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
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 There are also arch-specific kernel-parameters not documented here.
108 See for example <Documentation/x86_64/boot-options.txt>.
110 Note that ALL kernel parameters listed below are CASE SENSITIVE, and that
111 a trailing = on the name of any parameter states that that parameter will
112 be entered as an environment variable, whereas its absence indicates that
113 it will appear as a kernel argument readable via /proc/cmdline by programs
114 running once the system is up.
116 The number of kernel parameters is not limited, but the length of the
117 complete command line (parameters including spaces etc.) is limited to
118 a fixed number of characters. This limit depends on the architecture
119 and is between 256 and 4096 characters. It is defined in the file
120 ./include/asm/setup.h as COMMAND_LINE_SIZE.
123 53c7xx= [HW,SCSI] Amiga SCSI controllers
124 See header of drivers/scsi/53c7xx.c.
125 See also Documentation/scsi/ncr53c7xx.txt.
127 acpi= [HW,ACPI] Advanced Configuration and Power Interface
128 Format: { force | off | ht | strict | noirq }
129 force -- enable ACPI if default was off
130 off -- disable ACPI if default was on
131 noirq -- do not use ACPI for IRQ routing
132 ht -- run only enough ACPI to enable Hyper Threading
133 strict -- Be less tolerant of platforms that are not
134 strictly ACPI specification compliant.
136 See also Documentation/pm.txt, pci=noacpi
138 acpi_sleep= [HW,ACPI] Sleep options
139 Format: { s3_bios, s3_mode }
140 See Documentation/power/video.txt
142 acpi_sci= [HW,ACPI] ACPI System Control Interrupt trigger mode
143 Format: { level | edge | high | low }
145 acpi_irq_balance [HW,ACPI]
146 ACPI will balance active IRQs
149 acpi_irq_nobalance [HW,ACPI]
150 ACPI will not move active IRQs (default)
153 acpi_irq_pci= [HW,ACPI] If irq_balance, clear listed IRQs for
155 Format: <irq>,<irq>...
157 acpi_irq_isa= [HW,ACPI] If irq_balance, mark listed IRQs used by ISA
158 Format: <irq>,<irq>...
160 acpi_os_name= [HW,ACPI] Tell ACPI BIOS the name of the OS
161 Format: To spoof as Windows 98: ="Microsoft Windows"
163 acpi_osi= [HW,ACPI] empty param disables _OSI
165 acpi_serialize [HW,ACPI] force serialization of AML methods
167 acpi_skip_timer_override [HW,ACPI]
168 Recognize and ignore IRQ0/pin2 Interrupt Override.
169 For broken nForce2 BIOS resulting in XT-PIC timer.
170 acpi_use_timer_override [HW,ACPI}
171 Use timer override. For some broken Nvidia NF5 boards
172 that require a timer override, but don't have
175 acpi_dbg_layer= [HW,ACPI]
177 Each bit of the <int> indicates an ACPI debug layer,
178 1: enable, 0: disable. It is useful for boot time
179 debugging. After system has booted up, it can be set
180 via /proc/acpi/debug_layer.
182 acpi_dbg_level= [HW,ACPI]
184 Each bit of the <int> indicates an ACPI debug level,
185 1: enable, 0: disable. It is useful for boot time
186 debugging. After system has booted up, it can be set
187 via /proc/acpi/debug_level.
189 acpi_fake_ecdt [HW,ACPI] Workaround failure due to BIOS lacking ECDT
191 acpi_generic_hotkey [HW,ACPI]
192 Allow consolidated generic hotkey driver to
193 override platform specific driver.
194 See also Documentation/acpi-hotkey.txt.
196 acpi_pm_good [IA-32,X86-64]
197 Override the pmtimer bug detection: force the kernel
198 to assume that this machine's pmtimer latches its value
199 and always returns good values.
201 enable_timer_pin_1 [i386,x86-64]
202 Enable PIN 1 of APIC timer
203 Can be useful to work around chipset bugs
204 (in particular on some ATI chipsets).
205 The kernel tries to set a reasonable default.
207 disable_timer_pin_1 [i386,x86-64]
208 Disable PIN 1 of APIC timer
209 Can be useful to work around chipset bugs.
212 Format: <io>,<irq>,<dma>,<dma2>
213 See also Documentation/sound/oss/AD1816.
216 Format: <io>,<irq>,<dma>,<dma2>,<type>
222 See header of drivers/scsi/advansys.c.
224 advwdt= [HW,WDT] Advantech WDT
225 Format: <iostart>,<iostop>
227 aedsp16= [HW,OSS] Audio Excel DSP 16
228 Format: <io>,<irq>,<dma>,<mss_io>,<mpu_io>,<mpu_irq>
229 See also header of sound/oss/aedsp16.c.
232 See Documentation/scsi/aha152x.txt.
235 Format: <portbase>[,<buson>,<busoff>[,<dmaspeed>]]
238 See Documentation/scsi/aic7xxx.txt.
241 See Documentation/scsi/aic79xx.txt.
243 amijoy.map= [HW,JOY] Amiga joystick support
244 Map of devices attached to JOY0DAT and JOY1DAT
246 See also Documentation/kernel/input/joystick.txt
248 analog.map= [HW,JOY] Analog joystick and gamepad support
249 Specifies type or capabilities of an analog joystick
250 connected to one of 16 gameports
251 Format: <type1>,<type2>,..<type16>
254 Power management functions (SPARCstation-4/5 + deriv.)
256 Disable APC CPU standby support. SPARCstation-Fox does
257 not play well with APC CPU idle - disable it if you have
258 APC and your system crashes randomly.
260 apic= [APIC,i386] Change the output verbosity whilst booting
261 Format: { quiet (default) | verbose | debug }
262 Change the amount of debugging information output
263 when initialising the APIC and IO-APIC components.
265 apm= [APM] Advanced Power Management
266 See header of arch/i386/kernel/apm.c.
271 arcrimi= [HW,NET] ARCnet - "RIM I" (entirely mem-mapped) cards
272 Format: <io>,<irq>,<nodeID>
276 atarimouse= [HW,MOUSE] Atari Mouse
278 atascsi= [HW,SCSI] Atari SCSI
280 atkbd.extra= [HW] Enable extra LEDs and keys on IBM RapidAccess,
281 EzKey and similar keyboards
283 atkbd.reset= [HW] Reset keyboard during initialization
285 atkbd.set= [HW] Select keyboard code set
286 Format: <int> (2 = AT (default), 3 = PS/2)
288 atkbd.scroll= [HW] Enable scroll wheel on MS Office and similar
291 atkbd.softraw= [HW] Choose between synthetic and real raw mode
292 Format: <bool> (0 = real, 1 = synthetic (default))
294 atkbd.softrepeat= [HW]
295 Use software keyboard repeat
299 aztcd= [HW,CD] Aztech CD268 CDROM driver
300 Format: <io>,0x79 (?)
302 baycom_epp= [HW,AX25]
305 baycom_par= [HW,AX25] BayCom Parallel Port AX.25 Modem
307 See header of drivers/net/hamradio/baycom_par.c.
309 baycom_ser_fdx= [HW,AX25]
310 BayCom Serial Port AX.25 Modem (Full Duplex Mode)
311 Format: <io>,<irq>,<mode>[,<baud>]
312 See header of drivers/net/hamradio/baycom_ser_fdx.c.
314 baycom_ser_hdx= [HW,AX25]
315 BayCom Serial Port AX.25 Modem (Half Duplex Mode)
316 Format: <io>,<irq>,<mode>
317 See header of drivers/net/hamradio/baycom_ser_hdx.c.
319 blkmtd_device= [HW,MTD]
325 bttv.card= [HW,V4L] bttv (bt848 + bt878 based grabber cards)
326 bttv.radio= Most important insmod options are available as
328 bttv.pll= See Documentation/video4linux/bttv/Insmod-options
329 bttv.tuner= and Documentation/video4linux/bttv/CARDLIST
332 See drivers/scsi/BusLogic.c, comment before function
333 BusLogic_ParseDriverOptions().
335 c101= [NET] Moxa C101 synchronous serial card
337 cachesize= [BUGS=IA-32] Override level 2 CPU cache size detection.
338 Sometimes CPU hardware bugs make them report the cache
339 size incorrectly. The kernel will attempt work arounds
340 to fix known problems, but for some CPUs it is not
341 possible to determine what the correct size should be.
342 This option provides an override for these situations.
345 Format: <io>,<irq>[,PAS]
346 See header of drivers/cdrom/cdu31a.c.
348 chandev= [HW,NET] Generic channel device initialisation
350 checkreqprot [SELINUX] Set initial checkreqprot flag value.
351 Format: { "0" | "1" }
352 See security/selinux/Kconfig help text.
353 0 -- check protection applied by kernel (includes
354 any implied execute protection).
355 1 -- check protection requested by application.
356 Default value is set via a kernel config option.
357 Value can be changed at runtime via
358 /selinux/checkreqprot.
360 clock= [BUGS=IA-32, HW] gettimeofday clocksource override.
362 Forces specified clocksource (if available) to be used
363 when calculating gettimeofday(). If specified
364 clocksource is not available, it defaults to PIT.
365 Format: { pit | tsc | cyclone | pmtmr }
367 code_bytes [IA32] How many bytes of object code to print in an
374 [IA32/X86_64] Disable/Enable interrupt 0 timer routing
375 over the 8254 in addition to over the IO-APIC. The
376 kernel tries to set a sensible default.
378 hpet= [IA-32,HPET] option to disable HPET and use PIT.
382 Format: { auto | [<io>,][<irq>] }
384 com20020= [HW,NET] ARCnet - COM20020 chipset
386 <io>[,<irq>[,<nodeID>[,<backplane>[,<ckp>[,<timeout>]]]]]
388 com90io= [HW,NET] ARCnet - COM90xx chipset (IO-mapped buffers)
392 ARCnet - COM90xx chipset (memory-mapped buffers)
393 Format: <io>[,<irq>[,<memstart>]]
395 condev= [HW,S390] console device
398 console= [KNL] Output console device and options.
400 tty<n> Use the virtual console device <n>.
404 Use the specified serial port. The options are of
405 the form "bbbbpnf", where "bbbb" is the baud rate,
406 "p" is parity ("n", "o", or "e"), "n" is number of
407 bits, and "f" is flow control ("r" for RTS or
408 omit it). Default is "9600n8".
410 See Documentation/serial-console.txt for more
412 Documentation/networking/netconsole.txt for an
415 uart,io,<addr>[,options]
416 uart,mmio,<addr>[,options]
417 Start an early, polled-mode console on the 8250/16550
418 UART at the specified I/O port or MMIO address,
419 switching to the matching ttyS device later. The
420 options are the same as for ttyS, above.
422 cpcihp_generic= [HW,PCI] Generic port I/O CompactPCI driver
424 <first_slot>,<last_slot>,<port>,<enum_bit>[,<debug>]
427 Format: { parport<nr> | auto | none }
429 crashkernel=nn[KMG]@ss[KMG]
430 [KNL] Reserve a chunk of physical memory to
431 hold a kernel to switch to with kexec on panic.
434 Format: <io>,<irq>,<dma>,<dma2>,<mpuio>,<mpuirq>
439 cs89x0_media= [HW,NET]
440 Format: { rj45 | aui | bnc }
442 cyclades= [HW,SERIAL] Cyclades multi-serial port adapter.
445 See header of drivers/s390/block/dasd_devmap.c.
447 db9.dev[2|3]= [HW,JOY] Multisystem joystick support via parallel port
448 (one device per port)
449 Format: <port#>,<type>
450 See also Documentation/input/joystick-parport.txt
452 debug [KNL] Enable kernel debugging (events log level).
455 [KNL] verbose self-tests
457 Print debugging info while doing the locking API
459 We default to 0 (no extra messages), setting it to
460 1 will print _a lot_ more information - normally
461 only useful to kernel developers.
464 Format: <area>[,<node>]
465 See also Documentation/networking/decnet.txt.
468 Set number of hash buckets for dentry cache.
471 IO parameters + enable/disable command.
473 digiepca= [HW,SERIAL]
474 See drivers/char/README.epca and
475 Documentation/digiepca.txt.
477 dmascc= [HW,AX25,SERIAL] AX.25 Z80SCC driver with DMA
479 Format: <io_dev0>[,<io_dev1>[,..<io_dev32>]]
481 dmasound= [HW,OSS] Sound subsystem buffers
487 earlyprintk= [IA-32,X86-64]
489 earlyprintk=serial[,ttySn[,baudrate]]
491 Append ",keep" to not disable it when the real console
494 Only vga or serial at a time, not both.
496 Currently only ttyS0 and ttyS1 are supported.
498 Interaction with the standard serial driver is not
501 The VGA output is eventually overwritten by the real
506 ec_intr= [HW,ACPI] ACPI Embedded Controller interrupt mode
509 non-0: interrupt mode (default)
516 Format: {"of[f]" | "sk[ipmbr]"}
517 See comment in arch/i386/boot/edd.S
520 Format: <id>,<membase>,<irq>
522 eisa_irq_edge= [PARISC,HW]
523 See header of drivers/parisc/eisa.c.
526 See comment before function elanfreq_setup() in
527 arch/i386/kernel/cpu/cpufreq/elanfreq.c.
530 Format: {"anticipatory" | "cfq" | "deadline" | "noop"}
531 See Documentation/block/as-iosched.txt and
532 Documentation/block/deadline-iosched.txt for details.
534 elfcorehdr= [IA-32, X86_64]
535 Specifies physical address of start of kernel core
536 image elf header. Generally kexec loader will
537 pass this option to capture kernel.
538 See Documentation/kdump/kdump.txt for details.
540 enforcing [SELINUX] Set initial enforcing status.
542 See security/selinux/Kconfig help text.
543 0 -- permissive (log only, no denials).
544 1 -- enforcing (deny and log).
546 Value can be changed at runtime via /selinux/enforce.
549 Format: <spdif>,[<nomix>,[<amplifier>]]
550 See also header of sound/oss/es1371.c.
552 ether= [HW,NET] Ethernet cards parameters
553 This option is obsoleted by the "netdev=" option, which
554 has equivalent usage. See its documentation for details.
556 eurwdt= [HW,WDT] Eurotech CPU-1220/1410 onboard watchdog.
561 fail_make_request=[KNL]
562 General fault injection mechanism.
563 Format: <interval>,<probability>,<space>,<times>
564 See also /Documentation/fault-injection/.
567 See header of drivers/scsi/fd_mcs.c.
570 See header of drivers/scsi/fdomain.c.
573 See Documentation/floppy.txt.
576 [HW,JOY] Multisystem joystick and NES/SNES/PSX pad
577 support via parallel port (up to 5 devices per port)
578 Format: <port#>,<pad1>,<pad2>,<pad3>,<pad4>,<pad5>
579 See also Documentation/input/joystick-parport.txt
584 See header of drivers/scsi/gdth.c.
586 gpt [EFI] Forces disk with valid GPT signature but
587 invalid Protective MBR to be treated as GPT.
594 hashdist= [KNL,NUMA] Large hashes allocated during boot
595 are distributed across NUMA nodes. Defaults on
596 for IA-64, off otherwise.
597 Format: 0 | 1 (for off | on)
599 hcl= [IA-64] SGI's Hardware Graph compatibility layer
601 hd= [EIDE] (E)IDE hard drive subsystem geometry
602 Format: <cyl>,<head>,<sect>
604 hd?= [HW] (E)IDE subsystem
605 hd?lun= See Documentation/ide.txt.
607 highmem=nn[KMG] [KNL,BOOT] forces the highmem zone to have an exact
608 size of <nn>. This works even on boxes that have no
609 highmem otherwise. This also works to reduce highmem
610 size on bigger boxes.
613 See Documentation/isdn/README.HiSax.
615 hugepages= [HW,IA-32,IA-64] Maximal number of HugeTLB pages.
617 i8042.direct [HW] Put keyboard port into non-translated mode
618 i8042.dumbkbd [HW] Pretend that controller can only read data from
619 keyboard and cannot control its state
620 (Don't attempt to blink the leds)
621 i8042.noaux [HW] Don't check for auxiliary (== mouse) port
622 i8042.nokbd [HW] Don't check/create keyboard port
623 i8042.nomux [HW] Don't check presence of an active multiplexing
625 i8042.nopnp [HW] Don't use ACPIPnP / PnPBIOS to discover KBD/AUX
628 [HW] Frequency with which keyboard LEDs should blink
629 when kernel panics (default is 0.5 sec)
630 i8042.reset [HW] Reset the controller during init and cleanup
631 i8042.unlock [HW] Unlock (ignore) the keylock
635 i8k.ignore_dmi [HW] Continue probing hardware even if DMI data
636 indicates that the driver is running on unsupported
638 i8k.force [HW] Activate i8k driver even if SMM BIOS signature
639 does not match list of supported models.
641 [HW] Report power status in /proc/i8k
642 (disabled by default)
643 i8k.restricted [HW] Allow controlling fans only if SYS_ADMIN
646 ibmmcascsi= [HW,MCA,SCSI] IBM MicroChannel SCSI adapter
647 See Documentation/mca.txt.
650 Format: <io>[,<membase>[,<icn_id>[,<icn_id2>]]]
652 ide= [HW] (E)IDE subsystem
653 Format: ide=nodma or ide=doubler or ide=reverse
654 See Documentation/ide.txt.
656 ide?= [HW] (E)IDE subsystem
657 Format: ide?=noprobe or chipset specific parameters.
658 See Documentation/ide.txt.
660 idebus= [HW] (E)IDE subsystem - VLB/PCI bus speed
661 See Documentation/ide.txt.
664 Format: idle=poll or idle=halt
666 ignore_loglevel [KNL]
667 Ignore loglevel setting - this will print /all/
668 kernel messages to the console. Useful for debugging.
671 Set number of hash buckets for inode cache.
674 See header of drivers/scsi/in2000.c.
678 Run specified binary instead of /sbin/init as init
681 initcall_debug [KNL] Trace initcalls as they are executed. Useful
682 for working out where the kernel is dying during
685 initrd= [BOOT] Specify the location of the initial ramdisk
687 inport.irq= [HW] Inport (ATI XL and Microsoft) busmouse driver
690 combined_mode= [HW] control which driver uses IDE ports in combined
691 mode: legacy IDE driver, libata, or both
692 (in the libata case, libata.atapi_enabled=1 may be
693 useful as well). Note that using the ide or libata
694 options may affect your device naming (e.g. by
695 changing hdc to sdb).
696 Format: combined (default), ide, or libata
700 io7= [HW] IO7 for Marvel based alpha systems
701 See comment before marvel_specify_io7 in
702 arch/alpha/kernel/core_marvel.c.
705 See Documentation/nfsroot.txt.
707 ip2= [HW] Set IO/IRQ pairs for up to 4 IntelliPort boards
708 See comment before ip2_setup() in drivers/char/ip2.c.
710 ips= [HW,SCSI] Adaptec / IBM ServeRAID controller
711 See header of drivers/scsi/ips.c.
713 ports= [IP_VS_FTP] IPVS ftp helper module
715 Up to 8 (IP_VS_APP_MAX_PORTS) ports
717 Format: <port>,<port>....
720 When an interrupt is not handled search all handlers
721 for it. Intended to get systems with badly broken
725 When an interrupt is not handled search all handlers
726 for it. Also check all handlers each timer
727 interrupt. Intended to get systems with badly broken
731 Format: <RDP>,<reset>,<pci_scan>,<verbosity>
733 isolcpus= [KNL,SMP] Isolate CPUs from the general scheduler.
735 <cpu number>,...,<cpu number>
737 <cpu number>-<cpu number> (must be a positive range in ascending order)
739 <cpu number>,...,<cpu number>-<cpu number>
740 This option can be used to specify one or more CPUs
741 to isolate from the general SMP balancing and scheduling
742 algorithms. The only way to move a process onto or off
743 an "isolated" CPU is via the CPU affinity syscalls.
744 <cpu number> begins at 0 and the maximum value is
745 "number of CPUs in system - 1".
747 This option is the preferred way to isolate CPUs. The
748 alternative -- manually setting the CPU mask of all
749 tasks in the system -- can cause problems and
750 suboptimal load balancer performance.
753 Format: <io>,<irq>,<dma>,<setup>
757 js= [HW,JOY] Analog joystick
758 See Documentation/input/joystick.txt.
762 kstack=N [IA-32,X86-64] Print N words from the kernel stack
767 lapic [IA-32,APIC] Enable the local APIC even if BIOS
770 lasi= [HW,SCSI] PARISC LASI driver for the 53c700 chip
771 Format: addr:<io>,irq:<irq>
773 llsc*= [IA64] See function print_params() in
774 arch/ia64/sn/kernel/llsc4.c.
776 load_ramdisk= [RAM] List of ramdisks to load from floppy
777 See Documentation/ramdisk.txt.
779 lockd.nlm_grace_period=P [NFS] Assign grace period.
782 lockd.nlm_tcpport=N [NFS] Assign TCP port.
785 lockd.nlm_timeout=T [NFS] Assign timeout value.
788 lockd.nlm_udpport=M [NFS] Assign UDP port.
791 logibm.irq= [HW,MOUSE] Logitech Bus Mouse Driver
794 loglevel= All Kernel Messages with a loglevel smaller than the
795 console loglevel will be printed to the console. It can
796 also be changed with klogd or other programs. The
797 loglevels are defined as follows:
799 0 (KERN_EMERG) system is unusable
800 1 (KERN_ALERT) action must be taken immediately
801 2 (KERN_CRIT) critical conditions
802 3 (KERN_ERR) error conditions
803 4 (KERN_WARNING) warning conditions
804 5 (KERN_NOTICE) normal but significant condition
805 6 (KERN_INFO) informational
806 7 (KERN_DEBUG) debug-level messages
808 log_buf_len=n Sets the size of the printk ring buffer, in bytes.
809 Format: { n | nk | nM }
810 n must be a power of two. The default size
811 is set in the kernel config file.
813 lp=0 [LP] Specify parallel ports to use, e.g,
814 lp=port[,port...] lp=none,parport0 (lp0 not configured, lp1 uses
815 lp=reset first parallel port). 'lp=0' disables the
816 lp=auto printer driver. 'lp=reset' (which can be
817 specified in addition to the ports) causes
818 attached printers to be reset. Using
819 lp=port1,port2,... specifies the parallel ports
820 to associate lp devices with, starting with
821 lp0. A port specification may be 'none' to skip
822 that lp device, or a parport name such as
823 'parport0'. Specifying 'lp=auto' instead of a
824 port specification list means that device IDs
825 from each port should be examined, to see if
826 an IEEE 1284-compliant printer is attached; if
827 so, the driver will manage that printer.
828 See also header of drivers/char/lp.c.
831 Sets loops_per_jiffy to given constant, thus avoiding
832 time-consuming boot-time autodetection (up to 250 ms per
833 CPU). 0 enables autodetection (default). To determine
834 the correct value for your kernel, boot with normal
835 autodetection and see what value is printed. Note that
836 on SMP systems the preset will be applied to all CPUs,
837 which is likely to cause problems if your CPUs need
838 significantly divergent settings. An incorrect value
839 will cause delays in the kernel to be wrong, leading to
840 unpredictable I/O errors and other breakage. Although
841 unlikely, in the extreme case this might damage your
845 Format: <io>,<irq>,<dma>
847 mac5380= [HW,SCSI] Format:
848 <can_queue>,<cmd_per_lun>,<sg_tablesize>,<hostid>,<use_tags>
850 mac53c9x= [HW,SCSI] Format:
851 <num_esps>,<disconnect>,<nosync>,<can_queue>,<cmd_per_lun>,<sg_tablesize>,<hostid>,<use_tags>
853 machvec= [IA64] Force the use of a particular machine-vector
854 (machvec) in a generic kernel.
855 Example: machvec=hpzx1_swiotlb
857 max_loop= [LOOP] Maximum number of loopback devices that can
861 maxcpus= [SMP] Maximum number of processors that an SMP kernel
864 max_addr=[KMG] [KNL,BOOT,ia64] All physical memory greater than or
865 equal to this physical address is ignored.
867 max_luns= [SCSI] Maximum number of LUNs to probe.
868 Should be between 1 and 2^32-1.
871 [SCSI] Maximum number of LUNs received.
872 Should be between 1 and 16384.
874 mca-pentium [BUGS=IA-32]
879 Format: <port>,<irq>,<mitsumi_bug_93_wait>
883 mce [IA-32] Machine Check Exception
885 md= [HW] RAID subsystems devices and level
886 See Documentation/md.txt.
889 Format: <first>,<last>
890 Specifies range of consoles to be captured by the MDA.
892 mem=nn[KMG] [KNL,BOOT] Force usage of a specific amount of memory
893 Amount of memory to be used when the kernel is not able
894 to see the whole system memory or for test.
895 [IA-32] Use together with memmap= to avoid physical
896 address space collisions. Without memmap= PCI devices
897 could be placed at addresses belonging to unused RAM.
899 mem=nopentium [BUGS=IA-32] Disable usage of 4MB pages for kernel
902 memmap=exactmap [KNL,IA-32,X86_64] Enable setting of an exact
903 E820 memory map, as specified by the user.
904 Such memmap=exactmap lines can be constructed based on
905 BIOS output or other requirements. See the memmap=nn@ss
908 memmap=nn[KMG]@ss[KMG]
909 [KNL] Force usage of a specific region of memory
910 Region of memory to be used, from ss to ss+nn.
912 memmap=nn[KMG]#ss[KMG]
913 [KNL,ACPI] Mark specific memory as ACPI data.
914 Region of memory to be used, from ss to ss+nn.
916 memmap=nn[KMG]$ss[KMG]
917 [KNL,ACPI] Mark specific memory as reserved.
918 Region of memory to be used, from ss to ss+nn.
920 meye.*= [HW] Set MotionEye Camera parameters
921 See Documentation/video4linux/meye.txt.
926 [KNL,SMP] debug: override scheduler migration costs
927 Format: <level-1-usecs>,<level-2-usecs>,...
928 This debugging option can be used to override the
929 default scheduler migration cost matrix. The numbers
930 are indexed by 'CPU domain distance'.
931 E.g. migration_cost=1000,2000,3000 on an SMT NUMA
932 box will set up an intra-core migration cost of
933 1 msec, an inter-core migration cost of 2 msecs,
934 and an inter-node migration cost of 3 msecs.
936 WARNING: using the wrong values here can break
937 scheduler performance, so it's only for scheduler
938 development purposes, not production environments.
941 [KNL,SMP] migration cost auto-detect verbosity
943 If a system's migration matrix reported at bootup
944 seems erroneous then this option can be used to
945 increase verbosity of the detection process.
946 We default to 0 (no extra messages), 1 will print
947 some more information, and 2 will be really
948 verbose (probably only useful if you also have a
949 serial console attached to the system).
952 [KNL,SMP] multiply/divide migration costs by a factor
954 This debug option can be used to proportionally
955 increase or decrease the auto-detected migration
956 costs for all entries of the migration matrix.
957 E.g. migration_factor=150 will increase migration
958 costs by 50%. (and thus the scheduler will be less
959 eager migrating cache-hot tasks)
960 migration_factor=80 will decrease migration costs
961 by 20%. (thus the scheduler will be more eager to
964 WARNING: using the wrong values here can break
965 scheduler performance, so it's only for scheduler
966 development purposes, not production environments.
969 [MOUSE] Maximum time between finger touching and
970 leaving touchpad surface for touch to be considered
971 a tap and be reported as a left button click (for
972 touchpads working in absolute mode only).
974 mousedev.xres= [MOUSE] Horizontal screen resolution, used for devices
975 reporting absolute coordinates, such as tablets
976 mousedev.yres= [MOUSE] Vertical screen resolution, used for devices
977 reporting absolute coordinates, such as tablets
983 Format: <name>,<region-number>,<size>,<offset>
985 MTD_Region= [MTD] Format:
986 <name>,<region-number>[,<base>,<size>,<buswidth>,<altbuswidth>]
989 See drivers/mtd/cmdline.c.
991 mtouchusb.raw_coordinates=
992 [HW] Make the MicroTouch USB driver use raw coordinates
993 ('y', default) or cooked coordinates ('n')
995 n2= [NET] SDL Inc. RISCom/N2 synchronous serial card
998 See header of drivers/scsi/NCR_D700.c.
1002 ncr53c400= [HW,SCSI]
1004 ncr53c400a= [HW,SCSI]
1006 ncr53c406a= [HW,SCSI]
1008 ncr53c8xx= [HW,SCSI]
1010 netdev= [NET] Network devices parameters
1011 Format: <irq>,<io>,<mem_start>,<mem_end>,<name>
1012 Note that mem_start is often overloaded to mean
1013 something different and driver-specific.
1014 This usage is only documented in each driver source
1018 See Documentation/nfsroot.txt.
1020 nfsroot= [NFS] nfs root filesystem for disk-less boxes.
1021 See Documentation/nfsroot.txt.
1023 nfs.callback_tcpport=
1024 [NFS] set the TCP port on which the NFSv4 callback
1025 channel should listen.
1027 nfs.idmap_cache_timeout=
1028 [NFS] set the maximum lifetime for idmapper cache
1031 nmi_watchdog= [KNL,BUGS=IA-32] Debugging features for SMP kernels
1033 no387 [BUGS=IA-32] Tells the kernel to use the 387 maths
1034 emulation library even if a 387 maths coprocessor
1037 noaliencache [MM, NUMA] Disables the allcoation of alien caches in
1038 the slab allocator. Saves per-node memory, but will
1039 impact performance on real NUMA hardware.
1043 noapic [SMP,APIC] Tells the kernel to not make use of any
1044 IOAPICs that may be present in the system.
1046 noasync [HW,M68K] Disables async and sync negotiation for
1049 nobats [PPC] Do not use BATs for mapping kernel lowmem
1050 on "Classic" PPC cores.
1054 nodelayacct [KNL] Disable per-task delay accounting
1056 nodisconnect [HW,SCSI,M68K] Disables SCSI disconnects.
1060 noexec [IA-32,X86-64]
1061 noexec=on: enable non-executable mappings (default)
1062 noexec=off: disable nn-executable mappings
1064 nofxsr [BUGS=IA-32] Disables x86 floating point extended
1065 register save and restore. The kernel will only save
1066 legacy floating-point registers on task switch.
1070 no-hlt [BUGS=IA-32] Tells the kernel that the hlt
1071 instruction doesn't work correctly and not to
1074 nohalt [IA-64] Tells the kernel not to use the power saving
1075 function PAL_HALT_LIGHT when idle. This increases
1076 power-consumption. On the positive side, it reduces
1077 interrupt wake-up latency, which may improve performance
1078 in certain environments such as networked servers or
1081 nohz= [KNL] Boottime enable/disable dynamic ticks
1082 Valid arguments: on, off
1085 noirqbalance [IA-32,SMP,KNL] Disable kernel irq balancing
1087 noirqdebug [IA-32] Disables the code which attempts to detect and
1088 disable unhandled interrupt sources.
1090 no_timer_check [IA-32,X86_64,APIC] Disables the code which tests for
1091 broken timer IRQ sources.
1093 noisapnp [ISAPNP] Disables ISA PnP code.
1095 noinitrd [RAM] Tells the kernel not to load any configured
1100 nolapic [IA-32,APIC] Do not enable or use the local APIC.
1102 noltlbs [PPC] Do not use large page/tlb entries for kernel
1103 lowmem mapping on PPC40x.
1105 nomca [IA-64] Disable machine check abort handling
1107 nomce [IA-32] Machine Check Exception
1109 noresidual [PPC] Don't use residual data on PReP machines.
1111 noresume [SWSUSP] Disables resume and restores original swap
1114 no-scroll [VGA] Disables scrollback.
1115 This is required for the Braillex ib80-piezo Braille
1116 reader made by F.H. Papenmeier (Germany).
1120 nosep [BUGS=IA-32] Disables x86 SYSENTER/SYSEXIT support.
1122 nosmp [SMP] Tells an SMP kernel to act as a UP kernel.
1124 nosync [HW,M68K] Disables sync negotiation for all devices.
1126 notsc [BUGS=IA-32] Disable Time Stamp Counter
1128 nousb [USB] Disable the USB subsystem
1132 nr_uarts= [SERIAL] maximum number of UARTs to be registered.
1137 opl3sa2= [HW,OSS] Format:
1138 <io>,<irq>,<dma>,<dma2>,<mss_io>,<mpu_io>,<ymode>,<loopback>[,<isapnp>,<multiple]
1140 oprofile.timer= [HW]
1141 Use timer interrupt instead of performance counters
1146 osst= [HW,SCSI] SCSI Tape Driver
1147 Format: <buffer_size>,<write_threshold>
1148 See also Documentation/scsi/st.txt.
1150 panic= [KNL] Kernel behaviour on panic
1153 parkbd.port= [HW] Parallel port number the keyboard adapter is
1154 connected to, default is 0.
1156 parkbd.mode= [HW] Parallel port keyboard adapter mode of operation,
1157 0 for XT, 1 for AT (default is AT).
1160 parport= [HW,PPT] Specify parallel ports. 0 disables.
1161 Format: { 0 | auto | 0xBBB[,IRQ[,DMA]] }
1162 Use 'auto' to force the driver to use any
1163 IRQ/DMA settings detected (the default is to
1164 ignore detected IRQ/DMA settings because of
1165 possible conflicts). You can specify the base
1166 address, IRQ, and DMA settings; IRQ and DMA
1167 should be numbers, or 'auto' (for using detected
1168 settings on that particular port), or 'nofifo'
1169 (to avoid using a FIFO even if it is detected).
1170 Parallel ports are assigned in the order they
1171 are specified on the command line, starting
1174 parport_init_mode= [HW,PPT]
1175 Configure VIA parallel port to operate in
1176 a specific mode. This is necessary on Pegasos
1177 computer where firmware has no options for setting
1178 up parallel port mode and sets it to spp.
1179 Currently this function knows 686a and 8231 chips.
1180 Format: [spp|ps2|epp|ecp|ecpepp]
1182 pas2= [HW,OSS] Format:
1183 <io>,<irq>,<dma>,<dma16>,<sb_io>,<sb_irq>,<sb_dma>,<sb_dma16>
1186 See header of drivers/scsi/pas16.c.
1189 Halt all CPUs after the first oops has been printed for
1190 the specified number of seconds. This is to be used if
1191 your oopses keep scrolling off the screen.
1196 See header of drivers/block/paride/pcd.c.
1197 See also Documentation/paride.txt.
1199 pci=option[,option...] [PCI] various PCI subsystem options:
1200 off [IA-32] don't probe for the PCI bus
1201 bios [IA-32] force use of PCI BIOS, don't access
1202 the hardware directly. Use this if your machine
1203 has a non-standard PCI host bridge.
1204 nobios [IA-32] disallow use of PCI BIOS, only direct
1205 hardware access methods are allowed. Use this
1206 if you experience crashes upon bootup and you
1207 suspect they are caused by the BIOS.
1208 conf1 [IA-32] Force use of PCI Configuration
1210 conf2 [IA-32] Force use of PCI Configuration
1212 nommconf [IA-32,X86_64] Disable use of MMCONFIG for PCI
1214 nomsi [MSI] If the PCI_MSI kernel config parameter is
1215 enabled, this kernel boot option can be used to
1216 disable the use of MSI interrupts system-wide.
1217 nosort [IA-32] Don't sort PCI devices according to
1218 order given by the PCI BIOS. This sorting is
1219 done to get a device order compatible with
1221 biosirq [IA-32] Use PCI BIOS calls to get the interrupt
1222 routing table. These calls are known to be buggy
1223 on several machines and they hang the machine
1224 when used, but on other computers it's the only
1225 way to get the interrupt routing table. Try
1226 this option if the kernel is unable to allocate
1227 IRQs or discover secondary PCI buses on your
1229 rom [IA-32] Assign address space to expansion ROMs.
1230 Use with caution as certain devices share
1231 address decoders between ROMs and other
1233 irqmask=0xMMMM [IA-32] Set a bit mask of IRQs allowed to be
1234 assigned automatically to PCI devices. You can
1235 make the kernel exclude IRQs of your ISA cards
1237 pirqaddr=0xAAAAA [IA-32] Specify the physical address
1238 of the PIRQ table (normally generated
1239 by the BIOS) if it is outside the
1240 F0000h-100000h range.
1241 lastbus=N [IA-32] Scan all buses thru bus #N. Can be
1242 useful if the kernel is unable to find your
1243 secondary buses and you want to tell it
1244 explicitly which ones they are.
1245 assign-busses [IA-32] Always assign all PCI bus
1246 numbers ourselves, overriding
1247 whatever the firmware may have done.
1248 usepirqmask [IA-32] Honor the possible IRQ mask stored
1249 in the BIOS $PIR table. This is needed on
1250 some systems with broken BIOSes, notably
1251 some HP Pavilion N5400 and Omnibook XE3
1252 notebooks. This will have no effect if ACPI
1253 IRQ routing is enabled.
1254 noacpi [IA-32] Do not use ACPI for IRQ routing
1255 or for PCI scanning.
1256 routeirq Do IRQ routing for all PCI devices.
1257 This is normally done in pci_enable_device(),
1258 so this option is a temporary workaround
1259 for broken drivers that don't call it.
1260 firmware [ARM] Do not re-enumerate the bus but instead
1261 just use the configuration from the
1262 bootloader. This is currently used on
1263 IXP2000 systems where the bus has to be
1264 configured a certain way for adjunct CPUs.
1265 noearly [X86] Don't do any early type 1 scanning.
1266 This might help on some broken boards which
1267 machine check when some devices' config space
1268 is read. But various workarounds are disabled
1269 and some IOMMU drivers will not work.
1270 bfsort Sort PCI devices into breadth-first order.
1271 This sorting is done to get a device
1272 order compatible with older (<= 2.4) kernels.
1273 nobfsort Don't sort PCI devices into breadth-first order.
1275 pcmv= [HW,PCMCIA] BadgePAD 4
1278 See Documentation/paride.txt.
1280 pdcchassis= [PARISC,HW] Disable/Enable PDC Chassis Status codes at
1283 See arch/parisc/kernel/pdc_chassis.c
1286 See Documentation/paride.txt.
1289 See Documentation/paride.txt.
1291 pirq= [SMP,APIC] Manual mp-table setup
1292 See Documentation/i386/IO-APIC.txt.
1294 plip= [PPT,NET] Parallel port network link
1295 Format: { parport<nr> | timid | 0 }
1296 See also Documentation/parport.txt.
1302 { on | off | curr | res | no-curr | no-res }
1305 [ISAPNP] Exclude IRQs for the autoconfiguration
1308 [ISAPNP] Exclude DMAs for the autoconfiguration
1310 pnp_reserve_io= [ISAPNP] Exclude I/O ports for the autoconfiguration
1311 Ranges are in pairs (I/O port base and size).
1314 [ISAPNP] Exclude memory regions for the
1316 Ranges are in pairs (memory base and size).
1318 profile= [KNL] Enable kernel profiling via /proc/profile
1319 Format: [schedule,]<number>
1320 Param: "schedule" - profile schedule points.
1321 Param: <number> - step/bucket size as a power of 2 for
1322 statistical time based profiling.
1323 Param: "sleep" - profile D-state sleeping (millisecs)
1325 processor.max_cstate= [HW,ACPI]
1326 Limit processor to maximum C-state
1327 max_cstate=9 overrides any DMI blacklist limit.
1329 processor.nocst [HW,ACPI]
1330 Ignore the _CST method to determine C-states,
1331 instead using the legacy FADT method
1333 prompt_ramdisk= [RAM] List of RAM disks to prompt for floppy disk
1335 See Documentation/ramdisk.txt.
1337 psmouse.proto= [HW,MOUSE] Highest PS2 mouse protocol extension to
1338 probe for; one of (bare|imps|exps|lifebook|any).
1339 psmouse.rate= [HW,MOUSE] Set desired mouse report rate, in reports
1341 psmouse.resetafter= [HW,MOUSE]
1342 Try to reset the device after so many bad packets
1345 [HW,MOUSE] Set desired mouse resolution, in dpi.
1346 psmouse.smartscroll=
1347 [HW,MOUSE] Controls Logitech smartscroll autorepeat.
1348 0 = disabled, 1 = enabled (default).
1350 pss= [HW,OSS] Personal Sound System (ECHO ESC614)
1352 <io>,<mss_io>,<mss_irq>,<mss_dma>,<mpu_io>,<mpu_irq>
1355 See Documentation/paride.txt.
1357 quiet [KNL] Disable most log messages
1362 See Documentation/md.txt.
1364 ramdisk= [RAM] Sizes of RAM disks in kilobytes [deprecated]
1365 See Documentation/ramdisk.txt.
1367 ramdisk_blocksize= [RAM]
1368 See Documentation/ramdisk.txt.
1370 ramdisk_size= [RAM] Sizes of RAM disks in kilobytes
1371 New name for the ramdisk parameter.
1372 See Documentation/ramdisk.txt.
1374 rcu.blimit= [KNL,BOOT] Set maximum number of finished
1375 RCU callbacks to process in one batch.
1377 rcu.qhimark= [KNL,BOOT] Set threshold of queued
1378 RCU callbacks over which batch limiting is disabled.
1380 rcu.qlowmark= [KNL,BOOT] Set threshold of queued
1381 RCU callbacks below which batch limiting is re-enabled.
1385 Run specified binary instead of /init from the ramdisk,
1386 used for early userspace startup. See initrd.
1388 reboot= [BUGS=IA-32,BUGS=ARM,BUGS=IA-64] Rebooting mode
1389 Format: <reboot_mode>[,<reboot_mode2>[,...]]
1390 See arch/*/kernel/reboot.c or arch/*/kernel/process.c
1392 reserve= [KNL,BUGS] Force the kernel to ignore some iomem area
1396 Reserves a hole at the top of the kernel virtual
1399 reset_devices [KNL] Force drivers to reset the underlying device
1400 during initialization.
1403 Specify the partition device for software suspend
1405 resume_offset= [SWSUSP]
1406 Specify the offset from the beginning of the partition
1407 given by "resume=" at which the swap header is located,
1408 in <PAGE_SIZE> units (needed only for swap files).
1409 See Documentation/power/swsusp-and-swap-files.txt
1411 retain_initrd [RAM] Keep initrd memory after extraction
1413 rhash_entries= [KNL,NET]
1414 Set number of hash buckets for route cache
1416 riscom8= [HW,SERIAL]
1417 Format: <io_board1>[,<io_board2>[,...<io_boardN>]]
1419 ro [KNL] Mount root device read-only on boot
1421 root= [KNL] Root filesystem
1423 rootdelay= [KNL] Delay (in seconds) to pause before attempting to
1424 mount the root filesystem
1426 rootflags= [KNL] Set root filesystem mount option string
1428 rootfstype= [KNL] Set root filesystem type
1430 rw [KNL] Mount root device read-write on boot
1432 S [KNL] Run init in single mode
1435 See drivers/net/irda/sa1100_ir.c.
1438 Format: <io>,<irq>,<dma>,<dma2>
1440 sbni= [NET] Granch SBNI12 leased line adapter
1442 sbpcd= [HW,CD] Soundblaster CD adapter
1444 See a comment before function sbpcd_setup() in
1445 drivers/cdrom/sbpcd.c.
1447 sc1200wdt= [HW,WDT] SC1200 WDT (watchdog) driver
1448 Format: <io>[,<timeout>[,<isapnp>]]
1450 scsi_debug_*= [SCSI]
1451 See drivers/scsi/scsi_debug.c.
1453 scsi_default_dev_flags=
1454 [SCSI] SCSI default device flags
1457 scsi_dev_flags= [SCSI] Black/white list entry for vendor and model
1458 Format: <vendor>:<model>:<flags>
1459 (flags are integer value)
1461 scsi_logging= [SCSI]
1463 scsi_mod.scan= [SCSI] sync (default) scans SCSI busses as they are
1464 discovered. async scans them in kernel threads,
1465 allowing boot to proceed. none ignores them, expecting
1466 user space to do the scan.
1468 selinux [SELINUX] Disable or enable SELinux at boot time.
1469 Format: { "0" | "1" }
1470 See security/selinux/Kconfig help text.
1473 Default value is set via kernel config option.
1474 If enabled at boot time, /selinux/disable can be used
1475 later to disable prior to initial policy load.
1477 selinux_compat_net =
1478 [SELINUX] Set initial selinux_compat_net flag value.
1479 Format: { "0" | "1" }
1480 0 -- use new secmark-based packet controls
1481 1 -- use legacy packet controls
1482 Default value is 0 (preferred).
1483 Value can be changed at runtime via
1484 /selinux/compat_net.
1486 serialnumber [BUGS=IA-32]
1488 sg_def_reserved_size= [SCSI]
1491 Maximal number of shapers.
1494 See header of drivers/scsi/sim710.c.
1500 Format: <io>,<irq>,<dma>
1501 See header of drivers/cdrom/sjcd.c.
1506 Format: <io1>[,<io2>[,...,<io8>]]
1508 snd-ad1816a= [HW,ALSA]
1510 snd-ad1848= [HW,ALSA]
1512 snd-ali5451= [HW,ALSA]
1514 snd-als100= [HW,ALSA]
1516 snd-als4000= [HW,ALSA]
1518 snd-azt2320= [HW,ALSA]
1520 snd-cmi8330= [HW,ALSA]
1522 snd-cmipci= [HW,ALSA]
1524 snd-cs4231= [HW,ALSA]
1526 snd-cs4232= [HW,ALSA]
1528 snd-cs4236= [HW,ALSA]
1530 snd-cs4281= [HW,ALSA]
1532 snd-cs46xx= [HW,ALSA]
1534 snd-dt019x= [HW,ALSA]
1536 snd-dummy= [HW,ALSA]
1538 snd-emu10k1= [HW,ALSA]
1540 snd-ens1370= [HW,ALSA]
1542 snd-ens1371= [HW,ALSA]
1544 snd-es968= [HW,ALSA]
1546 snd-es1688= [HW,ALSA]
1548 snd-es18xx= [HW,ALSA]
1550 snd-es1938= [HW,ALSA]
1552 snd-es1968= [HW,ALSA]
1554 snd-fm801= [HW,ALSA]
1556 snd-gusclassic= [HW,ALSA]
1558 snd-gusextreme= [HW,ALSA]
1560 snd-gusmax= [HW,ALSA]
1564 snd-ice1712= [HW,ALSA]
1566 snd-intel8x0= [HW,ALSA]
1568 snd-interwave= [HW,ALSA]
1573 snd-korg1212= [HW,ALSA]
1575 snd-maestro3= [HW,ALSA]
1577 snd-mpu401= [HW,ALSA]
1579 snd-mtpav= [HW,ALSA]
1581 snd-nm256= [HW,ALSA]
1583 snd-opl3sa2= [HW,ALSA]
1591 snd-opti93x= [HW,ALSA]
1595 snd-rme32= [HW,ALSA]
1597 snd-rme96= [HW,ALSA]
1599 snd-rme9652= [HW,ALSA]
1605 snd-sbawe= [HW,ALSA]
1607 snd-serial= [HW,ALSA]
1609 snd-sgalaxy= [HW,ALSA]
1611 snd-sonicvibes= [HW,ALSA]
1616 snd-sun-cs4231= [HW,ALSA]
1618 snd-trident= [HW,ALSA]
1620 snd-usb-audio= [HW,ALSA,USB]
1622 snd-via82xx= [HW,ALSA]
1624 snd-virmidi= [HW,ALSA]
1626 snd-wavefront= [HW,ALSA]
1628 snd-ymfpci= [HW,ALSA]
1631 Format: <io>[,<irq>]
1633 sonypi.*= [HW] Sony Programmable I/O Control Device driver
1634 See Documentation/sonypi.txt
1636 specialix= [HW,SERIAL] Specialix multi-serial port adapter
1637 See Documentation/specialix.txt.
1639 spia_io_base= [HW,MTD]
1645 Format: <io>,<irq>,<dma>,<mpu_io>,<mpu_irq>
1647 st= [HW,SCSI] SCSI tape parameters (buffers, etc.)
1648 See Documentation/scsi/st.txt.
1651 See header of drivers/scsi/seagate.c.
1655 Set the STI (builtin display/keyboard on the HP-PARISC
1656 machines) console (graphic card) which should be used
1657 as the initial boot-console.
1658 See also comment in drivers/video/console/sticore.c.
1661 See comment in drivers/video/console/sticore.c.
1664 Format: bpp:<bpp1>[:<bpp2>[:<bpp3>...]]
1666 swiotlb= [IA-64] Number of I/O TLB slabs
1670 sym53c416= [HW,SCSI]
1671 See header of drivers/scsi/sym53c416.c.
1673 sysrq_always_enabled
1675 Ignore sysrq setting - this boot parameter will
1676 neutralize any effect of /proc/sys/kernel/sysrq.
1677 Useful for debugging.
1680 See header of drivers/scsi/t128.c.
1684 thash_entries= [KNL,NET]
1685 Set number of hash buckets for TCP connection
1687 time Show timing data prefixed to each printk message line
1689 clocksource= [GENERIC_TIME] Override the default clocksource
1690 Override the default clocksource and use the clocksource
1691 with the name specified.
1693 tipar.timeout= [HW,PPT]
1694 Set communications timeout in tenths of a second
1697 tipar.delay= [HW,PPT]
1698 Set inter-bit delay in microseconds (default 10).
1701 See header of drivers/scsi/seagate.c.
1704 See comment before function dc390_setup() in
1705 drivers/scsi/tmscsim.c.
1709 trix= [HW,OSS] MediaTrix AudioTrix Pro
1711 <io>,<irq>,<dma>,<dma2>,<sb_io>,<sb_irq>,<sb_dma>,<mpu_io>,<mpu_irq>
1713 tsdev.xres= [TS] Horizontal screen resolution.
1714 tsdev.yres= [TS] Vertical screen resolution.
1716 turbografx.map[2|3]= [HW,JOY]
1717 TurboGraFX parallel port interface
1719 <port#>,<js1>,<js2>,<js3>,<js4>,<js5>,<js6>,<js7>
1720 See also Documentation/input/joystick-parport.txt
1722 u14-34f= [HW,SCSI] UltraStor 14F/34F SCSI host adapter
1723 See header of drivers/scsi/u14-34f.c.
1732 [USB] Ignore overcurrent events (default N).
1733 Some badly-designed motherboards generate lots of
1734 bogus events, for ports that aren't wired to
1735 anything. Set this parameter to avoid log spamming.
1736 Note that genuine overcurrent events won't be
1740 [USBHID] The interval which mice are to be polled at.
1743 vdso=1: enable VDSO (default)
1744 vdso=0: disable VDSO mapping
1746 video= [FB] Frame buffer configuration
1747 See Documentation/fb/modedb.txt.
1749 vga= [BOOT,IA-32] Select a particular video mode
1750 See Documentation/i386/boot.txt and
1751 Documentation/svga.txt.
1752 Use vga=ask for menu.
1753 This is actually a boot loader parameter; the value is
1754 passed to the kernel using a special protocol.
1756 vmalloc=nn[KMG] [KNL,BOOT] Forces the vmalloc area to have an exact
1757 size of <nn>. This can be used to increase the
1758 minimum size (128MB on x86). It can also be used to
1759 decrease the size and leave more room for directly
1762 vmhalt= [KNL,S390] Perform z/VM CP command after system halt.
1765 vmpanic= [KNL,S390] Perform z/VM CP command after kernel panic.
1768 vmpoff= [KNL,S390] Perform z/VM CP command after power off.
1771 waveartist= [HW,OSS]
1772 Format: <io>,<irq>,<dma>,<dma2>
1775 See header of drivers/scsi/wd33c93.c.
1778 See header of drivers/scsi/wd7000.c.
1781 See Documentation/watchdog/watchdog.txt.
1783 xd= [HW,XT] Original XT pre-IDE (RLL encoded) disks.
1784 xd_geo= See header of drivers/block/xd.c.
1786 xirc2ps_cs= [NET,PCMCIA]
1788 <irq>,<irq_mask>,<io>,<full_duplex>,<do_sound>,<lockup_hack>[,<irq2>[,<irq3>[,<irq4>]]]
1790 norandmaps Don't use address space randomization
1791 Equivalent to echo 0 > /proc/sys/kernel/randomize_va_space
1793 unwind_debug=N N > 0 will enable dwarf2 unwinder debugging
1794 This is useful to get more information why
1795 you got a "dwarf2 unwinder stuck"
1797 ______________________________________________________________________
1801 Add documentation for ALSA options.
1802 Add more DRM drivers.