err.no Git - linux-2.6/blob - Documentation/kernel-parameters.txt

   1 February 2003             Kernel Parameters                     v2.5.59
   2                           ~~~~~~~~~~~~~~~~~
   3
   4 The following is a consolidated list of the kernel parameters as implemented
   5 (mostly) by the __setup() macro and sorted into English Dictionary order
   6 (defined as ignoring all punctuation and sorting digits before letters in a
   7 case insensitive manner), and with descriptions where known.
   8
   9 Module parameters for loadable modules are specified only as the
  10 parameter name with optional '=' and value as appropriate, such as:
  11
  12         modprobe usbcore blinkenlights=1
  13
  14 Module parameters for modules that are built into the kernel image
  15 are specified on the kernel command line with the module name plus
  16 '.' plus parameter name, with '=' and value if appropriate, such as:
  17
  18         usbcore.blinkenlights=1
  19
  20 The text in square brackets at the beginning of the description state the
  21 restrictions on the kernel for the said kernel parameter to be valid. The
  22 restrictions referred to are that the relevant option is valid if:
  23
  24         ACPI    ACPI support is enabled.
  25         ALSA    ALSA sound support is enabled.
  26         APIC    APIC support is enabled.
  27         APM     Advanced Power Management support is enabled.
  28         AX25    Appropriate AX.25 support is enabled.
  29         CD      Appropriate CD support is enabled.
  30         DEVFS   devfs support is enabled.
  31         DRM     Direct Rendering Management support is enabled.
  32         EDD     BIOS Enhanced Disk Drive Services (EDD) is enabled
  33         EFI     EFI Partitioning (GPT) is enabled
  34         EIDE    EIDE/ATAPI support is enabled.
  35         FB      The frame buffer device is enabled.
  36         HW      Appropriate hardware is enabled.
  37         IA-32   IA-32 aka i386 architecture is enabled.
  38         IA-64   IA-64 architecture is enabled.
  39         IOSCHED More than one I/O scheduler is enabled.
  40         IP_PNP  IP DCHP, BOOTP, or RARP is enabled.
  41         ISAPNP  ISA PnP code is enabled.
  42         ISDN    Appropriate ISDN support is enabled.
  43         JOY     Appropriate joystick support is enabled.
  44         LP      Printer support is enabled.
  45         LOOP    Loopback device support is enabled.
  46         M68k    M68k architecture is enabled.
  47                         These options have more detailed description inside of
  48                         Documentation/m68k/kernel-options.txt.
  49         MCA     MCA bus support is enabled.
  50         MDA     MDA console support is enabled.
  51         MOUSE   Appropriate mouse support is enabled.
  52         MTD     MTD support is enabled.
  53         NET     Appropriate network support is enabled.
  54         NUMA    NUMA support is enabled.
  55         NFS     Appropriate NFS support is enabled.
  56         OSS     OSS sound support is enabled.
  57         PARIDE  The ParIDE subsystem is enabled.
  58         PARISC  The PA-RISC architecture is enabled.
  59         PCI     PCI bus support is enabled.
  60         PCMCIA  The PCMCIA subsystem is enabled.
  61         PNP     Plug & Play support is enabled.
  62         PPC     PowerPC architecture is enabled.
  63         PPT     Parallel port support is enabled.
  64         PS2     Appropriate PS/2 support is enabled.
  65         RAM     RAM disk support is enabled.
  66         S390    S390 architecture is enabled.
  67         SCSI    Appropriate SCSI support is enabled.
  68                         A lot of drivers has their options described inside of
  69                         Documentation/scsi/.
  70         SELINUX SELinux support is enabled.
  71         SERIAL  Serial support is enabled.
  72         SMP     The kernel is an SMP kernel.
  73         SPARC   Sparc architecture is enabled.
  74         SWSUSP  Software suspension is enabled.
  75         TS      Appropriate touchscreen support is enabled.
  76         USB     USB support is enabled.
  77         USBHID  USB Human Interface Device support is enabled.
  78         V4L     Video For Linux support is enabled.
  79         VGA     The VGA console has been enabled.
  80         VT      Virtual terminal support is enabled.
  81         WDT     Watchdog support is enabled.
  82         XT      IBM PC/XT MFM hard disk support is enabled.
  83         X86-64  X86-64 architecture is enabled.
  84                         More X86-64 boot options can be found in
  85                         Documentation/x86_64/boot-options.txt .
  86
  87 In addition, the following text indicates that the option:
  88
  89         BUGS=   Relates to possible processor bugs on the said processor.
  90         KNL     Is a kernel start-up parameter.
  91         BOOT    Is a boot loader parameter.
  92
  93 Parameters denoted with BOOT are actually interpreted by the boot
  94 loader, and have no meaning to the kernel directly.
  95 Do not modify the syntax of boot loader parameters without extreme
  96 need or coordination with <Documentation/i386/boot.txt>.
  97
  98 Note that ALL kernel parameters listed below are CASE SENSITIVE, and that
  99 a trailing = on the name of any parameter states that that parameter will
 100 be entered as an environment variable, whereas its absence indicates that
 101 it will appear as a kernel argument readable via /proc/cmdline by programs
 102 running once the system is up.
 103
 104         53c7xx=         [HW,SCSI] Amiga SCSI controllers
 105                         See header of drivers/scsi/53c7xx.c.
 106                         See also Documentation/scsi/ncr53c7xx.txt.
 107
 108         acpi=           [HW,ACPI] Advanced Configuration and Power Interface
 109                         Format: { force | off | ht | strict }
 110                         force -- enable ACPI if default was off
 111                         off -- disable ACPI if default was on
 112                         noirq -- do not use ACPI for IRQ routing
 113                         ht -- run only enough ACPI to enable Hyper Threading
 114                         strict --  Be less tolerant of platforms that are not
 115                                 strictly ACPI specification compliant.
 116
 117                         See also Documentation/pm.txt, pci=noacpi
 118
 119         acpi_sleep=     [HW,ACPI] Sleep options
 120                         Format: { s3_bios, s3_mode }
 121                         See Documentation/power/video.txt
 122
 123         acpi_sci=       [HW,ACPI] ACPI System Control Interrupt trigger mode
 124                         Format: { level | edge |  high | low }
 125
 126         acpi_irq_balance        [HW,ACPI] ACPI will balance active IRQs
 127                                 default in APIC mode
 128
 129         acpi_irq_nobalance      [HW,ACPI] ACPI will not move active IRQs (default)
 130                                 default in PIC mode
 131
 132         acpi_irq_pci=   [HW,ACPI] If irq_balance, Clear listed IRQs for use by PCI
 133                         Format: <irq>,<irq>...
 134
 135         acpi_irq_isa=   [HW,ACPI] If irq_balance, Mark listed IRQs used by ISA
 136                         Format: <irq>,<irq>...
 137
 138         acpi_osi=       [HW,ACPI] empty param disables _OSI
 139
 140         acpi_serialize  [HW,ACPI] force serialization of AML methods
 141
 142         acpi_skip_timer_override [HW,ACPI]
 143                         Recognize and ignore IRQ0/pin2 Interrupt Override.
 144                         For broken nForce2 BIOS resulting in XT-PIC timer.
 145
 146         acpi_dbg_layer= [HW,ACPI]
 147                         Format: <int>
 148                         Each bit of the <int> indicates an acpi debug layer,
 149                         1: enable, 0: disable. It is useful for boot time
 150                         debugging. After system has booted up, it can be set
 151                         via /proc/acpi/debug_layer.
 152
 153         acpi_dbg_level= [HW,ACPI]
 154                         Format: <int>
 155                         Each bit of the <int> indicates an acpi debug level,
 156                         1: enable, 0: disable. It is useful for boot time
 157                         debugging. After system has booted up, it can be set
 158                         via /proc/acpi/debug_level.
 159
 160         acpi_fake_ecdt  [HW,ACPI] Workaround failure due to BIOS lacking ECDT
 161
 162         ad1816=         [HW,OSS]
 163                         Format: <io>,<irq>,<dma>,<dma2>
 164                         See also Documentation/sound/oss/AD1816.
 165
 166         ad1848=         [HW,OSS]
 167                         Format: <io>,<irq>,<dma>,<dma2>,<type>
 168
 169         adlib=          [HW,OSS]
 170                         Format: <io>
 171
 172         advansys=       [HW,SCSI]
 173                         See header of drivers/scsi/advansys.c.
 174
 175         advwdt=         [HW,WDT] Advantech WDT
 176                         Format: <iostart>,<iostop>
 177
 178         aedsp16=        [HW,OSS] Audio Excel DSP 16
 179                         Format: <io>,<irq>,<dma>,<mss_io>,<mpu_io>,<mpu_irq>
 180                         See also header of sound/oss/aedsp16.c.
 181
 182         aha152x=        [HW,SCSI]
 183                         See Documentation/scsi/aha152x.txt.
 184
 185         aha1542=        [HW,SCSI]
 186                         Format: <portbase>[,<buson>,<busoff>[,<dmaspeed>]]
 187
 188         aic7xxx=        [HW,SCSI]
 189                         See Documentation/scsi/aic7xxx.txt.
 190
 191         aic79xx=        [HW,SCSI]
 192                         See Documentation/scsi/aic79xx.txt.
 193
 194         AM53C974=       [HW,SCSI]
 195                         Format: <host-scsi-id>,<target-scsi-id>,<max-rate>,<max-offset>
 196                         See also header of drivers/scsi/AM53C974.c.
 197
 198         amijoy.map=     [HW,JOY] Amiga joystick support
 199                         Map of devices attached to JOY0DAT and JOY1DAT
 200                         Format: <a>,<b>
 201                         See also Documentation/kernel/input/joystick.txt
 202
 203         analog.map=     [HW,JOY] Analog joystick and gamepad support
 204                         Specifies type or capabilities of an analog joystick
 205                         connected to one of 16 gameports
 206                         Format: <type1>,<type2>,..<type16>
 207
 208         apc=            [HW,SPARC] Power management functions (SPARCstation-4/5 + deriv.)
 209                         Format: noidle
 210                         Disable APC CPU standby support. SPARCstation-Fox does
 211                         not play well with APC CPU idle - disable it if you have
 212                         APC and your system crashes randomly.
 213
 214         apic=           [APIC,i386] Change the output verbosity  whilst booting
 215                         Format: { quiet (default) | verbose | debug }
 216                         Change the amount of debugging information output
 217                         when initialising the APIC and IO-APIC components.
 218
 219         apm=            [APM] Advanced Power Management
 220                         See header of arch/i386/kernel/apm.c.
 221
 222         applicom=       [HW]
 223                         Format: <mem>,<irq>
 224
 225         arcrimi=        [HW,NET] ARCnet - "RIM I" (entirely mem-mapped) cards
 226                         Format: <io>,<irq>,<nodeID>
 227
 228         ataflop=        [HW,M68k]
 229
 230         atarimouse=     [HW,MOUSE] Atari Mouse
 231
 232         atascsi=        [HW,SCSI] Atari SCSI
 233
 234         atkbd.extra=    [HW] Enable extra LEDs and keys on IBM RapidAccess,
 235                         EzKey and similar keyboards
 236
 237         atkbd.reset=    [HW] Reset keyboard during initialization
 238
 239         atkbd.set=      [HW] Select keyboard code set
 240                         Format: <int> (2 = AT (default) 3 = PS/2)
 241
 242         atkbd.scroll=   [HW] Enable scroll wheel on MS Office and similar
 243                         keyboards
 244
 245         atkbd.softraw=  [HW] Choose between synthetic and real raw mode
 246                         Format: <bool> (0 = real, 1 = synthetic (default))
 247
 248         atkbd.softrepeat=
 249                         [HW] Use software keyboard repeat
 250
 251         autotest        [IA64]
 252
 253         awe=            [HW,OSS] AWE32/SB32/AWE64 wave table synth
 254                         Format: <io>,<memsize>,<isapnp>
 255
 256         aztcd=          [HW,CD] Aztech CD268 CDROM driver
 257                         Format: <io>,0x79 (?)
 258
 259         baycom_epp=     [HW,AX25]
 260                         Format: <io>,<mode>
 261
 262         baycom_par=     [HW,AX25] BayCom Parallel Port AX.25 Modem
 263                         Format: <io>,<mode>
 264                         See header of drivers/net/hamradio/baycom_par.c.
 265
 266         baycom_ser_fdx= [HW,AX25] BayCom Serial Port AX.25 Modem (Full Duplex Mode)
 267                         Format: <io>,<irq>,<mode>[,<baud>]
 268                         See header of drivers/net/hamradio/baycom_ser_fdx.c.
 269
 270         baycom_ser_hdx= [HW,AX25] BayCom Serial Port AX.25 Modem (Half Duplex Mode)
 271                         Format: <io>,<irq>,<mode>
 272                         See header of drivers/net/hamradio/baycom_ser_hdx.c.
 273
 274         blkmtd_device=  [HW,MTD]
 275         blkmtd_erasesz=
 276         blkmtd_ro=
 277         blkmtd_bs=
 278         blkmtd_count=
 279
 280         bttv.card=      [HW,V4L] bttv (bt848 + bt878 based grabber cards)
 281         bttv.radio=     Most important insmod options are available as kernel args too.
 282         bttv.pll=       See Documentation/video4linux/bttv/Insmod-options
 283         bttv.tuner=     and Documentation/video4linux/bttv/CARDLIST
 284
 285         BusLogic=       [HW,SCSI]
 286                         See drivers/scsi/BusLogic.c, comment before function
 287                         BusLogic_ParseDriverOptions().
 288
 289         c101=           [NET] Moxa C101 synchronous serial card
 290
 291         cachesize=      [BUGS=IA-32] Override level 2 CPU cache size detection.
 292                         Sometimes CPU hardware bugs make them report the cache
 293                         size incorrectly. The kernel will attempt work arounds
 294                         to fix known problems, but for some CPUs it is not
 295                         possible to determine what the correct size should be.
 296                         This option provides an override for these situations.
 297
 298         cdu31a=         [HW,CD]
 299                         Format: <io>,<irq>[,PAS]
 300                         See header of drivers/cdrom/cdu31a.c.
 301
 302         chandev=        [HW,NET] Generic channel device initialisation
 303
 304         checkreqprot    [SELINUX] Set initial checkreqprot flag value.
 305                         Format: { "0" | "1" }
 306                         See security/selinux/Kconfig help text.
 307                         0 -- check protection applied by kernel (includes any implied execute protection).
 308                         1 -- check protection requested by application.
 309                         Default value is set via a kernel config option.
 310                         Value can be changed at runtime via /selinux/checkreqprot.
 311
 312         clock=          [BUGS=IA-32, HW] gettimeofday timesource override.
 313                         Forces specified timesource (if avaliable) to be used
 314                         when calculating gettimeofday(). If specicified timesource
 315                         is not avalible, it defaults to PIT.
 316                         Format: { pit | tsc | cyclone | pmtmr }
 317
 318         hpet=           [IA-32,HPET] option to disable HPET and use PIT.
 319                         Format: disable
 320
 321         cm206=          [HW,CD]
 322                         Format: { auto | [<io>,][<irq>] }
 323
 324         com20020=       [HW,NET] ARCnet - COM20020 chipset
 325                         Format: <io>[,<irq>[,<nodeID>[,<backplane>[,<ckp>[,<timeout>]]]]]
 326
 327         com90io=        [HW,NET] ARCnet - COM90xx chipset (IO-mapped buffers)
 328                         Format: <io>[,<irq>]
 329
 330         com90xx=        [HW,NET] ARCnet - COM90xx chipset (memory-mapped buffers)
 331                         Format: <io>[,<irq>[,<memstart>]]
 332
 333         condev=         [HW,S390] console device
 334         conmode=
 335
 336         console=        [KNL] Output console device and options.
 337
 338                 tty<n>  Use the virtual console device <n>.
 339
 340                 ttyS<n>[,options]
 341                         Use the specified serial port.  The options are of
 342                         the form "bbbbpn", where "bbbb" is the baud rate,
 343                         "p" is parity ("n", "o", or "e"), and "n" is bits.
 344                         Default is "9600n8".
 345
 346                         See also Documentation/serial-console.txt.
 347
 348                 uart,io,<addr>[,options]
 349                 uart,mmio,<addr>[,options]
 350                         Start an early, polled-mode console on the 8250/16550
 351                         UART at the specified I/O port or MMIO address,
 352                         switching to the matching ttyS device later.  The
 353                         options are the same as for ttyS, above.
 354
 355         cpcihp_generic= [HW,PCI] Generic port I/O CompactPCI driver
 356                         Format: <first_slot>,<last_slot>,<port>,<enum_bit>[,<debug>]
 357
 358         cpia_pp=        [HW,PPT]
 359                         Format: { parport<nr> | auto | none }
 360
 361         crashkernel=nn[KMG]@ss[KMG]
 362                         [KNL] Reserve a chunk of physical memory to
 363                         hold a kernel to switch to with kexec on panic.
 364
 365         cs4232=         [HW,OSS]
 366                         Format: <io>,<irq>,<dma>,<dma2>,<mpuio>,<mpuirq>
 367
 368         cs89x0_dma=     [HW,NET]
 369                         Format: <dma>
 370
 371         cs89x0_media=   [HW,NET]
 372                         Format: { rj45 | aui | bnc }
 373
 374         cyclades=       [HW,SERIAL] Cyclades multi-serial port adapter.
 375
 376         dasd=           [HW,NET]
 377                         See header of drivers/s390/block/dasd_devmap.c.
 378
 379         db9.dev[2|3]=   [HW,JOY] Multisystem joystick support via parallel port
 380                         (one device per port)
 381                         Format: <port#>,<type>
 382                         See also Documentation/input/joystick-parport.txt
 383
 384         debug           [KNL] Enable kernel debugging (events log level).
 385
 386         decnet=         [HW,NET]
 387                         Format: <area>[,<node>]
 388                         See also Documentation/networking/decnet.txt.
 389
 390         devfs=          [DEVFS]
 391                         See Documentation/filesystems/devfs/boot-options.
 392
 393         dhash_entries=  [KNL]
 394                         Set number of hash buckets for dentry cache.
 395
 396         digi=           [HW,SERIAL]
 397                         IO parameters + enable/disable command.
 398
 399         digiepca=       [HW,SERIAL]
 400                         See drivers/char/README.epca and
 401                         Documentation/digiepca.txt.
 402
 403         dmascc=         [HW,AX25,SERIAL] AX.25 Z80SCC driver with DMA
 404                         support available.
 405                         Format: <io_dev0>[,<io_dev1>[,..<io_dev32>]]
 406
 407         dmasound=       [HW,OSS] Sound subsystem buffers
 408
 409         dscc4.setup=    [NET]
 410
 411         dtc3181e=       [HW,SCSI]
 412
 413         earlyprintk=    [IA-32, X86-64]
 414                         earlyprintk=vga
 415                         earlyprintk=serial[,ttySn[,baudrate]]
 416
 417                         Append ,keep to not disable it when the real console
 418                         takes over.
 419
 420                         Only vga or serial at a time, not both.
 421
 422                         Currently only ttyS0 and ttyS1 are supported.
 423
 424                         Interaction with the standard serial driver is not
 425                         very good.
 426
 427                         The VGA output is eventually overwritten by the real
 428                         console.
 429
 430         eata=           [HW,SCSI]
 431
 432         eda=            [HW,PS2]
 433
 434         edb=            [HW,PS2]
 435
 436         edd=            [EDD]
 437                         Format: {"of[f]" | "sk[ipmbr]"}
 438                         See comment in arch/i386/boot/edd.S
 439
 440         edd             [EDD]
 441                         Format: {"of[f]" | "sk[ipmbr]"}
 442                         See comment in arch/i386/boot/edd.S
 443
 444         eicon=          [HW,ISDN]
 445                         Format: <id>,<membase>,<irq>
 446
 447         eisa_irq_edge=  [PARISC,HW]
 448                         See header of drivers/parisc/eisa.c.
 449
 450         elanfreq=       [IA-32]
 451                         See comment before function elanfreq_setup() in
 452                         arch/i386/kernel/cpu/cpufreq/elanfreq.c.
 453
 454         elevator=       [IOSCHED]
 455                         Format: {"as"|"cfq"|"deadline"|"noop"}
 456                         See Documentation/block/as-iosched.txt
 457                         and Documentation/block/deadline-iosched.txt for details.
 458         elfcorehdr=     [IA-32]
 459                         Specifies physical address of start of kernel core image
 460                         elf header.
 461                         See Documentation/kdump.txt for details.
 462
 463         enforcing       [SELINUX] Set initial enforcing status.
 464                         Format: {"0" | "1"}
 465                         See security/selinux/Kconfig help text.
 466                         0 -- permissive (log only, no denials).
 467                         1 -- enforcing (deny and log).
 468                         Default value is 0.
 469                         Value can be changed at runtime via /selinux/enforce.
 470
 471         es1370=         [HW,OSS]
 472                         Format: <lineout>[,<micbias>]
 473                         See also header of sound/oss/es1370.c.
 474
 475         es1371=         [HW,OSS]
 476                         Format: <spdif>,[<nomix>,[<amplifier>]]
 477                         See also header of sound/oss/es1371.c.
 478
 479         ether=          [HW,NET] Ethernet cards parameters
 480                         This option is obsoleted by the "netdev=" option, which
 481                         has equivalent usage. See its documentation for details.
 482
 483         eurwdt=         [HW,WDT] Eurotech CPU-1220/1410 onboard watchdog.
 484                         Format: <io>[,<irq>]
 485
 486         fd_mcs=         [HW,SCSI]
 487                         See header of drivers/scsi/fd_mcs.c.
 488
 489         fdomain=        [HW,SCSI]
 490                         See header of drivers/scsi/fdomain.c.
 491
 492         floppy=         [HW]
 493                         See Documentation/floppy.txt.
 494
 495         ftape=          [HW] Floppy Tape subsystem debugging options.
 496                         See Documentation/ftape.txt.
 497
 498         gamecon.map[2|3]=
 499                         [HW,JOY] Multisystem joystick and NES/SNES/PSX pad
 500                         support via parallel port (up to 5 devices per port)
 501                         Format: <port#>,<pad1>,<pad2>,<pad3>,<pad4>,<pad5>
 502                         See also Documentation/input/joystick-parport.txt
 503
 504         gamma=          [HW,DRM]
 505
 506         gdth=           [HW,SCSI]
 507                         See header of drivers/scsi/gdth.c.
 508
 509         gpt             [EFI] Forces disk with valid GPT signature but
 510                         invalid Protective MBR to be treated as GPT.
 511
 512         gscd=           [HW,CD]
 513                         Format: <io>
 514
 515         gt96100eth=     [NET] MIPS GT96100 Advanced Communication Controller
 516
 517         gus=            [HW,OSS]
 518                         Format: <io>,<irq>,<dma>,<dma16>
 519
 520         gvp11=          [HW,SCSI]
 521
 522         hashdist=       [KNL,NUMA] Large hashes allocated during boot
 523                         are distributed across NUMA nodes.  Defaults on
 524                         for IA-64, off otherwise.
 525
 526         hcl=            [IA-64] SGI's Hardware Graph compatibility layer
 527
 528         hd=             [EIDE] (E)IDE hard drive subsystem geometry
 529                         Format: <cyl>,<head>,<sect>
 530
 531         hd?=            [HW] (E)IDE subsystem
 532         hd?lun=         See Documentation/ide.txt.
 533
 534         highmem=nn[KMG] [KNL,BOOT] forces the highmem zone to have an exact
 535                         size of <nn>. This works even on boxes that have no
 536                         highmem otherwise. This also works to reduce highmem
 537                         size on bigger boxes.
 538
 539         hisax=          [HW,ISDN]
 540                         See Documentation/isdn/README.HiSax.
 541
 542         hugepages=      [HW,IA-32,IA-64] Maximal number of HugeTLB pages.
 543
 544         noirqbalance    [IA-32,SMP,KNL] Disable kernel irq balancing
 545
 546         i8042.direct    [HW] Put keyboard port into non-translated mode
 547         i8042.dumbkbd   [HW] Pretend that controlled can only read data from
 548                              keyboard and can not control its state
 549                              (Don't attempt to blink the leds)
 550         i8042.noaux     [HW] Don't check for auxiliary (== mouse) port
 551         i8042.nomux     [HW] Don't check presence of an active multiplexing
 552                              controller
 553         i8042.nopnp     [HW] Don't use ACPIPnP / PnPBIOS to discover KBD/AUX
 554                              controllers
 555         i8042.panicblink=
 556                         [HW] Frequency with which keyboard LEDs should blink
 557                              when kernel panics (default is 0.5 sec)
 558         i8042.reset     [HW] Reset the controller during init and cleanup
 559         i8042.unlock    [HW] Unlock (ignore) the keylock
 560
 561         i810=           [HW,DRM]
 562
 563         i8k.ignore_dmi  [HW] Continue probing hardware even if DMI data
 564                         indicates that the driver is running on unsupported
 565                         hardware.
 566         i8k.force       [HW] Activate i8k driver even if SMM BIOS signature
 567                         does not match list of supported models.
 568         i8k.power_status
 569                         [HW] Report power status in /proc/i8k
 570                         (disabled by default)
 571         i8k.restricted  [HW] Allow controlling fans only if SYS_ADMIN
 572                         capability is set.
 573
 574         ibmmcascsi=     [HW,MCA,SCSI] IBM MicroChannel SCSI adapter
 575                         See Documentation/mca.txt.
 576
 577         icn=            [HW,ISDN]
 578                         Format: <io>[,<membase>[,<icn_id>[,<icn_id2>]]]
 579
 580         ide=            [HW] (E)IDE subsystem
 581                         Format: ide=nodma or ide=doubler or ide=reverse
 582                         See Documentation/ide.txt.
 583
 584         ide?=           [HW] (E)IDE subsystem
 585                         Format: ide?=noprobe or chipset specific parameters.
 586                         See Documentation/ide.txt.
 587
 588         idebus=         [HW] (E)IDE subsystem - VLB/PCI bus speed
 589                         See Documentation/ide.txt.
 590
 591         idle=           [HW]
 592                         Format: idle=poll or idle=halt
 593
 594         ihash_entries=  [KNL]
 595                         Set number of hash buckets for inode cache.
 596
 597         in2000=         [HW,SCSI]
 598                         See header of drivers/scsi/in2000.c.
 599
 600         init=           [KNL]
 601                         Format: <full_path>
 602                         Run specified binary instead of /sbin/init as init
 603                         process.
 604
 605         initcall_debug  [KNL] Trace initcalls as they are executed.  Useful
 606                         for working out where the kernel is dying during
 607                         startup.
 608
 609         initrd=         [BOOT] Specify the location of the initial ramdisk
 610
 611         inport.irq=     [HW] Inport (ATI XL and Microsoft) busmouse driver
 612                         Format: <irq>
 613
 614         inttest=        [IA64]
 615
 616         io7=            [HW] IO7 for Marvel based alpha systems
 617                         See comment before marvel_specify_io7 in
 618                         arch/alpha/kernel/core_marvel.c.
 619
 620         ip=             [IP_PNP]
 621                         See Documentation/nfsroot.txt.
 622
 623         ip2=            [HW] Set IO/IRQ pairs for up to 4 IntelliPort boards
 624                         See comment before ip2_setup() in drivers/char/ip2.c.
 625
 626         ips=            [HW,SCSI] Adaptec / IBM ServeRAID controller
 627                         See header of drivers/scsi/ips.c.
 628
 629         irqfixup        [HW]
 630                         When an interrupt is not handled search all handlers
 631                         for it. Intended to get systems with badly broken
 632                         firmware running.
 633
 634         irqpoll         [HW]
 635                         When an interrupt is not handled search all handlers
 636                         for it. Also check all handlers each timer
 637                         interrupt. Intended to get systems with badly broken
 638                         firmware running.
 639
 640         isapnp=         [ISAPNP]
 641                         Format: <RDP>, <reset>, <pci_scan>, <verbosity>
 642
 643         isolcpus=       [KNL,SMP] Isolate CPUs from the general scheduler.
 644                         Format: <cpu number>,...,<cpu number>
 645                         This option can be used to specify one or more CPUs
 646                         to isolate from the general SMP balancing and scheduling
 647                         algorithms. The only way to move a process onto or off
 648                         an "isolated" CPU is via the CPU affinity syscalls.
 649                         <cpu number> begins at 0 and the maximum value is
 650                         "number of CPUs in system - 1".
 651
 652                         This option is the preferred way to isolate CPUs. The
 653                         alternative - manually setting the CPU mask of all tasks
 654                         in the system can cause problems and suboptimal load
 655                         balancer performance.
 656
 657         isp16=          [HW,CD]
 658                         Format: <io>,<irq>,<dma>,<setup>
 659
 660         iucv=           [HW,NET]
 661
 662         js=             [HW,JOY] Analog joystick
 663                         See Documentation/input/joystick.txt.
 664
 665         keepinitrd      [HW,ARM]
 666
 667         kstack=N        [IA-32, X86-64] Print N words from the kernel stack
 668                         in oops dumps.
 669
 670         l2cr=           [PPC]
 671
 672         lapic           [IA-32,APIC] Enable the local APIC even if BIOS disabled it.
 673
 674         lasi=           [HW,SCSI] PARISC LASI driver for the 53c700 chip
 675                         Format: addr:<io>,irq:<irq>
 676
 677         llsc*=          [IA64]
 678                         See function print_params() in arch/ia64/sn/kernel/llsc4.c.
 679
 680         load_ramdisk=   [RAM] List of ramdisks to load from floppy
 681                         See Documentation/ramdisk.txt.
 682
 683         lockd.udpport=  [NFS]
 684
 685         lockd.tcpport=  [NFS]
 686
 687         logibm.irq=     [HW,MOUSE] Logitech Bus Mouse Driver
 688                         Format: <irq>
 689
 690         loglevel=       All Kernel Messages with a loglevel smaller than the
 691                         console loglevel will be printed to the console. It can
 692                         also be changed with klogd or other programs. The
 693                         loglevels are defined as follows:
 694
 695                         0 (KERN_EMERG)          system is unusable
 696                         1 (KERN_ALERT)          action must be taken immediately
 697                         2 (KERN_CRIT)           critical conditions
 698                         3 (KERN_ERR)            error conditions
 699                         4 (KERN_WARNING)        warning conditions
 700                         5 (KERN_NOTICE)         normal but significant condition
 701                         6 (KERN_INFO)           informational
 702                         7 (KERN_DEBUG)          debug-level messages
 703
 704         log_buf_len=n   Sets the size of the printk ring buffer, in bytes.
 705                         Format is n, nk, nM.  n must be a power of two.  The
 706                         default is set in kernel config.
 707
 708         lp=0            [LP]    Specify parallel ports to use, e.g,
 709         lp=port[,port...]       lp=none,parport0 (lp0 not configured, lp1 uses
 710         lp=reset                first parallel port). 'lp=0' disables the
 711         lp=auto                 printer driver. 'lp=reset' (which can be
 712                                 specified in addition to the ports) causes
 713                                 attached printers to be reset. Using
 714                                 lp=port1,port2,... specifies the parallel ports
 715                                 to associate lp devices with, starting with
 716                                 lp0. A port specification may be 'none' to skip
 717                                 that lp device, or a parport name such as
 718                                 'parport0'. Specifying 'lp=auto' instead of a
 719                                 port specification list means that device IDs
 720                                 from each port should be examined, to see if
 721                                 an IEEE 1284-compliant printer is attached; if
 722                                 so, the driver will manage that printer.
 723                                 See also header of drivers/char/lp.c.
 724
 725         lpj=n           [KNL]
 726                         Sets loops_per_jiffy to given constant, thus avoiding
 727                         time-consuming boot-time autodetection (up to 250 ms per
 728                         CPU). 0 enables autodetection (default). To determine
 729                         the correct value for your kernel, boot with normal
 730                         autodetection and see what value is printed. Note that
 731                         on SMP systems the preset will be applied to all CPUs,
 732                         which is likely to cause problems if your CPUs need
 733                         significantly divergent settings. An incorrect value
 734                         will cause delays in the kernel to be wrong, leading to
 735                         unpredictable I/O errors and other breakage. Although
 736                         unlikely, in the extreme case this might damage your
 737                         hardware.
 738
 739         ltpc=           [NET]
 740                         Format: <io>,<irq>,<dma>
 741
 742         mac5380=        [HW,SCSI]
 743                         Format: <can_queue>,<cmd_per_lun>,<sg_tablesize>,<hostid>,<use_tags>
 744
 745         mac53c9x=       [HW,SCSI]
 746                         Format: <num_esps>,<disconnect>,<nosync>,<can_queue>,<cmd_per_lun>,<sg_tablesize>,<hostid>,<use_tags>
 747
 748         machvec=        [IA64]
 749                         Force the use of a particular machine-vector (machvec) in a generic
 750                         kernel.  Example: machvec=hpzx1_swiotlb
 751
 752         mad16=          [HW,OSS]
 753                         Format: <io>,<irq>,<dma>,<dma16>,<mpu_io>,<mpu_irq>,<joystick>
 754
 755         maui=           [HW,OSS]
 756                         Format: <io>,<irq>
 757
 758         max_loop=       [LOOP] Maximum number of loopback devices that can
 759                         be mounted
 760                         Format: <1-256>
 761
 762         maxcpus=        [SMP] Maximum number of processors that an SMP kernel
 763                         should make use of
 764
 765         max_luns=       [SCSI] Maximum number of LUNs to probe
 766                         Should be between 1 and 2^32-1.
 767
 768         max_report_luns=
 769                         [SCSI] Maximum number of LUNs received
 770                         Should be between 1 and 16384.
 771
 772         mca-pentium     [BUGS=IA-32]
 773
 774         mcatest=        [IA-64]
 775
 776         mcd=            [HW,CD]
 777                         Format: <port>,<irq>,<mitsumi_bug_93_wait>
 778
 779         mcdx=           [HW,CD]
 780
 781         mce             [IA-32] Machine Check Exception
 782
 783         md=             [HW] RAID subsystems devices and level
 784                         See Documentation/md.txt.
 785
 786         mdacon=         [MDA]
 787                         Format: <first>,<last>
 788                         Specifies range of consoles to be captured by the MDA.
 789
 790         mem=nn[KMG]     [KNL,BOOT] Force usage of a specific amount of memory
 791                         Amount of memory to be used when the kernel is not able
 792                         to see the whole system memory or for test.
 793                         [IA-32] Use together with memmap= to avoid physical
 794                         address space collisions. Without memmap= PCI devices
 795                         could be placed at addresses belonging to unused RAM.
 796
 797         mem=nopentium   [BUGS=IA-32] Disable usage of 4MB pages for kernel
 798                         memory.
 799
 800         memmap=exactmap [KNL,IA-32] Enable setting of an exact
 801                         E820 memory map, as specified by the user.
 802                         Such memmap=exactmap lines can be constructed based on
 803                         BIOS output or other requirements. See the memmap=nn@ss
 804                         option description.
 805
 806         memmap=nn[KMG]@ss[KMG]
 807                         [KNL] Force usage of a specific region of memory
 808                         Region of memory to be used, from ss to ss+nn.
 809
 810         memmap=nn[KMG]#ss[KMG]
 811                         [KNL,ACPI] Mark specific memory as ACPI data.
 812                         Region of memory to be used, from ss to ss+nn.
 813
 814         memmap=nn[KMG]$ss[KMG]
 815                         [KNL,ACPI] Mark specific memory as reserved.
 816                         Region of memory to be used, from ss to ss+nn.
 817
 818         meye.*=         [HW] Set MotionEye Camera parameters
 819                         See Documentation/video4linux/meye.txt.
 820
 821         mga=            [HW,DRM]
 822
 823         mousedev.tap_time=
 824                         [MOUSE] Maximum time between finger touching and
 825                         leaving touchpad surface for touch to be considered
 826                         a tap and be reported as a left button click (for
 827                         touchpads working in absolute mode only).
 828                         Format: <msecs>
 829         mousedev.xres=  [MOUSE] Horizontal screen resolution, used for devices
 830                         reporting absolute coordinates, such as tablets
 831         mousedev.yres=  [MOUSE] Vertical screen resolution, used for devices
 832                         reporting absolute coordinates, such as tablets
 833
 834         mpu401=         [HW,OSS]
 835                         Format: <io>,<irq>
 836
 837         MTD_Partition=  [MTD]
 838                         Format: <name>,<region-number>,<size>,<offset>
 839
 840         MTD_Region=     [MTD]
 841                         Format: <name>,<region-number>[,<base>,<size>,<buswidth>,<altbuswidth>]
 842
 843         mtdparts=       [MTD]
 844                         See drivers/mtd/cmdline.c.
 845
 846         mtouchusb.raw_coordinates=
 847                         [HW] Make the MicroTouch USB driver use raw coordinates ('y', default)
 848                         or cooked coordinates ('n')
 849
 850         n2=             [NET] SDL Inc. RISCom/N2 synchronous serial card
 851
 852         NCR_D700=       [HW,SCSI]
 853                         See header of drivers/scsi/NCR_D700.c.
 854
 855         ncr5380=        [HW,SCSI]
 856
 857         ncr53c400=      [HW,SCSI]
 858
 859         ncr53c400a=     [HW,SCSI]
 860
 861         ncr53c406a=     [HW,SCSI]
 862
 863         ncr53c8xx=      [HW,SCSI]
 864
 865         netdev=         [NET] Network devices parameters
 866                         Format: <irq>,<io>,<mem_start>,<mem_end>,<name>
 867                         Note that mem_start is often overloaded to mean
 868                         something different and driver-specific.
 869
 870         nfsaddrs=       [NFS]
 871                         See Documentation/nfsroot.txt.
 872
 873         nfsroot=        [NFS] nfs root filesystem for disk-less boxes.
 874                         See Documentation/nfsroot.txt.
 875
 876         nmi_watchdog=   [KNL,BUGS=IA-32] Debugging features for SMP kernels
 877
 878         no387           [BUGS=IA-32] Tells the kernel to use the 387 maths
 879                         emulation library even if a 387 maths coprocessor
 880                         is present.
 881
 882         noalign         [KNL,ARM]
 883
 884         noapic          [SMP,APIC] Tells the kernel to not make use of any
 885                         IOAPICs that may be present in the system.
 886
 887         noasync         [HW,M68K] Disables async and sync negotiation for
 888                         all devices.
 889
 890         nobats          [PPC] Do not use BATs for mapping kernel lowmem
 891                         on "Classic" PPC cores.
 892
 893         nocache         [ARM]
 894
 895         nodisconnect    [HW,SCSI,M68K] Disables SCSI disconnects.
 896
 897         noexec          [IA-64]
 898
 899         noexec          [IA-32, X86-64]
 900                         noexec=on: enable non-executable mappings (default)
 901                         noexec=off: disable nn-executable mappings
 902
 903         nofxsr          [BUGS=IA-32]
 904
 905         nohlt           [BUGS=ARM]
 906
 907         no-hlt          [BUGS=IA-32] Tells the kernel that the hlt
 908                         instruction doesn't work correctly and not to
 909                         use it.
 910
 911         nohalt          [IA-64] Tells the kernel not to use the power saving
 912                         function PAL_HALT_LIGHT when idle. This increases
 913                         power-consumption. On the positive side, it reduces
 914                         interrupt wake-up latency, which may improve performance
 915                         in certain environments such as networked servers or
 916                         real-time systems.
 917
 918         noirqdebug      [IA-32] Disables the code which attempts to detect and
 919                         disable unhandled interrupt sources.
 920
 921         noisapnp        [ISAPNP] Disables ISA PnP code.
 922
 923         noinitrd        [RAM] Tells the kernel not to load any configured
 924                         initial RAM disk.
 925
 926         nointroute      [IA-64]
 927
 928         nolapic         [IA-32,APIC] Do not enable or use the local APIC.
 929
 930         noltlbs         [PPC] Do not use large page/tlb entries for kernel
 931                         lowmem mapping on PPC40x.
 932
 933         nomce           [IA-32] Machine Check Exception
 934
 935         noresidual      [PPC] Don't use residual data on PReP machines.
 936
 937         noresume        [SWSUSP] Disables resume and restore original swap space.
 938
 939         no-scroll       [VGA] Disables scrollback.
 940                         This is required for the Braillex ib80-piezo Braille
 941                         reader made by F.H. Papenmeier (Germany).
 942
 943         nosbagart       [IA-64]
 944
 945         nosmp           [SMP] Tells an SMP kernel to act as a UP kernel.
 946
 947         nosync          [HW,M68K] Disables sync negotiation for all devices.
 948
 949         notsc           [BUGS=IA-32] Disable Time Stamp Counter
 950
 951         nousb           [USB] Disable the USB subsystem
 952
 953         nowb            [ARM]
 954
 955         opl3=           [HW,OSS]
 956                         Format: <io>
 957
 958         opl3sa=         [HW,OSS]
 959                         Format: <io>,<irq>,<dma>,<dma2>,<mpu_io>,<mpu_irq>
 960
 961         opl3sa2=        [HW,OSS]
 962                         Format: <io>,<irq>,<dma>,<dma2>,<mss_io>,<mpu_io>,<ymode>,<loopback>[,<isapnp>,<multiple]
 963
 964         oprofile.timer= [HW]
 965                         Use timer interrupt instead of performance counters
 966
 967         optcd=          [HW,CD]
 968                         Format: <io>
 969
 970         osst=           [HW,SCSI] SCSI Tape Driver
 971                         Format: <buffer_size>,<write_threshold>
 972                         See also Documentation/scsi/st.txt.
 973
 974         panic=          [KNL] Kernel behaviour on panic
 975                         Format: <timeout>
 976
 977         parkbd.port=    [HW] Parallel port number the keyboard adapter is
 978                         connected to, default is 0.
 979                         Format: <parport#>
 980         parkbd.mode=    [HW] Parallel port keyboard adapter mode of operation,
 981                         0 for XT, 1 for AT (default is AT).
 982                         Format: <mode>
 983
 984         parport=0       [HW,PPT]        Specify parallel ports. 0 disables.
 985         parport=auto                    Use 'auto' to force the driver to use
 986         parport=0xBBB[,IRQ[,DMA]]       any IRQ/DMA settings detected (the
 987                                         default is to ignore detected IRQ/DMA
 988                                         settings because of possible
 989                                         conflicts). You can specify the base
 990                                         address, IRQ, and DMA settings; IRQ and
 991                                         DMA should be numbers, or 'auto' (for
 992                                         using detected settings on that
 993                                         particular port), or 'nofifo' (to avoid
 994                                         using a FIFO even if it is detected).
 995                                         Parallel ports are assigned in the
 996                                         order they are specified on the command
 997                                         line, starting with parport0.
 998
 999         parport_init_mode=
1000                         [HW,PPT]        Configure VIA parallel port to
1001                                         operate in specific mode. This is
1002                                         necessary on Pegasos computer where
1003                                         firmware has no options for setting up
1004                                         parallel port mode and sets it to
1005                                         spp. Currently this function knows
1006                                         686a and 8231 chips.
1007                         Format: [spp|ps2|epp|ecp|ecpepp]
1008
1009         pas2=           [HW,OSS]
1010                         Format: <io>,<irq>,<dma>,<dma16>,<sb_io>,<sb_irq>,<sb_dma>,<sb_dma16>
1011
1012         pas16=          [HW,SCSI]
1013                         See header of drivers/scsi/pas16.c.
1014
1015         pcbit=          [HW,ISDN]
1016
1017         pcd.            [PARIDE]
1018                         See header of drivers/block/paride/pcd.c.
1019                         See also Documentation/paride.txt.
1020
1021         pci=option[,option...]          [PCI] various PCI subsystem options:
1022                 off                     [IA-32] don't probe for the PCI bus
1023                 bios                    [IA-32] force use of PCI BIOS, don't access
1024                                         the hardware directly. Use this if your machine
1025                                         has a non-standard PCI host bridge.
1026                 nobios                  [IA-32] disallow use of PCI BIOS, only direct
1027                                         hardware access methods are allowed. Use this
1028                                         if you experience crashes upon bootup and you
1029                                         suspect they are caused by the BIOS.
1030                 conf1                   [IA-32] Force use of PCI Configuration Mechanism 1.
1031                 conf2                   [IA-32] Force use of PCI Configuration Mechanism 2.
1032                 nosort                  [IA-32] Don't sort PCI devices according to
1033                                         order given by the PCI BIOS. This sorting is done
1034                                         to get a device order compatible with older kernels.
1035                 biosirq                 [IA-32] Use PCI BIOS calls to get the interrupt
1036                                         routing table. These calls are known to be buggy
1037                                         on several machines and they hang the machine when used,
1038                                         but on other computers it's the only way to get the
1039                                         interrupt routing table. Try this option if the kernel
1040                                         is unable to allocate IRQs or discover secondary PCI
1041                                         buses on your motherboard.
1042                 rom                     [IA-32] Assign address space to expansion ROMs.
1043                                         Use with caution as certain devices share address
1044                                         decoders between ROMs and other resources.
1045                 irqmask=0xMMMM          [IA-32] Set a bit mask of IRQs allowed to be assigned
1046                                         automatically to PCI devices. You can make the kernel
1047                                         exclude IRQs of your ISA cards this way.
1048                 pirqaddr=0xAAAAA        [IA-32] Specify the physical address
1049                                         of the PIRQ table (normally generated
1050                                         by the BIOS) if it is outside the
1051                                         F0000h-100000h range.
1052                 lastbus=N               [IA-32] Scan all buses till bus #N. Can be useful
1053                                         if the kernel is unable to find your secondary buses
1054                                         and you want to tell it explicitly which ones they are.
1055                 assign-busses           [IA-32] Always assign all PCI bus
1056                                         numbers ourselves, overriding
1057                                         whatever the firmware may have
1058                                         done.
1059                 usepirqmask             [IA-32] Honor the possible IRQ mask
1060                                         stored in the BIOS $PIR table. This is
1061                                         needed on some systems with broken
1062                                         BIOSes, notably some HP Pavilion N5400
1063                                         and Omnibook XE3 notebooks. This will
1064                                         have no effect if ACPI IRQ routing is
1065                                         enabled.
1066                 noacpi                  [IA-32] Do not use ACPI for IRQ routing
1067                                         or for PCI scanning.
1068                 routeirq                Do IRQ routing for all PCI devices.
1069                                         This is normally done in pci_enable_device(),
1070                                         so this option is a temporary workaround
1071                                         for broken drivers that don't call it.
1072
1073                 firmware                [ARM] Do not re-enumerate the bus but
1074                                         instead just use the configuration
1075                                         from the bootloader. This is currently
1076                                         used on IXP2000 systems where the
1077                                         bus has to be configured a certain way
1078                                         for adjunct CPUs.
1079
1080         pcmv=           [HW,PCMCIA] BadgePAD 4
1081
1082         pd.             [PARIDE]
1083                         See Documentation/paride.txt.
1084
1085         pdcchassis=     [PARISC,HW] Disable/Enable PDC Chassis Status codes at
1086                         boot time.
1087                         Format: { 0 | 1 }
1088                         See arch/parisc/kernel/pdc_chassis.c
1089
1090         pf.             [PARIDE]
1091                         See Documentation/paride.txt.
1092
1093         pg.             [PARIDE]
1094                         See Documentation/paride.txt.
1095
1096         pirq=           [SMP,APIC] Manual mp-table setup
1097                         See Documentation/i386/IO-APIC.txt.
1098
1099         plip=           [PPT,NET] Parallel port network link
1100                         Format: { parport<nr> | timid | 0 }
1101                         See also Documentation/parport.txt.
1102
1103         pnpacpi=        [ACPI]
1104                         { off }
1105
1106         pnpbios=        [ISAPNP]
1107                         { on | off | curr | res | no-curr | no-res }
1108
1109         pnp_reserve_irq=
1110                         [ISAPNP] Exclude IRQs for the autoconfiguration
1111
1112         pnp_reserve_dma=
1113                         [ISAPNP] Exclude DMAs for the autoconfiguration
1114
1115         pnp_reserve_io= [ISAPNP] Exclude I/O ports for the autoconfiguration
1116                         Ranges are in pairs (I/O port base and size).
1117
1118         pnp_reserve_mem=
1119                         [ISAPNP] Exclude memory regions for the autoconfiguration
1120                         Ranges are in pairs (memory base and size).
1121
1122         profile=        [KNL] Enable kernel profiling via /proc/profile
1123                         { schedule | <number> }
1124                         (param: schedule - profile schedule points}
1125                         (param: profile step/bucket size as a power of 2 for
1126                                 statistical time based profiling)
1127
1128         processor.max_cstate=   [HW, ACPI]
1129                         Limit processor to maximum C-state
1130                         max_cstate=9 overrides any DMI blacklist limit.
1131
1132         prompt_ramdisk= [RAM] List of RAM disks to prompt for floppy disk
1133                         before loading.
1134                         See Documentation/ramdisk.txt.
1135
1136         psmouse.proto=  [HW,MOUSE] Highest PS2 mouse protocol extension to
1137                         probe for (bare|imps|exps|lifebook|any).
1138         psmouse.rate=   [HW,MOUSE] Set desired mouse report rate, in reports
1139                         per second.
1140         psmouse.resetafter=
1141                         [HW,MOUSE] Try to reset the device after so many bad packets
1142                         (0 = never).
1143         psmouse.resolution=
1144                         [HW,MOUSE] Set desired mouse resolution, in dpi.
1145         psmouse.smartscroll=
1146                         [HW,MOUSE] Controls Logitech smartscroll autorepeat,
1147                         0 = disabled, 1 = enabled (default).
1148
1149         pss=            [HW,OSS] Personal Sound System (ECHO ESC614)
1150                         Format: <io>,<mss_io>,<mss_irq>,<mss_dma>,<mpu_io>,<mpu_irq>
1151
1152         pt.             [PARIDE]
1153                         See Documentation/paride.txt.
1154
1155         quiet=          [KNL] Disable log messages
1156
1157         r128=           [HW,DRM]
1158
1159         raid=           [HW,RAID]
1160                         See Documentation/md.txt.
1161
1162         ramdisk=        [RAM] Sizes of RAM disks in kilobytes [deprecated]
1163                         See Documentation/ramdisk.txt.
1164
1165         ramdisk_blocksize=
1166                         [RAM]
1167                         See Documentation/ramdisk.txt.
1168
1169         ramdisk_size=   [RAM] Sizes of RAM disks in kilobytes
1170                         New name for the ramdisk parameter.
1171                         See Documentation/ramdisk.txt.
1172
1173         reboot=         [BUGS=IA-32,BUGS=ARM,BUGS=IA-64] Rebooting mode
1174                         Format: <reboot_mode>[,<reboot_mode2>[,...]]
1175                         See arch/*/kernel/reboot.c.
1176
1177         reserve=        [KNL,BUGS] Force the kernel to ignore some iomem area
1178
1179         resume=         [SWSUSP] Specify the partition device for software suspension
1180
1181         rhash_entries=  [KNL,NET]
1182                         Set number of hash buckets for route cache
1183
1184         riscom8=        [HW,SERIAL]
1185                         Format: <io_board1>[,<io_board2>[,...<io_boardN>]]
1186
1187         ro              [KNL] Mount root device read-only on boot
1188
1189         root=           [KNL] Root filesystem
1190
1191         rootdelay=      [KNL] Delay (in seconds) to pause before attempting to
1192                         mount the root filesystem
1193
1194         rootflags=      [KNL] Set root filesystem mount option string
1195
1196         rootfstype=     [KNL] Set root filesystem type
1197
1198         rw              [KNL] Mount root device read-write on boot
1199
1200         S               [KNL] Run init in single mode
1201
1202         sa1100ir        [NET]
1203                         See drivers/net/irda/sa1100_ir.c.
1204
1205         sb=             [HW,OSS]
1206                         Format: <io>,<irq>,<dma>,<dma2>
1207
1208         sbni=           [NET] Granch SBNI12 leased line adapter
1209
1210         sbpcd=          [HW,CD] Soundblaster CD adapter
1211                         Format: <io>,<type>
1212                         See a comment before function sbpcd_setup() in
1213                         drivers/cdrom/sbpcd.c.
1214
1215         sc1200wdt=      [HW,WDT] SC1200 WDT (watchdog) driver
1216                         Format: <io>[,<timeout>[,<isapnp>]]
1217
1218         scsi_debug_*=   [SCSI]
1219                         See drivers/scsi/scsi_debug.c.
1220
1221         scsi_default_dev_flags=
1222                         [SCSI] SCSI default device flags
1223                         Format: <integer>
1224
1225         scsi_dev_flags= [SCSI] Black/white list entry for vendor and model
1226                         Format: <vendor>:<model>:<flags>
1227                         (flags are integer value)
1228
1229         scsi_logging=   [SCSI]
1230
1231         selinux         [SELINUX] Disable or enable SELinux at boot time.
1232                         Format: { "0" | "1" }
1233                         See security/selinux/Kconfig help text.
1234                         0 -- disable.
1235                         1 -- enable.
1236                         Default value is set via kernel config option.
1237                         If enabled at boot time, /selinux/disable can be used
1238                         later to disable prior to initial policy load.
1239
1240         serialnumber    [BUGS=IA-32]
1241
1242         sg_def_reserved_size=
1243                         [SCSI]
1244
1245         sgalaxy=        [HW,OSS]
1246                         Format: <io>,<irq>,<dma>,<dma2>,<sgbase>
1247
1248         shapers=        [NET]
1249                         Maximal number of shapers.
1250
1251         sim710=         [SCSI,HW]
1252                         See header of drivers/scsi/sim710.c.
1253
1254         simeth=         [IA-64]
1255         simscsi=
1256
1257         sjcd=           [HW,CD]
1258                         Format: <io>,<irq>,<dma>
1259                         See header of drivers/cdrom/sjcd.c.
1260
1261         slram=          [HW,MTD]
1262
1263         smart2=         [HW]
1264                         Format: <io1>[,<io2>[,...,<io8>]]
1265
1266         snd-ad1816a=    [HW,ALSA]
1267
1268         snd-ad1848=     [HW,ALSA]
1269
1270         snd-ali5451=    [HW,ALSA]
1271
1272         snd-als100=     [HW,ALSA]
1273
1274         snd-als4000=    [HW,ALSA]
1275
1276         snd-azt2320=    [HW,ALSA]
1277
1278         snd-cmi8330=    [HW,ALSA]
1279
1280         snd-cmipci=     [HW,ALSA]
1281
1282         snd-cs4231=     [HW,ALSA]
1283
1284         snd-cs4232=     [HW,ALSA]
1285
1286         snd-cs4236=     [HW,ALSA]
1287
1288         snd-cs4281=     [HW,ALSA]
1289
1290         snd-cs46xx=     [HW,ALSA]
1291
1292         snd-dt019x=     [HW,ALSA]
1293
1294         snd-dummy=      [HW,ALSA]
1295
1296         snd-emu10k1=    [HW,ALSA]
1297
1298         snd-ens1370=    [HW,ALSA]
1299
1300         snd-ens1371=    [HW,ALSA]
1301
1302         snd-es968=      [HW,ALSA]
1303
1304         snd-es1688=     [HW,ALSA]
1305
1306         snd-es18xx=     [HW,ALSA]
1307
1308         snd-es1938=     [HW,ALSA]
1309
1310         snd-es1968=     [HW,ALSA]
1311
1312         snd-fm801=      [HW,ALSA]
1313
1314         snd-gusclassic= [HW,ALSA]
1315
1316         snd-gusextreme= [HW,ALSA]
1317
1318         snd-gusmax=     [HW,ALSA]
1319
1320         snd-hdsp=       [HW,ALSA]
1321
1322         snd-ice1712=    [HW,ALSA]
1323
1324         snd-intel8x0=   [HW,ALSA]
1325
1326         snd-interwave=  [HW,ALSA]
1327
1328         snd-interwave-stb=
1329                         [HW,ALSA]
1330
1331         snd-korg1212=   [HW,ALSA]
1332
1333         snd-maestro3=   [HW,ALSA]
1334
1335         snd-mpu401=     [HW,ALSA]
1336
1337         snd-mtpav=      [HW,ALSA]
1338
1339         snd-nm256=      [HW,ALSA]
1340
1341         snd-opl3sa2=    [HW,ALSA]
1342
1343         snd-opti92x-ad1848=
1344                         [HW,ALSA]
1345
1346         snd-opti92x-cs4231=
1347                         [HW,ALSA]
1348
1349         snd-opti93x=    [HW,ALSA]
1350
1351         snd-pmac=       [HW,ALSA]
1352
1353         snd-rme32=      [HW,ALSA]
1354
1355         snd-rme96=      [HW,ALSA]
1356
1357         snd-rme9652=    [HW,ALSA]
1358
1359         snd-sb8=        [HW,ALSA]
1360
1361         snd-sb16=       [HW,ALSA]
1362
1363         snd-sbawe=      [HW,ALSA]
1364
1365         snd-serial=     [HW,ALSA]
1366
1367         snd-sgalaxy=    [HW,ALSA]
1368
1369         snd-sonicvibes= [HW,ALSA]
1370
1371         snd-sun-amd7930=
1372                         [HW,ALSA]
1373
1374         snd-sun-cs4231= [HW,ALSA]
1375
1376         snd-trident=    [HW,ALSA]
1377
1378         snd-usb-audio=  [HW,ALSA,USB]
1379
1380         snd-via82xx=    [HW,ALSA]
1381
1382         snd-virmidi=    [HW,ALSA]
1383
1384         snd-wavefront=  [HW,ALSA]
1385
1386         snd-ymfpci=     [HW,ALSA]
1387
1388         sonicvibes=     [HW,OSS]
1389                         Format: <reverb>
1390
1391         sonycd535=      [HW,CD]
1392                         Format: <io>[,<irq>]
1393
1394         sonypi.*=       [HW] Sony Programmable I/O Control Device driver
1395                         See Documentation/sonypi.txt
1396
1397         specialix=      [HW,SERIAL] Specialix multi-serial port adapter
1398                         See Documentation/specialix.txt.
1399
1400         spia_io_base=   [HW,MTD]
1401         spia_fio_base=
1402         spia_pedr=
1403         spia_peddr=
1404
1405         sscape=         [HW,OSS]
1406                         Format: <io>,<irq>,<dma>,<mpu_io>,<mpu_irq>
1407
1408         st=             [HW,SCSI] SCSI tape parameters (buffers, etc.)
1409                         See Documentation/scsi/st.txt.
1410
1411         st0x=           [HW,SCSI]
1412                         See header of drivers/scsi/seagate.c.
1413
1414         sti=            [PARISC,HW]
1415                         Format: <num>
1416                         Set the STI (builtin display/keyboard on the HP-PARISC
1417                         machines) console (graphic card) which should be used
1418                         as the initial boot-console.
1419                         See also comment in drivers/video/console/sticore.c.
1420
1421         sti_font=       [HW]
1422                         See comment in drivers/video/console/sticore.c.
1423
1424         stifb=          [HW]
1425                         Format: bpp:<bpp1>[:<bpp2>[:<bpp3>...]]
1426
1427         stram_swap=     [HW,M68k]
1428
1429         swiotlb=        [IA-64] Number of I/O TLB slabs
1430
1431         switches=       [HW,M68k]
1432
1433         sym53c416=      [HW,SCSI]
1434                         See header of drivers/scsi/sym53c416.c.
1435
1436         t128=           [HW,SCSI]
1437                         See header of drivers/scsi/t128.c.
1438
1439         tdfx=           [HW,DRM]
1440
1441         thash_entries=  [KNL,NET]
1442                         Set number of hash buckets for TCP connection
1443
1444         time            Show timing data prefixed to each printk message line
1445
1446         tipar.timeout=  [HW,PPT]
1447                         Set communications timeout in tenths of a second
1448                         (default 15).
1449
1450         tipar.delay=    [HW,PPT]
1451                         Set inter-bit delay in microseconds (default 10).
1452
1453         tmc8xx=         [HW,SCSI]
1454                         See header of drivers/scsi/seagate.c.
1455
1456         tmscsim=        [HW,SCSI]
1457                         See comment before function dc390_setup() in
1458                         drivers/scsi/tmscsim.c.
1459
1460         tp720=          [HW,PS2]
1461
1462         trix=           [HW,OSS] MediaTrix AudioTrix Pro
1463                         Format: <io>,<irq>,<dma>,<dma2>,<sb_io>,<sb_irq>,<sb_dma>,<mpu_io>,<mpu_irq>
1464
1465         tsdev.xres=     [TS] Horizontal screen resolution.
1466         tsdev.yres=     [TS] Vertical screen resolution.
1467
1468         turbografx.map[2|3]=
1469                         [HW,JOY] TurboGraFX parallel port interface
1470                         Format: <port#>,<js1>,<js2>,<js3>,<js4>,<js5>,<js6>,<js7>
1471                         See also Documentation/input/joystick-parport.txt
1472
1473         u14-34f=        [HW,SCSI] UltraStor 14F/34F SCSI host adapter
1474                         See header of drivers/scsi/u14-34f.c.
1475
1476         uart401=        [HW,OSS]
1477                         Format: <io>,<irq>
1478
1479         uart6850=       [HW,OSS]
1480                         Format: <io>,<irq>
1481
1482         usb-handoff     [HW] Enable early USB BIOS -> OS handoff
1483
1484         usbhid.mousepoll=
1485                         [USBHID] The interval which mice are to be polled at.
1486
1487         video=          [FB] Frame buffer configuration
1488                         See Documentation/fb/modedb.txt.
1489
1490         vga=            [BOOT,IA-32] Select a particular video mode
1491                         See Documentation/i386/boot.txt and Documentation/svga.txt.
1492                         Use vga=ask for menu.
1493                         This is actually a boot loader parameter; the value is
1494                         passed to the kernel using a special protocol.
1495
1496         vmalloc=nn[KMG] [KNL,BOOT] forces the vmalloc area to have an exact
1497                         size of <nn>. This can be used to increase the
1498                         minimum size (128MB on x86). It can also be used to
1499                         decrease the size and leave more room for directly
1500                         mapped kernel RAM.
1501
1502         vmhalt=         [KNL,S390]
1503
1504         vmpoff=         [KNL,S390]
1505
1506         waveartist=     [HW,OSS]
1507                         Format: <io>,<irq>,<dma>,<dma2>
1508
1509         wd33c93=        [HW,SCSI]
1510                         See header of drivers/scsi/wd33c93.c.
1511
1512         wd7000=         [HW,SCSI]
1513                         See header of drivers/scsi/wd7000.c.
1514
1515         wdt=            [WDT] Watchdog
1516                         See Documentation/watchdog/watchdog.txt.
1517
1518         xd=             [HW,XT] Original XT pre-IDE (RLL encoded) disks.
1519         xd_geo=         See header of drivers/block/xd.c.
1520
1521         xirc2ps_cs=     [NET,PCMCIA]
1522                         Format: <irq>,<irq_mask>,<io>,<full_duplex>,<do_sound>,<lockup_hack>[,<irq2>[,<irq3>[,<irq4>]]]
1523
1524
1525
1526 Changelog:
1527
1528         The last known update (for 2.4.0) - the changelog was not kept before.
1529         2000-06-??      Mr. Unknown
1530
1531         Update for 2.5.49, description for most of the options introduced,
1532         references to other documentation (C files, READMEs, ..), added S390,
1533         PPC, SPARC, MTD, ALSA and OSS category. Minor corrections and
1534         reformatting.
1535         2002-11-24      Petr Baudis <pasky@ucw.cz>
1536                         Randy Dunlap <randy.dunlap@verizon.net>
1537
1538 TODO:
1539
1540         Add documentation for ALSA options.
1541         Add more DRM drivers.