Documentation/kernel-parameters.txt

   1                           Kernel Parameters
   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 This document may not be entirely up to date and comprehensive. The command
  21 "modinfo -p ${modulename}" shows a current list of all parameters of a loadable
  22 module. Loadable modules, after being loaded into the running kernel, also
  23 reveal their parameters in /sys/module/${modulename}/parameters/. Some of these
  24 parameters may be changed at runtime by the command
  25 "echo -n ${value} > /sys/module/${modulename}/parameters/${parm}".
  26
  27 The parameters listed below are only valid if certain kernel build options were
  28 enabled and if respective hardware is present. The text in square brackets at
  29 the beginning of each description states the restrictions within which a
  30 parameter is applicable:
  31
  32         ACPI    ACPI support is enabled.
  33         ALSA    ALSA sound support is enabled.
  34         APIC    APIC support is enabled.
  35         APM     Advanced Power Management support is enabled.
  36         AX25    Appropriate AX.25 support is enabled.
  37         CD      Appropriate CD support is enabled.
  38         DRM     Direct Rendering Management support is enabled.
  39         EDD     BIOS Enhanced Disk Drive Services (EDD) is enabled
  40         EFI     EFI Partitioning (GPT) is enabled
  41         EIDE    EIDE/ATAPI support is enabled.
  42         FB      The frame buffer device is enabled.
  43         HW      Appropriate hardware is enabled.
  44         IA-32   IA-32 aka i386 architecture is enabled.
  45         IA-64   IA-64 architecture is enabled.
  46         IOSCHED More than one I/O scheduler is enabled.
  47         IP_PNP  IP DHCP, BOOTP, or RARP is enabled.
  48         ISAPNP  ISA PnP code is enabled.
  49         ISDN    Appropriate ISDN support is enabled.
  50         JOY     Appropriate joystick support is enabled.
  51         LIBATA  Libata driver is enabled
  52         LP      Printer support is enabled.
  53         LOOP    Loopback device support is enabled.
  54         M68k    M68k architecture is enabled.
  55                         These options have more detailed description inside of
  56                         Documentation/m68k/kernel-options.txt.
  57         MCA     MCA bus support is enabled.
  58         MDA     MDA console support is enabled.
  59         MOUSE   Appropriate mouse support is enabled.
  60         MSI     Message Signaled Interrupts (PCI).
  61         MTD     MTD support is enabled.
  62         NET     Appropriate network support is enabled.
  63         NUMA    NUMA support is enabled.
  64         GENERIC_TIME The generic timeofday code is enabled.
  65         NFS     Appropriate NFS support is enabled.
  66         OSS     OSS sound support is enabled.
  67         PARIDE  The ParIDE subsystem is enabled.
  68         PARISC  The PA-RISC architecture is enabled.
  69         PCI     PCI bus support is enabled.
  70         PCMCIA  The PCMCIA subsystem is enabled.
  71         PNP     Plug & Play support is enabled.
  72         PPC     PowerPC architecture is enabled.
  73         PPT     Parallel port support is enabled.
  74         PS2     Appropriate PS/2 support is enabled.
  75         RAM     RAM disk support is enabled.
  76         S390    S390 architecture is enabled.
  77         SCSI    Appropriate SCSI support is enabled.
  78                         A lot of drivers has their options described inside of
  79                         Documentation/scsi/.
  80         SELINUX SELinux support is enabled.
  81         SERIAL  Serial support is enabled.
  82         SMP     The kernel is an SMP kernel.
  83         SPARC   Sparc architecture is enabled.
  84         SWSUSP  Software suspend is enabled.
  85         TS      Appropriate touchscreen support is enabled.
  86         USB     USB support is enabled.
  87         USBHID  USB Human Interface Device support is enabled.
  88         V4L     Video For Linux support is enabled.
  89         VGA     The VGA console has been enabled.
  90         VT      Virtual terminal support is enabled.
  91         WDT     Watchdog support is enabled.
  92         XT      IBM PC/XT MFM hard disk support is enabled.
  93         X86-64  X86-64 architecture is enabled.
  94                         More X86-64 boot options can be found in
  95                         Documentation/x86_64/boot-options.txt .
  96
  97 In addition, the following text indicates that the option:
  98
  99         BUGS=   Relates to possible processor bugs on the said processor.
 100         KNL     Is a kernel start-up parameter.
 101         BOOT    Is a boot loader parameter.
 102
 103 Parameters denoted with BOOT are actually interpreted by the boot
 104 loader, and have no meaning to the kernel directly.
 105 Do not modify the syntax of boot loader parameters without extreme
 106 need or coordination with <Documentation/i386/boot.txt>.
 107
 108 There are also arch-specific kernel-parameters not documented here.
 109 See for example <Documentation/x86_64/boot-options.txt>.
 110
 111 Note that ALL kernel parameters listed below are CASE SENSITIVE, and that
 112 a trailing = on the name of any parameter states that that parameter will
 113 be entered as an environment variable, whereas its absence indicates that
 114 it will appear as a kernel argument readable via /proc/cmdline by programs
 115 running once the system is up.
 116
 117 The number of kernel parameters is not limited, but the length of the
 118 complete command line (parameters including spaces etc.) is limited to
 119 a fixed number of characters. This limit depends on the architecture
 120 and is between 256 and 4096 characters. It is defined in the file
 121 ./include/asm/setup.h as COMMAND_LINE_SIZE.
 122
 123
 124         53c7xx=         [HW,SCSI] Amiga SCSI controllers
 125                         See header of drivers/scsi/53c7xx.c.
 126                         See also Documentation/scsi/ncr53c7xx.txt.
 127
 128         acpi=           [HW,ACPI] Advanced Configuration and Power Interface
 129                         Format: { force | off | ht | strict | noirq }
 130                         force -- enable ACPI if default was off
 131                         off -- disable ACPI if default was on
 132                         noirq -- do not use ACPI for IRQ routing
 133                         ht -- run only enough ACPI to enable Hyper Threading
 134                         strict -- Be less tolerant of platforms that are not
 135                                 strictly ACPI specification compliant.
 136
 137                         See also Documentation/pm.txt, pci=noacpi
 138
 139         acpi_sleep=     [HW,ACPI] Sleep options
 140                         Format: { s3_bios, s3_mode }
 141                         See Documentation/power/video.txt
 142
 143         acpi_sci=       [HW,ACPI] ACPI System Control Interrupt trigger mode
 144                         Format: { level | edge | high | low }
 145
 146         acpi_irq_balance [HW,ACPI]
 147                         ACPI will balance active IRQs
 148                         default in APIC mode
 149
 150         acpi_irq_nobalance [HW,ACPI]
 151                         ACPI will not move active IRQs (default)
 152                         default in PIC mode
 153
 154         acpi_irq_pci=   [HW,ACPI] If irq_balance, clear listed IRQs for
 155                         use by PCI
 156                         Format: <irq>,<irq>...
 157
 158         acpi_irq_isa=   [HW,ACPI] If irq_balance, mark listed IRQs used by ISA
 159                         Format: <irq>,<irq>...
 160
 161         acpi_os_name=   [HW,ACPI] Tell ACPI BIOS the name of the OS
 162                         Format: To spoof as Windows 98: ="Microsoft Windows"
 163
 164         acpi_osi=       [HW,ACPI] empty param disables _OSI
 165
 166         acpi_serialize  [HW,ACPI] force serialization of AML methods
 167
 168         acpi_skip_timer_override [HW,ACPI]
 169                         Recognize and ignore IRQ0/pin2 Interrupt Override.
 170                         For broken nForce2 BIOS resulting in XT-PIC timer.
 171         acpi_use_timer_override [HW,ACPI}
 172                         Use timer override. For some broken Nvidia NF5 boards
 173                         that require a timer override, but don't have
 174                         HPET
 175
 176         acpi_dbg_layer= [HW,ACPI]
 177                         Format: <int>
 178                         Each bit of the <int> indicates an ACPI debug layer,
 179                         1: enable, 0: disable. It is useful for boot time
 180                         debugging. After system has booted up, it can be set
 181                         via /proc/acpi/debug_layer.
 182
 183         acpi_dbg_level= [HW,ACPI]
 184                         Format: <int>
 185                         Each bit of the <int> indicates an ACPI debug level,
 186                         1: enable, 0: disable. It is useful for boot time
 187                         debugging. After system has booted up, it can be set
 188                         via /proc/acpi/debug_level.
 189
 190         acpi_fake_ecdt  [HW,ACPI] Workaround failure due to BIOS lacking ECDT
 191
 192         acpi_generic_hotkey [HW,ACPI]
 193                         Allow consolidated generic hotkey driver to
 194                         override platform specific driver.
 195                         See also Documentation/acpi-hotkey.txt.
 196
 197         acpi_pm_good    [IA-32,X86-64]
 198                         Override the pmtimer bug detection: force the kernel
 199                         to assume that this machine's pmtimer latches its value
 200                         and always returns good values.
 201
 202         enable_timer_pin_1 [i386,x86-64]
 203                         Enable PIN 1 of APIC timer
 204                         Can be useful to work around chipset bugs
 205                         (in particular on some ATI chipsets).
 206                         The kernel tries to set a reasonable default.
 207
 208         disable_timer_pin_1 [i386,x86-64]
 209                         Disable PIN 1 of APIC timer
 210                         Can be useful to work around chipset bugs.
 211
 212         ad1816=         [HW,OSS]
 213                         Format: <io>,<irq>,<dma>,<dma2>
 214                         See also Documentation/sound/oss/AD1816.
 215
 216         ad1848=         [HW,OSS]
 217                         Format: <io>,<irq>,<dma>,<dma2>,<type>
 218
 219         adlib=          [HW,OSS]
 220                         Format: <io>
 221
 222         advansys=       [HW,SCSI]
 223                         See header of drivers/scsi/advansys.c.
 224
 225         advwdt=         [HW,WDT] Advantech WDT
 226                         Format: <iostart>,<iostop>
 227
 228         aedsp16=        [HW,OSS] Audio Excel DSP 16
 229                         Format: <io>,<irq>,<dma>,<mss_io>,<mpu_io>,<mpu_irq>
 230                         See also header of sound/oss/aedsp16.c.
 231
 232         aha152x=        [HW,SCSI]
 233                         See Documentation/scsi/aha152x.txt.
 234
 235         aha1542=        [HW,SCSI]
 236                         Format: <portbase>[,<buson>,<busoff>[,<dmaspeed>]]
 237
 238         aic7xxx=        [HW,SCSI]
 239                         See Documentation/scsi/aic7xxx.txt.
 240
 241         aic79xx=        [HW,SCSI]
 242                         See Documentation/scsi/aic79xx.txt.
 243
 244         amijoy.map=     [HW,JOY] Amiga joystick support
 245                         Map of devices attached to JOY0DAT and JOY1DAT
 246                         Format: <a>,<b>
 247                         See also Documentation/kernel/input/joystick.txt
 248
 249         analog.map=     [HW,JOY] Analog joystick and gamepad support
 250                         Specifies type or capabilities of an analog joystick
 251                         connected to one of 16 gameports
 252                         Format: <type1>,<type2>,..<type16>
 253
 254         apc=            [HW,SPARC]
 255                         Power management functions (SPARCstation-4/5 + deriv.)
 256                         Format: noidle
 257                         Disable APC CPU standby support. SPARCstation-Fox does
 258                         not play well with APC CPU idle - disable it if you have
 259                         APC and your system crashes randomly.
 260
 261         apic=           [APIC,i386] Change the output verbosity whilst booting
 262                         Format: { quiet (default) | verbose | debug }
 263                         Change the amount of debugging information output
 264                         when initialising the APIC and IO-APIC components.
 265
 266         apm=            [APM] Advanced Power Management
 267                         See header of arch/i386/kernel/apm.c.
 268
 269         applicom=       [HW]
 270                         Format: <mem>,<irq>
 271
 272         arcrimi=        [HW,NET] ARCnet - "RIM I" (entirely mem-mapped) cards
 273                         Format: <io>,<irq>,<nodeID>
 274
 275         ataflop=        [HW,M68k]
 276
 277         atarimouse=     [HW,MOUSE] Atari Mouse
 278
 279         atascsi=        [HW,SCSI] Atari SCSI
 280
 281         atkbd.extra=    [HW] Enable extra LEDs and keys on IBM RapidAccess,
 282                         EzKey and similar keyboards
 283
 284         atkbd.reset=    [HW] Reset keyboard during initialization
 285
 286         atkbd.set=      [HW] Select keyboard code set
 287                         Format: <int> (2 = AT (default), 3 = PS/2)
 288
 289         atkbd.scroll=   [HW] Enable scroll wheel on MS Office and similar
 290                         keyboards
 291
 292         atkbd.softraw=  [HW] Choose between synthetic and real raw mode
 293                         Format: <bool> (0 = real, 1 = synthetic (default))
 294
 295         atkbd.softrepeat= [HW]
 296                         Use software keyboard repeat
 297
 298         autotest        [IA64]
 299
 300         aztcd=          [HW,CD] Aztech CD268 CDROM driver
 301                         Format: <io>,0x79 (?)
 302
 303         baycom_epp=     [HW,AX25]
 304                         Format: <io>,<mode>
 305
 306         baycom_par=     [HW,AX25] BayCom Parallel Port AX.25 Modem
 307                         Format: <io>,<mode>
 308                         See header of drivers/net/hamradio/baycom_par.c.
 309
 310         baycom_ser_fdx= [HW,AX25]
 311                         BayCom Serial Port AX.25 Modem (Full Duplex Mode)
 312                         Format: <io>,<irq>,<mode>[,<baud>]
 313                         See header of drivers/net/hamradio/baycom_ser_fdx.c.
 314
 315         baycom_ser_hdx= [HW,AX25]
 316                         BayCom Serial Port AX.25 Modem (Half Duplex Mode)
 317                         Format: <io>,<irq>,<mode>
 318                         See header of drivers/net/hamradio/baycom_ser_hdx.c.
 319
 320         blkmtd_device=  [HW,MTD]
 321         blkmtd_erasesz=
 322         blkmtd_ro=
 323         blkmtd_bs=
 324         blkmtd_count=
 325
 326         bttv.card=      [HW,V4L] bttv (bt848 + bt878 based grabber cards)
 327         bttv.radio=     Most important insmod options are available as
 328                         kernel args too.
 329         bttv.pll=       See Documentation/video4linux/bttv/Insmod-options
 330         bttv.tuner=     and Documentation/video4linux/bttv/CARDLIST
 331
 332         BusLogic=       [HW,SCSI]
 333                         See drivers/scsi/BusLogic.c, comment before function
 334                         BusLogic_ParseDriverOptions().
 335
 336         c101=           [NET] Moxa C101 synchronous serial card
 337
 338         cachesize=      [BUGS=IA-32] Override level 2 CPU cache size detection.
 339                         Sometimes CPU hardware bugs make them report the cache
 340                         size incorrectly. The kernel will attempt work arounds
 341                         to fix known problems, but for some CPUs it is not
 342                         possible to determine what the correct size should be.
 343                         This option provides an override for these situations.
 344
 345         cdu31a=         [HW,CD]
 346                         Format: <io>,<irq>[,PAS]
 347                         See header of drivers/cdrom/cdu31a.c.
 348
 349         chandev=        [HW,NET] Generic channel device initialisation
 350
 351         checkreqprot    [SELINUX] Set initial checkreqprot flag value.
 352                         Format: { "0" | "1" }
 353                         See security/selinux/Kconfig help text.
 354                         0 -- check protection applied by kernel (includes
 355                                 any implied execute protection).
 356                         1 -- check protection requested by application.
 357                         Default value is set via a kernel config option.
 358                         Value can be changed at runtime via
 359                                 /selinux/checkreqprot.
 360
 361         clock=          [BUGS=IA-32, HW] gettimeofday clocksource override.
 362                         [Deprecated]
 363                         Forces specified clocksource (if available) to be used
 364                         when calculating gettimeofday(). If specified
 365                         clocksource is not available, it defaults to PIT.
 366                         Format: { pit | tsc | cyclone | pmtmr }
 367
 368         code_bytes      [IA32] How many bytes of object code to print in an
 369                         oops report.
 370                         Range: 0 - 8192
 371                         Default: 64
 372
 373         disable_8254_timer
 374         enable_8254_timer
 375                         [IA32/X86_64] Disable/Enable interrupt 0 timer routing
 376                         over the 8254 in addition to over the IO-APIC. The
 377                         kernel tries to set a sensible default.
 378
 379         hpet=           [IA-32,HPET] option to disable HPET and use PIT.
 380                         Format: disable
 381
 382         cm206=          [HW,CD]
 383                         Format: { auto | [<io>,][<irq>] }
 384
 385         com20020=       [HW,NET] ARCnet - COM20020 chipset
 386                         Format:
 387                         <io>[,<irq>[,<nodeID>[,<backplane>[,<ckp>[,<timeout>]]]]]
 388
 389         com90io=        [HW,NET] ARCnet - COM90xx chipset (IO-mapped buffers)
 390                         Format: <io>[,<irq>]
 391
 392         com90xx=        [HW,NET]
 393                         ARCnet - COM90xx chipset (memory-mapped buffers)
 394                         Format: <io>[,<irq>[,<memstart>]]
 395
 396         condev=         [HW,S390] console device
 397         conmode=
 398
 399         console=        [KNL] Output console device and options.
 400
 401                 tty<n>  Use the virtual console device <n>.
 402
 403                 ttyS<n>[,options]
 404                 ttyUSB0[,options]
 405                         Use the specified serial port.  The options are of
 406                         the form "bbbbpnf", where "bbbb" is the baud rate,
 407                         "p" is parity ("n", "o", or "e"), "n" is number of
 408                         bits, and "f" is flow control ("r" for RTS or
 409                         omit it).  Default is "9600n8".
 410
 411                         See Documentation/serial-console.txt for more
 412                         information.  See
 413                         Documentation/networking/netconsole.txt for an
 414                         alternative.
 415
 416                 uart,io,<addr>[,options]
 417                 uart,mmio,<addr>[,options]
 418                         Start an early, polled-mode console on the 8250/16550
 419                         UART at the specified I/O port or MMIO address,
 420                         switching to the matching ttyS device later.  The
 421                         options are the same as for ttyS, above.
 422
 423         cpcihp_generic= [HW,PCI] Generic port I/O CompactPCI driver
 424                         Format:
 425                         <first_slot>,<last_slot>,<port>,<enum_bit>[,<debug>]
 426
 427         cpia_pp=        [HW,PPT]
 428                         Format: { parport<nr> | auto | none }
 429
 430         crashkernel=nn[KMG]@ss[KMG]
 431                         [KNL] Reserve a chunk of physical memory to
 432                         hold a kernel to switch to with kexec on panic.
 433
 434         cs4232=         [HW,OSS]
 435                         Format: <io>,<irq>,<dma>,<dma2>,<mpuio>,<mpuirq>
 436
 437         cs89x0_dma=     [HW,NET]
 438                         Format: <dma>
 439
 440         cs89x0_media=   [HW,NET]
 441                         Format: { rj45 | aui | bnc }
 442
 443         cyclades=       [HW,SERIAL] Cyclades multi-serial port adapter.
 444
 445         dasd=           [HW,NET]
 446                         See header of drivers/s390/block/dasd_devmap.c.
 447
 448         db9.dev[2|3]=   [HW,JOY] Multisystem joystick support via parallel port
 449                         (one device per port)
 450                         Format: <port#>,<type>
 451                         See also Documentation/input/joystick-parport.txt
 452
 453         debug           [KNL] Enable kernel debugging (events log level).
 454
 455         debug_locks_verbose=
 456                         [KNL] verbose self-tests
 457                         Format=<0|1>
 458                         Print debugging info while doing the locking API
 459                         self-tests.
 460                         We default to 0 (no extra messages), setting it to
 461                         1 will print _a lot_ more information - normally
 462                         only useful to kernel developers.
 463
 464         decnet=         [HW,NET]
 465                         Format: <area>[,<node>]
 466                         See also Documentation/networking/decnet.txt.
 467
 468         dhash_entries=  [KNL]
 469                         Set number of hash buckets for dentry cache.
 470
 471         digi=           [HW,SERIAL]
 472                         IO parameters + enable/disable command.
 473
 474         digiepca=       [HW,SERIAL]
 475                         See drivers/char/README.epca and
 476                         Documentation/digiepca.txt.
 477
 478         dmascc=         [HW,AX25,SERIAL] AX.25 Z80SCC driver with DMA
 479                         support available.
 480                         Format: <io_dev0>[,<io_dev1>[,..<io_dev32>]]
 481
 482         dmasound=       [HW,OSS] Sound subsystem buffers
 483
 484         dscc4.setup=    [NET]
 485
 486         dtc3181e=       [HW,SCSI]
 487
 488         earlyprintk=    [IA-32,X86-64]
 489                         earlyprintk=vga
 490                         earlyprintk=serial[,ttySn[,baudrate]]
 491
 492                         Append ",keep" to not disable it when the real console
 493                         takes over.
 494
 495                         Only vga or serial at a time, not both.
 496
 497                         Currently only ttyS0 and ttyS1 are supported.
 498
 499                         Interaction with the standard serial driver is not
 500                         very good.
 501
 502                         The VGA output is eventually overwritten by the real
 503                         console.
 504
 505         eata=           [HW,SCSI]
 506
 507         ec_intr=        [HW,ACPI] ACPI Embedded Controller interrupt mode
 508                         Format: <int>
 509                         0: polling mode
 510                         non-0: interrupt mode (default)
 511
 512         eda=            [HW,PS2]
 513
 514         edb=            [HW,PS2]
 515
 516         edd=            [EDD]
 517                         Format: {"of[f]" | "sk[ipmbr]"}
 518                         See comment in arch/i386/boot/edd.S
 519
 520         eicon=          [HW,ISDN]
 521                         Format: <id>,<membase>,<irq>
 522
 523         eisa_irq_edge=  [PARISC,HW]
 524                         See header of drivers/parisc/eisa.c.
 525
 526         elanfreq=       [IA-32]
 527                         See comment before function elanfreq_setup() in
 528                         arch/i386/kernel/cpu/cpufreq/elanfreq.c.
 529
 530         elevator=       [IOSCHED]
 531                         Format: {"anticipatory" | "cfq" | "deadline" | "noop"}
 532                         See Documentation/block/as-iosched.txt and
 533                         Documentation/block/deadline-iosched.txt for details.
 534
 535         elfcorehdr=     [IA-32, X86_64]
 536                         Specifies physical address of start of kernel core
 537                         image elf header. Generally kexec loader will
 538                         pass this option to capture kernel.
 539                         See Documentation/kdump/kdump.txt for details.
 540
 541         enforcing       [SELINUX] Set initial enforcing status.
 542                         Format: {"0" | "1"}
 543                         See security/selinux/Kconfig help text.
 544                         0 -- permissive (log only, no denials).
 545                         1 -- enforcing (deny and log).
 546                         Default value is 0.
 547                         Value can be changed at runtime via /selinux/enforce.
 548
 549         es1371=         [HW,OSS]
 550                         Format: <spdif>,[<nomix>,[<amplifier>]]
 551                         See also header of sound/oss/es1371.c.
 552
 553         ether=          [HW,NET] Ethernet cards parameters
 554                         This option is obsoleted by the "netdev=" option, which
 555                         has equivalent usage. See its documentation for details.
 556
 557         eurwdt=         [HW,WDT] Eurotech CPU-1220/1410 onboard watchdog.
 558                         Format: <io>[,<irq>]
 559
 560         failslab=
 561         fail_page_alloc=
 562         fail_make_request=[KNL]
 563                         General fault injection mechanism.
 564                         Format: <interval>,<probability>,<space>,<times>
 565                         See also /Documentation/fault-injection/.
 566
 567         fd_mcs=         [HW,SCSI]
 568                         See header of drivers/scsi/fd_mcs.c.
 569
 570         fdomain=        [HW,SCSI]
 571                         See header of drivers/scsi/fdomain.c.
 572
 573         floppy=         [HW]
 574                         See Documentation/floppy.txt.
 575
 576         gamecon.map[2|3]=
 577                         [HW,JOY] Multisystem joystick and NES/SNES/PSX pad
 578                         support via parallel port (up to 5 devices per port)
 579                         Format: <port#>,<pad1>,<pad2>,<pad3>,<pad4>,<pad5>
 580                         See also Documentation/input/joystick-parport.txt
 581
 582         gamma=          [HW,DRM]
 583
 584         gdth=           [HW,SCSI]
 585                         See header of drivers/scsi/gdth.c.
 586
 587         gpt             [EFI] Forces disk with valid GPT signature but
 588                         invalid Protective MBR to be treated as GPT.
 589
 590         gscd=           [HW,CD]
 591                         Format: <io>
 592
 593         gvp11=          [HW,SCSI]
 594
 595         hashdist=       [KNL,NUMA] Large hashes allocated during boot
 596                         are distributed across NUMA nodes.  Defaults on
 597                         for IA-64, off otherwise.
 598                         Format: 0 | 1 (for off | on)
 599
 600         hcl=            [IA-64] SGI's Hardware Graph compatibility layer
 601
 602         hd=             [EIDE] (E)IDE hard drive subsystem geometry
 603                         Format: <cyl>,<head>,<sect>
 604
 605         hd?=            [HW] (E)IDE subsystem
 606         hd?lun=         See Documentation/ide.txt.
 607
 608         highmem=nn[KMG] [KNL,BOOT] forces the highmem zone to have an exact
 609                         size of <nn>. This works even on boxes that have no
 610                         highmem otherwise. This also works to reduce highmem
 611                         size on bigger boxes.
 612
 613         highres=        [KNL] Enable/disable high resolution timer mode.
 614                         Valid parameters: "on", "off"
 615                         Default: "on"
 616
 617         hisax=          [HW,ISDN]
 618                         See Documentation/isdn/README.HiSax.
 619
 620         hugepages=      [HW,IA-32,IA-64] Maximal number of HugeTLB pages.
 621
 622         i8042.direct    [HW] Put keyboard port into non-translated mode
 623         i8042.dumbkbd   [HW] Pretend that controller can only read data from
 624                              keyboard and cannot control its state
 625                              (Don't attempt to blink the leds)
 626         i8042.noaux     [HW] Don't check for auxiliary (== mouse) port
 627         i8042.nokbd     [HW] Don't check/create keyboard port
 628         i8042.nomux     [HW] Don't check presence of an active multiplexing
 629                              controller
 630         i8042.nopnp     [HW] Don't use ACPIPnP / PnPBIOS to discover KBD/AUX
 631                              controllers
 632         i8042.panicblink=
 633                         [HW] Frequency with which keyboard LEDs should blink
 634                              when kernel panics (default is 0.5 sec)
 635         i8042.reset     [HW] Reset the controller during init and cleanup
 636         i8042.unlock    [HW] Unlock (ignore) the keylock
 637
 638         i810=           [HW,DRM]
 639
 640         i8k.ignore_dmi  [HW] Continue probing hardware even if DMI data
 641                         indicates that the driver is running on unsupported
 642                         hardware.
 643         i8k.force       [HW] Activate i8k driver even if SMM BIOS signature
 644                         does not match list of supported models.
 645         i8k.power_status
 646                         [HW] Report power status in /proc/i8k
 647                         (disabled by default)
 648         i8k.restricted  [HW] Allow controlling fans only if SYS_ADMIN
 649                         capability is set.
 650
 651         ibmmcascsi=     [HW,MCA,SCSI] IBM MicroChannel SCSI adapter
 652                         See Documentation/mca.txt.
 653
 654         icn=            [HW,ISDN]
 655                         Format: <io>[,<membase>[,<icn_id>[,<icn_id2>]]]
 656
 657         ide=            [HW] (E)IDE subsystem
 658                         Format: ide=nodma or ide=doubler or ide=reverse
 659                         See Documentation/ide.txt.
 660
 661         ide?=           [HW] (E)IDE subsystem
 662                         Format: ide?=noprobe or chipset specific parameters.
 663                         See Documentation/ide.txt.
 664
 665         idebus=         [HW] (E)IDE subsystem - VLB/PCI bus speed
 666                         See Documentation/ide.txt.
 667
 668         idle=           [HW]
 669                         Format: idle=poll or idle=halt
 670
 671         ignore_loglevel [KNL]
 672                         Ignore loglevel setting - this will print /all/
 673                         kernel messages to the console. Useful for debugging.
 674
 675         ihash_entries=  [KNL]
 676                         Set number of hash buckets for inode cache.
 677
 678         in2000=         [HW,SCSI]
 679                         See header of drivers/scsi/in2000.c.
 680
 681         init=           [KNL]
 682                         Format: <full_path>
 683                         Run specified binary instead of /sbin/init as init
 684                         process.
 685
 686         initcall_debug  [KNL] Trace initcalls as they are executed.  Useful
 687                         for working out where the kernel is dying during
 688                         startup.
 689
 690         initrd=         [BOOT] Specify the location of the initial ramdisk
 691
 692         inport.irq=     [HW] Inport (ATI XL and Microsoft) busmouse driver
 693                         Format: <irq>
 694
 695         combined_mode=  [HW] control which driver uses IDE ports in combined
 696                         mode: legacy IDE driver, libata, or both
 697                         (in the libata case, libata.atapi_enabled=1 may be
 698                         useful as well).  Note that using the ide or libata
 699                         options may affect your device naming (e.g. by
 700                         changing hdc to sdb).
 701                         Format: combined (default), ide, or libata
 702
 703         inttest=        [IA64]
 704
 705         io7=            [HW] IO7 for Marvel based alpha systems
 706                         See comment before marvel_specify_io7 in
 707                         arch/alpha/kernel/core_marvel.c.
 708
 709         ip=             [IP_PNP]
 710                         See Documentation/nfsroot.txt.
 711
 712         ip2=            [HW] Set IO/IRQ pairs for up to 4 IntelliPort boards
 713                         See comment before ip2_setup() in drivers/char/ip2.c.
 714
 715         ips=            [HW,SCSI] Adaptec / IBM ServeRAID controller
 716                         See header of drivers/scsi/ips.c.
 717
 718         ports=          [IP_VS_FTP] IPVS ftp helper module
 719                         Default is 21.
 720                         Up to 8 (IP_VS_APP_MAX_PORTS) ports
 721                         may be specified.
 722                         Format: <port>,<port>....
 723
 724         irqfixup        [HW]
 725                         When an interrupt is not handled search all handlers
 726                         for it. Intended to get systems with badly broken
 727                         firmware running.
 728
 729         irqpoll         [HW]
 730                         When an interrupt is not handled search all handlers
 731                         for it. Also check all handlers each timer
 732                         interrupt. Intended to get systems with badly broken
 733                         firmware running.
 734
 735         isapnp=         [ISAPNP]
 736                         Format: <RDP>,<reset>,<pci_scan>,<verbosity>
 737
 738         isolcpus=       [KNL,SMP] Isolate CPUs from the general scheduler.
 739                         Format:
 740                         <cpu number>,...,<cpu number>
 741                         or
 742                         <cpu number>-<cpu number>  (must be a positive range in ascending order)
 743                         or a mixture
 744                         <cpu number>,...,<cpu number>-<cpu number>
 745                         This option can be used to specify one or more CPUs
 746                         to isolate from the general SMP balancing and scheduling
 747                         algorithms. The only way to move a process onto or off
 748                         an "isolated" CPU is via the CPU affinity syscalls.
 749                         <cpu number> begins at 0 and the maximum value is
 750                         "number of CPUs in system - 1".
 751
 752                         This option is the preferred way to isolate CPUs. The
 753                         alternative -- manually setting the CPU mask of all
 754                         tasks in the system -- can cause problems and
 755                         suboptimal load balancer performance.
 756
 757         isp16=          [HW,CD]
 758                         Format: <io>,<irq>,<dma>,<setup>
 759
 760         iucv=           [HW,NET]
 761
 762         js=             [HW,JOY] Analog joystick
 763                         See Documentation/input/joystick.txt.
 764
 765         keepinitrd      [HW,ARM]
 766
 767         kstack=N        [IA-32,X86-64] Print N words from the kernel stack
 768                         in oops dumps.
 769
 770         l2cr=           [PPC]
 771
 772         lapic           [IA-32,APIC] Enable the local APIC even if BIOS
 773                         disabled it.
 774
 775         lasi=           [HW,SCSI] PARISC LASI driver for the 53c700 chip
 776                         Format: addr:<io>,irq:<irq>
 777
 778         llsc*=          [IA64] See function print_params() in
 779                         arch/ia64/sn/kernel/llsc4.c.
 780
 781         load_ramdisk=   [RAM] List of ramdisks to load from floppy
 782                         See Documentation/ramdisk.txt.
 783
 784         lockd.nlm_grace_period=P  [NFS] Assign grace period.
 785                         Format: <integer>
 786
 787         lockd.nlm_tcpport=N     [NFS] Assign TCP port.
 788                         Format: <integer>
 789
 790         lockd.nlm_timeout=T     [NFS] Assign timeout value.
 791                         Format: <integer>
 792
 793         lockd.nlm_udpport=M     [NFS] Assign UDP port.
 794                         Format: <integer>
 795
 796         logibm.irq=     [HW,MOUSE] Logitech Bus Mouse Driver
 797                         Format: <irq>
 798
 799         loglevel=       All Kernel Messages with a loglevel smaller than the
 800                         console loglevel will be printed to the console. It can
 801                         also be changed with klogd or other programs. The
 802                         loglevels are defined as follows:
 803
 804                         0 (KERN_EMERG)          system is unusable
 805                         1 (KERN_ALERT)          action must be taken immediately
 806                         2 (KERN_CRIT)           critical conditions
 807                         3 (KERN_ERR)            error conditions
 808                         4 (KERN_WARNING)        warning conditions
 809                         5 (KERN_NOTICE)         normal but significant condition
 810                         6 (KERN_INFO)           informational
 811                         7 (KERN_DEBUG)          debug-level messages
 812
 813         log_buf_len=n   Sets the size of the printk ring buffer, in bytes.
 814                         Format: { n | nk | nM }
 815                         n must be a power of two.  The default size
 816                         is set in the kernel config file.
 817
 818         lp=0            [LP]    Specify parallel ports to use, e.g,
 819         lp=port[,port...]       lp=none,parport0 (lp0 not configured, lp1 uses
 820         lp=reset                first parallel port). 'lp=0' disables the
 821         lp=auto                 printer driver. 'lp=reset' (which can be
 822                                 specified in addition to the ports) causes
 823                                 attached printers to be reset. Using
 824                                 lp=port1,port2,... specifies the parallel ports
 825                                 to associate lp devices with, starting with
 826                                 lp0. A port specification may be 'none' to skip
 827                                 that lp device, or a parport name such as
 828                                 'parport0'. Specifying 'lp=auto' instead of a
 829                                 port specification list means that device IDs
 830                                 from each port should be examined, to see if
 831                                 an IEEE 1284-compliant printer is attached; if
 832                                 so, the driver will manage that printer.
 833                                 See also header of drivers/char/lp.c.
 834
 835         lpj=n           [KNL]
 836                         Sets loops_per_jiffy to given constant, thus avoiding
 837                         time-consuming boot-time autodetection (up to 250 ms per
 838                         CPU). 0 enables autodetection (default). To determine
 839                         the correct value for your kernel, boot with normal
 840                         autodetection and see what value is printed. Note that
 841                         on SMP systems the preset will be applied to all CPUs,
 842                         which is likely to cause problems if your CPUs need
 843                         significantly divergent settings. An incorrect value
 844                         will cause delays in the kernel to be wrong, leading to
 845                         unpredictable I/O errors and other breakage. Although
 846                         unlikely, in the extreme case this might damage your
 847                         hardware.
 848
 849         ltpc=           [NET]
 850                         Format: <io>,<irq>,<dma>
 851
 852         mac5380=        [HW,SCSI] Format:
 853                         <can_queue>,<cmd_per_lun>,<sg_tablesize>,<hostid>,<use_tags>
 854
 855         mac53c9x=       [HW,SCSI] Format:
 856                         <num_esps>,<disconnect>,<nosync>,<can_queue>,<cmd_per_lun>,<sg_tablesize>,<hostid>,<use_tags>
 857
 858         machvec=        [IA64] Force the use of a particular machine-vector
 859                         (machvec) in a generic kernel.
 860                         Example: machvec=hpzx1_swiotlb
 861
 862         max_loop=       [LOOP] Maximum number of loopback devices that can
 863                         be mounted
 864                         Format: <1-256>
 865
 866         maxcpus=        [SMP] Maximum number of processors that an SMP kernel
 867                         should make use of.
 868                         Using "nosmp" or "maxcpus=0" will disable SMP
 869                         entirely (the MPS table probe still happens, though).
 870                         A command-line option of "maxcpus=<NUM>", where <NUM>
 871                         is an integer greater than 0, limits the maximum number
 872                         of CPUs activated in SMP mode to <NUM>.
 873                         Using "maxcpus=1" on an SMP kernel is the trivial
 874                         case of an SMP kernel with only one CPU.
 875
 876         max_addr=[KMG]  [KNL,BOOT,ia64] All physical memory greater than or
 877                         equal to this physical address is ignored.
 878
 879         max_luns=       [SCSI] Maximum number of LUNs to probe.
 880                         Should be between 1 and 2^32-1.
 881
 882         max_report_luns=
 883                         [SCSI] Maximum number of LUNs received.
 884                         Should be between 1 and 16384.
 885
 886         mca-pentium     [BUGS=IA-32]
 887
 888         mcatest=        [IA-64]
 889
 890         mcd=            [HW,CD]
 891                         Format: <port>,<irq>,<mitsumi_bug_93_wait>
 892
 893         mcdx=           [HW,CD]
 894
 895         mce             [IA-32] Machine Check Exception
 896
 897         md=             [HW] RAID subsystems devices and level
 898                         See Documentation/md.txt.
 899
 900         mdacon=         [MDA]
 901                         Format: <first>,<last>
 902                         Specifies range of consoles to be captured by the MDA.
 903
 904         mem=nn[KMG]     [KNL,BOOT] Force usage of a specific amount of memory
 905                         Amount of memory to be used when the kernel is not able
 906                         to see the whole system memory or for test.
 907                         [IA-32] Use together with memmap= to avoid physical
 908                         address space collisions. Without memmap= PCI devices
 909                         could be placed at addresses belonging to unused RAM.
 910
 911         mem=nopentium   [BUGS=IA-32] Disable usage of 4MB pages for kernel
 912                         memory.
 913
 914         memmap=exactmap [KNL,IA-32,X86_64] Enable setting of an exact
 915                         E820 memory map, as specified by the user.
 916                         Such memmap=exactmap lines can be constructed based on
 917                         BIOS output or other requirements. See the memmap=nn@ss
 918                         option description.
 919
 920         memmap=nn[KMG]@ss[KMG]
 921                         [KNL] Force usage of a specific region of memory
 922                         Region of memory to be used, from ss to ss+nn.
 923
 924         memmap=nn[KMG]#ss[KMG]
 925                         [KNL,ACPI] Mark specific memory as ACPI data.
 926                         Region of memory to be used, from ss to ss+nn.
 927
 928         memmap=nn[KMG]$ss[KMG]
 929                         [KNL,ACPI] Mark specific memory as reserved.
 930                         Region of memory to be used, from ss to ss+nn.
 931
 932         meye.*=         [HW] Set MotionEye Camera parameters
 933                         See Documentation/video4linux/meye.txt.
 934
 935         mga=            [HW,DRM]
 936
 937         migration_cost=
 938                         [KNL,SMP] debug: override scheduler migration costs
 939                         Format: <level-1-usecs>,<level-2-usecs>,...
 940                         This debugging option can be used to override the
 941                         default scheduler migration cost matrix. The numbers
 942                         are indexed by 'CPU domain distance'.
 943                         E.g. migration_cost=1000,2000,3000 on an SMT NUMA
 944                         box will set up an intra-core migration cost of
 945                         1 msec, an inter-core migration cost of 2 msecs,
 946                         and an inter-node migration cost of 3 msecs.
 947
 948                         WARNING: using the wrong values here can break
 949                         scheduler performance, so it's only for scheduler
 950                         development purposes, not production environments.
 951
 952         migration_debug=
 953                         [KNL,SMP] migration cost auto-detect verbosity
 954                         Format=<0|1|2>
 955                         If a system's migration matrix reported at bootup
 956                         seems erroneous then this option can be used to
 957                         increase verbosity of the detection process.
 958                         We default to 0 (no extra messages), 1 will print
 959                         some more information, and 2 will be really
 960                         verbose (probably only useful if you also have a
 961                         serial console attached to the system).
 962
 963         migration_factor=
 964                         [KNL,SMP] multiply/divide migration costs by a factor
 965                         Format=<percent>
 966                         This debug option can be used to proportionally
 967                         increase or decrease the auto-detected migration
 968                         costs for all entries of the migration matrix.
 969                         E.g. migration_factor=150 will increase migration
 970                         costs by 50%. (and thus the scheduler will be less
 971                         eager migrating cache-hot tasks)
 972                         migration_factor=80 will decrease migration costs
 973                         by 20%. (thus the scheduler will be more eager to
 974                         migrate tasks)
 975
 976                         WARNING: using the wrong values here can break
 977                         scheduler performance, so it's only for scheduler
 978                         development purposes, not production environments.
 979
 980         mousedev.tap_time=
 981                         [MOUSE] Maximum time between finger touching and
 982                         leaving touchpad surface for touch to be considered
 983                         a tap and be reported as a left button click (for
 984                         touchpads working in absolute mode only).
 985                         Format: <msecs>
 986         mousedev.xres=  [MOUSE] Horizontal screen resolution, used for devices
 987                         reporting absolute coordinates, such as tablets
 988         mousedev.yres=  [MOUSE] Vertical screen resolution, used for devices
 989                         reporting absolute coordinates, such as tablets
 990
 991         mpu401=         [HW,OSS]
 992                         Format: <io>,<irq>
 993
 994         MTD_Partition=  [MTD]
 995                         Format: <name>,<region-number>,<size>,<offset>
 996
 997         MTD_Region=     [MTD] Format:
 998                         <name>,<region-number>[,<base>,<size>,<buswidth>,<altbuswidth>]
 999
1000         mtdparts=       [MTD]
1001                         See drivers/mtd/cmdline.c.
1002
1003         mtouchusb.raw_coordinates=
1004                         [HW] Make the MicroTouch USB driver use raw coordinates
1005                         ('y', default) or cooked coordinates ('n')
1006
1007         n2=             [NET] SDL Inc. RISCom/N2 synchronous serial card
1008
1009         NCR_D700=       [HW,SCSI]
1010                         See header of drivers/scsi/NCR_D700.c.
1011
1012         ncr5380=        [HW,SCSI]
1013
1014         ncr53c400=      [HW,SCSI]
1015
1016         ncr53c400a=     [HW,SCSI]
1017
1018         ncr53c406a=     [HW,SCSI]
1019
1020         ncr53c8xx=      [HW,SCSI]
1021
1022         netdev=         [NET] Network devices parameters
1023                         Format: <irq>,<io>,<mem_start>,<mem_end>,<name>
1024                         Note that mem_start is often overloaded to mean
1025                         something different and driver-specific.
1026                         This usage is only documented in each driver source
1027                         file if at all.
1028
1029         nfsaddrs=       [NFS]
1030                         See Documentation/nfsroot.txt.
1031
1032         nfsroot=        [NFS] nfs root filesystem for disk-less boxes.
1033                         See Documentation/nfsroot.txt.
1034
1035         nfs.callback_tcpport=
1036                         [NFS] set the TCP port on which the NFSv4 callback
1037                         channel should listen.
1038
1039         nfs.idmap_cache_timeout=
1040                         [NFS] set the maximum lifetime for idmapper cache
1041                         entries.
1042
1043         nmi_watchdog=   [KNL,BUGS=IA-32] Debugging features for SMP kernels
1044
1045         no387           [BUGS=IA-32] Tells the kernel to use the 387 maths
1046                         emulation library even if a 387 maths coprocessor
1047                         is present.
1048
1049         noacpi          [LIBATA] Disables use of ACPI in libata suspend/resume
1050                         when set.
1051                         Format: <int>
1052
1053         noaliencache    [MM, NUMA] Disables the allcoation of alien caches in
1054                         the slab allocator.  Saves per-node memory, but will
1055                         impact performance on real NUMA hardware.
1056
1057         noalign         [KNL,ARM]
1058
1059         noapic          [SMP,APIC] Tells the kernel to not make use of any
1060                         IOAPICs that may be present in the system.
1061
1062         noasync         [HW,M68K] Disables async and sync negotiation for
1063                         all devices.
1064
1065         nobats          [PPC] Do not use BATs for mapping kernel lowmem
1066                         on "Classic" PPC cores.
1067
1068         nocache         [ARM]
1069
1070         nodelayacct     [KNL] Disable per-task delay accounting
1071
1072         nodisconnect    [HW,SCSI,M68K] Disables SCSI disconnects.
1073
1074         noexec          [IA-64]
1075
1076         noexec          [IA-32,X86-64]
1077                         noexec=on: enable non-executable mappings (default)
1078                         noexec=off: disable nn-executable mappings
1079
1080         nofxsr          [BUGS=IA-32] Disables x86 floating point extended
1081                         register save and restore. The kernel will only save
1082                         legacy floating-point registers on task switch.
1083
1084         nohlt           [BUGS=ARM]
1085
1086         no-hlt          [BUGS=IA-32] Tells the kernel that the hlt
1087                         instruction doesn't work correctly and not to
1088                         use it.
1089
1090         nohalt          [IA-64] Tells the kernel not to use the power saving
1091                         function PAL_HALT_LIGHT when idle. This increases
1092                         power-consumption. On the positive side, it reduces
1093                         interrupt wake-up latency, which may improve performance
1094                         in certain environments such as networked servers or
1095                         real-time systems.
1096
1097         nohz=           [KNL] Boottime enable/disable dynamic ticks
1098                         Valid arguments: on, off
1099                         Default: on
1100
1101         noirqbalance    [IA-32,SMP,KNL] Disable kernel irq balancing
1102
1103         noirqdebug      [IA-32] Disables the code which attempts to detect and
1104                         disable unhandled interrupt sources.
1105
1106         no_timer_check  [IA-32,X86_64,APIC] Disables the code which tests for
1107                         broken timer IRQ sources.
1108
1109         noisapnp        [ISAPNP] Disables ISA PnP code.
1110
1111         noinitrd        [RAM] Tells the kernel not to load any configured
1112                         initial RAM disk.
1113
1114         nointroute      [IA-64]
1115
1116         nolapic         [IA-32,APIC] Do not enable or use the local APIC.
1117
1118         noltlbs         [PPC] Do not use large page/tlb entries for kernel
1119                         lowmem mapping on PPC40x.
1120
1121         nomca           [IA-64] Disable machine check abort handling
1122
1123         nomce           [IA-32] Machine Check Exception
1124
1125         noresidual      [PPC] Don't use residual data on PReP machines.
1126
1127         noresume        [SWSUSP] Disables resume and restores original swap
1128                         space.
1129
1130         no-scroll       [VGA] Disables scrollback.
1131                         This is required for the Braillex ib80-piezo Braille
1132                         reader made by F.H. Papenmeier (Germany).
1133
1134         nosbagart       [IA-64]
1135
1136         nosep           [BUGS=IA-32] Disables x86 SYSENTER/SYSEXIT support.
1137
1138         nosmp           [SMP] Tells an SMP kernel to act as a UP kernel.
1139
1140         nosync          [HW,M68K] Disables sync negotiation for all devices.
1141
1142         notsc           [BUGS=IA-32] Disable Time Stamp Counter
1143
1144         nousb           [USB] Disable the USB subsystem
1145
1146         nowb            [ARM]
1147
1148         nr_uarts=       [SERIAL] maximum number of UARTs to be registered.
1149
1150         opl3=           [HW,OSS]
1151                         Format: <io>
1152
1153         opl3sa2=        [HW,OSS] Format:
1154                         <io>,<irq>,<dma>,<dma2>,<mss_io>,<mpu_io>,<ymode>,<loopback>[,<isapnp>,<multiple]
1155
1156         oprofile.timer= [HW]
1157                         Use timer interrupt instead of performance counters
1158
1159         optcd=          [HW,CD]
1160                         Format: <io>
1161
1162         osst=           [HW,SCSI] SCSI Tape Driver
1163                         Format: <buffer_size>,<write_threshold>
1164                         See also Documentation/scsi/st.txt.
1165
1166         panic=          [KNL] Kernel behaviour on panic
1167                         Format: <timeout>
1168
1169         parkbd.port=    [HW] Parallel port number the keyboard adapter is
1170                         connected to, default is 0.
1171                         Format: <parport#>
1172         parkbd.mode=    [HW] Parallel port keyboard adapter mode of operation,
1173                         0 for XT, 1 for AT (default is AT).
1174                         Format: <mode>
1175
1176         parport=        [HW,PPT] Specify parallel ports. 0 disables.
1177                         Format: { 0 | auto | 0xBBB[,IRQ[,DMA]] }
1178                         Use 'auto' to force the driver to use any
1179                         IRQ/DMA settings detected (the default is to
1180                         ignore detected IRQ/DMA settings because of
1181                         possible conflicts). You can specify the base
1182                         address, IRQ, and DMA settings; IRQ and DMA
1183                         should be numbers, or 'auto' (for using detected
1184                         settings on that particular port), or 'nofifo'
1185                         (to avoid using a FIFO even if it is detected).
1186                         Parallel ports are assigned in the order they
1187                         are specified on the command line, starting
1188                         with parport0.
1189
1190         parport_init_mode=      [HW,PPT]
1191                         Configure VIA parallel port to operate in
1192                         a specific mode. This is necessary on Pegasos
1193                         computer where firmware has no options for setting
1194                         up parallel port mode and sets it to spp.
1195                         Currently this function knows 686a and 8231 chips.
1196                         Format: [spp|ps2|epp|ecp|ecpepp]
1197
1198         pas2=           [HW,OSS] Format:
1199                         <io>,<irq>,<dma>,<dma16>,<sb_io>,<sb_irq>,<sb_dma>,<sb_dma16>
1200
1201         pas16=          [HW,SCSI]
1202                         See header of drivers/scsi/pas16.c.
1203
1204         pause_on_oops=
1205                         Halt all CPUs after the first oops has been printed for
1206                         the specified number of seconds.  This is to be used if
1207                         your oopses keep scrolling off the screen.
1208
1209         pcbit=          [HW,ISDN]
1210
1211         pcd.            [PARIDE]
1212                         See header of drivers/block/paride/pcd.c.
1213                         See also Documentation/paride.txt.
1214
1215         pci=option[,option...]  [PCI] various PCI subsystem options:
1216                 off             [IA-32] don't probe for the PCI bus
1217                 bios            [IA-32] force use of PCI BIOS, don't access
1218                                 the hardware directly. Use this if your machine
1219                                 has a non-standard PCI host bridge.
1220                 nobios          [IA-32] disallow use of PCI BIOS, only direct
1221                                 hardware access methods are allowed. Use this
1222                                 if you experience crashes upon bootup and you
1223                                 suspect they are caused by the BIOS.
1224                 conf1           [IA-32] Force use of PCI Configuration
1225                                 Mechanism 1.
1226                 conf2           [IA-32] Force use of PCI Configuration
1227                                 Mechanism 2.
1228                 nommconf        [IA-32,X86_64] Disable use of MMCONFIG for PCI
1229                                 Configuration
1230                 nomsi           [MSI] If the PCI_MSI kernel config parameter is
1231                                 enabled, this kernel boot option can be used to
1232                                 disable the use of MSI interrupts system-wide.
1233                 nosort          [IA-32] Don't sort PCI devices according to
1234                                 order given by the PCI BIOS. This sorting is
1235                                 done to get a device order compatible with
1236                                 older kernels.
1237                 biosirq         [IA-32] Use PCI BIOS calls to get the interrupt
1238                                 routing table. These calls are known to be buggy
1239                                 on several machines and they hang the machine
1240                                 when used, but on other computers it's the only
1241                                 way to get the interrupt routing table. Try
1242                                 this option if the kernel is unable to allocate
1243                                 IRQs or discover secondary PCI buses on your
1244                                 motherboard.
1245                 rom             [IA-32] Assign address space to expansion ROMs.
1246                                 Use with caution as certain devices share
1247                                 address decoders between ROMs and other
1248                                 resources.
1249                 irqmask=0xMMMM  [IA-32] Set a bit mask of IRQs allowed to be
1250                                 assigned automatically to PCI devices. You can
1251                                 make the kernel exclude IRQs of your ISA cards
1252                                 this way.
1253                 pirqaddr=0xAAAAA        [IA-32] Specify the physical address
1254                                 of the PIRQ table (normally generated
1255                                 by the BIOS) if it is outside the
1256                                 F0000h-100000h range.
1257                 lastbus=N       [IA-32] Scan all buses thru bus #N. Can be
1258                                 useful if the kernel is unable to find your
1259                                 secondary buses and you want to tell it
1260                                 explicitly which ones they are.
1261                 assign-busses   [IA-32] Always assign all PCI bus
1262                                 numbers ourselves, overriding
1263                                 whatever the firmware may have done.
1264                 usepirqmask     [IA-32] Honor the possible IRQ mask stored
1265                                 in the BIOS $PIR table. This is needed on
1266                                 some systems with broken BIOSes, notably
1267                                 some HP Pavilion N5400 and Omnibook XE3
1268                                 notebooks. This will have no effect if ACPI
1269                                 IRQ routing is enabled.
1270                 noacpi          [IA-32] Do not use ACPI for IRQ routing
1271                                 or for PCI scanning.
1272                 routeirq        Do IRQ routing for all PCI devices.
1273                                 This is normally done in pci_enable_device(),
1274                                 so this option is a temporary workaround
1275                                 for broken drivers that don't call it.
1276                 firmware        [ARM] Do not re-enumerate the bus but instead
1277                                 just use the configuration from the
1278                                 bootloader. This is currently used on
1279                                 IXP2000 systems where the bus has to be
1280                                 configured a certain way for adjunct CPUs.
1281                 noearly         [X86] Don't do any early type 1 scanning.
1282                                 This might help on some broken boards which
1283                                 machine check when some devices' config space
1284                                 is read. But various workarounds are disabled
1285                                 and some IOMMU drivers will not work.
1286                 bfsort          Sort PCI devices into breadth-first order.
1287                                 This sorting is done to get a device
1288                                 order compatible with older (<= 2.4) kernels.
1289                 nobfsort        Don't sort PCI devices into breadth-first order.
1290                 cbiosize=nn[KMG]        The fixed amount of bus space which is
1291                                 reserved for the CardBus bridge's IO window.
1292                                 The default value is 256 bytes.
1293                 cbmemsize=nn[KMG]       The fixed amount of bus space which is
1294                                 reserved for the CardBus bridge's memory
1295                                 window. The default value is 64 megabytes.
1296
1297         pcmv=           [HW,PCMCIA] BadgePAD 4
1298
1299         pd.             [PARIDE]
1300                         See Documentation/paride.txt.
1301
1302         pdcchassis=     [PARISC,HW] Disable/Enable PDC Chassis Status codes at
1303                         boot time.
1304                         Format: { 0 | 1 }
1305                         See arch/parisc/kernel/pdc_chassis.c
1306
1307         pf.             [PARIDE]
1308                         See Documentation/paride.txt.
1309
1310         pg.             [PARIDE]
1311                         See Documentation/paride.txt.
1312
1313         pirq=           [SMP,APIC] Manual mp-table setup
1314                         See Documentation/i386/IO-APIC.txt.
1315
1316         plip=           [PPT,NET] Parallel port network link
1317                         Format: { parport<nr> | timid | 0 }
1318                         See also Documentation/parport.txt.
1319
1320         pnpacpi=        [ACPI]
1321                         { off }
1322
1323         pnpbios=        [ISAPNP]
1324                         { on | off | curr | res | no-curr | no-res }
1325
1326         pnp_reserve_irq=
1327                         [ISAPNP] Exclude IRQs for the autoconfiguration
1328
1329         pnp_reserve_dma=
1330                         [ISAPNP] Exclude DMAs for the autoconfiguration
1331
1332         pnp_reserve_io= [ISAPNP] Exclude I/O ports for the autoconfiguration
1333                         Ranges are in pairs (I/O port base and size).
1334
1335         pnp_reserve_mem=
1336                         [ISAPNP] Exclude memory regions for the
1337                         autoconfiguration.
1338                         Ranges are in pairs (memory base and size).
1339
1340         profile=        [KNL] Enable kernel profiling via /proc/profile
1341                         Format: [schedule,]<number>
1342                         Param: "schedule" - profile schedule points.
1343                         Param: <number> - step/bucket size as a power of 2 for
1344                                 statistical time based profiling.
1345                         Param: "sleep" - profile D-state sleeping (millisecs)
1346
1347         processor.max_cstate=   [HW,ACPI]
1348                         Limit processor to maximum C-state
1349                         max_cstate=9 overrides any DMI blacklist limit.
1350
1351         processor.nocst [HW,ACPI]
1352                         Ignore the _CST method to determine C-states,
1353                         instead using the legacy FADT method
1354
1355         prompt_ramdisk= [RAM] List of RAM disks to prompt for floppy disk
1356                         before loading.
1357                         See Documentation/ramdisk.txt.
1358
1359         psmouse.proto=  [HW,MOUSE] Highest PS2 mouse protocol extension to
1360                         probe for; one of (bare|imps|exps|lifebook|any).
1361         psmouse.rate=   [HW,MOUSE] Set desired mouse report rate, in reports
1362                         per second.
1363         psmouse.resetafter=     [HW,MOUSE]
1364                         Try to reset the device after so many bad packets
1365                         (0 = never).
1366         psmouse.resolution=
1367                         [HW,MOUSE] Set desired mouse resolution, in dpi.
1368         psmouse.smartscroll=
1369                         [HW,MOUSE] Controls Logitech smartscroll autorepeat.
1370                         0 = disabled, 1 = enabled (default).
1371
1372         pss=            [HW,OSS] Personal Sound System (ECHO ESC614)
1373                         Format:
1374                         <io>,<mss_io>,<mss_irq>,<mss_dma>,<mpu_io>,<mpu_irq>
1375
1376         pt.             [PARIDE]
1377                         See Documentation/paride.txt.
1378
1379         quiet           [KNL] Disable most log messages
1380
1381         r128=           [HW,DRM]
1382
1383         raid=           [HW,RAID]
1384                         See Documentation/md.txt.
1385
1386         ramdisk=        [RAM] Sizes of RAM disks in kilobytes [deprecated]
1387                         See Documentation/ramdisk.txt.
1388
1389         ramdisk_blocksize=      [RAM]
1390                         See Documentation/ramdisk.txt.
1391
1392         ramdisk_size=   [RAM] Sizes of RAM disks in kilobytes
1393                         New name for the ramdisk parameter.
1394                         See Documentation/ramdisk.txt.
1395
1396         rcu.blimit=     [KNL,BOOT] Set maximum number of finished
1397                         RCU callbacks to process in one batch.
1398
1399         rcu.qhimark=    [KNL,BOOT] Set threshold of queued
1400                         RCU callbacks over which batch limiting is disabled.
1401
1402         rcu.qlowmark=   [KNL,BOOT] Set threshold of queued
1403                         RCU callbacks below which batch limiting is re-enabled.
1404
1405         rdinit=         [KNL]
1406                         Format: <full_path>
1407                         Run specified binary instead of /init from the ramdisk,
1408                         used for early userspace startup. See initrd.
1409
1410         reboot=         [BUGS=IA-32,BUGS=ARM,BUGS=IA-64] Rebooting mode
1411                         Format: <reboot_mode>[,<reboot_mode2>[,...]]
1412                         See arch/*/kernel/reboot.c or arch/*/kernel/process.c
1413
1414         reserve=        [KNL,BUGS] Force the kernel to ignore some iomem area
1415
1416         reservetop=     [IA-32]
1417                         Format: nn[KMG]
1418                         Reserves a hole at the top of the kernel virtual
1419                         address space.
1420
1421         reset_devices   [KNL] Force drivers to reset the underlying device
1422                         during initialization.
1423
1424         resume=         [SWSUSP]
1425                         Specify the partition device for software suspend
1426
1427         resume_offset=  [SWSUSP]
1428                         Specify the offset from the beginning of the partition
1429                         given by "resume=" at which the swap header is located,
1430                         in <PAGE_SIZE> units (needed only for swap files).
1431                         See  Documentation/power/swsusp-and-swap-files.txt
1432
1433         retain_initrd   [RAM] Keep initrd memory after extraction
1434
1435         rhash_entries=  [KNL,NET]
1436                         Set number of hash buckets for route cache
1437
1438         riscom8=        [HW,SERIAL]
1439                         Format: <io_board1>[,<io_board2>[,...<io_boardN>]]
1440
1441         ro              [KNL] Mount root device read-only on boot
1442
1443         root=           [KNL] Root filesystem
1444
1445         rootdelay=      [KNL] Delay (in seconds) to pause before attempting to
1446                         mount the root filesystem
1447
1448         rootflags=      [KNL] Set root filesystem mount option string
1449
1450         rootfstype=     [KNL] Set root filesystem type
1451
1452         rw              [KNL] Mount root device read-write on boot
1453
1454         S               [KNL] Run init in single mode
1455
1456         sa1100ir        [NET]
1457                         See drivers/net/irda/sa1100_ir.c.
1458
1459         sb=             [HW,OSS]
1460                         Format: <io>,<irq>,<dma>,<dma2>
1461
1462         sbni=           [NET] Granch SBNI12 leased line adapter
1463
1464         sbpcd=          [HW,CD] Soundblaster CD adapter
1465                         Format: <io>,<type>
1466                         See a comment before function sbpcd_setup() in
1467                         drivers/cdrom/sbpcd.c.
1468
1469         sc1200wdt=      [HW,WDT] SC1200 WDT (watchdog) driver
1470                         Format: <io>[,<timeout>[,<isapnp>]]
1471
1472         scsi_debug_*=   [SCSI]
1473                         See drivers/scsi/scsi_debug.c.
1474
1475         scsi_default_dev_flags=
1476                         [SCSI] SCSI default device flags
1477                         Format: <integer>
1478
1479         scsi_dev_flags= [SCSI] Black/white list entry for vendor and model
1480                         Format: <vendor>:<model>:<flags>
1481                         (flags are integer value)
1482
1483         scsi_logging=   [SCSI]
1484
1485         scsi_mod.scan=  [SCSI] sync (default) scans SCSI busses as they are
1486                         discovered.  async scans them in kernel threads,
1487                         allowing boot to proceed.  none ignores them, expecting
1488                         user space to do the scan.
1489
1490         selinux         [SELINUX] Disable or enable SELinux at boot time.
1491                         Format: { "0" | "1" }
1492                         See security/selinux/Kconfig help text.
1493                         0 -- disable.
1494                         1 -- enable.
1495                         Default value is set via kernel config option.
1496                         If enabled at boot time, /selinux/disable can be used
1497                         later to disable prior to initial policy load.
1498
1499         selinux_compat_net =
1500                         [SELINUX] Set initial selinux_compat_net flag value.
1501                         Format: { "0" | "1" }
1502                         0 -- use new secmark-based packet controls
1503                         1 -- use legacy packet controls
1504                         Default value is 0 (preferred).
1505                         Value can be changed at runtime via
1506                         /selinux/compat_net.
1507
1508         serialnumber    [BUGS=IA-32]
1509
1510         sg_def_reserved_size=   [SCSI]
1511
1512         shapers=        [NET]
1513                         Maximal number of shapers.
1514
1515         sim710=         [SCSI,HW]
1516                         See header of drivers/scsi/sim710.c.
1517
1518         simeth=         [IA-64]
1519         simscsi=
1520
1521         sjcd=           [HW,CD]
1522                         Format: <io>,<irq>,<dma>
1523                         See header of drivers/cdrom/sjcd.c.
1524
1525         slram=          [HW,MTD]
1526
1527         smart2=         [HW]
1528                         Format: <io1>[,<io2>[,...,<io8>]]
1529
1530         snd-ad1816a=    [HW,ALSA]
1531
1532         snd-ad1848=     [HW,ALSA]
1533
1534         snd-ali5451=    [HW,ALSA]
1535
1536         snd-als100=     [HW,ALSA]
1537
1538         snd-als4000=    [HW,ALSA]
1539
1540         snd-azt2320=    [HW,ALSA]
1541
1542         snd-cmi8330=    [HW,ALSA]
1543
1544         snd-cmipci=     [HW,ALSA]
1545
1546         snd-cs4231=     [HW,ALSA]
1547
1548         snd-cs4232=     [HW,ALSA]
1549
1550         snd-cs4236=     [HW,ALSA]
1551
1552         snd-cs4281=     [HW,ALSA]
1553
1554         snd-cs46xx=     [HW,ALSA]
1555
1556         snd-dt019x=     [HW,ALSA]
1557
1558         snd-dummy=      [HW,ALSA]
1559
1560         snd-emu10k1=    [HW,ALSA]
1561
1562         snd-ens1370=    [HW,ALSA]
1563
1564         snd-ens1371=    [HW,ALSA]
1565
1566         snd-es968=      [HW,ALSA]
1567
1568         snd-es1688=     [HW,ALSA]
1569
1570         snd-es18xx=     [HW,ALSA]
1571
1572         snd-es1938=     [HW,ALSA]
1573
1574         snd-es1968=     [HW,ALSA]
1575
1576         snd-fm801=      [HW,ALSA]
1577
1578         snd-gusclassic= [HW,ALSA]
1579
1580         snd-gusextreme= [HW,ALSA]
1581
1582         snd-gusmax=     [HW,ALSA]
1583
1584         snd-hdsp=       [HW,ALSA]
1585
1586         snd-ice1712=    [HW,ALSA]
1587
1588         snd-intel8x0=   [HW,ALSA]
1589
1590         snd-interwave=  [HW,ALSA]
1591
1592         snd-interwave-stb=
1593                         [HW,ALSA]
1594
1595         snd-korg1212=   [HW,ALSA]
1596
1597         snd-maestro3=   [HW,ALSA]
1598
1599         snd-mpu401=     [HW,ALSA]
1600
1601         snd-mtpav=      [HW,ALSA]
1602
1603         snd-nm256=      [HW,ALSA]
1604
1605         snd-opl3sa2=    [HW,ALSA]
1606
1607         snd-opti92x-ad1848=
1608                         [HW,ALSA]
1609
1610         snd-opti92x-cs4231=
1611                         [HW,ALSA]
1612
1613         snd-opti93x=    [HW,ALSA]
1614
1615         snd-pmac=       [HW,ALSA]
1616
1617         snd-rme32=      [HW,ALSA]
1618
1619         snd-rme96=      [HW,ALSA]
1620
1621         snd-rme9652=    [HW,ALSA]
1622
1623         snd-sb8=        [HW,ALSA]
1624
1625         snd-sb16=       [HW,ALSA]
1626
1627         snd-sbawe=      [HW,ALSA]
1628
1629         snd-serial=     [HW,ALSA]
1630
1631         snd-sgalaxy=    [HW,ALSA]
1632
1633         snd-sonicvibes= [HW,ALSA]
1634
1635         snd-sun-amd7930=
1636                         [HW,ALSA]
1637
1638         snd-sun-cs4231= [HW,ALSA]
1639
1640         snd-trident=    [HW,ALSA]
1641
1642         snd-usb-audio=  [HW,ALSA,USB]
1643
1644         snd-via82xx=    [HW,ALSA]
1645
1646         snd-virmidi=    [HW,ALSA]
1647
1648         snd-wavefront=  [HW,ALSA]
1649
1650         snd-ymfpci=     [HW,ALSA]
1651
1652         sonycd535=      [HW,CD]
1653                         Format: <io>[,<irq>]
1654
1655         sonypi.*=       [HW] Sony Programmable I/O Control Device driver
1656                         See Documentation/sonypi.txt
1657
1658         specialix=      [HW,SERIAL] Specialix multi-serial port adapter
1659                         See Documentation/specialix.txt.
1660
1661         spia_io_base=   [HW,MTD]
1662         spia_fio_base=
1663         spia_pedr=
1664         spia_peddr=
1665
1666         sscape=         [HW,OSS]
1667                         Format: <io>,<irq>,<dma>,<mpu_io>,<mpu_irq>
1668
1669         st=             [HW,SCSI] SCSI tape parameters (buffers, etc.)
1670                         See Documentation/scsi/st.txt.
1671
1672         st0x=           [HW,SCSI]
1673                         See header of drivers/scsi/seagate.c.
1674
1675         sti=            [PARISC,HW]
1676                         Format: <num>
1677                         Set the STI (builtin display/keyboard on the HP-PARISC
1678                         machines) console (graphic card) which should be used
1679                         as the initial boot-console.
1680                         See also comment in drivers/video/console/sticore.c.
1681
1682         sti_font=       [HW]
1683                         See comment in drivers/video/console/sticore.c.
1684
1685         stifb=          [HW]
1686                         Format: bpp:<bpp1>[:<bpp2>[:<bpp3>...]]
1687
1688         swiotlb=        [IA-64] Number of I/O TLB slabs
1689
1690         switches=       [HW,M68k]
1691
1692         sym53c416=      [HW,SCSI]
1693                         See header of drivers/scsi/sym53c416.c.
1694
1695         sysrq_always_enabled
1696                         [KNL]
1697                         Ignore sysrq setting - this boot parameter will
1698                         neutralize any effect of /proc/sys/kernel/sysrq.
1699                         Useful for debugging.
1700
1701         t128=           [HW,SCSI]
1702                         See header of drivers/scsi/t128.c.
1703
1704         tdfx=           [HW,DRM]
1705
1706         thash_entries=  [KNL,NET]
1707                         Set number of hash buckets for TCP connection
1708
1709         time            Show timing data prefixed to each printk message line
1710
1711         clocksource=    [GENERIC_TIME] Override the default clocksource
1712                         Override the default clocksource and use the clocksource
1713                         with the name specified.
1714
1715         tipar.timeout=  [HW,PPT]
1716                         Set communications timeout in tenths of a second
1717                         (default 15).
1718
1719         tipar.delay=    [HW,PPT]
1720                         Set inter-bit delay in microseconds (default 10).
1721
1722         tmc8xx=         [HW,SCSI]
1723                         See header of drivers/scsi/seagate.c.
1724
1725         tmscsim=        [HW,SCSI]
1726                         See comment before function dc390_setup() in
1727                         drivers/scsi/tmscsim.c.
1728
1729         tp720=          [HW,PS2]
1730
1731         trix=           [HW,OSS] MediaTrix AudioTrix Pro
1732                         Format:
1733                         <io>,<irq>,<dma>,<dma2>,<sb_io>,<sb_irq>,<sb_dma>,<mpu_io>,<mpu_irq>
1734
1735         tsdev.xres=     [TS] Horizontal screen resolution.
1736         tsdev.yres=     [TS] Vertical screen resolution.
1737
1738         turbografx.map[2|3]=    [HW,JOY]
1739                         TurboGraFX parallel port interface
1740                         Format:
1741                         <port#>,<js1>,<js2>,<js3>,<js4>,<js5>,<js6>,<js7>
1742                         See also Documentation/input/joystick-parport.txt
1743
1744         u14-34f=        [HW,SCSI] UltraStor 14F/34F SCSI host adapter
1745                         See header of drivers/scsi/u14-34f.c.
1746
1747         uart401=        [HW,OSS]
1748                         Format: <io>,<irq>
1749
1750         uart6850=       [HW,OSS]
1751                         Format: <io>,<irq>
1752
1753         uhci-hcd.ignore_oc=
1754                         [USB] Ignore overcurrent events (default N).
1755                         Some badly-designed motherboards generate lots of
1756                         bogus events, for ports that aren't wired to
1757                         anything.  Set this parameter to avoid log spamming.
1758                         Note that genuine overcurrent events won't be
1759                         reported either.
1760
1761         usbcore.autosuspend=
1762                         [USB] The autosuspend time delay (in seconds) used
1763                         for newly-detected USB devices (default 2).  This
1764                         is the time required before an idle device will be
1765                         autosuspended.  Devices for which the delay is set
1766                         to 0 won't be autosuspended at all.
1767
1768         usbhid.mousepoll=
1769                         [USBHID] The interval which mice are to be polled at.
1770
1771         vdso=           [IA-32]
1772                         vdso=1: enable VDSO (default)
1773                         vdso=0: disable VDSO mapping
1774
1775         video=          [FB] Frame buffer configuration
1776                         See Documentation/fb/modedb.txt.
1777
1778         vga=            [BOOT,IA-32] Select a particular video mode
1779                         See Documentation/i386/boot.txt and
1780                         Documentation/svga.txt.
1781                         Use vga=ask for menu.
1782                         This is actually a boot loader parameter; the value is
1783                         passed to the kernel using a special protocol.
1784
1785         vmalloc=nn[KMG] [KNL,BOOT] Forces the vmalloc area to have an exact
1786                         size of <nn>. This can be used to increase the
1787                         minimum size (128MB on x86). It can also be used to
1788                         decrease the size and leave more room for directly
1789                         mapped kernel RAM.
1790
1791         vmhalt=         [KNL,S390] Perform z/VM CP command after system halt.
1792                         Format: <command>
1793
1794         vmpanic=        [KNL,S390] Perform z/VM CP command after kernel panic.
1795                         Format: <command>
1796
1797         vmpoff=         [KNL,S390] Perform z/VM CP command after power off.
1798                         Format: <command>
1799
1800         waveartist=     [HW,OSS]
1801                         Format: <io>,<irq>,<dma>,<dma2>
1802
1803         wd33c93=        [HW,SCSI]
1804                         See header of drivers/scsi/wd33c93.c.
1805
1806         wd7000=         [HW,SCSI]
1807                         See header of drivers/scsi/wd7000.c.
1808
1809         wdt=            [WDT] Watchdog
1810                         See Documentation/watchdog/watchdog.txt.
1811
1812         xd=             [HW,XT] Original XT pre-IDE (RLL encoded) disks.
1813         xd_geo=         See header of drivers/block/xd.c.
1814
1815         xirc2ps_cs=     [NET,PCMCIA]
1816                         Format:
1817                         <irq>,<irq_mask>,<io>,<full_duplex>,<do_sound>,<lockup_hack>[,<irq2>[,<irq3>[,<irq4>]]]
1818
1819         norandmaps      Don't use address space randomization
1820                         Equivalent to echo 0 > /proc/sys/kernel/randomize_va_space
1821
1822         unwind_debug=N  N > 0 will enable dwarf2 unwinder debugging
1823                         This is useful to get more information why
1824                         you got a "dwarf2 unwinder stuck"
1825
1826 ______________________________________________________________________
1827
1828 TODO:
1829
1830         Add documentation for ALSA options.
1831         Add more DRM drivers.