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 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 Note that ALL kernel parameters listed below are CASE SENSITIVE, and that
108 a trailing = on the name of any parameter states that that parameter will
109 be entered as an environment variable, whereas its absence indicates that
110 it will appear as a kernel argument readable via /proc/cmdline by programs
111 running once the system is up.
113 53c7xx= [HW,SCSI] Amiga SCSI controllers
114 See header of drivers/scsi/53c7xx.c.
115 See also Documentation/scsi/ncr53c7xx.txt.
117 acpi= [HW,ACPI] Advanced Configuration and Power Interface
118 Format: { force | off | ht | strict | noirq }
119 force -- enable ACPI if default was off
120 off -- disable ACPI if default was on
121 noirq -- do not use ACPI for IRQ routing
122 ht -- run only enough ACPI to enable Hyper Threading
123 strict -- Be less tolerant of platforms that are not
124 strictly ACPI specification compliant.
126 See also Documentation/pm.txt, pci=noacpi
128 acpi_sleep= [HW,ACPI] Sleep options
129 Format: { s3_bios, s3_mode }
130 See Documentation/power/video.txt
132 acpi_sci= [HW,ACPI] ACPI System Control Interrupt trigger mode
133 Format: { level | edge | high | low }
135 acpi_irq_balance [HW,ACPI]
136 ACPI will balance active IRQs
139 acpi_irq_nobalance [HW,ACPI]
140 ACPI will not move active IRQs (default)
143 acpi_irq_pci= [HW,ACPI] If irq_balance, clear listed IRQs for
145 Format: <irq>,<irq>...
147 acpi_irq_isa= [HW,ACPI] If irq_balance, mark listed IRQs used by ISA
148 Format: <irq>,<irq>...
150 acpi_os_name= [HW,ACPI] Tell ACPI BIOS the name of the OS
151 Format: To spoof as Windows 98: ="Microsoft Windows"
153 acpi_osi= [HW,ACPI] empty param disables _OSI
155 acpi_serialize [HW,ACPI] force serialization of AML methods
157 acpi_skip_timer_override [HW,ACPI]
158 Recognize and ignore IRQ0/pin2 Interrupt Override.
159 For broken nForce2 BIOS resulting in XT-PIC timer.
161 acpi_dbg_layer= [HW,ACPI]
163 Each bit of the <int> indicates an ACPI debug layer,
164 1: enable, 0: disable. It is useful for boot time
165 debugging. After system has booted up, it can be set
166 via /proc/acpi/debug_layer.
168 acpi_dbg_level= [HW,ACPI]
170 Each bit of the <int> indicates an ACPI debug level,
171 1: enable, 0: disable. It is useful for boot time
172 debugging. After system has booted up, it can be set
173 via /proc/acpi/debug_level.
175 acpi_fake_ecdt [HW,ACPI] Workaround failure due to BIOS lacking ECDT
177 acpi_generic_hotkey [HW,ACPI]
178 Allow consolidated generic hotkey driver to
179 override platform specific driver.
180 See also Documentation/acpi-hotkey.txt.
182 enable_timer_pin_1 [i386,x86-64]
183 Enable PIN 1 of APIC timer
184 Can be useful to work around chipset bugs
185 (in particular on some ATI chipsets).
186 The kernel tries to set a reasonable default.
188 disable_timer_pin_1 [i386,x86-64]
189 Disable PIN 1 of APIC timer
190 Can be useful to work around chipset bugs.
193 Format: <io>,<irq>,<dma>,<dma2>
194 See also Documentation/sound/oss/AD1816.
197 Format: <io>,<irq>,<dma>,<dma2>,<type>
203 See header of drivers/scsi/advansys.c.
205 advwdt= [HW,WDT] Advantech WDT
206 Format: <iostart>,<iostop>
208 aedsp16= [HW,OSS] Audio Excel DSP 16
209 Format: <io>,<irq>,<dma>,<mss_io>,<mpu_io>,<mpu_irq>
210 See also header of sound/oss/aedsp16.c.
213 See Documentation/scsi/aha152x.txt.
216 Format: <portbase>[,<buson>,<busoff>[,<dmaspeed>]]
219 See Documentation/scsi/aic7xxx.txt.
222 See Documentation/scsi/aic79xx.txt.
224 amijoy.map= [HW,JOY] Amiga joystick support
225 Map of devices attached to JOY0DAT and JOY1DAT
227 See also Documentation/kernel/input/joystick.txt
229 analog.map= [HW,JOY] Analog joystick and gamepad support
230 Specifies type or capabilities of an analog joystick
231 connected to one of 16 gameports
232 Format: <type1>,<type2>,..<type16>
235 Power management functions (SPARCstation-4/5 + deriv.)
237 Disable APC CPU standby support. SPARCstation-Fox does
238 not play well with APC CPU idle - disable it if you have
239 APC and your system crashes randomly.
241 apic= [APIC,i386] Change the output verbosity whilst booting
242 Format: { quiet (default) | verbose | debug }
243 Change the amount of debugging information output
244 when initialising the APIC and IO-APIC components.
246 apm= [APM] Advanced Power Management
247 See header of arch/i386/kernel/apm.c.
252 arcrimi= [HW,NET] ARCnet - "RIM I" (entirely mem-mapped) cards
253 Format: <io>,<irq>,<nodeID>
257 atarimouse= [HW,MOUSE] Atari Mouse
259 atascsi= [HW,SCSI] Atari SCSI
261 atkbd.extra= [HW] Enable extra LEDs and keys on IBM RapidAccess,
262 EzKey and similar keyboards
264 atkbd.reset= [HW] Reset keyboard during initialization
266 atkbd.set= [HW] Select keyboard code set
267 Format: <int> (2 = AT (default), 3 = PS/2)
269 atkbd.scroll= [HW] Enable scroll wheel on MS Office and similar
272 atkbd.softraw= [HW] Choose between synthetic and real raw mode
273 Format: <bool> (0 = real, 1 = synthetic (default))
275 atkbd.softrepeat= [HW]
276 Use software keyboard repeat
280 awe= [HW,OSS] AWE32/SB32/AWE64 wave table synth
281 Format: <io>,<memsize>,<isapnp>
283 aztcd= [HW,CD] Aztech CD268 CDROM driver
284 Format: <io>,0x79 (?)
286 baycom_epp= [HW,AX25]
289 baycom_par= [HW,AX25] BayCom Parallel Port AX.25 Modem
291 See header of drivers/net/hamradio/baycom_par.c.
293 baycom_ser_fdx= [HW,AX25]
294 BayCom Serial Port AX.25 Modem (Full Duplex Mode)
295 Format: <io>,<irq>,<mode>[,<baud>]
296 See header of drivers/net/hamradio/baycom_ser_fdx.c.
298 baycom_ser_hdx= [HW,AX25]
299 BayCom Serial Port AX.25 Modem (Half Duplex Mode)
300 Format: <io>,<irq>,<mode>
301 See header of drivers/net/hamradio/baycom_ser_hdx.c.
303 blkmtd_device= [HW,MTD]
309 bttv.card= [HW,V4L] bttv (bt848 + bt878 based grabber cards)
310 bttv.radio= Most important insmod options are available as
312 bttv.pll= See Documentation/video4linux/bttv/Insmod-options
313 bttv.tuner= and Documentation/video4linux/bttv/CARDLIST
316 See drivers/scsi/BusLogic.c, comment before function
317 BusLogic_ParseDriverOptions().
319 c101= [NET] Moxa C101 synchronous serial card
321 cachesize= [BUGS=IA-32] Override level 2 CPU cache size detection.
322 Sometimes CPU hardware bugs make them report the cache
323 size incorrectly. The kernel will attempt work arounds
324 to fix known problems, but for some CPUs it is not
325 possible to determine what the correct size should be.
326 This option provides an override for these situations.
329 Format: <io>,<irq>[,PAS]
330 See header of drivers/cdrom/cdu31a.c.
332 chandev= [HW,NET] Generic channel device initialisation
334 checkreqprot [SELINUX] Set initial checkreqprot flag value.
335 Format: { "0" | "1" }
336 See security/selinux/Kconfig help text.
337 0 -- check protection applied by kernel (includes
338 any implied execute protection).
339 1 -- check protection requested by application.
340 Default value is set via a kernel config option.
341 Value can be changed at runtime via
342 /selinux/checkreqprot.
344 clock= [BUGS=IA-32,HW] gettimeofday timesource override.
345 Forces specified timesource (if avaliable) to be used
346 when calculating gettimeofday(). If specicified
347 timesource is not avalible, it defaults to PIT.
348 Format: { pit | tsc | cyclone | pmtmr }
352 [IA32/X86_64] Disable/Enable interrupt 0 timer routing
353 over the 8254 in addition to over the IO-APIC. The
354 kernel tries to set a sensible default.
356 hpet= [IA-32,HPET] option to disable HPET and use PIT.
360 Format: { auto | [<io>,][<irq>] }
362 com20020= [HW,NET] ARCnet - COM20020 chipset
364 <io>[,<irq>[,<nodeID>[,<backplane>[,<ckp>[,<timeout>]]]]]
366 com90io= [HW,NET] ARCnet - COM90xx chipset (IO-mapped buffers)
370 ARCnet - COM90xx chipset (memory-mapped buffers)
371 Format: <io>[,<irq>[,<memstart>]]
373 condev= [HW,S390] console device
376 console= [KNL] Output console device and options.
378 tty<n> Use the virtual console device <n>.
382 Use the specified serial port. The options are of
383 the form "bbbbpnf", where "bbbb" is the baud rate,
384 "p" is parity ("n", "o", or "e"), "n" is number of
385 bits, and "f" is flow control ("r" for RTS or
386 omit it). Default is "9600n8".
388 See Documentation/serial-console.txt for more
390 Documentation/networking/netconsole.txt for an
393 uart,io,<addr>[,options]
394 uart,mmio,<addr>[,options]
395 Start an early, polled-mode console on the 8250/16550
396 UART at the specified I/O port or MMIO address,
397 switching to the matching ttyS device later. The
398 options are the same as for ttyS, above.
400 cpcihp_generic= [HW,PCI] Generic port I/O CompactPCI driver
402 <first_slot>,<last_slot>,<port>,<enum_bit>[,<debug>]
405 Format: { parport<nr> | auto | none }
407 crashkernel=nn[KMG]@ss[KMG]
408 [KNL] Reserve a chunk of physical memory to
409 hold a kernel to switch to with kexec on panic.
412 Format: <io>,<irq>,<dma>,<dma2>,<mpuio>,<mpuirq>
417 cs89x0_media= [HW,NET]
418 Format: { rj45 | aui | bnc }
420 cyclades= [HW,SERIAL] Cyclades multi-serial port adapter.
423 See header of drivers/s390/block/dasd_devmap.c.
425 db9.dev[2|3]= [HW,JOY] Multisystem joystick support via parallel port
426 (one device per port)
427 Format: <port#>,<type>
428 See also Documentation/input/joystick-parport.txt
430 debug [KNL] Enable kernel debugging (events log level).
433 Format: <area>[,<node>]
434 See also Documentation/networking/decnet.txt.
437 See Documentation/filesystems/devfs/boot-options.
440 Set number of hash buckets for dentry cache.
443 IO parameters + enable/disable command.
445 digiepca= [HW,SERIAL]
446 See drivers/char/README.epca and
447 Documentation/digiepca.txt.
449 dmascc= [HW,AX25,SERIAL] AX.25 Z80SCC driver with DMA
451 Format: <io_dev0>[,<io_dev1>[,..<io_dev32>]]
453 dmasound= [HW,OSS] Sound subsystem buffers
459 earlyprintk= [IA-32,X86-64]
461 earlyprintk=serial[,ttySn[,baudrate]]
463 Append ",keep" to not disable it when the real console
466 Only vga or serial at a time, not both.
468 Currently only ttyS0 and ttyS1 are supported.
470 Interaction with the standard serial driver is not
473 The VGA output is eventually overwritten by the real
478 ec_intr= [HW,ACPI] ACPI Embedded Controller interrupt mode
481 non-0: interrupt mode (default)
488 Format: {"of[f]" | "sk[ipmbr]"}
489 See comment in arch/i386/boot/edd.S
492 Format: <id>,<membase>,<irq>
494 eisa_irq_edge= [PARISC,HW]
495 See header of drivers/parisc/eisa.c.
498 See comment before function elanfreq_setup() in
499 arch/i386/kernel/cpu/cpufreq/elanfreq.c.
502 Format: {"anticipatory" | "cfq" | "deadline" | "noop"}
503 See Documentation/block/as-iosched.txt and
504 Documentation/block/deadline-iosched.txt for details.
506 elfcorehdr= [IA-32, X86_64]
507 Specifies physical address of start of kernel core
508 image elf header. Generally kexec loader will
509 pass this option to capture kernel.
510 See Documentation/kdump/kdump.txt for details.
512 enforcing [SELINUX] Set initial enforcing status.
514 See security/selinux/Kconfig help text.
515 0 -- permissive (log only, no denials).
516 1 -- enforcing (deny and log).
518 Value can be changed at runtime via /selinux/enforce.
521 Format: <lineout>[,<micbias>]
522 See also header of sound/oss/es1370.c.
525 Format: <spdif>,[<nomix>,[<amplifier>]]
526 See also header of sound/oss/es1371.c.
528 ether= [HW,NET] Ethernet cards parameters
529 This option is obsoleted by the "netdev=" option, which
530 has equivalent usage. See its documentation for details.
532 eurwdt= [HW,WDT] Eurotech CPU-1220/1410 onboard watchdog.
536 See header of drivers/scsi/fd_mcs.c.
539 See header of drivers/scsi/fdomain.c.
542 See Documentation/floppy.txt.
544 ftape= [HW] Floppy Tape subsystem debugging options.
545 See Documentation/ftape.txt.
548 [HW,JOY] Multisystem joystick and NES/SNES/PSX pad
549 support via parallel port (up to 5 devices per port)
550 Format: <port#>,<pad1>,<pad2>,<pad3>,<pad4>,<pad5>
551 See also Documentation/input/joystick-parport.txt
556 See header of drivers/scsi/gdth.c.
558 gpt [EFI] Forces disk with valid GPT signature but
559 invalid Protective MBR to be treated as GPT.
564 gt96100eth= [NET] MIPS GT96100 Advanced Communication Controller
567 Format: <io>,<irq>,<dma>,<dma16>
571 hashdist= [KNL,NUMA] Large hashes allocated during boot
572 are distributed across NUMA nodes. Defaults on
573 for IA-64, off otherwise.
574 Format: 0 | 1 (for off | on)
576 hcl= [IA-64] SGI's Hardware Graph compatibility layer
578 hd= [EIDE] (E)IDE hard drive subsystem geometry
579 Format: <cyl>,<head>,<sect>
581 hd?= [HW] (E)IDE subsystem
582 hd?lun= See Documentation/ide.txt.
584 highmem=nn[KMG] [KNL,BOOT] forces the highmem zone to have an exact
585 size of <nn>. This works even on boxes that have no
586 highmem otherwise. This also works to reduce highmem
587 size on bigger boxes.
590 See Documentation/isdn/README.HiSax.
592 hugepages= [HW,IA-32,IA-64] Maximal number of HugeTLB pages.
594 noirqbalance [IA-32,SMP,KNL] Disable kernel irq balancing
596 i8042.direct [HW] Put keyboard port into non-translated mode
597 i8042.dumbkbd [HW] Pretend that controlled can only read data from
598 keyboard and can not control its state
599 (Don't attempt to blink the leds)
600 i8042.noaux [HW] Don't check for auxiliary (== mouse) port
601 i8042.nokbd [HW] Don't check/create keyboard port
602 i8042.nomux [HW] Don't check presence of an active multiplexing
604 i8042.nopnp [HW] Don't use ACPIPnP / PnPBIOS to discover KBD/AUX
607 [HW] Frequency with which keyboard LEDs should blink
608 when kernel panics (default is 0.5 sec)
609 i8042.reset [HW] Reset the controller during init and cleanup
610 i8042.unlock [HW] Unlock (ignore) the keylock
614 i8k.ignore_dmi [HW] Continue probing hardware even if DMI data
615 indicates that the driver is running on unsupported
617 i8k.force [HW] Activate i8k driver even if SMM BIOS signature
618 does not match list of supported models.
620 [HW] Report power status in /proc/i8k
621 (disabled by default)
622 i8k.restricted [HW] Allow controlling fans only if SYS_ADMIN
625 ibmmcascsi= [HW,MCA,SCSI] IBM MicroChannel SCSI adapter
626 See Documentation/mca.txt.
629 Format: <io>[,<membase>[,<icn_id>[,<icn_id2>]]]
631 ide= [HW] (E)IDE subsystem
632 Format: ide=nodma or ide=doubler or ide=reverse
633 See Documentation/ide.txt.
635 ide?= [HW] (E)IDE subsystem
636 Format: ide?=noprobe or chipset specific parameters.
637 See Documentation/ide.txt.
639 idebus= [HW] (E)IDE subsystem - VLB/PCI bus speed
640 See Documentation/ide.txt.
643 Format: idle=poll or idle=halt
646 Set number of hash buckets for inode cache.
649 See header of drivers/scsi/in2000.c.
653 Run specified binary instead of /sbin/init as init
656 initcall_debug [KNL] Trace initcalls as they are executed. Useful
657 for working out where the kernel is dying during
660 initrd= [BOOT] Specify the location of the initial ramdisk
662 inport.irq= [HW] Inport (ATI XL and Microsoft) busmouse driver
665 combined_mode= [HW] control which driver uses IDE ports in combined
666 mode: legacy IDE driver, libata, or both
667 (in the libata case, libata.atapi_enabled=1 may be
668 useful as well). Note that using the ide or libata
669 options may affect your device naming (e.g. by
670 changing hdc to sdb).
671 Format: combined (default), ide, or libata
675 io7= [HW] IO7 for Marvel based alpha systems
676 See comment before marvel_specify_io7 in
677 arch/alpha/kernel/core_marvel.c.
680 See Documentation/nfsroot.txt.
682 ip2= [HW] Set IO/IRQ pairs for up to 4 IntelliPort boards
683 See comment before ip2_setup() in drivers/char/ip2.c.
685 ips= [HW,SCSI] Adaptec / IBM ServeRAID controller
686 See header of drivers/scsi/ips.c.
689 When an interrupt is not handled search all handlers
690 for it. Intended to get systems with badly broken
694 When an interrupt is not handled search all handlers
695 for it. Also check all handlers each timer
696 interrupt. Intended to get systems with badly broken
700 Format: <RDP>,<reset>,<pci_scan>,<verbosity>
702 isolcpus= [KNL,SMP] Isolate CPUs from the general scheduler.
703 Format: <cpu number>,...,<cpu number>
704 This option can be used to specify one or more CPUs
705 to isolate from the general SMP balancing and scheduling
706 algorithms. The only way to move a process onto or off
707 an "isolated" CPU is via the CPU affinity syscalls.
708 <cpu number> begins at 0 and the maximum value is
709 "number of CPUs in system - 1".
711 This option is the preferred way to isolate CPUs. The
712 alternative -- manually setting the CPU mask of all
713 tasks in the system -- can cause problems and
714 suboptimal load balancer performance.
717 Format: <io>,<irq>,<dma>,<setup>
721 js= [HW,JOY] Analog joystick
722 See Documentation/input/joystick.txt.
726 kstack=N [IA-32,X86-64] Print N words from the kernel stack
731 lapic [IA-32,APIC] Enable the local APIC even if BIOS
734 lasi= [HW,SCSI] PARISC LASI driver for the 53c700 chip
735 Format: addr:<io>,irq:<irq>
737 llsc*= [IA64] See function print_params() in
738 arch/ia64/sn/kernel/llsc4.c.
740 load_ramdisk= [RAM] List of ramdisks to load from floppy
741 See Documentation/ramdisk.txt.
743 lockd.nlm_grace_period=P [NFS] Assign grace period.
746 lockd.nlm_tcpport=N [NFS] Assign TCP port.
749 lockd.nlm_timeout=T [NFS] Assign timeout value.
752 lockd.nlm_udpport=M [NFS] Assign UDP port.
755 logibm.irq= [HW,MOUSE] Logitech Bus Mouse Driver
758 loglevel= All Kernel Messages with a loglevel smaller than the
759 console loglevel will be printed to the console. It can
760 also be changed with klogd or other programs. The
761 loglevels are defined as follows:
763 0 (KERN_EMERG) system is unusable
764 1 (KERN_ALERT) action must be taken immediately
765 2 (KERN_CRIT) critical conditions
766 3 (KERN_ERR) error conditions
767 4 (KERN_WARNING) warning conditions
768 5 (KERN_NOTICE) normal but significant condition
769 6 (KERN_INFO) informational
770 7 (KERN_DEBUG) debug-level messages
772 log_buf_len=n Sets the size of the printk ring buffer, in bytes.
773 Format: { n | nk | nM }
774 n must be a power of two. The default size
775 is set in the kernel config file.
777 lp=0 [LP] Specify parallel ports to use, e.g,
778 lp=port[,port...] lp=none,parport0 (lp0 not configured, lp1 uses
779 lp=reset first parallel port). 'lp=0' disables the
780 lp=auto printer driver. 'lp=reset' (which can be
781 specified in addition to the ports) causes
782 attached printers to be reset. Using
783 lp=port1,port2,... specifies the parallel ports
784 to associate lp devices with, starting with
785 lp0. A port specification may be 'none' to skip
786 that lp device, or a parport name such as
787 'parport0'. Specifying 'lp=auto' instead of a
788 port specification list means that device IDs
789 from each port should be examined, to see if
790 an IEEE 1284-compliant printer is attached; if
791 so, the driver will manage that printer.
792 See also header of drivers/char/lp.c.
795 Sets loops_per_jiffy to given constant, thus avoiding
796 time-consuming boot-time autodetection (up to 250 ms per
797 CPU). 0 enables autodetection (default). To determine
798 the correct value for your kernel, boot with normal
799 autodetection and see what value is printed. Note that
800 on SMP systems the preset will be applied to all CPUs,
801 which is likely to cause problems if your CPUs need
802 significantly divergent settings. An incorrect value
803 will cause delays in the kernel to be wrong, leading to
804 unpredictable I/O errors and other breakage. Although
805 unlikely, in the extreme case this might damage your
809 Format: <io>,<irq>,<dma>
811 mac5380= [HW,SCSI] Format:
812 <can_queue>,<cmd_per_lun>,<sg_tablesize>,<hostid>,<use_tags>
814 mac53c9x= [HW,SCSI] Format:
815 <num_esps>,<disconnect>,<nosync>,<can_queue>,<cmd_per_lun>,<sg_tablesize>,<hostid>,<use_tags>
817 machvec= [IA64] Force the use of a particular machine-vector
818 (machvec) in a generic kernel.
819 Example: machvec=hpzx1_swiotlb
821 mad16= [HW,OSS] Format:
822 <io>,<irq>,<dma>,<dma16>,<mpu_io>,<mpu_irq>,<joystick>
827 max_loop= [LOOP] Maximum number of loopback devices that can
831 maxcpus= [SMP] Maximum number of processors that an SMP kernel
834 max_addr=[KMG] [KNL,BOOT,ia64] All physical memory greater than or
835 equal to this physical address is ignored.
837 max_luns= [SCSI] Maximum number of LUNs to probe.
838 Should be between 1 and 2^32-1.
841 [SCSI] Maximum number of LUNs received.
842 Should be between 1 and 16384.
844 mca-pentium [BUGS=IA-32]
849 Format: <port>,<irq>,<mitsumi_bug_93_wait>
853 mce [IA-32] Machine Check Exception
855 md= [HW] RAID subsystems devices and level
856 See Documentation/md.txt.
859 Format: <first>,<last>
860 Specifies range of consoles to be captured by the MDA.
862 mem=nn[KMG] [KNL,BOOT] Force usage of a specific amount of memory
863 Amount of memory to be used when the kernel is not able
864 to see the whole system memory or for test.
865 [IA-32] Use together with memmap= to avoid physical
866 address space collisions. Without memmap= PCI devices
867 could be placed at addresses belonging to unused RAM.
869 mem=nopentium [BUGS=IA-32] Disable usage of 4MB pages for kernel
872 memmap=exactmap [KNL,IA-32,X86_64] Enable setting of an exact
873 E820 memory map, as specified by the user.
874 Such memmap=exactmap lines can be constructed based on
875 BIOS output or other requirements. See the memmap=nn@ss
878 memmap=nn[KMG]@ss[KMG]
879 [KNL] Force usage of a specific region of memory
880 Region of memory to be used, from ss to ss+nn.
882 memmap=nn[KMG]#ss[KMG]
883 [KNL,ACPI] Mark specific memory as ACPI data.
884 Region of memory to be used, from ss to ss+nn.
886 memmap=nn[KMG]$ss[KMG]
887 [KNL,ACPI] Mark specific memory as reserved.
888 Region of memory to be used, from ss to ss+nn.
890 meye.*= [HW] Set MotionEye Camera parameters
891 See Documentation/video4linux/meye.txt.
896 [KNL,SMP] debug: override scheduler migration costs
897 Format: <level-1-usecs>,<level-2-usecs>,...
898 This debugging option can be used to override the
899 default scheduler migration cost matrix. The numbers
900 are indexed by 'CPU domain distance'.
901 E.g. migration_cost=1000,2000,3000 on an SMT NUMA
902 box will set up an intra-core migration cost of
903 1 msec, an inter-core migration cost of 2 msecs,
904 and an inter-node migration cost of 3 msecs.
906 WARNING: using the wrong values here can break
907 scheduler performance, so it's only for scheduler
908 development purposes, not production environments.
911 [KNL,SMP] migration cost auto-detect verbosity
913 If a system's migration matrix reported at bootup
914 seems erroneous then this option can be used to
915 increase verbosity of the detection process.
916 We default to 0 (no extra messages), 1 will print
917 some more information, and 2 will be really
918 verbose (probably only useful if you also have a
919 serial console attached to the system).
922 [KNL,SMP] multiply/divide migration costs by a factor
924 This debug option can be used to proportionally
925 increase or decrease the auto-detected migration
926 costs for all entries of the migration matrix.
927 E.g. migration_factor=150 will increase migration
928 costs by 50%. (and thus the scheduler will be less
929 eager migrating cache-hot tasks)
930 migration_factor=80 will decrease migration costs
931 by 20%. (thus the scheduler will be more eager to
934 WARNING: using the wrong values here can break
935 scheduler performance, so it's only for scheduler
936 development purposes, not production environments.
939 [MOUSE] Maximum time between finger touching and
940 leaving touchpad surface for touch to be considered
941 a tap and be reported as a left button click (for
942 touchpads working in absolute mode only).
944 mousedev.xres= [MOUSE] Horizontal screen resolution, used for devices
945 reporting absolute coordinates, such as tablets
946 mousedev.yres= [MOUSE] Vertical screen resolution, used for devices
947 reporting absolute coordinates, such as tablets
953 Format: <name>,<region-number>,<size>,<offset>
955 MTD_Region= [MTD] Format:
956 <name>,<region-number>[,<base>,<size>,<buswidth>,<altbuswidth>]
959 See drivers/mtd/cmdline.c.
961 mtouchusb.raw_coordinates=
962 [HW] Make the MicroTouch USB driver use raw coordinates
963 ('y', default) or cooked coordinates ('n')
965 n2= [NET] SDL Inc. RISCom/N2 synchronous serial card
968 See header of drivers/scsi/NCR_D700.c.
974 ncr53c400a= [HW,SCSI]
976 ncr53c406a= [HW,SCSI]
980 netdev= [NET] Network devices parameters
981 Format: <irq>,<io>,<mem_start>,<mem_end>,<name>
982 Note that mem_start is often overloaded to mean
983 something different and driver-specific.
984 This usage is only documented in each driver source
988 See Documentation/nfsroot.txt.
990 nfsroot= [NFS] nfs root filesystem for disk-less boxes.
991 See Documentation/nfsroot.txt.
993 nfs.callback_tcpport=
994 [NFS] set the TCP port on which the NFSv4 callback
995 channel should listen.
997 nfs.idmap_cache_timeout=
998 [NFS] set the maximum lifetime for idmapper cache
1001 nmi_watchdog= [KNL,BUGS=IA-32] Debugging features for SMP kernels
1003 no387 [BUGS=IA-32] Tells the kernel to use the 387 maths
1004 emulation library even if a 387 maths coprocessor
1009 noapic [SMP,APIC] Tells the kernel to not make use of any
1010 IOAPICs that may be present in the system.
1012 noasync [HW,M68K] Disables async and sync negotiation for
1015 nobats [PPC] Do not use BATs for mapping kernel lowmem
1016 on "Classic" PPC cores.
1020 nodisconnect [HW,SCSI,M68K] Disables SCSI disconnects.
1024 noexec [IA-32,X86-64]
1025 noexec=on: enable non-executable mappings (default)
1026 noexec=off: disable nn-executable mappings
1028 nofxsr [BUGS=IA-32] Disables x86 floating point extended
1029 register save and restore. The kernel will only save
1030 legacy floating-point registers on task switch.
1034 no-hlt [BUGS=IA-32] Tells the kernel that the hlt
1035 instruction doesn't work correctly and not to
1038 nohalt [IA-64] Tells the kernel not to use the power saving
1039 function PAL_HALT_LIGHT when idle. This increases
1040 power-consumption. On the positive side, it reduces
1041 interrupt wake-up latency, which may improve performance
1042 in certain environments such as networked servers or
1045 noirqdebug [IA-32] Disables the code which attempts to detect and
1046 disable unhandled interrupt sources.
1048 noisapnp [ISAPNP] Disables ISA PnP code.
1050 noinitrd [RAM] Tells the kernel not to load any configured
1055 nolapic [IA-32,APIC] Do not enable or use the local APIC.
1057 noltlbs [PPC] Do not use large page/tlb entries for kernel
1058 lowmem mapping on PPC40x.
1060 nomca [IA-64] Disable machine check abort handling
1062 nomce [IA-32] Machine Check Exception
1064 noresidual [PPC] Don't use residual data on PReP machines.
1066 noresume [SWSUSP] Disables resume and restores original swap
1069 no-scroll [VGA] Disables scrollback.
1070 This is required for the Braillex ib80-piezo Braille
1071 reader made by F.H. Papenmeier (Germany).
1075 nosep [BUGS=IA-32] Disables x86 SYSENTER/SYSEXIT support.
1077 nosmp [SMP] Tells an SMP kernel to act as a UP kernel.
1079 nosync [HW,M68K] Disables sync negotiation for all devices.
1081 notsc [BUGS=IA-32] Disable Time Stamp Counter
1083 nousb [USB] Disable the USB subsystem
1087 nr_uarts= [SERIAL] maximum number of UARTs to be registered.
1093 Format: <io>,<irq>,<dma>,<dma2>,<mpu_io>,<mpu_irq>
1095 opl3sa2= [HW,OSS] Format:
1096 <io>,<irq>,<dma>,<dma2>,<mss_io>,<mpu_io>,<ymode>,<loopback>[,<isapnp>,<multiple]
1098 oprofile.timer= [HW]
1099 Use timer interrupt instead of performance counters
1104 osst= [HW,SCSI] SCSI Tape Driver
1105 Format: <buffer_size>,<write_threshold>
1106 See also Documentation/scsi/st.txt.
1108 panic= [KNL] Kernel behaviour on panic
1111 parkbd.port= [HW] Parallel port number the keyboard adapter is
1112 connected to, default is 0.
1114 parkbd.mode= [HW] Parallel port keyboard adapter mode of operation,
1115 0 for XT, 1 for AT (default is AT).
1118 parport= [HW,PPT] Specify parallel ports. 0 disables.
1119 Format: { 0 | auto | 0xBBB[,IRQ[,DMA]] }
1120 Use 'auto' to force the driver to use any
1121 IRQ/DMA settings detected (the default is to
1122 ignore detected IRQ/DMA settings because of
1123 possible conflicts). You can specify the base
1124 address, IRQ, and DMA settings; IRQ and DMA
1125 should be numbers, or 'auto' (for using detected
1126 settings on that particular port), or 'nofifo'
1127 (to avoid using a FIFO even if it is detected).
1128 Parallel ports are assigned in the order they
1129 are specified on the command line, starting
1132 parport_init_mode= [HW,PPT]
1133 Configure VIA parallel port to operate in
1134 a specific mode. This is necessary on Pegasos
1135 computer where firmware has no options for setting
1136 up parallel port mode and sets it to spp.
1137 Currently this function knows 686a and 8231 chips.
1138 Format: [spp|ps2|epp|ecp|ecpepp]
1140 pas2= [HW,OSS] Format:
1141 <io>,<irq>,<dma>,<dma16>,<sb_io>,<sb_irq>,<sb_dma>,<sb_dma16>
1144 See header of drivers/scsi/pas16.c.
1147 Halt all CPUs after the first oops has been printed for
1148 the specified number of seconds. This is to be used if
1149 your oopses keep scrolling off the screen.
1154 See header of drivers/block/paride/pcd.c.
1155 See also Documentation/paride.txt.
1157 pci=option[,option...] [PCI] various PCI subsystem options:
1158 off [IA-32] don't probe for the PCI bus
1159 bios [IA-32] force use of PCI BIOS, don't access
1160 the hardware directly. Use this if your machine
1161 has a non-standard PCI host bridge.
1162 nobios [IA-32] disallow use of PCI BIOS, only direct
1163 hardware access methods are allowed. Use this
1164 if you experience crashes upon bootup and you
1165 suspect they are caused by the BIOS.
1166 conf1 [IA-32] Force use of PCI Configuration
1168 conf2 [IA-32] Force use of PCI Configuration
1170 nommconf [IA-32,X86_64] Disable use of MMCONFIG for PCI
1172 nomsi [MSI] If the PCI_MSI kernel config parameter is
1173 enabled, this kernel boot option can be used to
1174 disable the use of MSI interrupts system-wide.
1175 nosort [IA-32] Don't sort PCI devices according to
1176 order given by the PCI BIOS. This sorting is
1177 done to get a device order compatible with
1179 biosirq [IA-32] Use PCI BIOS calls to get the interrupt
1180 routing table. These calls are known to be buggy
1181 on several machines and they hang the machine
1182 when used, but on other computers it's the only
1183 way to get the interrupt routing table. Try
1184 this option if the kernel is unable to allocate
1185 IRQs or discover secondary PCI buses on your
1187 rom [IA-32] Assign address space to expansion ROMs.
1188 Use with caution as certain devices share
1189 address decoders between ROMs and other
1191 irqmask=0xMMMM [IA-32] Set a bit mask of IRQs allowed to be
1192 assigned automatically to PCI devices. You can
1193 make the kernel exclude IRQs of your ISA cards
1195 pirqaddr=0xAAAAA [IA-32] Specify the physical address
1196 of the PIRQ table (normally generated
1197 by the BIOS) if it is outside the
1198 F0000h-100000h range.
1199 lastbus=N [IA-32] Scan all buses thru bus #N. Can be
1200 useful if the kernel is unable to find your
1201 secondary buses and you want to tell it
1202 explicitly which ones they are.
1203 assign-busses [IA-32] Always assign all PCI bus
1204 numbers ourselves, overriding
1205 whatever the firmware may have done.
1206 usepirqmask [IA-32] Honor the possible IRQ mask stored
1207 in the BIOS $PIR table. This is needed on
1208 some systems with broken BIOSes, notably
1209 some HP Pavilion N5400 and Omnibook XE3
1210 notebooks. This will have no effect if ACPI
1211 IRQ routing is enabled.
1212 noacpi [IA-32] Do not use ACPI for IRQ routing
1213 or for PCI scanning.
1214 routeirq Do IRQ routing for all PCI devices.
1215 This is normally done in pci_enable_device(),
1216 so this option is a temporary workaround
1217 for broken drivers that don't call it.
1218 firmware [ARM] Do not re-enumerate the bus but instead
1219 just use the configuration from the
1220 bootloader. This is currently used on
1221 IXP2000 systems where the bus has to be
1222 configured a certain way for adjunct CPUs.
1224 pcmv= [HW,PCMCIA] BadgePAD 4
1227 See Documentation/paride.txt.
1229 pdcchassis= [PARISC,HW] Disable/Enable PDC Chassis Status codes at
1232 See arch/parisc/kernel/pdc_chassis.c
1235 See Documentation/paride.txt.
1238 See Documentation/paride.txt.
1240 pirq= [SMP,APIC] Manual mp-table setup
1241 See Documentation/i386/IO-APIC.txt.
1243 plip= [PPT,NET] Parallel port network link
1244 Format: { parport<nr> | timid | 0 }
1245 See also Documentation/parport.txt.
1251 { on | off | curr | res | no-curr | no-res }
1254 [ISAPNP] Exclude IRQs for the autoconfiguration
1257 [ISAPNP] Exclude DMAs for the autoconfiguration
1259 pnp_reserve_io= [ISAPNP] Exclude I/O ports for the autoconfiguration
1260 Ranges are in pairs (I/O port base and size).
1263 [ISAPNP] Exclude memory regions for the
1265 Ranges are in pairs (memory base and size).
1267 profile= [KNL] Enable kernel profiling via /proc/profile
1268 Format: [schedule,]<number>
1269 Param: "schedule" - profile schedule points.
1270 Param: <number> - step/bucket size as a power of 2 for
1271 statistical time based profiling.
1273 processor.max_cstate= [HW,ACPI]
1274 Limit processor to maximum C-state
1275 max_cstate=9 overrides any DMI blacklist limit.
1277 processor.nocst [HW,ACPI]
1278 Ignore the _CST method to determine C-states,
1279 instead using the legacy FADT method
1281 prompt_ramdisk= [RAM] List of RAM disks to prompt for floppy disk
1283 See Documentation/ramdisk.txt.
1285 psmouse.proto= [HW,MOUSE] Highest PS2 mouse protocol extension to
1286 probe for; one of (bare|imps|exps|lifebook|any).
1287 psmouse.rate= [HW,MOUSE] Set desired mouse report rate, in reports
1289 psmouse.resetafter= [HW,MOUSE]
1290 Try to reset the device after so many bad packets
1293 [HW,MOUSE] Set desired mouse resolution, in dpi.
1294 psmouse.smartscroll=
1295 [HW,MOUSE] Controls Logitech smartscroll autorepeat.
1296 0 = disabled, 1 = enabled (default).
1298 pss= [HW,OSS] Personal Sound System (ECHO ESC614)
1300 <io>,<mss_io>,<mss_irq>,<mss_dma>,<mpu_io>,<mpu_irq>
1303 See Documentation/paride.txt.
1305 quiet= [KNL] Disable log messages
1310 See Documentation/md.txt.
1312 ramdisk= [RAM] Sizes of RAM disks in kilobytes [deprecated]
1313 See Documentation/ramdisk.txt.
1315 ramdisk_blocksize= [RAM]
1316 See Documentation/ramdisk.txt.
1318 ramdisk_size= [RAM] Sizes of RAM disks in kilobytes
1319 New name for the ramdisk parameter.
1320 See Documentation/ramdisk.txt.
1322 rcu.blimit= [KNL,BOOT] Set maximum number of finished
1323 RCU callbacks to process in one batch.
1325 rcu.qhimark= [KNL,BOOT] Set threshold of queued
1326 RCU callbacks over which batch limiting is disabled.
1328 rcu.qlowmark= [KNL,BOOT] Set threshold of queued
1329 RCU callbacks below which batch limiting is re-enabled.
1331 rcu.rsinterval= [KNL,BOOT,SMP] Set the number of additional
1332 RCU callbacks to queued before forcing reschedule
1337 Run specified binary instead of /init from the ramdisk,
1338 used for early userspace startup. See initrd.
1340 reboot= [BUGS=IA-32,BUGS=ARM,BUGS=IA-64] Rebooting mode
1341 Format: <reboot_mode>[,<reboot_mode2>[,...]]
1342 See arch/*/kernel/reboot.c.
1344 reserve= [KNL,BUGS] Force the kernel to ignore some iomem area
1347 Specify the partition device for software suspend
1349 rhash_entries= [KNL,NET]
1350 Set number of hash buckets for route cache
1352 riscom8= [HW,SERIAL]
1353 Format: <io_board1>[,<io_board2>[,...<io_boardN>]]
1355 ro [KNL] Mount root device read-only on boot
1357 root= [KNL] Root filesystem
1359 rootdelay= [KNL] Delay (in seconds) to pause before attempting to
1360 mount the root filesystem
1362 rootflags= [KNL] Set root filesystem mount option string
1364 rootfstype= [KNL] Set root filesystem type
1366 rw [KNL] Mount root device read-write on boot
1368 S [KNL] Run init in single mode
1371 See drivers/net/irda/sa1100_ir.c.
1374 Format: <io>,<irq>,<dma>,<dma2>
1376 sbni= [NET] Granch SBNI12 leased line adapter
1378 sbpcd= [HW,CD] Soundblaster CD adapter
1380 See a comment before function sbpcd_setup() in
1381 drivers/cdrom/sbpcd.c.
1383 sc1200wdt= [HW,WDT] SC1200 WDT (watchdog) driver
1384 Format: <io>[,<timeout>[,<isapnp>]]
1386 scsi_debug_*= [SCSI]
1387 See drivers/scsi/scsi_debug.c.
1389 scsi_default_dev_flags=
1390 [SCSI] SCSI default device flags
1393 scsi_dev_flags= [SCSI] Black/white list entry for vendor and model
1394 Format: <vendor>:<model>:<flags>
1395 (flags are integer value)
1397 scsi_logging= [SCSI]
1399 selinux [SELINUX] Disable or enable SELinux at boot time.
1400 Format: { "0" | "1" }
1401 See security/selinux/Kconfig help text.
1404 Default value is set via kernel config option.
1405 If enabled at boot time, /selinux/disable can be used
1406 later to disable prior to initial policy load.
1408 selinux_compat_net =
1409 [SELINUX] Set initial selinux_compat_net flag value.
1410 Format: { "0" | "1" }
1411 0 -- use new secmark-based packet controls
1412 1 -- use legacy packet controls
1413 Default value is 0 (preferred).
1414 Value can be changed at runtime via
1415 /selinux/compat_net.
1417 serialnumber [BUGS=IA-32]
1419 sg_def_reserved_size= [SCSI]
1422 Format: <io>,<irq>,<dma>,<dma2>,<sgbase>
1425 Maximal number of shapers.
1428 See header of drivers/scsi/sim710.c.
1434 Format: <io>,<irq>,<dma>
1435 See header of drivers/cdrom/sjcd.c.
1440 Format: <io1>[,<io2>[,...,<io8>]]
1442 snd-ad1816a= [HW,ALSA]
1444 snd-ad1848= [HW,ALSA]
1446 snd-ali5451= [HW,ALSA]
1448 snd-als100= [HW,ALSA]
1450 snd-als4000= [HW,ALSA]
1452 snd-azt2320= [HW,ALSA]
1454 snd-cmi8330= [HW,ALSA]
1456 snd-cmipci= [HW,ALSA]
1458 snd-cs4231= [HW,ALSA]
1460 snd-cs4232= [HW,ALSA]
1462 snd-cs4236= [HW,ALSA]
1464 snd-cs4281= [HW,ALSA]
1466 snd-cs46xx= [HW,ALSA]
1468 snd-dt019x= [HW,ALSA]
1470 snd-dummy= [HW,ALSA]
1472 snd-emu10k1= [HW,ALSA]
1474 snd-ens1370= [HW,ALSA]
1476 snd-ens1371= [HW,ALSA]
1478 snd-es968= [HW,ALSA]
1480 snd-es1688= [HW,ALSA]
1482 snd-es18xx= [HW,ALSA]
1484 snd-es1938= [HW,ALSA]
1486 snd-es1968= [HW,ALSA]
1488 snd-fm801= [HW,ALSA]
1490 snd-gusclassic= [HW,ALSA]
1492 snd-gusextreme= [HW,ALSA]
1494 snd-gusmax= [HW,ALSA]
1498 snd-ice1712= [HW,ALSA]
1500 snd-intel8x0= [HW,ALSA]
1502 snd-interwave= [HW,ALSA]
1507 snd-korg1212= [HW,ALSA]
1509 snd-maestro3= [HW,ALSA]
1511 snd-mpu401= [HW,ALSA]
1513 snd-mtpav= [HW,ALSA]
1515 snd-nm256= [HW,ALSA]
1517 snd-opl3sa2= [HW,ALSA]
1525 snd-opti93x= [HW,ALSA]
1529 snd-rme32= [HW,ALSA]
1531 snd-rme96= [HW,ALSA]
1533 snd-rme9652= [HW,ALSA]
1539 snd-sbawe= [HW,ALSA]
1541 snd-serial= [HW,ALSA]
1543 snd-sgalaxy= [HW,ALSA]
1545 snd-sonicvibes= [HW,ALSA]
1550 snd-sun-cs4231= [HW,ALSA]
1552 snd-trident= [HW,ALSA]
1554 snd-usb-audio= [HW,ALSA,USB]
1556 snd-via82xx= [HW,ALSA]
1558 snd-virmidi= [HW,ALSA]
1560 snd-wavefront= [HW,ALSA]
1562 snd-ymfpci= [HW,ALSA]
1564 sonicvibes= [HW,OSS]
1568 Format: <io>[,<irq>]
1570 sonypi.*= [HW] Sony Programmable I/O Control Device driver
1571 See Documentation/sonypi.txt
1573 specialix= [HW,SERIAL] Specialix multi-serial port adapter
1574 See Documentation/specialix.txt.
1576 spia_io_base= [HW,MTD]
1582 Format: <io>,<irq>,<dma>,<mpu_io>,<mpu_irq>
1584 st= [HW,SCSI] SCSI tape parameters (buffers, etc.)
1585 See Documentation/scsi/st.txt.
1588 See header of drivers/scsi/seagate.c.
1592 Set the STI (builtin display/keyboard on the HP-PARISC
1593 machines) console (graphic card) which should be used
1594 as the initial boot-console.
1595 See also comment in drivers/video/console/sticore.c.
1598 See comment in drivers/video/console/sticore.c.
1601 Format: bpp:<bpp1>[:<bpp2>[:<bpp3>...]]
1603 swiotlb= [IA-64] Number of I/O TLB slabs
1607 sym53c416= [HW,SCSI]
1608 See header of drivers/scsi/sym53c416.c.
1611 See header of drivers/scsi/t128.c.
1615 thash_entries= [KNL,NET]
1616 Set number of hash buckets for TCP connection
1618 time Show timing data prefixed to each printk message line
1620 tipar.timeout= [HW,PPT]
1621 Set communications timeout in tenths of a second
1624 tipar.delay= [HW,PPT]
1625 Set inter-bit delay in microseconds (default 10).
1628 See header of drivers/scsi/seagate.c.
1631 See comment before function dc390_setup() in
1632 drivers/scsi/tmscsim.c.
1636 trix= [HW,OSS] MediaTrix AudioTrix Pro
1638 <io>,<irq>,<dma>,<dma2>,<sb_io>,<sb_irq>,<sb_dma>,<mpu_io>,<mpu_irq>
1640 tsdev.xres= [TS] Horizontal screen resolution.
1641 tsdev.yres= [TS] Vertical screen resolution.
1643 turbografx.map[2|3]= [HW,JOY]
1644 TurboGraFX parallel port interface
1646 <port#>,<js1>,<js2>,<js3>,<js4>,<js5>,<js6>,<js7>
1647 See also Documentation/input/joystick-parport.txt
1649 u14-34f= [HW,SCSI] UltraStor 14F/34F SCSI host adapter
1650 See header of drivers/scsi/u14-34f.c.
1659 [USBHID] The interval which mice are to be polled at.
1661 video= [FB] Frame buffer configuration
1662 See Documentation/fb/modedb.txt.
1664 vga= [BOOT,IA-32] Select a particular video mode
1665 See Documentation/i386/boot.txt and
1666 Documentation/svga.txt.
1667 Use vga=ask for menu.
1668 This is actually a boot loader parameter; the value is
1669 passed to the kernel using a special protocol.
1671 vmalloc=nn[KMG] [KNL,BOOT] Forces the vmalloc area to have an exact
1672 size of <nn>. This can be used to increase the
1673 minimum size (128MB on x86). It can also be used to
1674 decrease the size and leave more room for directly
1681 waveartist= [HW,OSS]
1682 Format: <io>,<irq>,<dma>,<dma2>
1685 See header of drivers/scsi/wd33c93.c.
1688 See header of drivers/scsi/wd7000.c.
1691 See Documentation/watchdog/watchdog.txt.
1693 xd= [HW,XT] Original XT pre-IDE (RLL encoded) disks.
1694 xd_geo= See header of drivers/block/xd.c.
1696 xirc2ps_cs= [NET,PCMCIA]
1698 <irq>,<irq_mask>,<io>,<full_duplex>,<do_sound>,<lockup_hack>[,<irq2>[,<irq3>[,<irq4>]]]
1700 norandmaps Don't use address space randomization
1701 Equivalent to echo 0 > /proc/sys/kernel/randomize_va_space
1704 ______________________________________________________________________
1708 Add documentation for ALSA options.
1709 Add more DRM drivers.