X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=Documentation%2Fkernel-parameters.txt;h=b3a6187e53051866004696e4d5718cd85240e1c2;hb=43bc926fffd92024b46cafaf7350d669ba9ca884;hp=4924d387a6573223e9877b56d4d28219f9f650b2;hpb=cee37fe97739d85991964371c1f3a745c00dd236;p=linux-2.6.git diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 4924d387a..b3a6187e5 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -1,4 +1,4 @@ -February 2003 Kernel Parameters v2.5.59 + Kernel Parameters ~~~~~~~~~~~~~~~~~ The following is a consolidated list of the kernel parameters as implemented @@ -17,9 +17,17 @@ are specified on the kernel command line with the module name plus usbcore.blinkenlights=1 -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: +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. @@ -27,8 +35,8 @@ restrictions referred to are that the relevant option is valid if: 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. + DEVFS devfs 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. @@ -37,7 +45,7 @@ restrictions referred to are that the relevant option is valid if: 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. + 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. @@ -49,6 +57,7 @@ restrictions referred to are that the relevant option is valid if: 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. @@ -71,7 +80,7 @@ restrictions referred to are that the relevant option is valid if: SERIAL Serial support is enabled. SMP The kernel is an SMP kernel. SPARC Sparc architecture is enabled. - SWSUSP Software suspension 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. @@ -105,13 +114,13 @@ running once the system is up. See header of drivers/scsi/53c7xx.c. See also Documentation/scsi/ncr53c7xx.txt. - acpi= [HW,ACPI] Advanced Configuration and Power Interface - Format: { force | off | ht | strict } + acpi= [HW,ACPI] 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 + strict -- Be less tolerant of platforms that are not strictly ACPI specification compliant. See also Documentation/pm.txt, pci=noacpi @@ -119,20 +128,23 @@ running once the system is up. 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 } + Format: { level | edge | high | low } - acpi_irq_balance [HW,ACPI] ACPI will balance active IRQs - default in APIC mode + 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_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 + 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 + acpi_irq_isa= [HW,ACPI] If irq_balance, mark listed IRQs used by ISA Format: ,... acpi_osi= [HW,ACPI] empty param disables _OSI @@ -145,20 +157,35 @@ running once the system is up. acpi_dbg_layer= [HW,ACPI] Format: - Each bit of the indicates an acpi debug layer, + Each bit of the 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: - Each bit of the indicates an acpi debug level, + Each bit of the 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. + + 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: ,,, See also Documentation/sound/oss/AD1816. @@ -168,7 +195,7 @@ running once the system is up. adlib= [HW,OSS] Format: - + advansys= [HW,SCSI] See header of drivers/scsi/advansys.c. @@ -178,7 +205,7 @@ running once the system is up. aedsp16= [HW,OSS] Audio Excel DSP 16 Format: ,,,,, See also header of sound/oss/aedsp16.c. - + aha152x= [HW,SCSI] See Documentation/scsi/aha152x.txt. @@ -191,10 +218,6 @@ running once the system is up. aic79xx= [HW,SCSI] See Documentation/scsi/aic79xx.txt. - 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: , @@ -205,23 +228,24 @@ running once the system is up. connected to one of 16 gameports Format: ,,.. - apc= [HW,SPARC] Power management functions (SPARCstation-4/5 + deriv.) + 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 + 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: , - + arcrimi= [HW,NET] ARCnet - "RIM I" (entirely mem-mapped) cards Format: ,, @@ -236,38 +260,40 @@ running once the system is up. atkbd.reset= [HW] Reset keyboard during initialization - atkbd.set= [HW] Select keyboard code set - Format: (2 = AT (default) 3 = PS/2) + 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.softraw= [HW] Choose between synthetic and real raw mode Format: (0 = real, 1 = synthetic (default)) - - atkbd.softrepeat= - [HW] Use software keyboard repeat + + 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) + 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) + 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. @@ -278,7 +304,8 @@ running once the system is up. 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.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 @@ -304,17 +331,25 @@ running once the system is up. 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). + 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 timesource override. + Value can be changed at runtime via + /selinux/checkreqprot. + + 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. + when calculating gettimeofday(). If specicified + timesource is not avalible, it defaults to PIT. Format: { pit | tsc | cyclone | pmtmr } + 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 @@ -322,28 +357,35 @@ running once the system is up. Format: { auto | [,][] } com20020= [HW,NET] ARCnet - COM20020 chipset - Format: [,[,[,[,[,]]]]] + Format: + [,[,[,[,[,]]]]] com90io= [HW,NET] ARCnet - COM90xx chipset (IO-mapped buffers) Format: [,] - com90xx= [HW,NET] ARCnet - COM90xx chipset (memory-mapped buffers) + com90xx= [HW,NET] + ARCnet - COM90xx chipset (memory-mapped buffers) Format: [,[,]] condev= [HW,S390] console device conmode= - + console= [KNL] Output console device and options. tty Use the virtual console device . ttyS[,options] + ttyUSB0[,options] Use the specified serial port. The options are of - the form "bbbbpn", where "bbbb" is the baud rate, - "p" is parity ("n", "o", or "e"), and "n" is bits. - Default is "9600n8". + 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 also Documentation/serial-console.txt. + See Documentation/serial-console.txt for more + information. See + Documentation/networking/netconsole.txt for an + alternative. uart,io,[,options] uart,mmio,[,options] @@ -353,11 +395,16 @@ running once the system is up. options are the same as for ttyS, above. cpcihp_generic= [HW,PCI] Generic port I/O CompactPCI driver - Format: ,,,[,] + Format: + ,,,[,] cpia_pp= [HW,PPT] Format: { parport | 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: ,,,,, @@ -366,10 +413,10 @@ running once the system is up. cs89x0_media= [HW,NET] Format: { rj45 | aui | bnc } - + cyclades= [HW,SERIAL] Cyclades multi-serial port adapter. - - dasd= [HW,NET] + + dasd= [HW,NET] See header of drivers/s390/block/dasd_devmap.c. db9.dev[2|3]= [HW,JOY] Multisystem joystick support via parallel port @@ -388,7 +435,7 @@ running once the system is up. dhash_entries= [KNL] Set number of hash buckets for dentry cache. - + digi= [HW,SERIAL] IO parameters + enable/disable command. @@ -406,11 +453,11 @@ running once the system is up. dtc3181e= [HW,SCSI] - earlyprintk= [IA-32, X86-64] + earlyprintk= [IA-32,X86-64] earlyprintk=vga earlyprintk=serial[,ttySn[,baudrate]] - Append ,keep to not disable it when the real console + Append ",keep" to not disable it when the real console takes over. Only vga or serial at a time, not both. @@ -425,6 +472,11 @@ running once the system is up. eata= [HW,SCSI] + ec_intr= [HW,ACPI] ACPI Embedded Controller interrupt mode + Format: + 0: polling mode + non-0: interrupt mode (default) + eda= [HW,PS2] edb= [HW,PS2] @@ -433,7 +485,7 @@ running once the system is up. Format: {"of[f]" | "sk[ipmbr]"} See comment in arch/i386/boot/edd.S - eicon= [HW,ISDN] + eicon= [HW,ISDN] Format: ,, eisa_irq_edge= [PARISC,HW] @@ -444,9 +496,15 @@ running once the system is up. arch/i386/kernel/cpu/cpufreq/elanfreq.c. elevator= [IOSCHED] - Format: {"as"|"cfq"|"deadline"|"noop"} - See Documentation/block/as-iosched.txt - and Documentation/block/deadline-iosched.txt for details. + 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"} @@ -463,7 +521,7 @@ running once the system is up. 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. @@ -504,12 +562,13 @@ running once the system is up. gus= [HW,OSS] Format: ,,, - + 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 @@ -536,6 +595,7 @@ running once the system is up. 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.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 @@ -548,6 +608,9 @@ running once the system is up. 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 @@ -569,13 +632,13 @@ running once the system is up. 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 - + ihash_entries= [KNL] Set number of hash buckets for inode cache. @@ -596,6 +659,14 @@ running once the system is up. inport.irq= [HW] Inport (ATI XL and Microsoft) busmouse driver Format: + 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 @@ -611,8 +682,19 @@ running once the system is up. ips= [HW,SCSI] Adaptec / IBM ServeRAID controller See header of drivers/scsi/ips.c. + 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: , , , + Format: ,,, isolcpus= [KNL,SMP] Isolate CPUs from the general scheduler. Format: ,..., @@ -624,39 +706,48 @@ running once the system is up. "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. + alternative -- manually setting the CPU mask of all + tasks in the system -- can cause problems and + suboptimal load balancer performance. isp16= [HW,CD] Format: ,,, - iucv= [HW,NET] + 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 + 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 [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. + 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.nlm_grace_period=P [NFS] Assign grace period. + Format: + + lockd.nlm_tcpport=N [NFS] Assign TCP port. + Format: + + lockd.nlm_timeout=T [NFS] Assign timeout value. + Format: - lockd.tcpport= [NFS] + lockd.nlm_udpport=M [NFS] Assign UDP port. + Format: logibm.irq= [HW,MOUSE] Logitech Bus Mouse Driver Format: @@ -676,8 +767,9 @@ running once the system is up. 7 (KERN_DEBUG) debug-level messages 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. + 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 @@ -713,34 +805,37 @@ running once the system is up. ltpc= [NET] Format: ,, - mac5380= [HW,SCSI] - Format: ,,,, + mac5380= [HW,SCSI] Format: + ,,,, - mac53c9x= [HW,SCSI] - Format: ,,,,,,, + mac53c9x= [HW,SCSI] Format: + ,,,,,,, - machvec= [IA64] - Force the use of a particular machine-vector (machvec) in a generic - kernel. Example: machvec=hpzx1_swiotlb + machvec= [IA64] Force the use of a particular machine-vector + (machvec) in a generic kernel. + Example: machvec=hpzx1_swiotlb - mad16= [HW,OSS] - Format: ,,,,,, + mad16= [HW,OSS] Format: + ,,,,,, maui= [HW,OSS] Format: , - - max_loop= [LOOP] Maximum number of loopback devices that can + + 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_luns= [SCSI] Maximum number of LUNs to probe + 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 + [SCSI] Maximum number of LUNs received. Should be between 1 and 16384. mca-pentium [BUGS=IA-32] @@ -756,11 +851,11 @@ running once the system is up. 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. @@ -771,7 +866,7 @@ running once the system is up. mem=nopentium [BUGS=IA-32] Disable usage of 4MB pages for kernel memory. - memmap=exactmap [KNL,IA-32] Enable setting of an exact + 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 @@ -794,6 +889,49 @@ running once the system is up. mga= [HW,DRM] + migration_cost= + [KNL,SMP] debug: override scheduler migration costs + Format: ,,... + This debugging option can be used to override the + default scheduler migration cost matrix. The numbers + are indexed by 'CPU domain distance'. + E.g. migration_cost=1000,2000,3000 on an SMT NUMA + box will set up an intra-core migration cost of + 1 msec, an inter-core migration cost of 2 msecs, + and an inter-node migration cost of 3 msecs. + + WARNING: using the wrong values here can break + scheduler performance, so it's only for scheduler + development purposes, not production environments. + + migration_debug= + [KNL,SMP] migration cost auto-detect verbosity + Format=<0|1|2> + If a system's migration matrix reported at bootup + seems erroneous then this option can be used to + increase verbosity of the detection process. + We default to 0 (no extra messages), 1 will print + some more information, and 2 will be really + verbose (probably only useful if you also have a + serial console attached to the system). + + migration_factor= + [KNL,SMP] multiply/divide migration costs by a factor + Format= + This debug option can be used to proportionally + increase or decrease the auto-detected migration + costs for all entries of the migration matrix. + E.g. migration_factor=150 will increase migration + costs by 50%. (and thus the scheduler will be less + eager migrating cache-hot tasks) + migration_factor=80 will decrease migration costs + by 20%. (thus the scheduler will be more eager to + migrate tasks) + + WARNING: using the wrong values here can break + scheduler performance, so it's only for scheduler + development purposes, not production environments. + mousedev.tap_time= [MOUSE] Maximum time between finger touching and leaving touchpad surface for touch to be considered @@ -811,15 +949,15 @@ running once the system is up. MTD_Partition= [MTD] Format: ,,, - MTD_Region= [MTD] - Format: ,[,,,,] + MTD_Region= [MTD] Format: + ,[,,,,] 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') + [HW] Make the MicroTouch USB driver use raw coordinates + ('y', default) or cooked coordinates ('n') n2= [NET] SDL Inc. RISCom/N2 synchronous serial card @@ -840,21 +978,31 @@ running once the system is up. Format: ,,,, 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. - noalign [KNL,ARM] - + noalign [KNL,ARM] + noapic [SMP,APIC] Tells the kernel to not make use of any IOAPICs that may be present in the system. @@ -865,19 +1013,21 @@ running once the system is up. on "Classic" PPC cores. nocache [ARM] - + nodisconnect [HW,SCSI,M68K] Disables SCSI disconnects. noexec [IA-64] - noexec [IA-32, X86-64] + noexec [IA-32,X86-64] noexec=on: enable non-executable mappings (default) noexec=off: disable nn-executable mappings - nofxsr [BUGS=IA-32] + 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. @@ -904,18 +1054,23 @@ running once the system is up. 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 restore original swap space. - + 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. @@ -925,16 +1080,18 @@ running once the system is up. nousb [USB] Disable the USB subsystem nowb [ARM] - + + nr_uarts= [SERIAL] maximum number of UARTs to be registered. + opl3= [HW,OSS] Format: opl3sa= [HW,OSS] Format: ,,,,, - opl3sa2= [HW,OSS] - Format: ,,,,,,,[,,,,,,,,,[,, parkbd.mode= [HW] Parallel port keyboard adapter mode of operation, 0 for XT, 1 for AT (default is AT). - 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. - - parport_init_mode= - [HW,PPT] Configure VIA parallel port to - operate in 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: + + 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: ,,,,,,, - + pas2= [HW,OSS] Format: + ,,,,,,, + 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. - 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 - 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. + 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. pcmv= [HW,PCMCIA] BadgePAD 4 @@ -1083,47 +1254,53 @@ running once the system is up. [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). + Ranges are in pairs (I/O port base and size). pnp_reserve_mem= - [ISAPNP] Exclude memory regions for the autoconfiguration + [ISAPNP] Exclude memory regions for the + autoconfiguration. Ranges are in pairs (memory base and size). profile= [KNL] Enable kernel profiling via /proc/profile - { schedule | } - (param: schedule - profile schedule points} - (param: profile step/bucket size as a power of 2 for - statistical time based profiling) + Format: [schedule,] + Param: "schedule" - profile schedule points. + Param: - step/bucket size as a power of 2 for + statistical time based profiling. - processor.max_cstate= [HW, ACPI] + 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 (bare|imps|exps). + 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 + 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, + [HW,MOUSE] Controls Logitech smartscroll autorepeat. 0 = disabled, 1 = enabled (default). pss= [HW,OSS] Personal Sound System (ECHO ESC614) - Format: ,,,,, + Format: + ,,,,, pt. [PARIDE] See Documentation/paride.txt. quiet= [KNL] Disable log messages - + r128= [HW,DRM] raid= [HW,RAID] @@ -1132,21 +1309,39 @@ running once the system is up. ramdisk= [RAM] Sizes of RAM disks in kilobytes [deprecated] See Documentation/ramdisk.txt. - ramdisk_blocksize= - [RAM] + 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. + + rcu.rsinterval= [KNL,BOOT,SMP] Set the number of additional + RCU callbacks to queued before forcing reschedule + on all cpus. + + rdinit= [KNL] + Format: + 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: [,[,...]] 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 + resume= [SWSUSP] + Specify the partition device for software suspend rhash_entries= [KNL,NET] Set number of hash buckets for route cache @@ -1176,7 +1371,7 @@ running once the system is up. Format: ,,, sbni= [NET] Granch SBNI12 leased line adapter - + sbpcd= [HW,CD] Soundblaster CD adapter Format: , See a comment before function sbpcd_setup() in @@ -1209,21 +1404,20 @@ running once the system is up. serialnumber [BUGS=IA-32] - sg_def_reserved_size= - [SCSI] - + 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. @@ -1354,10 +1548,10 @@ running once the system is up. snd-wavefront= [HW,ALSA] snd-ymfpci= [HW,ALSA] - + sonicvibes= [HW,OSS] Format: - + sonycd535= [HW,CD] Format: [,] @@ -1374,7 +1568,7 @@ running once the system is up. sscape= [HW,OSS] Format: ,,,, - + st= [HW,SCSI] SCSI tape parameters (buffers, etc.) See Documentation/scsi/st.txt. @@ -1394,10 +1588,8 @@ running once the system is up. stifb= [HW] Format: bpp:[:[:...]] - stram_swap= [HW,M68k] - swiotlb= [IA-64] Number of I/O TLB slabs - + switches= [HW,M68k] sym53c416= [HW,SCSI] @@ -1430,14 +1622,16 @@ running once the system is up. tp720= [HW,PS2] trix= [HW,OSS] MediaTrix AudioTrix Pro - Format: ,,,,,,,, - + Format: + ,,,,,,,, + tsdev.xres= [TS] Horizontal screen resolution. tsdev.yres= [TS] Vertical screen resolution. - turbografx.map[2|3]= - [HW,JOY] TurboGraFX parallel port interface - Format: ,,,,,,, + 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 @@ -1449,21 +1643,20 @@ running once the system is up. uart6850= [HW,OSS] Format: , - usb-handoff [HW] Enable early USB BIOS -> OS handoff - usbhid.mousepoll= [USBHID] The interval which mice are to be polled at. - + 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. + 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 + vmalloc=nn[KMG] [KNL,BOOT] Forces the vmalloc area to have an exact size of . 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 @@ -1471,11 +1664,11 @@ running once the system is up. vmhalt= [KNL,S390] - vmpoff= [KNL,S390] - + vmpoff= [KNL,S390] + waveartist= [HW,OSS] Format: ,,, - + wd33c93= [HW,SCSI] See header of drivers/scsi/wd33c93.c. @@ -1489,21 +1682,14 @@ running once the system is up. xd_geo= See header of drivers/block/xd.c. xirc2ps_cs= [NET,PCMCIA] - Format: ,,,,,[,[,[,]]] - - + Format: + ,,,,,[,[,[,]]] -Changelog: + norandmaps Don't use address space randomization + Equivalent to echo 0 > /proc/sys/kernel/randomize_va_space - 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: