view Documentation/kernel-parameters.txt @ 452:c7ed6fe5dca0

kexec: dont initialise regions in reserve_memory()

There is no need to initialise efi_memmap_res and boot_param_res in
reserve_memory() for the initial xen domain as it is done in
machine_kexec_setup_resources() using values from the kexec hypercall.

Signed-off-by: Simon Horman <horms@verge.net.au>
author Keir Fraser <keir.fraser@citrix.com>
date Thu Feb 28 10:55:18 2008 +0000 (2008-02-28)
parents 831230e53067
children 2fdc121e9b5d
line source
1 Kernel Parameters
2 ~~~~~~~~~~~~~~~~~
4 The 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
7 case insensitive manner), and with descriptions where known.
9 Module parameters for loadable modules are specified only as the
10 parameter name with optional '=' and value as appropriate, such as:
12 modprobe usbcore blinkenlights=1
14 Module parameters for modules that are built into the kernel image
15 are specified on the kernel command line with the module name plus
16 '.' plus parameter name, with '=' and value if appropriate, such as:
18 usbcore.blinkenlights=1
20 This document may not be entirely up to date and comprehensive. The command
21 "modinfo -p ${modulename}" shows a current list of all parameters of a loadable
22 module. Loadable modules, after being loaded into the running kernel, also
23 reveal their parameters in /sys/module/${modulename}/parameters/. Some of these
24 parameters may be changed at runtime by the command
25 "echo -n ${value} > /sys/module/${modulename}/parameters/${parm}".
27 The parameters listed below are only valid if certain kernel build options were
28 enabled and if respective hardware is present. The text in square brackets at
29 the beginning of each description states the restrictions within which a
30 parameter is applicable:
32 ACPI ACPI support is enabled.
33 ALSA ALSA sound support is enabled.
34 APIC APIC support is enabled.
35 APM Advanced Power Management support is enabled.
36 AX25 Appropriate AX.25 support is enabled.
37 CD Appropriate CD support is enabled.
38 DRM Direct Rendering Management support is enabled.
39 EDD BIOS Enhanced Disk Drive Services (EDD) is enabled
40 EFI EFI Partitioning (GPT) is enabled
41 EIDE EIDE/ATAPI support is enabled.
42 FB The frame buffer device is enabled.
43 HW Appropriate hardware is enabled.
44 IA-32 IA-32 aka i386 architecture is enabled.
45 IA-64 IA-64 architecture is enabled.
46 IOSCHED More than one I/O scheduler is enabled.
47 IP_PNP IP DHCP, BOOTP, or RARP is enabled.
48 ISAPNP ISA PnP code is enabled.
49 ISDN Appropriate ISDN support is enabled.
50 JOY Appropriate joystick support is enabled.
51 LP Printer support is enabled.
52 LOOP Loopback device support is enabled.
53 M68k M68k architecture is enabled.
54 These options have more detailed description inside of
55 Documentation/m68k/kernel-options.txt.
56 MCA MCA bus support is enabled.
57 MDA MDA console support is enabled.
58 MOUSE Appropriate mouse support is enabled.
59 MSI Message Signaled Interrupts (PCI).
60 MTD MTD support is enabled.
61 NET Appropriate network support is enabled.
62 NUMA NUMA support is enabled.
63 GENERIC_TIME The generic timeofday code is enabled.
64 NFS Appropriate NFS support is enabled.
65 OSS OSS sound support is enabled.
66 PARIDE The ParIDE subsystem is enabled.
67 PARISC The PA-RISC architecture is enabled.
68 PCI PCI bus support is enabled.
69 PCMCIA The PCMCIA subsystem is enabled.
70 PNP Plug & Play support is enabled.
71 PPC PowerPC architecture is enabled.
72 PPT Parallel port support is enabled.
73 PS2 Appropriate PS/2 support is enabled.
74 RAM RAM disk support is enabled.
75 S390 S390 architecture is enabled.
76 SCSI Appropriate SCSI support is enabled.
77 A lot of drivers has their options described inside of
78 Documentation/scsi/.
79 SELINUX SELinux support is enabled.
80 SERIAL Serial support is enabled.
81 SMP The kernel is an SMP kernel.
82 SPARC Sparc architecture is enabled.
83 SWSUSP Software suspend is enabled.
84 TS Appropriate touchscreen support is enabled.
85 USB USB support is enabled.
86 USBHID USB Human Interface Device support is enabled.
87 V4L Video For Linux support is enabled.
88 VGA The VGA console has been enabled.
89 VT Virtual terminal support is enabled.
90 WDT Watchdog support is enabled.
91 XT IBM PC/XT MFM hard disk support is enabled.
92 X86-64 X86-64 architecture is enabled.
93 More X86-64 boot options can be found in
94 Documentation/x86_64/boot-options.txt .
96 In addition, the following text indicates that the option:
98 BUGS= Relates to possible processor bugs on the said processor.
99 KNL Is a kernel start-up parameter.
100 BOOT Is a boot loader parameter.
102 Parameters denoted with BOOT are actually interpreted by the boot
103 loader, and have no meaning to the kernel directly.
104 Do not modify the syntax of boot loader parameters without extreme
105 need or coordination with <Documentation/i386/boot.txt>.
107 Note that ALL kernel parameters listed below are CASE SENSITIVE, and that
108 a trailing = on the name of any parameter states that that parameter will
109 be entered as an environment variable, whereas its absence indicates that
110 it will appear as a kernel argument readable via /proc/cmdline by programs
111 running once the system is up.
113 53c7xx= [HW,SCSI] Amiga SCSI controllers
114 See header of drivers/scsi/53c7xx.c.
115 See also Documentation/scsi/ncr53c7xx.txt.
117 acpi= [HW,ACPI] Advanced Configuration and Power Interface
118 Format: { force | off | ht | strict | noirq }
119 force -- enable ACPI if default was off
120 off -- disable ACPI if default was on
121 noirq -- do not use ACPI for IRQ routing
122 ht -- run only enough ACPI to enable Hyper Threading
123 strict -- Be less tolerant of platforms that are not
124 strictly ACPI specification compliant.
126 See also Documentation/pm.txt, pci=noacpi
128 acpi_sleep= [HW,ACPI] Sleep options
129 Format: { s3_bios, s3_mode }
130 See Documentation/power/video.txt
132 acpi_sci= [HW,ACPI] ACPI System Control Interrupt trigger mode
133 Format: { level | edge | high | low }
135 acpi_irq_balance [HW,ACPI]
136 ACPI will balance active IRQs
137 default in APIC mode
139 acpi_irq_nobalance [HW,ACPI]
140 ACPI will not move active IRQs (default)
141 default in PIC mode
143 acpi_irq_pci= [HW,ACPI] If irq_balance, clear listed IRQs for
144 use by PCI
145 Format: <irq>,<irq>...
147 acpi_irq_isa= [HW,ACPI] If irq_balance, mark listed IRQs used by ISA
148 Format: <irq>,<irq>...
150 acpi_os_name= [HW,ACPI] Tell ACPI BIOS the name of the OS
151 Format: To spoof as Windows 98: ="Microsoft Windows"
153 acpi_osi= [HW,ACPI] empty param disables _OSI
155 acpi_serialize [HW,ACPI] force serialization of AML methods
157 acpi_skip_timer_override [HW,ACPI]
158 Recognize and ignore IRQ0/pin2 Interrupt Override.
159 For broken nForce2 BIOS resulting in XT-PIC timer.
161 acpi_dbg_layer= [HW,ACPI]
162 Format: <int>
163 Each bit of the <int> indicates an ACPI debug layer,
164 1: enable, 0: disable. It is useful for boot time
165 debugging. After system has booted up, it can be set
166 via /proc/acpi/debug_layer.
168 acpi_dbg_level= [HW,ACPI]
169 Format: <int>
170 Each bit of the <int> indicates an ACPI debug level,
171 1: enable, 0: disable. It is useful for boot time
172 debugging. After system has booted up, it can be set
173 via /proc/acpi/debug_level.
175 acpi_fake_ecdt [HW,ACPI] Workaround failure due to BIOS lacking ECDT
177 acpi_generic_hotkey [HW,ACPI]
178 Allow consolidated generic hotkey driver to
179 override platform specific driver.
180 See also Documentation/acpi-hotkey.txt.
182 acpi_pm_good [IA-32,X86-64]
183 Override the pmtimer bug detection: force the kernel
184 to assume that this machine's pmtimer latches its value
185 and always returns good values.
187 enable_timer_pin_1 [i386,x86-64]
188 Enable PIN 1 of APIC timer
189 Can be useful to work around chipset bugs
190 (in particular on some ATI chipsets).
191 The kernel tries to set a reasonable default.
193 disable_timer_pin_1 [i386,x86-64]
194 Disable PIN 1 of APIC timer
195 Can be useful to work around chipset bugs.
197 ad1816= [HW,OSS]
198 Format: <io>,<irq>,<dma>,<dma2>
199 See also Documentation/sound/oss/AD1816.
201 ad1848= [HW,OSS]
202 Format: <io>,<irq>,<dma>,<dma2>,<type>
204 adlib= [HW,OSS]
205 Format: <io>
207 advansys= [HW,SCSI]
208 See header of drivers/scsi/advansys.c.
210 advwdt= [HW,WDT] Advantech WDT
211 Format: <iostart>,<iostop>
213 aedsp16= [HW,OSS] Audio Excel DSP 16
214 Format: <io>,<irq>,<dma>,<mss_io>,<mpu_io>,<mpu_irq>
215 See also header of sound/oss/aedsp16.c.
217 aha152x= [HW,SCSI]
218 See Documentation/scsi/aha152x.txt.
220 aha1542= [HW,SCSI]
221 Format: <portbase>[,<buson>,<busoff>[,<dmaspeed>]]
223 aic7xxx= [HW,SCSI]
224 See Documentation/scsi/aic7xxx.txt.
226 aic79xx= [HW,SCSI]
227 See Documentation/scsi/aic79xx.txt.
229 amijoy.map= [HW,JOY] Amiga joystick support
230 Map of devices attached to JOY0DAT and JOY1DAT
231 Format: <a>,<b>
232 See also Documentation/kernel/input/joystick.txt
234 analog.map= [HW,JOY] Analog joystick and gamepad support
235 Specifies type or capabilities of an analog joystick
236 connected to one of 16 gameports
237 Format: <type1>,<type2>,..<type16>
239 apc= [HW,SPARC]
240 Power management functions (SPARCstation-4/5 + deriv.)
241 Format: noidle
242 Disable APC CPU standby support. SPARCstation-Fox does
243 not play well with APC CPU idle - disable it if you have
244 APC and your system crashes randomly.
246 apic= [APIC,i386] Change the output verbosity whilst booting
247 Format: { quiet (default) | verbose | debug }
248 Change the amount of debugging information output
249 when initialising the APIC and IO-APIC components.
251 apm= [APM] Advanced Power Management
252 See header of arch/i386/kernel/apm.c.
254 applicom= [HW]
255 Format: <mem>,<irq>
257 arcrimi= [HW,NET] ARCnet - "RIM I" (entirely mem-mapped) cards
258 Format: <io>,<irq>,<nodeID>
260 ataflop= [HW,M68k]
262 atarimouse= [HW,MOUSE] Atari Mouse
264 atascsi= [HW,SCSI] Atari SCSI
266 atkbd.extra= [HW] Enable extra LEDs and keys on IBM RapidAccess,
267 EzKey and similar keyboards
269 atkbd.reset= [HW] Reset keyboard during initialization
271 atkbd.set= [HW] Select keyboard code set
272 Format: <int> (2 = AT (default), 3 = PS/2)
274 atkbd.scroll= [HW] Enable scroll wheel on MS Office and similar
275 keyboards
277 atkbd.softraw= [HW] Choose between synthetic and real raw mode
278 Format: <bool> (0 = real, 1 = synthetic (default))
280 atkbd.softrepeat= [HW]
281 Use software keyboard repeat
283 autotest [IA64]
285 awe= [HW,OSS] AWE32/SB32/AWE64 wave table synth
286 Format: <io>,<memsize>,<isapnp>
288 aztcd= [HW,CD] Aztech CD268 CDROM driver
289 Format: <io>,0x79 (?)
291 baycom_epp= [HW,AX25]
292 Format: <io>,<mode>
294 baycom_par= [HW,AX25] BayCom Parallel Port AX.25 Modem
295 Format: <io>,<mode>
296 See header of drivers/net/hamradio/baycom_par.c.
298 baycom_ser_fdx= [HW,AX25]
299 BayCom Serial Port AX.25 Modem (Full Duplex Mode)
300 Format: <io>,<irq>,<mode>[,<baud>]
301 See header of drivers/net/hamradio/baycom_ser_fdx.c.
303 baycom_ser_hdx= [HW,AX25]
304 BayCom Serial Port AX.25 Modem (Half Duplex Mode)
305 Format: <io>,<irq>,<mode>
306 See header of drivers/net/hamradio/baycom_ser_hdx.c.
308 blkmtd_device= [HW,MTD]
309 blkmtd_erasesz=
310 blkmtd_ro=
311 blkmtd_bs=
312 blkmtd_count=
314 bttv.card= [HW,V4L] bttv (bt848 + bt878 based grabber cards)
315 bttv.radio= Most important insmod options are available as
316 kernel args too.
317 bttv.pll= See Documentation/video4linux/bttv/Insmod-options
318 bttv.tuner= and Documentation/video4linux/bttv/CARDLIST
320 BusLogic= [HW,SCSI]
321 See drivers/scsi/BusLogic.c, comment before function
322 BusLogic_ParseDriverOptions().
324 c101= [NET] Moxa C101 synchronous serial card
326 cachesize= [BUGS=IA-32] Override level 2 CPU cache size detection.
327 Sometimes CPU hardware bugs make them report the cache
328 size incorrectly. The kernel will attempt work arounds
329 to fix known problems, but for some CPUs it is not
330 possible to determine what the correct size should be.
331 This option provides an override for these situations.
333 cdu31a= [HW,CD]
334 Format: <io>,<irq>[,PAS]
335 See header of drivers/cdrom/cdu31a.c.
337 chandev= [HW,NET] Generic channel device initialisation
339 checkreqprot [SELINUX] Set initial checkreqprot flag value.
340 Format: { "0" | "1" }
341 See security/selinux/Kconfig help text.
342 0 -- check protection applied by kernel (includes
343 any implied execute protection).
344 1 -- check protection requested by application.
345 Default value is set via a kernel config option.
346 Value can be changed at runtime via
347 /selinux/checkreqprot.
349 clock= [BUGS=IA-32, HW] gettimeofday clocksource override.
350 [Deprecated]
351 Forces specified clocksource (if avaliable) to be used
352 when calculating gettimeofday(). If specified
353 clocksource is not avalible, it defaults to PIT.
354 Format: { pit | tsc | cyclone | pmtmr }
356 disable_8254_timer
357 enable_8254_timer
358 [IA32/X86_64] Disable/Enable interrupt 0 timer routing
359 over the 8254 in addition to over the IO-APIC. The
360 kernel tries to set a sensible default.
362 hpet= [IA-32,HPET] option to disable HPET and use PIT.
363 Format: disable
365 cm206= [HW,CD]
366 Format: { auto | [<io>,][<irq>] }
368 com20020= [HW,NET] ARCnet - COM20020 chipset
369 Format:
370 <io>[,<irq>[,<nodeID>[,<backplane>[,<ckp>[,<timeout>]]]]]
372 com90io= [HW,NET] ARCnet - COM90xx chipset (IO-mapped buffers)
373 Format: <io>[,<irq>]
375 com90xx= [HW,NET]
376 ARCnet - COM90xx chipset (memory-mapped buffers)
377 Format: <io>[,<irq>[,<memstart>]]
379 condev= [HW,S390] console device
380 conmode=
382 console= [KNL] Output console device and options.
384 tty<n> Use the virtual console device <n>.
386 ttyS<n>[,options]
387 ttyUSB0[,options]
388 Use the specified serial port. The options are of
389 the form "bbbbpnf", where "bbbb" is the baud rate,
390 "p" is parity ("n", "o", or "e"), "n" is number of
391 bits, and "f" is flow control ("r" for RTS or
392 omit it). Default is "9600n8".
394 See Documentation/serial-console.txt for more
395 information. See
396 Documentation/networking/netconsole.txt for an
397 alternative.
399 uart,io,<addr>[,options]
400 uart,mmio,<addr>[,options]
401 Start an early, polled-mode console on the 8250/16550
402 UART at the specified I/O port or MMIO address,
403 switching to the matching ttyS device later. The
404 options are the same as for ttyS, above.
406 cpcihp_generic= [HW,PCI] Generic port I/O CompactPCI driver
407 Format:
408 <first_slot>,<last_slot>,<port>,<enum_bit>[,<debug>]
410 cpia_pp= [HW,PPT]
411 Format: { parport<nr> | auto | none }
413 crashkernel=nn[KMG]@ss[KMG]
414 [KNL] Reserve a chunk of physical memory to
415 hold a kernel to switch to with kexec on panic.
417 cs4232= [HW,OSS]
418 Format: <io>,<irq>,<dma>,<dma2>,<mpuio>,<mpuirq>
420 cs89x0_dma= [HW,NET]
421 Format: <dma>
423 cs89x0_media= [HW,NET]
424 Format: { rj45 | aui | bnc }
426 cyclades= [HW,SERIAL] Cyclades multi-serial port adapter.
428 dasd= [HW,NET]
429 See header of drivers/s390/block/dasd_devmap.c.
431 db9.dev[2|3]= [HW,JOY] Multisystem joystick support via parallel port
432 (one device per port)
433 Format: <port#>,<type>
434 See also Documentation/input/joystick-parport.txt
436 debug [KNL] Enable kernel debugging (events log level).
438 debug_locks_verbose=
439 [KNL] verbose self-tests
440 Format=<0|1>
441 Print debugging info while doing the locking API
442 self-tests.
443 We default to 0 (no extra messages), setting it to
444 1 will print _a lot_ more information - normally
445 only useful to kernel developers.
447 decnet= [HW,NET]
448 Format: <area>[,<node>]
449 See also Documentation/networking/decnet.txt.
451 dhash_entries= [KNL]
452 Set number of hash buckets for dentry cache.
454 digi= [HW,SERIAL]
455 IO parameters + enable/disable command.
457 digiepca= [HW,SERIAL]
458 See drivers/char/README.epca and
459 Documentation/digiepca.txt.
461 dmascc= [HW,AX25,SERIAL] AX.25 Z80SCC driver with DMA
462 support available.
463 Format: <io_dev0>[,<io_dev1>[,..<io_dev32>]]
465 dmasound= [HW,OSS] Sound subsystem buffers
467 dscc4.setup= [NET]
469 dtc3181e= [HW,SCSI]
471 earlyprintk= [IA-32,X86-64]
472 earlyprintk=vga
473 earlyprintk=serial[,ttySn[,baudrate]]
475 Append ",keep" to not disable it when the real console
476 takes over.
478 Only vga or serial at a time, not both.
480 Currently only ttyS0 and ttyS1 are supported.
482 Interaction with the standard serial driver is not
483 very good.
485 The VGA output is eventually overwritten by the real
486 console.
488 eata= [HW,SCSI]
490 ec_intr= [HW,ACPI] ACPI Embedded Controller interrupt mode
491 Format: <int>
492 0: polling mode
493 non-0: interrupt mode (default)
495 eda= [HW,PS2]
497 edb= [HW,PS2]
499 edd= [EDD]
500 Format: {"of[f]" | "sk[ipmbr]"}
501 See comment in arch/i386/boot/edd.S
503 eicon= [HW,ISDN]
504 Format: <id>,<membase>,<irq>
506 eisa_irq_edge= [PARISC,HW]
507 See header of drivers/parisc/eisa.c.
509 elanfreq= [IA-32]
510 See comment before function elanfreq_setup() in
511 arch/i386/kernel/cpu/cpufreq/elanfreq.c.
513 elevator= [IOSCHED]
514 Format: {"anticipatory" | "cfq" | "deadline" | "noop"}
515 See Documentation/block/as-iosched.txt and
516 Documentation/block/deadline-iosched.txt for details.
518 elfcorehdr= [IA-32, X86_64]
519 Specifies physical address of start of kernel core
520 image elf header. Generally kexec loader will
521 pass this option to capture kernel.
522 See Documentation/kdump/kdump.txt for details.
524 enforcing [SELINUX] Set initial enforcing status.
525 Format: {"0" | "1"}
526 See security/selinux/Kconfig help text.
527 0 -- permissive (log only, no denials).
528 1 -- enforcing (deny and log).
529 Default value is 0.
530 Value can be changed at runtime via /selinux/enforce.
532 es1370= [HW,OSS]
533 Format: <lineout>[,<micbias>]
534 See also header of sound/oss/es1370.c.
536 es1371= [HW,OSS]
537 Format: <spdif>,[<nomix>,[<amplifier>]]
538 See also header of sound/oss/es1371.c.
540 ether= [HW,NET] Ethernet cards parameters
541 This option is obsoleted by the "netdev=" option, which
542 has equivalent usage. See its documentation for details.
544 eurwdt= [HW,WDT] Eurotech CPU-1220/1410 onboard watchdog.
545 Format: <io>[,<irq>]
547 fd_mcs= [HW,SCSI]
548 See header of drivers/scsi/fd_mcs.c.
550 fdomain= [HW,SCSI]
551 See header of drivers/scsi/fdomain.c.
553 floppy= [HW]
554 See Documentation/floppy.txt.
556 ftape= [HW] Floppy Tape subsystem debugging options.
557 See Documentation/ftape.txt.
559 gamecon.map[2|3]=
560 [HW,JOY] Multisystem joystick and NES/SNES/PSX pad
561 support via parallel port (up to 5 devices per port)
562 Format: <port#>,<pad1>,<pad2>,<pad3>,<pad4>,<pad5>
563 See also Documentation/input/joystick-parport.txt
565 gamma= [HW,DRM]
567 gdth= [HW,SCSI]
568 See header of drivers/scsi/gdth.c.
570 gpt [EFI] Forces disk with valid GPT signature but
571 invalid Protective MBR to be treated as GPT.
573 gscd= [HW,CD]
574 Format: <io>
576 gt96100eth= [NET] MIPS GT96100 Advanced Communication Controller
578 gus= [HW,OSS]
579 Format: <io>,<irq>,<dma>,<dma16>
581 gvp11= [HW,SCSI]
583 hashdist= [KNL,NUMA] Large hashes allocated during boot
584 are distributed across NUMA nodes. Defaults on
585 for IA-64, off otherwise.
586 Format: 0 | 1 (for off | on)
588 hcl= [IA-64] SGI's Hardware Graph compatibility layer
590 hd= [EIDE] (E)IDE hard drive subsystem geometry
591 Format: <cyl>,<head>,<sect>
593 hd?= [HW] (E)IDE subsystem
594 hd?lun= See Documentation/ide.txt.
596 highmem=nn[KMG] [KNL,BOOT] forces the highmem zone to have an exact
597 size of <nn>. This works even on boxes that have no
598 highmem otherwise. This also works to reduce highmem
599 size on bigger boxes.
601 hisax= [HW,ISDN]
602 See Documentation/isdn/README.HiSax.
604 hugepages= [HW,IA-32,IA-64] Maximal number of HugeTLB pages.
606 noirqbalance [IA-32,SMP,KNL] Disable kernel irq balancing
608 i8042.direct [HW] Put keyboard port into non-translated mode
609 i8042.dumbkbd [HW] Pretend that controlled can only read data from
610 keyboard and can not control its state
611 (Don't attempt to blink the leds)
612 i8042.noaux [HW] Don't check for auxiliary (== mouse) port
613 i8042.nokbd [HW] Don't check/create keyboard port
614 i8042.nomux [HW] Don't check presence of an active multiplexing
615 controller
616 i8042.nopnp [HW] Don't use ACPIPnP / PnPBIOS to discover KBD/AUX
617 controllers
618 i8042.panicblink=
619 [HW] Frequency with which keyboard LEDs should blink
620 when kernel panics (default is 0.5 sec)
621 i8042.reset [HW] Reset the controller during init and cleanup
622 i8042.unlock [HW] Unlock (ignore) the keylock
624 i810= [HW,DRM]
626 i8k.ignore_dmi [HW] Continue probing hardware even if DMI data
627 indicates that the driver is running on unsupported
628 hardware.
629 i8k.force [HW] Activate i8k driver even if SMM BIOS signature
630 does not match list of supported models.
631 i8k.power_status
632 [HW] Report power status in /proc/i8k
633 (disabled by default)
634 i8k.restricted [HW] Allow controlling fans only if SYS_ADMIN
635 capability is set.
637 ibmmcascsi= [HW,MCA,SCSI] IBM MicroChannel SCSI adapter
638 See Documentation/mca.txt.
640 icn= [HW,ISDN]
641 Format: <io>[,<membase>[,<icn_id>[,<icn_id2>]]]
643 ide= [HW] (E)IDE subsystem
644 Format: ide=nodma or ide=doubler or ide=reverse
645 See Documentation/ide.txt.
647 ide?= [HW] (E)IDE subsystem
648 Format: ide?=noprobe or chipset specific parameters.
649 See Documentation/ide.txt.
651 idebus= [HW] (E)IDE subsystem - VLB/PCI bus speed
652 See Documentation/ide.txt.
654 idle= [HW]
655 Format: idle=poll or idle=halt
657 ihash_entries= [KNL]
658 Set number of hash buckets for inode cache.
660 in2000= [HW,SCSI]
661 See header of drivers/scsi/in2000.c.
663 init= [KNL]
664 Format: <full_path>
665 Run specified binary instead of /sbin/init as init
666 process.
668 initcall_debug [KNL] Trace initcalls as they are executed. Useful
669 for working out where the kernel is dying during
670 startup.
672 initrd= [BOOT] Specify the location of the initial ramdisk
674 inport.irq= [HW] Inport (ATI XL and Microsoft) busmouse driver
675 Format: <irq>
677 combined_mode= [HW] control which driver uses IDE ports in combined
678 mode: legacy IDE driver, libata, or both
679 (in the libata case, libata.atapi_enabled=1 may be
680 useful as well). Note that using the ide or libata
681 options may affect your device naming (e.g. by
682 changing hdc to sdb).
683 Format: combined (default), ide, or libata
685 inttest= [IA64]
687 io7= [HW] IO7 for Marvel based alpha systems
688 See comment before marvel_specify_io7 in
689 arch/alpha/kernel/core_marvel.c.
691 ip= [IP_PNP]
692 See Documentation/nfsroot.txt.
694 ip2= [HW] Set IO/IRQ pairs for up to 4 IntelliPort boards
695 See comment before ip2_setup() in drivers/char/ip2.c.
697 ips= [HW,SCSI] Adaptec / IBM ServeRAID controller
698 See header of drivers/scsi/ips.c.
700 ports= [IP_VS_FTP] IPVS ftp helper module
701 Default is 21.
702 Up to 8 (IP_VS_APP_MAX_PORTS) ports
703 may be specified.
704 Format: <port>,<port>....
706 irqfixup [HW]
707 When an interrupt is not handled search all handlers
708 for it. Intended to get systems with badly broken
709 firmware running.
711 irqpoll [HW]
712 When an interrupt is not handled search all handlers
713 for it. Also check all handlers each timer
714 interrupt. Intended to get systems with badly broken
715 firmware running.
717 isapnp= [ISAPNP]
718 Format: <RDP>,<reset>,<pci_scan>,<verbosity>
720 isolcpus= [KNL,SMP] Isolate CPUs from the general scheduler.
721 Format: <cpu number>,...,<cpu number>
722 This option can be used to specify one or more CPUs
723 to isolate from the general SMP balancing and scheduling
724 algorithms. The only way to move a process onto or off
725 an "isolated" CPU is via the CPU affinity syscalls.
726 <cpu number> begins at 0 and the maximum value is
727 "number of CPUs in system - 1".
729 This option is the preferred way to isolate CPUs. The
730 alternative -- manually setting the CPU mask of all
731 tasks in the system -- can cause problems and
732 suboptimal load balancer performance.
734 isp16= [HW,CD]
735 Format: <io>,<irq>,<dma>,<setup>
737 iucv= [HW,NET]
739 js= [HW,JOY] Analog joystick
740 See Documentation/input/joystick.txt.
742 keepinitrd [HW,ARM]
744 kstack=N [IA-32,X86-64] Print N words from the kernel stack
745 in oops dumps.
747 l2cr= [PPC]
749 lapic [IA-32,APIC] Enable the local APIC even if BIOS
750 disabled it.
752 lasi= [HW,SCSI] PARISC LASI driver for the 53c700 chip
753 Format: addr:<io>,irq:<irq>
755 llsc*= [IA64] See function print_params() in
756 arch/ia64/sn/kernel/llsc4.c.
758 load_ramdisk= [RAM] List of ramdisks to load from floppy
759 See Documentation/ramdisk.txt.
761 lockd.nlm_grace_period=P [NFS] Assign grace period.
762 Format: <integer>
764 lockd.nlm_tcpport=N [NFS] Assign TCP port.
765 Format: <integer>
767 lockd.nlm_timeout=T [NFS] Assign timeout value.
768 Format: <integer>
770 lockd.nlm_udpport=M [NFS] Assign UDP port.
771 Format: <integer>
773 logibm.irq= [HW,MOUSE] Logitech Bus Mouse Driver
774 Format: <irq>
776 loglevel= All Kernel Messages with a loglevel smaller than the
777 console loglevel will be printed to the console. It can
778 also be changed with klogd or other programs. The
779 loglevels are defined as follows:
781 0 (KERN_EMERG) system is unusable
782 1 (KERN_ALERT) action must be taken immediately
783 2 (KERN_CRIT) critical conditions
784 3 (KERN_ERR) error conditions
785 4 (KERN_WARNING) warning conditions
786 5 (KERN_NOTICE) normal but significant condition
787 6 (KERN_INFO) informational
788 7 (KERN_DEBUG) debug-level messages
790 log_buf_len=n Sets the size of the printk ring buffer, in bytes.
791 Format: { n | nk | nM }
792 n must be a power of two. The default size
793 is set in the kernel config file.
795 lp=0 [LP] Specify parallel ports to use, e.g,
796 lp=port[,port...] lp=none,parport0 (lp0 not configured, lp1 uses
797 lp=reset first parallel port). 'lp=0' disables the
798 lp=auto printer driver. 'lp=reset' (which can be
799 specified in addition to the ports) causes
800 attached printers to be reset. Using
801 lp=port1,port2,... specifies the parallel ports
802 to associate lp devices with, starting with
803 lp0. A port specification may be 'none' to skip
804 that lp device, or a parport name such as
805 'parport0'. Specifying 'lp=auto' instead of a
806 port specification list means that device IDs
807 from each port should be examined, to see if
808 an IEEE 1284-compliant printer is attached; if
809 so, the driver will manage that printer.
810 See also header of drivers/char/lp.c.
812 lpj=n [KNL]
813 Sets loops_per_jiffy to given constant, thus avoiding
814 time-consuming boot-time autodetection (up to 250 ms per
815 CPU). 0 enables autodetection (default). To determine
816 the correct value for your kernel, boot with normal
817 autodetection and see what value is printed. Note that
818 on SMP systems the preset will be applied to all CPUs,
819 which is likely to cause problems if your CPUs need
820 significantly divergent settings. An incorrect value
821 will cause delays in the kernel to be wrong, leading to
822 unpredictable I/O errors and other breakage. Although
823 unlikely, in the extreme case this might damage your
824 hardware.
826 ltpc= [NET]
827 Format: <io>,<irq>,<dma>
829 mac5380= [HW,SCSI] Format:
830 <can_queue>,<cmd_per_lun>,<sg_tablesize>,<hostid>,<use_tags>
832 mac53c9x= [HW,SCSI] Format:
833 <num_esps>,<disconnect>,<nosync>,<can_queue>,<cmd_per_lun>,<sg_tablesize>,<hostid>,<use_tags>
835 machvec= [IA64] Force the use of a particular machine-vector
836 (machvec) in a generic kernel.
837 Example: machvec=hpzx1_swiotlb
839 mad16= [HW,OSS] Format:
840 <io>,<irq>,<dma>,<dma16>,<mpu_io>,<mpu_irq>,<joystick>
842 maui= [HW,OSS]
843 Format: <io>,<irq>
845 max_loop= [LOOP] Maximum number of loopback devices that can
846 be mounted
847 Format: <1-256>
849 maxcpus= [SMP] Maximum number of processors that an SMP kernel
850 should make use of
852 max_addr=[KMG] [KNL,BOOT,ia64] All physical memory greater than or
853 equal to this physical address is ignored.
855 max_luns= [SCSI] Maximum number of LUNs to probe.
856 Should be between 1 and 2^32-1.
858 max_report_luns=
859 [SCSI] Maximum number of LUNs received.
860 Should be between 1 and 16384.
862 mca-pentium [BUGS=IA-32]
864 mcatest= [IA-64]
866 mcd= [HW,CD]
867 Format: <port>,<irq>,<mitsumi_bug_93_wait>
869 mcdx= [HW,CD]
871 mce [IA-32] Machine Check Exception
873 md= [HW] RAID subsystems devices and level
874 See Documentation/md.txt.
876 mdacon= [MDA]
877 Format: <first>,<last>
878 Specifies range of consoles to be captured by the MDA.
880 mem=nn[KMG] [KNL,BOOT] Force usage of a specific amount of memory
881 Amount of memory to be used when the kernel is not able
882 to see the whole system memory or for test.
883 [IA-32] Use together with memmap= to avoid physical
884 address space collisions. Without memmap= PCI devices
885 could be placed at addresses belonging to unused RAM.
887 mem=nopentium [BUGS=IA-32] Disable usage of 4MB pages for kernel
888 memory.
890 memmap=exactmap [KNL,IA-32,X86_64] Enable setting of an exact
891 E820 memory map, as specified by the user.
892 Such memmap=exactmap lines can be constructed based on
893 BIOS output or other requirements. See the memmap=nn@ss
894 option description.
896 memmap=nn[KMG]@ss[KMG]
897 [KNL] Force usage of a specific region of memory
898 Region of memory to be used, from ss to ss+nn.
900 memmap=nn[KMG]#ss[KMG]
901 [KNL,ACPI] Mark specific memory as ACPI data.
902 Region of memory to be used, from ss to ss+nn.
904 memmap=nn[KMG]$ss[KMG]
905 [KNL,ACPI] Mark specific memory as reserved.
906 Region of memory to be used, from ss to ss+nn.
908 meye.*= [HW] Set MotionEye Camera parameters
909 See Documentation/video4linux/meye.txt.
911 mga= [HW,DRM]
913 migration_cost=
914 [KNL,SMP] debug: override scheduler migration costs
915 Format: <level-1-usecs>,<level-2-usecs>,...
916 This debugging option can be used to override the
917 default scheduler migration cost matrix. The numbers
918 are indexed by 'CPU domain distance'.
919 E.g. migration_cost=1000,2000,3000 on an SMT NUMA
920 box will set up an intra-core migration cost of
921 1 msec, an inter-core migration cost of 2 msecs,
922 and an inter-node migration cost of 3 msecs.
924 WARNING: using the wrong values here can break
925 scheduler performance, so it's only for scheduler
926 development purposes, not production environments.
928 migration_debug=
929 [KNL,SMP] migration cost auto-detect verbosity
930 Format=<0|1|2>
931 If a system's migration matrix reported at bootup
932 seems erroneous then this option can be used to
933 increase verbosity of the detection process.
934 We default to 0 (no extra messages), 1 will print
935 some more information, and 2 will be really
936 verbose (probably only useful if you also have a
937 serial console attached to the system).
939 migration_factor=
940 [KNL,SMP] multiply/divide migration costs by a factor
941 Format=<percent>
942 This debug option can be used to proportionally
943 increase or decrease the auto-detected migration
944 costs for all entries of the migration matrix.
945 E.g. migration_factor=150 will increase migration
946 costs by 50%. (and thus the scheduler will be less
947 eager migrating cache-hot tasks)
948 migration_factor=80 will decrease migration costs
949 by 20%. (thus the scheduler will be more eager to
950 migrate tasks)
952 WARNING: using the wrong values here can break
953 scheduler performance, so it's only for scheduler
954 development purposes, not production environments.
956 mousedev.tap_time=
957 [MOUSE] Maximum time between finger touching and
958 leaving touchpad surface for touch to be considered
959 a tap and be reported as a left button click (for
960 touchpads working in absolute mode only).
961 Format: <msecs>
962 mousedev.xres= [MOUSE] Horizontal screen resolution, used for devices
963 reporting absolute coordinates, such as tablets
964 mousedev.yres= [MOUSE] Vertical screen resolution, used for devices
965 reporting absolute coordinates, such as tablets
967 mpu401= [HW,OSS]
968 Format: <io>,<irq>
970 MTD_Partition= [MTD]
971 Format: <name>,<region-number>,<size>,<offset>
973 MTD_Region= [MTD] Format:
974 <name>,<region-number>[,<base>,<size>,<buswidth>,<altbuswidth>]
976 mtdparts= [MTD]
977 See drivers/mtd/cmdline.c.
979 mtouchusb.raw_coordinates=
980 [HW] Make the MicroTouch USB driver use raw coordinates
981 ('y', default) or cooked coordinates ('n')
983 n2= [NET] SDL Inc. RISCom/N2 synchronous serial card
985 NCR_D700= [HW,SCSI]
986 See header of drivers/scsi/NCR_D700.c.
988 ncr5380= [HW,SCSI]
990 ncr53c400= [HW,SCSI]
992 ncr53c400a= [HW,SCSI]
994 ncr53c406a= [HW,SCSI]
996 ncr53c8xx= [HW,SCSI]
998 netdev= [NET] Network devices parameters
999 Format: <irq>,<io>,<mem_start>,<mem_end>,<name>
1000 Note that mem_start is often overloaded to mean
1001 something different and driver-specific.
1002 This usage is only documented in each driver source
1003 file if at all.
1005 nfsaddrs= [NFS]
1006 See Documentation/nfsroot.txt.
1008 nfsroot= [NFS] nfs root filesystem for disk-less boxes.
1009 See Documentation/nfsroot.txt.
1011 nfs.callback_tcpport=
1012 [NFS] set the TCP port on which the NFSv4 callback
1013 channel should listen.
1015 nfs.idmap_cache_timeout=
1016 [NFS] set the maximum lifetime for idmapper cache
1017 entries.
1019 nmi_watchdog= [KNL,BUGS=IA-32] Debugging features for SMP kernels
1021 no387 [BUGS=IA-32] Tells the kernel to use the 387 maths
1022 emulation library even if a 387 maths coprocessor
1023 is present.
1025 noalign [KNL,ARM]
1027 noapic [SMP,APIC] Tells the kernel to not make use of any
1028 IOAPICs that may be present in the system.
1030 noasync [HW,M68K] Disables async and sync negotiation for
1031 all devices.
1033 nobats [PPC] Do not use BATs for mapping kernel lowmem
1034 on "Classic" PPC cores.
1036 nocache [ARM]
1038 nodelayacct [KNL] Disable per-task delay accounting
1040 nodisconnect [HW,SCSI,M68K] Disables SCSI disconnects.
1042 noexec [IA-64]
1044 noexec [IA-32,X86-64]
1045 noexec=on: enable non-executable mappings (default)
1046 noexec=off: disable nn-executable mappings
1048 nofxsr [BUGS=IA-32] Disables x86 floating point extended
1049 register save and restore. The kernel will only save
1050 legacy floating-point registers on task switch.
1052 nohlt [BUGS=ARM]
1054 no-hlt [BUGS=IA-32] Tells the kernel that the hlt
1055 instruction doesn't work correctly and not to
1056 use it.
1058 nohalt [IA-64] Tells the kernel not to use the power saving
1059 function PAL_HALT_LIGHT when idle. This increases
1060 power-consumption. On the positive side, it reduces
1061 interrupt wake-up latency, which may improve performance
1062 in certain environments such as networked servers or
1063 real-time systems.
1065 noirqdebug [IA-32] Disables the code which attempts to detect and
1066 disable unhandled interrupt sources.
1068 noisapnp [ISAPNP] Disables ISA PnP code.
1070 noinitrd [RAM] Tells the kernel not to load any configured
1071 initial RAM disk.
1073 nointroute [IA-64]
1075 nolapic [IA-32,APIC] Do not enable or use the local APIC.
1077 noltlbs [PPC] Do not use large page/tlb entries for kernel
1078 lowmem mapping on PPC40x.
1080 nomca [IA-64] Disable machine check abort handling
1082 nomce [IA-32] Machine Check Exception
1084 noresidual [PPC] Don't use residual data on PReP machines.
1086 noresume [SWSUSP] Disables resume and restores original swap
1087 space.
1089 no-scroll [VGA] Disables scrollback.
1090 This is required for the Braillex ib80-piezo Braille
1091 reader made by F.H. Papenmeier (Germany).
1093 nosbagart [IA-64]
1095 nosep [BUGS=IA-32] Disables x86 SYSENTER/SYSEXIT support.
1097 nosmp [SMP] Tells an SMP kernel to act as a UP kernel.
1099 nosync [HW,M68K] Disables sync negotiation for all devices.
1101 notsc [BUGS=IA-32] Disable Time Stamp Counter
1103 nousb [USB] Disable the USB subsystem
1105 nowb [ARM]
1107 nr_uarts= [SERIAL] maximum number of UARTs to be registered.
1109 opl3= [HW,OSS]
1110 Format: <io>
1112 opl3sa= [HW,OSS]
1113 Format: <io>,<irq>,<dma>,<dma2>,<mpu_io>,<mpu_irq>
1115 opl3sa2= [HW,OSS] Format:
1116 <io>,<irq>,<dma>,<dma2>,<mss_io>,<mpu_io>,<ymode>,<loopback>[,<isapnp>,<multiple]
1118 oprofile.timer= [HW]
1119 Use timer interrupt instead of performance counters
1121 optcd= [HW,CD]
1122 Format: <io>
1124 osst= [HW,SCSI] SCSI Tape Driver
1125 Format: <buffer_size>,<write_threshold>
1126 See also Documentation/scsi/st.txt.
1128 panic= [KNL] Kernel behaviour on panic
1129 Format: <timeout>
1131 parkbd.port= [HW] Parallel port number the keyboard adapter is
1132 connected to, default is 0.
1133 Format: <parport#>
1134 parkbd.mode= [HW] Parallel port keyboard adapter mode of operation,
1135 0 for XT, 1 for AT (default is AT).
1136 Format: <mode>
1138 parport= [HW,PPT] Specify parallel ports. 0 disables.
1139 Format: { 0 | auto | 0xBBB[,IRQ[,DMA]] }
1140 Use 'auto' to force the driver to use any
1141 IRQ/DMA settings detected (the default is to
1142 ignore detected IRQ/DMA settings because of
1143 possible conflicts). You can specify the base
1144 address, IRQ, and DMA settings; IRQ and DMA
1145 should be numbers, or 'auto' (for using detected
1146 settings on that particular port), or 'nofifo'
1147 (to avoid using a FIFO even if it is detected).
1148 Parallel ports are assigned in the order they
1149 are specified on the command line, starting
1150 with parport0.
1152 parport_init_mode= [HW,PPT]
1153 Configure VIA parallel port to operate in
1154 a specific mode. This is necessary on Pegasos
1155 computer where firmware has no options for setting
1156 up parallel port mode and sets it to spp.
1157 Currently this function knows 686a and 8231 chips.
1158 Format: [spp|ps2|epp|ecp|ecpepp]
1160 pas2= [HW,OSS] Format:
1161 <io>,<irq>,<dma>,<dma16>,<sb_io>,<sb_irq>,<sb_dma>,<sb_dma16>
1163 pas16= [HW,SCSI]
1164 See header of drivers/scsi/pas16.c.
1166 pause_on_oops=
1167 Halt all CPUs after the first oops has been printed for
1168 the specified number of seconds. This is to be used if
1169 your oopses keep scrolling off the screen.
1171 pcbit= [HW,ISDN]
1173 pcd. [PARIDE]
1174 See header of drivers/block/paride/pcd.c.
1175 See also Documentation/paride.txt.
1177 pci=option[,option...] [PCI] various PCI subsystem options:
1178 off [IA-32] don't probe for the PCI bus
1179 bios [IA-32] force use of PCI BIOS, don't access
1180 the hardware directly. Use this if your machine
1181 has a non-standard PCI host bridge.
1182 nobios [IA-32] disallow use of PCI BIOS, only direct
1183 hardware access methods are allowed. Use this
1184 if you experience crashes upon bootup and you
1185 suspect they are caused by the BIOS.
1186 conf1 [IA-32] Force use of PCI Configuration
1187 Mechanism 1.
1188 conf2 [IA-32] Force use of PCI Configuration
1189 Mechanism 2.
1190 nommconf [IA-32,X86_64] Disable use of MMCONFIG for PCI
1191 Configuration
1192 nomsi [MSI] If the PCI_MSI kernel config parameter is
1193 enabled, this kernel boot option can be used to
1194 disable the use of MSI interrupts system-wide.
1195 nosort [IA-32] Don't sort PCI devices according to
1196 order given by the PCI BIOS. This sorting is
1197 done to get a device order compatible with
1198 older kernels.
1199 biosirq [IA-32] Use PCI BIOS calls to get the interrupt
1200 routing table. These calls are known to be buggy
1201 on several machines and they hang the machine
1202 when used, but on other computers it's the only
1203 way to get the interrupt routing table. Try
1204 this option if the kernel is unable to allocate
1205 IRQs or discover secondary PCI buses on your
1206 motherboard.
1207 rom [IA-32] Assign address space to expansion ROMs.
1208 Use with caution as certain devices share
1209 address decoders between ROMs and other
1210 resources.
1211 irqmask=0xMMMM [IA-32] Set a bit mask of IRQs allowed to be
1212 assigned automatically to PCI devices. You can
1213 make the kernel exclude IRQs of your ISA cards
1214 this way.
1215 pirqaddr=0xAAAAA [IA-32] Specify the physical address
1216 of the PIRQ table (normally generated
1217 by the BIOS) if it is outside the
1218 F0000h-100000h range.
1219 lastbus=N [IA-32] Scan all buses thru bus #N. Can be
1220 useful if the kernel is unable to find your
1221 secondary buses and you want to tell it
1222 explicitly which ones they are.
1223 assign-busses [IA-32] Always assign all PCI bus
1224 numbers ourselves, overriding
1225 whatever the firmware may have done.
1226 usepirqmask [IA-32] Honor the possible IRQ mask stored
1227 in the BIOS $PIR table. This is needed on
1228 some systems with broken BIOSes, notably
1229 some HP Pavilion N5400 and Omnibook XE3
1230 notebooks. This will have no effect if ACPI
1231 IRQ routing is enabled.
1232 noacpi [IA-32] Do not use ACPI for IRQ routing
1233 or for PCI scanning.
1234 routeirq Do IRQ routing for all PCI devices.
1235 This is normally done in pci_enable_device(),
1236 so this option is a temporary workaround
1237 for broken drivers that don't call it.
1238 firmware [ARM] Do not re-enumerate the bus but instead
1239 just use the configuration from the
1240 bootloader. This is currently used on
1241 IXP2000 systems where the bus has to be
1242 configured a certain way for adjunct CPUs.
1244 pcmv= [HW,PCMCIA] BadgePAD 4
1246 pd. [PARIDE]
1247 See Documentation/paride.txt.
1249 pdcchassis= [PARISC,HW] Disable/Enable PDC Chassis Status codes at
1250 boot time.
1251 Format: { 0 | 1 }
1252 See arch/parisc/kernel/pdc_chassis.c
1254 pf. [PARIDE]
1255 See Documentation/paride.txt.
1257 pg. [PARIDE]
1258 See Documentation/paride.txt.
1260 pirq= [SMP,APIC] Manual mp-table setup
1261 See Documentation/i386/IO-APIC.txt.
1263 plip= [PPT,NET] Parallel port network link
1264 Format: { parport<nr> | timid | 0 }
1265 See also Documentation/parport.txt.
1267 pnpacpi= [ACPI]
1268 { off }
1270 pnpbios= [ISAPNP]
1271 { on | off | curr | res | no-curr | no-res }
1273 pnp_reserve_irq=
1274 [ISAPNP] Exclude IRQs for the autoconfiguration
1276 pnp_reserve_dma=
1277 [ISAPNP] Exclude DMAs for the autoconfiguration
1279 pnp_reserve_io= [ISAPNP] Exclude I/O ports for the autoconfiguration
1280 Ranges are in pairs (I/O port base and size).
1282 pnp_reserve_mem=
1283 [ISAPNP] Exclude memory regions for the
1284 autoconfiguration.
1285 Ranges are in pairs (memory base and size).
1287 profile= [KNL] Enable kernel profiling via /proc/profile
1288 Format: [schedule,]<number>
1289 Param: "schedule" - profile schedule points.
1290 Param: <number> - step/bucket size as a power of 2 for
1291 statistical time based profiling.
1293 processor.max_cstate= [HW,ACPI]
1294 Limit processor to maximum C-state
1295 max_cstate=9 overrides any DMI blacklist limit.
1297 processor.nocst [HW,ACPI]
1298 Ignore the _CST method to determine C-states,
1299 instead using the legacy FADT method
1301 prompt_ramdisk= [RAM] List of RAM disks to prompt for floppy disk
1302 before loading.
1303 See Documentation/ramdisk.txt.
1305 psmouse.proto= [HW,MOUSE] Highest PS2 mouse protocol extension to
1306 probe for; one of (bare|imps|exps|lifebook|any).
1307 psmouse.rate= [HW,MOUSE] Set desired mouse report rate, in reports
1308 per second.
1309 psmouse.resetafter= [HW,MOUSE]
1310 Try to reset the device after so many bad packets
1311 (0 = never).
1312 psmouse.resolution=
1313 [HW,MOUSE] Set desired mouse resolution, in dpi.
1314 psmouse.smartscroll=
1315 [HW,MOUSE] Controls Logitech smartscroll autorepeat.
1316 0 = disabled, 1 = enabled (default).
1318 pss= [HW,OSS] Personal Sound System (ECHO ESC614)
1319 Format:
1320 <io>,<mss_io>,<mss_irq>,<mss_dma>,<mpu_io>,<mpu_irq>
1322 pt. [PARIDE]
1323 See Documentation/paride.txt.
1325 quiet= [KNL] Disable log messages
1327 r128= [HW,DRM]
1329 raid= [HW,RAID]
1330 See Documentation/md.txt.
1332 ramdisk= [RAM] Sizes of RAM disks in kilobytes [deprecated]
1333 See Documentation/ramdisk.txt.
1335 ramdisk_blocksize= [RAM]
1336 See Documentation/ramdisk.txt.
1338 ramdisk_size= [RAM] Sizes of RAM disks in kilobytes
1339 New name for the ramdisk parameter.
1340 See Documentation/ramdisk.txt.
1342 rcu.blimit= [KNL,BOOT] Set maximum number of finished
1343 RCU callbacks to process in one batch.
1345 rcu.qhimark= [KNL,BOOT] Set threshold of queued
1346 RCU callbacks over which batch limiting is disabled.
1348 rcu.qlowmark= [KNL,BOOT] Set threshold of queued
1349 RCU callbacks below which batch limiting is re-enabled.
1351 rcu.rsinterval= [KNL,BOOT,SMP] Set the number of additional
1352 RCU callbacks to queued before forcing reschedule
1353 on all cpus.
1355 rdinit= [KNL]
1356 Format: <full_path>
1357 Run specified binary instead of /init from the ramdisk,
1358 used for early userspace startup. See initrd.
1360 reboot= [BUGS=IA-32,BUGS=ARM,BUGS=IA-64] Rebooting mode
1361 Format: <reboot_mode>[,<reboot_mode2>[,...]]
1362 See arch/*/kernel/reboot.c.
1364 reserve= [KNL,BUGS] Force the kernel to ignore some iomem area
1366 resume= [SWSUSP]
1367 Specify the partition device for software suspend
1369 rhash_entries= [KNL,NET]
1370 Set number of hash buckets for route cache
1372 riscom8= [HW,SERIAL]
1373 Format: <io_board1>[,<io_board2>[,...<io_boardN>]]
1375 ro [KNL] Mount root device read-only on boot
1377 root= [KNL] Root filesystem
1379 rootdelay= [KNL] Delay (in seconds) to pause before attempting to
1380 mount the root filesystem
1382 rootflags= [KNL] Set root filesystem mount option string
1384 rootfstype= [KNL] Set root filesystem type
1386 rw [KNL] Mount root device read-write on boot
1388 S [KNL] Run init in single mode
1390 sa1100ir [NET]
1391 See drivers/net/irda/sa1100_ir.c.
1393 sb= [HW,OSS]
1394 Format: <io>,<irq>,<dma>,<dma2>
1396 sbni= [NET] Granch SBNI12 leased line adapter
1398 sbpcd= [HW,CD] Soundblaster CD adapter
1399 Format: <io>,<type>
1400 See a comment before function sbpcd_setup() in
1401 drivers/cdrom/sbpcd.c.
1403 sc1200wdt= [HW,WDT] SC1200 WDT (watchdog) driver
1404 Format: <io>[,<timeout>[,<isapnp>]]
1406 scsi_debug_*= [SCSI]
1407 See drivers/scsi/scsi_debug.c.
1409 scsi_default_dev_flags=
1410 [SCSI] SCSI default device flags
1411 Format: <integer>
1413 scsi_dev_flags= [SCSI] Black/white list entry for vendor and model
1414 Format: <vendor>:<model>:<flags>
1415 (flags are integer value)
1417 scsi_logging= [SCSI]
1419 selinux [SELINUX] Disable or enable SELinux at boot time.
1420 Format: { "0" | "1" }
1421 See security/selinux/Kconfig help text.
1422 0 -- disable.
1423 1 -- enable.
1424 Default value is set via kernel config option.
1425 If enabled at boot time, /selinux/disable can be used
1426 later to disable prior to initial policy load.
1428 selinux_compat_net =
1429 [SELINUX] Set initial selinux_compat_net flag value.
1430 Format: { "0" | "1" }
1431 0 -- use new secmark-based packet controls
1432 1 -- use legacy packet controls
1433 Default value is 0 (preferred).
1434 Value can be changed at runtime via
1435 /selinux/compat_net.
1437 serialnumber [BUGS=IA-32]
1439 sg_def_reserved_size= [SCSI]
1441 sgalaxy= [HW,OSS]
1442 Format: <io>,<irq>,<dma>,<dma2>,<sgbase>
1444 shapers= [NET]
1445 Maximal number of shapers.
1447 sim710= [SCSI,HW]
1448 See header of drivers/scsi/sim710.c.
1450 simeth= [IA-64]
1451 simscsi=
1453 sjcd= [HW,CD]
1454 Format: <io>,<irq>,<dma>
1455 See header of drivers/cdrom/sjcd.c.
1457 slram= [HW,MTD]
1459 smart2= [HW]
1460 Format: <io1>[,<io2>[,...,<io8>]]
1462 snd-ad1816a= [HW,ALSA]
1464 snd-ad1848= [HW,ALSA]
1466 snd-ali5451= [HW,ALSA]
1468 snd-als100= [HW,ALSA]
1470 snd-als4000= [HW,ALSA]
1472 snd-azt2320= [HW,ALSA]
1474 snd-cmi8330= [HW,ALSA]
1476 snd-cmipci= [HW,ALSA]
1478 snd-cs4231= [HW,ALSA]
1480 snd-cs4232= [HW,ALSA]
1482 snd-cs4236= [HW,ALSA]
1484 snd-cs4281= [HW,ALSA]
1486 snd-cs46xx= [HW,ALSA]
1488 snd-dt019x= [HW,ALSA]
1490 snd-dummy= [HW,ALSA]
1492 snd-emu10k1= [HW,ALSA]
1494 snd-ens1370= [HW,ALSA]
1496 snd-ens1371= [HW,ALSA]
1498 snd-es968= [HW,ALSA]
1500 snd-es1688= [HW,ALSA]
1502 snd-es18xx= [HW,ALSA]
1504 snd-es1938= [HW,ALSA]
1506 snd-es1968= [HW,ALSA]
1508 snd-fm801= [HW,ALSA]
1510 snd-gusclassic= [HW,ALSA]
1512 snd-gusextreme= [HW,ALSA]
1514 snd-gusmax= [HW,ALSA]
1516 snd-hdsp= [HW,ALSA]
1518 snd-ice1712= [HW,ALSA]
1520 snd-intel8x0= [HW,ALSA]
1522 snd-interwave= [HW,ALSA]
1524 snd-interwave-stb=
1525 [HW,ALSA]
1527 snd-korg1212= [HW,ALSA]
1529 snd-maestro3= [HW,ALSA]
1531 snd-mpu401= [HW,ALSA]
1533 snd-mtpav= [HW,ALSA]
1535 snd-nm256= [HW,ALSA]
1537 snd-opl3sa2= [HW,ALSA]
1539 snd-opti92x-ad1848=
1540 [HW,ALSA]
1542 snd-opti92x-cs4231=
1543 [HW,ALSA]
1545 snd-opti93x= [HW,ALSA]
1547 snd-pmac= [HW,ALSA]
1549 snd-rme32= [HW,ALSA]
1551 snd-rme96= [HW,ALSA]
1553 snd-rme9652= [HW,ALSA]
1555 snd-sb8= [HW,ALSA]
1557 snd-sb16= [HW,ALSA]
1559 snd-sbawe= [HW,ALSA]
1561 snd-serial= [HW,ALSA]
1563 snd-sgalaxy= [HW,ALSA]
1565 snd-sonicvibes= [HW,ALSA]
1567 snd-sun-amd7930=
1568 [HW,ALSA]
1570 snd-sun-cs4231= [HW,ALSA]
1572 snd-trident= [HW,ALSA]
1574 snd-usb-audio= [HW,ALSA,USB]
1576 snd-via82xx= [HW,ALSA]
1578 snd-virmidi= [HW,ALSA]
1580 snd-wavefront= [HW,ALSA]
1582 snd-ymfpci= [HW,ALSA]
1584 sonicvibes= [HW,OSS]
1585 Format: <reverb>
1587 sonycd535= [HW,CD]
1588 Format: <io>[,<irq>]
1590 sonypi.*= [HW] Sony Programmable I/O Control Device driver
1591 See Documentation/sonypi.txt
1593 specialix= [HW,SERIAL] Specialix multi-serial port adapter
1594 See Documentation/specialix.txt.
1596 spia_io_base= [HW,MTD]
1597 spia_fio_base=
1598 spia_pedr=
1599 spia_peddr=
1601 sscape= [HW,OSS]
1602 Format: <io>,<irq>,<dma>,<mpu_io>,<mpu_irq>
1604 st= [HW,SCSI] SCSI tape parameters (buffers, etc.)
1605 See Documentation/scsi/st.txt.
1607 st0x= [HW,SCSI]
1608 See header of drivers/scsi/seagate.c.
1610 sti= [PARISC,HW]
1611 Format: <num>
1612 Set the STI (builtin display/keyboard on the HP-PARISC
1613 machines) console (graphic card) which should be used
1614 as the initial boot-console.
1615 See also comment in drivers/video/console/sticore.c.
1617 sti_font= [HW]
1618 See comment in drivers/video/console/sticore.c.
1620 stifb= [HW]
1621 Format: bpp:<bpp1>[:<bpp2>[:<bpp3>...]]
1623 swiotlb= [IA-64] Number of I/O TLB slabs
1625 switches= [HW,M68k]
1627 sym53c416= [HW,SCSI]
1628 See header of drivers/scsi/sym53c416.c.
1630 t128= [HW,SCSI]
1631 See header of drivers/scsi/t128.c.
1633 tdfx= [HW,DRM]
1635 thash_entries= [KNL,NET]
1636 Set number of hash buckets for TCP connection
1638 time Show timing data prefixed to each printk message line
1640 clocksource= [GENERIC_TIME] Override the default clocksource
1641 Override the default clocksource and use the clocksource
1642 with the name specified.
1644 tipar.timeout= [HW,PPT]
1645 Set communications timeout in tenths of a second
1646 (default 15).
1648 tipar.delay= [HW,PPT]
1649 Set inter-bit delay in microseconds (default 10).
1651 tmc8xx= [HW,SCSI]
1652 See header of drivers/scsi/seagate.c.
1654 tmscsim= [HW,SCSI]
1655 See comment before function dc390_setup() in
1656 drivers/scsi/tmscsim.c.
1658 tp720= [HW,PS2]
1660 trix= [HW,OSS] MediaTrix AudioTrix Pro
1661 Format:
1662 <io>,<irq>,<dma>,<dma2>,<sb_io>,<sb_irq>,<sb_dma>,<mpu_io>,<mpu_irq>
1664 tsdev.xres= [TS] Horizontal screen resolution.
1665 tsdev.yres= [TS] Vertical screen resolution.
1667 turbografx.map[2|3]= [HW,JOY]
1668 TurboGraFX parallel port interface
1669 Format:
1670 <port#>,<js1>,<js2>,<js3>,<js4>,<js5>,<js6>,<js7>
1671 See also Documentation/input/joystick-parport.txt
1673 u14-34f= [HW,SCSI] UltraStor 14F/34F SCSI host adapter
1674 See header of drivers/scsi/u14-34f.c.
1676 uart401= [HW,OSS]
1677 Format: <io>,<irq>
1679 uart6850= [HW,OSS]
1680 Format: <io>,<irq>
1682 usbhid.mousepoll=
1683 [USBHID] The interval which mice are to be polled at.
1685 vdso= [IA-32]
1686 vdso=1: enable VDSO (default)
1687 vdso=0: disable VDSO mapping
1689 video= [FB] Frame buffer configuration
1690 See Documentation/fb/modedb.txt.
1692 vga= [BOOT,IA-32] Select a particular video mode
1693 See Documentation/i386/boot.txt and
1694 Documentation/svga.txt.
1695 Use vga=ask for menu.
1696 This is actually a boot loader parameter; the value is
1697 passed to the kernel using a special protocol.
1699 vmalloc=nn[KMG] [KNL,BOOT] Forces the vmalloc area to have an exact
1700 size of <nn>. This can be used to increase the
1701 minimum size (128MB on x86). It can also be used to
1702 decrease the size and leave more room for directly
1703 mapped kernel RAM.
1705 vmhalt= [KNL,S390] Perform z/VM CP command after system halt.
1706 Format: <command>
1708 vmpanic= [KNL,S390] Perform z/VM CP command after kernel panic.
1709 Format: <command>
1711 vmpoff= [KNL,S390] Perform z/VM CP command after power off.
1712 Format: <command>
1714 waveartist= [HW,OSS]
1715 Format: <io>,<irq>,<dma>,<dma2>
1717 wd33c93= [HW,SCSI]
1718 See header of drivers/scsi/wd33c93.c.
1720 wd7000= [HW,SCSI]
1721 See header of drivers/scsi/wd7000.c.
1723 wdt= [WDT] Watchdog
1724 See Documentation/watchdog/watchdog.txt.
1726 xd= [HW,XT] Original XT pre-IDE (RLL encoded) disks.
1727 xd_geo= See header of drivers/block/xd.c.
1729 xirc2ps_cs= [NET,PCMCIA]
1730 Format:
1731 <irq>,<irq_mask>,<io>,<full_duplex>,<do_sound>,<lockup_hack>[,<irq2>[,<irq3>[,<irq4>]]]
1733 norandmaps Don't use address space randomization
1734 Equivalent to echo 0 > /proc/sys/kernel/randomize_va_space
1737 ______________________________________________________________________
1739 TODO:
1741 Add documentation for ALSA options.
1742 Add more DRM drivers.