1 February 2003 Kernel Parameters v2.5.59
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 The text in square brackets at the beginning of the description states the
21 restrictions on the kernel for the said kernel parameter to be valid. The
22 restrictions referred to are that the relevant option is valid if:
24 ACPI ACPI support is enabled.
25 ALSA ALSA sound support is enabled.
26 APIC APIC support is enabled.
27 APM Advanced Power Management support is enabled.
28 AX25 Appropriate AX.25 support is enabled.
29 CD Appropriate CD support is enabled.
30 DEVFS devfs support is enabled.
31 DRM Direct Rendering Management support is enabled.
32 EDD BIOS Enhanced Disk Drive Services (EDD) is enabled
33 EFI EFI Partitioning (GPT) is enabled
34 EIDE EIDE/ATAPI support is enabled.
35 FB The frame buffer device is enabled.
36 HW Appropriate hardware is enabled.
37 IA-32 IA-32 aka i386 architecture is enabled.
38 IA-64 IA-64 architecture is enabled.
39 IOSCHED More than one I/O scheduler is enabled.
40 IP_PNP IP DHCP, BOOTP, or RARP is enabled.
41 ISAPNP ISA PnP code is enabled.
42 ISDN Appropriate ISDN support is enabled.
43 JOY Appropriate joystick support is enabled.
44 LP Printer support is enabled.
45 LOOP Loopback device support is enabled.
46 M68k M68k architecture is enabled.
47 These options have more detailed description inside of
48 Documentation/m68k/kernel-options.txt.
49 MCA MCA bus support is enabled.
50 MDA MDA console support is enabled.
51 MOUSE Appropriate mouse support is enabled.
52 MTD MTD support is enabled.
53 NET Appropriate network support is enabled.
54 NUMA NUMA support is enabled.
55 NFS Appropriate NFS support is enabled.
56 OSS OSS sound support is enabled.
57 PARIDE The ParIDE subsystem is enabled.
58 PARISC The PA-RISC architecture is enabled.
59 PCI PCI bus support is enabled.
60 PCMCIA The PCMCIA subsystem is enabled.
61 PNP Plug & Play support is enabled.
62 PPC PowerPC architecture is enabled.
63 PPT Parallel port support is enabled.
64 PS2 Appropriate PS/2 support is enabled.
65 RAM RAM disk support is enabled.
66 S390 S390 architecture is enabled.
67 SCSI Appropriate SCSI support is enabled.
68 A lot of drivers has their options described inside of
70 SELINUX SELinux support is enabled.
71 SERIAL Serial support is enabled.
72 SMP The kernel is an SMP kernel.
73 SPARC Sparc architecture is enabled.
74 SWSUSP Software suspend is enabled.
75 TS Appropriate touchscreen support is enabled.
76 USB USB support is enabled.
77 USBHID USB Human Interface Device support is enabled.
78 V4L Video For Linux support is enabled.
79 VGA The VGA console has been enabled.
80 VT Virtual terminal support is enabled.
81 WDT Watchdog support is enabled.
82 XT IBM PC/XT MFM hard disk support is enabled.
83 X86-64 X86-64 architecture is enabled.
84 More X86-64 boot options can be found in
85 Documentation/x86_64/boot-options.txt .
87 In addition, the following text indicates that the option:
89 BUGS= Relates to possible processor bugs on the said processor.
90 KNL Is a kernel start-up parameter.
91 BOOT Is a boot loader parameter.
93 Parameters denoted with BOOT are actually interpreted by the boot
94 loader, and have no meaning to the kernel directly.
95 Do not modify the syntax of boot loader parameters without extreme
96 need or coordination with <Documentation/i386/boot.txt>.
98 Note that ALL kernel parameters listed below are CASE SENSITIVE, and that
99 a trailing = on the name of any parameter states that that parameter will
100 be entered as an environment variable, whereas its absence indicates that
101 it will appear as a kernel argument readable via /proc/cmdline by programs
102 running once the system is up.
104 53c7xx= [HW,SCSI] Amiga SCSI controllers
105 See header of drivers/scsi/53c7xx.c.
106 See also Documentation/scsi/ncr53c7xx.txt.
108 acpi= [HW,ACPI] Advanced Configuration and Power Interface
109 Format: { force | off | ht | strict | noirq }
110 force -- enable ACPI if default was off
111 off -- disable ACPI if default was on
112 noirq -- do not use ACPI for IRQ routing
113 ht -- run only enough ACPI to enable Hyper Threading
114 strict -- Be less tolerant of platforms that are not
115 strictly ACPI specification compliant.
117 See also Documentation/pm.txt, pci=noacpi
119 acpi_sleep= [HW,ACPI] Sleep options
120 Format: { s3_bios, s3_mode }
121 See Documentation/power/video.txt
123 acpi_sci= [HW,ACPI] ACPI System Control Interrupt trigger mode
124 Format: { level | edge | high | low }
126 acpi_irq_balance [HW,ACPI]
127 ACPI will balance active IRQs
130 acpi_irq_nobalance [HW,ACPI]
131 ACPI will not move active IRQs (default)
134 acpi_irq_pci= [HW,ACPI] If irq_balance, clear listed IRQs for
136 Format: <irq>,<irq>...
138 acpi_irq_isa= [HW,ACPI] If irq_balance, mark listed IRQs used by ISA
139 Format: <irq>,<irq>...
141 acpi_osi= [HW,ACPI] empty param disables _OSI
143 acpi_serialize [HW,ACPI] force serialization of AML methods
145 acpi_skip_timer_override [HW,ACPI]
146 Recognize and ignore IRQ0/pin2 Interrupt Override.
147 For broken nForce2 BIOS resulting in XT-PIC timer.
149 acpi_dbg_layer= [HW,ACPI]
151 Each bit of the <int> indicates an ACPI debug layer,
152 1: enable, 0: disable. It is useful for boot time
153 debugging. After system has booted up, it can be set
154 via /proc/acpi/debug_layer.
156 acpi_dbg_level= [HW,ACPI]
158 Each bit of the <int> indicates an ACPI debug level,
159 1: enable, 0: disable. It is useful for boot time
160 debugging. After system has booted up, it can be set
161 via /proc/acpi/debug_level.
163 acpi_fake_ecdt [HW,ACPI] Workaround failure due to BIOS lacking ECDT
165 acpi_generic_hotkey [HW,ACPI]
166 Allow consolidated generic hotkey driver to
167 override platform specific driver.
168 See also Documentation/acpi-hotkey.txt.
170 enable_timer_pin_1 [i386,x86-64]
171 Enable PIN 1 of APIC timer
172 Can be useful to work around chipset bugs
173 (in particular on some ATI chipsets).
174 The kernel tries to set a reasonable default.
176 disable_timer_pin_1 [i386,x86-64]
177 Disable PIN 1 of APIC timer
178 Can be useful to work around chipset bugs.
181 Format: <io>,<irq>,<dma>,<dma2>
182 See also Documentation/sound/oss/AD1816.
185 Format: <io>,<irq>,<dma>,<dma2>,<type>
191 See header of drivers/scsi/advansys.c.
193 advwdt= [HW,WDT] Advantech WDT
194 Format: <iostart>,<iostop>
196 aedsp16= [HW,OSS] Audio Excel DSP 16
197 Format: <io>,<irq>,<dma>,<mss_io>,<mpu_io>,<mpu_irq>
198 See also header of sound/oss/aedsp16.c.
201 See Documentation/scsi/aha152x.txt.
204 Format: <portbase>[,<buson>,<busoff>[,<dmaspeed>]]
207 See Documentation/scsi/aic7xxx.txt.
210 See Documentation/scsi/aic79xx.txt.
212 amijoy.map= [HW,JOY] Amiga joystick support
213 Map of devices attached to JOY0DAT and JOY1DAT
215 See also Documentation/kernel/input/joystick.txt
217 analog.map= [HW,JOY] Analog joystick and gamepad support
218 Specifies type or capabilities of an analog joystick
219 connected to one of 16 gameports
220 Format: <type1>,<type2>,..<type16>
223 Power management functions (SPARCstation-4/5 + deriv.)
225 Disable APC CPU standby support. SPARCstation-Fox does
226 not play well with APC CPU idle - disable it if you have
227 APC and your system crashes randomly.
229 apic= [APIC,i386] Change the output verbosity whilst booting
230 Format: { quiet (default) | verbose | debug }
231 Change the amount of debugging information output
232 when initialising the APIC and IO-APIC components.
234 apm= [APM] Advanced Power Management
235 See header of arch/i386/kernel/apm.c.
240 arcrimi= [HW,NET] ARCnet - "RIM I" (entirely mem-mapped) cards
241 Format: <io>,<irq>,<nodeID>
245 atarimouse= [HW,MOUSE] Atari Mouse
247 atascsi= [HW,SCSI] Atari SCSI
249 atkbd.extra= [HW] Enable extra LEDs and keys on IBM RapidAccess,
250 EzKey and similar keyboards
252 atkbd.reset= [HW] Reset keyboard during initialization
254 atkbd.set= [HW] Select keyboard code set
255 Format: <int> (2 = AT (default), 3 = PS/2)
257 atkbd.scroll= [HW] Enable scroll wheel on MS Office and similar
260 atkbd.softraw= [HW] Choose between synthetic and real raw mode
261 Format: <bool> (0 = real, 1 = synthetic (default))
263 atkbd.softrepeat= [HW]
264 Use software keyboard repeat
268 awe= [HW,OSS] AWE32/SB32/AWE64 wave table synth
269 Format: <io>,<memsize>,<isapnp>
271 aztcd= [HW,CD] Aztech CD268 CDROM driver
272 Format: <io>,0x79 (?)
274 baycom_epp= [HW,AX25]
277 baycom_par= [HW,AX25] BayCom Parallel Port AX.25 Modem
279 See header of drivers/net/hamradio/baycom_par.c.
281 baycom_ser_fdx= [HW,AX25]
282 BayCom Serial Port AX.25 Modem (Full Duplex Mode)
283 Format: <io>,<irq>,<mode>[,<baud>]
284 See header of drivers/net/hamradio/baycom_ser_fdx.c.
286 baycom_ser_hdx= [HW,AX25]
287 BayCom Serial Port AX.25 Modem (Half Duplex Mode)
288 Format: <io>,<irq>,<mode>
289 See header of drivers/net/hamradio/baycom_ser_hdx.c.
291 blkmtd_device= [HW,MTD]
297 bttv.card= [HW,V4L] bttv (bt848 + bt878 based grabber cards)
298 bttv.radio= Most important insmod options are available as
300 bttv.pll= See Documentation/video4linux/bttv/Insmod-options
301 bttv.tuner= and Documentation/video4linux/bttv/CARDLIST
304 See drivers/scsi/BusLogic.c, comment before function
305 BusLogic_ParseDriverOptions().
307 c101= [NET] Moxa C101 synchronous serial card
309 cachesize= [BUGS=IA-32] Override level 2 CPU cache size detection.
310 Sometimes CPU hardware bugs make them report the cache
311 size incorrectly. The kernel will attempt work arounds
312 to fix known problems, but for some CPUs it is not
313 possible to determine what the correct size should be.
314 This option provides an override for these situations.
317 Format: <io>,<irq>[,PAS]
318 See header of drivers/cdrom/cdu31a.c.
320 chandev= [HW,NET] Generic channel device initialisation
322 checkreqprot [SELINUX] Set initial checkreqprot flag value.
323 Format: { "0" | "1" }
324 See security/selinux/Kconfig help text.
325 0 -- check protection applied by kernel (includes
326 any implied execute protection).
327 1 -- check protection requested by application.
328 Default value is set via a kernel config option.
329 Value can be changed at runtime via
330 /selinux/checkreqprot.
332 clock= [BUGS=IA-32,HW] gettimeofday timesource override.
333 Forces specified timesource (if avaliable) to be used
334 when calculating gettimeofday(). If specicified
335 timesource is not avalible, it defaults to PIT.
336 Format: { pit | tsc | cyclone | pmtmr }
340 [IA32/X86_64] Disable/Enable interrupt 0 timer routing
341 over the 8254 in addition to over the IO-APIC. The
342 kernel tries to set a sensible default.
344 hpet= [IA-32,HPET] option to disable HPET and use PIT.
348 Format: { auto | [<io>,][<irq>] }
350 com20020= [HW,NET] ARCnet - COM20020 chipset
352 <io>[,<irq>[,<nodeID>[,<backplane>[,<ckp>[,<timeout>]]]]]
354 com90io= [HW,NET] ARCnet - COM90xx chipset (IO-mapped buffers)
358 ARCnet - COM90xx chipset (memory-mapped buffers)
359 Format: <io>[,<irq>[,<memstart>]]
361 condev= [HW,S390] console device
364 console= [KNL] Output console device and options.
366 tty<n> Use the virtual console device <n>.
369 Use the specified serial port. The options are of
370 the form "bbbbpn", where "bbbb" is the baud rate,
371 "p" is parity ("n", "o", or "e"), and "n" is bits.
374 See also Documentation/serial-console.txt.
376 uart,io,<addr>[,options]
377 uart,mmio,<addr>[,options]
378 Start an early, polled-mode console on the 8250/16550
379 UART at the specified I/O port or MMIO address,
380 switching to the matching ttyS device later. The
381 options are the same as for ttyS, above.
383 cpcihp_generic= [HW,PCI] Generic port I/O CompactPCI driver
385 <first_slot>,<last_slot>,<port>,<enum_bit>[,<debug>]
388 Format: { parport<nr> | auto | none }
390 crashkernel=nn[KMG]@ss[KMG]
391 [KNL] Reserve a chunk of physical memory to
392 hold a kernel to switch to with kexec on panic.
395 Format: <io>,<irq>,<dma>,<dma2>,<mpuio>,<mpuirq>
400 cs89x0_media= [HW,NET]
401 Format: { rj45 | aui | bnc }
403 cyclades= [HW,SERIAL] Cyclades multi-serial port adapter.
406 See header of drivers/s390/block/dasd_devmap.c.
408 db9.dev[2|3]= [HW,JOY] Multisystem joystick support via parallel port
409 (one device per port)
410 Format: <port#>,<type>
411 See also Documentation/input/joystick-parport.txt
413 debug [KNL] Enable kernel debugging (events log level).
416 Format: <area>[,<node>]
417 See also Documentation/networking/decnet.txt.
420 See Documentation/filesystems/devfs/boot-options.
423 Set number of hash buckets for dentry cache.
426 IO parameters + enable/disable command.
428 digiepca= [HW,SERIAL]
429 See drivers/char/README.epca and
430 Documentation/digiepca.txt.
432 dmascc= [HW,AX25,SERIAL] AX.25 Z80SCC driver with DMA
434 Format: <io_dev0>[,<io_dev1>[,..<io_dev32>]]
436 dmasound= [HW,OSS] Sound subsystem buffers
442 earlyprintk= [IA-32,X86-64]
444 earlyprintk=serial[,ttySn[,baudrate]]
446 Append ",keep" to not disable it when the real console
449 Only vga or serial at a time, not both.
451 Currently only ttyS0 and ttyS1 are supported.
453 Interaction with the standard serial driver is not
456 The VGA output is eventually overwritten by the real
461 ec_intr= [HW,ACPI] ACPI Embedded Controller interrupt mode
464 non-0: interrupt mode (default)
471 Format: {"of[f]" | "sk[ipmbr]"}
472 See comment in arch/i386/boot/edd.S
475 Format: <id>,<membase>,<irq>
477 eisa_irq_edge= [PARISC,HW]
478 See header of drivers/parisc/eisa.c.
481 See comment before function elanfreq_setup() in
482 arch/i386/kernel/cpu/cpufreq/elanfreq.c.
485 Format: {"anticipatory" | "cfq" | "deadline" | "noop"}
486 See Documentation/block/as-iosched.txt and
487 Documentation/block/deadline-iosched.txt for details.
489 elfcorehdr= [IA-32, X86_64]
490 Specifies physical address of start of kernel core
491 image elf header. Generally kexec loader will
492 pass this option to capture kernel.
493 See Documentation/kdump/kdump.txt for details.
495 enforcing [SELINUX] Set initial enforcing status.
497 See security/selinux/Kconfig help text.
498 0 -- permissive (log only, no denials).
499 1 -- enforcing (deny and log).
501 Value can be changed at runtime via /selinux/enforce.
504 Format: <lineout>[,<micbias>]
505 See also header of sound/oss/es1370.c.
508 Format: <spdif>,[<nomix>,[<amplifier>]]
509 See also header of sound/oss/es1371.c.
511 ether= [HW,NET] Ethernet cards parameters
512 This option is obsoleted by the "netdev=" option, which
513 has equivalent usage. See its documentation for details.
515 eurwdt= [HW,WDT] Eurotech CPU-1220/1410 onboard watchdog.
519 See header of drivers/scsi/fd_mcs.c.
522 See header of drivers/scsi/fdomain.c.
525 See Documentation/floppy.txt.
527 ftape= [HW] Floppy Tape subsystem debugging options.
528 See Documentation/ftape.txt.
531 [HW,JOY] Multisystem joystick and NES/SNES/PSX pad
532 support via parallel port (up to 5 devices per port)
533 Format: <port#>,<pad1>,<pad2>,<pad3>,<pad4>,<pad5>
534 See also Documentation/input/joystick-parport.txt
539 See header of drivers/scsi/gdth.c.
541 gpt [EFI] Forces disk with valid GPT signature but
542 invalid Protective MBR to be treated as GPT.
547 gt96100eth= [NET] MIPS GT96100 Advanced Communication Controller
550 Format: <io>,<irq>,<dma>,<dma16>
554 hashdist= [KNL,NUMA] Large hashes allocated during boot
555 are distributed across NUMA nodes. Defaults on
556 for IA-64, off otherwise.
557 Format: 0 | 1 (for off | on)
559 hcl= [IA-64] SGI's Hardware Graph compatibility layer
561 hd= [EIDE] (E)IDE hard drive subsystem geometry
562 Format: <cyl>,<head>,<sect>
564 hd?= [HW] (E)IDE subsystem
565 hd?lun= See Documentation/ide.txt.
567 highmem=nn[KMG] [KNL,BOOT] forces the highmem zone to have an exact
568 size of <nn>. This works even on boxes that have no
569 highmem otherwise. This also works to reduce highmem
570 size on bigger boxes.
573 See Documentation/isdn/README.HiSax.
575 hugepages= [HW,IA-32,IA-64] Maximal number of HugeTLB pages.
577 noirqbalance [IA-32,SMP,KNL] Disable kernel irq balancing
579 i8042.direct [HW] Put keyboard port into non-translated mode
580 i8042.dumbkbd [HW] Pretend that controlled can only read data from
581 keyboard and can not control its state
582 (Don't attempt to blink the leds)
583 i8042.noaux [HW] Don't check for auxiliary (== mouse) port
584 i8042.nokbd [HW] Don't check/create keyboard port
585 i8042.nomux [HW] Don't check presence of an active multiplexing
587 i8042.nopnp [HW] Don't use ACPIPnP / PnPBIOS to discover KBD/AUX
590 [HW] Frequency with which keyboard LEDs should blink
591 when kernel panics (default is 0.5 sec)
592 i8042.reset [HW] Reset the controller during init and cleanup
593 i8042.unlock [HW] Unlock (ignore) the keylock
597 i8k.ignore_dmi [HW] Continue probing hardware even if DMI data
598 indicates that the driver is running on unsupported
600 i8k.force [HW] Activate i8k driver even if SMM BIOS signature
601 does not match list of supported models.
603 [HW] Report power status in /proc/i8k
604 (disabled by default)
605 i8k.restricted [HW] Allow controlling fans only if SYS_ADMIN
608 ibmmcascsi= [HW,MCA,SCSI] IBM MicroChannel SCSI adapter
609 See Documentation/mca.txt.
612 Format: <io>[,<membase>[,<icn_id>[,<icn_id2>]]]
614 ide= [HW] (E)IDE subsystem
615 Format: ide=nodma or ide=doubler or ide=reverse
616 See Documentation/ide.txt.
618 ide?= [HW] (E)IDE subsystem
619 Format: ide?=noprobe or chipset specific parameters.
620 See Documentation/ide.txt.
622 idebus= [HW] (E)IDE subsystem - VLB/PCI bus speed
623 See Documentation/ide.txt.
626 Format: idle=poll or idle=halt
629 Set number of hash buckets for inode cache.
632 See header of drivers/scsi/in2000.c.
636 Run specified binary instead of /sbin/init as init
639 initcall_debug [KNL] Trace initcalls as they are executed. Useful
640 for working out where the kernel is dying during
643 initrd= [BOOT] Specify the location of the initial ramdisk
645 inport.irq= [HW] Inport (ATI XL and Microsoft) busmouse driver
648 combined_mode= [HW] control which driver uses IDE ports in combined
649 mode: legacy IDE driver, libata, or both
650 (in the libata case, libata.atapi_enabled=1 may be
651 useful as well). Note that using the ide or libata
652 options may affect your device naming (e.g. by
653 changing hdc to sdb).
654 Format: combined (default), ide, or libata
658 io7= [HW] IO7 for Marvel based alpha systems
659 See comment before marvel_specify_io7 in
660 arch/alpha/kernel/core_marvel.c.
663 See Documentation/nfsroot.txt.
665 ip2= [HW] Set IO/IRQ pairs for up to 4 IntelliPort boards
666 See comment before ip2_setup() in drivers/char/ip2.c.
668 ips= [HW,SCSI] Adaptec / IBM ServeRAID controller
669 See header of drivers/scsi/ips.c.
672 When an interrupt is not handled search all handlers
673 for it. Intended to get systems with badly broken
677 When an interrupt is not handled search all handlers
678 for it. Also check all handlers each timer
679 interrupt. Intended to get systems with badly broken
683 Format: <RDP>,<reset>,<pci_scan>,<verbosity>
685 isolcpus= [KNL,SMP] Isolate CPUs from the general scheduler.
686 Format: <cpu number>,...,<cpu number>
687 This option can be used to specify one or more CPUs
688 to isolate from the general SMP balancing and scheduling
689 algorithms. The only way to move a process onto or off
690 an "isolated" CPU is via the CPU affinity syscalls.
691 <cpu number> begins at 0 and the maximum value is
692 "number of CPUs in system - 1".
694 This option is the preferred way to isolate CPUs. The
695 alternative -- manually setting the CPU mask of all
696 tasks in the system -- can cause problems and
697 suboptimal load balancer performance.
700 Format: <io>,<irq>,<dma>,<setup>
704 js= [HW,JOY] Analog joystick
705 See Documentation/input/joystick.txt.
709 kstack=N [IA-32,X86-64] Print N words from the kernel stack
714 lapic [IA-32,APIC] Enable the local APIC even if BIOS
717 lasi= [HW,SCSI] PARISC LASI driver for the 53c700 chip
718 Format: addr:<io>,irq:<irq>
720 llsc*= [IA64] See function print_params() in
721 arch/ia64/sn/kernel/llsc4.c.
723 load_ramdisk= [RAM] List of ramdisks to load from floppy
724 See Documentation/ramdisk.txt.
726 lockd.nlm_grace_period=P [NFS] Assign grace period.
729 lockd.nlm_tcpport=N [NFS] Assign TCP port.
732 lockd.nlm_timeout=T [NFS] Assign timeout value.
735 lockd.nlm_udpport=M [NFS] Assign UDP port.
738 logibm.irq= [HW,MOUSE] Logitech Bus Mouse Driver
741 loglevel= All Kernel Messages with a loglevel smaller than the
742 console loglevel will be printed to the console. It can
743 also be changed with klogd or other programs. The
744 loglevels are defined as follows:
746 0 (KERN_EMERG) system is unusable
747 1 (KERN_ALERT) action must be taken immediately
748 2 (KERN_CRIT) critical conditions
749 3 (KERN_ERR) error conditions
750 4 (KERN_WARNING) warning conditions
751 5 (KERN_NOTICE) normal but significant condition
752 6 (KERN_INFO) informational
753 7 (KERN_DEBUG) debug-level messages
755 log_buf_len=n Sets the size of the printk ring buffer, in bytes.
756 Format: { n | nk | nM }
757 n must be a power of two. The default size
758 is set in the kernel config file.
760 lp=0 [LP] Specify parallel ports to use, e.g,
761 lp=port[,port...] lp=none,parport0 (lp0 not configured, lp1 uses
762 lp=reset first parallel port). 'lp=0' disables the
763 lp=auto printer driver. 'lp=reset' (which can be
764 specified in addition to the ports) causes
765 attached printers to be reset. Using
766 lp=port1,port2,... specifies the parallel ports
767 to associate lp devices with, starting with
768 lp0. A port specification may be 'none' to skip
769 that lp device, or a parport name such as
770 'parport0'. Specifying 'lp=auto' instead of a
771 port specification list means that device IDs
772 from each port should be examined, to see if
773 an IEEE 1284-compliant printer is attached; if
774 so, the driver will manage that printer.
775 See also header of drivers/char/lp.c.
778 Sets loops_per_jiffy to given constant, thus avoiding
779 time-consuming boot-time autodetection (up to 250 ms per
780 CPU). 0 enables autodetection (default). To determine
781 the correct value for your kernel, boot with normal
782 autodetection and see what value is printed. Note that
783 on SMP systems the preset will be applied to all CPUs,
784 which is likely to cause problems if your CPUs need
785 significantly divergent settings. An incorrect value
786 will cause delays in the kernel to be wrong, leading to
787 unpredictable I/O errors and other breakage. Although
788 unlikely, in the extreme case this might damage your
792 Format: <io>,<irq>,<dma>
794 mac5380= [HW,SCSI] Format:
795 <can_queue>,<cmd_per_lun>,<sg_tablesize>,<hostid>,<use_tags>
797 mac53c9x= [HW,SCSI] Format:
798 <num_esps>,<disconnect>,<nosync>,<can_queue>,<cmd_per_lun>,<sg_tablesize>,<hostid>,<use_tags>
800 machvec= [IA64] Force the use of a particular machine-vector
801 (machvec) in a generic kernel.
802 Example: machvec=hpzx1_swiotlb
804 mad16= [HW,OSS] Format:
805 <io>,<irq>,<dma>,<dma16>,<mpu_io>,<mpu_irq>,<joystick>
810 max_loop= [LOOP] Maximum number of loopback devices that can
814 maxcpus= [SMP] Maximum number of processors that an SMP kernel
817 max_addr=[KMG] [KNL,BOOT,ia64] All physical memory greater than or
818 equal to this physical address is ignored.
820 max_luns= [SCSI] Maximum number of LUNs to probe.
821 Should be between 1 and 2^32-1.
824 [SCSI] Maximum number of LUNs received.
825 Should be between 1 and 16384.
827 mca-pentium [BUGS=IA-32]
832 Format: <port>,<irq>,<mitsumi_bug_93_wait>
836 mce [IA-32] Machine Check Exception
838 md= [HW] RAID subsystems devices and level
839 See Documentation/md.txt.
842 Format: <first>,<last>
843 Specifies range of consoles to be captured by the MDA.
845 mem=nn[KMG] [KNL,BOOT] Force usage of a specific amount of memory
846 Amount of memory to be used when the kernel is not able
847 to see the whole system memory or for test.
848 [IA-32] Use together with memmap= to avoid physical
849 address space collisions. Without memmap= PCI devices
850 could be placed at addresses belonging to unused RAM.
852 mem=nopentium [BUGS=IA-32] Disable usage of 4MB pages for kernel
855 memmap=exactmap [KNL,IA-32,X86_64] Enable setting of an exact
856 E820 memory map, as specified by the user.
857 Such memmap=exactmap lines can be constructed based on
858 BIOS output or other requirements. See the memmap=nn@ss
861 memmap=nn[KMG]@ss[KMG]
862 [KNL] Force usage of a specific region of memory
863 Region of memory to be used, from ss to ss+nn.
865 memmap=nn[KMG]#ss[KMG]
866 [KNL,ACPI] Mark specific memory as ACPI data.
867 Region of memory to be used, from ss to ss+nn.
869 memmap=nn[KMG]$ss[KMG]
870 [KNL,ACPI] Mark specific memory as reserved.
871 Region of memory to be used, from ss to ss+nn.
873 meye.*= [HW] Set MotionEye Camera parameters
874 See Documentation/video4linux/meye.txt.
879 [KNL,SMP] debug: override scheduler migration costs
880 Format: <level-1-usecs>,<level-2-usecs>,...
881 This debugging option can be used to override the
882 default scheduler migration cost matrix. The numbers
883 are indexed by 'CPU domain distance'.
884 E.g. migration_cost=1000,2000,3000 on an SMT NUMA
885 box will set up an intra-core migration cost of
886 1 msec, an inter-core migration cost of 2 msecs,
887 and an inter-node migration cost of 3 msecs.
889 WARNING: using the wrong values here can break
890 scheduler performance, so it's only for scheduler
891 development purposes, not production environments.
894 [KNL,SMP] migration cost auto-detect verbosity
896 If a system's migration matrix reported at bootup
897 seems erroneous then this option can be used to
898 increase verbosity of the detection process.
899 We default to 0 (no extra messages), 1 will print
900 some more information, and 2 will be really
901 verbose (probably only useful if you also have a
902 serial console attached to the system).
905 [KNL,SMP] multiply/divide migration costs by a factor
907 This debug option can be used to proportionally
908 increase or decrease the auto-detected migration
909 costs for all entries of the migration matrix.
910 E.g. migration_factor=150 will increase migration
911 costs by 50%. (and thus the scheduler will be less
912 eager migrating cache-hot tasks)
913 migration_factor=80 will decrease migration costs
914 by 20%. (thus the scheduler will be more eager to
917 WARNING: using the wrong values here can break
918 scheduler performance, so it's only for scheduler
919 development purposes, not production environments.
922 [MOUSE] Maximum time between finger touching and
923 leaving touchpad surface for touch to be considered
924 a tap and be reported as a left button click (for
925 touchpads working in absolute mode only).
927 mousedev.xres= [MOUSE] Horizontal screen resolution, used for devices
928 reporting absolute coordinates, such as tablets
929 mousedev.yres= [MOUSE] Vertical screen resolution, used for devices
930 reporting absolute coordinates, such as tablets
936 Format: <name>,<region-number>,<size>,<offset>
938 MTD_Region= [MTD] Format:
939 <name>,<region-number>[,<base>,<size>,<buswidth>,<altbuswidth>]
942 See drivers/mtd/cmdline.c.
944 mtouchusb.raw_coordinates=
945 [HW] Make the MicroTouch USB driver use raw coordinates
946 ('y', default) or cooked coordinates ('n')
948 n2= [NET] SDL Inc. RISCom/N2 synchronous serial card
951 See header of drivers/scsi/NCR_D700.c.
957 ncr53c400a= [HW,SCSI]
959 ncr53c406a= [HW,SCSI]
963 netdev= [NET] Network devices parameters
964 Format: <irq>,<io>,<mem_start>,<mem_end>,<name>
965 Note that mem_start is often overloaded to mean
966 something different and driver-specific.
967 This usage is only documented in each driver source
971 See Documentation/nfsroot.txt.
973 nfsroot= [NFS] nfs root filesystem for disk-less boxes.
974 See Documentation/nfsroot.txt.
976 nfs.callback_tcpport=
977 [NFS] set the TCP port on which the NFSv4 callback
978 channel should listen.
980 nfs.idmap_cache_timeout=
981 [NFS] set the maximum lifetime for idmapper cache
984 nmi_watchdog= [KNL,BUGS=IA-32] Debugging features for SMP kernels
986 no387 [BUGS=IA-32] Tells the kernel to use the 387 maths
987 emulation library even if a 387 maths coprocessor
992 noapic [SMP,APIC] Tells the kernel to not make use of any
993 IOAPICs that may be present in the system.
995 noasync [HW,M68K] Disables async and sync negotiation for
998 nobats [PPC] Do not use BATs for mapping kernel lowmem
999 on "Classic" PPC cores.
1003 nodisconnect [HW,SCSI,M68K] Disables SCSI disconnects.
1007 noexec [IA-32,X86-64]
1008 noexec=on: enable non-executable mappings (default)
1009 noexec=off: disable nn-executable mappings
1011 nofxsr [BUGS=IA-32] Disables x86 floating point extended
1012 register save and restore. The kernel will only save
1013 legacy floating-point registers on task switch.
1017 no-hlt [BUGS=IA-32] Tells the kernel that the hlt
1018 instruction doesn't work correctly and not to
1021 nohalt [IA-64] Tells the kernel not to use the power saving
1022 function PAL_HALT_LIGHT when idle. This increases
1023 power-consumption. On the positive side, it reduces
1024 interrupt wake-up latency, which may improve performance
1025 in certain environments such as networked servers or
1028 noirqdebug [IA-32] Disables the code which attempts to detect and
1029 disable unhandled interrupt sources.
1031 noisapnp [ISAPNP] Disables ISA PnP code.
1033 noinitrd [RAM] Tells the kernel not to load any configured
1038 nolapic [IA-32,APIC] Do not enable or use the local APIC.
1040 noltlbs [PPC] Do not use large page/tlb entries for kernel
1041 lowmem mapping on PPC40x.
1043 nomce [IA-32] Machine Check Exception
1045 nomca [IA-64] Disable machine check abort handling
1047 noresidual [PPC] Don't use residual data on PReP machines.
1049 noresume [SWSUSP] Disables resume and restores original swap
1052 no-scroll [VGA] Disables scrollback.
1053 This is required for the Braillex ib80-piezo Braille
1054 reader made by F.H. Papenmeier (Germany).
1058 nosep [BUGS=IA-32] Disables x86 SYSENTER/SYSEXIT support.
1060 nosmp [SMP] Tells an SMP kernel to act as a UP kernel.
1062 nosync [HW,M68K] Disables sync negotiation for all devices.
1064 notsc [BUGS=IA-32] Disable Time Stamp Counter
1066 nousb [USB] Disable the USB subsystem
1070 nr_uarts= [SERIAL] maximum number of UARTs to be registered.
1076 Format: <io>,<irq>,<dma>,<dma2>,<mpu_io>,<mpu_irq>
1078 opl3sa2= [HW,OSS] Format:
1079 <io>,<irq>,<dma>,<dma2>,<mss_io>,<mpu_io>,<ymode>,<loopback>[,<isapnp>,<multiple]
1081 oprofile.timer= [HW]
1082 Use timer interrupt instead of performance counters
1087 osst= [HW,SCSI] SCSI Tape Driver
1088 Format: <buffer_size>,<write_threshold>
1089 See also Documentation/scsi/st.txt.
1091 panic= [KNL] Kernel behaviour on panic
1094 parkbd.port= [HW] Parallel port number the keyboard adapter is
1095 connected to, default is 0.
1097 parkbd.mode= [HW] Parallel port keyboard adapter mode of operation,
1098 0 for XT, 1 for AT (default is AT).
1101 parport= [HW,PPT] Specify parallel ports. 0 disables.
1102 Format: { 0 | auto | 0xBBB[,IRQ[,DMA]] }
1103 Use 'auto' to force the driver to use any
1104 IRQ/DMA settings detected (the default is to
1105 ignore detected IRQ/DMA settings because of
1106 possible conflicts). You can specify the base
1107 address, IRQ, and DMA settings; IRQ and DMA
1108 should be numbers, or 'auto' (for using detected
1109 settings on that particular port), or 'nofifo'
1110 (to avoid using a FIFO even if it is detected).
1111 Parallel ports are assigned in the order they
1112 are specified on the command line, starting
1115 parport_init_mode= [HW,PPT]
1116 Configure VIA parallel port to operate in
1117 a specific mode. This is necessary on Pegasos
1118 computer where firmware has no options for setting
1119 up parallel port mode and sets it to spp.
1120 Currently this function knows 686a and 8231 chips.
1121 Format: [spp|ps2|epp|ecp|ecpepp]
1123 pas2= [HW,OSS] Format:
1124 <io>,<irq>,<dma>,<dma16>,<sb_io>,<sb_irq>,<sb_dma>,<sb_dma16>
1127 See header of drivers/scsi/pas16.c.
1130 Halt all CPUs after the first oops has been printed for
1131 the specified number of seconds. This is to be used if
1132 your oopses keep scrolling off the screen.
1137 See header of drivers/block/paride/pcd.c.
1138 See also Documentation/paride.txt.
1140 pci=option[,option...] [PCI] various PCI subsystem options:
1141 off [IA-32] don't probe for the PCI bus
1142 bios [IA-32] force use of PCI BIOS, don't access
1143 the hardware directly. Use this if your machine
1144 has a non-standard PCI host bridge.
1145 nobios [IA-32] disallow use of PCI BIOS, only direct
1146 hardware access methods are allowed. Use this
1147 if you experience crashes upon bootup and you
1148 suspect they are caused by the BIOS.
1149 conf1 [IA-32] Force use of PCI Configuration
1151 conf2 [IA-32] Force use of PCI Configuration
1153 nommconf [IA-32,X86_64] Disable use of MMCONFIG for PCI
1155 nosort [IA-32] Don't sort PCI devices according to
1156 order given by the PCI BIOS. This sorting is
1157 done to get a device order compatible with
1159 biosirq [IA-32] Use PCI BIOS calls to get the interrupt
1160 routing table. These calls are known to be buggy
1161 on several machines and they hang the machine
1162 when used, but on other computers it's the only
1163 way to get the interrupt routing table. Try
1164 this option if the kernel is unable to allocate
1165 IRQs or discover secondary PCI buses on your
1167 rom [IA-32] Assign address space to expansion ROMs.
1168 Use with caution as certain devices share
1169 address decoders between ROMs and other
1171 irqmask=0xMMMM [IA-32] Set a bit mask of IRQs allowed to be
1172 assigned automatically to PCI devices. You can
1173 make the kernel exclude IRQs of your ISA cards
1175 pirqaddr=0xAAAAA [IA-32] Specify the physical address
1176 of the PIRQ table (normally generated
1177 by the BIOS) if it is outside the
1178 F0000h-100000h range.
1179 lastbus=N [IA-32] Scan all buses thru bus #N. Can be
1180 useful if the kernel is unable to find your
1181 secondary buses and you want to tell it
1182 explicitly which ones they are.
1183 assign-busses [IA-32] Always assign all PCI bus
1184 numbers ourselves, overriding
1185 whatever the firmware may have done.
1186 usepirqmask [IA-32] Honor the possible IRQ mask stored
1187 in the BIOS $PIR table. This is needed on
1188 some systems with broken BIOSes, notably
1189 some HP Pavilion N5400 and Omnibook XE3
1190 notebooks. This will have no effect if ACPI
1191 IRQ routing is enabled.
1192 noacpi [IA-32] Do not use ACPI for IRQ routing
1193 or for PCI scanning.
1194 routeirq Do IRQ routing for all PCI devices.
1195 This is normally done in pci_enable_device(),
1196 so this option is a temporary workaround
1197 for broken drivers that don't call it.
1198 firmware [ARM] Do not re-enumerate the bus but instead
1199 just use the configuration from the
1200 bootloader. This is currently used on
1201 IXP2000 systems where the bus has to be
1202 configured a certain way for adjunct CPUs.
1204 pcmv= [HW,PCMCIA] BadgePAD 4
1207 See Documentation/paride.txt.
1209 pdcchassis= [PARISC,HW] Disable/Enable PDC Chassis Status codes at
1212 See arch/parisc/kernel/pdc_chassis.c
1215 See Documentation/paride.txt.
1218 See Documentation/paride.txt.
1220 pirq= [SMP,APIC] Manual mp-table setup
1221 See Documentation/i386/IO-APIC.txt.
1223 plip= [PPT,NET] Parallel port network link
1224 Format: { parport<nr> | timid | 0 }
1225 See also Documentation/parport.txt.
1231 { on | off | curr | res | no-curr | no-res }
1234 [ISAPNP] Exclude IRQs for the autoconfiguration
1237 [ISAPNP] Exclude DMAs for the autoconfiguration
1239 pnp_reserve_io= [ISAPNP] Exclude I/O ports for the autoconfiguration
1240 Ranges are in pairs (I/O port base and size).
1243 [ISAPNP] Exclude memory regions for the
1245 Ranges are in pairs (memory base and size).
1247 profile= [KNL] Enable kernel profiling via /proc/profile
1248 Format: [schedule,]<number>
1249 Param: "schedule" - profile schedule points.
1250 Param: <number> - step/bucket size as a power of 2 for
1251 statistical time based profiling.
1253 processor.max_cstate= [HW,ACPI]
1254 Limit processor to maximum C-state
1255 max_cstate=9 overrides any DMI blacklist limit.
1257 processor.nocst [HW,ACPI]
1258 Ignore the _CST method to determine C-states,
1259 instead using the legacy FADT method
1261 prompt_ramdisk= [RAM] List of RAM disks to prompt for floppy disk
1263 See Documentation/ramdisk.txt.
1265 psmouse.proto= [HW,MOUSE] Highest PS2 mouse protocol extension to
1266 probe for; one of (bare|imps|exps|lifebook|any).
1267 psmouse.rate= [HW,MOUSE] Set desired mouse report rate, in reports
1269 psmouse.resetafter= [HW,MOUSE]
1270 Try to reset the device after so many bad packets
1273 [HW,MOUSE] Set desired mouse resolution, in dpi.
1274 psmouse.smartscroll=
1275 [HW,MOUSE] Controls Logitech smartscroll autorepeat.
1276 0 = disabled, 1 = enabled (default).
1278 pss= [HW,OSS] Personal Sound System (ECHO ESC614)
1280 <io>,<mss_io>,<mss_irq>,<mss_dma>,<mpu_io>,<mpu_irq>
1283 See Documentation/paride.txt.
1285 quiet= [KNL] Disable log messages
1290 See Documentation/md.txt.
1292 ramdisk= [RAM] Sizes of RAM disks in kilobytes [deprecated]
1293 See Documentation/ramdisk.txt.
1295 ramdisk_blocksize= [RAM]
1296 See Documentation/ramdisk.txt.
1298 ramdisk_size= [RAM] Sizes of RAM disks in kilobytes
1299 New name for the ramdisk parameter.
1300 See Documentation/ramdisk.txt.
1302 rcu.blimit= [KNL,BOOT] Set maximum number of finished
1303 RCU callbacks to process in one batch.
1305 rcu.qhimark= [KNL,BOOT] Set threshold of queued
1306 RCU callbacks over which batch limiting is disabled.
1308 rcu.qlowmark= [KNL,BOOT] Set threshold of queued
1309 RCU callbacks below which batch limiting is re-enabled.
1311 rcu.rsinterval= [KNL,BOOT,SMP] Set the number of additional
1312 RCU callbacks to queued before forcing reschedule
1317 Run specified binary instead of /init from the ramdisk,
1318 used for early userspace startup. See initrd.
1320 reboot= [BUGS=IA-32,BUGS=ARM,BUGS=IA-64] Rebooting mode
1321 Format: <reboot_mode>[,<reboot_mode2>[,...]]
1322 See arch/*/kernel/reboot.c.
1324 reserve= [KNL,BUGS] Force the kernel to ignore some iomem area
1327 Specify the partition device for software suspend
1329 rhash_entries= [KNL,NET]
1330 Set number of hash buckets for route cache
1332 riscom8= [HW,SERIAL]
1333 Format: <io_board1>[,<io_board2>[,...<io_boardN>]]
1335 ro [KNL] Mount root device read-only on boot
1337 root= [KNL] Root filesystem
1339 rootdelay= [KNL] Delay (in seconds) to pause before attempting to
1340 mount the root filesystem
1342 rootflags= [KNL] Set root filesystem mount option string
1344 rootfstype= [KNL] Set root filesystem type
1346 rw [KNL] Mount root device read-write on boot
1348 S [KNL] Run init in single mode
1351 See drivers/net/irda/sa1100_ir.c.
1354 Format: <io>,<irq>,<dma>,<dma2>
1356 sbni= [NET] Granch SBNI12 leased line adapter
1358 sbpcd= [HW,CD] Soundblaster CD adapter
1360 See a comment before function sbpcd_setup() in
1361 drivers/cdrom/sbpcd.c.
1363 sc1200wdt= [HW,WDT] SC1200 WDT (watchdog) driver
1364 Format: <io>[,<timeout>[,<isapnp>]]
1366 scsi_debug_*= [SCSI]
1367 See drivers/scsi/scsi_debug.c.
1369 scsi_default_dev_flags=
1370 [SCSI] SCSI default device flags
1373 scsi_dev_flags= [SCSI] Black/white list entry for vendor and model
1374 Format: <vendor>:<model>:<flags>
1375 (flags are integer value)
1377 scsi_logging= [SCSI]
1379 selinux [SELINUX] Disable or enable SELinux at boot time.
1380 Format: { "0" | "1" }
1381 See security/selinux/Kconfig help text.
1384 Default value is set via kernel config option.
1385 If enabled at boot time, /selinux/disable can be used
1386 later to disable prior to initial policy load.
1388 serialnumber [BUGS=IA-32]
1390 sg_def_reserved_size= [SCSI]
1393 Format: <io>,<irq>,<dma>,<dma2>,<sgbase>
1396 Maximal number of shapers.
1399 See header of drivers/scsi/sim710.c.
1405 Format: <io>,<irq>,<dma>
1406 See header of drivers/cdrom/sjcd.c.
1411 Format: <io1>[,<io2>[,...,<io8>]]
1413 snd-ad1816a= [HW,ALSA]
1415 snd-ad1848= [HW,ALSA]
1417 snd-ali5451= [HW,ALSA]
1419 snd-als100= [HW,ALSA]
1421 snd-als4000= [HW,ALSA]
1423 snd-azt2320= [HW,ALSA]
1425 snd-cmi8330= [HW,ALSA]
1427 snd-cmipci= [HW,ALSA]
1429 snd-cs4231= [HW,ALSA]
1431 snd-cs4232= [HW,ALSA]
1433 snd-cs4236= [HW,ALSA]
1435 snd-cs4281= [HW,ALSA]
1437 snd-cs46xx= [HW,ALSA]
1439 snd-dt019x= [HW,ALSA]
1441 snd-dummy= [HW,ALSA]
1443 snd-emu10k1= [HW,ALSA]
1445 snd-ens1370= [HW,ALSA]
1447 snd-ens1371= [HW,ALSA]
1449 snd-es968= [HW,ALSA]
1451 snd-es1688= [HW,ALSA]
1453 snd-es18xx= [HW,ALSA]
1455 snd-es1938= [HW,ALSA]
1457 snd-es1968= [HW,ALSA]
1459 snd-fm801= [HW,ALSA]
1461 snd-gusclassic= [HW,ALSA]
1463 snd-gusextreme= [HW,ALSA]
1465 snd-gusmax= [HW,ALSA]
1469 snd-ice1712= [HW,ALSA]
1471 snd-intel8x0= [HW,ALSA]
1473 snd-interwave= [HW,ALSA]
1478 snd-korg1212= [HW,ALSA]
1480 snd-maestro3= [HW,ALSA]
1482 snd-mpu401= [HW,ALSA]
1484 snd-mtpav= [HW,ALSA]
1486 snd-nm256= [HW,ALSA]
1488 snd-opl3sa2= [HW,ALSA]
1496 snd-opti93x= [HW,ALSA]
1500 snd-rme32= [HW,ALSA]
1502 snd-rme96= [HW,ALSA]
1504 snd-rme9652= [HW,ALSA]
1510 snd-sbawe= [HW,ALSA]
1512 snd-serial= [HW,ALSA]
1514 snd-sgalaxy= [HW,ALSA]
1516 snd-sonicvibes= [HW,ALSA]
1521 snd-sun-cs4231= [HW,ALSA]
1523 snd-trident= [HW,ALSA]
1525 snd-usb-audio= [HW,ALSA,USB]
1527 snd-via82xx= [HW,ALSA]
1529 snd-virmidi= [HW,ALSA]
1531 snd-wavefront= [HW,ALSA]
1533 snd-ymfpci= [HW,ALSA]
1535 sonicvibes= [HW,OSS]
1539 Format: <io>[,<irq>]
1541 sonypi.*= [HW] Sony Programmable I/O Control Device driver
1542 See Documentation/sonypi.txt
1544 specialix= [HW,SERIAL] Specialix multi-serial port adapter
1545 See Documentation/specialix.txt.
1547 spia_io_base= [HW,MTD]
1553 Format: <io>,<irq>,<dma>,<mpu_io>,<mpu_irq>
1555 st= [HW,SCSI] SCSI tape parameters (buffers, etc.)
1556 See Documentation/scsi/st.txt.
1559 See header of drivers/scsi/seagate.c.
1563 Set the STI (builtin display/keyboard on the HP-PARISC
1564 machines) console (graphic card) which should be used
1565 as the initial boot-console.
1566 See also comment in drivers/video/console/sticore.c.
1569 See comment in drivers/video/console/sticore.c.
1572 Format: bpp:<bpp1>[:<bpp2>[:<bpp3>...]]
1574 swiotlb= [IA-64] Number of I/O TLB slabs
1578 sym53c416= [HW,SCSI]
1579 See header of drivers/scsi/sym53c416.c.
1582 See header of drivers/scsi/t128.c.
1586 thash_entries= [KNL,NET]
1587 Set number of hash buckets for TCP connection
1589 time Show timing data prefixed to each printk message line
1591 tipar.timeout= [HW,PPT]
1592 Set communications timeout in tenths of a second
1595 tipar.delay= [HW,PPT]
1596 Set inter-bit delay in microseconds (default 10).
1599 See header of drivers/scsi/seagate.c.
1602 See comment before function dc390_setup() in
1603 drivers/scsi/tmscsim.c.
1607 trix= [HW,OSS] MediaTrix AudioTrix Pro
1609 <io>,<irq>,<dma>,<dma2>,<sb_io>,<sb_irq>,<sb_dma>,<mpu_io>,<mpu_irq>
1611 tsdev.xres= [TS] Horizontal screen resolution.
1612 tsdev.yres= [TS] Vertical screen resolution.
1614 turbografx.map[2|3]= [HW,JOY]
1615 TurboGraFX parallel port interface
1617 <port#>,<js1>,<js2>,<js3>,<js4>,<js5>,<js6>,<js7>
1618 See also Documentation/input/joystick-parport.txt
1620 u14-34f= [HW,SCSI] UltraStor 14F/34F SCSI host adapter
1621 See header of drivers/scsi/u14-34f.c.
1630 [USBHID] The interval which mice are to be polled at.
1632 video= [FB] Frame buffer configuration
1633 See Documentation/fb/modedb.txt.
1635 vga= [BOOT,IA-32] Select a particular video mode
1636 See Documentation/i386/boot.txt and
1637 Documentation/svga.txt.
1638 Use vga=ask for menu.
1639 This is actually a boot loader parameter; the value is
1640 passed to the kernel using a special protocol.
1642 vmalloc=nn[KMG] [KNL,BOOT] Forces the vmalloc area to have an exact
1643 size of <nn>. This can be used to increase the
1644 minimum size (128MB on x86). It can also be used to
1645 decrease the size and leave more room for directly
1652 waveartist= [HW,OSS]
1653 Format: <io>,<irq>,<dma>,<dma2>
1656 See header of drivers/scsi/wd33c93.c.
1659 See header of drivers/scsi/wd7000.c.
1662 See Documentation/watchdog/watchdog.txt.
1664 xd= [HW,XT] Original XT pre-IDE (RLL encoded) disks.
1665 xd_geo= See header of drivers/block/xd.c.
1667 xirc2ps_cs= [NET,PCMCIA]
1669 <irq>,<irq_mask>,<io>,<full_duplex>,<do_sound>,<lockup_hack>[,<irq2>[,<irq3>[,<irq4>]]]
1671 norandmaps Don't use address space randomization
1672 Equivalent to echo 0 > /proc/sys/kernel/randomize_va_space
1675 ______________________________________________________________________
1678 2000-06-?? Mr. Unknown
1679 The last known update (for 2.4.0) - the changelog was not kept before.
1681 2002-11-24 Petr Baudis <pasky@ucw.cz>
1682 Randy Dunlap <randy.dunlap@verizon.net>
1683 Update for 2.5.49, description for most of the options introduced,
1684 references to other documentation (C files, READMEs, ..), added S390,
1685 PPC, SPARC, MTD, ALSA and OSS category. Minor corrections and
1688 2005-10-19 Randy Dunlap <rdunlap@xenotime.net>
1689 Lots of typos, whitespace, some reformatting.
1693 Add documentation for ALSA options.
1694 Add more DRM drivers.