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 state 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 EFI EFI Partitioning (GPT) is enabled
33 EIDE EIDE/ATAPI support is enabled.
34 FB The frame buffer device is enabled.
35 HW Appropriate hardware is enabled.
36 IA-32 IA-32 aka i386 architecture is enabled.
37 IA-64 IA-64 architecture is enabled.
38 IOSCHED More than one I/O scheduler is enabled.
39 IP_PNP IP DCHP, BOOTP, or RARP is enabled.
40 ISAPNP ISA PnP code is enabled.
41 ISDN Appropriate ISDN support is enabled.
42 JOY Appropriate joystick support is enabled.
43 LP Printer support is enabled.
44 LOOP Loopback device support is enabled.
45 M68k M68k architecture is enabled.
46 These options have more detailed description inside of
47 Documentation/m68k/kernel-options.txt.
48 MCA MCA bus support is enabled.
49 MDA MDA console support is enabled.
50 MOUSE Appropriate mouse support is enabled.
51 MTD MTD support is enabled.
52 NET Appropriate network support is enabled.
53 NFS Appropriate NFS support is enabled.
54 OSS OSS sound support is enabled.
55 PARIDE The ParIDE subsystem is enabled.
56 PCI PCI bus support is enabled.
57 PCMCIA The PCMCIA subsystem is enabled.
58 PNP Plug & Play support is enabled.
59 PPC PowerPC architecture is enabled.
60 PPT Parallel port support is enabled.
61 PS2 Appropriate PS/2 support is enabled.
62 RAM RAM disk support is enabled.
63 S390 S390 architecture is enabled.
64 SCSI Appropriate SCSI support is enabled.
65 A lot of drivers has their options described inside of
67 SERIAL Serial support is enabled.
68 SMP The kernel is an SMP kernel.
69 SPARC Sparc architecture is enabled.
70 SWSUSP Software suspension is enabled.
71 TS Appropriate touchscreen support is enabled.
72 USB USB support is enabled.
73 V4L Video For Linux support is enabled.
74 VGA The VGA console has been enabled.
75 VT Virtual terminal support is enabled.
76 WDT Watchdog support is enabled.
77 XT IBM PC/XT MFM hard disk support is enabled.
79 In addition, the following text indicates that the option:
81 BUGS= Relates to possible processor bugs on the said processor.
82 KNL Is a kernel start-up parameter.
83 BOOT Is a boot loader parameter.
85 Parameters denoted with BOOT are actually interpreted by the boot
86 loader, and have no meaning to the kernel directly.
87 Do not modify the syntax of boot loader parameters without extreme
88 need or coordination with <Documentation/i386/boot.txt>.
90 Note that ALL kernel parameters listed below are CASE SENSITIVE, and that
91 a trailing = on the name of any parameter states that that parameter will
92 be entered as an environment variable, whereas its absence indicates that
93 it will appear as a kernel argument readable via /proc/cmdline by programs
94 running once the system is up.
96 53c7xx= [HW,SCSI] Amiga SCSI controllers
97 See header of drivers/scsi/53c7xx.c.
98 See also Documentation/scsi/ncr53c7xx.txt.
100 98busmouse.irq= [HW,MOUSE] PC-9801 Bus Mouse Driver
101 Format: <irq>, default is 13
103 acpi= [HW,ACPI] Advanced Configuration and Power Interface
104 Format: { force | off | ht | strict }
105 force -- enable ACPI if default was off
106 off -- disable ACPI if default was on
107 noirq -- do not use ACPI for IRQ routing
108 ht -- run only enough ACPI to enable Hyper Threading
109 strict -- Be less tolerant of platforms that are not
110 strictly ACPI specification compliant.
112 See also Documentation/pm.txt, pci=noacpi
114 acpi_sleep= [HW,ACPI] Sleep options
115 Format: { s3_bios, s3_mode }
116 See Documentation/power/video.txt
118 acpi_sci= [HW,ACPI] ACPI System Control Interrupt trigger mode
119 Format: { level | edge | high | low }
121 acpi_irq_balance [HW,ACPI] ACPI will balance active IRQs
124 acpi_irq_nobalance [HW,ACPI] ACPI will not move active IRQs (default)
127 acpi_irq_pci= [HW,ACPI] If irq_balance, Clear listed IRQs for use by PCI
128 Format: <irq>,<irq>...
130 acpi_irq_isa= [HW,ACPI] If irq_balance, Mark listed IRQs used by ISA
131 Format: <irq>,<irq>...
133 acpi_osi= [HW,ACPI] empty param disables _OSI
135 acpi_serialize [HW,ACPI] force serialization of AML methods
137 acpi_skip_timer_override [HW,ACPI]
138 Recognize and ignore IRQ0/pin2 Interrupt Override.
139 For broken nForce2 BIOS resulting in XT-PIC timer.
142 Format: <io>,<irq>,<dma>,<dma2>
143 See also Documentation/sound/oss/AD1816.
146 Format: <io>,<irq>,<dma>,<dma2>,<type>
152 See header of drivers/scsi/advansys.c.
154 advwdt= [HW,WDT] Advantech WDT
155 Format: <iostart>,<iostop>
157 aedsp16= [HW,OSS] Audio Excel DSP 16
158 Format: <io>,<irq>,<dma>,<mss_io>,<mpu_io>,<mpu_irq>
159 See also header of sound/oss/aedsp16.c.
162 See Documentation/scsi/aha152x.txt.
165 Format: <portbase>[,<buson>,<busoff>[,<dmaspeed>]]
168 See Documentation/scsi/aic7xxx.txt.
171 See Documentation/scsi/aic79xx.txt.
174 Format: <host-scsi-id>,<target-scsi-id>,<max-rate>,<max-offset>
175 See also header of drivers/scsi/AM53C974.c.
177 amijoy.map= [HW,JOY] Amiga joystick support
178 Map of devices attached to JOY0DAT and JOY1DAT
180 See also Documentation/kernel/input/joystick.txt
182 analog.map= [HW,JOY] Analog joystick and gamepad support
183 Specifies type or capabilities of an analog joystick
184 connected to one of 16 gameports
185 Format: <type1>,<type2>,..<type16>
187 apc= [HW,SPARC] Power management functions (SPARCstation-4/5 + deriv.)
189 Disable APC CPU standby support. SPARCstation-Fox does
190 not play well with APC CPU idle - disable it if you have
191 APC and your system crashes randomly.
193 apm= [APM] Advanced Power Management
194 See header of arch/i386/kernel/apm.c.
199 arcrimi= [HW,NET] ARCnet - "RIM I" (entirely mem-mapped) cards
200 Format: <io>,<irq>,<nodeID>
204 atarimouse= [HW,MOUSE] Atari Mouse
206 atascsi= [HW,SCSI] Atari SCSI
208 atkbd.extra= [HW] Enable extra LEDs and keys on IBM RapidAccess, EzKey
209 and similar keyboards
211 atkbd.reset= [HW] Reset keyboard during initialization
213 atkbd.set= [HW] Select keyboard code set
214 Format: <int> (2 = AT (default) 3 = PS/2)
216 atkbd.scroll= [HW] Enable scroll wheel on MS Office and similar keyboards
219 [HW] Use software keyboard repeat
223 awe= [HW,OSS] AWE32/SB32/AWE64 wave table synth
224 Format: <io>,<memsize>,<isapnp>
226 aztcd= [HW,CD] Aztech CD268 CDROM driver
227 Format: <io>,0x79 (?)
229 baycom_epp= [HW,AX25]
232 baycom_par= [HW,AX25] BayCom Parallel Port AX.25 Modem
234 See header of drivers/net/hamradio/baycom_par.c.
236 baycom_ser_fdx= [HW,AX25] BayCom Serial Port AX.25 Modem (Full Duplex Mode)
237 Format: <io>,<irq>,<mode>[,<baud>]
238 See header of drivers/net/hamradio/baycom_ser_fdx.c.
240 baycom_ser_hdx= [HW,AX25] BayCom Serial Port AX.25 Modem (Half Duplex Mode)
241 Format: <io>,<irq>,<mode>
242 See header of drivers/net/hamradio/baycom_ser_hdx.c.
244 blkmtd_device= [HW,MTD]
250 bttv.card= [HW,V4L] bttv (bt848 + bt878 based grabber cards)
251 bttv.radio= Most important insmod options are available as kernel args too.
252 bttv.pll= See Documentation/video4linux/bttv/Insmod-options
253 bttv.tuner= and Documentation/video4linux/bttv/CARDLIST
256 See drivers/scsi/BusLogic.c, comment before function
257 BusLogic_ParseDriverOptions().
259 c101= [NET] Moxa C101 synchronous serial card
261 cachesize= [BUGS=IA-32] Override level 2 CPU cache size detection.
262 Sometimes CPU hardware bugs make them report the cache
263 size incorrectly. The kernel will attempt work arounds
264 to fix known problems, but for some CPUs it is not
265 possible to determine what the correct size should be.
266 This option provides an override for these situations.
269 Format: <io>,<irq>[,PAS]
270 See header of drivers/cdrom/cdu31a.c.
272 chandev= [HW,NET] Generic channel device initialisation
274 clock= [BUGS=IA-32, HW] gettimeofday timesource override.
275 Forces specified timesource (if avaliable) to be used
276 when calculating gettimeofday(). If specicified timesource
277 is not avalible, it defaults to PIT.
278 Format: { pit | tsc | cyclone | pmtmr }
280 hpet= [IA-32,HPET] option to disable HPET and use PIT.
284 Format: { auto | [<io>,][<irq>] }
286 com20020= [HW,NET] ARCnet - COM20020 chipset
287 Format: <io>[,<irq>[,<nodeID>[,<backplane>[,<ckp>[,<timeout>]]]]]
289 com90io= [HW,NET] ARCnet - COM90xx chipset (IO-mapped buffers)
292 com90xx= [HW,NET] ARCnet - COM90xx chipset (memory-mapped buffers)
293 Format: <io>[,<irq>[,<memstart>]]
295 condev= [HW,S390] console device
298 console= [KNL] Output console
299 Console device and comm spec (speed, control, parity).
301 cpcihp_generic= [HW,PCI] Generic port I/O CompactPCI driver
302 Format: <first_slot>,<last_slot>,<port>,<enum_bit>[,<debug>]
305 Format: { parport<nr> | auto | none }
308 Format: <io>,<irq>,<dma>,<dma2>,<mpuio>,<mpuirq>
313 cs89x0_media= [HW,NET]
314 Format: { rj45 | aui | bnc }
316 cyclades= [HW,SERIAL] Cyclades multi-serial port adapter.
319 See header of drivers/s390/block/dasd_devmap.c.
321 db9.dev[2|3]= [HW,JOY] Multisystem joystick support via parallel port
322 (one device per port)
323 Format: <port#>,<type>
324 See also Documentation/input/joystick-parport.txt
326 debug [KNL] Enable kernel debugging (events log level).
329 Format: <area>[,<node>]
330 See also Documentation/networking/decnet.txt.
333 See Documentation/filesystems/devfs/boot-options.
336 Set number of hash buckets for dentry cache.
339 IO parameters + enable/disable command.
341 digiepca= [HW,SERIAL]
342 See drivers/char/README.epca and
343 Documentation/digiepca.txt.
345 dmascc= [HW,AX25,SERIAL] AX.25 Z80SCC driver with DMA
347 Format: <io_dev0>[,<io_dev1>[,..<io_dev32>]]
349 dmasound= [HW,OSS] Sound subsystem buffers
355 earlyprintk= [x86, x86_64]
357 earlyprintk=serial[,ttySn[,baudrate]]
359 Append ,keep to not disable it when the real console
362 Only vga or serial at a time, not both.
364 Currently only ttyS0 and ttyS1 are supported.
366 Interaction with the standard serial driver is not
369 The VGA output is eventually overwritten by the real
379 Format: <id>,<membase>,<irq>
381 eisa_irq_edge= [PARISC]
382 See header of drivers/parisc/eisa.c.
385 See comment before function elanfreq_setup() in
386 arch/i386/kernel/cpu/cpufreq/elanfreq.c.
389 Format: {"as"|"cfq"|"deadline"|"noop"}
390 See Documentation/as-iosched.txt for details
393 Format: <lineout>[,<micbias>]
394 See also header of sound/oss/es1370.c.
397 Format: <spdif>,[<nomix>,[<amplifier>]]
398 See also header of sound/oss/es1371.c.
400 ether= [HW,NET] Ethernet cards parameters
401 This option is obsoleted by the "netdev=" option, which
402 has equivalent usage. See its documentation for details.
404 eurwdt= [HW,WDT] Eurotech CPU-1220/1410 onboard watchdog.
408 See header of drivers/scsi/fd_mcs.c.
411 See header of drivers/scsi/fdomain.c.
414 See Documentation/floppy.txt.
416 ftape= [HW] Floppy Tape subsystem debugging options.
417 See Documentation/ftape.txt.
420 [HW,JOY] Multisystem joystick and NES/SNES/PSX pad
421 support via parallel port (up to 5 devices per port)
422 Format: <port#>,<pad1>,<pad2>,<pad3>,<pad4>,<pad5>
423 See also Documentation/input/joystick-parport.txt
428 See header of drivers/scsi/gdth.c.
430 gpt [EFI] Forces disk with valid GPT signature but
431 invalid Protective MBR to be treated as GPT.
436 gt96100eth= [NET] MIPS GT96100 Advanced Communication Controller
439 Format: <io>,<irq>,<dma>,<dma16>
443 hcl= [IA-64] SGI's Hardware Graph compatibility layer
445 hd= [EIDE] (E)IDE hard drive subsystem geometry
446 Format: <cyl>,<head>,<sect>
448 hd?= [HW] (E)IDE subsystem
449 hd?lun= See Documentation/ide.txt.
452 See Documentation/isdn/README.HiSax.
454 hugepages= [HW,IA-32,IA-64] Maximal number of HugeTLB pages.
456 noirqbalance [IA-32,SMP,KNL] Disable kernel irq balancing
458 i8042.direct [HW] Put keyboard port into non-translated mode
459 i8042.dumbkbd [HW] Pretend that controlled can only read data from
460 keyboard and can not control its state
461 (Don't attempt to blink the leds)
462 i8042.noaux [HW] Don't check for auxiliary (== mouse) port
463 i8042.nomux [HW] Don't check presence of an active multiplexing
465 i8042.reset [HW] Reset the controller during init and cleanup
466 i8042.unlock [HW] Unlock (ignore) the keylock
470 ibmmcascsi= [HW,MCA,SCSI] IBM MicroChannel SCSI adapter
471 See Documentation/mca.txt.
474 Format: <io>[,<membase>[,<icn_id>[,<icn_id2>]]]
476 ide?= [HW] (E)IDE subsystem
477 Config (iomem/irq), tuning or debugging
478 (serialize,reset,no{dma,tune,probe}) or chipset
480 See Documentation/ide.txt.
482 idebus= [HW] (E)IDE subsystem - VLB/PCI bus speed
483 See Documentation/ide.txt.
486 Format: idle=poll or idle=halt
489 Set number of hash buckets for inode cache.
492 See header of drivers/scsi/in2000.c.
496 Run specified binary instead of /sbin/init as init
499 initcall_debug [KNL] Trace initcalls as they are executed. Useful
500 for working out where the kernel is dying during
503 initrd= [BOOT] Specify the location of the initial ramdisk
505 inport.irq= [HW] Inport (ATI XL and Microsoft) busmouse driver
510 io7= [HW] IO7 for Marvel based alpha systems
511 See comment before marvel_specify_io7 in
512 arch/alpha/kernel/core_marvel.c.
515 See Documentation/nfsroot.txt.
517 ip2= [HW] Set IO/IRQ pairs for up to 4 IntelliPort boards
518 See comment before ip2_setup() in drivers/char/ip2.c.
520 ips= [HW,SCSI] Adaptec / IBM ServeRAID controller
521 See header of drivers/scsi/ips.c.
524 Format: <RDP>, <reset>, <pci_scan>, <verbosity>
527 Format: <io>,<irq>,<dma>,<setup>
531 js= [HW,JOY] Analog joystick
532 See Documentation/input/joystick.txt.
538 lapic [IA-32,APIC] Enable the local APIC even if BIOS disabled it.
540 lasi= [HW,SCSI] PARISC LASI driver for the 53c700 chip
541 Format: addr:<io>,irq:<irq>
544 See function print_params() in arch/ia64/sn/kernel/llsc4.c.
546 load_ramdisk= [RAM] List of ramdisks to load from floppy
547 See Documentation/ramdisk.txt.
553 logibm.irq= [HW,MOUSE] Logitech Bus Mouse Driver
556 log_buf_len=n Sets the size of the printk ring buffer, in bytes.
557 Format is n, nk, nM. n must be a power of two. The
558 default is set in kernel config.
560 lp=0 [LP] Specify parallel ports to use, e.g,
561 lp=port[,port...] lp=none,parport0 (lp0 not configured, lp1 uses
562 lp=reset first parallel port). 'lp=0' disables the
563 lp=auto printer driver. 'lp=reset' (which can be
564 specified in addition to the ports) causes
565 attached printers to be reset. Using
566 lp=port1,port2,... specifies the parallel ports
567 to associate lp devices with, starting with
568 lp0. A port specification may be 'none' to skip
569 that lp device, or a parport name such as
570 'parport0'. Specifying 'lp=auto' instead of a
571 port specification list means that device IDs
572 from each port should be examined, to see if
573 an IEEE 1284-compliant printer is attached; if
574 so, the driver will manage that printer.
575 See also header of drivers/char/lp.c.
578 Format: <io>,<irq>,<dma>
581 Format: <can_queue>,<cmd_per_lun>,<sg_tablesize>,<hostid>,<use_tags>
584 Format: <num_esps>,<disconnect>,<nosync>,<can_queue>,<cmd_per_lun>,<sg_tablesize>,<hostid>,<use_tags>
587 Format: <io>,<irq>,<dma>,<dma16>,<mpu_io>,<mpu_irq>,<joystick>
592 max_loop= [LOOP] Maximum number of loopback devices that can
596 maxcpus= [SMP] Maximum number of processors that an SMP kernel
599 max_scsi_luns= [SCSI]
601 max_scsi_report_luns=
602 [SCSI] Maximum number of LUNs received
603 Should be between 1 and 16384.
605 mca-pentium [BUGS=IA-32]
610 Format: <port>,<irq>,<mitsumi_bug_93_wait>
614 mce [IA-32] Machine Check Exception
616 md= [HW] RAID subsystems devices and level
617 See Documentation/md.txt.
620 Format: <first>,<last>
621 Specifies range of consoles to be captured by the MDA.
623 mem=nn[KMG] [KNL,BOOT] Force usage of a specific amount of memory
624 Amount of memory to be used when the kernel is not able
625 to see the whole system memory or for test.
627 mem=nopentium [BUGS=IA-32] Disable usage of 4MB pages for kernel
630 memmap=exactmap [KNL,IA-32] Enable setting of an exact
631 E820 memory map, as specified by the user.
632 Such memmap=exactmap lines can be constructed based on
633 BIOS output or other requirements. See the memmap=nn@ss
636 memmap=nn[KMG]@ss[KMG]
637 [KNL] Force usage of a specific region of memory
638 Region of memory to be used, from ss to ss+nn.
640 memmap=nn[KMG]#ss[KMG]
641 [KNL,ACPI] Mark specific memory as ACPI data.
642 Region of memory to be used, from ss to ss+nn.
644 memmap=nn[KMG]$ss[KMG]
645 [KNL,ACPI] Mark specific memory as reserved.
646 Region of memory to be used, from ss to ss+nn.
648 meye= [HW] Set MotionEye Camera parameters
649 See Documentation/video4linux/meye.txt.
653 mousedev.xres= [MOUSE] Horizontal screen resolution, used for devices
654 reporting absolute coordinates, such as tablets
655 mousedev.yres= [MOUSE] Vertical screen resolution, used for devices
656 reporting absolute coordinates, such as tablets
662 Format: <name>,<region-number>,<size>,<offset>
665 Format: <name>,<region-number>[,<base>,<size>,<buswidth>,<altbuswidth>]
668 See drivers/mtd/cmdline.c.
670 n2= [NET] SDL Inc. RISCom/N2 synchronous serial card
673 See header of drivers/scsi/NCR_D700.c.
679 ncr53c400a= [HW,SCSI]
681 ncr53c406a= [HW,SCSI]
685 netdev= [NET] Network devices parameters
686 Format: <irq>,<io>,<mem_start>,<mem_end>,<name>
687 Note that mem_start is often overloaded to mean
688 something different and driver-specific.
691 See Documentation/nfsroot.txt.
693 nfsroot= [NFS] nfs root filesystem for disk-less boxes.
694 See Documentation/nfsroot.txt.
696 nmi_watchdog= [KNL,BUGS=IA-32] Debugging features for SMP kernels
698 no387 [BUGS=IA-32] Tells the kernel to use the 387 maths
699 emulation library even if a 387 maths coprocessor
704 noapic [SMP,APIC] Tells the kernel not to make use of any
705 APIC that may be present on the system.
707 noasync [HW,M68K] Disables async and sync negotiation for
712 nodisconnect [HW,SCSI,M68K] Disables SCSI disconnects.
717 noexec=on: enable non-executable mappings (default)
718 noexec=off: disable nn-executable mappings
722 nohighio [BUGS=IA-32] Disable highmem block I/O.
726 no-hlt [BUGS=IA-32] Tells the kernel that the hlt
727 instruction doesn't work correctly and not to
730 noirqdebug [IA-32] Disables the code which attempts to detect and
731 disable unhandled interrupt sources.
733 noisapnp [ISAPNP] Disables ISA PnP code.
735 noinitrd [RAM] Tells the kernel not to load any configured
740 nolapic [IA-32,APIC] Do not enable or use the local APIC.
742 nomce [IA-32] Machine Check Exception
744 noresume [SWSUSP] Disables resume and restore original swap space.
746 no-scroll [VGA] Disables scrollback.
747 This is required for the Braillex ib80-piezo Braille
748 reader made by F.H. Papenmeier (Germany).
752 nosmp [SMP] Tells an SMP kernel to act as a UP kernel.
754 nosync [HW,M68K] Disables sync negotiation for all devices.
756 notsc [BUGS=IA-32] Disable Time Stamp Counter
758 nousb [USB] Disable the USB subsystem
766 Format: <io>,<irq>,<dma>,<dma2>,<mpu_io>,<mpu_irq>
769 Format: <io>,<irq>,<dma>,<dma2>,<mss_io>,<mpu_io>,<ymode>,<loopback>[,<isapnp>,<multiple]
772 Use timer interrupt instead of performance counters
777 osst= [HW,SCSI] SCSI Tape Driver
778 Format: <buffer_size>,<write_threshold>
779 See also Documentation/scsi/st.txt.
781 panic= [KNL] Kernel behaviour on panic
784 parport=0 [HW,PPT] Specify parallel ports. 0 disables.
785 parport=auto Use 'auto' to force the driver to use
786 parport=0xBBB[,IRQ[,DMA]] any IRQ/DMA settings detected (the
787 default is to ignore detected IRQ/DMA
788 settings because of possible
789 conflicts). You can specify the base
790 address, IRQ, and DMA settings; IRQ and
791 DMA should be numbers, or 'auto' (for
792 using detected settings on that
793 particular port), or 'nofifo' (to avoid
794 using a FIFO even if it is detected).
795 Parallel ports are assigned in the
796 order they are specified on the command
797 line, starting with parport0.
800 Format: <io>,<irq>,<dma>,<dma16>,<sb_io>,<sb_irq>,<sb_dma>,<sb_dma16>
803 See header of drivers/scsi/pas16.c.
808 See header of drivers/block/paride/pcd.c.
809 See also Documentation/paride.txt.
811 pci=option[,option...] [PCI] various PCI subsystem options:
812 off [IA-32] don't probe for the PCI bus
813 bios [IA-32] force use of PCI BIOS, don't access
814 the hardware directly. Use this if your machine
815 has a non-standard PCI host bridge.
816 nobios [IA-32] disallow use of PCI BIOS, only direct
817 hardware access methods are allowed. Use this
818 if you experience crashes upon bootup and you
819 suspect they are caused by the BIOS.
820 conf1 [IA-32] Force use of PCI Configuration Mechanism 1.
821 conf2 [IA-32] Force use of PCI Configuration Mechanism 2.
822 nosort [IA-32] Don't sort PCI devices according to
823 order given by the PCI BIOS. This sorting is done
824 to get a device order compatible with older kernels.
825 biosirq [IA-32] Use PCI BIOS calls to get the interrupt
826 routing table. These calls are known to be buggy
827 on several machines and they hang the machine when used,
828 but on other computers it's the only way to get the
829 interrupt routing table. Try this option if the kernel
830 is unable to allocate IRQs or discover secondary PCI
831 buses on your motherboard.
832 rom [IA-32] Assign address space to expansion ROMs.
833 Use with caution as certain devices share address
834 decoders between ROMs and other resources.
835 irqmask=0xMMMM [IA-32] Set a bit mask of IRQs allowed to be assigned
836 automatically to PCI devices. You can make the kernel
837 exclude IRQs of your ISA cards this way.
838 lastbus=N [IA-32] Scan all buses till bus #N. Can be useful
839 if the kernel is unable to find your secondary buses
840 and you want to tell it explicitly which ones they are.
841 assign-busses [IA-32] Always assign all PCI bus
842 numbers ourselves, overriding
843 whatever the firmware may have
845 usepirqmask [IA-32] Honor the possible IRQ mask
846 stored in the BIOS $PIR table. This is
847 needed on some systems with broken
848 BIOSes, notably some HP Pavilion N5400
849 and Omnibook XE3 notebooks. This will
850 have no effect if ACPI IRQ routing is
852 noacpi [IA-32] Do not use ACPI for IRQ routing
855 pcmv= [HW,PCMCIA] BadgePAD 4
858 See Documentation/paride.txt.
861 See Documentation/paride.txt.
864 See Documentation/paride.txt.
866 pirq= [SMP,APIC] Manual mp-table setup
867 See Documentation/i386/IO-APIC.txt.
869 plip= [PPT,NET] Parallel port network link
870 Format: { parport<nr> | timid | 0 }
871 See also Documentation/parport.txt.
874 { on | off | curr | res | no-curr | no-res }
877 [ISAPNP] Exclude IRQs for the autoconfiguration
880 [ISAPNP] Exclude DMAs for the autoconfiguration
882 pnp_reserve_io= [ISAPNP] Exclude I/O ports for the autoconfiguration
883 Ranges are in pairs (I/O port base and size).
886 [ISAPNP] Exclude memory regions for the autoconfiguration
887 Ranges are in pairs (memory base and size).
889 profile= [KNL] Enable kernel profiling via /proc/profile
890 (param: profile step/bucket size as a power of 2)
892 prompt_ramdisk= [RAM] List of RAM disks to prompt for floppy disk
894 See Documentation/ramdisk.txt.
896 psmouse.proto= [HW,MOUSE] Highest PS2 mouse protocol extension to
897 probe for (bare|imps|exps).
898 psmouse.rate= [HW,MOUSE] Set desired mouse report rate, in reports
901 [HW,MOUSE] Try to reset the device after so many bad packets
904 [HW,MOUSE] Set desired mouse resolution, in dpi.
906 [HW,MOUSE] Controls Logitech smartscroll autorepeat,
907 0 = disabled, 1 = enabled (default).
909 pss= [HW,OSS] Personal Sound System (ECHO ESC614)
910 Format: <io>,<mss_io>,<mss_irq>,<mss_dma>,<mpu_io>,<mpu_irq>
913 See Documentation/paride.txt.
915 quiet= [KNL] Disable log messages
920 See Documentation/md.txt.
922 ramdisk= [RAM] Sizes of RAM disks in kilobytes [deprecated]
923 See Documentation/ramdisk.txt.
927 See Documentation/ramdisk.txt.
929 ramdisk_size= [RAM] Sizes of RAM disks in kilobytes
930 New name for the ramdisk parameter.
931 See Documentation/ramdisk.txt.
933 ramdisk_start= [RAM] Starting block of RAM disk image (so you can
934 place it after the kernel image on a boot floppy).
935 See Documentation/ramdisk.txt.
937 reboot= [BUGS=IA-32,BUGS=ARM,BUGS=IA-64] Rebooting mode
938 Format: <reboot_mode>[,<reboot_mode2>[,...]]
939 See arch/*/kernel/reboot.c.
941 reserve= [KNL,BUGS] Force the kernel to ignore some iomem area
943 resume= [SWSUSP] Specify the partition device for software suspension
945 rhash_entries= [KNL,NET]
946 Set number of hash buckets for route cache
949 Format: <io_board1>[,<io_board2>[,...<io_boardN>]]
951 ro [KNL] Mount root device read-only on boot
953 root= [KNL] Root filesystem
955 rootflags= [KNL] Set root filesystem mount option string
957 rootfstype= [KNL] Set root filesystem type
959 rw [KNL] Mount root device read-write on boot
961 S [KNL] Run init in single mode
964 See drivers/net/irda/sa1100_ir.c.
967 Format: <io>,<irq>,<dma>,<dma2>
969 sbni= [NET] Granch SBNI12 leased line adapter
971 sbpcd= [HW,CD] Soundblaster CD adapter
973 See a comment before function sbpcd_setup() in
974 drivers/cdrom/sbpcd.c.
976 sc1200wdt= [HW,WDT] SC1200 WDT (watchdog) driver
977 Format: <io>[,<timeout>[,<isapnp>]]
980 See drivers/scsi/scsi_debug.c.
982 scsi_default_dev_flags=
983 [SCSI] SCSI default device flags
986 scsi_dev_flags= [SCSI] Black/white list entry for vendor and model
987 Format: <vendor>:<model>:<flags>
988 (flags are integer value)
994 serialnumber [BUGS=IA-32]
996 sf16fm= [HW] SF16FMI radio driver for Linux
999 sg_def_reserved_size=
1003 Format: <io>,<irq>,<dma>,<dma2>,<sgbase>
1006 Maximal number of shapers.
1009 See header of drivers/scsi/sim710.c.
1015 Format: <io>,<irq>,<dma>
1016 See header of drivers/cdrom/sjcd.c.
1021 Format: <io1>[,<io2>[,...,<io8>]]
1023 snd-ad1816a= [HW,ALSA]
1025 snd-ad1848= [HW,ALSA]
1027 snd-ali5451= [HW,ALSA]
1029 snd-als100= [HW,ALSA]
1031 snd-als4000= [HW,ALSA]
1033 snd-azt2320= [HW,ALSA]
1035 snd-cmi8330= [HW,ALSA]
1037 snd-cmipci= [HW,ALSA]
1039 snd-cs4231= [HW,ALSA]
1041 snd-cs4232= [HW,ALSA]
1043 snd-cs4236= [HW,ALSA]
1045 snd-cs4281= [HW,ALSA]
1047 snd-cs46xx= [HW,ALSA]
1049 snd-dt019x= [HW,ALSA]
1051 snd-dummy= [HW,ALSA]
1053 snd-emu10k1= [HW,ALSA]
1055 snd-ens1370= [HW,ALSA]
1057 snd-ens1371= [HW,ALSA]
1059 snd-es968= [HW,ALSA]
1061 snd-es1688= [HW,ALSA]
1063 snd-es18xx= [HW,ALSA]
1065 snd-es1938= [HW,ALSA]
1067 snd-es1968= [HW,ALSA]
1069 snd-fm801= [HW,ALSA]
1071 snd-gusclassic= [HW,ALSA]
1073 snd-gusextreme= [HW,ALSA]
1075 snd-gusmax= [HW,ALSA]
1079 snd-ice1712= [HW,ALSA]
1081 snd-intel8x0= [HW,ALSA]
1083 snd-interwave= [HW,ALSA]
1088 snd-korg1212= [HW,ALSA]
1090 snd-maestro3= [HW,ALSA]
1092 snd-mpu401= [HW,ALSA]
1094 snd-mtpav= [HW,ALSA]
1096 snd-nm256= [HW,ALSA]
1098 snd-opl3sa2= [HW,ALSA]
1106 snd-opti93x= [HW,ALSA]
1110 snd-rme32= [HW,ALSA]
1112 snd-rme96= [HW,ALSA]
1114 snd-rme9652= [HW,ALSA]
1120 snd-sbawe= [HW,ALSA]
1122 snd-serial= [HW,ALSA]
1124 snd-sgalaxy= [HW,ALSA]
1126 snd-sonicvibes= [HW,ALSA]
1131 snd-sun-cs4231= [HW,ALSA]
1133 snd-trident= [HW,ALSA]
1135 snd-usb-audio= [HW,ALSA,USB]
1137 snd-via82xx= [HW,ALSA]
1139 snd-virmidi= [HW,ALSA]
1141 snd-wavefront= [HW,ALSA]
1143 snd-ymfpci= [HW,ALSA]
1145 sonicvibes= [HW,OSS]
1149 Format: <io>[,<irq>]
1151 sonypi= [HW] Sony Programmable I/O Control Device driver
1152 Format: <minor>,<verbose>,<fnkeyinit>,<camera>,<compat>,<nojogdial>
1154 specialix= [HW,SERIAL] Specialix multi-serial port adapter
1155 See Documentation/specialix.txt.
1157 speedstep_coppermine=
1158 [HW,IA-32] Take CPU in your notebook as SpeedStep-capable
1159 See comment before function speedstep_setup() in
1160 arch/i386/kernel/cpu/cpufreq/speedstep.c.
1162 spia_io_base= [HW,MTD]
1168 Format: <io>,<irq>,<dma>,<mpu_io>,<mpu_irq>
1170 st= [HW,SCSI] SCSI tape parameters (buffers, etc.)
1171 See Documentation/scsi/st.txt.
1174 See header of drivers/scsi/seagate.c.
1178 Set the STI (builtin display/keyboard on the HP-PARISC
1179 machines) console (graphic card) which should be used
1180 as the initial boot-console.
1181 See also comment in drivers/video/console/sticore.c.
1184 See comment in drivers/video/console/sticore.c.
1187 Format: bpp:<bpp1>[:<bpp2>[:<bpp3>...]]
1189 stram_swap= [HW,M68k]
1191 swiotlb= [IA-64] Number of I/O TLB slabs
1195 sym53c416= [HW,SCSI]
1196 See header of drivers/scsi/sym53c416.c.
1198 sym53c8xx= [HW,SCSI]
1199 See Documentation/scsi/ncr53c8xx.txt.
1202 See header of drivers/scsi/t128.c.
1206 thash_entries= [KNL,NET]
1207 Set number of hash buckets for TCP connection
1210 See header of drivers/char/tipar.c.
1212 tiusb= [HW,USB] Texas Instruments' USB GraphLink (aka SilverLink)
1216 See header of drivers/scsi/seagate.c.
1219 See comment before function dc390_setup() in
1220 drivers/scsi/tmscsim.c.
1224 trix= [HW,OSS] MediaTrix AudioTrix Pro
1225 Format: <io>,<irq>,<dma>,<dma2>,<sb_io>,<sb_irq>,<sb_dma>,<mpu_io>,<mpu_irq>
1227 tsdev.xres= [TS] Horizontal screen resolution.
1228 tsdev.yres= [TS] Vertical screen resolution.
1230 turbografx.map[2|3]=
1231 [HW,JOY] TurboGraFX parallel port interface
1232 Format: <port#>,<js1>,<js2>,<js3>,<js4>,<js5>,<js6>,<js7>
1233 See also Documentation/input/joystick-parport.txt
1235 u14-34f= [HW,SCSI] UltraStor 14F/34F SCSI host adapter
1236 See header of drivers/scsi/u14-34f.c.
1244 video= [FB] Frame buffer configuration
1245 See Documentation/fb/modedb.txt.
1247 vga= [BOOT,IA-32] Select a particular video mode
1248 See Documentation/i386/boot.txt and Documentation/svga.txt.
1249 Use vga=ask for menu.
1250 This is actually a boot loader parameter; the value is
1251 passed to the kernel using a special protocol.
1257 waveartist= [HW,OSS]
1258 Format: <io>,<irq>,<dma>,<dma2>
1261 See header of drivers/scsi/wd33c93.c.
1264 See header of drivers/scsi/wd7000.c.
1267 See Documentation/watchdog/watchdog.txt.
1269 xd= [HW,XT] Original XT pre-IDE (RLL encoded) disks.
1270 xd_geo= See header of drivers/block/xd.c.
1272 xirc2ps_cs= [NET,PCMCIA]
1273 Format: <irq>,<irq_mask>,<io>,<full_duplex>,<do_sound>,<lockup_hack>[,<irq2>[,<irq3>[,<irq4>]]]
1279 The last known update (for 2.4.0) - the changelog was not kept before.
1280 2000-06-?? Mr. Unknown
1282 Update for 2.5.49, description for most of the options introduced,
1283 references to other documentation (C files, READMEs, ..), added S390,
1284 PPC, SPARC, MTD, ALSA and OSS category. Minor corrections and
1286 2002-11-24 Petr Baudis <pasky@ucw.cz>
1287 Randy Dunlap <randy.dunlap@verizon.net>
1291 Add documentation for ALSA options.
1292 Add more DRM drivers.