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         SERIAL  Serial support is enabled.
  71         SMP     The kernel is an SMP kernel.
  72         SPARC   Sparc architecture is enabled.
  73         SWSUSP  Software suspension is enabled.
  74         TS      Appropriate touchscreen support is enabled.
  75         USB     USB support is enabled.
  76         V4L     Video For Linux support is enabled.
  77         VGA     The VGA console has been enabled.
  78         VT      Virtual terminal support is enabled.
  79         WDT     Watchdog support is enabled.
  80         XT      IBM PC/XT MFM hard disk support is enabled.
  81
  82 In addition, the following text indicates that the option:
  83
  84         BUGS=   Relates to possible processor bugs on the said processor.
  85         KNL     Is a kernel start-up parameter.
  86         BOOT    Is a boot loader parameter.
  87
  88 Parameters denoted with BOOT are actually interpreted by the boot
  89 loader, and have no meaning to the kernel directly.
  90 Do not modify the syntax of boot loader parameters without extreme
  91 need or coordination with <Documentation/i386/boot.txt>.
  92
  93 Note that ALL kernel parameters listed below are CASE SENSITIVE, and that
  94 a trailing = on the name of any parameter states that that parameter will
  95 be entered as an environment variable, whereas its absence indicates that
  96 it will appear as a kernel argument readable via /proc/cmdline by programs
  97 running once the system is up.
  98
  99         53c7xx=         [HW,SCSI] Amiga SCSI controllers
 100                         See header of drivers/scsi/53c7xx.c.
 101                         See also Documentation/scsi/ncr53c7xx.txt.
 102
 103         acpi=           [HW,ACPI] Advanced Configuration and Power Interface
 104                         Format: { force | off | ht | strict }
 105                         force -- enable ACPI if default was off
 106                         off -- disable ACPI if default was on
 107                         noirq -- do not use ACPI for IRQ routing
 108                         ht -- run only enough ACPI to enable Hyper Threading
 109                         strict --  Be less tolerant of platforms that are not
 110                                 strictly ACPI specification compliant.
 111
 112                         See also Documentation/pm.txt, pci=noacpi
 113
 114         acpi_sleep=     [HW,ACPI] Sleep options
 115                         Format: { s3_bios, s3_mode }
 116                         See Documentation/power/video.txt
 117
 118         acpi_sci=       [HW,ACPI] ACPI System Control Interrupt trigger mode
 119                         Format: { level | edge |  high | low }
 120
 121         acpi_irq_balance        [HW,ACPI] ACPI will balance active IRQs
 122                                 default in APIC mode
 123
 124         acpi_irq_nobalance      [HW,ACPI] ACPI will not move active IRQs (default)
 125                                 default in PIC mode
 126
 127         acpi_irq_pci=   [HW,ACPI] If irq_balance, Clear listed IRQs for use by PCI
 128                         Format: <irq>,<irq>...
 129
 130         acpi_irq_isa=   [HW,ACPI] If irq_balance, Mark listed IRQs used by ISA
 131                         Format: <irq>,<irq>...
 132
 133         acpi_osi=       [HW,ACPI] empty param disables _OSI
 134
 135         acpi_serialize  [HW,ACPI] force serialization of AML methods
 136
 137         acpi_skip_timer_override [HW,ACPI]
 138                         Recognize and ignore IRQ0/pin2 Interrupt Override.
 139                         For broken nForce2 BIOS resulting in XT-PIC timer.
 140
 141         acpi_dbg_layer= [HW,ACPI]
 142                         Format: <int>
 143                         Each bit of the <int> indicates an acpi debug layer,
 144                         1: enable, 0: disable. It is useful for boot time
 145                         debugging. After system has booted up, it can be set
 146                         via /proc/acpi/debug_layer.
 147
 148         acpi_dbg_level= [HW,ACPI]
 149                         Format: <int>
 150                         Each bit of the <int> indicates an acpi debug level,
 151                         1: enable, 0: disable. It is useful for boot time
 152                         debugging. After system has booted up, it can be set
 153                         via /proc/acpi/debug_level.
 154
 155         acpi_fake_ecdt  [HW,ACPI] Workaround failure due to BIOS lacking ECDT
 156
 157         ad1816=         [HW,OSS]
 158                         Format: <io>,<irq>,<dma>,<dma2>
 159                         See also Documentation/sound/oss/AD1816.
 160
 161         ad1848=         [HW,OSS]
 162                         Format: <io>,<irq>,<dma>,<dma2>,<type>
 163
 164         adlib=          [HW,OSS]
 165                         Format: <io>
 166
 167         advansys=       [HW,SCSI]
 168                         See header of drivers/scsi/advansys.c.
 169
 170         advwdt=         [HW,WDT] Advantech WDT
 171                         Format: <iostart>,<iostop>
 172
 173         aedsp16=        [HW,OSS] Audio Excel DSP 16
 174                         Format: <io>,<irq>,<dma>,<mss_io>,<mpu_io>,<mpu_irq>
 175                         See also header of sound/oss/aedsp16.c.
 176
 177         aha152x=        [HW,SCSI]
 178                         See Documentation/scsi/aha152x.txt.
 179
 180         aha1542=        [HW,SCSI]
 181                         Format: <portbase>[,<buson>,<busoff>[,<dmaspeed>]]
 182
 183         aic7xxx=        [HW,SCSI]
 184                         See Documentation/scsi/aic7xxx.txt.
 185
 186         aic79xx=        [HW,SCSI]
 187                         See Documentation/scsi/aic79xx.txt.
 188
 189         AM53C974=       [HW,SCSI]
 190                         Format: <host-scsi-id>,<target-scsi-id>,<max-rate>,<max-offset>
 191                         See also header of drivers/scsi/AM53C974.c.
 192
 193         amijoy.map=     [HW,JOY] Amiga joystick support
 194                         Map of devices attached to JOY0DAT and JOY1DAT
 195                         Format: <a>,<b>
 196                         See also Documentation/kernel/input/joystick.txt
 197
 198         analog.map=     [HW,JOY] Analog joystick and gamepad support
 199                         Specifies type or capabilities of an analog joystick
 200                         connected to one of 16 gameports
 201                         Format: <type1>,<type2>,..<type16>
 202
 203         apc=            [HW,SPARC] Power management functions (SPARCstation-4/5 + deriv.)
 204                         Format: noidle
 205                         Disable APC CPU standby support. SPARCstation-Fox does
 206                         not play well with APC CPU idle - disable it if you have
 207                         APC and your system crashes randomly.
 208
 209         apic=           [APIC,i386] Change the output verbosity  whilst booting
 210                         Format: { quiet (default) | verbose | debug }
 211                         Change the amount of debugging information output
 212                         when initialising the APIC and IO-APIC components.
 213
 214         apm=            [APM] Advanced Power Management
 215                         See header of arch/i386/kernel/apm.c.
 216
 217         applicom=       [HW]
 218                         Format: <mem>,<irq>
 219
 220         arcrimi=        [HW,NET] ARCnet - "RIM I" (entirely mem-mapped) cards
 221                         Format: <io>,<irq>,<nodeID>
 222
 223         ataflop=        [HW,M68k]
 224
 225         atarimouse=     [HW,MOUSE] Atari Mouse
 226
 227         atascsi=        [HW,SCSI] Atari SCSI
 228
 229         atkbd.extra=    [HW] Enable extra LEDs and keys on IBM RapidAccess,
 230                         EzKey and similar keyboards
 231
 232         atkbd.reset=    [HW] Reset keyboard during initialization
 233
 234         atkbd.set=      [HW] Select keyboard code set
 235                         Format: <int> (2 = AT (default) 3 = PS/2)
 236
 237         atkbd.scroll=   [HW] Enable scroll wheel on MS Office and similar
 238                         keyboards
 239
 240         atkbd.softraw=  [HW] Choose between synthetic and real raw mode
 241                         Format: <bool> (0 = real, 1 = synthetic (default))
 242
 243         atkbd.softrepeat=
 244                         [HW] Use software keyboard repeat
 245
 246         autotest        [IA64]
 247
 248         awe=            [HW,OSS] AWE32/SB32/AWE64 wave table synth
 249                         Format: <io>,<memsize>,<isapnp>
 250
 251         aztcd=          [HW,CD] Aztech CD268 CDROM driver
 252                         Format: <io>,0x79 (?)
 253
 254         baycom_epp=     [HW,AX25]
 255                         Format: <io>,<mode>
 256
 257         baycom_par=     [HW,AX25] BayCom Parallel Port AX.25 Modem
 258                         Format: <io>,<mode>
 259                         See header of drivers/net/hamradio/baycom_par.c.
 260
 261         baycom_ser_fdx= [HW,AX25] BayCom Serial Port AX.25 Modem (Full Duplex Mode)
 262                         Format: <io>,<irq>,<mode>[,<baud>]
 263                         See header of drivers/net/hamradio/baycom_ser_fdx.c.
 264
 265         baycom_ser_hdx= [HW,AX25] BayCom Serial Port AX.25 Modem (Half Duplex Mode)
 266                         Format: <io>,<irq>,<mode>
 267                         See header of drivers/net/hamradio/baycom_ser_hdx.c.
 268
 269         blkmtd_device=  [HW,MTD]
 270         blkmtd_erasesz=
 271         blkmtd_ro=
 272         blkmtd_bs=
 273         blkmtd_count=
 274
 275         bttv.card=      [HW,V4L] bttv (bt848 + bt878 based grabber cards)
 276         bttv.radio=     Most important insmod options are available as kernel args too.
 277         bttv.pll=       See Documentation/video4linux/bttv/Insmod-options
 278         bttv.tuner=     and Documentation/video4linux/bttv/CARDLIST
 279
 280         BusLogic=       [HW,SCSI]
 281                         See drivers/scsi/BusLogic.c, comment before function
 282                         BusLogic_ParseDriverOptions().
 283
 284         c101=           [NET] Moxa C101 synchronous serial card
 285
 286         cachesize=      [BUGS=IA-32] Override level 2 CPU cache size detection.
 287                         Sometimes CPU hardware bugs make them report the cache
 288                         size incorrectly. The kernel will attempt work arounds
 289                         to fix known problems, but for some CPUs it is not
 290                         possible to determine what the correct size should be.
 291                         This option provides an override for these situations.
 292
 293         cdu31a=         [HW,CD]
 294                         Format: <io>,<irq>[,PAS]
 295                         See header of drivers/cdrom/cdu31a.c.
 296
 297         chandev=        [HW,NET] Generic channel device initialisation
 298
 299         clock=          [BUGS=IA-32, HW] gettimeofday timesource override.
 300                         Forces specified timesource (if avaliable) to be used
 301                         when calculating gettimeofday(). If specicified timesource
 302                         is not avalible, it defaults to PIT.
 303                         Format: { pit | tsc | cyclone | pmtmr }
 304
 305         hpet=           [IA-32,HPET] option to disable HPET and use PIT.
 306                         Format: disable
 307
 308         cm206=          [HW,CD]
 309                         Format: { auto | [<io>,][<irq>] }
 310
 311         com20020=       [HW,NET] ARCnet - COM20020 chipset
 312                         Format: <io>[,<irq>[,<nodeID>[,<backplane>[,<ckp>[,<timeout>]]]]]
 313
 314         com90io=        [HW,NET] ARCnet - COM90xx chipset (IO-mapped buffers)
 315                         Format: <io>[,<irq>]
 316
 317         com90xx=        [HW,NET] ARCnet - COM90xx chipset (memory-mapped buffers)
 318                         Format: <io>[,<irq>[,<memstart>]]
 319
 320         condev=         [HW,S390] console device
 321         conmode=
 322
 323         console=        [KNL] Output console device and options.
 324
 325                 tty<n>  Use the virtual console device <n>.
 326
 327                 ttyS<n>[,options]
 328                         Use the specified serial port.  The options are of
 329                         the form "bbbbpn", where "bbbb" is the baud rate,
 330                         "p" is parity ("n", "o", or "e"), and "n" is bits.
 331                         Default is "9600n8".
 332
 333                         See also Documentation/serial-console.txt.
 334
 335                 uart,io,<addr>[,options]
 336                 uart,mmio,<addr>[,options]
 337                         Start an early, polled-mode console on the 8250/16550
 338                         UART at the specified I/O port or MMIO address,
 339                         switching to the matching ttyS device later.  The
 340                         options are the same as for ttyS, above.
 341
 342         cpcihp_generic= [HW,PCI] Generic port I/O CompactPCI driver
 343                         Format: <first_slot>,<last_slot>,<port>,<enum_bit>[,<debug>]
 344
 345         cpia_pp=        [HW,PPT]
 346                         Format: { parport<nr> | auto | none }
 347
 348         cs4232=         [HW,OSS]
 349                         Format: <io>,<irq>,<dma>,<dma2>,<mpuio>,<mpuirq>
 350
 351         cs89x0_dma=     [HW,NET]
 352                         Format: <dma>
 353
 354         cs89x0_media=   [HW,NET]
 355                         Format: { rj45 | aui | bnc }
 356
 357         cyclades=       [HW,SERIAL] Cyclades multi-serial port adapter.
 358
 359         dasd=           [HW,NET]
 360                         See header of drivers/s390/block/dasd_devmap.c.
 361
 362         db9.dev[2|3]=   [HW,JOY] Multisystem joystick support via parallel port
 363                         (one device per port)
 364                         Format: <port#>,<type>
 365                         See also Documentation/input/joystick-parport.txt
 366
 367         debug           [KNL] Enable kernel debugging (events log level).
 368
 369         decnet=         [HW,NET]
 370                         Format: <area>[,<node>]
 371                         See also Documentation/networking/decnet.txt.
 372
 373         devfs=          [DEVFS]
 374                         See Documentation/filesystems/devfs/boot-options.
 375
 376         dhash_entries=  [KNL]
 377                         Set number of hash buckets for dentry cache.
 378
 379         digi=           [HW,SERIAL]
 380                         IO parameters + enable/disable command.
 381
 382         digiepca=       [HW,SERIAL]
 383                         See drivers/char/README.epca and
 384                         Documentation/digiepca.txt.
 385
 386         dmascc=         [HW,AX25,SERIAL] AX.25 Z80SCC driver with DMA
 387                         support available.
 388                         Format: <io_dev0>[,<io_dev1>[,..<io_dev32>]]
 389
 390         dmasound=       [HW,OSS] Sound subsystem buffers
 391
 392         dscc4.setup=    [NET]
 393
 394         dtc3181e=       [HW,SCSI]
 395
 396         earlyprintk=    [x86, x86_64]
 397                         earlyprintk=vga
 398                         earlyprintk=serial[,ttySn[,baudrate]]
 399
 400                         Append ,keep to not disable it when the real console
 401                         takes over.
 402
 403                         Only vga or serial at a time, not both.
 404
 405                         Currently only ttyS0 and ttyS1 are supported.
 406
 407                         Interaction with the standard serial driver is not
 408                         very good.
 409
 410                         The VGA output is eventually overwritten by the real
 411                         console.
 412
 413         eata=           [HW,SCSI]
 414
 415         eda=            [HW,PS2]
 416
 417         edb=            [HW,PS2]
 418
 419         edd=            [EDD]
 420                         Format: {"of[f]" | "sk[ipmbr]"}
 421                         See comment in arch/i386/boot/edd.S
 422
 423         eicon=          [HW,ISDN]
 424                         Format: <id>,<membase>,<irq>
 425
 426         eisa_irq_edge=  [PARISC,HW]
 427                         See header of drivers/parisc/eisa.c.
 428
 429         elanfreq=       [IA-32]
 430                         See comment before function elanfreq_setup() in
 431                         arch/i386/kernel/cpu/cpufreq/elanfreq.c.
 432
 433         elevator=       [IOSCHED]
 434                         Format: {"as"|"cfq"|"deadline"|"noop"}
 435                         See Documentation/block/as-iosched.txt
 436                         and Documentation/block/deadline-iosched.txt for details.
 437
 438         es1370=         [HW,OSS]
 439                         Format: <lineout>[,<micbias>]
 440                         See also header of sound/oss/es1370.c.
 441
 442         es1371=         [HW,OSS]
 443                         Format: <spdif>,[<nomix>,[<amplifier>]]
 444                         See also header of sound/oss/es1371.c.
 445
 446         ether=          [HW,NET] Ethernet cards parameters
 447                         This option is obsoleted by the "netdev=" option, which
 448                         has equivalent usage. See its documentation for details.
 449
 450         eurwdt=         [HW,WDT] Eurotech CPU-1220/1410 onboard watchdog.
 451                         Format: <io>[,<irq>]
 452
 453         fd_mcs=         [HW,SCSI]
 454                         See header of drivers/scsi/fd_mcs.c.
 455
 456         fdomain=        [HW,SCSI]
 457                         See header of drivers/scsi/fdomain.c.
 458
 459         floppy=         [HW]
 460                         See Documentation/floppy.txt.
 461
 462         ftape=          [HW] Floppy Tape subsystem debugging options.
 463                         See Documentation/ftape.txt.
 464
 465         gamecon.map[2|3]=
 466                         [HW,JOY] Multisystem joystick and NES/SNES/PSX pad
 467                         support via parallel port (up to 5 devices per port)
 468                         Format: <port#>,<pad1>,<pad2>,<pad3>,<pad4>,<pad5>
 469                         See also Documentation/input/joystick-parport.txt
 470
 471         gamma=          [HW,DRM]
 472
 473         gdth=           [HW,SCSI]
 474                         See header of drivers/scsi/gdth.c.
 475
 476         gpt             [EFI] Forces disk with valid GPT signature but
 477                         invalid Protective MBR to be treated as GPT.
 478
 479         gscd=           [HW,CD]
 480                         Format: <io>
 481
 482         gt96100eth=     [NET] MIPS GT96100 Advanced Communication Controller
 483
 484         gus=            [HW,OSS]
 485                         Format: <io>,<irq>,<dma>,<dma16>
 486
 487         gvp11=          [HW,SCSI]
 488
 489         hashdist=       [KNL,NUMA] Large hashes allocated during boot
 490                         are distributed across NUMA nodes.  Defaults on
 491                         for IA-64, off otherwise.
 492
 493         hcl=            [IA-64] SGI's Hardware Graph compatibility layer
 494
 495         hd=             [EIDE] (E)IDE hard drive subsystem geometry
 496                         Format: <cyl>,<head>,<sect>
 497
 498         hd?=            [HW] (E)IDE subsystem
 499         hd?lun=         See Documentation/ide.txt.
 500
 501         highmem=nn[KMG] [KNL,BOOT] forces the highmem zone to have an exact
 502                         size of <nn>. This works even on boxes that have no
 503                         highmem otherwise. This also works to reduce highmem
 504                         size on bigger boxes.
 505
 506         hisax=          [HW,ISDN]
 507                         See Documentation/isdn/README.HiSax.
 508
 509         hugepages=      [HW,IA-32,IA-64] Maximal number of HugeTLB pages.
 510
 511         noirqbalance    [IA-32,SMP,KNL] Disable kernel irq balancing
 512
 513         i8042.direct    [HW] Put keyboard port into non-translated mode
 514         i8042.dumbkbd   [HW] Pretend that controlled can only read data from
 515                              keyboard and can not control its state
 516                              (Don't attempt to blink the leds)
 517         i8042.noacpi    [HW] Don't use ACPI to discover KBD/AUX controller
 518                              settings
 519         i8042.noaux     [HW] Don't check for auxiliary (== mouse) port
 520         i8042.nomux     [HW] Don't check presence of an active multiplexing
 521                              controller
 522         i8042.reset     [HW] Reset the controller during init and cleanup
 523         i8042.unlock    [HW] Unlock (ignore) the keylock
 524
 525         i810=           [HW,DRM]
 526
 527         i8k.force       [HW] Activate i8k driver even if SMM BIOS signature
 528                         does not match list of supported models.
 529         i8k.power_status
 530                         [HW] Report power status in /proc/i8k
 531                         (disabled by default)
 532         i8k.restricted  [HW] Allow controlling fans only if SYS_ADMIN
 533                         capability is set.
 534
 535         ibmmcascsi=     [HW,MCA,SCSI] IBM MicroChannel SCSI adapter
 536                         See Documentation/mca.txt.
 537
 538         icn=            [HW,ISDN]
 539                         Format: <io>[,<membase>[,<icn_id>[,<icn_id2>]]]
 540
 541         ide=            [HW] (E)IDE subsystem
 542                         Format: ide=nodma or ide=doubler or ide=reverse
 543                         See Documentation/ide.txt.
 544
 545         ide?=           [HW] (E)IDE subsystem
 546                         Format: ide?=noprobe or chipset specific parameters.
 547                         See Documentation/ide.txt.
 548
 549         idebus=         [HW] (E)IDE subsystem - VLB/PCI bus speed
 550                         See Documentation/ide.txt.
 551
 552         idle=           [HW]
 553                         Format: idle=poll or idle=halt
 554
 555         ihash_entries=  [KNL]
 556                         Set number of hash buckets for inode cache.
 557
 558         in2000=         [HW,SCSI]
 559                         See header of drivers/scsi/in2000.c.
 560
 561         init=           [KNL]
 562                         Format: <full_path>
 563                         Run specified binary instead of /sbin/init as init
 564                         process.
 565
 566         initcall_debug  [KNL] Trace initcalls as they are executed.  Useful
 567                         for working out where the kernel is dying during
 568                         startup.
 569
 570         initrd=         [BOOT] Specify the location of the initial ramdisk
 571
 572         inport.irq=     [HW] Inport (ATI XL and Microsoft) busmouse driver
 573                         Format: <irq>
 574
 575         inttest=        [IA64]
 576
 577         io7=            [HW] IO7 for Marvel based alpha systems
 578                         See comment before marvel_specify_io7 in
 579                         arch/alpha/kernel/core_marvel.c.
 580
 581         ip=             [IP_PNP]
 582                         See Documentation/nfsroot.txt.
 583
 584         ip2=            [HW] Set IO/IRQ pairs for up to 4 IntelliPort boards
 585                         See comment before ip2_setup() in drivers/char/ip2.c.
 586
 587         ips=            [HW,SCSI] Adaptec / IBM ServeRAID controller
 588                         See header of drivers/scsi/ips.c.
 589
 590         isapnp=         [ISAPNP]
 591                         Format: <RDP>, <reset>, <pci_scan>, <verbosity>
 592
 593         isolcpus=       [KNL,SMP] Isolate CPUs from the general scheduler.
 594                         Format: <cpu number>,...,<cpu number>
 595                         This option can be used to specify one or more CPUs
 596                         to isolate from the general SMP balancing and scheduling
 597                         algorithms. The only way to move a process onto or off
 598                         an "isolated" CPU is via the CPU affinity syscalls.
 599                         <cpu number> begins at 0 and the maximum value is
 600                         "number of CPUs in system - 1".
 601
 602                         This option is the preferred way to isolate CPUs. The
 603                         alternative - manually setting the CPU mask of all tasks
 604                         in the system can cause problems and suboptimal load
 605                         balancer performance.
 606
 607         isp16=          [HW,CD]
 608                         Format: <io>,<irq>,<dma>,<setup>
 609
 610         iucv=           [HW,NET]
 611
 612         js=             [HW,JOY] Analog joystick
 613                         See Documentation/input/joystick.txt.
 614
 615         keepinitrd      [HW,ARM]
 616
 617         l2cr=           [PPC]
 618
 619         lapic           [IA-32,APIC] Enable the local APIC even if BIOS disabled it.
 620
 621         lasi=           [HW,SCSI] PARISC LASI driver for the 53c700 chip
 622                         Format: addr:<io>,irq:<irq>
 623
 624         llsc*=          [IA64]
 625                         See function print_params() in arch/ia64/sn/kernel/llsc4.c.
 626
 627         load_ramdisk=   [RAM] List of ramdisks to load from floppy
 628                         See Documentation/ramdisk.txt.
 629
 630         lockd.udpport=  [NFS]
 631
 632         lockd.tcpport=  [NFS]
 633
 634         logibm.irq=     [HW,MOUSE] Logitech Bus Mouse Driver
 635                         Format: <irq>
 636
 637         log_buf_len=n   Sets the size of the printk ring buffer, in bytes.
 638                         Format is n, nk, nM.  n must be a power of two.  The
 639                         default is set in kernel config.
 640
 641         lp=0            [LP]    Specify parallel ports to use, e.g,
 642         lp=port[,port...]       lp=none,parport0 (lp0 not configured, lp1 uses
 643         lp=reset                first parallel port). 'lp=0' disables the
 644         lp=auto                 printer driver. 'lp=reset' (which can be
 645                                 specified in addition to the ports) causes
 646                                 attached printers to be reset. Using
 647                                 lp=port1,port2,... specifies the parallel ports
 648                                 to associate lp devices with, starting with
 649                                 lp0. A port specification may be 'none' to skip
 650                                 that lp device, or a parport name such as
 651                                 'parport0'. Specifying 'lp=auto' instead of a
 652                                 port specification list means that device IDs
 653                                 from each port should be examined, to see if
 654                                 an IEEE 1284-compliant printer is attached; if
 655                                 so, the driver will manage that printer.
 656                                 See also header of drivers/char/lp.c.
 657
 658         lpj=n           [KNL]
 659                         Sets loops_per_jiffy to given constant, thus avoiding
 660                         time-consuming boot-time autodetection (up to 250 ms per
 661                         CPU). 0 enables autodetection (default). To determine
 662                         the correct value for your kernel, boot with normal
 663                         autodetection and see what value is printed. Note that
 664                         on SMP systems the preset will be applied to all CPUs,
 665                         which is likely to cause problems if your CPUs need
 666                         significantly divergent settings. An incorrect value
 667                         will cause delays in the kernel to be wrong, leading to
 668                         unpredictable I/O errors and other breakage. Although
 669                         unlikely, in the extreme case this might damage your
 670                         hardware.
 671
 672         ltpc=           [NET]
 673                         Format: <io>,<irq>,<dma>
 674
 675         mac5380=        [HW,SCSI]
 676                         Format: <can_queue>,<cmd_per_lun>,<sg_tablesize>,<hostid>,<use_tags>
 677
 678         mac53c9x=       [HW,SCSI]
 679                         Format: <num_esps>,<disconnect>,<nosync>,<can_queue>,<cmd_per_lun>,<sg_tablesize>,<hostid>,<use_tags>
 680
 681         machvec=        [IA64]
 682                         Force the use of a particular machine-vector (machvec) in a generic
 683                         kernel.  Example: machvec=hpzx1_swiotlb
 684
 685         mad16=          [HW,OSS]
 686                         Format: <io>,<irq>,<dma>,<dma16>,<mpu_io>,<mpu_irq>,<joystick>
 687
 688         maui=           [HW,OSS]
 689                         Format: <io>,<irq>
 690
 691         max_loop=       [LOOP] Maximum number of loopback devices that can
 692                         be mounted
 693                         Format: <1-256>
 694
 695         maxcpus=        [SMP] Maximum number of processors that an SMP kernel
 696                         should make use of
 697
 698         max_luns=       [SCSI] Maximum number of LUNs to probe
 699                         Should be between 1 and 2^32-1.
 700
 701         max_report_luns=
 702                         [SCSI] Maximum number of LUNs received
 703                         Should be between 1 and 16384.
 704
 705         mca-pentium     [BUGS=IA-32]
 706
 707         mcatest=        [IA-64]
 708
 709         mcd=            [HW,CD]
 710                         Format: <port>,<irq>,<mitsumi_bug_93_wait>
 711
 712         mcdx=           [HW,CD]
 713
 714         mce             [IA-32] Machine Check Exception
 715
 716         md=             [HW] RAID subsystems devices and level
 717                         See Documentation/md.txt.
 718
 719         mdacon=         [MDA]
 720                         Format: <first>,<last>
 721                         Specifies range of consoles to be captured by the MDA.
 722
 723         mem=nn[KMG]     [KNL,BOOT] Force usage of a specific amount of memory
 724                         Amount of memory to be used when the kernel is not able
 725                         to see the whole system memory or for test.
 726                         [IA-32] Use together with memmap= to avoid physical
 727                         address space collisions. Without memmap= PCI devices
 728                         could be placed at addresses belonging to unused RAM.
 729
 730         mem=nopentium   [BUGS=IA-32] Disable usage of 4MB pages for kernel
 731                         memory.
 732
 733         memmap=exactmap [KNL,IA-32] Enable setting of an exact
 734                         E820 memory map, as specified by the user.
 735                         Such memmap=exactmap lines can be constructed based on
 736                         BIOS output or other requirements. See the memmap=nn@ss
 737                         option description.
 738
 739         memmap=nn[KMG]@ss[KMG]
 740                         [KNL] Force usage of a specific region of memory
 741                         Region of memory to be used, from ss to ss+nn.
 742
 743         memmap=nn[KMG]#ss[KMG]
 744                         [KNL,ACPI] Mark specific memory as ACPI data.
 745                         Region of memory to be used, from ss to ss+nn.
 746
 747         memmap=nn[KMG]$ss[KMG]
 748                         [KNL,ACPI] Mark specific memory as reserved.
 749                         Region of memory to be used, from ss to ss+nn.
 750
 751         meye.*=         [HW] Set MotionEye Camera parameters
 752                         See Documentation/video4linux/meye.txt.
 753
 754         mga=            [HW,DRM]
 755
 756         mousedev.tap_time=
 757                         [MOUSE] Maximum time between finger touching and
 758                         leaving touchpad surface for touch to be considered
 759                         a tap and be reported as a left button click (for
 760                         touchpads working in absolute mode only).
 761                         Format: <msecs>
 762         mousedev.xres=  [MOUSE] Horizontal screen resolution, used for devices
 763                         reporting absolute coordinates, such as tablets
 764         mousedev.yres=  [MOUSE] Vertical screen resolution, used for devices
 765                         reporting absolute coordinates, such as tablets
 766
 767         mpu401=         [HW,OSS]
 768                         Format: <io>,<irq>
 769
 770         MTD_Partition=  [MTD]
 771                         Format: <name>,<region-number>,<size>,<offset>
 772
 773         MTD_Region=     [MTD]
 774                         Format: <name>,<region-number>[,<base>,<size>,<buswidth>,<altbuswidth>]
 775
 776         mtdparts=       [MTD]
 777                         See drivers/mtd/cmdline.c.
 778
 779         n2=             [NET] SDL Inc. RISCom/N2 synchronous serial card
 780
 781         NCR_D700=       [HW,SCSI]
 782                         See header of drivers/scsi/NCR_D700.c.
 783
 784         ncr5380=        [HW,SCSI]
 785
 786         ncr53c400=      [HW,SCSI]
 787
 788         ncr53c400a=     [HW,SCSI]
 789
 790         ncr53c406a=     [HW,SCSI]
 791
 792         ncr53c8xx=      [HW,SCSI]
 793
 794         netdev=         [NET] Network devices parameters
 795                         Format: <irq>,<io>,<mem_start>,<mem_end>,<name>
 796                         Note that mem_start is often overloaded to mean
 797                         something different and driver-specific.
 798
 799         nfsaddrs=       [NFS]
 800                         See Documentation/nfsroot.txt.
 801
 802         nfsroot=        [NFS] nfs root filesystem for disk-less boxes.
 803                         See Documentation/nfsroot.txt.
 804
 805         nmi_watchdog=   [KNL,BUGS=IA-32] Debugging features for SMP kernels
 806
 807         no387           [BUGS=IA-32] Tells the kernel to use the 387 maths
 808                         emulation library even if a 387 maths coprocessor
 809                         is present.
 810
 811         noalign         [KNL,ARM]
 812
 813         noapic          [SMP,APIC] Tells the kernel to not make use of any
 814                         IOAPICs that may be present in the system.
 815
 816         noasync         [HW,M68K] Disables async and sync negotiation for
 817                         all devices.
 818
 819         nobats          [PPC] Do not use BATs for mapping kernel lowmem
 820                         on "Classic" PPC cores.
 821
 822         nocache         [ARM]
 823
 824         nodisconnect    [HW,SCSI,M68K] Disables SCSI disconnects.
 825
 826         noexec          [IA-64]
 827
 828         noexec          [i386, x86_64]
 829                         noexec=on: enable non-executable mappings (default)
 830                         noexec=off: disable nn-executable mappings
 831
 832         nofxsr          [BUGS=IA-32]
 833
 834         nohlt           [BUGS=ARM]
 835
 836         no-hlt          [BUGS=IA-32] Tells the kernel that the hlt
 837                         instruction doesn't work correctly and not to
 838                         use it.
 839
 840         noirqdebug      [IA-32] Disables the code which attempts to detect and
 841                         disable unhandled interrupt sources.
 842
 843         noisapnp        [ISAPNP] Disables ISA PnP code.
 844
 845         noinitrd        [RAM] Tells the kernel not to load any configured
 846                         initial RAM disk.
 847
 848         nointroute      [IA-64]
 849
 850         nolapic         [IA-32,APIC] Do not enable or use the local APIC.
 851
 852         noltlbs         [PPC] Do not use large page/tlb entries for kernel
 853                         lowmem mapping on PPC40x.
 854
 855         nomce           [IA-32] Machine Check Exception
 856
 857         noresidual      [PPC] Don't use residual data on PReP machines.
 858
 859         noresume        [SWSUSP] Disables resume and restore original swap space.
 860
 861         no-scroll       [VGA] Disables scrollback.
 862                         This is required for the Braillex ib80-piezo Braille
 863                         reader made by F.H. Papenmeier (Germany).
 864
 865         nosbagart       [IA-64]
 866
 867         nosmp           [SMP] Tells an SMP kernel to act as a UP kernel.
 868
 869         nosync          [HW,M68K] Disables sync negotiation for all devices.
 870
 871         notsc           [BUGS=IA-32] Disable Time Stamp Counter
 872
 873         nousb           [USB] Disable the USB subsystem
 874
 875         nowb            [ARM]
 876
 877         opl3=           [HW,OSS]
 878                         Format: <io>
 879
 880         opl3sa=         [HW,OSS]
 881                         Format: <io>,<irq>,<dma>,<dma2>,<mpu_io>,<mpu_irq>
 882
 883         opl3sa2=        [HW,OSS]
 884                         Format: <io>,<irq>,<dma>,<dma2>,<mss_io>,<mpu_io>,<ymode>,<loopback>[,<isapnp>,<multiple]
 885
 886         oprofile.timer= [HW]
 887                         Use timer interrupt instead of performance counters
 888
 889         optcd=          [HW,CD]
 890                         Format: <io>
 891
 892         osst=           [HW,SCSI] SCSI Tape Driver
 893                         Format: <buffer_size>,<write_threshold>
 894                         See also Documentation/scsi/st.txt.
 895
 896         panic=          [KNL] Kernel behaviour on panic
 897                         Format: <timeout>
 898
 899         parkbd.port=    [HW] Parallel port number the keyboard adapter is
 900                         connected to, default is 0.
 901                         Format: <parport#>
 902         parkbd.mode=    [HW] Parallel port keyboard adapter mode of operation,
 903                         0 for XT, 1 for AT (default is AT).
 904                         Format: <mode>
 905
 906         parport=0       [HW,PPT]        Specify parallel ports. 0 disables.
 907         parport=auto                    Use 'auto' to force the driver to use
 908         parport=0xBBB[,IRQ[,DMA]]       any IRQ/DMA settings detected (the
 909                                         default is to ignore detected IRQ/DMA
 910                                         settings because of possible
 911                                         conflicts). You can specify the base
 912                                         address, IRQ, and DMA settings; IRQ and
 913                                         DMA should be numbers, or 'auto' (for
 914                                         using detected settings on that
 915                                         particular port), or 'nofifo' (to avoid
 916                                         using a FIFO even if it is detected).
 917                                         Parallel ports are assigned in the
 918                                         order they are specified on the command
 919                                         line, starting with parport0.
 920
 921         parport_init_mode=
 922                         [HW,PPT]        Configure VIA parallel port to
 923                                         operate in specific mode. This is
 924                                         necessary on Pegasos computer where
 925                                         firmware has no options for setting up
 926                                         parallel port mode and sets it to
 927                                         spp. Currently this function knows
 928                                         686a and 8231 chips.
 929                         Format: [spp|ps2|epp|ecp|ecpepp]
 930
 931         pas2=           [HW,OSS]
 932                         Format: <io>,<irq>,<dma>,<dma16>,<sb_io>,<sb_irq>,<sb_dma>,<sb_dma16>
 933
 934         pas16=          [HW,SCSI]
 935                         See header of drivers/scsi/pas16.c.
 936
 937         pcbit=          [HW,ISDN]
 938
 939         pcd.            [PARIDE]
 940                         See header of drivers/block/paride/pcd.c.
 941                         See also Documentation/paride.txt.
 942
 943         pci=option[,option...]          [PCI] various PCI subsystem options:
 944                 off                     [IA-32] don't probe for the PCI bus
 945                 bios                    [IA-32] force use of PCI BIOS, don't access
 946                                         the hardware directly. Use this if your machine
 947                                         has a non-standard PCI host bridge.
 948                 nobios                  [IA-32] disallow use of PCI BIOS, only direct
 949                                         hardware access methods are allowed. Use this
 950                                         if you experience crashes upon bootup and you
 951                                         suspect they are caused by the BIOS.
 952                 conf1                   [IA-32] Force use of PCI Configuration Mechanism 1.
 953                 conf2                   [IA-32] Force use of PCI Configuration Mechanism 2.
 954                 nosort                  [IA-32] Don't sort PCI devices according to
 955                                         order given by the PCI BIOS. This sorting is done
 956                                         to get a device order compatible with older kernels.
 957                 biosirq                 [IA-32] Use PCI BIOS calls to get the interrupt
 958                                         routing table. These calls are known to be buggy
 959                                         on several machines and they hang the machine when used,
 960                                         but on other computers it's the only way to get the
 961                                         interrupt routing table. Try this option if the kernel
 962                                         is unable to allocate IRQs or discover secondary PCI
 963                                         buses on your motherboard.
 964                 rom                     [IA-32] Assign address space to expansion ROMs.
 965                                         Use with caution as certain devices share address
 966                                         decoders between ROMs and other resources.
 967                 irqmask=0xMMMM          [IA-32] Set a bit mask of IRQs allowed to be assigned
 968                                         automatically to PCI devices. You can make the kernel
 969                                         exclude IRQs of your ISA cards this way.
 970                 lastbus=N               [IA-32] Scan all buses till bus #N. Can be useful
 971                                         if the kernel is unable to find your secondary buses
 972                                         and you want to tell it explicitly which ones they are.
 973                 assign-busses           [IA-32] Always assign all PCI bus
 974                                         numbers ourselves, overriding
 975                                         whatever the firmware may have
 976                                         done.
 977                 usepirqmask             [IA-32] Honor the possible IRQ mask
 978                                         stored in the BIOS $PIR table. This is
 979                                         needed on some systems with broken
 980                                         BIOSes, notably some HP Pavilion N5400
 981                                         and Omnibook XE3 notebooks. This will
 982                                         have no effect if ACPI IRQ routing is
 983                                         enabled.
 984                 noacpi                  [IA-32] Do not use ACPI for IRQ routing
 985                                         or for PCI scanning.
 986                 routeirq                Do IRQ routing for all PCI devices.
 987                                         This is normally done in pci_enable_device(),
 988                                         so this option is a temporary workaround
 989                                         for broken drivers that don't call it.
 990
 991                 firmware                [ARM] Do not re-enumerate the bus but
 992                                         instead just use the configuration
 993                                         from the bootloader. This is currently
 994                                         used on IXP2000 systems where the
 995                                         bus has to be configured a certain way
 996                                         for adjunct CPUs.
 997
 998         pcmv=           [HW,PCMCIA] BadgePAD 4
 999
1000         pd.             [PARIDE]
1001                         See Documentation/paride.txt.
1002
1003         pdcchassis=     [PARISC,HW] Disable/Enable PDC Chassis Status codes at
1004                         boot time.
1005                         Format: { 0 | 1 }
1006                         See arch/parisc/kernel/pdc_chassis.c
1007
1008         pf.             [PARIDE]
1009                         See Documentation/paride.txt.
1010
1011         pg.             [PARIDE]
1012                         See Documentation/paride.txt.
1013
1014         pirq=           [SMP,APIC] Manual mp-table setup
1015                         See Documentation/i386/IO-APIC.txt.
1016
1017         plip=           [PPT,NET] Parallel port network link
1018                         Format: { parport<nr> | timid | 0 }
1019                         See also Documentation/parport.txt.
1020
1021         pnpacpi=        [ACPI]
1022                         { off }
1023
1024         pnpbios=        [ISAPNP]
1025                         { on | off | curr | res | no-curr | no-res }
1026
1027         pnp_reserve_irq=
1028                         [ISAPNP] Exclude IRQs for the autoconfiguration
1029
1030         pnp_reserve_dma=
1031                         [ISAPNP] Exclude DMAs for the autoconfiguration
1032
1033         pnp_reserve_io= [ISAPNP] Exclude I/O ports for the autoconfiguration
1034                         Ranges are in pairs (I/O port base and size).
1035
1036         pnp_reserve_mem=
1037                         [ISAPNP] Exclude memory regions for the autoconfiguration
1038                         Ranges are in pairs (memory base and size).
1039
1040         profile=        [KNL] Enable kernel profiling via /proc/profile
1041                         { schedule | <number> }
1042                         (param: schedule - profile schedule points}
1043                         (param: profile step/bucket size as a power of 2 for
1044                                 statistical time based profiling)
1045
1046         processor.max_cstate=   [HW, ACPI]
1047                         Limit processor to maximum C-state
1048                         max_cstate=9 overrides any DMI blacklist limit.
1049
1050         prompt_ramdisk= [RAM] List of RAM disks to prompt for floppy disk
1051                         before loading.
1052                         See Documentation/ramdisk.txt.
1053
1054         psmouse.proto=  [HW,MOUSE] Highest PS2 mouse protocol extension to
1055                         probe for (bare|imps|exps).
1056         psmouse.rate=   [HW,MOUSE] Set desired mouse report rate, in reports
1057                         per second.
1058         psmouse.resetafter=
1059                         [HW,MOUSE] Try to reset the device after so many bad packets
1060                         (0 = never).
1061         psmouse.resolution=
1062                         [HW,MOUSE] Set desired mouse resolution, in dpi.
1063         psmouse.smartscroll=
1064                         [HW,MOUSE] Controls Logitech smartscroll autorepeat,
1065                         0 = disabled, 1 = enabled (default).
1066
1067         pss=            [HW,OSS] Personal Sound System (ECHO ESC614)
1068                         Format: <io>,<mss_io>,<mss_irq>,<mss_dma>,<mpu_io>,<mpu_irq>
1069
1070         pt.             [PARIDE]
1071                         See Documentation/paride.txt.
1072
1073         quiet=          [KNL] Disable log messages
1074
1075         r128=           [HW,DRM]
1076
1077         raid=           [HW,RAID]
1078                         See Documentation/md.txt.
1079
1080         ramdisk=        [RAM] Sizes of RAM disks in kilobytes [deprecated]
1081                         See Documentation/ramdisk.txt.
1082
1083         ramdisk_blocksize=
1084                         [RAM]
1085                         See Documentation/ramdisk.txt.
1086
1087         ramdisk_size=   [RAM] Sizes of RAM disks in kilobytes
1088                         New name for the ramdisk parameter.
1089                         See Documentation/ramdisk.txt.
1090
1091         reboot=         [BUGS=IA-32,BUGS=ARM,BUGS=IA-64] Rebooting mode
1092                         Format: <reboot_mode>[,<reboot_mode2>[,...]]
1093                         See arch/*/kernel/reboot.c.
1094
1095         reserve=        [KNL,BUGS] Force the kernel to ignore some iomem area
1096
1097         resume=         [SWSUSP] Specify the partition device for software suspension
1098
1099         rhash_entries=  [KNL,NET]
1100                         Set number of hash buckets for route cache
1101
1102         riscom8=        [HW,SERIAL]
1103                         Format: <io_board1>[,<io_board2>[,...<io_boardN>]]
1104
1105         ro              [KNL] Mount root device read-only on boot
1106
1107         root=           [KNL] Root filesystem
1108
1109         rootdelay=      [KNL] Delay (in seconds) to pause before attempting to
1110                         mount the root filesystem
1111
1112         rootflags=      [KNL] Set root filesystem mount option string
1113
1114         rootfstype=     [KNL] Set root filesystem type
1115
1116         rw              [KNL] Mount root device read-write on boot
1117
1118         S               [KNL] Run init in single mode
1119
1120         sa1100ir        [NET]
1121                         See drivers/net/irda/sa1100_ir.c.
1122
1123         sb=             [HW,OSS]
1124                         Format: <io>,<irq>,<dma>,<dma2>
1125
1126         sbni=           [NET] Granch SBNI12 leased line adapter
1127
1128         sbpcd=          [HW,CD] Soundblaster CD adapter
1129                         Format: <io>,<type>
1130                         See a comment before function sbpcd_setup() in
1131                         drivers/cdrom/sbpcd.c.
1132
1133         sc1200wdt=      [HW,WDT] SC1200 WDT (watchdog) driver
1134                         Format: <io>[,<timeout>[,<isapnp>]]
1135
1136         scsi_debug_*=   [SCSI]
1137                         See drivers/scsi/scsi_debug.c.
1138
1139         scsi_default_dev_flags=
1140                         [SCSI] SCSI default device flags
1141                         Format: <integer>
1142
1143         scsi_dev_flags= [SCSI] Black/white list entry for vendor and model
1144                         Format: <vendor>:<model>:<flags>
1145                         (flags are integer value)
1146
1147         scsi_logging=   [SCSI]
1148
1149         serialnumber    [BUGS=IA-32]
1150
1151         sf16fm=         [HW] SF16FMI radio driver for Linux
1152                         Format: <io>
1153
1154         sg_def_reserved_size=
1155                         [SCSI]
1156
1157         sgalaxy=        [HW,OSS]
1158                         Format: <io>,<irq>,<dma>,<dma2>,<sgbase>
1159
1160         shapers=        [NET]
1161                         Maximal number of shapers.
1162
1163         sim710=         [SCSI,HW]
1164                         See header of drivers/scsi/sim710.c.
1165
1166         simeth=         [IA-64]
1167         simscsi=
1168
1169         sjcd=           [HW,CD]
1170                         Format: <io>,<irq>,<dma>
1171                         See header of drivers/cdrom/sjcd.c.
1172
1173         slram=          [HW,MTD]
1174
1175         smart2=         [HW]
1176                         Format: <io1>[,<io2>[,...,<io8>]]
1177
1178         snd-ad1816a=    [HW,ALSA]
1179
1180         snd-ad1848=     [HW,ALSA]
1181
1182         snd-ali5451=    [HW,ALSA]
1183
1184         snd-als100=     [HW,ALSA]
1185
1186         snd-als4000=    [HW,ALSA]
1187
1188         snd-azt2320=    [HW,ALSA]
1189
1190         snd-cmi8330=    [HW,ALSA]
1191
1192         snd-cmipci=     [HW,ALSA]
1193
1194         snd-cs4231=     [HW,ALSA]
1195
1196         snd-cs4232=     [HW,ALSA]
1197
1198         snd-cs4236=     [HW,ALSA]
1199
1200         snd-cs4281=     [HW,ALSA]
1201
1202         snd-cs46xx=     [HW,ALSA]
1203
1204         snd-dt019x=     [HW,ALSA]
1205
1206         snd-dummy=      [HW,ALSA]
1207
1208         snd-emu10k1=    [HW,ALSA]
1209
1210         snd-ens1370=    [HW,ALSA]
1211
1212         snd-ens1371=    [HW,ALSA]
1213
1214         snd-es968=      [HW,ALSA]
1215
1216         snd-es1688=     [HW,ALSA]
1217
1218         snd-es18xx=     [HW,ALSA]
1219
1220         snd-es1938=     [HW,ALSA]
1221
1222         snd-es1968=     [HW,ALSA]
1223
1224         snd-fm801=      [HW,ALSA]
1225
1226         snd-gusclassic= [HW,ALSA]
1227
1228         snd-gusextreme= [HW,ALSA]
1229
1230         snd-gusmax=     [HW,ALSA]
1231
1232         snd-hdsp=       [HW,ALSA]
1233
1234         snd-ice1712=    [HW,ALSA]
1235
1236         snd-intel8x0=   [HW,ALSA]
1237
1238         snd-interwave=  [HW,ALSA]
1239
1240         snd-interwave-stb=
1241                         [HW,ALSA]
1242
1243         snd-korg1212=   [HW,ALSA]
1244
1245         snd-maestro3=   [HW,ALSA]
1246
1247         snd-mpu401=     [HW,ALSA]
1248
1249         snd-mtpav=      [HW,ALSA]
1250
1251         snd-nm256=      [HW,ALSA]
1252
1253         snd-opl3sa2=    [HW,ALSA]
1254
1255         snd-opti92x-ad1848=
1256                         [HW,ALSA]
1257
1258         snd-opti92x-cs4231=
1259                         [HW,ALSA]
1260
1261         snd-opti93x=    [HW,ALSA]
1262
1263         snd-pmac=       [HW,ALSA]
1264
1265         snd-rme32=      [HW,ALSA]
1266
1267         snd-rme96=      [HW,ALSA]
1268
1269         snd-rme9652=    [HW,ALSA]
1270
1271         snd-sb8=        [HW,ALSA]
1272
1273         snd-sb16=       [HW,ALSA]
1274
1275         snd-sbawe=      [HW,ALSA]
1276
1277         snd-serial=     [HW,ALSA]
1278
1279         snd-sgalaxy=    [HW,ALSA]
1280
1281         snd-sonicvibes= [HW,ALSA]
1282
1283         snd-sun-amd7930=
1284                         [HW,ALSA]
1285
1286         snd-sun-cs4231= [HW,ALSA]
1287
1288         snd-trident=    [HW,ALSA]
1289
1290         snd-usb-audio=  [HW,ALSA,USB]
1291
1292         snd-via82xx=    [HW,ALSA]
1293
1294         snd-virmidi=    [HW,ALSA]
1295
1296         snd-wavefront=  [HW,ALSA]
1297
1298         snd-ymfpci=     [HW,ALSA]
1299
1300         sonicvibes=     [HW,OSS]
1301                         Format: <reverb>
1302
1303         sonycd535=      [HW,CD]
1304                         Format: <io>[,<irq>]
1305
1306         sonypi.*=       [HW] Sony Programmable I/O Control Device driver
1307                         See Documentation/sonypi.txt
1308
1309         specialix=      [HW,SERIAL] Specialix multi-serial port adapter
1310                         See Documentation/specialix.txt.
1311
1312         spia_io_base=   [HW,MTD]
1313         spia_fio_base=
1314         spia_pedr=
1315         spia_peddr=
1316
1317         sscape=         [HW,OSS]
1318                         Format: <io>,<irq>,<dma>,<mpu_io>,<mpu_irq>
1319
1320         st=             [HW,SCSI] SCSI tape parameters (buffers, etc.)
1321                         See Documentation/scsi/st.txt.
1322
1323         st0x=           [HW,SCSI]
1324                         See header of drivers/scsi/seagate.c.
1325
1326         sti=            [PARISC,HW]
1327                         Format: <num>
1328                         Set the STI (builtin display/keyboard on the HP-PARISC
1329                         machines) console (graphic card) which should be used
1330                         as the initial boot-console.
1331                         See also comment in drivers/video/console/sticore.c.
1332
1333         sti_font=       [HW]
1334                         See comment in drivers/video/console/sticore.c.
1335
1336         stifb=          [HW]
1337                         Format: bpp:<bpp1>[:<bpp2>[:<bpp3>...]]
1338
1339         stram_swap=     [HW,M68k]
1340
1341         swiotlb=        [IA-64] Number of I/O TLB slabs
1342
1343         switches=       [HW,M68k]
1344
1345         sym53c416=      [HW,SCSI]
1346                         See header of drivers/scsi/sym53c416.c.
1347
1348         sym53c8xx=      [HW,SCSI]
1349                         See Documentation/scsi/ncr53c8xx.txt.
1350
1351         t128=           [HW,SCSI]
1352                         See header of drivers/scsi/t128.c.
1353
1354         tdfx=           [HW,DRM]
1355
1356         thash_entries=  [KNL,NET]
1357                         Set number of hash buckets for TCP connection
1358
1359         tipar.timeout=  [HW,PPT]
1360                         Set communications timeout in tenths of a second
1361                         (default 15).
1362
1363         tipar.delay=    [HW,PPT]
1364                         Set inter-bit delay in microseconds (default 10).
1365
1366         tmc8xx=         [HW,SCSI]
1367                         See header of drivers/scsi/seagate.c.
1368
1369         tmscsim=        [HW,SCSI]
1370                         See comment before function dc390_setup() in
1371                         drivers/scsi/tmscsim.c.
1372
1373         tp720=          [HW,PS2]
1374
1375         trix=           [HW,OSS] MediaTrix AudioTrix Pro
1376                         Format: <io>,<irq>,<dma>,<dma2>,<sb_io>,<sb_irq>,<sb_dma>,<mpu_io>,<mpu_irq>
1377
1378         tsdev.xres=     [TS] Horizontal screen resolution.
1379         tsdev.yres=     [TS] Vertical screen resolution.
1380
1381         turbografx.map[2|3]=
1382                         [HW,JOY] TurboGraFX parallel port interface
1383                         Format: <port#>,<js1>,<js2>,<js3>,<js4>,<js5>,<js6>,<js7>
1384                         See also Documentation/input/joystick-parport.txt
1385
1386         u14-34f=        [HW,SCSI] UltraStor 14F/34F SCSI host adapter
1387                         See header of drivers/scsi/u14-34f.c.
1388
1389         uart401=        [HW,OSS]
1390                         Format: <io>,<irq>
1391
1392         uart6850=       [HW,OSS]
1393                         Format: <io>,<irq>
1394
1395         usb-handoff     [HW] Enable early USB BIOS -> OS handoff
1396
1397         video=          [FB] Frame buffer configuration
1398                         See Documentation/fb/modedb.txt.
1399
1400         vga=            [BOOT,IA-32] Select a particular video mode
1401                         See Documentation/i386/boot.txt and Documentation/svga.txt.
1402                         Use vga=ask for menu.
1403                         This is actually a boot loader parameter; the value is
1404                         passed to the kernel using a special protocol.
1405
1406         vmalloc=nn[KMG] [KNL,BOOT] forces the vmalloc area to have an exact
1407                         size of <nn>. This can be used to increase the
1408                         minimum size (128MB on x86). It can also be used to
1409                         decrease the size and leave more room for directly
1410                         mapped kernel RAM.
1411
1412         vmhalt=         [KNL,S390]
1413
1414         vmpoff=         [KNL,S390]
1415
1416         waveartist=     [HW,OSS]
1417                         Format: <io>,<irq>,<dma>,<dma2>
1418
1419         wd33c93=        [HW,SCSI]
1420                         See header of drivers/scsi/wd33c93.c.
1421
1422         wd7000=         [HW,SCSI]
1423                         See header of drivers/scsi/wd7000.c.
1424
1425         wdt=            [WDT] Watchdog
1426                         See Documentation/watchdog/watchdog.txt.
1427
1428         xd=             [HW,XT] Original XT pre-IDE (RLL encoded) disks.
1429         xd_geo=         See header of drivers/block/xd.c.
1430
1431         xirc2ps_cs=     [NET,PCMCIA]
1432                         Format: <irq>,<irq_mask>,<io>,<full_duplex>,<do_sound>,<lockup_hack>[,<irq2>[,<irq3>[,<irq4>]]]
1433
1434
1435
1436 Changelog:
1437
1438         The last known update (for 2.4.0) - the changelog was not kept before.
1439         2000-06-??      Mr. Unknown
1440
1441         Update for 2.5.49, description for most of the options introduced,
1442         references to other documentation (C files, READMEs, ..), added S390,
1443         PPC, SPARC, MTD, ALSA and OSS category. Minor corrections and
1444         reformatting.
1445         2002-11-24      Petr Baudis <pasky@ucw.cz>
1446                         Randy Dunlap <randy.dunlap@verizon.net>
1447
1448 TODO:
1449
1450         Add documentation for ALSA options.
1451         Add more DRM drivers.