February 2003 Kernel Parameters v2.5.59 ~~~~~~~~~~~~~~~~~ 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. The text in square brackets at the beginning of the description state the restrictions on the kernel for the said kernel parameter to be valid. The restrictions referred to are that the relevant option is valid if: 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. DEVFS devfs support is enabled. DRM Direct Rendering Management support 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 DCHP, BOOTP, or RARP is enabled. ISAPNP ISA PnP code is enabled. ISDN Appropriate ISDN support is enabled. JOY Appropriate joystick support 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. MTD MTD support is enabled. NET Appropriate network support is enabled. NFS Appropriate NFS support is enabled. OSS OSS sound support is enabled. PARIDE The ParIDE subsystem 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/. SERIAL Serial support is enabled. SMP The kernel is an SMP kernel. SPARC Sparc architecture is enabled. SWSUSP Software suspension is enabled. TS Appropriate touchscreen support is enabled. USB USB 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. 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 . 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. 53c7xx= [HW,SCSI] Amiga SCSI controllers See header of drivers/scsi/53c7xx.c. See also Documentation/scsi/ncr53c7xx.txt. 98busmouse.irq= [HW,MOUSE] PC-9801 Bus Mouse Driver Format: , default is 13 acpi= [HW,ACPI] Advanced Configuration and Power Interface Format: { force | off | ht | strict } force -- enables ACPI for systems with default off off -- disabled ACPI for systems with default on 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. 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: ,... acpi_irq_isa= [HW,ACPI] If irq_balance, Mark listed IRQs used by ISA Format: ,... acpi_osi= [HW,ACPI] empty param disables _OSI acpi_serialize [HW,ACPI] force serialization of AML methods ad1816= [HW,OSS] Format: ,,, See also Documentation/sound/oss/AD1816. ad1848= [HW,OSS] Format: ,,,, adlib= [HW,OSS] Format: advansys= [HW,SCSI] See header of drivers/scsi/advansys.c. advwdt= [HW,WDT] Advantech WDT Format: , aedsp16= [HW,OSS] Audio Excel DSP 16 Format: ,,,,, See also header of sound/oss/aedsp16.c. aha152x= [HW,SCSI] See Documentation/scsi/aha152x.txt. aha1542= [HW,SCSI] Format: [,,[,]] aic7xxx= [HW,SCSI] See Documentation/scsi/aic7xxx.txt. aic79xx= [HW,SCSI] See Documentation/scsi/aic79xx.txt. allowdma0 [ISAPNP] AM53C974= [HW,SCSI] Format: ,,, See also header of drivers/scsi/AM53C974.c. amijoy.map= [HW,JOY] Amiga joystick support Map of devices attached to JOY0DAT and JOY1DAT Format: , 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: ,,.. 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. apm= [APM] Advanced Power Management See header of arch/i386/kernel/apm.c. applicom= [HW] Format: , arcrimi= [HW,NET] ARCnet - "RIM I" (entirely mem-mapped) cards Format: ,, 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: (2 = AT (default) 3 = PS/2) atkbd.scroll= [HW] Enable scroll wheel on MS Office and similar keyboards atkbd.softrepeat= [HW] Use software keyboard repeat autotest [IA64] awe= [HW,OSS] AWE32/SB32/AWE64 wave table synth Format: ,, aztcd= [HW,CD] Aztech CD268 CDROM driver Format: ,0x79 (?) baycom_epp= [HW,AX25] Format: , baycom_par= [HW,AX25] BayCom Parallel Port AX.25 Modem Format: , See header of drivers/net/hamradio/baycom_par.c. baycom_ser_fdx= [HW,AX25] BayCom Serial Port AX.25 Modem (Full Duplex Mode) Format: ,,[,] 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: ,, 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: ,[,PAS] See header of drivers/cdrom/cdu31a.c. chandev= [HW,NET] Generic channel device initialisation clock= [BUGS=IA-32, HW] gettimeofday timesource override. Forces specified timesource (if avaliable) to be used when calculating gettimeofday(). If specicified timesource is not avalible, it defaults to PIT. Format: { pit | tsc | cyclone | pmtmr } hpet= [IA-32,HPET] option to disable HPET and use PIT. Format: disable cm206= [HW,CD] Format: { auto | [,][] } com20020= [HW,NET] ARCnet - COM20020 chipset Format: [,[,[,[,[,]]]]] com90io= [HW,NET] ARCnet - COM90xx chipset (IO-mapped buffers) Format: [,] com90xx= [HW,NET] ARCnet - COM90xx chipset (memory-mapped buffers) Format: [,[,]] condev= [HW,S390] console device conmode= console= [KNL] Output console Console device and comm spec (speed, control, parity). cpcihp_generic= [HW,PCI] Generic port I/O CompactPCI driver Format: ,,,[,] cpia_pp= [HW,PPT] Format: { parport | auto | none } cs4232= [HW,OSS] Format: ,,,,, cs89x0_dma= [HW,NET] Format: 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: , See also Documentation/input/joystick-parport.txt debug [KNL] Enable kernel debugging (events log level). decnet= [HW,NET] Format: [,] See also Documentation/networking/decnet.txt. devfs= [DEVFS] See Documentation/filesystems/devfs/boot-options. 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: [,[,..]] dmasound= [HW,OSS] Sound subsystem buffers dscc4.setup= [NET] dtc3181e= [HW,SCSI] earlyprintk= [x86, x86_64] 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] eda= [HW,PS2] edb= [HW,PS2] eicon= [HW,ISDN] Format: ,, eisa_irq_edge= [PARISC] 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: {"as"|"cfq"|"deadline"|"noop"} See Documentation/as-iosched.txt for details es1370= [HW,OSS] Format: [,] See also header of sound/oss/es1370.c. es1371= [HW,OSS] Format: ,[,[]] 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: [,] 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. ftape= [HW] Floppy Tape subsystem debugging options. See Documentation/ftape.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: ,,,,, 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: gt96100eth= [NET] MIPS GT96100 Advanced Communication Controller gus= [HW,OSS] Format: ,,, gvp11= [HW,SCSI] hcl= [IA-64] SGI's Hardware Graph compatibility layer hd= [EIDE] (E)IDE hard drive subsystem geometry Format: ,, hd?= [HW] (E)IDE subsystem hd?lun= See Documentation/ide.txt. hisax= [HW,ISDN] See Documentation/isdn/README.HiSax. hugepages= [HW,IA-32,IA-64] Maximal number of HugeTLB pages. noirqbalance [IA-32,SMP,KNL] Disable kernel irq balancing i8042.direct [HW] Put keyboard port into non-translated mode i8042.dumbkbd [HW] Pretend that controlled can only read data from keyboard and can not control its state (Don't attempt to blink the leds) i8042.noaux [HW] Don't check for auxiliary (== mouse) port i8042.nomux [HW] Don't check presence of an active multiplexing controller i8042.reset [HW] Reset the controller during init and cleanup i8042.unlock [HW] Unlock (ignore) the keylock i810= [HW,DRM] ibmmcascsi= [HW,MCA,SCSI] IBM MicroChannel SCSI adapter See Documentation/mca.txt. icn= [HW,ISDN] Format: [,[,[,]]] ide?= [HW] (E)IDE subsystem Config (iomem/irq), tuning or debugging (serialize,reset,no{dma,tune,probe}) 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 ihash_entries= [KNL] Set number of hash buckets for inode cache. in2000= [HW,SCSI] See header of drivers/scsi/in2000.c. init= [KNL] Format: 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: 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. isapnp= [ISAPNP] Format: , , , isp16= [HW,CD] Format: ,,, iucv= [HW,NET] js= [HW,JOY] Analog joystick See Documentation/input/joystick.txt. keepinitrd [HW,ARM] l2cr= [PPC] lapic [IA-32,APIC] Enable the local APIC even if BIOS disabled it. lasi= [HW,SCSI] PARISC LASI driver for the 53c700 chip Format: addr:,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.udpport= [NFS] lockd.tcpport= [NFS] logibm.irq= [HW,MOUSE] Logitech Bus Mouse Driver Format: log_buf_len=n Sets the size of the printk ring buffer, in bytes. Format is n, nk, nM. n must be a power of two. The default is set in kernel config. 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. ltpc= [NET] Format: ,, mac5380= [HW,SCSI] Format: ,,,, mac53c9x= [HW,SCSI] Format: ,,,,,,, mad16= [HW,OSS] Format: ,,,,,, maui= [HW,OSS] Format: , 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 max_scsi_luns= [SCSI] max_scsi_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: ,, mcdx= [HW,CD] mce [IA-32] Machine Check Exception md= [HW] RAID subsystems devices and level See Documentation/md.txt. mdacon= [MDA] Format: , 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. mem=nopentium [BUGS=IA-32] Disable usage of 4MB pages for kernel memory. memmap=exactmap [KNL,IA-32] 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.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: , MTD_Partition= [MTD] Format: ,,, MTD_Region= [MTD] Format: ,[,,,,] mtdparts= [MTD] See drivers/mtd/cmdline.c. 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: ,,,, Note that mem_start is often overloaded to mean something different and driver-specific. nfsaddrs= [NFS] See Documentation/nfsroot.txt. nfsroot= [NFS] nfs root filesystem for disk-less boxes. See Documentation/nfsroot.txt. 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. noalign [KNL,ARM] noapic [SMP,APIC] Tells the kernel not to make use of any APIC that may be present on the system. noasync [HW,M68K] Disables async and sync negotiation for all devices. nocache [ARM] nodisconnect [HW,SCSI,M68K] Disables SCSI disconnects. noexec [IA-64] nofxsr [BUGS=IA-32] nohighio [BUGS=IA-32] Disable highmem block I/O. nohlt [BUGS=ARM] no-hlt [BUGS=IA-32] Tells the kernel that the hlt instruction doesn't work correctly and not to use it. noirqdebug [IA-32] Disables the code which attempts to detect and disable unhandled interrupt 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. nomce [IA-32] Machine Check Exception noresume [SWSUSP] Disables resume and restore 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] 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] opl3= [HW,OSS] Format: opl3sa= [HW,OSS] Format: ,,,,, opl3sa2= [HW,OSS] Format: ,,,,,,,[,, osst= [HW,SCSI] SCSI Tape Driver Format: , See also Documentation/scsi/st.txt. panic= [KNL] Kernel behaviour on panic Format: parport=0 [HW,PPT] Specify parallel ports. 0 disables. parport=auto Use 'auto' to force the driver to use parport=0xBBB[,IRQ[,DMA]] 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. pas2= [HW,OSS] Format: ,,,,,,, pas16= [HW,SCSI] See header of drivers/scsi/pas16.c. 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. 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. lastbus=N [IA-32] Scan all buses till 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. pcmv= [HW,PCMCIA] BadgePAD 4 pd. [PARIDE] See Documentation/paride.txt. 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 | timid | 0 } See also Documentation/parport.txt. 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 (param: profile step/bucket size as a power of 2) 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 (bare|imps|exps). psmouse.rate= [HW,MOUSE] Set desired mouse report rate, in reports per second. psmouse.resetafter= [HW,MOUSE] Try to reset Synaptics Touchpad 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: ,,,,, pt. [PARIDE] See Documentation/paride.txt. quiet= [KNL] Disable 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. ramdisk_start= [RAM] Starting block of RAM disk image (so you can place it after the kernel image on a boot floppy). See Documentation/ramdisk.txt. reboot= [BUGS=IA-32,BUGS=ARM,BUGS=IA-64] Rebooting mode Format: [,[,...]] See arch/*/kernel/reboot.c. reserve= [KNL,BUGS] Force the kernel to ignore some iomem area resume= [SWSUSP] Specify the partition device for software suspension rhash_entries= [KNL,NET] Set number of hash buckets for route cache riscom8= [HW,SERIAL] Format: [,[,...]] ro [KNL] Mount root device read-only on boot root= [KNL] 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: ,,, sbni= [NET] Granch SBNI12 leased line adapter sbpcd= [HW,CD] Soundblaster CD adapter Format: , See a comment before function sbpcd_setup() in drivers/cdrom/sbpcd.c. sc1200wdt= [HW,WDT] SC1200 WDT (watchdog) driver Format: [,[,]] scsi_debug_*= [SCSI] See drivers/scsi/scsi_debug.c. scsi_default_dev_flags= [SCSI] SCSI default device flags Format: scsi_dev_flags= [SCSI] Black/white list entry for vendor and model Format: :: (flags are integer value) scsi_logging= [SCSI] scsihosts= [SCSI] serialnumber [BUGS=IA-32] sf16fm= [HW] SF16FMI radio driver for Linux Format: sg_def_reserved_size= [SCSI] sgalaxy= [HW,OSS] Format: ,,,, shapers= [NET] Maximal number of shapers. sim710= [SCSI,HW] See header of drivers/scsi/sim710.c. simeth= [IA-64] simscsi= sjcd= [HW,CD] Format: ,, See header of drivers/cdrom/sjcd.c. slram= [HW,MTD] smart2= [HW] Format: [,[,...,]] 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] sonicvibes= [HW,OSS] Format: sonycd535= [HW,CD] Format: [,] sonypi= [HW] Sony Programmable I/O Control Device driver Format: ,,,,, specialix= [HW,SERIAL] Specialix multi-serial port adapter See Documentation/specialix.txt. speedstep_coppermine= [HW,IA-32] Take CPU in your notebook as SpeedStep-capable See comment before function speedstep_setup() in arch/i386/kernel/cpu/cpufreq/speedstep.c. spia_io_base= [HW,MTD] spia_fio_base= spia_pedr= spia_peddr= sscape= [HW,OSS] Format: ,,,, st= [HW,SCSI] SCSI tape parameters (buffers, etc.) See Documentation/scsi/st.txt. st0x= [HW,SCSI] See header of drivers/scsi/seagate.c. sti= [HW] Format: 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:[:[:...]] stram_swap= [HW,M68k] swiotlb= [IA-64] Number of I/O TLB slabs switches= [HW,M68k] sym53c416= [HW,SCSI] See header of drivers/scsi/sym53c416.c. sym53c8xx= [HW,SCSI] See Documentation/scsi/ncr53c8xx.txt. 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 tipar= [HW] See header of drivers/char/tipar.c. tiusb= [HW,USB] Texas Instruments' USB GraphLink (aka SilverLink) Format: 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: ,,,,,,,, tsdev.xres= [TS] Horizontal screen resolution. tsdev.yres= [TS] Vertical screen resolution. turbografx.map[2|3]= [HW,JOY] TurboGraFX parallel port interface Format: ,,,,,,, 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: , uart6850= [HW,OSS] Format: , 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. vmhalt= [KNL,S390] vmpoff= [KNL,S390] waveartist= [HW,OSS] Format: ,,, 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: ,,,,,[,[,[,]]] Changelog: The last known update (for 2.4.0) - the changelog was not kept before. 2000-06-?? Mr. Unknown Update for 2.5.49, description for most of the options introduced, references to other documentation (C files, READMEs, ..), added S390, PPC, SPARC, MTD, ALSA and OSS category. Minor corrections and reformatting. 2002-11-24 Petr Baudis Randy Dunlap TODO: Add documentation for ALSA options. Add more DRM drivers.