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1 | Kernel Parameters | |
2 | ~~~~~~~~~~~~~~~~~ | |
3 | ||
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. | |
8 | ||
9 | Module parameters for loadable modules are specified only as the | |
10 | parameter name with optional '=' and value as appropriate, such as: | |
11 | ||
12 | modprobe usbcore blinkenlights=1 | |
13 | ||
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: | |
17 | ||
18 | usbcore.blinkenlights=1 | |
19 | ||
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 | |
24 | ||
25 | ||
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}". | |
32 | ||
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: | |
37 | ||
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 | EDD BIOS Enhanced Disk Drive Services (EDD) is enabled | |
47 | EFI EFI Partitioning (GPT) is enabled | |
48 | EIDE EIDE/ATAPI support is enabled. | |
49 | DRM Direct Rendering Management support is enabled. | |
50 | DYNAMIC_DEBUG Build in debug messages and enable them at runtime | |
51 | FB The frame buffer device is enabled. | |
52 | GCOV GCOV profiling is enabled. | |
53 | HW Appropriate hardware is enabled. | |
54 | IA-64 IA-64 architecture is enabled. | |
55 | IMA Integrity measurement architecture is enabled. | |
56 | IOSCHED More than one I/O scheduler is enabled. | |
57 | IP_PNP IP DHCP, BOOTP, or RARP is enabled. | |
58 | IPV6 IPv6 support is enabled. | |
59 | ISAPNP ISA PnP code is enabled. | |
60 | ISDN Appropriate ISDN support is enabled. | |
61 | JOY Appropriate joystick support is enabled. | |
62 | KGDB Kernel debugger support is enabled. | |
63 | KVM Kernel Virtual Machine support is enabled. | |
64 | LIBATA Libata driver is enabled | |
65 | LP Printer support is enabled. | |
66 | LOOP Loopback device support is enabled. | |
67 | M68k M68k architecture is enabled. | |
68 | These options have more detailed description inside of | |
69 | Documentation/m68k/kernel-options.txt. | |
70 | MCA MCA bus support is enabled. | |
71 | MDA MDA console support is enabled. | |
72 | MOUSE Appropriate mouse support is enabled. | |
73 | MSI Message Signaled Interrupts (PCI). | |
74 | MTD MTD (Memory Technology Device) support is enabled. | |
75 | NET Appropriate network support is enabled. | |
76 | NUMA NUMA support 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 have their options described inside | |
93 | the Documentation/scsi/ sub-directory. | |
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 | |
120 | ||
121 | In addition, the following text indicates that the option: | |
122 | ||
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. | |
126 | ||
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>. | |
131 | ||
132 | There are also arch-specific kernel-parameters not documented here. | |
133 | See for example <Documentation/x86/x86_64/boot-options.txt>. | |
134 | ||
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. | |
140 | ||
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. | |
146 | ||
147 | ||
148 | acpi= [HW,ACPI,X86] | |
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 | |
158 | ||
159 | See also Documentation/power/pm.txt, pci=noacpi | |
160 | ||
161 | acpi_apic_instance= [ACPI, IOAPIC] | |
162 | Format: <int> | |
163 | 2: use 2nd APIC table, if available | |
164 | 1,0: use 1st APIC table | |
165 | default: 0 | |
166 | ||
167 | acpi_backlight= [HW,ACPI] | |
168 | acpi_backlight=vendor | |
169 | acpi_backlight=video | |
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. | |
173 | ||
174 | acpi.debug_layer= [HW,ACPI,ACPI_DEBUG] | |
175 | acpi.debug_level= [HW,ACPI,ACPI_DEBUG] | |
176 | Format: <int> | |
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. | |
187 | ||
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 | |
197 | ||
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. | |
201 | ||
202 | acpi_display_output= [HW,ACPI] | |
203 | acpi_display_output=vendor | |
204 | acpi_display_output=video | |
205 | See above. | |
206 | ||
207 | acpi_irq_balance [HW,ACPI] | |
208 | ACPI will balance active IRQs | |
209 | default in APIC mode | |
210 | ||
211 | acpi_irq_nobalance [HW,ACPI] | |
212 | ACPI will not move active IRQs (default) | |
213 | default in PIC mode | |
214 | ||
215 | acpi_irq_isa= [HW,ACPI] If irq_balance, mark listed IRQs used by ISA | |
216 | Format: <irq>,<irq>... | |
217 | ||
218 | acpi_irq_pci= [HW,ACPI] If irq_balance, clear listed IRQs for | |
219 | use by PCI | |
220 | Format: <irq>,<irq>... | |
221 | ||
222 | acpi_no_auto_ssdt [HW,ACPI] Disable automatic loading of SSDT | |
223 | ||
224 | acpi_os_name= [HW,ACPI] Tell ACPI BIOS the name of the OS | |
225 | Format: To spoof as Windows 98: ="Microsoft Windows" | |
226 | ||
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 | |
231 | ||
232 | acpi_pm_good [X86] | |
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. | |
236 | ||
237 | acpi_sci= [HW,ACPI] ACPI System Control Interrupt trigger mode | |
238 | Format: { level | edge | high | low } | |
239 | ||
240 | acpi_serialize [HW,ACPI] force serialization of AML methods | |
241 | ||
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. | |
245 | ||
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 | |
250 | s3_bios and s3_mode. | |
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). | |
264 | ||
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 | |
268 | ||
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. | |
284 | ||
285 | add_efi_memmap [EFI; X86] Include EFI memory map in | |
286 | kernel's map of available physical RAM. | |
287 | ||
288 | agp= [AGP] | |
289 | { off | try_unsupported } | |
290 | off: disable AGP support | |
291 | try_unsupported: try to drive unsupported chipsets | |
292 | (may crash computer or cause data corruption) | |
293 | ||
294 | ALSA [HW,ALSA] | |
295 | See Documentation/sound/alsa/alsa-parameters.txt | |
296 | ||
297 | alignment= [KNL,ARM] | |
298 | Allow the default userspace alignment fault handler | |
299 | behaviour to be specified. Bit 0 enables warnings, | |
300 | bit 1 enables fixups, and bit 2 sends a segfault. | |
301 | ||
302 | amd_iommu= [HW,X86-84] | |
303 | Pass parameters to the AMD IOMMU driver in the system. | |
304 | Possible values are: | |
305 | fullflush - enable flushing of IO/TLB entries when | |
306 | they are unmapped. Otherwise they are | |
307 | flushed before they will be reused, which | |
308 | is a lot of faster | |
309 | off - do not initialize any AMD IOMMU found in | |
310 | the system | |
311 | ||
312 | amijoy.map= [HW,JOY] Amiga joystick support | |
313 | Map of devices attached to JOY0DAT and JOY1DAT | |
314 | Format: <a>,<b> | |
315 | See also Documentation/kernel/input/joystick.txt | |
316 | ||
317 | analog.map= [HW,JOY] Analog joystick and gamepad support | |
318 | Specifies type or capabilities of an analog joystick | |
319 | connected to one of 16 gameports | |
320 | Format: <type1>,<type2>,..<type16> | |
321 | ||
322 | apc= [HW,SPARC] | |
323 | Power management functions (SPARCstation-4/5 + deriv.) | |
324 | Format: noidle | |
325 | Disable APC CPU standby support. SPARCstation-Fox does | |
326 | not play well with APC CPU idle - disable it if you have | |
327 | APC and your system crashes randomly. | |
328 | ||
329 | apic= [APIC,X86-32] Advanced Programmable Interrupt Controller | |
330 | Change the output verbosity whilst booting | |
331 | Format: { quiet (default) | verbose | debug } | |
332 | Change the amount of debugging information output | |
333 | when initialising the APIC and IO-APIC components. | |
334 | ||
335 | autoconf= [IPV6] | |
336 | See Documentation/networking/ipv6.txt. | |
337 | ||
338 | show_lapic= [APIC,X86] Advanced Programmable Interrupt Controller | |
339 | Limit apic dumping. The parameter defines the maximal | |
340 | number of local apics being dumped. Also it is possible | |
341 | to set it to "all" by meaning -- no limit here. | |
342 | Format: { 1 (default) | 2 | ... | all }. | |
343 | The parameter valid if only apic=debug or | |
344 | apic=verbose is specified. | |
345 | Example: apic=debug show_lapic=all | |
346 | ||
347 | apm= [APM] Advanced Power Management | |
348 | See header of arch/x86/kernel/apm_32.c. | |
349 | ||
350 | arcrimi= [HW,NET] ARCnet - "RIM I" (entirely mem-mapped) cards | |
351 | Format: <io>,<irq>,<nodeID> | |
352 | ||
353 | ataflop= [HW,M68k] | |
354 | ||
355 | atarimouse= [HW,MOUSE] Atari Mouse | |
356 | ||
357 | atkbd.extra= [HW] Enable extra LEDs and keys on IBM RapidAccess, | |
358 | EzKey and similar keyboards | |
359 | ||
360 | atkbd.reset= [HW] Reset keyboard during initialization | |
361 | ||
362 | atkbd.set= [HW] Select keyboard code set | |
363 | Format: <int> (2 = AT (default), 3 = PS/2) | |
364 | ||
365 | atkbd.scroll= [HW] Enable scroll wheel on MS Office and similar | |
366 | keyboards | |
367 | ||
368 | atkbd.softraw= [HW] Choose between synthetic and real raw mode | |
369 | Format: <bool> (0 = real, 1 = synthetic (default)) | |
370 | ||
371 | atkbd.softrepeat= [HW] | |
372 | Use software keyboard repeat | |
373 | ||
374 | autotest [IA64] | |
375 | ||
376 | baycom_epp= [HW,AX25] | |
377 | Format: <io>,<mode> | |
378 | ||
379 | baycom_par= [HW,AX25] BayCom Parallel Port AX.25 Modem | |
380 | Format: <io>,<mode> | |
381 | See header of drivers/net/hamradio/baycom_par.c. | |
382 | ||
383 | baycom_ser_fdx= [HW,AX25] | |
384 | BayCom Serial Port AX.25 Modem (Full Duplex Mode) | |
385 | Format: <io>,<irq>,<mode>[,<baud>] | |
386 | See header of drivers/net/hamradio/baycom_ser_fdx.c. | |
387 | ||
388 | baycom_ser_hdx= [HW,AX25] | |
389 | BayCom Serial Port AX.25 Modem (Half Duplex Mode) | |
390 | Format: <io>,<irq>,<mode> | |
391 | See header of drivers/net/hamradio/baycom_ser_hdx.c. | |
392 | ||
393 | boot_delay= Milliseconds to delay each printk during boot. | |
394 | Values larger than 10 seconds (10000) are changed to | |
395 | no delay (0). | |
396 | Format: integer | |
397 | ||
398 | bootmem_debug [KNL] Enable bootmem allocator debug messages. | |
399 | ||
400 | bttv.card= [HW,V4L] bttv (bt848 + bt878 based grabber cards) | |
401 | bttv.radio= Most important insmod options are available as | |
402 | kernel args too. | |
403 | bttv.pll= See Documentation/video4linux/bttv/Insmod-options | |
404 | bttv.tuner= and Documentation/video4linux/bttv/CARDLIST | |
405 | ||
406 | c101= [NET] Moxa C101 synchronous serial card | |
407 | ||
408 | cachesize= [BUGS=X86-32] Override level 2 CPU cache size detection. | |
409 | Sometimes CPU hardware bugs make them report the cache | |
410 | size incorrectly. The kernel will attempt work arounds | |
411 | to fix known problems, but for some CPUs it is not | |
412 | possible to determine what the correct size should be. | |
413 | This option provides an override for these situations. | |
414 | ||
415 | capability.disable= | |
416 | [SECURITY] Disable capabilities. This would normally | |
417 | be used only if an alternative security model is to be | |
418 | configured. Potentially dangerous and should only be | |
419 | used if you are entirely sure of the consequences. | |
420 | ||
421 | ccw_timeout_log [S390] | |
422 | See Documentation/s390/CommonIO for details. | |
423 | ||
424 | cgroup_disable= [KNL] Disable a particular controller | |
425 | Format: {name of the controller(s) to disable} | |
426 | {Currently supported controllers - "memory"} | |
427 | ||
428 | checkreqprot [SELINUX] Set initial checkreqprot flag value. | |
429 | Format: { "0" | "1" } | |
430 | See security/selinux/Kconfig help text. | |
431 | 0 -- check protection applied by kernel (includes | |
432 | any implied execute protection). | |
433 | 1 -- check protection requested by application. | |
434 | Default value is set via a kernel config option. | |
435 | Value can be changed at runtime via | |
436 | /selinux/checkreqprot. | |
437 | ||
438 | cio_ignore= [S390] | |
439 | See Documentation/s390/CommonIO for details. | |
440 | ||
441 | clock= [BUGS=X86-32, HW] gettimeofday clocksource override. | |
442 | [Deprecated] | |
443 | Forces specified clocksource (if available) to be used | |
444 | when calculating gettimeofday(). If specified | |
445 | clocksource is not available, it defaults to PIT. | |
446 | Format: { pit | tsc | cyclone | pmtmr } | |
447 | ||
448 | clocksource= Override the default clocksource | |
449 | Format: <string> | |
450 | Override the default clocksource and use the clocksource | |
451 | with the name specified. | |
452 | Some clocksource names to choose from, depending on | |
453 | the platform: | |
454 | [all] jiffies (this is the base, fallback clocksource) | |
455 | [ACPI] acpi_pm | |
456 | [ARM] imx_timer1,OSTS,netx_timer,mpu_timer2, | |
457 | pxa_timer,timer3,32k_counter,timer0_1 | |
458 | [AVR32] avr32 | |
459 | [X86-32] pit,hpet,tsc; | |
460 | scx200_hrt on Geode; cyclone on IBM x440 | |
461 | [MIPS] MIPS | |
462 | [PARISC] cr16 | |
463 | [S390] tod | |
464 | [SH] SuperH | |
465 | [SPARC64] tick | |
466 | [X86-64] hpet,tsc | |
467 | ||
468 | clearcpuid=BITNUM [X86] | |
469 | Disable CPUID feature X for the kernel. See | |
470 | arch/x86/include/asm/cpufeature.h for the valid bit | |
471 | numbers. Note the Linux specific bits are not necessarily | |
472 | stable over kernel options, but the vendor specific | |
473 | ones should be. | |
474 | Also note that user programs calling CPUID directly | |
475 | or using the feature without checking anything | |
476 | will still see it. This just prevents it from | |
477 | being used by the kernel or shown in /proc/cpuinfo. | |
478 | Also note the kernel might malfunction if you disable | |
479 | some critical bits. | |
480 | ||
481 | cmo_free_hint= [PPC] Format: { yes | no } | |
482 | Specify whether pages are marked as being inactive | |
483 | when they are freed. This is used in CMO environments | |
484 | to determine OS memory pressure for page stealing by | |
485 | a hypervisor. | |
486 | Default: yes | |
487 | ||
488 | code_bytes [X86] How many bytes of object code to print | |
489 | in an oops report. | |
490 | Range: 0 - 8192 | |
491 | Default: 64 | |
492 | ||
493 | com20020= [HW,NET] ARCnet - COM20020 chipset | |
494 | Format: | |
495 | <io>[,<irq>[,<nodeID>[,<backplane>[,<ckp>[,<timeout>]]]]] | |
496 | ||
497 | com90io= [HW,NET] ARCnet - COM90xx chipset (IO-mapped buffers) | |
498 | Format: <io>[,<irq>] | |
499 | ||
500 | com90xx= [HW,NET] | |
501 | ARCnet - COM90xx chipset (memory-mapped buffers) | |
502 | Format: <io>[,<irq>[,<memstart>]] | |
503 | ||
504 | condev= [HW,S390] console device | |
505 | conmode= | |
506 | ||
507 | console= [KNL] Output console device and options. | |
508 | ||
509 | tty<n> Use the virtual console device <n>. | |
510 | ||
511 | ttyS<n>[,options] | |
512 | ttyUSB0[,options] | |
513 | Use the specified serial port. The options are of | |
514 | the form "bbbbpnf", where "bbbb" is the baud rate, | |
515 | "p" is parity ("n", "o", or "e"), "n" is number of | |
516 | bits, and "f" is flow control ("r" for RTS or | |
517 | omit it). Default is "9600n8". | |
518 | ||
519 | See Documentation/serial-console.txt for more | |
520 | information. See | |
521 | Documentation/networking/netconsole.txt for an | |
522 | alternative. | |
523 | ||
524 | uart[8250],io,<addr>[,options] | |
525 | uart[8250],mmio,<addr>[,options] | |
526 | Start an early, polled-mode console on the 8250/16550 | |
527 | UART at the specified I/O port or MMIO address, | |
528 | switching to the matching ttyS device later. The | |
529 | options are the same as for ttyS, above. | |
530 | ||
531 | If the device connected to the port is not a TTY but a braille | |
532 | device, prepend "brl," before the device type, for instance | |
533 | console=brl,ttyS0 | |
534 | For now, only VisioBraille is supported. | |
535 | ||
536 | consoleblank= [KNL] The console blank (screen saver) timeout in | |
537 | seconds. Defaults to 10*60 = 10mins. A value of 0 | |
538 | disables the blank timer. | |
539 | ||
540 | coredump_filter= | |
541 | [KNL] Change the default value for | |
542 | /proc/<pid>/coredump_filter. | |
543 | See also Documentation/filesystems/proc.txt. | |
544 | ||
545 | cpcihp_generic= [HW,PCI] Generic port I/O CompactPCI driver | |
546 | Format: | |
547 | <first_slot>,<last_slot>,<port>,<enum_bit>[,<debug>] | |
548 | ||
549 | crashkernel=nn[KMG]@ss[KMG] | |
550 | [KNL] Reserve a chunk of physical memory to | |
551 | hold a kernel to switch to with kexec on panic. | |
552 | ||
553 | crashkernel=range1:size1[,range2:size2,...][@offset] | |
554 | [KNL] Same as above, but depends on the memory | |
555 | in the running system. The syntax of range is | |
556 | start-[end] where start and end are both | |
557 | a memory unit (amount[KMG]). See also | |
558 | Documentation/kdump/kdump.txt for a example. | |
559 | ||
560 | cs89x0_dma= [HW,NET] | |
561 | Format: <dma> | |
562 | ||
563 | cs89x0_media= [HW,NET] | |
564 | Format: { rj45 | aui | bnc } | |
565 | ||
566 | dasd= [HW,NET] | |
567 | See header of drivers/s390/block/dasd_devmap.c. | |
568 | ||
569 | db9.dev[2|3]= [HW,JOY] Multisystem joystick support via parallel port | |
570 | (one device per port) | |
571 | Format: <port#>,<type> | |
572 | See also Documentation/input/joystick-parport.txt | |
573 | ||
574 | ddebug_query= [KNL,DYNAMIC_DEBUG] Enable debug messages at early boot | |
575 | time. See Documentation/dynamic-debug-howto.txt for | |
576 | details. | |
577 | ||
578 | debug [KNL] Enable kernel debugging (events log level). | |
579 | ||
580 | debug_locks_verbose= | |
581 | [KNL] verbose self-tests | |
582 | Format=<0|1> | |
583 | Print debugging info while doing the locking API | |
584 | self-tests. | |
585 | We default to 0 (no extra messages), setting it to | |
586 | 1 will print _a lot_ more information - normally | |
587 | only useful to kernel developers. | |
588 | ||
589 | debug_objects [KNL] Enable object debugging | |
590 | ||
591 | no_debug_objects | |
592 | [KNL] Disable object debugging | |
593 | ||
594 | debugpat [X86] Enable PAT debugging | |
595 | ||
596 | decnet.addr= [HW,NET] | |
597 | Format: <area>[,<node>] | |
598 | See also Documentation/networking/decnet.txt. | |
599 | ||
600 | default_hugepagesz= | |
601 | [same as hugepagesz=] The size of the default | |
602 | HugeTLB page size. This is the size represented by | |
603 | the legacy /proc/ hugepages APIs, used for SHM, and | |
604 | default size when mounting hugetlbfs filesystems. | |
605 | Defaults to the default architecture's huge page size | |
606 | if not specified. | |
607 | ||
608 | dhash_entries= [KNL] | |
609 | Set number of hash buckets for dentry cache. | |
610 | ||
611 | digi= [HW,SERIAL] | |
612 | IO parameters + enable/disable command. | |
613 | ||
614 | digiepca= [HW,SERIAL] | |
615 | See drivers/char/README.epca and | |
616 | Documentation/serial/digiepca.txt. | |
617 | ||
618 | disable= [IPV6] | |
619 | See Documentation/networking/ipv6.txt. | |
620 | ||
621 | disable_ipv6= [IPV6] | |
622 | See Documentation/networking/ipv6.txt. | |
623 | ||
624 | disable_mtrr_cleanup [X86] | |
625 | The kernel tries to adjust MTRR layout from continuous | |
626 | to discrete, to make X server driver able to add WB | |
627 | entry later. This parameter disables that. | |
628 | ||
629 | disable_mtrr_trim [X86, Intel and AMD only] | |
630 | By default the kernel will trim any uncacheable | |
631 | memory out of your available memory pool based on | |
632 | MTRR settings. This parameter disables that behavior, | |
633 | possibly causing your machine to run very slowly. | |
634 | ||
635 | disable_timer_pin_1 [X86] | |
636 | Disable PIN 1 of APIC timer | |
637 | Can be useful to work around chipset bugs. | |
638 | ||
639 | dma_debug=off If the kernel is compiled with DMA_API_DEBUG support, | |
640 | this option disables the debugging code at boot. | |
641 | ||
642 | dma_debug_entries=<number> | |
643 | This option allows to tune the number of preallocated | |
644 | entries for DMA-API debugging code. One entry is | |
645 | required per DMA-API allocation. Use this if the | |
646 | DMA-API debugging code disables itself because the | |
647 | architectural default is too low. | |
648 | ||
649 | dma_debug_driver=<driver_name> | |
650 | With this option the DMA-API debugging driver | |
651 | filter feature can be enabled at boot time. Just | |
652 | pass the driver to filter for as the parameter. | |
653 | The filter can be disabled or changed to another | |
654 | driver later using sysfs. | |
655 | ||
656 | dscc4.setup= [NET] | |
657 | ||
658 | dynamic_printk Enables pr_debug()/dev_dbg() calls if | |
659 | CONFIG_DYNAMIC_PRINTK_DEBUG has been enabled. | |
660 | These can also be switched on/off via | |
661 | <debugfs>/dynamic_printk/modules | |
662 | ||
663 | earlycon= [KNL] Output early console device and options. | |
664 | uart[8250],io,<addr>[,options] | |
665 | uart[8250],mmio,<addr>[,options] | |
666 | uart[8250],mmio32,<addr>[,options] | |
667 | Start an early, polled-mode console on the 8250/16550 | |
668 | UART at the specified I/O port or MMIO address. | |
669 | MMIO inter-register address stride is either 8bit (mmio) | |
670 | or 32bit (mmio32). | |
671 | The options are the same as for ttyS, above. | |
672 | ||
673 | earlyprintk= [X86,SH,BLACKFIN] | |
674 | earlyprintk=vga | |
675 | earlyprintk=serial[,ttySn[,baudrate]] | |
676 | earlyprintk=ttySn[,baudrate] | |
677 | earlyprintk=dbgp[debugController#] | |
678 | ||
679 | Append ",keep" to not disable it when the real console | |
680 | takes over. | |
681 | ||
682 | Only vga or serial or usb debug port at a time. | |
683 | ||
684 | Currently only ttyS0 and ttyS1 are supported. | |
685 | ||
686 | Interaction with the standard serial driver is not | |
687 | very good. | |
688 | ||
689 | The VGA output is eventually overwritten by the real | |
690 | console. | |
691 | ||
692 | ekgdboc= [X86,KGDB] Allow early kernel console debugging | |
693 | ekgdboc=kbd | |
694 | ||
695 | This is desgined to be used in conjunction with | |
696 | the boot argument: earlyprintk=vga | |
697 | ||
698 | edd= [EDD] | |
699 | Format: {"off" | "on" | "skip[mbr]"} | |
700 | ||
701 | eisa_irq_edge= [PARISC,HW] | |
702 | See header of drivers/parisc/eisa.c. | |
703 | ||
704 | elanfreq= [X86-32] | |
705 | See comment before function elanfreq_setup() in | |
706 | arch/x86/kernel/cpu/cpufreq/elanfreq.c. | |
707 | ||
708 | elevator= [IOSCHED] | |
709 | Format: {"anticipatory" | "cfq" | "deadline" | "noop"} | |
710 | See Documentation/block/as-iosched.txt and | |
711 | Documentation/block/deadline-iosched.txt for details. | |
712 | ||
713 | elfcorehdr= [IA64,PPC,SH,X86] | |
714 | Specifies physical address of start of kernel core | |
715 | image elf header. Generally kexec loader will | |
716 | pass this option to capture kernel. | |
717 | See Documentation/kdump/kdump.txt for details. | |
718 | ||
719 | enable_mtrr_cleanup [X86] | |
720 | The kernel tries to adjust MTRR layout from continuous | |
721 | to discrete, to make X server driver able to add WB | |
722 | entry later. This parameter enables that. | |
723 | ||
724 | enable_timer_pin_1 [X86] | |
725 | Enable PIN 1 of APIC timer | |
726 | Can be useful to work around chipset bugs | |
727 | (in particular on some ATI chipsets). | |
728 | The kernel tries to set a reasonable default. | |
729 | ||
730 | enforcing [SELINUX] Set initial enforcing status. | |
731 | Format: {"0" | "1"} | |
732 | See security/selinux/Kconfig help text. | |
733 | 0 -- permissive (log only, no denials). | |
734 | 1 -- enforcing (deny and log). | |
735 | Default value is 0. | |
736 | Value can be changed at runtime via /selinux/enforce. | |
737 | ||
738 | erst_disable [ACPI] | |
739 | Disable Error Record Serialization Table (ERST) | |
740 | support. | |
741 | ||
742 | ether= [HW,NET] Ethernet cards parameters | |
743 | This option is obsoleted by the "netdev=" option, which | |
744 | has equivalent usage. See its documentation for details. | |
745 | ||
746 | failslab= | |
747 | fail_page_alloc= | |
748 | fail_make_request=[KNL] | |
749 | General fault injection mechanism. | |
750 | Format: <interval>,<probability>,<space>,<times> | |
751 | See also /Documentation/fault-injection/. | |
752 | ||
753 | floppy= [HW] | |
754 | See Documentation/blockdev/floppy.txt. | |
755 | ||
756 | force_pal_cache_flush | |
757 | [IA-64] Avoid check_sal_cache_flush which may hang on | |
758 | buggy SAL_CACHE_FLUSH implementations. Using this | |
759 | parameter will force ia64_sal_cache_flush to call | |
760 | ia64_pal_cache_flush instead of SAL_CACHE_FLUSH. | |
761 | ||
762 | ftrace=[tracer] | |
763 | [FTRACE] will set and start the specified tracer | |
764 | as early as possible in order to facilitate early | |
765 | boot debugging. | |
766 | ||
767 | ftrace_dump_on_oops[=orig_cpu] | |
768 | [FTRACE] will dump the trace buffers on oops. | |
769 | If no parameter is passed, ftrace will dump | |
770 | buffers of all CPUs, but if you pass orig_cpu, it will | |
771 | dump only the buffer of the CPU that triggered the | |
772 | oops. | |
773 | ||
774 | ftrace_filter=[function-list] | |
775 | [FTRACE] Limit the functions traced by the function | |
776 | tracer at boot up. function-list is a comma separated | |
777 | list of functions. This list can be changed at run | |
778 | time by the set_ftrace_filter file in the debugfs | |
779 | tracing directory. | |
780 | ||
781 | ftrace_notrace=[function-list] | |
782 | [FTRACE] Do not trace the functions specified in | |
783 | function-list. This list can be changed at run time | |
784 | by the set_ftrace_notrace file in the debugfs | |
785 | tracing directory. | |
786 | ||
787 | ftrace_graph_filter=[function-list] | |
788 | [FTRACE] Limit the top level callers functions traced | |
789 | by the function graph tracer at boot up. | |
790 | function-list is a comma separated list of functions | |
791 | that can be changed at run time by the | |
792 | set_graph_function file in the debugfs tracing directory. | |
793 | ||
794 | gamecon.map[2|3]= | |
795 | [HW,JOY] Multisystem joystick and NES/SNES/PSX pad | |
796 | support via parallel port (up to 5 devices per port) | |
797 | Format: <port#>,<pad1>,<pad2>,<pad3>,<pad4>,<pad5> | |
798 | See also Documentation/input/joystick-parport.txt | |
799 | ||
800 | gamma= [HW,DRM] | |
801 | ||
802 | gart_fix_e820= [X86_64] disable the fix e820 for K8 GART | |
803 | Format: off | on | |
804 | default: on | |
805 | ||
806 | gcov_persist= [GCOV] When non-zero (default), profiling data for | |
807 | kernel modules is saved and remains accessible via | |
808 | debugfs, even when the module is unloaded/reloaded. | |
809 | When zero, profiling data is discarded and associated | |
810 | debugfs files are removed at module unload time. | |
811 | ||
812 | gpt [EFI] Forces disk with valid GPT signature but | |
813 | invalid Protective MBR to be treated as GPT. | |
814 | ||
815 | hashdist= [KNL,NUMA] Large hashes allocated during boot | |
816 | are distributed across NUMA nodes. Defaults on | |
817 | for 64bit NUMA, off otherwise. | |
818 | Format: 0 | 1 (for off | on) | |
819 | ||
820 | hcl= [IA-64] SGI's Hardware Graph compatibility layer | |
821 | ||
822 | hd= [EIDE] (E)IDE hard drive subsystem geometry | |
823 | Format: <cyl>,<head>,<sect> | |
824 | ||
825 | hest_disable [ACPI] | |
826 | Disable Hardware Error Source Table (HEST) support; | |
827 | corresponding firmware-first mode error processing | |
828 | logic will be disabled. | |
829 | ||
830 | highmem=nn[KMG] [KNL,BOOT] forces the highmem zone to have an exact | |
831 | size of <nn>. This works even on boxes that have no | |
832 | highmem otherwise. This also works to reduce highmem | |
833 | size on bigger boxes. | |
834 | ||
835 | highres= [KNL] Enable/disable high resolution timer mode. | |
836 | Valid parameters: "on", "off" | |
837 | Default: "on" | |
838 | ||
839 | hisax= [HW,ISDN] | |
840 | See Documentation/isdn/README.HiSax. | |
841 | ||
842 | hlt [BUGS=ARM,SH] | |
843 | ||
844 | hpet= [X86-32,HPET] option to control HPET usage | |
845 | Format: { enable (default) | disable | force | | |
846 | verbose } | |
847 | disable: disable HPET and use PIT instead | |
848 | force: allow force enabled of undocumented chips (ICH4, | |
849 | VIA, nVidia) | |
850 | verbose: show contents of HPET registers during setup | |
851 | ||
852 | hugepages= [HW,X86-32,IA-64] HugeTLB pages to allocate at boot. | |
853 | hugepagesz= [HW,IA-64,PPC,X86-64] The size of the HugeTLB pages. | |
854 | On x86-64 and powerpc, this option can be specified | |
855 | multiple times interleaved with hugepages= to reserve | |
856 | huge pages of different sizes. Valid pages sizes on | |
857 | x86-64 are 2M (when the CPU supports "pse") and 1G | |
858 | (when the CPU supports the "pdpe1gb" cpuinfo flag) | |
859 | Note that 1GB pages can only be allocated at boot time | |
860 | using hugepages= and not freed afterwards. | |
861 | ||
862 | hvc_iucv= [S390] Number of z/VM IUCV hypervisor console (HVC) | |
863 | terminal devices. Valid values: 0..8 | |
864 | hvc_iucv_allow= [S390] Comma-separated list of z/VM user IDs. | |
865 | If specified, z/VM IUCV HVC accepts connections | |
866 | from listed z/VM user IDs only. | |
867 | ||
868 | i2c_bus= [HW] Override the default board specific I2C bus speed | |
869 | or register an additional I2C bus that is not | |
870 | registered from board initialization code. | |
871 | Format: | |
872 | <bus_id>,<clkrate> | |
873 | ||
874 | i8042.debug [HW] Toggle i8042 debug mode | |
875 | i8042.direct [HW] Put keyboard port into non-translated mode | |
876 | i8042.dumbkbd [HW] Pretend that controller can only read data from | |
877 | keyboard and cannot control its state | |
878 | (Don't attempt to blink the leds) | |
879 | i8042.noaux [HW] Don't check for auxiliary (== mouse) port | |
880 | i8042.nokbd [HW] Don't check/create keyboard port | |
881 | i8042.noloop [HW] Disable the AUX Loopback command while probing | |
882 | for the AUX port | |
883 | i8042.nomux [HW] Don't check presence of an active multiplexing | |
884 | controller | |
885 | i8042.nopnp [HW] Don't use ACPIPnP / PnPBIOS to discover KBD/AUX | |
886 | controllers | |
887 | i8042.reset [HW] Reset the controller during init and cleanup | |
888 | i8042.unlock [HW] Unlock (ignore) the keylock | |
889 | ||
890 | i810= [HW,DRM] | |
891 | ||
892 | i8k.ignore_dmi [HW] Continue probing hardware even if DMI data | |
893 | indicates that the driver is running on unsupported | |
894 | hardware. | |
895 | i8k.force [HW] Activate i8k driver even if SMM BIOS signature | |
896 | does not match list of supported models. | |
897 | i8k.power_status | |
898 | [HW] Report power status in /proc/i8k | |
899 | (disabled by default) | |
900 | i8k.restricted [HW] Allow controlling fans only if SYS_ADMIN | |
901 | capability is set. | |
902 | ||
903 | icn= [HW,ISDN] | |
904 | Format: <io>[,<membase>[,<icn_id>[,<icn_id2>]]] | |
905 | ||
906 | ide-core.nodma= [HW] (E)IDE subsystem | |
907 | Format: =0.0 to prevent dma on hda, =0.1 hdb =1.0 hdc | |
908 | .vlb_clock .pci_clock .noflush .nohpa .noprobe .nowerr | |
909 | .cdrom .chs .ignore_cable are additional options | |
910 | See Documentation/ide/ide.txt. | |
911 | ||
912 | ide-pci-generic.all-generic-ide [HW] (E)IDE subsystem | |
913 | Claim all unknown PCI IDE storage controllers. | |
914 | ||
915 | idle= [X86] | |
916 | Format: idle=poll, idle=mwait, idle=halt, idle=nomwait | |
917 | Poll forces a polling idle loop that can slightly | |
918 | improve the performance of waking up a idle CPU, but | |
919 | will use a lot of power and make the system run hot. | |
920 | Not recommended. | |
921 | idle=mwait: On systems which support MONITOR/MWAIT but | |
922 | the kernel chose to not use it because it doesn't save | |
923 | as much power as a normal idle loop, use the | |
924 | MONITOR/MWAIT idle loop anyways. Performance should be | |
925 | the same as idle=poll. | |
926 | idle=halt: Halt is forced to be used for CPU idle. | |
927 | In such case C2/C3 won't be used again. | |
928 | idle=nomwait: Disable mwait for CPU C-states | |
929 | ||
930 | ignore_loglevel [KNL] | |
931 | Ignore loglevel setting - this will print /all/ | |
932 | kernel messages to the console. Useful for debugging. | |
933 | ||
934 | ihash_entries= [KNL] | |
935 | Set number of hash buckets for inode cache. | |
936 | ||
937 | ima_audit= [IMA] | |
938 | Format: { "0" | "1" } | |
939 | 0 -- integrity auditing messages. (Default) | |
940 | 1 -- enable informational integrity auditing messages. | |
941 | ||
942 | ima_hash= [IMA] | |
943 | Format: { "sha1" | "md5" } | |
944 | default: "sha1" | |
945 | ||
946 | ima_tcb [IMA] | |
947 | Load a policy which meets the needs of the Trusted | |
948 | Computing Base. This means IMA will measure all | |
949 | programs exec'd, files mmap'd for exec, and all files | |
950 | opened for read by uid=0. | |
951 | ||
952 | init= [KNL] | |
953 | Format: <full_path> | |
954 | Run specified binary instead of /sbin/init as init | |
955 | process. | |
956 | ||
957 | initcall_debug [KNL] Trace initcalls as they are executed. Useful | |
958 | for working out where the kernel is dying during | |
959 | startup. | |
960 | ||
961 | initrd= [BOOT] Specify the location of the initial ramdisk | |
962 | ||
963 | inport.irq= [HW] Inport (ATI XL and Microsoft) busmouse driver | |
964 | Format: <irq> | |
965 | ||
966 | intel_iommu= [DMAR] Intel IOMMU driver (DMAR) option | |
967 | on | |
968 | Enable intel iommu driver. | |
969 | off | |
970 | Disable intel iommu driver. | |
971 | igfx_off [Default Off] | |
972 | By default, gfx is mapped as normal device. If a gfx | |
973 | device has a dedicated DMAR unit, the DMAR unit is | |
974 | bypassed by not enabling DMAR with this option. In | |
975 | this case, gfx device will use physical address for | |
976 | DMA. | |
977 | forcedac [x86_64] | |
978 | With this option iommu will not optimize to look | |
979 | for io virtual address below 32 bit forcing dual | |
980 | address cycle on pci bus for cards supporting greater | |
981 | than 32 bit addressing. The default is to look | |
982 | for translation below 32 bit and if not available | |
983 | then look in the higher range. | |
984 | strict [Default Off] | |
985 | With this option on every unmap_single operation will | |
986 | result in a hardware IOTLB flush operation as opposed | |
987 | to batching them for performance. | |
988 | ||
989 | intremap= [X86-64, Intel-IOMMU] | |
990 | Format: { on (default) | off | nosid } | |
991 | on enable Interrupt Remapping (default) | |
992 | off disable Interrupt Remapping | |
993 | nosid disable Source ID checking | |
994 | ||
995 | inttest= [IA64] | |
996 | ||
997 | iomem= Disable strict checking of access to MMIO memory | |
998 | strict regions from userspace. | |
999 | relaxed | |
1000 | ||
1001 | iommu= [x86] | |
1002 | off | |
1003 | force | |
1004 | noforce | |
1005 | biomerge | |
1006 | panic | |
1007 | nopanic | |
1008 | merge | |
1009 | nomerge | |
1010 | forcesac | |
1011 | soft | |
1012 | pt [x86, IA64] | |
1013 | ||
1014 | io7= [HW] IO7 for Marvel based alpha systems | |
1015 | See comment before marvel_specify_io7 in | |
1016 | arch/alpha/kernel/core_marvel.c. | |
1017 | ||
1018 | io_delay= [X86] I/O delay method | |
1019 | 0x80 | |
1020 | Standard port 0x80 based delay | |
1021 | 0xed | |
1022 | Alternate port 0xed based delay (needed on some systems) | |
1023 | udelay | |
1024 | Simple two microseconds delay | |
1025 | none | |
1026 | No delay | |
1027 | ||
1028 | ip= [IP_PNP] | |
1029 | See Documentation/filesystems/nfs/nfsroot.txt. | |
1030 | ||
1031 | ip2= [HW] Set IO/IRQ pairs for up to 4 IntelliPort boards | |
1032 | See comment before ip2_setup() in | |
1033 | drivers/char/ip2/ip2base.c. | |
1034 | ||
1035 | irqfixup [HW] | |
1036 | When an interrupt is not handled search all handlers | |
1037 | for it. Intended to get systems with badly broken | |
1038 | firmware running. | |
1039 | ||
1040 | irqpoll [HW] | |
1041 | When an interrupt is not handled search all handlers | |
1042 | for it. Also check all handlers each timer | |
1043 | interrupt. Intended to get systems with badly broken | |
1044 | firmware running. | |
1045 | ||
1046 | isapnp= [ISAPNP] | |
1047 | Format: <RDP>,<reset>,<pci_scan>,<verbosity> | |
1048 | ||
1049 | isolcpus= [KNL,SMP] Isolate CPUs from the general scheduler. | |
1050 | Format: | |
1051 | <cpu number>,...,<cpu number> | |
1052 | or | |
1053 | <cpu number>-<cpu number> | |
1054 | (must be a positive range in ascending order) | |
1055 | or a mixture | |
1056 | <cpu number>,...,<cpu number>-<cpu number> | |
1057 | ||
1058 | This option can be used to specify one or more CPUs | |
1059 | to isolate from the general SMP balancing and scheduling | |
1060 | algorithms. You can move a process onto or off an | |
1061 | "isolated" CPU via the CPU affinity syscalls or cpuset. | |
1062 | <cpu number> begins at 0 and the maximum value is | |
1063 | "number of CPUs in system - 1". | |
1064 | ||
1065 | This option is the preferred way to isolate CPUs. The | |
1066 | alternative -- manually setting the CPU mask of all | |
1067 | tasks in the system -- can cause problems and | |
1068 | suboptimal load balancer performance. | |
1069 | ||
1070 | iucv= [HW,NET] | |
1071 | ||
1072 | js= [HW,JOY] Analog joystick | |
1073 | See Documentation/input/joystick.txt. | |
1074 | ||
1075 | keepinitrd [HW,ARM] | |
1076 | ||
1077 | kernelcore=nn[KMG] [KNL,X86,IA-64,PPC] This parameter | |
1078 | specifies the amount of memory usable by the kernel | |
1079 | for non-movable allocations. The requested amount is | |
1080 | spread evenly throughout all nodes in the system. The | |
1081 | remaining memory in each node is used for Movable | |
1082 | pages. In the event, a node is too small to have both | |
1083 | kernelcore and Movable pages, kernelcore pages will | |
1084 | take priority and other nodes will have a larger number | |
1085 | of kernelcore pages. The Movable zone is used for the | |
1086 | allocation of pages that may be reclaimed or moved | |
1087 | by the page migration subsystem. This means that | |
1088 | HugeTLB pages may not be allocated from this zone. | |
1089 | Note that allocations like PTEs-from-HighMem still | |
1090 | use the HighMem zone if it exists, and the Normal | |
1091 | zone if it does not. | |
1092 | ||
1093 | kgdbdbgp= [KGDB,HW] kgdb over EHCI usb debug port. | |
1094 | Format: <Controller#>[,poll interval] | |
1095 | The controller # is the number of the ehci usb debug | |
1096 | port as it is probed via PCI. The poll interval is | |
1097 | optional and is the number seconds in between | |
1098 | each poll cycle to the debug port in case you need | |
1099 | the functionality for interrupting the kernel with | |
1100 | gdb or control-c on the dbgp connection. When | |
1101 | not using this parameter you use sysrq-g to break into | |
1102 | the kernel debugger. | |
1103 | ||
1104 | kgdboc= [KGDB,HW] kgdb over consoles. | |
1105 | Requires a tty driver that supports console polling, | |
1106 | or a supported polling keyboard driver (non-usb). | |
1107 | Serial only format: <serial_device>[,baud] | |
1108 | keyboard only format: kbd | |
1109 | keyboard and serial format: kbd,<serial_device>[,baud] | |
1110 | Optional Kernel mode setting: | |
1111 | kms, kbd format: kms,kbd | |
1112 | kms, kbd and serial format: kms,kbd,<ser_dev>[,baud] | |
1113 | ||
1114 | kgdbwait [KGDB] Stop kernel execution and enter the | |
1115 | kernel debugger at the earliest opportunity. | |
1116 | ||
1117 | kmac= [MIPS] korina ethernet MAC address. | |
1118 | Configure the RouterBoard 532 series on-chip | |
1119 | Ethernet adapter MAC address. | |
1120 | ||
1121 | kmemleak= [KNL] Boot-time kmemleak enable/disable | |
1122 | Valid arguments: on, off | |
1123 | Default: on | |
1124 | ||
1125 | kstack=N [X86] Print N words from the kernel stack | |
1126 | in oops dumps. | |
1127 | ||
1128 | kvm.ignore_msrs=[KVM] Ignore guest accesses to unhandled MSRs. | |
1129 | Default is 0 (don't ignore, but inject #GP) | |
1130 | ||
1131 | kvm.oos_shadow= [KVM] Disable out-of-sync shadow paging. | |
1132 | Default is 1 (enabled) | |
1133 | ||
1134 | kvm.mmu_audit= [KVM] This is a R/W parameter which allows audit | |
1135 | KVM MMU at runtime. | |
1136 | Default is 0 (off) | |
1137 | ||
1138 | kvm-amd.nested= [KVM,AMD] Allow nested virtualization in KVM/SVM. | |
1139 | Default is 1 (enabled) | |
1140 | ||
1141 | kvm-amd.npt= [KVM,AMD] Disable nested paging (virtualized MMU) | |
1142 | for all guests. | |
1143 | Default is 1 (enabled) if in 64bit or 32bit-PAE mode | |
1144 | ||
1145 | kvm-intel.bypass_guest_pf= | |
1146 | [KVM,Intel] Disables bypassing of guest page faults | |
1147 | on Intel chips. Default is 1 (enabled) | |
1148 | ||
1149 | kvm-intel.ept= [KVM,Intel] Disable extended page tables | |
1150 | (virtualized MMU) support on capable Intel chips. | |
1151 | Default is 1 (enabled) | |
1152 | ||
1153 | kvm-intel.emulate_invalid_guest_state= | |
1154 | [KVM,Intel] Enable emulation of invalid guest states | |
1155 | Default is 0 (disabled) | |
1156 | ||
1157 | kvm-intel.flexpriority= | |
1158 | [KVM,Intel] Disable FlexPriority feature (TPR shadow). | |
1159 | Default is 1 (enabled) | |
1160 | ||
1161 | kvm-intel.unrestricted_guest= | |
1162 | [KVM,Intel] Disable unrestricted guest feature | |
1163 | (virtualized real and unpaged mode) on capable | |
1164 | Intel chips. Default is 1 (enabled) | |
1165 | ||
1166 | kvm-intel.vpid= [KVM,Intel] Disable Virtual Processor Identification | |
1167 | feature (tagged TLBs) on capable Intel chips. | |
1168 | Default is 1 (enabled) | |
1169 | ||
1170 | l2cr= [PPC] | |
1171 | ||
1172 | l3cr= [PPC] | |
1173 | ||
1174 | lapic [X86-32,APIC] Enable the local APIC even if BIOS | |
1175 | disabled it. | |
1176 | ||
1177 | lapic_timer_c2_ok [X86,APIC] trust the local apic timer | |
1178 | in C2 power state. | |
1179 | ||
1180 | libata.dma= [LIBATA] DMA control | |
1181 | libata.dma=0 Disable all PATA and SATA DMA | |
1182 | libata.dma=1 PATA and SATA Disk DMA only | |
1183 | libata.dma=2 ATAPI (CDROM) DMA only | |
1184 | libata.dma=4 Compact Flash DMA only | |
1185 | Combinations also work, so libata.dma=3 enables DMA | |
1186 | for disks and CDROMs, but not CFs. | |
1187 | ||
1188 | libata.ignore_hpa= [LIBATA] Ignore HPA limit | |
1189 | libata.ignore_hpa=0 keep BIOS limits (default) | |
1190 | libata.ignore_hpa=1 ignore limits, using full disk | |
1191 | ||
1192 | libata.noacpi [LIBATA] Disables use of ACPI in libata suspend/resume | |
1193 | when set. | |
1194 | Format: <int> | |
1195 | ||
1196 | libata.force= [LIBATA] Force configurations. The format is comma | |
1197 | separated list of "[ID:]VAL" where ID is | |
1198 | PORT[.DEVICE]. PORT and DEVICE are decimal numbers | |
1199 | matching port, link or device. Basically, it matches | |
1200 | the ATA ID string printed on console by libata. If | |
1201 | the whole ID part is omitted, the last PORT and DEVICE | |
1202 | values are used. If ID hasn't been specified yet, the | |
1203 | configuration applies to all ports, links and devices. | |
1204 | ||
1205 | If only DEVICE is omitted, the parameter applies to | |
1206 | the port and all links and devices behind it. DEVICE | |
1207 | number of 0 either selects the first device or the | |
1208 | first fan-out link behind PMP device. It does not | |
1209 | select the host link. DEVICE number of 15 selects the | |
1210 | host link and device attached to it. | |
1211 | ||
1212 | The VAL specifies the configuration to force. As long | |
1213 | as there's no ambiguity shortcut notation is allowed. | |
1214 | For example, both 1.5 and 1.5G would work for 1.5Gbps. | |
1215 | The following configurations can be forced. | |
1216 | ||
1217 | * Cable type: 40c, 80c, short40c, unk, ign or sata. | |
1218 | Any ID with matching PORT is used. | |
1219 | ||
1220 | * SATA link speed limit: 1.5Gbps or 3.0Gbps. | |
1221 | ||
1222 | * Transfer mode: pio[0-7], mwdma[0-4] and udma[0-7]. | |
1223 | udma[/][16,25,33,44,66,100,133] notation is also | |
1224 | allowed. | |
1225 | ||
1226 | * [no]ncq: Turn on or off NCQ. | |
1227 | ||
1228 | * nohrst, nosrst, norst: suppress hard, soft | |
1229 | and both resets. | |
1230 | ||
1231 | * dump_id: dump IDENTIFY data. | |
1232 | ||
1233 | If there are multiple matching configurations changing | |
1234 | the same attribute, the last one is used. | |
1235 | ||
1236 | memblock=debug [KNL] Enable memblock debug messages. | |
1237 | ||
1238 | load_ramdisk= [RAM] List of ramdisks to load from floppy | |
1239 | See Documentation/blockdev/ramdisk.txt. | |
1240 | ||
1241 | lockd.nlm_grace_period=P [NFS] Assign grace period. | |
1242 | Format: <integer> | |
1243 | ||
1244 | lockd.nlm_tcpport=N [NFS] Assign TCP port. | |
1245 | Format: <integer> | |
1246 | ||
1247 | lockd.nlm_timeout=T [NFS] Assign timeout value. | |
1248 | Format: <integer> | |
1249 | ||
1250 | lockd.nlm_udpport=M [NFS] Assign UDP port. | |
1251 | Format: <integer> | |
1252 | ||
1253 | logibm.irq= [HW,MOUSE] Logitech Bus Mouse Driver | |
1254 | Format: <irq> | |
1255 | ||
1256 | loglevel= All Kernel Messages with a loglevel smaller than the | |
1257 | console loglevel will be printed to the console. It can | |
1258 | also be changed with klogd or other programs. The | |
1259 | loglevels are defined as follows: | |
1260 | ||
1261 | 0 (KERN_EMERG) system is unusable | |
1262 | 1 (KERN_ALERT) action must be taken immediately | |
1263 | 2 (KERN_CRIT) critical conditions | |
1264 | 3 (KERN_ERR) error conditions | |
1265 | 4 (KERN_WARNING) warning conditions | |
1266 | 5 (KERN_NOTICE) normal but significant condition | |
1267 | 6 (KERN_INFO) informational | |
1268 | 7 (KERN_DEBUG) debug-level messages | |
1269 | ||
1270 | log_buf_len=n Sets the size of the printk ring buffer, in bytes. | |
1271 | Format: { n | nk | nM } | |
1272 | n must be a power of two. The default size | |
1273 | is set in the kernel config file. | |
1274 | ||
1275 | logo.nologo [FB] Disables display of the built-in Linux logo. | |
1276 | This may be used to provide more screen space for | |
1277 | kernel log messages and is useful when debugging | |
1278 | kernel boot problems. | |
1279 | ||
1280 | lp=0 [LP] Specify parallel ports to use, e.g, | |
1281 | lp=port[,port...] lp=none,parport0 (lp0 not configured, lp1 uses | |
1282 | lp=reset first parallel port). 'lp=0' disables the | |
1283 | lp=auto printer driver. 'lp=reset' (which can be | |
1284 | specified in addition to the ports) causes | |
1285 | attached printers to be reset. Using | |
1286 | lp=port1,port2,... specifies the parallel ports | |
1287 | to associate lp devices with, starting with | |
1288 | lp0. A port specification may be 'none' to skip | |
1289 | that lp device, or a parport name such as | |
1290 | 'parport0'. Specifying 'lp=auto' instead of a | |
1291 | port specification list means that device IDs | |
1292 | from each port should be examined, to see if | |
1293 | an IEEE 1284-compliant printer is attached; if | |
1294 | so, the driver will manage that printer. | |
1295 | See also header of drivers/char/lp.c. | |
1296 | ||
1297 | lpj=n [KNL] | |
1298 | Sets loops_per_jiffy to given constant, thus avoiding | |
1299 | time-consuming boot-time autodetection (up to 250 ms per | |
1300 | CPU). 0 enables autodetection (default). To determine | |
1301 | the correct value for your kernel, boot with normal | |
1302 | autodetection and see what value is printed. Note that | |
1303 | on SMP systems the preset will be applied to all CPUs, | |
1304 | which is likely to cause problems if your CPUs need | |
1305 | significantly divergent settings. An incorrect value | |
1306 | will cause delays in the kernel to be wrong, leading to | |
1307 | unpredictable I/O errors and other breakage. Although | |
1308 | unlikely, in the extreme case this might damage your | |
1309 | hardware. | |
1310 | ||
1311 | ltpc= [NET] | |
1312 | Format: <io>,<irq>,<dma> | |
1313 | ||
1314 | machvec= [IA64] Force the use of a particular machine-vector | |
1315 | (machvec) in a generic kernel. | |
1316 | Example: machvec=hpzx1_swiotlb | |
1317 | ||
1318 | machtype= [Loongson] Share the same kernel image file between different | |
1319 | yeeloong laptop. | |
1320 | Example: machtype=lemote-yeeloong-2f-7inch | |
1321 | ||
1322 | max_addr=nn[KMG] [KNL,BOOT,ia64] All physical memory greater | |
1323 | than or equal to this physical address is ignored. | |
1324 | ||
1325 | maxcpus= [SMP] Maximum number of processors that an SMP kernel | |
1326 | should make use of. maxcpus=n : n >= 0 limits the | |
1327 | kernel to using 'n' processors. n=0 is a special case, | |
1328 | it is equivalent to "nosmp", which also disables | |
1329 | the IO APIC. | |
1330 | ||
1331 | max_loop= [LOOP] Maximum number of loopback devices that can | |
1332 | be mounted | |
1333 | Format: <1-256> | |
1334 | ||
1335 | mcatest= [IA-64] | |
1336 | ||
1337 | mce [X86-32] Machine Check Exception | |
1338 | ||
1339 | mce=option [X86-64] See Documentation/x86/x86_64/boot-options.txt | |
1340 | ||
1341 | md= [HW] RAID subsystems devices and level | |
1342 | See Documentation/md.txt. | |
1343 | ||
1344 | mdacon= [MDA] | |
1345 | Format: <first>,<last> | |
1346 | Specifies range of consoles to be captured by the MDA. | |
1347 | ||
1348 | mem=nn[KMG] [KNL,BOOT] Force usage of a specific amount of memory | |
1349 | Amount of memory to be used when the kernel is not able | |
1350 | to see the whole system memory or for test. | |
1351 | [X86-32] Use together with memmap= to avoid physical | |
1352 | address space collisions. Without memmap= PCI devices | |
1353 | could be placed at addresses belonging to unused RAM. | |
1354 | ||
1355 | mem=nopentium [BUGS=X86-32] Disable usage of 4MB pages for kernel | |
1356 | memory. | |
1357 | ||
1358 | memchunk=nn[KMG] | |
1359 | [KNL,SH] Allow user to override the default size for | |
1360 | per-device physically contiguous DMA buffers. | |
1361 | ||
1362 | memmap=exactmap [KNL,X86] Enable setting of an exact | |
1363 | E820 memory map, as specified by the user. | |
1364 | Such memmap=exactmap lines can be constructed based on | |
1365 | BIOS output or other requirements. See the memmap=nn@ss | |
1366 | option description. | |
1367 | ||
1368 | memmap=nn[KMG]@ss[KMG] | |
1369 | [KNL] Force usage of a specific region of memory | |
1370 | Region of memory to be used, from ss to ss+nn. | |
1371 | ||
1372 | memmap=nn[KMG]#ss[KMG] | |
1373 | [KNL,ACPI] Mark specific memory as ACPI data. | |
1374 | Region of memory to be used, from ss to ss+nn. | |
1375 | ||
1376 | memmap=nn[KMG]$ss[KMG] | |
1377 | [KNL,ACPI] Mark specific memory as reserved. | |
1378 | Region of memory to be used, from ss to ss+nn. | |
1379 | Example: Exclude memory from 0x18690000-0x1869ffff | |
1380 | memmap=64K$0x18690000 | |
1381 | or | |
1382 | memmap=0x10000$0x18690000 | |
1383 | ||
1384 | memory_corruption_check=0/1 [X86] | |
1385 | Some BIOSes seem to corrupt the first 64k of | |
1386 | memory when doing things like suspend/resume. | |
1387 | Setting this option will scan the memory | |
1388 | looking for corruption. Enabling this will | |
1389 | both detect corruption and prevent the kernel | |
1390 | from using the memory being corrupted. | |
1391 | However, its intended as a diagnostic tool; if | |
1392 | repeatable BIOS-originated corruption always | |
1393 | affects the same memory, you can use memmap= | |
1394 | to prevent the kernel from using that memory. | |
1395 | ||
1396 | memory_corruption_check_size=size [X86] | |
1397 | By default it checks for corruption in the low | |
1398 | 64k, making this memory unavailable for normal | |
1399 | use. Use this parameter to scan for | |
1400 | corruption in more or less memory. | |
1401 | ||
1402 | memory_corruption_check_period=seconds [X86] | |
1403 | By default it checks for corruption every 60 | |
1404 | seconds. Use this parameter to check at some | |
1405 | other rate. 0 disables periodic checking. | |
1406 | ||
1407 | memtest= [KNL,X86] Enable memtest | |
1408 | Format: <integer> | |
1409 | default : 0 <disable> | |
1410 | Specifies the number of memtest passes to be | |
1411 | performed. Each pass selects another test | |
1412 | pattern from a given set of patterns. Memtest | |
1413 | fills the memory with this pattern, validates | |
1414 | memory contents and reserves bad memory | |
1415 | regions that are detected. | |
1416 | ||
1417 | meye.*= [HW] Set MotionEye Camera parameters | |
1418 | See Documentation/video4linux/meye.txt. | |
1419 | ||
1420 | mfgpt_irq= [IA-32] Specify the IRQ to use for the | |
1421 | Multi-Function General Purpose Timers on AMD Geode | |
1422 | platforms. | |
1423 | ||
1424 | mfgptfix [X86-32] Fix MFGPT timers on AMD Geode platforms when | |
1425 | the BIOS has incorrectly applied a workaround. TinyBIOS | |
1426 | version 0.98 is known to be affected, 0.99 fixes the | |
1427 | problem by letting the user disable the workaround. | |
1428 | ||
1429 | mga= [HW,DRM] | |
1430 | ||
1431 | min_addr=nn[KMG] [KNL,BOOT,ia64] All physical memory below this | |
1432 | physical address is ignored. | |
1433 | ||
1434 | mini2440= [ARM,HW,KNL] | |
1435 | Format:[0..2][b][c][t] | |
1436 | Default: "0tb" | |
1437 | MINI2440 configuration specification: | |
1438 | 0 - The attached screen is the 3.5" TFT | |
1439 | 1 - The attached screen is the 7" TFT | |
1440 | 2 - The VGA Shield is attached (1024x768) | |
1441 | Leaving out the screen size parameter will not load | |
1442 | the TFT driver, and the framebuffer will be left | |
1443 | unconfigured. | |
1444 | b - Enable backlight. The TFT backlight pin will be | |
1445 | linked to the kernel VESA blanking code and a GPIO | |
1446 | LED. This parameter is not necessary when using the | |
1447 | VGA shield. | |
1448 | c - Enable the s3c camera interface. | |
1449 | t - Reserved for enabling touchscreen support. The | |
1450 | touchscreen support is not enabled in the mainstream | |
1451 | kernel as of 2.6.30, a preliminary port can be found | |
1452 | in the "bleeding edge" mini2440 support kernel at | |
1453 | http://repo.or.cz/w/linux-2.6/mini2440.git | |
1454 | ||
1455 | mminit_loglevel= | |
1456 | [KNL] When CONFIG_DEBUG_MEMORY_INIT is set, this | |
1457 | parameter allows control of the logging verbosity for | |
1458 | the additional memory initialisation checks. A value | |
1459 | of 0 disables mminit logging and a level of 4 will | |
1460 | log everything. Information is printed at KERN_DEBUG | |
1461 | so loglevel=8 may also need to be specified. | |
1462 | ||
1463 | mousedev.tap_time= | |
1464 | [MOUSE] Maximum time between finger touching and | |
1465 | leaving touchpad surface for touch to be considered | |
1466 | a tap and be reported as a left button click (for | |
1467 | touchpads working in absolute mode only). | |
1468 | Format: <msecs> | |
1469 | mousedev.xres= [MOUSE] Horizontal screen resolution, used for devices | |
1470 | reporting absolute coordinates, such as tablets | |
1471 | mousedev.yres= [MOUSE] Vertical screen resolution, used for devices | |
1472 | reporting absolute coordinates, such as tablets | |
1473 | ||
1474 | movablecore=nn[KMG] [KNL,X86,IA-64,PPC] This parameter | |
1475 | is similar to kernelcore except it specifies the | |
1476 | amount of memory used for migratable allocations. | |
1477 | If both kernelcore and movablecore is specified, | |
1478 | then kernelcore will be at *least* the specified | |
1479 | value but may be more. If movablecore on its own | |
1480 | is specified, the administrator must be careful | |
1481 | that the amount of memory usable for all allocations | |
1482 | is not too small. | |
1483 | ||
1484 | MTD_Partition= [MTD] | |
1485 | Format: <name>,<region-number>,<size>,<offset> | |
1486 | ||
1487 | MTD_Region= [MTD] Format: | |
1488 | <name>,<region-number>[,<base>,<size>,<buswidth>,<altbuswidth>] | |
1489 | ||
1490 | mtdparts= [MTD] | |
1491 | See drivers/mtd/cmdlinepart.c. | |
1492 | ||
1493 | onenand.bdry= [HW,MTD] Flex-OneNAND Boundary Configuration | |
1494 | ||
1495 | Format: [die0_boundary][,die0_lock][,die1_boundary][,die1_lock] | |
1496 | ||
1497 | boundary - index of last SLC block on Flex-OneNAND. | |
1498 | The remaining blocks are configured as MLC blocks. | |
1499 | lock - Configure if Flex-OneNAND boundary should be locked. | |
1500 | Once locked, the boundary cannot be changed. | |
1501 | 1 indicates lock status, 0 indicates unlock status. | |
1502 | ||
1503 | mtdset= [ARM] | |
1504 | ARM/S3C2412 JIVE boot control | |
1505 | ||
1506 | See arch/arm/mach-s3c2412/mach-jive.c | |
1507 | ||
1508 | mtouchusb.raw_coordinates= | |
1509 | [HW] Make the MicroTouch USB driver use raw coordinates | |
1510 | ('y', default) or cooked coordinates ('n') | |
1511 | ||
1512 | mtrr_chunk_size=nn[KMG] [X86] | |
1513 | used for mtrr cleanup. It is largest continuous chunk | |
1514 | that could hold holes aka. UC entries. | |
1515 | ||
1516 | mtrr_gran_size=nn[KMG] [X86] | |
1517 | Used for mtrr cleanup. It is granularity of mtrr block. | |
1518 | Default is 1. | |
1519 | Large value could prevent small alignment from | |
1520 | using up MTRRs. | |
1521 | ||
1522 | mtrr_spare_reg_nr=n [X86] | |
1523 | Format: <integer> | |
1524 | Range: 0,7 : spare reg number | |
1525 | Default : 1 | |
1526 | Used for mtrr cleanup. It is spare mtrr entries number. | |
1527 | Set to 2 or more if your graphical card needs more. | |
1528 | ||
1529 | n2= [NET] SDL Inc. RISCom/N2 synchronous serial card | |
1530 | ||
1531 | netdev= [NET] Network devices parameters | |
1532 | Format: <irq>,<io>,<mem_start>,<mem_end>,<name> | |
1533 | Note that mem_start is often overloaded to mean | |
1534 | something different and driver-specific. | |
1535 | This usage is only documented in each driver source | |
1536 | file if at all. | |
1537 | ||
1538 | nf_conntrack.acct= | |
1539 | [NETFILTER] Enable connection tracking flow accounting | |
1540 | 0 to disable accounting | |
1541 | 1 to enable accounting | |
1542 | Default value is 0. | |
1543 | ||
1544 | nfsaddrs= [NFS] Deprecated. Use ip= instead. | |
1545 | See Documentation/filesystems/nfs/nfsroot.txt. | |
1546 | ||
1547 | nfsroot= [NFS] nfs root filesystem for disk-less boxes. | |
1548 | See Documentation/filesystems/nfs/nfsroot.txt. | |
1549 | ||
1550 | nfsrootdebug [NFS] enable nfsroot debugging messages. | |
1551 | See Documentation/filesystems/nfs/nfsroot.txt. | |
1552 | ||
1553 | nfs.callback_tcpport= | |
1554 | [NFS] set the TCP port on which the NFSv4 callback | |
1555 | channel should listen. | |
1556 | ||
1557 | nfs.cache_getent= | |
1558 | [NFS] sets the pathname to the program which is used | |
1559 | to update the NFS client cache entries. | |
1560 | ||
1561 | nfs.cache_getent_timeout= | |
1562 | [NFS] sets the timeout after which an attempt to | |
1563 | update a cache entry is deemed to have failed. | |
1564 | ||
1565 | nfs.idmap_cache_timeout= | |
1566 | [NFS] set the maximum lifetime for idmapper cache | |
1567 | entries. | |
1568 | ||
1569 | nfs.enable_ino64= | |
1570 | [NFS] enable 64-bit inode numbers. | |
1571 | If zero, the NFS client will fake up a 32-bit inode | |
1572 | number for the readdir() and stat() syscalls instead | |
1573 | of returning the full 64-bit number. | |
1574 | The default is to return 64-bit inode numbers. | |
1575 | ||
1576 | nmi_debug= [KNL,AVR32,SH] Specify one or more actions to take | |
1577 | when a NMI is triggered. | |
1578 | Format: [state][,regs][,debounce][,die] | |
1579 | ||
1580 | nmi_watchdog= [KNL,BUGS=X86] Debugging features for SMP kernels | |
1581 | Format: [panic,][num] | |
1582 | Valid num: 0,1,2 | |
1583 | 0 - turn nmi_watchdog off | |
1584 | 1 - use the IO-APIC timer for the NMI watchdog | |
1585 | 2 - use the local APIC for the NMI watchdog using | |
1586 | a performance counter. Note: This will use one | |
1587 | performance counter and the local APIC's performance | |
1588 | vector. | |
1589 | When panic is specified, panic when an NMI watchdog | |
1590 | timeout occurs. | |
1591 | This is useful when you use a panic=... timeout and | |
1592 | need the box quickly up again. | |
1593 | Instead of 1 and 2 it is possible to use the following | |
1594 | symbolic names: lapic and ioapic | |
1595 | Example: nmi_watchdog=2 or nmi_watchdog=panic,lapic | |
1596 | ||
1597 | netpoll.carrier_timeout= | |
1598 | [NET] Specifies amount of time (in seconds) that | |
1599 | netpoll should wait for a carrier. By default netpoll | |
1600 | waits 4 seconds. | |
1601 | ||
1602 | no387 [BUGS=X86-32] Tells the kernel to use the 387 maths | |
1603 | emulation library even if a 387 maths coprocessor | |
1604 | is present. | |
1605 | ||
1606 | no_console_suspend | |
1607 | [HW] Never suspend the console | |
1608 | Disable suspending of consoles during suspend and | |
1609 | hibernate operations. Once disabled, debugging | |
1610 | messages can reach various consoles while the rest | |
1611 | of the system is being put to sleep (ie, while | |
1612 | debugging driver suspend/resume hooks). This may | |
1613 | not work reliably with all consoles, but is known | |
1614 | to work with serial and VGA consoles. | |
1615 | ||
1616 | noaliencache [MM, NUMA, SLAB] Disables the allocation of alien | |
1617 | caches in the slab allocator. Saves per-node memory, | |
1618 | but will impact performance. | |
1619 | ||
1620 | noalign [KNL,ARM] | |
1621 | ||
1622 | noapic [SMP,APIC] Tells the kernel to not make use of any | |
1623 | IOAPICs that may be present in the system. | |
1624 | ||
1625 | nobats [PPC] Do not use BATs for mapping kernel lowmem | |
1626 | on "Classic" PPC cores. | |
1627 | ||
1628 | nocache [ARM] | |
1629 | ||
1630 | noclflush [BUGS=X86] Don't use the CLFLUSH instruction | |
1631 | ||
1632 | nodelayacct [KNL] Disable per-task delay accounting | |
1633 | ||
1634 | nodisconnect [HW,SCSI,M68K] Disables SCSI disconnects. | |
1635 | ||
1636 | nodsp [SH] Disable hardware DSP at boot time. | |
1637 | ||
1638 | noefi [X86] Disable EFI runtime services support. | |
1639 | ||
1640 | noexec [IA-64] | |
1641 | ||
1642 | noexec [X86] | |
1643 | On X86-32 available only on PAE configured kernels. | |
1644 | noexec=on: enable non-executable mappings (default) | |
1645 | noexec=off: disable non-executable mappings | |
1646 | ||
1647 | noexec32 [X86-64] | |
1648 | This affects only 32-bit executables. | |
1649 | noexec32=on: enable non-executable mappings (default) | |
1650 | read doesn't imply executable mappings | |
1651 | noexec32=off: disable non-executable mappings | |
1652 | read implies executable mappings | |
1653 | ||
1654 | nofpu [SH] Disable hardware FPU at boot time. | |
1655 | ||
1656 | nofxsr [BUGS=X86-32] Disables x86 floating point extended | |
1657 | register save and restore. The kernel will only save | |
1658 | legacy floating-point registers on task switch. | |
1659 | ||
1660 | noxsave [BUGS=X86] Disables x86 extended register state save | |
1661 | and restore using xsave. The kernel will fallback to | |
1662 | enabling legacy floating-point and sse state. | |
1663 | ||
1664 | nohlt [BUGS=ARM,SH] Tells the kernel that the sleep(SH) or | |
1665 | wfi(ARM) instruction doesn't work correctly and not to | |
1666 | use it. This is also useful when using JTAG debugger. | |
1667 | ||
1668 | no-hlt [BUGS=X86-32] Tells the kernel that the hlt | |
1669 | instruction doesn't work correctly and not to | |
1670 | use it. | |
1671 | ||
1672 | no_file_caps Tells the kernel not to honor file capabilities. The | |
1673 | only way then for a file to be executed with privilege | |
1674 | is to be setuid root or executed by root. | |
1675 | ||
1676 | nohalt [IA-64] Tells the kernel not to use the power saving | |
1677 | function PAL_HALT_LIGHT when idle. This increases | |
1678 | power-consumption. On the positive side, it reduces | |
1679 | interrupt wake-up latency, which may improve performance | |
1680 | in certain environments such as networked servers or | |
1681 | real-time systems. | |
1682 | ||
1683 | nohz= [KNL] Boottime enable/disable dynamic ticks | |
1684 | Valid arguments: on, off | |
1685 | Default: on | |
1686 | ||
1687 | noiotrap [SH] Disables trapped I/O port accesses. | |
1688 | ||
1689 | noirqdebug [X86-32] Disables the code which attempts to detect and | |
1690 | disable unhandled interrupt sources. | |
1691 | ||
1692 | no_timer_check [X86,APIC] Disables the code which tests for | |
1693 | broken timer IRQ sources. | |
1694 | ||
1695 | noisapnp [ISAPNP] Disables ISA PnP code. | |
1696 | ||
1697 | noinitrd [RAM] Tells the kernel not to load any configured | |
1698 | initial RAM disk. | |
1699 | ||
1700 | nointremap [X86-64, Intel-IOMMU] Do not enable interrupt | |
1701 | remapping. | |
1702 | [Deprecated - use intremap=off] | |
1703 | ||
1704 | nointroute [IA-64] | |
1705 | ||
1706 | nojitter [IA64] Disables jitter checking for ITC timers. | |
1707 | ||
1708 | no-kvmclock [X86,KVM] Disable paravirtualized KVM clock driver | |
1709 | ||
1710 | nolapic [X86-32,APIC] Do not enable or use the local APIC. | |
1711 | ||
1712 | nolapic_timer [X86-32,APIC] Do not use the local APIC timer. | |
1713 | ||
1714 | noltlbs [PPC] Do not use large page/tlb entries for kernel | |
1715 | lowmem mapping on PPC40x. | |
1716 | ||
1717 | nomca [IA-64] Disable machine check abort handling | |
1718 | ||
1719 | nomce [X86-32] Machine Check Exception | |
1720 | ||
1721 | nomfgpt [X86-32] Disable Multi-Function General Purpose | |
1722 | Timer usage (for AMD Geode machines). | |
1723 | ||
1724 | nopat [X86] Disable PAT (page attribute table extension of | |
1725 | pagetables) support. | |
1726 | ||
1727 | norandmaps Don't use address space randomization. Equivalent to | |
1728 | echo 0 > /proc/sys/kernel/randomize_va_space | |
1729 | ||
1730 | noreplace-paravirt [X86,IA-64,PV_OPS] Don't patch paravirt_ops | |
1731 | ||
1732 | noreplace-smp [X86-32,SMP] Don't replace SMP instructions | |
1733 | with UP alternatives | |
1734 | ||
1735 | noresidual [PPC] Don't use residual data on PReP machines. | |
1736 | ||
1737 | noresume [SWSUSP] Disables resume and restores original swap | |
1738 | space. | |
1739 | ||
1740 | no-scroll [VGA] Disables scrollback. | |
1741 | This is required for the Braillex ib80-piezo Braille | |
1742 | reader made by F.H. Papenmeier (Germany). | |
1743 | ||
1744 | nosbagart [IA-64] | |
1745 | ||
1746 | nosep [BUGS=X86-32] Disables x86 SYSENTER/SYSEXIT support. | |
1747 | ||
1748 | nosmp [SMP] Tells an SMP kernel to act as a UP kernel, | |
1749 | and disable the IO APIC. legacy for "maxcpus=0". | |
1750 | ||
1751 | nosoftlockup [KNL] Disable the soft-lockup detector. | |
1752 | ||
1753 | noswapaccount [KNL] Disable accounting of swap in memory resource | |
1754 | controller. (See Documentation/cgroups/memory.txt) | |
1755 | ||
1756 | nosync [HW,M68K] Disables sync negotiation for all devices. | |
1757 | ||
1758 | notsc [BUGS=X86-32] Disable Time Stamp Counter | |
1759 | ||
1760 | nousb [USB] Disable the USB subsystem | |
1761 | ||
1762 | nowatchdog [KNL] Disable the lockup detector. | |
1763 | ||
1764 | nowb [ARM] | |
1765 | ||
1766 | nox2apic [X86-64,APIC] Do not enable x2APIC mode. | |
1767 | ||
1768 | nptcg= [IA64] Override max number of concurrent global TLB | |
1769 | purges which is reported from either PAL_VM_SUMMARY or | |
1770 | SAL PALO. | |
1771 | ||
1772 | nr_cpus= [SMP] Maximum number of processors that an SMP kernel | |
1773 | could support. nr_cpus=n : n >= 1 limits the kernel to | |
1774 | supporting 'n' processors. Later in runtime you can not | |
1775 | use hotplug cpu feature to put more cpu back to online. | |
1776 | just like you compile the kernel NR_CPUS=n | |
1777 | ||
1778 | nr_uarts= [SERIAL] maximum number of UARTs to be registered. | |
1779 | ||
1780 | numa_zonelist_order= [KNL, BOOT] Select zonelist order for NUMA. | |
1781 | one of ['zone', 'node', 'default'] can be specified | |
1782 | This can be set from sysctl after boot. | |
1783 | See Documentation/sysctl/vm.txt for details. | |
1784 | ||
1785 | ohci1394_dma=early [HW] enable debugging via the ohci1394 driver. | |
1786 | See Documentation/debugging-via-ohci1394.txt for more | |
1787 | info. | |
1788 | ||
1789 | olpc_ec_timeout= [OLPC] ms delay when issuing EC commands | |
1790 | Rather than timing out after 20 ms if an EC | |
1791 | command is not properly ACKed, override the length | |
1792 | of the timeout. We have interrupts disabled while | |
1793 | waiting for the ACK, so if this is set too high | |
1794 | interrupts *may* be lost! | |
1795 | ||
1796 | omap_mux= [OMAP] Override bootloader pin multiplexing. | |
1797 | Format: <mux_mode0.mode_name=value>... | |
1798 | For example, to override I2C bus2: | |
1799 | omap_mux=i2c2_scl.i2c2_scl=0x100,i2c2_sda.i2c2_sda=0x100 | |
1800 | ||
1801 | oprofile.timer= [HW] | |
1802 | Use timer interrupt instead of performance counters | |
1803 | ||
1804 | oprofile.cpu_type= Force an oprofile cpu type | |
1805 | This might be useful if you have an older oprofile | |
1806 | userland or if you want common events. | |
1807 | Format: { arch_perfmon } | |
1808 | arch_perfmon: [X86] Force use of architectural | |
1809 | perfmon on Intel CPUs instead of the | |
1810 | CPU specific event set. | |
1811 | ||
1812 | OSS [HW,OSS] | |
1813 | See Documentation/sound/oss/oss-parameters.txt | |
1814 | ||
1815 | panic= [KNL] Kernel behaviour on panic | |
1816 | Format: <timeout> | |
1817 | ||
1818 | parkbd.port= [HW] Parallel port number the keyboard adapter is | |
1819 | connected to, default is 0. | |
1820 | Format: <parport#> | |
1821 | parkbd.mode= [HW] Parallel port keyboard adapter mode of operation, | |
1822 | 0 for XT, 1 for AT (default is AT). | |
1823 | Format: <mode> | |
1824 | ||
1825 | parport= [HW,PPT] Specify parallel ports. 0 disables. | |
1826 | Format: { 0 | auto | 0xBBB[,IRQ[,DMA]] } | |
1827 | Use 'auto' to force the driver to use any | |
1828 | IRQ/DMA settings detected (the default is to | |
1829 | ignore detected IRQ/DMA settings because of | |
1830 | possible conflicts). You can specify the base | |
1831 | address, IRQ, and DMA settings; IRQ and DMA | |
1832 | should be numbers, or 'auto' (for using detected | |
1833 | settings on that particular port), or 'nofifo' | |
1834 | (to avoid using a FIFO even if it is detected). | |
1835 | Parallel ports are assigned in the order they | |
1836 | are specified on the command line, starting | |
1837 | with parport0. | |
1838 | ||
1839 | parport_init_mode= [HW,PPT] | |
1840 | Configure VIA parallel port to operate in | |
1841 | a specific mode. This is necessary on Pegasos | |
1842 | computer where firmware has no options for setting | |
1843 | up parallel port mode and sets it to spp. | |
1844 | Currently this function knows 686a and 8231 chips. | |
1845 | Format: [spp|ps2|epp|ecp|ecpepp] | |
1846 | ||
1847 | pause_on_oops= | |
1848 | Halt all CPUs after the first oops has been printed for | |
1849 | the specified number of seconds. This is to be used if | |
1850 | your oopses keep scrolling off the screen. | |
1851 | ||
1852 | pcbit= [HW,ISDN] | |
1853 | ||
1854 | pcd. [PARIDE] | |
1855 | See header of drivers/block/paride/pcd.c. | |
1856 | See also Documentation/blockdev/paride.txt. | |
1857 | ||
1858 | pci=option[,option...] [PCI] various PCI subsystem options: | |
1859 | earlydump [X86] dump PCI config space before the kernel | |
1860 | changes anything | |
1861 | off [X86] don't probe for the PCI bus | |
1862 | bios [X86-32] force use of PCI BIOS, don't access | |
1863 | the hardware directly. Use this if your machine | |
1864 | has a non-standard PCI host bridge. | |
1865 | nobios [X86-32] disallow use of PCI BIOS, only direct | |
1866 | hardware access methods are allowed. Use this | |
1867 | if you experience crashes upon bootup and you | |
1868 | suspect they are caused by the BIOS. | |
1869 | conf1 [X86] Force use of PCI Configuration | |
1870 | Mechanism 1. | |
1871 | conf2 [X86] Force use of PCI Configuration | |
1872 | Mechanism 2. | |
1873 | noaer [PCIE] If the PCIEAER kernel config parameter is | |
1874 | enabled, this kernel boot option can be used to | |
1875 | disable the use of PCIE advanced error reporting. | |
1876 | nodomains [PCI] Disable support for multiple PCI | |
1877 | root domains (aka PCI segments, in ACPI-speak). | |
1878 | nommconf [X86] Disable use of MMCONFIG for PCI | |
1879 | Configuration | |
1880 | check_enable_amd_mmconf [X86] check for and enable | |
1881 | properly configured MMIO access to PCI | |
1882 | config space on AMD family 10h CPU | |
1883 | nomsi [MSI] If the PCI_MSI kernel config parameter is | |
1884 | enabled, this kernel boot option can be used to | |
1885 | disable the use of MSI interrupts system-wide. | |
1886 | noioapicquirk [APIC] Disable all boot interrupt quirks. | |
1887 | Safety option to keep boot IRQs enabled. This | |
1888 | should never be necessary. | |
1889 | ioapicreroute [APIC] Enable rerouting of boot IRQs to the | |
1890 | primary IO-APIC for bridges that cannot disable | |
1891 | boot IRQs. This fixes a source of spurious IRQs | |
1892 | when the system masks IRQs. | |
1893 | noioapicreroute [APIC] Disable workaround that uses the | |
1894 | boot IRQ equivalent of an IRQ that connects to | |
1895 | a chipset where boot IRQs cannot be disabled. | |
1896 | The opposite of ioapicreroute. | |
1897 | biosirq [X86-32] Use PCI BIOS calls to get the interrupt | |
1898 | routing table. These calls are known to be buggy | |
1899 | on several machines and they hang the machine | |
1900 | when used, but on other computers it's the only | |
1901 | way to get the interrupt routing table. Try | |
1902 | this option if the kernel is unable to allocate | |
1903 | IRQs or discover secondary PCI buses on your | |
1904 | motherboard. | |
1905 | rom [X86] Assign address space to expansion ROMs. | |
1906 | Use with caution as certain devices share | |
1907 | address decoders between ROMs and other | |
1908 | resources. | |
1909 | norom [X86] Do not assign address space to | |
1910 | expansion ROMs that do not already have | |
1911 | BIOS assigned address ranges. | |
1912 | nobar [X86] Do not assign address space to the | |
1913 | BARs that weren't assigned by the BIOS. | |
1914 | irqmask=0xMMMM [X86] Set a bit mask of IRQs allowed to be | |
1915 | assigned automatically to PCI devices. You can | |
1916 | make the kernel exclude IRQs of your ISA cards | |
1917 | this way. | |
1918 | pirqaddr=0xAAAAA [X86] Specify the physical address | |
1919 | of the PIRQ table (normally generated | |
1920 | by the BIOS) if it is outside the | |
1921 | F0000h-100000h range. | |
1922 | lastbus=N [X86] Scan all buses thru bus #N. Can be | |
1923 | useful if the kernel is unable to find your | |
1924 | secondary buses and you want to tell it | |
1925 | explicitly which ones they are. | |
1926 | assign-busses [X86] Always assign all PCI bus | |
1927 | numbers ourselves, overriding | |
1928 | whatever the firmware may have done. | |
1929 | usepirqmask [X86] Honor the possible IRQ mask stored | |
1930 | in the BIOS $PIR table. This is needed on | |
1931 | some systems with broken BIOSes, notably | |
1932 | some HP Pavilion N5400 and Omnibook XE3 | |
1933 | notebooks. This will have no effect if ACPI | |
1934 | IRQ routing is enabled. | |
1935 | noacpi [X86] Do not use ACPI for IRQ routing | |
1936 | or for PCI scanning. | |
1937 | use_crs [X86] Use PCI host bridge window information | |
1938 | from ACPI. On BIOSes from 2008 or later, this | |
1939 | is enabled by default. If you need to use this, | |
1940 | please report a bug. | |
1941 | nocrs [X86] Ignore PCI host bridge windows from ACPI. | |
1942 | If you need to use this, please report a bug. | |
1943 | routeirq Do IRQ routing for all PCI devices. | |
1944 | This is normally done in pci_enable_device(), | |
1945 | so this option is a temporary workaround | |
1946 | for broken drivers that don't call it. | |
1947 | skip_isa_align [X86] do not align io start addr, so can | |
1948 | handle more pci cards | |
1949 | firmware [ARM] Do not re-enumerate the bus but instead | |
1950 | just use the configuration from the | |
1951 | bootloader. This is currently used on | |
1952 | IXP2000 systems where the bus has to be | |
1953 | configured a certain way for adjunct CPUs. | |
1954 | noearly [X86] Don't do any early type 1 scanning. | |
1955 | This might help on some broken boards which | |
1956 | machine check when some devices' config space | |
1957 | is read. But various workarounds are disabled | |
1958 | and some IOMMU drivers will not work. | |
1959 | bfsort Sort PCI devices into breadth-first order. | |
1960 | This sorting is done to get a device | |
1961 | order compatible with older (<= 2.4) kernels. | |
1962 | nobfsort Don't sort PCI devices into breadth-first order. | |
1963 | cbiosize=nn[KMG] The fixed amount of bus space which is | |
1964 | reserved for the CardBus bridge's IO window. | |
1965 | The default value is 256 bytes. | |
1966 | cbmemsize=nn[KMG] The fixed amount of bus space which is | |
1967 | reserved for the CardBus bridge's memory | |
1968 | window. The default value is 64 megabytes. | |
1969 | resource_alignment= | |
1970 | Format: | |
1971 | [<order of align>@][<domain>:]<bus>:<slot>.<func>[; ...] | |
1972 | Specifies alignment and device to reassign | |
1973 | aligned memory resources. | |
1974 | If <order of align> is not specified, | |
1975 | PAGE_SIZE is used as alignment. | |
1976 | PCI-PCI bridge can be specified, if resource | |
1977 | windows need to be expanded. | |
1978 | ecrc= Enable/disable PCIe ECRC (transaction layer | |
1979 | end-to-end CRC checking). | |
1980 | bios: Use BIOS/firmware settings. This is the | |
1981 | the default. | |
1982 | off: Turn ECRC off | |
1983 | on: Turn ECRC on. | |
1984 | ||
1985 | pcie_aspm= [PCIE] Forcibly enable or disable PCIe Active State Power | |
1986 | Management. | |
1987 | off Disable ASPM. | |
1988 | force Enable ASPM even on devices that claim not to support it. | |
1989 | WARNING: Forcing ASPM on may cause system lockups. | |
1990 | ||
1991 | pcie_ports= [PCIE] PCIe ports handling: | |
1992 | auto Ask the BIOS whether or not to use native PCIe services | |
1993 | associated with PCIe ports (PME, hot-plug, AER). Use | |
1994 | them only if that is allowed by the BIOS. | |
1995 | native Use native PCIe services associated with PCIe ports | |
1996 | unconditionally. | |
1997 | compat Treat PCIe ports as PCI-to-PCI bridges, disable the PCIe | |
1998 | ports driver. | |
1999 | ||
2000 | pcie_pme= [PCIE,PM] Native PCIe PME signaling options: | |
2001 | nomsi Do not use MSI for native PCIe PME signaling (this makes | |
2002 | all PCIe root ports use INTx for all services). | |
2003 | ||
2004 | pcmv= [HW,PCMCIA] BadgePAD 4 | |
2005 | ||
2006 | pd. [PARIDE] | |
2007 | See Documentation/blockdev/paride.txt. | |
2008 | ||
2009 | pdcchassis= [PARISC,HW] Disable/Enable PDC Chassis Status codes at | |
2010 | boot time. | |
2011 | Format: { 0 | 1 } | |
2012 | See arch/parisc/kernel/pdc_chassis.c | |
2013 | ||
2014 | percpu_alloc= Select which percpu first chunk allocator to use. | |
2015 | Currently supported values are "embed" and "page". | |
2016 | Archs may support subset or none of the selections. | |
2017 | See comments in mm/percpu.c for details on each | |
2018 | allocator. This parameter is primarily for debugging | |
2019 | and performance comparison. | |
2020 | ||
2021 | pf. [PARIDE] | |
2022 | See Documentation/blockdev/paride.txt. | |
2023 | ||
2024 | pg. [PARIDE] | |
2025 | See Documentation/blockdev/paride.txt. | |
2026 | ||
2027 | pirq= [SMP,APIC] Manual mp-table setup | |
2028 | See Documentation/x86/i386/IO-APIC.txt. | |
2029 | ||
2030 | plip= [PPT,NET] Parallel port network link | |
2031 | Format: { parport<nr> | timid | 0 } | |
2032 | See also Documentation/parport.txt. | |
2033 | ||
2034 | pmtmr= [X86] Manual setup of pmtmr I/O Port. | |
2035 | Override pmtimer IOPort with a hex value. | |
2036 | e.g. pmtmr=0x508 | |
2037 | ||
2038 | pnp.debug [PNP] | |
2039 | Enable PNP debug messages. This depends on the | |
2040 | CONFIG_PNP_DEBUG_MESSAGES option. | |
2041 | ||
2042 | pnpacpi= [ACPI] | |
2043 | { off } | |
2044 | ||
2045 | pnpbios= [ISAPNP] | |
2046 | { on | off | curr | res | no-curr | no-res } | |
2047 | ||
2048 | pnp_reserve_irq= | |
2049 | [ISAPNP] Exclude IRQs for the autoconfiguration | |
2050 | ||
2051 | pnp_reserve_dma= | |
2052 | [ISAPNP] Exclude DMAs for the autoconfiguration | |
2053 | ||
2054 | pnp_reserve_io= [ISAPNP] Exclude I/O ports for the autoconfiguration | |
2055 | Ranges are in pairs (I/O port base and size). | |
2056 | ||
2057 | pnp_reserve_mem= | |
2058 | [ISAPNP] Exclude memory regions for the | |
2059 | autoconfiguration. | |
2060 | Ranges are in pairs (memory base and size). | |
2061 | ||
2062 | ports= [IP_VS_FTP] IPVS ftp helper module | |
2063 | Default is 21. | |
2064 | Up to 8 (IP_VS_APP_MAX_PORTS) ports | |
2065 | may be specified. | |
2066 | Format: <port>,<port>.... | |
2067 | ||
2068 | print-fatal-signals= | |
2069 | [KNL] debug: print fatal signals | |
2070 | ||
2071 | If enabled, warn about various signal handling | |
2072 | related application anomalies: too many signals, | |
2073 | too many POSIX.1 timers, fatal signals causing a | |
2074 | coredump - etc. | |
2075 | ||
2076 | If you hit the warning due to signal overflow, | |
2077 | you might want to try "ulimit -i unlimited". | |
2078 | ||
2079 | default: off. | |
2080 | ||
2081 | printk.time= Show timing data prefixed to each printk message line | |
2082 | Format: <bool> (1/Y/y=enable, 0/N/n=disable) | |
2083 | ||
2084 | processor.max_cstate= [HW,ACPI] | |
2085 | Limit processor to maximum C-state | |
2086 | max_cstate=9 overrides any DMI blacklist limit. | |
2087 | ||
2088 | processor.nocst [HW,ACPI] | |
2089 | Ignore the _CST method to determine C-states, | |
2090 | instead using the legacy FADT method | |
2091 | ||
2092 | profile= [KNL] Enable kernel profiling via /proc/profile | |
2093 | Format: [schedule,]<number> | |
2094 | Param: "schedule" - profile schedule points. | |
2095 | Param: <number> - step/bucket size as a power of 2 for | |
2096 | statistical time based profiling. | |
2097 | Param: "sleep" - profile D-state sleeping (millisecs). | |
2098 | Requires CONFIG_SCHEDSTATS | |
2099 | Param: "kvm" - profile VM exits. | |
2100 | ||
2101 | prompt_ramdisk= [RAM] List of RAM disks to prompt for floppy disk | |
2102 | before loading. | |
2103 | See Documentation/blockdev/ramdisk.txt. | |
2104 | ||
2105 | psmouse.proto= [HW,MOUSE] Highest PS2 mouse protocol extension to | |
2106 | probe for; one of (bare|imps|exps|lifebook|any). | |
2107 | psmouse.rate= [HW,MOUSE] Set desired mouse report rate, in reports | |
2108 | per second. | |
2109 | psmouse.resetafter= [HW,MOUSE] | |
2110 | Try to reset the device after so many bad packets | |
2111 | (0 = never). | |
2112 | psmouse.resolution= | |
2113 | [HW,MOUSE] Set desired mouse resolution, in dpi. | |
2114 | psmouse.smartscroll= | |
2115 | [HW,MOUSE] Controls Logitech smartscroll autorepeat. | |
2116 | 0 = disabled, 1 = enabled (default). | |
2117 | ||
2118 | pt. [PARIDE] | |
2119 | See Documentation/blockdev/paride.txt. | |
2120 | ||
2121 | pty.legacy_count= | |
2122 | [KNL] Number of legacy pty's. Overwrites compiled-in | |
2123 | default number. | |
2124 | ||
2125 | quiet [KNL] Disable most log messages | |
2126 | ||
2127 | r128= [HW,DRM] | |
2128 | ||
2129 | raid= [HW,RAID] | |
2130 | See Documentation/md.txt. | |
2131 | ||
2132 | ramdisk_blocksize= [RAM] | |
2133 | See Documentation/blockdev/ramdisk.txt. | |
2134 | ||
2135 | ramdisk_size= [RAM] Sizes of RAM disks in kilobytes | |
2136 | See Documentation/blockdev/ramdisk.txt. | |
2137 | ||
2138 | rcupdate.blimit= [KNL,BOOT] | |
2139 | Set maximum number of finished RCU callbacks to process | |
2140 | in one batch. | |
2141 | ||
2142 | rcupdate.qhimark= [KNL,BOOT] | |
2143 | Set threshold of queued | |
2144 | RCU callbacks over which batch limiting is disabled. | |
2145 | ||
2146 | rcupdate.qlowmark= [KNL,BOOT] | |
2147 | Set threshold of queued RCU callbacks below which | |
2148 | batch limiting is re-enabled. | |
2149 | ||
2150 | rdinit= [KNL] | |
2151 | Format: <full_path> | |
2152 | Run specified binary instead of /init from the ramdisk, | |
2153 | used for early userspace startup. See initrd. | |
2154 | ||
2155 | reboot= [BUGS=X86-32,BUGS=ARM,BUGS=IA-64] Rebooting mode | |
2156 | Format: <reboot_mode>[,<reboot_mode2>[,...]] | |
2157 | See arch/*/kernel/reboot.c or arch/*/kernel/process.c | |
2158 | ||
2159 | relax_domain_level= | |
2160 | [KNL, SMP] Set scheduler's default relax_domain_level. | |
2161 | See Documentation/cgroups/cpusets.txt. | |
2162 | ||
2163 | reserve= [KNL,BUGS] Force the kernel to ignore some iomem area | |
2164 | ||
2165 | reservetop= [X86-32] | |
2166 | Format: nn[KMG] | |
2167 | Reserves a hole at the top of the kernel virtual | |
2168 | address space. | |
2169 | ||
2170 | reservelow= [X86] | |
2171 | Format: nn[K] | |
2172 | Set the amount of memory to reserve for BIOS at | |
2173 | the bottom of the address space. | |
2174 | ||
2175 | reset_devices [KNL] Force drivers to reset the underlying device | |
2176 | during initialization. | |
2177 | ||
2178 | resume= [SWSUSP] | |
2179 | Specify the partition device for software suspend | |
2180 | ||
2181 | resume_offset= [SWSUSP] | |
2182 | Specify the offset from the beginning of the partition | |
2183 | given by "resume=" at which the swap header is located, | |
2184 | in <PAGE_SIZE> units (needed only for swap files). | |
2185 | See Documentation/power/swsusp-and-swap-files.txt | |
2186 | ||
2187 | hibernate= [HIBERNATION] | |
2188 | noresume Don't check if there's a hibernation image | |
2189 | present during boot. | |
2190 | nocompress Don't compress/decompress hibernation images. | |
2191 | ||
2192 | retain_initrd [RAM] Keep initrd memory after extraction | |
2193 | ||
2194 | rhash_entries= [KNL,NET] | |
2195 | Set number of hash buckets for route cache | |
2196 | ||
2197 | riscom8= [HW,SERIAL] | |
2198 | Format: <io_board1>[,<io_board2>[,...<io_boardN>]] | |
2199 | ||
2200 | ro [KNL] Mount root device read-only on boot | |
2201 | ||
2202 | root= [KNL] Root filesystem | |
2203 | ||
2204 | rootdelay= [KNL] Delay (in seconds) to pause before attempting to | |
2205 | mount the root filesystem | |
2206 | ||
2207 | rootflags= [KNL] Set root filesystem mount option string | |
2208 | ||
2209 | rootfstype= [KNL] Set root filesystem type | |
2210 | ||
2211 | rootwait [KNL] Wait (indefinitely) for root device to show up. | |
2212 | Useful for devices that are detected asynchronously | |
2213 | (e.g. USB and MMC devices). | |
2214 | ||
2215 | rw [KNL] Mount root device read-write on boot | |
2216 | ||
2217 | S [KNL] Run init in single mode | |
2218 | ||
2219 | sa1100ir [NET] | |
2220 | See drivers/net/irda/sa1100_ir.c. | |
2221 | ||
2222 | sbni= [NET] Granch SBNI12 leased line adapter | |
2223 | ||
2224 | sched_debug [KNL] Enables verbose scheduler debug messages. | |
2225 | ||
2226 | security= [SECURITY] Choose a security module to enable at boot. | |
2227 | If this boot parameter is not specified, only the first | |
2228 | security module asking for security registration will be | |
2229 | loaded. An invalid security module name will be treated | |
2230 | as if no module has been chosen. | |
2231 | ||
2232 | selinux= [SELINUX] Disable or enable SELinux at boot time. | |
2233 | Format: { "0" | "1" } | |
2234 | See security/selinux/Kconfig help text. | |
2235 | 0 -- disable. | |
2236 | 1 -- enable. | |
2237 | Default value is set via kernel config option. | |
2238 | If enabled at boot time, /selinux/disable can be used | |
2239 | later to disable prior to initial policy load. | |
2240 | ||
2241 | apparmor= [APPARMOR] Disable or enable AppArmor at boot time | |
2242 | Format: { "0" | "1" } | |
2243 | See security/apparmor/Kconfig help text | |
2244 | 0 -- disable. | |
2245 | 1 -- enable. | |
2246 | Default value is set via kernel config option. | |
2247 | ||
2248 | serialnumber [BUGS=X86-32] | |
2249 | ||
2250 | shapers= [NET] | |
2251 | Maximal number of shapers. | |
2252 | ||
2253 | show_msr= [x86] show boot-time MSR settings | |
2254 | Format: { <integer> } | |
2255 | Show boot-time (BIOS-initialized) MSR settings. | |
2256 | The parameter means the number of CPUs to show, | |
2257 | for example 1 means boot CPU only. | |
2258 | ||
2259 | simeth= [IA-64] | |
2260 | simscsi= | |
2261 | ||
2262 | slram= [HW,MTD] | |
2263 | ||
2264 | slub_debug[=options[,slabs]] [MM, SLUB] | |
2265 | Enabling slub_debug allows one to determine the | |
2266 | culprit if slab objects become corrupted. Enabling | |
2267 | slub_debug can create guard zones around objects and | |
2268 | may poison objects when not in use. Also tracks the | |
2269 | last alloc / free. For more information see | |
2270 | Documentation/vm/slub.txt. | |
2271 | ||
2272 | slub_max_order= [MM, SLUB] | |
2273 | Determines the maximum allowed order for slabs. | |
2274 | A high setting may cause OOMs due to memory | |
2275 | fragmentation. For more information see | |
2276 | Documentation/vm/slub.txt. | |
2277 | ||
2278 | slub_min_objects= [MM, SLUB] | |
2279 | The minimum number of objects per slab. SLUB will | |
2280 | increase the slab order up to slub_max_order to | |
2281 | generate a sufficiently large slab able to contain | |
2282 | the number of objects indicated. The higher the number | |
2283 | of objects the smaller the overhead of tracking slabs | |
2284 | and the less frequently locks need to be acquired. | |
2285 | For more information see Documentation/vm/slub.txt. | |
2286 | ||
2287 | slub_min_order= [MM, SLUB] | |
2288 | Determines the mininum page order for slabs. Must be | |
2289 | lower than slub_max_order. | |
2290 | For more information see Documentation/vm/slub.txt. | |
2291 | ||
2292 | slub_nomerge [MM, SLUB] | |
2293 | Disable merging of slabs with similar size. May be | |
2294 | necessary if there is some reason to distinguish | |
2295 | allocs to different slabs. Debug options disable | |
2296 | merging on their own. | |
2297 | For more information see Documentation/vm/slub.txt. | |
2298 | ||
2299 | smart2= [HW] | |
2300 | Format: <io1>[,<io2>[,...,<io8>]] | |
2301 | ||
2302 | smp-alt-once [X86-32,SMP] On a hotplug CPU system, only | |
2303 | attempt to substitute SMP alternatives once at boot. | |
2304 | ||
2305 | smsc-ircc2.nopnp [HW] Don't use PNP to discover SMC devices | |
2306 | smsc-ircc2.ircc_cfg= [HW] Device configuration I/O port | |
2307 | smsc-ircc2.ircc_sir= [HW] SIR base I/O port | |
2308 | smsc-ircc2.ircc_fir= [HW] FIR base I/O port | |
2309 | smsc-ircc2.ircc_irq= [HW] IRQ line | |
2310 | smsc-ircc2.ircc_dma= [HW] DMA channel | |
2311 | smsc-ircc2.ircc_transceiver= [HW] Transceiver type: | |
2312 | 0: Toshiba Satellite 1800 (GP data pin select) | |
2313 | 1: Fast pin select (default) | |
2314 | 2: ATC IRMode | |
2315 | ||
2316 | softlockup_panic= | |
2317 | [KNL] Should the soft-lockup detector generate panics. | |
2318 | ||
2319 | sonypi.*= [HW] Sony Programmable I/O Control Device driver | |
2320 | See Documentation/sonypi.txt | |
2321 | ||
2322 | specialix= [HW,SERIAL] Specialix multi-serial port adapter | |
2323 | See Documentation/serial/specialix.txt. | |
2324 | ||
2325 | spia_io_base= [HW,MTD] | |
2326 | spia_fio_base= | |
2327 | spia_pedr= | |
2328 | spia_peddr= | |
2329 | ||
2330 | stacktrace [FTRACE] | |
2331 | Enabled the stack tracer on boot up. | |
2332 | ||
2333 | sti= [PARISC,HW] | |
2334 | Format: <num> | |
2335 | Set the STI (builtin display/keyboard on the HP-PARISC | |
2336 | machines) console (graphic card) which should be used | |
2337 | as the initial boot-console. | |
2338 | See also comment in drivers/video/console/sticore.c. | |
2339 | ||
2340 | sti_font= [HW] | |
2341 | See comment in drivers/video/console/sticore.c. | |
2342 | ||
2343 | stifb= [HW] | |
2344 | Format: bpp:<bpp1>[:<bpp2>[:<bpp3>...]] | |
2345 | ||
2346 | sunrpc.min_resvport= | |
2347 | sunrpc.max_resvport= | |
2348 | [NFS,SUNRPC] | |
2349 | SunRPC servers often require that client requests | |
2350 | originate from a privileged port (i.e. a port in the | |
2351 | range 0 < portnr < 1024). | |
2352 | An administrator who wishes to reserve some of these | |
2353 | ports for other uses may adjust the range that the | |
2354 | kernel's sunrpc client considers to be privileged | |
2355 | using these two parameters to set the minimum and | |
2356 | maximum port values. | |
2357 | ||
2358 | sunrpc.pool_mode= | |
2359 | [NFS] | |
2360 | Control how the NFS server code allocates CPUs to | |
2361 | service thread pools. Depending on how many NICs | |
2362 | you have and where their interrupts are bound, this | |
2363 | option will affect which CPUs will do NFS serving. | |
2364 | Note: this parameter cannot be changed while the | |
2365 | NFS server is running. | |
2366 | ||
2367 | auto the server chooses an appropriate mode | |
2368 | automatically using heuristics | |
2369 | global a single global pool contains all CPUs | |
2370 | percpu one pool for each CPU | |
2371 | pernode one pool for each NUMA node (equivalent | |
2372 | to global on non-NUMA machines) | |
2373 | ||
2374 | sunrpc.tcp_slot_table_entries= | |
2375 | sunrpc.udp_slot_table_entries= | |
2376 | [NFS,SUNRPC] | |
2377 | Sets the upper limit on the number of simultaneous | |
2378 | RPC calls that can be sent from the client to a | |
2379 | server. Increasing these values may allow you to | |
2380 | improve throughput, but will also increase the | |
2381 | amount of memory reserved for use by the client. | |
2382 | ||
2383 | swiotlb= [IA-64] Number of I/O TLB slabs | |
2384 | ||
2385 | switches= [HW,M68k] | |
2386 | ||
2387 | sysfs.deprecated=0|1 [KNL] | |
2388 | Enable/disable old style sysfs layout for old udev | |
2389 | on older distributions. When this option is enabled | |
2390 | very new udev will not work anymore. When this option | |
2391 | is disabled (or CONFIG_SYSFS_DEPRECATED not compiled) | |
2392 | in older udev will not work anymore. | |
2393 | Default depends on CONFIG_SYSFS_DEPRECATED_V2 set in | |
2394 | the kernel configuration. | |
2395 | ||
2396 | sysrq_always_enabled | |
2397 | [KNL] | |
2398 | Ignore sysrq setting - this boot parameter will | |
2399 | neutralize any effect of /proc/sys/kernel/sysrq. | |
2400 | Useful for debugging. | |
2401 | ||
2402 | tdfx= [HW,DRM] | |
2403 | ||
2404 | test_suspend= [SUSPEND] | |
2405 | Specify "mem" (for Suspend-to-RAM) or "standby" (for | |
2406 | standby suspend) as the system sleep state to briefly | |
2407 | enter during system startup. The system is woken from | |
2408 | this state using a wakeup-capable RTC alarm. | |
2409 | ||
2410 | thash_entries= [KNL,NET] | |
2411 | Set number of hash buckets for TCP connection | |
2412 | ||
2413 | thermal.act= [HW,ACPI] | |
2414 | -1: disable all active trip points in all thermal zones | |
2415 | <degrees C>: override all lowest active trip points | |
2416 | ||
2417 | thermal.crt= [HW,ACPI] | |
2418 | -1: disable all critical trip points in all thermal zones | |
2419 | <degrees C>: override all critical trip points | |
2420 | ||
2421 | thermal.nocrt= [HW,ACPI] | |
2422 | Set to disable actions on ACPI thermal zone | |
2423 | critical and hot trip points. | |
2424 | ||
2425 | thermal.off= [HW,ACPI] | |
2426 | 1: disable ACPI thermal control | |
2427 | ||
2428 | thermal.psv= [HW,ACPI] | |
2429 | -1: disable all passive trip points | |
2430 | <degrees C>: override all passive trip points to this | |
2431 | value | |
2432 | ||
2433 | thermal.tzp= [HW,ACPI] | |
2434 | Specify global default ACPI thermal zone polling rate | |
2435 | <deci-seconds>: poll all this frequency | |
2436 | 0: no polling (default) | |
2437 | ||
2438 | topology= [S390] | |
2439 | Format: {off | on} | |
2440 | Specify if the kernel should make use of the cpu | |
2441 | topology informations if the hardware supports these. | |
2442 | The scheduler will make use of these informations and | |
2443 | e.g. base its process migration decisions on it. | |
2444 | Default is on. | |
2445 | ||
2446 | tp720= [HW,PS2] | |
2447 | ||
2448 | tpm_suspend_pcr=[HW,TPM] | |
2449 | Format: integer pcr id | |
2450 | Specify that at suspend time, the tpm driver | |
2451 | should extend the specified pcr with zeros, | |
2452 | as a workaround for some chips which fail to | |
2453 | flush the last written pcr on TPM_SaveState. | |
2454 | This will guarantee that all the other pcrs | |
2455 | are saved. | |
2456 | ||
2457 | trace_buf_size=nn[KMG] | |
2458 | [FTRACE] will set tracing buffer size. | |
2459 | ||
2460 | trace_event=[event-list] | |
2461 | [FTRACE] Set and start specified trace events in order | |
2462 | to facilitate early boot debugging. | |
2463 | See also Documentation/trace/events.txt | |
2464 | ||
2465 | tsc= Disable clocksource-must-verify flag for TSC. | |
2466 | Format: <string> | |
2467 | [x86] reliable: mark tsc clocksource as reliable, this | |
2468 | disables clocksource verification at runtime. | |
2469 | Used to enable high-resolution timer mode on older | |
2470 | hardware, and in virtualized environment. | |
2471 | [x86] noirqtime: Do not use TSC to do irq accounting. | |
2472 | Used to run time disable IRQ_TIME_ACCOUNTING on any | |
2473 | platforms where RDTSC is slow and this accounting | |
2474 | can add overhead. | |
2475 | ||
2476 | turbografx.map[2|3]= [HW,JOY] | |
2477 | TurboGraFX parallel port interface | |
2478 | Format: | |
2479 | <port#>,<js1>,<js2>,<js3>,<js4>,<js5>,<js6>,<js7> | |
2480 | See also Documentation/input/joystick-parport.txt | |
2481 | ||
2482 | uhash_entries= [KNL,NET] | |
2483 | Set number of hash buckets for UDP/UDP-Lite connections | |
2484 | ||
2485 | uhci-hcd.ignore_oc= | |
2486 | [USB] Ignore overcurrent events (default N). | |
2487 | Some badly-designed motherboards generate lots of | |
2488 | bogus events, for ports that aren't wired to | |
2489 | anything. Set this parameter to avoid log spamming. | |
2490 | Note that genuine overcurrent events won't be | |
2491 | reported either. | |
2492 | ||
2493 | unknown_nmi_panic | |
2494 | [X86] | |
2495 | Set unknown_nmi_panic=1 early on boot. | |
2496 | ||
2497 | usbcore.autosuspend= | |
2498 | [USB] The autosuspend time delay (in seconds) used | |
2499 | for newly-detected USB devices (default 2). This | |
2500 | is the time required before an idle device will be | |
2501 | autosuspended. Devices for which the delay is set | |
2502 | to a negative value won't be autosuspended at all. | |
2503 | ||
2504 | usbcore.usbfs_snoop= | |
2505 | [USB] Set to log all usbfs traffic (default 0 = off). | |
2506 | ||
2507 | usbcore.blinkenlights= | |
2508 | [USB] Set to cycle leds on hubs (default 0 = off). | |
2509 | ||
2510 | usbcore.old_scheme_first= | |
2511 | [USB] Start with the old device initialization | |
2512 | scheme (default 0 = off). | |
2513 | ||
2514 | usbcore.use_both_schemes= | |
2515 | [USB] Try the other device initialization scheme | |
2516 | if the first one fails (default 1 = enabled). | |
2517 | ||
2518 | usbcore.initial_descriptor_timeout= | |
2519 | [USB] Specifies timeout for the initial 64-byte | |
2520 | USB_REQ_GET_DESCRIPTOR request in milliseconds | |
2521 | (default 5000 = 5.0 seconds). | |
2522 | ||
2523 | usbhid.mousepoll= | |
2524 | [USBHID] The interval which mice are to be polled at. | |
2525 | ||
2526 | usb-storage.delay_use= | |
2527 | [UMS] The delay in seconds before a new device is | |
2528 | scanned for Logical Units (default 5). | |
2529 | ||
2530 | usb-storage.quirks= | |
2531 | [UMS] A list of quirks entries to supplement or | |
2532 | override the built-in unusual_devs list. List | |
2533 | entries are separated by commas. Each entry has | |
2534 | the form VID:PID:Flags where VID and PID are Vendor | |
2535 | and Product ID values (4-digit hex numbers) and | |
2536 | Flags is a set of characters, each corresponding | |
2537 | to a common usb-storage quirk flag as follows: | |
2538 | a = SANE_SENSE (collect more than 18 bytes | |
2539 | of sense data); | |
2540 | b = BAD_SENSE (don't collect more than 18 | |
2541 | bytes of sense data); | |
2542 | c = FIX_CAPACITY (decrease the reported | |
2543 | device capacity by one sector); | |
2544 | h = CAPACITY_HEURISTICS (decrease the | |
2545 | reported device capacity by one | |
2546 | sector if the number is odd); | |
2547 | i = IGNORE_DEVICE (don't bind to this | |
2548 | device); | |
2549 | l = NOT_LOCKABLE (don't try to lock and | |
2550 | unlock ejectable media); | |
2551 | m = MAX_SECTORS_64 (don't transfer more | |
2552 | than 64 sectors = 32 KB at a time); | |
2553 | o = CAPACITY_OK (accept the capacity | |
2554 | reported by the device); | |
2555 | r = IGNORE_RESIDUE (the device reports | |
2556 | bogus residue values); | |
2557 | s = SINGLE_LUN (the device has only one | |
2558 | Logical Unit); | |
2559 | w = NO_WP_DETECT (don't test whether the | |
2560 | medium is write-protected). | |
2561 | Example: quirks=0419:aaf5:rl,0421:0433:rc | |
2562 | ||
2563 | userpte= | |
2564 | [X86] Flags controlling user PTE allocations. | |
2565 | ||
2566 | nohigh = do not allocate PTE pages in | |
2567 | HIGHMEM regardless of setting | |
2568 | of CONFIG_HIGHPTE. | |
2569 | ||
2570 | vdso= [X86,SH] | |
2571 | vdso=2: enable compat VDSO (default with COMPAT_VDSO) | |
2572 | vdso=1: enable VDSO (default) | |
2573 | vdso=0: disable VDSO mapping | |
2574 | ||
2575 | vdso32= [X86] | |
2576 | vdso32=2: enable compat VDSO (default with COMPAT_VDSO) | |
2577 | vdso32=1: enable 32-bit VDSO (default) | |
2578 | vdso32=0: disable 32-bit VDSO mapping | |
2579 | ||
2580 | vector= [IA-64,SMP] | |
2581 | vector=percpu: enable percpu vector domain | |
2582 | ||
2583 | video= [FB] Frame buffer configuration | |
2584 | See Documentation/fb/modedb.txt. | |
2585 | ||
2586 | vga= [BOOT,X86-32] Select a particular video mode | |
2587 | See Documentation/x86/boot.txt and | |
2588 | Documentation/svga.txt. | |
2589 | Use vga=ask for menu. | |
2590 | This is actually a boot loader parameter; the value is | |
2591 | passed to the kernel using a special protocol. | |
2592 | ||
2593 | vmalloc=nn[KMG] [KNL,BOOT] Forces the vmalloc area to have an exact | |
2594 | size of <nn>. This can be used to increase the | |
2595 | minimum size (128MB on x86). It can also be used to | |
2596 | decrease the size and leave more room for directly | |
2597 | mapped kernel RAM. | |
2598 | ||
2599 | vmhalt= [KNL,S390] Perform z/VM CP command after system halt. | |
2600 | Format: <command> | |
2601 | ||
2602 | vmpanic= [KNL,S390] Perform z/VM CP command after kernel panic. | |
2603 | Format: <command> | |
2604 | ||
2605 | vmpoff= [KNL,S390] Perform z/VM CP command after power off. | |
2606 | Format: <command> | |
2607 | ||
2608 | vt.cur_default= [VT] Default cursor shape. | |
2609 | Format: 0xCCBBAA, where AA, BB, and CC are the same as | |
2610 | the parameters of the <Esc>[?A;B;Cc escape sequence; | |
2611 | see VGA-softcursor.txt. Default: 2 = underline. | |
2612 | ||
2613 | vt.default_blu= [VT] | |
2614 | Format: <blue0>,<blue1>,<blue2>,...,<blue15> | |
2615 | Change the default blue palette of the console. | |
2616 | This is a 16-member array composed of values | |
2617 | ranging from 0-255. | |
2618 | ||
2619 | vt.default_grn= [VT] | |
2620 | Format: <green0>,<green1>,<green2>,...,<green15> | |
2621 | Change the default green palette of the console. | |
2622 | This is a 16-member array composed of values | |
2623 | ranging from 0-255. | |
2624 | ||
2625 | vt.default_red= [VT] | |
2626 | Format: <red0>,<red1>,<red2>,...,<red15> | |
2627 | Change the default red palette of the console. | |
2628 | This is a 16-member array composed of values | |
2629 | ranging from 0-255. | |
2630 | ||
2631 | vt.default_utf8= | |
2632 | [VT] | |
2633 | Format=<0|1> | |
2634 | Set system-wide default UTF-8 mode for all tty's. | |
2635 | Default is 1, i.e. UTF-8 mode is enabled for all | |
2636 | newly opened terminals. | |
2637 | ||
2638 | vt.global_cursor_default= | |
2639 | [VT] | |
2640 | Format=<-1|0|1> | |
2641 | Set system-wide default for whether a cursor | |
2642 | is shown on new VTs. Default is -1, | |
2643 | i.e. cursors will be created by default unless | |
2644 | overridden by individual drivers. 0 will hide | |
2645 | cursors, 1 will display them. | |
2646 | ||
2647 | watchdog timers [HW,WDT] For information on watchdog timers, | |
2648 | see Documentation/watchdog/watchdog-parameters.txt | |
2649 | or other driver-specific files in the | |
2650 | Documentation/watchdog/ directory. | |
2651 | ||
2652 | x2apic_phys [X86-64,APIC] Use x2apic physical mode instead of | |
2653 | default x2apic cluster mode on platforms | |
2654 | supporting x2apic. | |
2655 | ||
2656 | x86_mrst_timer= [X86-32,APBT] | |
2657 | Choose timer option for x86 Moorestown MID platform. | |
2658 | Two valid options are apbt timer only and lapic timer | |
2659 | plus one apbt timer for broadcast timer. | |
2660 | x86_mrst_timer=apbt_only | lapic_and_apbt | |
2661 | ||
2662 | xd= [HW,XT] Original XT pre-IDE (RLL encoded) disks. | |
2663 | xd_geo= See header of drivers/block/xd.c. | |
2664 | ||
2665 | xen_emul_unplug= [HW,X86,XEN] | |
2666 | Unplug Xen emulated devices | |
2667 | Format: [unplug0,][unplug1] | |
2668 | ide-disks -- unplug primary master IDE devices | |
2669 | aux-ide-disks -- unplug non-primary-master IDE devices | |
2670 | nics -- unplug network devices | |
2671 | all -- unplug all emulated devices (NICs and IDE disks) | |
2672 | unnecessary -- unplugging emulated devices is | |
2673 | unnecessary even if the host did not respond to | |
2674 | the unplug protocol | |
2675 | never -- do not unplug even if version check succeeds | |
2676 | ||
2677 | xirc2ps_cs= [NET,PCMCIA] | |
2678 | Format: | |
2679 | <irq>,<irq_mask>,<io>,<full_duplex>,<do_sound>,<lockup_hack>[,<irq2>[,<irq3>[,<irq4>]]] | |
2680 | ||
2681 | ______________________________________________________________________ | |
2682 | ||
2683 | TODO: | |
2684 | ||
2685 | Add more DRM drivers. |