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 Hyphens (dashes) and underscores are equivalent in parameter names, so
21 log_buf_len=1M print-fatal-signals=1
22 can also be entered as
23 log-buf-len=1M print_fatal_signals=1
26 This document may not be entirely up to date and comprehensive. The command
27 "modinfo -p ${modulename}" shows a current list of all parameters of a loadable
28 module. Loadable modules, after being loaded into the running kernel, also
29 reveal their parameters in /sys/module/${modulename}/parameters/. Some of these
30 parameters may be changed at runtime by the command
31 "echo -n ${value} > /sys/module/${modulename}/parameters/${parm}".
33 The parameters listed below are only valid if certain kernel build options were
34 enabled and if respective hardware is present. The text in square brackets at
35 the beginning of each description states the restrictions within which a
36 parameter is applicable:
38 ACPI ACPI support is enabled.
39 AGP AGP (Accelerated Graphics Port) is enabled.
40 ALSA ALSA sound support is enabled.
41 APIC APIC support is enabled.
42 APM Advanced Power Management support is enabled.
43 AVR32 AVR32 architecture is enabled.
44 AX25 Appropriate AX.25 support is enabled.
45 BLACKFIN Blackfin architecture is enabled.
46 DRM Direct Rendering Management support is enabled.
47 EDD BIOS Enhanced Disk Drive Services (EDD) is enabled
48 EFI EFI Partitioning (GPT) is enabled
49 EIDE EIDE/ATAPI support is enabled.
50 FB The frame buffer device is enabled.
51 GCOV GCOV profiling is enabled.
52 HW Appropriate hardware is enabled.
53 IA-64 IA-64 architecture is enabled.
54 IMA Integrity measurement architecture is enabled.
55 IOSCHED More than one I/O scheduler is enabled.
56 IP_PNP IP DHCP, BOOTP, or RARP is enabled.
57 IPV6 IPv6 support is enabled.
58 ISAPNP ISA PnP code is enabled.
59 ISDN Appropriate ISDN support is enabled.
60 JOY Appropriate joystick support is enabled.
61 KGDB Kernel debugger support is enabled.
62 KVM Kernel Virtual Machine support is enabled.
63 LIBATA Libata driver is enabled
64 LP Printer support is enabled.
65 LOOP Loopback device support is enabled.
66 M68k M68k architecture is enabled.
67 These options have more detailed description inside of
68 Documentation/m68k/kernel-options.txt.
69 MCA MCA bus support is enabled.
70 MDA MDA console support is enabled.
71 MOUSE Appropriate mouse support is enabled.
72 MSI Message Signaled Interrupts (PCI).
73 MTD MTD (Memory Technology Device) support is enabled.
74 NET Appropriate network support is enabled.
75 NUMA NUMA support is enabled.
76 GENERIC_TIME The generic timeofday code is enabled.
77 NFS Appropriate NFS support is enabled.
78 OSS OSS sound support is enabled.
79 PV_OPS A paravirtualized kernel is enabled.
80 PARIDE The ParIDE (parallel port IDE) subsystem is enabled.
81 PARISC The PA-RISC architecture is enabled.
82 PCI PCI bus support is enabled.
83 PCIE PCI Express support is enabled.
84 PCMCIA The PCMCIA subsystem is enabled.
85 PNP Plug & Play support is enabled.
86 PPC PowerPC architecture is enabled.
87 PPT Parallel port support is enabled.
88 PS2 Appropriate PS/2 support is enabled.
89 RAM RAM disk support is enabled.
90 S390 S390 architecture is enabled.
91 SCSI Appropriate SCSI support is enabled.
92 A lot of drivers has their options described inside of
94 SECURITY Different security models are enabled.
95 SELINUX SELinux support is enabled.
96 APPARMOR AppArmor support is enabled.
97 SERIAL Serial support is enabled.
98 SH SuperH architecture is enabled.
99 SMP The kernel is an SMP kernel.
100 SPARC Sparc architecture is enabled.
101 SWSUSP Software suspend (hibernation) is enabled.
102 SUSPEND System suspend states are enabled.
103 FTRACE Function tracing enabled.
104 TPM TPM drivers are enabled.
105 TS Appropriate touchscreen support is enabled.
106 UMS USB Mass Storage support is enabled.
107 USB USB support is enabled.
108 USBHID USB Human Interface Device support is enabled.
109 V4L Video For Linux support is enabled.
110 VGA The VGA console has been enabled.
111 VT Virtual terminal support is enabled.
112 WDT Watchdog support is enabled.
113 XT IBM PC/XT MFM hard disk support is enabled.
114 X86-32 X86-32, aka i386 architecture is enabled.
115 X86-64 X86-64 architecture is enabled.
116 More X86-64 boot options can be found in
117 Documentation/x86/x86_64/boot-options.txt .
118 X86 Either 32bit or 64bit x86 (same as X86-32+X86-64)
119 XEN Xen support is enabled
121 In addition, the following text indicates that the option:
123 BUGS= Relates to possible processor bugs on the said processor.
124 KNL Is a kernel start-up parameter.
125 BOOT Is a boot loader parameter.
127 Parameters denoted with BOOT are actually interpreted by the boot
128 loader, and have no meaning to the kernel directly.
129 Do not modify the syntax of boot loader parameters without extreme
130 need or coordination with <Documentation/x86/boot.txt>.
132 There are also arch-specific kernel-parameters not documented here.
133 See for example <Documentation/x86/x86_64/boot-options.txt>.
135 Note that ALL kernel parameters listed below are CASE SENSITIVE, and that
136 a trailing = on the name of any parameter states that that parameter will
137 be entered as an environment variable, whereas its absence indicates that
138 it will appear as a kernel argument readable via /proc/cmdline by programs
139 running once the system is up.
141 The number of kernel parameters is not limited, but the length of the
142 complete command line (parameters including spaces etc.) is limited to
143 a fixed number of characters. This limit depends on the architecture
144 and is between 256 and 4096 characters. It is defined in the file
145 ./include/asm/setup.h as COMMAND_LINE_SIZE.
149 Advanced Configuration and Power Interface
150 Format: { force | off | strict | noirq | rsdt }
151 force -- enable ACPI if default was off
152 off -- disable ACPI if default was on
153 noirq -- do not use ACPI for IRQ routing
154 strict -- Be less tolerant of platforms that are not
155 strictly ACPI specification compliant.
156 rsdt -- prefer RSDT over (default) XSDT
157 copy_dsdt -- copy DSDT to memory
159 See also Documentation/power/pm.txt, pci=noacpi
161 acpi_apic_instance= [ACPI, IOAPIC]
163 2: use 2nd APIC table, if available
164 1,0: use 1st APIC table
167 acpi_backlight= [HW,ACPI]
168 acpi_backlight=vendor
170 If set to vendor, prefer vendor specific driver
171 (e.g. thinkpad_acpi, sony_acpi, etc.) instead
172 of the ACPI video.ko driver.
174 acpi.debug_layer= [HW,ACPI,ACPI_DEBUG]
175 acpi.debug_level= [HW,ACPI,ACPI_DEBUG]
177 CONFIG_ACPI_DEBUG must be enabled to produce any ACPI
178 debug output. Bits in debug_layer correspond to a
179 _COMPONENT in an ACPI source file, e.g.,
180 #define _COMPONENT ACPI_PCI_COMPONENT
181 Bits in debug_level correspond to a level in
182 ACPI_DEBUG_PRINT statements, e.g.,
183 ACPI_DEBUG_PRINT((ACPI_DB_INFO, ...
184 The debug_level mask defaults to "info". See
185 Documentation/acpi/debug.txt for more information about
186 debug layers and levels.
188 Enable processor driver info messages:
189 acpi.debug_layer=0x20000000
190 Enable PCI/PCI interrupt routing info messages:
191 acpi.debug_layer=0x400000
192 Enable AML "Debug" output, i.e., stores to the Debug
193 object while interpreting AML:
194 acpi.debug_layer=0xffffffff acpi.debug_level=0x2
195 Enable all messages related to ACPI hardware:
196 acpi.debug_layer=0x2 acpi.debug_level=0xffffffff
198 Some values produce so much output that the system is
199 unusable. The "log_buf_len" parameter may be useful
200 if you need to capture more output.
202 acpi_display_output= [HW,ACPI]
203 acpi_display_output=vendor
204 acpi_display_output=video
207 acpi_irq_balance [HW,ACPI]
208 ACPI will balance active IRQs
211 acpi_irq_nobalance [HW,ACPI]
212 ACPI will not move active IRQs (default)
215 acpi_irq_isa= [HW,ACPI] If irq_balance, mark listed IRQs used by ISA
216 Format: <irq>,<irq>...
218 acpi_irq_pci= [HW,ACPI] If irq_balance, clear listed IRQs for
220 Format: <irq>,<irq>...
222 acpi_no_auto_ssdt [HW,ACPI] Disable automatic loading of SSDT
224 acpi_os_name= [HW,ACPI] Tell ACPI BIOS the name of the OS
225 Format: To spoof as Windows 98: ="Microsoft Windows"
227 acpi_osi= [HW,ACPI] Modify list of supported OS interface strings
228 acpi_osi="string1" # add string1 -- only one string
229 acpi_osi="!string2" # remove built-in string2
230 acpi_osi= # disable all strings
233 Override the pmtimer bug detection: force the kernel
234 to assume that this machine's pmtimer latches its value
235 and always returns good values.
237 acpi_sci= [HW,ACPI] ACPI System Control Interrupt trigger mode
238 Format: { level | edge | high | low }
240 acpi_serialize [HW,ACPI] force serialization of AML methods
242 acpi_skip_timer_override [HW,ACPI]
243 Recognize and ignore IRQ0/pin2 Interrupt Override.
244 For broken nForce2 BIOS resulting in XT-PIC timer.
246 acpi_sleep= [HW,ACPI] Sleep options
247 Format: { s3_bios, s3_mode, s3_beep, s4_nohwsig,
248 old_ordering, s4_nonvs, sci_force_enable }
249 See Documentation/power/video.txt for information on
251 s3_beep is for debugging; it makes the PC's speaker beep
252 as soon as the kernel's real-mode entry point is called.
253 s4_nohwsig prevents ACPI hardware signature from being
254 used during resume from hibernation.
255 old_ordering causes the ACPI 1.0 ordering of the _PTS
256 control method, with respect to putting devices into
257 low power states, to be enforced (the ACPI 2.0 ordering
258 of _PTS is used by default).
259 nonvs prevents the kernel from saving/restoring the
260 ACPI NVS memory during suspend/hibernation and resume.
261 sci_force_enable causes the kernel to set SCI_EN directly
262 on resume from S1/S3 (which is against the ACPI spec,
263 but some broken systems don't work without it).
265 acpi_use_timer_override [HW,ACPI]
266 Use timer override. For some broken Nvidia NF5 boards
267 that require a timer override, but don't have HPET
269 acpi_enforce_resources= [ACPI]
270 { strict | lax | no }
271 Check for resource conflicts between native drivers
272 and ACPI OperationRegions (SystemIO and SystemMemory
273 only). IO ports and memory declared in ACPI might be
274 used by the ACPI subsystem in arbitrary AML code and
275 can interfere with legacy drivers.
276 strict (default): access to resources claimed by ACPI
277 is denied; legacy drivers trying to access reserved
278 resources will fail to bind to device using them.
279 lax: access to resources claimed by ACPI is allowed;
280 legacy drivers trying to access reserved resources
281 will bind successfully but a warning message is logged.
282 no: ACPI OperationRegions are not marked as reserved,
283 no further checks are performed.
286 Format: <io>,<irq>,<dma>,<dma2>,<type>
288 add_efi_memmap [EFI; X86] Include EFI memory map in
289 kernel's map of available physical RAM.
292 See header of drivers/scsi/advansys.c.
294 aedsp16= [HW,OSS] Audio Excel DSP 16
295 Format: <io>,<irq>,<dma>,<mss_io>,<mpu_io>,<mpu_irq>
296 See also header of sound/oss/aedsp16.c.
299 { off | try_unsupported }
300 off: disable AGP support
301 try_unsupported: try to drive unsupported chipsets
302 (may crash computer or cause data corruption)
305 See Documentation/scsi/aha152x.txt.
308 Format: <portbase>[,<buson>,<busoff>[,<dmaspeed>]]
311 See Documentation/scsi/aic7xxx.txt.
314 See Documentation/scsi/aic79xx.txt.
317 Allow the default userspace alignment fault handler
318 behaviour to be specified. Bit 0 enables warnings,
319 bit 1 enables fixups, and bit 2 sends a segfault.
321 amd_iommu= [HW,X86-84]
322 Pass parameters to the AMD IOMMU driver in the system.
324 fullflush - enable flushing of IO/TLB entries when
325 they are unmapped. Otherwise they are
326 flushed before they will be reused, which
328 off - do not initialize any AMD IOMMU found in
331 amijoy.map= [HW,JOY] Amiga joystick support
332 Map of devices attached to JOY0DAT and JOY1DAT
334 See also Documentation/kernel/input/joystick.txt
336 analog.map= [HW,JOY] Analog joystick and gamepad support
337 Specifies type or capabilities of an analog joystick
338 connected to one of 16 gameports
339 Format: <type1>,<type2>,..<type16>
342 Power management functions (SPARCstation-4/5 + deriv.)
344 Disable APC CPU standby support. SPARCstation-Fox does
345 not play well with APC CPU idle - disable it if you have
346 APC and your system crashes randomly.
348 apic= [APIC,X86-32] Advanced Programmable Interrupt Controller
349 Change the output verbosity whilst booting
350 Format: { quiet (default) | verbose | debug }
351 Change the amount of debugging information output
352 when initialising the APIC and IO-APIC components.
355 See Documentation/networking/ipv6.txt.
357 show_lapic= [APIC,X86] Advanced Programmable Interrupt Controller
358 Limit apic dumping. The parameter defines the maximal
359 number of local apics being dumped. Also it is possible
360 to set it to "all" by meaning -- no limit here.
361 Format: { 1 (default) | 2 | ... | all }.
362 The parameter valid if only apic=debug or
363 apic=verbose is specified.
364 Example: apic=debug show_lapic=all
366 apm= [APM] Advanced Power Management
367 See header of arch/x86/kernel/apm_32.c.
369 arcrimi= [HW,NET] ARCnet - "RIM I" (entirely mem-mapped) cards
370 Format: <io>,<irq>,<nodeID>
374 atarimouse= [HW,MOUSE] Atari Mouse
376 atascsi= [HW,SCSI] Atari SCSI
378 atkbd.extra= [HW] Enable extra LEDs and keys on IBM RapidAccess,
379 EzKey and similar keyboards
381 atkbd.reset= [HW] Reset keyboard during initialization
383 atkbd.set= [HW] Select keyboard code set
384 Format: <int> (2 = AT (default), 3 = PS/2)
386 atkbd.scroll= [HW] Enable scroll wheel on MS Office and similar
389 atkbd.softraw= [HW] Choose between synthetic and real raw mode
390 Format: <bool> (0 = real, 1 = synthetic (default))
392 atkbd.softrepeat= [HW]
393 Use software keyboard repeat
397 baycom_epp= [HW,AX25]
400 baycom_par= [HW,AX25] BayCom Parallel Port AX.25 Modem
402 See header of drivers/net/hamradio/baycom_par.c.
404 baycom_ser_fdx= [HW,AX25]
405 BayCom Serial Port AX.25 Modem (Full Duplex Mode)
406 Format: <io>,<irq>,<mode>[,<baud>]
407 See header of drivers/net/hamradio/baycom_ser_fdx.c.
409 baycom_ser_hdx= [HW,AX25]
410 BayCom Serial Port AX.25 Modem (Half Duplex Mode)
411 Format: <io>,<irq>,<mode>
412 See header of drivers/net/hamradio/baycom_ser_hdx.c.
414 boot_delay= Milliseconds to delay each printk during boot.
415 Values larger than 10 seconds (10000) are changed to
419 bootmem_debug [KNL] Enable bootmem allocator debug messages.
421 bttv.card= [HW,V4L] bttv (bt848 + bt878 based grabber cards)
422 bttv.radio= Most important insmod options are available as
424 bttv.pll= See Documentation/video4linux/bttv/Insmod-options
425 bttv.tuner= and Documentation/video4linux/bttv/CARDLIST
428 See drivers/scsi/BusLogic.c, comment before function
429 BusLogic_ParseDriverOptions().
431 c101= [NET] Moxa C101 synchronous serial card
433 cachesize= [BUGS=X86-32] Override level 2 CPU cache size detection.
434 Sometimes CPU hardware bugs make them report the cache
435 size incorrectly. The kernel will attempt work arounds
436 to fix known problems, but for some CPUs it is not
437 possible to determine what the correct size should be.
438 This option provides an override for these situations.
441 [SECURITY] Disable capabilities. This would normally
442 be used only if an alternative security model is to be
443 configured. Potentially dangerous and should only be
444 used if you are entirely sure of the consequences.
446 ccw_timeout_log [S390]
447 See Documentation/s390/CommonIO for details.
449 cgroup_disable= [KNL] Disable a particular controller
450 Format: {name of the controller(s) to disable}
451 {Currently supported controllers - "memory"}
453 checkreqprot [SELINUX] Set initial checkreqprot flag value.
454 Format: { "0" | "1" }
455 See security/selinux/Kconfig help text.
456 0 -- check protection applied by kernel (includes
457 any implied execute protection).
458 1 -- check protection requested by application.
459 Default value is set via a kernel config option.
460 Value can be changed at runtime via
461 /selinux/checkreqprot.
464 See Documentation/s390/CommonIO for details.
466 clock= [BUGS=X86-32, HW] gettimeofday clocksource override.
468 Forces specified clocksource (if available) to be used
469 when calculating gettimeofday(). If specified
470 clocksource is not available, it defaults to PIT.
471 Format: { pit | tsc | cyclone | pmtmr }
473 clocksource= [GENERIC_TIME] Override the default clocksource
475 Override the default clocksource and use the clocksource
476 with the name specified.
477 Some clocksource names to choose from, depending on
479 [all] jiffies (this is the base, fallback clocksource)
481 [ARM] imx_timer1,OSTS,netx_timer,mpu_timer2,
482 pxa_timer,timer3,32k_counter,timer0_1
484 [X86-32] pit,hpet,tsc,vmi-timer;
485 scx200_hrt on Geode; cyclone on IBM x440
493 clearcpuid=BITNUM [X86]
494 Disable CPUID feature X for the kernel. See
495 arch/x86/include/asm/cpufeature.h for the valid bit
496 numbers. Note the Linux specific bits are not necessarily
497 stable over kernel options, but the vendor specific
499 Also note that user programs calling CPUID directly
500 or using the feature without checking anything
501 will still see it. This just prevents it from
502 being used by the kernel or shown in /proc/cpuinfo.
503 Also note the kernel might malfunction if you disable
506 cmo_free_hint= [PPC] Format: { yes | no }
507 Specify whether pages are marked as being inactive
508 when they are freed. This is used in CMO environments
509 to determine OS memory pressure for page stealing by
513 code_bytes [X86] How many bytes of object code to print
518 com20020= [HW,NET] ARCnet - COM20020 chipset
520 <io>[,<irq>[,<nodeID>[,<backplane>[,<ckp>[,<timeout>]]]]]
522 com90io= [HW,NET] ARCnet - COM90xx chipset (IO-mapped buffers)
526 ARCnet - COM90xx chipset (memory-mapped buffers)
527 Format: <io>[,<irq>[,<memstart>]]
529 condev= [HW,S390] console device
532 console= [KNL] Output console device and options.
534 tty<n> Use the virtual console device <n>.
538 Use the specified serial port. The options are of
539 the form "bbbbpnf", where "bbbb" is the baud rate,
540 "p" is parity ("n", "o", or "e"), "n" is number of
541 bits, and "f" is flow control ("r" for RTS or
542 omit it). Default is "9600n8".
544 See Documentation/serial-console.txt for more
546 Documentation/networking/netconsole.txt for an
549 uart[8250],io,<addr>[,options]
550 uart[8250],mmio,<addr>[,options]
551 Start an early, polled-mode console on the 8250/16550
552 UART at the specified I/O port or MMIO address,
553 switching to the matching ttyS device later. The
554 options are the same as for ttyS, above.
556 If the device connected to the port is not a TTY but a braille
557 device, prepend "brl," before the device type, for instance
559 For now, only VisioBraille is supported.
561 consoleblank= [KNL] The console blank (screen saver) timeout in
562 seconds. Defaults to 10*60 = 10mins. A value of 0
563 disables the blank timer.
566 [KNL] Change the default value for
567 /proc/<pid>/coredump_filter.
568 See also Documentation/filesystems/proc.txt.
570 cpcihp_generic= [HW,PCI] Generic port I/O CompactPCI driver
572 <first_slot>,<last_slot>,<port>,<enum_bit>[,<debug>]
574 crashkernel=nn[KMG]@ss[KMG]
575 [KNL] Reserve a chunk of physical memory to
576 hold a kernel to switch to with kexec on panic.
578 crashkernel=range1:size1[,range2:size2,...][@offset]
579 [KNL] Same as above, but depends on the memory
580 in the running system. The syntax of range is
581 start-[end] where start and end are both
582 a memory unit (amount[KMG]). See also
583 Documentation/kdump/kdump.txt for a example.
588 cs89x0_media= [HW,NET]
589 Format: { rj45 | aui | bnc }
592 See header of drivers/s390/block/dasd_devmap.c.
594 db9.dev[2|3]= [HW,JOY] Multisystem joystick support via parallel port
595 (one device per port)
596 Format: <port#>,<type>
597 See also Documentation/input/joystick-parport.txt
599 debug [KNL] Enable kernel debugging (events log level).
602 [KNL] verbose self-tests
604 Print debugging info while doing the locking API
606 We default to 0 (no extra messages), setting it to
607 1 will print _a lot_ more information - normally
608 only useful to kernel developers.
610 debug_objects [KNL] Enable object debugging
613 [KNL] Disable object debugging
615 debugpat [X86] Enable PAT debugging
617 decnet.addr= [HW,NET]
618 Format: <area>[,<node>]
619 See also Documentation/networking/decnet.txt.
622 [same as hugepagesz=] The size of the default
623 HugeTLB page size. This is the size represented by
624 the legacy /proc/ hugepages APIs, used for SHM, and
625 default size when mounting hugetlbfs filesystems.
626 Defaults to the default architecture's huge page size
630 Set number of hash buckets for dentry cache.
633 IO parameters + enable/disable command.
635 digiepca= [HW,SERIAL]
636 See drivers/char/README.epca and
637 Documentation/serial/digiepca.txt.
640 See Documentation/networking/ipv6.txt.
643 See Documentation/networking/ipv6.txt.
645 disable_mtrr_cleanup [X86]
646 The kernel tries to adjust MTRR layout from continuous
647 to discrete, to make X server driver able to add WB
648 entry later. This parameter disables that.
650 disable_mtrr_trim [X86, Intel and AMD only]
651 By default the kernel will trim any uncacheable
652 memory out of your available memory pool based on
653 MTRR settings. This parameter disables that behavior,
654 possibly causing your machine to run very slowly.
656 disable_timer_pin_1 [X86]
657 Disable PIN 1 of APIC timer
658 Can be useful to work around chipset bugs.
660 dmasound= [HW,OSS] Sound subsystem buffers
662 dma_debug=off If the kernel is compiled with DMA_API_DEBUG support,
663 this option disables the debugging code at boot.
665 dma_debug_entries=<number>
666 This option allows to tune the number of preallocated
667 entries for DMA-API debugging code. One entry is
668 required per DMA-API allocation. Use this if the
669 DMA-API debugging code disables itself because the
670 architectural default is too low.
672 dma_debug_driver=<driver_name>
673 With this option the DMA-API debugging driver
674 filter feature can be enabled at boot time. Just
675 pass the driver to filter for as the parameter.
676 The filter can be disabled or changed to another
677 driver later using sysfs.
683 dynamic_printk Enables pr_debug()/dev_dbg() calls if
684 CONFIG_DYNAMIC_PRINTK_DEBUG has been enabled.
685 These can also be switched on/off via
686 <debugfs>/dynamic_printk/modules
688 earlycon= [KNL] Output early console device and options.
689 uart[8250],io,<addr>[,options]
690 uart[8250],mmio,<addr>[,options]
691 Start an early, polled-mode console on the 8250/16550
692 UART at the specified I/O port or MMIO address.
693 The options are the same as for ttyS, above.
695 earlyprintk= [X86,SH,BLACKFIN]
697 earlyprintk=serial[,ttySn[,baudrate]]
698 earlyprintk=ttySn[,baudrate]
699 earlyprintk=dbgp[debugController#]
701 Append ",keep" to not disable it when the real console
704 Only vga or serial or usb debug port at a time.
706 Currently only ttyS0 and ttyS1 are supported.
708 Interaction with the standard serial driver is not
711 The VGA output is eventually overwritten by the real
714 ekgdboc= [X86,KGDB] Allow early kernel console debugging
717 This is desgined to be used in conjunction with
718 the boot argument: earlyprintk=vga
723 Format: {"off" | "on" | "skip[mbr]"}
725 eisa_irq_edge= [PARISC,HW]
726 See header of drivers/parisc/eisa.c.
729 See comment before function elanfreq_setup() in
730 arch/x86/kernel/cpu/cpufreq/elanfreq.c.
733 Format: {"anticipatory" | "cfq" | "deadline" | "noop"}
734 See Documentation/block/as-iosched.txt and
735 Documentation/block/deadline-iosched.txt for details.
737 elfcorehdr= [IA64,PPC,SH,X86]
738 Specifies physical address of start of kernel core
739 image elf header. Generally kexec loader will
740 pass this option to capture kernel.
741 See Documentation/kdump/kdump.txt for details.
743 enable_mtrr_cleanup [X86]
744 The kernel tries to adjust MTRR layout from continuous
745 to discrete, to make X server driver able to add WB
746 entry later. This parameter enables that.
748 enable_timer_pin_1 [X86]
749 Enable PIN 1 of APIC timer
750 Can be useful to work around chipset bugs
751 (in particular on some ATI chipsets).
752 The kernel tries to set a reasonable default.
754 enforcing [SELINUX] Set initial enforcing status.
756 See security/selinux/Kconfig help text.
757 0 -- permissive (log only, no denials).
758 1 -- enforcing (deny and log).
760 Value can be changed at runtime via /selinux/enforce.
763 Disable Error Record Serialization Table (ERST)
766 ether= [HW,NET] Ethernet cards parameters
767 This option is obsoleted by the "netdev=" option, which
768 has equivalent usage. See its documentation for details.
772 fail_make_request=[KNL]
773 General fault injection mechanism.
774 Format: <interval>,<probability>,<space>,<times>
775 See also /Documentation/fault-injection/.
778 See header of drivers/scsi/fd_mcs.c.
781 See header of drivers/scsi/fdomain.c.
784 See Documentation/blockdev/floppy.txt.
786 force_pal_cache_flush
787 [IA-64] Avoid check_sal_cache_flush which may hang on
788 buggy SAL_CACHE_FLUSH implementations. Using this
789 parameter will force ia64_sal_cache_flush to call
790 ia64_pal_cache_flush instead of SAL_CACHE_FLUSH.
793 [FTRACE] will set and start the specified tracer
794 as early as possible in order to facilitate early
797 ftrace_dump_on_oops[=orig_cpu]
798 [FTRACE] will dump the trace buffers on oops.
799 If no parameter is passed, ftrace will dump
800 buffers of all CPUs, but if you pass orig_cpu, it will
801 dump only the buffer of the CPU that triggered the
804 ftrace_filter=[function-list]
805 [FTRACE] Limit the functions traced by the function
806 tracer at boot up. function-list is a comma separated
807 list of functions. This list can be changed at run
808 time by the set_ftrace_filter file in the debugfs
811 ftrace_notrace=[function-list]
812 [FTRACE] Do not trace the functions specified in
813 function-list. This list can be changed at run time
814 by the set_ftrace_notrace file in the debugfs
817 ftrace_graph_filter=[function-list]
818 [FTRACE] Limit the top level callers functions traced
819 by the function graph tracer at boot up.
820 function-list is a comma separated list of functions
821 that can be changed at run time by the
822 set_graph_function file in the debugfs tracing directory.
825 [HW,JOY] Multisystem joystick and NES/SNES/PSX pad
826 support via parallel port (up to 5 devices per port)
827 Format: <port#>,<pad1>,<pad2>,<pad3>,<pad4>,<pad5>
828 See also Documentation/input/joystick-parport.txt
832 gart_fix_e820= [X86_64] disable the fix e820 for K8 GART
836 gcov_persist= [GCOV] When non-zero (default), profiling data for
837 kernel modules is saved and remains accessible via
838 debugfs, even when the module is unloaded/reloaded.
839 When zero, profiling data is discarded and associated
840 debugfs files are removed at module unload time.
843 See header of drivers/scsi/gdth.c.
845 gpt [EFI] Forces disk with valid GPT signature but
846 invalid Protective MBR to be treated as GPT.
850 hashdist= [KNL,NUMA] Large hashes allocated during boot
851 are distributed across NUMA nodes. Defaults on
852 for 64bit NUMA, off otherwise.
853 Format: 0 | 1 (for off | on)
855 hcl= [IA-64] SGI's Hardware Graph compatibility layer
857 hd= [EIDE] (E)IDE hard drive subsystem geometry
858 Format: <cyl>,<head>,<sect>
861 Disable Hardware Error Source Table (HEST) support;
862 corresponding firmware-first mode error processing
863 logic will be disabled.
865 highmem=nn[KMG] [KNL,BOOT] forces the highmem zone to have an exact
866 size of <nn>. This works even on boxes that have no
867 highmem otherwise. This also works to reduce highmem
868 size on bigger boxes.
870 highres= [KNL] Enable/disable high resolution timer mode.
871 Valid parameters: "on", "off"
875 See Documentation/isdn/README.HiSax.
879 hpet= [X86-32,HPET] option to control HPET usage
880 Format: { enable (default) | disable | force |
882 disable: disable HPET and use PIT instead
883 force: allow force enabled of undocumented chips (ICH4,
885 verbose: show contents of HPET registers during setup
887 hugepages= [HW,X86-32,IA-64] HugeTLB pages to allocate at boot.
888 hugepagesz= [HW,IA-64,PPC,X86-64] The size of the HugeTLB pages.
889 On x86-64 and powerpc, this option can be specified
890 multiple times interleaved with hugepages= to reserve
891 huge pages of different sizes. Valid pages sizes on
892 x86-64 are 2M (when the CPU supports "pse") and 1G
893 (when the CPU supports the "pdpe1gb" cpuinfo flag)
894 Note that 1GB pages can only be allocated at boot time
895 using hugepages= and not freed afterwards.
897 hvc_iucv= [S390] Number of z/VM IUCV hypervisor console (HVC)
898 terminal devices. Valid values: 0..8
899 hvc_iucv_allow= [S390] Comma-separated list of z/VM user IDs.
900 If specified, z/VM IUCV HVC accepts connections
901 from listed z/VM user IDs only.
903 i2c_bus= [HW] Override the default board specific I2C bus speed
904 or register an additional I2C bus that is not
905 registered from board initialization code.
909 i8042.debug [HW] Toggle i8042 debug mode
910 i8042.direct [HW] Put keyboard port into non-translated mode
911 i8042.dumbkbd [HW] Pretend that controller can only read data from
912 keyboard and cannot control its state
913 (Don't attempt to blink the leds)
914 i8042.noaux [HW] Don't check for auxiliary (== mouse) port
915 i8042.nokbd [HW] Don't check/create keyboard port
916 i8042.noloop [HW] Disable the AUX Loopback command while probing
918 i8042.nomux [HW] Don't check presence of an active multiplexing
920 i8042.nopnp [HW] Don't use ACPIPnP / PnPBIOS to discover KBD/AUX
923 [HW] Frequency with which keyboard LEDs should blink
924 when kernel panics (default is 0.5 sec)
925 i8042.reset [HW] Reset the controller during init and cleanup
926 i8042.unlock [HW] Unlock (ignore) the keylock
930 i8k.ignore_dmi [HW] Continue probing hardware even if DMI data
931 indicates that the driver is running on unsupported
933 i8k.force [HW] Activate i8k driver even if SMM BIOS signature
934 does not match list of supported models.
936 [HW] Report power status in /proc/i8k
937 (disabled by default)
938 i8k.restricted [HW] Allow controlling fans only if SYS_ADMIN
941 ibmmcascsi= [HW,MCA,SCSI] IBM MicroChannel SCSI adapter
942 See Documentation/mca.txt.
945 Format: <io>[,<membase>[,<icn_id>[,<icn_id2>]]]
947 ide-core.nodma= [HW] (E)IDE subsystem
948 Format: =0.0 to prevent dma on hda, =0.1 hdb =1.0 hdc
949 .vlb_clock .pci_clock .noflush .nohpa .noprobe .nowerr
950 .cdrom .chs .ignore_cable are additional options
951 See Documentation/ide/ide.txt.
953 ide-pci-generic.all-generic-ide [HW] (E)IDE subsystem
954 Claim all unknown PCI IDE storage controllers.
957 Format: idle=poll, idle=mwait, idle=halt, idle=nomwait
958 Poll forces a polling idle loop that can slightly
959 improve the performance of waking up a idle CPU, but
960 will use a lot of power and make the system run hot.
962 idle=mwait: On systems which support MONITOR/MWAIT but
963 the kernel chose to not use it because it doesn't save
964 as much power as a normal idle loop, use the
965 MONITOR/MWAIT idle loop anyways. Performance should be
966 the same as idle=poll.
967 idle=halt: Halt is forced to be used for CPU idle.
968 In such case C2/C3 won't be used again.
969 idle=nomwait: Disable mwait for CPU C-states
971 ignore_loglevel [KNL]
972 Ignore loglevel setting - this will print /all/
973 kernel messages to the console. Useful for debugging.
976 Set number of hash buckets for inode cache.
979 Format: { "0" | "1" }
980 0 -- integrity auditing messages. (Default)
981 1 -- enable informational integrity auditing messages.
984 Format: { "sha1" | "md5" }
988 Load a policy which meets the needs of the Trusted
989 Computing Base. This means IMA will measure all
990 programs exec'd, files mmap'd for exec, and all files
991 opened for read by uid=0.
994 See header of drivers/scsi/in2000.c.
998 Run specified binary instead of /sbin/init as init
1001 initcall_debug [KNL] Trace initcalls as they are executed. Useful
1002 for working out where the kernel is dying during
1005 initrd= [BOOT] Specify the location of the initial ramdisk
1007 inport.irq= [HW] Inport (ATI XL and Microsoft) busmouse driver
1010 intel_iommu= [DMAR] Intel IOMMU driver (DMAR) option
1012 Enable intel iommu driver.
1014 Disable intel iommu driver.
1015 igfx_off [Default Off]
1016 By default, gfx is mapped as normal device. If a gfx
1017 device has a dedicated DMAR unit, the DMAR unit is
1018 bypassed by not enabling DMAR with this option. In
1019 this case, gfx device will use physical address for
1022 With this option iommu will not optimize to look
1023 for io virtual address below 32 bit forcing dual
1024 address cycle on pci bus for cards supporting greater
1025 than 32 bit addressing. The default is to look
1026 for translation below 32 bit and if not available
1027 then look in the higher range.
1028 strict [Default Off]
1029 With this option on every unmap_single operation will
1030 result in a hardware IOTLB flush operation as opposed
1031 to batching them for performance.
1035 iomem= Disable strict checking of access to MMIO memory
1036 strict regions from userspace.
1052 io7= [HW] IO7 for Marvel based alpha systems
1053 See comment before marvel_specify_io7 in
1054 arch/alpha/kernel/core_marvel.c.
1056 io_delay= [X86] I/O delay method
1058 Standard port 0x80 based delay
1060 Alternate port 0xed based delay (needed on some systems)
1062 Simple two microseconds delay
1067 See Documentation/filesystems/nfs/nfsroot.txt.
1069 ip2= [HW] Set IO/IRQ pairs for up to 4 IntelliPort boards
1070 See comment before ip2_setup() in
1071 drivers/char/ip2/ip2base.c.
1073 ips= [HW,SCSI] Adaptec / IBM ServeRAID controller
1074 See header of drivers/scsi/ips.c.
1077 When an interrupt is not handled search all handlers
1078 for it. Intended to get systems with badly broken
1082 When an interrupt is not handled search all handlers
1083 for it. Also check all handlers each timer
1084 interrupt. Intended to get systems with badly broken
1088 Format: <RDP>,<reset>,<pci_scan>,<verbosity>
1090 isolcpus= [KNL,SMP] Isolate CPUs from the general scheduler.
1092 <cpu number>,...,<cpu number>
1094 <cpu number>-<cpu number>
1095 (must be a positive range in ascending order)
1097 <cpu number>,...,<cpu number>-<cpu number>
1099 This option can be used to specify one or more CPUs
1100 to isolate from the general SMP balancing and scheduling
1101 algorithms. You can move a process onto or off an
1102 "isolated" CPU via the CPU affinity syscalls or cpuset.
1103 <cpu number> begins at 0 and the maximum value is
1104 "number of CPUs in system - 1".
1106 This option is the preferred way to isolate CPUs. The
1107 alternative -- manually setting the CPU mask of all
1108 tasks in the system -- can cause problems and
1109 suboptimal load balancer performance.
1113 js= [HW,JOY] Analog joystick
1114 See Documentation/input/joystick.txt.
1118 kernelcore=nn[KMG] [KNL,X86,IA-64,PPC] This parameter
1119 specifies the amount of memory usable by the kernel
1120 for non-movable allocations. The requested amount is
1121 spread evenly throughout all nodes in the system. The
1122 remaining memory in each node is used for Movable
1123 pages. In the event, a node is too small to have both
1124 kernelcore and Movable pages, kernelcore pages will
1125 take priority and other nodes will have a larger number
1126 of kernelcore pages. The Movable zone is used for the
1127 allocation of pages that may be reclaimed or moved
1128 by the page migration subsystem. This means that
1129 HugeTLB pages may not be allocated from this zone.
1130 Note that allocations like PTEs-from-HighMem still
1131 use the HighMem zone if it exists, and the Normal
1132 zone if it does not.
1134 kgdbdbgp= [KGDB,HW] kgdb over EHCI usb debug port.
1135 Format: <Controller#>[,poll interval]
1136 The controller # is the number of the ehci usb debug
1137 port as it is probed via PCI. The poll interval is
1138 optional and is the number seconds in between
1139 each poll cycle to the debug port in case you need
1140 the functionality for interrupting the kernel with
1141 gdb or control-c on the dbgp connection. When
1142 not using this parameter you use sysrq-g to break into
1143 the kernel debugger.
1145 kgdboc= [KGDB,HW] kgdb over consoles.
1146 Requires a tty driver that supports console polling,
1147 or a supported polling keyboard driver (non-usb).
1148 Serial only format: <serial_device>[,baud]
1149 keyboard only format: kbd
1150 keyboard and serial format: kbd,<serial_device>[,baud]
1152 kgdbwait [KGDB] Stop kernel execution and enter the
1153 kernel debugger at the earliest opportunity.
1155 kmac= [MIPS] korina ethernet MAC address.
1156 Configure the RouterBoard 532 series on-chip
1157 Ethernet adapter MAC address.
1159 kmemleak= [KNL] Boot-time kmemleak enable/disable
1160 Valid arguments: on, off
1163 kstack=N [X86] Print N words from the kernel stack
1166 kvm.ignore_msrs=[KVM] Ignore guest accesses to unhandled MSRs.
1167 Default is 0 (don't ignore, but inject #GP)
1169 kvm.oos_shadow= [KVM] Disable out-of-sync shadow paging.
1170 Default is 1 (enabled)
1172 kvm-amd.nested= [KVM,AMD] Allow nested virtualization in KVM/SVM.
1175 kvm-amd.npt= [KVM,AMD] Disable nested paging (virtualized MMU)
1177 Default is 1 (enabled) if in 64bit or 32bit-PAE mode
1179 kvm-intel.bypass_guest_pf=
1180 [KVM,Intel] Disables bypassing of guest page faults
1181 on Intel chips. Default is 1 (enabled)
1183 kvm-intel.ept= [KVM,Intel] Disable extended page tables
1184 (virtualized MMU) support on capable Intel chips.
1185 Default is 1 (enabled)
1187 kvm-intel.emulate_invalid_guest_state=
1188 [KVM,Intel] Enable emulation of invalid guest states
1189 Default is 0 (disabled)
1191 kvm-intel.flexpriority=
1192 [KVM,Intel] Disable FlexPriority feature (TPR shadow).
1193 Default is 1 (enabled)
1195 kvm-intel.unrestricted_guest=
1196 [KVM,Intel] Disable unrestricted guest feature
1197 (virtualized real and unpaged mode) on capable
1198 Intel chips. Default is 1 (enabled)
1200 kvm-intel.vpid= [KVM,Intel] Disable Virtual Processor Identification
1201 feature (tagged TLBs) on capable Intel chips.
1202 Default is 1 (enabled)
1208 lapic [X86-32,APIC] Enable the local APIC even if BIOS
1211 lapic_timer_c2_ok [X86,APIC] trust the local apic timer
1214 libata.dma= [LIBATA] DMA control
1215 libata.dma=0 Disable all PATA and SATA DMA
1216 libata.dma=1 PATA and SATA Disk DMA only
1217 libata.dma=2 ATAPI (CDROM) DMA only
1218 libata.dma=4 Compact Flash DMA only
1219 Combinations also work, so libata.dma=3 enables DMA
1220 for disks and CDROMs, but not CFs.
1222 libata.ignore_hpa= [LIBATA] Ignore HPA limit
1223 libata.ignore_hpa=0 keep BIOS limits (default)
1224 libata.ignore_hpa=1 ignore limits, using full disk
1226 libata.noacpi [LIBATA] Disables use of ACPI in libata suspend/resume
1230 libata.force= [LIBATA] Force configurations. The format is comma
1231 separated list of "[ID:]VAL" where ID is
1232 PORT[.DEVICE]. PORT and DEVICE are decimal numbers
1233 matching port, link or device. Basically, it matches
1234 the ATA ID string printed on console by libata. If
1235 the whole ID part is omitted, the last PORT and DEVICE
1236 values are used. If ID hasn't been specified yet, the
1237 configuration applies to all ports, links and devices.
1239 If only DEVICE is omitted, the parameter applies to
1240 the port and all links and devices behind it. DEVICE
1241 number of 0 either selects the first device or the
1242 first fan-out link behind PMP device. It does not
1243 select the host link. DEVICE number of 15 selects the
1244 host link and device attached to it.
1246 The VAL specifies the configuration to force. As long
1247 as there's no ambiguity shortcut notation is allowed.
1248 For example, both 1.5 and 1.5G would work for 1.5Gbps.
1249 The following configurations can be forced.
1251 * Cable type: 40c, 80c, short40c, unk, ign or sata.
1252 Any ID with matching PORT is used.
1254 * SATA link speed limit: 1.5Gbps or 3.0Gbps.
1256 * Transfer mode: pio[0-7], mwdma[0-4] and udma[0-7].
1257 udma[/][16,25,33,44,66,100,133] notation is also
1260 * [no]ncq: Turn on or off NCQ.
1262 * nohrst, nosrst, norst: suppress hard, soft
1265 * dump_id: dump IDENTIFY data.
1267 If there are multiple matching configurations changing
1268 the same attribute, the last one is used.
1270 memblock=debug [KNL] Enable memblock debug messages.
1272 load_ramdisk= [RAM] List of ramdisks to load from floppy
1273 See Documentation/blockdev/ramdisk.txt.
1275 lockd.nlm_grace_period=P [NFS] Assign grace period.
1278 lockd.nlm_tcpport=N [NFS] Assign TCP port.
1281 lockd.nlm_timeout=T [NFS] Assign timeout value.
1284 lockd.nlm_udpport=M [NFS] Assign UDP port.
1287 logibm.irq= [HW,MOUSE] Logitech Bus Mouse Driver
1290 loglevel= All Kernel Messages with a loglevel smaller than the
1291 console loglevel will be printed to the console. It can
1292 also be changed with klogd or other programs. The
1293 loglevels are defined as follows:
1295 0 (KERN_EMERG) system is unusable
1296 1 (KERN_ALERT) action must be taken immediately
1297 2 (KERN_CRIT) critical conditions
1298 3 (KERN_ERR) error conditions
1299 4 (KERN_WARNING) warning conditions
1300 5 (KERN_NOTICE) normal but significant condition
1301 6 (KERN_INFO) informational
1302 7 (KERN_DEBUG) debug-level messages
1304 log_buf_len=n Sets the size of the printk ring buffer, in bytes.
1305 Format: { n | nk | nM }
1306 n must be a power of two. The default size
1307 is set in the kernel config file.
1309 logo.nologo [FB] Disables display of the built-in Linux logo.
1310 This may be used to provide more screen space for
1311 kernel log messages and is useful when debugging
1312 kernel boot problems.
1314 lp=0 [LP] Specify parallel ports to use, e.g,
1315 lp=port[,port...] lp=none,parport0 (lp0 not configured, lp1 uses
1316 lp=reset first parallel port). 'lp=0' disables the
1317 lp=auto printer driver. 'lp=reset' (which can be
1318 specified in addition to the ports) causes
1319 attached printers to be reset. Using
1320 lp=port1,port2,... specifies the parallel ports
1321 to associate lp devices with, starting with
1322 lp0. A port specification may be 'none' to skip
1323 that lp device, or a parport name such as
1324 'parport0'. Specifying 'lp=auto' instead of a
1325 port specification list means that device IDs
1326 from each port should be examined, to see if
1327 an IEEE 1284-compliant printer is attached; if
1328 so, the driver will manage that printer.
1329 See also header of drivers/char/lp.c.
1332 Sets loops_per_jiffy to given constant, thus avoiding
1333 time-consuming boot-time autodetection (up to 250 ms per
1334 CPU). 0 enables autodetection (default). To determine
1335 the correct value for your kernel, boot with normal
1336 autodetection and see what value is printed. Note that
1337 on SMP systems the preset will be applied to all CPUs,
1338 which is likely to cause problems if your CPUs need
1339 significantly divergent settings. An incorrect value
1340 will cause delays in the kernel to be wrong, leading to
1341 unpredictable I/O errors and other breakage. Although
1342 unlikely, in the extreme case this might damage your
1346 Format: <io>,<irq>,<dma>
1348 mac5380= [HW,SCSI] Format:
1349 <can_queue>,<cmd_per_lun>,<sg_tablesize>,<hostid>,<use_tags>
1351 machvec= [IA64] Force the use of a particular machine-vector
1352 (machvec) in a generic kernel.
1353 Example: machvec=hpzx1_swiotlb
1355 machtype= [Loongson] Share the same kernel image file between different
1357 Example: machtype=lemote-yeeloong-2f-7inch
1359 max_addr=nn[KMG] [KNL,BOOT,ia64] All physical memory greater
1360 than or equal to this physical address is ignored.
1362 maxcpus= [SMP] Maximum number of processors that an SMP kernel
1363 should make use of. maxcpus=n : n >= 0 limits the
1364 kernel to using 'n' processors. n=0 is a special case,
1365 it is equivalent to "nosmp", which also disables
1368 max_loop= [LOOP] Maximum number of loopback devices that can
1372 max_luns= [SCSI] Maximum number of LUNs to probe.
1373 Should be between 1 and 2^32-1.
1376 [SCSI] Maximum number of LUNs received.
1377 Should be between 1 and 16384.
1381 mce [X86-32] Machine Check Exception
1383 mce=option [X86-64] See Documentation/x86/x86_64/boot-options.txt
1385 md= [HW] RAID subsystems devices and level
1386 See Documentation/md.txt.
1389 Format: <first>,<last>
1390 Specifies range of consoles to be captured by the MDA.
1392 mem=nn[KMG] [KNL,BOOT] Force usage of a specific amount of memory
1393 Amount of memory to be used when the kernel is not able
1394 to see the whole system memory or for test.
1395 [X86-32] Use together with memmap= to avoid physical
1396 address space collisions. Without memmap= PCI devices
1397 could be placed at addresses belonging to unused RAM.
1399 mem=nopentium [BUGS=X86-32] Disable usage of 4MB pages for kernel
1403 [KNL,SH] Allow user to override the default size for
1404 per-device physically contiguous DMA buffers.
1406 memmap=exactmap [KNL,X86] Enable setting of an exact
1407 E820 memory map, as specified by the user.
1408 Such memmap=exactmap lines can be constructed based on
1409 BIOS output or other requirements. See the memmap=nn@ss
1412 memmap=nn[KMG]@ss[KMG]
1413 [KNL] Force usage of a specific region of memory
1414 Region of memory to be used, from ss to ss+nn.
1416 memmap=nn[KMG]#ss[KMG]
1417 [KNL,ACPI] Mark specific memory as ACPI data.
1418 Region of memory to be used, from ss to ss+nn.
1420 memmap=nn[KMG]$ss[KMG]
1421 [KNL,ACPI] Mark specific memory as reserved.
1422 Region of memory to be used, from ss to ss+nn.
1423 Example: Exclude memory from 0x18690000-0x1869ffff
1424 memmap=64K$0x18690000
1426 memmap=0x10000$0x18690000
1428 memory_corruption_check=0/1 [X86]
1429 Some BIOSes seem to corrupt the first 64k of
1430 memory when doing things like suspend/resume.
1431 Setting this option will scan the memory
1432 looking for corruption. Enabling this will
1433 both detect corruption and prevent the kernel
1434 from using the memory being corrupted.
1435 However, its intended as a diagnostic tool; if
1436 repeatable BIOS-originated corruption always
1437 affects the same memory, you can use memmap=
1438 to prevent the kernel from using that memory.
1440 memory_corruption_check_size=size [X86]
1441 By default it checks for corruption in the low
1442 64k, making this memory unavailable for normal
1443 use. Use this parameter to scan for
1444 corruption in more or less memory.
1446 memory_corruption_check_period=seconds [X86]
1447 By default it checks for corruption every 60
1448 seconds. Use this parameter to check at some
1449 other rate. 0 disables periodic checking.
1451 memtest= [KNL,X86] Enable memtest
1453 default : 0 <disable>
1454 Specifies the number of memtest passes to be
1455 performed. Each pass selects another test
1456 pattern from a given set of patterns. Memtest
1457 fills the memory with this pattern, validates
1458 memory contents and reserves bad memory
1459 regions that are detected.
1461 meye.*= [HW] Set MotionEye Camera parameters
1462 See Documentation/video4linux/meye.txt.
1464 mfgpt_irq= [IA-32] Specify the IRQ to use for the
1465 Multi-Function General Purpose Timers on AMD Geode
1468 mfgptfix [X86-32] Fix MFGPT timers on AMD Geode platforms when
1469 the BIOS has incorrectly applied a workaround. TinyBIOS
1470 version 0.98 is known to be affected, 0.99 fixes the
1471 problem by letting the user disable the workaround.
1475 min_addr=nn[KMG] [KNL,BOOT,ia64] All physical memory below this
1476 physical address is ignored.
1478 mini2440= [ARM,HW,KNL]
1479 Format:[0..2][b][c][t]
1481 MINI2440 configuration specification:
1482 0 - The attached screen is the 3.5" TFT
1483 1 - The attached screen is the 7" TFT
1484 2 - The VGA Shield is attached (1024x768)
1485 Leaving out the screen size parameter will not load
1486 the TFT driver, and the framebuffer will be left
1488 b - Enable backlight. The TFT backlight pin will be
1489 linked to the kernel VESA blanking code and a GPIO
1490 LED. This parameter is not necessary when using the
1492 c - Enable the s3c camera interface.
1493 t - Reserved for enabling touchscreen support. The
1494 touchscreen support is not enabled in the mainstream
1495 kernel as of 2.6.30, a preliminary port can be found
1496 in the "bleeding edge" mini2440 support kernel at
1497 http://repo.or.cz/w/linux-2.6/mini2440.git
1500 [KNL] When CONFIG_DEBUG_MEMORY_INIT is set, this
1501 parameter allows control of the logging verbosity for
1502 the additional memory initialisation checks. A value
1503 of 0 disables mminit logging and a level of 4 will
1504 log everything. Information is printed at KERN_DEBUG
1505 so loglevel=8 may also need to be specified.
1508 [MOUSE] Maximum time between finger touching and
1509 leaving touchpad surface for touch to be considered
1510 a tap and be reported as a left button click (for
1511 touchpads working in absolute mode only).
1513 mousedev.xres= [MOUSE] Horizontal screen resolution, used for devices
1514 reporting absolute coordinates, such as tablets
1515 mousedev.yres= [MOUSE] Vertical screen resolution, used for devices
1516 reporting absolute coordinates, such as tablets
1518 movablecore=nn[KMG] [KNL,X86,IA-64,PPC] This parameter
1519 is similar to kernelcore except it specifies the
1520 amount of memory used for migratable allocations.
1521 If both kernelcore and movablecore is specified,
1522 then kernelcore will be at *least* the specified
1523 value but may be more. If movablecore on its own
1524 is specified, the administrator must be careful
1525 that the amount of memory usable for all allocations
1531 MTD_Partition= [MTD]
1532 Format: <name>,<region-number>,<size>,<offset>
1534 MTD_Region= [MTD] Format:
1535 <name>,<region-number>[,<base>,<size>,<buswidth>,<altbuswidth>]
1538 See drivers/mtd/cmdlinepart.c.
1540 onenand.bdry= [HW,MTD] Flex-OneNAND Boundary Configuration
1542 Format: [die0_boundary][,die0_lock][,die1_boundary][,die1_lock]
1544 boundary - index of last SLC block on Flex-OneNAND.
1545 The remaining blocks are configured as MLC blocks.
1546 lock - Configure if Flex-OneNAND boundary should be locked.
1547 Once locked, the boundary cannot be changed.
1548 1 indicates lock status, 0 indicates unlock status.
1551 ARM/S3C2412 JIVE boot control
1553 See arch/arm/mach-s3c2412/mach-jive.c
1555 mtouchusb.raw_coordinates=
1556 [HW] Make the MicroTouch USB driver use raw coordinates
1557 ('y', default) or cooked coordinates ('n')
1559 mtrr_chunk_size=nn[KMG] [X86]
1560 used for mtrr cleanup. It is largest continuous chunk
1561 that could hold holes aka. UC entries.
1563 mtrr_gran_size=nn[KMG] [X86]
1564 Used for mtrr cleanup. It is granularity of mtrr block.
1566 Large value could prevent small alignment from
1569 mtrr_spare_reg_nr=n [X86]
1571 Range: 0,7 : spare reg number
1573 Used for mtrr cleanup. It is spare mtrr entries number.
1574 Set to 2 or more if your graphical card needs more.
1576 n2= [NET] SDL Inc. RISCom/N2 synchronous serial card
1579 See header of drivers/scsi/NCR_D700.c.
1583 ncr53c400= [HW,SCSI]
1585 ncr53c400a= [HW,SCSI]
1587 ncr53c406a= [HW,SCSI]
1589 ncr53c8xx= [HW,SCSI]
1591 netdev= [NET] Network devices parameters
1592 Format: <irq>,<io>,<mem_start>,<mem_end>,<name>
1593 Note that mem_start is often overloaded to mean
1594 something different and driver-specific.
1595 This usage is only documented in each driver source
1599 [NETFILTER] Enable connection tracking flow accounting
1600 0 to disable accounting
1601 1 to enable accounting
1605 See Documentation/filesystems/nfs/nfsroot.txt.
1607 nfsroot= [NFS] nfs root filesystem for disk-less boxes.
1608 See Documentation/filesystems/nfs/nfsroot.txt.
1610 nfs.callback_tcpport=
1611 [NFS] set the TCP port on which the NFSv4 callback
1612 channel should listen.
1615 [NFS] sets the pathname to the program which is used
1616 to update the NFS client cache entries.
1618 nfs.cache_getent_timeout=
1619 [NFS] sets the timeout after which an attempt to
1620 update a cache entry is deemed to have failed.
1622 nfs.idmap_cache_timeout=
1623 [NFS] set the maximum lifetime for idmapper cache
1627 [NFS] enable 64-bit inode numbers.
1628 If zero, the NFS client will fake up a 32-bit inode
1629 number for the readdir() and stat() syscalls instead
1630 of returning the full 64-bit number.
1631 The default is to return 64-bit inode numbers.
1633 nmi_debug= [KNL,AVR32,SH] Specify one or more actions to take
1634 when a NMI is triggered.
1635 Format: [state][,regs][,debounce][,die]
1637 nmi_watchdog= [KNL,BUGS=X86] Debugging features for SMP kernels
1638 Format: [panic,][num]
1640 0 - turn nmi_watchdog off
1641 1 - use the IO-APIC timer for the NMI watchdog
1642 2 - use the local APIC for the NMI watchdog using
1643 a performance counter. Note: This will use one
1644 performance counter and the local APIC's performance
1646 When panic is specified, panic when an NMI watchdog
1648 This is useful when you use a panic=... timeout and
1649 need the box quickly up again.
1650 Instead of 1 and 2 it is possible to use the following
1651 symbolic names: lapic and ioapic
1652 Example: nmi_watchdog=2 or nmi_watchdog=panic,lapic
1654 netpoll.carrier_timeout=
1655 [NET] Specifies amount of time (in seconds) that
1656 netpoll should wait for a carrier. By default netpoll
1659 no387 [BUGS=X86-32] Tells the kernel to use the 387 maths
1660 emulation library even if a 387 maths coprocessor
1664 [HW] Never suspend the console
1665 Disable suspending of consoles during suspend and
1666 hibernate operations. Once disabled, debugging
1667 messages can reach various consoles while the rest
1668 of the system is being put to sleep (ie, while
1669 debugging driver suspend/resume hooks). This may
1670 not work reliably with all consoles, but is known
1671 to work with serial and VGA consoles.
1673 noaliencache [MM, NUMA, SLAB] Disables the allocation of alien
1674 caches in the slab allocator. Saves per-node memory,
1675 but will impact performance.
1679 noapic [SMP,APIC] Tells the kernel to not make use of any
1680 IOAPICs that may be present in the system.
1682 nobats [PPC] Do not use BATs for mapping kernel lowmem
1683 on "Classic" PPC cores.
1687 noclflush [BUGS=X86] Don't use the CLFLUSH instruction
1689 nodelayacct [KNL] Disable per-task delay accounting
1691 nodisconnect [HW,SCSI,M68K] Disables SCSI disconnects.
1693 nodsp [SH] Disable hardware DSP at boot time.
1695 noefi [X86] Disable EFI runtime services support.
1700 On X86-32 available only on PAE configured kernels.
1701 noexec=on: enable non-executable mappings (default)
1702 noexec=off: disable non-executable mappings
1705 This affects only 32-bit executables.
1706 noexec32=on: enable non-executable mappings (default)
1707 read doesn't imply executable mappings
1708 noexec32=off: disable non-executable mappings
1709 read implies executable mappings
1711 nofpu [SH] Disable hardware FPU at boot time.
1713 nofxsr [BUGS=X86-32] Disables x86 floating point extended
1714 register save and restore. The kernel will only save
1715 legacy floating-point registers on task switch.
1717 noxsave [BUGS=X86] Disables x86 extended register state save
1718 and restore using xsave. The kernel will fallback to
1719 enabling legacy floating-point and sse state.
1721 nohlt [BUGS=ARM,SH] Tells the kernel that the sleep(SH) or
1722 wfi(ARM) instruction doesn't work correctly and not to
1723 use it. This is also useful when using JTAG debugger.
1725 no-hlt [BUGS=X86-32] Tells the kernel that the hlt
1726 instruction doesn't work correctly and not to
1729 no_file_caps Tells the kernel not to honor file capabilities. The
1730 only way then for a file to be executed with privilege
1731 is to be setuid root or executed by root.
1733 nohalt [IA-64] Tells the kernel not to use the power saving
1734 function PAL_HALT_LIGHT when idle. This increases
1735 power-consumption. On the positive side, it reduces
1736 interrupt wake-up latency, which may improve performance
1737 in certain environments such as networked servers or
1740 nohz= [KNL] Boottime enable/disable dynamic ticks
1741 Valid arguments: on, off
1744 noiotrap [SH] Disables trapped I/O port accesses.
1746 noirqdebug [X86-32] Disables the code which attempts to detect and
1747 disable unhandled interrupt sources.
1749 no_timer_check [X86,APIC] Disables the code which tests for
1750 broken timer IRQ sources.
1752 noisapnp [ISAPNP] Disables ISA PnP code.
1754 noinitrd [RAM] Tells the kernel not to load any configured
1757 nointremap [X86-64, Intel-IOMMU] Do not enable interrupt
1762 nojitter [IA64] Disables jitter checking for ITC timers.
1764 nolapic [X86-32,APIC] Do not enable or use the local APIC.
1766 nolapic_timer [X86-32,APIC] Do not use the local APIC timer.
1768 noltlbs [PPC] Do not use large page/tlb entries for kernel
1769 lowmem mapping on PPC40x.
1771 nomca [IA-64] Disable machine check abort handling
1773 nomce [X86-32] Machine Check Exception
1775 nomfgpt [X86-32] Disable Multi-Function General Purpose
1776 Timer usage (for AMD Geode machines).
1778 nopat [X86] Disable PAT (page attribute table extension of
1779 pagetables) support.
1781 norandmaps Don't use address space randomization. Equivalent to
1782 echo 0 > /proc/sys/kernel/randomize_va_space
1784 noreplace-paravirt [X86-32,PV_OPS] Don't patch paravirt_ops
1786 noreplace-smp [X86-32,SMP] Don't replace SMP instructions
1787 with UP alternatives
1789 noresidual [PPC] Don't use residual data on PReP machines.
1791 noresume [SWSUSP] Disables resume and restores original swap
1794 no-scroll [VGA] Disables scrollback.
1795 This is required for the Braillex ib80-piezo Braille
1796 reader made by F.H. Papenmeier (Germany).
1800 nosep [BUGS=X86-32] Disables x86 SYSENTER/SYSEXIT support.
1802 nosmp [SMP] Tells an SMP kernel to act as a UP kernel,
1803 and disable the IO APIC. legacy for "maxcpus=0".
1805 nosoftlockup [KNL] Disable the soft-lockup detector.
1807 noswapaccount [KNL] Disable accounting of swap in memory resource
1808 controller. (See Documentation/cgroups/memory.txt)
1810 nosync [HW,M68K] Disables sync negotiation for all devices.
1812 notsc [BUGS=X86-32] Disable Time Stamp Counter
1814 nousb [USB] Disable the USB subsystem
1818 nox2apic [X86-64,APIC] Do not enable x2APIC mode.
1820 nptcg= [IA64] Override max number of concurrent global TLB
1821 purges which is reported from either PAL_VM_SUMMARY or
1824 nr_cpus= [SMP] Maximum number of processors that an SMP kernel
1825 could support. nr_cpus=n : n >= 1 limits the kernel to
1826 supporting 'n' processors. Later in runtime you can not
1827 use hotplug cpu feature to put more cpu back to online.
1828 just like you compile the kernel NR_CPUS=n
1830 nr_uarts= [SERIAL] maximum number of UARTs to be registered.
1832 numa_zonelist_order= [KNL, BOOT] Select zonelist order for NUMA.
1833 one of ['zone', 'node', 'default'] can be specified
1834 This can be set from sysctl after boot.
1835 See Documentation/sysctl/vm.txt for details.
1837 ohci1394_dma=early [HW] enable debugging via the ohci1394 driver.
1838 See Documentation/debugging-via-ohci1394.txt for more
1841 olpc_ec_timeout= [OLPC] ms delay when issuing EC commands
1842 Rather than timing out after 20 ms if an EC
1843 command is not properly ACKed, override the length
1844 of the timeout. We have interrupts disabled while
1845 waiting for the ACK, so if this is set too high
1846 interrupts *may* be lost!
1848 omap_mux= [OMAP] Override bootloader pin multiplexing.
1849 Format: <mux_mode0.mode_name=value>...
1850 For example, to override I2C bus2:
1851 omap_mux=i2c2_scl.i2c2_scl=0x100,i2c2_sda.i2c2_sda=0x100
1856 oprofile.timer= [HW]
1857 Use timer interrupt instead of performance counters
1859 oprofile.cpu_type= Force an oprofile cpu type
1860 This might be useful if you have an older oprofile
1861 userland or if you want common events.
1862 Format: { arch_perfmon }
1863 arch_perfmon: [X86] Force use of architectural
1864 perfmon on Intel CPUs instead of the
1865 CPU specific event set.
1867 osst= [HW,SCSI] SCSI Tape Driver
1868 Format: <buffer_size>,<write_threshold>
1869 See also Documentation/scsi/st.txt.
1871 panic= [KNL] Kernel behaviour on panic
1874 parkbd.port= [HW] Parallel port number the keyboard adapter is
1875 connected to, default is 0.
1877 parkbd.mode= [HW] Parallel port keyboard adapter mode of operation,
1878 0 for XT, 1 for AT (default is AT).
1881 parport= [HW,PPT] Specify parallel ports. 0 disables.
1882 Format: { 0 | auto | 0xBBB[,IRQ[,DMA]] }
1883 Use 'auto' to force the driver to use any
1884 IRQ/DMA settings detected (the default is to
1885 ignore detected IRQ/DMA settings because of
1886 possible conflicts). You can specify the base
1887 address, IRQ, and DMA settings; IRQ and DMA
1888 should be numbers, or 'auto' (for using detected
1889 settings on that particular port), or 'nofifo'
1890 (to avoid using a FIFO even if it is detected).
1891 Parallel ports are assigned in the order they
1892 are specified on the command line, starting
1895 parport_init_mode= [HW,PPT]
1896 Configure VIA parallel port to operate in
1897 a specific mode. This is necessary on Pegasos
1898 computer where firmware has no options for setting
1899 up parallel port mode and sets it to spp.
1900 Currently this function knows 686a and 8231 chips.
1901 Format: [spp|ps2|epp|ecp|ecpepp]
1903 pas2= [HW,OSS] Format:
1904 <io>,<irq>,<dma>,<dma16>,<sb_io>,<sb_irq>,<sb_dma>,<sb_dma16>
1907 See header of drivers/scsi/pas16.c.
1910 Halt all CPUs after the first oops has been printed for
1911 the specified number of seconds. This is to be used if
1912 your oopses keep scrolling off the screen.
1917 See header of drivers/block/paride/pcd.c.
1918 See also Documentation/blockdev/paride.txt.
1920 pci=option[,option...] [PCI] various PCI subsystem options:
1921 earlydump [X86] dump PCI config space before the kernel
1923 off [X86] don't probe for the PCI bus
1924 bios [X86-32] force use of PCI BIOS, don't access
1925 the hardware directly. Use this if your machine
1926 has a non-standard PCI host bridge.
1927 nobios [X86-32] disallow use of PCI BIOS, only direct
1928 hardware access methods are allowed. Use this
1929 if you experience crashes upon bootup and you
1930 suspect they are caused by the BIOS.
1931 conf1 [X86] Force use of PCI Configuration
1933 conf2 [X86] Force use of PCI Configuration
1935 noaer [PCIE] If the PCIEAER kernel config parameter is
1936 enabled, this kernel boot option can be used to
1937 disable the use of PCIE advanced error reporting.
1938 nodomains [PCI] Disable support for multiple PCI
1939 root domains (aka PCI segments, in ACPI-speak).
1940 nommconf [X86] Disable use of MMCONFIG for PCI
1942 check_enable_amd_mmconf [X86] check for and enable
1943 properly configured MMIO access to PCI
1944 config space on AMD family 10h CPU
1945 nomsi [MSI] If the PCI_MSI kernel config parameter is
1946 enabled, this kernel boot option can be used to
1947 disable the use of MSI interrupts system-wide.
1948 noioapicquirk [APIC] Disable all boot interrupt quirks.
1949 Safety option to keep boot IRQs enabled. This
1950 should never be necessary.
1951 ioapicreroute [APIC] Enable rerouting of boot IRQs to the
1952 primary IO-APIC for bridges that cannot disable
1953 boot IRQs. This fixes a source of spurious IRQs
1954 when the system masks IRQs.
1955 noioapicreroute [APIC] Disable workaround that uses the
1956 boot IRQ equivalent of an IRQ that connects to
1957 a chipset where boot IRQs cannot be disabled.
1958 The opposite of ioapicreroute.
1959 biosirq [X86-32] Use PCI BIOS calls to get the interrupt
1960 routing table. These calls are known to be buggy
1961 on several machines and they hang the machine
1962 when used, but on other computers it's the only
1963 way to get the interrupt routing table. Try
1964 this option if the kernel is unable to allocate
1965 IRQs or discover secondary PCI buses on your
1967 rom [X86] Assign address space to expansion ROMs.
1968 Use with caution as certain devices share
1969 address decoders between ROMs and other
1971 norom [X86] Do not assign address space to
1972 expansion ROMs that do not already have
1973 BIOS assigned address ranges.
1974 irqmask=0xMMMM [X86] Set a bit mask of IRQs allowed to be
1975 assigned automatically to PCI devices. You can
1976 make the kernel exclude IRQs of your ISA cards
1978 pirqaddr=0xAAAAA [X86] Specify the physical address
1979 of the PIRQ table (normally generated
1980 by the BIOS) if it is outside the
1981 F0000h-100000h range.
1982 lastbus=N [X86] Scan all buses thru bus #N. Can be
1983 useful if the kernel is unable to find your
1984 secondary buses and you want to tell it
1985 explicitly which ones they are.
1986 assign-busses [X86] Always assign all PCI bus
1987 numbers ourselves, overriding
1988 whatever the firmware may have done.
1989 usepirqmask [X86] Honor the possible IRQ mask stored
1990 in the BIOS $PIR table. This is needed on
1991 some systems with broken BIOSes, notably
1992 some HP Pavilion N5400 and Omnibook XE3
1993 notebooks. This will have no effect if ACPI
1994 IRQ routing is enabled.
1995 noacpi [X86] Do not use ACPI for IRQ routing
1996 or for PCI scanning.
1997 use_crs [X86] Use PCI host bridge window information
1998 from ACPI. On BIOSes from 2008 or later, this
1999 is enabled by default. If you need to use this,
2000 please report a bug.
2001 nocrs [X86] Ignore PCI host bridge windows from ACPI.
2002 If you need to use this, please report a bug.
2003 routeirq Do IRQ routing for all PCI devices.
2004 This is normally done in pci_enable_device(),
2005 so this option is a temporary workaround
2006 for broken drivers that don't call it.
2007 skip_isa_align [X86] do not align io start addr, so can
2008 handle more pci cards
2009 firmware [ARM] Do not re-enumerate the bus but instead
2010 just use the configuration from the
2011 bootloader. This is currently used on
2012 IXP2000 systems where the bus has to be
2013 configured a certain way for adjunct CPUs.
2014 noearly [X86] Don't do any early type 1 scanning.
2015 This might help on some broken boards which
2016 machine check when some devices' config space
2017 is read. But various workarounds are disabled
2018 and some IOMMU drivers will not work.
2019 bfsort Sort PCI devices into breadth-first order.
2020 This sorting is done to get a device
2021 order compatible with older (<= 2.4) kernels.
2022 nobfsort Don't sort PCI devices into breadth-first order.
2023 cbiosize=nn[KMG] The fixed amount of bus space which is
2024 reserved for the CardBus bridge's IO window.
2025 The default value is 256 bytes.
2026 cbmemsize=nn[KMG] The fixed amount of bus space which is
2027 reserved for the CardBus bridge's memory
2028 window. The default value is 64 megabytes.
2031 [<order of align>@][<domain>:]<bus>:<slot>.<func>[; ...]
2032 Specifies alignment and device to reassign
2033 aligned memory resources.
2034 If <order of align> is not specified,
2035 PAGE_SIZE is used as alignment.
2036 PCI-PCI bridge can be specified, if resource
2037 windows need to be expanded.
2038 ecrc= Enable/disable PCIe ECRC (transaction layer
2039 end-to-end CRC checking).
2040 bios: Use BIOS/firmware settings. This is the
2045 pcie_aspm= [PCIE] Forcibly enable or disable PCIe Active State Power
2048 force Enable ASPM even on devices that claim not to support it.
2049 WARNING: Forcing ASPM on may cause system lockups.
2051 pcie_pme= [PCIE,PM] Native PCIe PME signaling options:
2052 Format: {auto|force}[,nomsi]
2053 auto Use native PCIe PME signaling if the BIOS allows the
2054 kernel to control PCIe config registers of root ports.
2055 force Use native PCIe PME signaling even if the BIOS refuses
2056 to allow the kernel to control the relevant PCIe config
2058 nomsi Do not use MSI for native PCIe PME signaling (this makes
2059 all PCIe root ports use INTx for everything).
2061 pcmv= [HW,PCMCIA] BadgePAD 4
2064 See Documentation/blockdev/paride.txt.
2066 pdcchassis= [PARISC,HW] Disable/Enable PDC Chassis Status codes at
2069 See arch/parisc/kernel/pdc_chassis.c
2071 percpu_alloc= Select which percpu first chunk allocator to use.
2072 Currently supported values are "embed" and "page".
2073 Archs may support subset or none of the selections.
2074 See comments in mm/percpu.c for details on each
2075 allocator. This parameter is primarily for debugging
2076 and performance comparison.
2079 See Documentation/blockdev/paride.txt.
2082 See Documentation/blockdev/paride.txt.
2084 pirq= [SMP,APIC] Manual mp-table setup
2085 See Documentation/x86/i386/IO-APIC.txt.
2087 plip= [PPT,NET] Parallel port network link
2088 Format: { parport<nr> | timid | 0 }
2089 See also Documentation/parport.txt.
2091 pmtmr= [X86] Manual setup of pmtmr I/O Port.
2092 Override pmtimer IOPort with a hex value.
2096 Enable PNP debug messages. This depends on the
2097 CONFIG_PNP_DEBUG_MESSAGES option.
2103 { on | off | curr | res | no-curr | no-res }
2106 [ISAPNP] Exclude IRQs for the autoconfiguration
2109 [ISAPNP] Exclude DMAs for the autoconfiguration
2111 pnp_reserve_io= [ISAPNP] Exclude I/O ports for the autoconfiguration
2112 Ranges are in pairs (I/O port base and size).
2115 [ISAPNP] Exclude memory regions for the
2117 Ranges are in pairs (memory base and size).
2119 ports= [IP_VS_FTP] IPVS ftp helper module
2121 Up to 8 (IP_VS_APP_MAX_PORTS) ports
2123 Format: <port>,<port>....
2125 print-fatal-signals=
2126 [KNL] debug: print fatal signals
2128 If enabled, warn about various signal handling
2129 related application anomalies: too many signals,
2130 too many POSIX.1 timers, fatal signals causing a
2133 If you hit the warning due to signal overflow,
2134 you might want to try "ulimit -i unlimited".
2138 printk.time= Show timing data prefixed to each printk message line
2139 Format: <bool> (1/Y/y=enable, 0/N/n=disable)
2141 processor.max_cstate= [HW,ACPI]
2142 Limit processor to maximum C-state
2143 max_cstate=9 overrides any DMI blacklist limit.
2145 processor.nocst [HW,ACPI]
2146 Ignore the _CST method to determine C-states,
2147 instead using the legacy FADT method
2149 profile= [KNL] Enable kernel profiling via /proc/profile
2150 Format: [schedule,]<number>
2151 Param: "schedule" - profile schedule points.
2152 Param: <number> - step/bucket size as a power of 2 for
2153 statistical time based profiling.
2154 Param: "sleep" - profile D-state sleeping (millisecs).
2155 Requires CONFIG_SCHEDSTATS
2156 Param: "kvm" - profile VM exits.
2158 prompt_ramdisk= [RAM] List of RAM disks to prompt for floppy disk
2160 See Documentation/blockdev/ramdisk.txt.
2162 psmouse.proto= [HW,MOUSE] Highest PS2 mouse protocol extension to
2163 probe for; one of (bare|imps|exps|lifebook|any).
2164 psmouse.rate= [HW,MOUSE] Set desired mouse report rate, in reports
2166 psmouse.resetafter= [HW,MOUSE]
2167 Try to reset the device after so many bad packets
2170 [HW,MOUSE] Set desired mouse resolution, in dpi.
2171 psmouse.smartscroll=
2172 [HW,MOUSE] Controls Logitech smartscroll autorepeat.
2173 0 = disabled, 1 = enabled (default).
2175 pss= [HW,OSS] Personal Sound System (ECHO ESC614)
2177 <io>,<mss_io>,<mss_irq>,<mss_dma>,<mpu_io>,<mpu_irq>
2180 See Documentation/blockdev/paride.txt.
2183 [KNL] Number of legacy pty's. Overwrites compiled-in
2186 quiet [KNL] Disable most log messages
2191 See Documentation/md.txt.
2193 ramdisk_blocksize= [RAM]
2194 See Documentation/blockdev/ramdisk.txt.
2196 ramdisk_size= [RAM] Sizes of RAM disks in kilobytes
2197 See Documentation/blockdev/ramdisk.txt.
2199 rcupdate.blimit= [KNL,BOOT]
2200 Set maximum number of finished RCU callbacks to process
2203 rcupdate.qhimark= [KNL,BOOT]
2204 Set threshold of queued
2205 RCU callbacks over which batch limiting is disabled.
2207 rcupdate.qlowmark= [KNL,BOOT]
2208 Set threshold of queued RCU callbacks below which
2209 batch limiting is re-enabled.
2213 Run specified binary instead of /init from the ramdisk,
2214 used for early userspace startup. See initrd.
2216 reboot= [BUGS=X86-32,BUGS=ARM,BUGS=IA-64] Rebooting mode
2217 Format: <reboot_mode>[,<reboot_mode2>[,...]]
2218 See arch/*/kernel/reboot.c or arch/*/kernel/process.c
2221 [KNL, SMP] Set scheduler's default relax_domain_level.
2222 See Documentation/cgroups/cpusets.txt.
2224 reserve= [KNL,BUGS] Force the kernel to ignore some iomem area
2226 reservetop= [X86-32]
2228 Reserves a hole at the top of the kernel virtual
2231 reset_devices [KNL] Force drivers to reset the underlying device
2232 during initialization.
2235 Specify the partition device for software suspend
2237 resume_offset= [SWSUSP]
2238 Specify the offset from the beginning of the partition
2239 given by "resume=" at which the swap header is located,
2240 in <PAGE_SIZE> units (needed only for swap files).
2241 See Documentation/power/swsusp-and-swap-files.txt
2243 retain_initrd [RAM] Keep initrd memory after extraction
2245 rhash_entries= [KNL,NET]
2246 Set number of hash buckets for route cache
2248 riscom8= [HW,SERIAL]
2249 Format: <io_board1>[,<io_board2>[,...<io_boardN>]]
2251 ro [KNL] Mount root device read-only on boot
2253 root= [KNL] Root filesystem
2255 rootdelay= [KNL] Delay (in seconds) to pause before attempting to
2256 mount the root filesystem
2258 rootflags= [KNL] Set root filesystem mount option string
2260 rootfstype= [KNL] Set root filesystem type
2262 rootwait [KNL] Wait (indefinitely) for root device to show up.
2263 Useful for devices that are detected asynchronously
2264 (e.g. USB and MMC devices).
2266 rw [KNL] Mount root device read-write on boot
2268 S [KNL] Run init in single mode
2271 See drivers/net/irda/sa1100_ir.c.
2273 sbni= [NET] Granch SBNI12 leased line adapter
2275 sched_debug [KNL] Enables verbose scheduler debug messages.
2277 scsi_debug_*= [SCSI]
2278 See drivers/scsi/scsi_debug.c.
2280 scsi_default_dev_flags=
2281 [SCSI] SCSI default device flags
2284 scsi_dev_flags= [SCSI] Black/white list entry for vendor and model
2285 Format: <vendor>:<model>:<flags>
2286 (flags are integer value)
2288 scsi_logging_level= [SCSI] a bit mask of logging levels
2289 See drivers/scsi/scsi_logging.h for bits. Also
2290 settable via sysctl at dev.scsi.logging_level
2291 (/proc/sys/dev/scsi/logging_level).
2292 There is also a nice 'scsi_logging_level' script in the
2293 S390-tools package, available for download at
2294 http://www-128.ibm.com/developerworks/linux/linux390/s390-tools-1.5.4.html
2296 scsi_mod.scan= [SCSI] sync (default) scans SCSI busses as they are
2297 discovered. async scans them in kernel threads,
2298 allowing boot to proceed. none ignores them, expecting
2299 user space to do the scan.
2301 security= [SECURITY] Choose a security module to enable at boot.
2302 If this boot parameter is not specified, only the first
2303 security module asking for security registration will be
2304 loaded. An invalid security module name will be treated
2305 as if no module has been chosen.
2307 selinux= [SELINUX] Disable or enable SELinux at boot time.
2308 Format: { "0" | "1" }
2309 See security/selinux/Kconfig help text.
2312 Default value is set via kernel config option.
2313 If enabled at boot time, /selinux/disable can be used
2314 later to disable prior to initial policy load.
2316 apparmor= [APPARMOR] Disable or enable AppArmor at boot time
2317 Format: { "0" | "1" }
2318 See security/apparmor/Kconfig help text
2321 Default value is set via kernel config option.
2323 serialnumber [BUGS=X86-32]
2326 Maximal number of shapers.
2328 show_msr= [x86] show boot-time MSR settings
2329 Format: { <integer> }
2330 Show boot-time (BIOS-initialized) MSR settings.
2331 The parameter means the number of CPUs to show,
2332 for example 1 means boot CPU only.
2335 See header of drivers/scsi/sim710.c.
2342 slub_debug[=options[,slabs]] [MM, SLUB]
2343 Enabling slub_debug allows one to determine the
2344 culprit if slab objects become corrupted. Enabling
2345 slub_debug can create guard zones around objects and
2346 may poison objects when not in use. Also tracks the
2347 last alloc / free. For more information see
2348 Documentation/vm/slub.txt.
2350 slub_max_order= [MM, SLUB]
2351 Determines the maximum allowed order for slabs.
2352 A high setting may cause OOMs due to memory
2353 fragmentation. For more information see
2354 Documentation/vm/slub.txt.
2356 slub_min_objects= [MM, SLUB]
2357 The minimum number of objects per slab. SLUB will
2358 increase the slab order up to slub_max_order to
2359 generate a sufficiently large slab able to contain
2360 the number of objects indicated. The higher the number
2361 of objects the smaller the overhead of tracking slabs
2362 and the less frequently locks need to be acquired.
2363 For more information see Documentation/vm/slub.txt.
2365 slub_min_order= [MM, SLUB]
2366 Determines the mininum page order for slabs. Must be
2367 lower than slub_max_order.
2368 For more information see Documentation/vm/slub.txt.
2370 slub_nomerge [MM, SLUB]
2371 Disable merging of slabs with similar size. May be
2372 necessary if there is some reason to distinguish
2373 allocs to different slabs. Debug options disable
2374 merging on their own.
2375 For more information see Documentation/vm/slub.txt.
2378 Format: <io1>[,<io2>[,...,<io8>]]
2380 smp-alt-once [X86-32,SMP] On a hotplug CPU system, only
2381 attempt to substitute SMP alternatives once at boot.
2383 smsc-ircc2.nopnp [HW] Don't use PNP to discover SMC devices
2384 smsc-ircc2.ircc_cfg= [HW] Device configuration I/O port
2385 smsc-ircc2.ircc_sir= [HW] SIR base I/O port
2386 smsc-ircc2.ircc_fir= [HW] FIR base I/O port
2387 smsc-ircc2.ircc_irq= [HW] IRQ line
2388 smsc-ircc2.ircc_dma= [HW] DMA channel
2389 smsc-ircc2.ircc_transceiver= [HW] Transceiver type:
2390 0: Toshiba Satellite 1800 (GP data pin select)
2391 1: Fast pin select (default)
2394 snd-ad1816a= [HW,ALSA]
2396 snd-ad1848= [HW,ALSA]
2398 snd-ali5451= [HW,ALSA]
2400 snd-als100= [HW,ALSA]
2402 snd-als4000= [HW,ALSA]
2404 snd-azt2320= [HW,ALSA]
2406 snd-cmi8330= [HW,ALSA]
2408 snd-cmipci= [HW,ALSA]
2410 snd-cs4231= [HW,ALSA]
2412 snd-cs4232= [HW,ALSA]
2414 snd-cs4236= [HW,ALSA]
2416 snd-cs4281= [HW,ALSA]
2418 snd-cs46xx= [HW,ALSA]
2420 snd-dt019x= [HW,ALSA]
2422 snd-dummy= [HW,ALSA]
2424 snd-emu10k1= [HW,ALSA]
2426 snd-ens1370= [HW,ALSA]
2428 snd-ens1371= [HW,ALSA]
2430 snd-es968= [HW,ALSA]
2432 snd-es1688= [HW,ALSA]
2434 snd-es18xx= [HW,ALSA]
2436 snd-es1938= [HW,ALSA]
2438 snd-es1968= [HW,ALSA]
2440 snd-fm801= [HW,ALSA]
2442 snd-gusclassic= [HW,ALSA]
2444 snd-gusextreme= [HW,ALSA]
2446 snd-gusmax= [HW,ALSA]
2450 snd-ice1712= [HW,ALSA]
2452 snd-intel8x0= [HW,ALSA]
2454 snd-interwave= [HW,ALSA]
2459 snd-korg1212= [HW,ALSA]
2461 snd-maestro3= [HW,ALSA]
2463 snd-mpu401= [HW,ALSA]
2465 snd-mtpav= [HW,ALSA]
2467 snd-nm256= [HW,ALSA]
2469 snd-opl3sa2= [HW,ALSA]
2477 snd-opti93x= [HW,ALSA]
2481 snd-rme32= [HW,ALSA]
2483 snd-rme96= [HW,ALSA]
2485 snd-rme9652= [HW,ALSA]
2491 snd-sbawe= [HW,ALSA]
2493 snd-serial= [HW,ALSA]
2495 snd-sgalaxy= [HW,ALSA]
2497 snd-sonicvibes= [HW,ALSA]
2502 snd-sun-cs4231= [HW,ALSA]
2504 snd-trident= [HW,ALSA]
2506 snd-usb-audio= [HW,ALSA,USB]
2508 snd-via82xx= [HW,ALSA]
2510 snd-virmidi= [HW,ALSA]
2512 snd-wavefront= [HW,ALSA]
2514 snd-ymfpci= [HW,ALSA]
2517 [KNL] Should the soft-lockup detector generate panics.
2519 sonypi.*= [HW] Sony Programmable I/O Control Device driver
2520 See Documentation/sonypi.txt
2522 specialix= [HW,SERIAL] Specialix multi-serial port adapter
2523 See Documentation/serial/specialix.txt.
2525 spia_io_base= [HW,MTD]
2531 Format: <io>,<irq>,<dma>,<mpu_io>,<mpu_irq>
2533 st= [HW,SCSI] SCSI tape parameters (buffers, etc.)
2534 See Documentation/scsi/st.txt.
2537 Enabled the stack tracer on boot up.
2541 Set the STI (builtin display/keyboard on the HP-PARISC
2542 machines) console (graphic card) which should be used
2543 as the initial boot-console.
2544 See also comment in drivers/video/console/sticore.c.
2547 See comment in drivers/video/console/sticore.c.
2550 Format: bpp:<bpp1>[:<bpp2>[:<bpp3>...]]
2552 sunrpc.min_resvport=
2553 sunrpc.max_resvport=
2555 SunRPC servers often require that client requests
2556 originate from a privileged port (i.e. a port in the
2557 range 0 < portnr < 1024).
2558 An administrator who wishes to reserve some of these
2559 ports for other uses may adjust the range that the
2560 kernel's sunrpc client considers to be privileged
2561 using these two parameters to set the minimum and
2562 maximum port values.
2566 Control how the NFS server code allocates CPUs to
2567 service thread pools. Depending on how many NICs
2568 you have and where their interrupts are bound, this
2569 option will affect which CPUs will do NFS serving.
2570 Note: this parameter cannot be changed while the
2571 NFS server is running.
2573 auto the server chooses an appropriate mode
2574 automatically using heuristics
2575 global a single global pool contains all CPUs
2576 percpu one pool for each CPU
2577 pernode one pool for each NUMA node (equivalent
2578 to global on non-NUMA machines)
2580 sunrpc.tcp_slot_table_entries=
2581 sunrpc.udp_slot_table_entries=
2583 Sets the upper limit on the number of simultaneous
2584 RPC calls that can be sent from the client to a
2585 server. Increasing these values may allow you to
2586 improve throughput, but will also increase the
2587 amount of memory reserved for use by the client.
2589 swiotlb= [IA-64] Number of I/O TLB slabs
2593 sym53c416= [HW,SCSI]
2594 See header of drivers/scsi/sym53c416.c.
2596 sysrq_always_enabled
2598 Ignore sysrq setting - this boot parameter will
2599 neutralize any effect of /proc/sys/kernel/sysrq.
2600 Useful for debugging.
2603 See header of drivers/scsi/t128.c.
2607 test_suspend= [SUSPEND]
2608 Specify "mem" (for Suspend-to-RAM) or "standby" (for
2609 standby suspend) as the system sleep state to briefly
2610 enter during system startup. The system is woken from
2611 this state using a wakeup-capable RTC alarm.
2613 thash_entries= [KNL,NET]
2614 Set number of hash buckets for TCP connection
2616 thermal.act= [HW,ACPI]
2617 -1: disable all active trip points in all thermal zones
2618 <degrees C>: override all lowest active trip points
2620 thermal.crt= [HW,ACPI]
2621 -1: disable all critical trip points in all thermal zones
2622 <degrees C>: override all critical trip points
2624 thermal.nocrt= [HW,ACPI]
2625 Set to disable actions on ACPI thermal zone
2626 critical and hot trip points.
2628 thermal.off= [HW,ACPI]
2629 1: disable ACPI thermal control
2631 thermal.psv= [HW,ACPI]
2632 -1: disable all passive trip points
2633 <degrees C>: override all passive trip points to this
2636 thermal.tzp= [HW,ACPI]
2637 Specify global default ACPI thermal zone polling rate
2638 <deci-seconds>: poll all this frequency
2639 0: no polling (default)
2642 See comment before function dc390_setup() in
2643 drivers/scsi/tmscsim.c.
2647 Specify if the kernel should make use of the cpu
2648 topology informations if the hardware supports these.
2649 The scheduler will make use of these informations and
2650 e.g. base its process migration decisions on it.
2655 tpm_suspend_pcr=[HW,TPM]
2656 Format: integer pcr id
2657 Specify that at suspend time, the tpm driver
2658 should extend the specified pcr with zeros,
2659 as a workaround for some chips which fail to
2660 flush the last written pcr on TPM_SaveState.
2661 This will guarantee that all the other pcrs
2664 trace_buf_size=nn[KMG]
2665 [FTRACE] will set tracing buffer size.
2667 trace_event=[event-list]
2668 [FTRACE] Set and start specified trace events in order
2669 to facilitate early boot debugging.
2670 See also Documentation/trace/events.txt
2672 trix= [HW,OSS] MediaTrix AudioTrix Pro
2674 <io>,<irq>,<dma>,<dma2>,<sb_io>,<sb_irq>,<sb_dma>,<mpu_io>,<mpu_irq>
2676 tsc= Disable clocksource-must-verify flag for TSC.
2678 [x86] reliable: mark tsc clocksource as reliable, this
2679 disables clocksource verification at runtime.
2680 Used to enable high-resolution timer mode on older
2681 hardware, and in virtualized environment.
2683 turbografx.map[2|3]= [HW,JOY]
2684 TurboGraFX parallel port interface
2686 <port#>,<js1>,<js2>,<js3>,<js4>,<js5>,<js6>,<js7>
2687 See also Documentation/input/joystick-parport.txt
2689 u14-34f= [HW,SCSI] UltraStor 14F/34F SCSI host adapter
2690 See header of drivers/scsi/u14-34f.c.
2698 uhash_entries= [KNL,NET]
2699 Set number of hash buckets for UDP/UDP-Lite connections
2702 [USB] Ignore overcurrent events (default N).
2703 Some badly-designed motherboards generate lots of
2704 bogus events, for ports that aren't wired to
2705 anything. Set this parameter to avoid log spamming.
2706 Note that genuine overcurrent events won't be
2711 Set unknown_nmi_panic=1 early on boot.
2713 usbcore.autosuspend=
2714 [USB] The autosuspend time delay (in seconds) used
2715 for newly-detected USB devices (default 2). This
2716 is the time required before an idle device will be
2717 autosuspended. Devices for which the delay is set
2718 to a negative value won't be autosuspended at all.
2720 usbcore.usbfs_snoop=
2721 [USB] Set to log all usbfs traffic (default 0 = off).
2723 usbcore.blinkenlights=
2724 [USB] Set to cycle leds on hubs (default 0 = off).
2726 usbcore.old_scheme_first=
2727 [USB] Start with the old device initialization
2728 scheme (default 0 = off).
2730 usbcore.use_both_schemes=
2731 [USB] Try the other device initialization scheme
2732 if the first one fails (default 1 = enabled).
2734 usbcore.initial_descriptor_timeout=
2735 [USB] Specifies timeout for the initial 64-byte
2736 USB_REQ_GET_DESCRIPTOR request in milliseconds
2737 (default 5000 = 5.0 seconds).
2740 [USBHID] The interval which mice are to be polled at.
2742 usb-storage.delay_use=
2743 [UMS] The delay in seconds before a new device is
2744 scanned for Logical Units (default 5).
2747 [UMS] A list of quirks entries to supplement or
2748 override the built-in unusual_devs list. List
2749 entries are separated by commas. Each entry has
2750 the form VID:PID:Flags where VID and PID are Vendor
2751 and Product ID values (4-digit hex numbers) and
2752 Flags is a set of characters, each corresponding
2753 to a common usb-storage quirk flag as follows:
2754 a = SANE_SENSE (collect more than 18 bytes
2756 b = BAD_SENSE (don't collect more than 18
2757 bytes of sense data);
2758 c = FIX_CAPACITY (decrease the reported
2759 device capacity by one sector);
2760 h = CAPACITY_HEURISTICS (decrease the
2761 reported device capacity by one
2762 sector if the number is odd);
2763 i = IGNORE_DEVICE (don't bind to this
2765 l = NOT_LOCKABLE (don't try to lock and
2766 unlock ejectable media);
2767 m = MAX_SECTORS_64 (don't transfer more
2768 than 64 sectors = 32 KB at a time);
2769 o = CAPACITY_OK (accept the capacity
2770 reported by the device);
2771 r = IGNORE_RESIDUE (the device reports
2772 bogus residue values);
2773 s = SINGLE_LUN (the device has only one
2775 w = NO_WP_DETECT (don't test whether the
2776 medium is write-protected).
2777 Example: quirks=0419:aaf5:rl,0421:0433:rc
2780 [X86] Flags controlling user PTE allocations.
2782 nohigh = do not allocate PTE pages in
2783 HIGHMEM regardless of setting
2787 vdso=2: enable compat VDSO (default with COMPAT_VDSO)
2788 vdso=1: enable VDSO (default)
2789 vdso=0: disable VDSO mapping
2792 vdso32=2: enable compat VDSO (default with COMPAT_VDSO)
2793 vdso32=1: enable 32-bit VDSO (default)
2794 vdso32=0: disable 32-bit VDSO mapping
2797 vector=percpu: enable percpu vector domain
2799 video= [FB] Frame buffer configuration
2800 See Documentation/fb/modedb.txt.
2802 vga= [BOOT,X86-32] Select a particular video mode
2803 See Documentation/x86/boot.txt and
2804 Documentation/svga.txt.
2805 Use vga=ask for menu.
2806 This is actually a boot loader parameter; the value is
2807 passed to the kernel using a special protocol.
2809 vmalloc=nn[KMG] [KNL,BOOT] Forces the vmalloc area to have an exact
2810 size of <nn>. This can be used to increase the
2811 minimum size (128MB on x86). It can also be used to
2812 decrease the size and leave more room for directly
2815 vmhalt= [KNL,S390] Perform z/VM CP command after system halt.
2818 vmpanic= [KNL,S390] Perform z/VM CP command after kernel panic.
2821 vmpoff= [KNL,S390] Perform z/VM CP command after power off.
2824 vt.cur_default= [VT] Default cursor shape.
2825 Format: 0xCCBBAA, where AA, BB, and CC are the same as
2826 the parameters of the <Esc>[?A;B;Cc escape sequence;
2827 see VGA-softcursor.txt. Default: 2 = underline.
2829 vt.default_blu= [VT]
2830 Format: <blue0>,<blue1>,<blue2>,...,<blue15>
2831 Change the default blue palette of the console.
2832 This is a 16-member array composed of values
2835 vt.default_grn= [VT]
2836 Format: <green0>,<green1>,<green2>,...,<green15>
2837 Change the default green palette of the console.
2838 This is a 16-member array composed of values
2841 vt.default_red= [VT]
2842 Format: <red0>,<red1>,<red2>,...,<red15>
2843 Change the default red palette of the console.
2844 This is a 16-member array composed of values
2850 Set system-wide default UTF-8 mode for all tty's.
2851 Default is 1, i.e. UTF-8 mode is enabled for all
2852 newly opened terminals.
2854 vt.global_cursor_default=
2857 Set system-wide default for whether a cursor
2858 is shown on new VTs. Default is -1,
2859 i.e. cursors will be created by default unless
2860 overridden by individual drivers. 0 will hide
2861 cursors, 1 will display them.
2863 waveartist= [HW,OSS]
2864 Format: <io>,<irq>,<dma>,<dma2>
2867 See header of drivers/scsi/wd33c93.c.
2870 See header of drivers/scsi/wd7000.c.
2872 watchdog timers [HW,WDT] For information on watchdog timers,
2873 see Documentation/watchdog/watchdog-parameters.txt
2874 or other driver-specific files in the
2875 Documentation/watchdog/ directory.
2877 x2apic_phys [X86-64,APIC] Use x2apic physical mode instead of
2878 default x2apic cluster mode on platforms
2881 x86_mrst_timer= [X86-32,APBT]
2882 Choose timer option for x86 Moorestown MID platform.
2883 Two valid options are apbt timer only and lapic timer
2884 plus one apbt timer for broadcast timer.
2885 x86_mrst_timer=apbt_only | lapic_and_apbt
2887 xd= [HW,XT] Original XT pre-IDE (RLL encoded) disks.
2888 xd_geo= See header of drivers/block/xd.c.
2890 xen_emul_unplug= [HW,X86,XEN]
2891 Unplug Xen emulated devices
2892 Format: [unplug0,][unplug1]
2893 ide-disks -- unplug primary master IDE devices
2894 aux-ide-disks -- unplug non-primary-master IDE devices
2895 nics -- unplug network devices
2896 all -- unplug all emulated devices (NICs and IDE disks)
2897 ignore -- continue loading the Xen platform PCI driver even
2898 if the version check failed
2900 xirc2ps_cs= [NET,PCMCIA]
2902 <irq>,<irq_mask>,<io>,<full_duplex>,<do_sound>,<lockup_hack>[,<irq2>[,<irq3>[,<irq4>]]]
2904 ______________________________________________________________________
2908 Add documentation for ALSA options.
2909 Add more DRM drivers.
git.samba.org / sfrench / cifs-2.6.git / blob