x80 load
221 0x100 dispatch 0x200 execute 0x400 names 0x800 operation region
222 0x1000 bfield 0x2000 tables 0x4000 values 0x8000 objects
223 0x10000 resources 0x20000 user requests 0x40000 package.
224 The number can be in decimal or prefixed with 0x in hex.
225 Warning: Many of these options can produce a lot of
226 output and make your system unusable. Be very careful.
227
Alan Coxcd4f0ef2007-07-31 00:37:59 -0700228 acpi_pm_good [X86-32,X86-64]
john stultz5d0cf412006-06-26 00:25:12 -0700229 Override the pmtimer bug detection: force the kernel
230 to assume that this machine's pmtimer latches its value
231 and always returns good values.
232
Chuck Ebbertc99c1082007-07-27 10:46:20 +1000233 agp= [AGP]
234 { off | try_unsupported }
235 off: disable AGP support
236 try_unsupported: try to drive unsupported chipsets
237 (may crash computer or cause data corruption)
238
Chuck Ebbert66759a02005-09-12 18:49:25 +0200239 enable_timer_pin_1 [i386,x86-64]
240 Enable PIN 1 of APIC timer
Randy Dunlapa9913042005-10-23 12:57:11 -0700241 Can be useful to work around chipset bugs
242 (in particular on some ATI chipsets).
Chuck Ebbert66759a02005-09-12 18:49:25 +0200243 The kernel tries to set a reasonable default.
244
245 disable_timer_pin_1 [i386,x86-64]
246 Disable PIN 1 of APIC timer
247 Can be useful to work around chipset bugs.
248
Linus Torvalds1da177e2005-04-16 15:20:36 -0700249 ad1848= [HW,OSS]
250 Format: <io>,<irq>,<dma>,<dma2>,<type>
251
Linus Torvalds1da177e2005-04-16 15:20:36 -0700252 advansys= [HW,SCSI]
253 See header of drivers/scsi/advansys.c.
254
255 advwdt= [HW,WDT] Advantech WDT
256 Format: <iostart>,<iostop>
257
258 aedsp16= [HW,OSS] Audio Excel DSP 16
259 Format: <io>,<irq>,<dma>,<mss_io>,<mpu_io>,<mpu_irq>
260 See also header of sound/oss/aedsp16.c.
Randy Dunlapa9913042005-10-23 12:57:11 -0700261
Linus Torvalds1da177e2005-04-16 15:20:36 -0700262 aha152x= [HW,SCSI]
263 See Documentation/scsi/aha152x.txt.
264
265 aha1542= [HW,SCSI]
266 Format: <portbase>[,<buson>,<busoff>[,<dmaspeed>]]
267
268 aic7xxx= [HW,SCSI]
269 See Documentation/scsi/aic7xxx.txt.
270
271 aic79xx= [HW,SCSI]
272 See Documentation/scsi/aic79xx.txt.
273
Linus Torvalds1da177e2005-04-16 15:20:36 -0700274 amijoy.map= [HW,JOY] Amiga joystick support
275 Map of devices attached to JOY0DAT and JOY1DAT
276 Format: <a>,<b>
277 See also Documentation/kernel/input/joystick.txt
278
279 analog.map= [HW,JOY] Analog joystick and gamepad support
280 Specifies type or capabilities of an analog joystick
281 connected to one of 16 gameports
282 Format: <type1>,<type2>,..<type16>
283
Randy Dunlapa9913042005-10-23 12:57:11 -0700284 apc= [HW,SPARC]
285 Power management functions (SPARCstation-4/5 + deriv.)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700286 Format: noidle
287 Disable APC CPU standby support. SPARCstation-Fox does
288 not play well with APC CPU idle - disable it if you have
289 APC and your system crashes randomly.
290
Randy Dunlapc8facbb2007-07-31 00:37:40 -0700291 apic= [APIC,i386] Advanced Programmable Interrupt Controller
292 Change the output verbosity whilst booting
Linus Torvalds1da177e2005-04-16 15:20:36 -0700293 Format: { quiet (default) | verbose | debug }
294 Change the amount of debugging information output
295 when initialising the APIC and IO-APIC components.
Randy Dunlapa9913042005-10-23 12:57:11 -0700296
Linus Torvalds1da177e2005-04-16 15:20:36 -0700297 apm= [APM] Advanced Power Management
298 See header of arch/i386/kernel/apm.c.
299
Linus Torvalds1da177e2005-04-16 15:20:36 -0700300 arcrimi= [HW,NET] ARCnet - "RIM I" (entirely mem-mapped) cards
301 Format: <io>,<irq>,<nodeID>
302
303 ataflop= [HW,M68k]
304
305 atarimouse= [HW,MOUSE] Atari Mouse
306
307 atascsi= [HW,SCSI] Atari SCSI
308
309 atkbd.extra= [HW] Enable extra LEDs and keys on IBM RapidAccess,
310 EzKey and similar keyboards
311
312 atkbd.reset= [HW] Reset keyboard during initialization
313
Randy Dunlapa9913042005-10-23 12:57:11 -0700314 atkbd.set= [HW] Select keyboard code set
315 Format: <int> (2 = AT (default), 3 = PS/2)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700316
317 atkbd.scroll= [HW] Enable scroll wheel on MS Office and similar
318 keyboards
319
320 atkbd.softraw= [HW] Choose between synthetic and real raw mode
321 Format: <bool> (0 = real, 1 = synthetic (default))
Randy Dunlapa9913042005-10-23 12:57:11 -0700322
323 atkbd.softrepeat= [HW]
324 Use software keyboard repeat
Linus Torvalds1da177e2005-04-16 15:20:36 -0700325
326 autotest [IA64]
327
Linus Torvalds1da177e2005-04-16 15:20:36 -0700328 baycom_epp= [HW,AX25]
329 Format: <io>,<mode>
Randy Dunlapa9913042005-10-23 12:57:11 -0700330
Linus Torvalds1da177e2005-04-16 15:20:36 -0700331 baycom_par= [HW,AX25] BayCom Parallel Port AX.25 Modem
332 Format: <io>,<mode>
333 See header of drivers/net/hamradio/baycom_par.c.
334
Randy Dunlapa9913042005-10-23 12:57:11 -0700335 baycom_ser_fdx= [HW,AX25]
336 BayCom Serial Port AX.25 Modem (Full Duplex Mode)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700337 Format: <io>,<irq>,<mode>[,<baud>]
338 See header of drivers/net/hamradio/baycom_ser_fdx.c.
339
Randy Dunlapa9913042005-10-23 12:57:11 -0700340 baycom_ser_hdx= [HW,AX25]
341 BayCom Serial Port AX.25 Modem (Half Duplex Mode)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700342 Format: <io>,<irq>,<mode>
343 See header of drivers/net/hamradio/baycom_ser_hdx.c.
344
Randy Dunlapbfe8df32007-10-16 01:23:46 -0700345 boot_delay= Milliseconds to delay each printk during boot.
346 Values larger than 10 seconds (10000) are changed to
347 no delay (0).
348 Format: integer
349
Linus Torvalds1da177e2005-04-16 15:20:36 -0700350 bttv.card= [HW,V4L] bttv (bt848 + bt878 based grabber cards)
Randy Dunlapa9913042005-10-23 12:57:11 -0700351 bttv.radio= Most important insmod options are available as
352 kernel args too.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700353 bttv.pll= See Documentation/video4linux/bttv/Insmod-options
354 bttv.tuner= and Documentation/video4linux/bttv/CARDLIST
355
356 BusLogic= [HW,SCSI]
357 See drivers/scsi/BusLogic.c, comment before function
358 BusLogic_ParseDriverOptions().
359
360 c101= [NET] Moxa C101 synchronous serial card
361
Alan Coxcd4f0ef2007-07-31 00:37:59 -0700362 cachesize= [BUGS=X86-32] Override level 2 CPU cache size detection.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700363 Sometimes CPU hardware bugs make them report the cache
364 size incorrectly. The kernel will attempt work arounds
365 to fix known problems, but for some CPUs it is not
366 possible to determine what the correct size should be.
367 This option provides an override for these situations.
368
Ahmed S. Darwish076c54c2008-03-06 18:09:10 +0200369 security= [SECURITY] Choose a security module to enable at boot.
370 If this boot parameter is not specified, only the first
371 security module asking for security registration will be
372 loaded. An invalid security module name will be treated
373 as if no module has been chosen.
374
James Morris20510f22007-10-16 23:31:32 -0700375 capability.disable=
376 [SECURITY] Disable capabilities. This would normally
377 be used only if an alternative security model is to be
378 configured. Potentially dangerous and should only be
379 used if you are entirely sure of the consequences.
380
Sebastian Ott14ff56b2008-01-26 14:10:37 +0100381 ccw_timeout_log [S390]
382 See Documentation/s390/CommonIO for details.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700383
Paul Menage8bab8dd2008-04-04 14:29:57 -0700384 cgroup_disable= [KNL] Disable a particular controller
385 Format: {name of the controller(s) to disable}
386 {Currently supported controllers - "memory"}
387
Linus Torvalds1da177e2005-04-16 15:20:36 -0700388 checkreqprot [SELINUX] Set initial checkreqprot flag value.
389 Format: { "0" | "1" }
390 See security/selinux/Kconfig help text.
Randy Dunlapa9913042005-10-23 12:57:11 -0700391 0 -- check protection applied by kernel (includes
392 any implied execute protection).
Linus Torvalds1da177e2005-04-16 15:20:36 -0700393 1 -- check protection requested by application.
394 Default value is set via a kernel config option.
Randy Dunlapa9913042005-10-23 12:57:11 -0700395 Value can be changed at runtime via
396 /selinux/checkreqprot.
397
Sebastian Ott661ca0d2008-01-26 14:10:36 +0100398 cio_ignore= [S390]
399 See Documentation/s390/CommonIO for details.
400
401 cio_msg= [S390]
402 See Documentation/s390/CommonIO for details.
403
Alan Coxcd4f0ef2007-07-31 00:37:59 -0700404 clock= [BUGS=X86-32, HW] gettimeofday clocksource override.
john stultz734efb42006-06-26 00:25:05 -0700405 [Deprecated]
Matt LaPlante3f6dee92006-10-03 22:45:33 +0200406 Forces specified clocksource (if available) to be used
john stultz734efb42006-06-26 00:25:05 -0700407 when calculating gettimeofday(). If specified
Matt LaPlante3f6dee92006-10-03 22:45:33 +0200408 clocksource is not available, it defaults to PIT.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700409 Format: { pit | tsc | cyclone | pmtmr }
410
Randy Dunlap3d6ac982007-05-23 13:58:16 -0700411 clocksource= [GENERIC_TIME] Override the default clocksource
412 Format: <string>
413 Override the default clocksource and use the clocksource
414 with the name specified.
415 Some clocksource names to choose from, depending on
416 the platform:
417 [all] jiffies (this is the base, fallback clocksource)
418 [ACPI] acpi_pm
419 [ARM] imx_timer1,OSTS,netx_timer,mpu_timer2,
420 pxa_timer,timer3,32k_counter,timer0_1
421 [AVR32] avr32
Alan Coxcd4f0ef2007-07-31 00:37:59 -0700422 [X86-32] pit,hpet,tsc,vmi-timer;
Randy Dunlap3d6ac982007-05-23 13:58:16 -0700423 scx200_hrt on Geode; cyclone on IBM x440
424 [MIPS] MIPS
425 [PARISC] cr16
426 [S390] tod
427 [SH] SuperH
428 [SPARC64] tick
429 [X86-64] hpet,tsc
430
Andi Kleenac72e782008-01-30 13:33:21 +0100431 clearcpuid=BITNUM [X86]
432 Disable CPUID feature X for the kernel. See
433 include/asm-x86/cpufeature.h for the valid bit numbers.
434 Note the Linux specific bits are not necessarily
435 stable over kernel options, but the vendor specific
436 ones should be.
437 Also note that user programs calling CPUID directly
438 or using the feature without checking anything
439 will still see it. This just prevents it from
440 being used by the kernel or shown in /proc/cpuinfo.
441 Also note the kernel might malfunction if you disable
442 some critical bits.
443
Arjan van de Vena25bd942008-01-30 13:33:08 +0100444 code_bytes [IA32/X86_64] How many bytes of object code to print
445 in an oops report.
Chuck Ebbert86c41832007-02-13 13:26:25 +0100446 Range: 0 - 8192
447 Default: 64
448
Andi Kleenf9262c12006-03-08 17:57:25 -0800449 disable_8254_timer
450 enable_8254_timer
451 [IA32/X86_64] Disable/Enable interrupt 0 timer routing
452 over the 8254 in addition to over the IO-APIC. The
453 kernel tries to set a sensible default.
454
Thomas Gleixnerb17530b2007-10-19 20:35:02 +0200455 hpet= [X86-32,HPET] option to control HPET usage
456 Format: { enable (default) | disable | force }
457 disable: disable HPET and use PIT instead
Carlos Corbachod79a5f82007-10-19 18:51:27 +0100458 force: allow force enabled of undocumented chips (ICH4,
459 VIA, nVidia)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700460
Linus Torvalds1da177e2005-04-16 15:20:36 -0700461 com20020= [HW,NET] ARCnet - COM20020 chipset
Randy Dunlapa9913042005-10-23 12:57:11 -0700462 Format:
463 <io>[,<irq>[,<nodeID>[,<backplane>[,<ckp>[,<timeout>]]]]]
Linus Torvalds1da177e2005-04-16 15:20:36 -0700464
465 com90io= [HW,NET] ARCnet - COM90xx chipset (IO-mapped buffers)
466 Format: <io>[,<irq>]
467
Randy Dunlapa9913042005-10-23 12:57:11 -0700468 com90xx= [HW,NET]
469 ARCnet - COM90xx chipset (memory-mapped buffers)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700470 Format: <io>[,<irq>[,<memstart>]]
471
472 condev= [HW,S390] console device
473 conmode=
Randy Dunlapa9913042005-10-23 12:57:11 -0700474
Linus Torvalds1da177e2005-04-16 15:20:36 -0700475 console= [KNL] Output console device and options.
476
477 tty<n> Use the virtual console device <n>.
478
479 ttyS<n>[,options]
Randy Dunlapf1a1c2d2006-03-25 03:08:17 -0800480 ttyUSB0[,options]
Linus Torvalds1da177e2005-04-16 15:20:36 -0700481 Use the specified serial port. The options are of
Randy Dunlapf1a1c2d2006-03-25 03:08:17 -0800482 the form "bbbbpnf", where "bbbb" is the baud rate,
483 "p" is parity ("n", "o", or "e"), "n" is number of
484 bits, and "f" is flow control ("r" for RTS or
485 omit it). Default is "9600n8".
Linus Torvalds1da177e2005-04-16 15:20:36 -0700486
Randy Dunlapf1a1c2d2006-03-25 03:08:17 -0800487 See Documentation/serial-console.txt for more
488 information. See
489 Documentation/networking/netconsole.txt for an
490 alternative.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700491
Yinghai Lu18a8bd92007-07-15 23:37:59 -0700492 uart[8250],io,<addr>[,options]
493 uart[8250],mmio,<addr>[,options]
Linus Torvalds1da177e2005-04-16 15:20:36 -0700494 Start an early, polled-mode console on the 8250/16550
495 UART at the specified I/O port or MMIO address,
496 switching to the matching ttyS device later. The
497 options are the same as for ttyS, above.
498
Samuel Thibaultf7511d52008-04-30 00:54:51 -0700499 If the device connected to the port is not a TTY but a braille
500 device, prepend "brl," before the device type, for instance
501 console=brl,ttyS0
502 For now, only VisioBraille is supported.
503
Yinghai Lu18a8bd92007-07-15 23:37:59 -0700504 earlycon= [KNL] Output early console device and options.
505 uart[8250],io,<addr>[,options]
506 uart[8250],mmio,<addr>[,options]
507 Start an early, polled-mode console on the 8250/16550
508 UART at the specified I/O port or MMIO address.
509 The options are the same as for ttyS, above.
510
Andres Salomon8f4ce8c2007-10-18 03:04:50 -0700511 no_console_suspend
512 [HW] Never suspend the console
513 Disable suspending of consoles during suspend and
514 hibernate operations. Once disabled, debugging
515 messages can reach various consoles while the rest
516 of the system is being put to sleep (ie, while
517 debugging driver suspend/resume hooks). This may
518 not work reliably with all consoles, but is known
519 to work with serial and VGA consoles.
520
Linus Torvalds1da177e2005-04-16 15:20:36 -0700521 cpcihp_generic= [HW,PCI] Generic port I/O CompactPCI driver
Randy Dunlapa9913042005-10-23 12:57:11 -0700522 Format:
523 <first_slot>,<last_slot>,<port>,<enum_bit>[,<debug>]
Linus Torvalds1da177e2005-04-16 15:20:36 -0700524
Eric W. Biedermandc009d92005-06-25 14:57:52 -0700525 crashkernel=nn[KMG]@ss[KMG]
526 [KNL] Reserve a chunk of physical memory to
527 hold a kernel to switch to with kexec on panic.
528
Bernhard Wallefb391592007-10-18 23:41:02 -0700529 crashkernel=range1:size1[,range2:size2,...][@offset]
530 [KNL] Same as above, but depends on the memory
531 in the running system. The syntax of range is
532 start-[end] where start and end are both
533 a memory unit (amount[KMG]). See also
534 Documentation/kdump/kdump.txt for a example.
535
Linus Torvalds1da177e2005-04-16 15:20:36 -0700536 cs4232= [HW,OSS]
537 Format: <io>,<irq>,<dma>,<dma2>,<mpuio>,<mpuirq>
538
539 cs89x0_dma= [HW,NET]
540 Format: <dma>
541
542 cs89x0_media= [HW,NET]
543 Format: { rj45 | aui | bnc }
Randy Dunlapa9913042005-10-23 12:57:11 -0700544
Randy Dunlapa9913042005-10-23 12:57:11 -0700545 dasd= [HW,NET]
Linus Torvalds1da177e2005-04-16 15:20:36 -0700546 See header of drivers/s390/block/dasd_devmap.c.
547
548 db9.dev[2|3]= [HW,JOY] Multisystem joystick support via parallel port
549 (one device per port)
550 Format: <port#>,<type>
551 See also Documentation/input/joystick-parport.txt
552
553 debug [KNL] Enable kernel debugging (events log level).
554
Ingo Molnarcae2ed92006-07-03 00:24:48 -0700555 debug_locks_verbose=
556 [KNL] verbose self-tests
557 Format=<0|1>
558 Print debugging info while doing the locking API
559 self-tests.
560 We default to 0 (no extra messages), setting it to
561 1 will print _a lot_ more information - normally
562 only useful to kernel developers.
563
Robert P. J. Day2d27a962008-02-03 15:18:45 +0200564 decnet.addr= [HW,NET]
Linus Torvalds1da177e2005-04-16 15:20:36 -0700565 Format: <area>[,<node>]
566 See also Documentation/networking/decnet.txt.
567
Samuel Thibaultecb77fa2008-01-03 16:17:54 +0000568 vt.default_blu= [VT]
Antonino A. Daplas55ff9782007-05-08 00:38:53 -0700569 Format: <blue0>,<blue1>,<blue2>,...,<blue15>
570 Change the default blue palette of the console.
571 This is a 16-member array composed of values
572 ranging from 0-255.
573
Samuel Thibaultecb77fa2008-01-03 16:17:54 +0000574 vt.default_grn= [VT]
Antonino A. Daplas55ff9782007-05-08 00:38:53 -0700575 Format: <green0>,<green1>,<green2>,...,<green15>
576 Change the default green palette of the console.
577 This is a 16-member array composed of values
578 ranging from 0-255.
579
Samuel Thibaultecb77fa2008-01-03 16:17:54 +0000580 vt.default_red= [VT]
Antonino A. Daplas55ff9782007-05-08 00:38:53 -0700581 Format: <red0>,<red1>,<red2>,...,<red15>
582 Change the default red palette of the console.
583 This is a 16-member array composed of values
584 ranging from 0-255.
585
Samuel Thibaultecb77fa2008-01-03 16:17:54 +0000586 vt.default_utf8=
587 [VT]
Antonino A. Daplas55ff9782007-05-08 00:38:53 -0700588 Format=<0|1>
589 Set system-wide default UTF-8 mode for all tty's.
Samuel Thibaultecb77fa2008-01-03 16:17:54 +0000590 Default is 1, i.e. UTF-8 mode is enabled for all
591 newly opened terminals.
Antonino A. Daplas55ff9782007-05-08 00:38:53 -0700592
Linus Torvalds1da177e2005-04-16 15:20:36 -0700593 dhash_entries= [KNL]
594 Set number of hash buckets for dentry cache.
Randy Dunlapa9913042005-10-23 12:57:11 -0700595
Linus Torvalds1da177e2005-04-16 15:20:36 -0700596 digi= [HW,SERIAL]
597 IO parameters + enable/disable command.
598
599 digiepca= [HW,SERIAL]
600 See drivers/char/README.epca and
601 Documentation/digiepca.txt.
602
Yinghai Lu093af8d2008-01-30 13:33:32 +0100603 disable_mtrr_trim [X86, Intel and AMD only]
Jesse Barnes99fc8d42008-01-30 13:33:18 +0100604 By default the kernel will trim any uncacheable
605 memory out of your available memory pool based on
606 MTRR settings. This parameter disables that behavior,
607 possibly causing your machine to run very slowly.
608
Linus Torvalds1da177e2005-04-16 15:20:36 -0700609 dmasound= [HW,OSS] Sound subsystem buffers
610
611 dscc4.setup= [NET]
612
613 dtc3181e= [HW,SCSI]
614
Robin Getz0ae53642007-10-09 17:24:49 +0800615 earlyprintk= [X86-32,X86-64,SH,BLACKFIN]
Linus Torvalds1da177e2005-04-16 15:20:36 -0700616 earlyprintk=vga
617 earlyprintk=serial[,ttySn[,baudrate]]
618
Randy Dunlapa9913042005-10-23 12:57:11 -0700619 Append ",keep" to not disable it when the real console
Linus Torvalds1da177e2005-04-16 15:20:36 -0700620 takes over.
621
622 Only vga or serial at a time, not both.
623
624 Currently only ttyS0 and ttyS1 are supported.
625
626 Interaction with the standard serial driver is not
627 very good.
628
629 The VGA output is eventually overwritten by the real
630 console.
631
632 eata= [HW,SCSI]
633
Linus Torvalds1da177e2005-04-16 15:20:36 -0700634 edd= [EDD]
Tim Gardner8c4dd602008-04-29 01:02:45 -0700635 Format: {"off" | "on" | "skip[mbr]"}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700636
Linus Torvalds1da177e2005-04-16 15:20:36 -0700637 eisa_irq_edge= [PARISC,HW]
638 See header of drivers/parisc/eisa.c.
639
Alan Coxcd4f0ef2007-07-31 00:37:59 -0700640 elanfreq= [X86-32]
Linus Torvalds1da177e2005-04-16 15:20:36 -0700641 See comment before function elanfreq_setup() in
642 arch/i386/kernel/cpu/cpufreq/elanfreq.c.
643
644 elevator= [IOSCHED]
Randy Dunlap16ab3ad2006-01-14 13:21:20 -0800645 Format: {"anticipatory" | "cfq" | "deadline" | "noop"}
Randy Dunlapa9913042005-10-23 12:57:11 -0700646 See Documentation/block/as-iosched.txt and
647 Documentation/block/deadline-iosched.txt for details.
648
Alan Coxcd4f0ef2007-07-31 00:37:59 -0700649 elfcorehdr= [X86-32, X86_64]
Randy Dunlapa9913042005-10-23 12:57:11 -0700650 Specifies physical address of start of kernel core
Vivek Goyalaac04b32006-01-09 20:51:47 -0800651 image elf header. Generally kexec loader will
652 pass this option to capture kernel.
653 See Documentation/kdump/kdump.txt for details.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700654
655 enforcing [SELINUX] Set initial enforcing status.
656 Format: {"0" | "1"}
657 See security/selinux/Kconfig help text.
658 0 -- permissive (log only, no denials).
659 1 -- enforcing (deny and log).
660 Default value is 0.
661 Value can be changed at runtime via /selinux/enforce.
662
Linus Torvalds1da177e2005-04-16 15:20:36 -0700663 es1371= [HW,OSS]
664 Format: <spdif>,[<nomix>,[<amplifier>]]
665 See also header of sound/oss/es1371.c.
Randy Dunlapa9913042005-10-23 12:57:11 -0700666
Linus Torvalds1da177e2005-04-16 15:20:36 -0700667 ether= [HW,NET] Ethernet cards parameters
668 This option is obsoleted by the "netdev=" option, which
669 has equivalent usage. See its documentation for details.
670
671 eurwdt= [HW,WDT] Eurotech CPU-1220/1410 onboard watchdog.
672 Format: <io>[,<irq>]
673
Akinobu Mitade1ba092006-12-08 02:39:42 -0800674 failslab=
675 fail_page_alloc=
676 fail_make_request=[KNL]
677 General fault injection mechanism.
678 Format: <interval>,<probability>,<space>,<times>
679 See also /Documentation/fault-injection/.
680
Linus Torvalds1da177e2005-04-16 15:20:36 -0700681 fd_mcs= [HW,SCSI]
682 See header of drivers/scsi/fd_mcs.c.
683
684 fdomain= [HW,SCSI]
685 See header of drivers/scsi/fdomain.c.
686
687 floppy= [HW]
688 See Documentation/floppy.txt.
689
Linus Torvalds1da177e2005-04-16 15:20:36 -0700690 gamecon.map[2|3]=
691 [HW,JOY] Multisystem joystick and NES/SNES/PSX pad
692 support via parallel port (up to 5 devices per port)
693 Format: <port#>,<pad1>,<pad2>,<pad3>,<pad4>,<pad5>
694 See also Documentation/input/joystick-parport.txt
695
696 gamma= [HW,DRM]
697
Yinghai Luaaf23042008-01-30 13:33:09 +0100698 gart_fix_e820= [X86_64] disable the fix e820 for K8 GART
699 Format: off | on
700 default: on
701
Linus Torvalds1da177e2005-04-16 15:20:36 -0700702 gdth= [HW,SCSI]
703 See header of drivers/scsi/gdth.c.
704
705 gpt [EFI] Forces disk with valid GPT signature but
706 invalid Protective MBR to be treated as GPT.
707
Linus Torvalds1da177e2005-04-16 15:20:36 -0700708 gvp11= [HW,SCSI]
709
710 hashdist= [KNL,NUMA] Large hashes allocated during boot
711 are distributed across NUMA nodes. Defaults on
712 for IA-64, off otherwise.
Randy Dunlapa9913042005-10-23 12:57:11 -0700713 Format: 0 | 1 (for off | on)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700714
715 hcl= [IA-64] SGI's Hardware Graph compatibility layer
716
717 hd= [EIDE] (E)IDE hard drive subsystem geometry
718 Format: <cyl>,<head>,<sect>
719
720 hd?= [HW] (E)IDE subsystem
Randy Dunlap1c10e932008-03-07 21:53:50 +0100721 hd?lun= See Documentation/ide/ide.txt.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700722
723 highmem=nn[KMG] [KNL,BOOT] forces the highmem zone to have an exact
724 size of <nn>. This works even on boxes that have no
725 highmem otherwise. This also works to reduce highmem
726 size on bigger boxes.
727
Thomas Gleixner54cdfdb2007-02-16 01:28:11 -0800728 highres= [KNL] Enable/disable high resolution timer mode.
729 Valid parameters: "on", "off"
730 Default: "on"
731
Linus Torvalds1da177e2005-04-16 15:20:36 -0700732 hisax= [HW,ISDN]
733 See Documentation/isdn/README.HiSax.
734
Alan Coxcd4f0ef2007-07-31 00:37:59 -0700735 hugepages= [HW,X86-32,IA-64] Maximal number of HugeTLB pages.
Jon Tollefson4ec161c2008-01-04 09:59:50 +1100736 hugepagesz= [HW,IA-64,PPC] The size of the HugeTLB pages.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700737
Linus Torvalds1da177e2005-04-16 15:20:36 -0700738 i8042.direct [HW] Put keyboard port into non-translated mode
Matt LaPlante84eb8d02006-10-03 22:53:09 +0200739 i8042.dumbkbd [HW] Pretend that controller can only read data from
740 keyboard and cannot control its state
Linus Torvalds1da177e2005-04-16 15:20:36 -0700741 (Don't attempt to blink the leds)
742 i8042.noaux [HW] Don't check for auxiliary (== mouse) port
Dmitry Torokhov945ef0d2005-09-04 01:42:00 -0500743 i8042.nokbd [HW] Don't check/create keyboard port
Jiri Kosina75d08c72008-03-13 16:13:59 -0400744 i8042.noloop [HW] Disable the AUX Loopback command while probing
745 for the AUX port
Linus Torvalds1da177e2005-04-16 15:20:36 -0700746 i8042.nomux [HW] Don't check presence of an active multiplexing
747 controller
748 i8042.nopnp [HW] Don't use ACPIPnP / PnPBIOS to discover KBD/AUX
749 controllers
750 i8042.panicblink=
751 [HW] Frequency with which keyboard LEDs should blink
752 when kernel panics (default is 0.5 sec)
753 i8042.reset [HW] Reset the controller during init and cleanup
754 i8042.unlock [HW] Unlock (ignore) the keylock
755
756 i810= [HW,DRM]
757
Dmitry Torokhove70c9d52005-06-25 14:54:25 -0700758 i8k.ignore_dmi [HW] Continue probing hardware even if DMI data
759 indicates that the driver is running on unsupported
760 hardware.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700761 i8k.force [HW] Activate i8k driver even if SMM BIOS signature
762 does not match list of supported models.
763 i8k.power_status
764 [HW] Report power status in /proc/i8k
765 (disabled by default)
766 i8k.restricted [HW] Allow controlling fans only if SYS_ADMIN
767 capability is set.
768
769 ibmmcascsi= [HW,MCA,SCSI] IBM MicroChannel SCSI adapter
770 See Documentation/mca.txt.
771
772 icn= [HW,ISDN]
773 Format: <io>[,<membase>[,<icn_id>[,<icn_id2>]]]
774
775 ide= [HW] (E)IDE subsystem
Greg Kroah-Hartmana594eeb2008-04-18 00:46:20 +0200776 Format: ide=nodma or ide=doubler
Randy Dunlap1c10e932008-03-07 21:53:50 +0100777 See Documentation/ide/ide.txt.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700778
Linus Torvalds1da177e2005-04-16 15:20:36 -0700779 idebus= [HW] (E)IDE subsystem - VLB/PCI bus speed
Randy Dunlap1c10e932008-03-07 21:53:50 +0100780 See Documentation/ide/ide.txt.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700781
Andi Kleenf039b752007-05-02 19:27:12 +0200782 idle= [X86]
783 Format: idle=poll or idle=mwait
784 Poll forces a polling idle loop that can slightly improves the performance
785 of waking up a idle CPU, but will use a lot of power and make the system
786 run hot. Not recommended.
787 idle=mwait. On systems which support MONITOR/MWAIT but the kernel chose
788 to not use it because it doesn't save as much power as a normal idle
789 loop use the MONITOR/MWAIT idle loop anyways. Performance should be the same
790 as idle=poll.
Randy Dunlapa9913042005-10-23 12:57:11 -0700791
Denis Cheng594765a2008-02-06 02:57:49 +0100792 ide-pci-generic.all-generic-ide [HW] (E)IDE subsystem
793 Claim all unknown PCI IDE storage controllers.
794
Ingo Molnar792908222006-12-06 20:40:51 -0800795 ignore_loglevel [KNL]
796 Ignore loglevel setting - this will print /all/
797 kernel messages to the console. Useful for debugging.
798
Linus Torvalds1da177e2005-04-16 15:20:36 -0700799 ihash_entries= [KNL]
800 Set number of hash buckets for inode cache.
801
802 in2000= [HW,SCSI]
803 See header of drivers/scsi/in2000.c.
804
805 init= [KNL]
806 Format: <full_path>
807 Run specified binary instead of /sbin/init as init
808 process.
809
810 initcall_debug [KNL] Trace initcalls as they are executed. Useful
811 for working out where the kernel is dying during
812 startup.
813
814 initrd= [BOOT] Specify the location of the initial ramdisk
815
816 inport.irq= [HW] Inport (ATI XL and Microsoft) busmouse driver
817 Format: <irq>
818
819 inttest= [IA64]
820
Pavel Machekb552da82008-03-19 15:58:11 +0100821 iommu= [x86]
822 off
823 force
824 noforce
825 biomerge
826 panic
827 nopanic
828 merge
829 nomerge
830 forcesac
831 soft
832
833
Keshavamurthy, Anil Sba395922007-10-21 16:41:49 -0700834 intel_iommu= [DMAR] Intel IOMMU driver (DMAR) option
835 off
836 Disable intel iommu driver.
837 igfx_off [Default Off]
838 By default, gfx is mapped as normal device. If a gfx
839 device has a dedicated DMAR unit, the DMAR unit is
840 bypassed by not enabling DMAR with this option. In
841 this case, gfx device will use physical address for
842 DMA.
Keshavamurthy, Anil S7d3b03c2007-10-21 16:41:53 -0700843 forcedac [x86_64]
844 With this option iommu will not optimize to look
845 for io virtual address below 32 bit forcing dual
846 address cycle on pci bus for cards supporting greater
847 than 32 bit addressing. The default is to look
848 for translation below 32 bit and if not available
849 then look in the higher range.
mark gross5e0d2a62008-03-04 15:22:08 -0800850 strict [Default Off]
851 With this option on every unmap_single operation will
852 result in a hardware IOTLB flush operation as opposed
853 to batching them for performance.
Keshavamurthy, Anil Sba395922007-10-21 16:41:49 -0700854
Rene Hermanb02aae92008-01-30 13:30:05 +0100855 io_delay= [X86-32,X86-64] I/O delay method
Ingo Molnar6e7c4022008-01-30 13:30:05 +0100856 0x80
857 Standard port 0x80 based delay
858 0xed
859 Alternate port 0xed based delay (needed on some systems)
Rene Hermanb02aae92008-01-30 13:30:05 +0100860 udelay
Ingo Molnar6e7c4022008-01-30 13:30:05 +0100861 Simple two microseconds delay
862 none
863 No delay
Rene Hermanb02aae92008-01-30 13:30:05 +0100864
Linus Torvalds1da177e2005-04-16 15:20:36 -0700865 io7= [HW] IO7 for Marvel based alpha systems
866 See comment before marvel_specify_io7 in
867 arch/alpha/kernel/core_marvel.c.
868
869 ip= [IP_PNP]
J. Bruce Fields6ded55d2008-04-07 15:59:03 -0400870 See Documentation/filesystems/nfsroot.txt.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700871
872 ip2= [HW] Set IO/IRQ pairs for up to 4 IntelliPort boards
Randy Dunlapc8facbb2007-07-31 00:37:40 -0700873 See comment before ip2_setup() in
874 drivers/char/ip2/ip2base.c.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700875
876 ips= [HW,SCSI] Adaptec / IBM ServeRAID controller
877 See header of drivers/scsi/ips.c.
878
Simon Horman72c4a132006-09-13 19:57:18 -0700879 ports= [IP_VS_FTP] IPVS ftp helper module
880 Default is 21.
881 Up to 8 (IP_VS_APP_MAX_PORTS) ports
882 may be specified.
883 Format: <port>,<port>....
884
Alan Cox200803d2005-06-28 20:45:18 -0700885 irqfixup [HW]
886 When an interrupt is not handled search all handlers
887 for it. Intended to get systems with badly broken
888 firmware running.
889
890 irqpoll [HW]
891 When an interrupt is not handled search all handlers
892 for it. Also check all handlers each timer
893 interrupt. Intended to get systems with badly broken
894 firmware running.
895
Linus Torvalds1da177e2005-04-16 15:20:36 -0700896 isapnp= [ISAPNP]
Randy Dunlapa9913042005-10-23 12:57:11 -0700897 Format: <RDP>,<reset>,<pci_scan>,<verbosity>
Linus Torvalds1da177e2005-04-16 15:20:36 -0700898
899 isolcpus= [KNL,SMP] Isolate CPUs from the general scheduler.
Derek Fults22f2e282006-12-06 20:37:11 -0800900 Format:
901 <cpu number>,...,<cpu number>
902 or
903 <cpu number>-<cpu number> (must be a positive range in ascending order)
904 or a mixture
905 <cpu number>,...,<cpu number>-<cpu number>
Linus Torvalds1da177e2005-04-16 15:20:36 -0700906 This option can be used to specify one or more CPUs
907 to isolate from the general SMP balancing and scheduling
908 algorithms. The only way to move a process onto or off
909 an "isolated" CPU is via the CPU affinity syscalls.
910 <cpu number> begins at 0 and the maximum value is
911 "number of CPUs in system - 1".
912
913 This option is the preferred way to isolate CPUs. The
Randy Dunlapa9913042005-10-23 12:57:11 -0700914 alternative -- manually setting the CPU mask of all
915 tasks in the system -- can cause problems and
916 suboptimal load balancer performance.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700917
Randy Dunlapa9913042005-10-23 12:57:11 -0700918 iucv= [HW,NET]
Linus Torvalds1da177e2005-04-16 15:20:36 -0700919
920 js= [HW,JOY] Analog joystick
921 See Documentation/input/joystick.txt.
922
Alan Coxcd4f0ef2007-07-31 00:37:59 -0700923 kernelcore=nn[KMG] [KNL,X86-32,IA-64,PPC,X86-64] This parameter
Mel Gormaned7ed362007-07-17 04:03:14 -0700924 specifies the amount of memory usable by the kernel
925 for non-movable allocations. The requested amount is
926 spread evenly throughout all nodes in the system. The
927 remaining memory in each node is used for Movable
928 pages. In the event, a node is too small to have both
929 kernelcore and Movable pages, kernelcore pages will
930 take priority and other nodes will have a larger number
931 of kernelcore pages. The Movable zone is used for the
932 allocation of pages that may be reclaimed or moved
933 by the page migration subsystem. This means that
934 HugeTLB pages may not be allocated from this zone.
935 Note that allocations like PTEs-from-HighMem still
936 use the HighMem zone if it exists, and the Normal
937 zone if it does not.
938
Alan Coxcd4f0ef2007-07-31 00:37:59 -0700939 movablecore=nn[KMG] [KNL,X86-32,IA-64,PPC,X86-64] This parameter
Mel Gorman7e63efe2007-07-17 04:03:15 -0700940 is similar to kernelcore except it specifies the
941 amount of memory used for migratable allocations.
942 If both kernelcore and movablecore is specified,
943 then kernelcore will be at *least* the specified
944 value but may be more. If movablecore on its own
945 is specified, the administrator must be careful
946 that the amount of memory usable for all allocations
947 is not too small.
948
Linus Torvalds1da177e2005-04-16 15:20:36 -0700949 keepinitrd [HW,ARM]
950
Alan Coxcd4f0ef2007-07-31 00:37:59 -0700951 kstack=N [X86-32,X86-64] Print N words from the kernel stack
Linus Torvalds1da177e2005-04-16 15:20:36 -0700952 in oops dumps.
953
Jason Wessel6cdf6e02008-04-17 20:05:38 +0200954 kgdboc= [HW] kgdb over consoles.
955 Requires a tty driver that supports console polling.
956 (only serial suported for now)
957 Format: <serial_device>[,baud]
958
Linus Torvalds1da177e2005-04-16 15:20:36 -0700959 l2cr= [PPC]
960
Robert Brosea78bfbf2008-03-29 07:20:23 +1100961 l3cr= [PPC]
962
Alan Coxcd4f0ef2007-07-31 00:37:59 -0700963 lapic [X86-32,APIC] Enable the local APIC even if BIOS
Randy Dunlapa9913042005-10-23 12:57:11 -0700964 disabled it.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700965
Alan Coxcd4f0ef2007-07-31 00:37:59 -0700966 lapic_timer_c2_ok [X86-32,x86-64,APIC] trust the local apic timer in
Thomas Gleixnere585bef2007-03-23 16:08:01 +0100967 C2 power state.
968
FD Camifcb71f62008-01-06 19:08:56 +0100969 libata.dma= [LIBATA] DMA control
970 libata.dma=0 Disable all PATA and SATA DMA
971 libata.dma=1 PATA and SATA Disk DMA only
972 libata.dma=2 ATAPI (CDROM) DMA only
973 libata.dma=4 Compact Flash DMA only
974 Combinations also work, so libata.dma=3 enables DMA
975 for disks and CDROMs, but not CFs.
976
Dave Jones78e70c22007-09-27 11:50:13 -0400977 libata.noacpi [LIBATA] Disables use of ACPI in libata suspend/resume
978 when set.
979 Format: <int>
980
Tejun Heo33267322008-02-13 09:15:09 +0900981 libata.force= [LIBATA] Force configurations. The format is comma
982 separated list of "[ID:]VAL" where ID is
983 PORT[:DEVICE]. PORT and DEVICE are decimal numbers
984 matching port, link or device. Basically, it matches
985 the ATA ID string printed on console by libata. If
986 the whole ID part is omitted, the last PORT and DEVICE
987 values are used. If ID hasn't been specified yet, the
988 configuration applies to all ports, links and devices.
989
990 If only DEVICE is omitted, the parameter applies to
991 the port and all links and devices behind it. DEVICE
992 number of 0 either selects the first device or the
993 first fan-out link behind PMP device. It does not
994 select the host link. DEVICE number of 15 selects the
995 host link and device attached to it.
996
997 The VAL specifies the configuration to force. As long
998 as there's no ambiguity shortcut notation is allowed.
999 For example, both 1.5 and 1.5G would work for 1.5Gbps.
1000 The following configurations can be forced.
1001
1002 * Cable type: 40c, 80c, short40c, unk, ign or sata.
1003 Any ID with matching PORT is used.
1004
1005 * SATA link speed limit: 1.5Gbps or 3.0Gbps.
1006
1007 * Transfer mode: pio[0-7], mwdma[0-4] and udma[0-7].
1008 udma[/][16,25,33,44,66,100,133] notation is also
1009 allowed.
1010
1011 * [no]ncq: Turn on or off NCQ.
1012
1013 If there are multiple matching configurations changing
1014 the same attribute, the last one is used.
1015
Linus Torvalds1da177e2005-04-16 15:20:36 -07001016 load_ramdisk= [RAM] List of ramdisks to load from floppy
1017 See Documentation/ramdisk.txt.
1018
Randy Dunlapa6b25b62006-01-14 13:21:19 -08001019 lockd.nlm_grace_period=P [NFS] Assign grace period.
1020 Format: <integer>
Linus Torvalds1da177e2005-04-16 15:20:36 -07001021
Randy Dunlapa6b25b62006-01-14 13:21:19 -08001022 lockd.nlm_tcpport=N [NFS] Assign TCP port.
1023 Format: <integer>
1024
1025 lockd.nlm_timeout=T [NFS] Assign timeout value.
1026 Format: <integer>
1027
1028 lockd.nlm_udpport=M [NFS] Assign UDP port.
1029 Format: <integer>
Linus Torvalds1da177e2005-04-16 15:20:36 -07001030
1031 logibm.irq= [HW,MOUSE] Logitech Bus Mouse Driver
1032 Format: <irq>
1033
1034 loglevel= All Kernel Messages with a loglevel smaller than the
1035 console loglevel will be printed to the console. It can
1036 also be changed with klogd or other programs. The
1037 loglevels are defined as follows:
1038
1039 0 (KERN_EMERG) system is unusable
1040 1 (KERN_ALERT) action must be taken immediately
1041 2 (KERN_CRIT) critical conditions
1042 3 (KERN_ERR) error conditions
1043 4 (KERN_WARNING) warning conditions
1044 5 (KERN_NOTICE) normal but significant condition
1045 6 (KERN_INFO) informational
1046 7 (KERN_DEBUG) debug-level messages
1047
1048 log_buf_len=n Sets the size of the printk ring buffer, in bytes.
Randy Dunlapa9913042005-10-23 12:57:11 -07001049 Format: { n | nk | nM }
1050 n must be a power of two. The default size
1051 is set in the kernel config file.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001052
Randy Dunlapaccaa242007-10-16 01:29:37 -07001053 logo.nologo [FB] Disables display of the built-in Linux logo.
1054 This may be used to provide more screen space for
1055 kernel log messages and is useful when debugging
1056 kernel boot problems.
1057
Linus Torvalds1da177e2005-04-16 15:20:36 -07001058 lp=0 [LP] Specify parallel ports to use, e.g,
1059 lp=port[,port...] lp=none,parport0 (lp0 not configured, lp1 uses
1060 lp=reset first parallel port). 'lp=0' disables the
1061 lp=auto printer driver. 'lp=reset' (which can be
1062 specified in addition to the ports) causes
1063 attached printers to be reset. Using
1064 lp=port1,port2,... specifies the parallel ports
1065 to associate lp devices with, starting with
1066 lp0. A port specification may be 'none' to skip
1067 that lp device, or a parport name such as
1068 'parport0'. Specifying 'lp=auto' instead of a
1069 port specification list means that device IDs
1070 from each port should be examined, to see if
1071 an IEEE 1284-compliant printer is attached; if
1072 so, the driver will manage that printer.
1073 See also header of drivers/char/lp.c.
1074
1075 lpj=n [KNL]
1076 Sets loops_per_jiffy to given constant, thus avoiding
1077 time-consuming boot-time autodetection (up to 250 ms per
1078 CPU). 0 enables autodetection (default). To determine
1079 the correct value for your kernel, boot with normal
1080 autodetection and see what value is printed. Note that
1081 on SMP systems the preset will be applied to all CPUs,
1082 which is likely to cause problems if your CPUs need
1083 significantly divergent settings. An incorrect value
1084 will cause delays in the kernel to be wrong, leading to
1085 unpredictable I/O errors and other breakage. Although
1086 unlikely, in the extreme case this might damage your
1087 hardware.
1088
1089 ltpc= [NET]
1090 Format: <io>,<irq>,<dma>
1091
Randy Dunlapa9913042005-10-23 12:57:11 -07001092 mac5380= [HW,SCSI] Format:
1093 <can_queue>,<cmd_per_lun>,<sg_tablesize>,<hostid>,<use_tags>
Linus Torvalds1da177e2005-04-16 15:20:36 -07001094
Randy Dunlapa9913042005-10-23 12:57:11 -07001095 mac53c9x= [HW,SCSI] Format:
1096 <num_esps>,<disconnect>,<nosync>,<can_queue>,<cmd_per_lun>,<sg_tablesize>,<hostid>,<use_tags>
Linus Torvalds1da177e2005-04-16 15:20:36 -07001097
Randy Dunlapa9913042005-10-23 12:57:11 -07001098 machvec= [IA64] Force the use of a particular machine-vector
1099 (machvec) in a generic kernel.
1100 Example: machvec=hpzx1_swiotlb
Linus Torvalds1da177e2005-04-16 15:20:36 -07001101
Randy Dunlapa9913042005-10-23 12:57:11 -07001102 max_loop= [LOOP] Maximum number of loopback devices that can
Linus Torvalds1da177e2005-04-16 15:20:36 -07001103 be mounted
1104 Format: <1-256>
1105
1106 maxcpus= [SMP] Maximum number of processors that an SMP kernel
Len Brown61ec7562007-08-16 03:34:22 -04001107 should make use of. maxcpus=n : n >= 0 limits the
1108 kernel to using 'n' processors. n=0 is a special case,
1109 it is equivalent to "nosmp", which also disables
1110 the IO APIC.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001111
Bob Picco2b2c3752005-06-29 18:00:00 -07001112 max_addr=[KMG] [KNL,BOOT,ia64] All physical memory greater than or
1113 equal to this physical address is ignored.
1114
Randy Dunlapa9913042005-10-23 12:57:11 -07001115 max_luns= [SCSI] Maximum number of LUNs to probe.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001116 Should be between 1 and 2^32-1.
1117
1118 max_report_luns=
Randy Dunlapa9913042005-10-23 12:57:11 -07001119 [SCSI] Maximum number of LUNs received.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001120 Should be between 1 and 16384.
1121
Linus Torvalds1da177e2005-04-16 15:20:36 -07001122 mcatest= [IA-64]
1123
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001124 mce [X86-32] Machine Check Exception
Linus Torvalds1da177e2005-04-16 15:20:36 -07001125
Andi Kleen909dd322007-10-17 18:04:38 +02001126 mce=option [X86-64] See Documentation/x86_64/boot-options.txt
1127
Linus Torvalds1da177e2005-04-16 15:20:36 -07001128 md= [HW] RAID subsystems devices and level
1129 See Documentation/md.txt.
Randy Dunlapa9913042005-10-23 12:57:11 -07001130
Linus Torvalds1da177e2005-04-16 15:20:36 -07001131 mdacon= [MDA]
1132 Format: <first>,<last>
1133 Specifies range of consoles to be captured by the MDA.
Randy Dunlapa9913042005-10-23 12:57:11 -07001134
Linus Torvalds1da177e2005-04-16 15:20:36 -07001135 mem=nn[KMG] [KNL,BOOT] Force usage of a specific amount of memory
1136 Amount of memory to be used when the kernel is not able
1137 to see the whole system memory or for test.
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001138 [X86-32] Use together with memmap= to avoid physical
Linus Torvalds1da177e2005-04-16 15:20:36 -07001139 address space collisions. Without memmap= PCI devices
1140 could be placed at addresses belonging to unused RAM.
1141
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001142 mem=nopentium [BUGS=X86-32] Disable usage of 4MB pages for kernel
Linus Torvalds1da177e2005-04-16 15:20:36 -07001143 memory.
1144
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001145 memmap=exactmap [KNL,X86-32,X86_64] Enable setting of an exact
Linus Torvalds1da177e2005-04-16 15:20:36 -07001146 E820 memory map, as specified by the user.
1147 Such memmap=exactmap lines can be constructed based on
1148 BIOS output or other requirements. See the memmap=nn@ss
1149 option description.
1150
1151 memmap=nn[KMG]@ss[KMG]
1152 [KNL] Force usage of a specific region of memory
1153 Region of memory to be used, from ss to ss+nn.
1154
1155 memmap=nn[KMG]#ss[KMG]
1156 [KNL,ACPI] Mark specific memory as ACPI data.
1157 Region of memory to be used, from ss to ss+nn.
1158
1159 memmap=nn[KMG]$ss[KMG]
1160 [KNL,ACPI] Mark specific memory as reserved.
1161 Region of memory to be used, from ss to ss+nn.
Pavel Machek13128482008-03-24 12:29:43 -07001162 Example: Exclude memory from 0x18690000-0x1869ffff
1163 memmap=64K$0x18690000
1164 or
1165 memmap=0x10000$0x18690000
Linus Torvalds1da177e2005-04-16 15:20:36 -07001166
Yinghai Luc64df702008-03-21 18:56:19 -07001167 memtest= [KNL,X86_64] Enable memtest
1168 Format: <integer>
1169 range: 0,4 : pattern number
1170 default : 0 <disable>
1171
Linus Torvalds1da177e2005-04-16 15:20:36 -07001172 meye.*= [HW] Set MotionEye Camera parameters
1173 See Documentation/video4linux/meye.txt.
1174
Andres Salomon8f368812007-10-12 23:04:06 +02001175 mfgpt_irq= [IA-32] Specify the IRQ to use for the
1176 Multi-Function General Purpose Timers on AMD Geode
1177 platforms.
1178
Willy Tarreaue6c4dc62008-01-30 13:33:33 +01001179 mfgptfix [X86-32] Fix MFGPT timers on AMD Geode platforms when
1180 the BIOS has incorrectly applied a workaround. TinyBIOS
1181 version 0.98 is known to be affected, 0.99 fixes the
1182 problem by letting the user disable the workaround.
1183
Linus Torvalds1da177e2005-04-16 15:20:36 -07001184 mga= [HW,DRM]
1185
1186 mousedev.tap_time=
1187 [MOUSE] Maximum time between finger touching and
1188 leaving touchpad surface for touch to be considered
1189 a tap and be reported as a left button click (for
1190 touchpads working in absolute mode only).
1191 Format: <msecs>
1192 mousedev.xres= [MOUSE] Horizontal screen resolution, used for devices
1193 reporting absolute coordinates, such as tablets
1194 mousedev.yres= [MOUSE] Vertical screen resolution, used for devices
1195 reporting absolute coordinates, such as tablets
1196
1197 mpu401= [HW,OSS]
1198 Format: <io>,<irq>
1199
1200 MTD_Partition= [MTD]
1201 Format: <name>,<region-number>,<size>,<offset>
1202
Randy Dunlapa9913042005-10-23 12:57:11 -07001203 MTD_Region= [MTD] Format:
1204 <name>,<region-number>[,<base>,<size>,<buswidth>,<altbuswidth>]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001205
1206 mtdparts= [MTD]
Randy Dunlapc8facbb2007-07-31 00:37:40 -07001207 See drivers/mtd/cmdlinepart.c.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001208
1209 mtouchusb.raw_coordinates=
Randy Dunlapa9913042005-10-23 12:57:11 -07001210 [HW] Make the MicroTouch USB driver use raw coordinates
1211 ('y', default) or cooked coordinates ('n')
Linus Torvalds1da177e2005-04-16 15:20:36 -07001212
1213 n2= [NET] SDL Inc. RISCom/N2 synchronous serial card
1214
1215 NCR_D700= [HW,SCSI]
1216 See header of drivers/scsi/NCR_D700.c.
1217
1218 ncr5380= [HW,SCSI]
1219
1220 ncr53c400= [HW,SCSI]
1221
1222 ncr53c400a= [HW,SCSI]
1223
1224 ncr53c406a= [HW,SCSI]
1225
1226 ncr53c8xx= [HW,SCSI]
1227
1228 netdev= [NET] Network devices parameters
1229 Format: <irq>,<io>,<mem_start>,<mem_end>,<name>
1230 Note that mem_start is often overloaded to mean
1231 something different and driver-specific.
Randy Dunlapa9913042005-10-23 12:57:11 -07001232 This usage is only documented in each driver source
1233 file if at all.
1234
Linus Torvalds1da177e2005-04-16 15:20:36 -07001235 nfsaddrs= [NFS]
J. Bruce Fields6ded55d2008-04-07 15:59:03 -04001236 See Documentation/filesystems/nfsroot.txt.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001237
1238 nfsroot= [NFS] nfs root filesystem for disk-less boxes.
J. Bruce Fields6ded55d2008-04-07 15:59:03 -04001239 See Documentation/filesystems/nfsroot.txt.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001240
Trond Myklebusta72b4422006-01-03 09:55:41 +01001241 nfs.callback_tcpport=
1242 [NFS] set the TCP port on which the NFSv4 callback
1243 channel should listen.
1244
Trond Myklebust58df0952006-01-03 09:55:57 +01001245 nfs.idmap_cache_timeout=
1246 [NFS] set the maximum lifetime for idmapper cache
1247 entries.
1248
Trond Myklebustf43bf0b2007-10-09 12:01:04 -04001249 nfs.enable_ino64=
1250 [NFS] enable 64-bit inode numbers.
1251 If zero, the NFS client will fake up a 32-bit inode
1252 number for the readdir() and stat() syscalls instead
1253 of returning the full 64-bit number.
1254 The default is to return 64-bit inode numbers.
1255
Haavard Skinnemoene7ba1762007-10-10 14:58:29 +02001256 nmi_debug= [KNL,AVR32] Specify one or more actions to take
1257 when a NMI is triggered.
1258 Format: [state][,regs][,debounce][,die]
1259
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001260 nmi_watchdog= [KNL,BUGS=X86-32] Debugging features for SMP kernels
Linus Torvalds1da177e2005-04-16 15:20:36 -07001261
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001262 no387 [BUGS=X86-32] Tells the kernel to use the 387 maths
Linus Torvalds1da177e2005-04-16 15:20:36 -07001263 emulation library even if a 387 maths coprocessor
1264 is present.
1265
Christoph Lameterc1aee212007-05-31 00:40:47 -07001266 noaliencache [MM, NUMA, SLAB] Disables the allocation of alien
1267 caches in the slab allocator. Saves per-node memory,
1268 but will impact performance.
Paul Menage3395ee02006-12-06 20:32:16 -08001269
Randy Dunlapa9913042005-10-23 12:57:11 -07001270 noalign [KNL,ARM]
1271
Linus Torvalds1da177e2005-04-16 15:20:36 -07001272 noapic [SMP,APIC] Tells the kernel to not make use of any
1273 IOAPICs that may be present in the system.
1274
Linus Torvalds1da177e2005-04-16 15:20:36 -07001275 nobats [PPC] Do not use BATs for mapping kernel lowmem
1276 on "Classic" PPC cores.
1277
1278 nocache [ARM]
Randy Dunlapa9913042005-10-23 12:57:11 -07001279
Shailabh Nagar163ecdf2006-07-30 03:03:11 -07001280 nodelayacct [KNL] Disable per-task delay accounting
1281
Linus Torvalds1da177e2005-04-16 15:20:36 -07001282 nodisconnect [HW,SCSI,M68K] Disables SCSI disconnects.
1283
Huang, Ying8b2cb7a2008-01-30 13:32:11 +01001284 noefi [X86-32,X86-64] Disable EFI runtime services support.
1285
Linus Torvalds1da177e2005-04-16 15:20:36 -07001286 noexec [IA-64]
1287
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001288 noexec [X86-32,X86-64]
Jiri Slabyf5a1b192008-04-12 10:28:25 +02001289 On X86-32 available only on PAE configured kernels.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001290 noexec=on: enable non-executable mappings (default)
Jiri Slabyf5a1b192008-04-12 10:28:25 +02001291 noexec=off: disable non-executable mappings
1292
1293 noexec32 [X86-64]
1294 This affects only 32-bit executables.
1295 noexec32=on: enable non-executable mappings (default)
1296 read doesn't imply executable mappings
1297 noexec32=off: disable non-executable mappings
1298 read implies executable mappings
Linus Torvalds1da177e2005-04-16 15:20:36 -07001299
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001300 nofxsr [BUGS=X86-32] Disables x86 floating point extended
Chuck Ebbert4f886512006-03-23 02:59:34 -08001301 register save and restore. The kernel will only save
1302 legacy floating-point registers on task switch.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001303
Andi Kleen191679f2008-01-30 13:33:21 +01001304 noclflush [BUGS=X86] Don't use the CLFLUSH instruction
1305
Linus Torvalds1da177e2005-04-16 15:20:36 -07001306 nohlt [BUGS=ARM]
Randy Dunlapa9913042005-10-23 12:57:11 -07001307
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001308 no-hlt [BUGS=X86-32] Tells the kernel that the hlt
Linus Torvalds1da177e2005-04-16 15:20:36 -07001309 instruction doesn't work correctly and not to
1310 use it.
1311
1312 nohalt [IA-64] Tells the kernel not to use the power saving
1313 function PAL_HALT_LIGHT when idle. This increases
1314 power-consumption. On the positive side, it reduces
1315 interrupt wake-up latency, which may improve performance
1316 in certain environments such as networked servers or
1317 real-time systems.
1318
Thomas Gleixner79bf2bb2007-02-16 01:28:03 -08001319 nohz= [KNL] Boottime enable/disable dynamic ticks
1320 Valid arguments: on, off
1321 Default: on
1322
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001323 noirqbalance [X86-32,SMP,KNL] Disable kernel irq balancing
Zachary Amsden8542b202006-12-07 02:14:09 +01001324
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001325 noirqdebug [X86-32] Disables the code which attempts to detect and
Linus Torvalds1da177e2005-04-16 15:20:36 -07001326 disable unhandled interrupt sources.
1327
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001328 no_timer_check [X86-32,X86_64,APIC] Disables the code which tests for
Zachary Amsden8542b202006-12-07 02:14:09 +01001329 broken timer IRQ sources.
1330
Linus Torvalds1da177e2005-04-16 15:20:36 -07001331 noisapnp [ISAPNP] Disables ISA PnP code.
1332
1333 noinitrd [RAM] Tells the kernel not to load any configured
1334 initial RAM disk.
1335
1336 nointroute [IA-64]
1337
Tony Luck0aa366f2007-07-20 11:22:30 -07001338 nojitter [IA64] Disables jitter checking for ITC timers.
1339
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001340 nolapic [X86-32,APIC] Do not enable or use the local APIC.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001341
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001342 nolapic_timer [X86-32,APIC] Do not use the local APIC timer.
Thomas Gleixnerad62ca22007-03-22 00:11:21 -08001343
Linus Torvalds1da177e2005-04-16 15:20:36 -07001344 noltlbs [PPC] Do not use large page/tlb entries for kernel
1345 lowmem mapping on PPC40x.
1346
Horms312f1f02006-02-22 09:57:55 +09001347 nomca [IA-64] Disable machine check abort handling
1348
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001349 nomce [X86-32] Machine Check Exception
Hormsabe37e52006-04-01 01:36:09 +02001350
Andres Salomon83d73842007-10-12 23:04:06 +02001351 nomfgpt [X86-32] Disable Multi-Function General Purpose
1352 Timer usage (for AMD Geode machines).
1353
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001354 noreplace-paravirt [X86-32,PV_OPS] Don't patch paravirt_ops
Jeremy Fitzhardinge959b4fd2007-05-02 19:27:16 +02001355
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001356 noreplace-smp [X86-32,SMP] Don't replace SMP instructions
Jeremy Fitzhardingeb7fb4af2007-05-02 19:27:13 +02001357 with UP alternatives
1358
Linus Torvalds1da177e2005-04-16 15:20:36 -07001359 noresidual [PPC] Don't use residual data on PReP machines.
1360
Randy Dunlapa9913042005-10-23 12:57:11 -07001361 noresume [SWSUSP] Disables resume and restores original swap
1362 space.
1363
Linus Torvalds1da177e2005-04-16 15:20:36 -07001364 no-scroll [VGA] Disables scrollback.
1365 This is required for the Braillex ib80-piezo Braille
1366 reader made by F.H. Papenmeier (Germany).
1367
1368 nosbagart [IA-64]
1369
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001370 nosep [BUGS=X86-32] Disables x86 SYSENTER/SYSEXIT support.
Chuck Ebbert4f886512006-03-23 02:59:34 -08001371
Len Brown61ec7562007-08-16 03:34:22 -04001372 nosmp [SMP] Tells an SMP kernel to act as a UP kernel,
1373 and disable the IO APIC. legacy for "maxcpus=0".
Linus Torvalds1da177e2005-04-16 15:20:36 -07001374
Dave Jones97842212007-07-15 23:41:05 -07001375 nosoftlockup [KNL] Disable the soft-lockup detector.
1376
Linus Torvalds1da177e2005-04-16 15:20:36 -07001377 nosync [HW,M68K] Disables sync negotiation for all devices.
1378
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001379 notsc [BUGS=X86-32] Disable Time Stamp Counter
Linus Torvalds1da177e2005-04-16 15:20:36 -07001380
1381 nousb [USB] Disable the USB subsystem
1382
1383 nowb [ARM]
Randy Dunlapa9913042005-10-23 12:57:11 -07001384
Fenghua Yua6c75b862008-03-14 13:57:08 -07001385 nptcg= [IA64] Override max number of concurrent global TLB
1386 purges which is reported from either PAL_VM_SUMMARY or
1387 SAL PALO.
1388
KAMEZAWA Hiroyukif0c0b2b2007-07-15 23:38:01 -07001389 numa_zonelist_order= [KNL, BOOT] Select zonelist order for NUMA.
1390 one of ['zone', 'node', 'default'] can be specified
1391 This can be set from sysctl after boot.
1392 See Documentation/sysctl/vm.txt for details.
1393
Dave Jonesa61c2d72006-01-07 23:18:19 +00001394 nr_uarts= [SERIAL] maximum number of UARTs to be registered.
1395
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07001396 olpc_ec_timeout= [OLPC] ms delay when issuing EC commands
1397 Rather than timing out after 20 ms if an EC
1398 command is not properly ACKed, override the length
1399 of the timeout. We have interrupts disabled while
1400 waiting for the ACK, so if this is set too high
1401 interrupts *may* be lost!
1402
Linus Torvalds1da177e2005-04-16 15:20:36 -07001403 opl3= [HW,OSS]
1404 Format: <io>
1405
Linus Torvalds1da177e2005-04-16 15:20:36 -07001406 oprofile.timer= [HW]
1407 Use timer interrupt instead of performance counters
1408
Linus Torvalds1da177e2005-04-16 15:20:36 -07001409 osst= [HW,SCSI] SCSI Tape Driver
1410 Format: <buffer_size>,<write_threshold>
1411 See also Documentation/scsi/st.txt.
1412
1413 panic= [KNL] Kernel behaviour on panic
1414 Format: <timeout>
1415
1416 parkbd.port= [HW] Parallel port number the keyboard adapter is
1417 connected to, default is 0.
1418 Format: <parport#>
1419 parkbd.mode= [HW] Parallel port keyboard adapter mode of operation,
1420 0 for XT, 1 for AT (default is AT).
Randy Dunlapa9913042005-10-23 12:57:11 -07001421 Format: <mode>
Linus Torvalds1da177e2005-04-16 15:20:36 -07001422
Randy Dunlapa9913042005-10-23 12:57:11 -07001423 parport= [HW,PPT] Specify parallel ports. 0 disables.
1424 Format: { 0 | auto | 0xBBB[,IRQ[,DMA]] }
1425 Use 'auto' to force the driver to use any
1426 IRQ/DMA settings detected (the default is to
1427 ignore detected IRQ/DMA settings because of
1428 possible conflicts). You can specify the base
1429 address, IRQ, and DMA settings; IRQ and DMA
1430 should be numbers, or 'auto' (for using detected
1431 settings on that particular port), or 'nofifo'
1432 (to avoid using a FIFO even if it is detected).
1433 Parallel ports are assigned in the order they
1434 are specified on the command line, starting
1435 with parport0.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001436
Randy Dunlapa9913042005-10-23 12:57:11 -07001437 parport_init_mode= [HW,PPT]
1438 Configure VIA parallel port to operate in
1439 a specific mode. This is necessary on Pegasos
1440 computer where firmware has no options for setting
1441 up parallel port mode and sets it to spp.
1442 Currently this function knows 686a and 8231 chips.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001443 Format: [spp|ps2|epp|ecp|ecpepp]
1444
Randy Dunlapa9913042005-10-23 12:57:11 -07001445 pas2= [HW,OSS] Format:
1446 <io>,<irq>,<dma>,<dma16>,<sb_io>,<sb_irq>,<sb_dma>,<sb_dma16>
1447
Linus Torvalds1da177e2005-04-16 15:20:36 -07001448 pas16= [HW,SCSI]
1449 See header of drivers/scsi/pas16.c.
1450
Andrew Mortondd287792006-03-23 03:00:57 -08001451 pause_on_oops=
1452 Halt all CPUs after the first oops has been printed for
1453 the specified number of seconds. This is to be used if
1454 your oopses keep scrolling off the screen.
1455
Linus Torvalds1da177e2005-04-16 15:20:36 -07001456 pcbit= [HW,ISDN]
1457
1458 pcd. [PARIDE]
1459 See header of drivers/block/paride/pcd.c.
1460 See also Documentation/paride.txt.
1461
Randy Dunlapa9913042005-10-23 12:57:11 -07001462 pci=option[,option...] [PCI] various PCI subsystem options:
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001463 off [X86-32] don't probe for the PCI bus
1464 bios [X86-32] force use of PCI BIOS, don't access
Randy Dunlapa9913042005-10-23 12:57:11 -07001465 the hardware directly. Use this if your machine
1466 has a non-standard PCI host bridge.
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001467 nobios [X86-32] disallow use of PCI BIOS, only direct
Randy Dunlapa9913042005-10-23 12:57:11 -07001468 hardware access methods are allowed. Use this
1469 if you experience crashes upon bootup and you
1470 suspect they are caused by the BIOS.
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001471 conf1 [X86-32] Force use of PCI Configuration
Randy Dunlapa9913042005-10-23 12:57:11 -07001472 Mechanism 1.
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001473 conf2 [X86-32] Force use of PCI Configuration
Randy Dunlapa9913042005-10-23 12:57:11 -07001474 Mechanism 2.
Randy Dunlap7f785762007-10-05 13:17:58 -07001475 noaer [PCIE] If the PCIEAER kernel config parameter is
1476 enabled, this kernel boot option can be used to
1477 disable the use of PCIE advanced error reporting.
Jeff Garzik32a2eea2007-10-11 16:57:27 -04001478 nodomains [PCI] Disable support for multiple PCI
1479 root domains (aka PCI segments, in ACPI-speak).
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001480 nommconf [X86-32,X86_64] Disable use of MMCONFIG for PCI
Bjorn Helgaas61be6d62006-02-15 15:17:43 -08001481 Configuration
Matthew Wilcox309e57d2006-03-05 22:33:34 -07001482 nomsi [MSI] If the PCI_MSI kernel config parameter is
1483 enabled, this kernel boot option can be used to
1484 disable the use of MSI interrupts system-wide.
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001485 biosirq [X86-32] Use PCI BIOS calls to get the interrupt
Randy Dunlapa9913042005-10-23 12:57:11 -07001486 routing table. These calls are known to be buggy
1487 on several machines and they hang the machine
1488 when used, but on other computers it's the only
1489 way to get the interrupt routing table. Try
1490 this option if the kernel is unable to allocate
1491 IRQs or discover secondary PCI buses on your
1492 motherboard.
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001493 rom [X86-32] Assign address space to expansion ROMs.
Randy Dunlapa9913042005-10-23 12:57:11 -07001494 Use with caution as certain devices share
1495 address decoders between ROMs and other
1496 resources.
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001497 irqmask=0xMMMM [X86-32] Set a bit mask of IRQs allowed to be
Randy Dunlapa9913042005-10-23 12:57:11 -07001498 assigned automatically to PCI devices. You can
1499 make the kernel exclude IRQs of your ISA cards
1500 this way.
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001501 pirqaddr=0xAAAAA [X86-32] Specify the physical address
Randy Dunlapa9913042005-10-23 12:57:11 -07001502 of the PIRQ table (normally generated
1503 by the BIOS) if it is outside the
1504 F0000h-100000h range.
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001505 lastbus=N [X86-32] Scan all buses thru bus #N. Can be
Randy Dunlapa9913042005-10-23 12:57:11 -07001506 useful if the kernel is unable to find your
1507 secondary buses and you want to tell it
1508 explicitly which ones they are.
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001509 assign-busses [X86-32] Always assign all PCI bus
Randy Dunlapa9913042005-10-23 12:57:11 -07001510 numbers ourselves, overriding
1511 whatever the firmware may have done.
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001512 usepirqmask [X86-32] Honor the possible IRQ mask stored
Randy Dunlapa9913042005-10-23 12:57:11 -07001513 in the BIOS $PIR table. This is needed on
1514 some systems with broken BIOSes, notably
1515 some HP Pavilion N5400 and Omnibook XE3
1516 notebooks. This will have no effect if ACPI
1517 IRQ routing is enabled.
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001518 noacpi [X86-32] Do not use ACPI for IRQ routing
Randy Dunlapa9913042005-10-23 12:57:11 -07001519 or for PCI scanning.
Gary Hade62f420f2007-10-03 15:56:51 -07001520 use_crs [X86-32] Use _CRS for PCI resource
1521 allocation.
Randy Dunlapa9913042005-10-23 12:57:11 -07001522 routeirq Do IRQ routing for all PCI devices.
1523 This is normally done in pci_enable_device(),
1524 so this option is a temporary workaround
1525 for broken drivers that don't call it.
1526 firmware [ARM] Do not re-enumerate the bus but instead
1527 just use the configuration from the
1528 bootloader. This is currently used on
1529 IXP2000 systems where the bus has to be
1530 configured a certain way for adjunct CPUs.
Andi Kleen0637a702006-09-26 10:52:41 +02001531 noearly [X86] Don't do any early type 1 scanning.
1532 This might help on some broken boards which
1533 machine check when some devices' config space
1534 is read. But various workarounds are disabled
1535 and some IOMMU drivers will not work.
Matt Domsch6b4b78f2006-09-29 15:23:23 -05001536 bfsort Sort PCI devices into breadth-first order.
1537 This sorting is done to get a device
1538 order compatible with older (<= 2.4) kernels.
1539 nobfsort Don't sort PCI devices into breadth-first order.
Atsushi Nemoto4516a612007-02-05 16:36:06 -08001540 cbiosize=nn[KMG] The fixed amount of bus space which is
1541 reserved for the CardBus bridge's IO window.
1542 The default value is 256 bytes.
1543 cbmemsize=nn[KMG] The fixed amount of bus space which is
1544 reserved for the CardBus bridge's memory
1545 window. The default value is 64 megabytes.
Matt Domsch6b4b78f2006-09-29 15:23:23 -05001546
Linus Torvalds1da177e2005-04-16 15:20:36 -07001547 pcmv= [HW,PCMCIA] BadgePAD 4
1548
1549 pd. [PARIDE]
1550 See Documentation/paride.txt.
1551
1552 pdcchassis= [PARISC,HW] Disable/Enable PDC Chassis Status codes at
1553 boot time.
1554 Format: { 0 | 1 }
1555 See arch/parisc/kernel/pdc_chassis.c
1556
1557 pf. [PARIDE]
1558 See Documentation/paride.txt.
1559
1560 pg. [PARIDE]
1561 See Documentation/paride.txt.
1562
1563 pirq= [SMP,APIC] Manual mp-table setup
1564 See Documentation/i386/IO-APIC.txt.
1565
1566 plip= [PPT,NET] Parallel port network link
1567 Format: { parport<nr> | timid | 0 }
1568 See also Documentation/parport.txt.
1569
1570 pnpacpi= [ACPI]
1571 { off }
1572
1573 pnpbios= [ISAPNP]
1574 { on | off | curr | res | no-curr | no-res }
1575
1576 pnp_reserve_irq=
1577 [ISAPNP] Exclude IRQs for the autoconfiguration
1578
1579 pnp_reserve_dma=
1580 [ISAPNP] Exclude DMAs for the autoconfiguration
1581
1582 pnp_reserve_io= [ISAPNP] Exclude I/O ports for the autoconfiguration
Randy Dunlapa9913042005-10-23 12:57:11 -07001583 Ranges are in pairs (I/O port base and size).
Linus Torvalds1da177e2005-04-16 15:20:36 -07001584
1585 pnp_reserve_mem=
Randy Dunlapa9913042005-10-23 12:57:11 -07001586 [ISAPNP] Exclude memory regions for the
1587 autoconfiguration.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001588 Ranges are in pairs (memory base and size).
1589
Ingo Molnar45807a12007-07-15 23:40:10 -07001590 print-fatal-signals=
1591 [KNL] debug: print fatal signals
1592 print-fatal-signals=1: print segfault info to
1593 the kernel console.
1594 default: off.
1595
Randy Dunlape84845c2007-07-15 23:40:25 -07001596 printk.time= Show timing data prefixed to each printk message line
1597 Format: <bool> (1/Y/y=enable, 0/N/n=disable)
1598
Linus Torvalds1da177e2005-04-16 15:20:36 -07001599 profile= [KNL] Enable kernel profiling via /proc/profile
Randy Dunlapa9913042005-10-23 12:57:11 -07001600 Format: [schedule,]<number>
1601 Param: "schedule" - profile schedule points.
1602 Param: <number> - step/bucket size as a power of 2 for
1603 statistical time based profiling.
Mel Gormanb3da2a72007-10-24 18:23:50 +02001604 Param: "sleep" - profile D-state sleeping (millisecs).
1605 Requires CONFIG_SCHEDSTATS
Dave Jonesc0fe2e62007-10-20 03:08:22 +02001606 Param: "kvm" - profile VM exits.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001607
Randy Dunlapa9913042005-10-23 12:57:11 -07001608 processor.max_cstate= [HW,ACPI]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001609 Limit processor to maximum C-state
1610 max_cstate=9 overrides any DMI blacklist limit.
1611
Len Brown41c0d862005-12-28 12:43:51 -05001612 processor.nocst [HW,ACPI]
1613 Ignore the _CST method to determine C-states,
1614 instead using the legacy FADT method
1615
Linus Torvalds1da177e2005-04-16 15:20:36 -07001616 prompt_ramdisk= [RAM] List of RAM disks to prompt for floppy disk
1617 before loading.
1618 See Documentation/ramdisk.txt.
1619
Randy Dunlapa9913042005-10-23 12:57:11 -07001620 psmouse.proto= [HW,MOUSE] Highest PS2 mouse protocol extension to
1621 probe for; one of (bare|imps|exps|lifebook|any).
Linus Torvalds1da177e2005-04-16 15:20:36 -07001622 psmouse.rate= [HW,MOUSE] Set desired mouse report rate, in reports
1623 per second.
Randy Dunlapa9913042005-10-23 12:57:11 -07001624 psmouse.resetafter= [HW,MOUSE]
1625 Try to reset the device after so many bad packets
Linus Torvalds1da177e2005-04-16 15:20:36 -07001626 (0 = never).
1627 psmouse.resolution=
1628 [HW,MOUSE] Set desired mouse resolution, in dpi.
1629 psmouse.smartscroll=
Randy Dunlapa9913042005-10-23 12:57:11 -07001630 [HW,MOUSE] Controls Logitech smartscroll autorepeat.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001631 0 = disabled, 1 = enabled (default).
1632
1633 pss= [HW,OSS] Personal Sound System (ECHO ESC614)
Randy Dunlapa9913042005-10-23 12:57:11 -07001634 Format:
1635 <io>,<mss_io>,<mss_irq>,<mss_dma>,<mpu_io>,<mpu_irq>
Linus Torvalds1da177e2005-04-16 15:20:36 -07001636
1637 pt. [PARIDE]
1638 See Documentation/paride.txt.
1639
Kay Sieversdc8c8582007-08-15 12:25:38 +02001640 pty.legacy_count=
1641 [KNL] Number of legacy pty's. Overwrites compiled-in
1642 default number.
1643
Randy Dunlap7d2c5022006-09-29 02:01:02 -07001644 quiet [KNL] Disable most log messages
Randy Dunlapa9913042005-10-23 12:57:11 -07001645
Linus Torvalds1da177e2005-04-16 15:20:36 -07001646 r128= [HW,DRM]
1647
1648 raid= [HW,RAID]
1649 See Documentation/md.txt.
1650
Randy Dunlapa9913042005-10-23 12:57:11 -07001651 ramdisk_blocksize= [RAM]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001652 See Documentation/ramdisk.txt.
Randy Dunlapa9913042005-10-23 12:57:11 -07001653
Linus Torvalds1da177e2005-04-16 15:20:36 -07001654 ramdisk_size= [RAM] Sizes of RAM disks in kilobytes
Linus Torvalds1da177e2005-04-16 15:20:36 -07001655 See Documentation/ramdisk.txt.
1656
Robert P. J. Day24aaef82008-02-03 15:20:26 +02001657 rcupdate.blimit= [KNL,BOOT]
1658 Set maximum number of finished RCU callbacks to process
1659 in one batch.
Dipankar Sarma21a1ea92006-03-07 21:55:33 -08001660
Robert P. J. Day24aaef82008-02-03 15:20:26 +02001661 rcupdate.qhimark= [KNL,BOOT]
1662 Set threshold of queued
Dipankar Sarma21a1ea92006-03-07 21:55:33 -08001663 RCU callbacks over which batch limiting is disabled.
1664
Robert P. J. Day24aaef82008-02-03 15:20:26 +02001665 rcupdate.qlowmark= [KNL,BOOT]
1666 Set threshold of queued RCU callbacks below which
1667 batch limiting is re-enabled.
Dipankar Sarma21a1ea92006-03-07 21:55:33 -08001668
Olof Johanssonffdfc402005-09-06 15:17:19 -07001669 rdinit= [KNL]
1670 Format: <full_path>
1671 Run specified binary instead of /init from the ramdisk,
1672 used for early userspace startup. See initrd.
1673
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001674 reboot= [BUGS=X86-32,BUGS=ARM,BUGS=IA-64] Rebooting mode
Linus Torvalds1da177e2005-04-16 15:20:36 -07001675 Format: <reboot_mode>[,<reboot_mode2>[,...]]
Mauro Carvalho Chehabe53dd082007-09-15 07:38:47 -03001676 See arch/*/kernel/reboot.c or arch/*/kernel/process.c
Linus Torvalds1da177e2005-04-16 15:20:36 -07001677
1678 reserve= [KNL,BUGS] Force the kernel to ignore some iomem area
1679
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001680 reservetop= [X86-32]
Zachary Amsden461a9af2006-09-25 23:32:25 -07001681 Format: nn[KMG]
1682 Reserves a hole at the top of the kernel virtual
1683 address space.
1684
Vivek Goyal7e962872006-09-27 01:50:44 -07001685 reset_devices [KNL] Force drivers to reset the underlying device
1686 during initialization.
1687
Randy Dunlapa9913042005-10-23 12:57:11 -07001688 resume= [SWSUSP]
1689 Specify the partition device for software suspend
Linus Torvalds1da177e2005-04-16 15:20:36 -07001690
Rafael J. Wysockiecbd0da2006-12-06 20:34:13 -08001691 resume_offset= [SWSUSP]
1692 Specify the offset from the beginning of the partition
1693 given by "resume=" at which the swap header is located,
1694 in <PAGE_SIZE> units (needed only for swap files).
1695 See Documentation/power/swsusp-and-swap-files.txt
1696
Michael Neuling0a7b35cb2007-02-10 01:44:33 -08001697 retain_initrd [RAM] Keep initrd memory after extraction
1698
Linus Torvalds1da177e2005-04-16 15:20:36 -07001699 rhash_entries= [KNL,NET]
1700 Set number of hash buckets for route cache
1701
1702 riscom8= [HW,SERIAL]
1703 Format: <io_board1>[,<io_board2>[,...<io_boardN>]]
1704
1705 ro [KNL] Mount root device read-only on boot
1706
1707 root= [KNL] Root filesystem
1708
1709 rootdelay= [KNL] Delay (in seconds) to pause before attempting to
1710 mount the root filesystem
1711
1712 rootflags= [KNL] Set root filesystem mount option string
1713
1714 rootfstype= [KNL] Set root filesystem type
1715
Pierre Ossmancc1ed752007-07-15 23:40:35 -07001716 rootwait [KNL] Wait (indefinitely) for root device to show up.
1717 Useful for devices that are detected asynchronously
1718 (e.g. USB and MMC devices).
1719
James Morris20510f22007-10-16 23:31:32 -07001720 root_plug.vendor_id=
1721 [ROOTPLUG] Override the default vendor ID
1722
1723 root_plug.product_id=
1724 [ROOTPLUG] Override the default product ID
1725
1726 root_plug.debug=
1727 [ROOTPLUG] Enable debugging output
1728
Linus Torvalds1da177e2005-04-16 15:20:36 -07001729 rw [KNL] Mount root device read-write on boot
1730
1731 S [KNL] Run init in single mode
1732
1733 sa1100ir [NET]
1734 See drivers/net/irda/sa1100_ir.c.
1735
Linus Torvalds1da177e2005-04-16 15:20:36 -07001736 sbni= [NET] Granch SBNI12 leased line adapter
Randy Dunlapa9913042005-10-23 12:57:11 -07001737
Linus Torvalds1da177e2005-04-16 15:20:36 -07001738 sc1200wdt= [HW,WDT] SC1200 WDT (watchdog) driver
1739 Format: <io>[,<timeout>[,<isapnp>]]
1740
1741 scsi_debug_*= [SCSI]
1742 See drivers/scsi/scsi_debug.c.
1743
1744 scsi_default_dev_flags=
1745 [SCSI] SCSI default device flags
1746 Format: <integer>
1747
1748 scsi_dev_flags= [SCSI] Black/white list entry for vendor and model
1749 Format: <vendor>:<model>:<flags>
1750 (flags are integer value)
1751
Randy Dunlap6af66322007-11-14 16:52:25 -08001752 scsi_logging_level= [SCSI] a bit mask of logging levels
1753 See drivers/scsi/scsi_logging.h for bits. Also
1754 settable via sysctl at dev.scsi.logging_level
1755 (/proc/sys/dev/scsi/logging_level).
1756 There is also a nice 'scsi_logging_level' script in the
1757 S390-tools package, available for download at
1758 http://www-128.ibm.com/developerworks/linux/linux390/s390-tools-1.5.4.html
Linus Torvalds1da177e2005-04-16 15:20:36 -07001759
Matthew Wilcox3e082a92006-09-28 15:19:20 -06001760 scsi_mod.scan= [SCSI] sync (default) scans SCSI busses as they are
1761 discovered. async scans them in kernel threads,
1762 allowing boot to proceed. none ignores them, expecting
1763 user space to do the scan.
1764
Linus Torvalds1da177e2005-04-16 15:20:36 -07001765 selinux [SELINUX] Disable or enable SELinux at boot time.
1766 Format: { "0" | "1" }
1767 See security/selinux/Kconfig help text.
1768 0 -- disable.
1769 1 -- enable.
1770 Default value is set via kernel config option.
1771 If enabled at boot time, /selinux/disable can be used
1772 later to disable prior to initial policy load.
1773
James Morris4e5ab4c2006-06-09 00:33:33 -07001774 selinux_compat_net =
1775 [SELINUX] Set initial selinux_compat_net flag value.
Mauro Carvalho Chehabe53dd082007-09-15 07:38:47 -03001776 Format: { "0" | "1" }
1777 0 -- use new secmark-based packet controls
1778 1 -- use legacy packet controls
1779 Default value is 0 (preferred).
1780 Value can be changed at runtime via
1781 /selinux/compat_net.
James Morris4e5ab4c2006-06-09 00:33:33 -07001782
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001783 serialnumber [BUGS=X86-32]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001784
Linus Torvalds1da177e2005-04-16 15:20:36 -07001785 shapers= [NET]
1786 Maximal number of shapers.
Randy Dunlapa9913042005-10-23 12:57:11 -07001787
Linus Torvalds1da177e2005-04-16 15:20:36 -07001788 sim710= [SCSI,HW]
1789 See header of drivers/scsi/sim710.c.
1790
1791 simeth= [IA-64]
1792 simscsi=
Randy Dunlapa9913042005-10-23 12:57:11 -07001793
Linus Torvalds1da177e2005-04-16 15:20:36 -07001794 slram= [HW,MTD]
1795
Christoph Lameterf0630ff2007-07-15 23:38:14 -07001796 slub_debug[=options[,slabs]] [MM, SLUB]
1797 Enabling slub_debug allows one to determine the
1798 culprit if slab objects become corrupted. Enabling
1799 slub_debug can create guard zones around objects and
1800 may poison objects when not in use. Also tracks the
1801 last alloc / free. For more information see
1802 Documentation/vm/slub.txt.
Christoph Lameterc1aee212007-05-31 00:40:47 -07001803
1804 slub_max_order= [MM, SLUB]
Christoph Lameterf0630ff2007-07-15 23:38:14 -07001805 Determines the maximum allowed order for slabs.
1806 A high setting may cause OOMs due to memory
1807 fragmentation. For more information see
1808 Documentation/vm/slub.txt.
Christoph Lameterc1aee212007-05-31 00:40:47 -07001809
1810 slub_min_objects= [MM, SLUB]
Christoph Lameterf0630ff2007-07-15 23:38:14 -07001811 The minimum number of objects per slab. SLUB will
1812 increase the slab order up to slub_max_order to
1813 generate a sufficiently large slab able to contain
1814 the number of objects indicated. The higher the number
1815 of objects the smaller the overhead of tracking slabs
1816 and the less frequently locks need to be acquired.
Christoph Lameterc1aee212007-05-31 00:40:47 -07001817 For more information see Documentation/vm/slub.txt.
1818
1819 slub_min_order= [MM, SLUB]
1820 Determines the mininum page order for slabs. Must be
Christoph Lameterf0630ff2007-07-15 23:38:14 -07001821 lower than slub_max_order.
Christoph Lameterc1aee212007-05-31 00:40:47 -07001822 For more information see Documentation/vm/slub.txt.
1823
1824 slub_nomerge [MM, SLUB]
Christoph Lameterf0630ff2007-07-15 23:38:14 -07001825 Disable merging of slabs with similar size. May be
Christoph Lameterc1aee212007-05-31 00:40:47 -07001826 necessary if there is some reason to distinguish
Christoph Lameterf0630ff2007-07-15 23:38:14 -07001827 allocs to different slabs. Debug options disable
1828 merging on their own.
Christoph Lameterc1aee212007-05-31 00:40:47 -07001829 For more information see Documentation/vm/slub.txt.
1830
Linus Torvalds1da177e2005-04-16 15:20:36 -07001831 smart2= [HW]
1832 Format: <io1>[,<io2>[,...,<io8>]]
1833
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001834 smp-alt-once [X86-32,SMP] On a hotplug CPU system, only
Jeremy Fitzhardingeb7fb4af2007-05-02 19:27:13 +02001835 attempt to substitute SMP alternatives once at boot.
1836
Bjorn Helgaasd0d4f692007-05-08 00:36:05 -07001837 smsc-ircc2.nopnp [HW] Don't use PNP to discover SMC devices
1838 smsc-ircc2.ircc_cfg= [HW] Device configuration I/O port
1839 smsc-ircc2.ircc_sir= [HW] SIR base I/O port
1840 smsc-ircc2.ircc_fir= [HW] FIR base I/O port
1841 smsc-ircc2.ircc_irq= [HW] IRQ line
1842 smsc-ircc2.ircc_dma= [HW] DMA channel
1843 smsc-ircc2.ircc_transceiver= [HW] Transceiver type:
1844 0: Toshiba Satellite 1800 (GP data pin select)
1845 1: Fast pin select (default)
1846 2: ATC IRMode
1847
Linus Torvalds1da177e2005-04-16 15:20:36 -07001848 snd-ad1816a= [HW,ALSA]
1849
1850 snd-ad1848= [HW,ALSA]
1851
1852 snd-ali5451= [HW,ALSA]
1853
1854 snd-als100= [HW,ALSA]
1855
1856 snd-als4000= [HW,ALSA]
1857
1858 snd-azt2320= [HW,ALSA]
1859
1860 snd-cmi8330= [HW,ALSA]
1861
1862 snd-cmipci= [HW,ALSA]
1863
1864 snd-cs4231= [HW,ALSA]
1865
1866 snd-cs4232= [HW,ALSA]
1867
1868 snd-cs4236= [HW,ALSA]
1869
1870 snd-cs4281= [HW,ALSA]
1871
1872 snd-cs46xx= [HW,ALSA]
1873
1874 snd-dt019x= [HW,ALSA]
1875
1876 snd-dummy= [HW,ALSA]
1877
1878 snd-emu10k1= [HW,ALSA]
1879
1880 snd-ens1370= [HW,ALSA]
1881
1882 snd-ens1371= [HW,ALSA]
1883
1884 snd-es968= [HW,ALSA]
1885
1886 snd-es1688= [HW,ALSA]
1887
1888 snd-es18xx= [HW,ALSA]
1889
1890 snd-es1938= [HW,ALSA]
1891
1892 snd-es1968= [HW,ALSA]
1893
1894 snd-fm801= [HW,ALSA]
1895
1896 snd-gusclassic= [HW,ALSA]
1897
1898 snd-gusextreme= [HW,ALSA]
1899
1900 snd-gusmax= [HW,ALSA]
1901
1902 snd-hdsp= [HW,ALSA]
1903
1904 snd-ice1712= [HW,ALSA]
1905
1906 snd-intel8x0= [HW,ALSA]
1907
1908 snd-interwave= [HW,ALSA]
1909
1910 snd-interwave-stb=
1911 [HW,ALSA]
1912
1913 snd-korg1212= [HW,ALSA]
1914
1915 snd-maestro3= [HW,ALSA]
1916
1917 snd-mpu401= [HW,ALSA]
1918
1919 snd-mtpav= [HW,ALSA]
1920
1921 snd-nm256= [HW,ALSA]
1922
1923 snd-opl3sa2= [HW,ALSA]
1924
1925 snd-opti92x-ad1848=
1926 [HW,ALSA]
1927
1928 snd-opti92x-cs4231=
1929 [HW,ALSA]
1930
1931 snd-opti93x= [HW,ALSA]
1932
1933 snd-pmac= [HW,ALSA]
1934
1935 snd-rme32= [HW,ALSA]
1936
1937 snd-rme96= [HW,ALSA]
1938
1939 snd-rme9652= [HW,ALSA]
1940
1941 snd-sb8= [HW,ALSA]
1942
1943 snd-sb16= [HW,ALSA]
1944
1945 snd-sbawe= [HW,ALSA]
1946
1947 snd-serial= [HW,ALSA]
1948
1949 snd-sgalaxy= [HW,ALSA]
1950
1951 snd-sonicvibes= [HW,ALSA]
1952
1953 snd-sun-amd7930=
1954 [HW,ALSA]
1955
1956 snd-sun-cs4231= [HW,ALSA]
1957
1958 snd-trident= [HW,ALSA]
1959
1960 snd-usb-audio= [HW,ALSA,USB]
1961
1962 snd-via82xx= [HW,ALSA]
1963
1964 snd-virmidi= [HW,ALSA]
1965
1966 snd-wavefront= [HW,ALSA]
1967
1968 snd-ymfpci= [HW,ALSA]
Randy Dunlapa9913042005-10-23 12:57:11 -07001969
Linus Torvalds1da177e2005-04-16 15:20:36 -07001970 sonypi.*= [HW] Sony Programmable I/O Control Device driver
1971 See Documentation/sonypi.txt
1972
1973 specialix= [HW,SERIAL] Specialix multi-serial port adapter
1974 See Documentation/specialix.txt.
1975
1976 spia_io_base= [HW,MTD]
1977 spia_fio_base=
1978 spia_pedr=
1979 spia_peddr=
1980
1981 sscape= [HW,OSS]
1982 Format: <io>,<irq>,<dma>,<mpu_io>,<mpu_irq>
Randy Dunlapa9913042005-10-23 12:57:11 -07001983
Linus Torvalds1da177e2005-04-16 15:20:36 -07001984 st= [HW,SCSI] SCSI tape parameters (buffers, etc.)
1985 See Documentation/scsi/st.txt.
1986
Linus Torvalds1da177e2005-04-16 15:20:36 -07001987 sti= [PARISC,HW]
1988 Format: <num>
1989 Set the STI (builtin display/keyboard on the HP-PARISC
1990 machines) console (graphic card) which should be used
1991 as the initial boot-console.
1992 See also comment in drivers/video/console/sticore.c.
1993
1994 sti_font= [HW]
1995 See comment in drivers/video/console/sticore.c.
1996
1997 stifb= [HW]
1998 Format: bpp:<bpp1>[:<bpp2>[:<bpp3>...]]
1999
Greg Banks42a7fc42007-03-06 01:42:23 -08002000 sunrpc.pool_mode=
2001 [NFS]
2002 Control how the NFS server code allocates CPUs to
2003 service thread pools. Depending on how many NICs
2004 you have and where their interrupts are bound, this
2005 option will affect which CPUs will do NFS serving.
2006 Note: this parameter cannot be changed while the
2007 NFS server is running.
2008
2009 auto the server chooses an appropriate mode
2010 automatically using heuristics
2011 global a single global pool contains all CPUs
2012 percpu one pool for each CPU
2013 pernode one pool for each NUMA node (equivalent
2014 to global on non-NUMA machines)
2015
Linus Torvalds1da177e2005-04-16 15:20:36 -07002016 swiotlb= [IA-64] Number of I/O TLB slabs
Randy Dunlapa9913042005-10-23 12:57:11 -07002017
Linus Torvalds1da177e2005-04-16 15:20:36 -07002018 switches= [HW,M68k]
2019
2020 sym53c416= [HW,SCSI]
2021 See header of drivers/scsi/sym53c416.c.
2022
Ingo Molnar5d6f6472006-12-13 00:34:36 -08002023 sysrq_always_enabled
2024 [KNL]
2025 Ignore sysrq setting - this boot parameter will
2026 neutralize any effect of /proc/sys/kernel/sysrq.
2027 Useful for debugging.
2028
Linus Torvalds1da177e2005-04-16 15:20:36 -07002029 t128= [HW,SCSI]
2030 See header of drivers/scsi/t128.c.
2031
2032 tdfx= [HW,DRM]
2033
2034 thash_entries= [KNL,NET]
2035 Set number of hash buckets for TCP connection
2036
Len Brownf8707ec2007-08-12 00:12:54 -04002037 thermal.act= [HW,ACPI]
2038 -1: disable all active trip points in all thermal zones
2039 <degrees C>: override all lowest active trip points
2040
Len Brownc52a7412007-08-14 15:49:32 -04002041 thermal.crt= [HW,ACPI]
2042 -1: disable all critical trip points in all thermal zones
2043 <degrees C>: lower all critical trip points
2044
Len Brownf5487142007-08-12 00:12:44 -04002045 thermal.nocrt= [HW,ACPI]
2046 Set to disable actions on ACPI thermal zone
2047 critical and hot trip points.
2048
Len Brown72b33ef2007-08-12 00:12:17 -04002049 thermal.off= [HW,ACPI]
2050 1: disable ACPI thermal control
2051
Len Browna70cdc52007-08-12 00:12:35 -04002052 thermal.psv= [HW,ACPI]
2053 -1: disable all passive trip points
2054 <degrees C>: override all passive trip points to this value
2055
Len Brown730ff342007-08-12 00:12:26 -04002056 thermal.tzp= [HW,ACPI]
2057 Specify global default ACPI thermal zone polling rate
2058 <deci-seconds>: poll all this frequency
2059 0: no polling (default)
2060
Linus Torvalds1da177e2005-04-16 15:20:36 -07002061 tipar.timeout= [HW,PPT]
2062 Set communications timeout in tenths of a second
2063 (default 15).
2064
2065 tipar.delay= [HW,PPT]
2066 Set inter-bit delay in microseconds (default 10).
2067
Linus Torvalds1da177e2005-04-16 15:20:36 -07002068 tmscsim= [HW,SCSI]
2069 See comment before function dc390_setup() in
2070 drivers/scsi/tmscsim.c.
2071
2072 tp720= [HW,PS2]
2073
2074 trix= [HW,OSS] MediaTrix AudioTrix Pro
Randy Dunlapa9913042005-10-23 12:57:11 -07002075 Format:
2076 <io>,<irq>,<dma>,<dma2>,<sb_io>,<sb_irq>,<sb_dma>,<mpu_io>,<mpu_irq>
2077
Randy Dunlapa9913042005-10-23 12:57:11 -07002078 turbografx.map[2|3]= [HW,JOY]
2079 TurboGraFX parallel port interface
2080 Format:
2081 <port#>,<js1>,<js2>,<js3>,<js4>,<js5>,<js6>,<js7>
Linus Torvalds1da177e2005-04-16 15:20:36 -07002082 See also Documentation/input/joystick-parport.txt
2083
2084 u14-34f= [HW,SCSI] UltraStor 14F/34F SCSI host adapter
2085 See header of drivers/scsi/u14-34f.c.
2086
2087 uart401= [HW,OSS]
2088 Format: <io>,<irq>
2089
2090 uart6850= [HW,OSS]
2091 Format: <io>,<irq>
2092
Alan Stern5f8364b2006-12-05 16:29:55 -05002093 uhci-hcd.ignore_oc=
2094 [USB] Ignore overcurrent events (default N).
2095 Some badly-designed motherboards generate lots of
2096 bogus events, for ports that aren't wired to
2097 anything. Set this parameter to avoid log spamming.
2098 Note that genuine overcurrent events won't be
2099 reported either.
2100
Alan Sternb5e795f2007-02-20 15:00:53 -05002101 usbcore.autosuspend=
2102 [USB] The autosuspend time delay (in seconds) used
2103 for newly-detected USB devices (default 2). This
2104 is the time required before an idle device will be
2105 autosuspended. Devices for which the delay is set
Alan Sterneaafbc32007-03-13 16:39:15 -04002106 to a negative value won't be autosuspended at all.
Alan Sternb5e795f2007-02-20 15:00:53 -05002107
Linus Torvalds1da177e2005-04-16 15:20:36 -07002108 usbhid.mousepoll=
2109 [USBHID] The interval which mice are to be polled at.
Randy Dunlapa9913042005-10-23 12:57:11 -07002110
Alan Coxcd4f0ef2007-07-31 00:37:59 -07002111 vdso= [X86-32,SH,x86-64]
Jeremy Fitzhardinge1dbf527c2007-05-02 19:27:12 +02002112 vdso=2: enable compat VDSO (default with COMPAT_VDSO)
Ingo Molnare6e54942006-06-27 02:53:50 -07002113 vdso=1: enable VDSO (default)
2114 vdso=0: disable VDSO mapping
2115
Roland McGrathaf65d642008-01-30 13:30:43 +01002116 vdso32= [X86-32,X86-64]
2117 vdso32=2: enable compat VDSO (default with COMPAT_VDSO)
2118 vdso32=1: enable 32-bit VDSO (default)
2119 vdso32=0: disable 32-bit VDSO mapping
2120
Yasuaki Ishimatsud080d392007-07-17 21:22:55 +09002121 vector= [IA-64,SMP]
2122 vector=percpu: enable percpu vector domain
2123
Linus Torvalds1da177e2005-04-16 15:20:36 -07002124 video= [FB] Frame buffer configuration
2125 See Documentation/fb/modedb.txt.
2126
Alan Coxcd4f0ef2007-07-31 00:37:59 -07002127 vga= [BOOT,X86-32] Select a particular video mode
Randy Dunlapa9913042005-10-23 12:57:11 -07002128 See Documentation/i386/boot.txt and
2129 Documentation/svga.txt.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002130 Use vga=ask for menu.
2131 This is actually a boot loader parameter; the value is
2132 passed to the kernel using a special protocol.
2133
Randy Dunlapa9913042005-10-23 12:57:11 -07002134 vmalloc=nn[KMG] [KNL,BOOT] Forces the vmalloc area to have an exact
Linus Torvalds1da177e2005-04-16 15:20:36 -07002135 size of <nn>. This can be used to increase the
2136 minimum size (128MB on x86). It can also be used to
2137 decrease the size and leave more room for directly
2138 mapped kernel RAM.
2139
Peter Oberparleiter585c3042006-06-29 15:08:25 +02002140 vmhalt= [KNL,S390] Perform z/VM CP command after system halt.
2141 Format: <command>
Linus Torvalds1da177e2005-04-16 15:20:36 -07002142
Peter Oberparleiter585c3042006-06-29 15:08:25 +02002143 vmpanic= [KNL,S390] Perform z/VM CP command after kernel panic.
2144 Format: <command>
2145
2146 vmpoff= [KNL,S390] Perform z/VM CP command after power off.
2147 Format: <command>
Randy Dunlapa9913042005-10-23 12:57:11 -07002148
Linus Torvalds1da177e2005-04-16 15:20:36 -07002149 waveartist= [HW,OSS]
2150 Format: <io>,<irq>,<dma>,<dma2>
Randy Dunlapa9913042005-10-23 12:57:11 -07002151
Linus Torvalds1da177e2005-04-16 15:20:36 -07002152 wd33c93= [HW,SCSI]
2153 See header of drivers/scsi/wd33c93.c.
2154
2155 wd7000= [HW,SCSI]
2156 See header of drivers/scsi/wd7000.c.
2157
2158 wdt= [WDT] Watchdog
Gabriel C8dfe9c22007-08-10 13:01:00 -07002159 See Documentation/watchdog/wdt.txt.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002160
2161 xd= [HW,XT] Original XT pre-IDE (RLL encoded) disks.
2162 xd_geo= See header of drivers/block/xd.c.
2163
2164 xirc2ps_cs= [NET,PCMCIA]
Randy Dunlapa9913042005-10-23 12:57:11 -07002165 Format:
2166 <irq>,<irq_mask>,<io>,<full_duplex>,<do_sound>,<lockup_hack>[,<irq2>[,<irq3>[,<irq4>]]]
Linus Torvalds1da177e2005-04-16 15:20:36 -07002167
Andi Kleena62eaf12006-02-16 23:41:58 +01002168 norandmaps Don't use address space randomization
2169 Equivalent to echo 0 > /proc/sys/kernel/randomize_va_space
2170
Randy Dunlapa9913042005-10-23 12:57:11 -07002171______________________________________________________________________
Linus Torvalds1da177e2005-04-16 15:20:36 -07002172
2173TODO:
2174
2175 Add documentation for ALSA options.
2176 Add more DRM drivers.