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