kernel-parameters.txt 50 KB

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  1. Kernel Parameters
  2. ~~~~~~~~~~~~~~~~~
  3. The following is a consolidated list of the kernel parameters as implemented
  4. (mostly) by the __setup() macro and sorted into English Dictionary order
  5. (defined as ignoring all punctuation and sorting digits before letters in a
  6. case insensitive manner), and with descriptions where known.
  7. Module parameters for loadable modules are specified only as the
  8. parameter name with optional '=' and value as appropriate, such as:
  9. modprobe usbcore blinkenlights=1
  10. Module parameters for modules that are built into the kernel image
  11. are specified on the kernel command line with the module name plus
  12. '.' plus parameter name, with '=' and value if appropriate, such as:
  13. usbcore.blinkenlights=1
  14. This document may not be entirely up to date and comprehensive. The command
  15. "modinfo -p ${modulename}" shows a current list of all parameters of a loadable
  16. module. Loadable modules, after being loaded into the running kernel, also
  17. reveal their parameters in /sys/module/${modulename}/parameters/. Some of these
  18. parameters may be changed at runtime by the command
  19. "echo -n ${value} > /sys/module/${modulename}/parameters/${parm}".
  20. The parameters listed below are only valid if certain kernel build options were
  21. enabled and if respective hardware is present. The text in square brackets at
  22. the beginning of each description states the restrictions within which a
  23. parameter is applicable:
  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. DRM Direct Rendering Management support is enabled.
  31. EDD BIOS Enhanced Disk Drive Services (EDD) is enabled
  32. EFI EFI Partitioning (GPT) is enabled
  33. EIDE EIDE/ATAPI support is enabled.
  34. FB The frame buffer device is enabled.
  35. HW Appropriate hardware is enabled.
  36. IA-32 IA-32 aka i386 architecture is enabled.
  37. IA-64 IA-64 architecture is enabled.
  38. IOSCHED More than one I/O scheduler is enabled.
  39. IP_PNP IP DHCP, BOOTP, or RARP is enabled.
  40. ISAPNP ISA PnP code is enabled.
  41. ISDN Appropriate ISDN support is enabled.
  42. JOY Appropriate joystick support is enabled.
  43. LP Printer support is enabled.
  44. LOOP Loopback device support is enabled.
  45. M68k M68k architecture is enabled.
  46. These options have more detailed description inside of
  47. Documentation/m68k/kernel-options.txt.
  48. MCA MCA bus support is enabled.
  49. MDA MDA console support is enabled.
  50. MOUSE Appropriate mouse support is enabled.
  51. MSI Message Signaled Interrupts (PCI).
  52. MTD MTD support is enabled.
  53. NET Appropriate network support is enabled.
  54. NUMA NUMA support is enabled.
  55. GENERIC_TIME The generic timeofday code is enabled.
  56. NFS Appropriate NFS support is enabled.
  57. OSS OSS sound support is enabled.
  58. PARIDE The ParIDE subsystem is enabled.
  59. PARISC The PA-RISC architecture is enabled.
  60. PCI PCI bus support is enabled.
  61. PCMCIA The PCMCIA subsystem is enabled.
  62. PNP Plug & Play support is enabled.
  63. PPC PowerPC architecture is enabled.
  64. PPT Parallel port support is enabled.
  65. PS2 Appropriate PS/2 support is enabled.
  66. RAM RAM disk support is enabled.
  67. S390 S390 architecture is enabled.
  68. SCSI Appropriate SCSI support is enabled.
  69. A lot of drivers has their options described inside of
  70. Documentation/scsi/.
  71. SELINUX SELinux support is enabled.
  72. SERIAL Serial support is enabled.
  73. SMP The kernel is an SMP kernel.
  74. SPARC Sparc architecture is enabled.
  75. SWSUSP Software suspend is enabled.
  76. TS Appropriate touchscreen support is enabled.
  77. USB USB support is enabled.
  78. USBHID USB Human Interface Device support is enabled.
  79. V4L Video For Linux support is enabled.
  80. VGA The VGA console has been enabled.
  81. VT Virtual terminal support is enabled.
  82. WDT Watchdog support is enabled.
  83. XT IBM PC/XT MFM hard disk support is enabled.
  84. X86-64 X86-64 architecture is enabled.
  85. More X86-64 boot options can be found in
  86. Documentation/x86_64/boot-options.txt .
  87. In addition, the following text indicates that the option:
  88. BUGS= Relates to possible processor bugs on the said processor.
  89. KNL Is a kernel start-up parameter.
  90. BOOT Is a boot loader parameter.
  91. Parameters denoted with BOOT are actually interpreted by the boot
  92. loader, and have no meaning to the kernel directly.
  93. Do not modify the syntax of boot loader parameters without extreme
  94. need or coordination with <Documentation/i386/boot.txt>.
  95. Note that ALL kernel parameters listed below are CASE SENSITIVE, and that
  96. a trailing = on the name of any parameter states that that parameter will
  97. be entered as an environment variable, whereas its absence indicates that
  98. it will appear as a kernel argument readable via /proc/cmdline by programs
  99. running once the system is up.
  100. 53c7xx= [HW,SCSI] Amiga SCSI controllers
  101. See header of drivers/scsi/53c7xx.c.
  102. See also Documentation/scsi/ncr53c7xx.txt.
  103. acpi= [HW,ACPI] Advanced Configuration and Power Interface
  104. Format: { force | off | ht | strict | noirq }
  105. force -- enable ACPI if default was off
  106. off -- disable ACPI if default was on
  107. noirq -- do not use ACPI for IRQ routing
  108. ht -- run only enough ACPI to enable Hyper Threading
  109. strict -- Be less tolerant of platforms that are not
  110. strictly ACPI specification compliant.
  111. See also Documentation/pm.txt, pci=noacpi
  112. acpi_sleep= [HW,ACPI] Sleep options
  113. Format: { s3_bios, s3_mode }
  114. See Documentation/power/video.txt
  115. acpi_sci= [HW,ACPI] ACPI System Control Interrupt trigger mode
  116. Format: { level | edge | high | low }
  117. acpi_irq_balance [HW,ACPI]
  118. ACPI will balance active IRQs
  119. default in APIC mode
  120. acpi_irq_nobalance [HW,ACPI]
  121. ACPI will not move active IRQs (default)
  122. default in PIC mode
  123. acpi_irq_pci= [HW,ACPI] If irq_balance, clear listed IRQs for
  124. use by PCI
  125. Format: <irq>,<irq>...
  126. acpi_irq_isa= [HW,ACPI] If irq_balance, mark listed IRQs used by ISA
  127. Format: <irq>,<irq>...
  128. acpi_os_name= [HW,ACPI] Tell ACPI BIOS the name of the OS
  129. Format: To spoof as Windows 98: ="Microsoft Windows"
  130. acpi_osi= [HW,ACPI] empty param disables _OSI
  131. acpi_serialize [HW,ACPI] force serialization of AML methods
  132. acpi_skip_timer_override [HW,ACPI]
  133. Recognize and ignore IRQ0/pin2 Interrupt Override.
  134. For broken nForce2 BIOS resulting in XT-PIC timer.
  135. acpi_dbg_layer= [HW,ACPI]
  136. Format: <int>
  137. Each bit of the <int> indicates an ACPI debug layer,
  138. 1: enable, 0: disable. It is useful for boot time
  139. debugging. After system has booted up, it can be set
  140. via /proc/acpi/debug_layer.
  141. acpi_dbg_level= [HW,ACPI]
  142. Format: <int>
  143. Each bit of the <int> indicates an ACPI debug level,
  144. 1: enable, 0: disable. It is useful for boot time
  145. debugging. After system has booted up, it can be set
  146. via /proc/acpi/debug_level.
  147. acpi_fake_ecdt [HW,ACPI] Workaround failure due to BIOS lacking ECDT
  148. acpi_generic_hotkey [HW,ACPI]
  149. Allow consolidated generic hotkey driver to
  150. override platform specific driver.
  151. See also Documentation/acpi-hotkey.txt.
  152. acpi_pm_good [IA-32,X86-64]
  153. Override the pmtimer bug detection: force the kernel
  154. to assume that this machine's pmtimer latches its value
  155. and always returns good values.
  156. enable_timer_pin_1 [i386,x86-64]
  157. Enable PIN 1 of APIC timer
  158. Can be useful to work around chipset bugs
  159. (in particular on some ATI chipsets).
  160. The kernel tries to set a reasonable default.
  161. disable_timer_pin_1 [i386,x86-64]
  162. Disable PIN 1 of APIC timer
  163. Can be useful to work around chipset bugs.
  164. ad1816= [HW,OSS]
  165. Format: <io>,<irq>,<dma>,<dma2>
  166. See also Documentation/sound/oss/AD1816.
  167. ad1848= [HW,OSS]
  168. Format: <io>,<irq>,<dma>,<dma2>,<type>
  169. adlib= [HW,OSS]
  170. Format: <io>
  171. advansys= [HW,SCSI]
  172. See header of drivers/scsi/advansys.c.
  173. advwdt= [HW,WDT] Advantech WDT
  174. Format: <iostart>,<iostop>
  175. aedsp16= [HW,OSS] Audio Excel DSP 16
  176. Format: <io>,<irq>,<dma>,<mss_io>,<mpu_io>,<mpu_irq>
  177. See also header of sound/oss/aedsp16.c.
  178. aha152x= [HW,SCSI]
  179. See Documentation/scsi/aha152x.txt.
  180. aha1542= [HW,SCSI]
  181. Format: <portbase>[,<buson>,<busoff>[,<dmaspeed>]]
  182. aic7xxx= [HW,SCSI]
  183. See Documentation/scsi/aic7xxx.txt.
  184. aic79xx= [HW,SCSI]
  185. See Documentation/scsi/aic79xx.txt.
  186. amijoy.map= [HW,JOY] Amiga joystick support
  187. Map of devices attached to JOY0DAT and JOY1DAT
  188. Format: <a>,<b>
  189. See also Documentation/kernel/input/joystick.txt
  190. analog.map= [HW,JOY] Analog joystick and gamepad support
  191. Specifies type or capabilities of an analog joystick
  192. connected to one of 16 gameports
  193. Format: <type1>,<type2>,..<type16>
  194. apc= [HW,SPARC]
  195. Power management functions (SPARCstation-4/5 + deriv.)
  196. Format: noidle
  197. Disable APC CPU standby support. SPARCstation-Fox does
  198. not play well with APC CPU idle - disable it if you have
  199. APC and your system crashes randomly.
  200. apic= [APIC,i386] Change the output verbosity whilst booting
  201. Format: { quiet (default) | verbose | debug }
  202. Change the amount of debugging information output
  203. when initialising the APIC and IO-APIC components.
  204. apm= [APM] Advanced Power Management
  205. See header of arch/i386/kernel/apm.c.
  206. applicom= [HW]
  207. Format: <mem>,<irq>
  208. arcrimi= [HW,NET] ARCnet - "RIM I" (entirely mem-mapped) cards
  209. Format: <io>,<irq>,<nodeID>
  210. ataflop= [HW,M68k]
  211. atarimouse= [HW,MOUSE] Atari Mouse
  212. atascsi= [HW,SCSI] Atari SCSI
  213. atkbd.extra= [HW] Enable extra LEDs and keys on IBM RapidAccess,
  214. EzKey and similar keyboards
  215. atkbd.reset= [HW] Reset keyboard during initialization
  216. atkbd.set= [HW] Select keyboard code set
  217. Format: <int> (2 = AT (default), 3 = PS/2)
  218. atkbd.scroll= [HW] Enable scroll wheel on MS Office and similar
  219. keyboards
  220. atkbd.softraw= [HW] Choose between synthetic and real raw mode
  221. Format: <bool> (0 = real, 1 = synthetic (default))
  222. atkbd.softrepeat= [HW]
  223. Use software keyboard repeat
  224. autotest [IA64]
  225. awe= [HW,OSS] AWE32/SB32/AWE64 wave table synth
  226. Format: <io>,<memsize>,<isapnp>
  227. aztcd= [HW,CD] Aztech CD268 CDROM driver
  228. Format: <io>,0x79 (?)
  229. baycom_epp= [HW,AX25]
  230. Format: <io>,<mode>
  231. baycom_par= [HW,AX25] BayCom Parallel Port AX.25 Modem
  232. Format: <io>,<mode>
  233. See header of drivers/net/hamradio/baycom_par.c.
  234. baycom_ser_fdx= [HW,AX25]
  235. BayCom Serial Port AX.25 Modem (Full Duplex Mode)
  236. Format: <io>,<irq>,<mode>[,<baud>]
  237. See header of drivers/net/hamradio/baycom_ser_fdx.c.
  238. baycom_ser_hdx= [HW,AX25]
  239. BayCom Serial Port AX.25 Modem (Half Duplex Mode)
  240. Format: <io>,<irq>,<mode>
  241. See header of drivers/net/hamradio/baycom_ser_hdx.c.
  242. blkmtd_device= [HW,MTD]
  243. blkmtd_erasesz=
  244. blkmtd_ro=
  245. blkmtd_bs=
  246. blkmtd_count=
  247. bttv.card= [HW,V4L] bttv (bt848 + bt878 based grabber cards)
  248. bttv.radio= Most important insmod options are available as
  249. kernel args too.
  250. bttv.pll= See Documentation/video4linux/bttv/Insmod-options
  251. bttv.tuner= and Documentation/video4linux/bttv/CARDLIST
  252. BusLogic= [HW,SCSI]
  253. See drivers/scsi/BusLogic.c, comment before function
  254. BusLogic_ParseDriverOptions().
  255. c101= [NET] Moxa C101 synchronous serial card
  256. cachesize= [BUGS=IA-32] Override level 2 CPU cache size detection.
  257. Sometimes CPU hardware bugs make them report the cache
  258. size incorrectly. The kernel will attempt work arounds
  259. to fix known problems, but for some CPUs it is not
  260. possible to determine what the correct size should be.
  261. This option provides an override for these situations.
  262. cdu31a= [HW,CD]
  263. Format: <io>,<irq>[,PAS]
  264. See header of drivers/cdrom/cdu31a.c.
  265. chandev= [HW,NET] Generic channel device initialisation
  266. checkreqprot [SELINUX] Set initial checkreqprot flag value.
  267. Format: { "0" | "1" }
  268. See security/selinux/Kconfig help text.
  269. 0 -- check protection applied by kernel (includes
  270. any implied execute protection).
  271. 1 -- check protection requested by application.
  272. Default value is set via a kernel config option.
  273. Value can be changed at runtime via
  274. /selinux/checkreqprot.
  275. clock= [BUGS=IA-32, HW] gettimeofday clocksource override.
  276. [Deprecated]
  277. Forces specified clocksource (if avaliable) to be used
  278. when calculating gettimeofday(). If specified
  279. clocksource is not avalible, it defaults to PIT.
  280. Format: { pit | tsc | cyclone | pmtmr }
  281. disable_8254_timer
  282. enable_8254_timer
  283. [IA32/X86_64] Disable/Enable interrupt 0 timer routing
  284. over the 8254 in addition to over the IO-APIC. The
  285. kernel tries to set a sensible default.
  286. hpet= [IA-32,HPET] option to disable HPET and use PIT.
  287. Format: disable
  288. cm206= [HW,CD]
  289. Format: { auto | [<io>,][<irq>] }
  290. com20020= [HW,NET] ARCnet - COM20020 chipset
  291. Format:
  292. <io>[,<irq>[,<nodeID>[,<backplane>[,<ckp>[,<timeout>]]]]]
  293. com90io= [HW,NET] ARCnet - COM90xx chipset (IO-mapped buffers)
  294. Format: <io>[,<irq>]
  295. com90xx= [HW,NET]
  296. ARCnet - COM90xx chipset (memory-mapped buffers)
  297. Format: <io>[,<irq>[,<memstart>]]
  298. condev= [HW,S390] console device
  299. conmode=
  300. console= [KNL] Output console device and options.
  301. tty<n> Use the virtual console device <n>.
  302. ttyS<n>[,options]
  303. ttyUSB0[,options]
  304. Use the specified serial port. The options are of
  305. the form "bbbbpnf", where "bbbb" is the baud rate,
  306. "p" is parity ("n", "o", or "e"), "n" is number of
  307. bits, and "f" is flow control ("r" for RTS or
  308. omit it). Default is "9600n8".
  309. See Documentation/serial-console.txt for more
  310. information. See
  311. Documentation/networking/netconsole.txt for an
  312. alternative.
  313. uart,io,<addr>[,options]
  314. uart,mmio,<addr>[,options]
  315. Start an early, polled-mode console on the 8250/16550
  316. UART at the specified I/O port or MMIO address,
  317. switching to the matching ttyS device later. The
  318. options are the same as for ttyS, above.
  319. cpcihp_generic= [HW,PCI] Generic port I/O CompactPCI driver
  320. Format:
  321. <first_slot>,<last_slot>,<port>,<enum_bit>[,<debug>]
  322. cpia_pp= [HW,PPT]
  323. Format: { parport<nr> | auto | none }
  324. crashkernel=nn[KMG]@ss[KMG]
  325. [KNL] Reserve a chunk of physical memory to
  326. hold a kernel to switch to with kexec on panic.
  327. cs4232= [HW,OSS]
  328. Format: <io>,<irq>,<dma>,<dma2>,<mpuio>,<mpuirq>
  329. cs89x0_dma= [HW,NET]
  330. Format: <dma>
  331. cs89x0_media= [HW,NET]
  332. Format: { rj45 | aui | bnc }
  333. cyclades= [HW,SERIAL] Cyclades multi-serial port adapter.
  334. dasd= [HW,NET]
  335. See header of drivers/s390/block/dasd_devmap.c.
  336. db9.dev[2|3]= [HW,JOY] Multisystem joystick support via parallel port
  337. (one device per port)
  338. Format: <port#>,<type>
  339. See also Documentation/input/joystick-parport.txt
  340. debug [KNL] Enable kernel debugging (events log level).
  341. debug_locks_verbose=
  342. [KNL] verbose self-tests
  343. Format=<0|1>
  344. Print debugging info while doing the locking API
  345. self-tests.
  346. We default to 0 (no extra messages), setting it to
  347. 1 will print _a lot_ more information - normally
  348. only useful to kernel developers.
  349. decnet= [HW,NET]
  350. Format: <area>[,<node>]
  351. See also Documentation/networking/decnet.txt.
  352. dhash_entries= [KNL]
  353. Set number of hash buckets for dentry cache.
  354. digi= [HW,SERIAL]
  355. IO parameters + enable/disable command.
  356. digiepca= [HW,SERIAL]
  357. See drivers/char/README.epca and
  358. Documentation/digiepca.txt.
  359. dmascc= [HW,AX25,SERIAL] AX.25 Z80SCC driver with DMA
  360. support available.
  361. Format: <io_dev0>[,<io_dev1>[,..<io_dev32>]]
  362. dmasound= [HW,OSS] Sound subsystem buffers
  363. dscc4.setup= [NET]
  364. dtc3181e= [HW,SCSI]
  365. earlyprintk= [IA-32,X86-64]
  366. earlyprintk=vga
  367. earlyprintk=serial[,ttySn[,baudrate]]
  368. Append ",keep" to not disable it when the real console
  369. takes over.
  370. Only vga or serial at a time, not both.
  371. Currently only ttyS0 and ttyS1 are supported.
  372. Interaction with the standard serial driver is not
  373. very good.
  374. The VGA output is eventually overwritten by the real
  375. console.
  376. eata= [HW,SCSI]
  377. ec_intr= [HW,ACPI] ACPI Embedded Controller interrupt mode
  378. Format: <int>
  379. 0: polling mode
  380. non-0: interrupt mode (default)
  381. eda= [HW,PS2]
  382. edb= [HW,PS2]
  383. edd= [EDD]
  384. Format: {"of[f]" | "sk[ipmbr]"}
  385. See comment in arch/i386/boot/edd.S
  386. eicon= [HW,ISDN]
  387. Format: <id>,<membase>,<irq>
  388. eisa_irq_edge= [PARISC,HW]
  389. See header of drivers/parisc/eisa.c.
  390. elanfreq= [IA-32]
  391. See comment before function elanfreq_setup() in
  392. arch/i386/kernel/cpu/cpufreq/elanfreq.c.
  393. elevator= [IOSCHED]
  394. Format: {"anticipatory" | "cfq" | "deadline" | "noop"}
  395. See Documentation/block/as-iosched.txt and
  396. Documentation/block/deadline-iosched.txt for details.
  397. elfcorehdr= [IA-32, X86_64]
  398. Specifies physical address of start of kernel core
  399. image elf header. Generally kexec loader will
  400. pass this option to capture kernel.
  401. See Documentation/kdump/kdump.txt for details.
  402. enforcing [SELINUX] Set initial enforcing status.
  403. Format: {"0" | "1"}
  404. See security/selinux/Kconfig help text.
  405. 0 -- permissive (log only, no denials).
  406. 1 -- enforcing (deny and log).
  407. Default value is 0.
  408. Value can be changed at runtime via /selinux/enforce.
  409. es1370= [HW,OSS]
  410. Format: <lineout>[,<micbias>]
  411. See also header of sound/oss/es1370.c.
  412. es1371= [HW,OSS]
  413. Format: <spdif>,[<nomix>,[<amplifier>]]
  414. See also header of sound/oss/es1371.c.
  415. ether= [HW,NET] Ethernet cards parameters
  416. This option is obsoleted by the "netdev=" option, which
  417. has equivalent usage. See its documentation for details.
  418. eurwdt= [HW,WDT] Eurotech CPU-1220/1410 onboard watchdog.
  419. Format: <io>[,<irq>]
  420. fd_mcs= [HW,SCSI]
  421. See header of drivers/scsi/fd_mcs.c.
  422. fdomain= [HW,SCSI]
  423. See header of drivers/scsi/fdomain.c.
  424. floppy= [HW]
  425. See Documentation/floppy.txt.
  426. ftape= [HW] Floppy Tape subsystem debugging options.
  427. See Documentation/ftape.txt.
  428. gamecon.map[2|3]=
  429. [HW,JOY] Multisystem joystick and NES/SNES/PSX pad
  430. support via parallel port (up to 5 devices per port)
  431. Format: <port#>,<pad1>,<pad2>,<pad3>,<pad4>,<pad5>
  432. See also Documentation/input/joystick-parport.txt
  433. gamma= [HW,DRM]
  434. gdth= [HW,SCSI]
  435. See header of drivers/scsi/gdth.c.
  436. gpt [EFI] Forces disk with valid GPT signature but
  437. invalid Protective MBR to be treated as GPT.
  438. gscd= [HW,CD]
  439. Format: <io>
  440. gt96100eth= [NET] MIPS GT96100 Advanced Communication Controller
  441. gus= [HW,OSS]
  442. Format: <io>,<irq>,<dma>,<dma16>
  443. gvp11= [HW,SCSI]
  444. hashdist= [KNL,NUMA] Large hashes allocated during boot
  445. are distributed across NUMA nodes. Defaults on
  446. for IA-64, off otherwise.
  447. Format: 0 | 1 (for off | on)
  448. hcl= [IA-64] SGI's Hardware Graph compatibility layer
  449. hd= [EIDE] (E)IDE hard drive subsystem geometry
  450. Format: <cyl>,<head>,<sect>
  451. hd?= [HW] (E)IDE subsystem
  452. hd?lun= See Documentation/ide.txt.
  453. highmem=nn[KMG] [KNL,BOOT] forces the highmem zone to have an exact
  454. size of <nn>. This works even on boxes that have no
  455. highmem otherwise. This also works to reduce highmem
  456. size on bigger boxes.
  457. hisax= [HW,ISDN]
  458. See Documentation/isdn/README.HiSax.
  459. hugepages= [HW,IA-32,IA-64] Maximal number of HugeTLB pages.
  460. noirqbalance [IA-32,SMP,KNL] Disable kernel irq balancing
  461. i8042.direct [HW] Put keyboard port into non-translated mode
  462. i8042.dumbkbd [HW] Pretend that controlled can only read data from
  463. keyboard and can not control its state
  464. (Don't attempt to blink the leds)
  465. i8042.noaux [HW] Don't check for auxiliary (== mouse) port
  466. i8042.nokbd [HW] Don't check/create keyboard port
  467. i8042.nomux [HW] Don't check presence of an active multiplexing
  468. controller
  469. i8042.nopnp [HW] Don't use ACPIPnP / PnPBIOS to discover KBD/AUX
  470. controllers
  471. i8042.panicblink=
  472. [HW] Frequency with which keyboard LEDs should blink
  473. when kernel panics (default is 0.5 sec)
  474. i8042.reset [HW] Reset the controller during init and cleanup
  475. i8042.unlock [HW] Unlock (ignore) the keylock
  476. i810= [HW,DRM]
  477. i8k.ignore_dmi [HW] Continue probing hardware even if DMI data
  478. indicates that the driver is running on unsupported
  479. hardware.
  480. i8k.force [HW] Activate i8k driver even if SMM BIOS signature
  481. does not match list of supported models.
  482. i8k.power_status
  483. [HW] Report power status in /proc/i8k
  484. (disabled by default)
  485. i8k.restricted [HW] Allow controlling fans only if SYS_ADMIN
  486. capability is set.
  487. ibmmcascsi= [HW,MCA,SCSI] IBM MicroChannel SCSI adapter
  488. See Documentation/mca.txt.
  489. icn= [HW,ISDN]
  490. Format: <io>[,<membase>[,<icn_id>[,<icn_id2>]]]
  491. ide= [HW] (E)IDE subsystem
  492. Format: ide=nodma or ide=doubler or ide=reverse
  493. See Documentation/ide.txt.
  494. ide?= [HW] (E)IDE subsystem
  495. Format: ide?=noprobe or chipset specific parameters.
  496. See Documentation/ide.txt.
  497. idebus= [HW] (E)IDE subsystem - VLB/PCI bus speed
  498. See Documentation/ide.txt.
  499. idle= [HW]
  500. Format: idle=poll or idle=halt
  501. ihash_entries= [KNL]
  502. Set number of hash buckets for inode cache.
  503. in2000= [HW,SCSI]
  504. See header of drivers/scsi/in2000.c.
  505. init= [KNL]
  506. Format: <full_path>
  507. Run specified binary instead of /sbin/init as init
  508. process.
  509. initcall_debug [KNL] Trace initcalls as they are executed. Useful
  510. for working out where the kernel is dying during
  511. startup.
  512. initrd= [BOOT] Specify the location of the initial ramdisk
  513. inport.irq= [HW] Inport (ATI XL and Microsoft) busmouse driver
  514. Format: <irq>
  515. combined_mode= [HW] control which driver uses IDE ports in combined
  516. mode: legacy IDE driver, libata, or both
  517. (in the libata case, libata.atapi_enabled=1 may be
  518. useful as well). Note that using the ide or libata
  519. options may affect your device naming (e.g. by
  520. changing hdc to sdb).
  521. Format: combined (default), ide, or libata
  522. inttest= [IA64]
  523. io7= [HW] IO7 for Marvel based alpha systems
  524. See comment before marvel_specify_io7 in
  525. arch/alpha/kernel/core_marvel.c.
  526. ip= [IP_PNP]
  527. See Documentation/nfsroot.txt.
  528. ip2= [HW] Set IO/IRQ pairs for up to 4 IntelliPort boards
  529. See comment before ip2_setup() in drivers/char/ip2.c.
  530. ips= [HW,SCSI] Adaptec / IBM ServeRAID controller
  531. See header of drivers/scsi/ips.c.
  532. ports= [IP_VS_FTP] IPVS ftp helper module
  533. Default is 21.
  534. Up to 8 (IP_VS_APP_MAX_PORTS) ports
  535. may be specified.
  536. Format: <port>,<port>....
  537. irqfixup [HW]
  538. When an interrupt is not handled search all handlers
  539. for it. Intended to get systems with badly broken
  540. firmware running.
  541. irqpoll [HW]
  542. When an interrupt is not handled search all handlers
  543. for it. Also check all handlers each timer
  544. interrupt. Intended to get systems with badly broken
  545. firmware running.
  546. isapnp= [ISAPNP]
  547. Format: <RDP>,<reset>,<pci_scan>,<verbosity>
  548. isolcpus= [KNL,SMP] Isolate CPUs from the general scheduler.
  549. Format: <cpu number>,...,<cpu number>
  550. This option can be used to specify one or more CPUs
  551. to isolate from the general SMP balancing and scheduling
  552. algorithms. The only way to move a process onto or off
  553. an "isolated" CPU is via the CPU affinity syscalls.
  554. <cpu number> begins at 0 and the maximum value is
  555. "number of CPUs in system - 1".
  556. This option is the preferred way to isolate CPUs. The
  557. alternative -- manually setting the CPU mask of all
  558. tasks in the system -- can cause problems and
  559. suboptimal load balancer performance.
  560. isp16= [HW,CD]
  561. Format: <io>,<irq>,<dma>,<setup>
  562. iucv= [HW,NET]
  563. js= [HW,JOY] Analog joystick
  564. See Documentation/input/joystick.txt.
  565. keepinitrd [HW,ARM]
  566. kstack=N [IA-32,X86-64] Print N words from the kernel stack
  567. in oops dumps.
  568. l2cr= [PPC]
  569. lapic [IA-32,APIC] Enable the local APIC even if BIOS
  570. disabled it.
  571. lasi= [HW,SCSI] PARISC LASI driver for the 53c700 chip
  572. Format: addr:<io>,irq:<irq>
  573. llsc*= [IA64] See function print_params() in
  574. arch/ia64/sn/kernel/llsc4.c.
  575. load_ramdisk= [RAM] List of ramdisks to load from floppy
  576. See Documentation/ramdisk.txt.
  577. lockd.nlm_grace_period=P [NFS] Assign grace period.
  578. Format: <integer>
  579. lockd.nlm_tcpport=N [NFS] Assign TCP port.
  580. Format: <integer>
  581. lockd.nlm_timeout=T [NFS] Assign timeout value.
  582. Format: <integer>
  583. lockd.nlm_udpport=M [NFS] Assign UDP port.
  584. Format: <integer>
  585. logibm.irq= [HW,MOUSE] Logitech Bus Mouse Driver
  586. Format: <irq>
  587. loglevel= All Kernel Messages with a loglevel smaller than the
  588. console loglevel will be printed to the console. It can
  589. also be changed with klogd or other programs. The
  590. loglevels are defined as follows:
  591. 0 (KERN_EMERG) system is unusable
  592. 1 (KERN_ALERT) action must be taken immediately
  593. 2 (KERN_CRIT) critical conditions
  594. 3 (KERN_ERR) error conditions
  595. 4 (KERN_WARNING) warning conditions
  596. 5 (KERN_NOTICE) normal but significant condition
  597. 6 (KERN_INFO) informational
  598. 7 (KERN_DEBUG) debug-level messages
  599. log_buf_len=n Sets the size of the printk ring buffer, in bytes.
  600. Format: { n | nk | nM }
  601. n must be a power of two. The default size
  602. is set in the kernel config file.
  603. lp=0 [LP] Specify parallel ports to use, e.g,
  604. lp=port[,port...] lp=none,parport0 (lp0 not configured, lp1 uses
  605. lp=reset first parallel port). 'lp=0' disables the
  606. lp=auto printer driver. 'lp=reset' (which can be
  607. specified in addition to the ports) causes
  608. attached printers to be reset. Using
  609. lp=port1,port2,... specifies the parallel ports
  610. to associate lp devices with, starting with
  611. lp0. A port specification may be 'none' to skip
  612. that lp device, or a parport name such as
  613. 'parport0'. Specifying 'lp=auto' instead of a
  614. port specification list means that device IDs
  615. from each port should be examined, to see if
  616. an IEEE 1284-compliant printer is attached; if
  617. so, the driver will manage that printer.
  618. See also header of drivers/char/lp.c.
  619. lpj=n [KNL]
  620. Sets loops_per_jiffy to given constant, thus avoiding
  621. time-consuming boot-time autodetection (up to 250 ms per
  622. CPU). 0 enables autodetection (default). To determine
  623. the correct value for your kernel, boot with normal
  624. autodetection and see what value is printed. Note that
  625. on SMP systems the preset will be applied to all CPUs,
  626. which is likely to cause problems if your CPUs need
  627. significantly divergent settings. An incorrect value
  628. will cause delays in the kernel to be wrong, leading to
  629. unpredictable I/O errors and other breakage. Although
  630. unlikely, in the extreme case this might damage your
  631. hardware.
  632. ltpc= [NET]
  633. Format: <io>,<irq>,<dma>
  634. mac5380= [HW,SCSI] Format:
  635. <can_queue>,<cmd_per_lun>,<sg_tablesize>,<hostid>,<use_tags>
  636. mac53c9x= [HW,SCSI] Format:
  637. <num_esps>,<disconnect>,<nosync>,<can_queue>,<cmd_per_lun>,<sg_tablesize>,<hostid>,<use_tags>
  638. machvec= [IA64] Force the use of a particular machine-vector
  639. (machvec) in a generic kernel.
  640. Example: machvec=hpzx1_swiotlb
  641. mad16= [HW,OSS] Format:
  642. <io>,<irq>,<dma>,<dma16>,<mpu_io>,<mpu_irq>,<joystick>
  643. maui= [HW,OSS]
  644. Format: <io>,<irq>
  645. max_loop= [LOOP] Maximum number of loopback devices that can
  646. be mounted
  647. Format: <1-256>
  648. maxcpus= [SMP] Maximum number of processors that an SMP kernel
  649. should make use of
  650. max_addr=[KMG] [KNL,BOOT,ia64] All physical memory greater than or
  651. equal to this physical address is ignored.
  652. max_luns= [SCSI] Maximum number of LUNs to probe.
  653. Should be between 1 and 2^32-1.
  654. max_report_luns=
  655. [SCSI] Maximum number of LUNs received.
  656. Should be between 1 and 16384.
  657. mca-pentium [BUGS=IA-32]
  658. mcatest= [IA-64]
  659. mcd= [HW,CD]
  660. Format: <port>,<irq>,<mitsumi_bug_93_wait>
  661. mcdx= [HW,CD]
  662. mce [IA-32] Machine Check Exception
  663. md= [HW] RAID subsystems devices and level
  664. See Documentation/md.txt.
  665. mdacon= [MDA]
  666. Format: <first>,<last>
  667. Specifies range of consoles to be captured by the MDA.
  668. mem=nn[KMG] [KNL,BOOT] Force usage of a specific amount of memory
  669. Amount of memory to be used when the kernel is not able
  670. to see the whole system memory or for test.
  671. [IA-32] Use together with memmap= to avoid physical
  672. address space collisions. Without memmap= PCI devices
  673. could be placed at addresses belonging to unused RAM.
  674. mem=nopentium [BUGS=IA-32] Disable usage of 4MB pages for kernel
  675. memory.
  676. memmap=exactmap [KNL,IA-32,X86_64] Enable setting of an exact
  677. E820 memory map, as specified by the user.
  678. Such memmap=exactmap lines can be constructed based on
  679. BIOS output or other requirements. See the memmap=nn@ss
  680. option description.
  681. memmap=nn[KMG]@ss[KMG]
  682. [KNL] Force usage of a specific region of memory
  683. Region of memory to be used, from ss to ss+nn.
  684. memmap=nn[KMG]#ss[KMG]
  685. [KNL,ACPI] Mark specific memory as ACPI data.
  686. Region of memory to be used, from ss to ss+nn.
  687. memmap=nn[KMG]$ss[KMG]
  688. [KNL,ACPI] Mark specific memory as reserved.
  689. Region of memory to be used, from ss to ss+nn.
  690. meye.*= [HW] Set MotionEye Camera parameters
  691. See Documentation/video4linux/meye.txt.
  692. mga= [HW,DRM]
  693. migration_cost=
  694. [KNL,SMP] debug: override scheduler migration costs
  695. Format: <level-1-usecs>,<level-2-usecs>,...
  696. This debugging option can be used to override the
  697. default scheduler migration cost matrix. The numbers
  698. are indexed by 'CPU domain distance'.
  699. E.g. migration_cost=1000,2000,3000 on an SMT NUMA
  700. box will set up an intra-core migration cost of
  701. 1 msec, an inter-core migration cost of 2 msecs,
  702. and an inter-node migration cost of 3 msecs.
  703. WARNING: using the wrong values here can break
  704. scheduler performance, so it's only for scheduler
  705. development purposes, not production environments.
  706. migration_debug=
  707. [KNL,SMP] migration cost auto-detect verbosity
  708. Format=<0|1|2>
  709. If a system's migration matrix reported at bootup
  710. seems erroneous then this option can be used to
  711. increase verbosity of the detection process.
  712. We default to 0 (no extra messages), 1 will print
  713. some more information, and 2 will be really
  714. verbose (probably only useful if you also have a
  715. serial console attached to the system).
  716. migration_factor=
  717. [KNL,SMP] multiply/divide migration costs by a factor
  718. Format=<percent>
  719. This debug option can be used to proportionally
  720. increase or decrease the auto-detected migration
  721. costs for all entries of the migration matrix.
  722. E.g. migration_factor=150 will increase migration
  723. costs by 50%. (and thus the scheduler will be less
  724. eager migrating cache-hot tasks)
  725. migration_factor=80 will decrease migration costs
  726. by 20%. (thus the scheduler will be more eager to
  727. migrate tasks)
  728. WARNING: using the wrong values here can break
  729. scheduler performance, so it's only for scheduler
  730. development purposes, not production environments.
  731. mousedev.tap_time=
  732. [MOUSE] Maximum time between finger touching and
  733. leaving touchpad surface for touch to be considered
  734. a tap and be reported as a left button click (for
  735. touchpads working in absolute mode only).
  736. Format: <msecs>
  737. mousedev.xres= [MOUSE] Horizontal screen resolution, used for devices
  738. reporting absolute coordinates, such as tablets
  739. mousedev.yres= [MOUSE] Vertical screen resolution, used for devices
  740. reporting absolute coordinates, such as tablets
  741. mpu401= [HW,OSS]
  742. Format: <io>,<irq>
  743. MTD_Partition= [MTD]
  744. Format: <name>,<region-number>,<size>,<offset>
  745. MTD_Region= [MTD] Format:
  746. <name>,<region-number>[,<base>,<size>,<buswidth>,<altbuswidth>]
  747. mtdparts= [MTD]
  748. See drivers/mtd/cmdline.c.
  749. mtouchusb.raw_coordinates=
  750. [HW] Make the MicroTouch USB driver use raw coordinates
  751. ('y', default) or cooked coordinates ('n')
  752. n2= [NET] SDL Inc. RISCom/N2 synchronous serial card
  753. NCR_D700= [HW,SCSI]
  754. See header of drivers/scsi/NCR_D700.c.
  755. ncr5380= [HW,SCSI]
  756. ncr53c400= [HW,SCSI]
  757. ncr53c400a= [HW,SCSI]
  758. ncr53c406a= [HW,SCSI]
  759. ncr53c8xx= [HW,SCSI]
  760. netdev= [NET] Network devices parameters
  761. Format: <irq>,<io>,<mem_start>,<mem_end>,<name>
  762. Note that mem_start is often overloaded to mean
  763. something different and driver-specific.
  764. This usage is only documented in each driver source
  765. file if at all.
  766. nfsaddrs= [NFS]
  767. See Documentation/nfsroot.txt.
  768. nfsroot= [NFS] nfs root filesystem for disk-less boxes.
  769. See Documentation/nfsroot.txt.
  770. nfs.callback_tcpport=
  771. [NFS] set the TCP port on which the NFSv4 callback
  772. channel should listen.
  773. nfs.idmap_cache_timeout=
  774. [NFS] set the maximum lifetime for idmapper cache
  775. entries.
  776. nmi_watchdog= [KNL,BUGS=IA-32] Debugging features for SMP kernels
  777. no387 [BUGS=IA-32] Tells the kernel to use the 387 maths
  778. emulation library even if a 387 maths coprocessor
  779. is present.
  780. noalign [KNL,ARM]
  781. noapic [SMP,APIC] Tells the kernel to not make use of any
  782. IOAPICs that may be present in the system.
  783. noasync [HW,M68K] Disables async and sync negotiation for
  784. all devices.
  785. nobats [PPC] Do not use BATs for mapping kernel lowmem
  786. on "Classic" PPC cores.
  787. nocache [ARM]
  788. nodelayacct [KNL] Disable per-task delay accounting
  789. nodisconnect [HW,SCSI,M68K] Disables SCSI disconnects.
  790. noexec [IA-64]
  791. noexec [IA-32,X86-64]
  792. noexec=on: enable non-executable mappings (default)
  793. noexec=off: disable nn-executable mappings
  794. nofxsr [BUGS=IA-32] Disables x86 floating point extended
  795. register save and restore. The kernel will only save
  796. legacy floating-point registers on task switch.
  797. nohlt [BUGS=ARM]
  798. no-hlt [BUGS=IA-32] Tells the kernel that the hlt
  799. instruction doesn't work correctly and not to
  800. use it.
  801. nohalt [IA-64] Tells the kernel not to use the power saving
  802. function PAL_HALT_LIGHT when idle. This increases
  803. power-consumption. On the positive side, it reduces
  804. interrupt wake-up latency, which may improve performance
  805. in certain environments such as networked servers or
  806. real-time systems.
  807. noirqdebug [IA-32] Disables the code which attempts to detect and
  808. disable unhandled interrupt sources.
  809. noisapnp [ISAPNP] Disables ISA PnP code.
  810. noinitrd [RAM] Tells the kernel not to load any configured
  811. initial RAM disk.
  812. nointroute [IA-64]
  813. nolapic [IA-32,APIC] Do not enable or use the local APIC.
  814. noltlbs [PPC] Do not use large page/tlb entries for kernel
  815. lowmem mapping on PPC40x.
  816. nomca [IA-64] Disable machine check abort handling
  817. nomce [IA-32] Machine Check Exception
  818. noresidual [PPC] Don't use residual data on PReP machines.
  819. noresume [SWSUSP] Disables resume and restores original swap
  820. space.
  821. no-scroll [VGA] Disables scrollback.
  822. This is required for the Braillex ib80-piezo Braille
  823. reader made by F.H. Papenmeier (Germany).
  824. nosbagart [IA-64]
  825. nosep [BUGS=IA-32] Disables x86 SYSENTER/SYSEXIT support.
  826. nosmp [SMP] Tells an SMP kernel to act as a UP kernel.
  827. nosync [HW,M68K] Disables sync negotiation for all devices.
  828. notsc [BUGS=IA-32] Disable Time Stamp Counter
  829. nousb [USB] Disable the USB subsystem
  830. nowb [ARM]
  831. nr_uarts= [SERIAL] maximum number of UARTs to be registered.
  832. opl3= [HW,OSS]
  833. Format: <io>
  834. opl3sa= [HW,OSS]
  835. Format: <io>,<irq>,<dma>,<dma2>,<mpu_io>,<mpu_irq>
  836. opl3sa2= [HW,OSS] Format:
  837. <io>,<irq>,<dma>,<dma2>,<mss_io>,<mpu_io>,<ymode>,<loopback>[,<isapnp>,<multiple]
  838. oprofile.timer= [HW]
  839. Use timer interrupt instead of performance counters
  840. optcd= [HW,CD]
  841. Format: <io>
  842. osst= [HW,SCSI] SCSI Tape Driver
  843. Format: <buffer_size>,<write_threshold>
  844. See also Documentation/scsi/st.txt.
  845. panic= [KNL] Kernel behaviour on panic
  846. Format: <timeout>
  847. parkbd.port= [HW] Parallel port number the keyboard adapter is
  848. connected to, default is 0.
  849. Format: <parport#>
  850. parkbd.mode= [HW] Parallel port keyboard adapter mode of operation,
  851. 0 for XT, 1 for AT (default is AT).
  852. Format: <mode>
  853. parport= [HW,PPT] Specify parallel ports. 0 disables.
  854. Format: { 0 | auto | 0xBBB[,IRQ[,DMA]] }
  855. Use 'auto' to force the driver to use any
  856. IRQ/DMA settings detected (the default is to
  857. ignore detected IRQ/DMA settings because of
  858. possible conflicts). You can specify the base
  859. address, IRQ, and DMA settings; IRQ and DMA
  860. should be numbers, or 'auto' (for using detected
  861. settings on that particular port), or 'nofifo'
  862. (to avoid using a FIFO even if it is detected).
  863. Parallel ports are assigned in the order they
  864. are specified on the command line, starting
  865. with parport0.
  866. parport_init_mode= [HW,PPT]
  867. Configure VIA parallel port to operate in
  868. a specific mode. This is necessary on Pegasos
  869. computer where firmware has no options for setting
  870. up parallel port mode and sets it to spp.
  871. Currently this function knows 686a and 8231 chips.
  872. Format: [spp|ps2|epp|ecp|ecpepp]
  873. pas2= [HW,OSS] Format:
  874. <io>,<irq>,<dma>,<dma16>,<sb_io>,<sb_irq>,<sb_dma>,<sb_dma16>
  875. pas16= [HW,SCSI]
  876. See header of drivers/scsi/pas16.c.
  877. pause_on_oops=
  878. Halt all CPUs after the first oops has been printed for
  879. the specified number of seconds. This is to be used if
  880. your oopses keep scrolling off the screen.
  881. pcbit= [HW,ISDN]
  882. pcd. [PARIDE]
  883. See header of drivers/block/paride/pcd.c.
  884. See also Documentation/paride.txt.
  885. pci=option[,option...] [PCI] various PCI subsystem options:
  886. off [IA-32] don't probe for the PCI bus
  887. bios [IA-32] force use of PCI BIOS, don't access
  888. the hardware directly. Use this if your machine
  889. has a non-standard PCI host bridge.
  890. nobios [IA-32] disallow use of PCI BIOS, only direct
  891. hardware access methods are allowed. Use this
  892. if you experience crashes upon bootup and you
  893. suspect they are caused by the BIOS.
  894. conf1 [IA-32] Force use of PCI Configuration
  895. Mechanism 1.
  896. conf2 [IA-32] Force use of PCI Configuration
  897. Mechanism 2.
  898. nommconf [IA-32,X86_64] Disable use of MMCONFIG for PCI
  899. Configuration
  900. nomsi [MSI] If the PCI_MSI kernel config parameter is
  901. enabled, this kernel boot option can be used to
  902. disable the use of MSI interrupts system-wide.
  903. nosort [IA-32] Don't sort PCI devices according to
  904. order given by the PCI BIOS. This sorting is
  905. done to get a device order compatible with
  906. older kernels.
  907. biosirq [IA-32] Use PCI BIOS calls to get the interrupt
  908. routing table. These calls are known to be buggy
  909. on several machines and they hang the machine
  910. when used, but on other computers it's the only
  911. way to get the interrupt routing table. Try
  912. this option if the kernel is unable to allocate
  913. IRQs or discover secondary PCI buses on your
  914. motherboard.
  915. rom [IA-32] Assign address space to expansion ROMs.
  916. Use with caution as certain devices share
  917. address decoders between ROMs and other
  918. resources.
  919. irqmask=0xMMMM [IA-32] Set a bit mask of IRQs allowed to be
  920. assigned automatically to PCI devices. You can
  921. make the kernel exclude IRQs of your ISA cards
  922. this way.
  923. pirqaddr=0xAAAAA [IA-32] Specify the physical address
  924. of the PIRQ table (normally generated
  925. by the BIOS) if it is outside the
  926. F0000h-100000h range.
  927. lastbus=N [IA-32] Scan all buses thru bus #N. Can be
  928. useful if the kernel is unable to find your
  929. secondary buses and you want to tell it
  930. explicitly which ones they are.
  931. assign-busses [IA-32] Always assign all PCI bus
  932. numbers ourselves, overriding
  933. whatever the firmware may have done.
  934. usepirqmask [IA-32] Honor the possible IRQ mask stored
  935. in the BIOS $PIR table. This is needed on
  936. some systems with broken BIOSes, notably
  937. some HP Pavilion N5400 and Omnibook XE3
  938. notebooks. This will have no effect if ACPI
  939. IRQ routing is enabled.
  940. noacpi [IA-32] Do not use ACPI for IRQ routing
  941. or for PCI scanning.
  942. routeirq Do IRQ routing for all PCI devices.
  943. This is normally done in pci_enable_device(),
  944. so this option is a temporary workaround
  945. for broken drivers that don't call it.
  946. firmware [ARM] Do not re-enumerate the bus but instead
  947. just use the configuration from the
  948. bootloader. This is currently used on
  949. IXP2000 systems where the bus has to be
  950. configured a certain way for adjunct CPUs.
  951. pcmv= [HW,PCMCIA] BadgePAD 4
  952. pd. [PARIDE]
  953. See Documentation/paride.txt.
  954. pdcchassis= [PARISC,HW] Disable/Enable PDC Chassis Status codes at
  955. boot time.
  956. Format: { 0 | 1 }
  957. See arch/parisc/kernel/pdc_chassis.c
  958. pf. [PARIDE]
  959. See Documentation/paride.txt.
  960. pg. [PARIDE]
  961. See Documentation/paride.txt.
  962. pirq= [SMP,APIC] Manual mp-table setup
  963. See Documentation/i386/IO-APIC.txt.
  964. plip= [PPT,NET] Parallel port network link
  965. Format: { parport<nr> | timid | 0 }
  966. See also Documentation/parport.txt.
  967. pnpacpi= [ACPI]
  968. { off }
  969. pnpbios= [ISAPNP]
  970. { on | off | curr | res | no-curr | no-res }
  971. pnp_reserve_irq=
  972. [ISAPNP] Exclude IRQs for the autoconfiguration
  973. pnp_reserve_dma=
  974. [ISAPNP] Exclude DMAs for the autoconfiguration
  975. pnp_reserve_io= [ISAPNP] Exclude I/O ports for the autoconfiguration
  976. Ranges are in pairs (I/O port base and size).
  977. pnp_reserve_mem=
  978. [ISAPNP] Exclude memory regions for the
  979. autoconfiguration.
  980. Ranges are in pairs (memory base and size).
  981. profile= [KNL] Enable kernel profiling via /proc/profile
  982. Format: [schedule,]<number>
  983. Param: "schedule" - profile schedule points.
  984. Param: <number> - step/bucket size as a power of 2 for
  985. statistical time based profiling.
  986. processor.max_cstate= [HW,ACPI]
  987. Limit processor to maximum C-state
  988. max_cstate=9 overrides any DMI blacklist limit.
  989. processor.nocst [HW,ACPI]
  990. Ignore the _CST method to determine C-states,
  991. instead using the legacy FADT method
  992. prompt_ramdisk= [RAM] List of RAM disks to prompt for floppy disk
  993. before loading.
  994. See Documentation/ramdisk.txt.
  995. psmouse.proto= [HW,MOUSE] Highest PS2 mouse protocol extension to
  996. probe for; one of (bare|imps|exps|lifebook|any).
  997. psmouse.rate= [HW,MOUSE] Set desired mouse report rate, in reports
  998. per second.
  999. psmouse.resetafter= [HW,MOUSE]
  1000. Try to reset the device after so many bad packets
  1001. (0 = never).
  1002. psmouse.resolution=
  1003. [HW,MOUSE] Set desired mouse resolution, in dpi.
  1004. psmouse.smartscroll=
  1005. [HW,MOUSE] Controls Logitech smartscroll autorepeat.
  1006. 0 = disabled, 1 = enabled (default).
  1007. pss= [HW,OSS] Personal Sound System (ECHO ESC614)
  1008. Format:
  1009. <io>,<mss_io>,<mss_irq>,<mss_dma>,<mpu_io>,<mpu_irq>
  1010. pt. [PARIDE]
  1011. See Documentation/paride.txt.
  1012. quiet= [KNL] Disable log messages
  1013. r128= [HW,DRM]
  1014. raid= [HW,RAID]
  1015. See Documentation/md.txt.
  1016. ramdisk= [RAM] Sizes of RAM disks in kilobytes [deprecated]
  1017. See Documentation/ramdisk.txt.
  1018. ramdisk_blocksize= [RAM]
  1019. See Documentation/ramdisk.txt.
  1020. ramdisk_size= [RAM] Sizes of RAM disks in kilobytes
  1021. New name for the ramdisk parameter.
  1022. See Documentation/ramdisk.txt.
  1023. rcu.blimit= [KNL,BOOT] Set maximum number of finished
  1024. RCU callbacks to process in one batch.
  1025. rcu.qhimark= [KNL,BOOT] Set threshold of queued
  1026. RCU callbacks over which batch limiting is disabled.
  1027. rcu.qlowmark= [KNL,BOOT] Set threshold of queued
  1028. RCU callbacks below which batch limiting is re-enabled.
  1029. rcu.rsinterval= [KNL,BOOT,SMP] Set the number of additional
  1030. RCU callbacks to queued before forcing reschedule
  1031. on all cpus.
  1032. rdinit= [KNL]
  1033. Format: <full_path>
  1034. Run specified binary instead of /init from the ramdisk,
  1035. used for early userspace startup. See initrd.
  1036. reboot= [BUGS=IA-32,BUGS=ARM,BUGS=IA-64] Rebooting mode
  1037. Format: <reboot_mode>[,<reboot_mode2>[,...]]
  1038. See arch/*/kernel/reboot.c.
  1039. reserve= [KNL,BUGS] Force the kernel to ignore some iomem area
  1040. resume= [SWSUSP]
  1041. Specify the partition device for software suspend
  1042. rhash_entries= [KNL,NET]
  1043. Set number of hash buckets for route cache
  1044. riscom8= [HW,SERIAL]
  1045. Format: <io_board1>[,<io_board2>[,...<io_boardN>]]
  1046. ro [KNL] Mount root device read-only on boot
  1047. root= [KNL] Root filesystem
  1048. rootdelay= [KNL] Delay (in seconds) to pause before attempting to
  1049. mount the root filesystem
  1050. rootflags= [KNL] Set root filesystem mount option string
  1051. rootfstype= [KNL] Set root filesystem type
  1052. rw [KNL] Mount root device read-write on boot
  1053. S [KNL] Run init in single mode
  1054. sa1100ir [NET]
  1055. See drivers/net/irda/sa1100_ir.c.
  1056. sb= [HW,OSS]
  1057. Format: <io>,<irq>,<dma>,<dma2>
  1058. sbni= [NET] Granch SBNI12 leased line adapter
  1059. sbpcd= [HW,CD] Soundblaster CD adapter
  1060. Format: <io>,<type>
  1061. See a comment before function sbpcd_setup() in
  1062. drivers/cdrom/sbpcd.c.
  1063. sc1200wdt= [HW,WDT] SC1200 WDT (watchdog) driver
  1064. Format: <io>[,<timeout>[,<isapnp>]]
  1065. scsi_debug_*= [SCSI]
  1066. See drivers/scsi/scsi_debug.c.
  1067. scsi_default_dev_flags=
  1068. [SCSI] SCSI default device flags
  1069. Format: <integer>
  1070. scsi_dev_flags= [SCSI] Black/white list entry for vendor and model
  1071. Format: <vendor>:<model>:<flags>
  1072. (flags are integer value)
  1073. scsi_logging= [SCSI]
  1074. selinux [SELINUX] Disable or enable SELinux at boot time.
  1075. Format: { "0" | "1" }
  1076. See security/selinux/Kconfig help text.
  1077. 0 -- disable.
  1078. 1 -- enable.
  1079. Default value is set via kernel config option.
  1080. If enabled at boot time, /selinux/disable can be used
  1081. later to disable prior to initial policy load.
  1082. selinux_compat_net =
  1083. [SELINUX] Set initial selinux_compat_net flag value.
  1084. Format: { "0" | "1" }
  1085. 0 -- use new secmark-based packet controls
  1086. 1 -- use legacy packet controls
  1087. Default value is 0 (preferred).
  1088. Value can be changed at runtime via
  1089. /selinux/compat_net.
  1090. serialnumber [BUGS=IA-32]
  1091. sg_def_reserved_size= [SCSI]
  1092. sgalaxy= [HW,OSS]
  1093. Format: <io>,<irq>,<dma>,<dma2>,<sgbase>
  1094. shapers= [NET]
  1095. Maximal number of shapers.
  1096. sim710= [SCSI,HW]
  1097. See header of drivers/scsi/sim710.c.
  1098. simeth= [IA-64]
  1099. simscsi=
  1100. sjcd= [HW,CD]
  1101. Format: <io>,<irq>,<dma>
  1102. See header of drivers/cdrom/sjcd.c.
  1103. slram= [HW,MTD]
  1104. smart2= [HW]
  1105. Format: <io1>[,<io2>[,...,<io8>]]
  1106. snd-ad1816a= [HW,ALSA]
  1107. snd-ad1848= [HW,ALSA]
  1108. snd-ali5451= [HW,ALSA]
  1109. snd-als100= [HW,ALSA]
  1110. snd-als4000= [HW,ALSA]
  1111. snd-azt2320= [HW,ALSA]
  1112. snd-cmi8330= [HW,ALSA]
  1113. snd-cmipci= [HW,ALSA]
  1114. snd-cs4231= [HW,ALSA]
  1115. snd-cs4232= [HW,ALSA]
  1116. snd-cs4236= [HW,ALSA]
  1117. snd-cs4281= [HW,ALSA]
  1118. snd-cs46xx= [HW,ALSA]
  1119. snd-dt019x= [HW,ALSA]
  1120. snd-dummy= [HW,ALSA]
  1121. snd-emu10k1= [HW,ALSA]
  1122. snd-ens1370= [HW,ALSA]
  1123. snd-ens1371= [HW,ALSA]
  1124. snd-es968= [HW,ALSA]
  1125. snd-es1688= [HW,ALSA]
  1126. snd-es18xx= [HW,ALSA]
  1127. snd-es1938= [HW,ALSA]
  1128. snd-es1968= [HW,ALSA]
  1129. snd-fm801= [HW,ALSA]
  1130. snd-gusclassic= [HW,ALSA]
  1131. snd-gusextreme= [HW,ALSA]
  1132. snd-gusmax= [HW,ALSA]
  1133. snd-hdsp= [HW,ALSA]
  1134. snd-ice1712= [HW,ALSA]
  1135. snd-intel8x0= [HW,ALSA]
  1136. snd-interwave= [HW,ALSA]
  1137. snd-interwave-stb=
  1138. [HW,ALSA]
  1139. snd-korg1212= [HW,ALSA]
  1140. snd-maestro3= [HW,ALSA]
  1141. snd-mpu401= [HW,ALSA]
  1142. snd-mtpav= [HW,ALSA]
  1143. snd-nm256= [HW,ALSA]
  1144. snd-opl3sa2= [HW,ALSA]
  1145. snd-opti92x-ad1848=
  1146. [HW,ALSA]
  1147. snd-opti92x-cs4231=
  1148. [HW,ALSA]
  1149. snd-opti93x= [HW,ALSA]
  1150. snd-pmac= [HW,ALSA]
  1151. snd-rme32= [HW,ALSA]
  1152. snd-rme96= [HW,ALSA]
  1153. snd-rme9652= [HW,ALSA]
  1154. snd-sb8= [HW,ALSA]
  1155. snd-sb16= [HW,ALSA]
  1156. snd-sbawe= [HW,ALSA]
  1157. snd-serial= [HW,ALSA]
  1158. snd-sgalaxy= [HW,ALSA]
  1159. snd-sonicvibes= [HW,ALSA]
  1160. snd-sun-amd7930=
  1161. [HW,ALSA]
  1162. snd-sun-cs4231= [HW,ALSA]
  1163. snd-trident= [HW,ALSA]
  1164. snd-usb-audio= [HW,ALSA,USB]
  1165. snd-via82xx= [HW,ALSA]
  1166. snd-virmidi= [HW,ALSA]
  1167. snd-wavefront= [HW,ALSA]
  1168. snd-ymfpci= [HW,ALSA]
  1169. sonicvibes= [HW,OSS]
  1170. Format: <reverb>
  1171. sonycd535= [HW,CD]
  1172. Format: <io>[,<irq>]
  1173. sonypi.*= [HW] Sony Programmable I/O Control Device driver
  1174. See Documentation/sonypi.txt
  1175. specialix= [HW,SERIAL] Specialix multi-serial port adapter
  1176. See Documentation/specialix.txt.
  1177. spia_io_base= [HW,MTD]
  1178. spia_fio_base=
  1179. spia_pedr=
  1180. spia_peddr=
  1181. sscape= [HW,OSS]
  1182. Format: <io>,<irq>,<dma>,<mpu_io>,<mpu_irq>
  1183. st= [HW,SCSI] SCSI tape parameters (buffers, etc.)
  1184. See Documentation/scsi/st.txt.
  1185. st0x= [HW,SCSI]
  1186. See header of drivers/scsi/seagate.c.
  1187. sti= [PARISC,HW]
  1188. Format: <num>
  1189. Set the STI (builtin display/keyboard on the HP-PARISC
  1190. machines) console (graphic card) which should be used
  1191. as the initial boot-console.
  1192. See also comment in drivers/video/console/sticore.c.
  1193. sti_font= [HW]
  1194. See comment in drivers/video/console/sticore.c.
  1195. stifb= [HW]
  1196. Format: bpp:<bpp1>[:<bpp2>[:<bpp3>...]]
  1197. swiotlb= [IA-64] Number of I/O TLB slabs
  1198. switches= [HW,M68k]
  1199. sym53c416= [HW,SCSI]
  1200. See header of drivers/scsi/sym53c416.c.
  1201. t128= [HW,SCSI]
  1202. See header of drivers/scsi/t128.c.
  1203. tdfx= [HW,DRM]
  1204. thash_entries= [KNL,NET]
  1205. Set number of hash buckets for TCP connection
  1206. time Show timing data prefixed to each printk message line
  1207. clocksource= [GENERIC_TIME] Override the default clocksource
  1208. Override the default clocksource and use the clocksource
  1209. with the name specified.
  1210. tipar.timeout= [HW,PPT]
  1211. Set communications timeout in tenths of a second
  1212. (default 15).
  1213. tipar.delay= [HW,PPT]
  1214. Set inter-bit delay in microseconds (default 10).
  1215. tmc8xx= [HW,SCSI]
  1216. See header of drivers/scsi/seagate.c.
  1217. tmscsim= [HW,SCSI]
  1218. See comment before function dc390_setup() in
  1219. drivers/scsi/tmscsim.c.
  1220. tp720= [HW,PS2]
  1221. trix= [HW,OSS] MediaTrix AudioTrix Pro
  1222. Format:
  1223. <io>,<irq>,<dma>,<dma2>,<sb_io>,<sb_irq>,<sb_dma>,<mpu_io>,<mpu_irq>
  1224. tsdev.xres= [TS] Horizontal screen resolution.
  1225. tsdev.yres= [TS] Vertical screen resolution.
  1226. turbografx.map[2|3]= [HW,JOY]
  1227. TurboGraFX parallel port interface
  1228. Format:
  1229. <port#>,<js1>,<js2>,<js3>,<js4>,<js5>,<js6>,<js7>
  1230. See also Documentation/input/joystick-parport.txt
  1231. u14-34f= [HW,SCSI] UltraStor 14F/34F SCSI host adapter
  1232. See header of drivers/scsi/u14-34f.c.
  1233. uart401= [HW,OSS]
  1234. Format: <io>,<irq>
  1235. uart6850= [HW,OSS]
  1236. Format: <io>,<irq>
  1237. usbhid.mousepoll=
  1238. [USBHID] The interval which mice are to be polled at.
  1239. vdso= [IA-32]
  1240. vdso=1: enable VDSO (default)
  1241. vdso=0: disable VDSO mapping
  1242. video= [FB] Frame buffer configuration
  1243. See Documentation/fb/modedb.txt.
  1244. vga= [BOOT,IA-32] Select a particular video mode
  1245. See Documentation/i386/boot.txt and
  1246. Documentation/svga.txt.
  1247. Use vga=ask for menu.
  1248. This is actually a boot loader parameter; the value is
  1249. passed to the kernel using a special protocol.
  1250. vmalloc=nn[KMG] [KNL,BOOT] Forces the vmalloc area to have an exact
  1251. size of <nn>. This can be used to increase the
  1252. minimum size (128MB on x86). It can also be used to
  1253. decrease the size and leave more room for directly
  1254. mapped kernel RAM.
  1255. vmhalt= [KNL,S390] Perform z/VM CP command after system halt.
  1256. Format: <command>
  1257. vmpanic= [KNL,S390] Perform z/VM CP command after kernel panic.
  1258. Format: <command>
  1259. vmpoff= [KNL,S390] Perform z/VM CP command after power off.
  1260. Format: <command>
  1261. waveartist= [HW,OSS]
  1262. Format: <io>,<irq>,<dma>,<dma2>
  1263. wd33c93= [HW,SCSI]
  1264. See header of drivers/scsi/wd33c93.c.
  1265. wd7000= [HW,SCSI]
  1266. See header of drivers/scsi/wd7000.c.
  1267. wdt= [WDT] Watchdog
  1268. See Documentation/watchdog/watchdog.txt.
  1269. xd= [HW,XT] Original XT pre-IDE (RLL encoded) disks.
  1270. xd_geo= See header of drivers/block/xd.c.
  1271. xirc2ps_cs= [NET,PCMCIA]
  1272. Format:
  1273. <irq>,<irq_mask>,<io>,<full_duplex>,<do_sound>,<lockup_hack>[,<irq2>[,<irq3>[,<irq4>]]]
  1274. norandmaps Don't use address space randomization
  1275. Equivalent to echo 0 > /proc/sys/kernel/randomize_va_space
  1276. ______________________________________________________________________
  1277. TODO:
  1278. Add documentation for ALSA options.
  1279. Add more DRM drivers.