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- Kernel Parameters
- ~~~~~~~~~~~~~~~~~
- The following is a consolidated list of the kernel parameters as implemented
- (mostly) by the __setup() macro and sorted into English Dictionary order
- (defined as ignoring all punctuation and sorting digits before letters in a
- case insensitive manner), and with descriptions where known.
- Module parameters for loadable modules are specified only as the
- parameter name with optional '=' and value as appropriate, such as:
- modprobe usbcore blinkenlights=1
- Module parameters for modules that are built into the kernel image
- are specified on the kernel command line with the module name plus
- '.' plus parameter name, with '=' and value if appropriate, such as:
- usbcore.blinkenlights=1
- This document may not be entirely up to date and comprehensive. The command
- "modinfo -p ${modulename}" shows a current list of all parameters of a loadable
- module. Loadable modules, after being loaded into the running kernel, also
- reveal their parameters in /sys/module/${modulename}/parameters/. Some of these
- parameters may be changed at runtime by the command
- "echo -n ${value} > /sys/module/${modulename}/parameters/${parm}".
- The parameters listed below are only valid if certain kernel build options were
- enabled and if respective hardware is present. The text in square brackets at
- the beginning of each description states the restrictions within which a
- parameter is applicable:
- ACPI ACPI support is enabled.
- ALSA ALSA sound support is enabled.
- APIC APIC support is enabled.
- APM Advanced Power Management support is enabled.
- AX25 Appropriate AX.25 support is enabled.
- CD Appropriate CD support is enabled.
- DRM Direct Rendering Management support is enabled.
- EDD BIOS Enhanced Disk Drive Services (EDD) is enabled
- EFI EFI Partitioning (GPT) is enabled
- EIDE EIDE/ATAPI support is enabled.
- FB The frame buffer device is enabled.
- HW Appropriate hardware is enabled.
- IA-32 IA-32 aka i386 architecture is enabled.
- IA-64 IA-64 architecture is enabled.
- IOSCHED More than one I/O scheduler is enabled.
- IP_PNP IP DHCP, BOOTP, or RARP is enabled.
- ISAPNP ISA PnP code is enabled.
- ISDN Appropriate ISDN support is enabled.
- JOY Appropriate joystick support is enabled.
- LIBATA Libata driver is enabled
- LP Printer support is enabled.
- LOOP Loopback device support is enabled.
- M68k M68k architecture is enabled.
- These options have more detailed description inside of
- Documentation/m68k/kernel-options.txt.
- MCA MCA bus support is enabled.
- MDA MDA console support is enabled.
- MOUSE Appropriate mouse support is enabled.
- MSI Message Signaled Interrupts (PCI).
- MTD MTD support is enabled.
- NET Appropriate network support is enabled.
- NUMA NUMA support is enabled.
- GENERIC_TIME The generic timeofday code is enabled.
- NFS Appropriate NFS support is enabled.
- OSS OSS sound support is enabled.
- PARIDE The ParIDE subsystem is enabled.
- PARISC The PA-RISC architecture is enabled.
- PCI PCI bus support is enabled.
- PCMCIA The PCMCIA subsystem is enabled.
- PNP Plug & Play support is enabled.
- PPC PowerPC architecture is enabled.
- PPT Parallel port support is enabled.
- PS2 Appropriate PS/2 support is enabled.
- RAM RAM disk support is enabled.
- S390 S390 architecture is enabled.
- SCSI Appropriate SCSI support is enabled.
- A lot of drivers has their options described inside of
- Documentation/scsi/.
- SELINUX SELinux support is enabled.
- SERIAL Serial support is enabled.
- SH SuperH architecture is enabled.
- SMP The kernel is an SMP kernel.
- SPARC Sparc architecture is enabled.
- SWSUSP Software suspend is enabled.
- TS Appropriate touchscreen support is enabled.
- USB USB support is enabled.
- USBHID USB Human Interface Device support is enabled.
- V4L Video For Linux support is enabled.
- VGA The VGA console has been enabled.
- VT Virtual terminal support is enabled.
- WDT Watchdog support is enabled.
- XT IBM PC/XT MFM hard disk support is enabled.
- X86-64 X86-64 architecture is enabled.
- More X86-64 boot options can be found in
- Documentation/x86_64/boot-options.txt .
- In addition, the following text indicates that the option:
- BUGS= Relates to possible processor bugs on the said processor.
- KNL Is a kernel start-up parameter.
- BOOT Is a boot loader parameter.
- Parameters denoted with BOOT are actually interpreted by the boot
- loader, and have no meaning to the kernel directly.
- Do not modify the syntax of boot loader parameters without extreme
- need or coordination with <Documentation/i386/boot.txt>.
- There are also arch-specific kernel-parameters not documented here.
- See for example <Documentation/x86_64/boot-options.txt>.
- Note that ALL kernel parameters listed below are CASE SENSITIVE, and that
- a trailing = on the name of any parameter states that that parameter will
- be entered as an environment variable, whereas its absence indicates that
- it will appear as a kernel argument readable via /proc/cmdline by programs
- running once the system is up.
- The number of kernel parameters is not limited, but the length of the
- complete command line (parameters including spaces etc.) is limited to
- a fixed number of characters. This limit depends on the architecture
- and is between 256 and 4096 characters. It is defined in the file
- ./include/asm/setup.h as COMMAND_LINE_SIZE.
- 53c7xx= [HW,SCSI] Amiga SCSI controllers
- See header of drivers/scsi/53c7xx.c.
- See also Documentation/scsi/ncr53c7xx.txt.
- acpi= [HW,ACPI,X86-64,i386]
- Advanced Configuration and Power Interface
- Format: { force | off | ht | strict | noirq }
- force -- enable ACPI if default was off
- off -- disable ACPI if default was on
- noirq -- do not use ACPI for IRQ routing
- ht -- run only enough ACPI to enable Hyper Threading
- strict -- Be less tolerant of platforms that are not
- strictly ACPI specification compliant.
- See also Documentation/pm.txt, pci=noacpi
- acpi_apic_instance= [ACPI, IOAPIC]
- Format: <int>
- 2: use 2nd APIC table, if available
- 1,0: use 1st APIC table
- default: 0
- acpi_sleep= [HW,ACPI] Sleep options
- Format: { s3_bios, s3_mode }
- See Documentation/power/video.txt
- acpi_sci= [HW,ACPI] ACPI System Control Interrupt trigger mode
- Format: { level | edge | high | low }
- acpi_irq_balance [HW,ACPI]
- ACPI will balance active IRQs
- default in APIC mode
- acpi_irq_nobalance [HW,ACPI]
- ACPI will not move active IRQs (default)
- default in PIC mode
- acpi_irq_pci= [HW,ACPI] If irq_balance, clear listed IRQs for
- use by PCI
- Format: <irq>,<irq>...
- acpi_irq_isa= [HW,ACPI] If irq_balance, mark listed IRQs used by ISA
- Format: <irq>,<irq>...
- acpi_os_name= [HW,ACPI] Tell ACPI BIOS the name of the OS
- Format: To spoof as Windows 98: ="Microsoft Windows"
- acpi_osi= [HW,ACPI] empty param disables _OSI
- acpi_serialize [HW,ACPI] force serialization of AML methods
- acpi_skip_timer_override [HW,ACPI]
- Recognize and ignore IRQ0/pin2 Interrupt Override.
- For broken nForce2 BIOS resulting in XT-PIC timer.
- acpi_use_timer_override [HW,ACPI}
- Use timer override. For some broken Nvidia NF5 boards
- that require a timer override, but don't have
- HPET
- acpi_dbg_layer= [HW,ACPI]
- Format: <int>
- Each bit of the <int> indicates an ACPI debug layer,
- 1: enable, 0: disable. It is useful for boot time
- debugging. After system has booted up, it can be set
- via /proc/acpi/debug_layer.
- acpi_dbg_level= [HW,ACPI]
- Format: <int>
- Each bit of the <int> indicates an ACPI debug level,
- 1: enable, 0: disable. It is useful for boot time
- debugging. After system has booted up, it can be set
- via /proc/acpi/debug_level.
- acpi_fake_ecdt [HW,ACPI] Workaround failure due to BIOS lacking ECDT
- acpi_generic_hotkey [HW,ACPI]
- Allow consolidated generic hotkey driver to
- override platform specific driver.
- See also Documentation/acpi-hotkey.txt.
- acpi_pm_good [IA-32,X86-64]
- Override the pmtimer bug detection: force the kernel
- to assume that this machine's pmtimer latches its value
- and always returns good values.
- enable_timer_pin_1 [i386,x86-64]
- Enable PIN 1 of APIC timer
- Can be useful to work around chipset bugs
- (in particular on some ATI chipsets).
- The kernel tries to set a reasonable default.
- disable_timer_pin_1 [i386,x86-64]
- Disable PIN 1 of APIC timer
- Can be useful to work around chipset bugs.
- ad1816= [HW,OSS]
- Format: <io>,<irq>,<dma>,<dma2>
- See also Documentation/sound/oss/AD1816.
- ad1848= [HW,OSS]
- Format: <io>,<irq>,<dma>,<dma2>,<type>
- adlib= [HW,OSS]
- Format: <io>
- advansys= [HW,SCSI]
- See header of drivers/scsi/advansys.c.
- advwdt= [HW,WDT] Advantech WDT
- Format: <iostart>,<iostop>
- aedsp16= [HW,OSS] Audio Excel DSP 16
- Format: <io>,<irq>,<dma>,<mss_io>,<mpu_io>,<mpu_irq>
- See also header of sound/oss/aedsp16.c.
- aha152x= [HW,SCSI]
- See Documentation/scsi/aha152x.txt.
- aha1542= [HW,SCSI]
- Format: <portbase>[,<buson>,<busoff>[,<dmaspeed>]]
- aic7xxx= [HW,SCSI]
- See Documentation/scsi/aic7xxx.txt.
- aic79xx= [HW,SCSI]
- See Documentation/scsi/aic79xx.txt.
- amijoy.map= [HW,JOY] Amiga joystick support
- Map of devices attached to JOY0DAT and JOY1DAT
- Format: <a>,<b>
- See also Documentation/kernel/input/joystick.txt
- analog.map= [HW,JOY] Analog joystick and gamepad support
- Specifies type or capabilities of an analog joystick
- connected to one of 16 gameports
- Format: <type1>,<type2>,..<type16>
- apc= [HW,SPARC]
- Power management functions (SPARCstation-4/5 + deriv.)
- Format: noidle
- Disable APC CPU standby support. SPARCstation-Fox does
- not play well with APC CPU idle - disable it if you have
- APC and your system crashes randomly.
- apic= [APIC,i386] Change the output verbosity whilst booting
- Format: { quiet (default) | verbose | debug }
- Change the amount of debugging information output
- when initialising the APIC and IO-APIC components.
- apm= [APM] Advanced Power Management
- See header of arch/i386/kernel/apm.c.
- applicom= [HW]
- Format: <mem>,<irq>
- arcrimi= [HW,NET] ARCnet - "RIM I" (entirely mem-mapped) cards
- Format: <io>,<irq>,<nodeID>
- ataflop= [HW,M68k]
- atarimouse= [HW,MOUSE] Atari Mouse
- atascsi= [HW,SCSI] Atari SCSI
- atkbd.extra= [HW] Enable extra LEDs and keys on IBM RapidAccess,
- EzKey and similar keyboards
- atkbd.reset= [HW] Reset keyboard during initialization
- atkbd.set= [HW] Select keyboard code set
- Format: <int> (2 = AT (default), 3 = PS/2)
- atkbd.scroll= [HW] Enable scroll wheel on MS Office and similar
- keyboards
- atkbd.softraw= [HW] Choose between synthetic and real raw mode
- Format: <bool> (0 = real, 1 = synthetic (default))
- atkbd.softrepeat= [HW]
- Use software keyboard repeat
- autotest [IA64]
- aztcd= [HW,CD] Aztech CD268 CDROM driver
- Format: <io>,0x79 (?)
- baycom_epp= [HW,AX25]
- Format: <io>,<mode>
- baycom_par= [HW,AX25] BayCom Parallel Port AX.25 Modem
- Format: <io>,<mode>
- See header of drivers/net/hamradio/baycom_par.c.
- baycom_ser_fdx= [HW,AX25]
- BayCom Serial Port AX.25 Modem (Full Duplex Mode)
- Format: <io>,<irq>,<mode>[,<baud>]
- See header of drivers/net/hamradio/baycom_ser_fdx.c.
- baycom_ser_hdx= [HW,AX25]
- BayCom Serial Port AX.25 Modem (Half Duplex Mode)
- Format: <io>,<irq>,<mode>
- See header of drivers/net/hamradio/baycom_ser_hdx.c.
- blkmtd_device= [HW,MTD]
- blkmtd_erasesz=
- blkmtd_ro=
- blkmtd_bs=
- blkmtd_count=
- bttv.card= [HW,V4L] bttv (bt848 + bt878 based grabber cards)
- bttv.radio= Most important insmod options are available as
- kernel args too.
- bttv.pll= See Documentation/video4linux/bttv/Insmod-options
- bttv.tuner= and Documentation/video4linux/bttv/CARDLIST
- BusLogic= [HW,SCSI]
- See drivers/scsi/BusLogic.c, comment before function
- BusLogic_ParseDriverOptions().
- c101= [NET] Moxa C101 synchronous serial card
- cachesize= [BUGS=IA-32] Override level 2 CPU cache size detection.
- Sometimes CPU hardware bugs make them report the cache
- size incorrectly. The kernel will attempt work arounds
- to fix known problems, but for some CPUs it is not
- possible to determine what the correct size should be.
- This option provides an override for these situations.
- cdu31a= [HW,CD]
- Format: <io>,<irq>[,PAS]
- See header of drivers/cdrom/cdu31a.c.
- chandev= [HW,NET] Generic channel device initialisation
- checkreqprot [SELINUX] Set initial checkreqprot flag value.
- Format: { "0" | "1" }
- See security/selinux/Kconfig help text.
- 0 -- check protection applied by kernel (includes
- any implied execute protection).
- 1 -- check protection requested by application.
- Default value is set via a kernel config option.
- Value can be changed at runtime via
- /selinux/checkreqprot.
- clock= [BUGS=IA-32, HW] gettimeofday clocksource override.
- [Deprecated]
- Forces specified clocksource (if available) to be used
- when calculating gettimeofday(). If specified
- clocksource is not available, it defaults to PIT.
- Format: { pit | tsc | cyclone | pmtmr }
- code_bytes [IA32] How many bytes of object code to print in an
- oops report.
- Range: 0 - 8192
- Default: 64
- disable_8254_timer
- enable_8254_timer
- [IA32/X86_64] Disable/Enable interrupt 0 timer routing
- over the 8254 in addition to over the IO-APIC. The
- kernel tries to set a sensible default.
- hpet= [IA-32,HPET] option to disable HPET and use PIT.
- Format: disable
- cm206= [HW,CD]
- Format: { auto | [<io>,][<irq>] }
- com20020= [HW,NET] ARCnet - COM20020 chipset
- Format:
- <io>[,<irq>[,<nodeID>[,<backplane>[,<ckp>[,<timeout>]]]]]
- com90io= [HW,NET] ARCnet - COM90xx chipset (IO-mapped buffers)
- Format: <io>[,<irq>]
- com90xx= [HW,NET]
- ARCnet - COM90xx chipset (memory-mapped buffers)
- Format: <io>[,<irq>[,<memstart>]]
- condev= [HW,S390] console device
- conmode=
- console= [KNL] Output console device and options.
- tty<n> Use the virtual console device <n>.
- ttyS<n>[,options]
- ttyUSB0[,options]
- Use the specified serial port. The options are of
- the form "bbbbpnf", where "bbbb" is the baud rate,
- "p" is parity ("n", "o", or "e"), "n" is number of
- bits, and "f" is flow control ("r" for RTS or
- omit it). Default is "9600n8".
- See Documentation/serial-console.txt for more
- information. See
- Documentation/networking/netconsole.txt for an
- alternative.
- uart,io,<addr>[,options]
- uart,mmio,<addr>[,options]
- Start an early, polled-mode console on the 8250/16550
- UART at the specified I/O port or MMIO address,
- switching to the matching ttyS device later. The
- options are the same as for ttyS, above.
- cpcihp_generic= [HW,PCI] Generic port I/O CompactPCI driver
- Format:
- <first_slot>,<last_slot>,<port>,<enum_bit>[,<debug>]
- cpia_pp= [HW,PPT]
- Format: { parport<nr> | auto | none }
- crashkernel=nn[KMG]@ss[KMG]
- [KNL] Reserve a chunk of physical memory to
- hold a kernel to switch to with kexec on panic.
- cs4232= [HW,OSS]
- Format: <io>,<irq>,<dma>,<dma2>,<mpuio>,<mpuirq>
- cs89x0_dma= [HW,NET]
- Format: <dma>
- cs89x0_media= [HW,NET]
- Format: { rj45 | aui | bnc }
- cyclades= [HW,SERIAL] Cyclades multi-serial port adapter.
- dasd= [HW,NET]
- See header of drivers/s390/block/dasd_devmap.c.
- db9.dev[2|3]= [HW,JOY] Multisystem joystick support via parallel port
- (one device per port)
- Format: <port#>,<type>
- See also Documentation/input/joystick-parport.txt
- debug [KNL] Enable kernel debugging (events log level).
- debug_locks_verbose=
- [KNL] verbose self-tests
- Format=<0|1>
- Print debugging info while doing the locking API
- self-tests.
- We default to 0 (no extra messages), setting it to
- 1 will print _a lot_ more information - normally
- only useful to kernel developers.
- decnet= [HW,NET]
- Format: <area>[,<node>]
- See also Documentation/networking/decnet.txt.
- dhash_entries= [KNL]
- Set number of hash buckets for dentry cache.
- digi= [HW,SERIAL]
- IO parameters + enable/disable command.
- digiepca= [HW,SERIAL]
- See drivers/char/README.epca and
- Documentation/digiepca.txt.
- dmascc= [HW,AX25,SERIAL] AX.25 Z80SCC driver with DMA
- support available.
- Format: <io_dev0>[,<io_dev1>[,..<io_dev32>]]
- dmasound= [HW,OSS] Sound subsystem buffers
- dscc4.setup= [NET]
- dtc3181e= [HW,SCSI]
- earlyprintk= [IA-32,X86-64,SH]
- earlyprintk=vga
- earlyprintk=serial[,ttySn[,baudrate]]
- Append ",keep" to not disable it when the real console
- takes over.
- Only vga or serial at a time, not both.
- Currently only ttyS0 and ttyS1 are supported.
- Interaction with the standard serial driver is not
- very good.
- The VGA output is eventually overwritten by the real
- console.
- eata= [HW,SCSI]
- ec_intr= [HW,ACPI] ACPI Embedded Controller interrupt mode
- Format: <int>
- 0: polling mode
- non-0: interrupt mode (default)
- eda= [HW,PS2]
- edb= [HW,PS2]
- edd= [EDD]
- Format: {"of[f]" | "sk[ipmbr]"}
- See comment in arch/i386/boot/edd.S
- eicon= [HW,ISDN]
- Format: <id>,<membase>,<irq>
- eisa_irq_edge= [PARISC,HW]
- See header of drivers/parisc/eisa.c.
- elanfreq= [IA-32]
- See comment before function elanfreq_setup() in
- arch/i386/kernel/cpu/cpufreq/elanfreq.c.
- elevator= [IOSCHED]
- Format: {"anticipatory" | "cfq" | "deadline" | "noop"}
- See Documentation/block/as-iosched.txt and
- Documentation/block/deadline-iosched.txt for details.
- elfcorehdr= [IA-32, X86_64]
- Specifies physical address of start of kernel core
- image elf header. Generally kexec loader will
- pass this option to capture kernel.
- See Documentation/kdump/kdump.txt for details.
- enforcing [SELINUX] Set initial enforcing status.
- Format: {"0" | "1"}
- See security/selinux/Kconfig help text.
- 0 -- permissive (log only, no denials).
- 1 -- enforcing (deny and log).
- Default value is 0.
- Value can be changed at runtime via /selinux/enforce.
- es1371= [HW,OSS]
- Format: <spdif>,[<nomix>,[<amplifier>]]
- See also header of sound/oss/es1371.c.
- ether= [HW,NET] Ethernet cards parameters
- This option is obsoleted by the "netdev=" option, which
- has equivalent usage. See its documentation for details.
- eurwdt= [HW,WDT] Eurotech CPU-1220/1410 onboard watchdog.
- Format: <io>[,<irq>]
- failslab=
- fail_page_alloc=
- fail_make_request=[KNL]
- General fault injection mechanism.
- Format: <interval>,<probability>,<space>,<times>
- See also /Documentation/fault-injection/.
- fd_mcs= [HW,SCSI]
- See header of drivers/scsi/fd_mcs.c.
- fdomain= [HW,SCSI]
- See header of drivers/scsi/fdomain.c.
- floppy= [HW]
- See Documentation/floppy.txt.
- gamecon.map[2|3]=
- [HW,JOY] Multisystem joystick and NES/SNES/PSX pad
- support via parallel port (up to 5 devices per port)
- Format: <port#>,<pad1>,<pad2>,<pad3>,<pad4>,<pad5>
- See also Documentation/input/joystick-parport.txt
- gamma= [HW,DRM]
- gdth= [HW,SCSI]
- See header of drivers/scsi/gdth.c.
- gpt [EFI] Forces disk with valid GPT signature but
- invalid Protective MBR to be treated as GPT.
- gscd= [HW,CD]
- Format: <io>
- gvp11= [HW,SCSI]
- hashdist= [KNL,NUMA] Large hashes allocated during boot
- are distributed across NUMA nodes. Defaults on
- for IA-64, off otherwise.
- Format: 0 | 1 (for off | on)
- hcl= [IA-64] SGI's Hardware Graph compatibility layer
- hd= [EIDE] (E)IDE hard drive subsystem geometry
- Format: <cyl>,<head>,<sect>
- hd?= [HW] (E)IDE subsystem
- hd?lun= See Documentation/ide.txt.
- highmem=nn[KMG] [KNL,BOOT] forces the highmem zone to have an exact
- size of <nn>. This works even on boxes that have no
- highmem otherwise. This also works to reduce highmem
- size on bigger boxes.
- highres= [KNL] Enable/disable high resolution timer mode.
- Valid parameters: "on", "off"
- Default: "on"
- hisax= [HW,ISDN]
- See Documentation/isdn/README.HiSax.
- hugepages= [HW,IA-32,IA-64] Maximal number of HugeTLB pages.
- i8042.direct [HW] Put keyboard port into non-translated mode
- i8042.dumbkbd [HW] Pretend that controller can only read data from
- keyboard and cannot control its state
- (Don't attempt to blink the leds)
- i8042.noaux [HW] Don't check for auxiliary (== mouse) port
- i8042.nokbd [HW] Don't check/create keyboard port
- i8042.nomux [HW] Don't check presence of an active multiplexing
- controller
- i8042.nopnp [HW] Don't use ACPIPnP / PnPBIOS to discover KBD/AUX
- controllers
- i8042.panicblink=
- [HW] Frequency with which keyboard LEDs should blink
- when kernel panics (default is 0.5 sec)
- i8042.reset [HW] Reset the controller during init and cleanup
- i8042.unlock [HW] Unlock (ignore) the keylock
- i810= [HW,DRM]
- i8k.ignore_dmi [HW] Continue probing hardware even if DMI data
- indicates that the driver is running on unsupported
- hardware.
- i8k.force [HW] Activate i8k driver even if SMM BIOS signature
- does not match list of supported models.
- i8k.power_status
- [HW] Report power status in /proc/i8k
- (disabled by default)
- i8k.restricted [HW] Allow controlling fans only if SYS_ADMIN
- capability is set.
- ibmmcascsi= [HW,MCA,SCSI] IBM MicroChannel SCSI adapter
- See Documentation/mca.txt.
- icn= [HW,ISDN]
- Format: <io>[,<membase>[,<icn_id>[,<icn_id2>]]]
- ide= [HW] (E)IDE subsystem
- Format: ide=nodma or ide=doubler or ide=reverse
- See Documentation/ide.txt.
- ide?= [HW] (E)IDE subsystem
- Format: ide?=noprobe or chipset specific parameters.
- See Documentation/ide.txt.
- idebus= [HW] (E)IDE subsystem - VLB/PCI bus speed
- See Documentation/ide.txt.
- idle= [HW]
- Format: idle=poll or idle=halt
- ignore_loglevel [KNL]
- Ignore loglevel setting - this will print /all/
- kernel messages to the console. Useful for debugging.
- ihash_entries= [KNL]
- Set number of hash buckets for inode cache.
- in2000= [HW,SCSI]
- See header of drivers/scsi/in2000.c.
- init= [KNL]
- Format: <full_path>
- Run specified binary instead of /sbin/init as init
- process.
- initcall_debug [KNL] Trace initcalls as they are executed. Useful
- for working out where the kernel is dying during
- startup.
- initrd= [BOOT] Specify the location of the initial ramdisk
- inport.irq= [HW] Inport (ATI XL and Microsoft) busmouse driver
- Format: <irq>
- combined_mode= [HW] control which driver uses IDE ports in combined
- mode: legacy IDE driver, libata, or both
- (in the libata case, libata.atapi_enabled=1 may be
- useful as well). Note that using the ide or libata
- options may affect your device naming (e.g. by
- changing hdc to sdb).
- Format: combined (default), ide, or libata
- inttest= [IA64]
- io7= [HW] IO7 for Marvel based alpha systems
- See comment before marvel_specify_io7 in
- arch/alpha/kernel/core_marvel.c.
- ip= [IP_PNP]
- See Documentation/nfsroot.txt.
- ip2= [HW] Set IO/IRQ pairs for up to 4 IntelliPort boards
- See comment before ip2_setup() in drivers/char/ip2.c.
- ips= [HW,SCSI] Adaptec / IBM ServeRAID controller
- See header of drivers/scsi/ips.c.
- ports= [IP_VS_FTP] IPVS ftp helper module
- Default is 21.
- Up to 8 (IP_VS_APP_MAX_PORTS) ports
- may be specified.
- Format: <port>,<port>....
- irqfixup [HW]
- When an interrupt is not handled search all handlers
- for it. Intended to get systems with badly broken
- firmware running.
- irqpoll [HW]
- When an interrupt is not handled search all handlers
- for it. Also check all handlers each timer
- interrupt. Intended to get systems with badly broken
- firmware running.
- isapnp= [ISAPNP]
- Format: <RDP>,<reset>,<pci_scan>,<verbosity>
- isolcpus= [KNL,SMP] Isolate CPUs from the general scheduler.
- Format:
- <cpu number>,...,<cpu number>
- or
- <cpu number>-<cpu number> (must be a positive range in ascending order)
- or a mixture
- <cpu number>,...,<cpu number>-<cpu number>
- This option can be used to specify one or more CPUs
- to isolate from the general SMP balancing and scheduling
- algorithms. The only way to move a process onto or off
- an "isolated" CPU is via the CPU affinity syscalls.
- <cpu number> begins at 0 and the maximum value is
- "number of CPUs in system - 1".
- This option is the preferred way to isolate CPUs. The
- alternative -- manually setting the CPU mask of all
- tasks in the system -- can cause problems and
- suboptimal load balancer performance.
- isp16= [HW,CD]
- Format: <io>,<irq>,<dma>,<setup>
- iucv= [HW,NET]
- js= [HW,JOY] Analog joystick
- See Documentation/input/joystick.txt.
- keepinitrd [HW,ARM]
- kstack=N [IA-32,X86-64] Print N words from the kernel stack
- in oops dumps.
- l2cr= [PPC]
- lapic [IA-32,APIC] Enable the local APIC even if BIOS
- disabled it.
- lapic_timer_c2_ok [IA-32,x86-64,APIC] trust the local apic timer in
- C2 power state.
- lasi= [HW,SCSI] PARISC LASI driver for the 53c700 chip
- Format: addr:<io>,irq:<irq>
- llsc*= [IA64] See function print_params() in
- arch/ia64/sn/kernel/llsc4.c.
- load_ramdisk= [RAM] List of ramdisks to load from floppy
- See Documentation/ramdisk.txt.
- lockd.nlm_grace_period=P [NFS] Assign grace period.
- Format: <integer>
- lockd.nlm_tcpport=N [NFS] Assign TCP port.
- Format: <integer>
- lockd.nlm_timeout=T [NFS] Assign timeout value.
- Format: <integer>
- lockd.nlm_udpport=M [NFS] Assign UDP port.
- Format: <integer>
- logibm.irq= [HW,MOUSE] Logitech Bus Mouse Driver
- Format: <irq>
- loglevel= All Kernel Messages with a loglevel smaller than the
- console loglevel will be printed to the console. It can
- also be changed with klogd or other programs. The
- loglevels are defined as follows:
- 0 (KERN_EMERG) system is unusable
- 1 (KERN_ALERT) action must be taken immediately
- 2 (KERN_CRIT) critical conditions
- 3 (KERN_ERR) error conditions
- 4 (KERN_WARNING) warning conditions
- 5 (KERN_NOTICE) normal but significant condition
- 6 (KERN_INFO) informational
- 7 (KERN_DEBUG) debug-level messages
- log_buf_len=n Sets the size of the printk ring buffer, in bytes.
- Format: { n | nk | nM }
- n must be a power of two. The default size
- is set in the kernel config file.
- lp=0 [LP] Specify parallel ports to use, e.g,
- lp=port[,port...] lp=none,parport0 (lp0 not configured, lp1 uses
- lp=reset first parallel port). 'lp=0' disables the
- lp=auto printer driver. 'lp=reset' (which can be
- specified in addition to the ports) causes
- attached printers to be reset. Using
- lp=port1,port2,... specifies the parallel ports
- to associate lp devices with, starting with
- lp0. A port specification may be 'none' to skip
- that lp device, or a parport name such as
- 'parport0'. Specifying 'lp=auto' instead of a
- port specification list means that device IDs
- from each port should be examined, to see if
- an IEEE 1284-compliant printer is attached; if
- so, the driver will manage that printer.
- See also header of drivers/char/lp.c.
- lpj=n [KNL]
- Sets loops_per_jiffy to given constant, thus avoiding
- time-consuming boot-time autodetection (up to 250 ms per
- CPU). 0 enables autodetection (default). To determine
- the correct value for your kernel, boot with normal
- autodetection and see what value is printed. Note that
- on SMP systems the preset will be applied to all CPUs,
- which is likely to cause problems if your CPUs need
- significantly divergent settings. An incorrect value
- will cause delays in the kernel to be wrong, leading to
- unpredictable I/O errors and other breakage. Although
- unlikely, in the extreme case this might damage your
- hardware.
- ltpc= [NET]
- Format: <io>,<irq>,<dma>
- mac5380= [HW,SCSI] Format:
- <can_queue>,<cmd_per_lun>,<sg_tablesize>,<hostid>,<use_tags>
- mac53c9x= [HW,SCSI] Format:
- <num_esps>,<disconnect>,<nosync>,<can_queue>,<cmd_per_lun>,<sg_tablesize>,<hostid>,<use_tags>
- machvec= [IA64] Force the use of a particular machine-vector
- (machvec) in a generic kernel.
- Example: machvec=hpzx1_swiotlb
- max_loop= [LOOP] Maximum number of loopback devices that can
- be mounted
- Format: <1-256>
- maxcpus= [SMP] Maximum number of processors that an SMP kernel
- should make use of.
- Using "nosmp" or "maxcpus=0" will disable SMP
- entirely (the MPS table probe still happens, though).
- A command-line option of "maxcpus=<NUM>", where <NUM>
- is an integer greater than 0, limits the maximum number
- of CPUs activated in SMP mode to <NUM>.
- Using "maxcpus=1" on an SMP kernel is the trivial
- case of an SMP kernel with only one CPU.
- max_addr=[KMG] [KNL,BOOT,ia64] All physical memory greater than or
- equal to this physical address is ignored.
- max_luns= [SCSI] Maximum number of LUNs to probe.
- Should be between 1 and 2^32-1.
- max_report_luns=
- [SCSI] Maximum number of LUNs received.
- Should be between 1 and 16384.
- mca-pentium [BUGS=IA-32]
- mcatest= [IA-64]
- mcd= [HW,CD]
- Format: <port>,<irq>,<mitsumi_bug_93_wait>
- mcdx= [HW,CD]
- mce [IA-32] Machine Check Exception
- md= [HW] RAID subsystems devices and level
- See Documentation/md.txt.
- mdacon= [MDA]
- Format: <first>,<last>
- Specifies range of consoles to be captured by the MDA.
- mem=nn[KMG] [KNL,BOOT] Force usage of a specific amount of memory
- Amount of memory to be used when the kernel is not able
- to see the whole system memory or for test.
- [IA-32] Use together with memmap= to avoid physical
- address space collisions. Without memmap= PCI devices
- could be placed at addresses belonging to unused RAM.
- mem=nopentium [BUGS=IA-32] Disable usage of 4MB pages for kernel
- memory.
- memmap=exactmap [KNL,IA-32,X86_64] Enable setting of an exact
- E820 memory map, as specified by the user.
- Such memmap=exactmap lines can be constructed based on
- BIOS output or other requirements. See the memmap=nn@ss
- option description.
- memmap=nn[KMG]@ss[KMG]
- [KNL] Force usage of a specific region of memory
- Region of memory to be used, from ss to ss+nn.
- memmap=nn[KMG]#ss[KMG]
- [KNL,ACPI] Mark specific memory as ACPI data.
- Region of memory to be used, from ss to ss+nn.
- memmap=nn[KMG]$ss[KMG]
- [KNL,ACPI] Mark specific memory as reserved.
- Region of memory to be used, from ss to ss+nn.
- meye.*= [HW] Set MotionEye Camera parameters
- See Documentation/video4linux/meye.txt.
- mga= [HW,DRM]
- mousedev.tap_time=
- [MOUSE] Maximum time between finger touching and
- leaving touchpad surface for touch to be considered
- a tap and be reported as a left button click (for
- touchpads working in absolute mode only).
- Format: <msecs>
- mousedev.xres= [MOUSE] Horizontal screen resolution, used for devices
- reporting absolute coordinates, such as tablets
- mousedev.yres= [MOUSE] Vertical screen resolution, used for devices
- reporting absolute coordinates, such as tablets
- mpu401= [HW,OSS]
- Format: <io>,<irq>
- MTD_Partition= [MTD]
- Format: <name>,<region-number>,<size>,<offset>
- MTD_Region= [MTD] Format:
- <name>,<region-number>[,<base>,<size>,<buswidth>,<altbuswidth>]
- mtdparts= [MTD]
- See drivers/mtd/cmdline.c.
- mtouchusb.raw_coordinates=
- [HW] Make the MicroTouch USB driver use raw coordinates
- ('y', default) or cooked coordinates ('n')
- n2= [NET] SDL Inc. RISCom/N2 synchronous serial card
- NCR_D700= [HW,SCSI]
- See header of drivers/scsi/NCR_D700.c.
- ncr5380= [HW,SCSI]
- ncr53c400= [HW,SCSI]
- ncr53c400a= [HW,SCSI]
- ncr53c406a= [HW,SCSI]
- ncr53c8xx= [HW,SCSI]
- netdev= [NET] Network devices parameters
- Format: <irq>,<io>,<mem_start>,<mem_end>,<name>
- Note that mem_start is often overloaded to mean
- something different and driver-specific.
- This usage is only documented in each driver source
- file if at all.
- nfsaddrs= [NFS]
- See Documentation/nfsroot.txt.
- nfsroot= [NFS] nfs root filesystem for disk-less boxes.
- See Documentation/nfsroot.txt.
- nfs.callback_tcpport=
- [NFS] set the TCP port on which the NFSv4 callback
- channel should listen.
- nfs.idmap_cache_timeout=
- [NFS] set the maximum lifetime for idmapper cache
- entries.
- nmi_watchdog= [KNL,BUGS=IA-32] Debugging features for SMP kernels
- no387 [BUGS=IA-32] Tells the kernel to use the 387 maths
- emulation library even if a 387 maths coprocessor
- is present.
- noacpi [LIBATA] Disables use of ACPI in libata suspend/resume
- when set.
- Format: <int>
- noaliencache [MM, NUMA] Disables the allcoation of alien caches in
- the slab allocator. Saves per-node memory, but will
- impact performance on real NUMA hardware.
- noalign [KNL,ARM]
- noapic [SMP,APIC] Tells the kernel to not make use of any
- IOAPICs that may be present in the system.
- noasync [HW,M68K] Disables async and sync negotiation for
- all devices.
- nobats [PPC] Do not use BATs for mapping kernel lowmem
- on "Classic" PPC cores.
- nocache [ARM]
- nodelayacct [KNL] Disable per-task delay accounting
- nodisconnect [HW,SCSI,M68K] Disables SCSI disconnects.
- noexec [IA-64]
- noexec [IA-32,X86-64]
- noexec=on: enable non-executable mappings (default)
- noexec=off: disable nn-executable mappings
- nofxsr [BUGS=IA-32] Disables x86 floating point extended
- register save and restore. The kernel will only save
- legacy floating-point registers on task switch.
- nohlt [BUGS=ARM]
- no-hlt [BUGS=IA-32] Tells the kernel that the hlt
- instruction doesn't work correctly and not to
- use it.
- nohalt [IA-64] Tells the kernel not to use the power saving
- function PAL_HALT_LIGHT when idle. This increases
- power-consumption. On the positive side, it reduces
- interrupt wake-up latency, which may improve performance
- in certain environments such as networked servers or
- real-time systems.
- nohz= [KNL] Boottime enable/disable dynamic ticks
- Valid arguments: on, off
- Default: on
- noirqbalance [IA-32,SMP,KNL] Disable kernel irq balancing
- noirqdebug [IA-32] Disables the code which attempts to detect and
- disable unhandled interrupt sources.
- no_timer_check [IA-32,X86_64,APIC] Disables the code which tests for
- broken timer IRQ sources.
- noisapnp [ISAPNP] Disables ISA PnP code.
- noinitrd [RAM] Tells the kernel not to load any configured
- initial RAM disk.
- nointroute [IA-64]
- nolapic [IA-32,APIC] Do not enable or use the local APIC.
- nolapic_timer [IA-32,APIC] Do not use the local APIC timer.
- noltlbs [PPC] Do not use large page/tlb entries for kernel
- lowmem mapping on PPC40x.
- nomca [IA-64] Disable machine check abort handling
- nomce [IA-32] Machine Check Exception
- noresidual [PPC] Don't use residual data on PReP machines.
- noresume [SWSUSP] Disables resume and restores original swap
- space.
- no-scroll [VGA] Disables scrollback.
- This is required for the Braillex ib80-piezo Braille
- reader made by F.H. Papenmeier (Germany).
- nosbagart [IA-64]
- nosep [BUGS=IA-32] Disables x86 SYSENTER/SYSEXIT support.
- nosmp [SMP] Tells an SMP kernel to act as a UP kernel.
- nosync [HW,M68K] Disables sync negotiation for all devices.
- notsc [BUGS=IA-32] Disable Time Stamp Counter
- nousb [USB] Disable the USB subsystem
- nowb [ARM]
- nr_uarts= [SERIAL] maximum number of UARTs to be registered.
- opl3= [HW,OSS]
- Format: <io>
- opl3sa2= [HW,OSS] Format:
- <io>,<irq>,<dma>,<dma2>,<mss_io>,<mpu_io>,<ymode>,<loopback>[,<isapnp>,<multiple]
- oprofile.timer= [HW]
- Use timer interrupt instead of performance counters
- optcd= [HW,CD]
- Format: <io>
- osst= [HW,SCSI] SCSI Tape Driver
- Format: <buffer_size>,<write_threshold>
- See also Documentation/scsi/st.txt.
- panic= [KNL] Kernel behaviour on panic
- Format: <timeout>
- parkbd.port= [HW] Parallel port number the keyboard adapter is
- connected to, default is 0.
- Format: <parport#>
- parkbd.mode= [HW] Parallel port keyboard adapter mode of operation,
- 0 for XT, 1 for AT (default is AT).
- Format: <mode>
- parport= [HW,PPT] Specify parallel ports. 0 disables.
- Format: { 0 | auto | 0xBBB[,IRQ[,DMA]] }
- Use 'auto' to force the driver to use any
- IRQ/DMA settings detected (the default is to
- ignore detected IRQ/DMA settings because of
- possible conflicts). You can specify the base
- address, IRQ, and DMA settings; IRQ and DMA
- should be numbers, or 'auto' (for using detected
- settings on that particular port), or 'nofifo'
- (to avoid using a FIFO even if it is detected).
- Parallel ports are assigned in the order they
- are specified on the command line, starting
- with parport0.
- parport_init_mode= [HW,PPT]
- Configure VIA parallel port to operate in
- a specific mode. This is necessary on Pegasos
- computer where firmware has no options for setting
- up parallel port mode and sets it to spp.
- Currently this function knows 686a and 8231 chips.
- Format: [spp|ps2|epp|ecp|ecpepp]
- pas2= [HW,OSS] Format:
- <io>,<irq>,<dma>,<dma16>,<sb_io>,<sb_irq>,<sb_dma>,<sb_dma16>
- pas16= [HW,SCSI]
- See header of drivers/scsi/pas16.c.
- pause_on_oops=
- Halt all CPUs after the first oops has been printed for
- the specified number of seconds. This is to be used if
- your oopses keep scrolling off the screen.
- pcbit= [HW,ISDN]
- pcd. [PARIDE]
- See header of drivers/block/paride/pcd.c.
- See also Documentation/paride.txt.
- pci=option[,option...] [PCI] various PCI subsystem options:
- off [IA-32] don't probe for the PCI bus
- bios [IA-32] force use of PCI BIOS, don't access
- the hardware directly. Use this if your machine
- has a non-standard PCI host bridge.
- nobios [IA-32] disallow use of PCI BIOS, only direct
- hardware access methods are allowed. Use this
- if you experience crashes upon bootup and you
- suspect they are caused by the BIOS.
- conf1 [IA-32] Force use of PCI Configuration
- Mechanism 1.
- conf2 [IA-32] Force use of PCI Configuration
- Mechanism 2.
- nommconf [IA-32,X86_64] Disable use of MMCONFIG for PCI
- Configuration
- nomsi [MSI] If the PCI_MSI kernel config parameter is
- enabled, this kernel boot option can be used to
- disable the use of MSI interrupts system-wide.
- nosort [IA-32] Don't sort PCI devices according to
- order given by the PCI BIOS. This sorting is
- done to get a device order compatible with
- older kernels.
- biosirq [IA-32] Use PCI BIOS calls to get the interrupt
- routing table. These calls are known to be buggy
- on several machines and they hang the machine
- when used, but on other computers it's the only
- way to get the interrupt routing table. Try
- this option if the kernel is unable to allocate
- IRQs or discover secondary PCI buses on your
- motherboard.
- rom [IA-32] Assign address space to expansion ROMs.
- Use with caution as certain devices share
- address decoders between ROMs and other
- resources.
- irqmask=0xMMMM [IA-32] Set a bit mask of IRQs allowed to be
- assigned automatically to PCI devices. You can
- make the kernel exclude IRQs of your ISA cards
- this way.
- pirqaddr=0xAAAAA [IA-32] Specify the physical address
- of the PIRQ table (normally generated
- by the BIOS) if it is outside the
- F0000h-100000h range.
- lastbus=N [IA-32] Scan all buses thru bus #N. Can be
- useful if the kernel is unable to find your
- secondary buses and you want to tell it
- explicitly which ones they are.
- assign-busses [IA-32] Always assign all PCI bus
- numbers ourselves, overriding
- whatever the firmware may have done.
- usepirqmask [IA-32] Honor the possible IRQ mask stored
- in the BIOS $PIR table. This is needed on
- some systems with broken BIOSes, notably
- some HP Pavilion N5400 and Omnibook XE3
- notebooks. This will have no effect if ACPI
- IRQ routing is enabled.
- noacpi [IA-32] Do not use ACPI for IRQ routing
- or for PCI scanning.
- routeirq Do IRQ routing for all PCI devices.
- This is normally done in pci_enable_device(),
- so this option is a temporary workaround
- for broken drivers that don't call it.
- firmware [ARM] Do not re-enumerate the bus but instead
- just use the configuration from the
- bootloader. This is currently used on
- IXP2000 systems where the bus has to be
- configured a certain way for adjunct CPUs.
- noearly [X86] Don't do any early type 1 scanning.
- This might help on some broken boards which
- machine check when some devices' config space
- is read. But various workarounds are disabled
- and some IOMMU drivers will not work.
- bfsort Sort PCI devices into breadth-first order.
- This sorting is done to get a device
- order compatible with older (<= 2.4) kernels.
- nobfsort Don't sort PCI devices into breadth-first order.
- cbiosize=nn[KMG] The fixed amount of bus space which is
- reserved for the CardBus bridge's IO window.
- The default value is 256 bytes.
- cbmemsize=nn[KMG] The fixed amount of bus space which is
- reserved for the CardBus bridge's memory
- window. The default value is 64 megabytes.
- pcmv= [HW,PCMCIA] BadgePAD 4
- pd. [PARIDE]
- See Documentation/paride.txt.
- pdcchassis= [PARISC,HW] Disable/Enable PDC Chassis Status codes at
- boot time.
- Format: { 0 | 1 }
- See arch/parisc/kernel/pdc_chassis.c
- pf. [PARIDE]
- See Documentation/paride.txt.
- pg. [PARIDE]
- See Documentation/paride.txt.
- pirq= [SMP,APIC] Manual mp-table setup
- See Documentation/i386/IO-APIC.txt.
- plip= [PPT,NET] Parallel port network link
- Format: { parport<nr> | timid | 0 }
- See also Documentation/parport.txt.
- pnpacpi= [ACPI]
- { off }
- pnpbios= [ISAPNP]
- { on | off | curr | res | no-curr | no-res }
- pnp_reserve_irq=
- [ISAPNP] Exclude IRQs for the autoconfiguration
- pnp_reserve_dma=
- [ISAPNP] Exclude DMAs for the autoconfiguration
- pnp_reserve_io= [ISAPNP] Exclude I/O ports for the autoconfiguration
- Ranges are in pairs (I/O port base and size).
- pnp_reserve_mem=
- [ISAPNP] Exclude memory regions for the
- autoconfiguration.
- Ranges are in pairs (memory base and size).
- profile= [KNL] Enable kernel profiling via /proc/profile
- Format: [schedule,]<number>
- Param: "schedule" - profile schedule points.
- Param: <number> - step/bucket size as a power of 2 for
- statistical time based profiling.
- Param: "sleep" - profile D-state sleeping (millisecs)
- processor.max_cstate= [HW,ACPI]
- Limit processor to maximum C-state
- max_cstate=9 overrides any DMI blacklist limit.
- processor.nocst [HW,ACPI]
- Ignore the _CST method to determine C-states,
- instead using the legacy FADT method
- prompt_ramdisk= [RAM] List of RAM disks to prompt for floppy disk
- before loading.
- See Documentation/ramdisk.txt.
- psmouse.proto= [HW,MOUSE] Highest PS2 mouse protocol extension to
- probe for; one of (bare|imps|exps|lifebook|any).
- psmouse.rate= [HW,MOUSE] Set desired mouse report rate, in reports
- per second.
- psmouse.resetafter= [HW,MOUSE]
- Try to reset the device after so many bad packets
- (0 = never).
- psmouse.resolution=
- [HW,MOUSE] Set desired mouse resolution, in dpi.
- psmouse.smartscroll=
- [HW,MOUSE] Controls Logitech smartscroll autorepeat.
- 0 = disabled, 1 = enabled (default).
- pss= [HW,OSS] Personal Sound System (ECHO ESC614)
- Format:
- <io>,<mss_io>,<mss_irq>,<mss_dma>,<mpu_io>,<mpu_irq>
- pt. [PARIDE]
- See Documentation/paride.txt.
- quiet [KNL] Disable most log messages
- r128= [HW,DRM]
- raid= [HW,RAID]
- See Documentation/md.txt.
- ramdisk= [RAM] Sizes of RAM disks in kilobytes [deprecated]
- See Documentation/ramdisk.txt.
- ramdisk_blocksize= [RAM]
- See Documentation/ramdisk.txt.
- ramdisk_size= [RAM] Sizes of RAM disks in kilobytes
- New name for the ramdisk parameter.
- See Documentation/ramdisk.txt.
- rcu.blimit= [KNL,BOOT] Set maximum number of finished
- RCU callbacks to process in one batch.
- rcu.qhimark= [KNL,BOOT] Set threshold of queued
- RCU callbacks over which batch limiting is disabled.
- rcu.qlowmark= [KNL,BOOT] Set threshold of queued
- RCU callbacks below which batch limiting is re-enabled.
- rdinit= [KNL]
- Format: <full_path>
- Run specified binary instead of /init from the ramdisk,
- used for early userspace startup. See initrd.
- reboot= [BUGS=IA-32,BUGS=ARM,BUGS=IA-64] Rebooting mode
- Format: <reboot_mode>[,<reboot_mode2>[,...]]
- See arch/*/kernel/reboot.c or arch/*/kernel/process.c
- reserve= [KNL,BUGS] Force the kernel to ignore some iomem area
- reservetop= [IA-32]
- Format: nn[KMG]
- Reserves a hole at the top of the kernel virtual
- address space.
- reset_devices [KNL] Force drivers to reset the underlying device
- during initialization.
- resume= [SWSUSP]
- Specify the partition device for software suspend
- resume_offset= [SWSUSP]
- Specify the offset from the beginning of the partition
- given by "resume=" at which the swap header is located,
- in <PAGE_SIZE> units (needed only for swap files).
- See Documentation/power/swsusp-and-swap-files.txt
- retain_initrd [RAM] Keep initrd memory after extraction
- rhash_entries= [KNL,NET]
- Set number of hash buckets for route cache
- riscom8= [HW,SERIAL]
- Format: <io_board1>[,<io_board2>[,...<io_boardN>]]
- ro [KNL] Mount root device read-only on boot
- root= [KNL] Root filesystem
- rootdelay= [KNL] Delay (in seconds) to pause before attempting to
- mount the root filesystem
- rootflags= [KNL] Set root filesystem mount option string
- rootfstype= [KNL] Set root filesystem type
- rw [KNL] Mount root device read-write on boot
- S [KNL] Run init in single mode
- sa1100ir [NET]
- See drivers/net/irda/sa1100_ir.c.
- sb= [HW,OSS]
- Format: <io>,<irq>,<dma>,<dma2>
- sbni= [NET] Granch SBNI12 leased line adapter
- sbpcd= [HW,CD] Soundblaster CD adapter
- Format: <io>,<type>
- See a comment before function sbpcd_setup() in
- drivers/cdrom/sbpcd.c.
- sc1200wdt= [HW,WDT] SC1200 WDT (watchdog) driver
- Format: <io>[,<timeout>[,<isapnp>]]
- scsi_debug_*= [SCSI]
- See drivers/scsi/scsi_debug.c.
- scsi_default_dev_flags=
- [SCSI] SCSI default device flags
- Format: <integer>
- scsi_dev_flags= [SCSI] Black/white list entry for vendor and model
- Format: <vendor>:<model>:<flags>
- (flags are integer value)
- scsi_logging= [SCSI]
- scsi_mod.scan= [SCSI] sync (default) scans SCSI busses as they are
- discovered. async scans them in kernel threads,
- allowing boot to proceed. none ignores them, expecting
- user space to do the scan.
- selinux [SELINUX] Disable or enable SELinux at boot time.
- Format: { "0" | "1" }
- See security/selinux/Kconfig help text.
- 0 -- disable.
- 1 -- enable.
- Default value is set via kernel config option.
- If enabled at boot time, /selinux/disable can be used
- later to disable prior to initial policy load.
- selinux_compat_net =
- [SELINUX] Set initial selinux_compat_net flag value.
- Format: { "0" | "1" }
- 0 -- use new secmark-based packet controls
- 1 -- use legacy packet controls
- Default value is 0 (preferred).
- Value can be changed at runtime via
- /selinux/compat_net.
- serialnumber [BUGS=IA-32]
- sg_def_reserved_size= [SCSI]
- shapers= [NET]
- Maximal number of shapers.
- sim710= [SCSI,HW]
- See header of drivers/scsi/sim710.c.
- simeth= [IA-64]
- simscsi=
- sjcd= [HW,CD]
- Format: <io>,<irq>,<dma>
- See header of drivers/cdrom/sjcd.c.
- slram= [HW,MTD]
- smart2= [HW]
- Format: <io1>[,<io2>[,...,<io8>]]
- snd-ad1816a= [HW,ALSA]
- snd-ad1848= [HW,ALSA]
- snd-ali5451= [HW,ALSA]
- snd-als100= [HW,ALSA]
- snd-als4000= [HW,ALSA]
- snd-azt2320= [HW,ALSA]
- snd-cmi8330= [HW,ALSA]
- snd-cmipci= [HW,ALSA]
- snd-cs4231= [HW,ALSA]
- snd-cs4232= [HW,ALSA]
- snd-cs4236= [HW,ALSA]
- snd-cs4281= [HW,ALSA]
- snd-cs46xx= [HW,ALSA]
- snd-dt019x= [HW,ALSA]
- snd-dummy= [HW,ALSA]
- snd-emu10k1= [HW,ALSA]
- snd-ens1370= [HW,ALSA]
- snd-ens1371= [HW,ALSA]
- snd-es968= [HW,ALSA]
- snd-es1688= [HW,ALSA]
- snd-es18xx= [HW,ALSA]
- snd-es1938= [HW,ALSA]
- snd-es1968= [HW,ALSA]
- snd-fm801= [HW,ALSA]
- snd-gusclassic= [HW,ALSA]
- snd-gusextreme= [HW,ALSA]
- snd-gusmax= [HW,ALSA]
- snd-hdsp= [HW,ALSA]
- snd-ice1712= [HW,ALSA]
- snd-intel8x0= [HW,ALSA]
- snd-interwave= [HW,ALSA]
- snd-interwave-stb=
- [HW,ALSA]
- snd-korg1212= [HW,ALSA]
- snd-maestro3= [HW,ALSA]
- snd-mpu401= [HW,ALSA]
- snd-mtpav= [HW,ALSA]
- snd-nm256= [HW,ALSA]
- snd-opl3sa2= [HW,ALSA]
- snd-opti92x-ad1848=
- [HW,ALSA]
- snd-opti92x-cs4231=
- [HW,ALSA]
- snd-opti93x= [HW,ALSA]
- snd-pmac= [HW,ALSA]
- snd-rme32= [HW,ALSA]
- snd-rme96= [HW,ALSA]
- snd-rme9652= [HW,ALSA]
- snd-sb8= [HW,ALSA]
- snd-sb16= [HW,ALSA]
- snd-sbawe= [HW,ALSA]
- snd-serial= [HW,ALSA]
- snd-sgalaxy= [HW,ALSA]
- snd-sonicvibes= [HW,ALSA]
- snd-sun-amd7930=
- [HW,ALSA]
- snd-sun-cs4231= [HW,ALSA]
- snd-trident= [HW,ALSA]
- snd-usb-audio= [HW,ALSA,USB]
- snd-via82xx= [HW,ALSA]
- snd-virmidi= [HW,ALSA]
- snd-wavefront= [HW,ALSA]
- snd-ymfpci= [HW,ALSA]
- sonycd535= [HW,CD]
- Format: <io>[,<irq>]
- sonypi.*= [HW] Sony Programmable I/O Control Device driver
- See Documentation/sonypi.txt
- specialix= [HW,SERIAL] Specialix multi-serial port adapter
- See Documentation/specialix.txt.
- spia_io_base= [HW,MTD]
- spia_fio_base=
- spia_pedr=
- spia_peddr=
- sscape= [HW,OSS]
- Format: <io>,<irq>,<dma>,<mpu_io>,<mpu_irq>
- st= [HW,SCSI] SCSI tape parameters (buffers, etc.)
- See Documentation/scsi/st.txt.
- st0x= [HW,SCSI]
- See header of drivers/scsi/seagate.c.
- sti= [PARISC,HW]
- Format: <num>
- Set the STI (builtin display/keyboard on the HP-PARISC
- machines) console (graphic card) which should be used
- as the initial boot-console.
- See also comment in drivers/video/console/sticore.c.
- sti_font= [HW]
- See comment in drivers/video/console/sticore.c.
- stifb= [HW]
- Format: bpp:<bpp1>[:<bpp2>[:<bpp3>...]]
- sunrpc.pool_mode=
- [NFS]
- Control how the NFS server code allocates CPUs to
- service thread pools. Depending on how many NICs
- you have and where their interrupts are bound, this
- option will affect which CPUs will do NFS serving.
- Note: this parameter cannot be changed while the
- NFS server is running.
- auto the server chooses an appropriate mode
- automatically using heuristics
- global a single global pool contains all CPUs
- percpu one pool for each CPU
- pernode one pool for each NUMA node (equivalent
- to global on non-NUMA machines)
- swiotlb= [IA-64] Number of I/O TLB slabs
- switches= [HW,M68k]
- sym53c416= [HW,SCSI]
- See header of drivers/scsi/sym53c416.c.
- sysrq_always_enabled
- [KNL]
- Ignore sysrq setting - this boot parameter will
- neutralize any effect of /proc/sys/kernel/sysrq.
- Useful for debugging.
- t128= [HW,SCSI]
- See header of drivers/scsi/t128.c.
- tdfx= [HW,DRM]
- thash_entries= [KNL,NET]
- Set number of hash buckets for TCP connection
- time Show timing data prefixed to each printk message line
- clocksource= [GENERIC_TIME] Override the default clocksource
- Override the default clocksource and use the clocksource
- with the name specified.
- tipar.timeout= [HW,PPT]
- Set communications timeout in tenths of a second
- (default 15).
- tipar.delay= [HW,PPT]
- Set inter-bit delay in microseconds (default 10).
- tmc8xx= [HW,SCSI]
- See header of drivers/scsi/seagate.c.
- tmscsim= [HW,SCSI]
- See comment before function dc390_setup() in
- drivers/scsi/tmscsim.c.
- tp720= [HW,PS2]
- trix= [HW,OSS] MediaTrix AudioTrix Pro
- Format:
- <io>,<irq>,<dma>,<dma2>,<sb_io>,<sb_irq>,<sb_dma>,<mpu_io>,<mpu_irq>
- tsdev.xres= [TS] Horizontal screen resolution.
- tsdev.yres= [TS] Vertical screen resolution.
- turbografx.map[2|3]= [HW,JOY]
- TurboGraFX parallel port interface
- Format:
- <port#>,<js1>,<js2>,<js3>,<js4>,<js5>,<js6>,<js7>
- See also Documentation/input/joystick-parport.txt
- u14-34f= [HW,SCSI] UltraStor 14F/34F SCSI host adapter
- See header of drivers/scsi/u14-34f.c.
- uart401= [HW,OSS]
- Format: <io>,<irq>
- uart6850= [HW,OSS]
- Format: <io>,<irq>
- uhci-hcd.ignore_oc=
- [USB] Ignore overcurrent events (default N).
- Some badly-designed motherboards generate lots of
- bogus events, for ports that aren't wired to
- anything. Set this parameter to avoid log spamming.
- Note that genuine overcurrent events won't be
- reported either.
- usbcore.autosuspend=
- [USB] The autosuspend time delay (in seconds) used
- for newly-detected USB devices (default 2). This
- is the time required before an idle device will be
- autosuspended. Devices for which the delay is set
- to 0 won't be autosuspended at all.
- usbhid.mousepoll=
- [USBHID] The interval which mice are to be polled at.
- vdso= [IA-32,SH]
- vdso=1: enable VDSO (default)
- vdso=0: disable VDSO mapping
- video= [FB] Frame buffer configuration
- See Documentation/fb/modedb.txt.
- vga= [BOOT,IA-32] Select a particular video mode
- See Documentation/i386/boot.txt and
- Documentation/svga.txt.
- Use vga=ask for menu.
- This is actually a boot loader parameter; the value is
- passed to the kernel using a special protocol.
- vmalloc=nn[KMG] [KNL,BOOT] Forces the vmalloc area to have an exact
- size of <nn>. This can be used to increase the
- minimum size (128MB on x86). It can also be used to
- decrease the size and leave more room for directly
- mapped kernel RAM.
- vmhalt= [KNL,S390] Perform z/VM CP command after system halt.
- Format: <command>
- vmpanic= [KNL,S390] Perform z/VM CP command after kernel panic.
- Format: <command>
- vmpoff= [KNL,S390] Perform z/VM CP command after power off.
- Format: <command>
- waveartist= [HW,OSS]
- Format: <io>,<irq>,<dma>,<dma2>
- wd33c93= [HW,SCSI]
- See header of drivers/scsi/wd33c93.c.
- wd7000= [HW,SCSI]
- See header of drivers/scsi/wd7000.c.
- wdt= [WDT] Watchdog
- See Documentation/watchdog/watchdog.txt.
- xd= [HW,XT] Original XT pre-IDE (RLL encoded) disks.
- xd_geo= See header of drivers/block/xd.c.
- xirc2ps_cs= [NET,PCMCIA]
- Format:
- <irq>,<irq_mask>,<io>,<full_duplex>,<do_sound>,<lockup_hack>[,<irq2>[,<irq3>[,<irq4>]]]
- norandmaps Don't use address space randomization
- Equivalent to echo 0 > /proc/sys/kernel/randomize_va_space
- unwind_debug=N N > 0 will enable dwarf2 unwinder debugging
- This is useful to get more information why
- you got a "dwarf2 unwinder stuck"
- ______________________________________________________________________
- TODO:
- Add documentation for ALSA options.
- Add more DRM drivers.
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