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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.
Mimi Zohar6146f0d2009-02-04 09:06:57 -050047 IMA Integrity measurement architecture is enabled.
Linus Torvalds1da177e2005-04-16 15:20:36 -070048 IOSCHED More than one I/O scheduler is enabled.
Adrian Bunk41e2e8b2005-07-12 13:58:33 -070049 IP_PNP IP DHCP, BOOTP, or RARP is enabled.
Linus Torvalds1da177e2005-04-16 15:20:36 -070050 ISAPNP ISA PnP code is enabled.
51 ISDN Appropriate ISDN support is enabled.
52 JOY Appropriate joystick support is enabled.
Kristen Carlson Accardi11ef6972006-09-28 11:29:01 -070053 LIBATA Libata driver is enabled
Linus Torvalds1da177e2005-04-16 15:20:36 -070054 LP Printer support is enabled.
55 LOOP Loopback device support is enabled.
56 M68k M68k architecture is enabled.
57 These options have more detailed description inside of
58 Documentation/m68k/kernel-options.txt.
59 MCA MCA bus support is enabled.
60 MDA MDA console support is enabled.
61 MOUSE Appropriate mouse support is enabled.
Matthew Wilcox309e57d2006-03-05 22:33:34 -070062 MSI Message Signaled Interrupts (PCI).
Randy Dunlapc8facbb2007-07-31 00:37:40 -070063 MTD MTD (Memory Technology Device) support is enabled.
Linus Torvalds1da177e2005-04-16 15:20:36 -070064 NET Appropriate network support is enabled.
65 NUMA NUMA support is enabled.
john stultz734efb42006-06-26 00:25:05 -070066 GENERIC_TIME The generic timeofday code is enabled.
Linus Torvalds1da177e2005-04-16 15:20:36 -070067 NFS Appropriate NFS support is enabled.
68 OSS OSS sound support is enabled.
Randy Dunlapc8facbb2007-07-31 00:37:40 -070069 PV_OPS A paravirtualized kernel is enabled.
70 PARIDE The ParIDE (parallel port IDE) subsystem is enabled.
Linus Torvalds1da177e2005-04-16 15:20:36 -070071 PARISC The PA-RISC architecture is enabled.
72 PCI PCI bus support is enabled.
Randy Dunlap7f785762007-10-05 13:17:58 -070073 PCIE PCI Express support is enabled.
Linus Torvalds1da177e2005-04-16 15:20:36 -070074 PCMCIA The PCMCIA subsystem is enabled.
75 PNP Plug & Play support is enabled.
76 PPC PowerPC architecture is enabled.
77 PPT Parallel port support is enabled.
78 PS2 Appropriate PS/2 support is enabled.
79 RAM RAM disk support is enabled.
James Morris20510f22007-10-16 23:31:32 -070080 ROOTPLUG The example Root Plug LSM is enabled.
Linus Torvalds1da177e2005-04-16 15:20:36 -070081 S390 S390 architecture is enabled.
82 SCSI Appropriate SCSI support is enabled.
83 A lot of drivers has their options described inside of
84 Documentation/scsi/.
James Morris20510f22007-10-16 23:31:32 -070085 SECURITY Different security models are enabled.
Linus Torvalds1da177e2005-04-16 15:20:36 -070086 SELINUX SELinux support is enabled.
87 SERIAL Serial support is enabled.
Paul Mundte523d932007-02-28 18:30:01 +090088 SH SuperH architecture is enabled.
Linus Torvalds1da177e2005-04-16 15:20:36 -070089 SMP The kernel is an SMP kernel.
90 SPARC Sparc architecture is enabled.
David Brownell77437fd2008-07-23 21:28:33 -070091 SWSUSP Software suspend (hibernation) is enabled.
92 SUSPEND System suspend states are enabled.
Steven Rostedtf38f1d22008-12-16 23:06:40 -050093 FTRACE Function tracing enabled.
Linus Torvalds1da177e2005-04-16 15:20:36 -070094 TS Appropriate touchscreen support is enabled.
Alan Sternd4f373e2008-11-10 14:07:45 -050095 UMS USB Mass Storage support is enabled.
Linus Torvalds1da177e2005-04-16 15:20:36 -070096 USB USB support is enabled.
97 USBHID USB Human Interface Device support is enabled.
98 V4L Video For Linux support is enabled.
99 VGA The VGA console has been enabled.
100 VT Virtual terminal support is enabled.
101 WDT Watchdog support is enabled.
102 XT IBM PC/XT MFM hard disk support is enabled.
Alan Coxcd4f0ef2007-07-31 00:37:59 -0700103 X86-32 X86-32, aka i386 architecture is enabled.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700104 X86-64 X86-64 architecture is enabled.
105 More X86-64 boot options can be found in
Uwe Hermann71cced62008-10-20 09:32:21 -0700106 Documentation/x86/x86_64/boot-options.txt .
Andi Kleenc0115602008-08-22 09:53:39 +0200107 X86 Either 32bit or 64bit x86 (same as X86-32+X86-64)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700108
109In addition, the following text indicates that the option:
110
111 BUGS= Relates to possible processor bugs on the said processor.
112 KNL Is a kernel start-up parameter.
113 BOOT Is a boot loader parameter.
114
115Parameters denoted with BOOT are actually interpreted by the boot
116loader, and have no meaning to the kernel directly.
117Do not modify the syntax of boot loader parameters without extreme
Kyle McMartin954a8b82009-02-19 16:48:14 -0500118need or coordination with <Documentation/x86/boot.txt>.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700119
Karsten Weiss55588702007-02-13 13:26:21 +0100120There are also arch-specific kernel-parameters not documented here.
Uwe Hermann71cced62008-10-20 09:32:21 -0700121See for example <Documentation/x86/x86_64/boot-options.txt>.
Karsten Weiss55588702007-02-13 13:26:21 +0100122
Linus Torvalds1da177e2005-04-16 15:20:36 -0700123Note that ALL kernel parameters listed below are CASE SENSITIVE, and that
124a trailing = on the name of any parameter states that that parameter will
125be entered as an environment variable, whereas its absence indicates that
126it will appear as a kernel argument readable via /proc/cmdline by programs
127running once the system is up.
128
jens m. noedler9c4751f2006-09-29 02:00:27 -0700129The number of kernel parameters is not limited, but the length of the
130complete command line (parameters including spaces etc.) is limited to
131a fixed number of characters. This limit depends on the architecture
132and is between 256 and 4096 characters. It is defined in the file
133./include/asm/setup.h as COMMAND_LINE_SIZE.
134
135
Bernhard Walle03d926f2007-03-06 02:29:44 -0800136 acpi= [HW,ACPI,X86-64,i386]
137 Advanced Configuration and Power Interface
Randy Dunlapaf23f572009-02-22 17:05:22 -0800138 Format: { force | off | ht | strict | noirq | rsdt }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700139 force -- enable ACPI if default was off
140 off -- disable ACPI if default was on
141 noirq -- do not use ACPI for IRQ routing
142 ht -- run only enough ACPI to enable Hyper Threading
Randy Dunlapa9913042005-10-23 12:57:11 -0700143 strict -- Be less tolerant of platforms that are not
Linus Torvalds1da177e2005-04-16 15:20:36 -0700144 strictly ACPI specification compliant.
Zhao Yakui237889b2008-12-17 16:55:18 +0800145 rsdt -- prefer RSDT over (default) XSDT
Linus Torvalds1da177e2005-04-16 15:20:36 -0700146
Randy Dunlap53471122008-03-12 18:10:51 -0400147 See also Documentation/power/pm.txt, pci=noacpi
Linus Torvalds1da177e2005-04-16 15:20:36 -0700148
Len Browna1fdcc02007-03-11 03:26:14 -0400149 acpi_apic_instance= [ACPI, IOAPIC]
150 Format: <int>
151 2: use 2nd APIC table, if available
152 1,0: use 1st APIC table
Len Brown4e381a42007-03-30 14:16:10 -0400153 default: 0
Len Browna1fdcc02007-03-11 03:26:14 -0400154
Linus Torvalds1da177e2005-04-16 15:20:36 -0700155 acpi_sleep= [HW,ACPI] Sleep options
Rafael J. Wysockiba84ed92008-10-26 20:56:30 +0100156 Format: { s3_bios, s3_mode, s3_beep, s4_nohwsig,
157 old_ordering, s4_nonvs }
Randy Dunlapada9cfd2008-12-19 10:57:32 -0800158 See Documentation/power/video.txt for information on
159 s3_bios and s3_mode.
Pavel Machek23b168d2008-02-05 19:27:12 +0100160 s3_beep is for debugging; it makes the PC's speaker beep
161 as soon as the kernel's real-mode entry point is called.
Shaohua Libdfe6b72008-07-23 21:28:41 -0700162 s4_nohwsig prevents ACPI hardware signature from being
163 used during resume from hibernation.
Rafael J. Wysockid8f3de02008-06-12 23:24:06 +0200164 old_ordering causes the ACPI 1.0 ordering of the _PTS
Randy Dunlapada9cfd2008-12-19 10:57:32 -0800165 control method, with respect to putting devices into
166 low power states, to be enforced (the ACPI 2.0 ordering
167 of _PTS is used by default).
Rafael J. Wysockiba84ed92008-10-26 20:56:30 +0100168 s4_nonvs prevents the kernel from saving/restoring the
169 ACPI NVS memory during hibernation.
Randy Dunlapa9913042005-10-23 12:57:11 -0700170
Linus Torvalds1da177e2005-04-16 15:20:36 -0700171 acpi_sci= [HW,ACPI] ACPI System Control Interrupt trigger mode
Randy Dunlapa9913042005-10-23 12:57:11 -0700172 Format: { level | edge | high | low }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700173
Randy Dunlapa9913042005-10-23 12:57:11 -0700174 acpi_irq_balance [HW,ACPI]
175 ACPI will balance active IRQs
176 default in APIC mode
Linus Torvalds1da177e2005-04-16 15:20:36 -0700177
Randy Dunlapa9913042005-10-23 12:57:11 -0700178 acpi_irq_nobalance [HW,ACPI]
179 ACPI will not move active IRQs (default)
180 default in PIC mode
Linus Torvalds1da177e2005-04-16 15:20:36 -0700181
Randy Dunlapa9913042005-10-23 12:57:11 -0700182 acpi_irq_pci= [HW,ACPI] If irq_balance, clear listed IRQs for
183 use by PCI
Linus Torvalds1da177e2005-04-16 15:20:36 -0700184 Format: <irq>,<irq>...
185
Randy Dunlapa9913042005-10-23 12:57:11 -0700186 acpi_irq_isa= [HW,ACPI] If irq_balance, mark listed IRQs used by ISA
Linus Torvalds1da177e2005-04-16 15:20:36 -0700187 Format: <irq>,<irq>...
188
Len Brown67effe82007-07-26 00:50:06 -0400189 acpi_no_auto_ssdt [HW,ACPI] Disable automatic loading of SSDT
190
Len Browna1f9e652006-01-25 23:47:36 -0500191 acpi_os_name= [HW,ACPI] Tell ACPI BIOS the name of the OS
192 Format: To spoof as Windows 98: ="Microsoft Windows"
193
Len Brownae00d812007-05-29 18:43:33 -0400194 acpi_osi= [HW,ACPI] Modify list of supported OS interface strings
195 acpi_osi="string1" # add string1 -- only one string
196 acpi_osi="!string2" # remove built-in string2
197 acpi_osi= # disable all strings
Linus Torvalds1da177e2005-04-16 15:20:36 -0700198
199 acpi_serialize [HW,ACPI] force serialization of AML methods
200
201 acpi_skip_timer_override [HW,ACPI]
202 Recognize and ignore IRQ0/pin2 Interrupt Override.
203 For broken nForce2 BIOS resulting in XT-PIC timer.
Randy Dunlapada9cfd2008-12-19 10:57:32 -0800204 acpi_use_timer_override [HW,ACPI]
Andi Kleenfa18f472006-11-14 16:57:46 +0100205 Use timer override. For some broken Nvidia NF5 boards
206 that require a timer override, but don't have
207 HPET
Linus Torvalds1da177e2005-04-16 15:20:36 -0700208
Thomas Renningerc3d6de62008-08-01 17:37:55 +0200209 acpi_backlight= [HW,ACPI]
210 acpi_backlight=vendor
211 acpi_backlight=video
212 If set to vendor, prefer vendor specific driver
213 (e.g. thinkpad_acpi, sony_acpi, etc.) instead
214 of the ACPI video.ko driver.
215
216 acpi_display_output= [HW,ACPI]
217 acpi_display_output=vendor
218 acpi_display_output=video
219 See above.
220
Bjorn Helgaasa0d84a92008-11-07 16:58:05 -0700221 acpi.debug_layer= [HW,ACPI,ACPI_DEBUG]
222 acpi.debug_level= [HW,ACPI,ACPI_DEBUG]
Linus Torvalds1da177e2005-04-16 15:20:36 -0700223 Format: <int>
Bjorn Helgaasa0d84a92008-11-07 16:58:05 -0700224 CONFIG_ACPI_DEBUG must be enabled to produce any ACPI
225 debug output. Bits in debug_layer correspond to a
226 _COMPONENT in an ACPI source file, e.g.,
227 #define _COMPONENT ACPI_PCI_COMPONENT
228 Bits in debug_level correspond to a level in
229 ACPI_DEBUG_PRINT statements, e.g.,
230 ACPI_DEBUG_PRINT((ACPI_DB_INFO, ...
Bjorn Helgaase76f4272008-11-13 17:30:13 -0600231 The debug_level mask defaults to "info". See
232 Documentation/acpi/debug.txt for more information about
233 debug layers and levels.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700234
Bjorn Helgaase76f4272008-11-13 17:30:13 -0600235 Enable processor driver info messages:
236 acpi.debug_layer=0x20000000
237 Enable PCI/PCI interrupt routing info messages:
238 acpi.debug_layer=0x400000
Bjorn Helgaasa0d84a92008-11-07 16:58:05 -0700239 Enable AML "Debug" output, i.e., stores to the Debug
240 object while interpreting AML:
241 acpi.debug_layer=0xffffffff acpi.debug_level=0x2
Bjorn Helgaasa0d84a92008-11-07 16:58:05 -0700242 Enable all messages related to ACPI hardware:
243 acpi.debug_layer=0x2 acpi.debug_level=0xffffffff
Thomas Renninger36eec5e2008-08-11 15:03:20 +0200244
Bjorn Helgaasa0d84a92008-11-07 16:58:05 -0700245 Some values produce so much output that the system is
246 unusable. The "log_buf_len" parameter may be useful
247 if you need to capture more output.
Zhang Ruif9891062007-04-24 13:53:22 +0800248
Zhao Yakuif5adfaa2008-08-11 14:57:50 +0800249 acpi.power_nocheck= [HW,ACPI]
250 Format: 1/0 enable/disable the check of power state.
251 On some bogus BIOS the _PSC object/_STA object of
252 power resource can't return the correct device power
253 state. In such case it is unneccessary to check its
254 power state again in power transition.
255 1 : disable the power state check
256
Alan Coxcd4f0ef2007-07-31 00:37:59 -0700257 acpi_pm_good [X86-32,X86-64]
john stultz5d0cf412006-06-26 00:25:12 -0700258 Override the pmtimer bug detection: force the kernel
259 to assume that this machine's pmtimer latches its value
260 and always returns good values.
261
Chuck Ebbertc99c1082007-07-27 10:46:20 +1000262 agp= [AGP]
263 { off | try_unsupported }
264 off: disable AGP support
265 try_unsupported: try to drive unsupported chipsets
266 (may crash computer or cause data corruption)
267
Chuck Ebbert66759a02005-09-12 18:49:25 +0200268 enable_timer_pin_1 [i386,x86-64]
269 Enable PIN 1 of APIC timer
Randy Dunlapa9913042005-10-23 12:57:11 -0700270 Can be useful to work around chipset bugs
271 (in particular on some ATI chipsets).
Chuck Ebbert66759a02005-09-12 18:49:25 +0200272 The kernel tries to set a reasonable default.
273
274 disable_timer_pin_1 [i386,x86-64]
275 Disable PIN 1 of APIC timer
276 Can be useful to work around chipset bugs.
277
Linus Torvalds1da177e2005-04-16 15:20:36 -0700278 ad1848= [HW,OSS]
279 Format: <io>,<irq>,<dma>,<dma2>,<type>
280
Linus Torvalds1da177e2005-04-16 15:20:36 -0700281 advansys= [HW,SCSI]
282 See header of drivers/scsi/advansys.c.
283
284 advwdt= [HW,WDT] Advantech WDT
285 Format: <iostart>,<iostop>
286
287 aedsp16= [HW,OSS] Audio Excel DSP 16
288 Format: <io>,<irq>,<dma>,<mss_io>,<mpu_io>,<mpu_irq>
289 See also header of sound/oss/aedsp16.c.
Randy Dunlapa9913042005-10-23 12:57:11 -0700290
Linus Torvalds1da177e2005-04-16 15:20:36 -0700291 aha152x= [HW,SCSI]
292 See Documentation/scsi/aha152x.txt.
293
294 aha1542= [HW,SCSI]
295 Format: <portbase>[,<buson>,<busoff>[,<dmaspeed>]]
296
297 aic7xxx= [HW,SCSI]
298 See Documentation/scsi/aic7xxx.txt.
299
300 aic79xx= [HW,SCSI]
301 See Documentation/scsi/aic79xx.txt.
302
Joerg Roedel54b4cbd2008-06-26 21:28:10 +0200303 amd_iommu= [HW,X86-84]
304 Pass parameters to the AMD IOMMU driver in the system.
305 Possible values are:
Joerg Roedel54b4cbd2008-06-26 21:28:10 +0200306 isolate - enable device isolation (each device, as far
307 as possible, will get its own protection
Joerg Roedel3ce1f932008-11-17 15:09:20 +0100308 domain) [default]
Joerg Roedele5e1f602008-11-17 15:07:17 +0100309 share - put every device behind one IOMMU into the
310 same protection domain
FUJITA Tomonoriafa9fdc2008-09-20 01:23:30 +0900311 fullflush - enable flushing of IO/TLB entries when
312 they are unmapped. Otherwise they are
313 flushed before they will be reused, which
314 is a lot of faster
315
Joerg Roedel54b4cbd2008-06-26 21:28:10 +0200316 amd_iommu_size= [HW,X86-64]
317 Define the size of the aperture for the AMD IOMMU
318 driver. Possible values are:
319 '32M', '64M' (default), '128M', '256M', '512M', '1G'
320
Linus Torvalds1da177e2005-04-16 15:20:36 -0700321 amijoy.map= [HW,JOY] Amiga joystick support
322 Map of devices attached to JOY0DAT and JOY1DAT
323 Format: <a>,<b>
324 See also Documentation/kernel/input/joystick.txt
325
326 analog.map= [HW,JOY] Analog joystick and gamepad support
327 Specifies type or capabilities of an analog joystick
328 connected to one of 16 gameports
329 Format: <type1>,<type2>,..<type16>
330
Randy Dunlapa9913042005-10-23 12:57:11 -0700331 apc= [HW,SPARC]
332 Power management functions (SPARCstation-4/5 + deriv.)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700333 Format: noidle
334 Disable APC CPU standby support. SPARCstation-Fox does
335 not play well with APC CPU idle - disable it if you have
336 APC and your system crashes randomly.
337
Randy Dunlapc8facbb2007-07-31 00:37:40 -0700338 apic= [APIC,i386] Advanced Programmable Interrupt Controller
339 Change the output verbosity whilst booting
Linus Torvalds1da177e2005-04-16 15:20:36 -0700340 Format: { quiet (default) | verbose | debug }
341 Change the amount of debugging information output
342 when initialising the APIC and IO-APIC components.
Randy Dunlapa9913042005-10-23 12:57:11 -0700343
Linus Torvalds1da177e2005-04-16 15:20:36 -0700344 apm= [APM] Advanced Power Management
Pavel Machek71f77052008-07-04 09:59:43 -0700345 See header of arch/x86/kernel/apm_32.c.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700346
Linus Torvalds1da177e2005-04-16 15:20:36 -0700347 arcrimi= [HW,NET] ARCnet - "RIM I" (entirely mem-mapped) cards
348 Format: <io>,<irq>,<nodeID>
349
350 ataflop= [HW,M68k]
351
352 atarimouse= [HW,MOUSE] Atari Mouse
353
354 atascsi= [HW,SCSI] Atari SCSI
355
356 atkbd.extra= [HW] Enable extra LEDs and keys on IBM RapidAccess,
357 EzKey and similar keyboards
358
359 atkbd.reset= [HW] Reset keyboard during initialization
360
Randy Dunlapa9913042005-10-23 12:57:11 -0700361 atkbd.set= [HW] Select keyboard code set
362 Format: <int> (2 = AT (default), 3 = PS/2)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700363
364 atkbd.scroll= [HW] Enable scroll wheel on MS Office and similar
365 keyboards
366
367 atkbd.softraw= [HW] Choose between synthetic and real raw mode
368 Format: <bool> (0 = real, 1 = synthetic (default))
Randy Dunlapa9913042005-10-23 12:57:11 -0700369
370 atkbd.softrepeat= [HW]
371 Use software keyboard repeat
Linus Torvalds1da177e2005-04-16 15:20:36 -0700372
373 autotest [IA64]
374
Linus Torvalds1da177e2005-04-16 15:20:36 -0700375 baycom_epp= [HW,AX25]
376 Format: <io>,<mode>
Randy Dunlapa9913042005-10-23 12:57:11 -0700377
Linus Torvalds1da177e2005-04-16 15:20:36 -0700378 baycom_par= [HW,AX25] BayCom Parallel Port AX.25 Modem
379 Format: <io>,<mode>
380 See header of drivers/net/hamradio/baycom_par.c.
381
Randy Dunlapa9913042005-10-23 12:57:11 -0700382 baycom_ser_fdx= [HW,AX25]
383 BayCom Serial Port AX.25 Modem (Full Duplex Mode)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700384 Format: <io>,<irq>,<mode>[,<baud>]
385 See header of drivers/net/hamradio/baycom_ser_fdx.c.
386
Randy Dunlapa9913042005-10-23 12:57:11 -0700387 baycom_ser_hdx= [HW,AX25]
388 BayCom Serial Port AX.25 Modem (Half Duplex Mode)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700389 Format: <io>,<irq>,<mode>
390 See header of drivers/net/hamradio/baycom_ser_hdx.c.
391
Randy Dunlapbfe8df32007-10-16 01:23:46 -0700392 boot_delay= Milliseconds to delay each printk during boot.
393 Values larger than 10 seconds (10000) are changed to
394 no delay (0).
395 Format: integer
396
Andreas Herrmann35fc9082008-08-20 14:08:58 -0700397 bootmem_debug [KNL] Enable bootmem allocator debug messages.
398
Linus Torvalds1da177e2005-04-16 15:20:36 -0700399 bttv.card= [HW,V4L] bttv (bt848 + bt878 based grabber cards)
Randy Dunlapa9913042005-10-23 12:57:11 -0700400 bttv.radio= Most important insmod options are available as
401 kernel args too.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700402 bttv.pll= See Documentation/video4linux/bttv/Insmod-options
403 bttv.tuner= and Documentation/video4linux/bttv/CARDLIST
404
405 BusLogic= [HW,SCSI]
406 See drivers/scsi/BusLogic.c, comment before function
407 BusLogic_ParseDriverOptions().
408
409 c101= [NET] Moxa C101 synchronous serial card
410
Alan Coxcd4f0ef2007-07-31 00:37:59 -0700411 cachesize= [BUGS=X86-32] Override level 2 CPU cache size detection.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700412 Sometimes CPU hardware bugs make them report the cache
413 size incorrectly. The kernel will attempt work arounds
414 to fix known problems, but for some CPUs it is not
415 possible to determine what the correct size should be.
416 This option provides an override for these situations.
417
Ahmed S. Darwish076c54c2008-03-06 18:09:10 +0200418 security= [SECURITY] Choose a security module to enable at boot.
419 If this boot parameter is not specified, only the first
420 security module asking for security registration will be
421 loaded. An invalid security module name will be treated
422 as if no module has been chosen.
423
James Morris20510f22007-10-16 23:31:32 -0700424 capability.disable=
425 [SECURITY] Disable capabilities. This would normally
426 be used only if an alternative security model is to be
427 configured. Potentially dangerous and should only be
428 used if you are entirely sure of the consequences.
429
Sebastian Ott14ff56b2008-01-26 14:10:37 +0100430 ccw_timeout_log [S390]
431 See Documentation/s390/CommonIO for details.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700432
Paul Menage8bab8dd2008-04-04 14:29:57 -0700433 cgroup_disable= [KNL] Disable a particular controller
434 Format: {name of the controller(s) to disable}
435 {Currently supported controllers - "memory"}
436
Linus Torvalds1da177e2005-04-16 15:20:36 -0700437 checkreqprot [SELINUX] Set initial checkreqprot flag value.
438 Format: { "0" | "1" }
439 See security/selinux/Kconfig help text.
Randy Dunlapa9913042005-10-23 12:57:11 -0700440 0 -- check protection applied by kernel (includes
441 any implied execute protection).
Linus Torvalds1da177e2005-04-16 15:20:36 -0700442 1 -- check protection requested by application.
443 Default value is set via a kernel config option.
Randy Dunlapa9913042005-10-23 12:57:11 -0700444 Value can be changed at runtime via
445 /selinux/checkreqprot.
446
Sebastian Ott661ca0d2008-01-26 14:10:36 +0100447 cio_ignore= [S390]
448 See Documentation/s390/CommonIO for details.
449
Alan Coxcd4f0ef2007-07-31 00:37:59 -0700450 clock= [BUGS=X86-32, HW] gettimeofday clocksource override.
john stultz734efb42006-06-26 00:25:05 -0700451 [Deprecated]
Matt LaPlante3f6dee92006-10-03 22:45:33 +0200452 Forces specified clocksource (if available) to be used
john stultz734efb42006-06-26 00:25:05 -0700453 when calculating gettimeofday(). If specified
Matt LaPlante3f6dee92006-10-03 22:45:33 +0200454 clocksource is not available, it defaults to PIT.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700455 Format: { pit | tsc | cyclone | pmtmr }
456
Randy Dunlap3d6ac982007-05-23 13:58:16 -0700457 clocksource= [GENERIC_TIME] Override the default clocksource
458 Format: <string>
459 Override the default clocksource and use the clocksource
460 with the name specified.
461 Some clocksource names to choose from, depending on
462 the platform:
463 [all] jiffies (this is the base, fallback clocksource)
464 [ACPI] acpi_pm
465 [ARM] imx_timer1,OSTS,netx_timer,mpu_timer2,
466 pxa_timer,timer3,32k_counter,timer0_1
467 [AVR32] avr32
Alan Coxcd4f0ef2007-07-31 00:37:59 -0700468 [X86-32] pit,hpet,tsc,vmi-timer;
Randy Dunlap3d6ac982007-05-23 13:58:16 -0700469 scx200_hrt on Geode; cyclone on IBM x440
470 [MIPS] MIPS
471 [PARISC] cr16
472 [S390] tod
473 [SH] SuperH
474 [SPARC64] tick
475 [X86-64] hpet,tsc
476
Andi Kleenac72e782008-01-30 13:33:21 +0100477 clearcpuid=BITNUM [X86]
478 Disable CPUID feature X for the kernel. See
Randy Dunlap07983f02009-01-06 14:42:41 -0800479 arch/x86/include/asm/cpufeature.h for the valid bit
480 numbers. Note the Linux specific bits are not necessarily
Andi Kleenac72e782008-01-30 13:33:21 +0100481 stable over kernel options, but the vendor specific
482 ones should be.
483 Also note that user programs calling CPUID directly
484 or using the feature without checking anything
485 will still see it. This just prevents it from
486 being used by the kernel or shown in /proc/cpuinfo.
487 Also note the kernel might malfunction if you disable
488 some critical bits.
489
Arjan van de Vena25bd942008-01-30 13:33:08 +0100490 code_bytes [IA32/X86_64] How many bytes of object code to print
491 in an oops report.
Chuck Ebbert86c41832007-02-13 13:26:25 +0100492 Range: 0 - 8192
493 Default: 64
494
Thomas Gleixnerb17530b2007-10-19 20:35:02 +0200495 hpet= [X86-32,HPET] option to control HPET usage
Andreas Herrmannb98103a2009-02-21 00:09:47 +0100496 Format: { enable (default) | disable | force |
497 verbose }
Thomas Gleixnerb17530b2007-10-19 20:35:02 +0200498 disable: disable HPET and use PIT instead
Carlos Corbachod79a5f82007-10-19 18:51:27 +0100499 force: allow force enabled of undocumented chips (ICH4,
500 VIA, nVidia)
Andreas Herrmannb98103a2009-02-21 00:09:47 +0100501 verbose: show contents of HPET registers during setup
Linus Torvalds1da177e2005-04-16 15:20:36 -0700502
Linus Torvalds1da177e2005-04-16 15:20:36 -0700503 com20020= [HW,NET] ARCnet - COM20020 chipset
Randy Dunlapa9913042005-10-23 12:57:11 -0700504 Format:
505 <io>[,<irq>[,<nodeID>[,<backplane>[,<ckp>[,<timeout>]]]]]
Linus Torvalds1da177e2005-04-16 15:20:36 -0700506
507 com90io= [HW,NET] ARCnet - COM90xx chipset (IO-mapped buffers)
508 Format: <io>[,<irq>]
509
Randy Dunlapa9913042005-10-23 12:57:11 -0700510 com90xx= [HW,NET]
511 ARCnet - COM90xx chipset (memory-mapped buffers)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700512 Format: <io>[,<irq>[,<memstart>]]
513
514 condev= [HW,S390] console device
515 conmode=
Randy Dunlapa9913042005-10-23 12:57:11 -0700516
Linus Torvalds1da177e2005-04-16 15:20:36 -0700517 console= [KNL] Output console device and options.
518
519 tty<n> Use the virtual console device <n>.
520
521 ttyS<n>[,options]
Randy Dunlapf1a1c2d2006-03-25 03:08:17 -0800522 ttyUSB0[,options]
Linus Torvalds1da177e2005-04-16 15:20:36 -0700523 Use the specified serial port. The options are of
Randy Dunlapf1a1c2d2006-03-25 03:08:17 -0800524 the form "bbbbpnf", where "bbbb" is the baud rate,
525 "p" is parity ("n", "o", or "e"), "n" is number of
526 bits, and "f" is flow control ("r" for RTS or
527 omit it). Default is "9600n8".
Linus Torvalds1da177e2005-04-16 15:20:36 -0700528
Randy Dunlapf1a1c2d2006-03-25 03:08:17 -0800529 See Documentation/serial-console.txt for more
530 information. See
531 Documentation/networking/netconsole.txt for an
532 alternative.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700533
Yinghai Lu18a8bd92007-07-15 23:37:59 -0700534 uart[8250],io,<addr>[,options]
535 uart[8250],mmio,<addr>[,options]
Linus Torvalds1da177e2005-04-16 15:20:36 -0700536 Start an early, polled-mode console on the 8250/16550
537 UART at the specified I/O port or MMIO address,
538 switching to the matching ttyS device later. The
539 options are the same as for ttyS, above.
540
Samuel Thibaultf7511d52008-04-30 00:54:51 -0700541 If the device connected to the port is not a TTY but a braille
542 device, prepend "brl," before the device type, for instance
543 console=brl,ttyS0
544 For now, only VisioBraille is supported.
545
Yinghai Lu18a8bd92007-07-15 23:37:59 -0700546 earlycon= [KNL] Output early console device and options.
547 uart[8250],io,<addr>[,options]
548 uart[8250],mmio,<addr>[,options]
549 Start an early, polled-mode console on the 8250/16550
550 UART at the specified I/O port or MMIO address.
551 The options are the same as for ttyS, above.
552
Andres Salomon8f4ce8c2007-10-18 03:04:50 -0700553 no_console_suspend
554 [HW] Never suspend the console
555 Disable suspending of consoles during suspend and
556 hibernate operations. Once disabled, debugging
557 messages can reach various consoles while the rest
558 of the system is being put to sleep (ie, while
559 debugging driver suspend/resume hooks). This may
560 not work reliably with all consoles, but is known
561 to work with serial and VGA consoles.
562
Hidehiro Kawai4cb0e112009-01-06 14:42:47 -0800563 coredump_filter=
564 [KNL] Change the default value for
565 /proc/<pid>/coredump_filter.
566 See also Documentation/filesystems/proc.txt.
567
Linus Torvalds1da177e2005-04-16 15:20:36 -0700568 cpcihp_generic= [HW,PCI] Generic port I/O CompactPCI driver
Randy Dunlapa9913042005-10-23 12:57:11 -0700569 Format:
570 <first_slot>,<last_slot>,<port>,<enum_bit>[,<debug>]
Linus Torvalds1da177e2005-04-16 15:20:36 -0700571
Eric W. Biedermandc009d92005-06-25 14:57:52 -0700572 crashkernel=nn[KMG]@ss[KMG]
573 [KNL] Reserve a chunk of physical memory to
574 hold a kernel to switch to with kexec on panic.
575
Bernhard Wallefb391592007-10-18 23:41:02 -0700576 crashkernel=range1:size1[,range2:size2,...][@offset]
577 [KNL] Same as above, but depends on the memory
578 in the running system. The syntax of range is
579 start-[end] where start and end are both
580 a memory unit (amount[KMG]). See also
581 Documentation/kdump/kdump.txt for a example.
582
Linus Torvalds1da177e2005-04-16 15:20:36 -0700583 cs89x0_dma= [HW,NET]
584 Format: <dma>
585
586 cs89x0_media= [HW,NET]
587 Format: { rj45 | aui | bnc }
Randy Dunlapa9913042005-10-23 12:57:11 -0700588
Randy Dunlapa9913042005-10-23 12:57:11 -0700589 dasd= [HW,NET]
Linus Torvalds1da177e2005-04-16 15:20:36 -0700590 See header of drivers/s390/block/dasd_devmap.c.
591
592 db9.dev[2|3]= [HW,JOY] Multisystem joystick support via parallel port
593 (one device per port)
594 Format: <port#>,<type>
595 See also Documentation/input/joystick-parport.txt
596
597 debug [KNL] Enable kernel debugging (events log level).
598
Ingo Molnarcae2ed92006-07-03 00:24:48 -0700599 debug_locks_verbose=
600 [KNL] verbose self-tests
601 Format=<0|1>
602 Print debugging info while doing the locking API
603 self-tests.
604 We default to 0 (no extra messages), setting it to
605 1 will print _a lot_ more information - normally
606 only useful to kernel developers.
607
Thomas Gleixner3ac7fe52008-04-30 00:55:01 -0700608 debug_objects [KNL] Enable object debugging
609
Thomas Gleixnerd3af01f2008-07-15 15:04:56 +0200610 debugpat [X86] Enable PAT debugging
611
Robert P. J. Day2d27a962008-02-03 15:18:45 +0200612 decnet.addr= [HW,NET]
Linus Torvalds1da177e2005-04-16 15:20:36 -0700613 Format: <area>[,<node>]
614 See also Documentation/networking/decnet.txt.
615
Samuel Thibaultecb77fa2008-01-03 16:17:54 +0000616 vt.default_blu= [VT]
Antonino A. Daplas55ff9782007-05-08 00:38:53 -0700617 Format: <blue0>,<blue1>,<blue2>,...,<blue15>
618 Change the default blue palette of the console.
619 This is a 16-member array composed of values
620 ranging from 0-255.
621
Samuel Thibaultecb77fa2008-01-03 16:17:54 +0000622 vt.default_grn= [VT]
Antonino A. Daplas55ff9782007-05-08 00:38:53 -0700623 Format: <green0>,<green1>,<green2>,...,<green15>
624 Change the default green palette of the console.
625 This is a 16-member array composed of values
626 ranging from 0-255.
627
Samuel Thibaultecb77fa2008-01-03 16:17:54 +0000628 vt.default_red= [VT]
Antonino A. Daplas55ff9782007-05-08 00:38:53 -0700629 Format: <red0>,<red1>,<red2>,...,<red15>
630 Change the default red palette of the console.
631 This is a 16-member array composed of values
632 ranging from 0-255.
633
Samuel Thibaultecb77fa2008-01-03 16:17:54 +0000634 vt.default_utf8=
635 [VT]
Antonino A. Daplas55ff9782007-05-08 00:38:53 -0700636 Format=<0|1>
637 Set system-wide default UTF-8 mode for all tty's.
Samuel Thibaultecb77fa2008-01-03 16:17:54 +0000638 Default is 1, i.e. UTF-8 mode is enabled for all
639 newly opened terminals.
Antonino A. Daplas55ff9782007-05-08 00:38:53 -0700640
Linus Torvalds1da177e2005-04-16 15:20:36 -0700641 dhash_entries= [KNL]
642 Set number of hash buckets for dentry cache.
Randy Dunlapa9913042005-10-23 12:57:11 -0700643
Linus Torvalds1da177e2005-04-16 15:20:36 -0700644 digi= [HW,SERIAL]
645 IO parameters + enable/disable command.
646
647 digiepca= [HW,SERIAL]
648 See drivers/char/README.epca and
Randy Dunlap31c00fc2008-11-13 21:33:24 +0000649 Documentation/serial/digiepca.txt.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700650
Yinghai Lu95ffa242008-04-29 03:52:33 -0700651 disable_mtrr_cleanup [X86]
652 enable_mtrr_cleanup [X86]
653 The kernel tries to adjust MTRR layout from continuous
654 to discrete, to make X server driver able to add WB
655 entry later. This parameter enables/disables that.
656
657 mtrr_chunk_size=nn[KMG] [X86]
658 used for mtrr cleanup. It is largest continous chunk
659 that could hold holes aka. UC entries.
660
661 mtrr_gran_size=nn[KMG] [X86]
Yinghai Lu12031a62008-05-02 02:40:22 -0700662 Used for mtrr cleanup. It is granularity of mtrr block.
663 Default is 1.
664 Large value could prevent small alignment from
665 using up MTRRs.
666
667 mtrr_spare_reg_nr=n [X86]
668 Format: <integer>
669 Range: 0,7 : spare reg number
670 Default : 1
671 Used for mtrr cleanup. It is spare mtrr entries number.
672 Set to 2 or more if your graphical card needs more.
Yinghai Lu95ffa242008-04-29 03:52:33 -0700673
Yinghai Lu093af8d2008-01-30 13:33:32 +0100674 disable_mtrr_trim [X86, Intel and AMD only]
Jesse Barnes99fc8d42008-01-30 13:33:18 +0100675 By default the kernel will trim any uncacheable
676 memory out of your available memory pool based on
677 MTRR settings. This parameter disables that behavior,
678 possibly causing your machine to run very slowly.
679
Linus Torvalds1da177e2005-04-16 15:20:36 -0700680 dmasound= [HW,OSS] Sound subsystem buffers
681
682 dscc4.setup= [NET]
683
684 dtc3181e= [HW,SCSI]
685
Robin Getz0ae53642007-10-09 17:24:49 +0800686 earlyprintk= [X86-32,X86-64,SH,BLACKFIN]
Linus Torvalds1da177e2005-04-16 15:20:36 -0700687 earlyprintk=vga
688 earlyprintk=serial[,ttySn[,baudrate]]
Yinghai Lu5c059172008-07-24 17:29:40 -0700689 earlyprintk=dbgp
Linus Torvalds1da177e2005-04-16 15:20:36 -0700690
Randy Dunlapa9913042005-10-23 12:57:11 -0700691 Append ",keep" to not disable it when the real console
Linus Torvalds1da177e2005-04-16 15:20:36 -0700692 takes over.
693
Yinghai Lu5c059172008-07-24 17:29:40 -0700694 Only vga or serial or usb debug port at a time.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700695
696 Currently only ttyS0 and ttyS1 are supported.
697
698 Interaction with the standard serial driver is not
699 very good.
700
701 The VGA output is eventually overwritten by the real
702 console.
703
704 eata= [HW,SCSI]
705
Linus Torvalds1da177e2005-04-16 15:20:36 -0700706 edd= [EDD]
Tim Gardner8c4dd602008-04-29 01:02:45 -0700707 Format: {"off" | "on" | "skip[mbr]"}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700708
Linus Torvalds1da177e2005-04-16 15:20:36 -0700709 eisa_irq_edge= [PARISC,HW]
710 See header of drivers/parisc/eisa.c.
711
Alan Coxcd4f0ef2007-07-31 00:37:59 -0700712 elanfreq= [X86-32]
Linus Torvalds1da177e2005-04-16 15:20:36 -0700713 See comment before function elanfreq_setup() in
Pavel Machek71f77052008-07-04 09:59:43 -0700714 arch/x86/kernel/cpu/cpufreq/elanfreq.c.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700715
716 elevator= [IOSCHED]
Randy Dunlap16ab3ad2006-01-14 13:21:20 -0800717 Format: {"anticipatory" | "cfq" | "deadline" | "noop"}
Randy Dunlapa9913042005-10-23 12:57:11 -0700718 See Documentation/block/as-iosched.txt and
719 Documentation/block/deadline-iosched.txt for details.
720
Simon Hormane515a0d2008-10-18 20:28:27 -0700721 elfcorehdr= [IA64,PPC,SH,X86-32,X86_64]
Randy Dunlapa9913042005-10-23 12:57:11 -0700722 Specifies physical address of start of kernel core
Vivek Goyalaac04b32006-01-09 20:51:47 -0800723 image elf header. Generally kexec loader will
724 pass this option to capture kernel.
725 See Documentation/kdump/kdump.txt for details.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700726
727 enforcing [SELINUX] Set initial enforcing status.
728 Format: {"0" | "1"}
729 See security/selinux/Kconfig help text.
730 0 -- permissive (log only, no denials).
731 1 -- enforcing (deny and log).
732 Default value is 0.
733 Value can be changed at runtime via /selinux/enforce.
734
Linus Torvalds1da177e2005-04-16 15:20:36 -0700735 ether= [HW,NET] Ethernet cards parameters
736 This option is obsoleted by the "netdev=" option, which
737 has equivalent usage. See its documentation for details.
738
739 eurwdt= [HW,WDT] Eurotech CPU-1220/1410 onboard watchdog.
740 Format: <io>[,<irq>]
741
Akinobu Mitade1ba092006-12-08 02:39:42 -0800742 failslab=
743 fail_page_alloc=
744 fail_make_request=[KNL]
745 General fault injection mechanism.
746 Format: <interval>,<probability>,<space>,<times>
747 See also /Documentation/fault-injection/.
748
Linus Torvalds1da177e2005-04-16 15:20:36 -0700749 fd_mcs= [HW,SCSI]
750 See header of drivers/scsi/fd_mcs.c.
751
752 fdomain= [HW,SCSI]
753 See header of drivers/scsi/fdomain.c.
754
755 floppy= [HW]
Randy Dunlap31c00fc2008-11-13 21:33:24 +0000756 See Documentation/blockdev/floppy.txt.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700757
Alex Chiangf13ae302008-05-08 14:03:23 -0600758 force_pal_cache_flush
759 [IA-64] Avoid check_sal_cache_flush which may hang on
760 buggy SAL_CACHE_FLUSH implementations. Using this
761 parameter will force ia64_sal_cache_flush to call
762 ia64_pal_cache_flush instead of SAL_CACHE_FLUSH.
763
Peter Zijlstrad9e54072008-11-01 19:57:37 +0100764 ftrace=[tracer]
765 [ftrace] will set and start the specified tracer
766 as early as possible in order to facilitate early
767 boot debugging.
768
769 ftrace_dump_on_oops
770 [ftrace] will dump the trace buffers on oops.
771
Linus Torvalds1da177e2005-04-16 15:20:36 -0700772 gamecon.map[2|3]=
773 [HW,JOY] Multisystem joystick and NES/SNES/PSX pad
774 support via parallel port (up to 5 devices per port)
775 Format: <port#>,<pad1>,<pad2>,<pad3>,<pad4>,<pad5>
776 See also Documentation/input/joystick-parport.txt
777
778 gamma= [HW,DRM]
779
Yinghai Luaaf23042008-01-30 13:33:09 +0100780 gart_fix_e820= [X86_64] disable the fix e820 for K8 GART
781 Format: off | on
782 default: on
783
Linus Torvalds1da177e2005-04-16 15:20:36 -0700784 gdth= [HW,SCSI]
785 See header of drivers/scsi/gdth.c.
786
787 gpt [EFI] Forces disk with valid GPT signature but
788 invalid Protective MBR to be treated as GPT.
789
Linus Torvalds1da177e2005-04-16 15:20:36 -0700790 gvp11= [HW,SCSI]
791
792 hashdist= [KNL,NUMA] Large hashes allocated during boot
793 are distributed across NUMA nodes. Defaults on
794 for IA-64, off otherwise.
Randy Dunlapa9913042005-10-23 12:57:11 -0700795 Format: 0 | 1 (for off | on)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700796
797 hcl= [IA-64] SGI's Hardware Graph compatibility layer
798
799 hd= [EIDE] (E)IDE hard drive subsystem geometry
800 Format: <cyl>,<head>,<sect>
801
Linus Torvalds1da177e2005-04-16 15:20:36 -0700802 highmem=nn[KMG] [KNL,BOOT] forces the highmem zone to have an exact
803 size of <nn>. This works even on boxes that have no
804 highmem otherwise. This also works to reduce highmem
805 size on bigger boxes.
806
Thomas Gleixner54cdfdb2007-02-16 01:28:11 -0800807 highres= [KNL] Enable/disable high resolution timer mode.
808 Valid parameters: "on", "off"
809 Default: "on"
810
Linus Torvalds1da177e2005-04-16 15:20:36 -0700811 hisax= [HW,ISDN]
812 See Documentation/isdn/README.HiSax.
813
Andi Kleenb4718e62008-07-23 21:27:51 -0700814 hugepages= [HW,X86-32,IA-64] HugeTLB pages to allocate at boot.
815 hugepagesz= [HW,IA-64,PPC,X86-64] The size of the HugeTLB pages.
Jon Tollefson0d9ea752008-07-23 21:27:56 -0700816 On x86-64 and powerpc, this option can be specified
817 multiple times interleaved with hugepages= to reserve
818 huge pages of different sizes. Valid pages sizes on
819 x86-64 are 2M (when the CPU supports "pse") and 1G
820 (when the CPU supports the "pdpe1gb" cpuinfo flag)
Andi Kleenb4718e62008-07-23 21:27:51 -0700821 Note that 1GB pages can only be allocated at boot time
822 using hugepages= and not freed afterwards.
Nick Piggine11bfbf2008-07-23 21:27:52 -0700823 default_hugepagesz=
824 [same as hugepagesz=] The size of the default
825 HugeTLB page size. This is the size represented by
826 the legacy /proc/ hugepages APIs, used for SHM, and
827 default size when mounting hugetlbfs filesystems.
828 Defaults to the default architecture's huge page size
829 if not specified.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700830
Paul Mundt6902aa82008-09-21 17:14:42 +0900831 hlt [BUGS=ARM,SH]
832
Hendrik Brueckner555d61d2009-01-09 12:15:02 +0100833 hvc_iucv= [S390] Number of z/VM IUCV hypervisor console (HVC)
834 terminal devices. Valid values: 0..8
Hendrik Brueckner431429f2009-03-26 15:23:55 +0100835 hvc_iucv_allow= [S390] Comma-separated list of z/VM user IDs.
836 If specified, z/VM IUCV HVC accepts connections
837 from listed z/VM user IDs only.
Hendrik Bruecknercef71252008-12-25 13:39:55 +0100838
Jarkko Nikula3a853fb2009-03-23 18:07:47 -0700839 i2c_bus= [HW] Override the default board specific I2C bus speed
Jarkko Nikula79547632009-03-23 18:07:48 -0700840 or register an additional I2C bus that is not
841 registered from board initialization code.
Jarkko Nikula3a853fb2009-03-23 18:07:47 -0700842 Format:
843 <bus_id>,<clkrate>
844
Jiri Kosina36d95732008-10-06 02:51:09 -0400845 i8042.debug [HW] Toggle i8042 debug mode
Linus Torvalds1da177e2005-04-16 15:20:36 -0700846 i8042.direct [HW] Put keyboard port into non-translated mode
Matt LaPlante84eb8d02006-10-03 22:53:09 +0200847 i8042.dumbkbd [HW] Pretend that controller can only read data from
848 keyboard and cannot control its state
Linus Torvalds1da177e2005-04-16 15:20:36 -0700849 (Don't attempt to blink the leds)
850 i8042.noaux [HW] Don't check for auxiliary (== mouse) port
Dmitry Torokhov945ef0d2005-09-04 01:42:00 -0500851 i8042.nokbd [HW] Don't check/create keyboard port
Jiri Kosina75d08c72008-03-13 16:13:59 -0400852 i8042.noloop [HW] Disable the AUX Loopback command while probing
853 for the AUX port
Linus Torvalds1da177e2005-04-16 15:20:36 -0700854 i8042.nomux [HW] Don't check presence of an active multiplexing
855 controller
856 i8042.nopnp [HW] Don't use ACPIPnP / PnPBIOS to discover KBD/AUX
857 controllers
858 i8042.panicblink=
859 [HW] Frequency with which keyboard LEDs should blink
860 when kernel panics (default is 0.5 sec)
861 i8042.reset [HW] Reset the controller during init and cleanup
862 i8042.unlock [HW] Unlock (ignore) the keylock
863
864 i810= [HW,DRM]
865
Dmitry Torokhove70c9d52005-06-25 14:54:25 -0700866 i8k.ignore_dmi [HW] Continue probing hardware even if DMI data
867 indicates that the driver is running on unsupported
868 hardware.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700869 i8k.force [HW] Activate i8k driver even if SMM BIOS signature
870 does not match list of supported models.
871 i8k.power_status
872 [HW] Report power status in /proc/i8k
873 (disabled by default)
874 i8k.restricted [HW] Allow controlling fans only if SYS_ADMIN
875 capability is set.
876
877 ibmmcascsi= [HW,MCA,SCSI] IBM MicroChannel SCSI adapter
878 See Documentation/mca.txt.
879
880 icn= [HW,ISDN]
881 Format: <io>[,<membase>[,<icn_id>[,<icn_id2>]]]
882
David Fries0af80c02009-02-25 20:28:21 +0100883 ide-core.nodma= [HW] (E)IDE subsystem
884 Format: =0.0 to prevent dma on hda, =0.1 hdb =1.0 hdc
885 .vlb_clock .pci_clock .noflush .noprobe .nowerr .cdrom
886 .chs .ignore_cable are additional options
Randy Dunlap1c10e932008-03-07 21:53:50 +0100887 See Documentation/ide/ide.txt.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700888
Linus Torvalds1da177e2005-04-16 15:20:36 -0700889 idebus= [HW] (E)IDE subsystem - VLB/PCI bus speed
Randy Dunlap1c10e932008-03-07 21:53:50 +0100890 See Documentation/ide/ide.txt.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700891
Andi Kleenf039b752007-05-02 19:27:12 +0200892 idle= [X86]
Randy Dunlapada9cfd2008-12-19 10:57:32 -0800893 Format: idle=poll, idle=mwait, idle=halt, idle=nomwait
894 Poll forces a polling idle loop that can slightly
895 improve the performance of waking up a idle CPU, but
896 will use a lot of power and make the system run hot.
897 Not recommended.
898 idle=mwait: On systems which support MONITOR/MWAIT but
899 the kernel chose to not use it because it doesn't save
900 as much power as a normal idle loop, use the
901 MONITOR/MWAIT idle loop anyways. Performance should be
902 the same as idle=poll.
903 idle=halt: Halt is forced to be used for CPU idle.
Zhao Yakuic1e3b372008-06-24 17:58:53 +0800904 In such case C2/C3 won't be used again.
Randy Dunlapada9cfd2008-12-19 10:57:32 -0800905 idle=nomwait: Disable mwait for CPU C-states
Randy Dunlapa9913042005-10-23 12:57:11 -0700906
Denis Cheng594765a2008-02-06 02:57:49 +0100907 ide-pci-generic.all-generic-ide [HW] (E)IDE subsystem
908 Claim all unknown PCI IDE storage controllers.
909
Ingo Molnar792908222006-12-06 20:40:51 -0800910 ignore_loglevel [KNL]
911 Ignore loglevel setting - this will print /all/
912 kernel messages to the console. Useful for debugging.
913
Linus Torvalds1da177e2005-04-16 15:20:36 -0700914 ihash_entries= [KNL]
915 Set number of hash buckets for inode cache.
916
Mimi Zohar3323eec2009-02-04 09:06:58 -0500917 ima_audit= [IMA]
918 Format: { "0" | "1" }
919 0 -- integrity auditing messages. (Default)
920 1 -- enable informational integrity auditing messages.
921
922 ima_hash= [IMA]
923 Formt: { "sha1" | "md5" }
924 default: "sha1"
925
Linus Torvalds1da177e2005-04-16 15:20:36 -0700926 in2000= [HW,SCSI]
927 See header of drivers/scsi/in2000.c.
928
929 init= [KNL]
930 Format: <full_path>
931 Run specified binary instead of /sbin/init as init
932 process.
933
934 initcall_debug [KNL] Trace initcalls as they are executed. Useful
935 for working out where the kernel is dying during
936 startup.
937
938 initrd= [BOOT] Specify the location of the initial ramdisk
939
940 inport.irq= [HW] Inport (ATI XL and Microsoft) busmouse driver
941 Format: <irq>
942
943 inttest= [IA64]
944
Arjan van de Vene8de1482008-10-22 19:55:31 -0700945 iomem= Disable strict checking of access to MMIO memory
946 strict regions from userspace.
947 relaxed
948
Pavel Machekb552da82008-03-19 15:58:11 +0100949 iommu= [x86]
950 off
951 force
952 noforce
953 biomerge
954 panic
955 nopanic
956 merge
957 nomerge
958 forcesac
959 soft
960
961
Keshavamurthy, Anil Sba395922007-10-21 16:41:49 -0700962 intel_iommu= [DMAR] Intel IOMMU driver (DMAR) option
Kyle McMartin0cd5c3c2009-02-04 14:29:19 -0800963 on
964 Enable intel iommu driver.
Keshavamurthy, Anil Sba395922007-10-21 16:41:49 -0700965 off
966 Disable intel iommu driver.
967 igfx_off [Default Off]
968 By default, gfx is mapped as normal device. If a gfx
969 device has a dedicated DMAR unit, the DMAR unit is
970 bypassed by not enabling DMAR with this option. In
971 this case, gfx device will use physical address for
972 DMA.
Keshavamurthy, Anil S7d3b03c2007-10-21 16:41:53 -0700973 forcedac [x86_64]
974 With this option iommu will not optimize to look
975 for io virtual address below 32 bit forcing dual
976 address cycle on pci bus for cards supporting greater
977 than 32 bit addressing. The default is to look
978 for translation below 32 bit and if not available
979 then look in the higher range.
mark gross5e0d2a62008-03-04 15:22:08 -0800980 strict [Default Off]
981 With this option on every unmap_single operation will
982 result in a hardware IOTLB flush operation as opposed
983 to batching them for performance.
Keshavamurthy, Anil Sba395922007-10-21 16:41:49 -0700984
Rene Hermanb02aae92008-01-30 13:30:05 +0100985 io_delay= [X86-32,X86-64] I/O delay method
Ingo Molnar6e7c4022008-01-30 13:30:05 +0100986 0x80
987 Standard port 0x80 based delay
988 0xed
989 Alternate port 0xed based delay (needed on some systems)
Rene Hermanb02aae92008-01-30 13:30:05 +0100990 udelay
Ingo Molnar6e7c4022008-01-30 13:30:05 +0100991 Simple two microseconds delay
992 none
993 No delay
Rene Hermanb02aae92008-01-30 13:30:05 +0100994
Linus Torvalds1da177e2005-04-16 15:20:36 -0700995 io7= [HW] IO7 for Marvel based alpha systems
996 See comment before marvel_specify_io7 in
997 arch/alpha/kernel/core_marvel.c.
998
999 ip= [IP_PNP]
J. Bruce Fields6ded55d2008-04-07 15:59:03 -04001000 See Documentation/filesystems/nfsroot.txt.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001001
1002 ip2= [HW] Set IO/IRQ pairs for up to 4 IntelliPort boards
Randy Dunlapc8facbb2007-07-31 00:37:40 -07001003 See comment before ip2_setup() in
1004 drivers/char/ip2/ip2base.c.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001005
1006 ips= [HW,SCSI] Adaptec / IBM ServeRAID controller
1007 See header of drivers/scsi/ips.c.
1008
Simon Horman72c4a132006-09-13 19:57:18 -07001009 ports= [IP_VS_FTP] IPVS ftp helper module
1010 Default is 21.
1011 Up to 8 (IP_VS_APP_MAX_PORTS) ports
1012 may be specified.
1013 Format: <port>,<port>....
1014
Alan Cox200803d2005-06-28 20:45:18 -07001015 irqfixup [HW]
1016 When an interrupt is not handled search all handlers
1017 for it. Intended to get systems with badly broken
1018 firmware running.
1019
1020 irqpoll [HW]
1021 When an interrupt is not handled search all handlers
1022 for it. Also check all handlers each timer
1023 interrupt. Intended to get systems with badly broken
1024 firmware running.
1025
Linus Torvalds1da177e2005-04-16 15:20:36 -07001026 isapnp= [ISAPNP]
Randy Dunlapa9913042005-10-23 12:57:11 -07001027 Format: <RDP>,<reset>,<pci_scan>,<verbosity>
Linus Torvalds1da177e2005-04-16 15:20:36 -07001028
1029 isolcpus= [KNL,SMP] Isolate CPUs from the general scheduler.
Derek Fults22f2e282006-12-06 20:37:11 -08001030 Format:
1031 <cpu number>,...,<cpu number>
1032 or
Li Zefanb225d442008-11-06 12:53:39 -08001033 <cpu number>-<cpu number>
1034 (must be a positive range in ascending order)
Derek Fults22f2e282006-12-06 20:37:11 -08001035 or a mixture
1036 <cpu number>,...,<cpu number>-<cpu number>
Li Zefanb225d442008-11-06 12:53:39 -08001037
Linus Torvalds1da177e2005-04-16 15:20:36 -07001038 This option can be used to specify one or more CPUs
1039 to isolate from the general SMP balancing and scheduling
Li Zefanb225d442008-11-06 12:53:39 -08001040 algorithms. You can move a process onto or off an
1041 "isolated" CPU via the CPU affinity syscalls or cpuset.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001042 <cpu number> begins at 0 and the maximum value is
1043 "number of CPUs in system - 1".
1044
1045 This option is the preferred way to isolate CPUs. The
Randy Dunlapa9913042005-10-23 12:57:11 -07001046 alternative -- manually setting the CPU mask of all
1047 tasks in the system -- can cause problems and
1048 suboptimal load balancer performance.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001049
Randy Dunlapa9913042005-10-23 12:57:11 -07001050 iucv= [HW,NET]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001051
1052 js= [HW,JOY] Analog joystick
1053 See Documentation/input/joystick.txt.
1054
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001055 kernelcore=nn[KMG] [KNL,X86-32,IA-64,PPC,X86-64] This parameter
Mel Gormaned7ed362007-07-17 04:03:14 -07001056 specifies the amount of memory usable by the kernel
1057 for non-movable allocations. The requested amount is
1058 spread evenly throughout all nodes in the system. The
1059 remaining memory in each node is used for Movable
1060 pages. In the event, a node is too small to have both
1061 kernelcore and Movable pages, kernelcore pages will
1062 take priority and other nodes will have a larger number
1063 of kernelcore pages. The Movable zone is used for the
1064 allocation of pages that may be reclaimed or moved
1065 by the page migration subsystem. This means that
1066 HugeTLB pages may not be allocated from this zone.
1067 Note that allocations like PTEs-from-HighMem still
1068 use the HighMem zone if it exists, and the Normal
1069 zone if it does not.
1070
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001071 movablecore=nn[KMG] [KNL,X86-32,IA-64,PPC,X86-64] This parameter
Mel Gorman7e63efef2007-07-17 04:03:15 -07001072 is similar to kernelcore except it specifies the
1073 amount of memory used for migratable allocations.
1074 If both kernelcore and movablecore is specified,
1075 then kernelcore will be at *least* the specified
1076 value but may be more. If movablecore on its own
1077 is specified, the administrator must be careful
1078 that the amount of memory usable for all allocations
1079 is not too small.
1080
Linus Torvalds1da177e2005-04-16 15:20:36 -07001081 keepinitrd [HW,ARM]
1082
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001083 kstack=N [X86-32,X86-64] Print N words from the kernel stack
Linus Torvalds1da177e2005-04-16 15:20:36 -07001084 in oops dumps.
1085
Jason Wessel6cdf6e02008-04-17 20:05:38 +02001086 kgdboc= [HW] kgdb over consoles.
1087 Requires a tty driver that supports console polling.
1088 (only serial suported for now)
1089 Format: <serial_device>[,baud]
1090
Florian Fainelli9bed90c62008-08-23 18:54:37 +02001091 kmac= [MIPS] korina ethernet MAC address.
1092 Configure the RouterBoard 532 series on-chip
1093 Ethernet adapter MAC address.
1094
Linus Torvalds1da177e2005-04-16 15:20:36 -07001095 l2cr= [PPC]
1096
Robert Brosea78bfbf2008-03-29 07:20:23 +11001097 l3cr= [PPC]
1098
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001099 lapic [X86-32,APIC] Enable the local APIC even if BIOS
Randy Dunlapa9913042005-10-23 12:57:11 -07001100 disabled it.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001101
Randy Dunlapada9cfd2008-12-19 10:57:32 -08001102 lapic_timer_c2_ok [X86-32,x86-64,APIC] trust the local apic timer
1103 in C2 power state.
Thomas Gleixnere585bef2007-03-23 16:08:01 +01001104
FD Camifcb71f62008-01-06 19:08:56 +01001105 libata.dma= [LIBATA] DMA control
1106 libata.dma=0 Disable all PATA and SATA DMA
1107 libata.dma=1 PATA and SATA Disk DMA only
1108 libata.dma=2 ATAPI (CDROM) DMA only
1109 libata.dma=4 Compact Flash DMA only
1110 Combinations also work, so libata.dma=3 enables DMA
1111 for disks and CDROMs, but not CFs.
1112
Dave Jones78e70c22007-09-27 11:50:13 -04001113 libata.noacpi [LIBATA] Disables use of ACPI in libata suspend/resume
1114 when set.
1115 Format: <int>
1116
Tejun Heo33267322008-02-13 09:15:09 +09001117 libata.force= [LIBATA] Force configurations. The format is comma
1118 separated list of "[ID:]VAL" where ID is
1119 PORT[:DEVICE]. PORT and DEVICE are decimal numbers
1120 matching port, link or device. Basically, it matches
1121 the ATA ID string printed on console by libata. If
1122 the whole ID part is omitted, the last PORT and DEVICE
1123 values are used. If ID hasn't been specified yet, the
1124 configuration applies to all ports, links and devices.
1125
1126 If only DEVICE is omitted, the parameter applies to
1127 the port and all links and devices behind it. DEVICE
1128 number of 0 either selects the first device or the
1129 first fan-out link behind PMP device. It does not
1130 select the host link. DEVICE number of 15 selects the
1131 host link and device attached to it.
1132
1133 The VAL specifies the configuration to force. As long
1134 as there's no ambiguity shortcut notation is allowed.
1135 For example, both 1.5 and 1.5G would work for 1.5Gbps.
1136 The following configurations can be forced.
1137
1138 * Cable type: 40c, 80c, short40c, unk, ign or sata.
1139 Any ID with matching PORT is used.
1140
1141 * SATA link speed limit: 1.5Gbps or 3.0Gbps.
1142
1143 * Transfer mode: pio[0-7], mwdma[0-4] and udma[0-7].
1144 udma[/][16,25,33,44,66,100,133] notation is also
1145 allowed.
1146
1147 * [no]ncq: Turn on or off NCQ.
1148
Tejun Heo05944bd2008-08-13 20:19:09 +09001149 * nohrst, nosrst, norst: suppress hard, soft
1150 and both resets.
1151
Tejun Heo33267322008-02-13 09:15:09 +09001152 If there are multiple matching configurations changing
1153 the same attribute, the last one is used.
1154
Randy Dunlap7c4be252009-01-06 14:42:44 -08001155 lmb=debug [KNL] Enable lmb debug messages.
1156
Linus Torvalds1da177e2005-04-16 15:20:36 -07001157 load_ramdisk= [RAM] List of ramdisks to load from floppy
Randy Dunlap31c00fc2008-11-13 21:33:24 +00001158 See Documentation/blockdev/ramdisk.txt.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001159
Randy Dunlapa6b25b62006-01-14 13:21:19 -08001160 lockd.nlm_grace_period=P [NFS] Assign grace period.
1161 Format: <integer>
Linus Torvalds1da177e2005-04-16 15:20:36 -07001162
Randy Dunlapa6b25b62006-01-14 13:21:19 -08001163 lockd.nlm_tcpport=N [NFS] Assign TCP port.
1164 Format: <integer>
1165
1166 lockd.nlm_timeout=T [NFS] Assign timeout value.
1167 Format: <integer>
1168
1169 lockd.nlm_udpport=M [NFS] Assign UDP port.
1170 Format: <integer>
Linus Torvalds1da177e2005-04-16 15:20:36 -07001171
1172 logibm.irq= [HW,MOUSE] Logitech Bus Mouse Driver
1173 Format: <irq>
1174
1175 loglevel= All Kernel Messages with a loglevel smaller than the
1176 console loglevel will be printed to the console. It can
1177 also be changed with klogd or other programs. The
1178 loglevels are defined as follows:
1179
1180 0 (KERN_EMERG) system is unusable
1181 1 (KERN_ALERT) action must be taken immediately
1182 2 (KERN_CRIT) critical conditions
1183 3 (KERN_ERR) error conditions
1184 4 (KERN_WARNING) warning conditions
1185 5 (KERN_NOTICE) normal but significant condition
1186 6 (KERN_INFO) informational
1187 7 (KERN_DEBUG) debug-level messages
1188
1189 log_buf_len=n Sets the size of the printk ring buffer, in bytes.
Randy Dunlapa9913042005-10-23 12:57:11 -07001190 Format: { n | nk | nM }
1191 n must be a power of two. The default size
1192 is set in the kernel config file.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001193
Randy Dunlapaccaa242007-10-16 01:29:37 -07001194 logo.nologo [FB] Disables display of the built-in Linux logo.
1195 This may be used to provide more screen space for
1196 kernel log messages and is useful when debugging
1197 kernel boot problems.
1198
Linus Torvalds1da177e2005-04-16 15:20:36 -07001199 lp=0 [LP] Specify parallel ports to use, e.g,
1200 lp=port[,port...] lp=none,parport0 (lp0 not configured, lp1 uses
1201 lp=reset first parallel port). 'lp=0' disables the
1202 lp=auto printer driver. 'lp=reset' (which can be
1203 specified in addition to the ports) causes
1204 attached printers to be reset. Using
1205 lp=port1,port2,... specifies the parallel ports
1206 to associate lp devices with, starting with
1207 lp0. A port specification may be 'none' to skip
1208 that lp device, or a parport name such as
1209 'parport0'. Specifying 'lp=auto' instead of a
1210 port specification list means that device IDs
1211 from each port should be examined, to see if
1212 an IEEE 1284-compliant printer is attached; if
1213 so, the driver will manage that printer.
1214 See also header of drivers/char/lp.c.
1215
1216 lpj=n [KNL]
1217 Sets loops_per_jiffy to given constant, thus avoiding
1218 time-consuming boot-time autodetection (up to 250 ms per
1219 CPU). 0 enables autodetection (default). To determine
1220 the correct value for your kernel, boot with normal
1221 autodetection and see what value is printed. Note that
1222 on SMP systems the preset will be applied to all CPUs,
1223 which is likely to cause problems if your CPUs need
1224 significantly divergent settings. An incorrect value
1225 will cause delays in the kernel to be wrong, leading to
1226 unpredictable I/O errors and other breakage. Although
1227 unlikely, in the extreme case this might damage your
1228 hardware.
1229
1230 ltpc= [NET]
1231 Format: <io>,<irq>,<dma>
1232
Randy Dunlapa9913042005-10-23 12:57:11 -07001233 mac5380= [HW,SCSI] Format:
1234 <can_queue>,<cmd_per_lun>,<sg_tablesize>,<hostid>,<use_tags>
Linus Torvalds1da177e2005-04-16 15:20:36 -07001235
Randy Dunlapa9913042005-10-23 12:57:11 -07001236 machvec= [IA64] Force the use of a particular machine-vector
1237 (machvec) in a generic kernel.
1238 Example: machvec=hpzx1_swiotlb
Linus Torvalds1da177e2005-04-16 15:20:36 -07001239
Randy Dunlapa9913042005-10-23 12:57:11 -07001240 max_loop= [LOOP] Maximum number of loopback devices that can
Linus Torvalds1da177e2005-04-16 15:20:36 -07001241 be mounted
1242 Format: <1-256>
1243
1244 maxcpus= [SMP] Maximum number of processors that an SMP kernel
Len Brown61ec7562007-08-16 03:34:22 -04001245 should make use of. maxcpus=n : n >= 0 limits the
1246 kernel to using 'n' processors. n=0 is a special case,
1247 it is equivalent to "nosmp", which also disables
1248 the IO APIC.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001249
Randy Dunlap1c207f952008-11-19 15:36:16 -08001250 max_addr=nn[KMG] [KNL,BOOT,ia64] All physical memory greater than
1251 or equal to this physical address is ignored.
Bob Picco2b2c3752005-06-29 18:00:00 -07001252
Randy Dunlapa9913042005-10-23 12:57:11 -07001253 max_luns= [SCSI] Maximum number of LUNs to probe.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001254 Should be between 1 and 2^32-1.
1255
1256 max_report_luns=
Randy Dunlapa9913042005-10-23 12:57:11 -07001257 [SCSI] Maximum number of LUNs received.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001258 Should be between 1 and 16384.
1259
Linus Torvalds1da177e2005-04-16 15:20:36 -07001260 mcatest= [IA-64]
1261
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001262 mce [X86-32] Machine Check Exception
Linus Torvalds1da177e2005-04-16 15:20:36 -07001263
Uwe Hermann71cced62008-10-20 09:32:21 -07001264 mce=option [X86-64] See Documentation/x86/x86_64/boot-options.txt
Andi Kleen909dd322007-10-17 18:04:38 +02001265
Linus Torvalds1da177e2005-04-16 15:20:36 -07001266 md= [HW] RAID subsystems devices and level
1267 See Documentation/md.txt.
Randy Dunlapa9913042005-10-23 12:57:11 -07001268
Linus Torvalds1da177e2005-04-16 15:20:36 -07001269 mdacon= [MDA]
1270 Format: <first>,<last>
1271 Specifies range of consoles to be captured by the MDA.
Randy Dunlapa9913042005-10-23 12:57:11 -07001272
Linus Torvalds1da177e2005-04-16 15:20:36 -07001273 mem=nn[KMG] [KNL,BOOT] Force usage of a specific amount of memory
1274 Amount of memory to be used when the kernel is not able
1275 to see the whole system memory or for test.
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001276 [X86-32] Use together with memmap= to avoid physical
Linus Torvalds1da177e2005-04-16 15:20:36 -07001277 address space collisions. Without memmap= PCI devices
1278 could be placed at addresses belonging to unused RAM.
1279
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001280 mem=nopentium [BUGS=X86-32] Disable usage of 4MB pages for kernel
Linus Torvalds1da177e2005-04-16 15:20:36 -07001281 memory.
1282
Paul Mundt6902aa82008-09-21 17:14:42 +09001283 memchunk=nn[KMG]
1284 [KNL,SH] Allow user to override the default size for
1285 per-device physically contiguous DMA buffers.
1286
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001287 memmap=exactmap [KNL,X86-32,X86_64] Enable setting of an exact
Linus Torvalds1da177e2005-04-16 15:20:36 -07001288 E820 memory map, as specified by the user.
1289 Such memmap=exactmap lines can be constructed based on
1290 BIOS output or other requirements. See the memmap=nn@ss
1291 option description.
1292
1293 memmap=nn[KMG]@ss[KMG]
1294 [KNL] Force usage of a specific region of memory
1295 Region of memory to be used, from ss to ss+nn.
1296
1297 memmap=nn[KMG]#ss[KMG]
1298 [KNL,ACPI] Mark specific memory as ACPI data.
1299 Region of memory to be used, from ss to ss+nn.
1300
1301 memmap=nn[KMG]$ss[KMG]
1302 [KNL,ACPI] Mark specific memory as reserved.
1303 Region of memory to be used, from ss to ss+nn.
Pavel Machek13128482008-03-24 12:29:43 -07001304 Example: Exclude memory from 0x18690000-0x1869ffff
1305 memmap=64K$0x18690000
1306 or
1307 memmap=0x10000$0x18690000
Linus Torvalds1da177e2005-04-16 15:20:36 -07001308
Jeremy Fitzhardinge9f077872008-09-07 01:51:34 -07001309 memory_corruption_check=0/1 [X86]
1310 Some BIOSes seem to corrupt the first 64k of
1311 memory when doing things like suspend/resume.
1312 Setting this option will scan the memory
1313 looking for corruption. Enabling this will
1314 both detect corruption and prevent the kernel
1315 from using the memory being corrupted.
1316 However, its intended as a diagnostic tool; if
1317 repeatable BIOS-originated corruption always
1318 affects the same memory, you can use memmap=
1319 to prevent the kernel from using that memory.
1320
1321 memory_corruption_check_size=size [X86]
1322 By default it checks for corruption in the low
1323 64k, making this memory unavailable for normal
1324 use. Use this parameter to scan for
1325 corruption in more or less memory.
1326
1327 memory_corruption_check_period=seconds [X86]
1328 By default it checks for corruption every 60
1329 seconds. Use this parameter to check at some
1330 other rate. 0 disables periodic checking.
1331
Yinghai Lucaadbdc2008-07-15 00:03:44 -07001332 memtest= [KNL,X86] Enable memtest
Yinghai Luc64df702008-03-21 18:56:19 -07001333 Format: <integer>
Yinghai Luc64df702008-03-21 18:56:19 -07001334 default : 0 <disable>
Andreas Herrmann9e5f6cf2009-02-25 11:30:45 +01001335 Specifies the number of memtest passes to be
1336 performed. Each pass selects another test
1337 pattern from a given set of patterns. Memtest
1338 fills the memory with this pattern, validates
1339 memory contents and reserves bad memory
1340 regions that are detected.
Yinghai Luc64df702008-03-21 18:56:19 -07001341
Linus Torvalds1da177e2005-04-16 15:20:36 -07001342 meye.*= [HW] Set MotionEye Camera parameters
1343 See Documentation/video4linux/meye.txt.
1344
Andres Salomon8f368812007-10-12 23:04:06 +02001345 mfgpt_irq= [IA-32] Specify the IRQ to use for the
1346 Multi-Function General Purpose Timers on AMD Geode
1347 platforms.
1348
Willy Tarreaue6c4dc62008-01-30 13:33:33 +01001349 mfgptfix [X86-32] Fix MFGPT timers on AMD Geode platforms when
1350 the BIOS has incorrectly applied a workaround. TinyBIOS
1351 version 0.98 is known to be affected, 0.99 fixes the
1352 problem by letting the user disable the workaround.
1353
Linus Torvalds1da177e2005-04-16 15:20:36 -07001354 mga= [HW,DRM]
1355
Randy Dunlap1c207f952008-11-19 15:36:16 -08001356 min_addr=nn[KMG] [KNL,BOOT,ia64] All physical memory below this
1357 physical address is ignored.
1358
Mel Gorman6b74ab92008-07-23 21:26:49 -07001359 mminit_loglevel=
1360 [KNL] When CONFIG_DEBUG_MEMORY_INIT is set, this
1361 parameter allows control of the logging verbosity for
1362 the additional memory initialisation checks. A value
1363 of 0 disables mminit logging and a level of 4 will
1364 log everything. Information is printed at KERN_DEBUG
1365 so loglevel=8 may also need to be specified.
1366
Linus Torvalds1da177e2005-04-16 15:20:36 -07001367 mousedev.tap_time=
1368 [MOUSE] Maximum time between finger touching and
1369 leaving touchpad surface for touch to be considered
1370 a tap and be reported as a left button click (for
1371 touchpads working in absolute mode only).
1372 Format: <msecs>
1373 mousedev.xres= [MOUSE] Horizontal screen resolution, used for devices
1374 reporting absolute coordinates, such as tablets
1375 mousedev.yres= [MOUSE] Vertical screen resolution, used for devices
1376 reporting absolute coordinates, such as tablets
1377
1378 mpu401= [HW,OSS]
1379 Format: <io>,<irq>
1380
1381 MTD_Partition= [MTD]
1382 Format: <name>,<region-number>,<size>,<offset>
1383
Randy Dunlapa9913042005-10-23 12:57:11 -07001384 MTD_Region= [MTD] Format:
1385 <name>,<region-number>[,<base>,<size>,<buswidth>,<altbuswidth>]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001386
1387 mtdparts= [MTD]
Randy Dunlapc8facbb2007-07-31 00:37:40 -07001388 See drivers/mtd/cmdlinepart.c.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001389
Ben Dooks9db829f2008-07-03 11:24:29 +01001390 mtdset= [ARM]
1391 ARM/S3C2412 JIVE boot control
1392
1393 See arch/arm/mach-s3c2412/mach-jive.c
1394
Linus Torvalds1da177e2005-04-16 15:20:36 -07001395 mtouchusb.raw_coordinates=
Randy Dunlapa9913042005-10-23 12:57:11 -07001396 [HW] Make the MicroTouch USB driver use raw coordinates
1397 ('y', default) or cooked coordinates ('n')
Linus Torvalds1da177e2005-04-16 15:20:36 -07001398
1399 n2= [NET] SDL Inc. RISCom/N2 synchronous serial card
1400
1401 NCR_D700= [HW,SCSI]
1402 See header of drivers/scsi/NCR_D700.c.
1403
1404 ncr5380= [HW,SCSI]
1405
1406 ncr53c400= [HW,SCSI]
1407
1408 ncr53c400a= [HW,SCSI]
1409
1410 ncr53c406a= [HW,SCSI]
1411
1412 ncr53c8xx= [HW,SCSI]
1413
1414 netdev= [NET] Network devices parameters
1415 Format: <irq>,<io>,<mem_start>,<mem_end>,<name>
1416 Note that mem_start is often overloaded to mean
1417 something different and driver-specific.
Randy Dunlapa9913042005-10-23 12:57:11 -07001418 This usage is only documented in each driver source
1419 file if at all.
1420
Krzysztof Piotr Oledzki58401572008-07-21 10:01:34 -07001421 nf_conntrack.acct=
1422 [NETFILTER] Enable connection tracking flow accounting
1423 0 to disable accounting
1424 1 to enable accounting
1425 Default value depends on CONFIG_NF_CT_ACCT that is
1426 going to be removed in 2.6.29.
1427
Linus Torvalds1da177e2005-04-16 15:20:36 -07001428 nfsaddrs= [NFS]
J. Bruce Fields6ded55d2008-04-07 15:59:03 -04001429 See Documentation/filesystems/nfsroot.txt.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001430
1431 nfsroot= [NFS] nfs root filesystem for disk-less boxes.
J. Bruce Fields6ded55d2008-04-07 15:59:03 -04001432 See Documentation/filesystems/nfsroot.txt.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001433
Trond Myklebusta72b4422006-01-03 09:55:41 +01001434 nfs.callback_tcpport=
1435 [NFS] set the TCP port on which the NFSv4 callback
1436 channel should listen.
1437
Trond Myklebust58df0952006-01-03 09:55:57 +01001438 nfs.idmap_cache_timeout=
1439 [NFS] set the maximum lifetime for idmapper cache
1440 entries.
1441
Trond Myklebustf43bf0b2007-10-09 12:01:04 -04001442 nfs.enable_ino64=
1443 [NFS] enable 64-bit inode numbers.
1444 If zero, the NFS client will fake up a 32-bit inode
1445 number for the readdir() and stat() syscalls instead
1446 of returning the full 64-bit number.
1447 The default is to return 64-bit inode numbers.
1448
Haavard Skinnemoene7ba1762007-10-10 14:58:29 +02001449 nmi_debug= [KNL,AVR32] Specify one or more actions to take
1450 when a NMI is triggered.
1451 Format: [state][,regs][,debounce][,die]
1452
Cyrill Gorcunov5b9a0e12008-11-01 18:06:51 +03001453 nmi_watchdog= [KNL,BUGS=X86-32,X86-64] Debugging features for SMP kernels
1454 Format: [panic,][num]
1455 Valid num: 0,1,2
1456 0 - turn nmi_watchdog off
1457 1 - use the IO-APIC timer for the NMI watchdog
1458 2 - use the local APIC for the NMI watchdog using
1459 a performance counter. Note: This will use one performance
1460 counter and the local APIC's performance vector.
1461 When panic is specified panic when an NMI watchdog timeout occurs.
1462 This is useful when you use a panic=... timeout and need the box
1463 quickly up again.
1464 Instead of 1 and 2 it is possible to use the following
1465 symbolic names: lapic and ioapic
1466 Example: nmi_watchdog=2 or nmi_watchdog=panic,lapic
Linus Torvalds1da177e2005-04-16 15:20:36 -07001467
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001468 no387 [BUGS=X86-32] Tells the kernel to use the 387 maths
Linus Torvalds1da177e2005-04-16 15:20:36 -07001469 emulation library even if a 387 maths coprocessor
1470 is present.
1471
Christoph Lameterc1aee212007-05-31 00:40:47 -07001472 noaliencache [MM, NUMA, SLAB] Disables the allocation of alien
1473 caches in the slab allocator. Saves per-node memory,
1474 but will impact performance.
Paul Menage3395ee02006-12-06 20:32:16 -08001475
Randy Dunlapa9913042005-10-23 12:57:11 -07001476 noalign [KNL,ARM]
1477
Linus Torvalds1da177e2005-04-16 15:20:36 -07001478 noapic [SMP,APIC] Tells the kernel to not make use of any
1479 IOAPICs that may be present in the system.
1480
Linus Torvalds1da177e2005-04-16 15:20:36 -07001481 nobats [PPC] Do not use BATs for mapping kernel lowmem
1482 on "Classic" PPC cores.
1483
1484 nocache [ARM]
Randy Dunlapa9913042005-10-23 12:57:11 -07001485
Shailabh Nagar163ecdf2006-07-30 03:03:11 -07001486 nodelayacct [KNL] Disable per-task delay accounting
1487
Linus Torvalds1da177e2005-04-16 15:20:36 -07001488 nodisconnect [HW,SCSI,M68K] Disables SCSI disconnects.
1489
Paul Mundt6902aa82008-09-21 17:14:42 +09001490 nodsp [SH] Disable hardware DSP at boot time.
1491
Huang, Ying8b2cb7a2008-01-30 13:32:11 +01001492 noefi [X86-32,X86-64] Disable EFI runtime services support.
1493
Linus Torvalds1da177e2005-04-16 15:20:36 -07001494 noexec [IA-64]
1495
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001496 noexec [X86-32,X86-64]
Jiri Slabyf5a1b192008-04-12 10:28:25 +02001497 On X86-32 available only on PAE configured kernels.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001498 noexec=on: enable non-executable mappings (default)
Jiri Slabyf5a1b192008-04-12 10:28:25 +02001499 noexec=off: disable non-executable mappings
1500
1501 noexec32 [X86-64]
1502 This affects only 32-bit executables.
1503 noexec32=on: enable non-executable mappings (default)
1504 read doesn't imply executable mappings
1505 noexec32=off: disable non-executable mappings
1506 read implies executable mappings
Linus Torvalds1da177e2005-04-16 15:20:36 -07001507
Paul Mundt6902aa82008-09-21 17:14:42 +09001508 nofpu [SH] Disable hardware FPU at boot time.
1509
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001510 nofxsr [BUGS=X86-32] Disables x86 floating point extended
Chuck Ebbert4f886512006-03-23 02:59:34 -08001511 register save and restore. The kernel will only save
1512 legacy floating-point registers on task switch.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001513
Andi Kleen191679f2008-01-30 13:33:21 +01001514 noclflush [BUGS=X86] Don't use the CLFLUSH instruction
1515
Paulius Zaleckas01a24d22009-03-31 13:55:44 +01001516 nohlt [BUGS=ARM,SH] Tells the kernel that the sleep(SH) or
1517 wfi(ARM) instruction doesn't work correctly and not to
1518 use it. This is also useful when using JTAG debugger.
Randy Dunlapa9913042005-10-23 12:57:11 -07001519
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001520 no-hlt [BUGS=X86-32] Tells the kernel that the hlt
Linus Torvalds1da177e2005-04-16 15:20:36 -07001521 instruction doesn't work correctly and not to
1522 use it.
1523
Serge E. Hallyn1f29fae2008-11-05 16:08:52 -06001524 no_file_caps Tells the kernel not to honor file capabilities. The
1525 only way then for a file to be executed with privilege
1526 is to be setuid root or executed by root.
1527
Linus Torvalds1da177e2005-04-16 15:20:36 -07001528 nohalt [IA-64] Tells the kernel not to use the power saving
1529 function PAL_HALT_LIGHT when idle. This increases
1530 power-consumption. On the positive side, it reduces
1531 interrupt wake-up latency, which may improve performance
1532 in certain environments such as networked servers or
1533 real-time systems.
1534
Thomas Gleixner79bf2bb2007-02-16 01:28:03 -08001535 nohz= [KNL] Boottime enable/disable dynamic ticks
1536 Valid arguments: on, off
1537 Default: on
1538
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001539 noirqdebug [X86-32] Disables the code which attempts to detect and
Linus Torvalds1da177e2005-04-16 15:20:36 -07001540 disable unhandled interrupt sources.
1541
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001542 no_timer_check [X86-32,X86_64,APIC] Disables the code which tests for
Zachary Amsden8542b202006-12-07 02:14:09 +01001543 broken timer IRQ sources.
1544
Linus Torvalds1da177e2005-04-16 15:20:36 -07001545 noisapnp [ISAPNP] Disables ISA PnP code.
1546
1547 noinitrd [RAM] Tells the kernel not to load any configured
1548 initial RAM disk.
1549
1550 nointroute [IA-64]
1551
Tony Luck0aa366f2007-07-20 11:22:30 -07001552 nojitter [IA64] Disables jitter checking for ITC timers.
1553
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001554 nolapic [X86-32,APIC] Do not enable or use the local APIC.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001555
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001556 nolapic_timer [X86-32,APIC] Do not use the local APIC timer.
Thomas Gleixnerad62ca22007-03-22 00:11:21 -08001557
Suresh Siddha6e1cb382008-07-10 11:16:58 -07001558 nox2apic [X86-64,APIC] Do not enable x2APIC mode.
1559
Suresh Siddhaaf9d1382008-07-11 13:11:57 -07001560 x2apic_phys [X86-64,APIC] Use x2apic physical mode instead of
1561 default x2apic cluster mode on platforms
1562 supporting x2apic.
1563
Linus Torvalds1da177e2005-04-16 15:20:36 -07001564 noltlbs [PPC] Do not use large page/tlb entries for kernel
1565 lowmem mapping on PPC40x.
1566
Horms312f1f02006-02-22 09:57:55 +09001567 nomca [IA-64] Disable machine check abort handling
1568
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001569 nomce [X86-32] Machine Check Exception
Hormsabe37e52006-04-01 01:36:09 +02001570
Andres Salomon83d73842007-10-12 23:04:06 +02001571 nomfgpt [X86-32] Disable Multi-Function General Purpose
1572 Timer usage (for AMD Geode machines).
1573
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001574 noreplace-paravirt [X86-32,PV_OPS] Don't patch paravirt_ops
Jeremy Fitzhardinge959b4fd2007-05-02 19:27:16 +02001575
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001576 noreplace-smp [X86-32,SMP] Don't replace SMP instructions
Jeremy Fitzhardingeb7fb4af2007-05-02 19:27:13 +02001577 with UP alternatives
1578
Linus Torvalds1da177e2005-04-16 15:20:36 -07001579 noresidual [PPC] Don't use residual data on PReP machines.
1580
Randy Dunlapa9913042005-10-23 12:57:11 -07001581 noresume [SWSUSP] Disables resume and restores original swap
1582 space.
1583
Linus Torvalds1da177e2005-04-16 15:20:36 -07001584 no-scroll [VGA] Disables scrollback.
1585 This is required for the Braillex ib80-piezo Braille
1586 reader made by F.H. Papenmeier (Germany).
1587
1588 nosbagart [IA-64]
1589
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001590 nosep [BUGS=X86-32] Disables x86 SYSENTER/SYSEXIT support.
Chuck Ebbert4f886512006-03-23 02:59:34 -08001591
Len Brown61ec7562007-08-16 03:34:22 -04001592 nosmp [SMP] Tells an SMP kernel to act as a UP kernel,
1593 and disable the IO APIC. legacy for "maxcpus=0".
Linus Torvalds1da177e2005-04-16 15:20:36 -07001594
Dave Jones97842212007-07-15 23:41:05 -07001595 nosoftlockup [KNL] Disable the soft-lockup detector.
1596
KAMEZAWA Hiroyukic0777192009-01-07 18:07:57 -08001597 noswapaccount [KNL] Disable accounting of swap in memory resource
1598 controller. (See Documentation/controllers/memory.txt)
1599
Linus Torvalds1da177e2005-04-16 15:20:36 -07001600 nosync [HW,M68K] Disables sync negotiation for all devices.
1601
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001602 notsc [BUGS=X86-32] Disable Time Stamp Counter
Linus Torvalds1da177e2005-04-16 15:20:36 -07001603
1604 nousb [USB] Disable the USB subsystem
1605
1606 nowb [ARM]
Randy Dunlapa9913042005-10-23 12:57:11 -07001607
Fenghua Yua6c75b862008-03-14 13:57:08 -07001608 nptcg= [IA64] Override max number of concurrent global TLB
1609 purges which is reported from either PAL_VM_SUMMARY or
1610 SAL PALO.
1611
KAMEZAWA Hiroyukif0c0b2b2007-07-15 23:38:01 -07001612 numa_zonelist_order= [KNL, BOOT] Select zonelist order for NUMA.
1613 one of ['zone', 'node', 'default'] can be specified
1614 This can be set from sysctl after boot.
1615 See Documentation/sysctl/vm.txt for details.
1616
Dave Jonesa61c2d72006-01-07 23:18:19 +00001617 nr_uarts= [SERIAL] maximum number of UARTs to be registered.
1618
Randy Dunlap7c4be252009-01-06 14:42:44 -08001619 ohci1394_dma=early [HW] enable debugging via the ohci1394 driver.
1620 See Documentation/debugging-via-ohci1394.txt for more
1621 info.
1622
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07001623 olpc_ec_timeout= [OLPC] ms delay when issuing EC commands
1624 Rather than timing out after 20 ms if an EC
1625 command is not properly ACKed, override the length
1626 of the timeout. We have interrupts disabled while
1627 waiting for the ACK, so if this is set too high
1628 interrupts *may* be lost!
1629
Linus Torvalds1da177e2005-04-16 15:20:36 -07001630 opl3= [HW,OSS]
1631 Format: <io>
1632
Linus Torvalds1da177e2005-04-16 15:20:36 -07001633 oprofile.timer= [HW]
1634 Use timer interrupt instead of performance counters
1635
Linus Torvalds1da177e2005-04-16 15:20:36 -07001636 osst= [HW,SCSI] SCSI Tape Driver
1637 Format: <buffer_size>,<write_threshold>
1638 See also Documentation/scsi/st.txt.
1639
1640 panic= [KNL] Kernel behaviour on panic
1641 Format: <timeout>
1642
1643 parkbd.port= [HW] Parallel port number the keyboard adapter is
1644 connected to, default is 0.
1645 Format: <parport#>
1646 parkbd.mode= [HW] Parallel port keyboard adapter mode of operation,
1647 0 for XT, 1 for AT (default is AT).
Randy Dunlapa9913042005-10-23 12:57:11 -07001648 Format: <mode>
Linus Torvalds1da177e2005-04-16 15:20:36 -07001649
Randy Dunlapa9913042005-10-23 12:57:11 -07001650 parport= [HW,PPT] Specify parallel ports. 0 disables.
1651 Format: { 0 | auto | 0xBBB[,IRQ[,DMA]] }
1652 Use 'auto' to force the driver to use any
1653 IRQ/DMA settings detected (the default is to
1654 ignore detected IRQ/DMA settings because of
1655 possible conflicts). You can specify the base
1656 address, IRQ, and DMA settings; IRQ and DMA
1657 should be numbers, or 'auto' (for using detected
1658 settings on that particular port), or 'nofifo'
1659 (to avoid using a FIFO even if it is detected).
1660 Parallel ports are assigned in the order they
1661 are specified on the command line, starting
1662 with parport0.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001663
Randy Dunlapa9913042005-10-23 12:57:11 -07001664 parport_init_mode= [HW,PPT]
1665 Configure VIA parallel port to operate in
1666 a specific mode. This is necessary on Pegasos
1667 computer where firmware has no options for setting
1668 up parallel port mode and sets it to spp.
1669 Currently this function knows 686a and 8231 chips.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001670 Format: [spp|ps2|epp|ecp|ecpepp]
1671
Randy Dunlapa9913042005-10-23 12:57:11 -07001672 pas2= [HW,OSS] Format:
1673 <io>,<irq>,<dma>,<dma16>,<sb_io>,<sb_irq>,<sb_dma>,<sb_dma16>
1674
Linus Torvalds1da177e2005-04-16 15:20:36 -07001675 pas16= [HW,SCSI]
1676 See header of drivers/scsi/pas16.c.
1677
Andrew Mortondd287792006-03-23 03:00:57 -08001678 pause_on_oops=
1679 Halt all CPUs after the first oops has been printed for
1680 the specified number of seconds. This is to be used if
1681 your oopses keep scrolling off the screen.
1682
Linus Torvalds1da177e2005-04-16 15:20:36 -07001683 pcbit= [HW,ISDN]
1684
1685 pcd. [PARIDE]
1686 See header of drivers/block/paride/pcd.c.
Randy Dunlap31c00fc2008-11-13 21:33:24 +00001687 See also Documentation/blockdev/paride.txt.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001688
Randy Dunlapa9913042005-10-23 12:57:11 -07001689 pci=option[,option...] [PCI] various PCI subsystem options:
Andi Kleenc0115602008-08-22 09:53:39 +02001690 off [X86] don't probe for the PCI bus
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001691 bios [X86-32] force use of PCI BIOS, don't access
Randy Dunlapa9913042005-10-23 12:57:11 -07001692 the hardware directly. Use this if your machine
1693 has a non-standard PCI host bridge.
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001694 nobios [X86-32] disallow use of PCI BIOS, only direct
Randy Dunlapa9913042005-10-23 12:57:11 -07001695 hardware access methods are allowed. Use this
1696 if you experience crashes upon bootup and you
1697 suspect they are caused by the BIOS.
Andi Kleenc0115602008-08-22 09:53:39 +02001698 conf1 [X86] Force use of PCI Configuration
Randy Dunlapa9913042005-10-23 12:57:11 -07001699 Mechanism 1.
Andi Kleenc0115602008-08-22 09:53:39 +02001700 conf2 [X86] Force use of PCI Configuration
Randy Dunlapa9913042005-10-23 12:57:11 -07001701 Mechanism 2.
Randy Dunlap7f785762007-10-05 13:17:58 -07001702 noaer [PCIE] If the PCIEAER kernel config parameter is
1703 enabled, this kernel boot option can be used to
1704 disable the use of PCIE advanced error reporting.
Jeff Garzik32a2eea2007-10-11 16:57:27 -04001705 nodomains [PCI] Disable support for multiple PCI
1706 root domains (aka PCI segments, in ACPI-speak).
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001707 nommconf [X86-32,X86_64] Disable use of MMCONFIG for PCI
Bjorn Helgaas61be6d62006-02-15 15:17:43 -08001708 Configuration
Matthew Wilcox309e57d2006-03-05 22:33:34 -07001709 nomsi [MSI] If the PCI_MSI kernel config parameter is
1710 enabled, this kernel boot option can be used to
1711 disable the use of MSI interrupts system-wide.
Stefan Assmanna9322f62008-06-11 16:35:14 +02001712 noioapicquirk [APIC] Disable all boot interrupt quirks.
1713 Safety option to keep boot IRQs enabled. This
1714 should never be necessary.
Stefan Assmann91979792008-06-11 16:35:15 +02001715 ioapicreroute [APIC] Enable rerouting of boot IRQs to the
1716 primary IO-APIC for bridges that cannot disable
1717 boot IRQs. This fixes a source of spurious IRQs
1718 when the system masks IRQs.
Stefan Assmann41b9eb22008-07-15 13:48:55 +02001719 noioapicreroute [APIC] Disable workaround that uses the
1720 boot IRQ equivalent of an IRQ that connects to
1721 a chipset where boot IRQs cannot be disabled.
1722 The opposite of ioapicreroute.
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001723 biosirq [X86-32] Use PCI BIOS calls to get the interrupt
Randy Dunlapa9913042005-10-23 12:57:11 -07001724 routing table. These calls are known to be buggy
1725 on several machines and they hang the machine
1726 when used, but on other computers it's the only
1727 way to get the interrupt routing table. Try
1728 this option if the kernel is unable to allocate
1729 IRQs or discover secondary PCI buses on your
1730 motherboard.
Andi Kleenc0115602008-08-22 09:53:39 +02001731 rom [X86] Assign address space to expansion ROMs.
Randy Dunlapa9913042005-10-23 12:57:11 -07001732 Use with caution as certain devices share
1733 address decoders between ROMs and other
1734 resources.
Andi Kleenc0115602008-08-22 09:53:39 +02001735 norom [X86] Do not assign address space to
Gary Hadebb71ad82008-05-12 13:57:46 -07001736 expansion ROMs that do not already have
1737 BIOS assigned address ranges.
Andi Kleenc0115602008-08-22 09:53:39 +02001738 irqmask=0xMMMM [X86] Set a bit mask of IRQs allowed to be
Randy Dunlapa9913042005-10-23 12:57:11 -07001739 assigned automatically to PCI devices. You can
1740 make the kernel exclude IRQs of your ISA cards
1741 this way.
Andi Kleenc0115602008-08-22 09:53:39 +02001742 pirqaddr=0xAAAAA [X86] Specify the physical address
Randy Dunlapa9913042005-10-23 12:57:11 -07001743 of the PIRQ table (normally generated
1744 by the BIOS) if it is outside the
1745 F0000h-100000h range.
Andi Kleenc0115602008-08-22 09:53:39 +02001746 lastbus=N [X86] Scan all buses thru bus #N. Can be
Randy Dunlapa9913042005-10-23 12:57:11 -07001747 useful if the kernel is unable to find your
1748 secondary buses and you want to tell it
1749 explicitly which ones they are.
Andi Kleenc0115602008-08-22 09:53:39 +02001750 assign-busses [X86] Always assign all PCI bus
Randy Dunlapa9913042005-10-23 12:57:11 -07001751 numbers ourselves, overriding
1752 whatever the firmware may have done.
Andi Kleenc0115602008-08-22 09:53:39 +02001753 usepirqmask [X86] Honor the possible IRQ mask stored
Randy Dunlapa9913042005-10-23 12:57:11 -07001754 in the BIOS $PIR table. This is needed on
1755 some systems with broken BIOSes, notably
1756 some HP Pavilion N5400 and Omnibook XE3
1757 notebooks. This will have no effect if ACPI
1758 IRQ routing is enabled.
Andi Kleenc0115602008-08-22 09:53:39 +02001759 noacpi [X86] Do not use ACPI for IRQ routing
Randy Dunlapa9913042005-10-23 12:57:11 -07001760 or for PCI scanning.
Andi Kleenc0115602008-08-22 09:53:39 +02001761 use_crs [X86] Use _CRS for PCI resource
Gary Hade62f420f2007-10-03 15:56:51 -07001762 allocation.
Randy Dunlapa9913042005-10-23 12:57:11 -07001763 routeirq Do IRQ routing for all PCI devices.
1764 This is normally done in pci_enable_device(),
1765 so this option is a temporary workaround
1766 for broken drivers that don't call it.
Yinghai Lu13a6ddb2008-03-27 01:31:18 -07001767 skip_isa_align [X86] do not align io start addr, so can
1768 handle more pci cards
Randy Dunlapa9913042005-10-23 12:57:11 -07001769 firmware [ARM] Do not re-enumerate the bus but instead
1770 just use the configuration from the
1771 bootloader. This is currently used on
1772 IXP2000 systems where the bus has to be
1773 configured a certain way for adjunct CPUs.
Andi Kleen0637a702006-09-26 10:52:41 +02001774 noearly [X86] Don't do any early type 1 scanning.
1775 This might help on some broken boards which
1776 machine check when some devices' config space
1777 is read. But various workarounds are disabled
1778 and some IOMMU drivers will not work.
Matt Domsch6b4b78f2006-09-29 15:23:23 -05001779 bfsort Sort PCI devices into breadth-first order.
1780 This sorting is done to get a device
1781 order compatible with older (<= 2.4) kernels.
1782 nobfsort Don't sort PCI devices into breadth-first order.
Atsushi Nemoto4516a612007-02-05 16:36:06 -08001783 cbiosize=nn[KMG] The fixed amount of bus space which is
1784 reserved for the CardBus bridge's IO window.
1785 The default value is 256 bytes.
1786 cbmemsize=nn[KMG] The fixed amount of bus space which is
1787 reserved for the CardBus bridge's memory
1788 window. The default value is 64 megabytes.
Matt Domsch6b4b78f2006-09-29 15:23:23 -05001789
Chuck Ebberte5665a42008-09-24 20:40:34 -04001790 pcie_aspm= [PCIE] Forcibly enable or disable PCIe Active State Power
1791 Management.
1792 off Disable ASPM.
1793 force Enable ASPM even on devices that claim not to support it.
1794 WARNING: Forcing ASPM on may cause system lockups.
1795
Linus Torvalds1da177e2005-04-16 15:20:36 -07001796 pcmv= [HW,PCMCIA] BadgePAD 4
1797
1798 pd. [PARIDE]
Randy Dunlap31c00fc2008-11-13 21:33:24 +00001799 See Documentation/blockdev/paride.txt.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001800
1801 pdcchassis= [PARISC,HW] Disable/Enable PDC Chassis Status codes at
1802 boot time.
1803 Format: { 0 | 1 }
1804 See arch/parisc/kernel/pdc_chassis.c
1805
1806 pf. [PARIDE]
Randy Dunlap31c00fc2008-11-13 21:33:24 +00001807 See Documentation/blockdev/paride.txt.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001808
1809 pg. [PARIDE]
Randy Dunlap31c00fc2008-11-13 21:33:24 +00001810 See Documentation/blockdev/paride.txt.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001811
1812 pirq= [SMP,APIC] Manual mp-table setup
Uwe Hermann71cced62008-10-20 09:32:21 -07001813 See Documentation/x86/i386/IO-APIC.txt.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001814
1815 plip= [PPT,NET] Parallel port network link
1816 Format: { parport<nr> | timid | 0 }
1817 See also Documentation/parport.txt.
1818
Thomas Gleixnerde32a242008-07-12 05:33:30 +02001819 pmtmr= [X86] Manual setup of pmtmr I/O Port.
1820 Override pmtimer IOPort with a hex value.
1821 e.g. pmtmr=0x508
1822
Bjorn Helgaas97ef0622008-08-19 16:53:41 -06001823 pnp.debug [PNP]
1824 Enable PNP debug messages. This depends on the
1825 CONFIG_PNP_DEBUG_MESSAGES option.
1826
Linus Torvalds1da177e2005-04-16 15:20:36 -07001827 pnpacpi= [ACPI]
1828 { off }
1829
1830 pnpbios= [ISAPNP]
1831 { on | off | curr | res | no-curr | no-res }
1832
1833 pnp_reserve_irq=
1834 [ISAPNP] Exclude IRQs for the autoconfiguration
1835
1836 pnp_reserve_dma=
1837 [ISAPNP] Exclude DMAs for the autoconfiguration
1838
1839 pnp_reserve_io= [ISAPNP] Exclude I/O ports for the autoconfiguration
Randy Dunlapa9913042005-10-23 12:57:11 -07001840 Ranges are in pairs (I/O port base and size).
Linus Torvalds1da177e2005-04-16 15:20:36 -07001841
1842 pnp_reserve_mem=
Randy Dunlapa9913042005-10-23 12:57:11 -07001843 [ISAPNP] Exclude memory regions for the
1844 autoconfiguration.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001845 Ranges are in pairs (memory base and size).
1846
Ingo Molnar45807a12007-07-15 23:40:10 -07001847 print-fatal-signals=
1848 [KNL] debug: print fatal signals
1849 print-fatal-signals=1: print segfault info to
1850 the kernel console.
1851 default: off.
1852
Randy Dunlape84845c2007-07-15 23:40:25 -07001853 printk.time= Show timing data prefixed to each printk message line
1854 Format: <bool> (1/Y/y=enable, 0/N/n=disable)
1855
Linus Torvalds1da177e2005-04-16 15:20:36 -07001856 profile= [KNL] Enable kernel profiling via /proc/profile
Randy Dunlapa9913042005-10-23 12:57:11 -07001857 Format: [schedule,]<number>
1858 Param: "schedule" - profile schedule points.
1859 Param: <number> - step/bucket size as a power of 2 for
1860 statistical time based profiling.
Mel Gormanb3da2a72007-10-24 18:23:50 +02001861 Param: "sleep" - profile D-state sleeping (millisecs).
1862 Requires CONFIG_SCHEDSTATS
Dave Jonesc0fe2e62007-10-20 03:08:22 +02001863 Param: "kvm" - profile VM exits.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001864
Randy Dunlapa9913042005-10-23 12:57:11 -07001865 processor.max_cstate= [HW,ACPI]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001866 Limit processor to maximum C-state
1867 max_cstate=9 overrides any DMI blacklist limit.
1868
Len Brown41c0d862005-12-28 12:43:51 -05001869 processor.nocst [HW,ACPI]
1870 Ignore the _CST method to determine C-states,
1871 instead using the legacy FADT method
1872
Linus Torvalds1da177e2005-04-16 15:20:36 -07001873 prompt_ramdisk= [RAM] List of RAM disks to prompt for floppy disk
1874 before loading.
Randy Dunlap31c00fc2008-11-13 21:33:24 +00001875 See Documentation/blockdev/ramdisk.txt.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001876
Randy Dunlapa9913042005-10-23 12:57:11 -07001877 psmouse.proto= [HW,MOUSE] Highest PS2 mouse protocol extension to
1878 probe for; one of (bare|imps|exps|lifebook|any).
Linus Torvalds1da177e2005-04-16 15:20:36 -07001879 psmouse.rate= [HW,MOUSE] Set desired mouse report rate, in reports
1880 per second.
Randy Dunlapa9913042005-10-23 12:57:11 -07001881 psmouse.resetafter= [HW,MOUSE]
1882 Try to reset the device after so many bad packets
Linus Torvalds1da177e2005-04-16 15:20:36 -07001883 (0 = never).
1884 psmouse.resolution=
1885 [HW,MOUSE] Set desired mouse resolution, in dpi.
1886 psmouse.smartscroll=
Randy Dunlapa9913042005-10-23 12:57:11 -07001887 [HW,MOUSE] Controls Logitech smartscroll autorepeat.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001888 0 = disabled, 1 = enabled (default).
1889
1890 pss= [HW,OSS] Personal Sound System (ECHO ESC614)
Randy Dunlapa9913042005-10-23 12:57:11 -07001891 Format:
1892 <io>,<mss_io>,<mss_irq>,<mss_dma>,<mpu_io>,<mpu_irq>
Linus Torvalds1da177e2005-04-16 15:20:36 -07001893
1894 pt. [PARIDE]
Randy Dunlap31c00fc2008-11-13 21:33:24 +00001895 See Documentation/blockdev/paride.txt.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001896
Kay Sieversdc8c8582007-08-15 12:25:38 +02001897 pty.legacy_count=
1898 [KNL] Number of legacy pty's. Overwrites compiled-in
1899 default number.
1900
Randy Dunlap7d2c5022006-09-29 02:01:02 -07001901 quiet [KNL] Disable most log messages
Randy Dunlapa9913042005-10-23 12:57:11 -07001902
Linus Torvalds1da177e2005-04-16 15:20:36 -07001903 r128= [HW,DRM]
1904
1905 raid= [HW,RAID]
1906 See Documentation/md.txt.
1907
Randy Dunlapa9913042005-10-23 12:57:11 -07001908 ramdisk_blocksize= [RAM]
Randy Dunlap31c00fc2008-11-13 21:33:24 +00001909 See Documentation/blockdev/ramdisk.txt.
Randy Dunlapa9913042005-10-23 12:57:11 -07001910
Linus Torvalds1da177e2005-04-16 15:20:36 -07001911 ramdisk_size= [RAM] Sizes of RAM disks in kilobytes
Randy Dunlap31c00fc2008-11-13 21:33:24 +00001912 See Documentation/blockdev/ramdisk.txt.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001913
Robert P. J. Day24aaef82008-02-03 15:20:26 +02001914 rcupdate.blimit= [KNL,BOOT]
1915 Set maximum number of finished RCU callbacks to process
1916 in one batch.
Dipankar Sarma21a1ea92006-03-07 21:55:33 -08001917
Robert P. J. Day24aaef82008-02-03 15:20:26 +02001918 rcupdate.qhimark= [KNL,BOOT]
1919 Set threshold of queued
Dipankar Sarma21a1ea92006-03-07 21:55:33 -08001920 RCU callbacks over which batch limiting is disabled.
1921
Robert P. J. Day24aaef82008-02-03 15:20:26 +02001922 rcupdate.qlowmark= [KNL,BOOT]
1923 Set threshold of queued RCU callbacks below which
1924 batch limiting is re-enabled.
Dipankar Sarma21a1ea92006-03-07 21:55:33 -08001925
Olof Johanssonffdfc402005-09-06 15:17:19 -07001926 rdinit= [KNL]
1927 Format: <full_path>
1928 Run specified binary instead of /init from the ramdisk,
1929 used for early userspace startup. See initrd.
1930
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001931 reboot= [BUGS=X86-32,BUGS=ARM,BUGS=IA-64] Rebooting mode
Linus Torvalds1da177e2005-04-16 15:20:36 -07001932 Format: <reboot_mode>[,<reboot_mode2>[,...]]
Randy Dunlapecb08d82009-01-06 14:42:44 -08001933 See arch/*/kernel/reboot.c or arch/*/kernel/process.c
Linus Torvalds1da177e2005-04-16 15:20:36 -07001934
Paul Jackson46b6d942008-07-04 10:00:09 -07001935 relax_domain_level=
1936 [KNL, SMP] Set scheduler's default relax_domain_level.
1937 See Documentation/cpusets.txt.
1938
Linus Torvalds1da177e2005-04-16 15:20:36 -07001939 reserve= [KNL,BUGS] Force the kernel to ignore some iomem area
1940
Alan Coxcd4f0ef2007-07-31 00:37:59 -07001941 reservetop= [X86-32]
Zachary Amsden461a9aff2006-09-25 23:32:25 -07001942 Format: nn[KMG]
1943 Reserves a hole at the top of the kernel virtual
1944 address space.
1945
Vivek Goyal7e962872006-09-27 01:50:44 -07001946 reset_devices [KNL] Force drivers to reset the underlying device
1947 during initialization.
1948
Randy Dunlapa9913042005-10-23 12:57:11 -07001949 resume= [SWSUSP]
1950 Specify the partition device for software suspend
Linus Torvalds1da177e2005-04-16 15:20:36 -07001951
Rafael J. Wysockiecbd0da2006-12-06 20:34:13 -08001952 resume_offset= [SWSUSP]
1953 Specify the offset from the beginning of the partition
1954 given by "resume=" at which the swap header is located,
1955 in <PAGE_SIZE> units (needed only for swap files).
1956 See Documentation/power/swsusp-and-swap-files.txt
1957
Michael Neuling0a7b35cb2007-02-10 01:44:33 -08001958 retain_initrd [RAM] Keep initrd memory after extraction
1959
Linus Torvalds1da177e2005-04-16 15:20:36 -07001960 rhash_entries= [KNL,NET]
1961 Set number of hash buckets for route cache
1962
1963 riscom8= [HW,SERIAL]
1964 Format: <io_board1>[,<io_board2>[,...<io_boardN>]]
1965
1966 ro [KNL] Mount root device read-only on boot
1967
1968 root= [KNL] Root filesystem
1969
1970 rootdelay= [KNL] Delay (in seconds) to pause before attempting to
1971 mount the root filesystem
1972
1973 rootflags= [KNL] Set root filesystem mount option string
1974
1975 rootfstype= [KNL] Set root filesystem type
1976
Pierre Ossmancc1ed752007-07-15 23:40:35 -07001977 rootwait [KNL] Wait (indefinitely) for root device to show up.
1978 Useful for devices that are detected asynchronously
1979 (e.g. USB and MMC devices).
1980
James Morris20510f22007-10-16 23:31:32 -07001981 root_plug.vendor_id=
1982 [ROOTPLUG] Override the default vendor ID
1983
1984 root_plug.product_id=
1985 [ROOTPLUG] Override the default product ID
1986
1987 root_plug.debug=
1988 [ROOTPLUG] Enable debugging output
1989
Linus Torvalds1da177e2005-04-16 15:20:36 -07001990 rw [KNL] Mount root device read-write on boot
1991
1992 S [KNL] Run init in single mode
1993
1994 sa1100ir [NET]
1995 See drivers/net/irda/sa1100_ir.c.
1996
Linus Torvalds1da177e2005-04-16 15:20:36 -07001997 sbni= [NET] Granch SBNI12 leased line adapter
Randy Dunlapa9913042005-10-23 12:57:11 -07001998
Linus Torvalds1da177e2005-04-16 15:20:36 -07001999 sc1200wdt= [HW,WDT] SC1200 WDT (watchdog) driver
2000 Format: <io>[,<timeout>[,<isapnp>]]
2001
2002 scsi_debug_*= [SCSI]
2003 See drivers/scsi/scsi_debug.c.
2004
2005 scsi_default_dev_flags=
2006 [SCSI] SCSI default device flags
2007 Format: <integer>
2008
2009 scsi_dev_flags= [SCSI] Black/white list entry for vendor and model
2010 Format: <vendor>:<model>:<flags>
2011 (flags are integer value)
2012
Randy Dunlap6af66322007-11-14 16:52:25 -08002013 scsi_logging_level= [SCSI] a bit mask of logging levels
2014 See drivers/scsi/scsi_logging.h for bits. Also
2015 settable via sysctl at dev.scsi.logging_level
2016 (/proc/sys/dev/scsi/logging_level).
2017 There is also a nice 'scsi_logging_level' script in the
2018 S390-tools package, available for download at
2019 http://www-128.ibm.com/developerworks/linux/linux390/s390-tools-1.5.4.html
Linus Torvalds1da177e2005-04-16 15:20:36 -07002020
Matthew Wilcox3e082a92006-09-28 15:19:20 -06002021 scsi_mod.scan= [SCSI] sync (default) scans SCSI busses as they are
2022 discovered. async scans them in kernel threads,
2023 allowing boot to proceed. none ignores them, expecting
2024 user space to do the scan.
2025
Linus Torvalds1da177e2005-04-16 15:20:36 -07002026 selinux [SELINUX] Disable or enable SELinux at boot time.
2027 Format: { "0" | "1" }
2028 See security/selinux/Kconfig help text.
2029 0 -- disable.
2030 1 -- enable.
2031 Default value is set via kernel config option.
2032 If enabled at boot time, /selinux/disable can be used
2033 later to disable prior to initial policy load.
2034
Alan Coxcd4f0ef2007-07-31 00:37:59 -07002035 serialnumber [BUGS=X86-32]
Linus Torvalds1da177e2005-04-16 15:20:36 -07002036
Linus Torvalds1da177e2005-04-16 15:20:36 -07002037 shapers= [NET]
2038 Maximal number of shapers.
Randy Dunlapa9913042005-10-23 12:57:11 -07002039
Yinghai Lub05f78f2008-08-22 01:32:50 -07002040 show_msr= [x86] show boot-time MSR settings
2041 Format: { <integer> }
2042 Show boot-time (BIOS-initialized) MSR settings.
2043 The parameter means the number of CPUs to show,
2044 for example 1 means boot CPU only.
2045
Linus Torvalds1da177e2005-04-16 15:20:36 -07002046 sim710= [SCSI,HW]
2047 See header of drivers/scsi/sim710.c.
2048
2049 simeth= [IA-64]
2050 simscsi=
Randy Dunlapa9913042005-10-23 12:57:11 -07002051
Linus Torvalds1da177e2005-04-16 15:20:36 -07002052 slram= [HW,MTD]
2053
Christoph Lameterf0630ff2007-07-15 23:38:14 -07002054 slub_debug[=options[,slabs]] [MM, SLUB]
2055 Enabling slub_debug allows one to determine the
2056 culprit if slab objects become corrupted. Enabling
2057 slub_debug can create guard zones around objects and
2058 may poison objects when not in use. Also tracks the
2059 last alloc / free. For more information see
2060 Documentation/vm/slub.txt.
Christoph Lameterc1aee212007-05-31 00:40:47 -07002061
2062 slub_max_order= [MM, SLUB]
Christoph Lameterf0630ff2007-07-15 23:38:14 -07002063 Determines the maximum allowed order for slabs.
2064 A high setting may cause OOMs due to memory
2065 fragmentation. For more information see
2066 Documentation/vm/slub.txt.
Christoph Lameterc1aee212007-05-31 00:40:47 -07002067
2068 slub_min_objects= [MM, SLUB]
Christoph Lameterf0630ff2007-07-15 23:38:14 -07002069 The minimum number of objects per slab. SLUB will
2070 increase the slab order up to slub_max_order to
2071 generate a sufficiently large slab able to contain
2072 the number of objects indicated. The higher the number
2073 of objects the smaller the overhead of tracking slabs
2074 and the less frequently locks need to be acquired.
Christoph Lameterc1aee212007-05-31 00:40:47 -07002075 For more information see Documentation/vm/slub.txt.
2076
2077 slub_min_order= [MM, SLUB]
2078 Determines the mininum page order for slabs. Must be
Christoph Lameterf0630ff2007-07-15 23:38:14 -07002079 lower than slub_max_order.
Christoph Lameterc1aee212007-05-31 00:40:47 -07002080 For more information see Documentation/vm/slub.txt.
2081
2082 slub_nomerge [MM, SLUB]
Christoph Lameterf0630ff2007-07-15 23:38:14 -07002083 Disable merging of slabs with similar size. May be
Christoph Lameterc1aee212007-05-31 00:40:47 -07002084 necessary if there is some reason to distinguish
Christoph Lameterf0630ff2007-07-15 23:38:14 -07002085 allocs to different slabs. Debug options disable
2086 merging on their own.
Christoph Lameterc1aee212007-05-31 00:40:47 -07002087 For more information see Documentation/vm/slub.txt.
2088
Linus Torvalds1da177e2005-04-16 15:20:36 -07002089 smart2= [HW]
2090 Format: <io1>[,<io2>[,...,<io8>]]
2091
Alan Coxcd4f0ef2007-07-31 00:37:59 -07002092 smp-alt-once [X86-32,SMP] On a hotplug CPU system, only
Jeremy Fitzhardingeb7fb4af2007-05-02 19:27:13 +02002093 attempt to substitute SMP alternatives once at boot.
2094
Bjorn Helgaasd0d4f692007-05-08 00:36:05 -07002095 smsc-ircc2.nopnp [HW] Don't use PNP to discover SMC devices
2096 smsc-ircc2.ircc_cfg= [HW] Device configuration I/O port
2097 smsc-ircc2.ircc_sir= [HW] SIR base I/O port
2098 smsc-ircc2.ircc_fir= [HW] FIR base I/O port
2099 smsc-ircc2.ircc_irq= [HW] IRQ line
2100 smsc-ircc2.ircc_dma= [HW] DMA channel
2101 smsc-ircc2.ircc_transceiver= [HW] Transceiver type:
2102 0: Toshiba Satellite 1800 (GP data pin select)
2103 1: Fast pin select (default)
2104 2: ATC IRMode
2105
Linus Torvalds1da177e2005-04-16 15:20:36 -07002106 snd-ad1816a= [HW,ALSA]
2107
2108 snd-ad1848= [HW,ALSA]
2109
2110 snd-ali5451= [HW,ALSA]
2111
2112 snd-als100= [HW,ALSA]
2113
2114 snd-als4000= [HW,ALSA]
2115
2116 snd-azt2320= [HW,ALSA]
2117
2118 snd-cmi8330= [HW,ALSA]
2119
2120 snd-cmipci= [HW,ALSA]
2121
2122 snd-cs4231= [HW,ALSA]
2123
2124 snd-cs4232= [HW,ALSA]
2125
2126 snd-cs4236= [HW,ALSA]
2127
2128 snd-cs4281= [HW,ALSA]
2129
2130 snd-cs46xx= [HW,ALSA]
2131
2132 snd-dt019x= [HW,ALSA]
2133
2134 snd-dummy= [HW,ALSA]
2135
2136 snd-emu10k1= [HW,ALSA]
2137
2138 snd-ens1370= [HW,ALSA]
2139
2140 snd-ens1371= [HW,ALSA]
2141
2142 snd-es968= [HW,ALSA]
2143
2144 snd-es1688= [HW,ALSA]
2145
2146 snd-es18xx= [HW,ALSA]
2147
2148 snd-es1938= [HW,ALSA]
2149
2150 snd-es1968= [HW,ALSA]
2151
2152 snd-fm801= [HW,ALSA]
2153
2154 snd-gusclassic= [HW,ALSA]
2155
2156 snd-gusextreme= [HW,ALSA]
2157
2158 snd-gusmax= [HW,ALSA]
2159
2160 snd-hdsp= [HW,ALSA]
2161
2162 snd-ice1712= [HW,ALSA]
2163
2164 snd-intel8x0= [HW,ALSA]
2165
2166 snd-interwave= [HW,ALSA]
2167
2168 snd-interwave-stb=
2169 [HW,ALSA]
2170
2171 snd-korg1212= [HW,ALSA]
2172
2173 snd-maestro3= [HW,ALSA]
2174
2175 snd-mpu401= [HW,ALSA]
2176
2177 snd-mtpav= [HW,ALSA]
2178
2179 snd-nm256= [HW,ALSA]
2180
2181 snd-opl3sa2= [HW,ALSA]
2182
2183 snd-opti92x-ad1848=
2184 [HW,ALSA]
2185
2186 snd-opti92x-cs4231=
2187 [HW,ALSA]
2188
2189 snd-opti93x= [HW,ALSA]
2190
2191 snd-pmac= [HW,ALSA]
2192
2193 snd-rme32= [HW,ALSA]
2194
2195 snd-rme96= [HW,ALSA]
2196
2197 snd-rme9652= [HW,ALSA]
2198
2199 snd-sb8= [HW,ALSA]
2200
2201 snd-sb16= [HW,ALSA]
2202
2203 snd-sbawe= [HW,ALSA]
2204
2205 snd-serial= [HW,ALSA]
2206
2207 snd-sgalaxy= [HW,ALSA]
2208
2209 snd-sonicvibes= [HW,ALSA]
2210
2211 snd-sun-amd7930=
2212 [HW,ALSA]
2213
2214 snd-sun-cs4231= [HW,ALSA]
2215
2216 snd-trident= [HW,ALSA]
2217
2218 snd-usb-audio= [HW,ALSA,USB]
2219
2220 snd-via82xx= [HW,ALSA]
2221
2222 snd-virmidi= [HW,ALSA]
2223
2224 snd-wavefront= [HW,ALSA]
2225
2226 snd-ymfpci= [HW,ALSA]
Randy Dunlapa9913042005-10-23 12:57:11 -07002227
Ingo Molnar9c44bc02008-05-12 21:21:04 +02002228 softlockup_panic=
2229 [KNL] Should the soft-lockup detector generate panics.
2230
Linus Torvalds1da177e2005-04-16 15:20:36 -07002231 sonypi.*= [HW] Sony Programmable I/O Control Device driver
2232 See Documentation/sonypi.txt
2233
2234 specialix= [HW,SERIAL] Specialix multi-serial port adapter
Randy Dunlap31c00fc2008-11-13 21:33:24 +00002235 See Documentation/serial/specialix.txt.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002236
2237 spia_io_base= [HW,MTD]
2238 spia_fio_base=
2239 spia_pedr=
2240 spia_peddr=
2241
2242 sscape= [HW,OSS]
2243 Format: <io>,<irq>,<dma>,<mpu_io>,<mpu_irq>
Randy Dunlapa9913042005-10-23 12:57:11 -07002244
Linus Torvalds1da177e2005-04-16 15:20:36 -07002245 st= [HW,SCSI] SCSI tape parameters (buffers, etc.)
2246 See Documentation/scsi/st.txt.
2247
Steven Rostedtf38f1d22008-12-16 23:06:40 -05002248 stacktrace [FTRACE]
2249 Enabled the stack tracer on boot up.
2250
Linus Torvalds1da177e2005-04-16 15:20:36 -07002251 sti= [PARISC,HW]
2252 Format: <num>
2253 Set the STI (builtin display/keyboard on the HP-PARISC
2254 machines) console (graphic card) which should be used
2255 as the initial boot-console.
2256 See also comment in drivers/video/console/sticore.c.
2257
2258 sti_font= [HW]
2259 See comment in drivers/video/console/sticore.c.
2260
2261 stifb= [HW]
2262 Format: bpp:<bpp1>[:<bpp2>[:<bpp3>...]]
2263
Greg Banks42a7fc42007-03-06 01:42:23 -08002264 sunrpc.pool_mode=
2265 [NFS]
2266 Control how the NFS server code allocates CPUs to
2267 service thread pools. Depending on how many NICs
2268 you have and where their interrupts are bound, this
2269 option will affect which CPUs will do NFS serving.
2270 Note: this parameter cannot be changed while the
2271 NFS server is running.
2272
2273 auto the server chooses an appropriate mode
2274 automatically using heuristics
2275 global a single global pool contains all CPUs
2276 percpu one pool for each CPU
2277 pernode one pool for each NUMA node (equivalent
2278 to global on non-NUMA machines)
2279
Linus Torvalds1da177e2005-04-16 15:20:36 -07002280 swiotlb= [IA-64] Number of I/O TLB slabs
Randy Dunlapa9913042005-10-23 12:57:11 -07002281
Linus Torvalds1da177e2005-04-16 15:20:36 -07002282 switches= [HW,M68k]
2283
2284 sym53c416= [HW,SCSI]
2285 See header of drivers/scsi/sym53c416.c.
2286
Ingo Molnar5d6f6472006-12-13 00:34:36 -08002287 sysrq_always_enabled
2288 [KNL]
2289 Ignore sysrq setting - this boot parameter will
2290 neutralize any effect of /proc/sys/kernel/sysrq.
2291 Useful for debugging.
2292
Linus Torvalds1da177e2005-04-16 15:20:36 -07002293 t128= [HW,SCSI]
2294 See header of drivers/scsi/t128.c.
2295
2296 tdfx= [HW,DRM]
2297
David Brownell77437fd2008-07-23 21:28:33 -07002298 test_suspend= [SUSPEND]
2299 Specify "mem" (for Suspend-to-RAM) or "standby" (for
2300 standby suspend) as the system sleep state to briefly
2301 enter during system startup. The system is woken from
2302 this state using a wakeup-capable RTC alarm.
2303
Linus Torvalds1da177e2005-04-16 15:20:36 -07002304 thash_entries= [KNL,NET]
2305 Set number of hash buckets for TCP connection
2306
Len Brownf8707ec2007-08-12 00:12:54 -04002307 thermal.act= [HW,ACPI]
2308 -1: disable all active trip points in all thermal zones
2309 <degrees C>: override all lowest active trip points
2310
Len Brownc52a7412007-08-14 15:49:32 -04002311 thermal.crt= [HW,ACPI]
2312 -1: disable all critical trip points in all thermal zones
Zhang Rui22a94d72008-10-17 02:41:20 -04002313 <degrees C>: override all critical trip points
Len Brownc52a7412007-08-14 15:49:32 -04002314
Len Brownf5487142007-08-12 00:12:44 -04002315 thermal.nocrt= [HW,ACPI]
2316 Set to disable actions on ACPI thermal zone
2317 critical and hot trip points.
2318
Len Brown72b33ef2007-08-12 00:12:17 -04002319 thermal.off= [HW,ACPI]
2320 1: disable ACPI thermal control
2321
Len Browna70cdc52007-08-12 00:12:35 -04002322 thermal.psv= [HW,ACPI]
2323 -1: disable all passive trip points
Randy Dunlapada9cfd2008-12-19 10:57:32 -08002324 <degrees C>: override all passive trip points to this
2325 value
Len Browna70cdc52007-08-12 00:12:35 -04002326
Len Brown730ff342007-08-12 00:12:26 -04002327 thermal.tzp= [HW,ACPI]
2328 Specify global default ACPI thermal zone polling rate
2329 <deci-seconds>: poll all this frequency
2330 0: no polling (default)
2331
Linus Torvalds1da177e2005-04-16 15:20:36 -07002332 tmscsim= [HW,SCSI]
2333 See comment before function dc390_setup() in
2334 drivers/scsi/tmscsim.c.
2335
Heiko Carstens2b1a61f2008-12-25 13:39:23 +01002336 topology= [S390]
2337 Format: {off | on}
2338 Specify if the kernel should make use of the cpu
2339 topology informations if the hardware supports these.
2340 The scheduler will make use of these informations and
2341 e.g. base its process migration decisions on it.
2342 Default is off.
2343
Linus Torvalds1da177e2005-04-16 15:20:36 -07002344 tp720= [HW,PS2]
2345
2346 trix= [HW,OSS] MediaTrix AudioTrix Pro
Randy Dunlapa9913042005-10-23 12:57:11 -07002347 Format:
2348 <io>,<irq>,<dma>,<dma2>,<sb_io>,<sb_irq>,<sb_dma>,<mpu_io>,<mpu_irq>
2349
Alok Kataria395628e2008-10-24 17:22:01 -07002350 tsc= Disable clocksource-must-verify flag for TSC.
2351 Format: <string>
2352 [x86] reliable: mark tsc clocksource as reliable, this
2353 disables clocksource verification at runtime.
2354 Used to enable high-resolution timer mode on older
2355 hardware, and in virtualized environment.
2356
Randy Dunlapa9913042005-10-23 12:57:11 -07002357 turbografx.map[2|3]= [HW,JOY]
2358 TurboGraFX parallel port interface
2359 Format:
2360 <port#>,<js1>,<js2>,<js3>,<js4>,<js5>,<js6>,<js7>
Linus Torvalds1da177e2005-04-16 15:20:36 -07002361 See also Documentation/input/joystick-parport.txt
2362
2363 u14-34f= [HW,SCSI] UltraStor 14F/34F SCSI host adapter
2364 See header of drivers/scsi/u14-34f.c.
2365
2366 uart401= [HW,OSS]
2367 Format: <io>,<irq>
2368
2369 uart6850= [HW,OSS]
2370 Format: <io>,<irq>
2371
Alan Stern5f8364b2006-12-05 16:29:55 -05002372 uhci-hcd.ignore_oc=
2373 [USB] Ignore overcurrent events (default N).
2374 Some badly-designed motherboards generate lots of
2375 bogus events, for ports that aren't wired to
2376 anything. Set this parameter to avoid log spamming.
2377 Note that genuine overcurrent events won't be
2378 reported either.
2379
Simon Arlotte3a61b02008-07-19 23:32:54 +01002380 unknown_nmi_panic
2381 [X86-32,X86-64]
2382 Set unknown_nmi_panic=1 early on boot.
2383
Alan Sternb5e795f2007-02-20 15:00:53 -05002384 usbcore.autosuspend=
2385 [USB] The autosuspend time delay (in seconds) used
2386 for newly-detected USB devices (default 2). This
2387 is the time required before an idle device will be
2388 autosuspended. Devices for which the delay is set
Alan Sterneaafbc32007-03-13 16:39:15 -04002389 to a negative value won't be autosuspended at all.
Alan Sternb5e795f2007-02-20 15:00:53 -05002390
Jaroslav Kyselafd7c5192008-10-10 16:24:45 +02002391 usbcore.usbfs_snoop=
2392 [USB] Set to log all usbfs traffic (default 0 = off).
2393
2394 usbcore.blinkenlights=
2395 [USB] Set to cycle leds on hubs (default 0 = off).
2396
2397 usbcore.old_scheme_first=
2398 [USB] Start with the old device initialization
2399 scheme (default 0 = off).
2400
2401 usbcore.use_both_schemes=
2402 [USB] Try the other device initialization scheme
2403 if the first one fails (default 1 = enabled).
2404
2405 usbcore.initial_descriptor_timeout=
2406 [USB] Specifies timeout for the initial 64-byte
2407 USB_REQ_GET_DESCRIPTOR request in milliseconds
2408 (default 5000 = 5.0 seconds).
2409
Linus Torvalds1da177e2005-04-16 15:20:36 -07002410 usbhid.mousepoll=
2411 [USBHID] The interval which mice are to be polled at.
Randy Dunlapa9913042005-10-23 12:57:11 -07002412
Alan Sternd4f373e2008-11-10 14:07:45 -05002413 usb-storage.delay_use=
2414 [UMS] The delay in seconds before a new device is
2415 scanned for Logical Units (default 5).
2416
2417 usb-storage.quirks=
2418 [UMS] A list of quirks entries to supplement or
2419 override the built-in unusual_devs list. List
2420 entries are separated by commas. Each entry has
2421 the form VID:PID:Flags where VID and PID are Vendor
2422 and Product ID values (4-digit hex numbers) and
2423 Flags is a set of characters, each corresponding
2424 to a common usb-storage quirk flag as follows:
Alan Sternc838ea42008-12-15 10:40:06 -05002425 a = SANE_SENSE (collect more than 18 bytes
2426 of sense data);
Alan Sternd4f373e2008-11-10 14:07:45 -05002427 c = FIX_CAPACITY (decrease the reported
2428 device capacity by one sector);
Alan Sternc838ea42008-12-15 10:40:06 -05002429 h = CAPACITY_HEURISTICS (decrease the
2430 reported device capacity by one
2431 sector if the number is odd);
Alan Sternd4f373e2008-11-10 14:07:45 -05002432 i = IGNORE_DEVICE (don't bind to this
2433 device);
2434 l = NOT_LOCKABLE (don't try to lock and
2435 unlock ejectable media);
2436 m = MAX_SECTORS_64 (don't transfer more
2437 than 64 sectors = 32 KB at a time);
Alan Sternc838ea42008-12-15 10:40:06 -05002438 o = CAPACITY_OK (accept the capacity
2439 reported by the device);
Alan Sternd4f373e2008-11-10 14:07:45 -05002440 r = IGNORE_RESIDUE (the device reports
2441 bogus residue values);
2442 s = SINGLE_LUN (the device has only one
2443 Logical Unit);
2444 w = NO_WP_DETECT (don't test whether the
2445 medium is write-protected).
2446 Example: quirks=0419:aaf5:rl,0421:0433:rc
2447
Paul Jackson200001e2008-06-25 05:44:46 -07002448 add_efi_memmap [EFI; x86-32,X86-64] Include EFI memory map in
2449 kernel's map of available physical RAM.
2450
Alan Coxcd4f0ef2007-07-31 00:37:59 -07002451 vdso= [X86-32,SH,x86-64]
Jeremy Fitzhardinge1dbf527c2007-05-02 19:27:12 +02002452 vdso=2: enable compat VDSO (default with COMPAT_VDSO)
Ingo Molnare6e54942006-06-27 02:53:50 -07002453 vdso=1: enable VDSO (default)
2454 vdso=0: disable VDSO mapping
2455
Roland McGrathaf65d642008-01-30 13:30:43 +01002456 vdso32= [X86-32,X86-64]
2457 vdso32=2: enable compat VDSO (default with COMPAT_VDSO)
2458 vdso32=1: enable 32-bit VDSO (default)
2459 vdso32=0: disable 32-bit VDSO mapping
2460
Yasuaki Ishimatsud080d392007-07-17 21:22:55 +09002461 vector= [IA-64,SMP]
2462 vector=percpu: enable percpu vector domain
2463
Linus Torvalds1da177e2005-04-16 15:20:36 -07002464 video= [FB] Frame buffer configuration
2465 See Documentation/fb/modedb.txt.
2466
Alan Coxcd4f0ef2007-07-31 00:37:59 -07002467 vga= [BOOT,X86-32] Select a particular video mode
Kyle McMartin954a8b82009-02-19 16:48:14 -05002468 See Documentation/x86/boot.txt and
Randy Dunlapa9913042005-10-23 12:57:11 -07002469 Documentation/svga.txt.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002470 Use vga=ask for menu.
2471 This is actually a boot loader parameter; the value is
2472 passed to the kernel using a special protocol.
2473
Randy Dunlapa9913042005-10-23 12:57:11 -07002474 vmalloc=nn[KMG] [KNL,BOOT] Forces the vmalloc area to have an exact
Linus Torvalds1da177e2005-04-16 15:20:36 -07002475 size of <nn>. This can be used to increase the
2476 minimum size (128MB on x86). It can also be used to
2477 decrease the size and leave more room for directly
2478 mapped kernel RAM.
2479
Peter Oberparleiter585c3042006-06-29 15:08:25 +02002480 vmhalt= [KNL,S390] Perform z/VM CP command after system halt.
2481 Format: <command>
Linus Torvalds1da177e2005-04-16 15:20:36 -07002482
Peter Oberparleiter585c3042006-06-29 15:08:25 +02002483 vmpanic= [KNL,S390] Perform z/VM CP command after kernel panic.
2484 Format: <command>
2485
2486 vmpoff= [KNL,S390] Perform z/VM CP command after power off.
2487 Format: <command>
Randy Dunlapa9913042005-10-23 12:57:11 -07002488
Linus Torvalds1da177e2005-04-16 15:20:36 -07002489 waveartist= [HW,OSS]
2490 Format: <io>,<irq>,<dma>,<dma2>
Randy Dunlapa9913042005-10-23 12:57:11 -07002491
Linus Torvalds1da177e2005-04-16 15:20:36 -07002492 wd33c93= [HW,SCSI]
2493 See header of drivers/scsi/wd33c93.c.
2494
2495 wd7000= [HW,SCSI]
2496 See header of drivers/scsi/wd7000.c.
2497
2498 wdt= [WDT] Watchdog
Gabriel C8dfe9c22007-08-10 13:01:00 -07002499 See Documentation/watchdog/wdt.txt.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002500
2501 xd= [HW,XT] Original XT pre-IDE (RLL encoded) disks.
2502 xd_geo= See header of drivers/block/xd.c.
2503
2504 xirc2ps_cs= [NET,PCMCIA]
Randy Dunlapa9913042005-10-23 12:57:11 -07002505 Format:
2506 <irq>,<irq_mask>,<io>,<full_duplex>,<do_sound>,<lockup_hack>[,<irq2>[,<irq3>[,<irq4>]]]
Linus Torvalds1da177e2005-04-16 15:20:36 -07002507
Randy Dunlapecb08d82009-01-06 14:42:44 -08002508 norandmaps Don't use address space randomization. Equivalent to
2509 echo 0 > /proc/sys/kernel/randomize_va_space
Andi Kleena62eaf12006-02-16 23:41:58 +01002510
Randy Dunlapa9913042005-10-23 12:57:11 -07002511______________________________________________________________________
Linus Torvalds1da177e2005-04-16 15:20:36 -07002512
2513TODO:
2514
2515 Add documentation for ALSA options.
2516 Add more DRM drivers.