Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel os linux
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1February 2003 Kernel Parameters v2.5.59 2 ~~~~~~~~~~~~~~~~~ 3 4The 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 7case insensitive manner), and with descriptions where known. 8 9Module parameters for loadable modules are specified only as the 10parameter name with optional '=' and value as appropriate, such as: 11 12 modprobe usbcore blinkenlights=1 13 14Module parameters for modules that are built into the kernel image 15are 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 20The text in square brackets at the beginning of the description states the 21restrictions on the kernel for the said kernel parameter to be valid. The 22restrictions 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 DHCP, BOOTP, or RARP is enabled. 41 ISAPNP ISA PnP code is enabled. 42 ISDN Appropriate ISDN support is enabled. 43 JOY Appropriate joystick support is enabled. 44 LP Printer support is enabled. 45 LOOP Loopback device support is enabled. 46 M68k M68k architecture is enabled. 47 These options have more detailed description inside of 48 Documentation/m68k/kernel-options.txt. 49 MCA MCA bus support is enabled. 50 MDA MDA console support is enabled. 51 MOUSE Appropriate mouse support is enabled. 52 MTD MTD support is enabled. 53 NET Appropriate network support is enabled. 54 NUMA NUMA support is enabled. 55 NFS Appropriate NFS support is enabled. 56 OSS OSS sound support is enabled. 57 PARIDE The ParIDE subsystem is enabled. 58 PARISC The PA-RISC architecture is enabled. 59 PCI PCI bus support is enabled. 60 PCMCIA The PCMCIA subsystem is enabled. 61 PNP Plug & Play support is enabled. 62 PPC PowerPC architecture is enabled. 63 PPT Parallel port support is enabled. 64 PS2 Appropriate PS/2 support is enabled. 65 RAM RAM disk support is enabled. 66 S390 S390 architecture is enabled. 67 SCSI Appropriate SCSI support is enabled. 68 A lot of drivers has their options described inside of 69 Documentation/scsi/. 70 SELINUX SELinux support is enabled. 71 SERIAL Serial support is enabled. 72 SMP The kernel is an SMP kernel. 73 SPARC Sparc architecture is enabled. 74 SWSUSP Software suspend is enabled. 75 TS Appropriate touchscreen support is enabled. 76 USB USB support is enabled. 77 USBHID USB Human Interface Device support is enabled. 78 V4L Video For Linux support is enabled. 79 VGA The VGA console has been enabled. 80 VT Virtual terminal support is enabled. 81 WDT Watchdog support is enabled. 82 XT IBM PC/XT MFM hard disk support is enabled. 83 X86-64 X86-64 architecture is enabled. 84 More X86-64 boot options can be found in 85 Documentation/x86_64/boot-options.txt . 86 87In addition, the following text indicates that the option: 88 89 BUGS= Relates to possible processor bugs on the said processor. 90 KNL Is a kernel start-up parameter. 91 BOOT Is a boot loader parameter. 92 93Parameters denoted with BOOT are actually interpreted by the boot 94loader, and have no meaning to the kernel directly. 95Do not modify the syntax of boot loader parameters without extreme 96need or coordination with <Documentation/i386/boot.txt>. 97 98Note that ALL kernel parameters listed below are CASE SENSITIVE, and that 99a trailing = on the name of any parameter states that that parameter will 100be entered as an environment variable, whereas its absence indicates that 101it will appear as a kernel argument readable via /proc/cmdline by programs 102running once the system is up. 103 104 53c7xx= [HW,SCSI] Amiga SCSI controllers 105 See header of drivers/scsi/53c7xx.c. 106 See also Documentation/scsi/ncr53c7xx.txt. 107 108 acpi= [HW,ACPI] Advanced Configuration and Power Interface 109 Format: { force | off | ht | strict | noirq } 110 force -- enable ACPI if default was off 111 off -- disable ACPI if default was on 112 noirq -- do not use ACPI for IRQ routing 113 ht -- run only enough ACPI to enable Hyper Threading 114 strict -- Be less tolerant of platforms that are not 115 strictly ACPI specification compliant. 116 117 See also Documentation/pm.txt, pci=noacpi 118 119 acpi_sleep= [HW,ACPI] Sleep options 120 Format: { s3_bios, s3_mode } 121 See Documentation/power/video.txt 122 123 acpi_sci= [HW,ACPI] ACPI System Control Interrupt trigger mode 124 Format: { level | edge | high | low } 125 126 acpi_irq_balance [HW,ACPI] 127 ACPI will balance active IRQs 128 default in APIC mode 129 130 acpi_irq_nobalance [HW,ACPI] 131 ACPI will not move active IRQs (default) 132 default in PIC mode 133 134 acpi_irq_pci= [HW,ACPI] If irq_balance, clear listed IRQs for 135 use by PCI 136 Format: <irq>,<irq>... 137 138 acpi_irq_isa= [HW,ACPI] If irq_balance, mark listed IRQs used by ISA 139 Format: <irq>,<irq>... 140 141 acpi_osi= [HW,ACPI] empty param disables _OSI 142 143 acpi_serialize [HW,ACPI] force serialization of AML methods 144 145 acpi_skip_timer_override [HW,ACPI] 146 Recognize and ignore IRQ0/pin2 Interrupt Override. 147 For broken nForce2 BIOS resulting in XT-PIC timer. 148 149 acpi_dbg_layer= [HW,ACPI] 150 Format: <int> 151 Each bit of the <int> indicates an ACPI debug layer, 152 1: enable, 0: disable. It is useful for boot time 153 debugging. After system has booted up, it can be set 154 via /proc/acpi/debug_layer. 155 156 acpi_dbg_level= [HW,ACPI] 157 Format: <int> 158 Each bit of the <int> indicates an ACPI debug level, 159 1: enable, 0: disable. It is useful for boot time 160 debugging. After system has booted up, it can be set 161 via /proc/acpi/debug_level. 162 163 acpi_fake_ecdt [HW,ACPI] Workaround failure due to BIOS lacking ECDT 164 165 acpi_generic_hotkey [HW,ACPI] 166 Allow consolidated generic hotkey driver to 167 override platform specific driver. 168 See also Documentation/acpi-hotkey.txt. 169 170 enable_timer_pin_1 [i386,x86-64] 171 Enable PIN 1 of APIC timer 172 Can be useful to work around chipset bugs 173 (in particular on some ATI chipsets). 174 The kernel tries to set a reasonable default. 175 176 disable_timer_pin_1 [i386,x86-64] 177 Disable PIN 1 of APIC timer 178 Can be useful to work around chipset bugs. 179 180 ad1816= [HW,OSS] 181 Format: <io>,<irq>,<dma>,<dma2> 182 See also Documentation/sound/oss/AD1816. 183 184 ad1848= [HW,OSS] 185 Format: <io>,<irq>,<dma>,<dma2>,<type> 186 187 adlib= [HW,OSS] 188 Format: <io> 189 190 advansys= [HW,SCSI] 191 See header of drivers/scsi/advansys.c. 192 193 advwdt= [HW,WDT] Advantech WDT 194 Format: <iostart>,<iostop> 195 196 aedsp16= [HW,OSS] Audio Excel DSP 16 197 Format: <io>,<irq>,<dma>,<mss_io>,<mpu_io>,<mpu_irq> 198 See also header of sound/oss/aedsp16.c. 199 200 aha152x= [HW,SCSI] 201 See Documentation/scsi/aha152x.txt. 202 203 aha1542= [HW,SCSI] 204 Format: <portbase>[,<buson>,<busoff>[,<dmaspeed>]] 205 206 aic7xxx= [HW,SCSI] 207 See Documentation/scsi/aic7xxx.txt. 208 209 aic79xx= [HW,SCSI] 210 See Documentation/scsi/aic79xx.txt. 211 212 amijoy.map= [HW,JOY] Amiga joystick support 213 Map of devices attached to JOY0DAT and JOY1DAT 214 Format: <a>,<b> 215 See also Documentation/kernel/input/joystick.txt 216 217 analog.map= [HW,JOY] Analog joystick and gamepad support 218 Specifies type or capabilities of an analog joystick 219 connected to one of 16 gameports 220 Format: <type1>,<type2>,..<type16> 221 222 apc= [HW,SPARC] 223 Power management functions (SPARCstation-4/5 + deriv.) 224 Format: noidle 225 Disable APC CPU standby support. SPARCstation-Fox does 226 not play well with APC CPU idle - disable it if you have 227 APC and your system crashes randomly. 228 229 apic= [APIC,i386] Change the output verbosity whilst booting 230 Format: { quiet (default) | verbose | debug } 231 Change the amount of debugging information output 232 when initialising the APIC and IO-APIC components. 233 234 apm= [APM] Advanced Power Management 235 See header of arch/i386/kernel/apm.c. 236 237 applicom= [HW] 238 Format: <mem>,<irq> 239 240 arcrimi= [HW,NET] ARCnet - "RIM I" (entirely mem-mapped) cards 241 Format: <io>,<irq>,<nodeID> 242 243 ataflop= [HW,M68k] 244 245 atarimouse= [HW,MOUSE] Atari Mouse 246 247 atascsi= [HW,SCSI] Atari SCSI 248 249 atkbd.extra= [HW] Enable extra LEDs and keys on IBM RapidAccess, 250 EzKey and similar keyboards 251 252 atkbd.reset= [HW] Reset keyboard during initialization 253 254 atkbd.set= [HW] Select keyboard code set 255 Format: <int> (2 = AT (default), 3 = PS/2) 256 257 atkbd.scroll= [HW] Enable scroll wheel on MS Office and similar 258 keyboards 259 260 atkbd.softraw= [HW] Choose between synthetic and real raw mode 261 Format: <bool> (0 = real, 1 = synthetic (default)) 262 263 atkbd.softrepeat= [HW] 264 Use software keyboard repeat 265 266 autotest [IA64] 267 268 awe= [HW,OSS] AWE32/SB32/AWE64 wave table synth 269 Format: <io>,<memsize>,<isapnp> 270 271 aztcd= [HW,CD] Aztech CD268 CDROM driver 272 Format: <io>,0x79 (?) 273 274 baycom_epp= [HW,AX25] 275 Format: <io>,<mode> 276 277 baycom_par= [HW,AX25] BayCom Parallel Port AX.25 Modem 278 Format: <io>,<mode> 279 See header of drivers/net/hamradio/baycom_par.c. 280 281 baycom_ser_fdx= [HW,AX25] 282 BayCom Serial Port AX.25 Modem (Full Duplex Mode) 283 Format: <io>,<irq>,<mode>[,<baud>] 284 See header of drivers/net/hamradio/baycom_ser_fdx.c. 285 286 baycom_ser_hdx= [HW,AX25] 287 BayCom Serial Port AX.25 Modem (Half Duplex Mode) 288 Format: <io>,<irq>,<mode> 289 See header of drivers/net/hamradio/baycom_ser_hdx.c. 290 291 blkmtd_device= [HW,MTD] 292 blkmtd_erasesz= 293 blkmtd_ro= 294 blkmtd_bs= 295 blkmtd_count= 296 297 bttv.card= [HW,V4L] bttv (bt848 + bt878 based grabber cards) 298 bttv.radio= Most important insmod options are available as 299 kernel args too. 300 bttv.pll= See Documentation/video4linux/bttv/Insmod-options 301 bttv.tuner= and Documentation/video4linux/bttv/CARDLIST 302 303 BusLogic= [HW,SCSI] 304 See drivers/scsi/BusLogic.c, comment before function 305 BusLogic_ParseDriverOptions(). 306 307 c101= [NET] Moxa C101 synchronous serial card 308 309 cachesize= [BUGS=IA-32] Override level 2 CPU cache size detection. 310 Sometimes CPU hardware bugs make them report the cache 311 size incorrectly. The kernel will attempt work arounds 312 to fix known problems, but for some CPUs it is not 313 possible to determine what the correct size should be. 314 This option provides an override for these situations. 315 316 cdu31a= [HW,CD] 317 Format: <io>,<irq>[,PAS] 318 See header of drivers/cdrom/cdu31a.c. 319 320 chandev= [HW,NET] Generic channel device initialisation 321 322 checkreqprot [SELINUX] Set initial checkreqprot flag value. 323 Format: { "0" | "1" } 324 See security/selinux/Kconfig help text. 325 0 -- check protection applied by kernel (includes 326 any implied execute protection). 327 1 -- check protection requested by application. 328 Default value is set via a kernel config option. 329 Value can be changed at runtime via 330 /selinux/checkreqprot. 331 332 clock= [BUGS=IA-32,HW] gettimeofday timesource override. 333 Forces specified timesource (if avaliable) to be used 334 when calculating gettimeofday(). If specicified 335 timesource is not avalible, it defaults to PIT. 336 Format: { pit | tsc | cyclone | pmtmr } 337 338 hpet= [IA-32,HPET] option to disable HPET and use PIT. 339 Format: disable 340 341 cm206= [HW,CD] 342 Format: { auto | [<io>,][<irq>] } 343 344 com20020= [HW,NET] ARCnet - COM20020 chipset 345 Format: 346 <io>[,<irq>[,<nodeID>[,<backplane>[,<ckp>[,<timeout>]]]]] 347 348 com90io= [HW,NET] ARCnet - COM90xx chipset (IO-mapped buffers) 349 Format: <io>[,<irq>] 350 351 com90xx= [HW,NET] 352 ARCnet - COM90xx chipset (memory-mapped buffers) 353 Format: <io>[,<irq>[,<memstart>]] 354 355 condev= [HW,S390] console device 356 conmode= 357 358 console= [KNL] Output console device and options. 359 360 tty<n> Use the virtual console device <n>. 361 362 ttyS<n>[,options] 363 Use the specified serial port. The options are of 364 the form "bbbbpn", where "bbbb" is the baud rate, 365 "p" is parity ("n", "o", or "e"), and "n" is bits. 366 Default is "9600n8". 367 368 See also Documentation/serial-console.txt. 369 370 uart,io,<addr>[,options] 371 uart,mmio,<addr>[,options] 372 Start an early, polled-mode console on the 8250/16550 373 UART at the specified I/O port or MMIO address, 374 switching to the matching ttyS device later. The 375 options are the same as for ttyS, above. 376 377 cpcihp_generic= [HW,PCI] Generic port I/O CompactPCI driver 378 Format: 379 <first_slot>,<last_slot>,<port>,<enum_bit>[,<debug>] 380 381 cpia_pp= [HW,PPT] 382 Format: { parport<nr> | auto | none } 383 384 crashkernel=nn[KMG]@ss[KMG] 385 [KNL] Reserve a chunk of physical memory to 386 hold a kernel to switch to with kexec on panic. 387 388 cs4232= [HW,OSS] 389 Format: <io>,<irq>,<dma>,<dma2>,<mpuio>,<mpuirq> 390 391 cs89x0_dma= [HW,NET] 392 Format: <dma> 393 394 cs89x0_media= [HW,NET] 395 Format: { rj45 | aui | bnc } 396 397 cyclades= [HW,SERIAL] Cyclades multi-serial port adapter. 398 399 dasd= [HW,NET] 400 See header of drivers/s390/block/dasd_devmap.c. 401 402 db9.dev[2|3]= [HW,JOY] Multisystem joystick support via parallel port 403 (one device per port) 404 Format: <port#>,<type> 405 See also Documentation/input/joystick-parport.txt 406 407 debug [KNL] Enable kernel debugging (events log level). 408 409 decnet= [HW,NET] 410 Format: <area>[,<node>] 411 See also Documentation/networking/decnet.txt. 412 413 devfs= [DEVFS] 414 See Documentation/filesystems/devfs/boot-options. 415 416 dhash_entries= [KNL] 417 Set number of hash buckets for dentry cache. 418 419 digi= [HW,SERIAL] 420 IO parameters + enable/disable command. 421 422 digiepca= [HW,SERIAL] 423 See drivers/char/README.epca and 424 Documentation/digiepca.txt. 425 426 dmascc= [HW,AX25,SERIAL] AX.25 Z80SCC driver with DMA 427 support available. 428 Format: <io_dev0>[,<io_dev1>[,..<io_dev32>]] 429 430 dmasound= [HW,OSS] Sound subsystem buffers 431 432 dscc4.setup= [NET] 433 434 dtc3181e= [HW,SCSI] 435 436 earlyprintk= [IA-32,X86-64] 437 earlyprintk=vga 438 earlyprintk=serial[,ttySn[,baudrate]] 439 440 Append ",keep" to not disable it when the real console 441 takes over. 442 443 Only vga or serial at a time, not both. 444 445 Currently only ttyS0 and ttyS1 are supported. 446 447 Interaction with the standard serial driver is not 448 very good. 449 450 The VGA output is eventually overwritten by the real 451 console. 452 453 eata= [HW,SCSI] 454 455 ec_intr= [HW,ACPI] ACPI Embedded Controller interrupt mode 456 Format: <int> 457 0: polling mode 458 non-0: interrupt mode (default) 459 460 eda= [HW,PS2] 461 462 edb= [HW,PS2] 463 464 edd= [EDD] 465 Format: {"of[f]" | "sk[ipmbr]"} 466 See comment in arch/i386/boot/edd.S 467 468 eicon= [HW,ISDN] 469 Format: <id>,<membase>,<irq> 470 471 eisa_irq_edge= [PARISC,HW] 472 See header of drivers/parisc/eisa.c. 473 474 elanfreq= [IA-32] 475 See comment before function elanfreq_setup() in 476 arch/i386/kernel/cpu/cpufreq/elanfreq.c. 477 478 elevator= [IOSCHED] 479 Format: {"anticipatory" | "cfq" | "deadline" | "noop"} 480 See Documentation/block/as-iosched.txt and 481 Documentation/block/deadline-iosched.txt for details. 482 483 elfcorehdr= [IA-32, X86_64] 484 Specifies physical address of start of kernel core 485 image elf header. Generally kexec loader will 486 pass this option to capture kernel. 487 See Documentation/kdump/kdump.txt for details. 488 489 enforcing [SELINUX] Set initial enforcing status. 490 Format: {"0" | "1"} 491 See security/selinux/Kconfig help text. 492 0 -- permissive (log only, no denials). 493 1 -- enforcing (deny and log). 494 Default value is 0. 495 Value can be changed at runtime via /selinux/enforce. 496 497 es1370= [HW,OSS] 498 Format: <lineout>[,<micbias>] 499 See also header of sound/oss/es1370.c. 500 501 es1371= [HW,OSS] 502 Format: <spdif>,[<nomix>,[<amplifier>]] 503 See also header of sound/oss/es1371.c. 504 505 ether= [HW,NET] Ethernet cards parameters 506 This option is obsoleted by the "netdev=" option, which 507 has equivalent usage. See its documentation for details. 508 509 eurwdt= [HW,WDT] Eurotech CPU-1220/1410 onboard watchdog. 510 Format: <io>[,<irq>] 511 512 fd_mcs= [HW,SCSI] 513 See header of drivers/scsi/fd_mcs.c. 514 515 fdomain= [HW,SCSI] 516 See header of drivers/scsi/fdomain.c. 517 518 floppy= [HW] 519 See Documentation/floppy.txt. 520 521 ftape= [HW] Floppy Tape subsystem debugging options. 522 See Documentation/ftape.txt. 523 524 gamecon.map[2|3]= 525 [HW,JOY] Multisystem joystick and NES/SNES/PSX pad 526 support via parallel port (up to 5 devices per port) 527 Format: <port#>,<pad1>,<pad2>,<pad3>,<pad4>,<pad5> 528 See also Documentation/input/joystick-parport.txt 529 530 gamma= [HW,DRM] 531 532 gdth= [HW,SCSI] 533 See header of drivers/scsi/gdth.c. 534 535 gpt [EFI] Forces disk with valid GPT signature but 536 invalid Protective MBR to be treated as GPT. 537 538 gscd= [HW,CD] 539 Format: <io> 540 541 gt96100eth= [NET] MIPS GT96100 Advanced Communication Controller 542 543 gus= [HW,OSS] 544 Format: <io>,<irq>,<dma>,<dma16> 545 546 gvp11= [HW,SCSI] 547 548 hashdist= [KNL,NUMA] Large hashes allocated during boot 549 are distributed across NUMA nodes. Defaults on 550 for IA-64, off otherwise. 551 Format: 0 | 1 (for off | on) 552 553 hcl= [IA-64] SGI's Hardware Graph compatibility layer 554 555 hd= [EIDE] (E)IDE hard drive subsystem geometry 556 Format: <cyl>,<head>,<sect> 557 558 hd?= [HW] (E)IDE subsystem 559 hd?lun= See Documentation/ide.txt. 560 561 highmem=nn[KMG] [KNL,BOOT] forces the highmem zone to have an exact 562 size of <nn>. This works even on boxes that have no 563 highmem otherwise. This also works to reduce highmem 564 size on bigger boxes. 565 566 hisax= [HW,ISDN] 567 See Documentation/isdn/README.HiSax. 568 569 hugepages= [HW,IA-32,IA-64] Maximal number of HugeTLB pages. 570 571 noirqbalance [IA-32,SMP,KNL] Disable kernel irq balancing 572 573 i8042.direct [HW] Put keyboard port into non-translated mode 574 i8042.dumbkbd [HW] Pretend that controlled can only read data from 575 keyboard and can not control its state 576 (Don't attempt to blink the leds) 577 i8042.noaux [HW] Don't check for auxiliary (== mouse) port 578 i8042.nokbd [HW] Don't check/create keyboard port 579 i8042.nomux [HW] Don't check presence of an active multiplexing 580 controller 581 i8042.nopnp [HW] Don't use ACPIPnP / PnPBIOS to discover KBD/AUX 582 controllers 583 i8042.panicblink= 584 [HW] Frequency with which keyboard LEDs should blink 585 when kernel panics (default is 0.5 sec) 586 i8042.reset [HW] Reset the controller during init and cleanup 587 i8042.unlock [HW] Unlock (ignore) the keylock 588 589 i810= [HW,DRM] 590 591 i8k.ignore_dmi [HW] Continue probing hardware even if DMI data 592 indicates that the driver is running on unsupported 593 hardware. 594 i8k.force [HW] Activate i8k driver even if SMM BIOS signature 595 does not match list of supported models. 596 i8k.power_status 597 [HW] Report power status in /proc/i8k 598 (disabled by default) 599 i8k.restricted [HW] Allow controlling fans only if SYS_ADMIN 600 capability is set. 601 602 ibmmcascsi= [HW,MCA,SCSI] IBM MicroChannel SCSI adapter 603 See Documentation/mca.txt. 604 605 icn= [HW,ISDN] 606 Format: <io>[,<membase>[,<icn_id>[,<icn_id2>]]] 607 608 ide= [HW] (E)IDE subsystem 609 Format: ide=nodma or ide=doubler or ide=reverse 610 See Documentation/ide.txt. 611 612 ide?= [HW] (E)IDE subsystem 613 Format: ide?=noprobe or chipset specific parameters. 614 See Documentation/ide.txt. 615 616 idebus= [HW] (E)IDE subsystem - VLB/PCI bus speed 617 See Documentation/ide.txt. 618 619 idle= [HW] 620 Format: idle=poll or idle=halt 621 622 ihash_entries= [KNL] 623 Set number of hash buckets for inode cache. 624 625 in2000= [HW,SCSI] 626 See header of drivers/scsi/in2000.c. 627 628 init= [KNL] 629 Format: <full_path> 630 Run specified binary instead of /sbin/init as init 631 process. 632 633 initcall_debug [KNL] Trace initcalls as they are executed. Useful 634 for working out where the kernel is dying during 635 startup. 636 637 initrd= [BOOT] Specify the location of the initial ramdisk 638 639 inport.irq= [HW] Inport (ATI XL and Microsoft) busmouse driver 640 Format: <irq> 641 642 combined_mode= [HW] control which driver uses IDE ports in combined 643 mode: legacy IDE driver, libata, or both 644 (in the libata case, libata.atapi_enabled=1 may be 645 useful as well). Note that using the ide or libata 646 options may affect your device naming (e.g. by 647 changing hdc to sdb). 648 Format: combined (default), ide, or libata 649 650 inttest= [IA64] 651 652 io7= [HW] IO7 for Marvel based alpha systems 653 See comment before marvel_specify_io7 in 654 arch/alpha/kernel/core_marvel.c. 655 656 ip= [IP_PNP] 657 See Documentation/nfsroot.txt. 658 659 ip2= [HW] Set IO/IRQ pairs for up to 4 IntelliPort boards 660 See comment before ip2_setup() in drivers/char/ip2.c. 661 662 ips= [HW,SCSI] Adaptec / IBM ServeRAID controller 663 See header of drivers/scsi/ips.c. 664 665 irqfixup [HW] 666 When an interrupt is not handled search all handlers 667 for it. Intended to get systems with badly broken 668 firmware running. 669 670 irqpoll [HW] 671 When an interrupt is not handled search all handlers 672 for it. Also check all handlers each timer 673 interrupt. Intended to get systems with badly broken 674 firmware running. 675 676 isapnp= [ISAPNP] 677 Format: <RDP>,<reset>,<pci_scan>,<verbosity> 678 679 isolcpus= [KNL,SMP] Isolate CPUs from the general scheduler. 680 Format: <cpu number>,...,<cpu number> 681 This option can be used to specify one or more CPUs 682 to isolate from the general SMP balancing and scheduling 683 algorithms. The only way to move a process onto or off 684 an "isolated" CPU is via the CPU affinity syscalls. 685 <cpu number> begins at 0 and the maximum value is 686 "number of CPUs in system - 1". 687 688 This option is the preferred way to isolate CPUs. The 689 alternative -- manually setting the CPU mask of all 690 tasks in the system -- can cause problems and 691 suboptimal load balancer performance. 692 693 isp16= [HW,CD] 694 Format: <io>,<irq>,<dma>,<setup> 695 696 iucv= [HW,NET] 697 698 js= [HW,JOY] Analog joystick 699 See Documentation/input/joystick.txt. 700 701 keepinitrd [HW,ARM] 702 703 kstack=N [IA-32,X86-64] Print N words from the kernel stack 704 in oops dumps. 705 706 l2cr= [PPC] 707 708 lapic [IA-32,APIC] Enable the local APIC even if BIOS 709 disabled it. 710 711 lasi= [HW,SCSI] PARISC LASI driver for the 53c700 chip 712 Format: addr:<io>,irq:<irq> 713 714 llsc*= [IA64] See function print_params() in 715 arch/ia64/sn/kernel/llsc4.c. 716 717 load_ramdisk= [RAM] List of ramdisks to load from floppy 718 See Documentation/ramdisk.txt. 719 720 lockd.nlm_grace_period=P [NFS] Assign grace period. 721 Format: <integer> 722 723 lockd.nlm_tcpport=N [NFS] Assign TCP port. 724 Format: <integer> 725 726 lockd.nlm_timeout=T [NFS] Assign timeout value. 727 Format: <integer> 728 729 lockd.nlm_udpport=M [NFS] Assign UDP port. 730 Format: <integer> 731 732 logibm.irq= [HW,MOUSE] Logitech Bus Mouse Driver 733 Format: <irq> 734 735 loglevel= All Kernel Messages with a loglevel smaller than the 736 console loglevel will be printed to the console. It can 737 also be changed with klogd or other programs. The 738 loglevels are defined as follows: 739 740 0 (KERN_EMERG) system is unusable 741 1 (KERN_ALERT) action must be taken immediately 742 2 (KERN_CRIT) critical conditions 743 3 (KERN_ERR) error conditions 744 4 (KERN_WARNING) warning conditions 745 5 (KERN_NOTICE) normal but significant condition 746 6 (KERN_INFO) informational 747 7 (KERN_DEBUG) debug-level messages 748 749 log_buf_len=n Sets the size of the printk ring buffer, in bytes. 750 Format: { n | nk | nM } 751 n must be a power of two. The default size 752 is set in the kernel config file. 753 754 lp=0 [LP] Specify parallel ports to use, e.g, 755 lp=port[,port...] lp=none,parport0 (lp0 not configured, lp1 uses 756 lp=reset first parallel port). 'lp=0' disables the 757 lp=auto printer driver. 'lp=reset' (which can be 758 specified in addition to the ports) causes 759 attached printers to be reset. Using 760 lp=port1,port2,... specifies the parallel ports 761 to associate lp devices with, starting with 762 lp0. A port specification may be 'none' to skip 763 that lp device, or a parport name such as 764 'parport0'. Specifying 'lp=auto' instead of a 765 port specification list means that device IDs 766 from each port should be examined, to see if 767 an IEEE 1284-compliant printer is attached; if 768 so, the driver will manage that printer. 769 See also header of drivers/char/lp.c. 770 771 lpj=n [KNL] 772 Sets loops_per_jiffy to given constant, thus avoiding 773 time-consuming boot-time autodetection (up to 250 ms per 774 CPU). 0 enables autodetection (default). To determine 775 the correct value for your kernel, boot with normal 776 autodetection and see what value is printed. Note that 777 on SMP systems the preset will be applied to all CPUs, 778 which is likely to cause problems if your CPUs need 779 significantly divergent settings. An incorrect value 780 will cause delays in the kernel to be wrong, leading to 781 unpredictable I/O errors and other breakage. Although 782 unlikely, in the extreme case this might damage your 783 hardware. 784 785 ltpc= [NET] 786 Format: <io>,<irq>,<dma> 787 788 mac5380= [HW,SCSI] Format: 789 <can_queue>,<cmd_per_lun>,<sg_tablesize>,<hostid>,<use_tags> 790 791 mac53c9x= [HW,SCSI] Format: 792 <num_esps>,<disconnect>,<nosync>,<can_queue>,<cmd_per_lun>,<sg_tablesize>,<hostid>,<use_tags> 793 794 machvec= [IA64] Force the use of a particular machine-vector 795 (machvec) in a generic kernel. 796 Example: machvec=hpzx1_swiotlb 797 798 mad16= [HW,OSS] Format: 799 <io>,<irq>,<dma>,<dma16>,<mpu_io>,<mpu_irq>,<joystick> 800 801 maui= [HW,OSS] 802 Format: <io>,<irq> 803 804 max_loop= [LOOP] Maximum number of loopback devices that can 805 be mounted 806 Format: <1-256> 807 808 maxcpus= [SMP] Maximum number of processors that an SMP kernel 809 should make use of 810 811 max_addr=[KMG] [KNL,BOOT,ia64] All physical memory greater than or 812 equal to this physical address is ignored. 813 814 max_luns= [SCSI] Maximum number of LUNs to probe. 815 Should be between 1 and 2^32-1. 816 817 max_report_luns= 818 [SCSI] Maximum number of LUNs received. 819 Should be between 1 and 16384. 820 821 mca-pentium [BUGS=IA-32] 822 823 mcatest= [IA-64] 824 825 mcd= [HW,CD] 826 Format: <port>,<irq>,<mitsumi_bug_93_wait> 827 828 mcdx= [HW,CD] 829 830 mce [IA-32] Machine Check Exception 831 832 md= [HW] RAID subsystems devices and level 833 See Documentation/md.txt. 834 835 mdacon= [MDA] 836 Format: <first>,<last> 837 Specifies range of consoles to be captured by the MDA. 838 839 mem=nn[KMG] [KNL,BOOT] Force usage of a specific amount of memory 840 Amount of memory to be used when the kernel is not able 841 to see the whole system memory or for test. 842 [IA-32] Use together with memmap= to avoid physical 843 address space collisions. Without memmap= PCI devices 844 could be placed at addresses belonging to unused RAM. 845 846 mem=nopentium [BUGS=IA-32] Disable usage of 4MB pages for kernel 847 memory. 848 849 memmap=exactmap [KNL,IA-32,X86_64] Enable setting of an exact 850 E820 memory map, as specified by the user. 851 Such memmap=exactmap lines can be constructed based on 852 BIOS output or other requirements. See the memmap=nn@ss 853 option description. 854 855 memmap=nn[KMG]@ss[KMG] 856 [KNL] Force usage of a specific region of memory 857 Region of memory to be used, from ss to ss+nn. 858 859 memmap=nn[KMG]#ss[KMG] 860 [KNL,ACPI] Mark specific memory as ACPI data. 861 Region of memory to be used, from ss to ss+nn. 862 863 memmap=nn[KMG]$ss[KMG] 864 [KNL,ACPI] Mark specific memory as reserved. 865 Region of memory to be used, from ss to ss+nn. 866 867 meye.*= [HW] Set MotionEye Camera parameters 868 See Documentation/video4linux/meye.txt. 869 870 mga= [HW,DRM] 871 872 migration_cost= 873 [KNL,SMP] debug: override scheduler migration costs 874 Format: <level-1-usecs>,<level-2-usecs>,... 875 This debugging option can be used to override the 876 default scheduler migration cost matrix. The numbers 877 are indexed by 'CPU domain distance'. 878 E.g. migration_cost=1000,2000,3000 on an SMT NUMA 879 box will set up an intra-core migration cost of 880 1 msec, an inter-core migration cost of 2 msecs, 881 and an inter-node migration cost of 3 msecs. 882 883 WARNING: using the wrong values here can break 884 scheduler performance, so it's only for scheduler 885 development purposes, not production environments. 886 887 migration_debug= 888 [KNL,SMP] migration cost auto-detect verbosity 889 Format=<0|1|2> 890 If a system's migration matrix reported at bootup 891 seems erroneous then this option can be used to 892 increase verbosity of the detection process. 893 We default to 0 (no extra messages), 1 will print 894 some more information, and 2 will be really 895 verbose (probably only useful if you also have a 896 serial console attached to the system). 897 898 migration_factor= 899 [KNL,SMP] multiply/divide migration costs by a factor 900 Format=<percent> 901 This debug option can be used to proportionally 902 increase or decrease the auto-detected migration 903 costs for all entries of the migration matrix. 904 E.g. migration_factor=150 will increase migration 905 costs by 50%. (and thus the scheduler will be less 906 eager migrating cache-hot tasks) 907 migration_factor=80 will decrease migration costs 908 by 20%. (thus the scheduler will be more eager to 909 migrate tasks) 910 911 WARNING: using the wrong values here can break 912 scheduler performance, so it's only for scheduler 913 development purposes, not production environments. 914 915 mousedev.tap_time= 916 [MOUSE] Maximum time between finger touching and 917 leaving touchpad surface for touch to be considered 918 a tap and be reported as a left button click (for 919 touchpads working in absolute mode only). 920 Format: <msecs> 921 mousedev.xres= [MOUSE] Horizontal screen resolution, used for devices 922 reporting absolute coordinates, such as tablets 923 mousedev.yres= [MOUSE] Vertical screen resolution, used for devices 924 reporting absolute coordinates, such as tablets 925 926 mpu401= [HW,OSS] 927 Format: <io>,<irq> 928 929 MTD_Partition= [MTD] 930 Format: <name>,<region-number>,<size>,<offset> 931 932 MTD_Region= [MTD] Format: 933 <name>,<region-number>[,<base>,<size>,<buswidth>,<altbuswidth>] 934 935 mtdparts= [MTD] 936 See drivers/mtd/cmdline.c. 937 938 mtouchusb.raw_coordinates= 939 [HW] Make the MicroTouch USB driver use raw coordinates 940 ('y', default) or cooked coordinates ('n') 941 942 n2= [NET] SDL Inc. RISCom/N2 synchronous serial card 943 944 NCR_D700= [HW,SCSI] 945 See header of drivers/scsi/NCR_D700.c. 946 947 ncr5380= [HW,SCSI] 948 949 ncr53c400= [HW,SCSI] 950 951 ncr53c400a= [HW,SCSI] 952 953 ncr53c406a= [HW,SCSI] 954 955 ncr53c8xx= [HW,SCSI] 956 957 netdev= [NET] Network devices parameters 958 Format: <irq>,<io>,<mem_start>,<mem_end>,<name> 959 Note that mem_start is often overloaded to mean 960 something different and driver-specific. 961 This usage is only documented in each driver source 962 file if at all. 963 964 nfsaddrs= [NFS] 965 See Documentation/nfsroot.txt. 966 967 nfsroot= [NFS] nfs root filesystem for disk-less boxes. 968 See Documentation/nfsroot.txt. 969 970 nfs.callback_tcpport= 971 [NFS] set the TCP port on which the NFSv4 callback 972 channel should listen. 973 974 nfs.idmap_cache_timeout= 975 [NFS] set the maximum lifetime for idmapper cache 976 entries. 977 978 nmi_watchdog= [KNL,BUGS=IA-32] Debugging features for SMP kernels 979 980 no387 [BUGS=IA-32] Tells the kernel to use the 387 maths 981 emulation library even if a 387 maths coprocessor 982 is present. 983 984 noalign [KNL,ARM] 985 986 noapic [SMP,APIC] Tells the kernel to not make use of any 987 IOAPICs that may be present in the system. 988 989 noasync [HW,M68K] Disables async and sync negotiation for 990 all devices. 991 992 nobats [PPC] Do not use BATs for mapping kernel lowmem 993 on "Classic" PPC cores. 994 995 nocache [ARM] 996 997 nodisconnect [HW,SCSI,M68K] Disables SCSI disconnects. 998 999 noexec [IA-64] 1000 1001 noexec [IA-32,X86-64] 1002 noexec=on: enable non-executable mappings (default) 1003 noexec=off: disable nn-executable mappings 1004 1005 nofxsr [BUGS=IA-32] 1006 1007 nohlt [BUGS=ARM] 1008 1009 no-hlt [BUGS=IA-32] Tells the kernel that the hlt 1010 instruction doesn't work correctly and not to 1011 use it. 1012 1013 nohalt [IA-64] Tells the kernel not to use the power saving 1014 function PAL_HALT_LIGHT when idle. This increases 1015 power-consumption. On the positive side, it reduces 1016 interrupt wake-up latency, which may improve performance 1017 in certain environments such as networked servers or 1018 real-time systems. 1019 1020 noirqdebug [IA-32] Disables the code which attempts to detect and 1021 disable unhandled interrupt sources. 1022 1023 noisapnp [ISAPNP] Disables ISA PnP code. 1024 1025 noinitrd [RAM] Tells the kernel not to load any configured 1026 initial RAM disk. 1027 1028 nointroute [IA-64] 1029 1030 nolapic [IA-32,APIC] Do not enable or use the local APIC. 1031 1032 noltlbs [PPC] Do not use large page/tlb entries for kernel 1033 lowmem mapping on PPC40x. 1034 1035 nomce [IA-32] Machine Check Exception 1036 1037 noresidual [PPC] Don't use residual data on PReP machines. 1038 1039 noresume [SWSUSP] Disables resume and restores original swap 1040 space. 1041 1042 no-scroll [VGA] Disables scrollback. 1043 This is required for the Braillex ib80-piezo Braille 1044 reader made by F.H. Papenmeier (Germany). 1045 1046 nosbagart [IA-64] 1047 1048 nosmp [SMP] Tells an SMP kernel to act as a UP kernel. 1049 1050 nosync [HW,M68K] Disables sync negotiation for all devices. 1051 1052 notsc [BUGS=IA-32] Disable Time Stamp Counter 1053 1054 nousb [USB] Disable the USB subsystem 1055 1056 nowb [ARM] 1057 1058 nr_uarts= [SERIAL] maximum number of UARTs to be registered. 1059 1060 opl3= [HW,OSS] 1061 Format: <io> 1062 1063 opl3sa= [HW,OSS] 1064 Format: <io>,<irq>,<dma>,<dma2>,<mpu_io>,<mpu_irq> 1065 1066 opl3sa2= [HW,OSS] Format: 1067 <io>,<irq>,<dma>,<dma2>,<mss_io>,<mpu_io>,<ymode>,<loopback>[,<isapnp>,<multiple] 1068 1069 oprofile.timer= [HW] 1070 Use timer interrupt instead of performance counters 1071 1072 optcd= [HW,CD] 1073 Format: <io> 1074 1075 osst= [HW,SCSI] SCSI Tape Driver 1076 Format: <buffer_size>,<write_threshold> 1077 See also Documentation/scsi/st.txt. 1078 1079 panic= [KNL] Kernel behaviour on panic 1080 Format: <timeout> 1081 1082 parkbd.port= [HW] Parallel port number the keyboard adapter is 1083 connected to, default is 0. 1084 Format: <parport#> 1085 parkbd.mode= [HW] Parallel port keyboard adapter mode of operation, 1086 0 for XT, 1 for AT (default is AT). 1087 Format: <mode> 1088 1089 parport= [HW,PPT] Specify parallel ports. 0 disables. 1090 Format: { 0 | auto | 0xBBB[,IRQ[,DMA]] } 1091 Use 'auto' to force the driver to use any 1092 IRQ/DMA settings detected (the default is to 1093 ignore detected IRQ/DMA settings because of 1094 possible conflicts). You can specify the base 1095 address, IRQ, and DMA settings; IRQ and DMA 1096 should be numbers, or 'auto' (for using detected 1097 settings on that particular port), or 'nofifo' 1098 (to avoid using a FIFO even if it is detected). 1099 Parallel ports are assigned in the order they 1100 are specified on the command line, starting 1101 with parport0. 1102 1103 parport_init_mode= [HW,PPT] 1104 Configure VIA parallel port to operate in 1105 a specific mode. This is necessary on Pegasos 1106 computer where firmware has no options for setting 1107 up parallel port mode and sets it to spp. 1108 Currently this function knows 686a and 8231 chips. 1109 Format: [spp|ps2|epp|ecp|ecpepp] 1110 1111 pas2= [HW,OSS] Format: 1112 <io>,<irq>,<dma>,<dma16>,<sb_io>,<sb_irq>,<sb_dma>,<sb_dma16> 1113 1114 pas16= [HW,SCSI] 1115 See header of drivers/scsi/pas16.c. 1116 1117 pcbit= [HW,ISDN] 1118 1119 pcd. [PARIDE] 1120 See header of drivers/block/paride/pcd.c. 1121 See also Documentation/paride.txt. 1122 1123 pci=option[,option...] [PCI] various PCI subsystem options: 1124 off [IA-32] don't probe for the PCI bus 1125 bios [IA-32] force use of PCI BIOS, don't access 1126 the hardware directly. Use this if your machine 1127 has a non-standard PCI host bridge. 1128 nobios [IA-32] disallow use of PCI BIOS, only direct 1129 hardware access methods are allowed. Use this 1130 if you experience crashes upon bootup and you 1131 suspect they are caused by the BIOS. 1132 conf1 [IA-32] Force use of PCI Configuration 1133 Mechanism 1. 1134 conf2 [IA-32] Force use of PCI Configuration 1135 Mechanism 2. 1136 nommconf [IA-32,X86_64] Disable use of MMCONFIG for PCI 1137 Configuration 1138 nosort [IA-32] Don't sort PCI devices according to 1139 order given by the PCI BIOS. This sorting is 1140 done to get a device order compatible with 1141 older kernels. 1142 biosirq [IA-32] Use PCI BIOS calls to get the interrupt 1143 routing table. These calls are known to be buggy 1144 on several machines and they hang the machine 1145 when used, but on other computers it's the only 1146 way to get the interrupt routing table. Try 1147 this option if the kernel is unable to allocate 1148 IRQs or discover secondary PCI buses on your 1149 motherboard. 1150 rom [IA-32] Assign address space to expansion ROMs. 1151 Use with caution as certain devices share 1152 address decoders between ROMs and other 1153 resources. 1154 irqmask=0xMMMM [IA-32] Set a bit mask of IRQs allowed to be 1155 assigned automatically to PCI devices. You can 1156 make the kernel exclude IRQs of your ISA cards 1157 this way. 1158 pirqaddr=0xAAAAA [IA-32] Specify the physical address 1159 of the PIRQ table (normally generated 1160 by the BIOS) if it is outside the 1161 F0000h-100000h range. 1162 lastbus=N [IA-32] Scan all buses thru bus #N. Can be 1163 useful if the kernel is unable to find your 1164 secondary buses and you want to tell it 1165 explicitly which ones they are. 1166 assign-busses [IA-32] Always assign all PCI bus 1167 numbers ourselves, overriding 1168 whatever the firmware may have done. 1169 usepirqmask [IA-32] Honor the possible IRQ mask stored 1170 in the BIOS $PIR table. This is needed on 1171 some systems with broken BIOSes, notably 1172 some HP Pavilion N5400 and Omnibook XE3 1173 notebooks. This will have no effect if ACPI 1174 IRQ routing is enabled. 1175 noacpi [IA-32] Do not use ACPI for IRQ routing 1176 or for PCI scanning. 1177 routeirq Do IRQ routing for all PCI devices. 1178 This is normally done in pci_enable_device(), 1179 so this option is a temporary workaround 1180 for broken drivers that don't call it. 1181 firmware [ARM] Do not re-enumerate the bus but instead 1182 just use the configuration from the 1183 bootloader. This is currently used on 1184 IXP2000 systems where the bus has to be 1185 configured a certain way for adjunct CPUs. 1186 1187 pcmv= [HW,PCMCIA] BadgePAD 4 1188 1189 pd. [PARIDE] 1190 See Documentation/paride.txt. 1191 1192 pdcchassis= [PARISC,HW] Disable/Enable PDC Chassis Status codes at 1193 boot time. 1194 Format: { 0 | 1 } 1195 See arch/parisc/kernel/pdc_chassis.c 1196 1197 pf. [PARIDE] 1198 See Documentation/paride.txt. 1199 1200 pg. [PARIDE] 1201 See Documentation/paride.txt. 1202 1203 pirq= [SMP,APIC] Manual mp-table setup 1204 See Documentation/i386/IO-APIC.txt. 1205 1206 plip= [PPT,NET] Parallel port network link 1207 Format: { parport<nr> | timid | 0 } 1208 See also Documentation/parport.txt. 1209 1210 pnpacpi= [ACPI] 1211 { off } 1212 1213 pnpbios= [ISAPNP] 1214 { on | off | curr | res | no-curr | no-res } 1215 1216 pnp_reserve_irq= 1217 [ISAPNP] Exclude IRQs for the autoconfiguration 1218 1219 pnp_reserve_dma= 1220 [ISAPNP] Exclude DMAs for the autoconfiguration 1221 1222 pnp_reserve_io= [ISAPNP] Exclude I/O ports for the autoconfiguration 1223 Ranges are in pairs (I/O port base and size). 1224 1225 pnp_reserve_mem= 1226 [ISAPNP] Exclude memory regions for the 1227 autoconfiguration. 1228 Ranges are in pairs (memory base and size). 1229 1230 profile= [KNL] Enable kernel profiling via /proc/profile 1231 Format: [schedule,]<number> 1232 Param: "schedule" - profile schedule points. 1233 Param: <number> - step/bucket size as a power of 2 for 1234 statistical time based profiling. 1235 1236 processor.max_cstate= [HW,ACPI] 1237 Limit processor to maximum C-state 1238 max_cstate=9 overrides any DMI blacklist limit. 1239 1240 processor.nocst [HW,ACPI] 1241 Ignore the _CST method to determine C-states, 1242 instead using the legacy FADT method 1243 1244 prompt_ramdisk= [RAM] List of RAM disks to prompt for floppy disk 1245 before loading. 1246 See Documentation/ramdisk.txt. 1247 1248 psmouse.proto= [HW,MOUSE] Highest PS2 mouse protocol extension to 1249 probe for; one of (bare|imps|exps|lifebook|any). 1250 psmouse.rate= [HW,MOUSE] Set desired mouse report rate, in reports 1251 per second. 1252 psmouse.resetafter= [HW,MOUSE] 1253 Try to reset the device after so many bad packets 1254 (0 = never). 1255 psmouse.resolution= 1256 [HW,MOUSE] Set desired mouse resolution, in dpi. 1257 psmouse.smartscroll= 1258 [HW,MOUSE] Controls Logitech smartscroll autorepeat. 1259 0 = disabled, 1 = enabled (default). 1260 1261 pss= [HW,OSS] Personal Sound System (ECHO ESC614) 1262 Format: 1263 <io>,<mss_io>,<mss_irq>,<mss_dma>,<mpu_io>,<mpu_irq> 1264 1265 pt. [PARIDE] 1266 See Documentation/paride.txt. 1267 1268 quiet= [KNL] Disable log messages 1269 1270 r128= [HW,DRM] 1271 1272 raid= [HW,RAID] 1273 See Documentation/md.txt. 1274 1275 ramdisk= [RAM] Sizes of RAM disks in kilobytes [deprecated] 1276 See Documentation/ramdisk.txt. 1277 1278 ramdisk_blocksize= [RAM] 1279 See Documentation/ramdisk.txt. 1280 1281 ramdisk_size= [RAM] Sizes of RAM disks in kilobytes 1282 New name for the ramdisk parameter. 1283 See Documentation/ramdisk.txt. 1284 1285 rdinit= [KNL] 1286 Format: <full_path> 1287 Run specified binary instead of /init from the ramdisk, 1288 used for early userspace startup. See initrd. 1289 1290 reboot= [BUGS=IA-32,BUGS=ARM,BUGS=IA-64] Rebooting mode 1291 Format: <reboot_mode>[,<reboot_mode2>[,...]] 1292 See arch/*/kernel/reboot.c. 1293 1294 reserve= [KNL,BUGS] Force the kernel to ignore some iomem area 1295 1296 resume= [SWSUSP] 1297 Specify the partition device for software suspend 1298 1299 rhash_entries= [KNL,NET] 1300 Set number of hash buckets for route cache 1301 1302 riscom8= [HW,SERIAL] 1303 Format: <io_board1>[,<io_board2>[,...<io_boardN>]] 1304 1305 ro [KNL] Mount root device read-only on boot 1306 1307 root= [KNL] Root filesystem 1308 1309 rootdelay= [KNL] Delay (in seconds) to pause before attempting to 1310 mount the root filesystem 1311 1312 rootflags= [KNL] Set root filesystem mount option string 1313 1314 rootfstype= [KNL] Set root filesystem type 1315 1316 rw [KNL] Mount root device read-write on boot 1317 1318 S [KNL] Run init in single mode 1319 1320 sa1100ir [NET] 1321 See drivers/net/irda/sa1100_ir.c. 1322 1323 sb= [HW,OSS] 1324 Format: <io>,<irq>,<dma>,<dma2> 1325 1326 sbni= [NET] Granch SBNI12 leased line adapter 1327 1328 sbpcd= [HW,CD] Soundblaster CD adapter 1329 Format: <io>,<type> 1330 See a comment before function sbpcd_setup() in 1331 drivers/cdrom/sbpcd.c. 1332 1333 sc1200wdt= [HW,WDT] SC1200 WDT (watchdog) driver 1334 Format: <io>[,<timeout>[,<isapnp>]] 1335 1336 scsi_debug_*= [SCSI] 1337 See drivers/scsi/scsi_debug.c. 1338 1339 scsi_default_dev_flags= 1340 [SCSI] SCSI default device flags 1341 Format: <integer> 1342 1343 scsi_dev_flags= [SCSI] Black/white list entry for vendor and model 1344 Format: <vendor>:<model>:<flags> 1345 (flags are integer value) 1346 1347 scsi_logging= [SCSI] 1348 1349 selinux [SELINUX] Disable or enable SELinux at boot time. 1350 Format: { "0" | "1" } 1351 See security/selinux/Kconfig help text. 1352 0 -- disable. 1353 1 -- enable. 1354 Default value is set via kernel config option. 1355 If enabled at boot time, /selinux/disable can be used 1356 later to disable prior to initial policy load. 1357 1358 serialnumber [BUGS=IA-32] 1359 1360 sg_def_reserved_size= [SCSI] 1361 1362 sgalaxy= [HW,OSS] 1363 Format: <io>,<irq>,<dma>,<dma2>,<sgbase> 1364 1365 shapers= [NET] 1366 Maximal number of shapers. 1367 1368 sim710= [SCSI,HW] 1369 See header of drivers/scsi/sim710.c. 1370 1371 simeth= [IA-64] 1372 simscsi= 1373 1374 sjcd= [HW,CD] 1375 Format: <io>,<irq>,<dma> 1376 See header of drivers/cdrom/sjcd.c. 1377 1378 slram= [HW,MTD] 1379 1380 smart2= [HW] 1381 Format: <io1>[,<io2>[,...,<io8>]] 1382 1383 snd-ad1816a= [HW,ALSA] 1384 1385 snd-ad1848= [HW,ALSA] 1386 1387 snd-ali5451= [HW,ALSA] 1388 1389 snd-als100= [HW,ALSA] 1390 1391 snd-als4000= [HW,ALSA] 1392 1393 snd-azt2320= [HW,ALSA] 1394 1395 snd-cmi8330= [HW,ALSA] 1396 1397 snd-cmipci= [HW,ALSA] 1398 1399 snd-cs4231= [HW,ALSA] 1400 1401 snd-cs4232= [HW,ALSA] 1402 1403 snd-cs4236= [HW,ALSA] 1404 1405 snd-cs4281= [HW,ALSA] 1406 1407 snd-cs46xx= [HW,ALSA] 1408 1409 snd-dt019x= [HW,ALSA] 1410 1411 snd-dummy= [HW,ALSA] 1412 1413 snd-emu10k1= [HW,ALSA] 1414 1415 snd-ens1370= [HW,ALSA] 1416 1417 snd-ens1371= [HW,ALSA] 1418 1419 snd-es968= [HW,ALSA] 1420 1421 snd-es1688= [HW,ALSA] 1422 1423 snd-es18xx= [HW,ALSA] 1424 1425 snd-es1938= [HW,ALSA] 1426 1427 snd-es1968= [HW,ALSA] 1428 1429 snd-fm801= [HW,ALSA] 1430 1431 snd-gusclassic= [HW,ALSA] 1432 1433 snd-gusextreme= [HW,ALSA] 1434 1435 snd-gusmax= [HW,ALSA] 1436 1437 snd-hdsp= [HW,ALSA] 1438 1439 snd-ice1712= [HW,ALSA] 1440 1441 snd-intel8x0= [HW,ALSA] 1442 1443 snd-interwave= [HW,ALSA] 1444 1445 snd-interwave-stb= 1446 [HW,ALSA] 1447 1448 snd-korg1212= [HW,ALSA] 1449 1450 snd-maestro3= [HW,ALSA] 1451 1452 snd-mpu401= [HW,ALSA] 1453 1454 snd-mtpav= [HW,ALSA] 1455 1456 snd-nm256= [HW,ALSA] 1457 1458 snd-opl3sa2= [HW,ALSA] 1459 1460 snd-opti92x-ad1848= 1461 [HW,ALSA] 1462 1463 snd-opti92x-cs4231= 1464 [HW,ALSA] 1465 1466 snd-opti93x= [HW,ALSA] 1467 1468 snd-pmac= [HW,ALSA] 1469 1470 snd-rme32= [HW,ALSA] 1471 1472 snd-rme96= [HW,ALSA] 1473 1474 snd-rme9652= [HW,ALSA] 1475 1476 snd-sb8= [HW,ALSA] 1477 1478 snd-sb16= [HW,ALSA] 1479 1480 snd-sbawe= [HW,ALSA] 1481 1482 snd-serial= [HW,ALSA] 1483 1484 snd-sgalaxy= [HW,ALSA] 1485 1486 snd-sonicvibes= [HW,ALSA] 1487 1488 snd-sun-amd7930= 1489 [HW,ALSA] 1490 1491 snd-sun-cs4231= [HW,ALSA] 1492 1493 snd-trident= [HW,ALSA] 1494 1495 snd-usb-audio= [HW,ALSA,USB] 1496 1497 snd-via82xx= [HW,ALSA] 1498 1499 snd-virmidi= [HW,ALSA] 1500 1501 snd-wavefront= [HW,ALSA] 1502 1503 snd-ymfpci= [HW,ALSA] 1504 1505 sonicvibes= [HW,OSS] 1506 Format: <reverb> 1507 1508 sonycd535= [HW,CD] 1509 Format: <io>[,<irq>] 1510 1511 sonypi.*= [HW] Sony Programmable I/O Control Device driver 1512 See Documentation/sonypi.txt 1513 1514 specialix= [HW,SERIAL] Specialix multi-serial port adapter 1515 See Documentation/specialix.txt. 1516 1517 spia_io_base= [HW,MTD] 1518 spia_fio_base= 1519 spia_pedr= 1520 spia_peddr= 1521 1522 sscape= [HW,OSS] 1523 Format: <io>,<irq>,<dma>,<mpu_io>,<mpu_irq> 1524 1525 st= [HW,SCSI] SCSI tape parameters (buffers, etc.) 1526 See Documentation/scsi/st.txt. 1527 1528 st0x= [HW,SCSI] 1529 See header of drivers/scsi/seagate.c. 1530 1531 sti= [PARISC,HW] 1532 Format: <num> 1533 Set the STI (builtin display/keyboard on the HP-PARISC 1534 machines) console (graphic card) which should be used 1535 as the initial boot-console. 1536 See also comment in drivers/video/console/sticore.c. 1537 1538 sti_font= [HW] 1539 See comment in drivers/video/console/sticore.c. 1540 1541 stifb= [HW] 1542 Format: bpp:<bpp1>[:<bpp2>[:<bpp3>...]] 1543 1544 swiotlb= [IA-64] Number of I/O TLB slabs 1545 1546 switches= [HW,M68k] 1547 1548 sym53c416= [HW,SCSI] 1549 See header of drivers/scsi/sym53c416.c. 1550 1551 t128= [HW,SCSI] 1552 See header of drivers/scsi/t128.c. 1553 1554 tdfx= [HW,DRM] 1555 1556 thash_entries= [KNL,NET] 1557 Set number of hash buckets for TCP connection 1558 1559 time Show timing data prefixed to each printk message line 1560 1561 tipar.timeout= [HW,PPT] 1562 Set communications timeout in tenths of a second 1563 (default 15). 1564 1565 tipar.delay= [HW,PPT] 1566 Set inter-bit delay in microseconds (default 10). 1567 1568 tmc8xx= [HW,SCSI] 1569 See header of drivers/scsi/seagate.c. 1570 1571 tmscsim= [HW,SCSI] 1572 See comment before function dc390_setup() in 1573 drivers/scsi/tmscsim.c. 1574 1575 tp720= [HW,PS2] 1576 1577 trix= [HW,OSS] MediaTrix AudioTrix Pro 1578 Format: 1579 <io>,<irq>,<dma>,<dma2>,<sb_io>,<sb_irq>,<sb_dma>,<mpu_io>,<mpu_irq> 1580 1581 tsdev.xres= [TS] Horizontal screen resolution. 1582 tsdev.yres= [TS] Vertical screen resolution. 1583 1584 turbografx.map[2|3]= [HW,JOY] 1585 TurboGraFX parallel port interface 1586 Format: 1587 <port#>,<js1>,<js2>,<js3>,<js4>,<js5>,<js6>,<js7> 1588 See also Documentation/input/joystick-parport.txt 1589 1590 u14-34f= [HW,SCSI] UltraStor 14F/34F SCSI host adapter 1591 See header of drivers/scsi/u14-34f.c. 1592 1593 uart401= [HW,OSS] 1594 Format: <io>,<irq> 1595 1596 uart6850= [HW,OSS] 1597 Format: <io>,<irq> 1598 1599 usbhid.mousepoll= 1600 [USBHID] The interval which mice are to be polled at. 1601 1602 video= [FB] Frame buffer configuration 1603 See Documentation/fb/modedb.txt. 1604 1605 vga= [BOOT,IA-32] Select a particular video mode 1606 See Documentation/i386/boot.txt and 1607 Documentation/svga.txt. 1608 Use vga=ask for menu. 1609 This is actually a boot loader parameter; the value is 1610 passed to the kernel using a special protocol. 1611 1612 vmalloc=nn[KMG] [KNL,BOOT] Forces the vmalloc area to have an exact 1613 size of <nn>. This can be used to increase the 1614 minimum size (128MB on x86). It can also be used to 1615 decrease the size and leave more room for directly 1616 mapped kernel RAM. 1617 1618 vmhalt= [KNL,S390] 1619 1620 vmpoff= [KNL,S390] 1621 1622 waveartist= [HW,OSS] 1623 Format: <io>,<irq>,<dma>,<dma2> 1624 1625 wd33c93= [HW,SCSI] 1626 See header of drivers/scsi/wd33c93.c. 1627 1628 wd7000= [HW,SCSI] 1629 See header of drivers/scsi/wd7000.c. 1630 1631 wdt= [WDT] Watchdog 1632 See Documentation/watchdog/watchdog.txt. 1633 1634 xd= [HW,XT] Original XT pre-IDE (RLL encoded) disks. 1635 xd_geo= See header of drivers/block/xd.c. 1636 1637 xirc2ps_cs= [NET,PCMCIA] 1638 Format: 1639 <irq>,<irq_mask>,<io>,<full_duplex>,<do_sound>,<lockup_hack>[,<irq2>[,<irq3>[,<irq4>]]] 1640 1641 norandmaps Don't use address space randomization 1642 Equivalent to echo 0 > /proc/sys/kernel/randomize_va_space 1643 1644 1645______________________________________________________________________ 1646Changelog: 1647 16482000-06-?? Mr. Unknown 1649 The last known update (for 2.4.0) - the changelog was not kept before. 1650 16512002-11-24 Petr Baudis <pasky@ucw.cz> 1652 Randy Dunlap <randy.dunlap@verizon.net> 1653 Update for 2.5.49, description for most of the options introduced, 1654 references to other documentation (C files, READMEs, ..), added S390, 1655 PPC, SPARC, MTD, ALSA and OSS category. Minor corrections and 1656 reformatting. 1657 16582005-10-19 Randy Dunlap <rdunlap@xenotime.net> 1659 Lots of typos, whitespace, some reformatting. 1660 1661TODO: 1662 1663 Add documentation for ALSA options. 1664 Add more DRM drivers.