| July 2000 Kernel Parameters v2.4.0 |
| ~~~~~~~~~~~~~~~~~ |
| |
| The following is a consolidated list of the kernel parameters as implemented |
| 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. |
| 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. |
| 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. |
| MCA MCA bus support is enabled. |
| MDA MDA console support is enabled. |
| MOUSE Appropriate mouse support is enabled. |
| NET Appropriate network support is enabled. |
| NFS Appropriate NFS 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. |
| PPT Parallel port support is enabled. |
| PS2 Appropriate PS/2 support is enabled. |
| RAM RAM disk support is enabled. |
| SCSI Appropriate SCSI support is enabled. |
| SERIAL Serial support is enabled. |
| SMP The kernel is an SMP kernel. |
| SOUND Appropriate sound system support is enabled. |
| V4L Video For Linux support is enabled. |
| VGA The VGA console has been enabled. |
| VT Virtual terminal 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. |
| |
| 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. |
| |
| acpi= [HW,ACPI] Advanced Configuration and Power Interface |
| force Enable ACPI if default was off |
| off Disable ACPI if default was on |
| noirq Do not use ACPI for IRQ routing (see pci=noacpi) |
| ht Limit ACPI to boot-time LAPIC enumeration for HT, |
| disabling the run-time AML interpreter. |
| strict Be less tolerant of platforms that are not |
| strictly ACPI specification compliant. |
| |
| acpi_sci= [HW,ACPI] ACPI System Control Interrupt trigger mode |
| Format: { level | edge | high | low } |
| |
| acpi_irq_balance ACPI will balance active IRQs |
| acpi_irq_nobalance ACPI will not move active IRQs |
| acpi_irq_pci= If irq_balance, Clear listed IRQs for use by PCI |
| acpi_irq_isa= If irq_balance, Mark listed IRQs used by ISA |
| |
| acpi_osi= [HW,ACPI] empty param disables _OSI |
| |
| acpi_serialize [HW,ACPI] force serialization of AML methods |
| |
| ad1816= [HW,SOUND] |
| |
| ad1848= [HW,SOUND] |
| |
| adb_buttons= [HW,MOUSE] |
| |
| adlib= [HW,SOUND] |
| |
| advansys= [HW,SCSI] |
| |
| aedsp16= [HW,SOUND] |
| |
| aha152x= [HW,SCSI] |
| |
| aha1542= [HW,SCSI] |
| |
| aic7xxx= [HW,SCSI] |
| |
| AM53C974= [HW,SCSI] |
| |
| amijoy= [HW,JOY] Amiga joystick support |
| |
| apm= [APM] Advanced Power Management. |
| |
| applicom= [HW] |
| |
| arcrimi= [HW,NET] |
| |
| ataflop= [HW,M68k] |
| |
| atarimouse= [HW,MOUSE] Atari Mouse. |
| |
| atascsi= [HW,SCSI] Atari SCSI. |
| |
| awe= [HW,SOUND] |
| |
| aztcd= [HW,CD] Aztec CD driver. |
| |
| baycom_epp= [HW,AX25] |
| |
| baycom_par= [HW,AX25] BayCom Parallel Port AX.25 Modem. |
| |
| baycom_ser_fdx= [HW,AX25] BayCom Serial Port AX.25 Modem in Full |
| Duplex Mode. |
| |
| baycom_ser_hdx= [HW,AX25] BayCom Serial Port AX.25 Modem in Half |
| Duplex Mode. |
| |
| bmouse= [HW,MOUSE,PS2] Bus mouse. |
| |
| bttv.card= [HW,V4L] bttv (bt848 + bt878 based grabber cards), most |
| bttv.radio= 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] |
| |
| cdu31a= [HW,CD] |
| |
| chandev= [HW,NET] |
| |
| cm206= [HW,CD] |
| |
| com20020= [HW,NET] |
| |
| com90io= [HW,NET] |
| |
| com90xx= [HW,NET] |
| |
| condev= [HW] |
| |
| console= [KNL] output console + comm spec (speed, control, |
| parity). |
| |
| cpia_pp= [HW,PPT] |
| |
| cs4232= [HW,SOUND] |
| |
| cs89x0_dma= [HW,NET] |
| |
| ctc= [HW,NET] |
| |
| cyclades= [HW,SERIAL] Cyclades multi-serial port adapter. |
| |
| dasd= [HW,NET] |
| |
| db9= [HW,JOY] |
| |
| db9_2= [HW,JOY] |
| |
| db9_3= [HW,JOY] |
| |
| debug [KNL] Enable kernel debugging (events log level). |
| |
| decnet= [HW,NET] |
| |
| devfs= [DEVFS] |
| |
| digi= [HW,SERIAL] io parameters + enable/disable command. |
| |
| digiepca= [HW,SERIAL] |
| |
| dmascc= [HW,AX25,SERIAL] AX.25 Z80SCC driver with DMA |
| support available. |
| |
| dmasound= [HW,SOUND] (sound subsystem buffers). |
| |
| dtc3181e= [HW,SCSI] |
| |
| eata= [HW,SCSI] |
| |
| eda= [HW,PS2] |
| |
| edb= [HW,PS2] |
| |
| eicon= [HW,ISDN] |
| |
| es1370= [HW,SOUND] |
| |
| es1371= [HW,SOUND] |
| |
| ether= [HW,NET] Ethernet cards parameters (irq, |
| base_io_addr, mem_start, mem_end, name. |
| (mem_start is often overloaded to mean something |
| different and driver-specific). |
| |
| fd_mcs= [HW,SCSI] |
| |
| fdomain= [HW,SCSI] |
| |
| floppy= [HW] |
| |
| ftape= [HW] Floppy Tape subsystem debugging options. |
| |
| gamma= [HW,DRM] |
| |
| gc= [HW,JOY] |
| |
| gc_2= [HW,JOY] |
| |
| gc_3= [HW,JOY] |
| |
| gdth= [HW,SCSI] |
| |
| gpt [EFI] Forces disk with valid GPT signature but |
| invalid Protective MBR to be treated as GPT. |
| |
| gscd= [HW,CD] |
| |
| gus= [HW,SOUND] |
| |
| gvp11= [HW,SCSI] |
| |
| hd= [EIDE] (E)IDE hard drive subsystem geometry |
| (Cyl/heads/sectors) or tune parameters. |
| |
| hfmodem= [HW,AX25] |
| |
| hisax= [HW,ISDN] |
| |
| i810= [HW,DRM] |
| |
| ibmmcascsi= [HW,MCA,SCSI] IBM MicroChannel SCSI adapter. |
| |
| icn= [HW,ISDN] |
| |
| ide?= [HW] (E)IDE subsystem : config (iomem/irq), tuning or |
| debugging (serialize,reset,no{dma,tune,probe}) or |
| chipset specific parameters. |
| |
| idebus= [HW] (E)IDE subsystem : VLB/PCI bus speed. |
| |
| idle= [HW] |
| |
| in2000= [HW,SCSI] |
| |
| init= [KNL] |
| |
| initrd= [BOOT] Specify the location of the initial ramdisk. |
| |
| ip= [IP_PNP] |
| |
| isapnp= [ISAPNP] Specify RDP, reset, pci_scan and verbosity. |
| |
| isapnp_reserve_irq= [ISAPNP] Exclude IRQs for the autoconfiguration. |
| |
| isapnp_reserve_dma= [ISAPNP] Exclude DMAs for the autoconfiguration. |
| |
| isapnp_reserve_io= [ISAPNP] Exclude I/O ports for the autoconfiguration. |
| Ranges are in pairs (I/O port base and size). |
| |
| isapnp_reserve_mem= [ISAPNP] Exclude memory regions for the autoconfiguration. |
| Ranges are in pairs (memory base and size). |
| |
| isp16= [HW,CD] |
| |
| iucv= [HW,NET] |
| |
| js= [HW,JOY] Analog joystick |
| |
| kbd-reset [VT] |
| |
| keepinitrd [HW, ARM] |
| |
| lapic [IA-32,APIC] Enable the local APIC even if BIOS disabled it. |
| |
| load_ramdisk= [RAM] List of ramdisks to load from floppy. |
| |
| lockd.udpport= [NFS] |
| |
| lockd.tcpport= [NFS] |
| |
| logi_busmouse= [HW, MOUSE] |
| |
| 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. |
| |
| ltpc= [HW] |
| |
| mac5380= [HW,SCSI] |
| |
| mac53c9x= [HW,SCSI] |
| |
| mad16= [HW,SOUND] |
| |
| maui= [HW,SOUND] |
| |
| max_loop=[0-255] [LOOP] Set the maximum number of loopback devices |
| that can be mounted. |
| |
| maxcpus= [SMP] States the maximum number of processors that |
| an SMP kernel should make use of. |
| |
| max_scsi_luns= [SCSI] |
| |
| mca-pentium [BUGS=IA-32] |
| |
| mcd= [HW,CD] |
| |
| mcdx= [HW,CD] |
| |
| md= [HW] RAID subsystems devices and level. |
| |
| mdisk= [HW] |
| |
| mdacon= [MDA] |
| |
| megaraid= [HW,SCSI] |
| |
| mem=exactmap [KNL,BOOT,IA-32] enable setting of an exact |
| e820 memory map, as specified by the user. |
| Such mem=exactmap lines can be constructed |
| based on BIOS output or other requirements. |
| |
| mem=nn[KMG] [KNL,BOOT] force use of a specific amount of |
| memory; to be used when the kernel is not able |
| to see the whole system memory or for test. |
| |
| mem=nn[KMG]@ss[KMG] |
| [KNL,BOOT] Force usage of a specific region of memory |
| Region of memory to be used, from ss to ss+nn. |
| |
| mem=nn[KMG]#ss[KMG] |
| [KNL,BOOT,ACPI] Mark specific memory as ACPI data. |
| Region of memory to be used, from ss to ss+nn. |
| |
| mem=nn[KMG]$ss[KMG] |
| [KNL,BOOT,ACPI] Mark specific memory as reserved. |
| Region of memory to be used, from ss to ss+nn. |
| |
| memfrac= [KNL] |
| |
| mga= [HW,DRM] |
| |
| mpu401= [HW,SOUND] |
| |
| msmouse= [HW,MOUSE] Microsoft Mouse. |
| |
| ncr5380= [HW,SCSI] |
| |
| ncr53c400= [HW,SCSI] |
| |
| ncr53c400a= [HW,SCSI] |
| |
| ncr53c406a= [HW,SCSI] |
| |
| ncr53c8xx= [HW,SCSI] |
| |
| netdev= [NET] Ethernet cards parameters (irq, |
| base_io_addr, mem_start, mem_end, name. |
| (mem_start is often overloaded to mean something |
| different and driver-specific). |
| (cf: ether=) |
| |
| nfsaddrs= [NFS] |
| |
| nfsroot= [NFS] nfs root filesystem for disk-less boxes. |
| |
| 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. |
| |
| nohlt [BUGS=ARM] |
| |
| no-hlt [BUGS=IA-32] Tells the kernel that the hlt |
| instruction doesn't work correctly and not to |
| use it. |
| |
| noisapnp [ISAPNP] Disables ISA PnP code. |
| |
| noinitrd [RAM] Tells the kernel not to load any configured |
| initial RAM disk. |
| |
| nointroute [IA-64] |
| |
| nokeyb [HW] Skip console keyboard initialization for systems |
| without a console keyboard, removable keyboard, or |
| bladecenters with a USB console keyboard switch, etc. |
| |
| nolapic [IA-32,APIC] Do not enable or use the local APIC. |
| |
| no-scroll [VGA] |
| |
| 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 |
| |
| nowb [ARM] |
| |
| opl3= [HW,SOUND] |
| |
| opl3sa= [HW,SOUND] |
| |
| opl3sa2= [HW,SOUND] |
| |
| optcd= [HW,CD] |
| |
| panic= [KNL] kernel behaviour on panic. |
| |
| 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,SOUND] |
| |
| pas16= [HW,SCSI] |
| |
| pcbit= [HW,ISDN] |
| |
| pcd. [PARIDE] |
| |
| 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. |
| |
| pd. [PARIDE] |
| |
| pf. [PARIDE] |
| |
| pg. [PARIDE] |
| |
| pirq= [SMP,APIC] mp-table. |
| |
| plip= [PPT,NET] Parallel port network link. |
| |
| 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. |
| |
| pss= [HW,SOUND] |
| |
| pt. [PARIDE] |
| |
| quiet= [KNL] Disable log messages. |
| |
| r128= [HW,DRM] |
| |
| raid= [HW,RAID] |
| |
| ramdisk= [RAM] Sizes of RAM disks in kilobytes [deprecated]. |
| |
| ramdisk_blocksize= |
| [RAM] |
| |
| ramdisk_size= [RAM] New name for the ramdisk parameter. |
| |
| ramdisk_start= [RAM] Starting block of RAM disk image (so you can |
| place it after the kernel image on a boot floppy). |
| |
| reboot= [BUGS=IA-32] |
| |
| reserve= [KNL,BUGS] force the kernel to ignore some iomem area. |
| |
| riscom8= [HW,SERIAL] |
| |
| 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. |
| |
| sb= [HW,SOUND] |
| |
| sbpcd= [HW,CD] Soundblaster CD adapter. |
| |
| scsi_logging= [SCSI] |
| |
| scsihosts= [SCSI] |
| |
| sg_def_reserved_size= |
| [SCSI] |
| |
| sgalaxy= [HW,SOUND] |
| |
| sim710= [SCSI,HW] |
| |
| sjcd= [HW,CD] |
| |
| smart2= [HW] |
| |
| sonicvibes= [HW,SOUND] |
| |
| sonycd535= [HW,CD] |
| |
| sound= [SOUND] |
| |
| soundmodem= [HW,AX25,SOUND] Use sound card as packet radio modem. |
| |
| specialix= [HW,SERIAL] Specialix multi-serial port adapter. |
| |
| sscape= [HW,SOUND] |
| |
| st= [HW,SCSI] SCSI tape parameters (buffers, etc.). |
| |
| st0x= [HW,SCSI] |
| |
| stram_swap= [HW] |
| |
| swiotlb= [IA-64] Number of I/O TLB slabs. |
| |
| switches= [HW, M68K] |
| |
| sym53c416= [HW,SCSI] |
| |
| sym53c8xx= [HW,SCSI] |
| |
| t128= [HW,SCSI] |
| |
| tdfx= [HW,DRM] |
| |
| tgfx= [HW,JOY] |
| |
| tgfx_2= [HW,JOY] |
| |
| tgfx_3= [HW,JOY] |
| |
| tmc8xx= [HW,SCSI] |
| |
| tmscsim= [HW,SCSI] |
| |
| tp720= [HW,PS2] |
| |
| trix= [HW,SOUND] |
| |
| u14-34f= [HW,SCSI] |
| |
| uart401= [HW,SOUND] |
| |
| uart6850= [HW,SOUND] |
| |
| usbfix [BUGS=IA-64] |
| |
| video= [FB] frame buffer configuration. |
| |
| vga= [BOOT] on ix386, select a particular video mode |
| (use vga=ask for menu). This is actually a |
| boot loader parameter; the value is passed to |
| the kernel using a special protocol. See |
| linux/Documentation/i386/boot.txt for information. |
| |
| vmhalt= [KNL,S390] |
| |
| vmpoff= [KNL,S390] |
| |
| waveartist= [HW,SOUND] |
| |
| wd33c93= [HW,SCSI] |
| |
| wd7000= [HW,SCSI] |
| |
| wdt= [HW] |
| |
| xd= [HW,XT] Original XT pre-IDE (RLL encoded) disks. |
| |
| xd_geo= [HW,XT] |