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 LIBATA Libata driver is enabled
52 LP Printer support is enabled.
53 LOOP Loopback device support is enabled.
54 M68k M68k architecture is enabled.
55 These options have more detailed description inside of
56 Documentation/m68k/kernel-options.txt.
57 MCA MCA bus support is enabled.
58 MDA MDA console support is enabled.
59 MOUSE Appropriate mouse support is enabled.
60 MSI Message Signaled Interrupts (PCI).
61 MTD MTD support is enabled.
62 NET Appropriate network support is enabled.
63 NUMA NUMA support is enabled.
64 GENERIC_TIME The generic timeofday code is enabled.
65 NFS Appropriate NFS support is enabled.
66 OSS OSS sound support is enabled.
67 PARIDE The ParIDE subsystem is enabled.
68 PARISC The PA-RISC architecture is enabled.
69 PCI PCI bus support is enabled.
70 PCMCIA The PCMCIA subsystem is enabled.
71 PNP Plug & Play support is enabled.
72 PPC PowerPC architecture is enabled.
73 PPT Parallel port support is enabled.
74 PS2 Appropriate PS/2 support is enabled.
75 RAM RAM disk support is enabled.
76 S390 S390 architecture is enabled.
77 SCSI Appropriate SCSI support is enabled.
78 A lot of drivers has their options described inside of
80 SELINUX SELinux support is enabled.
81 SERIAL Serial support is enabled.
82 SMP The kernel is an SMP kernel.
83 SPARC Sparc architecture is enabled.
84 SWSUSP Software suspend is enabled.
85 TS Appropriate touchscreen support is enabled.
86 USB USB support is enabled.
87 USBHID USB Human Interface Device support is enabled.
88 V4L Video For Linux support is enabled.
89 VGA The VGA console has been enabled.
90 VT Virtual terminal support is enabled.
91 WDT Watchdog support is enabled.
92 XT IBM PC/XT MFM hard disk support is enabled.
93 X86-64 X86-64 architecture is enabled.
94 More X86-64 boot options can be found in
95 Documentation/x86_64/boot-options.txt .
97 In addition, the following text indicates that the option:
99 BUGS= Relates to possible processor bugs on the said processor.
100 KNL Is a kernel start-up parameter.
101 BOOT Is a boot loader parameter.
103 Parameters denoted with BOOT are actually interpreted by the boot
104 loader, and have no meaning to the kernel directly.
105 Do not modify the syntax of boot loader parameters without extreme
106 need or coordination with <Documentation/i386/boot.txt>.
108 There are also arch-specific kernel-parameters not documented here.
109 See for example <Documentation/x86_64/boot-options.txt>.
111 Note that ALL kernel parameters listed below are CASE SENSITIVE, and that
112 a trailing = on the name of any parameter states that that parameter will
113 be entered as an environment variable, whereas its absence indicates that
114 it will appear as a kernel argument readable via /proc/cmdline by programs
115 running once the system is up.
117 The number of kernel parameters is not limited, but the length of the
118 complete command line (parameters including spaces etc.) is limited to
119 a fixed number of characters. This limit depends on the architecture
120 and is between 256 and 4096 characters. It is defined in the file
121 ./include/asm/setup.h as COMMAND_LINE_SIZE.
124 53c7xx= [HW,SCSI] Amiga SCSI controllers
125 See header of drivers/scsi/53c7xx.c.
126 See also Documentation/scsi/ncr53c7xx.txt.
128 acpi= [HW,ACPI] Advanced Configuration and Power Interface
129 Format: { force | off | ht | strict | noirq }
130 force -- enable ACPI if default was off
131 off -- disable ACPI if default was on
132 noirq -- do not use ACPI for IRQ routing
133 ht -- run only enough ACPI to enable Hyper Threading
134 strict -- Be less tolerant of platforms that are not
135 strictly ACPI specification compliant.
137 See also Documentation/pm.txt, pci=noacpi
139 acpi_sleep= [HW,ACPI] Sleep options
140 Format: { s3_bios, s3_mode }
141 See Documentation/power/video.txt
143 acpi_sci= [HW,ACPI] ACPI System Control Interrupt trigger mode
144 Format: { level | edge | high | low }
146 acpi_irq_balance [HW,ACPI]
147 ACPI will balance active IRQs
150 acpi_irq_nobalance [HW,ACPI]
151 ACPI will not move active IRQs (default)
154 acpi_irq_pci= [HW,ACPI] If irq_balance, clear listed IRQs for
156 Format: <irq>,<irq>...
158 acpi_irq_isa= [HW,ACPI] If irq_balance, mark listed IRQs used by ISA
159 Format: <irq>,<irq>...
161 acpi_os_name= [HW,ACPI] Tell ACPI BIOS the name of the OS
162 Format: To spoof as Windows 98: ="Microsoft Windows"
164 acpi_osi= [HW,ACPI] empty param disables _OSI
166 acpi_serialize [HW,ACPI] force serialization of AML methods
168 acpi_skip_timer_override [HW,ACPI]
169 Recognize and ignore IRQ0/pin2 Interrupt Override.
170 For broken nForce2 BIOS resulting in XT-PIC timer.
171 acpi_use_timer_override [HW,ACPI}
172 Use timer override. For some broken Nvidia NF5 boards
173 that require a timer override, but don't have
176 acpi_dbg_layer= [HW,ACPI]
178 Each bit of the <int> indicates an ACPI debug layer,
179 1: enable, 0: disable. It is useful for boot time
180 debugging. After system has booted up, it can be set
181 via /proc/acpi/debug_layer.
183 acpi_dbg_level= [HW,ACPI]
185 Each bit of the <int> indicates an ACPI debug level,
186 1: enable, 0: disable. It is useful for boot time
187 debugging. After system has booted up, it can be set
188 via /proc/acpi/debug_level.
190 acpi_fake_ecdt [HW,ACPI] Workaround failure due to BIOS lacking ECDT
192 acpi_generic_hotkey [HW,ACPI]
193 Allow consolidated generic hotkey driver to
194 override platform specific driver.
195 See also Documentation/acpi-hotkey.txt.
197 acpi_pm_good [IA-32,X86-64]
198 Override the pmtimer bug detection: force the kernel
199 to assume that this machine's pmtimer latches its value
200 and always returns good values.
202 enable_timer_pin_1 [i386,x86-64]
203 Enable PIN 1 of APIC timer
204 Can be useful to work around chipset bugs
205 (in particular on some ATI chipsets).
206 The kernel tries to set a reasonable default.
208 disable_timer_pin_1 [i386,x86-64]
209 Disable PIN 1 of APIC timer
210 Can be useful to work around chipset bugs.
213 Format: <io>,<irq>,<dma>,<dma2>
214 See also Documentation/sound/oss/AD1816.
217 Format: <io>,<irq>,<dma>,<dma2>,<type>
223 See header of drivers/scsi/advansys.c.
225 advwdt= [HW,WDT] Advantech WDT
226 Format: <iostart>,<iostop>
228 aedsp16= [HW,OSS] Audio Excel DSP 16
229 Format: <io>,<irq>,<dma>,<mss_io>,<mpu_io>,<mpu_irq>
230 See also header of sound/oss/aedsp16.c.
233 See Documentation/scsi/aha152x.txt.
236 Format: <portbase>[,<buson>,<busoff>[,<dmaspeed>]]
239 See Documentation/scsi/aic7xxx.txt.
242 See Documentation/scsi/aic79xx.txt.
244 amijoy.map= [HW,JOY] Amiga joystick support
245 Map of devices attached to JOY0DAT and JOY1DAT
247 See also Documentation/kernel/input/joystick.txt
249 analog.map= [HW,JOY] Analog joystick and gamepad support
250 Specifies type or capabilities of an analog joystick
251 connected to one of 16 gameports
252 Format: <type1>,<type2>,..<type16>
255 Power management functions (SPARCstation-4/5 + deriv.)
257 Disable APC CPU standby support. SPARCstation-Fox does
258 not play well with APC CPU idle - disable it if you have
259 APC and your system crashes randomly.
261 apic= [APIC,i386] Change the output verbosity whilst booting
262 Format: { quiet (default) | verbose | debug }
263 Change the amount of debugging information output
264 when initialising the APIC and IO-APIC components.
266 apm= [APM] Advanced Power Management
267 See header of arch/i386/kernel/apm.c.
272 arcrimi= [HW,NET] ARCnet - "RIM I" (entirely mem-mapped) cards
273 Format: <io>,<irq>,<nodeID>
277 atarimouse= [HW,MOUSE] Atari Mouse
279 atascsi= [HW,SCSI] Atari SCSI
281 atkbd.extra= [HW] Enable extra LEDs and keys on IBM RapidAccess,
282 EzKey and similar keyboards
284 atkbd.reset= [HW] Reset keyboard during initialization
286 atkbd.set= [HW] Select keyboard code set
287 Format: <int> (2 = AT (default), 3 = PS/2)
289 atkbd.scroll= [HW] Enable scroll wheel on MS Office and similar
292 atkbd.softraw= [HW] Choose between synthetic and real raw mode
293 Format: <bool> (0 = real, 1 = synthetic (default))
295 atkbd.softrepeat= [HW]
296 Use software keyboard repeat
300 aztcd= [HW,CD] Aztech CD268 CDROM driver
301 Format: <io>,0x79 (?)
303 baycom_epp= [HW,AX25]
306 baycom_par= [HW,AX25] BayCom Parallel Port AX.25 Modem
308 See header of drivers/net/hamradio/baycom_par.c.
310 baycom_ser_fdx= [HW,AX25]
311 BayCom Serial Port AX.25 Modem (Full Duplex Mode)
312 Format: <io>,<irq>,<mode>[,<baud>]
313 See header of drivers/net/hamradio/baycom_ser_fdx.c.
315 baycom_ser_hdx= [HW,AX25]
316 BayCom Serial Port AX.25 Modem (Half Duplex Mode)
317 Format: <io>,<irq>,<mode>
318 See header of drivers/net/hamradio/baycom_ser_hdx.c.
320 blkmtd_device= [HW,MTD]
326 bttv.card= [HW,V4L] bttv (bt848 + bt878 based grabber cards)
327 bttv.radio= Most important insmod options are available as
329 bttv.pll= See Documentation/video4linux/bttv/Insmod-options
330 bttv.tuner= and Documentation/video4linux/bttv/CARDLIST
333 See drivers/scsi/BusLogic.c, comment before function
334 BusLogic_ParseDriverOptions().
336 c101= [NET] Moxa C101 synchronous serial card
338 cachesize= [BUGS=IA-32] Override level 2 CPU cache size detection.
339 Sometimes CPU hardware bugs make them report the cache
340 size incorrectly. The kernel will attempt work arounds
341 to fix known problems, but for some CPUs it is not
342 possible to determine what the correct size should be.
343 This option provides an override for these situations.
346 Format: <io>,<irq>[,PAS]
347 See header of drivers/cdrom/cdu31a.c.
349 chandev= [HW,NET] Generic channel device initialisation
351 checkreqprot [SELINUX] Set initial checkreqprot flag value.
352 Format: { "0" | "1" }
353 See security/selinux/Kconfig help text.
354 0 -- check protection applied by kernel (includes
355 any implied execute protection).
356 1 -- check protection requested by application.
357 Default value is set via a kernel config option.
358 Value can be changed at runtime via
359 /selinux/checkreqprot.
361 clock= [BUGS=IA-32, HW] gettimeofday clocksource override.
363 Forces specified clocksource (if available) to be used
364 when calculating gettimeofday(). If specified
365 clocksource is not available, it defaults to PIT.
366 Format: { pit | tsc | cyclone | pmtmr }
368 code_bytes [IA32] How many bytes of object code to print in an
375 [IA32/X86_64] Disable/Enable interrupt 0 timer routing
376 over the 8254 in addition to over the IO-APIC. The
377 kernel tries to set a sensible default.
379 hpet= [IA-32,HPET] option to disable HPET and use PIT.
383 Format: { auto | [<io>,][<irq>] }
385 com20020= [HW,NET] ARCnet - COM20020 chipset
387 <io>[,<irq>[,<nodeID>[,<backplane>[,<ckp>[,<timeout>]]]]]
389 com90io= [HW,NET] ARCnet - COM90xx chipset (IO-mapped buffers)
393 ARCnet - COM90xx chipset (memory-mapped buffers)
394 Format: <io>[,<irq>[,<memstart>]]
396 condev= [HW,S390] console device
399 console= [KNL] Output console device and options.
401 tty<n> Use the virtual console device <n>.
405 Use the specified serial port. The options are of
406 the form "bbbbpnf", where "bbbb" is the baud rate,
407 "p" is parity ("n", "o", or "e"), "n" is number of
408 bits, and "f" is flow control ("r" for RTS or
409 omit it). Default is "9600n8".
411 See Documentation/serial-console.txt for more
413 Documentation/networking/netconsole.txt for an
416 uart,io,<addr>[,options]
417 uart,mmio,<addr>[,options]
418 Start an early, polled-mode console on the 8250/16550
419 UART at the specified I/O port or MMIO address,
420 switching to the matching ttyS device later. The
421 options are the same as for ttyS, above.
423 cpcihp_generic= [HW,PCI] Generic port I/O CompactPCI driver
425 <first_slot>,<last_slot>,<port>,<enum_bit>[,<debug>]
428 Format: { parport<nr> | auto | none }
430 crashkernel=nn[KMG]@ss[KMG]
431 [KNL] Reserve a chunk of physical memory to
432 hold a kernel to switch to with kexec on panic.
435 Format: <io>,<irq>,<dma>,<dma2>,<mpuio>,<mpuirq>
440 cs89x0_media= [HW,NET]
441 Format: { rj45 | aui | bnc }
443 cyclades= [HW,SERIAL] Cyclades multi-serial port adapter.
446 See header of drivers/s390/block/dasd_devmap.c.
448 db9.dev[2|3]= [HW,JOY] Multisystem joystick support via parallel port
449 (one device per port)
450 Format: <port#>,<type>
451 See also Documentation/input/joystick-parport.txt
453 debug [KNL] Enable kernel debugging (events log level).
456 [KNL] verbose self-tests
458 Print debugging info while doing the locking API
460 We default to 0 (no extra messages), setting it to
461 1 will print _a lot_ more information - normally
462 only useful to kernel developers.
465 Format: <area>[,<node>]
466 See also Documentation/networking/decnet.txt.
469 Set number of hash buckets for dentry cache.
472 IO parameters + enable/disable command.
474 digiepca= [HW,SERIAL]
475 See drivers/char/README.epca and
476 Documentation/digiepca.txt.
478 dmascc= [HW,AX25,SERIAL] AX.25 Z80SCC driver with DMA
480 Format: <io_dev0>[,<io_dev1>[,..<io_dev32>]]
482 dmasound= [HW,OSS] Sound subsystem buffers
488 earlyprintk= [IA-32,X86-64]
490 earlyprintk=serial[,ttySn[,baudrate]]
492 Append ",keep" to not disable it when the real console
495 Only vga or serial at a time, not both.
497 Currently only ttyS0 and ttyS1 are supported.
499 Interaction with the standard serial driver is not
502 The VGA output is eventually overwritten by the real
507 ec_intr= [HW,ACPI] ACPI Embedded Controller interrupt mode
510 non-0: interrupt mode (default)
517 Format: {"of[f]" | "sk[ipmbr]"}
518 See comment in arch/i386/boot/edd.S
521 Format: <id>,<membase>,<irq>
523 eisa_irq_edge= [PARISC,HW]
524 See header of drivers/parisc/eisa.c.
527 See comment before function elanfreq_setup() in
528 arch/i386/kernel/cpu/cpufreq/elanfreq.c.
531 Format: {"anticipatory" | "cfq" | "deadline" | "noop"}
532 See Documentation/block/as-iosched.txt and
533 Documentation/block/deadline-iosched.txt for details.
535 elfcorehdr= [IA-32, X86_64]
536 Specifies physical address of start of kernel core
537 image elf header. Generally kexec loader will
538 pass this option to capture kernel.
539 See Documentation/kdump/kdump.txt for details.
541 enforcing [SELINUX] Set initial enforcing status.
543 See security/selinux/Kconfig help text.
544 0 -- permissive (log only, no denials).
545 1 -- enforcing (deny and log).
547 Value can be changed at runtime via /selinux/enforce.
550 Format: <spdif>,[<nomix>,[<amplifier>]]
551 See also header of sound/oss/es1371.c.
553 ether= [HW,NET] Ethernet cards parameters
554 This option is obsoleted by the "netdev=" option, which
555 has equivalent usage. See its documentation for details.
557 eurwdt= [HW,WDT] Eurotech CPU-1220/1410 onboard watchdog.
562 fail_make_request=[KNL]
563 General fault injection mechanism.
564 Format: <interval>,<probability>,<space>,<times>
565 See also /Documentation/fault-injection/.
568 See header of drivers/scsi/fd_mcs.c.
571 See header of drivers/scsi/fdomain.c.
574 See Documentation/floppy.txt.
577 [HW,JOY] Multisystem joystick and NES/SNES/PSX pad
578 support via parallel port (up to 5 devices per port)
579 Format: <port#>,<pad1>,<pad2>,<pad3>,<pad4>,<pad5>
580 See also Documentation/input/joystick-parport.txt
585 See header of drivers/scsi/gdth.c.
587 gpt [EFI] Forces disk with valid GPT signature but
588 invalid Protective MBR to be treated as GPT.
595 hashdist= [KNL,NUMA] Large hashes allocated during boot
596 are distributed across NUMA nodes. Defaults on
597 for IA-64, off otherwise.
598 Format: 0 | 1 (for off | on)
600 hcl= [IA-64] SGI's Hardware Graph compatibility layer
602 hd= [EIDE] (E)IDE hard drive subsystem geometry
603 Format: <cyl>,<head>,<sect>
605 hd?= [HW] (E)IDE subsystem
606 hd?lun= See Documentation/ide.txt.
608 highmem=nn[KMG] [KNL,BOOT] forces the highmem zone to have an exact
609 size of <nn>. This works even on boxes that have no
610 highmem otherwise. This also works to reduce highmem
611 size on bigger boxes.
613 highres= [KNL] Enable/disable high resolution timer mode.
614 Valid parameters: "on", "off"
618 See Documentation/isdn/README.HiSax.
620 hugepages= [HW,IA-32,IA-64] Maximal number of HugeTLB pages.
622 i8042.direct [HW] Put keyboard port into non-translated mode
623 i8042.dumbkbd [HW] Pretend that controller can only read data from
624 keyboard and cannot control its state
625 (Don't attempt to blink the leds)
626 i8042.noaux [HW] Don't check for auxiliary (== mouse) port
627 i8042.nokbd [HW] Don't check/create keyboard port
628 i8042.nomux [HW] Don't check presence of an active multiplexing
630 i8042.nopnp [HW] Don't use ACPIPnP / PnPBIOS to discover KBD/AUX
633 [HW] Frequency with which keyboard LEDs should blink
634 when kernel panics (default is 0.5 sec)
635 i8042.reset [HW] Reset the controller during init and cleanup
636 i8042.unlock [HW] Unlock (ignore) the keylock
640 i8k.ignore_dmi [HW] Continue probing hardware even if DMI data
641 indicates that the driver is running on unsupported
643 i8k.force [HW] Activate i8k driver even if SMM BIOS signature
644 does not match list of supported models.
646 [HW] Report power status in /proc/i8k
647 (disabled by default)
648 i8k.restricted [HW] Allow controlling fans only if SYS_ADMIN
651 ibmmcascsi= [HW,MCA,SCSI] IBM MicroChannel SCSI adapter
652 See Documentation/mca.txt.
655 Format: <io>[,<membase>[,<icn_id>[,<icn_id2>]]]
657 ide= [HW] (E)IDE subsystem
658 Format: ide=nodma or ide=doubler or ide=reverse
659 See Documentation/ide.txt.
661 ide?= [HW] (E)IDE subsystem
662 Format: ide?=noprobe or chipset specific parameters.
663 See Documentation/ide.txt.
665 idebus= [HW] (E)IDE subsystem - VLB/PCI bus speed
666 See Documentation/ide.txt.
669 Format: idle=poll or idle=halt
671 ignore_loglevel [KNL]
672 Ignore loglevel setting - this will print /all/
673 kernel messages to the console. Useful for debugging.
676 Set number of hash buckets for inode cache.
679 See header of drivers/scsi/in2000.c.
683 Run specified binary instead of /sbin/init as init
686 initcall_debug [KNL] Trace initcalls as they are executed. Useful
687 for working out where the kernel is dying during
690 initrd= [BOOT] Specify the location of the initial ramdisk
692 inport.irq= [HW] Inport (ATI XL and Microsoft) busmouse driver
695 combined_mode= [HW] control which driver uses IDE ports in combined
696 mode: legacy IDE driver, libata, or both
697 (in the libata case, libata.atapi_enabled=1 may be
698 useful as well). Note that using the ide or libata
699 options may affect your device naming (e.g. by
700 changing hdc to sdb).
701 Format: combined (default), ide, or libata
705 io7= [HW] IO7 for Marvel based alpha systems
706 See comment before marvel_specify_io7 in
707 arch/alpha/kernel/core_marvel.c.
710 See Documentation/nfsroot.txt.
712 ip2= [HW] Set IO/IRQ pairs for up to 4 IntelliPort boards
713 See comment before ip2_setup() in drivers/char/ip2.c.
715 ips= [HW,SCSI] Adaptec / IBM ServeRAID controller
716 See header of drivers/scsi/ips.c.
718 ports= [IP_VS_FTP] IPVS ftp helper module
720 Up to 8 (IP_VS_APP_MAX_PORTS) ports
722 Format: <port>,<port>....
725 When an interrupt is not handled search all handlers
726 for it. Intended to get systems with badly broken
730 When an interrupt is not handled search all handlers
731 for it. Also check all handlers each timer
732 interrupt. Intended to get systems with badly broken
736 Format: <RDP>,<reset>,<pci_scan>,<verbosity>
738 isolcpus= [KNL,SMP] Isolate CPUs from the general scheduler.
740 <cpu number>,...,<cpu number>
742 <cpu number>-<cpu number> (must be a positive range in ascending order)
744 <cpu number>,...,<cpu number>-<cpu number>
745 This option can be used to specify one or more CPUs
746 to isolate from the general SMP balancing and scheduling
747 algorithms. The only way to move a process onto or off
748 an "isolated" CPU is via the CPU affinity syscalls.
749 <cpu number> begins at 0 and the maximum value is
750 "number of CPUs in system - 1".
752 This option is the preferred way to isolate CPUs. The
753 alternative -- manually setting the CPU mask of all
754 tasks in the system -- can cause problems and
755 suboptimal load balancer performance.
758 Format: <io>,<irq>,<dma>,<setup>
762 js= [HW,JOY] Analog joystick
763 See Documentation/input/joystick.txt.
767 kstack=N [IA-32,X86-64] Print N words from the kernel stack
772 lapic [IA-32,APIC] Enable the local APIC even if BIOS
775 lasi= [HW,SCSI] PARISC LASI driver for the 53c700 chip
776 Format: addr:<io>,irq:<irq>
778 llsc*= [IA64] See function print_params() in
779 arch/ia64/sn/kernel/llsc4.c.
781 load_ramdisk= [RAM] List of ramdisks to load from floppy
782 See Documentation/ramdisk.txt.
784 lockd.nlm_grace_period=P [NFS] Assign grace period.
787 lockd.nlm_tcpport=N [NFS] Assign TCP port.
790 lockd.nlm_timeout=T [NFS] Assign timeout value.
793 lockd.nlm_udpport=M [NFS] Assign UDP port.
796 logibm.irq= [HW,MOUSE] Logitech Bus Mouse Driver
799 loglevel= All Kernel Messages with a loglevel smaller than the
800 console loglevel will be printed to the console. It can
801 also be changed with klogd or other programs. The
802 loglevels are defined as follows:
804 0 (KERN_EMERG) system is unusable
805 1 (KERN_ALERT) action must be taken immediately
806 2 (KERN_CRIT) critical conditions
807 3 (KERN_ERR) error conditions
808 4 (KERN_WARNING) warning conditions
809 5 (KERN_NOTICE) normal but significant condition
810 6 (KERN_INFO) informational
811 7 (KERN_DEBUG) debug-level messages
813 log_buf_len=n Sets the size of the printk ring buffer, in bytes.
814 Format: { n | nk | nM }
815 n must be a power of two. The default size
816 is set in the kernel config file.
818 lp=0 [LP] Specify parallel ports to use, e.g,
819 lp=port[,port...] lp=none,parport0 (lp0 not configured, lp1 uses
820 lp=reset first parallel port). 'lp=0' disables the
821 lp=auto printer driver. 'lp=reset' (which can be
822 specified in addition to the ports) causes
823 attached printers to be reset. Using
824 lp=port1,port2,... specifies the parallel ports
825 to associate lp devices with, starting with
826 lp0. A port specification may be 'none' to skip
827 that lp device, or a parport name such as
828 'parport0'. Specifying 'lp=auto' instead of a
829 port specification list means that device IDs
830 from each port should be examined, to see if
831 an IEEE 1284-compliant printer is attached; if
832 so, the driver will manage that printer.
833 See also header of drivers/char/lp.c.
836 Sets loops_per_jiffy to given constant, thus avoiding
837 time-consuming boot-time autodetection (up to 250 ms per
838 CPU). 0 enables autodetection (default). To determine
839 the correct value for your kernel, boot with normal
840 autodetection and see what value is printed. Note that
841 on SMP systems the preset will be applied to all CPUs,
842 which is likely to cause problems if your CPUs need
843 significantly divergent settings. An incorrect value
844 will cause delays in the kernel to be wrong, leading to
845 unpredictable I/O errors and other breakage. Although
846 unlikely, in the extreme case this might damage your
850 Format: <io>,<irq>,<dma>
852 mac5380= [HW,SCSI] Format:
853 <can_queue>,<cmd_per_lun>,<sg_tablesize>,<hostid>,<use_tags>
855 mac53c9x= [HW,SCSI] Format:
856 <num_esps>,<disconnect>,<nosync>,<can_queue>,<cmd_per_lun>,<sg_tablesize>,<hostid>,<use_tags>
858 machvec= [IA64] Force the use of a particular machine-vector
859 (machvec) in a generic kernel.
860 Example: machvec=hpzx1_swiotlb
862 max_loop= [LOOP] Maximum number of loopback devices that can
866 maxcpus= [SMP] Maximum number of processors that an SMP kernel
869 max_addr=[KMG] [KNL,BOOT,ia64] All physical memory greater than or
870 equal to this physical address is ignored.
872 max_luns= [SCSI] Maximum number of LUNs to probe.
873 Should be between 1 and 2^32-1.
876 [SCSI] Maximum number of LUNs received.
877 Should be between 1 and 16384.
879 mca-pentium [BUGS=IA-32]
884 Format: <port>,<irq>,<mitsumi_bug_93_wait>
888 mce [IA-32] Machine Check Exception
890 md= [HW] RAID subsystems devices and level
891 See Documentation/md.txt.
894 Format: <first>,<last>
895 Specifies range of consoles to be captured by the MDA.
897 mem=nn[KMG] [KNL,BOOT] Force usage of a specific amount of memory
898 Amount of memory to be used when the kernel is not able
899 to see the whole system memory or for test.
900 [IA-32] Use together with memmap= to avoid physical
901 address space collisions. Without memmap= PCI devices
902 could be placed at addresses belonging to unused RAM.
904 mem=nopentium [BUGS=IA-32] Disable usage of 4MB pages for kernel
907 memmap=exactmap [KNL,IA-32,X86_64] Enable setting of an exact
908 E820 memory map, as specified by the user.
909 Such memmap=exactmap lines can be constructed based on
910 BIOS output or other requirements. See the memmap=nn@ss
913 memmap=nn[KMG]@ss[KMG]
914 [KNL] Force usage of a specific region of memory
915 Region of memory to be used, from ss to ss+nn.
917 memmap=nn[KMG]#ss[KMG]
918 [KNL,ACPI] Mark specific memory as ACPI data.
919 Region of memory to be used, from ss to ss+nn.
921 memmap=nn[KMG]$ss[KMG]
922 [KNL,ACPI] Mark specific memory as reserved.
923 Region of memory to be used, from ss to ss+nn.
925 meye.*= [HW] Set MotionEye Camera parameters
926 See Documentation/video4linux/meye.txt.
931 [KNL,SMP] debug: override scheduler migration costs
932 Format: <level-1-usecs>,<level-2-usecs>,...
933 This debugging option can be used to override the
934 default scheduler migration cost matrix. The numbers
935 are indexed by 'CPU domain distance'.
936 E.g. migration_cost=1000,2000,3000 on an SMT NUMA
937 box will set up an intra-core migration cost of
938 1 msec, an inter-core migration cost of 2 msecs,
939 and an inter-node migration cost of 3 msecs.
941 WARNING: using the wrong values here can break
942 scheduler performance, so it's only for scheduler
943 development purposes, not production environments.
946 [KNL,SMP] migration cost auto-detect verbosity
948 If a system's migration matrix reported at bootup
949 seems erroneous then this option can be used to
950 increase verbosity of the detection process.
951 We default to 0 (no extra messages), 1 will print
952 some more information, and 2 will be really
953 verbose (probably only useful if you also have a
954 serial console attached to the system).
957 [KNL,SMP] multiply/divide migration costs by a factor
959 This debug option can be used to proportionally
960 increase or decrease the auto-detected migration
961 costs for all entries of the migration matrix.
962 E.g. migration_factor=150 will increase migration
963 costs by 50%. (and thus the scheduler will be less
964 eager migrating cache-hot tasks)
965 migration_factor=80 will decrease migration costs
966 by 20%. (thus the scheduler will be more eager to
969 WARNING: using the wrong values here can break
970 scheduler performance, so it's only for scheduler
971 development purposes, not production environments.
974 [MOUSE] Maximum time between finger touching and
975 leaving touchpad surface for touch to be considered
976 a tap and be reported as a left button click (for
977 touchpads working in absolute mode only).
979 mousedev.xres= [MOUSE] Horizontal screen resolution, used for devices
980 reporting absolute coordinates, such as tablets
981 mousedev.yres= [MOUSE] Vertical screen resolution, used for devices
982 reporting absolute coordinates, such as tablets
988 Format: <name>,<region-number>,<size>,<offset>
990 MTD_Region= [MTD] Format:
991 <name>,<region-number>[,<base>,<size>,<buswidth>,<altbuswidth>]
994 See drivers/mtd/cmdline.c.
996 mtouchusb.raw_coordinates=
997 [HW] Make the MicroTouch USB driver use raw coordinates
998 ('y', default) or cooked coordinates ('n')
1000 n2= [NET] SDL Inc. RISCom/N2 synchronous serial card
1003 See header of drivers/scsi/NCR_D700.c.
1007 ncr53c400= [HW,SCSI]
1009 ncr53c400a= [HW,SCSI]
1011 ncr53c406a= [HW,SCSI]
1013 ncr53c8xx= [HW,SCSI]
1015 netdev= [NET] Network devices parameters
1016 Format: <irq>,<io>,<mem_start>,<mem_end>,<name>
1017 Note that mem_start is often overloaded to mean
1018 something different and driver-specific.
1019 This usage is only documented in each driver source
1023 See Documentation/nfsroot.txt.
1025 nfsroot= [NFS] nfs root filesystem for disk-less boxes.
1026 See Documentation/nfsroot.txt.
1028 nfs.callback_tcpport=
1029 [NFS] set the TCP port on which the NFSv4 callback
1030 channel should listen.
1032 nfs.idmap_cache_timeout=
1033 [NFS] set the maximum lifetime for idmapper cache
1036 nmi_watchdog= [KNL,BUGS=IA-32] Debugging features for SMP kernels
1038 no387 [BUGS=IA-32] Tells the kernel to use the 387 maths
1039 emulation library even if a 387 maths coprocessor
1042 noacpi [LIBATA] Disables use of ACPI in libata suspend/resume
1046 noaliencache [MM, NUMA] Disables the allcoation of alien caches in
1047 the slab allocator. Saves per-node memory, but will
1048 impact performance on real NUMA hardware.
1052 noapic [SMP,APIC] Tells the kernel to not make use of any
1053 IOAPICs that may be present in the system.
1055 noasync [HW,M68K] Disables async and sync negotiation for
1058 nobats [PPC] Do not use BATs for mapping kernel lowmem
1059 on "Classic" PPC cores.
1063 nodelayacct [KNL] Disable per-task delay accounting
1065 nodisconnect [HW,SCSI,M68K] Disables SCSI disconnects.
1069 noexec [IA-32,X86-64]
1070 noexec=on: enable non-executable mappings (default)
1071 noexec=off: disable nn-executable mappings
1073 nofxsr [BUGS=IA-32] Disables x86 floating point extended
1074 register save and restore. The kernel will only save
1075 legacy floating-point registers on task switch.
1079 no-hlt [BUGS=IA-32] Tells the kernel that the hlt
1080 instruction doesn't work correctly and not to
1083 nohalt [IA-64] Tells the kernel not to use the power saving
1084 function PAL_HALT_LIGHT when idle. This increases
1085 power-consumption. On the positive side, it reduces
1086 interrupt wake-up latency, which may improve performance
1087 in certain environments such as networked servers or
1090 nohz= [KNL] Boottime enable/disable dynamic ticks
1091 Valid arguments: on, off
1094 noirqbalance [IA-32,SMP,KNL] Disable kernel irq balancing
1096 noirqdebug [IA-32] Disables the code which attempts to detect and
1097 disable unhandled interrupt sources.
1099 no_timer_check [IA-32,X86_64,APIC] Disables the code which tests for
1100 broken timer IRQ sources.
1102 noisapnp [ISAPNP] Disables ISA PnP code.
1104 noinitrd [RAM] Tells the kernel not to load any configured
1109 nolapic [IA-32,APIC] Do not enable or use the local APIC.
1111 noltlbs [PPC] Do not use large page/tlb entries for kernel
1112 lowmem mapping on PPC40x.
1114 nomca [IA-64] Disable machine check abort handling
1116 nomce [IA-32] Machine Check Exception
1118 noresidual [PPC] Don't use residual data on PReP machines.
1120 noresume [SWSUSP] Disables resume and restores original swap
1123 no-scroll [VGA] Disables scrollback.
1124 This is required for the Braillex ib80-piezo Braille
1125 reader made by F.H. Papenmeier (Germany).
1129 nosep [BUGS=IA-32] Disables x86 SYSENTER/SYSEXIT support.
1131 nosmp [SMP] Tells an SMP kernel to act as a UP kernel.
1133 nosync [HW,M68K] Disables sync negotiation for all devices.
1135 notsc [BUGS=IA-32] Disable Time Stamp Counter
1137 nousb [USB] Disable the USB subsystem
1141 nr_uarts= [SERIAL] maximum number of UARTs to be registered.
1146 opl3sa2= [HW,OSS] Format:
1147 <io>,<irq>,<dma>,<dma2>,<mss_io>,<mpu_io>,<ymode>,<loopback>[,<isapnp>,<multiple]
1149 oprofile.timer= [HW]
1150 Use timer interrupt instead of performance counters
1155 osst= [HW,SCSI] SCSI Tape Driver
1156 Format: <buffer_size>,<write_threshold>
1157 See also Documentation/scsi/st.txt.
1159 panic= [KNL] Kernel behaviour on panic
1162 parkbd.port= [HW] Parallel port number the keyboard adapter is
1163 connected to, default is 0.
1165 parkbd.mode= [HW] Parallel port keyboard adapter mode of operation,
1166 0 for XT, 1 for AT (default is AT).
1169 parport= [HW,PPT] Specify parallel ports. 0 disables.
1170 Format: { 0 | auto | 0xBBB[,IRQ[,DMA]] }
1171 Use 'auto' to force the driver to use any
1172 IRQ/DMA settings detected (the default is to
1173 ignore detected IRQ/DMA settings because of
1174 possible conflicts). You can specify the base
1175 address, IRQ, and DMA settings; IRQ and DMA
1176 should be numbers, or 'auto' (for using detected
1177 settings on that particular port), or 'nofifo'
1178 (to avoid using a FIFO even if it is detected).
1179 Parallel ports are assigned in the order they
1180 are specified on the command line, starting
1183 parport_init_mode= [HW,PPT]
1184 Configure VIA parallel port to operate in
1185 a specific mode. This is necessary on Pegasos
1186 computer where firmware has no options for setting
1187 up parallel port mode and sets it to spp.
1188 Currently this function knows 686a and 8231 chips.
1189 Format: [spp|ps2|epp|ecp|ecpepp]
1191 pas2= [HW,OSS] Format:
1192 <io>,<irq>,<dma>,<dma16>,<sb_io>,<sb_irq>,<sb_dma>,<sb_dma16>
1195 See header of drivers/scsi/pas16.c.
1198 Halt all CPUs after the first oops has been printed for
1199 the specified number of seconds. This is to be used if
1200 your oopses keep scrolling off the screen.
1205 See header of drivers/block/paride/pcd.c.
1206 See also Documentation/paride.txt.
1208 pci=option[,option...] [PCI] various PCI subsystem options:
1209 off [IA-32] don't probe for the PCI bus
1210 bios [IA-32] force use of PCI BIOS, don't access
1211 the hardware directly. Use this if your machine
1212 has a non-standard PCI host bridge.
1213 nobios [IA-32] disallow use of PCI BIOS, only direct
1214 hardware access methods are allowed. Use this
1215 if you experience crashes upon bootup and you
1216 suspect they are caused by the BIOS.
1217 conf1 [IA-32] Force use of PCI Configuration
1219 conf2 [IA-32] Force use of PCI Configuration
1221 nommconf [IA-32,X86_64] Disable use of MMCONFIG for PCI
1223 nomsi [MSI] If the PCI_MSI kernel config parameter is
1224 enabled, this kernel boot option can be used to
1225 disable the use of MSI interrupts system-wide.
1226 nosort [IA-32] Don't sort PCI devices according to
1227 order given by the PCI BIOS. This sorting is
1228 done to get a device order compatible with
1230 biosirq [IA-32] Use PCI BIOS calls to get the interrupt
1231 routing table. These calls are known to be buggy
1232 on several machines and they hang the machine
1233 when used, but on other computers it's the only
1234 way to get the interrupt routing table. Try
1235 this option if the kernel is unable to allocate
1236 IRQs or discover secondary PCI buses on your
1238 rom [IA-32] Assign address space to expansion ROMs.
1239 Use with caution as certain devices share
1240 address decoders between ROMs and other
1242 irqmask=0xMMMM [IA-32] Set a bit mask of IRQs allowed to be
1243 assigned automatically to PCI devices. You can
1244 make the kernel exclude IRQs of your ISA cards
1246 pirqaddr=0xAAAAA [IA-32] Specify the physical address
1247 of the PIRQ table (normally generated
1248 by the BIOS) if it is outside the
1249 F0000h-100000h range.
1250 lastbus=N [IA-32] Scan all buses thru bus #N. Can be
1251 useful if the kernel is unable to find your
1252 secondary buses and you want to tell it
1253 explicitly which ones they are.
1254 assign-busses [IA-32] Always assign all PCI bus
1255 numbers ourselves, overriding
1256 whatever the firmware may have done.
1257 usepirqmask [IA-32] Honor the possible IRQ mask stored
1258 in the BIOS $PIR table. This is needed on
1259 some systems with broken BIOSes, notably
1260 some HP Pavilion N5400 and Omnibook XE3
1261 notebooks. This will have no effect if ACPI
1262 IRQ routing is enabled.
1263 noacpi [IA-32] Do not use ACPI for IRQ routing
1264 or for PCI scanning.
1265 routeirq Do IRQ routing for all PCI devices.
1266 This is normally done in pci_enable_device(),
1267 so this option is a temporary workaround
1268 for broken drivers that don't call it.
1269 firmware [ARM] Do not re-enumerate the bus but instead
1270 just use the configuration from the
1271 bootloader. This is currently used on
1272 IXP2000 systems where the bus has to be
1273 configured a certain way for adjunct CPUs.
1274 noearly [X86] Don't do any early type 1 scanning.
1275 This might help on some broken boards which
1276 machine check when some devices' config space
1277 is read. But various workarounds are disabled
1278 and some IOMMU drivers will not work.
1279 bfsort Sort PCI devices into breadth-first order.
1280 This sorting is done to get a device
1281 order compatible with older (<= 2.4) kernels.
1282 nobfsort Don't sort PCI devices into breadth-first order.
1283 cbiosize=nn[KMG] The fixed amount of bus space which is
1284 reserved for the CardBus bridge's IO window.
1285 The default value is 256 bytes.
1286 cbmemsize=nn[KMG] The fixed amount of bus space which is
1287 reserved for the CardBus bridge's memory
1288 window. The default value is 64 megabytes.
1290 pcmv= [HW,PCMCIA] BadgePAD 4
1293 See Documentation/paride.txt.
1295 pdcchassis= [PARISC,HW] Disable/Enable PDC Chassis Status codes at
1298 See arch/parisc/kernel/pdc_chassis.c
1301 See Documentation/paride.txt.
1304 See Documentation/paride.txt.
1306 pirq= [SMP,APIC] Manual mp-table setup
1307 See Documentation/i386/IO-APIC.txt.
1309 plip= [PPT,NET] Parallel port network link
1310 Format: { parport<nr> | timid | 0 }
1311 See also Documentation/parport.txt.
1317 { on | off | curr | res | no-curr | no-res }
1320 [ISAPNP] Exclude IRQs for the autoconfiguration
1323 [ISAPNP] Exclude DMAs for the autoconfiguration
1325 pnp_reserve_io= [ISAPNP] Exclude I/O ports for the autoconfiguration
1326 Ranges are in pairs (I/O port base and size).
1329 [ISAPNP] Exclude memory regions for the
1331 Ranges are in pairs (memory base and size).
1333 profile= [KNL] Enable kernel profiling via /proc/profile
1334 Format: [schedule,]<number>
1335 Param: "schedule" - profile schedule points.
1336 Param: <number> - step/bucket size as a power of 2 for
1337 statistical time based profiling.
1338 Param: "sleep" - profile D-state sleeping (millisecs)
1340 processor.max_cstate= [HW,ACPI]
1341 Limit processor to maximum C-state
1342 max_cstate=9 overrides any DMI blacklist limit.
1344 processor.nocst [HW,ACPI]
1345 Ignore the _CST method to determine C-states,
1346 instead using the legacy FADT method
1348 prompt_ramdisk= [RAM] List of RAM disks to prompt for floppy disk
1350 See Documentation/ramdisk.txt.
1352 psmouse.proto= [HW,MOUSE] Highest PS2 mouse protocol extension to
1353 probe for; one of (bare|imps|exps|lifebook|any).
1354 psmouse.rate= [HW,MOUSE] Set desired mouse report rate, in reports
1356 psmouse.resetafter= [HW,MOUSE]
1357 Try to reset the device after so many bad packets
1360 [HW,MOUSE] Set desired mouse resolution, in dpi.
1361 psmouse.smartscroll=
1362 [HW,MOUSE] Controls Logitech smartscroll autorepeat.
1363 0 = disabled, 1 = enabled (default).
1365 pss= [HW,OSS] Personal Sound System (ECHO ESC614)
1367 <io>,<mss_io>,<mss_irq>,<mss_dma>,<mpu_io>,<mpu_irq>
1370 See Documentation/paride.txt.
1372 quiet [KNL] Disable most log messages
1377 See Documentation/md.txt.
1379 ramdisk= [RAM] Sizes of RAM disks in kilobytes [deprecated]
1380 See Documentation/ramdisk.txt.
1382 ramdisk_blocksize= [RAM]
1383 See Documentation/ramdisk.txt.
1385 ramdisk_size= [RAM] Sizes of RAM disks in kilobytes
1386 New name for the ramdisk parameter.
1387 See Documentation/ramdisk.txt.
1389 rcu.blimit= [KNL,BOOT] Set maximum number of finished
1390 RCU callbacks to process in one batch.
1392 rcu.qhimark= [KNL,BOOT] Set threshold of queued
1393 RCU callbacks over which batch limiting is disabled.
1395 rcu.qlowmark= [KNL,BOOT] Set threshold of queued
1396 RCU callbacks below which batch limiting is re-enabled.
1400 Run specified binary instead of /init from the ramdisk,
1401 used for early userspace startup. See initrd.
1403 reboot= [BUGS=IA-32,BUGS=ARM,BUGS=IA-64] Rebooting mode
1404 Format: <reboot_mode>[,<reboot_mode2>[,...]]
1405 See arch/*/kernel/reboot.c or arch/*/kernel/process.c
1407 reserve= [KNL,BUGS] Force the kernel to ignore some iomem area
1411 Reserves a hole at the top of the kernel virtual
1414 reset_devices [KNL] Force drivers to reset the underlying device
1415 during initialization.
1418 Specify the partition device for software suspend
1420 resume_offset= [SWSUSP]
1421 Specify the offset from the beginning of the partition
1422 given by "resume=" at which the swap header is located,
1423 in <PAGE_SIZE> units (needed only for swap files).
1424 See Documentation/power/swsusp-and-swap-files.txt
1426 retain_initrd [RAM] Keep initrd memory after extraction
1428 rhash_entries= [KNL,NET]
1429 Set number of hash buckets for route cache
1431 riscom8= [HW,SERIAL]
1432 Format: <io_board1>[,<io_board2>[,...<io_boardN>]]
1434 ro [KNL] Mount root device read-only on boot
1436 root= [KNL] Root filesystem
1438 rootdelay= [KNL] Delay (in seconds) to pause before attempting to
1439 mount the root filesystem
1441 rootflags= [KNL] Set root filesystem mount option string
1443 rootfstype= [KNL] Set root filesystem type
1445 rw [KNL] Mount root device read-write on boot
1447 S [KNL] Run init in single mode
1450 See drivers/net/irda/sa1100_ir.c.
1453 Format: <io>,<irq>,<dma>,<dma2>
1455 sbni= [NET] Granch SBNI12 leased line adapter
1457 sbpcd= [HW,CD] Soundblaster CD adapter
1459 See a comment before function sbpcd_setup() in
1460 drivers/cdrom/sbpcd.c.
1462 sc1200wdt= [HW,WDT] SC1200 WDT (watchdog) driver
1463 Format: <io>[,<timeout>[,<isapnp>]]
1465 scsi_debug_*= [SCSI]
1466 See drivers/scsi/scsi_debug.c.
1468 scsi_default_dev_flags=
1469 [SCSI] SCSI default device flags
1472 scsi_dev_flags= [SCSI] Black/white list entry for vendor and model
1473 Format: <vendor>:<model>:<flags>
1474 (flags are integer value)
1476 scsi_logging= [SCSI]
1478 scsi_mod.scan= [SCSI] sync (default) scans SCSI busses as they are
1479 discovered. async scans them in kernel threads,
1480 allowing boot to proceed. none ignores them, expecting
1481 user space to do the scan.
1483 selinux [SELINUX] Disable or enable SELinux at boot time.
1484 Format: { "0" | "1" }
1485 See security/selinux/Kconfig help text.
1488 Default value is set via kernel config option.
1489 If enabled at boot time, /selinux/disable can be used
1490 later to disable prior to initial policy load.
1492 selinux_compat_net =
1493 [SELINUX] Set initial selinux_compat_net flag value.
1494 Format: { "0" | "1" }
1495 0 -- use new secmark-based packet controls
1496 1 -- use legacy packet controls
1497 Default value is 0 (preferred).
1498 Value can be changed at runtime via
1499 /selinux/compat_net.
1501 serialnumber [BUGS=IA-32]
1503 sg_def_reserved_size= [SCSI]
1506 Maximal number of shapers.
1509 See header of drivers/scsi/sim710.c.
1515 Format: <io>,<irq>,<dma>
1516 See header of drivers/cdrom/sjcd.c.
1521 Format: <io1>[,<io2>[,...,<io8>]]
1523 snd-ad1816a= [HW,ALSA]
1525 snd-ad1848= [HW,ALSA]
1527 snd-ali5451= [HW,ALSA]
1529 snd-als100= [HW,ALSA]
1531 snd-als4000= [HW,ALSA]
1533 snd-azt2320= [HW,ALSA]
1535 snd-cmi8330= [HW,ALSA]
1537 snd-cmipci= [HW,ALSA]
1539 snd-cs4231= [HW,ALSA]
1541 snd-cs4232= [HW,ALSA]
1543 snd-cs4236= [HW,ALSA]
1545 snd-cs4281= [HW,ALSA]
1547 snd-cs46xx= [HW,ALSA]
1549 snd-dt019x= [HW,ALSA]
1551 snd-dummy= [HW,ALSA]
1553 snd-emu10k1= [HW,ALSA]
1555 snd-ens1370= [HW,ALSA]
1557 snd-ens1371= [HW,ALSA]
1559 snd-es968= [HW,ALSA]
1561 snd-es1688= [HW,ALSA]
1563 snd-es18xx= [HW,ALSA]
1565 snd-es1938= [HW,ALSA]
1567 snd-es1968= [HW,ALSA]
1569 snd-fm801= [HW,ALSA]
1571 snd-gusclassic= [HW,ALSA]
1573 snd-gusextreme= [HW,ALSA]
1575 snd-gusmax= [HW,ALSA]
1579 snd-ice1712= [HW,ALSA]
1581 snd-intel8x0= [HW,ALSA]
1583 snd-interwave= [HW,ALSA]
1588 snd-korg1212= [HW,ALSA]
1590 snd-maestro3= [HW,ALSA]
1592 snd-mpu401= [HW,ALSA]
1594 snd-mtpav= [HW,ALSA]
1596 snd-nm256= [HW,ALSA]
1598 snd-opl3sa2= [HW,ALSA]
1606 snd-opti93x= [HW,ALSA]
1610 snd-rme32= [HW,ALSA]
1612 snd-rme96= [HW,ALSA]
1614 snd-rme9652= [HW,ALSA]
1620 snd-sbawe= [HW,ALSA]
1622 snd-serial= [HW,ALSA]
1624 snd-sgalaxy= [HW,ALSA]
1626 snd-sonicvibes= [HW,ALSA]
1631 snd-sun-cs4231= [HW,ALSA]
1633 snd-trident= [HW,ALSA]
1635 snd-usb-audio= [HW,ALSA,USB]
1637 snd-via82xx= [HW,ALSA]
1639 snd-virmidi= [HW,ALSA]
1641 snd-wavefront= [HW,ALSA]
1643 snd-ymfpci= [HW,ALSA]
1646 Format: <io>[,<irq>]
1648 sonypi.*= [HW] Sony Programmable I/O Control Device driver
1649 See Documentation/sonypi.txt
1651 specialix= [HW,SERIAL] Specialix multi-serial port adapter
1652 See Documentation/specialix.txt.
1654 spia_io_base= [HW,MTD]
1660 Format: <io>,<irq>,<dma>,<mpu_io>,<mpu_irq>
1662 st= [HW,SCSI] SCSI tape parameters (buffers, etc.)
1663 See Documentation/scsi/st.txt.
1666 See header of drivers/scsi/seagate.c.
1670 Set the STI (builtin display/keyboard on the HP-PARISC
1671 machines) console (graphic card) which should be used
1672 as the initial boot-console.
1673 See also comment in drivers/video/console/sticore.c.
1676 See comment in drivers/video/console/sticore.c.
1679 Format: bpp:<bpp1>[:<bpp2>[:<bpp3>...]]
1681 swiotlb= [IA-64] Number of I/O TLB slabs
1685 sym53c416= [HW,SCSI]
1686 See header of drivers/scsi/sym53c416.c.
1688 sysrq_always_enabled
1690 Ignore sysrq setting - this boot parameter will
1691 neutralize any effect of /proc/sys/kernel/sysrq.
1692 Useful for debugging.
1695 See header of drivers/scsi/t128.c.
1699 thash_entries= [KNL,NET]
1700 Set number of hash buckets for TCP connection
1702 time Show timing data prefixed to each printk message line
1704 clocksource= [GENERIC_TIME] Override the default clocksource
1705 Override the default clocksource and use the clocksource
1706 with the name specified.
1708 tipar.timeout= [HW,PPT]
1709 Set communications timeout in tenths of a second
1712 tipar.delay= [HW,PPT]
1713 Set inter-bit delay in microseconds (default 10).
1716 See header of drivers/scsi/seagate.c.
1719 See comment before function dc390_setup() in
1720 drivers/scsi/tmscsim.c.
1724 trix= [HW,OSS] MediaTrix AudioTrix Pro
1726 <io>,<irq>,<dma>,<dma2>,<sb_io>,<sb_irq>,<sb_dma>,<mpu_io>,<mpu_irq>
1728 tsdev.xres= [TS] Horizontal screen resolution.
1729 tsdev.yres= [TS] Vertical screen resolution.
1731 turbografx.map[2|3]= [HW,JOY]
1732 TurboGraFX parallel port interface
1734 <port#>,<js1>,<js2>,<js3>,<js4>,<js5>,<js6>,<js7>
1735 See also Documentation/input/joystick-parport.txt
1737 u14-34f= [HW,SCSI] UltraStor 14F/34F SCSI host adapter
1738 See header of drivers/scsi/u14-34f.c.
1747 [USB] Ignore overcurrent events (default N).
1748 Some badly-designed motherboards generate lots of
1749 bogus events, for ports that aren't wired to
1750 anything. Set this parameter to avoid log spamming.
1751 Note that genuine overcurrent events won't be
1755 [USBHID] The interval which mice are to be polled at.
1758 vdso=1: enable VDSO (default)
1759 vdso=0: disable VDSO mapping
1761 video= [FB] Frame buffer configuration
1762 See Documentation/fb/modedb.txt.
1764 vga= [BOOT,IA-32] Select a particular video mode
1765 See Documentation/i386/boot.txt and
1766 Documentation/svga.txt.
1767 Use vga=ask for menu.
1768 This is actually a boot loader parameter; the value is
1769 passed to the kernel using a special protocol.
1771 vmalloc=nn[KMG] [KNL,BOOT] Forces the vmalloc area to have an exact
1772 size of <nn>. This can be used to increase the
1773 minimum size (128MB on x86). It can also be used to
1774 decrease the size and leave more room for directly
1777 vmhalt= [KNL,S390] Perform z/VM CP command after system halt.
1780 vmpanic= [KNL,S390] Perform z/VM CP command after kernel panic.
1783 vmpoff= [KNL,S390] Perform z/VM CP command after power off.
1786 waveartist= [HW,OSS]
1787 Format: <io>,<irq>,<dma>,<dma2>
1790 See header of drivers/scsi/wd33c93.c.
1793 See header of drivers/scsi/wd7000.c.
1796 See Documentation/watchdog/watchdog.txt.
1798 xd= [HW,XT] Original XT pre-IDE (RLL encoded) disks.
1799 xd_geo= See header of drivers/block/xd.c.
1801 xirc2ps_cs= [NET,PCMCIA]
1803 <irq>,<irq_mask>,<io>,<full_duplex>,<do_sound>,<lockup_hack>[,<irq2>[,<irq3>[,<irq4>]]]
1805 norandmaps Don't use address space randomization
1806 Equivalent to echo 0 > /proc/sys/kernel/randomize_va_space
1808 unwind_debug=N N > 0 will enable dwarf2 unwinder debugging
1809 This is useful to get more information why
1810 you got a "dwarf2 unwinder stuck"
1812 ______________________________________________________________________
1816 Add documentation for ALSA options.
1817 Add more DRM drivers.