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1 Kernel Parameters
2 ~~~~~~~~~~~~~~~~~
4 The following is a consolidated list of the kernel parameters as implemented
5 (mostly) by the __setup() macro and sorted into English Dictionary order
6 (defined as ignoring all punctuation and sorting digits before letters in a
7 case insensitive manner), and with descriptions where known.
9 Module parameters for loadable modules are specified only as the
10 parameter name with optional '=' and value as appropriate, such as:
12 modprobe usbcore blinkenlights=1
14 Module parameters for modules that are built into the kernel image
15 are specified on the kernel command line with the module name plus
16 '.' plus parameter name, with '=' and value if appropriate, such as:
18 usbcore.blinkenlights=1
20 This document may not be entirely up to date and comprehensive. The command
21 "modinfo -p ${modulename}" shows a current list of all parameters of a loadable
22 module. Loadable modules, after being loaded into the running kernel, also
23 reveal their parameters in /sys/module/${modulename}/parameters/. Some of these
24 parameters may be changed at runtime by the command
25 "echo -n ${value} > /sys/module/${modulename}/parameters/${parm}".
27 The parameters listed below are only valid if certain kernel build options were
28 enabled and if respective hardware is present. The text in square brackets at
29 the beginning of each description states the restrictions within which a
30 parameter is applicable:
32 ACPI ACPI support is enabled.
33 AGP AGP (Accelerated Graphics Port) is enabled.
34 ALSA ALSA sound support is enabled.
35 APIC APIC support is enabled.
36 APM Advanced Power Management support is enabled.
37 AX25 Appropriate AX.25 support is enabled.
38 BLACKFIN Blackfin architecture is enabled.
39 DRM Direct Rendering Management support is enabled.
40 EDD BIOS Enhanced Disk Drive Services (EDD) is enabled
41 EFI EFI Partitioning (GPT) is enabled
42 EIDE EIDE/ATAPI support is enabled.
43 FB The frame buffer device is enabled.
44 HW Appropriate hardware is enabled.
45 IA-64 IA-64 architecture is enabled.
46 IOSCHED More than one I/O scheduler is enabled.
47 IP_PNP IP DHCP, BOOTP, or RARP is enabled.
48 ISAPNP ISA PnP code is enabled.
49 ISDN Appropriate ISDN support is enabled.
50 JOY Appropriate joystick support is enabled.
51 LIBATA Libata driver is enabled
52 LP Printer support is enabled.
53 LOOP Loopback device support is enabled.
54 M68k M68k architecture is enabled.
55 These options have more detailed description inside of
56 Documentation/m68k/kernel-options.txt.
57 MCA MCA bus support is enabled.
58 MDA MDA console support is enabled.
59 MOUSE Appropriate mouse support is enabled.
60 MSI Message Signaled Interrupts (PCI).
61 MTD MTD (Memory Technology Device) support is enabled.
62 NET Appropriate network support is enabled.
63 NUMA NUMA support is enabled.
64 GENERIC_TIME The generic timeofday code is enabled.
65 NFS Appropriate NFS support is enabled.
66 OSS OSS sound support is enabled.
67 PV_OPS A paravirtualized kernel is enabled.
68 PARIDE The ParIDE (parallel port IDE) subsystem is enabled.
69 PARISC The PA-RISC architecture is enabled.
70 PCI PCI bus support is enabled.
71 PCIE PCI Express support is enabled.
72 PCMCIA The PCMCIA subsystem is enabled.
73 PNP Plug & Play support is enabled.
74 PPC PowerPC architecture is enabled.
75 PPT Parallel port support is enabled.
76 PS2 Appropriate PS/2 support is enabled.
77 RAM RAM disk support is enabled.
78 ROOTPLUG The example Root Plug LSM is enabled.
79 S390 S390 architecture is enabled.
80 SCSI Appropriate SCSI support is enabled.
81 A lot of drivers has their options described inside of
82 Documentation/scsi/.
83 SECURITY Different security models are enabled.
84 SELINUX SELinux support is enabled.
85 SERIAL Serial support is enabled.
86 SH SuperH architecture is enabled.
87 SMP The kernel is an SMP kernel.
88 SPARC Sparc architecture is enabled.
89 SWSUSP Software suspend is enabled.
90 TS Appropriate touchscreen support is enabled.
91 USB USB support is enabled.
92 USBHID USB Human Interface Device support is enabled.
93 V4L Video For Linux support is enabled.
94 VGA The VGA console has been enabled.
95 VT Virtual terminal support is enabled.
96 WDT Watchdog support is enabled.
97 XT IBM PC/XT MFM hard disk support is enabled.
98 X86-32 X86-32, aka i386 architecture is enabled.
99 X86-64 X86-64 architecture is enabled.
100 More X86-64 boot options can be found in
101 Documentation/x86_64/boot-options.txt .
103 In addition, the following text indicates that the option:
105 BUGS= Relates to possible processor bugs on the said processor.
106 KNL Is a kernel start-up parameter.
107 BOOT Is a boot loader parameter.
109 Parameters denoted with BOOT are actually interpreted by the boot
110 loader, and have no meaning to the kernel directly.
111 Do not modify the syntax of boot loader parameters without extreme
112 need or coordination with <Documentation/i386/boot.txt>.
114 There are also arch-specific kernel-parameters not documented here.
115 See for example <Documentation/x86_64/boot-options.txt>.
117 Note that ALL kernel parameters listed below are CASE SENSITIVE, and that
118 a trailing = on the name of any parameter states that that parameter will
119 be entered as an environment variable, whereas its absence indicates that
120 it will appear as a kernel argument readable via /proc/cmdline by programs
121 running once the system is up.
123 The number of kernel parameters is not limited, but the length of the
124 complete command line (parameters including spaces etc.) is limited to
125 a fixed number of characters. This limit depends on the architecture
126 and is between 256 and 4096 characters. It is defined in the file
127 ./include/asm/setup.h as COMMAND_LINE_SIZE.
130 acpi= [HW,ACPI,X86-64,i386]
131 Advanced Configuration and Power Interface
132 Format: { force | off | ht | strict | noirq }
133 force -- enable ACPI if default was off
134 off -- disable ACPI if default was on
135 noirq -- do not use ACPI for IRQ routing
136 ht -- run only enough ACPI to enable Hyper Threading
137 strict -- Be less tolerant of platforms that are not
138 strictly ACPI specification compliant.
140 See also Documentation/pm.txt, pci=noacpi
142 acpi_apic_instance= [ACPI, IOAPIC]
143 Format: <int>
144 2: use 2nd APIC table, if available
145 1,0: use 1st APIC table
146 default: 0
148 acpi_sleep= [HW,ACPI] Sleep options
149 Format: { s3_bios, s3_mode }
150 See Documentation/power/video.txt
152 acpi_sci= [HW,ACPI] ACPI System Control Interrupt trigger mode
153 Format: { level | edge | high | low }
155 acpi_irq_balance [HW,ACPI]
156 ACPI will balance active IRQs
157 default in APIC mode
159 acpi_irq_nobalance [HW,ACPI]
160 ACPI will not move active IRQs (default)
161 default in PIC mode
163 acpi_irq_pci= [HW,ACPI] If irq_balance, clear listed IRQs for
164 use by PCI
165 Format: <irq>,<irq>...
167 acpi_irq_isa= [HW,ACPI] If irq_balance, mark listed IRQs used by ISA
168 Format: <irq>,<irq>...
170 acpi_no_auto_ssdt [HW,ACPI] Disable automatic loading of SSDT
172 acpi_os_name= [HW,ACPI] Tell ACPI BIOS the name of the OS
173 Format: To spoof as Windows 98: ="Microsoft Windows"
175 acpi_osi= [HW,ACPI] Modify list of supported OS interface strings
176 acpi_osi="string1" # add string1 -- only one string
177 acpi_osi="!string2" # remove built-in string2
178 acpi_osi= # disable all strings
180 acpi_serialize [HW,ACPI] force serialization of AML methods
182 acpi_skip_timer_override [HW,ACPI]
183 Recognize and ignore IRQ0/pin2 Interrupt Override.
184 For broken nForce2 BIOS resulting in XT-PIC timer.
185 acpi_use_timer_override [HW,ACPI}
186 Use timer override. For some broken Nvidia NF5 boards
187 that require a timer override, but don't have
188 HPET
190 acpi.debug_layer= [HW,ACPI]
191 Format: <int>
192 Each bit of the <int> indicates an ACPI debug layer,
193 1: enable, 0: disable. It is useful for boot time
194 debugging. After system has booted up, it can be set
195 via /sys/module/acpi/parameters/debug_layer.
196 CONFIG_ACPI_DEBUG must be enabled for this to produce any output.
197 Available bits (add the numbers together) to enable debug output
198 for specific parts of the ACPI subsystem:
199 0x01 utilities 0x02 hardware 0x04 events 0x08 tables
200 0x10 namespace 0x20 parser 0x40 dispatcher
201 0x80 executer 0x100 resources 0x200 acpica debugger
202 0x400 os services 0x800 acpica disassembler.
203 The number can be in decimal or prefixed with 0x in hex.
204 Warning: Many of these options can produce a lot of
205 output and make your system unusable. Be very careful.
207 acpi.debug_level= [HW,ACPI]
208 Format: <int>
209 Each bit of the <int> indicates an ACPI debug level,
210 1: enable, 0: disable. It is useful for boot time
211 debugging. After system has booted up, it can be set
212 via /sys/module/acpi/parameters/debug_level.
213 CONFIG_ACPI_DEBUG must be enabled for this to produce any output.
214 Available bits (add the numbers together) to enable different
215 debug output levels of the ACPI subsystem:
216 0x01 error 0x02 warn 0x04 init 0x08 debug object
217 0x10 info 0x20 init names 0x40 parse 0x80 load
218 0x100 dispatch 0x200 execute 0x400 names 0x800 operation region
219 0x1000 bfield 0x2000 tables 0x4000 values 0x8000 objects
220 0x10000 resources 0x20000 user requests 0x40000 package.
221 The number can be in decimal or prefixed with 0x in hex.
222 Warning: Many of these options can produce a lot of
223 output and make your system unusable. Be very careful.
226 acpi_fake_ecdt [HW,ACPI] Workaround failure due to BIOS lacking ECDT
228 acpi_pm_good [X86-32,X86-64]
229 Override the pmtimer bug detection: force the kernel
230 to assume that this machine's pmtimer latches its value
231 and always returns good values.
233 agp= [AGP]
234 { off | try_unsupported }
235 off: disable AGP support
236 try_unsupported: try to drive unsupported chipsets
237 (may crash computer or cause data corruption)
239 enable_timer_pin_1 [i386,x86-64]
240 Enable PIN 1 of APIC timer
241 Can be useful to work around chipset bugs
242 (in particular on some ATI chipsets).
243 The kernel tries to set a reasonable default.
245 disable_timer_pin_1 [i386,x86-64]
246 Disable PIN 1 of APIC timer
247 Can be useful to work around chipset bugs.
249 ad1848= [HW,OSS]
250 Format: <io>,<irq>,<dma>,<dma2>,<type>
252 advansys= [HW,SCSI]
253 See header of drivers/scsi/advansys.c.
255 advwdt= [HW,WDT] Advantech WDT
256 Format: <iostart>,<iostop>
258 aedsp16= [HW,OSS] Audio Excel DSP 16
259 Format: <io>,<irq>,<dma>,<mss_io>,<mpu_io>,<mpu_irq>
260 See also header of sound/oss/aedsp16.c.
262 aha152x= [HW,SCSI]
263 See Documentation/scsi/aha152x.txt.
265 aha1542= [HW,SCSI]
266 Format: <portbase>[,<buson>,<busoff>[,<dmaspeed>]]
268 aic7xxx= [HW,SCSI]
269 See Documentation/scsi/aic7xxx.txt.
271 aic79xx= [HW,SCSI]
272 See Documentation/scsi/aic79xx.txt.
274 amijoy.map= [HW,JOY] Amiga joystick support
275 Map of devices attached to JOY0DAT and JOY1DAT
276 Format: <a>,<b>
277 See also Documentation/kernel/input/joystick.txt
279 analog.map= [HW,JOY] Analog joystick and gamepad support
280 Specifies type or capabilities of an analog joystick
281 connected to one of 16 gameports
282 Format: <type1>,<type2>,..<type16>
284 apc= [HW,SPARC]
285 Power management functions (SPARCstation-4/5 + deriv.)
286 Format: noidle
287 Disable APC CPU standby support. SPARCstation-Fox does
288 not play well with APC CPU idle - disable it if you have
289 APC and your system crashes randomly.
291 apic= [APIC,i386] Advanced Programmable Interrupt Controller
292 Change the output verbosity whilst booting
293 Format: { quiet (default) | verbose | debug }
294 Change the amount of debugging information output
295 when initialising the APIC and IO-APIC components.
297 apm= [APM] Advanced Power Management
298 See header of arch/i386/kernel/apm.c.
300 applicom= [HW]
301 Format: <mem>,<irq>
303 arcrimi= [HW,NET] ARCnet - "RIM I" (entirely mem-mapped) cards
304 Format: <io>,<irq>,<nodeID>
306 ataflop= [HW,M68k]
308 atarimouse= [HW,MOUSE] Atari Mouse
310 atascsi= [HW,SCSI] Atari SCSI
312 atkbd.extra= [HW] Enable extra LEDs and keys on IBM RapidAccess,
313 EzKey and similar keyboards
315 atkbd.reset= [HW] Reset keyboard during initialization
317 atkbd.set= [HW] Select keyboard code set
318 Format: <int> (2 = AT (default), 3 = PS/2)
320 atkbd.scroll= [HW] Enable scroll wheel on MS Office and similar
321 keyboards
323 atkbd.softraw= [HW] Choose between synthetic and real raw mode
324 Format: <bool> (0 = real, 1 = synthetic (default))
326 atkbd.softrepeat= [HW]
327 Use software keyboard repeat
329 autotest [IA64]
331 baycom_epp= [HW,AX25]
332 Format: <io>,<mode>
334 baycom_par= [HW,AX25] BayCom Parallel Port AX.25 Modem
335 Format: <io>,<mode>
336 See header of drivers/net/hamradio/baycom_par.c.
338 baycom_ser_fdx= [HW,AX25]
339 BayCom Serial Port AX.25 Modem (Full Duplex Mode)
340 Format: <io>,<irq>,<mode>[,<baud>]
341 See header of drivers/net/hamradio/baycom_ser_fdx.c.
343 baycom_ser_hdx= [HW,AX25]
344 BayCom Serial Port AX.25 Modem (Half Duplex Mode)
345 Format: <io>,<irq>,<mode>
346 See header of drivers/net/hamradio/baycom_ser_hdx.c.
348 blkmtd_device= [HW,MTD]
349 blkmtd_erasesz=
350 blkmtd_ro=
351 blkmtd_bs=
352 blkmtd_count=
354 boot_delay= Milliseconds to delay each printk during boot.
355 Values larger than 10 seconds (10000) are changed to
356 no delay (0).
357 Format: integer
359 bttv.card= [HW,V4L] bttv (bt848 + bt878 based grabber cards)
360 bttv.radio= Most important insmod options are available as
361 kernel args too.
362 bttv.pll= See Documentation/video4linux/bttv/Insmod-options
363 bttv.tuner= and Documentation/video4linux/bttv/CARDLIST
365 BusLogic= [HW,SCSI]
366 See drivers/scsi/BusLogic.c, comment before function
367 BusLogic_ParseDriverOptions().
369 c101= [NET] Moxa C101 synchronous serial card
371 cachesize= [BUGS=X86-32] Override level 2 CPU cache size detection.
372 Sometimes CPU hardware bugs make them report the cache
373 size incorrectly. The kernel will attempt work arounds
374 to fix known problems, but for some CPUs it is not
375 possible to determine what the correct size should be.
376 This option provides an override for these situations.
378 capability.disable=
379 [SECURITY] Disable capabilities. This would normally
380 be used only if an alternative security model is to be
381 configured. Potentially dangerous and should only be
382 used if you are entirely sure of the consequences.
384 chandev= [HW,NET] Generic channel device initialisation
386 checkreqprot [SELINUX] Set initial checkreqprot flag value.
387 Format: { "0" | "1" }
388 See security/selinux/Kconfig help text.
389 0 -- check protection applied by kernel (includes
390 any implied execute protection).
391 1 -- check protection requested by application.
392 Default value is set via a kernel config option.
393 Value can be changed at runtime via
394 /selinux/checkreqprot.
396 clock= [BUGS=X86-32, HW] gettimeofday clocksource override.
397 [Deprecated]
398 Forces specified clocksource (if available) to be used
399 when calculating gettimeofday(). If specified
400 clocksource is not available, it defaults to PIT.
401 Format: { pit | tsc | cyclone | pmtmr }
403 clocksource= [GENERIC_TIME] Override the default clocksource
404 Format: <string>
405 Override the default clocksource and use the clocksource
406 with the name specified.
407 Some clocksource names to choose from, depending on
408 the platform:
409 [all] jiffies (this is the base, fallback clocksource)
410 [ACPI] acpi_pm
411 [ARM] imx_timer1,OSTS,netx_timer,mpu_timer2,
412 pxa_timer,timer3,32k_counter,timer0_1
413 [AVR32] avr32
414 [X86-32] pit,hpet,tsc,vmi-timer;
415 scx200_hrt on Geode; cyclone on IBM x440
416 [MIPS] MIPS
417 [PARISC] cr16
418 [S390] tod
419 [SH] SuperH
420 [SPARC64] tick
421 [X86-64] hpet,tsc
423 code_bytes [IA32] How many bytes of object code to print in an
424 oops report.
425 Range: 0 - 8192
426 Default: 64
428 disable_8254_timer
429 enable_8254_timer
430 [IA32/X86_64] Disable/Enable interrupt 0 timer routing
431 over the 8254 in addition to over the IO-APIC. The
432 kernel tries to set a sensible default.
434 hpet= [X86-32,HPET] option to disable HPET and use PIT.
435 Format: disable
437 com20020= [HW,NET] ARCnet - COM20020 chipset
438 Format:
439 <io>[,<irq>[,<nodeID>[,<backplane>[,<ckp>[,<timeout>]]]]]
441 com90io= [HW,NET] ARCnet - COM90xx chipset (IO-mapped buffers)
442 Format: <io>[,<irq>]
444 com90xx= [HW,NET]
445 ARCnet - COM90xx chipset (memory-mapped buffers)
446 Format: <io>[,<irq>[,<memstart>]]
448 condev= [HW,S390] console device
449 conmode=
451 console= [KNL] Output console device and options.
453 tty<n> Use the virtual console device <n>.
455 ttyS<n>[,options]
456 ttyUSB0[,options]
457 Use the specified serial port. The options are of
458 the form "bbbbpnf", where "bbbb" is the baud rate,
459 "p" is parity ("n", "o", or "e"), "n" is number of
460 bits, and "f" is flow control ("r" for RTS or
461 omit it). Default is "9600n8".
463 See Documentation/serial-console.txt for more
464 information. See
465 Documentation/networking/netconsole.txt for an
466 alternative.
468 uart[8250],io,<addr>[,options]
469 uart[8250],mmio,<addr>[,options]
470 Start an early, polled-mode console on the 8250/16550
471 UART at the specified I/O port or MMIO address,
472 switching to the matching ttyS device later. The
473 options are the same as for ttyS, above.
475 earlycon= [KNL] Output early console device and options.
476 uart[8250],io,<addr>[,options]
477 uart[8250],mmio,<addr>[,options]
478 Start an early, polled-mode console on the 8250/16550
479 UART at the specified I/O port or MMIO address.
480 The options are the same as for ttyS, above.
482 no_console_suspend
483 [HW] Never suspend the console
484 Disable suspending of consoles during suspend and
485 hibernate operations. Once disabled, debugging
486 messages can reach various consoles while the rest
487 of the system is being put to sleep (ie, while
488 debugging driver suspend/resume hooks). This may
489 not work reliably with all consoles, but is known
490 to work with serial and VGA consoles.
492 cpcihp_generic= [HW,PCI] Generic port I/O CompactPCI driver
493 Format:
494 <first_slot>,<last_slot>,<port>,<enum_bit>[,<debug>]
496 crashkernel=nn[KMG]@ss[KMG]
497 [KNL] Reserve a chunk of physical memory to
498 hold a kernel to switch to with kexec on panic.
500 cs4232= [HW,OSS]
501 Format: <io>,<irq>,<dma>,<dma2>,<mpuio>,<mpuirq>
503 cs89x0_dma= [HW,NET]
504 Format: <dma>
506 cs89x0_media= [HW,NET]
507 Format: { rj45 | aui | bnc }
509 cyclades= [HW,SERIAL] Cyclades multi-serial port adapter.
511 dasd= [HW,NET]
512 See header of drivers/s390/block/dasd_devmap.c.
514 db9.dev[2|3]= [HW,JOY] Multisystem joystick support via parallel port
515 (one device per port)
516 Format: <port#>,<type>
517 See also Documentation/input/joystick-parport.txt
519 debug [KNL] Enable kernel debugging (events log level).
521 debug_locks_verbose=
522 [KNL] verbose self-tests
523 Format=<0|1>
524 Print debugging info while doing the locking API
525 self-tests.
526 We default to 0 (no extra messages), setting it to
527 1 will print _a lot_ more information - normally
528 only useful to kernel developers.
530 decnet= [HW,NET]
531 Format: <area>[,<node>]
532 See also Documentation/networking/decnet.txt.
534 default_blu= [VT]
535 Format: <blue0>,<blue1>,<blue2>,...,<blue15>
536 Change the default blue palette of the console.
537 This is a 16-member array composed of values
538 ranging from 0-255.
540 default_grn= [VT]
541 Format: <green0>,<green1>,<green2>,...,<green15>
542 Change the default green palette of the console.
543 This is a 16-member array composed of values
544 ranging from 0-255.
546 default_red= [VT]
547 Format: <red0>,<red1>,<red2>,...,<red15>
548 Change the default red palette of the console.
549 This is a 16-member array composed of values
550 ranging from 0-255.
552 default_utf8= [VT]
553 Format=<0|1>
554 Set system-wide default UTF-8 mode for all tty's.
555 Default is 0 and by setting to 1, it enables UTF-8
556 mode for all newly opened or allocated terminals.
558 dhash_entries= [KNL]
559 Set number of hash buckets for dentry cache.
561 digi= [HW,SERIAL]
562 IO parameters + enable/disable command.
564 digiepca= [HW,SERIAL]
565 See drivers/char/README.epca and
566 Documentation/digiepca.txt.
568 dmascc= [HW,AX25,SERIAL] AX.25 Z80SCC driver with DMA
569 support available.
570 Format: <io_dev0>[,<io_dev1>[,..<io_dev32>]]
572 dmasound= [HW,OSS] Sound subsystem buffers
574 dscc4.setup= [NET]
576 dtc3181e= [HW,SCSI]
578 earlyprintk= [X86-32,X86-64,SH,BLACKFIN]
579 earlyprintk=vga
580 earlyprintk=serial[,ttySn[,baudrate]]
582 Append ",keep" to not disable it when the real console
583 takes over.
585 Only vga or serial at a time, not both.
587 Currently only ttyS0 and ttyS1 are supported.
589 Interaction with the standard serial driver is not
590 very good.
592 The VGA output is eventually overwritten by the real
593 console.
595 eata= [HW,SCSI]
597 ec_intr= [HW,ACPI] ACPI Embedded Controller interrupt mode
598 Format: <int>
599 0: polling mode
600 non-0: interrupt mode (default)
602 eda= [HW,PS2]
604 edb= [HW,PS2]
606 edd= [EDD]
607 Format: {"of[f]" | "sk[ipmbr]"}
608 See comment in arch/i386/boot/edd.S
610 eicon= [HW,ISDN]
611 Format: <id>,<membase>,<irq>
613 eisa_irq_edge= [PARISC,HW]
614 See header of drivers/parisc/eisa.c.
616 elanfreq= [X86-32]
617 See comment before function elanfreq_setup() in
618 arch/i386/kernel/cpu/cpufreq/elanfreq.c.
620 elevator= [IOSCHED]
621 Format: {"anticipatory" | "cfq" | "deadline" | "noop"}
622 See Documentation/block/as-iosched.txt and
623 Documentation/block/deadline-iosched.txt for details.
625 elfcorehdr= [X86-32, X86_64]
626 Specifies physical address of start of kernel core
627 image elf header. Generally kexec loader will
628 pass this option to capture kernel.
629 See Documentation/kdump/kdump.txt for details.
631 enforcing [SELINUX] Set initial enforcing status.
632 Format: {"0" | "1"}
633 See security/selinux/Kconfig help text.
634 0 -- permissive (log only, no denials).
635 1 -- enforcing (deny and log).
636 Default value is 0.
637 Value can be changed at runtime via /selinux/enforce.
639 es1371= [HW,OSS]
640 Format: <spdif>,[<nomix>,[<amplifier>]]
641 See also header of sound/oss/es1371.c.
643 ether= [HW,NET] Ethernet cards parameters
644 This option is obsoleted by the "netdev=" option, which
645 has equivalent usage. See its documentation for details.
647 eurwdt= [HW,WDT] Eurotech CPU-1220/1410 onboard watchdog.
648 Format: <io>[,<irq>]
650 failslab=
651 fail_page_alloc=
652 fail_make_request=[KNL]
653 General fault injection mechanism.
654 Format: <interval>,<probability>,<space>,<times>
655 See also /Documentation/fault-injection/.
657 fd_mcs= [HW,SCSI]
658 See header of drivers/scsi/fd_mcs.c.
660 fdomain= [HW,SCSI]
661 See header of drivers/scsi/fdomain.c.
663 floppy= [HW]
664 See Documentation/floppy.txt.
666 gamecon.map[2|3]=
667 [HW,JOY] Multisystem joystick and NES/SNES/PSX pad
668 support via parallel port (up to 5 devices per port)
669 Format: <port#>,<pad1>,<pad2>,<pad3>,<pad4>,<pad5>
670 See also Documentation/input/joystick-parport.txt
672 gamma= [HW,DRM]
674 gdth= [HW,SCSI]
675 See header of drivers/scsi/gdth.c.
677 gpt [EFI] Forces disk with valid GPT signature but
678 invalid Protective MBR to be treated as GPT.
680 gvp11= [HW,SCSI]
682 hashdist= [KNL,NUMA] Large hashes allocated during boot
683 are distributed across NUMA nodes. Defaults on
684 for IA-64, off otherwise.
685 Format: 0 | 1 (for off | on)
687 hcl= [IA-64] SGI's Hardware Graph compatibility layer
689 hd= [EIDE] (E)IDE hard drive subsystem geometry
690 Format: <cyl>,<head>,<sect>
692 hd?= [HW] (E)IDE subsystem
693 hd?lun= See Documentation/ide.txt.
695 highmem=nn[KMG] [KNL,BOOT] forces the highmem zone to have an exact
696 size of <nn>. This works even on boxes that have no
697 highmem otherwise. This also works to reduce highmem
698 size on bigger boxes.
700 highres= [KNL] Enable/disable high resolution timer mode.
701 Valid parameters: "on", "off"
702 Default: "on"
704 hisax= [HW,ISDN]
705 See Documentation/isdn/README.HiSax.
707 hugepages= [HW,X86-32,IA-64] Maximal number of HugeTLB pages.
709 i8042.direct [HW] Put keyboard port into non-translated mode
710 i8042.dumbkbd [HW] Pretend that controller can only read data from
711 keyboard and cannot control its state
712 (Don't attempt to blink the leds)
713 i8042.noaux [HW] Don't check for auxiliary (== mouse) port
714 i8042.nokbd [HW] Don't check/create keyboard port
715 i8042.nomux [HW] Don't check presence of an active multiplexing
716 controller
717 i8042.nopnp [HW] Don't use ACPIPnP / PnPBIOS to discover KBD/AUX
718 controllers
719 i8042.panicblink=
720 [HW] Frequency with which keyboard LEDs should blink
721 when kernel panics (default is 0.5 sec)
722 i8042.reset [HW] Reset the controller during init and cleanup
723 i8042.unlock [HW] Unlock (ignore) the keylock
725 i810= [HW,DRM]
727 i8k.ignore_dmi [HW] Continue probing hardware even if DMI data
728 indicates that the driver is running on unsupported
729 hardware.
730 i8k.force [HW] Activate i8k driver even if SMM BIOS signature
731 does not match list of supported models.
732 i8k.power_status
733 [HW] Report power status in /proc/i8k
734 (disabled by default)
735 i8k.restricted [HW] Allow controlling fans only if SYS_ADMIN
736 capability is set.
738 ibmmcascsi= [HW,MCA,SCSI] IBM MicroChannel SCSI adapter
739 See Documentation/mca.txt.
741 icn= [HW,ISDN]
742 Format: <io>[,<membase>[,<icn_id>[,<icn_id2>]]]
744 ide= [HW] (E)IDE subsystem
745 Format: ide=nodma or ide=doubler or ide=reverse
746 See Documentation/ide.txt.
748 ide?= [HW] (E)IDE subsystem
749 Format: ide?=noprobe or chipset specific parameters.
750 See Documentation/ide.txt.
752 idebus= [HW] (E)IDE subsystem - VLB/PCI bus speed
753 See Documentation/ide.txt.
755 idle= [X86]
756 Format: idle=poll or idle=mwait
757 Poll forces a polling idle loop that can slightly improves the performance
758 of waking up a idle CPU, but will use a lot of power and make the system
759 run hot. Not recommended.
760 idle=mwait. On systems which support MONITOR/MWAIT but the kernel chose
761 to not use it because it doesn't save as much power as a normal idle
762 loop use the MONITOR/MWAIT idle loop anyways. Performance should be the same
763 as idle=poll.
765 ignore_loglevel [KNL]
766 Ignore loglevel setting - this will print /all/
767 kernel messages to the console. Useful for debugging.
769 ihash_entries= [KNL]
770 Set number of hash buckets for inode cache.
772 in2000= [HW,SCSI]
773 See header of drivers/scsi/in2000.c.
775 init= [KNL]
776 Format: <full_path>
777 Run specified binary instead of /sbin/init as init
778 process.
780 initcall_debug [KNL] Trace initcalls as they are executed. Useful
781 for working out where the kernel is dying during
782 startup.
784 initrd= [BOOT] Specify the location of the initial ramdisk
786 inport.irq= [HW] Inport (ATI XL and Microsoft) busmouse driver
787 Format: <irq>
789 inttest= [IA64]
791 io7= [HW] IO7 for Marvel based alpha systems
792 See comment before marvel_specify_io7 in
793 arch/alpha/kernel/core_marvel.c.
795 ip= [IP_PNP]
796 See Documentation/nfsroot.txt.
798 ip2= [HW] Set IO/IRQ pairs for up to 4 IntelliPort boards
799 See comment before ip2_setup() in
800 drivers/char/ip2/ip2base.c.
802 ips= [HW,SCSI] Adaptec / IBM ServeRAID controller
803 See header of drivers/scsi/ips.c.
805 ports= [IP_VS_FTP] IPVS ftp helper module
806 Default is 21.
807 Up to 8 (IP_VS_APP_MAX_PORTS) ports
808 may be specified.
809 Format: <port>,<port>....
811 irqfixup [HW]
812 When an interrupt is not handled search all handlers
813 for it. Intended to get systems with badly broken
814 firmware running.
816 irqpoll [HW]
817 When an interrupt is not handled search all handlers
818 for it. Also check all handlers each timer
819 interrupt. Intended to get systems with badly broken
820 firmware running.
822 isapnp= [ISAPNP]
823 Format: <RDP>,<reset>,<pci_scan>,<verbosity>
825 isolcpus= [KNL,SMP] Isolate CPUs from the general scheduler.
826 Format:
827 <cpu number>,...,<cpu number>
828 or
829 <cpu number>-<cpu number> (must be a positive range in ascending order)
830 or a mixture
831 <cpu number>,...,<cpu number>-<cpu number>
832 This option can be used to specify one or more CPUs
833 to isolate from the general SMP balancing and scheduling
834 algorithms. The only way to move a process onto or off
835 an "isolated" CPU is via the CPU affinity syscalls.
836 <cpu number> begins at 0 and the maximum value is
837 "number of CPUs in system - 1".
839 This option is the preferred way to isolate CPUs. The
840 alternative -- manually setting the CPU mask of all
841 tasks in the system -- can cause problems and
842 suboptimal load balancer performance.
844 iucv= [HW,NET]
846 js= [HW,JOY] Analog joystick
847 See Documentation/input/joystick.txt.
849 kernelcore=nn[KMG] [KNL,X86-32,IA-64,PPC,X86-64] This parameter
850 specifies the amount of memory usable by the kernel
851 for non-movable allocations. The requested amount is
852 spread evenly throughout all nodes in the system. The
853 remaining memory in each node is used for Movable
854 pages. In the event, a node is too small to have both
855 kernelcore and Movable pages, kernelcore pages will
856 take priority and other nodes will have a larger number
857 of kernelcore pages. The Movable zone is used for the
858 allocation of pages that may be reclaimed or moved
859 by the page migration subsystem. This means that
860 HugeTLB pages may not be allocated from this zone.
861 Note that allocations like PTEs-from-HighMem still
862 use the HighMem zone if it exists, and the Normal
863 zone if it does not.
865 movablecore=nn[KMG] [KNL,X86-32,IA-64,PPC,X86-64] This parameter
866 is similar to kernelcore except it specifies the
867 amount of memory used for migratable allocations.
868 If both kernelcore and movablecore is specified,
869 then kernelcore will be at *least* the specified
870 value but may be more. If movablecore on its own
871 is specified, the administrator must be careful
872 that the amount of memory usable for all allocations
873 is not too small.
875 keepinitrd [HW,ARM]
877 kstack=N [X86-32,X86-64] Print N words from the kernel stack
878 in oops dumps.
880 l2cr= [PPC]
882 lapic [X86-32,APIC] Enable the local APIC even if BIOS
883 disabled it.
885 lapic_timer_c2_ok [X86-32,x86-64,APIC] trust the local apic timer in
886 C2 power state.
888 lasi= [HW,SCSI] PARISC LASI driver for the 53c700 chip
889 Format: addr:<io>,irq:<irq>
891 libata.noacpi [LIBATA] Disables use of ACPI in libata suspend/resume
892 when set.
893 Format: <int>
895 load_ramdisk= [RAM] List of ramdisks to load from floppy
896 See Documentation/ramdisk.txt.
898 lockd.nlm_grace_period=P [NFS] Assign grace period.
899 Format: <integer>
901 lockd.nlm_tcpport=N [NFS] Assign TCP port.
902 Format: <integer>
904 lockd.nlm_timeout=T [NFS] Assign timeout value.
905 Format: <integer>
907 lockd.nlm_udpport=M [NFS] Assign UDP port.
908 Format: <integer>
910 logibm.irq= [HW,MOUSE] Logitech Bus Mouse Driver
911 Format: <irq>
913 loglevel= All Kernel Messages with a loglevel smaller than the
914 console loglevel will be printed to the console. It can
915 also be changed with klogd or other programs. The
916 loglevels are defined as follows:
918 0 (KERN_EMERG) system is unusable
919 1 (KERN_ALERT) action must be taken immediately
920 2 (KERN_CRIT) critical conditions
921 3 (KERN_ERR) error conditions
922 4 (KERN_WARNING) warning conditions
923 5 (KERN_NOTICE) normal but significant condition
924 6 (KERN_INFO) informational
925 7 (KERN_DEBUG) debug-level messages
927 log_buf_len=n Sets the size of the printk ring buffer, in bytes.
928 Format: { n | nk | nM }
929 n must be a power of two. The default size
930 is set in the kernel config file.
932 logo.nologo [FB] Disables display of the built-in Linux logo.
933 This may be used to provide more screen space for
934 kernel log messages and is useful when debugging
935 kernel boot problems.
937 lp=0 [LP] Specify parallel ports to use, e.g,
938 lp=port[,port...] lp=none,parport0 (lp0 not configured, lp1 uses
939 lp=reset first parallel port). 'lp=0' disables the
940 lp=auto printer driver. 'lp=reset' (which can be
941 specified in addition to the ports) causes
942 attached printers to be reset. Using
943 lp=port1,port2,... specifies the parallel ports
944 to associate lp devices with, starting with
945 lp0. A port specification may be 'none' to skip
946 that lp device, or a parport name such as
947 'parport0'. Specifying 'lp=auto' instead of a
948 port specification list means that device IDs
949 from each port should be examined, to see if
950 an IEEE 1284-compliant printer is attached; if
951 so, the driver will manage that printer.
952 See also header of drivers/char/lp.c.
954 lpj=n [KNL]
955 Sets loops_per_jiffy to given constant, thus avoiding
956 time-consuming boot-time autodetection (up to 250 ms per
957 CPU). 0 enables autodetection (default). To determine
958 the correct value for your kernel, boot with normal
959 autodetection and see what value is printed. Note that
960 on SMP systems the preset will be applied to all CPUs,
961 which is likely to cause problems if your CPUs need
962 significantly divergent settings. An incorrect value
963 will cause delays in the kernel to be wrong, leading to
964 unpredictable I/O errors and other breakage. Although
965 unlikely, in the extreme case this might damage your
966 hardware.
968 ltpc= [NET]
969 Format: <io>,<irq>,<dma>
971 mac5380= [HW,SCSI] Format:
972 <can_queue>,<cmd_per_lun>,<sg_tablesize>,<hostid>,<use_tags>
974 mac53c9x= [HW,SCSI] Format:
975 <num_esps>,<disconnect>,<nosync>,<can_queue>,<cmd_per_lun>,<sg_tablesize>,<hostid>,<use_tags>
977 machvec= [IA64] Force the use of a particular machine-vector
978 (machvec) in a generic kernel.
979 Example: machvec=hpzx1_swiotlb
981 max_loop= [LOOP] Maximum number of loopback devices that can
982 be mounted
983 Format: <1-256>
985 maxcpus= [SMP] Maximum number of processors that an SMP kernel
986 should make use of. maxcpus=n : n >= 0 limits the
987 kernel to using 'n' processors. n=0 is a special case,
988 it is equivalent to "nosmp", which also disables
989 the IO APIC.
991 max_addr=[KMG] [KNL,BOOT,ia64] All physical memory greater than or
992 equal to this physical address is ignored.
994 max_luns= [SCSI] Maximum number of LUNs to probe.
995 Should be between 1 and 2^32-1.
997 max_report_luns=
998 [SCSI] Maximum number of LUNs received.
999 Should be between 1 and 16384.
1001 mca-pentium [BUGS=X86-32]
1003 mcatest= [IA-64]
1005 mce [X86-32] Machine Check Exception
1007 mce=option [X86-64] See Documentation/x86_64/boot-options.txt
1009 md= [HW] RAID subsystems devices and level
1010 See Documentation/md.txt.
1012 mdacon= [MDA]
1013 Format: <first>,<last>
1014 Specifies range of consoles to be captured by the MDA.
1016 mem=nn[KMG] [KNL,BOOT] Force usage of a specific amount of memory
1017 Amount of memory to be used when the kernel is not able
1018 to see the whole system memory or for test.
1019 [X86-32] Use together with memmap= to avoid physical
1020 address space collisions. Without memmap= PCI devices
1021 could be placed at addresses belonging to unused RAM.
1023 mem=nopentium [BUGS=X86-32] Disable usage of 4MB pages for kernel
1024 memory.
1026 memmap=exactmap [KNL,X86-32,X86_64] Enable setting of an exact
1027 E820 memory map, as specified by the user.
1028 Such memmap=exactmap lines can be constructed based on
1029 BIOS output or other requirements. See the memmap=nn@ss
1030 option description.
1032 memmap=nn[KMG]@ss[KMG]
1033 [KNL] Force usage of a specific region of memory
1034 Region of memory to be used, from ss to ss+nn.
1036 memmap=nn[KMG]#ss[KMG]
1037 [KNL,ACPI] Mark specific memory as ACPI data.
1038 Region of memory to be used, from ss to ss+nn.
1040 memmap=nn[KMG]$ss[KMG]
1041 [KNL,ACPI] Mark specific memory as reserved.
1042 Region of memory to be used, from ss to ss+nn.
1044 meye.*= [HW] Set MotionEye Camera parameters
1045 See Documentation/video4linux/meye.txt.
1047 mfgpt_irq= [IA-32] Specify the IRQ to use for the
1048 Multi-Function General Purpose Timers on AMD Geode
1049 platforms.
1051 mga= [HW,DRM]
1053 mousedev.tap_time=
1054 [MOUSE] Maximum time between finger touching and
1055 leaving touchpad surface for touch to be considered
1056 a tap and be reported as a left button click (for
1057 touchpads working in absolute mode only).
1058 Format: <msecs>
1059 mousedev.xres= [MOUSE] Horizontal screen resolution, used for devices
1060 reporting absolute coordinates, such as tablets
1061 mousedev.yres= [MOUSE] Vertical screen resolution, used for devices
1062 reporting absolute coordinates, such as tablets
1064 mpu401= [HW,OSS]
1065 Format: <io>,<irq>
1067 MTD_Partition= [MTD]
1068 Format: <name>,<region-number>,<size>,<offset>
1070 MTD_Region= [MTD] Format:
1071 <name>,<region-number>[,<base>,<size>,<buswidth>,<altbuswidth>]
1073 mtdparts= [MTD]
1074 See drivers/mtd/cmdlinepart.c.
1076 mtouchusb.raw_coordinates=
1077 [HW] Make the MicroTouch USB driver use raw coordinates
1078 ('y', default) or cooked coordinates ('n')
1080 n2= [NET] SDL Inc. RISCom/N2 synchronous serial card
1082 NCR_D700= [HW,SCSI]
1083 See header of drivers/scsi/NCR_D700.c.
1085 ncr5380= [HW,SCSI]
1087 ncr53c400= [HW,SCSI]
1089 ncr53c400a= [HW,SCSI]
1091 ncr53c406a= [HW,SCSI]
1093 ncr53c8xx= [HW,SCSI]
1095 netdev= [NET] Network devices parameters
1096 Format: <irq>,<io>,<mem_start>,<mem_end>,<name>
1097 Note that mem_start is often overloaded to mean
1098 something different and driver-specific.
1099 This usage is only documented in each driver source
1100 file if at all.
1102 nfsaddrs= [NFS]
1103 See Documentation/nfsroot.txt.
1105 nfsroot= [NFS] nfs root filesystem for disk-less boxes.
1106 See Documentation/nfsroot.txt.
1108 nfs.callback_tcpport=
1109 [NFS] set the TCP port on which the NFSv4 callback
1110 channel should listen.
1112 nfs.idmap_cache_timeout=
1113 [NFS] set the maximum lifetime for idmapper cache
1114 entries.
1116 nfs.enable_ino64=
1117 [NFS] enable 64-bit inode numbers.
1118 If zero, the NFS client will fake up a 32-bit inode
1119 number for the readdir() and stat() syscalls instead
1120 of returning the full 64-bit number.
1121 The default is to return 64-bit inode numbers.
1123 nmi_watchdog= [KNL,BUGS=X86-32] Debugging features for SMP kernels
1125 no387 [BUGS=X86-32] Tells the kernel to use the 387 maths
1126 emulation library even if a 387 maths coprocessor
1127 is present.
1129 noaliencache [MM, NUMA, SLAB] Disables the allocation of alien
1130 caches in the slab allocator. Saves per-node memory,
1131 but will impact performance.
1133 noalign [KNL,ARM]
1135 noapic [SMP,APIC] Tells the kernel to not make use of any
1136 IOAPICs that may be present in the system.
1138 noasync [HW,M68K] Disables async and sync negotiation for
1139 all devices.
1141 nobats [PPC] Do not use BATs for mapping kernel lowmem
1142 on "Classic" PPC cores.
1144 nocache [ARM]
1146 nodelayacct [KNL] Disable per-task delay accounting
1148 nodisconnect [HW,SCSI,M68K] Disables SCSI disconnects.
1150 noexec [IA-64]
1152 noexec [X86-32,X86-64]
1153 noexec=on: enable non-executable mappings (default)
1154 noexec=off: disable nn-executable mappings
1156 nofxsr [BUGS=X86-32] Disables x86 floating point extended
1157 register save and restore. The kernel will only save
1158 legacy floating-point registers on task switch.
1160 nohlt [BUGS=ARM]
1162 no-hlt [BUGS=X86-32] Tells the kernel that the hlt
1163 instruction doesn't work correctly and not to
1164 use it.
1166 nohalt [IA-64] Tells the kernel not to use the power saving
1167 function PAL_HALT_LIGHT when idle. This increases
1168 power-consumption. On the positive side, it reduces
1169 interrupt wake-up latency, which may improve performance
1170 in certain environments such as networked servers or
1171 real-time systems.
1173 nohz= [KNL] Boottime enable/disable dynamic ticks
1174 Valid arguments: on, off
1175 Default: on
1177 noirqbalance [X86-32,SMP,KNL] Disable kernel irq balancing
1179 noirqdebug [X86-32] Disables the code which attempts to detect and
1180 disable unhandled interrupt sources.
1182 no_timer_check [X86-32,X86_64,APIC] Disables the code which tests for
1183 broken timer IRQ sources.
1185 noisapnp [ISAPNP] Disables ISA PnP code.
1187 noinitrd [RAM] Tells the kernel not to load any configured
1188 initial RAM disk.
1190 nointroute [IA-64]
1192 nojitter [IA64] Disables jitter checking for ITC timers.
1194 nolapic [X86-32,APIC] Do not enable or use the local APIC.
1196 nolapic_timer [X86-32,APIC] Do not use the local APIC timer.
1198 noltlbs [PPC] Do not use large page/tlb entries for kernel
1199 lowmem mapping on PPC40x.
1201 nomca [IA-64] Disable machine check abort handling
1203 nomce [X86-32] Machine Check Exception
1205 nomfgpt [X86-32] Disable Multi-Function General Purpose
1206 Timer usage (for AMD Geode machines).
1208 noreplace-paravirt [X86-32,PV_OPS] Don't patch paravirt_ops
1210 noreplace-smp [X86-32,SMP] Don't replace SMP instructions
1211 with UP alternatives
1213 noresidual [PPC] Don't use residual data on PReP machines.
1215 noresume [SWSUSP] Disables resume and restores original swap
1216 space.
1218 no-scroll [VGA] Disables scrollback.
1219 This is required for the Braillex ib80-piezo Braille
1220 reader made by F.H. Papenmeier (Germany).
1222 nosbagart [IA-64]
1224 nosep [BUGS=X86-32] Disables x86 SYSENTER/SYSEXIT support.
1226 nosmp [SMP] Tells an SMP kernel to act as a UP kernel,
1227 and disable the IO APIC. legacy for "maxcpus=0".
1229 nosoftlockup [KNL] Disable the soft-lockup detector.
1231 nosync [HW,M68K] Disables sync negotiation for all devices.
1233 notsc [BUGS=X86-32] Disable Time Stamp Counter
1235 nousb [USB] Disable the USB subsystem
1237 nowb [ARM]
1239 numa_zonelist_order= [KNL, BOOT] Select zonelist order for NUMA.
1240 one of ['zone', 'node', 'default'] can be specified
1241 This can be set from sysctl after boot.
1242 See Documentation/sysctl/vm.txt for details.
1244 nr_uarts= [SERIAL] maximum number of UARTs to be registered.
1246 opl3= [HW,OSS]
1247 Format: <io>
1249 oprofile.timer= [HW]
1250 Use timer interrupt instead of performance counters
1252 osst= [HW,SCSI] SCSI Tape Driver
1253 Format: <buffer_size>,<write_threshold>
1254 See also Documentation/scsi/st.txt.
1256 panic= [KNL] Kernel behaviour on panic
1257 Format: <timeout>
1259 parkbd.port= [HW] Parallel port number the keyboard adapter is
1260 connected to, default is 0.
1261 Format: <parport#>
1262 parkbd.mode= [HW] Parallel port keyboard adapter mode of operation,
1263 0 for XT, 1 for AT (default is AT).
1264 Format: <mode>
1266 parport= [HW,PPT] Specify parallel ports. 0 disables.
1267 Format: { 0 | auto | 0xBBB[,IRQ[,DMA]] }
1268 Use 'auto' to force the driver to use any
1269 IRQ/DMA settings detected (the default is to
1270 ignore detected IRQ/DMA settings because of
1271 possible conflicts). You can specify the base
1272 address, IRQ, and DMA settings; IRQ and DMA
1273 should be numbers, or 'auto' (for using detected
1274 settings on that particular port), or 'nofifo'
1275 (to avoid using a FIFO even if it is detected).
1276 Parallel ports are assigned in the order they
1277 are specified on the command line, starting
1278 with parport0.
1280 parport_init_mode= [HW,PPT]
1281 Configure VIA parallel port to operate in
1282 a specific mode. This is necessary on Pegasos
1283 computer where firmware has no options for setting
1284 up parallel port mode and sets it to spp.
1285 Currently this function knows 686a and 8231 chips.
1286 Format: [spp|ps2|epp|ecp|ecpepp]
1288 pas2= [HW,OSS] Format:
1289 <io>,<irq>,<dma>,<dma16>,<sb_io>,<sb_irq>,<sb_dma>,<sb_dma16>
1291 pas16= [HW,SCSI]
1292 See header of drivers/scsi/pas16.c.
1294 pause_on_oops=
1295 Halt all CPUs after the first oops has been printed for
1296 the specified number of seconds. This is to be used if
1297 your oopses keep scrolling off the screen.
1299 pcbit= [HW,ISDN]
1301 pcd. [PARIDE]
1302 See header of drivers/block/paride/pcd.c.
1303 See also Documentation/paride.txt.
1305 pci=option[,option...] [PCI] various PCI subsystem options:
1306 off [X86-32] don't probe for the PCI bus
1307 bios [X86-32] force use of PCI BIOS, don't access
1308 the hardware directly. Use this if your machine
1309 has a non-standard PCI host bridge.
1310 nobios [X86-32] disallow use of PCI BIOS, only direct
1311 hardware access methods are allowed. Use this
1312 if you experience crashes upon bootup and you
1313 suspect they are caused by the BIOS.
1314 conf1 [X86-32] Force use of PCI Configuration
1315 Mechanism 1.
1316 conf2 [X86-32] Force use of PCI Configuration
1317 Mechanism 2.
1318 noaer [PCIE] If the PCIEAER kernel config parameter is
1319 enabled, this kernel boot option can be used to
1320 disable the use of PCIE advanced error reporting.
1321 nodomains [PCI] Disable support for multiple PCI
1322 root domains (aka PCI segments, in ACPI-speak).
1323 nommconf [X86-32,X86_64] Disable use of MMCONFIG for PCI
1324 Configuration
1325 nomsi [MSI] If the PCI_MSI kernel config parameter is
1326 enabled, this kernel boot option can be used to
1327 disable the use of MSI interrupts system-wide.
1328 nosort [X86-32] Don't sort PCI devices according to
1329 order given by the PCI BIOS. This sorting is
1330 done to get a device order compatible with
1331 older kernels.
1332 biosirq [X86-32] Use PCI BIOS calls to get the interrupt
1333 routing table. These calls are known to be buggy
1334 on several machines and they hang the machine
1335 when used, but on other computers it's the only
1336 way to get the interrupt routing table. Try
1337 this option if the kernel is unable to allocate
1338 IRQs or discover secondary PCI buses on your
1339 motherboard.
1340 rom [X86-32] Assign address space to expansion ROMs.
1341 Use with caution as certain devices share
1342 address decoders between ROMs and other
1343 resources.
1344 irqmask=0xMMMM [X86-32] Set a bit mask of IRQs allowed to be
1345 assigned automatically to PCI devices. You can
1346 make the kernel exclude IRQs of your ISA cards
1347 this way.
1348 pirqaddr=0xAAAAA [X86-32] Specify the physical address
1349 of the PIRQ table (normally generated
1350 by the BIOS) if it is outside the
1351 F0000h-100000h range.
1352 lastbus=N [X86-32] Scan all buses thru bus #N. Can be
1353 useful if the kernel is unable to find your
1354 secondary buses and you want to tell it
1355 explicitly which ones they are.
1356 assign-busses [X86-32] Always assign all PCI bus
1357 numbers ourselves, overriding
1358 whatever the firmware may have done.
1359 usepirqmask [X86-32] Honor the possible IRQ mask stored
1360 in the BIOS $PIR table. This is needed on
1361 some systems with broken BIOSes, notably
1362 some HP Pavilion N5400 and Omnibook XE3
1363 notebooks. This will have no effect if ACPI
1364 IRQ routing is enabled.
1365 noacpi [X86-32] Do not use ACPI for IRQ routing
1366 or for PCI scanning.
1367 use_crs [X86-32] Use _CRS for PCI resource
1368 allocation.
1369 routeirq Do IRQ routing for all PCI devices.
1370 This is normally done in pci_enable_device(),
1371 so this option is a temporary workaround
1372 for broken drivers that don't call it.
1373 firmware [ARM] Do not re-enumerate the bus but instead
1374 just use the configuration from the
1375 bootloader. This is currently used on
1376 IXP2000 systems where the bus has to be
1377 configured a certain way for adjunct CPUs.
1378 noearly [X86] Don't do any early type 1 scanning.
1379 This might help on some broken boards which
1380 machine check when some devices' config space
1381 is read. But various workarounds are disabled
1382 and some IOMMU drivers will not work.
1383 bfsort Sort PCI devices into breadth-first order.
1384 This sorting is done to get a device
1385 order compatible with older (<= 2.4) kernels.
1386 nobfsort Don't sort PCI devices into breadth-first order.
1387 cbiosize=nn[KMG] The fixed amount of bus space which is
1388 reserved for the CardBus bridge's IO window.
1389 The default value is 256 bytes.
1390 cbmemsize=nn[KMG] The fixed amount of bus space which is
1391 reserved for the CardBus bridge's memory
1392 window. The default value is 64 megabytes.
1394 pcmv= [HW,PCMCIA] BadgePAD 4
1396 pd. [PARIDE]
1397 See Documentation/paride.txt.
1399 pdcchassis= [PARISC,HW] Disable/Enable PDC Chassis Status codes at
1400 boot time.
1401 Format: { 0 | 1 }
1402 See arch/parisc/kernel/pdc_chassis.c
1404 pf. [PARIDE]
1405 See Documentation/paride.txt.
1407 pg. [PARIDE]
1408 See Documentation/paride.txt.
1410 pirq= [SMP,APIC] Manual mp-table setup
1411 See Documentation/i386/IO-APIC.txt.
1413 plip= [PPT,NET] Parallel port network link
1414 Format: { parport<nr> | timid | 0 }
1415 See also Documentation/parport.txt.
1417 pnpacpi= [ACPI]
1418 { off }
1420 pnpbios= [ISAPNP]
1421 { on | off | curr | res | no-curr | no-res }
1423 pnp_reserve_irq=
1424 [ISAPNP] Exclude IRQs for the autoconfiguration
1426 pnp_reserve_dma=
1427 [ISAPNP] Exclude DMAs for the autoconfiguration
1429 pnp_reserve_io= [ISAPNP] Exclude I/O ports for the autoconfiguration
1430 Ranges are in pairs (I/O port base and size).
1432 pnp_reserve_mem=
1433 [ISAPNP] Exclude memory regions for the
1434 autoconfiguration.
1435 Ranges are in pairs (memory base and size).
1437 print-fatal-signals=
1438 [KNL] debug: print fatal signals
1439 print-fatal-signals=1: print segfault info to
1440 the kernel console.
1441 default: off.
1443 printk.time= Show timing data prefixed to each printk message line
1444 Format: <bool> (1/Y/y=enable, 0/N/n=disable)
1446 profile= [KNL] Enable kernel profiling via /proc/profile
1447 Format: [schedule,]<number>
1448 Param: "schedule" - profile schedule points.
1449 Param: <number> - step/bucket size as a power of 2 for
1450 statistical time based profiling.
1451 Param: "sleep" - profile D-state sleeping (millisecs)
1453 processor.max_cstate= [HW,ACPI]
1454 Limit processor to maximum C-state
1455 max_cstate=9 overrides any DMI blacklist limit.
1457 processor.nocst [HW,ACPI]
1458 Ignore the _CST method to determine C-states,
1459 instead using the legacy FADT method
1461 prompt_ramdisk= [RAM] List of RAM disks to prompt for floppy disk
1462 before loading.
1463 See Documentation/ramdisk.txt.
1465 psmouse.proto= [HW,MOUSE] Highest PS2 mouse protocol extension to
1466 probe for; one of (bare|imps|exps|lifebook|any).
1467 psmouse.rate= [HW,MOUSE] Set desired mouse report rate, in reports
1468 per second.
1469 psmouse.resetafter= [HW,MOUSE]
1470 Try to reset the device after so many bad packets
1471 (0 = never).
1472 psmouse.resolution=
1473 [HW,MOUSE] Set desired mouse resolution, in dpi.
1474 psmouse.smartscroll=
1475 [HW,MOUSE] Controls Logitech smartscroll autorepeat.
1476 0 = disabled, 1 = enabled (default).
1478 pss= [HW,OSS] Personal Sound System (ECHO ESC614)
1479 Format:
1480 <io>,<mss_io>,<mss_irq>,<mss_dma>,<mpu_io>,<mpu_irq>
1482 pt. [PARIDE]
1483 See Documentation/paride.txt.
1485 pty.legacy_count=
1486 [KNL] Number of legacy pty's. Overwrites compiled-in
1487 default number.
1489 quiet [KNL] Disable most log messages
1491 r128= [HW,DRM]
1493 raid= [HW,RAID]
1494 See Documentation/md.txt.
1496 ramdisk_blocksize= [RAM]
1497 See Documentation/ramdisk.txt.
1499 ramdisk_size= [RAM] Sizes of RAM disks in kilobytes
1500 See Documentation/ramdisk.txt.
1502 rcu.blimit= [KNL,BOOT] Set maximum number of finished
1503 RCU callbacks to process in one batch.
1505 rcu.qhimark= [KNL,BOOT] Set threshold of queued
1506 RCU callbacks over which batch limiting is disabled.
1508 rcu.qlowmark= [KNL,BOOT] Set threshold of queued
1509 RCU callbacks below which batch limiting is re-enabled.
1511 rdinit= [KNL]
1512 Format: <full_path>
1513 Run specified binary instead of /init from the ramdisk,
1514 used for early userspace startup. See initrd.
1516 reboot= [BUGS=X86-32,BUGS=ARM,BUGS=IA-64] Rebooting mode
1517 Format: <reboot_mode>[,<reboot_mode2>[,...]]
1518 See arch/*/kernel/reboot.c or arch/*/kernel/process.c
1520 reserve= [KNL,BUGS] Force the kernel to ignore some iomem area
1522 reservetop= [X86-32]
1523 Format: nn[KMG]
1524 Reserves a hole at the top of the kernel virtual
1525 address space.
1527 reset_devices [KNL] Force drivers to reset the underlying device
1528 during initialization.
1530 resume= [SWSUSP]
1531 Specify the partition device for software suspend
1533 resume_offset= [SWSUSP]
1534 Specify the offset from the beginning of the partition
1535 given by "resume=" at which the swap header is located,
1536 in <PAGE_SIZE> units (needed only for swap files).
1537 See Documentation/power/swsusp-and-swap-files.txt
1539 retain_initrd [RAM] Keep initrd memory after extraction
1541 rhash_entries= [KNL,NET]
1542 Set number of hash buckets for route cache
1544 riscom8= [HW,SERIAL]
1545 Format: <io_board1>[,<io_board2>[,...<io_boardN>]]
1547 ro [KNL] Mount root device read-only on boot
1549 root= [KNL] Root filesystem
1551 rootdelay= [KNL] Delay (in seconds) to pause before attempting to
1552 mount the root filesystem
1554 rootflags= [KNL] Set root filesystem mount option string
1556 rootfstype= [KNL] Set root filesystem type
1558 rootwait [KNL] Wait (indefinitely) for root device to show up.
1559 Useful for devices that are detected asynchronously
1560 (e.g. USB and MMC devices).
1562 root_plug.vendor_id=
1563 [ROOTPLUG] Override the default vendor ID
1565 root_plug.product_id=
1566 [ROOTPLUG] Override the default product ID
1568 root_plug.debug=
1569 [ROOTPLUG] Enable debugging output
1571 rw [KNL] Mount root device read-write on boot
1573 S [KNL] Run init in single mode
1575 sa1100ir [NET]
1576 See drivers/net/irda/sa1100_ir.c.
1578 sb= [HW,OSS]
1579 Format: <io>,<irq>,<dma>,<dma2>
1581 sbni= [NET] Granch SBNI12 leased line adapter
1583 sc1200wdt= [HW,WDT] SC1200 WDT (watchdog) driver
1584 Format: <io>[,<timeout>[,<isapnp>]]
1586 scsi_debug_*= [SCSI]
1587 See drivers/scsi/scsi_debug.c.
1589 scsi_default_dev_flags=
1590 [SCSI] SCSI default device flags
1591 Format: <integer>
1593 scsi_dev_flags= [SCSI] Black/white list entry for vendor and model
1594 Format: <vendor>:<model>:<flags>
1595 (flags are integer value)
1597 scsi_logging= [SCSI]
1599 scsi_mod.scan= [SCSI] sync (default) scans SCSI busses as they are
1600 discovered. async scans them in kernel threads,
1601 allowing boot to proceed. none ignores them, expecting
1602 user space to do the scan.
1604 selinux [SELINUX] Disable or enable SELinux at boot time.
1605 Format: { "0" | "1" }
1606 See security/selinux/Kconfig help text.
1607 0 -- disable.
1608 1 -- enable.
1609 Default value is set via kernel config option.
1610 If enabled at boot time, /selinux/disable can be used
1611 later to disable prior to initial policy load.
1613 selinux_compat_net =
1614 [SELINUX] Set initial selinux_compat_net flag value.
1615 Format: { "0" | "1" }
1616 0 -- use new secmark-based packet controls
1617 1 -- use legacy packet controls
1618 Default value is 0 (preferred).
1619 Value can be changed at runtime via
1620 /selinux/compat_net.
1622 serialnumber [BUGS=X86-32]
1624 sg_def_reserved_size= [SCSI]
1626 shapers= [NET]
1627 Maximal number of shapers.
1629 sim710= [SCSI,HW]
1630 See header of drivers/scsi/sim710.c.
1632 simeth= [IA-64]
1633 simscsi=
1635 slram= [HW,MTD]
1637 slub_debug[=options[,slabs]] [MM, SLUB]
1638 Enabling slub_debug allows one to determine the
1639 culprit if slab objects become corrupted. Enabling
1640 slub_debug can create guard zones around objects and
1641 may poison objects when not in use. Also tracks the
1642 last alloc / free. For more information see
1643 Documentation/vm/slub.txt.
1645 slub_max_order= [MM, SLUB]
1646 Determines the maximum allowed order for slabs.
1647 A high setting may cause OOMs due to memory
1648 fragmentation. For more information see
1649 Documentation/vm/slub.txt.
1651 slub_min_objects= [MM, SLUB]
1652 The minimum number of objects per slab. SLUB will
1653 increase the slab order up to slub_max_order to
1654 generate a sufficiently large slab able to contain
1655 the number of objects indicated. The higher the number
1656 of objects the smaller the overhead of tracking slabs
1657 and the less frequently locks need to be acquired.
1658 For more information see Documentation/vm/slub.txt.
1660 slub_min_order= [MM, SLUB]
1661 Determines the mininum page order for slabs. Must be
1662 lower than slub_max_order.
1663 For more information see Documentation/vm/slub.txt.
1665 slub_nomerge [MM, SLUB]
1666 Disable merging of slabs with similar size. May be
1667 necessary if there is some reason to distinguish
1668 allocs to different slabs. Debug options disable
1669 merging on their own.
1670 For more information see Documentation/vm/slub.txt.
1672 smart2= [HW]
1673 Format: <io1>[,<io2>[,...,<io8>]]
1675 smp-alt-once [X86-32,SMP] On a hotplug CPU system, only
1676 attempt to substitute SMP alternatives once at boot.
1678 smsc-ircc2.nopnp [HW] Don't use PNP to discover SMC devices
1679 smsc-ircc2.ircc_cfg= [HW] Device configuration I/O port
1680 smsc-ircc2.ircc_sir= [HW] SIR base I/O port
1681 smsc-ircc2.ircc_fir= [HW] FIR base I/O port
1682 smsc-ircc2.ircc_irq= [HW] IRQ line
1683 smsc-ircc2.ircc_dma= [HW] DMA channel
1684 smsc-ircc2.ircc_transceiver= [HW] Transceiver type:
1685 0: Toshiba Satellite 1800 (GP data pin select)
1686 1: Fast pin select (default)
1687 2: ATC IRMode
1689 snd-ad1816a= [HW,ALSA]
1691 snd-ad1848= [HW,ALSA]
1693 snd-ali5451= [HW,ALSA]
1695 snd-als100= [HW,ALSA]
1697 snd-als4000= [HW,ALSA]
1699 snd-azt2320= [HW,ALSA]
1701 snd-cmi8330= [HW,ALSA]
1703 snd-cmipci= [HW,ALSA]
1705 snd-cs4231= [HW,ALSA]
1707 snd-cs4232= [HW,ALSA]
1709 snd-cs4236= [HW,ALSA]
1711 snd-cs4281= [HW,ALSA]
1713 snd-cs46xx= [HW,ALSA]
1715 snd-dt019x= [HW,ALSA]
1717 snd-dummy= [HW,ALSA]
1719 snd-emu10k1= [HW,ALSA]
1721 snd-ens1370= [HW,ALSA]
1723 snd-ens1371= [HW,ALSA]
1725 snd-es968= [HW,ALSA]
1727 snd-es1688= [HW,ALSA]
1729 snd-es18xx= [HW,ALSA]
1731 snd-es1938= [HW,ALSA]
1733 snd-es1968= [HW,ALSA]
1735 snd-fm801= [HW,ALSA]
1737 snd-gusclassic= [HW,ALSA]
1739 snd-gusextreme= [HW,ALSA]
1741 snd-gusmax= [HW,ALSA]
1743 snd-hdsp= [HW,ALSA]
1745 snd-ice1712= [HW,ALSA]
1747 snd-intel8x0= [HW,ALSA]
1749 snd-interwave= [HW,ALSA]
1751 snd-interwave-stb=
1752 [HW,ALSA]
1754 snd-korg1212= [HW,ALSA]
1756 snd-maestro3= [HW,ALSA]
1758 snd-mpu401= [HW,ALSA]
1760 snd-mtpav= [HW,ALSA]
1762 snd-nm256= [HW,ALSA]
1764 snd-opl3sa2= [HW,ALSA]
1766 snd-opti92x-ad1848=
1767 [HW,ALSA]
1769 snd-opti92x-cs4231=
1770 [HW,ALSA]
1772 snd-opti93x= [HW,ALSA]
1774 snd-pmac= [HW,ALSA]
1776 snd-rme32= [HW,ALSA]
1778 snd-rme96= [HW,ALSA]
1780 snd-rme9652= [HW,ALSA]
1782 snd-sb8= [HW,ALSA]
1784 snd-sb16= [HW,ALSA]
1786 snd-sbawe= [HW,ALSA]
1788 snd-serial= [HW,ALSA]
1790 snd-sgalaxy= [HW,ALSA]
1792 snd-sonicvibes= [HW,ALSA]
1794 snd-sun-amd7930=
1795 [HW,ALSA]
1797 snd-sun-cs4231= [HW,ALSA]
1799 snd-trident= [HW,ALSA]
1801 snd-usb-audio= [HW,ALSA,USB]
1803 snd-via82xx= [HW,ALSA]
1805 snd-virmidi= [HW,ALSA]
1807 snd-wavefront= [HW,ALSA]
1809 snd-ymfpci= [HW,ALSA]
1811 sonypi.*= [HW] Sony Programmable I/O Control Device driver
1812 See Documentation/sonypi.txt
1814 specialix= [HW,SERIAL] Specialix multi-serial port adapter
1815 See Documentation/specialix.txt.
1817 spia_io_base= [HW,MTD]
1818 spia_fio_base=
1819 spia_pedr=
1820 spia_peddr=
1822 sscape= [HW,OSS]
1823 Format: <io>,<irq>,<dma>,<mpu_io>,<mpu_irq>
1825 st= [HW,SCSI] SCSI tape parameters (buffers, etc.)
1826 See Documentation/scsi/st.txt.
1828 st0x= [HW,SCSI]
1829 See header of drivers/scsi/seagate.c.
1831 sti= [PARISC,HW]
1832 Format: <num>
1833 Set the STI (builtin display/keyboard on the HP-PARISC
1834 machines) console (graphic card) which should be used
1835 as the initial boot-console.
1836 See also comment in drivers/video/console/sticore.c.
1838 sti_font= [HW]
1839 See comment in drivers/video/console/sticore.c.
1841 stifb= [HW]
1842 Format: bpp:<bpp1>[:<bpp2>[:<bpp3>...]]
1844 sunrpc.pool_mode=
1845 [NFS]
1846 Control how the NFS server code allocates CPUs to
1847 service thread pools. Depending on how many NICs
1848 you have and where their interrupts are bound, this
1849 option will affect which CPUs will do NFS serving.
1850 Note: this parameter cannot be changed while the
1851 NFS server is running.
1853 auto the server chooses an appropriate mode
1854 automatically using heuristics
1855 global a single global pool contains all CPUs
1856 percpu one pool for each CPU
1857 pernode one pool for each NUMA node (equivalent
1858 to global on non-NUMA machines)
1860 swiotlb= [IA-64] Number of I/O TLB slabs
1862 switches= [HW,M68k]
1864 sym53c416= [HW,SCSI]
1865 See header of drivers/scsi/sym53c416.c.
1867 sysrq_always_enabled
1868 [KNL]
1869 Ignore sysrq setting - this boot parameter will
1870 neutralize any effect of /proc/sys/kernel/sysrq.
1871 Useful for debugging.
1873 t128= [HW,SCSI]
1874 See header of drivers/scsi/t128.c.
1876 tdfx= [HW,DRM]
1878 thash_entries= [KNL,NET]
1879 Set number of hash buckets for TCP connection
1881 thermal.act= [HW,ACPI]
1882 -1: disable all active trip points in all thermal zones
1883 <degrees C>: override all lowest active trip points
1885 thermal.crt= [HW,ACPI]
1886 -1: disable all critical trip points in all thermal zones
1887 <degrees C>: lower all critical trip points
1889 thermal.nocrt= [HW,ACPI]
1890 Set to disable actions on ACPI thermal zone
1891 critical and hot trip points.
1893 thermal.off= [HW,ACPI]
1894 1: disable ACPI thermal control
1896 thermal.psv= [HW,ACPI]
1897 -1: disable all passive trip points
1898 <degrees C>: override all passive trip points to this value
1900 thermal.tzp= [HW,ACPI]
1901 Specify global default ACPI thermal zone polling rate
1902 <deci-seconds>: poll all this frequency
1903 0: no polling (default)
1905 time Show timing data prefixed to each printk message line
1906 [deprecated, see 'printk.time']
1908 tipar.timeout= [HW,PPT]
1909 Set communications timeout in tenths of a second
1910 (default 15).
1912 tipar.delay= [HW,PPT]
1913 Set inter-bit delay in microseconds (default 10).
1915 tmc8xx= [HW,SCSI]
1916 See header of drivers/scsi/seagate.c.
1918 tmscsim= [HW,SCSI]
1919 See comment before function dc390_setup() in
1920 drivers/scsi/tmscsim.c.
1922 tp720= [HW,PS2]
1924 trix= [HW,OSS] MediaTrix AudioTrix Pro
1925 Format:
1926 <io>,<irq>,<dma>,<dma2>,<sb_io>,<sb_irq>,<sb_dma>,<mpu_io>,<mpu_irq>
1928 turbografx.map[2|3]= [HW,JOY]
1929 TurboGraFX parallel port interface
1930 Format:
1931 <port#>,<js1>,<js2>,<js3>,<js4>,<js5>,<js6>,<js7>
1932 See also Documentation/input/joystick-parport.txt
1934 u14-34f= [HW,SCSI] UltraStor 14F/34F SCSI host adapter
1935 See header of drivers/scsi/u14-34f.c.
1937 uart401= [HW,OSS]
1938 Format: <io>,<irq>
1940 uart6850= [HW,OSS]
1941 Format: <io>,<irq>
1943 uhci-hcd.ignore_oc=
1944 [USB] Ignore overcurrent events (default N).
1945 Some badly-designed motherboards generate lots of
1946 bogus events, for ports that aren't wired to
1947 anything. Set this parameter to avoid log spamming.
1948 Note that genuine overcurrent events won't be
1949 reported either.
1951 usbcore.autosuspend=
1952 [USB] The autosuspend time delay (in seconds) used
1953 for newly-detected USB devices (default 2). This
1954 is the time required before an idle device will be
1955 autosuspended. Devices for which the delay is set
1956 to a negative value won't be autosuspended at all.
1958 usbhid.mousepoll=
1959 [USBHID] The interval which mice are to be polled at.
1961 vdso= [X86-32,SH,x86-64]
1962 vdso=2: enable compat VDSO (default with COMPAT_VDSO)
1963 vdso=1: enable VDSO (default)
1964 vdso=0: disable VDSO mapping
1966 vector= [IA-64,SMP]
1967 vector=percpu: enable percpu vector domain
1969 video= [FB] Frame buffer configuration
1970 See Documentation/fb/modedb.txt.
1972 vga= [BOOT,X86-32] Select a particular video mode
1973 See Documentation/i386/boot.txt and
1974 Documentation/svga.txt.
1975 Use vga=ask for menu.
1976 This is actually a boot loader parameter; the value is
1977 passed to the kernel using a special protocol.
1979 vmalloc=nn[KMG] [KNL,BOOT] Forces the vmalloc area to have an exact
1980 size of <nn>. This can be used to increase the
1981 minimum size (128MB on x86). It can also be used to
1982 decrease the size and leave more room for directly
1983 mapped kernel RAM.
1985 vmhalt= [KNL,S390] Perform z/VM CP command after system halt.
1986 Format: <command>
1988 vmpanic= [KNL,S390] Perform z/VM CP command after kernel panic.
1989 Format: <command>
1991 vmpoff= [KNL,S390] Perform z/VM CP command after power off.
1992 Format: <command>
1994 waveartist= [HW,OSS]
1995 Format: <io>,<irq>,<dma>,<dma2>
1997 wd33c93= [HW,SCSI]
1998 See header of drivers/scsi/wd33c93.c.
2000 wd7000= [HW,SCSI]
2001 See header of drivers/scsi/wd7000.c.
2003 wdt= [WDT] Watchdog
2004 See Documentation/watchdog/wdt.txt.
2006 xd= [HW,XT] Original XT pre-IDE (RLL encoded) disks.
2007 xd_geo= See header of drivers/block/xd.c.
2009 xirc2ps_cs= [NET,PCMCIA]
2010 Format:
2011 <irq>,<irq_mask>,<io>,<full_duplex>,<do_sound>,<lockup_hack>[,<irq2>[,<irq3>[,<irq4>]]]
2013 norandmaps Don't use address space randomization
2014 Equivalent to echo 0 > /proc/sys/kernel/randomize_va_space
2016 unwind_debug=N N > 0 will enable dwarf2 unwinder debugging
2017 This is useful to get more information why
2018 you got a "dwarf2 unwinder stuck"
2020 ______________________________________________________________________
2022 TODO:
2024 Add documentation for ALSA options.
2025 Add more DRM drivers.