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 9The text in square brackets at the beginning of the description state the 10restrictions on the kernel for the said kernel parameter to be valid. The 11restrictions referred to are that the relevant option is valid if: 12 13 ACPI ACPI support is enabled. 14 ALSA ALSA sound support is enabled. 15 APIC APIC support is enabled. 16 APM Advanced Power Management support is enabled. 17 AX25 Appropriate AX.25 support is enabled. 18 CD Appropriate CD support is enabled. 19 DEVFS devfs support is enabled. 20 DRM Direct Rendering Management support is enabled. 21 EFI EFI Partitioning (GPT) is enabled 22 EIDE EIDE/ATAPI support is enabled. 23 FB The frame buffer device is enabled. 24 HW Appropriate hardware is enabled. 25 IA-32 IA-32 aka i386 architecture is enabled. 26 IA-64 IA-64 architecture is enabled. 27 IOSCHED More than one I/O scheduler is enabled. 28 IP_PNP IP DCHP, BOOTP, or RARP is enabled. 29 ISAPNP ISA PnP code is enabled. 30 ISDN Appropriate ISDN support is enabled. 31 JOY Appropriate joystick support is enabled. 32 LP Printer support is enabled. 33 LOOP Loopback device support is enabled. 34 M68k M68k architecture is enabled. 35 These options have more detailed description inside of 36 Documentation/m68k/kernel-options.txt. 37 MCA MCA bus support is enabled. 38 MDA MDA console support is enabled. 39 MOUSE Appropriate mouse support is enabled. 40 MTD MTD support is nebaled. 41 NET Appropriate network support is enabled. 42 NFS Appropriate NFS support is enabled. 43 OSS OSS sound support is enabled. 44 PARIDE The ParIDE subsystem is enabled. 45 PCI PCI bus support is enabled. 46 PCMCIA The PCMCIA subsystem is enabled. 47 PNP Plug & Play support is enabled. 48 PPC PowerPC architecture is enabled. 49 PPT Parallel port support is enabled. 50 PS2 Appropriate PS/2 support is enabled. 51 RAM RAM disk support is enabled. 52 S390 S390 architecture is enabled. 53 SCSI Appropriate SCSI support is enabled. 54 A lot of drivers has their options described inside of 55 Documentation/scsi/. 56 SERIAL Serial support is enabled. 57 SMP The kernel is an SMP kernel. 58 SPARC Sparc architecture is enabled. 59 SWSUSP Software suspension is enabled. 60 USB USB support is enabled. 61 V4L Video For Linux support is enabled. 62 VGA The VGA console has been enabled. 63 VT Virtual terminal support is enabled. 64 WDT Watchdog support is enabled. 65 XT IBM PC/XT MFM hard disk support is enabled. 66 67In addition, the following text indicates that the option: 68 69 BUGS= Relates to possible processor bugs on the said processor. 70 KNL Is a kernel start-up parameter. 71 BOOT Is a boot loader parameter. 72 73Parameters denoted with BOOT are actually interpreted by the boot 74loader, and have no meaning to the kernel directly. 75Do not modify the syntax of boot loader parameters without extreme 76need or coordination with <Documentation/i386/boot.txt>. 77 78Note that ALL kernel parameters listed below are CASE SENSITIVE, and that 79a trailing = on the name of any parameter states that that parameter will 80be entered as an environment variable, whereas its absence indicates that 81it will appear as a kernel argument readable via /proc/cmdline by programs 82running once the system is up. 83 84 53c7xx= [HW,SCSI] Amiga SCSI controllers 85 See header of drivers/scsi/53c7xx.c. 86 See also Documentation/scsi/ncr53c7xx.txt. 87 88 acpi= [HW,ACPI] Advanced Configuration and Power Interface 89 Format: { force | off | ht } 90 force -- enables ACPI for systems with default off 91 off -- disabled ACPI for systems with default on 92 ht -- run only enough ACPI to enable Hyper Threading 93 See also Documentation/pm.txt. 94 95 ad1816= [HW,OSS] 96 Format: <io>,<irq>,<dma>,<dma2> 97 See also Documentation/sound/oss/AD1816. 98 99 ad1848= [HW,OSS] 100 Format: <io>,<irq>,<dma>,<dma2>,<type> 101 102 adlib= [HW,OSS] 103 Format: <io> 104 105 advansys= [HW,SCSI] 106 See header of drivers/scsi/advansys.c. 107 108 advwdt= [HW,WDT] Advantech WDT 109 Format: <iostart>,<iostop> 110 111 aedsp16= [HW,OSS] Audio Excel DSP 16 112 Format: <io>,<irq>,<dma>,<mss_io>,<mpu_io>,<mpu_irq> 113 See also header of sound/oss/aedsp16.c. 114 115 aha152x= [HW,SCSI] 116 See Documentation/scsi/aha152x.txt. 117 118 aha1542= [HW,SCSI] 119 Format: <portbase>[,<buson>,<busoff>[,<dmaspeed>]] 120 121 aic7xxx= [HW,SCSI] 122 See Documentation/scsi/aic7xxx.txt. 123 124 aic79xx= [HW,SCSI] 125 See Documentation/scsi/aic79xx.txt. 126 127 allowdma0 [ISAPNP] 128 129 AM53C974= [HW,SCSI] 130 Format: <host-scsi-id>,<target-scsi-id>,<max-rate>,<max-offset> 131 See also header of drivers/scsi/AM53C974.c. 132 133 amijoy= [HW,JOY] Amiga joystick support 134 135 apc= [HW,SPARC] Power management functions (SPARCstation-4/5 + deriv.) 136 Format: noidle 137 Disable APC CPU standby support. SPARCstation-Fox does 138 not play well with APC CPU idle - disable it if you have 139 APC and your system crashes randomly. 140 141 apm= [APM] Advanced Power Management 142 See header of arch/i386/kernel/apm.c. 143 144 applicom= [HW] 145 Format: <mem>,<irq> 146 147 arcrimi= [HW,NET] ARCnet - "RIM I" (entirely mem-mapped) cards 148 Format: <io>,<irq>,<nodeID> 149 150 ataflop= [HW,M68k] 151 152 atarimouse= [HW,MOUSE] Atari Mouse 153 154 atascsi= [HW,SCSI] Atari SCSI 155 156 atkbd_set= [HW] Select keyboard code set 157 Format: <int> 158 159 atkbd_reset [HW] Reset keyboard during initialization 160 161 autotest [IA64] 162 163 awe= [HW,OSS] AWE32/SB32/AWE64 wave table synth 164 Format: <io>,<memsize>,<isapnp> 165 166 aztcd= [HW,CD] Aztech CD268 CDROM driver 167 Format: <io>,0x79 (?) 168 169 baycom_epp= [HW,AX25] 170 Format: <io>,<mode> 171 172 baycom_par= [HW,AX25] BayCom Parallel Port AX.25 Modem 173 Format: <io>,<mode> 174 See header of drivers/net/hamradio/baycom_par.c. 175 176 baycom_ser_fdx= [HW,AX25] BayCom Serial Port AX.25 Modem (Full Duplex Mode) 177 Format: <io>,<irq>,<mode>[,<baud>] 178 See header of drivers/net/hamradio/baycom_ser_fdx.c. 179 180 baycom_ser_hdx= [HW,AX25] BayCom Serial Port AX.25 Modem (Half Duplex Mode) 181 Format: <io>,<irq>,<mode> 182 See header of drivers/net/hamradio/baycom_ser_hdx.c. 183 184 blkmtd_device= [HW,MTD] 185 blkmtd_erasesz= 186 blkmtd_ro= 187 blkmtd_bs= 188 blkmtd_count= 189 190 bttv.card= [HW,V4L] bttv (bt848 + bt878 based grabber cards) 191 bttv.radio= Most important insmod options are available as kernel args too. 192 bttv.pll= See Documentation/video4linux/bttv/Insmod-options 193 bttv.tuner= and Documentation/video4linux/bttv/CARDLIST 194 195 BusLogic= [HW,SCSI] 196 See drivers/scsi/BusLogic.c, comment before function 197 BusLogic_ParseDriverOptions(). 198 199 c101= [NET] Moxa C101 synchronous serial card 200 201 cachesize= [BUGS=IA-32] Override level 2 CPU cache size detection. 202 Sometimes CPU hardware bugs make them report the cache 203 size incorrectly. The kernel will attempt work arounds 204 to fix known problems, but for some CPUs it is not 205 possible to determine what the correct size should be. 206 This option provides an override for these situations. 207 208 cdu31a= [HW,CD] 209 Format: <io>,<irq>[,PAS] 210 See header of drivers/cdrom/cdu31a.c. 211 212 chandev= [HW,NET] Generic channel device initialisation 213 214 clock= [BUGS=IA-32, HW] gettimeofday timesource override. 215 Forces specified timesource (if avaliable) to be used 216 when calculating gettimeofday(). If specicified timesource 217 is not avalible, it defaults to PIT. 218 Format: { pit | tsc | cyclone | ... } 219 220 hpet= [IA-32,HPET] option to disable HPET and use PIT. 221 Format: disable 222 223 cm206= [HW,CD] 224 Format: { auto | [<io>,][<irq>] } 225 226 com20020= [HW,NET] ARCnet - COM20020 chipset 227 Format: <io>[,<irq>[,<nodeID>[,<backplane>[,<ckp>[,<timeout>]]]]] 228 229 com90io= [HW,NET] ARCnet - COM90xx chipset (IO-mapped buffers) 230 Format: <io>[,<irq>] 231 232 com90xx= [HW,NET] ARCnet - COM90xx chipset (memory-mapped buffers) 233 Format: <io>[,<irq>[,<memstart>]] 234 235 condev= [HW,S390] console device 236 conmode= 237 238 console= [KNL] Output console 239 Console device and comm spec (speed, control, parity). 240 241 cpcihp_generic= [HW,PCI] Generic port I/O CompactPCI driver 242 Format: <first_slot>,<last_slot>,<port>,<enum_bit>[,<debug>] 243 244 cpia_pp= [HW,PPT] 245 Format: { parport<nr> | auto | none } 246 247 cs4232= [HW,OSS] 248 Format: <io>,<irq>,<dma>,<dma2>,<mpuio>,<mpuirq> 249 250 cs89x0_dma= [HW,NET] 251 Format: <dma> 252 253 cs89x0_media= [HW,NET] 254 Format: { rj45 | aui | bnc } 255 256 cyclades= [HW,SERIAL] Cyclades multi-serial port adapter. 257 258 dasd= [HW,NET] 259 See header of drivers/s390/block/dasd_devmap.c. 260 261 db9= [HW,JOY] 262 db9_2= 263 db9_3= 264 265 debug [KNL] Enable kernel debugging (events log level). 266 267 decnet= [HW,NET] 268 Format: <area>[,<node>] 269 See also Documentation/networking/decnet.txt. 270 271 devfs= [DEVFS] 272 See Documentation/filesystems/devfs/boot-options. 273 274 digi= [HW,SERIAL] 275 IO parameters + enable/disable command. 276 277 digiepca= [HW,SERIAL] 278 See drivers/char/README.epca and 279 Documentation/digiepca.txt. 280 281 dmascc= [HW,AX25,SERIAL] AX.25 Z80SCC driver with DMA 282 support available. 283 Format: <io_dev0>[,<io_dev1>[,..<io_dev32>]] 284 285 dmasound= [HW,OSS] Sound subsystem buffers 286 287 dscc4.setup= [NET] 288 289 dtc3181e= [HW,SCSI] 290 291 eata= [HW,SCSI] 292 293 eda= [HW,PS2] 294 295 edb= [HW,PS2] 296 297 eicon= [HW,ISDN] 298 Format: <id>,<membase>,<irq> 299 300 eisa_irq_edge= [PARISC] 301 See header of drivers/parisc/eisa.c. 302 303 elanfreq= [IA-32] 304 See comment before function elanfreq_setup() in 305 arch/i386/kernel/cpu/cpufreq/elanfreq.c. 306 307 elevator= [IOSCHED] 308 Format: {"as"|"cfq"|"deadline"|"noop"} 309 See Documentation/as-iosched.txt for details 310 311 es1370= [HW,OSS] 312 Format: <lineout>[,<micbias>] 313 See also header of sound/oss/es1370.c. 314 315 es1371= [HW,OSS] 316 Format: <spdif>,[<nomix>,[<amplifier>]] 317 See also header of sound/oss/es1371.c. 318 319 ether= [HW,NET] Ethernet cards parameters 320 This option is obsoleted by the "netdev=" option, which 321 has equivalent usage. See its documentation for details. 322 323 eurwdt= [HW,WDT] Eurotech CPU-1220/1410 onboard watchdog. 324 Format: <io>[,<irq>] 325 326 fd_mcs= [HW,SCSI] 327 See header of drivers/scsi/fd_mcs.c. 328 329 fdomain= [HW,SCSI] 330 See header of drivers/scsi/fdomain.c. 331 332 floppy= [HW] 333 See Documentation/floppy.txt. 334 335 ftape= [HW] Floppy Tape subsystem debugging options. 336 See Documentation/ftape.txt. 337 338 gamma= [HW,DRM] 339 340 gc= [HW,JOY] 341 gc_2= See Documentation/input/joystick-parport.txt. 342 gc_3= 343 344 gdth= [HW,SCSI] 345 See header of drivers/scsi/gdth.c. 346 347 gpt [EFI] Forces disk with valid GPT signature but 348 invalid Protective MBR to be treated as GPT. 349 350 gscd= [HW,CD] 351 Format: <io> 352 353 gt96100eth= [NET] MIPS GT96100 Advanced Communication Controller 354 355 gus= [HW,OSS] 356 Format: <io>,<irq>,<dma>,<dma16> 357 358 gvp11= [HW,SCSI] 359 360 hcl= [IA-64] SGI's Hardware Graph compatibility layer 361 362 hd= [EIDE] (E)IDE hard drive subsystem geometry 363 Format: <cyl>,<head>,<sect> 364 365 hd?= [HW] (E)IDE subsystem 366 hd?lun= See Documentation/ide.txt. 367 368 hisax= [HW,ISDN] 369 See Documentation/isdn/README.HiSax. 370 371 hugepages= [HW,IA-32,IA-64] Maximal number of HugeTLB pages. 372 373 noirqbalance [IA-32,SMP,KNL] Disable kernel irq balancing 374 375 i8042_direct [HW] Keyboard has been put into non-translated mode 376 by BIOS 377 i8042_dumbkbd [HW] Don't attempt to blink the leds 378 i8042_noaux [HW] Don't check for auxiliary (== mouse) port 379 i8042_nomux 380 i8042_reset [HW] Reset the controller during init and cleanup 381 i8042_unlock [HW] Unlock (ignore) the keylock 382 383 i810= [HW,DRM] 384 385 ibmmcascsi= [HW,MCA,SCSI] IBM MicroChannel SCSI adapter 386 See Documentation/mca.txt. 387 388 icn= [HW,ISDN] 389 Format: <io>[,<membase>[,<icn_id>[,<icn_id2>]]] 390 391 ide?= [HW] (E)IDE subsystem 392 Config (iomem/irq), tuning or debugging 393 (serialize,reset,no{dma,tune,probe}) or chipset 394 specific parameters. 395 See Documentation/ide.txt. 396 397 idebus= [HW] (E)IDE subsystem - VLB/PCI bus speed 398 See Documentation/ide.txt. 399 400 idle= [HW] 401 Format: idle=poll or idle=halt 402 403 in2000= [HW,SCSI] 404 See header of drivers/scsi/in2000.c. 405 406 init= [KNL] 407 Format: <full_path> 408 Run specified binary instead of /sbin/init as init 409 process. 410 411 initcall_debug [KNL] Trace initcalls as they are executed. Useful 412 for working out where the kernel is dying during 413 startup. 414 415 initrd= [BOOT] Specify the location of the initial ramdisk 416 417 inport_irq= [HW] Inport (ATI XL and Microsoft) busmouse driver 418 Format: <irq> 419 420 inttest= [IA64] 421 422 io7= [HW] IO7 for Marvel based alpha systems 423 See comment before marvel_specify_io7 in 424 arch/alpha/kernel/core_marvel.c. 425 426 ip= [IP_PNP] 427 See Documentation/nfsroot.txt. 428 429 ip2= [HW] Set IO/IRQ pairs for up to 4 IntelliPort boards 430 See comment before ip2_setup() in drivers/char/ip2.c. 431 432 ips= [HW,SCSI] Adaptec / IBM ServeRAID controller 433 See header of drivers/scsi/ips.c. 434 435 isapnp= [ISAPNP] 436 Format: <RDP>, <reset>, <pci_scan>, <verbosity> 437 438 isp16= [HW,CD] 439 Format: <io>,<irq>,<dma>,<setup> 440 441 iucv= [HW,NET] 442 443 js= [HW,JOY] Analog joystick 444 See Documentation/input/joystick.txt. 445 446 keepinitrd [HW,ARM] 447 448 l2cr= [PPC] 449 450 lapic [IA-32,APIC] Enable the local APIC even if BIOS disabled it. 451 452 lasi= [HW,SCSI] PARISC LASI driver for the 53c700 chip 453 Format: addr:<io>,irq:<irq> 454 455 llsc*= [IA64] 456 See function print_params() in arch/ia64/sn/kernel/llsc4.c. 457 458 load_ramdisk= [RAM] List of ramdisks to load from floppy 459 See Documentation/ramdisk.txt. 460 461 lockd.udpport= [NFS] 462 463 lockd.tcpport= [NFS] 464 465 logibm_irq= [HW,MOUSE] Logitech Bus Mouse Driver 466 Format: <irq> 467 468 log_buf_len=n Sets the size of the printk ring buffer, in bytes. 469 Format is n, nk, nM. n must be a power of two. The 470 default is set in kernel config. 471 472 lp=0 [LP] Specify parallel ports to use, e.g, 473 lp=port[,port...] lp=none,parport0 (lp0 not configured, lp1 uses 474 lp=reset first parallel port). 'lp=0' disables the 475 lp=auto printer driver. 'lp=reset' (which can be 476 specified in addition to the ports) causes 477 attached printers to be reset. Using 478 lp=port1,port2,... specifies the parallel ports 479 to associate lp devices with, starting with 480 lp0. A port specification may be 'none' to skip 481 that lp device, or a parport name such as 482 'parport0'. Specifying 'lp=auto' instead of a 483 port specification list means that device IDs 484 from each port should be examined, to see if 485 an IEEE 1284-compliant printer is attached; if 486 so, the driver will manage that printer. 487 See also header of drivers/char/lp.c. 488 489 ltpc= [NET] 490 Format: <io>,<irq>,<dma> 491 492 mac5380= [HW,SCSI] 493 Format: <can_queue>,<cmd_per_lun>,<sg_tablesize>,<hostid>,<use_tags> 494 495 mac53c9x= [HW,SCSI] 496 Format: <num_esps>,<disconnect>,<nosync>,<can_queue>,<cmd_per_lun>,<sg_tablesize>,<hostid>,<use_tags> 497 498 mad16= [HW,OSS] 499 Format: <io>,<irq>,<dma>,<dma16>,<mpu_io>,<mpu_irq>,<joystick> 500 501 maui= [HW,OSS] 502 Format: <io>,<irq> 503 504 max_loop= [LOOP] Maximum number of loopback devices that can 505 be mounted 506 Format: <1-256> 507 508 maxcpus= [SMP] Maximum number of processors that an SMP kernel 509 should make use of 510 511 max_scsi_luns= [SCSI] 512 513 max_scsi_report_luns= 514 [SCSI] Maximum number of LUNs received 515 Should be between 1 and 16384. 516 517 mca-pentium [BUGS=IA-32] 518 519 mcatest= [IA-64] 520 521 mcd= [HW,CD] 522 Format: <port>,<irq>,<mitsumi_bug_93_wait> 523 524 mcdx= [HW,CD] 525 526 mce [IA-32] Machine Check Exception 527 528 md= [HW] RAID subsystems devices and level 529 See Documentation/md.txt. 530 531 mdacon= [MDA] 532 Format: <first>,<last> 533 Specifies range of consoles to be captured by the MDA. 534 535 mem=nn[KMG] [KNL,BOOT] Force usage of a specific amount of memory 536 Amount of memory to be used when the kernel is not able 537 to see the whole system memory or for test. 538 539 mem=nopentium [BUGS=IA-32] Disable usage of 4MB pages for kernel 540 memory. 541 542 memmap=exactmap [KNL,IA-32] Enable setting of an exact 543 E820 memory map, as specified by the user. 544 Such memmap=exactmap lines can be constructed based on 545 BIOS output or other requirements. See the memmap=nn@ss 546 option description. 547 548 memmap=nn[KMG]@ss[KMG] 549 [KNL] Force usage of a specific region of memory 550 Region of memory to be used, from ss to ss+nn. 551 552 memmap=nn[KMG]#ss[KMG] 553 [KNL,ACPI] Mark specific memory as ACPI data. 554 Region of memory to be used, from ss to ss+nn. 555 556 memmap=nn[KMG]$ss[KMG] 557 [KNL,ACPI] Mark specific memory as reserved. 558 Region of memory to be used, from ss to ss+nn. 559 560 meye= [HW] Set MotionEye Camera parameters 561 See Documentation/video4linux/meye.txt. 562 563 mga= [HW,DRM] 564 565 mpu401= [HW,OSS] 566 Format: <io>,<irq> 567 568 MTD_Partition= [MTD] 569 Format: <name>,<region-number>,<size>,<offset> 570 571 MTD_Region= [MTD] 572 Format: <name>,<region-number>[,<base>,<size>,<buswidth>,<altbuswidth>] 573 574 mtdparts= [MTD] 575 See drivers/mtd/cmdline.c. 576 577 n2= [NET] SDL Inc. RISCom/N2 synchronous serial card 578 579 NCR_D700= [HW,SCSI] 580 See header of drivers/scsi/NCR_D700.c. 581 582 ncr5380= [HW,SCSI] 583 584 ncr53c400= [HW,SCSI] 585 586 ncr53c400a= [HW,SCSI] 587 588 ncr53c406a= [HW,SCSI] 589 590 ncr53c8xx= [HW,SCSI] 591 592 netdev= [NET] Network devices parameters 593 Format: <irq>,<io>,<mem_start>,<mem_end>,<name> 594 Note that mem_start is often overloaded to mean 595 something different and driver-specific. 596 597 nfsaddrs= [NFS] 598 See Documentation/nfsroot.txt. 599 600 nfsroot= [NFS] nfs root filesystem for disk-less boxes. 601 See Documentation/nfsroot.txt. 602 603 nmi_watchdog= [KNL,BUGS=IA-32] Debugging features for SMP kernels 604 605 no387 [BUGS=IA-32] Tells the kernel to use the 387 maths 606 emulation library even if a 387 maths coprocessor 607 is present. 608 609 noalign [KNL,ARM] 610 611 noapic [SMP,APIC] Tells the kernel not to make use of any 612 APIC that may be present on the system. 613 614 noasync [HW,M68K] Disables async and sync negotiation for 615 all devices. 616 617 nocache [ARM] 618 619 nodisconnect [HW,SCSI,M68K] Disables SCSI disconnects. 620 621 noexec [IA-64] 622 623 nofxsr [BUGS=IA-32] 624 625 nohighio [BUGS=IA-32] Disable highmem block I/O. 626 627 nohlt [BUGS=ARM] 628 629 no-hlt [BUGS=IA-32] Tells the kernel that the hlt 630 instruction doesn't work correctly and not to 631 use it. 632 633 noirqdebug [IA-32] Disables the code which attempts to detect and 634 disable unhandled interrupt sources. 635 636 noisapnp [ISAPNP] Disables ISA PnP code. 637 638 noinitrd [RAM] Tells the kernel not to load any configured 639 initial RAM disk. 640 641 nointroute [IA-64] 642 643 nolapic [IA-32,APIC] Do not enable or use the local APIC. 644 645 nomce [IA-32] Machine Check Exception 646 647 noresume [SWSUSP] Disables resume and restore original swap space. 648 649 no-scroll [VGA] Disables scrollback. 650 This is required for the Braillex ib80-piezo Braille 651 reader made by F.H. Papenmeier (Germany). 652 653 nosbagart [IA-64] 654 655 nosmp [SMP] Tells an SMP kernel to act as a UP kernel. 656 657 nosync [HW,M68K] Disables sync negotiation for all devices. 658 659 notsc [BUGS=IA-32] Disable Time Stamp Counter 660 661 nousb [USB] Disable the USB subsystem 662 663 nowb [ARM] 664 665 opl3= [HW,OSS] 666 Format: <io> 667 668 opl3sa= [HW,OSS] 669 Format: <io>,<irq>,<dma>,<dma2>,<mpu_io>,<mpu_irq> 670 671 opl3sa2= [HW,OSS] 672 Format: <io>,<irq>,<dma>,<dma2>,<mss_io>,<mpu_io>,<ymode>,<loopback>[,<isapnp>,<multiple] 673 674 oprofile.timer= [HW] 675 Use timer interrupt instead of performance counters 676 677 optcd= [HW,CD] 678 Format: <io> 679 680 osst= [HW,SCSI] SCSI Tape Driver 681 Format: <buffer_size>,<write_threshold> 682 See also Documentation/scsi/st.txt. 683 684 panic= [KNL] Kernel behaviour on panic 685 Format: <timeout> 686 687 parport=0 [HW,PPT] Specify parallel ports. 0 disables. 688 parport=auto Use 'auto' to force the driver to use 689 parport=0xBBB[,IRQ[,DMA]] any IRQ/DMA settings detected (the 690 default is to ignore detected IRQ/DMA 691 settings because of possible 692 conflicts). You can specify the base 693 address, IRQ, and DMA settings; IRQ and 694 DMA should be numbers, or 'auto' (for 695 using detected settings on that 696 particular port), or 'nofifo' (to avoid 697 using a FIFO even if it is detected). 698 Parallel ports are assigned in the 699 order they are specified on the command 700 line, starting with parport0. 701 702 pas2= [HW,OSS] 703 Format: <io>,<irq>,<dma>,<dma16>,<sb_io>,<sb_irq>,<sb_dma>,<sb_dma16> 704 705 pas16= [HW,SCSI] 706 See header of drivers/scsi/pas16.c. 707 708 pcbit= [HW,ISDN] 709 710 pcd. [PARIDE] 711 See header of drivers/block/paride/pcd.c. 712 See also Documentation/paride.txt. 713 714 pci=option[,option...] [PCI] various PCI subsystem options: 715 off [IA-32] don't probe for the PCI bus 716 bios [IA-32] force use of PCI BIOS, don't access 717 the hardware directly. Use this if your machine 718 has a non-standard PCI host bridge. 719 nobios [IA-32] disallow use of PCI BIOS, only direct 720 hardware access methods are allowed. Use this 721 if you experience crashes upon bootup and you 722 suspect they are caused by the BIOS. 723 conf1 [IA-32] Force use of PCI Configuration Mechanism 1. 724 conf2 [IA-32] Force use of PCI Configuration Mechanism 2. 725 nosort [IA-32] Don't sort PCI devices according to 726 order given by the PCI BIOS. This sorting is done 727 to get a device order compatible with older kernels. 728 biosirq [IA-32] Use PCI BIOS calls to get the interrupt 729 routing table. These calls are known to be buggy 730 on several machines and they hang the machine when used, 731 but on other computers it's the only way to get the 732 interrupt routing table. Try this option if the kernel 733 is unable to allocate IRQs or discover secondary PCI 734 buses on your motherboard. 735 rom [IA-32] Assign address space to expansion ROMs. 736 Use with caution as certain devices share address 737 decoders between ROMs and other resources. 738 irqmask=0xMMMM [IA-32] Set a bit mask of IRQs allowed to be assigned 739 automatically to PCI devices. You can make the kernel 740 exclude IRQs of your ISA cards this way. 741 lastbus=N [IA-32] Scan all buses till bus #N. Can be useful 742 if the kernel is unable to find your secondary buses 743 and you want to tell it explicitly which ones they are. 744 assign-busses [IA-32] Always assign all PCI bus 745 numbers ourselves, overriding 746 whatever the firmware may have 747 done. 748 usepirqmask [IA-32] Honor the possible IRQ mask 749 stored in the BIOS $PIR table. This is 750 needed on some systems with broken 751 BIOSes, notably some HP Pavilion N5400 752 and Omnibook XE3 notebooks. This will 753 have no effect if ACPI IRQ routing is 754 enabled. 755 noacpi [IA-32] Do not use ACPI for IRQ routing. 756 757 pcmv= [HW,PCMCIA] BadgePAD 4 758 759 pd. [PARIDE] 760 See Documentation/paride.txt. 761 762 pf. [PARIDE] 763 See Documentation/paride.txt. 764 765 pg. [PARIDE] 766 See Documentation/paride.txt. 767 768 pirq= [SMP,APIC] Manual mp-table setup 769 See Documentation/i386/IO-APIC.txt. 770 771 plip= [PPT,NET] Parallel port network link 772 Format: { parport<nr> | timid | 0 } 773 See also Documentation/parport.txt. 774 775 pnpbios= [ISAPNP] 776 { on | off | curr | res | no-curr | no-res } 777 778 pnp_reserve_irq= 779 [ISAPNP] Exclude IRQs for the autoconfiguration 780 781 pnp_reserve_dma= 782 [ISAPNP] Exclude DMAs for the autoconfiguration 783 784 pnp_reserve_io= [ISAPNP] Exclude I/O ports for the autoconfiguration 785 Ranges are in pairs (I/O port base and size). 786 787 pnp_reserve_mem= 788 [ISAPNP] Exclude memory regions for the autoconfiguration 789 Ranges are in pairs (memory base and size). 790 791 profile= [KNL] Enable kernel profiling via /proc/profile 792 (param: profile step/bucket size as a power of 2) 793 794 prompt_ramdisk= [RAM] List of RAM disks to prompt for floppy disk 795 before loading. 796 See Documentation/ramdisk.txt. 797 798 psmouse_proto= [HW,MOUSE] Highest PS2 mouse protocol extension to 799 probe for (bare|imps|exps). 800 801 psmouse_resetafter= 802 [HW,MOUSE] Try to reset Synaptics Touchpad after so many 803 bad packets (0 = never). 804 805 pss= [HW,OSS] Personal Sound System (ECHO ESC614) 806 Format: <io>,<mss_io>,<mss_irq>,<mss_dma>,<mpu_io>,<mpu_irq> 807 808 pt. [PARIDE] 809 See Documentation/paride.txt. 810 811 quiet= [KNL] Disable log messages 812 813 r128= [HW,DRM] 814 815 raid= [HW,RAID] 816 See Documentation/md.txt. 817 818 ramdisk= [RAM] Sizes of RAM disks in kilobytes [deprecated] 819 See Documentation/ramdisk.txt. 820 821 ramdisk_blocksize= 822 [RAM] 823 See Documentation/ramdisk.txt. 824 825 ramdisk_size= [RAM] Sizes of RAM disks in kilobytes 826 New name for the ramdisk parameter. 827 See Documentation/ramdisk.txt. 828 829 ramdisk_start= [RAM] Starting block of RAM disk image (so you can 830 place it after the kernel image on a boot floppy). 831 See Documentation/ramdisk.txt. 832 833 reboot= [BUGS=IA-32,BUGS=ARM,BUGS=IA-64] Rebooting mode 834 Format: <reboot_mode>[,<reboot_mode2>[,...]] 835 See arch/*/kernel/reboot.c. 836 837 reserve= [KNL,BUGS] Force the kernel to ignore some iomem area 838 839 resume= [SWSUSP] Specify the partition device for software suspension 840 841 riscom8= [HW,SERIAL] 842 Format: <io_board1>[,<io_board2>[,...<io_boardN>]] 843 844 ro [KNL] Mount root device read-only on boot 845 846 root= [KNL] Root filesystem 847 848 rootflags= [KNL] Set root filesystem mount option string 849 850 rootfstype= [KNL] Set root filesystem type 851 852 rw [KNL] Mount root device read-write on boot 853 854 S [KNL] Run init in single mode 855 856 sa1100ir [NET] 857 See drivers/net/irda/sa1100_ir.c. 858 859 sb= [HW,OSS] 860 Format: <io>,<irq>,<dma>,<dma2> 861 862 sbni= [NET] Granch SBNI12 leased line adapter 863 864 sbpcd= [HW,CD] Soundblaster CD adapter 865 Format: <io>,<type> 866 See a comment before function sbpcd_setup() in 867 drivers/cdrom/sbpcd.c. 868 869 sc1200wdt= [HW,WDT] SC1200 WDT (watchdog) driver 870 Format: <io>[,<timeout>[,<isapnp>]] 871 872 scsi_debug_*= [SCSI] 873 See drivers/scsi/scsi_debug.c. 874 875 scsi_default_dev_flags= 876 [SCSI] SCSI default device flags 877 Format: <integer> 878 879 scsi_dev_flags= [SCSI] Black/white list entry for vendor and model 880 Format: <vendor>:<model>:<flags> 881 (flags are integer value) 882 883 scsi_logging= [SCSI] 884 885 scsihosts= [SCSI] 886 887 serialnumber [BUGS=IA-32] 888 889 sf16fm= [HW] SF16FMI radio driver for Linux 890 Format: <io> 891 892 sg_def_reserved_size= 893 [SCSI] 894 895 sgalaxy= [HW,OSS] 896 Format: <io>,<irq>,<dma>,<dma2>,<sgbase> 897 898 shapers= [NET] 899 Maximal number of shapers. 900 901 sim710= [SCSI,HW] 902 See header of drivers/scsi/sim710.c. 903 904 simeth= [IA-64] 905 simscsi= 906 907 sjcd= [HW,CD] 908 Format: <io>,<irq>,<dma> 909 See header of drivers/cdrom/sjcd.c. 910 911 slram= [HW,MTD] 912 913 smart2= [HW] 914 Format: <io1>[,<io2>[,...,<io8>]] 915 916 snd-ad1816a= [HW,ALSA] 917 918 snd-ad1848= [HW,ALSA] 919 920 snd-ali5451= [HW,ALSA] 921 922 snd-als100= [HW,ALSA] 923 924 snd-als4000= [HW,ALSA] 925 926 snd-azt2320= [HW,ALSA] 927 928 snd-cmi8330= [HW,ALSA] 929 930 snd-cmipci= [HW,ALSA] 931 932 snd-cs4231= [HW,ALSA] 933 934 snd-cs4232= [HW,ALSA] 935 936 snd-cs4236= [HW,ALSA] 937 938 snd-cs4281= [HW,ALSA] 939 940 snd-cs46xx= [HW,ALSA] 941 942 snd-dt019x= [HW,ALSA] 943 944 snd-dummy= [HW,ALSA] 945 946 snd-emu10k1= [HW,ALSA] 947 948 snd-ens1370= [HW,ALSA] 949 950 snd-ens1371= [HW,ALSA] 951 952 snd-es968= [HW,ALSA] 953 954 snd-es1688= [HW,ALSA] 955 956 snd-es18xx= [HW,ALSA] 957 958 snd-es1938= [HW,ALSA] 959 960 snd-es1968= [HW,ALSA] 961 962 snd-fm801= [HW,ALSA] 963 964 snd-gusclassic= [HW,ALSA] 965 966 snd-gusextreme= [HW,ALSA] 967 968 snd-gusmax= [HW,ALSA] 969 970 snd-hdsp= [HW,ALSA] 971 972 snd-ice1712= [HW,ALSA] 973 974 snd-intel8x0= [HW,ALSA] 975 976 snd-interwave= [HW,ALSA] 977 978 snd-interwave-stb= 979 [HW,ALSA] 980 981 snd-korg1212= [HW,ALSA] 982 983 snd-maestro3= [HW,ALSA] 984 985 snd-mpu401= [HW,ALSA] 986 987 snd-mtpav= [HW,ALSA] 988 989 snd-nm256= [HW,ALSA] 990 991 snd-opl3sa2= [HW,ALSA] 992 993 snd-opti92x-ad1848= 994 [HW,ALSA] 995 996 snd-opti92x-cs4231= 997 [HW,ALSA] 998 999 snd-opti93x= [HW,ALSA] 1000
1001 snd-pmac= [HW,ALSA] 1002 1003 snd-rme32= [HW,ALSA] 1004 1005 snd-rme96= [HW,ALSA] 1006 1007 snd-rme9652= [HW,ALSA] 1008 1009 snd-sb8= [HW,ALSA] 1010 1011 snd-sb16= [HW,ALSA] 1012 1013 snd-sbawe= [HW,ALSA] 1014 1015 snd-serial= [HW,ALSA] 1016 1017 snd-sgalaxy= [HW,ALSA] 1018 1019 snd-sonicvibes= [HW,ALSA] 1020 1021 snd-sun-amd7930= 1022 [HW,ALSA] 1023 1024 snd-sun-cs4231= [HW,ALSA] 1025 1026 snd-trident= [HW,ALSA] 1027 1028 snd-usb-audio= [HW,ALSA,USB] 1029 1030 snd-via82xx= [HW,ALSA] 1031 1032 snd-virmidi= [HW,ALSA] 1033 1034 snd-wavefront= [HW,ALSA] 1035 1036 snd-ymfpci= [HW,ALSA] 1037 1038 sonicvibes= [HW,OSS] 1039 Format: <reverb> 1040 1041 sonycd535= [HW,CD] 1042 Format: <io>[,<irq>] 1043 1044 sonypi= [HW] Sony Programmable I/O Control Device driver 1045 Format: <minor>,<verbose>,<fnkeyinit>,<camera>,<compat>,<nojogdial> 1046 1047 specialix= [HW,SERIAL] Specialix multi-serial port adapter 1048 See Documentation/specialix.txt. 1049 1050 speedstep_coppermine= 1051 [HW,IA-32] Take CPU in your notebook as SpeedStep-capable 1052 See comment before function speedstep_setup() in 1053 arch/i386/kernel/cpu/cpufreq/speedstep.c. 1054 1055 spia_io_base= [HW,MTD] 1056 spia_fio_base= 1057 spia_pedr= 1058 spia_peddr= 1059 1060 sscape= [HW,OSS] 1061 Format: <io>,<irq>,<dma>,<mpu_io>,<mpu_irq> 1062 1063 st= [HW,SCSI] SCSI tape parameters (buffers, etc.) 1064 See Documentation/scsi/st.txt. 1065 1066 st0x= [HW,SCSI] 1067 See header of drivers/scsi/seagate.c. 1068 1069 sti= [HW] 1070 Format: <num> 1071 Set the STI (builtin display/keyboard on the HP-PARISC 1072 machines) console (graphic card) which should be used 1073 as the initial boot-console. 1074 See also comment in drivers/video/console/sticore.c. 1075 1076 sti_font= [HW] 1077 See comment in drivers/video/console/sticore.c. 1078 1079 stifb= [HW] 1080 Format: bpp:<bpp1>[:<bpp2>[:<bpp3>...]] 1081 1082 stram_swap= [HW,M68k] 1083 1084 swiotlb= [IA-64] Number of I/O TLB slabs 1085 1086 switches= [HW,M68k] 1087 1088 sym53c416= [HW,SCSI] 1089 See header of drivers/scsi/sym53c416.c. 1090 1091 sym53c8xx= [HW,SCSI] 1092 See Documentation/scsi/ncr53c8xx.txt. 1093 1094 t128= [HW,SCSI] 1095 See header of drivers/scsi/t128.c. 1096 1097 tdfx= [HW,DRM] 1098 1099 tgfx= [HW,JOY] TurboGraFX parallel port interface 1100 tgfx_2= See Documentation/input/joystick-parport.txt. 1101 tgfx_3= 1102 1103 tipar= [HW] 1104 See header of drivers/char/tipar.c. 1105 1106 tiusb= [HW,USB] Texas Instruments' USB GraphLink (aka SilverLink) 1107 Format: <timeout> 1108 1109 tmc8xx= [HW,SCSI] 1110 See header of drivers/scsi/seagate.c. 1111 1112 tmscsim= [HW,SCSI] 1113 See comment before function dc390_setup() in 1114 drivers/scsi/tmscsim.c. 1115 1116 tp720= [HW,PS2] 1117 1118 trix= [HW,OSS] MediaTrix AudioTrix Pro 1119 Format: <io>,<irq>,<dma>,<dma2>,<sb_io>,<sb_irq>,<sb_dma>,<mpu_io>,<mpu_irq> 1120 1121 u14-34f= [HW,SCSI] UltraStor 14F/34F SCSI host adapter 1122 See header of drivers/scsi/u14-34f.c. 1123 1124 uart401= [HW,OSS] 1125 Format: <io>,<irq> 1126 1127 uart6850= [HW,OSS] 1128 Format: <io>,<irq> 1129 1130 video= [FB] Frame buffer configuration 1131 See Documentation/fb/modedb.txt. 1132 1133 vga= [BOOT,IA-32] Select a particular video mode 1134 See Documentation/i386/boot.txt and Documentation/svga.txt. 1135 Use vga=ask for menu. 1136 This is actually a boot loader parameter; the value is 1137 passed to the kernel using a special protocol. 1138 1139 vmhalt= [KNL,S390] 1140 1141 vmpoff= [KNL,S390] 1142 1143 waveartist= [HW,OSS] 1144 Format: <io>,<irq>,<dma>,<dma2> 1145 1146 wd33c93= [HW,SCSI] 1147 See header of drivers/scsi/wd33c93.c. 1148 1149 wd7000= [HW,SCSI] 1150 See header of drivers/scsi/wd7000.c. 1151 1152 wdt= [WDT] Watchdog 1153 See Documentation/watchdog/watchdog.txt. 1154 1155 xd= [HW,XT] Original XT pre-IDE (RLL encoded) disks. 1156 xd_geo= See header of drivers/block/xd.c. 1157 1158 xirc2ps_cs= [NET,PCMCIA] 1159 Format: <irq>,<irq_mask>,<io>,<full_duplex>,<do_sound>,<lockup_hack>[,<irq2>[,<irq3>[,<irq4>]]] 1160 1161 1162 1163Changelog: 1164 1165 The last known update (for 2.4.0) - the changelog was not kept before. 1166 2000-06-?? Mr. Unknown 1167 1168 Update for 2.5.49, description for most of the options introduced, 1169 references to other documentation (C files, READMEs, ..), added S390, 1170 PPC, SPARC, MTD, ALSA and OSS category. Minor corrections and 1171 reformatting. 1172 2002-11-24 Petr Baudis <pasky@ucw.cz> 1173 Randy Dunlap <randy.dunlap@verizon.net> 1174 1175TODO: 1176 1177 Add documentation for ALSA options. 1178 Add more DRM drivers. 1179