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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 | ARM ARM architecture is enabled. |
44 | AVR32 AVR32 architecture is enabled. |
45 | AX25 Appropriate AX.25 support is enabled. |
46 | BLACKFIN Blackfin architecture is enabled. |
47 | DRM Direct Rendering Management support is enabled. |
48 | DYNAMIC_DEBUG Build in debug messages and enable them at runtime |
49 | EDD BIOS Enhanced Disk Drive Services (EDD) is enabled |
50 | EFI EFI Partitioning (GPT) is enabled |
51 | EIDE EIDE/ATAPI support is enabled. |
52 | EVM Extended Verification Module |
53 | FB The frame buffer device is enabled. |
54 | FTRACE Function tracing enabled. |
55 | GCOV GCOV profiling is enabled. |
56 | HW Appropriate hardware is enabled. |
57 | IA-64 IA-64 architecture is enabled. |
58 | IMA Integrity measurement architecture is enabled. |
59 | IOSCHED More than one I/O scheduler is enabled. |
60 | IP_PNP IP DHCP, BOOTP, or RARP is enabled. |
61 | IPV6 IPv6 support is enabled. |
62 | ISAPNP ISA PnP code is enabled. |
63 | ISDN Appropriate ISDN support is enabled. |
64 | JOY Appropriate joystick support is enabled. |
65 | KGDB Kernel debugger support is enabled. |
66 | KVM Kernel Virtual Machine support is enabled. |
67 | LIBATA Libata driver is enabled |
68 | LP Printer support is enabled. |
69 | LOOP Loopback device support is enabled. |
70 | M68k M68k architecture is enabled. |
71 | These options have more detailed description inside of |
72 | Documentation/m68k/kernel-options.txt. |
73 | MDA MDA console support is enabled. |
74 | MIPS MIPS architecture is enabled. |
75 | MOUSE Appropriate mouse support is enabled. |
76 | MSI Message Signaled Interrupts (PCI). |
77 | MTD MTD (Memory Technology Device) support is enabled. |
78 | NET Appropriate network support is enabled. |
79 | NUMA NUMA support is enabled. |
80 | NFS Appropriate NFS support is enabled. |
81 | OSS OSS sound support is enabled. |
82 | PV_OPS A paravirtualized kernel is enabled. |
83 | PARIDE The ParIDE (parallel port IDE) subsystem is enabled. |
84 | PARISC The PA-RISC architecture is enabled. |
85 | PCI PCI bus support is enabled. |
86 | PCIE PCI Express support is enabled. |
87 | PCMCIA The PCMCIA subsystem is enabled. |
88 | PNP Plug & Play support is enabled. |
89 | PPC PowerPC architecture is enabled. |
90 | PPT Parallel port support is enabled. |
91 | PS2 Appropriate PS/2 support is enabled. |
92 | RAM RAM disk support is enabled. |
93 | S390 S390 architecture is enabled. |
94 | SCSI Appropriate SCSI support is enabled. |
95 | A lot of drivers have their options described inside |
96 | the Documentation/scsi/ sub-directory. |
97 | SECURITY Different security models are enabled. |
98 | SELINUX SELinux support is enabled. |
99 | APPARMOR AppArmor support is enabled. |
100 | SERIAL Serial support is enabled. |
101 | SH SuperH architecture is enabled. |
102 | SMP The kernel is an SMP kernel. |
103 | SPARC Sparc architecture is enabled. |
104 | SWSUSP Software suspend (hibernation) is enabled. |
105 | SUSPEND System suspend states are enabled. |
106 | TPM TPM drivers are enabled. |
107 | TS Appropriate touchscreen support is enabled. |
108 | UMS USB Mass Storage support is enabled. |
109 | USB USB support is enabled. |
110 | USBHID USB Human Interface Device support is enabled. |
111 | V4L Video For Linux support is enabled. |
112 | VMMIO Driver for memory mapped virtio devices is enabled. |
113 | VGA The VGA console has been enabled. |
114 | VT Virtual terminal support is enabled. |
115 | WDT Watchdog support is enabled. |
116 | XT IBM PC/XT MFM hard disk support is enabled. |
117 | X86-32 X86-32, aka i386 architecture is enabled. |
118 | X86-64 X86-64 architecture is enabled. |
119 | More X86-64 boot options can be found in |
120 | Documentation/x86/x86_64/boot-options.txt . |
121 | X86 Either 32-bit or 64-bit x86 (same as X86-32+X86-64) |
122 | XEN Xen support is enabled |
123 | |
124 | In addition, the following text indicates that the option: |
125 | |
126 | BUGS= Relates to possible processor bugs on the said processor. |
127 | KNL Is a kernel start-up parameter. |
128 | BOOT Is a boot loader parameter. |
129 | |
130 | Parameters denoted with BOOT are actually interpreted by the boot |
131 | loader, and have no meaning to the kernel directly. |
132 | Do not modify the syntax of boot loader parameters without extreme |
133 | need or coordination with <Documentation/x86/boot.txt>. |
134 | |
135 | There are also arch-specific kernel-parameters not documented here. |
136 | See for example <Documentation/x86/x86_64/boot-options.txt>. |
137 | |
138 | Note that ALL kernel parameters listed below are CASE SENSITIVE, and that |
139 | a trailing = on the name of any parameter states that that parameter will |
140 | be entered as an environment variable, whereas its absence indicates that |
141 | it will appear as a kernel argument readable via /proc/cmdline by programs |
142 | running once the system is up. |
143 | |
144 | The number of kernel parameters is not limited, but the length of the |
145 | complete command line (parameters including spaces etc.) is limited to |
146 | a fixed number of characters. This limit depends on the architecture |
147 | and is between 256 and 4096 characters. It is defined in the file |
148 | ./include/asm/setup.h as COMMAND_LINE_SIZE. |
149 | |
150 | Finally, the [KMG] suffix is commonly described after a number of kernel |
151 | parameter values. These 'K', 'M', and 'G' letters represent the _binary_ |
152 | multipliers 'Kilo', 'Mega', and 'Giga', equalling 2^10, 2^20, and 2^30 |
153 | bytes respectively. Such letter suffixes can also be entirely omitted. |
154 | |
155 | |
156 | acpi= [HW,ACPI,X86] |
157 | Advanced Configuration and Power Interface |
158 | Format: { force | off | strict | noirq | rsdt } |
159 | force -- enable ACPI if default was off |
160 | off -- disable ACPI if default was on |
161 | noirq -- do not use ACPI for IRQ routing |
162 | strict -- Be less tolerant of platforms that are not |
163 | strictly ACPI specification compliant. |
164 | rsdt -- prefer RSDT over (default) XSDT |
165 | copy_dsdt -- copy DSDT to memory |
166 | |
167 | See also Documentation/power/runtime_pm.txt, pci=noacpi |
168 | |
169 | acpi_rsdp= [ACPI,EFI,KEXEC] |
170 | Pass the RSDP address to the kernel, mostly used |
171 | on machines running EFI runtime service to boot the |
172 | second kernel for kdump. |
173 | |
174 | acpi_apic_instance= [ACPI, IOAPIC] |
175 | Format: <int> |
176 | 2: use 2nd APIC table, if available |
177 | 1,0: use 1st APIC table |
178 | default: 0 |
179 | |
180 | acpi_backlight= [HW,ACPI] |
181 | acpi_backlight=vendor |
182 | acpi_backlight=video |
183 | If set to vendor, prefer vendor specific driver |
184 | (e.g. thinkpad_acpi, sony_acpi, etc.) instead |
185 | of the ACPI video.ko driver. |
186 | |
187 | acpi.debug_layer= [HW,ACPI,ACPI_DEBUG] |
188 | acpi.debug_level= [HW,ACPI,ACPI_DEBUG] |
189 | Format: <int> |
190 | CONFIG_ACPI_DEBUG must be enabled to produce any ACPI |
191 | debug output. Bits in debug_layer correspond to a |
192 | _COMPONENT in an ACPI source file, e.g., |
193 | #define _COMPONENT ACPI_PCI_COMPONENT |
194 | Bits in debug_level correspond to a level in |
195 | ACPI_DEBUG_PRINT statements, e.g., |
196 | ACPI_DEBUG_PRINT((ACPI_DB_INFO, ... |
197 | The debug_level mask defaults to "info". See |
198 | Documentation/acpi/debug.txt for more information about |
199 | debug layers and levels. |
200 | |
201 | Enable processor driver info messages: |
202 | acpi.debug_layer=0x20000000 |
203 | Enable PCI/PCI interrupt routing info messages: |
204 | acpi.debug_layer=0x400000 |
205 | Enable AML "Debug" output, i.e., stores to the Debug |
206 | object while interpreting AML: |
207 | acpi.debug_layer=0xffffffff acpi.debug_level=0x2 |
208 | Enable all messages related to ACPI hardware: |
209 | acpi.debug_layer=0x2 acpi.debug_level=0xffffffff |
210 | |
211 | Some values produce so much output that the system is |
212 | unusable. The "log_buf_len" parameter may be useful |
213 | if you need to capture more output. |
214 | |
215 | acpi_irq_balance [HW,ACPI] |
216 | ACPI will balance active IRQs |
217 | default in APIC mode |
218 | |
219 | acpi_irq_nobalance [HW,ACPI] |
220 | ACPI will not move active IRQs (default) |
221 | default in PIC mode |
222 | |
223 | acpi_irq_isa= [HW,ACPI] If irq_balance, mark listed IRQs used by ISA |
224 | Format: <irq>,<irq>... |
225 | |
226 | acpi_irq_pci= [HW,ACPI] If irq_balance, clear listed IRQs for |
227 | use by PCI |
228 | Format: <irq>,<irq>... |
229 | |
230 | acpi_no_auto_ssdt [HW,ACPI] Disable automatic loading of SSDT |
231 | |
232 | acpi_os_name= [HW,ACPI] Tell ACPI BIOS the name of the OS |
233 | Format: To spoof as Windows 98: ="Microsoft Windows" |
234 | |
235 | acpi_osi= [HW,ACPI] Modify list of supported OS interface strings |
236 | acpi_osi="string1" # add string1 -- only one string |
237 | acpi_osi="!string2" # remove built-in string2 |
238 | acpi_osi= # disable all strings |
239 | |
240 | acpi_pm_good [X86] |
241 | Override the pmtimer bug detection: force the kernel |
242 | to assume that this machine's pmtimer latches its value |
243 | and always returns good values. |
244 | |
245 | acpi_sci= [HW,ACPI] ACPI System Control Interrupt trigger mode |
246 | Format: { level | edge | high | low } |
247 | |
248 | acpi_serialize [HW,ACPI] force serialization of AML methods |
249 | |
250 | acpi_skip_timer_override [HW,ACPI] |
251 | Recognize and ignore IRQ0/pin2 Interrupt Override. |
252 | For broken nForce2 BIOS resulting in XT-PIC timer. |
253 | |
254 | acpi_sleep= [HW,ACPI] Sleep options |
255 | Format: { s3_bios, s3_mode, s3_beep, s4_nohwsig, |
256 | old_ordering, nonvs, sci_force_enable } |
257 | See Documentation/power/video.txt for information on |
258 | s3_bios and s3_mode. |
259 | s3_beep is for debugging; it makes the PC's speaker beep |
260 | as soon as the kernel's real-mode entry point is called. |
261 | s4_nohwsig prevents ACPI hardware signature from being |
262 | used during resume from hibernation. |
263 | old_ordering causes the ACPI 1.0 ordering of the _PTS |
264 | control method, with respect to putting devices into |
265 | low power states, to be enforced (the ACPI 2.0 ordering |
266 | of _PTS is used by default). |
267 | nonvs prevents the kernel from saving/restoring the |
268 | ACPI NVS memory during suspend/hibernation and resume. |
269 | sci_force_enable causes the kernel to set SCI_EN directly |
270 | on resume from S1/S3 (which is against the ACPI spec, |
271 | but some broken systems don't work without it). |
272 | |
273 | acpi_use_timer_override [HW,ACPI] |
274 | Use timer override. For some broken Nvidia NF5 boards |
275 | that require a timer override, but don't have HPET |
276 | |
277 | acpi_enforce_resources= [ACPI] |
278 | { strict | lax | no } |
279 | Check for resource conflicts between native drivers |
280 | and ACPI OperationRegions (SystemIO and SystemMemory |
281 | only). IO ports and memory declared in ACPI might be |
282 | used by the ACPI subsystem in arbitrary AML code and |
283 | can interfere with legacy drivers. |
284 | strict (default): access to resources claimed by ACPI |
285 | is denied; legacy drivers trying to access reserved |
286 | resources will fail to bind to device using them. |
287 | lax: access to resources claimed by ACPI is allowed; |
288 | legacy drivers trying to access reserved resources |
289 | will bind successfully but a warning message is logged. |
290 | no: ACPI OperationRegions are not marked as reserved, |
291 | no further checks are performed. |
292 | |
293 | add_efi_memmap [EFI; X86] Include EFI memory map in |
294 | kernel's map of available physical RAM. |
295 | |
296 | agp= [AGP] |
297 | { off | try_unsupported } |
298 | off: disable AGP support |
299 | try_unsupported: try to drive unsupported chipsets |
300 | (may crash computer or cause data corruption) |
301 | |
302 | ALSA [HW,ALSA] |
303 | See Documentation/sound/alsa/alsa-parameters.txt |
304 | |
305 | alignment= [KNL,ARM] |
306 | Allow the default userspace alignment fault handler |
307 | behaviour to be specified. Bit 0 enables warnings, |
308 | bit 1 enables fixups, and bit 2 sends a segfault. |
309 | |
310 | align_va_addr= [X86-64] |
311 | Align virtual addresses by clearing slice [14:12] when |
312 | allocating a VMA at process creation time. This option |
313 | gives you up to 3% performance improvement on AMD F15h |
314 | machines (where it is enabled by default) for a |
315 | CPU-intensive style benchmark, and it can vary highly in |
316 | a microbenchmark depending on workload and compiler. |
317 | |
318 | 32: only for 32-bit processes |
319 | 64: only for 64-bit processes |
320 | on: enable for both 32- and 64-bit processes |
321 | off: disable for both 32- and 64-bit processes |
322 | |
323 | amd_iommu= [HW,X86-64] |
324 | Pass parameters to the AMD IOMMU driver in the system. |
325 | Possible values are: |
326 | fullflush - enable flushing of IO/TLB entries when |
327 | they are unmapped. Otherwise they are |
328 | flushed before they will be reused, which |
329 | is a lot of faster |
330 | off - do not initialize any AMD IOMMU found in |
331 | the system |
332 | force_isolation - Force device isolation for all |
333 | devices. The IOMMU driver is not |
334 | allowed anymore to lift isolation |
335 | requirements as needed. This option |
336 | does not override iommu=pt |
337 | |
338 | amd_iommu_dump= [HW,X86-64] |
339 | Enable AMD IOMMU driver option to dump the ACPI table |
340 | for AMD IOMMU. With this option enabled, AMD IOMMU |
341 | driver will print ACPI tables for AMD IOMMU during |
342 | IOMMU initialization. |
343 | |
344 | amijoy.map= [HW,JOY] Amiga joystick support |
345 | Map of devices attached to JOY0DAT and JOY1DAT |
346 | Format: <a>,<b> |
347 | See also Documentation/input/joystick.txt |
348 | |
349 | analog.map= [HW,JOY] Analog joystick and gamepad support |
350 | Specifies type or capabilities of an analog joystick |
351 | connected to one of 16 gameports |
352 | Format: <type1>,<type2>,..<type16> |
353 | |
354 | apc= [HW,SPARC] |
355 | Power management functions (SPARCstation-4/5 + deriv.) |
356 | Format: noidle |
357 | Disable APC CPU standby support. SPARCstation-Fox does |
358 | not play well with APC CPU idle - disable it if you have |
359 | APC and your system crashes randomly. |
360 | |
361 | apic= [APIC,X86-32] Advanced Programmable Interrupt Controller |
362 | Change the output verbosity whilst booting |
363 | Format: { quiet (default) | verbose | debug } |
364 | Change the amount of debugging information output |
365 | when initialising the APIC and IO-APIC components. |
366 | |
367 | autoconf= [IPV6] |
368 | See Documentation/networking/ipv6.txt. |
369 | |
370 | show_lapic= [APIC,X86] Advanced Programmable Interrupt Controller |
371 | Limit apic dumping. The parameter defines the maximal |
372 | number of local apics being dumped. Also it is possible |
373 | to set it to "all" by meaning -- no limit here. |
374 | Format: { 1 (default) | 2 | ... | all }. |
375 | The parameter valid if only apic=debug or |
376 | apic=verbose is specified. |
377 | Example: apic=debug show_lapic=all |
378 | |
379 | apm= [APM] Advanced Power Management |
380 | See header of arch/x86/kernel/apm_32.c. |
381 | |
382 | arcrimi= [HW,NET] ARCnet - "RIM I" (entirely mem-mapped) cards |
383 | Format: <io>,<irq>,<nodeID> |
384 | |
385 | ataflop= [HW,M68k] |
386 | |
387 | atarimouse= [HW,MOUSE] Atari Mouse |
388 | |
389 | atkbd.extra= [HW] Enable extra LEDs and keys on IBM RapidAccess, |
390 | EzKey and similar keyboards |
391 | |
392 | atkbd.reset= [HW] Reset keyboard during initialization |
393 | |
394 | atkbd.set= [HW] Select keyboard code set |
395 | Format: <int> (2 = AT (default), 3 = PS/2) |
396 | |
397 | atkbd.scroll= [HW] Enable scroll wheel on MS Office and similar |
398 | keyboards |
399 | |
400 | atkbd.softraw= [HW] Choose between synthetic and real raw mode |
401 | Format: <bool> (0 = real, 1 = synthetic (default)) |
402 | |
403 | atkbd.softrepeat= [HW] |
404 | Use software keyboard repeat |
405 | |
406 | baycom_epp= [HW,AX25] |
407 | Format: <io>,<mode> |
408 | |
409 | baycom_par= [HW,AX25] BayCom Parallel Port AX.25 Modem |
410 | Format: <io>,<mode> |
411 | See header of drivers/net/hamradio/baycom_par.c. |
412 | |
413 | baycom_ser_fdx= [HW,AX25] |
414 | BayCom Serial Port AX.25 Modem (Full Duplex Mode) |
415 | Format: <io>,<irq>,<mode>[,<baud>] |
416 | See header of drivers/net/hamradio/baycom_ser_fdx.c. |
417 | |
418 | baycom_ser_hdx= [HW,AX25] |
419 | BayCom Serial Port AX.25 Modem (Half Duplex Mode) |
420 | Format: <io>,<irq>,<mode> |
421 | See header of drivers/net/hamradio/baycom_ser_hdx.c. |
422 | |
423 | boot_delay= Milliseconds to delay each printk during boot. |
424 | Values larger than 10 seconds (10000) are changed to |
425 | no delay (0). |
426 | Format: integer |
427 | |
428 | bootmem_debug [KNL] Enable bootmem allocator debug messages. |
429 | |
430 | bttv.card= [HW,V4L] bttv (bt848 + bt878 based grabber cards) |
431 | bttv.radio= Most important insmod options are available as |
432 | kernel args too. |
433 | bttv.pll= See Documentation/video4linux/bttv/Insmod-options |
434 | bttv.tuner= |
435 | |
436 | bulk_remove=off [PPC] This parameter disables the use of the pSeries |
437 | firmware feature for flushing multiple hpte entries |
438 | at a time. |
439 | |
440 | c101= [NET] Moxa C101 synchronous serial card |
441 | |
442 | cachesize= [BUGS=X86-32] Override level 2 CPU cache size detection. |
443 | Sometimes CPU hardware bugs make them report the cache |
444 | size incorrectly. The kernel will attempt work arounds |
445 | to fix known problems, but for some CPUs it is not |
446 | possible to determine what the correct size should be. |
447 | This option provides an override for these situations. |
448 | |
449 | ccw_timeout_log [S390] |
450 | See Documentation/s390/CommonIO for details. |
451 | |
452 | cgroup_disable= [KNL] Disable a particular controller |
453 | Format: {name of the controller(s) to disable} |
454 | {Currently supported controllers - "memory"} |
455 | |
456 | checkreqprot [SELINUX] Set initial checkreqprot flag value. |
457 | Format: { "0" | "1" } |
458 | See security/selinux/Kconfig help text. |
459 | 0 -- check protection applied by kernel (includes |
460 | any implied execute protection). |
461 | 1 -- check protection requested by application. |
462 | Default value is set via a kernel config option. |
463 | Value can be changed at runtime via |
464 | /selinux/checkreqprot. |
465 | |
466 | cio_ignore= [S390] |
467 | See Documentation/s390/CommonIO for details. |
468 | |
469 | clock= [BUGS=X86-32, HW] gettimeofday clocksource override. |
470 | [Deprecated] |
471 | Forces specified clocksource (if available) to be used |
472 | when calculating gettimeofday(). If specified |
473 | clocksource is not available, it defaults to PIT. |
474 | Format: { pit | tsc | cyclone | pmtmr } |
475 | |
476 | clocksource= Override the default clocksource |
477 | Format: <string> |
478 | Override the default clocksource and use the clocksource |
479 | with the name specified. |
480 | Some clocksource names to choose from, depending on |
481 | the platform: |
482 | [all] jiffies (this is the base, fallback clocksource) |
483 | [ACPI] acpi_pm |
484 | [ARM] imx_timer1,OSTS,netx_timer,mpu_timer2, |
485 | pxa_timer,timer3,32k_counter,timer0_1 |
486 | [AVR32] avr32 |
487 | [X86-32] pit,hpet,tsc; |
488 | scx200_hrt on Geode; cyclone on IBM x440 |
489 | [MIPS] MIPS |
490 | [PARISC] cr16 |
491 | [S390] tod |
492 | [SH] SuperH |
493 | [SPARC64] tick |
494 | [X86-64] hpet,tsc |
495 | |
496 | clearcpuid=BITNUM [X86] |
497 | Disable CPUID feature X for the kernel. See |
498 | arch/x86/include/asm/cpufeature.h for the valid bit |
499 | numbers. Note the Linux specific bits are not necessarily |
500 | stable over kernel options, but the vendor specific |
501 | ones should be. |
502 | Also note that user programs calling CPUID directly |
503 | or using the feature without checking anything |
504 | will still see it. This just prevents it from |
505 | being used by the kernel or shown in /proc/cpuinfo. |
506 | Also note the kernel might malfunction if you disable |
507 | some critical bits. |
508 | |
509 | cma=nn[MG] [ARM,KNL] |
510 | Sets the size of kernel global memory area for contiguous |
511 | memory allocations. For more information, see |
512 | include/linux/dma-contiguous.h |
513 | |
514 | cmo_free_hint= [PPC] Format: { yes | no } |
515 | Specify whether pages are marked as being inactive |
516 | when they are freed. This is used in CMO environments |
517 | to determine OS memory pressure for page stealing by |
518 | a hypervisor. |
519 | Default: yes |
520 | |
521 | coherent_pool=nn[KMG] [ARM,KNL] |
522 | Sets the size of memory pool for coherent, atomic dma |
523 | allocations, by default set to 256K. |
524 | |
525 | code_bytes [X86] How many bytes of object code to print |
526 | in an oops report. |
527 | Range: 0 - 8192 |
528 | Default: 64 |
529 | |
530 | com20020= [HW,NET] ARCnet - COM20020 chipset |
531 | Format: |
532 | <io>[,<irq>[,<nodeID>[,<backplane>[,<ckp>[,<timeout>]]]]] |
533 | |
534 | com90io= [HW,NET] ARCnet - COM90xx chipset (IO-mapped buffers) |
535 | Format: <io>[,<irq>] |
536 | |
537 | com90xx= [HW,NET] |
538 | ARCnet - COM90xx chipset (memory-mapped buffers) |
539 | Format: <io>[,<irq>[,<memstart>]] |
540 | |
541 | condev= [HW,S390] console device |
542 | conmode= |
543 | |
544 | console= [KNL] Output console device and options. |
545 | |
546 | tty<n> Use the virtual console device <n>. |
547 | |
548 | ttyS<n>[,options] |
549 | ttyUSB0[,options] |
550 | Use the specified serial port. The options are of |
551 | the form "bbbbpnf", where "bbbb" is the baud rate, |
552 | "p" is parity ("n", "o", or "e"), "n" is number of |
553 | bits, and "f" is flow control ("r" for RTS or |
554 | omit it). Default is "9600n8". |
555 | |
556 | See Documentation/serial-console.txt for more |
557 | information. See |
558 | Documentation/networking/netconsole.txt for an |
559 | alternative. |
560 | |
561 | uart[8250],io,<addr>[,options] |
562 | uart[8250],mmio,<addr>[,options] |
563 | Start an early, polled-mode console on the 8250/16550 |
564 | UART at the specified I/O port or MMIO address, |
565 | switching to the matching ttyS device later. The |
566 | options are the same as for ttyS, above. |
567 | hvc<n> Use the hypervisor console device <n>. This is for |
568 | both Xen and PowerPC hypervisors. |
569 | |
570 | If the device connected to the port is not a TTY but a braille |
571 | device, prepend "brl," before the device type, for instance |
572 | console=brl,ttyS0 |
573 | For now, only VisioBraille is supported. |
574 | |
575 | consoleblank= [KNL] The console blank (screen saver) timeout in |
576 | seconds. Defaults to 10*60 = 10mins. A value of 0 |
577 | disables the blank timer. |
578 | |
579 | coredump_filter= |
580 | [KNL] Change the default value for |
581 | /proc/<pid>/coredump_filter. |
582 | See also Documentation/filesystems/proc.txt. |
583 | |
584 | cpuidle.off=1 [CPU_IDLE] |
585 | disable the cpuidle sub-system |
586 | |
587 | cpcihp_generic= [HW,PCI] Generic port I/O CompactPCI driver |
588 | Format: |
589 | <first_slot>,<last_slot>,<port>,<enum_bit>[,<debug>] |
590 | |
591 | crashkernel=size[KMG][@offset[KMG]] |
592 | [KNL] Using kexec, Linux can switch to a 'crash kernel' |
593 | upon panic. This parameter reserves the physical |
594 | memory region [offset, offset + size] for that kernel |
595 | image. If '@offset' is omitted, then a suitable offset |
596 | is selected automatically. Check |
597 | Documentation/kdump/kdump.txt for further details. |
598 | |
599 | crashkernel=range1:size1[,range2:size2,...][@offset] |
600 | [KNL] Same as above, but depends on the memory |
601 | in the running system. The syntax of range is |
602 | start-[end] where start and end are both |
603 | a memory unit (amount[KMG]). See also |
604 | Documentation/kdump/kdump.txt for an example. |
605 | |
606 | crashkernel=size[KMG],high |
607 | [KNL, x86_64] range could be above 4G. Allow kernel |
608 | to allocate physical memory region from top, so could |
609 | be above 4G if system have more than 4G ram installed. |
610 | Otherwise memory region will be allocated below 4G, if |
611 | available. |
612 | It will be ignored if crashkernel=X is specified. |
613 | crashkernel=size[KMG],low |
614 | [KNL, x86_64] range under 4G. When crashkernel=X,high |
615 | is passed, kernel could allocate physical memory region |
616 | above 4G, that cause second kernel crash on system |
617 | that require some amount of low memory, e.g. swiotlb |
618 | requires at least 64M+32K low memory. Kernel would |
619 | try to allocate 72M below 4G automatically. |
620 | This one let user to specify own low range under 4G |
621 | for second kernel instead. |
622 | 0: to disable low allocation. |
623 | It will be ignored when crashkernel=X,high is not used |
624 | or memory reserved is below 4G. |
625 | |
626 | cs89x0_dma= [HW,NET] |
627 | Format: <dma> |
628 | |
629 | cs89x0_media= [HW,NET] |
630 | Format: { rj45 | aui | bnc } |
631 | |
632 | dasd= [HW,NET] |
633 | See header of drivers/s390/block/dasd_devmap.c. |
634 | |
635 | db9.dev[2|3]= [HW,JOY] Multisystem joystick support via parallel port |
636 | (one device per port) |
637 | Format: <port#>,<type> |
638 | See also Documentation/input/joystick-parport.txt |
639 | |
640 | ddebug_query= [KNL,DYNAMIC_DEBUG] Enable debug messages at early boot |
641 | time. See Documentation/dynamic-debug-howto.txt for |
642 | details. Deprecated, see dyndbg. |
643 | |
644 | debug [KNL] Enable kernel debugging (events log level). |
645 | |
646 | debug_locks_verbose= |
647 | [KNL] verbose self-tests |
648 | Format=<0|1> |
649 | Print debugging info while doing the locking API |
650 | self-tests. |
651 | We default to 0 (no extra messages), setting it to |
652 | 1 will print _a lot_ more information - normally |
653 | only useful to kernel developers. |
654 | |
655 | debug_objects [KNL] Enable object debugging |
656 | |
657 | no_debug_objects |
658 | [KNL] Disable object debugging |
659 | |
660 | debug_guardpage_minorder= |
661 | [KNL] When CONFIG_DEBUG_PAGEALLOC is set, this |
662 | parameter allows control of the order of pages that will |
663 | be intentionally kept free (and hence protected) by the |
664 | buddy allocator. Bigger value increase the probability |
665 | of catching random memory corruption, but reduce the |
666 | amount of memory for normal system use. The maximum |
667 | possible value is MAX_ORDER/2. Setting this parameter |
668 | to 1 or 2 should be enough to identify most random |
669 | memory corruption problems caused by bugs in kernel or |
670 | driver code when a CPU writes to (or reads from) a |
671 | random memory location. Note that there exists a class |
672 | of memory corruptions problems caused by buggy H/W or |
673 | F/W or by drivers badly programing DMA (basically when |
674 | memory is written at bus level and the CPU MMU is |
675 | bypassed) which are not detectable by |
676 | CONFIG_DEBUG_PAGEALLOC, hence this option will not help |
677 | tracking down these problems. |
678 | |
679 | debugpat [X86] Enable PAT debugging |
680 | |
681 | decnet.addr= [HW,NET] |
682 | Format: <area>[,<node>] |
683 | See also Documentation/networking/decnet.txt. |
684 | |
685 | default_hugepagesz= |
686 | [same as hugepagesz=] The size of the default |
687 | HugeTLB page size. This is the size represented by |
688 | the legacy /proc/ hugepages APIs, used for SHM, and |
689 | default size when mounting hugetlbfs filesystems. |
690 | Defaults to the default architecture's huge page size |
691 | if not specified. |
692 | |
693 | dhash_entries= [KNL] |
694 | Set number of hash buckets for dentry cache. |
695 | |
696 | digi= [HW,SERIAL] |
697 | IO parameters + enable/disable command. |
698 | |
699 | digiepca= [HW,SERIAL] |
700 | See drivers/char/README.epca and |
701 | Documentation/serial/digiepca.txt. |
702 | |
703 | disable= [IPV6] |
704 | See Documentation/networking/ipv6.txt. |
705 | |
706 | disable_ddw [PPC/PSERIES] |
707 | Disable Dynamic DMA Window support. Use this if |
708 | to workaround buggy firmware. |
709 | |
710 | disable_ipv6= [IPV6] |
711 | See Documentation/networking/ipv6.txt. |
712 | |
713 | disable_mtrr_cleanup [X86] |
714 | The kernel tries to adjust MTRR layout from continuous |
715 | to discrete, to make X server driver able to add WB |
716 | entry later. This parameter disables that. |
717 | |
718 | disable_mtrr_trim [X86, Intel and AMD only] |
719 | By default the kernel will trim any uncacheable |
720 | memory out of your available memory pool based on |
721 | MTRR settings. This parameter disables that behavior, |
722 | possibly causing your machine to run very slowly. |
723 | |
724 | disable_timer_pin_1 [X86] |
725 | Disable PIN 1 of APIC timer |
726 | Can be useful to work around chipset bugs. |
727 | |
728 | dma_debug=off If the kernel is compiled with DMA_API_DEBUG support, |
729 | this option disables the debugging code at boot. |
730 | |
731 | dma_debug_entries=<number> |
732 | This option allows to tune the number of preallocated |
733 | entries for DMA-API debugging code. One entry is |
734 | required per DMA-API allocation. Use this if the |
735 | DMA-API debugging code disables itself because the |
736 | architectural default is too low. |
737 | |
738 | dma_debug_driver=<driver_name> |
739 | With this option the DMA-API debugging driver |
740 | filter feature can be enabled at boot time. Just |
741 | pass the driver to filter for as the parameter. |
742 | The filter can be disabled or changed to another |
743 | driver later using sysfs. |
744 | |
745 | drm_kms_helper.edid_firmware=[<connector>:]<file> |
746 | Broken monitors, graphic adapters and KVMs may |
747 | send no or incorrect EDID data sets. This parameter |
748 | allows to specify an EDID data set in the |
749 | /lib/firmware directory that is used instead. |
750 | Generic built-in EDID data sets are used, if one of |
751 | edid/1024x768.bin, edid/1280x1024.bin, |
752 | edid/1680x1050.bin, or edid/1920x1080.bin is given |
753 | and no file with the same name exists. Details and |
754 | instructions how to build your own EDID data are |
755 | available in Documentation/EDID/HOWTO.txt. An EDID |
756 | data set will only be used for a particular connector, |
757 | if its name and a colon are prepended to the EDID |
758 | name. |
759 | |
760 | dscc4.setup= [NET] |
761 | |
762 | dyndbg[="val"] [KNL,DYNAMIC_DEBUG] |
763 | module.dyndbg[="val"] |
764 | Enable debug messages at boot time. See |
765 | Documentation/dynamic-debug-howto.txt for details. |
766 | |
767 | earlycon= [KNL] Output early console device and options. |
768 | uart[8250],io,<addr>[,options] |
769 | uart[8250],mmio,<addr>[,options] |
770 | uart[8250],mmio32,<addr>[,options] |
771 | Start an early, polled-mode console on the 8250/16550 |
772 | UART at the specified I/O port or MMIO address. |
773 | MMIO inter-register address stride is either 8-bit |
774 | (mmio) or 32-bit (mmio32). |
775 | The options are the same as for ttyS, above. |
776 | |
777 | earlyprintk= [X86,SH,BLACKFIN] |
778 | earlyprintk=vga |
779 | earlyprintk=xen |
780 | earlyprintk=serial[,ttySn[,baudrate]] |
781 | earlyprintk=ttySn[,baudrate] |
782 | earlyprintk=dbgp[debugController#] |
783 | |
784 | Append ",keep" to not disable it when the real console |
785 | takes over. |
786 | |
787 | Only vga or serial or usb debug port at a time. |
788 | |
789 | Currently only ttyS0 and ttyS1 are supported. |
790 | |
791 | Interaction with the standard serial driver is not |
792 | very good. |
793 | |
794 | The VGA output is eventually overwritten by the real |
795 | console. |
796 | |
797 | The xen output can only be used by Xen PV guests. |
798 | |
799 | ekgdboc= [X86,KGDB] Allow early kernel console debugging |
800 | ekgdboc=kbd |
801 | |
802 | This is designed to be used in conjunction with |
803 | the boot argument: earlyprintk=vga |
804 | |
805 | edd= [EDD] |
806 | Format: {"off" | "on" | "skip[mbr]"} |
807 | |
808 | efi_no_storage_paranoia [EFI; X86] |
809 | Using this parameter you can use more than 50% of |
810 | your efi variable storage. Use this parameter only if |
811 | you are really sure that your UEFI does sane gc and |
812 | fulfills the spec otherwise your board may brick. |
813 | |
814 | eisa_irq_edge= [PARISC,HW] |
815 | See header of drivers/parisc/eisa.c. |
816 | |
817 | elanfreq= [X86-32] |
818 | See comment before function elanfreq_setup() in |
819 | arch/x86/kernel/cpu/cpufreq/elanfreq.c. |
820 | |
821 | elevator= [IOSCHED] |
822 | Format: {"cfq" | "deadline" | "noop"} |
823 | See Documentation/block/cfq-iosched.txt and |
824 | Documentation/block/deadline-iosched.txt for details. |
825 | |
826 | elfcorehdr=[size[KMG]@]offset[KMG] [IA64,PPC,SH,X86,S390] |
827 | Specifies physical address of start of kernel core |
828 | image elf header and optionally the size. Generally |
829 | kexec loader will pass this option to capture kernel. |
830 | See Documentation/kdump/kdump.txt for details. |
831 | |
832 | enable_mtrr_cleanup [X86] |
833 | The kernel tries to adjust MTRR layout from continuous |
834 | to discrete, to make X server driver able to add WB |
835 | entry later. This parameter enables that. |
836 | |
837 | enable_timer_pin_1 [X86] |
838 | Enable PIN 1 of APIC timer |
839 | Can be useful to work around chipset bugs |
840 | (in particular on some ATI chipsets). |
841 | The kernel tries to set a reasonable default. |
842 | |
843 | enforcing [SELINUX] Set initial enforcing status. |
844 | Format: {"0" | "1"} |
845 | See security/selinux/Kconfig help text. |
846 | 0 -- permissive (log only, no denials). |
847 | 1 -- enforcing (deny and log). |
848 | Default value is 0. |
849 | Value can be changed at runtime via /selinux/enforce. |
850 | |
851 | erst_disable [ACPI] |
852 | Disable Error Record Serialization Table (ERST) |
853 | support. |
854 | |
855 | ether= [HW,NET] Ethernet cards parameters |
856 | This option is obsoleted by the "netdev=" option, which |
857 | has equivalent usage. See its documentation for details. |
858 | |
859 | evm= [EVM] |
860 | Format: { "fix" } |
861 | Permit 'security.evm' to be updated regardless of |
862 | current integrity status. |
863 | |
864 | failslab= |
865 | fail_page_alloc= |
866 | fail_make_request=[KNL] |
867 | General fault injection mechanism. |
868 | Format: <interval>,<probability>,<space>,<times> |
869 | See also Documentation/fault-injection/. |
870 | |
871 | floppy= [HW] |
872 | See Documentation/blockdev/floppy.txt. |
873 | |
874 | force_pal_cache_flush |
875 | [IA-64] Avoid check_sal_cache_flush which may hang on |
876 | buggy SAL_CACHE_FLUSH implementations. Using this |
877 | parameter will force ia64_sal_cache_flush to call |
878 | ia64_pal_cache_flush instead of SAL_CACHE_FLUSH. |
879 | |
880 | ftrace=[tracer] |
881 | [FTRACE] will set and start the specified tracer |
882 | as early as possible in order to facilitate early |
883 | boot debugging. |
884 | |
885 | ftrace_dump_on_oops[=orig_cpu] |
886 | [FTRACE] will dump the trace buffers on oops. |
887 | If no parameter is passed, ftrace will dump |
888 | buffers of all CPUs, but if you pass orig_cpu, it will |
889 | dump only the buffer of the CPU that triggered the |
890 | oops. |
891 | |
892 | ftrace_filter=[function-list] |
893 | [FTRACE] Limit the functions traced by the function |
894 | tracer at boot up. function-list is a comma separated |
895 | list of functions. This list can be changed at run |
896 | time by the set_ftrace_filter file in the debugfs |
897 | tracing directory. |
898 | |
899 | ftrace_notrace=[function-list] |
900 | [FTRACE] Do not trace the functions specified in |
901 | function-list. This list can be changed at run time |
902 | by the set_ftrace_notrace file in the debugfs |
903 | tracing directory. |
904 | |
905 | ftrace_graph_filter=[function-list] |
906 | [FTRACE] Limit the top level callers functions traced |
907 | by the function graph tracer at boot up. |
908 | function-list is a comma separated list of functions |
909 | that can be changed at run time by the |
910 | set_graph_function file in the debugfs tracing directory. |
911 | |
912 | gamecon.map[2|3]= |
913 | [HW,JOY] Multisystem joystick and NES/SNES/PSX pad |
914 | support via parallel port (up to 5 devices per port) |
915 | Format: <port#>,<pad1>,<pad2>,<pad3>,<pad4>,<pad5> |
916 | See also Documentation/input/joystick-parport.txt |
917 | |
918 | gamma= [HW,DRM] |
919 | |
920 | gart_fix_e820= [X86_64] disable the fix e820 for K8 GART |
921 | Format: off | on |
922 | default: on |
923 | |
924 | gcov_persist= [GCOV] When non-zero (default), profiling data for |
925 | kernel modules is saved and remains accessible via |
926 | debugfs, even when the module is unloaded/reloaded. |
927 | When zero, profiling data is discarded and associated |
928 | debugfs files are removed at module unload time. |
929 | |
930 | gpt [EFI] Forces disk with valid GPT signature but |
931 | invalid Protective MBR to be treated as GPT. |
932 | |
933 | grcan.enable0= [HW] Configuration of physical interface 0. Determines |
934 | the "Enable 0" bit of the configuration register. |
935 | Format: 0 | 1 |
936 | Default: 0 |
937 | grcan.enable1= [HW] Configuration of physical interface 1. Determines |
938 | the "Enable 0" bit of the configuration register. |
939 | Format: 0 | 1 |
940 | Default: 0 |
941 | grcan.select= [HW] Select which physical interface to use. |
942 | Format: 0 | 1 |
943 | Default: 0 |
944 | grcan.txsize= [HW] Sets the size of the tx buffer. |
945 | Format: <unsigned int> such that (txsize & ~0x1fffc0) == 0. |
946 | Default: 1024 |
947 | grcan.rxsize= [HW] Sets the size of the rx buffer. |
948 | Format: <unsigned int> such that (rxsize & ~0x1fffc0) == 0. |
949 | Default: 1024 |
950 | |
951 | hashdist= [KNL,NUMA] Large hashes allocated during boot |
952 | are distributed across NUMA nodes. Defaults on |
953 | for 64-bit NUMA, off otherwise. |
954 | Format: 0 | 1 (for off | on) |
955 | |
956 | hcl= [IA-64] SGI's Hardware Graph compatibility layer |
957 | |
958 | hd= [EIDE] (E)IDE hard drive subsystem geometry |
959 | Format: <cyl>,<head>,<sect> |
960 | |
961 | hest_disable [ACPI] |
962 | Disable Hardware Error Source Table (HEST) support; |
963 | corresponding firmware-first mode error processing |
964 | logic will be disabled. |
965 | |
966 | highmem=nn[KMG] [KNL,BOOT] forces the highmem zone to have an exact |
967 | size of <nn>. This works even on boxes that have no |
968 | highmem otherwise. This also works to reduce highmem |
969 | size on bigger boxes. |
970 | |
971 | highres= [KNL] Enable/disable high resolution timer mode. |
972 | Valid parameters: "on", "off" |
973 | Default: "on" |
974 | |
975 | hisax= [HW,ISDN] |
976 | See Documentation/isdn/README.HiSax. |
977 | |
978 | hlt [BUGS=ARM,SH] |
979 | |
980 | hpet= [X86-32,HPET] option to control HPET usage |
981 | Format: { enable (default) | disable | force | |
982 | verbose } |
983 | disable: disable HPET and use PIT instead |
984 | force: allow force enabled of undocumented chips (ICH4, |
985 | VIA, nVidia) |
986 | verbose: show contents of HPET registers during setup |
987 | |
988 | hugepages= [HW,X86-32,IA-64] HugeTLB pages to allocate at boot. |
989 | hugepagesz= [HW,IA-64,PPC,X86-64] The size of the HugeTLB pages. |
990 | On x86-64 and powerpc, this option can be specified |
991 | multiple times interleaved with hugepages= to reserve |
992 | huge pages of different sizes. Valid pages sizes on |
993 | x86-64 are 2M (when the CPU supports "pse") and 1G |
994 | (when the CPU supports the "pdpe1gb" cpuinfo flag) |
995 | Note that 1GB pages can only be allocated at boot time |
996 | using hugepages= and not freed afterwards. |
997 | |
998 | hvc_iucv= [S390] Number of z/VM IUCV hypervisor console (HVC) |
999 | terminal devices. Valid values: 0..8 |
1000 | hvc_iucv_allow= [S390] Comma-separated list of z/VM user IDs. |
1001 | If specified, z/VM IUCV HVC accepts connections |
1002 | from listed z/VM user IDs only. |
1003 | |
1004 | hwthread_map= [METAG] Comma-separated list of Linux cpu id to |
1005 | hardware thread id mappings. |
1006 | Format: <cpu>:<hwthread> |
1007 | |
1008 | keep_bootcon [KNL] |
1009 | Do not unregister boot console at start. This is only |
1010 | useful for debugging when something happens in the window |
1011 | between unregistering the boot console and initializing |
1012 | the real console. |
1013 | |
1014 | i2c_bus= [HW] Override the default board specific I2C bus speed |
1015 | or register an additional I2C bus that is not |
1016 | registered from board initialization code. |
1017 | Format: |
1018 | <bus_id>,<clkrate> |
1019 | |
1020 | i8042.debug [HW] Toggle i8042 debug mode |
1021 | i8042.direct [HW] Put keyboard port into non-translated mode |
1022 | i8042.dumbkbd [HW] Pretend that controller can only read data from |
1023 | keyboard and cannot control its state |
1024 | (Don't attempt to blink the leds) |
1025 | i8042.noaux [HW] Don't check for auxiliary (== mouse) port |
1026 | i8042.nokbd [HW] Don't check/create keyboard port |
1027 | i8042.noloop [HW] Disable the AUX Loopback command while probing |
1028 | for the AUX port |
1029 | i8042.nomux [HW] Don't check presence of an active multiplexing |
1030 | controller |
1031 | i8042.nopnp [HW] Don't use ACPIPnP / PnPBIOS to discover KBD/AUX |
1032 | controllers |
1033 | i8042.notimeout [HW] Ignore timeout condition signalled by controller |
1034 | i8042.reset [HW] Reset the controller during init and cleanup |
1035 | i8042.unlock [HW] Unlock (ignore) the keylock |
1036 | |
1037 | i810= [HW,DRM] |
1038 | |
1039 | i8k.ignore_dmi [HW] Continue probing hardware even if DMI data |
1040 | indicates that the driver is running on unsupported |
1041 | hardware. |
1042 | i8k.force [HW] Activate i8k driver even if SMM BIOS signature |
1043 | does not match list of supported models. |
1044 | i8k.power_status |
1045 | [HW] Report power status in /proc/i8k |
1046 | (disabled by default) |
1047 | i8k.restricted [HW] Allow controlling fans only if SYS_ADMIN |
1048 | capability is set. |
1049 | |
1050 | i915.invert_brightness= |
1051 | [DRM] Invert the sense of the variable that is used to |
1052 | set the brightness of the panel backlight. Normally a |
1053 | brightness value of 0 indicates backlight switched off, |
1054 | and the maximum of the brightness value sets the backlight |
1055 | to maximum brightness. If this parameter is set to 0 |
1056 | (default) and the machine requires it, or this parameter |
1057 | is set to 1, a brightness value of 0 sets the backlight |
1058 | to maximum brightness, and the maximum of the brightness |
1059 | value switches the backlight off. |
1060 | -1 -- never invert brightness |
1061 | 0 -- machine default |
1062 | 1 -- force brightness inversion |
1063 | |
1064 | icn= [HW,ISDN] |
1065 | Format: <io>[,<membase>[,<icn_id>[,<icn_id2>]]] |
1066 | |
1067 | ide-core.nodma= [HW] (E)IDE subsystem |
1068 | Format: =0.0 to prevent dma on hda, =0.1 hdb =1.0 hdc |
1069 | .vlb_clock .pci_clock .noflush .nohpa .noprobe .nowerr |
1070 | .cdrom .chs .ignore_cable are additional options |
1071 | See Documentation/ide/ide.txt. |
1072 | |
1073 | ide-pci-generic.all-generic-ide [HW] (E)IDE subsystem |
1074 | Claim all unknown PCI IDE storage controllers. |
1075 | |
1076 | idle= [X86] |
1077 | Format: idle=poll, idle=halt, idle=nomwait |
1078 | Poll forces a polling idle loop that can slightly |
1079 | improve the performance of waking up a idle CPU, but |
1080 | will use a lot of power and make the system run hot. |
1081 | Not recommended. |
1082 | idle=halt: Halt is forced to be used for CPU idle. |
1083 | In such case C2/C3 won't be used again. |
1084 | idle=nomwait: Disable mwait for CPU C-states |
1085 | |
1086 | ignore_loglevel [KNL] |
1087 | Ignore loglevel setting - this will print /all/ |
1088 | kernel messages to the console. Useful for debugging. |
1089 | We also add it as printk module parameter, so users |
1090 | could change it dynamically, usually by |
1091 | /sys/module/printk/parameters/ignore_loglevel. |
1092 | |
1093 | ihash_entries= [KNL] |
1094 | Set number of hash buckets for inode cache. |
1095 | |
1096 | ima_appraise= [IMA] appraise integrity measurements |
1097 | Format: { "off" | "enforce" | "fix" } |
1098 | default: "enforce" |
1099 | |
1100 | ima_appraise_tcb [IMA] |
1101 | The builtin appraise policy appraises all files |
1102 | owned by uid=0. |
1103 | |
1104 | ima_audit= [IMA] |
1105 | Format: { "0" | "1" } |
1106 | 0 -- integrity auditing messages. (Default) |
1107 | 1 -- enable informational integrity auditing messages. |
1108 | |
1109 | ima_hash= [IMA] |
1110 | Format: { "sha1" | "md5" } |
1111 | default: "sha1" |
1112 | |
1113 | ima_tcb [IMA] |
1114 | Load a policy which meets the needs of the Trusted |
1115 | Computing Base. This means IMA will measure all |
1116 | programs exec'd, files mmap'd for exec, and all files |
1117 | opened for read by uid=0. |
1118 | |
1119 | init= [KNL] |
1120 | Format: <full_path> |
1121 | Run specified binary instead of /sbin/init as init |
1122 | process. |
1123 | |
1124 | initcall_debug [KNL] Trace initcalls as they are executed. Useful |
1125 | for working out where the kernel is dying during |
1126 | startup. |
1127 | |
1128 | initrd= [BOOT] Specify the location of the initial ramdisk |
1129 | |
1130 | inport.irq= [HW] Inport (ATI XL and Microsoft) busmouse driver |
1131 | Format: <irq> |
1132 | |
1133 | intel_iommu= [DMAR] Intel IOMMU driver (DMAR) option |
1134 | on |
1135 | Enable intel iommu driver. |
1136 | off |
1137 | Disable intel iommu driver. |
1138 | igfx_off [Default Off] |
1139 | By default, gfx is mapped as normal device. If a gfx |
1140 | device has a dedicated DMAR unit, the DMAR unit is |
1141 | bypassed by not enabling DMAR with this option. In |
1142 | this case, gfx device will use physical address for |
1143 | DMA. |
1144 | forcedac [x86_64] |
1145 | With this option iommu will not optimize to look |
1146 | for io virtual address below 32-bit forcing dual |
1147 | address cycle on pci bus for cards supporting greater |
1148 | than 32-bit addressing. The default is to look |
1149 | for translation below 32-bit and if not available |
1150 | then look in the higher range. |
1151 | strict [Default Off] |
1152 | With this option on every unmap_single operation will |
1153 | result in a hardware IOTLB flush operation as opposed |
1154 | to batching them for performance. |
1155 | sp_off [Default Off] |
1156 | By default, super page will be supported if Intel IOMMU |
1157 | has the capability. With this option, super page will |
1158 | not be supported. |
1159 | |
1160 | intel_idle.max_cstate= [KNL,HW,ACPI,X86] |
1161 | 0 disables intel_idle and fall back on acpi_idle. |
1162 | 1 to 6 specify maximum depth of C-state. |
1163 | |
1164 | intel_pstate= [X86] |
1165 | disable |
1166 | Do not enable intel_pstate as the default |
1167 | scaling driver for the supported processors |
1168 | |
1169 | intremap= [X86-64, Intel-IOMMU] |
1170 | on enable Interrupt Remapping (default) |
1171 | off disable Interrupt Remapping |
1172 | nosid disable Source ID checking |
1173 | no_x2apic_optout |
1174 | BIOS x2APIC opt-out request will be ignored |
1175 | |
1176 | iomem= Disable strict checking of access to MMIO memory |
1177 | strict regions from userspace. |
1178 | relaxed |
1179 | |
1180 | iommu= [x86] |
1181 | off |
1182 | force |
1183 | noforce |
1184 | biomerge |
1185 | panic |
1186 | nopanic |
1187 | merge |
1188 | nomerge |
1189 | forcesac |
1190 | soft |
1191 | pt [x86, IA-64] |
1192 | |
1193 | |
1194 | io7= [HW] IO7 for Marvel based alpha systems |
1195 | See comment before marvel_specify_io7 in |
1196 | arch/alpha/kernel/core_marvel.c. |
1197 | |
1198 | io_delay= [X86] I/O delay method |
1199 | 0x80 |
1200 | Standard port 0x80 based delay |
1201 | 0xed |
1202 | Alternate port 0xed based delay (needed on some systems) |
1203 | udelay |
1204 | Simple two microseconds delay |
1205 | none |
1206 | No delay |
1207 | |
1208 | ip= [IP_PNP] |
1209 | See Documentation/filesystems/nfs/nfsroot.txt. |
1210 | |
1211 | ip2= [HW] Set IO/IRQ pairs for up to 4 IntelliPort boards |
1212 | See comment before ip2_setup() in |
1213 | drivers/char/ip2/ip2base.c. |
1214 | |
1215 | irqfixup [HW] |
1216 | When an interrupt is not handled search all handlers |
1217 | for it. Intended to get systems with badly broken |
1218 | firmware running. |
1219 | |
1220 | irqpoll [HW] |
1221 | When an interrupt is not handled search all handlers |
1222 | for it. Also check all handlers each timer |
1223 | interrupt. Intended to get systems with badly broken |
1224 | firmware running. |
1225 | |
1226 | isapnp= [ISAPNP] |
1227 | Format: <RDP>,<reset>,<pci_scan>,<verbosity> |
1228 | |
1229 | isolcpus= [KNL,SMP] Isolate CPUs from the general scheduler. |
1230 | Format: |
1231 | <cpu number>,...,<cpu number> |
1232 | or |
1233 | <cpu number>-<cpu number> |
1234 | (must be a positive range in ascending order) |
1235 | or a mixture |
1236 | <cpu number>,...,<cpu number>-<cpu number> |
1237 | |
1238 | This option can be used to specify one or more CPUs |
1239 | to isolate from the general SMP balancing and scheduling |
1240 | algorithms. You can move a process onto or off an |
1241 | "isolated" CPU via the CPU affinity syscalls or cpuset. |
1242 | <cpu number> begins at 0 and the maximum value is |
1243 | "number of CPUs in system - 1". |
1244 | |
1245 | This option is the preferred way to isolate CPUs. The |
1246 | alternative -- manually setting the CPU mask of all |
1247 | tasks in the system -- can cause problems and |
1248 | suboptimal load balancer performance. |
1249 | |
1250 | iucv= [HW,NET] |
1251 | |
1252 | js= [HW,JOY] Analog joystick |
1253 | See Documentation/input/joystick.txt. |
1254 | |
1255 | keepinitrd [HW,ARM] |
1256 | |
1257 | kernelcore=nn[KMG] [KNL,X86,IA-64,PPC] This parameter |
1258 | specifies the amount of memory usable by the kernel |
1259 | for non-movable allocations. The requested amount is |
1260 | spread evenly throughout all nodes in the system. The |
1261 | remaining memory in each node is used for Movable |
1262 | pages. In the event, a node is too small to have both |
1263 | kernelcore and Movable pages, kernelcore pages will |
1264 | take priority and other nodes will have a larger number |
1265 | of kernelcore pages. The Movable zone is used for the |
1266 | allocation of pages that may be reclaimed or moved |
1267 | by the page migration subsystem. This means that |
1268 | HugeTLB pages may not be allocated from this zone. |
1269 | Note that allocations like PTEs-from-HighMem still |
1270 | use the HighMem zone if it exists, and the Normal |
1271 | zone if it does not. |
1272 | |
1273 | kgdbdbgp= [KGDB,HW] kgdb over EHCI usb debug port. |
1274 | Format: <Controller#>[,poll interval] |
1275 | The controller # is the number of the ehci usb debug |
1276 | port as it is probed via PCI. The poll interval is |
1277 | optional and is the number seconds in between |
1278 | each poll cycle to the debug port in case you need |
1279 | the functionality for interrupting the kernel with |
1280 | gdb or control-c on the dbgp connection. When |
1281 | not using this parameter you use sysrq-g to break into |
1282 | the kernel debugger. |
1283 | |
1284 | kgdboc= [KGDB,HW] kgdb over consoles. |
1285 | Requires a tty driver that supports console polling, |
1286 | or a supported polling keyboard driver (non-usb). |
1287 | Serial only format: <serial_device>[,baud] |
1288 | keyboard only format: kbd |
1289 | keyboard and serial format: kbd,<serial_device>[,baud] |
1290 | Optional Kernel mode setting: |
1291 | kms, kbd format: kms,kbd |
1292 | kms, kbd and serial format: kms,kbd,<ser_dev>[,baud] |
1293 | |
1294 | kgdbwait [KGDB] Stop kernel execution and enter the |
1295 | kernel debugger at the earliest opportunity. |
1296 | |
1297 | kmac= [MIPS] korina ethernet MAC address. |
1298 | Configure the RouterBoard 532 series on-chip |
1299 | Ethernet adapter MAC address. |
1300 | |
1301 | kmemleak= [KNL] Boot-time kmemleak enable/disable |
1302 | Valid arguments: on, off |
1303 | Default: on |
1304 | |
1305 | kstack=N [X86] Print N words from the kernel stack |
1306 | in oops dumps. |
1307 | |
1308 | kvm.ignore_msrs=[KVM] Ignore guest accesses to unhandled MSRs. |
1309 | Default is 0 (don't ignore, but inject #GP) |
1310 | |
1311 | kvm.mmu_audit= [KVM] This is a R/W parameter which allows audit |
1312 | KVM MMU at runtime. |
1313 | Default is 0 (off) |
1314 | |
1315 | kvm-amd.nested= [KVM,AMD] Allow nested virtualization in KVM/SVM. |
1316 | Default is 1 (enabled) |
1317 | |
1318 | kvm-amd.npt= [KVM,AMD] Disable nested paging (virtualized MMU) |
1319 | for all guests. |
1320 | Default is 1 (enabled) if in 64-bit or 32-bit PAE mode. |
1321 | |
1322 | kvm-intel.ept= [KVM,Intel] Disable extended page tables |
1323 | (virtualized MMU) support on capable Intel chips. |
1324 | Default is 1 (enabled) |
1325 | |
1326 | kvm-intel.emulate_invalid_guest_state= |
1327 | [KVM,Intel] Enable emulation of invalid guest states |
1328 | Default is 0 (disabled) |
1329 | |
1330 | kvm-intel.flexpriority= |
1331 | [KVM,Intel] Disable FlexPriority feature (TPR shadow). |
1332 | Default is 1 (enabled) |
1333 | |
1334 | kvm-intel.nested= |
1335 | [KVM,Intel] Enable VMX nesting (nVMX). |
1336 | Default is 0 (disabled) |
1337 | |
1338 | kvm-intel.unrestricted_guest= |
1339 | [KVM,Intel] Disable unrestricted guest feature |
1340 | (virtualized real and unpaged mode) on capable |
1341 | Intel chips. Default is 1 (enabled) |
1342 | |
1343 | kvm-intel.vpid= [KVM,Intel] Disable Virtual Processor Identification |
1344 | feature (tagged TLBs) on capable Intel chips. |
1345 | Default is 1 (enabled) |
1346 | |
1347 | l2cr= [PPC] |
1348 | |
1349 | l3cr= [PPC] |
1350 | |
1351 | lapic [X86-32,APIC] Enable the local APIC even if BIOS |
1352 | disabled it. |
1353 | |
1354 | lapic= [x86,APIC] "notscdeadline" Do not use TSC deadline |
1355 | value for LAPIC timer one-shot implementation. Default |
1356 | back to the programmable timer unit in the LAPIC. |
1357 | |
1358 | lapic_timer_c2_ok [X86,APIC] trust the local apic timer |
1359 | in C2 power state. |
1360 | |
1361 | libata.dma= [LIBATA] DMA control |
1362 | libata.dma=0 Disable all PATA and SATA DMA |
1363 | libata.dma=1 PATA and SATA Disk DMA only |
1364 | libata.dma=2 ATAPI (CDROM) DMA only |
1365 | libata.dma=4 Compact Flash DMA only |
1366 | Combinations also work, so libata.dma=3 enables DMA |
1367 | for disks and CDROMs, but not CFs. |
1368 | |
1369 | libata.ignore_hpa= [LIBATA] Ignore HPA limit |
1370 | libata.ignore_hpa=0 keep BIOS limits (default) |
1371 | libata.ignore_hpa=1 ignore limits, using full disk |
1372 | |
1373 | libata.noacpi [LIBATA] Disables use of ACPI in libata suspend/resume |
1374 | when set. |
1375 | Format: <int> |
1376 | |
1377 | libata.force= [LIBATA] Force configurations. The format is comma |
1378 | separated list of "[ID:]VAL" where ID is |
1379 | PORT[.DEVICE]. PORT and DEVICE are decimal numbers |
1380 | matching port, link or device. Basically, it matches |
1381 | the ATA ID string printed on console by libata. If |
1382 | the whole ID part is omitted, the last PORT and DEVICE |
1383 | values are used. If ID hasn't been specified yet, the |
1384 | configuration applies to all ports, links and devices. |
1385 | |
1386 | If only DEVICE is omitted, the parameter applies to |
1387 | the port and all links and devices behind it. DEVICE |
1388 | number of 0 either selects the first device or the |
1389 | first fan-out link behind PMP device. It does not |
1390 | select the host link. DEVICE number of 15 selects the |
1391 | host link and device attached to it. |
1392 | |
1393 | The VAL specifies the configuration to force. As long |
1394 | as there's no ambiguity shortcut notation is allowed. |
1395 | For example, both 1.5 and 1.5G would work for 1.5Gbps. |
1396 | The following configurations can be forced. |
1397 | |
1398 | * Cable type: 40c, 80c, short40c, unk, ign or sata. |
1399 | Any ID with matching PORT is used. |
1400 | |
1401 | * SATA link speed limit: 1.5Gbps or 3.0Gbps. |
1402 | |
1403 | * Transfer mode: pio[0-7], mwdma[0-4] and udma[0-7]. |
1404 | udma[/][16,25,33,44,66,100,133] notation is also |
1405 | allowed. |
1406 | |
1407 | * [no]ncq: Turn on or off NCQ. |
1408 | |
1409 | * nohrst, nosrst, norst: suppress hard, soft |
1410 | and both resets. |
1411 | |
1412 | * rstonce: only attempt one reset during |
1413 | hot-unplug link recovery |
1414 | |
1415 | * dump_id: dump IDENTIFY data. |
1416 | |
1417 | If there are multiple matching configurations changing |
1418 | the same attribute, the last one is used. |
1419 | |
1420 | memblock=debug [KNL] Enable memblock debug messages. |
1421 | |
1422 | load_ramdisk= [RAM] List of ramdisks to load from floppy |
1423 | See Documentation/blockdev/ramdisk.txt. |
1424 | |
1425 | lockd.nlm_grace_period=P [NFS] Assign grace period. |
1426 | Format: <integer> |
1427 | |
1428 | lockd.nlm_tcpport=N [NFS] Assign TCP port. |
1429 | Format: <integer> |
1430 | |
1431 | lockd.nlm_timeout=T [NFS] Assign timeout value. |
1432 | Format: <integer> |
1433 | |
1434 | lockd.nlm_udpport=M [NFS] Assign UDP port. |
1435 | Format: <integer> |
1436 | |
1437 | logibm.irq= [HW,MOUSE] Logitech Bus Mouse Driver |
1438 | Format: <irq> |
1439 | |
1440 | loglevel= All Kernel Messages with a loglevel smaller than the |
1441 | console loglevel will be printed to the console. It can |
1442 | also be changed with klogd or other programs. The |
1443 | loglevels are defined as follows: |
1444 | |
1445 | 0 (KERN_EMERG) system is unusable |
1446 | 1 (KERN_ALERT) action must be taken immediately |
1447 | 2 (KERN_CRIT) critical conditions |
1448 | 3 (KERN_ERR) error conditions |
1449 | 4 (KERN_WARNING) warning conditions |
1450 | 5 (KERN_NOTICE) normal but significant condition |
1451 | 6 (KERN_INFO) informational |
1452 | 7 (KERN_DEBUG) debug-level messages |
1453 | |
1454 | log_buf_len=n[KMG] Sets the size of the printk ring buffer, |
1455 | in bytes. n must be a power of two. The default |
1456 | size is set in the kernel config file. |
1457 | |
1458 | logo.nologo [FB] Disables display of the built-in Linux logo. |
1459 | This may be used to provide more screen space for |
1460 | kernel log messages and is useful when debugging |
1461 | kernel boot problems. |
1462 | |
1463 | lp=0 [LP] Specify parallel ports to use, e.g, |
1464 | lp=port[,port...] lp=none,parport0 (lp0 not configured, lp1 uses |
1465 | lp=reset first parallel port). 'lp=0' disables the |
1466 | lp=auto printer driver. 'lp=reset' (which can be |
1467 | specified in addition to the ports) causes |
1468 | attached printers to be reset. Using |
1469 | lp=port1,port2,... specifies the parallel ports |
1470 | to associate lp devices with, starting with |
1471 | lp0. A port specification may be 'none' to skip |
1472 | that lp device, or a parport name such as |
1473 | 'parport0'. Specifying 'lp=auto' instead of a |
1474 | port specification list means that device IDs |
1475 | from each port should be examined, to see if |
1476 | an IEEE 1284-compliant printer is attached; if |
1477 | so, the driver will manage that printer. |
1478 | See also header of drivers/char/lp.c. |
1479 | |
1480 | lpj=n [KNL] |
1481 | Sets loops_per_jiffy to given constant, thus avoiding |
1482 | time-consuming boot-time autodetection (up to 250 ms per |
1483 | CPU). 0 enables autodetection (default). To determine |
1484 | the correct value for your kernel, boot with normal |
1485 | autodetection and see what value is printed. Note that |
1486 | on SMP systems the preset will be applied to all CPUs, |
1487 | which is likely to cause problems if your CPUs need |
1488 | significantly divergent settings. An incorrect value |
1489 | will cause delays in the kernel to be wrong, leading to |
1490 | unpredictable I/O errors and other breakage. Although |
1491 | unlikely, in the extreme case this might damage your |
1492 | hardware. |
1493 | |
1494 | ltpc= [NET] |
1495 | Format: <io>,<irq>,<dma> |
1496 | |
1497 | machvec= [IA-64] Force the use of a particular machine-vector |
1498 | (machvec) in a generic kernel. |
1499 | Example: machvec=hpzx1_swiotlb |
1500 | |
1501 | machtype= [Loongson] Share the same kernel image file between different |
1502 | yeeloong laptop. |
1503 | Example: machtype=lemote-yeeloong-2f-7inch |
1504 | |
1505 | max_addr=nn[KMG] [KNL,BOOT,ia64] All physical memory greater |
1506 | than or equal to this physical address is ignored. |
1507 | |
1508 | maxcpus= [SMP] Maximum number of processors that an SMP kernel |
1509 | should make use of. maxcpus=n : n >= 0 limits the |
1510 | kernel to using 'n' processors. n=0 is a special case, |
1511 | it is equivalent to "nosmp", which also disables |
1512 | the IO APIC. |
1513 | |
1514 | max_loop= [LOOP] The number of loop block devices that get |
1515 | (loop.max_loop) unconditionally pre-created at init time. The default |
1516 | number is configured by BLK_DEV_LOOP_MIN_COUNT. Instead |
1517 | of statically allocating a predefined number, loop |
1518 | devices can be requested on-demand with the |
1519 | /dev/loop-control interface. |
1520 | |
1521 | mce [X86-32] Machine Check Exception |
1522 | |
1523 | mce=option [X86-64] See Documentation/x86/x86_64/boot-options.txt |
1524 | |
1525 | md= [HW] RAID subsystems devices and level |
1526 | See Documentation/md.txt. |
1527 | |
1528 | mdacon= [MDA] |
1529 | Format: <first>,<last> |
1530 | Specifies range of consoles to be captured by the MDA. |
1531 | |
1532 | mem=nn[KMG] [KNL,BOOT] Force usage of a specific amount of memory |
1533 | Amount of memory to be used when the kernel is not able |
1534 | to see the whole system memory or for test. |
1535 | [X86] Work as limiting max address. Use together |
1536 | with memmap= to avoid physical address space collisions. |
1537 | Without memmap= PCI devices could be placed at addresses |
1538 | belonging to unused RAM. |
1539 | |
1540 | mem=nopentium [BUGS=X86-32] Disable usage of 4MB pages for kernel |
1541 | memory. |
1542 | |
1543 | memchunk=nn[KMG] |
1544 | [KNL,SH] Allow user to override the default size for |
1545 | per-device physically contiguous DMA buffers. |
1546 | |
1547 | memmap=exactmap [KNL,X86] Enable setting of an exact |
1548 | E820 memory map, as specified by the user. |
1549 | Such memmap=exactmap lines can be constructed based on |
1550 | BIOS output or other requirements. See the memmap=nn@ss |
1551 | option description. |
1552 | |
1553 | memmap=nn[KMG]@ss[KMG] |
1554 | [KNL] Force usage of a specific region of memory |
1555 | Region of memory to be used, from ss to ss+nn. |
1556 | |
1557 | memmap=nn[KMG]#ss[KMG] |
1558 | [KNL,ACPI] Mark specific memory as ACPI data. |
1559 | Region of memory to be used, from ss to ss+nn. |
1560 | |
1561 | memmap=nn[KMG]$ss[KMG] |
1562 | [KNL,ACPI] Mark specific memory as reserved. |
1563 | Region of memory to be used, from ss to ss+nn. |
1564 | Example: Exclude memory from 0x18690000-0x1869ffff |
1565 | memmap=64K$0x18690000 |
1566 | or |
1567 | memmap=0x10000$0x18690000 |
1568 | |
1569 | memory_corruption_check=0/1 [X86] |
1570 | Some BIOSes seem to corrupt the first 64k of |
1571 | memory when doing things like suspend/resume. |
1572 | Setting this option will scan the memory |
1573 | looking for corruption. Enabling this will |
1574 | both detect corruption and prevent the kernel |
1575 | from using the memory being corrupted. |
1576 | However, its intended as a diagnostic tool; if |
1577 | repeatable BIOS-originated corruption always |
1578 | affects the same memory, you can use memmap= |
1579 | to prevent the kernel from using that memory. |
1580 | |
1581 | memory_corruption_check_size=size [X86] |
1582 | By default it checks for corruption in the low |
1583 | 64k, making this memory unavailable for normal |
1584 | use. Use this parameter to scan for |
1585 | corruption in more or less memory. |
1586 | |
1587 | memory_corruption_check_period=seconds [X86] |
1588 | By default it checks for corruption every 60 |
1589 | seconds. Use this parameter to check at some |
1590 | other rate. 0 disables periodic checking. |
1591 | |
1592 | memtest= [KNL,X86] Enable memtest |
1593 | Format: <integer> |
1594 | default : 0 <disable> |
1595 | Specifies the number of memtest passes to be |
1596 | performed. Each pass selects another test |
1597 | pattern from a given set of patterns. Memtest |
1598 | fills the memory with this pattern, validates |
1599 | memory contents and reserves bad memory |
1600 | regions that are detected. |
1601 | |
1602 | meye.*= [HW] Set MotionEye Camera parameters |
1603 | See Documentation/video4linux/meye.txt. |
1604 | |
1605 | mfgpt_irq= [IA-32] Specify the IRQ to use for the |
1606 | Multi-Function General Purpose Timers on AMD Geode |
1607 | platforms. |
1608 | |
1609 | mfgptfix [X86-32] Fix MFGPT timers on AMD Geode platforms when |
1610 | the BIOS has incorrectly applied a workaround. TinyBIOS |
1611 | version 0.98 is known to be affected, 0.99 fixes the |
1612 | problem by letting the user disable the workaround. |
1613 | |
1614 | mga= [HW,DRM] |
1615 | |
1616 | min_addr=nn[KMG] [KNL,BOOT,ia64] All physical memory below this |
1617 | physical address is ignored. |
1618 | |
1619 | mini2440= [ARM,HW,KNL] |
1620 | Format:[0..2][b][c][t] |
1621 | Default: "0tb" |
1622 | MINI2440 configuration specification: |
1623 | 0 - The attached screen is the 3.5" TFT |
1624 | 1 - The attached screen is the 7" TFT |
1625 | 2 - The VGA Shield is attached (1024x768) |
1626 | Leaving out the screen size parameter will not load |
1627 | the TFT driver, and the framebuffer will be left |
1628 | unconfigured. |
1629 | b - Enable backlight. The TFT backlight pin will be |
1630 | linked to the kernel VESA blanking code and a GPIO |
1631 | LED. This parameter is not necessary when using the |
1632 | VGA shield. |
1633 | c - Enable the s3c camera interface. |
1634 | t - Reserved for enabling touchscreen support. The |
1635 | touchscreen support is not enabled in the mainstream |
1636 | kernel as of 2.6.30, a preliminary port can be found |
1637 | in the "bleeding edge" mini2440 support kernel at |
1638 | http://repo.or.cz/w/linux-2.6/mini2440.git |
1639 | |
1640 | mminit_loglevel= |
1641 | [KNL] When CONFIG_DEBUG_MEMORY_INIT is set, this |
1642 | parameter allows control of the logging verbosity for |
1643 | the additional memory initialisation checks. A value |
1644 | of 0 disables mminit logging and a level of 4 will |
1645 | log everything. Information is printed at KERN_DEBUG |
1646 | so loglevel=8 may also need to be specified. |
1647 | |
1648 | module.sig_enforce |
1649 | [KNL] When CONFIG_MODULE_SIG is set, this means that |
1650 | modules without (valid) signatures will fail to load. |
1651 | Note that if CONFIG_MODULE_SIG_ENFORCE is set, that |
1652 | is always true, so this option does nothing. |
1653 | |
1654 | mousedev.tap_time= |
1655 | [MOUSE] Maximum time between finger touching and |
1656 | leaving touchpad surface for touch to be considered |
1657 | a tap and be reported as a left button click (for |
1658 | touchpads working in absolute mode only). |
1659 | Format: <msecs> |
1660 | mousedev.xres= [MOUSE] Horizontal screen resolution, used for devices |
1661 | reporting absolute coordinates, such as tablets |
1662 | mousedev.yres= [MOUSE] Vertical screen resolution, used for devices |
1663 | reporting absolute coordinates, such as tablets |
1664 | |
1665 | movablecore=nn[KMG] [KNL,X86,IA-64,PPC] This parameter |
1666 | is similar to kernelcore except it specifies the |
1667 | amount of memory used for migratable allocations. |
1668 | If both kernelcore and movablecore is specified, |
1669 | then kernelcore will be at *least* the specified |
1670 | value but may be more. If movablecore on its own |
1671 | is specified, the administrator must be careful |
1672 | that the amount of memory usable for all allocations |
1673 | is not too small. |
1674 | |
1675 | MTD_Partition= [MTD] |
1676 | Format: <name>,<region-number>,<size>,<offset> |
1677 | |
1678 | MTD_Region= [MTD] Format: |
1679 | <name>,<region-number>[,<base>,<size>,<buswidth>,<altbuswidth>] |
1680 | |
1681 | mtdparts= [MTD] |
1682 | See drivers/mtd/cmdlinepart.c. |
1683 | |
1684 | multitce=off [PPC] This parameter disables the use of the pSeries |
1685 | firmware feature for updating multiple TCE entries |
1686 | at a time. |
1687 | |
1688 | onenand.bdry= [HW,MTD] Flex-OneNAND Boundary Configuration |
1689 | |
1690 | Format: [die0_boundary][,die0_lock][,die1_boundary][,die1_lock] |
1691 | |
1692 | boundary - index of last SLC block on Flex-OneNAND. |
1693 | The remaining blocks are configured as MLC blocks. |
1694 | lock - Configure if Flex-OneNAND boundary should be locked. |
1695 | Once locked, the boundary cannot be changed. |
1696 | 1 indicates lock status, 0 indicates unlock status. |
1697 | |
1698 | mtdset= [ARM] |
1699 | ARM/S3C2412 JIVE boot control |
1700 | |
1701 | See arch/arm/mach-s3c2412/mach-jive.c |
1702 | |
1703 | mtouchusb.raw_coordinates= |
1704 | [HW] Make the MicroTouch USB driver use raw coordinates |
1705 | ('y', default) or cooked coordinates ('n') |
1706 | |
1707 | mtrr_chunk_size=nn[KMG] [X86] |
1708 | used for mtrr cleanup. It is largest continuous chunk |
1709 | that could hold holes aka. UC entries. |
1710 | |
1711 | mtrr_gran_size=nn[KMG] [X86] |
1712 | Used for mtrr cleanup. It is granularity of mtrr block. |
1713 | Default is 1. |
1714 | Large value could prevent small alignment from |
1715 | using up MTRRs. |
1716 | |
1717 | mtrr_spare_reg_nr=n [X86] |
1718 | Format: <integer> |
1719 | Range: 0,7 : spare reg number |
1720 | Default : 1 |
1721 | Used for mtrr cleanup. It is spare mtrr entries number. |
1722 | Set to 2 or more if your graphical card needs more. |
1723 | |
1724 | n2= [NET] SDL Inc. RISCom/N2 synchronous serial card |
1725 | |
1726 | netdev= [NET] Network devices parameters |
1727 | Format: <irq>,<io>,<mem_start>,<mem_end>,<name> |
1728 | Note that mem_start is often overloaded to mean |
1729 | something different and driver-specific. |
1730 | This usage is only documented in each driver source |
1731 | file if at all. |
1732 | |
1733 | nf_conntrack.acct= |
1734 | [NETFILTER] Enable connection tracking flow accounting |
1735 | 0 to disable accounting |
1736 | 1 to enable accounting |
1737 | Default value is 0. |
1738 | |
1739 | nfsaddrs= [NFS] Deprecated. Use ip= instead. |
1740 | See Documentation/filesystems/nfs/nfsroot.txt. |
1741 | |
1742 | nfsroot= [NFS] nfs root filesystem for disk-less boxes. |
1743 | See Documentation/filesystems/nfs/nfsroot.txt. |
1744 | |
1745 | nfsrootdebug [NFS] enable nfsroot debugging messages. |
1746 | See Documentation/filesystems/nfs/nfsroot.txt. |
1747 | |
1748 | nfs.callback_tcpport= |
1749 | [NFS] set the TCP port on which the NFSv4 callback |
1750 | channel should listen. |
1751 | |
1752 | nfs.cache_getent= |
1753 | [NFS] sets the pathname to the program which is used |
1754 | to update the NFS client cache entries. |
1755 | |
1756 | nfs.cache_getent_timeout= |
1757 | [NFS] sets the timeout after which an attempt to |
1758 | update a cache entry is deemed to have failed. |
1759 | |
1760 | nfs.idmap_cache_timeout= |
1761 | [NFS] set the maximum lifetime for idmapper cache |
1762 | entries. |
1763 | |
1764 | nfs.enable_ino64= |
1765 | [NFS] enable 64-bit inode numbers. |
1766 | If zero, the NFS client will fake up a 32-bit inode |
1767 | number for the readdir() and stat() syscalls instead |
1768 | of returning the full 64-bit number. |
1769 | The default is to return 64-bit inode numbers. |
1770 | |
1771 | nfs.max_session_slots= |
1772 | [NFSv4.1] Sets the maximum number of session slots |
1773 | the client will attempt to negotiate with the server. |
1774 | This limits the number of simultaneous RPC requests |
1775 | that the client can send to the NFSv4.1 server. |
1776 | Note that there is little point in setting this |
1777 | value higher than the max_tcp_slot_table_limit. |
1778 | |
1779 | nfs.nfs4_disable_idmapping= |
1780 | [NFSv4] When set to the default of '1', this option |
1781 | ensures that both the RPC level authentication |
1782 | scheme and the NFS level operations agree to use |
1783 | numeric uids/gids if the mount is using the |
1784 | 'sec=sys' security flavour. In effect it is |
1785 | disabling idmapping, which can make migration from |
1786 | legacy NFSv2/v3 systems to NFSv4 easier. |
1787 | Servers that do not support this mode of operation |
1788 | will be autodetected by the client, and it will fall |
1789 | back to using the idmapper. |
1790 | To turn off this behaviour, set the value to '0'. |
1791 | nfs.nfs4_unique_id= |
1792 | [NFS4] Specify an additional fixed unique ident- |
1793 | ification string that NFSv4 clients can insert into |
1794 | their nfs_client_id4 string. This is typically a |
1795 | UUID that is generated at system install time. |
1796 | |
1797 | nfs.send_implementation_id = |
1798 | [NFSv4.1] Send client implementation identification |
1799 | information in exchange_id requests. |
1800 | If zero, no implementation identification information |
1801 | will be sent. |
1802 | The default is to send the implementation identification |
1803 | information. |
1804 | |
1805 | nfsd.nfs4_disable_idmapping= |
1806 | [NFSv4] When set to the default of '1', the NFSv4 |
1807 | server will return only numeric uids and gids to |
1808 | clients using auth_sys, and will accept numeric uids |
1809 | and gids from such clients. This is intended to ease |
1810 | migration from NFSv2/v3. |
1811 | |
1812 | objlayoutdriver.osd_login_prog= |
1813 | [NFS] [OBJLAYOUT] sets the pathname to the program which |
1814 | is used to automatically discover and login into new |
1815 | osd-targets. Please see: |
1816 | Documentation/filesystems/pnfs.txt for more explanations |
1817 | |
1818 | nmi_debug= [KNL,AVR32,SH] Specify one or more actions to take |
1819 | when a NMI is triggered. |
1820 | Format: [state][,regs][,debounce][,die] |
1821 | |
1822 | nmi_watchdog= [KNL,BUGS=X86] Debugging features for SMP kernels |
1823 | Format: [panic,][nopanic,][num] |
1824 | Valid num: 0 |
1825 | 0 - turn nmi_watchdog off |
1826 | When panic is specified, panic when an NMI watchdog |
1827 | timeout occurs (or 'nopanic' to override the opposite |
1828 | default). |
1829 | This is useful when you use a panic=... timeout and |
1830 | need the box quickly up again. |
1831 | |
1832 | netpoll.carrier_timeout= |
1833 | [NET] Specifies amount of time (in seconds) that |
1834 | netpoll should wait for a carrier. By default netpoll |
1835 | waits 4 seconds. |
1836 | |
1837 | no387 [BUGS=X86-32] Tells the kernel to use the 387 maths |
1838 | emulation library even if a 387 maths coprocessor |
1839 | is present. |
1840 | |
1841 | no_console_suspend |
1842 | [HW] Never suspend the console |
1843 | Disable suspending of consoles during suspend and |
1844 | hibernate operations. Once disabled, debugging |
1845 | messages can reach various consoles while the rest |
1846 | of the system is being put to sleep (ie, while |
1847 | debugging driver suspend/resume hooks). This may |
1848 | not work reliably with all consoles, but is known |
1849 | to work with serial and VGA consoles. |
1850 | To facilitate more flexible debugging, we also add |
1851 | console_suspend, a printk module parameter to control |
1852 | it. Users could use console_suspend (usually |
1853 | /sys/module/printk/parameters/console_suspend) to |
1854 | turn on/off it dynamically. |
1855 | |
1856 | noaliencache [MM, NUMA, SLAB] Disables the allocation of alien |
1857 | caches in the slab allocator. Saves per-node memory, |
1858 | but will impact performance. |
1859 | |
1860 | noalign [KNL,ARM] |
1861 | |
1862 | noapic [SMP,APIC] Tells the kernel to not make use of any |
1863 | IOAPICs that may be present in the system. |
1864 | |
1865 | noautogroup Disable scheduler automatic task group creation. |
1866 | |
1867 | nobats [PPC] Do not use BATs for mapping kernel lowmem |
1868 | on "Classic" PPC cores. |
1869 | |
1870 | nocache [ARM] |
1871 | |
1872 | noclflush [BUGS=X86] Don't use the CLFLUSH instruction |
1873 | |
1874 | nodelayacct [KNL] Disable per-task delay accounting |
1875 | |
1876 | nodisconnect [HW,SCSI,M68K] Disables SCSI disconnects. |
1877 | |
1878 | nodsp [SH] Disable hardware DSP at boot time. |
1879 | |
1880 | noefi [X86] Disable EFI runtime services support. |
1881 | |
1882 | noexec [IA-64] |
1883 | |
1884 | noexec [X86] |
1885 | On X86-32 available only on PAE configured kernels. |
1886 | noexec=on: enable non-executable mappings (default) |
1887 | noexec=off: disable non-executable mappings |
1888 | |
1889 | nosmap [X86] |
1890 | Disable SMAP (Supervisor Mode Access Prevention) |
1891 | even if it is supported by processor. |
1892 | |
1893 | nosmep [X86] |
1894 | Disable SMEP (Supervisor Mode Execution Prevention) |
1895 | even if it is supported by processor. |
1896 | |
1897 | noexec32 [X86-64] |
1898 | This affects only 32-bit executables. |
1899 | noexec32=on: enable non-executable mappings (default) |
1900 | read doesn't imply executable mappings |
1901 | noexec32=off: disable non-executable mappings |
1902 | read implies executable mappings |
1903 | |
1904 | nofpu [SH] Disable hardware FPU at boot time. |
1905 | |
1906 | nofxsr [BUGS=X86-32] Disables x86 floating point extended |
1907 | register save and restore. The kernel will only save |
1908 | legacy floating-point registers on task switch. |
1909 | |
1910 | noxsave [BUGS=X86] Disables x86 extended register state save |
1911 | and restore using xsave. The kernel will fallback to |
1912 | enabling legacy floating-point and sse state. |
1913 | |
1914 | eagerfpu= [X86] |
1915 | on enable eager fpu restore |
1916 | off disable eager fpu restore |
1917 | auto selects the default scheme, which automatically |
1918 | enables eagerfpu restore for xsaveopt. |
1919 | |
1920 | nohlt [BUGS=ARM,SH] Tells the kernel that the sleep(SH) or |
1921 | wfi(ARM) instruction doesn't work correctly and not to |
1922 | use it. This is also useful when using JTAG debugger. |
1923 | |
1924 | no_file_caps Tells the kernel not to honor file capabilities. The |
1925 | only way then for a file to be executed with privilege |
1926 | is to be setuid root or executed by root. |
1927 | |
1928 | nohalt [IA-64] Tells the kernel not to use the power saving |
1929 | function PAL_HALT_LIGHT when idle. This increases |
1930 | power-consumption. On the positive side, it reduces |
1931 | interrupt wake-up latency, which may improve performance |
1932 | in certain environments such as networked servers or |
1933 | real-time systems. |
1934 | |
1935 | nohz= [KNL] Boottime enable/disable dynamic ticks |
1936 | Valid arguments: on, off |
1937 | Default: on |
1938 | |
1939 | noiotrap [SH] Disables trapped I/O port accesses. |
1940 | |
1941 | noirqdebug [X86-32] Disables the code which attempts to detect and |
1942 | disable unhandled interrupt sources. |
1943 | |
1944 | no_timer_check [X86,APIC] Disables the code which tests for |
1945 | broken timer IRQ sources. |
1946 | |
1947 | noisapnp [ISAPNP] Disables ISA PnP code. |
1948 | |
1949 | noinitrd [RAM] Tells the kernel not to load any configured |
1950 | initial RAM disk. |
1951 | |
1952 | nointremap [X86-64, Intel-IOMMU] Do not enable interrupt |
1953 | remapping. |
1954 | [Deprecated - use intremap=off] |
1955 | |
1956 | nointroute [IA-64] |
1957 | |
1958 | nojitter [IA-64] Disables jitter checking for ITC timers. |
1959 | |
1960 | no-kvmclock [X86,KVM] Disable paravirtualized KVM clock driver |
1961 | |
1962 | no-kvmapf [X86,KVM] Disable paravirtualized asynchronous page |
1963 | fault handling. |
1964 | |
1965 | no-steal-acc [X86,KVM] Disable paravirtualized steal time accounting. |
1966 | steal time is computed, but won't influence scheduler |
1967 | behaviour |
1968 | |
1969 | nolapic [X86-32,APIC] Do not enable or use the local APIC. |
1970 | |
1971 | nolapic_timer [X86-32,APIC] Do not use the local APIC timer. |
1972 | |
1973 | noltlbs [PPC] Do not use large page/tlb entries for kernel |
1974 | lowmem mapping on PPC40x. |
1975 | |
1976 | nomca [IA-64] Disable machine check abort handling |
1977 | |
1978 | nomce [X86-32] Machine Check Exception |
1979 | |
1980 | nomfgpt [X86-32] Disable Multi-Function General Purpose |
1981 | Timer usage (for AMD Geode machines). |
1982 | |
1983 | nonmi_ipi [X86] Disable using NMI IPIs during panic/reboot to |
1984 | shutdown the other cpus. Instead use the REBOOT_VECTOR |
1985 | irq. |
1986 | |
1987 | nomodule Disable module load |
1988 | |
1989 | nopat [X86] Disable PAT (page attribute table extension of |
1990 | pagetables) support. |
1991 | |
1992 | norandmaps Don't use address space randomization. Equivalent to |
1993 | echo 0 > /proc/sys/kernel/randomize_va_space |
1994 | |
1995 | noreplace-paravirt [X86,IA-64,PV_OPS] Don't patch paravirt_ops |
1996 | |
1997 | noreplace-smp [X86-32,SMP] Don't replace SMP instructions |
1998 | with UP alternatives |
1999 | |
2000 | noresidual [PPC] Don't use residual data on PReP machines. |
2001 | |
2002 | nordrand [X86] Disable the direct use of the RDRAND |
2003 | instruction even if it is supported by the |
2004 | processor. RDRAND is still available to user |
2005 | space applications. |
2006 | |
2007 | noresume [SWSUSP] Disables resume and restores original swap |
2008 | space. |
2009 | |
2010 | no-scroll [VGA] Disables scrollback. |
2011 | This is required for the Braillex ib80-piezo Braille |
2012 | reader made by F.H. Papenmeier (Germany). |
2013 | |
2014 | nosbagart [IA-64] |
2015 | |
2016 | nosep [BUGS=X86-32] Disables x86 SYSENTER/SYSEXIT support. |
2017 | |
2018 | nosmp [SMP] Tells an SMP kernel to act as a UP kernel, |
2019 | and disable the IO APIC. legacy for "maxcpus=0". |
2020 | |
2021 | nosoftlockup [KNL] Disable the soft-lockup detector. |
2022 | |
2023 | nosync [HW,M68K] Disables sync negotiation for all devices. |
2024 | |
2025 | notsc [BUGS=X86-32] Disable Time Stamp Counter |
2026 | |
2027 | nousb [USB] Disable the USB subsystem |
2028 | |
2029 | nowatchdog [KNL] Disable the lockup detector (NMI watchdog). |
2030 | |
2031 | nowb [ARM] |
2032 | |
2033 | nox2apic [X86-64,APIC] Do not enable x2APIC mode. |
2034 | |
2035 | cpu0_hotplug [X86] Turn on CPU0 hotplug feature when |
2036 | CONFIG_BOOTPARAM_HOTPLUG_CPU0 is off. |
2037 | Some features depend on CPU0. Known dependencies are: |
2038 | 1. Resume from suspend/hibernate depends on CPU0. |
2039 | Suspend/hibernate will fail if CPU0 is offline and you |
2040 | need to online CPU0 before suspend/hibernate. |
2041 | 2. PIC interrupts also depend on CPU0. CPU0 can't be |
2042 | removed if a PIC interrupt is detected. |
2043 | It's said poweroff/reboot may depend on CPU0 on some |
2044 | machines although I haven't seen such issues so far |
2045 | after CPU0 is offline on a few tested machines. |
2046 | If the dependencies are under your control, you can |
2047 | turn on cpu0_hotplug. |
2048 | |
2049 | nptcg= [IA-64] Override max number of concurrent global TLB |
2050 | purges which is reported from either PAL_VM_SUMMARY or |
2051 | SAL PALO. |
2052 | |
2053 | nr_cpus= [SMP] Maximum number of processors that an SMP kernel |
2054 | could support. nr_cpus=n : n >= 1 limits the kernel to |
2055 | supporting 'n' processors. Later in runtime you can not |
2056 | use hotplug cpu feature to put more cpu back to online. |
2057 | just like you compile the kernel NR_CPUS=n |
2058 | |
2059 | nr_uarts= [SERIAL] maximum number of UARTs to be registered. |
2060 | |
2061 | numa_balancing= [KNL,X86] Enable or disable automatic NUMA balancing. |
2062 | Allowed values are enable and disable |
2063 | |
2064 | numa_zonelist_order= [KNL, BOOT] Select zonelist order for NUMA. |
2065 | one of ['zone', 'node', 'default'] can be specified |
2066 | This can be set from sysctl after boot. |
2067 | See Documentation/sysctl/vm.txt for details. |
2068 | |
2069 | ohci1394_dma=early [HW] enable debugging via the ohci1394 driver. |
2070 | See Documentation/debugging-via-ohci1394.txt for more |
2071 | info. |
2072 | |
2073 | olpc_ec_timeout= [OLPC] ms delay when issuing EC commands |
2074 | Rather than timing out after 20 ms if an EC |
2075 | command is not properly ACKed, override the length |
2076 | of the timeout. We have interrupts disabled while |
2077 | waiting for the ACK, so if this is set too high |
2078 | interrupts *may* be lost! |
2079 | |
2080 | omap_mux= [OMAP] Override bootloader pin multiplexing. |
2081 | Format: <mux_mode0.mode_name=value>... |
2082 | For example, to override I2C bus2: |
2083 | omap_mux=i2c2_scl.i2c2_scl=0x100,i2c2_sda.i2c2_sda=0x100 |
2084 | |
2085 | oprofile.timer= [HW] |
2086 | Use timer interrupt instead of performance counters |
2087 | |
2088 | oprofile.cpu_type= Force an oprofile cpu type |
2089 | This might be useful if you have an older oprofile |
2090 | userland or if you want common events. |
2091 | Format: { arch_perfmon } |
2092 | arch_perfmon: [X86] Force use of architectural |
2093 | perfmon on Intel CPUs instead of the |
2094 | CPU specific event set. |
2095 | timer: [X86] Force use of architectural NMI |
2096 | timer mode (see also oprofile.timer |
2097 | for generic hr timer mode) |
2098 | [s390] Force legacy basic mode sampling |
2099 | (report cpu_type "timer") |
2100 | |
2101 | oops=panic Always panic on oopses. Default is to just kill the |
2102 | process, but there is a small probability of |
2103 | deadlocking the machine. |
2104 | This will also cause panics on machine check exceptions. |
2105 | Useful together with panic=30 to trigger a reboot. |
2106 | |
2107 | OSS [HW,OSS] |
2108 | See Documentation/sound/oss/oss-parameters.txt |
2109 | |
2110 | panic= [KNL] Kernel behaviour on panic: delay <timeout> |
2111 | timeout > 0: seconds before rebooting |
2112 | timeout = 0: wait forever |
2113 | timeout < 0: reboot immediately |
2114 | Format: <timeout> |
2115 | |
2116 | parkbd.port= [HW] Parallel port number the keyboard adapter is |
2117 | connected to, default is 0. |
2118 | Format: <parport#> |
2119 | parkbd.mode= [HW] Parallel port keyboard adapter mode of operation, |
2120 | 0 for XT, 1 for AT (default is AT). |
2121 | Format: <mode> |
2122 | |
2123 | parport= [HW,PPT] Specify parallel ports. 0 disables. |
2124 | Format: { 0 | auto | 0xBBB[,IRQ[,DMA]] } |
2125 | Use 'auto' to force the driver to use any |
2126 | IRQ/DMA settings detected (the default is to |
2127 | ignore detected IRQ/DMA settings because of |
2128 | possible conflicts). You can specify the base |
2129 | address, IRQ, and DMA settings; IRQ and DMA |
2130 | should be numbers, or 'auto' (for using detected |
2131 | settings on that particular port), or 'nofifo' |
2132 | (to avoid using a FIFO even if it is detected). |
2133 | Parallel ports are assigned in the order they |
2134 | are specified on the command line, starting |
2135 | with parport0. |
2136 | |
2137 | parport_init_mode= [HW,PPT] |
2138 | Configure VIA parallel port to operate in |
2139 | a specific mode. This is necessary on Pegasos |
2140 | computer where firmware has no options for setting |
2141 | up parallel port mode and sets it to spp. |
2142 | Currently this function knows 686a and 8231 chips. |
2143 | Format: [spp|ps2|epp|ecp|ecpepp] |
2144 | |
2145 | pause_on_oops= |
2146 | Halt all CPUs after the first oops has been printed for |
2147 | the specified number of seconds. This is to be used if |
2148 | your oopses keep scrolling off the screen. |
2149 | |
2150 | pcbit= [HW,ISDN] |
2151 | |
2152 | pcd. [PARIDE] |
2153 | See header of drivers/block/paride/pcd.c. |
2154 | See also Documentation/blockdev/paride.txt. |
2155 | |
2156 | pci=option[,option...] [PCI] various PCI subsystem options: |
2157 | earlydump [X86] dump PCI config space before the kernel |
2158 | changes anything |
2159 | off [X86] don't probe for the PCI bus |
2160 | bios [X86-32] force use of PCI BIOS, don't access |
2161 | the hardware directly. Use this if your machine |
2162 | has a non-standard PCI host bridge. |
2163 | nobios [X86-32] disallow use of PCI BIOS, only direct |
2164 | hardware access methods are allowed. Use this |
2165 | if you experience crashes upon bootup and you |
2166 | suspect they are caused by the BIOS. |
2167 | conf1 [X86] Force use of PCI Configuration |
2168 | Mechanism 1. |
2169 | conf2 [X86] Force use of PCI Configuration |
2170 | Mechanism 2. |
2171 | noaer [PCIE] If the PCIEAER kernel config parameter is |
2172 | enabled, this kernel boot option can be used to |
2173 | disable the use of PCIE advanced error reporting. |
2174 | nodomains [PCI] Disable support for multiple PCI |
2175 | root domains (aka PCI segments, in ACPI-speak). |
2176 | nommconf [X86] Disable use of MMCONFIG for PCI |
2177 | Configuration |
2178 | check_enable_amd_mmconf [X86] check for and enable |
2179 | properly configured MMIO access to PCI |
2180 | config space on AMD family 10h CPU |
2181 | nomsi [MSI] If the PCI_MSI kernel config parameter is |
2182 | enabled, this kernel boot option can be used to |
2183 | disable the use of MSI interrupts system-wide. |
2184 | noioapicquirk [APIC] Disable all boot interrupt quirks. |
2185 | Safety option to keep boot IRQs enabled. This |
2186 | should never be necessary. |
2187 | ioapicreroute [APIC] Enable rerouting of boot IRQs to the |
2188 | primary IO-APIC for bridges that cannot disable |
2189 | boot IRQs. This fixes a source of spurious IRQs |
2190 | when the system masks IRQs. |
2191 | noioapicreroute [APIC] Disable workaround that uses the |
2192 | boot IRQ equivalent of an IRQ that connects to |
2193 | a chipset where boot IRQs cannot be disabled. |
2194 | The opposite of ioapicreroute. |
2195 | biosirq [X86-32] Use PCI BIOS calls to get the interrupt |
2196 | routing table. These calls are known to be buggy |
2197 | on several machines and they hang the machine |
2198 | when used, but on other computers it's the only |
2199 | way to get the interrupt routing table. Try |
2200 | this option if the kernel is unable to allocate |
2201 | IRQs or discover secondary PCI buses on your |
2202 | motherboard. |
2203 | rom [X86] Assign address space to expansion ROMs. |
2204 | Use with caution as certain devices share |
2205 | address decoders between ROMs and other |
2206 | resources. |
2207 | norom [X86] Do not assign address space to |
2208 | expansion ROMs that do not already have |
2209 | BIOS assigned address ranges. |
2210 | nobar [X86] Do not assign address space to the |
2211 | BARs that weren't assigned by the BIOS. |
2212 | irqmask=0xMMMM [X86] Set a bit mask of IRQs allowed to be |
2213 | assigned automatically to PCI devices. You can |
2214 | make the kernel exclude IRQs of your ISA cards |
2215 | this way. |
2216 | pirqaddr=0xAAAAA [X86] Specify the physical address |
2217 | of the PIRQ table (normally generated |
2218 | by the BIOS) if it is outside the |
2219 | F0000h-100000h range. |
2220 | lastbus=N [X86] Scan all buses thru bus #N. Can be |
2221 | useful if the kernel is unable to find your |
2222 | secondary buses and you want to tell it |
2223 | explicitly which ones they are. |
2224 | assign-busses [X86] Always assign all PCI bus |
2225 | numbers ourselves, overriding |
2226 | whatever the firmware may have done. |
2227 | usepirqmask [X86] Honor the possible IRQ mask stored |
2228 | in the BIOS $PIR table. This is needed on |
2229 | some systems with broken BIOSes, notably |
2230 | some HP Pavilion N5400 and Omnibook XE3 |
2231 | notebooks. This will have no effect if ACPI |
2232 | IRQ routing is enabled. |
2233 | noacpi [X86] Do not use ACPI for IRQ routing |
2234 | or for PCI scanning. |
2235 | use_crs [X86] Use PCI host bridge window information |
2236 | from ACPI. On BIOSes from 2008 or later, this |
2237 | is enabled by default. If you need to use this, |
2238 | please report a bug. |
2239 | nocrs [X86] Ignore PCI host bridge windows from ACPI. |
2240 | If you need to use this, please report a bug. |
2241 | routeirq Do IRQ routing for all PCI devices. |
2242 | This is normally done in pci_enable_device(), |
2243 | so this option is a temporary workaround |
2244 | for broken drivers that don't call it. |
2245 | skip_isa_align [X86] do not align io start addr, so can |
2246 | handle more pci cards |
2247 | firmware [ARM] Do not re-enumerate the bus but instead |
2248 | just use the configuration from the |
2249 | bootloader. This is currently used on |
2250 | IXP2000 systems where the bus has to be |
2251 | configured a certain way for adjunct CPUs. |
2252 | noearly [X86] Don't do any early type 1 scanning. |
2253 | This might help on some broken boards which |
2254 | machine check when some devices' config space |
2255 | is read. But various workarounds are disabled |
2256 | and some IOMMU drivers will not work. |
2257 | bfsort Sort PCI devices into breadth-first order. |
2258 | This sorting is done to get a device |
2259 | order compatible with older (<= 2.4) kernels. |
2260 | nobfsort Don't sort PCI devices into breadth-first order. |
2261 | pcie_bus_tune_off Disable PCIe MPS (Max Payload Size) |
2262 | tuning and use the BIOS-configured MPS defaults. |
2263 | pcie_bus_safe Set every device's MPS to the largest value |
2264 | supported by all devices below the root complex. |
2265 | pcie_bus_perf Set device MPS to the largest allowable MPS |
2266 | based on its parent bus. Also set MRRS (Max |
2267 | Read Request Size) to the largest supported |
2268 | value (no larger than the MPS that the device |
2269 | or bus can support) for best performance. |
2270 | pcie_bus_peer2peer Set every device's MPS to 128B, which |
2271 | every device is guaranteed to support. This |
2272 | configuration allows peer-to-peer DMA between |
2273 | any pair of devices, possibly at the cost of |
2274 | reduced performance. This also guarantees |
2275 | that hot-added devices will work. |
2276 | cbiosize=nn[KMG] The fixed amount of bus space which is |
2277 | reserved for the CardBus bridge's IO window. |
2278 | The default value is 256 bytes. |
2279 | cbmemsize=nn[KMG] The fixed amount of bus space which is |
2280 | reserved for the CardBus bridge's memory |
2281 | window. The default value is 64 megabytes. |
2282 | resource_alignment= |
2283 | Format: |
2284 | [<order of align>@][<domain>:]<bus>:<slot>.<func>[; ...] |
2285 | Specifies alignment and device to reassign |
2286 | aligned memory resources. |
2287 | If <order of align> is not specified, |
2288 | PAGE_SIZE is used as alignment. |
2289 | PCI-PCI bridge can be specified, if resource |
2290 | windows need to be expanded. |
2291 | ecrc= Enable/disable PCIe ECRC (transaction layer |
2292 | end-to-end CRC checking). |
2293 | bios: Use BIOS/firmware settings. This is the |
2294 | the default. |
2295 | off: Turn ECRC off |
2296 | on: Turn ECRC on. |
2297 | hpiosize=nn[KMG] The fixed amount of bus space which is |
2298 | reserved for hotplug bridge's IO window. |
2299 | Default size is 256 bytes. |
2300 | hpmemsize=nn[KMG] The fixed amount of bus space which is |
2301 | reserved for hotplug bridge's memory window. |
2302 | Default size is 2 megabytes. |
2303 | realloc= Enable/disable reallocating PCI bridge resources |
2304 | if allocations done by BIOS are too small to |
2305 | accommodate resources required by all child |
2306 | devices. |
2307 | off: Turn realloc off |
2308 | on: Turn realloc on |
2309 | realloc same as realloc=on |
2310 | noari do not use PCIe ARI. |
2311 | pcie_scan_all Scan all possible PCIe devices. Otherwise we |
2312 | only look for one device below a PCIe downstream |
2313 | port. |
2314 | |
2315 | pcie_aspm= [PCIE] Forcibly enable or disable PCIe Active State Power |
2316 | Management. |
2317 | off Disable ASPM. |
2318 | force Enable ASPM even on devices that claim not to support it. |
2319 | WARNING: Forcing ASPM on may cause system lockups. |
2320 | |
2321 | pcie_hp= [PCIE] PCI Express Hotplug driver options: |
2322 | nomsi Do not use MSI for PCI Express Native Hotplug (this |
2323 | makes all PCIe ports use INTx for hotplug services). |
2324 | |
2325 | pcie_ports= [PCIE] PCIe ports handling: |
2326 | auto Ask the BIOS whether or not to use native PCIe services |
2327 | associated with PCIe ports (PME, hot-plug, AER). Use |
2328 | them only if that is allowed by the BIOS. |
2329 | native Use native PCIe services associated with PCIe ports |
2330 | unconditionally. |
2331 | compat Treat PCIe ports as PCI-to-PCI bridges, disable the PCIe |
2332 | ports driver. |
2333 | |
2334 | pcie_pme= [PCIE,PM] Native PCIe PME signaling options: |
2335 | nomsi Do not use MSI for native PCIe PME signaling (this makes |
2336 | all PCIe root ports use INTx for all services). |
2337 | |
2338 | pcmv= [HW,PCMCIA] BadgePAD 4 |
2339 | |
2340 | pd. [PARIDE] |
2341 | See Documentation/blockdev/paride.txt. |
2342 | |
2343 | pdcchassis= [PARISC,HW] Disable/Enable PDC Chassis Status codes at |
2344 | boot time. |
2345 | Format: { 0 | 1 } |
2346 | See arch/parisc/kernel/pdc_chassis.c |
2347 | |
2348 | percpu_alloc= Select which percpu first chunk allocator to use. |
2349 | Currently supported values are "embed" and "page". |
2350 | Archs may support subset or none of the selections. |
2351 | See comments in mm/percpu.c for details on each |
2352 | allocator. This parameter is primarily for debugging |
2353 | and performance comparison. |
2354 | |
2355 | pf. [PARIDE] |
2356 | See Documentation/blockdev/paride.txt. |
2357 | |
2358 | pg. [PARIDE] |
2359 | See Documentation/blockdev/paride.txt. |
2360 | |
2361 | pirq= [SMP,APIC] Manual mp-table setup |
2362 | See Documentation/x86/i386/IO-APIC.txt. |
2363 | |
2364 | plip= [PPT,NET] Parallel port network link |
2365 | Format: { parport<nr> | timid | 0 } |
2366 | See also Documentation/parport.txt. |
2367 | |
2368 | pmtmr= [X86] Manual setup of pmtmr I/O Port. |
2369 | Override pmtimer IOPort with a hex value. |
2370 | e.g. pmtmr=0x508 |
2371 | |
2372 | pnp.debug=1 [PNP] |
2373 | Enable PNP debug messages (depends on the |
2374 | CONFIG_PNP_DEBUG_MESSAGES option). Change at run-time |
2375 | via /sys/module/pnp/parameters/debug. We always show |
2376 | current resource usage; turning this on also shows |
2377 | possible settings and some assignment information. |
2378 | |
2379 | pnpacpi= [ACPI] |
2380 | { off } |
2381 | |
2382 | pnpbios= [ISAPNP] |
2383 | { on | off | curr | res | no-curr | no-res } |
2384 | |
2385 | pnp_reserve_irq= |
2386 | [ISAPNP] Exclude IRQs for the autoconfiguration |
2387 | |
2388 | pnp_reserve_dma= |
2389 | [ISAPNP] Exclude DMAs for the autoconfiguration |
2390 | |
2391 | pnp_reserve_io= [ISAPNP] Exclude I/O ports for the autoconfiguration |
2392 | Ranges are in pairs (I/O port base and size). |
2393 | |
2394 | pnp_reserve_mem= |
2395 | [ISAPNP] Exclude memory regions for the |
2396 | autoconfiguration. |
2397 | Ranges are in pairs (memory base and size). |
2398 | |
2399 | ports= [IP_VS_FTP] IPVS ftp helper module |
2400 | Default is 21. |
2401 | Up to 8 (IP_VS_APP_MAX_PORTS) ports |
2402 | may be specified. |
2403 | Format: <port>,<port>.... |
2404 | |
2405 | print-fatal-signals= |
2406 | [KNL] debug: print fatal signals |
2407 | |
2408 | If enabled, warn about various signal handling |
2409 | related application anomalies: too many signals, |
2410 | too many POSIX.1 timers, fatal signals causing a |
2411 | coredump - etc. |
2412 | |
2413 | If you hit the warning due to signal overflow, |
2414 | you might want to try "ulimit -i unlimited". |
2415 | |
2416 | default: off. |
2417 | |
2418 | printk.always_kmsg_dump= |
2419 | Trigger kmsg_dump for cases other than kernel oops or |
2420 | panics |
2421 | Format: <bool> (1/Y/y=enable, 0/N/n=disable) |
2422 | default: disabled |
2423 | |
2424 | printk.time= Show timing data prefixed to each printk message line |
2425 | Format: <bool> (1/Y/y=enable, 0/N/n=disable) |
2426 | |
2427 | processor.max_cstate= [HW,ACPI] |
2428 | Limit processor to maximum C-state |
2429 | max_cstate=9 overrides any DMI blacklist limit. |
2430 | |
2431 | processor.nocst [HW,ACPI] |
2432 | Ignore the _CST method to determine C-states, |
2433 | instead using the legacy FADT method |
2434 | |
2435 | profile= [KNL] Enable kernel profiling via /proc/profile |
2436 | Format: [schedule,]<number> |
2437 | Param: "schedule" - profile schedule points. |
2438 | Param: <number> - step/bucket size as a power of 2 for |
2439 | statistical time based profiling. |
2440 | Param: "sleep" - profile D-state sleeping (millisecs). |
2441 | Requires CONFIG_SCHEDSTATS |
2442 | Param: "kvm" - profile VM exits. |
2443 | |
2444 | prompt_ramdisk= [RAM] List of RAM disks to prompt for floppy disk |
2445 | before loading. |
2446 | See Documentation/blockdev/ramdisk.txt. |
2447 | |
2448 | psmouse.proto= [HW,MOUSE] Highest PS2 mouse protocol extension to |
2449 | probe for; one of (bare|imps|exps|lifebook|any). |
2450 | psmouse.rate= [HW,MOUSE] Set desired mouse report rate, in reports |
2451 | per second. |
2452 | psmouse.resetafter= [HW,MOUSE] |
2453 | Try to reset the device after so many bad packets |
2454 | (0 = never). |
2455 | psmouse.resolution= |
2456 | [HW,MOUSE] Set desired mouse resolution, in dpi. |
2457 | psmouse.smartscroll= |
2458 | [HW,MOUSE] Controls Logitech smartscroll autorepeat. |
2459 | 0 = disabled, 1 = enabled (default). |
2460 | |
2461 | pstore.backend= Specify the name of the pstore backend to use |
2462 | |
2463 | pt. [PARIDE] |
2464 | See Documentation/blockdev/paride.txt. |
2465 | |
2466 | pty.legacy_count= |
2467 | [KNL] Number of legacy pty's. Overwrites compiled-in |
2468 | default number. |
2469 | |
2470 | quiet [KNL] Disable most log messages |
2471 | |
2472 | r128= [HW,DRM] |
2473 | |
2474 | raid= [HW,RAID] |
2475 | See Documentation/md.txt. |
2476 | |
2477 | ramdisk_blocksize= [RAM] |
2478 | See Documentation/blockdev/ramdisk.txt. |
2479 | |
2480 | ramdisk_size= [RAM] Sizes of RAM disks in kilobytes |
2481 | See Documentation/blockdev/ramdisk.txt. |
2482 | |
2483 | rcu_nocbs= [KNL,BOOT] |
2484 | In kernels built with CONFIG_RCU_NOCB_CPU=y, set |
2485 | the specified list of CPUs to be no-callback CPUs. |
2486 | Invocation of these CPUs' RCU callbacks will |
2487 | be offloaded to "rcuoN" kthreads created for |
2488 | that purpose. This reduces OS jitter on the |
2489 | offloaded CPUs, which can be useful for HPC and |
2490 | real-time workloads. It can also improve energy |
2491 | efficiency for asymmetric multiprocessors. |
2492 | |
2493 | rcu_nocb_poll [KNL,BOOT] |
2494 | Rather than requiring that offloaded CPUs |
2495 | (specified by rcu_nocbs= above) explicitly |
2496 | awaken the corresponding "rcuoN" kthreads, |
2497 | make these kthreads poll for callbacks. |
2498 | This improves the real-time response for the |
2499 | offloaded CPUs by relieving them of the need to |
2500 | wake up the corresponding kthread, but degrades |
2501 | energy efficiency by requiring that the kthreads |
2502 | periodically wake up to do the polling. |
2503 | |
2504 | rcutree.blimit= [KNL,BOOT] |
2505 | Set maximum number of finished RCU callbacks to process |
2506 | in one batch. |
2507 | |
2508 | rcutree.fanout_leaf= [KNL,BOOT] |
2509 | Increase the number of CPUs assigned to each |
2510 | leaf rcu_node structure. Useful for very large |
2511 | systems. |
2512 | |
2513 | rcutree.qhimark= [KNL,BOOT] |
2514 | Set threshold of queued |
2515 | RCU callbacks over which batch limiting is disabled. |
2516 | |
2517 | rcutree.qlowmark= [KNL,BOOT] |
2518 | Set threshold of queued RCU callbacks below which |
2519 | batch limiting is re-enabled. |
2520 | |
2521 | rcutree.rcu_cpu_stall_suppress= [KNL,BOOT] |
2522 | Suppress RCU CPU stall warning messages. |
2523 | |
2524 | rcutree.rcu_cpu_stall_timeout= [KNL,BOOT] |
2525 | Set timeout for RCU CPU stall warning messages. |
2526 | |
2527 | rcutree.jiffies_till_first_fqs= [KNL,BOOT] |
2528 | Set delay from grace-period initialization to |
2529 | first attempt to force quiescent states. |
2530 | Units are jiffies, minimum value is zero, |
2531 | and maximum value is HZ. |
2532 | |
2533 | rcutree.jiffies_till_next_fqs= [KNL,BOOT] |
2534 | Set delay between subsequent attempts to force |
2535 | quiescent states. Units are jiffies, minimum |
2536 | value is one, and maximum value is HZ. |
2537 | |
2538 | rcutorture.fqs_duration= [KNL,BOOT] |
2539 | Set duration of force_quiescent_state bursts. |
2540 | |
2541 | rcutorture.fqs_holdoff= [KNL,BOOT] |
2542 | Set holdoff time within force_quiescent_state bursts. |
2543 | |
2544 | rcutorture.fqs_stutter= [KNL,BOOT] |
2545 | Set wait time between force_quiescent_state bursts. |
2546 | |
2547 | rcutorture.irqreader= [KNL,BOOT] |
2548 | Test RCU readers from irq handlers. |
2549 | |
2550 | rcutorture.n_barrier_cbs= [KNL,BOOT] |
2551 | Set callbacks/threads for rcu_barrier() testing. |
2552 | |
2553 | rcutorture.nfakewriters= [KNL,BOOT] |
2554 | Set number of concurrent RCU writers. These just |
2555 | stress RCU, they don't participate in the actual |
2556 | test, hence the "fake". |
2557 | |
2558 | rcutorture.nreaders= [KNL,BOOT] |
2559 | Set number of RCU readers. |
2560 | |
2561 | rcutorture.onoff_holdoff= [KNL,BOOT] |
2562 | Set time (s) after boot for CPU-hotplug testing. |
2563 | |
2564 | rcutorture.onoff_interval= [KNL,BOOT] |
2565 | Set time (s) between CPU-hotplug operations, or |
2566 | zero to disable CPU-hotplug testing. |
2567 | |
2568 | rcutorture.shuffle_interval= [KNL,BOOT] |
2569 | Set task-shuffle interval (s). Shuffling tasks |
2570 | allows some CPUs to go into dyntick-idle mode |
2571 | during the rcutorture test. |
2572 | |
2573 | rcutorture.shutdown_secs= [KNL,BOOT] |
2574 | Set time (s) after boot system shutdown. This |
2575 | is useful for hands-off automated testing. |
2576 | |
2577 | rcutorture.stall_cpu= [KNL,BOOT] |
2578 | Duration of CPU stall (s) to test RCU CPU stall |
2579 | warnings, zero to disable. |
2580 | |
2581 | rcutorture.stall_cpu_holdoff= [KNL,BOOT] |
2582 | Time to wait (s) after boot before inducing stall. |
2583 | |
2584 | rcutorture.stat_interval= [KNL,BOOT] |
2585 | Time (s) between statistics printk()s. |
2586 | |
2587 | rcutorture.stutter= [KNL,BOOT] |
2588 | Time (s) to stutter testing, for example, specifying |
2589 | five seconds causes the test to run for five seconds, |
2590 | wait for five seconds, and so on. This tests RCU's |
2591 | ability to transition abruptly to and from idle. |
2592 | |
2593 | rcutorture.test_boost= [KNL,BOOT] |
2594 | Test RCU priority boosting? 0=no, 1=maybe, 2=yes. |
2595 | "Maybe" means test if the RCU implementation |
2596 | under test support RCU priority boosting. |
2597 | |
2598 | rcutorture.test_boost_duration= [KNL,BOOT] |
2599 | Duration (s) of each individual boost test. |
2600 | |
2601 | rcutorture.test_boost_interval= [KNL,BOOT] |
2602 | Interval (s) between each boost test. |
2603 | |
2604 | rcutorture.test_no_idle_hz= [KNL,BOOT] |
2605 | Test RCU's dyntick-idle handling. See also the |
2606 | rcutorture.shuffle_interval parameter. |
2607 | |
2608 | rcutorture.torture_type= [KNL,BOOT] |
2609 | Specify the RCU implementation to test. |
2610 | |
2611 | rcutorture.verbose= [KNL,BOOT] |
2612 | Enable additional printk() statements. |
2613 | |
2614 | rdinit= [KNL] |
2615 | Format: <full_path> |
2616 | Run specified binary instead of /init from the ramdisk, |
2617 | used for early userspace startup. See initrd. |
2618 | |
2619 | reboot= [BUGS=X86-32,BUGS=ARM,BUGS=IA-64] Rebooting mode |
2620 | Format: <reboot_mode>[,<reboot_mode2>[,...]] |
2621 | See arch/*/kernel/reboot.c or arch/*/kernel/process.c |
2622 | |
2623 | relax_domain_level= |
2624 | [KNL, SMP] Set scheduler's default relax_domain_level. |
2625 | See Documentation/cgroups/cpusets.txt. |
2626 | |
2627 | reserve= [KNL,BUGS] Force the kernel to ignore some iomem area |
2628 | |
2629 | reservetop= [X86-32] |
2630 | Format: nn[KMG] |
2631 | Reserves a hole at the top of the kernel virtual |
2632 | address space. |
2633 | |
2634 | reservelow= [X86] |
2635 | Format: nn[K] |
2636 | Set the amount of memory to reserve for BIOS at |
2637 | the bottom of the address space. |
2638 | |
2639 | reset_devices [KNL] Force drivers to reset the underlying device |
2640 | during initialization. |
2641 | |
2642 | resume= [SWSUSP] |
2643 | Specify the partition device for software suspend |
2644 | Format: |
2645 | {/dev/<dev> | PARTUUID=<uuid> | <int>:<int> | <hex>} |
2646 | |
2647 | resume_offset= [SWSUSP] |
2648 | Specify the offset from the beginning of the partition |
2649 | given by "resume=" at which the swap header is located, |
2650 | in <PAGE_SIZE> units (needed only for swap files). |
2651 | See Documentation/power/swsusp-and-swap-files.txt |
2652 | |
2653 | resumedelay= [HIBERNATION] Delay (in seconds) to pause before attempting to |
2654 | read the resume files |
2655 | |
2656 | resumewait [HIBERNATION] Wait (indefinitely) for resume device to show up. |
2657 | Useful for devices that are detected asynchronously |
2658 | (e.g. USB and MMC devices). |
2659 | |
2660 | hibernate= [HIBERNATION] |
2661 | noresume Don't check if there's a hibernation image |
2662 | present during boot. |
2663 | nocompress Don't compress/decompress hibernation images. |
2664 | |
2665 | retain_initrd [RAM] Keep initrd memory after extraction |
2666 | |
2667 | rhash_entries= [KNL,NET] |
2668 | Set number of hash buckets for route cache |
2669 | |
2670 | riscom8= [HW,SERIAL] |
2671 | Format: <io_board1>[,<io_board2>[,...<io_boardN>]] |
2672 | |
2673 | ro [KNL] Mount root device read-only on boot |
2674 | |
2675 | root= [KNL] Root filesystem |
2676 | See name_to_dev_t comment in init/do_mounts.c. |
2677 | |
2678 | rootdelay= [KNL] Delay (in seconds) to pause before attempting to |
2679 | mount the root filesystem |
2680 | |
2681 | rootflags= [KNL] Set root filesystem mount option string |
2682 | |
2683 | rootfstype= [KNL] Set root filesystem type |
2684 | |
2685 | rootwait [KNL] Wait (indefinitely) for root device to show up. |
2686 | Useful for devices that are detected asynchronously |
2687 | (e.g. USB and MMC devices). |
2688 | |
2689 | rw [KNL] Mount root device read-write on boot |
2690 | |
2691 | S [KNL] Run init in single mode |
2692 | |
2693 | sa1100ir [NET] |
2694 | See drivers/net/irda/sa1100_ir.c. |
2695 | |
2696 | sbni= [NET] Granch SBNI12 leased line adapter |
2697 | |
2698 | sched_debug [KNL] Enables verbose scheduler debug messages. |
2699 | |
2700 | skew_tick= [KNL] Offset the periodic timer tick per cpu to mitigate |
2701 | xtime_lock contention on larger systems, and/or RCU lock |
2702 | contention on all systems with CONFIG_MAXSMP set. |
2703 | Format: { "0" | "1" } |
2704 | 0 -- disable. (may be 1 via CONFIG_CMDLINE="skew_tick=1" |
2705 | 1 -- enable. |
2706 | Note: increases power consumption, thus should only be |
2707 | enabled if running jitter sensitive (HPC/RT) workloads. |
2708 | |
2709 | security= [SECURITY] Choose a security module to enable at boot. |
2710 | If this boot parameter is not specified, only the first |
2711 | security module asking for security registration will be |
2712 | loaded. An invalid security module name will be treated |
2713 | as if no module has been chosen. |
2714 | |
2715 | selinux= [SELINUX] Disable or enable SELinux at boot time. |
2716 | Format: { "0" | "1" } |
2717 | See security/selinux/Kconfig help text. |
2718 | 0 -- disable. |
2719 | 1 -- enable. |
2720 | Default value is set via kernel config option. |
2721 | If enabled at boot time, /selinux/disable can be used |
2722 | later to disable prior to initial policy load. |
2723 | |
2724 | apparmor= [APPARMOR] Disable or enable AppArmor at boot time |
2725 | Format: { "0" | "1" } |
2726 | See security/apparmor/Kconfig help text |
2727 | 0 -- disable. |
2728 | 1 -- enable. |
2729 | Default value is set via kernel config option. |
2730 | |
2731 | serialnumber [BUGS=X86-32] |
2732 | |
2733 | shapers= [NET] |
2734 | Maximal number of shapers. |
2735 | |
2736 | show_msr= [x86] show boot-time MSR settings |
2737 | Format: { <integer> } |
2738 | Show boot-time (BIOS-initialized) MSR settings. |
2739 | The parameter means the number of CPUs to show, |
2740 | for example 1 means boot CPU only. |
2741 | |
2742 | simeth= [IA-64] |
2743 | simscsi= |
2744 | |
2745 | slram= [HW,MTD] |
2746 | |
2747 | slab_max_order= [MM, SLAB] |
2748 | Determines the maximum allowed order for slabs. |
2749 | A high setting may cause OOMs due to memory |
2750 | fragmentation. Defaults to 1 for systems with |
2751 | more than 32MB of RAM, 0 otherwise. |
2752 | |
2753 | slub_debug[=options[,slabs]] [MM, SLUB] |
2754 | Enabling slub_debug allows one to determine the |
2755 | culprit if slab objects become corrupted. Enabling |
2756 | slub_debug can create guard zones around objects and |
2757 | may poison objects when not in use. Also tracks the |
2758 | last alloc / free. For more information see |
2759 | Documentation/vm/slub.txt. |
2760 | |
2761 | slub_max_order= [MM, SLUB] |
2762 | Determines the maximum allowed order for slabs. |
2763 | A high setting may cause OOMs due to memory |
2764 | fragmentation. For more information see |
2765 | Documentation/vm/slub.txt. |
2766 | |
2767 | slub_min_objects= [MM, SLUB] |
2768 | The minimum number of objects per slab. SLUB will |
2769 | increase the slab order up to slub_max_order to |
2770 | generate a sufficiently large slab able to contain |
2771 | the number of objects indicated. The higher the number |
2772 | of objects the smaller the overhead of tracking slabs |
2773 | and the less frequently locks need to be acquired. |
2774 | For more information see Documentation/vm/slub.txt. |
2775 | |
2776 | slub_min_order= [MM, SLUB] |
2777 | Determines the minimum page order for slabs. Must be |
2778 | lower than slub_max_order. |
2779 | For more information see Documentation/vm/slub.txt. |
2780 | |
2781 | slub_nomerge [MM, SLUB] |
2782 | Disable merging of slabs with similar size. May be |
2783 | necessary if there is some reason to distinguish |
2784 | allocs to different slabs. Debug options disable |
2785 | merging on their own. |
2786 | For more information see Documentation/vm/slub.txt. |
2787 | |
2788 | smart2= [HW] |
2789 | Format: <io1>[,<io2>[,...,<io8>]] |
2790 | |
2791 | smsc-ircc2.nopnp [HW] Don't use PNP to discover SMC devices |
2792 | smsc-ircc2.ircc_cfg= [HW] Device configuration I/O port |
2793 | smsc-ircc2.ircc_sir= [HW] SIR base I/O port |
2794 | smsc-ircc2.ircc_fir= [HW] FIR base I/O port |
2795 | smsc-ircc2.ircc_irq= [HW] IRQ line |
2796 | smsc-ircc2.ircc_dma= [HW] DMA channel |
2797 | smsc-ircc2.ircc_transceiver= [HW] Transceiver type: |
2798 | 0: Toshiba Satellite 1800 (GP data pin select) |
2799 | 1: Fast pin select (default) |
2800 | 2: ATC IRMode |
2801 | |
2802 | softlockup_panic= |
2803 | [KNL] Should the soft-lockup detector generate panics. |
2804 | Format: <integer> |
2805 | |
2806 | sonypi.*= [HW] Sony Programmable I/O Control Device driver |
2807 | See Documentation/laptops/sonypi.txt |
2808 | |
2809 | specialix= [HW,SERIAL] Specialix multi-serial port adapter |
2810 | See Documentation/serial/specialix.txt. |
2811 | |
2812 | spia_io_base= [HW,MTD] |
2813 | spia_fio_base= |
2814 | spia_pedr= |
2815 | spia_peddr= |
2816 | |
2817 | stacktrace [FTRACE] |
2818 | Enabled the stack tracer on boot up. |
2819 | |
2820 | stacktrace_filter=[function-list] |
2821 | [FTRACE] Limit the functions that the stack tracer |
2822 | will trace at boot up. function-list is a comma separated |
2823 | list of functions. This list can be changed at run |
2824 | time by the stack_trace_filter file in the debugfs |
2825 | tracing directory. Note, this enables stack tracing |
2826 | and the stacktrace above is not needed. |
2827 | |
2828 | sti= [PARISC,HW] |
2829 | Format: <num> |
2830 | Set the STI (builtin display/keyboard on the HP-PARISC |
2831 | machines) console (graphic card) which should be used |
2832 | as the initial boot-console. |
2833 | See also comment in drivers/video/console/sticore.c. |
2834 | |
2835 | sti_font= [HW] |
2836 | See comment in drivers/video/console/sticore.c. |
2837 | |
2838 | stifb= [HW] |
2839 | Format: bpp:<bpp1>[:<bpp2>[:<bpp3>...]] |
2840 | |
2841 | sunrpc.min_resvport= |
2842 | sunrpc.max_resvport= |
2843 | [NFS,SUNRPC] |
2844 | SunRPC servers often require that client requests |
2845 | originate from a privileged port (i.e. a port in the |
2846 | range 0 < portnr < 1024). |
2847 | An administrator who wishes to reserve some of these |
2848 | ports for other uses may adjust the range that the |
2849 | kernel's sunrpc client considers to be privileged |
2850 | using these two parameters to set the minimum and |
2851 | maximum port values. |
2852 | |
2853 | sunrpc.pool_mode= |
2854 | [NFS] |
2855 | Control how the NFS server code allocates CPUs to |
2856 | service thread pools. Depending on how many NICs |
2857 | you have and where their interrupts are bound, this |
2858 | option will affect which CPUs will do NFS serving. |
2859 | Note: this parameter cannot be changed while the |
2860 | NFS server is running. |
2861 | |
2862 | auto the server chooses an appropriate mode |
2863 | automatically using heuristics |
2864 | global a single global pool contains all CPUs |
2865 | percpu one pool for each CPU |
2866 | pernode one pool for each NUMA node (equivalent |
2867 | to global on non-NUMA machines) |
2868 | |
2869 | sunrpc.tcp_slot_table_entries= |
2870 | sunrpc.udp_slot_table_entries= |
2871 | [NFS,SUNRPC] |
2872 | Sets the upper limit on the number of simultaneous |
2873 | RPC calls that can be sent from the client to a |
2874 | server. Increasing these values may allow you to |
2875 | improve throughput, but will also increase the |
2876 | amount of memory reserved for use by the client. |
2877 | |
2878 | swapaccount[=0|1] |
2879 | [KNL] Enable accounting of swap in memory resource |
2880 | controller if no parameter or 1 is given or disable |
2881 | it if 0 is given (See Documentation/cgroups/memory.txt) |
2882 | |
2883 | swiotlb= [IA-64] Number of I/O TLB slabs |
2884 | |
2885 | switches= [HW,M68k] |
2886 | |
2887 | sysfs.deprecated=0|1 [KNL] |
2888 | Enable/disable old style sysfs layout for old udev |
2889 | on older distributions. When this option is enabled |
2890 | very new udev will not work anymore. When this option |
2891 | is disabled (or CONFIG_SYSFS_DEPRECATED not compiled) |
2892 | in older udev will not work anymore. |
2893 | Default depends on CONFIG_SYSFS_DEPRECATED_V2 set in |
2894 | the kernel configuration. |
2895 | |
2896 | sysrq_always_enabled |
2897 | [KNL] |
2898 | Ignore sysrq setting - this boot parameter will |
2899 | neutralize any effect of /proc/sys/kernel/sysrq. |
2900 | Useful for debugging. |
2901 | |
2902 | tdfx= [HW,DRM] |
2903 | |
2904 | test_suspend= [SUSPEND] |
2905 | Specify "mem" (for Suspend-to-RAM) or "standby" (for |
2906 | standby suspend) as the system sleep state to briefly |
2907 | enter during system startup. The system is woken from |
2908 | this state using a wakeup-capable RTC alarm. |
2909 | |
2910 | thash_entries= [KNL,NET] |
2911 | Set number of hash buckets for TCP connection |
2912 | |
2913 | thermal.act= [HW,ACPI] |
2914 | -1: disable all active trip points in all thermal zones |
2915 | <degrees C>: override all lowest active trip points |
2916 | |
2917 | thermal.crt= [HW,ACPI] |
2918 | -1: disable all critical trip points in all thermal zones |
2919 | <degrees C>: override all critical trip points |
2920 | |
2921 | thermal.nocrt= [HW,ACPI] |
2922 | Set to disable actions on ACPI thermal zone |
2923 | critical and hot trip points. |
2924 | |
2925 | thermal.off= [HW,ACPI] |
2926 | 1: disable ACPI thermal control |
2927 | |
2928 | thermal.psv= [HW,ACPI] |
2929 | -1: disable all passive trip points |
2930 | <degrees C>: override all passive trip points to this |
2931 | value |
2932 | |
2933 | thermal.tzp= [HW,ACPI] |
2934 | Specify global default ACPI thermal zone polling rate |
2935 | <deci-seconds>: poll all this frequency |
2936 | 0: no polling (default) |
2937 | |
2938 | threadirqs [KNL] |
2939 | Force threading of all interrupt handlers except those |
2940 | marked explicitly IRQF_NO_THREAD. |
2941 | |
2942 | topology= [S390] |
2943 | Format: {off | on} |
2944 | Specify if the kernel should make use of the cpu |
2945 | topology information if the hardware supports this. |
2946 | The scheduler will make use of this information and |
2947 | e.g. base its process migration decisions on it. |
2948 | Default is on. |
2949 | |
2950 | tp720= [HW,PS2] |
2951 | |
2952 | tpm_suspend_pcr=[HW,TPM] |
2953 | Format: integer pcr id |
2954 | Specify that at suspend time, the tpm driver |
2955 | should extend the specified pcr with zeros, |
2956 | as a workaround for some chips which fail to |
2957 | flush the last written pcr on TPM_SaveState. |
2958 | This will guarantee that all the other pcrs |
2959 | are saved. |
2960 | |
2961 | trace_buf_size=nn[KMG] |
2962 | [FTRACE] will set tracing buffer size. |
2963 | |
2964 | trace_event=[event-list] |
2965 | [FTRACE] Set and start specified trace events in order |
2966 | to facilitate early boot debugging. |
2967 | See also Documentation/trace/events.txt |
2968 | |
2969 | trace_options=[option-list] |
2970 | [FTRACE] Enable or disable tracer options at boot. |
2971 | The option-list is a comma delimited list of options |
2972 | that can be enabled or disabled just as if you were |
2973 | to echo the option name into |
2974 | |
2975 | /sys/kernel/debug/tracing/trace_options |
2976 | |
2977 | For example, to enable stacktrace option (to dump the |
2978 | stack trace of each event), add to the command line: |
2979 | |
2980 | trace_options=stacktrace |
2981 | |
2982 | See also Documentation/trace/ftrace.txt "trace options" |
2983 | section. |
2984 | |
2985 | transparent_hugepage= |
2986 | [KNL] |
2987 | Format: [always|madvise|never] |
2988 | Can be used to control the default behavior of the system |
2989 | with respect to transparent hugepages. |
2990 | See Documentation/vm/transhuge.txt for more details. |
2991 | |
2992 | tsc= Disable clocksource stability checks for TSC. |
2993 | Format: <string> |
2994 | [x86] reliable: mark tsc clocksource as reliable, this |
2995 | disables clocksource verification at runtime, as well |
2996 | as the stability checks done at bootup. Used to enable |
2997 | high-resolution timer mode on older hardware, and in |
2998 | virtualized environment. |
2999 | [x86] noirqtime: Do not use TSC to do irq accounting. |
3000 | Used to run time disable IRQ_TIME_ACCOUNTING on any |
3001 | platforms where RDTSC is slow and this accounting |
3002 | can add overhead. |
3003 | |
3004 | turbografx.map[2|3]= [HW,JOY] |
3005 | TurboGraFX parallel port interface |
3006 | Format: |
3007 | <port#>,<js1>,<js2>,<js3>,<js4>,<js5>,<js6>,<js7> |
3008 | See also Documentation/input/joystick-parport.txt |
3009 | |
3010 | udbg-immortal [PPC] When debugging early kernel crashes that |
3011 | happen after console_init() and before a proper |
3012 | console driver takes over, this boot options might |
3013 | help "seeing" what's going on. |
3014 | |
3015 | uhash_entries= [KNL,NET] |
3016 | Set number of hash buckets for UDP/UDP-Lite connections |
3017 | |
3018 | uhci-hcd.ignore_oc= |
3019 | [USB] Ignore overcurrent events (default N). |
3020 | Some badly-designed motherboards generate lots of |
3021 | bogus events, for ports that aren't wired to |
3022 | anything. Set this parameter to avoid log spamming. |
3023 | Note that genuine overcurrent events won't be |
3024 | reported either. |
3025 | |
3026 | unknown_nmi_panic |
3027 | [X86] Cause panic on unknown NMI. |
3028 | |
3029 | usbcore.authorized_default= |
3030 | [USB] Default USB device authorization: |
3031 | (default -1 = authorized except for wireless USB, |
3032 | 0 = not authorized, 1 = authorized) |
3033 | |
3034 | usbcore.autosuspend= |
3035 | [USB] The autosuspend time delay (in seconds) used |
3036 | for newly-detected USB devices (default 2). This |
3037 | is the time required before an idle device will be |
3038 | autosuspended. Devices for which the delay is set |
3039 | to a negative value won't be autosuspended at all. |
3040 | |
3041 | usbcore.usbfs_snoop= |
3042 | [USB] Set to log all usbfs traffic (default 0 = off). |
3043 | |
3044 | usbcore.blinkenlights= |
3045 | [USB] Set to cycle leds on hubs (default 0 = off). |
3046 | |
3047 | usbcore.old_scheme_first= |
3048 | [USB] Start with the old device initialization |
3049 | scheme (default 0 = off). |
3050 | |
3051 | usbcore.usbfs_memory_mb= |
3052 | [USB] Memory limit (in MB) for buffers allocated by |
3053 | usbfs (default = 16, 0 = max = 2047). |
3054 | |
3055 | usbcore.use_both_schemes= |
3056 | [USB] Try the other device initialization scheme |
3057 | if the first one fails (default 1 = enabled). |
3058 | |
3059 | usbcore.initial_descriptor_timeout= |
3060 | [USB] Specifies timeout for the initial 64-byte |
3061 | USB_REQ_GET_DESCRIPTOR request in milliseconds |
3062 | (default 5000 = 5.0 seconds). |
3063 | |
3064 | usbhid.mousepoll= |
3065 | [USBHID] The interval which mice are to be polled at. |
3066 | |
3067 | usb-storage.delay_use= |
3068 | [UMS] The delay in seconds before a new device is |
3069 | scanned for Logical Units (default 5). |
3070 | |
3071 | usb-storage.quirks= |
3072 | [UMS] A list of quirks entries to supplement or |
3073 | override the built-in unusual_devs list. List |
3074 | entries are separated by commas. Each entry has |
3075 | the form VID:PID:Flags where VID and PID are Vendor |
3076 | and Product ID values (4-digit hex numbers) and |
3077 | Flags is a set of characters, each corresponding |
3078 | to a common usb-storage quirk flag as follows: |
3079 | a = SANE_SENSE (collect more than 18 bytes |
3080 | of sense data); |
3081 | b = BAD_SENSE (don't collect more than 18 |
3082 | bytes of sense data); |
3083 | c = FIX_CAPACITY (decrease the reported |
3084 | device capacity by one sector); |
3085 | d = NO_READ_DISC_INFO (don't use |
3086 | READ_DISC_INFO command); |
3087 | e = NO_READ_CAPACITY_16 (don't use |
3088 | READ_CAPACITY_16 command); |
3089 | h = CAPACITY_HEURISTICS (decrease the |
3090 | reported device capacity by one |
3091 | sector if the number is odd); |
3092 | i = IGNORE_DEVICE (don't bind to this |
3093 | device); |
3094 | l = NOT_LOCKABLE (don't try to lock and |
3095 | unlock ejectable media); |
3096 | m = MAX_SECTORS_64 (don't transfer more |
3097 | than 64 sectors = 32 KB at a time); |
3098 | n = INITIAL_READ10 (force a retry of the |
3099 | initial READ(10) command); |
3100 | o = CAPACITY_OK (accept the capacity |
3101 | reported by the device); |
3102 | p = WRITE_CACHE (the device cache is ON |
3103 | by default); |
3104 | r = IGNORE_RESIDUE (the device reports |
3105 | bogus residue values); |
3106 | s = SINGLE_LUN (the device has only one |
3107 | Logical Unit); |
3108 | w = NO_WP_DETECT (don't test whether the |
3109 | medium is write-protected). |
3110 | Example: quirks=0419:aaf5:rl,0421:0433:rc |
3111 | |
3112 | user_debug= [KNL,ARM] |
3113 | Format: <int> |
3114 | See arch/arm/Kconfig.debug help text. |
3115 | 1 - undefined instruction events |
3116 | 2 - system calls |
3117 | 4 - invalid data aborts |
3118 | 8 - SIGSEGV faults |
3119 | 16 - SIGBUS faults |
3120 | Example: user_debug=31 |
3121 | |
3122 | userpte= |
3123 | [X86] Flags controlling user PTE allocations. |
3124 | |
3125 | nohigh = do not allocate PTE pages in |
3126 | HIGHMEM regardless of setting |
3127 | of CONFIG_HIGHPTE. |
3128 | |
3129 | vdso= [X86,SH] |
3130 | vdso=2: enable compat VDSO (default with COMPAT_VDSO) |
3131 | vdso=1: enable VDSO (default) |
3132 | vdso=0: disable VDSO mapping |
3133 | |
3134 | vdso32= [X86] |
3135 | vdso32=2: enable compat VDSO (default with COMPAT_VDSO) |
3136 | vdso32=1: enable 32-bit VDSO (default) |
3137 | vdso32=0: disable 32-bit VDSO mapping |
3138 | |
3139 | vector= [IA-64,SMP] |
3140 | vector=percpu: enable percpu vector domain |
3141 | |
3142 | video= [FB] Frame buffer configuration |
3143 | See Documentation/fb/modedb.txt. |
3144 | |
3145 | virtio_mmio.device= |
3146 | [VMMIO] Memory mapped virtio (platform) device. |
3147 | |
3148 | <size>@<baseaddr>:<irq>[:<id>] |
3149 | where: |
3150 | <size> := size (can use standard suffixes |
3151 | like K, M and G) |
3152 | <baseaddr> := physical base address |
3153 | <irq> := interrupt number (as passed to |
3154 | request_irq()) |
3155 | <id> := (optional) platform device id |
3156 | example: |
3157 | virtio_mmio.device=1K@0x100b0000:48:7 |
3158 | |
3159 | Can be used multiple times for multiple devices. |
3160 | |
3161 | vga= [BOOT,X86-32] Select a particular video mode |
3162 | See Documentation/x86/boot.txt and |
3163 | Documentation/svga.txt. |
3164 | Use vga=ask for menu. |
3165 | This is actually a boot loader parameter; the value is |
3166 | passed to the kernel using a special protocol. |
3167 | |
3168 | vmalloc=nn[KMG] [KNL,BOOT] Forces the vmalloc area to have an exact |
3169 | size of <nn>. This can be used to increase the |
3170 | minimum size (128MB on x86). It can also be used to |
3171 | decrease the size and leave more room for directly |
3172 | mapped kernel RAM. |
3173 | |
3174 | vmhalt= [KNL,S390] Perform z/VM CP command after system halt. |
3175 | Format: <command> |
3176 | |
3177 | vmpanic= [KNL,S390] Perform z/VM CP command after kernel panic. |
3178 | Format: <command> |
3179 | |
3180 | vmpoff= [KNL,S390] Perform z/VM CP command after power off. |
3181 | Format: <command> |
3182 | |
3183 | vsyscall= [X86-64] |
3184 | Controls the behavior of vsyscalls (i.e. calls to |
3185 | fixed addresses of 0xffffffffff600x00 from legacy |
3186 | code). Most statically-linked binaries and older |
3187 | versions of glibc use these calls. Because these |
3188 | functions are at fixed addresses, they make nice |
3189 | targets for exploits that can control RIP. |
3190 | |
3191 | emulate [default] Vsyscalls turn into traps and are |
3192 | emulated reasonably safely. |
3193 | |
3194 | native Vsyscalls are native syscall instructions. |
3195 | This is a little bit faster than trapping |
3196 | and makes a few dynamic recompilers work |
3197 | better than they would in emulation mode. |
3198 | It also makes exploits much easier to write. |
3199 | |
3200 | none Vsyscalls don't work at all. This makes |
3201 | them quite hard to use for exploits but |
3202 | might break your system. |
3203 | |
3204 | vt.cur_default= [VT] Default cursor shape. |
3205 | Format: 0xCCBBAA, where AA, BB, and CC are the same as |
3206 | the parameters of the <Esc>[?A;B;Cc escape sequence; |
3207 | see VGA-softcursor.txt. Default: 2 = underline. |
3208 | |
3209 | vt.default_blu= [VT] |
3210 | Format: <blue0>,<blue1>,<blue2>,...,<blue15> |
3211 | Change the default blue palette of the console. |
3212 | This is a 16-member array composed of values |
3213 | ranging from 0-255. |
3214 | |
3215 | vt.default_grn= [VT] |
3216 | Format: <green0>,<green1>,<green2>,...,<green15> |
3217 | Change the default green palette of the console. |
3218 | This is a 16-member array composed of values |
3219 | ranging from 0-255. |
3220 | |
3221 | vt.default_red= [VT] |
3222 | Format: <red0>,<red1>,<red2>,...,<red15> |
3223 | Change the default red palette of the console. |
3224 | This is a 16-member array composed of values |
3225 | ranging from 0-255. |
3226 | |
3227 | vt.default_utf8= |
3228 | [VT] |
3229 | Format=<0|1> |
3230 | Set system-wide default UTF-8 mode for all tty's. |
3231 | Default is 1, i.e. UTF-8 mode is enabled for all |
3232 | newly opened terminals. |
3233 | |
3234 | vt.global_cursor_default= |
3235 | [VT] |
3236 | Format=<-1|0|1> |
3237 | Set system-wide default for whether a cursor |
3238 | is shown on new VTs. Default is -1, |
3239 | i.e. cursors will be created by default unless |
3240 | overridden by individual drivers. 0 will hide |
3241 | cursors, 1 will display them. |
3242 | |
3243 | watchdog timers [HW,WDT] For information on watchdog timers, |
3244 | see Documentation/watchdog/watchdog-parameters.txt |
3245 | or other driver-specific files in the |
3246 | Documentation/watchdog/ directory. |
3247 | |
3248 | x2apic_phys [X86-64,APIC] Use x2apic physical mode instead of |
3249 | default x2apic cluster mode on platforms |
3250 | supporting x2apic. |
3251 | |
3252 | x86_mrst_timer= [X86-32,APBT] |
3253 | Choose timer option for x86 Moorestown MID platform. |
3254 | Two valid options are apbt timer only and lapic timer |
3255 | plus one apbt timer for broadcast timer. |
3256 | x86_mrst_timer=apbt_only | lapic_and_apbt |
3257 | |
3258 | xd= [HW,XT] Original XT pre-IDE (RLL encoded) disks. |
3259 | xd_geo= See header of drivers/block/xd.c. |
3260 | |
3261 | xen_emul_unplug= [HW,X86,XEN] |
3262 | Unplug Xen emulated devices |
3263 | Format: [unplug0,][unplug1] |
3264 | ide-disks -- unplug primary master IDE devices |
3265 | aux-ide-disks -- unplug non-primary-master IDE devices |
3266 | nics -- unplug network devices |
3267 | all -- unplug all emulated devices (NICs and IDE disks) |
3268 | unnecessary -- unplugging emulated devices is |
3269 | unnecessary even if the host did not respond to |
3270 | the unplug protocol |
3271 | never -- do not unplug even if version check succeeds |
3272 | |
3273 | xirc2ps_cs= [NET,PCMCIA] |
3274 | Format: |
3275 | <irq>,<irq_mask>,<io>,<full_duplex>,<do_sound>,<lockup_hack>[,<irq2>[,<irq3>[,<irq4>]]] |
3276 | |
3277 | ______________________________________________________________________ |
3278 | |
3279 | TODO: |
3280 | |
3281 | Add more DRM drivers. |
3282 |
Branches:
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Tags:
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od-2011-09-18
v2.6.34-rc5
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