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 DEVFS devfs support is enabled.
39 DRM Direct Rendering Management support is enabled.
40 EDD BIOS Enhanced Disk Drive Services (EDD) is enabled
41 EFI EFI Partitioning (GPT) is enabled
42 EIDE EIDE/ATAPI support is enabled.
43 FB The frame buffer device is enabled.
44 HW Appropriate hardware is enabled.
45 IA-32 IA-32 aka i386 architecture is enabled.
46 IA-64 IA-64 architecture is enabled.
47 IOSCHED More than one I/O scheduler is enabled.
48 IP_PNP IP DHCP, BOOTP, or RARP is enabled.
49 ISAPNP ISA PnP code is enabled.
50 ISDN Appropriate ISDN support is enabled.
51 JOY Appropriate joystick support 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 Note that ALL kernel parameters listed below are CASE SENSITIVE, and that
109 a trailing = on the name of any parameter states that that parameter will
110 be entered as an environment variable, whereas its absence indicates that
111 it will appear as a kernel argument readable via /proc/cmdline by programs
112 running once the system is up.
114 53c7xx= [HW,SCSI] Amiga SCSI controllers
115 See header of drivers/scsi/53c7xx.c.
116 See also Documentation/scsi/ncr53c7xx.txt.
118 acpi= [HW,ACPI] Advanced Configuration and Power Interface
119 Format: { force | off | ht | strict | noirq }
120 force -- enable ACPI if default was off
121 off -- disable ACPI if default was on
122 noirq -- do not use ACPI for IRQ routing
123 ht -- run only enough ACPI to enable Hyper Threading
124 strict -- Be less tolerant of platforms that are not
125 strictly ACPI specification compliant.
127 See also Documentation/pm.txt, pci=noacpi
129 acpi_sleep= [HW,ACPI] Sleep options
130 Format: { s3_bios, s3_mode }
131 See Documentation/power/video.txt
133 acpi_sci= [HW,ACPI] ACPI System Control Interrupt trigger mode
134 Format: { level | edge | high | low }
136 acpi_irq_balance [HW,ACPI]
137 ACPI will balance active IRQs
140 acpi_irq_nobalance [HW,ACPI]
141 ACPI will not move active IRQs (default)
144 acpi_irq_pci= [HW,ACPI] If irq_balance, clear listed IRQs for
146 Format: <irq>,<irq>...
148 acpi_irq_isa= [HW,ACPI] If irq_balance, mark listed IRQs used by ISA
149 Format: <irq>,<irq>...
151 acpi_os_name= [HW,ACPI] Tell ACPI BIOS the name of the OS
152 Format: To spoof as Windows 98: ="Microsoft Windows"
154 acpi_osi= [HW,ACPI] empty param disables _OSI
156 acpi_serialize [HW,ACPI] force serialization of AML methods
158 acpi_skip_timer_override [HW,ACPI]
159 Recognize and ignore IRQ0/pin2 Interrupt Override.
160 For broken nForce2 BIOS resulting in XT-PIC timer.
162 acpi_dbg_layer= [HW,ACPI]
164 Each bit of the <int> indicates an ACPI debug layer,
165 1: enable, 0: disable. It is useful for boot time
166 debugging. After system has booted up, it can be set
167 via /proc/acpi/debug_layer.
169 acpi_dbg_level= [HW,ACPI]
171 Each bit of the <int> indicates an ACPI debug level,
172 1: enable, 0: disable. It is useful for boot time
173 debugging. After system has booted up, it can be set
174 via /proc/acpi/debug_level.
176 acpi_fake_ecdt [HW,ACPI] Workaround failure due to BIOS lacking ECDT
178 acpi_generic_hotkey [HW,ACPI]
179 Allow consolidated generic hotkey driver to
180 override platform specific driver.
181 See also Documentation/acpi-hotkey.txt.
183 enable_timer_pin_1 [i386,x86-64]
184 Enable PIN 1 of APIC timer
185 Can be useful to work around chipset bugs
186 (in particular on some ATI chipsets).
187 The kernel tries to set a reasonable default.
189 disable_timer_pin_1 [i386,x86-64]
190 Disable PIN 1 of APIC timer
191 Can be useful to work around chipset bugs.
194 Format: <io>,<irq>,<dma>,<dma2>
195 See also Documentation/sound/oss/AD1816.
198 Format: <io>,<irq>,<dma>,<dma2>,<type>
204 See header of drivers/scsi/advansys.c.
206 advwdt= [HW,WDT] Advantech WDT
207 Format: <iostart>,<iostop>
209 aedsp16= [HW,OSS] Audio Excel DSP 16
210 Format: <io>,<irq>,<dma>,<mss_io>,<mpu_io>,<mpu_irq>
211 See also header of sound/oss/aedsp16.c.
214 See Documentation/scsi/aha152x.txt.
217 Format: <portbase>[,<buson>,<busoff>[,<dmaspeed>]]
220 See Documentation/scsi/aic7xxx.txt.
223 See Documentation/scsi/aic79xx.txt.
225 amijoy.map= [HW,JOY] Amiga joystick support
226 Map of devices attached to JOY0DAT and JOY1DAT
228 See also Documentation/kernel/input/joystick.txt
230 analog.map= [HW,JOY] Analog joystick and gamepad support
231 Specifies type or capabilities of an analog joystick
232 connected to one of 16 gameports
233 Format: <type1>,<type2>,..<type16>
236 Power management functions (SPARCstation-4/5 + deriv.)
238 Disable APC CPU standby support. SPARCstation-Fox does
239 not play well with APC CPU idle - disable it if you have
240 APC and your system crashes randomly.
242 apic= [APIC,i386] Change the output verbosity whilst booting
243 Format: { quiet (default) | verbose | debug }
244 Change the amount of debugging information output
245 when initialising the APIC and IO-APIC components.
247 apm= [APM] Advanced Power Management
248 See header of arch/i386/kernel/apm.c.
253 arcrimi= [HW,NET] ARCnet - "RIM I" (entirely mem-mapped) cards
254 Format: <io>,<irq>,<nodeID>
258 atarimouse= [HW,MOUSE] Atari Mouse
260 atascsi= [HW,SCSI] Atari SCSI
262 atkbd.extra= [HW] Enable extra LEDs and keys on IBM RapidAccess,
263 EzKey and similar keyboards
265 atkbd.reset= [HW] Reset keyboard during initialization
267 atkbd.set= [HW] Select keyboard code set
268 Format: <int> (2 = AT (default), 3 = PS/2)
270 atkbd.scroll= [HW] Enable scroll wheel on MS Office and similar
273 atkbd.softraw= [HW] Choose between synthetic and real raw mode
274 Format: <bool> (0 = real, 1 = synthetic (default))
276 atkbd.softrepeat= [HW]
277 Use software keyboard repeat
281 awe= [HW,OSS] AWE32/SB32/AWE64 wave table synth
282 Format: <io>,<memsize>,<isapnp>
284 aztcd= [HW,CD] Aztech CD268 CDROM driver
285 Format: <io>,0x79 (?)
287 baycom_epp= [HW,AX25]
290 baycom_par= [HW,AX25] BayCom Parallel Port AX.25 Modem
292 See header of drivers/net/hamradio/baycom_par.c.
294 baycom_ser_fdx= [HW,AX25]
295 BayCom Serial Port AX.25 Modem (Full Duplex Mode)
296 Format: <io>,<irq>,<mode>[,<baud>]
297 See header of drivers/net/hamradio/baycom_ser_fdx.c.
299 baycom_ser_hdx= [HW,AX25]
300 BayCom Serial Port AX.25 Modem (Half Duplex Mode)
301 Format: <io>,<irq>,<mode>
302 See header of drivers/net/hamradio/baycom_ser_hdx.c.
304 blkmtd_device= [HW,MTD]
310 bttv.card= [HW,V4L] bttv (bt848 + bt878 based grabber cards)
311 bttv.radio= Most important insmod options are available as
313 bttv.pll= See Documentation/video4linux/bttv/Insmod-options
314 bttv.tuner= and Documentation/video4linux/bttv/CARDLIST
317 See drivers/scsi/BusLogic.c, comment before function
318 BusLogic_ParseDriverOptions().
320 c101= [NET] Moxa C101 synchronous serial card
322 cachesize= [BUGS=IA-32] Override level 2 CPU cache size detection.
323 Sometimes CPU hardware bugs make them report the cache
324 size incorrectly. The kernel will attempt work arounds
325 to fix known problems, but for some CPUs it is not
326 possible to determine what the correct size should be.
327 This option provides an override for these situations.
330 Format: <io>,<irq>[,PAS]
331 See header of drivers/cdrom/cdu31a.c.
333 chandev= [HW,NET] Generic channel device initialisation
335 checkreqprot [SELINUX] Set initial checkreqprot flag value.
336 Format: { "0" | "1" }
337 See security/selinux/Kconfig help text.
338 0 -- check protection applied by kernel (includes
339 any implied execute protection).
340 1 -- check protection requested by application.
341 Default value is set via a kernel config option.
342 Value can be changed at runtime via
343 /selinux/checkreqprot.
345 clock= [BUGS=IA-32, HW] gettimeofday clocksource override.
347 Forces specified clocksource (if avaliable) to be used
348 when calculating gettimeofday(). If specified
349 clocksource is not avalible, it defaults to PIT.
350 Format: { pit | tsc | cyclone | pmtmr }
354 [IA32/X86_64] Disable/Enable interrupt 0 timer routing
355 over the 8254 in addition to over the IO-APIC. The
356 kernel tries to set a sensible default.
358 hpet= [IA-32,HPET] option to disable HPET and use PIT.
362 Format: { auto | [<io>,][<irq>] }
364 com20020= [HW,NET] ARCnet - COM20020 chipset
366 <io>[,<irq>[,<nodeID>[,<backplane>[,<ckp>[,<timeout>]]]]]
368 com90io= [HW,NET] ARCnet - COM90xx chipset (IO-mapped buffers)
372 ARCnet - COM90xx chipset (memory-mapped buffers)
373 Format: <io>[,<irq>[,<memstart>]]
375 condev= [HW,S390] console device
378 console= [KNL] Output console device and options.
380 tty<n> Use the virtual console device <n>.
384 Use the specified serial port. The options are of
385 the form "bbbbpnf", where "bbbb" is the baud rate,
386 "p" is parity ("n", "o", or "e"), "n" is number of
387 bits, and "f" is flow control ("r" for RTS or
388 omit it). Default is "9600n8".
390 See Documentation/serial-console.txt for more
392 Documentation/networking/netconsole.txt for an
395 uart,io,<addr>[,options]
396 uart,mmio,<addr>[,options]
397 Start an early, polled-mode console on the 8250/16550
398 UART at the specified I/O port or MMIO address,
399 switching to the matching ttyS device later. The
400 options are the same as for ttyS, above.
402 cpcihp_generic= [HW,PCI] Generic port I/O CompactPCI driver
404 <first_slot>,<last_slot>,<port>,<enum_bit>[,<debug>]
407 Format: { parport<nr> | auto | none }
409 crashkernel=nn[KMG]@ss[KMG]
410 [KNL] Reserve a chunk of physical memory to
411 hold a kernel to switch to with kexec on panic.
414 Format: <io>,<irq>,<dma>,<dma2>,<mpuio>,<mpuirq>
419 cs89x0_media= [HW,NET]
420 Format: { rj45 | aui | bnc }
422 cyclades= [HW,SERIAL] Cyclades multi-serial port adapter.
425 See header of drivers/s390/block/dasd_devmap.c.
427 db9.dev[2|3]= [HW,JOY] Multisystem joystick support via parallel port
428 (one device per port)
429 Format: <port#>,<type>
430 See also Documentation/input/joystick-parport.txt
432 debug [KNL] Enable kernel debugging (events log level).
435 Format: <area>[,<node>]
436 See also Documentation/networking/decnet.txt.
439 See Documentation/filesystems/devfs/boot-options.
442 Set number of hash buckets for dentry cache.
445 IO parameters + enable/disable command.
447 digiepca= [HW,SERIAL]
448 See drivers/char/README.epca and
449 Documentation/digiepca.txt.
451 dmascc= [HW,AX25,SERIAL] AX.25 Z80SCC driver with DMA
453 Format: <io_dev0>[,<io_dev1>[,..<io_dev32>]]
455 dmasound= [HW,OSS] Sound subsystem buffers
461 earlyprintk= [IA-32,X86-64]
463 earlyprintk=serial[,ttySn[,baudrate]]
465 Append ",keep" to not disable it when the real console
468 Only vga or serial at a time, not both.
470 Currently only ttyS0 and ttyS1 are supported.
472 Interaction with the standard serial driver is not
475 The VGA output is eventually overwritten by the real
480 ec_intr= [HW,ACPI] ACPI Embedded Controller interrupt mode
483 non-0: interrupt mode (default)
490 Format: {"of[f]" | "sk[ipmbr]"}
491 See comment in arch/i386/boot/edd.S
494 Format: <id>,<membase>,<irq>
496 eisa_irq_edge= [PARISC,HW]
497 See header of drivers/parisc/eisa.c.
500 See comment before function elanfreq_setup() in
501 arch/i386/kernel/cpu/cpufreq/elanfreq.c.
504 Format: {"anticipatory" | "cfq" | "deadline" | "noop"}
505 See Documentation/block/as-iosched.txt and
506 Documentation/block/deadline-iosched.txt for details.
508 elfcorehdr= [IA-32, X86_64]
509 Specifies physical address of start of kernel core
510 image elf header. Generally kexec loader will
511 pass this option to capture kernel.
512 See Documentation/kdump/kdump.txt for details.
514 enforcing [SELINUX] Set initial enforcing status.
516 See security/selinux/Kconfig help text.
517 0 -- permissive (log only, no denials).
518 1 -- enforcing (deny and log).
520 Value can be changed at runtime via /selinux/enforce.
523 Format: <lineout>[,<micbias>]
524 See also header of sound/oss/es1370.c.
527 Format: <spdif>,[<nomix>,[<amplifier>]]
528 See also header of sound/oss/es1371.c.
530 ether= [HW,NET] Ethernet cards parameters
531 This option is obsoleted by the "netdev=" option, which
532 has equivalent usage. See its documentation for details.
534 eurwdt= [HW,WDT] Eurotech CPU-1220/1410 onboard watchdog.
538 See header of drivers/scsi/fd_mcs.c.
541 See header of drivers/scsi/fdomain.c.
544 See Documentation/floppy.txt.
546 ftape= [HW] Floppy Tape subsystem debugging options.
547 See Documentation/ftape.txt.
550 [HW,JOY] Multisystem joystick and NES/SNES/PSX pad
551 support via parallel port (up to 5 devices per port)
552 Format: <port#>,<pad1>,<pad2>,<pad3>,<pad4>,<pad5>
553 See also Documentation/input/joystick-parport.txt
558 See header of drivers/scsi/gdth.c.
560 gpt [EFI] Forces disk with valid GPT signature but
561 invalid Protective MBR to be treated as GPT.
566 gt96100eth= [NET] MIPS GT96100 Advanced Communication Controller
569 Format: <io>,<irq>,<dma>,<dma16>
573 hashdist= [KNL,NUMA] Large hashes allocated during boot
574 are distributed across NUMA nodes. Defaults on
575 for IA-64, off otherwise.
576 Format: 0 | 1 (for off | on)
578 hcl= [IA-64] SGI's Hardware Graph compatibility layer
580 hd= [EIDE] (E)IDE hard drive subsystem geometry
581 Format: <cyl>,<head>,<sect>
583 hd?= [HW] (E)IDE subsystem
584 hd?lun= See Documentation/ide.txt.
586 highmem=nn[KMG] [KNL,BOOT] forces the highmem zone to have an exact
587 size of <nn>. This works even on boxes that have no
588 highmem otherwise. This also works to reduce highmem
589 size on bigger boxes.
592 See Documentation/isdn/README.HiSax.
594 hugepages= [HW,IA-32,IA-64] Maximal number of HugeTLB pages.
596 noirqbalance [IA-32,SMP,KNL] Disable kernel irq balancing
598 i8042.direct [HW] Put keyboard port into non-translated mode
599 i8042.dumbkbd [HW] Pretend that controlled can only read data from
600 keyboard and can not control its state
601 (Don't attempt to blink the leds)
602 i8042.noaux [HW] Don't check for auxiliary (== mouse) port
603 i8042.nokbd [HW] Don't check/create keyboard port
604 i8042.nomux [HW] Don't check presence of an active multiplexing
606 i8042.nopnp [HW] Don't use ACPIPnP / PnPBIOS to discover KBD/AUX
609 [HW] Frequency with which keyboard LEDs should blink
610 when kernel panics (default is 0.5 sec)
611 i8042.reset [HW] Reset the controller during init and cleanup
612 i8042.unlock [HW] Unlock (ignore) the keylock
616 i8k.ignore_dmi [HW] Continue probing hardware even if DMI data
617 indicates that the driver is running on unsupported
619 i8k.force [HW] Activate i8k driver even if SMM BIOS signature
620 does not match list of supported models.
622 [HW] Report power status in /proc/i8k
623 (disabled by default)
624 i8k.restricted [HW] Allow controlling fans only if SYS_ADMIN
627 ibmmcascsi= [HW,MCA,SCSI] IBM MicroChannel SCSI adapter
628 See Documentation/mca.txt.
631 Format: <io>[,<membase>[,<icn_id>[,<icn_id2>]]]
633 ide= [HW] (E)IDE subsystem
634 Format: ide=nodma or ide=doubler or ide=reverse
635 See Documentation/ide.txt.
637 ide?= [HW] (E)IDE subsystem
638 Format: ide?=noprobe or chipset specific parameters.
639 See Documentation/ide.txt.
641 idebus= [HW] (E)IDE subsystem - VLB/PCI bus speed
642 See Documentation/ide.txt.
645 Format: idle=poll or idle=halt
648 Set number of hash buckets for inode cache.
651 See header of drivers/scsi/in2000.c.
655 Run specified binary instead of /sbin/init as init
658 initcall_debug [KNL] Trace initcalls as they are executed. Useful
659 for working out where the kernel is dying during
662 initrd= [BOOT] Specify the location of the initial ramdisk
664 inport.irq= [HW] Inport (ATI XL and Microsoft) busmouse driver
667 combined_mode= [HW] control which driver uses IDE ports in combined
668 mode: legacy IDE driver, libata, or both
669 (in the libata case, libata.atapi_enabled=1 may be
670 useful as well). Note that using the ide or libata
671 options may affect your device naming (e.g. by
672 changing hdc to sdb).
673 Format: combined (default), ide, or libata
677 io7= [HW] IO7 for Marvel based alpha systems
678 See comment before marvel_specify_io7 in
679 arch/alpha/kernel/core_marvel.c.
682 See Documentation/nfsroot.txt.
684 ip2= [HW] Set IO/IRQ pairs for up to 4 IntelliPort boards
685 See comment before ip2_setup() in drivers/char/ip2.c.
687 ips= [HW,SCSI] Adaptec / IBM ServeRAID controller
688 See header of drivers/scsi/ips.c.
691 When an interrupt is not handled search all handlers
692 for it. Intended to get systems with badly broken
696 When an interrupt is not handled search all handlers
697 for it. Also check all handlers each timer
698 interrupt. Intended to get systems with badly broken
702 Format: <RDP>,<reset>,<pci_scan>,<verbosity>
704 isolcpus= [KNL,SMP] Isolate CPUs from the general scheduler.
705 Format: <cpu number>,...,<cpu number>
706 This option can be used to specify one or more CPUs
707 to isolate from the general SMP balancing and scheduling
708 algorithms. The only way to move a process onto or off
709 an "isolated" CPU is via the CPU affinity syscalls.
710 <cpu number> begins at 0 and the maximum value is
711 "number of CPUs in system - 1".
713 This option is the preferred way to isolate CPUs. The
714 alternative -- manually setting the CPU mask of all
715 tasks in the system -- can cause problems and
716 suboptimal load balancer performance.
719 Format: <io>,<irq>,<dma>,<setup>
723 js= [HW,JOY] Analog joystick
724 See Documentation/input/joystick.txt.
728 kstack=N [IA-32,X86-64] Print N words from the kernel stack
733 lapic [IA-32,APIC] Enable the local APIC even if BIOS
736 lasi= [HW,SCSI] PARISC LASI driver for the 53c700 chip
737 Format: addr:<io>,irq:<irq>
739 llsc*= [IA64] See function print_params() in
740 arch/ia64/sn/kernel/llsc4.c.
742 load_ramdisk= [RAM] List of ramdisks to load from floppy
743 See Documentation/ramdisk.txt.
745 lockd.nlm_grace_period=P [NFS] Assign grace period.
748 lockd.nlm_tcpport=N [NFS] Assign TCP port.
751 lockd.nlm_timeout=T [NFS] Assign timeout value.
754 lockd.nlm_udpport=M [NFS] Assign UDP port.
757 logibm.irq= [HW,MOUSE] Logitech Bus Mouse Driver
760 loglevel= All Kernel Messages with a loglevel smaller than the
761 console loglevel will be printed to the console. It can
762 also be changed with klogd or other programs. The
763 loglevels are defined as follows:
765 0 (KERN_EMERG) system is unusable
766 1 (KERN_ALERT) action must be taken immediately
767 2 (KERN_CRIT) critical conditions
768 3 (KERN_ERR) error conditions
769 4 (KERN_WARNING) warning conditions
770 5 (KERN_NOTICE) normal but significant condition
771 6 (KERN_INFO) informational
772 7 (KERN_DEBUG) debug-level messages
774 log_buf_len=n Sets the size of the printk ring buffer, in bytes.
775 Format: { n | nk | nM }
776 n must be a power of two. The default size
777 is set in the kernel config file.
779 lp=0 [LP] Specify parallel ports to use, e.g,
780 lp=port[,port...] lp=none,parport0 (lp0 not configured, lp1 uses
781 lp=reset first parallel port). 'lp=0' disables the
782 lp=auto printer driver. 'lp=reset' (which can be
783 specified in addition to the ports) causes
784 attached printers to be reset. Using
785 lp=port1,port2,... specifies the parallel ports
786 to associate lp devices with, starting with
787 lp0. A port specification may be 'none' to skip
788 that lp device, or a parport name such as
789 'parport0'. Specifying 'lp=auto' instead of a
790 port specification list means that device IDs
791 from each port should be examined, to see if
792 an IEEE 1284-compliant printer is attached; if
793 so, the driver will manage that printer.
794 See also header of drivers/char/lp.c.
797 Sets loops_per_jiffy to given constant, thus avoiding
798 time-consuming boot-time autodetection (up to 250 ms per
799 CPU). 0 enables autodetection (default). To determine
800 the correct value for your kernel, boot with normal
801 autodetection and see what value is printed. Note that
802 on SMP systems the preset will be applied to all CPUs,
803 which is likely to cause problems if your CPUs need
804 significantly divergent settings. An incorrect value
805 will cause delays in the kernel to be wrong, leading to
806 unpredictable I/O errors and other breakage. Although
807 unlikely, in the extreme case this might damage your
811 Format: <io>,<irq>,<dma>
813 mac5380= [HW,SCSI] Format:
814 <can_queue>,<cmd_per_lun>,<sg_tablesize>,<hostid>,<use_tags>
816 mac53c9x= [HW,SCSI] Format:
817 <num_esps>,<disconnect>,<nosync>,<can_queue>,<cmd_per_lun>,<sg_tablesize>,<hostid>,<use_tags>
819 machvec= [IA64] Force the use of a particular machine-vector
820 (machvec) in a generic kernel.
821 Example: machvec=hpzx1_swiotlb
823 mad16= [HW,OSS] Format:
824 <io>,<irq>,<dma>,<dma16>,<mpu_io>,<mpu_irq>,<joystick>
829 max_loop= [LOOP] Maximum number of loopback devices that can
833 maxcpus= [SMP] Maximum number of processors that an SMP kernel
836 max_addr=[KMG] [KNL,BOOT,ia64] All physical memory greater than or
837 equal to this physical address is ignored.
839 max_luns= [SCSI] Maximum number of LUNs to probe.
840 Should be between 1 and 2^32-1.
843 [SCSI] Maximum number of LUNs received.
844 Should be between 1 and 16384.
846 mca-pentium [BUGS=IA-32]
851 Format: <port>,<irq>,<mitsumi_bug_93_wait>
855 mce [IA-32] Machine Check Exception
857 md= [HW] RAID subsystems devices and level
858 See Documentation/md.txt.
861 Format: <first>,<last>
862 Specifies range of consoles to be captured by the MDA.
864 mem=nn[KMG] [KNL,BOOT] Force usage of a specific amount of memory
865 Amount of memory to be used when the kernel is not able
866 to see the whole system memory or for test.
867 [IA-32] Use together with memmap= to avoid physical
868 address space collisions. Without memmap= PCI devices
869 could be placed at addresses belonging to unused RAM.
871 mem=nopentium [BUGS=IA-32] Disable usage of 4MB pages for kernel
874 memmap=exactmap [KNL,IA-32,X86_64] Enable setting of an exact
875 E820 memory map, as specified by the user.
876 Such memmap=exactmap lines can be constructed based on
877 BIOS output or other requirements. See the memmap=nn@ss
880 memmap=nn[KMG]@ss[KMG]
881 [KNL] Force usage of a specific region of memory
882 Region of memory to be used, from ss to ss+nn.
884 memmap=nn[KMG]#ss[KMG]
885 [KNL,ACPI] Mark specific memory as ACPI data.
886 Region of memory to be used, from ss to ss+nn.
888 memmap=nn[KMG]$ss[KMG]
889 [KNL,ACPI] Mark specific memory as reserved.
890 Region of memory to be used, from ss to ss+nn.
892 meye.*= [HW] Set MotionEye Camera parameters
893 See Documentation/video4linux/meye.txt.
898 [KNL,SMP] debug: override scheduler migration costs
899 Format: <level-1-usecs>,<level-2-usecs>,...
900 This debugging option can be used to override the
901 default scheduler migration cost matrix. The numbers
902 are indexed by 'CPU domain distance'.
903 E.g. migration_cost=1000,2000,3000 on an SMT NUMA
904 box will set up an intra-core migration cost of
905 1 msec, an inter-core migration cost of 2 msecs,
906 and an inter-node migration cost of 3 msecs.
908 WARNING: using the wrong values here can break
909 scheduler performance, so it's only for scheduler
910 development purposes, not production environments.
913 [KNL,SMP] migration cost auto-detect verbosity
915 If a system's migration matrix reported at bootup
916 seems erroneous then this option can be used to
917 increase verbosity of the detection process.
918 We default to 0 (no extra messages), 1 will print
919 some more information, and 2 will be really
920 verbose (probably only useful if you also have a
921 serial console attached to the system).
924 [KNL,SMP] multiply/divide migration costs by a factor
926 This debug option can be used to proportionally
927 increase or decrease the auto-detected migration
928 costs for all entries of the migration matrix.
929 E.g. migration_factor=150 will increase migration
930 costs by 50%. (and thus the scheduler will be less
931 eager migrating cache-hot tasks)
932 migration_factor=80 will decrease migration costs
933 by 20%. (thus the scheduler will be more eager to
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 [MOUSE] Maximum time between finger touching and
942 leaving touchpad surface for touch to be considered
943 a tap and be reported as a left button click (for
944 touchpads working in absolute mode only).
946 mousedev.xres= [MOUSE] Horizontal screen resolution, used for devices
947 reporting absolute coordinates, such as tablets
948 mousedev.yres= [MOUSE] Vertical screen resolution, used for devices
949 reporting absolute coordinates, such as tablets
955 Format: <name>,<region-number>,<size>,<offset>
957 MTD_Region= [MTD] Format:
958 <name>,<region-number>[,<base>,<size>,<buswidth>,<altbuswidth>]
961 See drivers/mtd/cmdline.c.
963 mtouchusb.raw_coordinates=
964 [HW] Make the MicroTouch USB driver use raw coordinates
965 ('y', default) or cooked coordinates ('n')
967 n2= [NET] SDL Inc. RISCom/N2 synchronous serial card
970 See header of drivers/scsi/NCR_D700.c.
976 ncr53c400a= [HW,SCSI]
978 ncr53c406a= [HW,SCSI]
982 netdev= [NET] Network devices parameters
983 Format: <irq>,<io>,<mem_start>,<mem_end>,<name>
984 Note that mem_start is often overloaded to mean
985 something different and driver-specific.
986 This usage is only documented in each driver source
990 See Documentation/nfsroot.txt.
992 nfsroot= [NFS] nfs root filesystem for disk-less boxes.
993 See Documentation/nfsroot.txt.
995 nfs.callback_tcpport=
996 [NFS] set the TCP port on which the NFSv4 callback
997 channel should listen.
999 nfs.idmap_cache_timeout=
1000 [NFS] set the maximum lifetime for idmapper cache
1003 nmi_watchdog= [KNL,BUGS=IA-32] Debugging features for SMP kernels
1005 no387 [BUGS=IA-32] Tells the kernel to use the 387 maths
1006 emulation library even if a 387 maths coprocessor
1011 noapic [SMP,APIC] Tells the kernel to not make use of any
1012 IOAPICs that may be present in the system.
1014 noasync [HW,M68K] Disables async and sync negotiation for
1017 nobats [PPC] Do not use BATs for mapping kernel lowmem
1018 on "Classic" PPC cores.
1022 nodisconnect [HW,SCSI,M68K] Disables SCSI disconnects.
1026 noexec [IA-32,X86-64]
1027 noexec=on: enable non-executable mappings (default)
1028 noexec=off: disable nn-executable mappings
1030 nofxsr [BUGS=IA-32] Disables x86 floating point extended
1031 register save and restore. The kernel will only save
1032 legacy floating-point registers on task switch.
1036 no-hlt [BUGS=IA-32] Tells the kernel that the hlt
1037 instruction doesn't work correctly and not to
1040 nohalt [IA-64] Tells the kernel not to use the power saving
1041 function PAL_HALT_LIGHT when idle. This increases
1042 power-consumption. On the positive side, it reduces
1043 interrupt wake-up latency, which may improve performance
1044 in certain environments such as networked servers or
1047 noirqdebug [IA-32] Disables the code which attempts to detect and
1048 disable unhandled interrupt sources.
1050 noisapnp [ISAPNP] Disables ISA PnP code.
1052 noinitrd [RAM] Tells the kernel not to load any configured
1057 nolapic [IA-32,APIC] Do not enable or use the local APIC.
1059 noltlbs [PPC] Do not use large page/tlb entries for kernel
1060 lowmem mapping on PPC40x.
1062 nomca [IA-64] Disable machine check abort handling
1064 nomce [IA-32] Machine Check Exception
1066 noresidual [PPC] Don't use residual data on PReP machines.
1068 noresume [SWSUSP] Disables resume and restores original swap
1071 no-scroll [VGA] Disables scrollback.
1072 This is required for the Braillex ib80-piezo Braille
1073 reader made by F.H. Papenmeier (Germany).
1077 nosep [BUGS=IA-32] Disables x86 SYSENTER/SYSEXIT support.
1079 nosmp [SMP] Tells an SMP kernel to act as a UP kernel.
1081 nosync [HW,M68K] Disables sync negotiation for all devices.
1083 notsc [BUGS=IA-32] Disable Time Stamp Counter
1085 nousb [USB] Disable the USB subsystem
1089 nr_uarts= [SERIAL] maximum number of UARTs to be registered.
1095 Format: <io>,<irq>,<dma>,<dma2>,<mpu_io>,<mpu_irq>
1097 opl3sa2= [HW,OSS] Format:
1098 <io>,<irq>,<dma>,<dma2>,<mss_io>,<mpu_io>,<ymode>,<loopback>[,<isapnp>,<multiple]
1100 oprofile.timer= [HW]
1101 Use timer interrupt instead of performance counters
1106 osst= [HW,SCSI] SCSI Tape Driver
1107 Format: <buffer_size>,<write_threshold>
1108 See also Documentation/scsi/st.txt.
1110 panic= [KNL] Kernel behaviour on panic
1113 parkbd.port= [HW] Parallel port number the keyboard adapter is
1114 connected to, default is 0.
1116 parkbd.mode= [HW] Parallel port keyboard adapter mode of operation,
1117 0 for XT, 1 for AT (default is AT).
1120 parport= [HW,PPT] Specify parallel ports. 0 disables.
1121 Format: { 0 | auto | 0xBBB[,IRQ[,DMA]] }
1122 Use 'auto' to force the driver to use any
1123 IRQ/DMA settings detected (the default is to
1124 ignore detected IRQ/DMA settings because of
1125 possible conflicts). You can specify the base
1126 address, IRQ, and DMA settings; IRQ and DMA
1127 should be numbers, or 'auto' (for using detected
1128 settings on that particular port), or 'nofifo'
1129 (to avoid using a FIFO even if it is detected).
1130 Parallel ports are assigned in the order they
1131 are specified on the command line, starting
1134 parport_init_mode= [HW,PPT]
1135 Configure VIA parallel port to operate in
1136 a specific mode. This is necessary on Pegasos
1137 computer where firmware has no options for setting
1138 up parallel port mode and sets it to spp.
1139 Currently this function knows 686a and 8231 chips.
1140 Format: [spp|ps2|epp|ecp|ecpepp]
1142 pas2= [HW,OSS] Format:
1143 <io>,<irq>,<dma>,<dma16>,<sb_io>,<sb_irq>,<sb_dma>,<sb_dma16>
1146 See header of drivers/scsi/pas16.c.
1149 Halt all CPUs after the first oops has been printed for
1150 the specified number of seconds. This is to be used if
1151 your oopses keep scrolling off the screen.
1156 See header of drivers/block/paride/pcd.c.
1157 See also Documentation/paride.txt.
1159 pci=option[,option...] [PCI] various PCI subsystem options:
1160 off [IA-32] don't probe for the PCI bus
1161 bios [IA-32] force use of PCI BIOS, don't access
1162 the hardware directly. Use this if your machine
1163 has a non-standard PCI host bridge.
1164 nobios [IA-32] disallow use of PCI BIOS, only direct
1165 hardware access methods are allowed. Use this
1166 if you experience crashes upon bootup and you
1167 suspect they are caused by the BIOS.
1168 conf1 [IA-32] Force use of PCI Configuration
1170 conf2 [IA-32] Force use of PCI Configuration
1172 nommconf [IA-32,X86_64] Disable use of MMCONFIG for PCI
1174 nomsi [MSI] If the PCI_MSI kernel config parameter is
1175 enabled, this kernel boot option can be used to
1176 disable the use of MSI interrupts system-wide.
1177 nosort [IA-32] Don't sort PCI devices according to
1178 order given by the PCI BIOS. This sorting is
1179 done to get a device order compatible with
1181 biosirq [IA-32] Use PCI BIOS calls to get the interrupt
1182 routing table. These calls are known to be buggy
1183 on several machines and they hang the machine
1184 when used, but on other computers it's the only
1185 way to get the interrupt routing table. Try
1186 this option if the kernel is unable to allocate
1187 IRQs or discover secondary PCI buses on your
1189 rom [IA-32] Assign address space to expansion ROMs.
1190 Use with caution as certain devices share
1191 address decoders between ROMs and other
1193 irqmask=0xMMMM [IA-32] Set a bit mask of IRQs allowed to be
1194 assigned automatically to PCI devices. You can
1195 make the kernel exclude IRQs of your ISA cards
1197 pirqaddr=0xAAAAA [IA-32] Specify the physical address
1198 of the PIRQ table (normally generated
1199 by the BIOS) if it is outside the
1200 F0000h-100000h range.
1201 lastbus=N [IA-32] Scan all buses thru bus #N. Can be
1202 useful if the kernel is unable to find your
1203 secondary buses and you want to tell it
1204 explicitly which ones they are.
1205 assign-busses [IA-32] Always assign all PCI bus
1206 numbers ourselves, overriding
1207 whatever the firmware may have done.
1208 usepirqmask [IA-32] Honor the possible IRQ mask stored
1209 in the BIOS $PIR table. This is needed on
1210 some systems with broken BIOSes, notably
1211 some HP Pavilion N5400 and Omnibook XE3
1212 notebooks. This will have no effect if ACPI
1213 IRQ routing is enabled.
1214 noacpi [IA-32] Do not use ACPI for IRQ routing
1215 or for PCI scanning.
1216 routeirq Do IRQ routing for all PCI devices.
1217 This is normally done in pci_enable_device(),
1218 so this option is a temporary workaround
1219 for broken drivers that don't call it.
1220 firmware [ARM] Do not re-enumerate the bus but instead
1221 just use the configuration from the
1222 bootloader. This is currently used on
1223 IXP2000 systems where the bus has to be
1224 configured a certain way for adjunct CPUs.
1226 pcmv= [HW,PCMCIA] BadgePAD 4
1229 See Documentation/paride.txt.
1231 pdcchassis= [PARISC,HW] Disable/Enable PDC Chassis Status codes at
1234 See arch/parisc/kernel/pdc_chassis.c
1237 See Documentation/paride.txt.
1240 See Documentation/paride.txt.
1242 pirq= [SMP,APIC] Manual mp-table setup
1243 See Documentation/i386/IO-APIC.txt.
1245 plip= [PPT,NET] Parallel port network link
1246 Format: { parport<nr> | timid | 0 }
1247 See also Documentation/parport.txt.
1253 { on | off | curr | res | no-curr | no-res }
1256 [ISAPNP] Exclude IRQs for the autoconfiguration
1259 [ISAPNP] Exclude DMAs for the autoconfiguration
1261 pnp_reserve_io= [ISAPNP] Exclude I/O ports for the autoconfiguration
1262 Ranges are in pairs (I/O port base and size).
1265 [ISAPNP] Exclude memory regions for the
1267 Ranges are in pairs (memory base and size).
1269 profile= [KNL] Enable kernel profiling via /proc/profile
1270 Format: [schedule,]<number>
1271 Param: "schedule" - profile schedule points.
1272 Param: <number> - step/bucket size as a power of 2 for
1273 statistical time based profiling.
1275 processor.max_cstate= [HW,ACPI]
1276 Limit processor to maximum C-state
1277 max_cstate=9 overrides any DMI blacklist limit.
1279 processor.nocst [HW,ACPI]
1280 Ignore the _CST method to determine C-states,
1281 instead using the legacy FADT method
1283 prompt_ramdisk= [RAM] List of RAM disks to prompt for floppy disk
1285 See Documentation/ramdisk.txt.
1287 psmouse.proto= [HW,MOUSE] Highest PS2 mouse protocol extension to
1288 probe for; one of (bare|imps|exps|lifebook|any).
1289 psmouse.rate= [HW,MOUSE] Set desired mouse report rate, in reports
1291 psmouse.resetafter= [HW,MOUSE]
1292 Try to reset the device after so many bad packets
1295 [HW,MOUSE] Set desired mouse resolution, in dpi.
1296 psmouse.smartscroll=
1297 [HW,MOUSE] Controls Logitech smartscroll autorepeat.
1298 0 = disabled, 1 = enabled (default).
1300 pss= [HW,OSS] Personal Sound System (ECHO ESC614)
1302 <io>,<mss_io>,<mss_irq>,<mss_dma>,<mpu_io>,<mpu_irq>
1305 See Documentation/paride.txt.
1307 quiet= [KNL] Disable log messages
1312 See Documentation/md.txt.
1314 ramdisk= [RAM] Sizes of RAM disks in kilobytes [deprecated]
1315 See Documentation/ramdisk.txt.
1317 ramdisk_blocksize= [RAM]
1318 See Documentation/ramdisk.txt.
1320 ramdisk_size= [RAM] Sizes of RAM disks in kilobytes
1321 New name for the ramdisk parameter.
1322 See Documentation/ramdisk.txt.
1324 rcu.blimit= [KNL,BOOT] Set maximum number of finished
1325 RCU callbacks to process in one batch.
1327 rcu.qhimark= [KNL,BOOT] Set threshold of queued
1328 RCU callbacks over which batch limiting is disabled.
1330 rcu.qlowmark= [KNL,BOOT] Set threshold of queued
1331 RCU callbacks below which batch limiting is re-enabled.
1333 rcu.rsinterval= [KNL,BOOT,SMP] Set the number of additional
1334 RCU callbacks to queued before forcing reschedule
1339 Run specified binary instead of /init from the ramdisk,
1340 used for early userspace startup. See initrd.
1342 reboot= [BUGS=IA-32,BUGS=ARM,BUGS=IA-64] Rebooting mode
1343 Format: <reboot_mode>[,<reboot_mode2>[,...]]
1344 See arch/*/kernel/reboot.c.
1346 reserve= [KNL,BUGS] Force the kernel to ignore some iomem area
1349 Specify the partition device for software suspend
1351 rhash_entries= [KNL,NET]
1352 Set number of hash buckets for route cache
1354 riscom8= [HW,SERIAL]
1355 Format: <io_board1>[,<io_board2>[,...<io_boardN>]]
1357 ro [KNL] Mount root device read-only on boot
1359 root= [KNL] Root filesystem
1361 rootdelay= [KNL] Delay (in seconds) to pause before attempting to
1362 mount the root filesystem
1364 rootflags= [KNL] Set root filesystem mount option string
1366 rootfstype= [KNL] Set root filesystem type
1368 rw [KNL] Mount root device read-write on boot
1370 S [KNL] Run init in single mode
1373 See drivers/net/irda/sa1100_ir.c.
1376 Format: <io>,<irq>,<dma>,<dma2>
1378 sbni= [NET] Granch SBNI12 leased line adapter
1380 sbpcd= [HW,CD] Soundblaster CD adapter
1382 See a comment before function sbpcd_setup() in
1383 drivers/cdrom/sbpcd.c.
1385 sc1200wdt= [HW,WDT] SC1200 WDT (watchdog) driver
1386 Format: <io>[,<timeout>[,<isapnp>]]
1388 scsi_debug_*= [SCSI]
1389 See drivers/scsi/scsi_debug.c.
1391 scsi_default_dev_flags=
1392 [SCSI] SCSI default device flags
1395 scsi_dev_flags= [SCSI] Black/white list entry for vendor and model
1396 Format: <vendor>:<model>:<flags>
1397 (flags are integer value)
1399 scsi_logging= [SCSI]
1401 selinux [SELINUX] Disable or enable SELinux at boot time.
1402 Format: { "0" | "1" }
1403 See security/selinux/Kconfig help text.
1406 Default value is set via kernel config option.
1407 If enabled at boot time, /selinux/disable can be used
1408 later to disable prior to initial policy load.
1410 selinux_compat_net =
1411 [SELINUX] Set initial selinux_compat_net flag value.
1412 Format: { "0" | "1" }
1413 0 -- use new secmark-based packet controls
1414 1 -- use legacy packet controls
1415 Default value is 0 (preferred).
1416 Value can be changed at runtime via
1417 /selinux/compat_net.
1419 serialnumber [BUGS=IA-32]
1421 sg_def_reserved_size= [SCSI]
1424 Format: <io>,<irq>,<dma>,<dma2>,<sgbase>
1427 Maximal number of shapers.
1430 See header of drivers/scsi/sim710.c.
1436 Format: <io>,<irq>,<dma>
1437 See header of drivers/cdrom/sjcd.c.
1442 Format: <io1>[,<io2>[,...,<io8>]]
1444 snd-ad1816a= [HW,ALSA]
1446 snd-ad1848= [HW,ALSA]
1448 snd-ali5451= [HW,ALSA]
1450 snd-als100= [HW,ALSA]
1452 snd-als4000= [HW,ALSA]
1454 snd-azt2320= [HW,ALSA]
1456 snd-cmi8330= [HW,ALSA]
1458 snd-cmipci= [HW,ALSA]
1460 snd-cs4231= [HW,ALSA]
1462 snd-cs4232= [HW,ALSA]
1464 snd-cs4236= [HW,ALSA]
1466 snd-cs4281= [HW,ALSA]
1468 snd-cs46xx= [HW,ALSA]
1470 snd-dt019x= [HW,ALSA]
1472 snd-dummy= [HW,ALSA]
1474 snd-emu10k1= [HW,ALSA]
1476 snd-ens1370= [HW,ALSA]
1478 snd-ens1371= [HW,ALSA]
1480 snd-es968= [HW,ALSA]
1482 snd-es1688= [HW,ALSA]
1484 snd-es18xx= [HW,ALSA]
1486 snd-es1938= [HW,ALSA]
1488 snd-es1968= [HW,ALSA]
1490 snd-fm801= [HW,ALSA]
1492 snd-gusclassic= [HW,ALSA]
1494 snd-gusextreme= [HW,ALSA]
1496 snd-gusmax= [HW,ALSA]
1500 snd-ice1712= [HW,ALSA]
1502 snd-intel8x0= [HW,ALSA]
1504 snd-interwave= [HW,ALSA]
1509 snd-korg1212= [HW,ALSA]
1511 snd-maestro3= [HW,ALSA]
1513 snd-mpu401= [HW,ALSA]
1515 snd-mtpav= [HW,ALSA]
1517 snd-nm256= [HW,ALSA]
1519 snd-opl3sa2= [HW,ALSA]
1527 snd-opti93x= [HW,ALSA]
1531 snd-rme32= [HW,ALSA]
1533 snd-rme96= [HW,ALSA]
1535 snd-rme9652= [HW,ALSA]
1541 snd-sbawe= [HW,ALSA]
1543 snd-serial= [HW,ALSA]
1545 snd-sgalaxy= [HW,ALSA]
1547 snd-sonicvibes= [HW,ALSA]
1552 snd-sun-cs4231= [HW,ALSA]
1554 snd-trident= [HW,ALSA]
1556 snd-usb-audio= [HW,ALSA,USB]
1558 snd-via82xx= [HW,ALSA]
1560 snd-virmidi= [HW,ALSA]
1562 snd-wavefront= [HW,ALSA]
1564 snd-ymfpci= [HW,ALSA]
1566 sonicvibes= [HW,OSS]
1570 Format: <io>[,<irq>]
1572 sonypi.*= [HW] Sony Programmable I/O Control Device driver
1573 See Documentation/sonypi.txt
1575 specialix= [HW,SERIAL] Specialix multi-serial port adapter
1576 See Documentation/specialix.txt.
1578 spia_io_base= [HW,MTD]
1584 Format: <io>,<irq>,<dma>,<mpu_io>,<mpu_irq>
1586 st= [HW,SCSI] SCSI tape parameters (buffers, etc.)
1587 See Documentation/scsi/st.txt.
1590 See header of drivers/scsi/seagate.c.
1594 Set the STI (builtin display/keyboard on the HP-PARISC
1595 machines) console (graphic card) which should be used
1596 as the initial boot-console.
1597 See also comment in drivers/video/console/sticore.c.
1600 See comment in drivers/video/console/sticore.c.
1603 Format: bpp:<bpp1>[:<bpp2>[:<bpp3>...]]
1605 swiotlb= [IA-64] Number of I/O TLB slabs
1609 sym53c416= [HW,SCSI]
1610 See header of drivers/scsi/sym53c416.c.
1613 See header of drivers/scsi/t128.c.
1617 thash_entries= [KNL,NET]
1618 Set number of hash buckets for TCP connection
1620 time Show timing data prefixed to each printk message line
1622 clocksource= [GENERIC_TIME] Override the default clocksource
1623 Override the default clocksource and use the clocksource
1624 with the name specified.
1626 tipar.timeout= [HW,PPT]
1627 Set communications timeout in tenths of a second
1630 tipar.delay= [HW,PPT]
1631 Set inter-bit delay in microseconds (default 10).
1634 See header of drivers/scsi/seagate.c.
1637 See comment before function dc390_setup() in
1638 drivers/scsi/tmscsim.c.
1642 trix= [HW,OSS] MediaTrix AudioTrix Pro
1644 <io>,<irq>,<dma>,<dma2>,<sb_io>,<sb_irq>,<sb_dma>,<mpu_io>,<mpu_irq>
1646 tsdev.xres= [TS] Horizontal screen resolution.
1647 tsdev.yres= [TS] Vertical screen resolution.
1649 turbografx.map[2|3]= [HW,JOY]
1650 TurboGraFX parallel port interface
1652 <port#>,<js1>,<js2>,<js3>,<js4>,<js5>,<js6>,<js7>
1653 See also Documentation/input/joystick-parport.txt
1655 u14-34f= [HW,SCSI] UltraStor 14F/34F SCSI host adapter
1656 See header of drivers/scsi/u14-34f.c.
1665 [USBHID] The interval which mice are to be polled at.
1667 video= [FB] Frame buffer configuration
1668 See Documentation/fb/modedb.txt.
1670 vga= [BOOT,IA-32] Select a particular video mode
1671 See Documentation/i386/boot.txt and
1672 Documentation/svga.txt.
1673 Use vga=ask for menu.
1674 This is actually a boot loader parameter; the value is
1675 passed to the kernel using a special protocol.
1677 vmalloc=nn[KMG] [KNL,BOOT] Forces the vmalloc area to have an exact
1678 size of <nn>. This can be used to increase the
1679 minimum size (128MB on x86). It can also be used to
1680 decrease the size and leave more room for directly
1687 waveartist= [HW,OSS]
1688 Format: <io>,<irq>,<dma>,<dma2>
1691 See header of drivers/scsi/wd33c93.c.
1694 See header of drivers/scsi/wd7000.c.
1697 See Documentation/watchdog/watchdog.txt.
1699 xd= [HW,XT] Original XT pre-IDE (RLL encoded) disks.
1700 xd_geo= See header of drivers/block/xd.c.
1702 xirc2ps_cs= [NET,PCMCIA]
1704 <irq>,<irq_mask>,<io>,<full_duplex>,<do_sound>,<lockup_hack>[,<irq2>[,<irq3>[,<irq4>]]]
1706 norandmaps Don't use address space randomization
1707 Equivalent to echo 0 > /proc/sys/kernel/randomize_va_space
1710 ______________________________________________________________________
1714 Add documentation for ALSA options.
1715 Add more DRM drivers.