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Commit | Line | Data |
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e53dd083 MCC |
1 | Kernel Parameters |
2 | ~~~~~~~~~~~~~~~~~ | |
1da177e4 LT |
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 | ||
ca1eda2d RD |
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 | ||
a901ebb9 SR |
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 | ||
6585fa8a SR |
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: | |
1da177e4 LT |
37 | |
38 | ACPI ACPI support is enabled. | |
c99c108a | 39 | AGP AGP (Accelerated Graphics Port) is enabled. |
1da177e4 LT |
40 | ALSA ALSA sound support is enabled. |
41 | APIC APIC support is enabled. | |
42 | APM Advanced Power Management support is enabled. | |
e7ba176b | 43 | AVR32 AVR32 architecture is enabled. |
1da177e4 | 44 | AX25 Appropriate AX.25 support is enabled. |
0ae53640 | 45 | BLACKFIN Blackfin architecture is enabled. |
a9913044 | 46 | DRM Direct Rendering Management support is enabled. |
1da177e4 LT |
47 | EDD BIOS Enhanced Disk Drive Services (EDD) is enabled |
48 | EFI EFI Partitioning (GPT) is enabled | |
49 | EIDE EIDE/ATAPI support is enabled. | |
50 | FB The frame buffer device is enabled. | |
2521f2c2 | 51 | GCOV GCOV profiling is enabled. |
1da177e4 | 52 | HW Appropriate hardware is enabled. |
1da177e4 | 53 | IA-64 IA-64 architecture is enabled. |
6146f0d5 | 54 | IMA Integrity measurement architecture is enabled. |
1da177e4 | 55 | IOSCHED More than one I/O scheduler is enabled. |
41e2e8be | 56 | IP_PNP IP DHCP, BOOTP, or RARP is enabled. |
1da177e4 LT |
57 | ISAPNP ISA PnP code is enabled. |
58 | ISDN Appropriate ISDN support is enabled. | |
59 | JOY Appropriate joystick support is enabled. | |
fef07aae | 60 | KVM Kernel Virtual Machine support is enabled. |
11ef697b | 61 | LIBATA Libata driver is enabled |
1da177e4 LT |
62 | LP Printer support is enabled. |
63 | LOOP Loopback device support is enabled. | |
64 | M68k M68k architecture is enabled. | |
65 | These options have more detailed description inside of | |
66 | Documentation/m68k/kernel-options.txt. | |
67 | MCA MCA bus support is enabled. | |
68 | MDA MDA console support is enabled. | |
69 | MOUSE Appropriate mouse support is enabled. | |
309e57df | 70 | MSI Message Signaled Interrupts (PCI). |
c8facbb6 | 71 | MTD MTD (Memory Technology Device) support is enabled. |
1da177e4 LT |
72 | NET Appropriate network support is enabled. |
73 | NUMA NUMA support is enabled. | |
734efb46 | 74 | GENERIC_TIME The generic timeofday code is enabled. |
1da177e4 LT |
75 | NFS Appropriate NFS support is enabled. |
76 | OSS OSS sound support is enabled. | |
c8facbb6 RD |
77 | PV_OPS A paravirtualized kernel is enabled. |
78 | PARIDE The ParIDE (parallel port IDE) subsystem is enabled. | |
1da177e4 LT |
79 | PARISC The PA-RISC architecture is enabled. |
80 | PCI PCI bus support is enabled. | |
7f785763 | 81 | PCIE PCI Express support is enabled. |
1da177e4 LT |
82 | PCMCIA The PCMCIA subsystem is enabled. |
83 | PNP Plug & Play support is enabled. | |
84 | PPC PowerPC architecture is enabled. | |
85 | PPT Parallel port support is enabled. | |
86 | PS2 Appropriate PS/2 support is enabled. | |
87 | RAM RAM disk support is enabled. | |
20510f2f | 88 | ROOTPLUG The example Root Plug LSM is enabled. |
1da177e4 LT |
89 | S390 S390 architecture is enabled. |
90 | SCSI Appropriate SCSI support is enabled. | |
91 | A lot of drivers has their options described inside of | |
92 | Documentation/scsi/. | |
20510f2f | 93 | SECURITY Different security models are enabled. |
1da177e4 LT |
94 | SELINUX SELinux support is enabled. |
95 | SERIAL Serial support is enabled. | |
e523d93c | 96 | SH SuperH architecture is enabled. |
1da177e4 LT |
97 | SMP The kernel is an SMP kernel. |
98 | SPARC Sparc architecture is enabled. | |
77437fd4 DB |
99 | SWSUSP Software suspend (hibernation) is enabled. |
100 | SUSPEND System suspend states are enabled. | |
f38f1d2a | 101 | FTRACE Function tracing enabled. |
1da177e4 | 102 | TS Appropriate touchscreen support is enabled. |
d4f373e5 | 103 | UMS USB Mass Storage support is enabled. |
1da177e4 LT |
104 | USB USB support is enabled. |
105 | USBHID USB Human Interface Device support is enabled. | |
106 | V4L Video For Linux support is enabled. | |
107 | VGA The VGA console has been enabled. | |
108 | VT Virtual terminal support is enabled. | |
109 | WDT Watchdog support is enabled. | |
110 | XT IBM PC/XT MFM hard disk support is enabled. | |
cd4f0ef7 | 111 | X86-32 X86-32, aka i386 architecture is enabled. |
1da177e4 LT |
112 | X86-64 X86-64 architecture is enabled. |
113 | More X86-64 boot options can be found in | |
71cced6e | 114 | Documentation/x86/x86_64/boot-options.txt . |
c0115606 | 115 | X86 Either 32bit or 64bit x86 (same as X86-32+X86-64) |
1da177e4 LT |
116 | |
117 | In addition, the following text indicates that the option: | |
118 | ||
119 | BUGS= Relates to possible processor bugs on the said processor. | |
120 | KNL Is a kernel start-up parameter. | |
121 | BOOT Is a boot loader parameter. | |
122 | ||
123 | Parameters denoted with BOOT are actually interpreted by the boot | |
124 | loader, and have no meaning to the kernel directly. | |
125 | Do not modify the syntax of boot loader parameters without extreme | |
954a8b81 | 126 | need or coordination with <Documentation/x86/boot.txt>. |
1da177e4 | 127 | |
5558870b | 128 | There are also arch-specific kernel-parameters not documented here. |
71cced6e | 129 | See for example <Documentation/x86/x86_64/boot-options.txt>. |
5558870b | 130 | |
1da177e4 LT |
131 | Note that ALL kernel parameters listed below are CASE SENSITIVE, and that |
132 | a trailing = on the name of any parameter states that that parameter will | |
133 | be entered as an environment variable, whereas its absence indicates that | |
134 | it will appear as a kernel argument readable via /proc/cmdline by programs | |
135 | running once the system is up. | |
136 | ||
9c4751fd | 137 | The number of kernel parameters is not limited, but the length of the |
138 | complete command line (parameters including spaces etc.) is limited to | |
139 | a fixed number of characters. This limit depends on the architecture | |
140 | and is between 256 and 4096 characters. It is defined in the file | |
141 | ./include/asm/setup.h as COMMAND_LINE_SIZE. | |
142 | ||
143 | ||
6cececfc | 144 | acpi= [HW,ACPI,X86] |
03d926f8 | 145 | Advanced Configuration and Power Interface |
af23f573 | 146 | Format: { force | off | ht | strict | noirq | rsdt } |
1da177e4 LT |
147 | force -- enable ACPI if default was off |
148 | off -- disable ACPI if default was on | |
149 | noirq -- do not use ACPI for IRQ routing | |
150 | ht -- run only enough ACPI to enable Hyper Threading | |
a9913044 | 151 | strict -- Be less tolerant of platforms that are not |
1da177e4 | 152 | strictly ACPI specification compliant. |
237889bf | 153 | rsdt -- prefer RSDT over (default) XSDT |
1da177e4 | 154 | |
53471121 | 155 | See also Documentation/power/pm.txt, pci=noacpi |
1da177e4 | 156 | |
a1fdcc0d LB |
157 | acpi_apic_instance= [ACPI, IOAPIC] |
158 | Format: <int> | |
159 | 2: use 2nd APIC table, if available | |
160 | 1,0: use 1st APIC table | |
4e381a4f | 161 | default: 0 |
a1fdcc0d | 162 | |
c3d6de69 TR |
163 | acpi_backlight= [HW,ACPI] |
164 | acpi_backlight=vendor | |
165 | acpi_backlight=video | |
166 | If set to vendor, prefer vendor specific driver | |
167 | (e.g. thinkpad_acpi, sony_acpi, etc.) instead | |
168 | of the ACPI video.ko driver. | |
169 | ||
a0d84a92 BH |
170 | acpi.debug_layer= [HW,ACPI,ACPI_DEBUG] |
171 | acpi.debug_level= [HW,ACPI,ACPI_DEBUG] | |
1da177e4 | 172 | Format: <int> |
a0d84a92 BH |
173 | CONFIG_ACPI_DEBUG must be enabled to produce any ACPI |
174 | debug output. Bits in debug_layer correspond to a | |
175 | _COMPONENT in an ACPI source file, e.g., | |
176 | #define _COMPONENT ACPI_PCI_COMPONENT | |
177 | Bits in debug_level correspond to a level in | |
178 | ACPI_DEBUG_PRINT statements, e.g., | |
179 | ACPI_DEBUG_PRINT((ACPI_DB_INFO, ... | |
e76f4276 BH |
180 | The debug_level mask defaults to "info". See |
181 | Documentation/acpi/debug.txt for more information about | |
182 | debug layers and levels. | |
a0d84a92 | 183 | |
e76f4276 BH |
184 | Enable processor driver info messages: |
185 | acpi.debug_layer=0x20000000 | |
186 | Enable PCI/PCI interrupt routing info messages: | |
187 | acpi.debug_layer=0x400000 | |
a0d84a92 BH |
188 | Enable AML "Debug" output, i.e., stores to the Debug |
189 | object while interpreting AML: | |
190 | acpi.debug_layer=0xffffffff acpi.debug_level=0x2 | |
a0d84a92 BH |
191 | Enable all messages related to ACPI hardware: |
192 | acpi.debug_layer=0x2 acpi.debug_level=0xffffffff | |
193 | ||
194 | Some values produce so much output that the system is | |
195 | unusable. The "log_buf_len" parameter may be useful | |
196 | if you need to capture more output. | |
f989106c | 197 | |
0cb55ad2 RD |
198 | acpi_display_output= [HW,ACPI] |
199 | acpi_display_output=vendor | |
200 | acpi_display_output=video | |
201 | See above. | |
202 | ||
203 | acpi_irq_balance [HW,ACPI] | |
204 | ACPI will balance active IRQs | |
205 | default in APIC mode | |
206 | ||
207 | acpi_irq_nobalance [HW,ACPI] | |
208 | ACPI will not move active IRQs (default) | |
209 | default in PIC mode | |
210 | ||
211 | acpi_irq_isa= [HW,ACPI] If irq_balance, mark listed IRQs used by ISA | |
212 | Format: <irq>,<irq>... | |
213 | ||
214 | acpi_irq_pci= [HW,ACPI] If irq_balance, clear listed IRQs for | |
215 | use by PCI | |
216 | Format: <irq>,<irq>... | |
217 | ||
218 | acpi_no_auto_ssdt [HW,ACPI] Disable automatic loading of SSDT | |
219 | ||
220 | acpi_os_name= [HW,ACPI] Tell ACPI BIOS the name of the OS | |
221 | Format: To spoof as Windows 98: ="Microsoft Windows" | |
222 | ||
223 | acpi_osi= [HW,ACPI] Modify list of supported OS interface strings | |
224 | acpi_osi="string1" # add string1 -- only one string | |
225 | acpi_osi="!string2" # remove built-in string2 | |
226 | acpi_osi= # disable all strings | |
227 | ||
6cececfc | 228 | acpi_pm_good [X86] |
0cb55ad2 RD |
229 | Override the pmtimer bug detection: force the kernel |
230 | to assume that this machine's pmtimer latches its value | |
231 | and always returns good values. | |
232 | ||
4af94f39 RD |
233 | acpi_sci= [HW,ACPI] ACPI System Control Interrupt trigger mode |
234 | Format: { level | edge | high | low } | |
235 | ||
236 | acpi_serialize [HW,ACPI] force serialization of AML methods | |
237 | ||
238 | acpi_skip_timer_override [HW,ACPI] | |
239 | Recognize and ignore IRQ0/pin2 Interrupt Override. | |
240 | For broken nForce2 BIOS resulting in XT-PIC timer. | |
241 | ||
242 | acpi_sleep= [HW,ACPI] Sleep options | |
243 | Format: { s3_bios, s3_mode, s3_beep, s4_nohwsig, | |
244 | old_ordering, s4_nonvs } | |
245 | See Documentation/power/video.txt for information on | |
246 | s3_bios and s3_mode. | |
247 | s3_beep is for debugging; it makes the PC's speaker beep | |
248 | as soon as the kernel's real-mode entry point is called. | |
249 | s4_nohwsig prevents ACPI hardware signature from being | |
250 | used during resume from hibernation. | |
251 | old_ordering causes the ACPI 1.0 ordering of the _PTS | |
252 | control method, with respect to putting devices into | |
253 | low power states, to be enforced (the ACPI 2.0 ordering | |
254 | of _PTS is used by default). | |
255 | s4_nonvs prevents the kernel from saving/restoring the | |
256 | ACPI NVS memory during hibernation. | |
257 | ||
258 | acpi_use_timer_override [HW,ACPI] | |
259 | Use timer override. For some broken Nvidia NF5 boards | |
260 | that require a timer override, but don't have HPET | |
261 | ||
7e90560c LT |
262 | acpi_enforce_resources= [ACPI] |
263 | { strict | lax | no } | |
264 | Check for resource conflicts between native drivers | |
265 | and ACPI OperationRegions (SystemIO and SystemMemory | |
266 | only). IO ports and memory declared in ACPI might be | |
267 | used by the ACPI subsystem in arbitrary AML code and | |
268 | can interfere with legacy drivers. | |
269 | strict (default): access to resources claimed by ACPI | |
270 | is denied; legacy drivers trying to access reserved | |
271 | resources will fail to bind to device using them. | |
272 | lax: access to resources claimed by ACPI is allowed; | |
273 | legacy drivers trying to access reserved resources | |
274 | will bind successfully but a warning message is logged. | |
275 | no: ACPI OperationRegions are not marked as reserved, | |
276 | no further checks are performed. | |
277 | ||
1da177e4 LT |
278 | ad1848= [HW,OSS] |
279 | Format: <io>,<irq>,<dma>,<dma2>,<type> | |
280 | ||
4af94f39 RD |
281 | add_efi_memmap [EFI; X86] Include EFI memory map in |
282 | kernel's map of available physical RAM. | |
283 | ||
1da177e4 LT |
284 | advansys= [HW,SCSI] |
285 | See header of drivers/scsi/advansys.c. | |
286 | ||
287 | advwdt= [HW,WDT] Advantech WDT | |
288 | Format: <iostart>,<iostop> | |
289 | ||
290 | aedsp16= [HW,OSS] Audio Excel DSP 16 | |
291 | Format: <io>,<irq>,<dma>,<mss_io>,<mpu_io>,<mpu_irq> | |
292 | See also header of sound/oss/aedsp16.c. | |
a9913044 | 293 | |
0cb55ad2 RD |
294 | agp= [AGP] |
295 | { off | try_unsupported } | |
296 | off: disable AGP support | |
297 | try_unsupported: try to drive unsupported chipsets | |
298 | (may crash computer or cause data corruption) | |
299 | ||
1da177e4 LT |
300 | aha152x= [HW,SCSI] |
301 | See Documentation/scsi/aha152x.txt. | |
302 | ||
303 | aha1542= [HW,SCSI] | |
304 | Format: <portbase>[,<buson>,<busoff>[,<dmaspeed>]] | |
305 | ||
306 | aic7xxx= [HW,SCSI] | |
307 | See Documentation/scsi/aic7xxx.txt. | |
308 | ||
309 | aic79xx= [HW,SCSI] | |
310 | See Documentation/scsi/aic79xx.txt. | |
311 | ||
54b4cbd2 JR |
312 | amd_iommu= [HW,X86-84] |
313 | Pass parameters to the AMD IOMMU driver in the system. | |
314 | Possible values are: | |
54b4cbd2 JR |
315 | isolate - enable device isolation (each device, as far |
316 | as possible, will get its own protection | |
3ce1f93c | 317 | domain) [default] |
e5e1f606 JR |
318 | share - put every device behind one IOMMU into the |
319 | same protection domain | |
afa9fdc2 FT |
320 | fullflush - enable flushing of IO/TLB entries when |
321 | they are unmapped. Otherwise they are | |
322 | flushed before they will be reused, which | |
323 | is a lot of faster | |
324 | ||
1da177e4 LT |
325 | amijoy.map= [HW,JOY] Amiga joystick support |
326 | Map of devices attached to JOY0DAT and JOY1DAT | |
327 | Format: <a>,<b> | |
328 | See also Documentation/kernel/input/joystick.txt | |
329 | ||
330 | analog.map= [HW,JOY] Analog joystick and gamepad support | |
331 | Specifies type or capabilities of an analog joystick | |
332 | connected to one of 16 gameports | |
333 | Format: <type1>,<type2>,..<type16> | |
334 | ||
a9913044 RD |
335 | apc= [HW,SPARC] |
336 | Power management functions (SPARCstation-4/5 + deriv.) | |
1da177e4 LT |
337 | Format: noidle |
338 | Disable APC CPU standby support. SPARCstation-Fox does | |
339 | not play well with APC CPU idle - disable it if you have | |
340 | APC and your system crashes randomly. | |
341 | ||
ca1eda2d | 342 | apic= [APIC,X86-32] Advanced Programmable Interrupt Controller |
c8facbb6 | 343 | Change the output verbosity whilst booting |
1da177e4 LT |
344 | Format: { quiet (default) | verbose | debug } |
345 | Change the amount of debugging information output | |
346 | when initialising the APIC and IO-APIC components. | |
a9913044 | 347 | |
1da177e4 | 348 | apm= [APM] Advanced Power Management |
71f77055 | 349 | See header of arch/x86/kernel/apm_32.c. |
1da177e4 | 350 | |
1da177e4 LT |
351 | arcrimi= [HW,NET] ARCnet - "RIM I" (entirely mem-mapped) cards |
352 | Format: <io>,<irq>,<nodeID> | |
353 | ||
354 | ataflop= [HW,M68k] | |
355 | ||
356 | atarimouse= [HW,MOUSE] Atari Mouse | |
357 | ||
358 | atascsi= [HW,SCSI] Atari SCSI | |
359 | ||
360 | atkbd.extra= [HW] Enable extra LEDs and keys on IBM RapidAccess, | |
361 | EzKey and similar keyboards | |
362 | ||
363 | atkbd.reset= [HW] Reset keyboard during initialization | |
364 | ||
a9913044 RD |
365 | atkbd.set= [HW] Select keyboard code set |
366 | Format: <int> (2 = AT (default), 3 = PS/2) | |
1da177e4 LT |
367 | |
368 | atkbd.scroll= [HW] Enable scroll wheel on MS Office and similar | |
369 | keyboards | |
370 | ||
371 | atkbd.softraw= [HW] Choose between synthetic and real raw mode | |
372 | Format: <bool> (0 = real, 1 = synthetic (default)) | |
a9913044 RD |
373 | |
374 | atkbd.softrepeat= [HW] | |
375 | Use software keyboard repeat | |
1da177e4 LT |
376 | |
377 | autotest [IA64] | |
378 | ||
1da177e4 LT |
379 | baycom_epp= [HW,AX25] |
380 | Format: <io>,<mode> | |
a9913044 | 381 | |
1da177e4 LT |
382 | baycom_par= [HW,AX25] BayCom Parallel Port AX.25 Modem |
383 | Format: <io>,<mode> | |
384 | See header of drivers/net/hamradio/baycom_par.c. | |
385 | ||
a9913044 RD |
386 | baycom_ser_fdx= [HW,AX25] |
387 | BayCom Serial Port AX.25 Modem (Full Duplex Mode) | |
1da177e4 LT |
388 | Format: <io>,<irq>,<mode>[,<baud>] |
389 | See header of drivers/net/hamradio/baycom_ser_fdx.c. | |
390 | ||
a9913044 RD |
391 | baycom_ser_hdx= [HW,AX25] |
392 | BayCom Serial Port AX.25 Modem (Half Duplex Mode) | |
1da177e4 LT |
393 | Format: <io>,<irq>,<mode> |
394 | See header of drivers/net/hamradio/baycom_ser_hdx.c. | |
395 | ||
bfe8df3d RD |
396 | boot_delay= Milliseconds to delay each printk during boot. |
397 | Values larger than 10 seconds (10000) are changed to | |
398 | no delay (0). | |
399 | Format: integer | |
400 | ||
35fc908d AH |
401 | bootmem_debug [KNL] Enable bootmem allocator debug messages. |
402 | ||
1da177e4 | 403 | bttv.card= [HW,V4L] bttv (bt848 + bt878 based grabber cards) |
a9913044 RD |
404 | bttv.radio= Most important insmod options are available as |
405 | kernel args too. | |
1da177e4 LT |
406 | bttv.pll= See Documentation/video4linux/bttv/Insmod-options |
407 | bttv.tuner= and Documentation/video4linux/bttv/CARDLIST | |
408 | ||
409 | BusLogic= [HW,SCSI] | |
410 | See drivers/scsi/BusLogic.c, comment before function | |
411 | BusLogic_ParseDriverOptions(). | |
412 | ||
413 | c101= [NET] Moxa C101 synchronous serial card | |
414 | ||
cd4f0ef7 | 415 | cachesize= [BUGS=X86-32] Override level 2 CPU cache size detection. |
1da177e4 LT |
416 | Sometimes CPU hardware bugs make them report the cache |
417 | size incorrectly. The kernel will attempt work arounds | |
418 | to fix known problems, but for some CPUs it is not | |
419 | possible to determine what the correct size should be. | |
420 | This option provides an override for these situations. | |
421 | ||
20510f2f JM |
422 | capability.disable= |
423 | [SECURITY] Disable capabilities. This would normally | |
424 | be used only if an alternative security model is to be | |
425 | configured. Potentially dangerous and should only be | |
426 | used if you are entirely sure of the consequences. | |
427 | ||
14ff56bb SO |
428 | ccw_timeout_log [S390] |
429 | See Documentation/s390/CommonIO for details. | |
1da177e4 | 430 | |
8bab8dde PM |
431 | cgroup_disable= [KNL] Disable a particular controller |
432 | Format: {name of the controller(s) to disable} | |
433 | {Currently supported controllers - "memory"} | |
434 | ||
1da177e4 LT |
435 | checkreqprot [SELINUX] Set initial checkreqprot flag value. |
436 | Format: { "0" | "1" } | |
437 | See security/selinux/Kconfig help text. | |
a9913044 RD |
438 | 0 -- check protection applied by kernel (includes |
439 | any implied execute protection). | |
1da177e4 LT |
440 | 1 -- check protection requested by application. |
441 | Default value is set via a kernel config option. | |
a9913044 RD |
442 | Value can be changed at runtime via |
443 | /selinux/checkreqprot. | |
444 | ||
661ca0da SO |
445 | cio_ignore= [S390] |
446 | See Documentation/s390/CommonIO for details. | |
447 | ||
cd4f0ef7 | 448 | clock= [BUGS=X86-32, HW] gettimeofday clocksource override. |
734efb46 | 449 | [Deprecated] |
3f6dee9b | 450 | Forces specified clocksource (if available) to be used |
734efb46 | 451 | when calculating gettimeofday(). If specified |
3f6dee9b | 452 | clocksource is not available, it defaults to PIT. |
1da177e4 LT |
453 | Format: { pit | tsc | cyclone | pmtmr } |
454 | ||
3d6ac984 RD |
455 | clocksource= [GENERIC_TIME] Override the default clocksource |
456 | Format: <string> | |
457 | Override the default clocksource and use the clocksource | |
458 | with the name specified. | |
459 | Some clocksource names to choose from, depending on | |
460 | the platform: | |
461 | [all] jiffies (this is the base, fallback clocksource) | |
462 | [ACPI] acpi_pm | |
463 | [ARM] imx_timer1,OSTS,netx_timer,mpu_timer2, | |
464 | pxa_timer,timer3,32k_counter,timer0_1 | |
465 | [AVR32] avr32 | |
cd4f0ef7 | 466 | [X86-32] pit,hpet,tsc,vmi-timer; |
3d6ac984 RD |
467 | scx200_hrt on Geode; cyclone on IBM x440 |
468 | [MIPS] MIPS | |
469 | [PARISC] cr16 | |
470 | [S390] tod | |
471 | [SH] SuperH | |
472 | [SPARC64] tick | |
473 | [X86-64] hpet,tsc | |
474 | ||
ac72e788 AK |
475 | clearcpuid=BITNUM [X86] |
476 | Disable CPUID feature X for the kernel. See | |
07983f0e RD |
477 | arch/x86/include/asm/cpufeature.h for the valid bit |
478 | numbers. Note the Linux specific bits are not necessarily | |
ac72e788 AK |
479 | stable over kernel options, but the vendor specific |
480 | ones should be. | |
481 | Also note that user programs calling CPUID directly | |
482 | or using the feature without checking anything | |
483 | will still see it. This just prevents it from | |
484 | being used by the kernel or shown in /proc/cpuinfo. | |
485 | Also note the kernel might malfunction if you disable | |
486 | some critical bits. | |
487 | ||
14f966e7 RJ |
488 | cmo_free_hint= [PPC] Format: { yes | no } |
489 | Specify whether pages are marked as being inactive | |
490 | when they are freed. This is used in CMO environments | |
491 | to determine OS memory pressure for page stealing by | |
492 | a hypervisor. | |
493 | Default: yes | |
494 | ||
6cececfc | 495 | code_bytes [X86] How many bytes of object code to print |
a25bd949 | 496 | in an oops report. |
86c41837 CE |
497 | Range: 0 - 8192 |
498 | Default: 64 | |
499 | ||
1da177e4 | 500 | com20020= [HW,NET] ARCnet - COM20020 chipset |
a9913044 RD |
501 | Format: |
502 | <io>[,<irq>[,<nodeID>[,<backplane>[,<ckp>[,<timeout>]]]]] | |
1da177e4 LT |
503 | |
504 | com90io= [HW,NET] ARCnet - COM90xx chipset (IO-mapped buffers) | |
505 | Format: <io>[,<irq>] | |
506 | ||
a9913044 RD |
507 | com90xx= [HW,NET] |
508 | ARCnet - COM90xx chipset (memory-mapped buffers) | |
1da177e4 LT |
509 | Format: <io>[,<irq>[,<memstart>]] |
510 | ||
511 | condev= [HW,S390] console device | |
512 | conmode= | |
a9913044 | 513 | |
1da177e4 LT |
514 | console= [KNL] Output console device and options. |
515 | ||
516 | tty<n> Use the virtual console device <n>. | |
517 | ||
518 | ttyS<n>[,options] | |
f1a1c2dc | 519 | ttyUSB0[,options] |
1da177e4 | 520 | Use the specified serial port. The options are of |
f1a1c2dc RD |
521 | the form "bbbbpnf", where "bbbb" is the baud rate, |
522 | "p" is parity ("n", "o", or "e"), "n" is number of | |
523 | bits, and "f" is flow control ("r" for RTS or | |
524 | omit it). Default is "9600n8". | |
525 | ||
526 | See Documentation/serial-console.txt for more | |
527 | information. See | |
528 | Documentation/networking/netconsole.txt for an | |
529 | alternative. | |
1da177e4 | 530 | |
18a8bd94 YL |
531 | uart[8250],io,<addr>[,options] |
532 | uart[8250],mmio,<addr>[,options] | |
1da177e4 LT |
533 | Start an early, polled-mode console on the 8250/16550 |
534 | UART at the specified I/O port or MMIO address, | |
535 | switching to the matching ttyS device later. The | |
536 | options are the same as for ttyS, above. | |
537 | ||
f7511d5f ST |
538 | If the device connected to the port is not a TTY but a braille |
539 | device, prepend "brl," before the device type, for instance | |
540 | console=brl,ttyS0 | |
541 | For now, only VisioBraille is supported. | |
542 | ||
f324edc8 DM |
543 | consoleblank= [KNL] The console blank (screen saver) timeout in |
544 | seconds. Defaults to 10*60 = 10mins. A value of 0 | |
545 | disables the blank timer. | |
546 | ||
4cb0e11b HK |
547 | coredump_filter= |
548 | [KNL] Change the default value for | |
549 | /proc/<pid>/coredump_filter. | |
550 | See also Documentation/filesystems/proc.txt. | |
551 | ||
1da177e4 | 552 | cpcihp_generic= [HW,PCI] Generic port I/O CompactPCI driver |
a9913044 RD |
553 | Format: |
554 | <first_slot>,<last_slot>,<port>,<enum_bit>[,<debug>] | |
1da177e4 | 555 | |
dc009d92 EB |
556 | crashkernel=nn[KMG]@ss[KMG] |
557 | [KNL] Reserve a chunk of physical memory to | |
558 | hold a kernel to switch to with kexec on panic. | |
559 | ||
fb391599 BW |
560 | crashkernel=range1:size1[,range2:size2,...][@offset] |
561 | [KNL] Same as above, but depends on the memory | |
562 | in the running system. The syntax of range is | |
563 | start-[end] where start and end are both | |
564 | a memory unit (amount[KMG]). See also | |
565 | Documentation/kdump/kdump.txt for a example. | |
566 | ||
1da177e4 LT |
567 | cs89x0_dma= [HW,NET] |
568 | Format: <dma> | |
569 | ||
570 | cs89x0_media= [HW,NET] | |
571 | Format: { rj45 | aui | bnc } | |
a9913044 | 572 | |
a9913044 | 573 | dasd= [HW,NET] |
1da177e4 LT |
574 | See header of drivers/s390/block/dasd_devmap.c. |
575 | ||
576 | db9.dev[2|3]= [HW,JOY] Multisystem joystick support via parallel port | |
577 | (one device per port) | |
578 | Format: <port#>,<type> | |
579 | See also Documentation/input/joystick-parport.txt | |
580 | ||
581 | debug [KNL] Enable kernel debugging (events log level). | |
582 | ||
cae2ed9a IM |
583 | debug_locks_verbose= |
584 | [KNL] verbose self-tests | |
585 | Format=<0|1> | |
586 | Print debugging info while doing the locking API | |
587 | self-tests. | |
588 | We default to 0 (no extra messages), setting it to | |
589 | 1 will print _a lot_ more information - normally | |
590 | only useful to kernel developers. | |
591 | ||
3ac7fe5a TG |
592 | debug_objects [KNL] Enable object debugging |
593 | ||
3e8ebb5c KM |
594 | no_debug_objects |
595 | [KNL] Disable object debugging | |
596 | ||
d3af01f1 TG |
597 | debugpat [X86] Enable PAT debugging |
598 | ||
2d27a966 | 599 | decnet.addr= [HW,NET] |
1da177e4 LT |
600 | Format: <area>[,<node>] |
601 | See also Documentation/networking/decnet.txt. | |
602 | ||
0cb55ad2 RD |
603 | default_hugepagesz= |
604 | [same as hugepagesz=] The size of the default | |
605 | HugeTLB page size. This is the size represented by | |
606 | the legacy /proc/ hugepages APIs, used for SHM, and | |
607 | default size when mounting hugetlbfs filesystems. | |
608 | Defaults to the default architecture's huge page size | |
609 | if not specified. | |
55ff9780 | 610 | |
1da177e4 LT |
611 | dhash_entries= [KNL] |
612 | Set number of hash buckets for dentry cache. | |
a9913044 | 613 | |
1da177e4 LT |
614 | digi= [HW,SERIAL] |
615 | IO parameters + enable/disable command. | |
616 | ||
617 | digiepca= [HW,SERIAL] | |
618 | See drivers/char/README.epca and | |
31c00fc1 | 619 | Documentation/serial/digiepca.txt. |
1da177e4 | 620 | |
95ffa243 | 621 | disable_mtrr_cleanup [X86] |
95ffa243 YL |
622 | The kernel tries to adjust MTRR layout from continuous |
623 | to discrete, to make X server driver able to add WB | |
0cb55ad2 | 624 | entry later. This parameter disables that. |
95ffa243 | 625 | |
093af8d7 | 626 | disable_mtrr_trim [X86, Intel and AMD only] |
99fc8d42 JB |
627 | By default the kernel will trim any uncacheable |
628 | memory out of your available memory pool based on | |
629 | MTRR settings. This parameter disables that behavior, | |
630 | possibly causing your machine to run very slowly. | |
631 | ||
6cececfc | 632 | disable_timer_pin_1 [X86] |
0cb55ad2 RD |
633 | Disable PIN 1 of APIC timer |
634 | Can be useful to work around chipset bugs. | |
635 | ||
1da177e4 LT |
636 | dmasound= [HW,OSS] Sound subsystem buffers |
637 | ||
0cb55ad2 RD |
638 | dma_debug=off If the kernel is compiled with DMA_API_DEBUG support, |
639 | this option disables the debugging code at boot. | |
640 | ||
641 | dma_debug_entries=<number> | |
642 | This option allows to tune the number of preallocated | |
643 | entries for DMA-API debugging code. One entry is | |
644 | required per DMA-API allocation. Use this if the | |
645 | DMA-API debugging code disables itself because the | |
646 | architectural default is too low. | |
647 | ||
1745de5e JR |
648 | dma_debug_driver=<driver_name> |
649 | With this option the DMA-API debugging driver | |
650 | filter feature can be enabled at boot time. Just | |
651 | pass the driver to filter for as the parameter. | |
652 | The filter can be disabled or changed to another | |
653 | driver later using sysfs. | |
654 | ||
1da177e4 LT |
655 | dscc4.setup= [NET] |
656 | ||
657 | dtc3181e= [HW,SCSI] | |
658 | ||
0cb55ad2 RD |
659 | dynamic_printk Enables pr_debug()/dev_dbg() calls if |
660 | CONFIG_DYNAMIC_PRINTK_DEBUG has been enabled. | |
661 | These can also be switched on/off via | |
662 | <debugfs>/dynamic_printk/modules | |
663 | ||
664 | earlycon= [KNL] Output early console device and options. | |
665 | uart[8250],io,<addr>[,options] | |
666 | uart[8250],mmio,<addr>[,options] | |
667 | Start an early, polled-mode console on the 8250/16550 | |
668 | UART at the specified I/O port or MMIO address. | |
669 | The options are the same as for ttyS, above. | |
670 | ||
6cececfc | 671 | earlyprintk= [X86,SH,BLACKFIN] |
1da177e4 LT |
672 | earlyprintk=vga |
673 | earlyprintk=serial[,ttySn[,baudrate]] | |
ea3acb19 | 674 | earlyprintk=ttySn[,baudrate] |
9780bc41 | 675 | earlyprintk=dbgp[debugController#] |
1da177e4 | 676 | |
a9913044 | 677 | Append ",keep" to not disable it when the real console |
1da177e4 LT |
678 | takes over. |
679 | ||
5c05917e | 680 | Only vga or serial or usb debug port at a time. |
1da177e4 LT |
681 | |
682 | Currently only ttyS0 and ttyS1 are supported. | |
683 | ||
684 | Interaction with the standard serial driver is not | |
685 | very good. | |
686 | ||
687 | The VGA output is eventually overwritten by the real | |
688 | console. | |
689 | ||
690 | eata= [HW,SCSI] | |
691 | ||
1da177e4 | 692 | edd= [EDD] |
8c4dd606 | 693 | Format: {"off" | "on" | "skip[mbr]"} |
1da177e4 | 694 | |
1da177e4 LT |
695 | eisa_irq_edge= [PARISC,HW] |
696 | See header of drivers/parisc/eisa.c. | |
697 | ||
cd4f0ef7 | 698 | elanfreq= [X86-32] |
1da177e4 | 699 | See comment before function elanfreq_setup() in |
71f77055 | 700 | arch/x86/kernel/cpu/cpufreq/elanfreq.c. |
1da177e4 LT |
701 | |
702 | elevator= [IOSCHED] | |
16ab3adf | 703 | Format: {"anticipatory" | "cfq" | "deadline" | "noop"} |
a9913044 RD |
704 | See Documentation/block/as-iosched.txt and |
705 | Documentation/block/deadline-iosched.txt for details. | |
706 | ||
6cececfc | 707 | elfcorehdr= [IA64,PPC,SH,X86] |
a9913044 | 708 | Specifies physical address of start of kernel core |
aac04b32 VG |
709 | image elf header. Generally kexec loader will |
710 | pass this option to capture kernel. | |
711 | See Documentation/kdump/kdump.txt for details. | |
1da177e4 | 712 | |
0cb55ad2 RD |
713 | enable_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 enables that. | |
717 | ||
ca1eda2d | 718 | enable_timer_pin_1 [X86] |
0cb55ad2 RD |
719 | Enable PIN 1 of APIC timer |
720 | Can be useful to work around chipset bugs | |
721 | (in particular on some ATI chipsets). | |
722 | The kernel tries to set a reasonable default. | |
723 | ||
1da177e4 LT |
724 | enforcing [SELINUX] Set initial enforcing status. |
725 | Format: {"0" | "1"} | |
726 | See security/selinux/Kconfig help text. | |
727 | 0 -- permissive (log only, no denials). | |
728 | 1 -- enforcing (deny and log). | |
729 | Default value is 0. | |
730 | Value can be changed at runtime via /selinux/enforce. | |
731 | ||
1da177e4 LT |
732 | ether= [HW,NET] Ethernet cards parameters |
733 | This option is obsoleted by the "netdev=" option, which | |
734 | has equivalent usage. See its documentation for details. | |
735 | ||
736 | eurwdt= [HW,WDT] Eurotech CPU-1220/1410 onboard watchdog. | |
737 | Format: <io>[,<irq>] | |
738 | ||
de1ba09b AM |
739 | failslab= |
740 | fail_page_alloc= | |
741 | fail_make_request=[KNL] | |
742 | General fault injection mechanism. | |
743 | Format: <interval>,<probability>,<space>,<times> | |
744 | See also /Documentation/fault-injection/. | |
745 | ||
1da177e4 LT |
746 | fd_mcs= [HW,SCSI] |
747 | See header of drivers/scsi/fd_mcs.c. | |
748 | ||
749 | fdomain= [HW,SCSI] | |
750 | See header of drivers/scsi/fdomain.c. | |
751 | ||
752 | floppy= [HW] | |
31c00fc1 | 753 | See Documentation/blockdev/floppy.txt. |
1da177e4 | 754 | |
f13ae30e AC |
755 | force_pal_cache_flush |
756 | [IA-64] Avoid check_sal_cache_flush which may hang on | |
757 | buggy SAL_CACHE_FLUSH implementations. Using this | |
758 | parameter will force ia64_sal_cache_flush to call | |
759 | ia64_pal_cache_flush instead of SAL_CACHE_FLUSH. | |
760 | ||
d9e54076 | 761 | ftrace=[tracer] |
2af15d6a | 762 | [FTRACE] will set and start the specified tracer |
d9e54076 PZ |
763 | as early as possible in order to facilitate early |
764 | boot debugging. | |
765 | ||
766 | ftrace_dump_on_oops | |
2af15d6a SR |
767 | [FTRACE] will dump the trace buffers on oops. |
768 | ||
769 | ftrace_filter=[function-list] | |
770 | [FTRACE] Limit the functions traced by the function | |
771 | tracer at boot up. function-list is a comma separated | |
772 | list of functions. This list can be changed at run | |
773 | time by the set_ftrace_filter file in the debugfs | |
774 | tracing directory. | |
775 | ||
776 | ftrace_notrace=[function-list] | |
777 | [FTRACE] Do not trace the functions specified in | |
778 | function-list. This list can be changed at run time | |
779 | by the set_ftrace_notrace file in the debugfs | |
780 | tracing directory. | |
d9e54076 | 781 | |
1da177e4 LT |
782 | gamecon.map[2|3]= |
783 | [HW,JOY] Multisystem joystick and NES/SNES/PSX pad | |
784 | support via parallel port (up to 5 devices per port) | |
785 | Format: <port#>,<pad1>,<pad2>,<pad3>,<pad4>,<pad5> | |
786 | See also Documentation/input/joystick-parport.txt | |
787 | ||
788 | gamma= [HW,DRM] | |
789 | ||
aaf23042 YL |
790 | gart_fix_e820= [X86_64] disable the fix e820 for K8 GART |
791 | Format: off | on | |
792 | default: on | |
793 | ||
2521f2c2 PO |
794 | gcov_persist= [GCOV] When non-zero (default), profiling data for |
795 | kernel modules is saved and remains accessible via | |
796 | debugfs, even when the module is unloaded/reloaded. | |
797 | When zero, profiling data is discarded and associated | |
798 | debugfs files are removed at module unload time. | |
799 | ||
1da177e4 LT |
800 | gdth= [HW,SCSI] |
801 | See header of drivers/scsi/gdth.c. | |
802 | ||
803 | gpt [EFI] Forces disk with valid GPT signature but | |
804 | invalid Protective MBR to be treated as GPT. | |
805 | ||
1da177e4 LT |
806 | gvp11= [HW,SCSI] |
807 | ||
808 | hashdist= [KNL,NUMA] Large hashes allocated during boot | |
809 | are distributed across NUMA nodes. Defaults on | |
429aa0fc | 810 | for 64bit NUMA, off otherwise. |
a9913044 | 811 | Format: 0 | 1 (for off | on) |
1da177e4 LT |
812 | |
813 | hcl= [IA-64] SGI's Hardware Graph compatibility layer | |
814 | ||
815 | hd= [EIDE] (E)IDE hard drive subsystem geometry | |
816 | Format: <cyl>,<head>,<sect> | |
817 | ||
1da177e4 LT |
818 | highmem=nn[KMG] [KNL,BOOT] forces the highmem zone to have an exact |
819 | size of <nn>. This works even on boxes that have no | |
820 | highmem otherwise. This also works to reduce highmem | |
821 | size on bigger boxes. | |
822 | ||
54cdfdb4 TG |
823 | highres= [KNL] Enable/disable high resolution timer mode. |
824 | Valid parameters: "on", "off" | |
825 | Default: "on" | |
826 | ||
1da177e4 LT |
827 | hisax= [HW,ISDN] |
828 | See Documentation/isdn/README.HiSax. | |
829 | ||
0cb55ad2 RD |
830 | hlt [BUGS=ARM,SH] |
831 | ||
832 | hpet= [X86-32,HPET] option to control HPET usage | |
833 | Format: { enable (default) | disable | force | | |
834 | verbose } | |
835 | disable: disable HPET and use PIT instead | |
836 | force: allow force enabled of undocumented chips (ICH4, | |
837 | VIA, nVidia) | |
838 | verbose: show contents of HPET registers during setup | |
839 | ||
b4718e62 AK |
840 | hugepages= [HW,X86-32,IA-64] HugeTLB pages to allocate at boot. |
841 | hugepagesz= [HW,IA-64,PPC,X86-64] The size of the HugeTLB pages. | |
0d9ea754 JT |
842 | On x86-64 and powerpc, this option can be specified |
843 | multiple times interleaved with hugepages= to reserve | |
844 | huge pages of different sizes. Valid pages sizes on | |
845 | x86-64 are 2M (when the CPU supports "pse") and 1G | |
846 | (when the CPU supports the "pdpe1gb" cpuinfo flag) | |
b4718e62 AK |
847 | Note that 1GB pages can only be allocated at boot time |
848 | using hugepages= and not freed afterwards. | |
6902aa84 | 849 | |
555d61d6 HB |
850 | hvc_iucv= [S390] Number of z/VM IUCV hypervisor console (HVC) |
851 | terminal devices. Valid values: 0..8 | |
431429ff HB |
852 | hvc_iucv_allow= [S390] Comma-separated list of z/VM user IDs. |
853 | If specified, z/VM IUCV HVC accepts connections | |
854 | from listed z/VM user IDs only. | |
cef7125d | 855 | |
3a853fb9 | 856 | i2c_bus= [HW] Override the default board specific I2C bus speed |
7954763b JN |
857 | or register an additional I2C bus that is not |
858 | registered from board initialization code. | |
3a853fb9 JN |
859 | Format: |
860 | <bus_id>,<clkrate> | |
861 | ||
36d95739 | 862 | i8042.debug [HW] Toggle i8042 debug mode |
1da177e4 | 863 | i8042.direct [HW] Put keyboard port into non-translated mode |
84eb8d06 ML |
864 | i8042.dumbkbd [HW] Pretend that controller can only read data from |
865 | keyboard and cannot control its state | |
1da177e4 LT |
866 | (Don't attempt to blink the leds) |
867 | i8042.noaux [HW] Don't check for auxiliary (== mouse) port | |
945ef0d4 | 868 | i8042.nokbd [HW] Don't check/create keyboard port |
75d08c78 JK |
869 | i8042.noloop [HW] Disable the AUX Loopback command while probing |
870 | for the AUX port | |
1da177e4 LT |
871 | i8042.nomux [HW] Don't check presence of an active multiplexing |
872 | controller | |
873 | i8042.nopnp [HW] Don't use ACPIPnP / PnPBIOS to discover KBD/AUX | |
874 | controllers | |
875 | i8042.panicblink= | |
876 | [HW] Frequency with which keyboard LEDs should blink | |
877 | when kernel panics (default is 0.5 sec) | |
878 | i8042.reset [HW] Reset the controller during init and cleanup | |
879 | i8042.unlock [HW] Unlock (ignore) the keylock | |
880 | ||
881 | i810= [HW,DRM] | |
882 | ||
e70c9d5e DT |
883 | i8k.ignore_dmi [HW] Continue probing hardware even if DMI data |
884 | indicates that the driver is running on unsupported | |
885 | hardware. | |
1da177e4 LT |
886 | i8k.force [HW] Activate i8k driver even if SMM BIOS signature |
887 | does not match list of supported models. | |
888 | i8k.power_status | |
889 | [HW] Report power status in /proc/i8k | |
890 | (disabled by default) | |
891 | i8k.restricted [HW] Allow controlling fans only if SYS_ADMIN | |
892 | capability is set. | |
893 | ||
894 | ibmmcascsi= [HW,MCA,SCSI] IBM MicroChannel SCSI adapter | |
895 | See Documentation/mca.txt. | |
896 | ||
897 | icn= [HW,ISDN] | |
898 | Format: <io>[,<membase>[,<icn_id>[,<icn_id2>]]] | |
899 | ||
0af80c04 DF |
900 | ide-core.nodma= [HW] (E)IDE subsystem |
901 | Format: =0.0 to prevent dma on hda, =0.1 hdb =1.0 hdc | |
075affcb BZ |
902 | .vlb_clock .pci_clock .noflush .nohpa .noprobe .nowerr |
903 | .cdrom .chs .ignore_cable are additional options | |
1c10e938 | 904 | See Documentation/ide/ide.txt. |
1da177e4 | 905 | |
0cb55ad2 RD |
906 | ide-pci-generic.all-generic-ide [HW] (E)IDE subsystem |
907 | Claim all unknown PCI IDE storage controllers. | |
908 | ||
f039b754 | 909 | idle= [X86] |
ada9cfdd RD |
910 | Format: idle=poll, idle=mwait, idle=halt, idle=nomwait |
911 | Poll forces a polling idle loop that can slightly | |
912 | improve the performance of waking up a idle CPU, but | |
913 | will use a lot of power and make the system run hot. | |
914 | Not recommended. | |
915 | idle=mwait: On systems which support MONITOR/MWAIT but | |
916 | the kernel chose to not use it because it doesn't save | |
917 | as much power as a normal idle loop, use the | |
918 | MONITOR/MWAIT idle loop anyways. Performance should be | |
919 | the same as idle=poll. | |
920 | idle=halt: Halt is forced to be used for CPU idle. | |
c1e3b377 | 921 | In such case C2/C3 won't be used again. |
ada9cfdd | 922 | idle=nomwait: Disable mwait for CPU C-states |
a9913044 | 923 | |
79290822 IM |
924 | ignore_loglevel [KNL] |
925 | Ignore loglevel setting - this will print /all/ | |
926 | kernel messages to the console. Useful for debugging. | |
927 | ||
1da177e4 LT |
928 | ihash_entries= [KNL] |
929 | Set number of hash buckets for inode cache. | |
930 | ||
3323eec9 MZ |
931 | ima_audit= [IMA] |
932 | Format: { "0" | "1" } | |
933 | 0 -- integrity auditing messages. (Default) | |
934 | 1 -- enable informational integrity auditing messages. | |
935 | ||
936 | ima_hash= [IMA] | |
a9ed83a5 | 937 | Format: { "sha1" | "md5" } |
3323eec9 MZ |
938 | default: "sha1" |
939 | ||
5789ba3b EP |
940 | ima_tcb [IMA] |
941 | Load a policy which meets the needs of the Trusted | |
942 | Computing Base. This means IMA will measure all | |
943 | programs exec'd, files mmap'd for exec, and all files | |
944 | opened for read by uid=0. | |
945 | ||
1da177e4 LT |
946 | in2000= [HW,SCSI] |
947 | See header of drivers/scsi/in2000.c. | |
948 | ||
949 | init= [KNL] | |
950 | Format: <full_path> | |
951 | Run specified binary instead of /sbin/init as init | |
952 | process. | |
953 | ||
954 | initcall_debug [KNL] Trace initcalls as they are executed. Useful | |
955 | for working out where the kernel is dying during | |
956 | startup. | |
957 | ||
958 | initrd= [BOOT] Specify the location of the initial ramdisk | |
959 | ||
960 | inport.irq= [HW] Inport (ATI XL and Microsoft) busmouse driver | |
961 | Format: <irq> | |
962 | ||
ba395927 | 963 | intel_iommu= [DMAR] Intel IOMMU driver (DMAR) option |
0cd5c3c8 KM |
964 | on |
965 | Enable intel iommu driver. | |
ba395927 KA |
966 | off |
967 | Disable intel iommu driver. | |
968 | igfx_off [Default Off] | |
969 | By default, gfx is mapped as normal device. If a gfx | |
970 | device has a dedicated DMAR unit, the DMAR unit is | |
971 | bypassed by not enabling DMAR with this option. In | |
972 | this case, gfx device will use physical address for | |
973 | DMA. | |
7d3b03ce KA |
974 | forcedac [x86_64] |
975 | With this option iommu will not optimize to look | |
976 | for io virtual address below 32 bit forcing dual | |
977 | address cycle on pci bus for cards supporting greater | |
978 | than 32 bit addressing. The default is to look | |
979 | for translation below 32 bit and if not available | |
980 | then look in the higher range. | |
5e0d2a6f | 981 | strict [Default Off] |
982 | With this option on every unmap_single operation will | |
983 | result in a hardware IOTLB flush operation as opposed | |
984 | to batching them for performance. | |
ba395927 | 985 | |
0cb55ad2 RD |
986 | inttest= [IA64] |
987 | ||
988 | iomem= Disable strict checking of access to MMIO memory | |
989 | strict regions from userspace. | |
990 | relaxed | |
991 | ||
992 | iommu= [x86] | |
993 | off | |
994 | force | |
995 | noforce | |
996 | biomerge | |
997 | panic | |
998 | nopanic | |
999 | merge | |
1000 | nomerge | |
1001 | forcesac | |
1002 | soft | |
4ed0d3e6 | 1003 | pt [x86, IA64] |
0cb55ad2 RD |
1004 | |
1005 | io7= [HW] IO7 for Marvel based alpha systems | |
1006 | See comment before marvel_specify_io7 in | |
1007 | arch/alpha/kernel/core_marvel.c. | |
1008 | ||
6cececfc | 1009 | io_delay= [X86] I/O delay method |
6e7c4025 IM |
1010 | 0x80 |
1011 | Standard port 0x80 based delay | |
1012 | 0xed | |
1013 | Alternate port 0xed based delay (needed on some systems) | |
b02aae9c | 1014 | udelay |
6e7c4025 IM |
1015 | Simple two microseconds delay |
1016 | none | |
1017 | No delay | |
b02aae9c | 1018 | |
1da177e4 | 1019 | ip= [IP_PNP] |
6ded55da | 1020 | See Documentation/filesystems/nfsroot.txt. |
1da177e4 LT |
1021 | |
1022 | ip2= [HW] Set IO/IRQ pairs for up to 4 IntelliPort boards | |
c8facbb6 RD |
1023 | See comment before ip2_setup() in |
1024 | drivers/char/ip2/ip2base.c. | |
1da177e4 LT |
1025 | |
1026 | ips= [HW,SCSI] Adaptec / IBM ServeRAID controller | |
1027 | See header of drivers/scsi/ips.c. | |
1028 | ||
200803df AC |
1029 | irqfixup [HW] |
1030 | When an interrupt is not handled search all handlers | |
1031 | for it. Intended to get systems with badly broken | |
1032 | firmware running. | |
1033 | ||
1034 | irqpoll [HW] | |
1035 | When an interrupt is not handled search all handlers | |
1036 | for it. Also check all handlers each timer | |
1037 | interrupt. Intended to get systems with badly broken | |
1038 | firmware running. | |
1039 | ||
1da177e4 | 1040 | isapnp= [ISAPNP] |
a9913044 | 1041 | Format: <RDP>,<reset>,<pci_scan>,<verbosity> |
1da177e4 LT |
1042 | |
1043 | isolcpus= [KNL,SMP] Isolate CPUs from the general scheduler. | |
22f2e280 DF |
1044 | Format: |
1045 | <cpu number>,...,<cpu number> | |
1046 | or | |
b225d44e LZ |
1047 | <cpu number>-<cpu number> |
1048 | (must be a positive range in ascending order) | |
22f2e280 DF |
1049 | or a mixture |
1050 | <cpu number>,...,<cpu number>-<cpu number> | |
b225d44e | 1051 | |
1da177e4 LT |
1052 | This option can be used to specify one or more CPUs |
1053 | to isolate from the general SMP balancing and scheduling | |
b225d44e LZ |
1054 | algorithms. You can move a process onto or off an |
1055 | "isolated" CPU via the CPU affinity syscalls or cpuset. | |
1da177e4 LT |
1056 | <cpu number> begins at 0 and the maximum value is |
1057 | "number of CPUs in system - 1". | |
1058 | ||
1059 | This option is the preferred way to isolate CPUs. The | |
a9913044 RD |
1060 | alternative -- manually setting the CPU mask of all |
1061 | tasks in the system -- can cause problems and | |
1062 | suboptimal load balancer performance. | |
1da177e4 | 1063 | |
a9913044 | 1064 | iucv= [HW,NET] |
1da177e4 LT |
1065 | |
1066 | js= [HW,JOY] Analog joystick | |
1067 | See Documentation/input/joystick.txt. | |
1068 | ||
0cb55ad2 RD |
1069 | keepinitrd [HW,ARM] |
1070 | ||
6cececfc | 1071 | kernelcore=nn[KMG] [KNL,X86,IA-64,PPC] This parameter |
ed7ed365 MG |
1072 | specifies the amount of memory usable by the kernel |
1073 | for non-movable allocations. The requested amount is | |
1074 | spread evenly throughout all nodes in the system. The | |
1075 | remaining memory in each node is used for Movable | |
1076 | pages. In the event, a node is too small to have both | |
1077 | kernelcore and Movable pages, kernelcore pages will | |
1078 | take priority and other nodes will have a larger number | |
1079 | of kernelcore pages. The Movable zone is used for the | |
1080 | allocation of pages that may be reclaimed or moved | |
1081 | by the page migration subsystem. This means that | |
1082 | HugeTLB pages may not be allocated from this zone. | |
1083 | Note that allocations like PTEs-from-HighMem still | |
1084 | use the HighMem zone if it exists, and the Normal | |
1085 | zone if it does not. | |
1086 | ||
6cdf6e06 JW |
1087 | kgdboc= [HW] kgdb over consoles. |
1088 | Requires a tty driver that supports console polling. | |
19f59460 | 1089 | (only serial supported for now) |
6cdf6e06 JW |
1090 | Format: <serial_device>[,baud] |
1091 | ||
9bed90c6 FF |
1092 | kmac= [MIPS] korina ethernet MAC address. |
1093 | Configure the RouterBoard 532 series on-chip | |
1094 | Ethernet adapter MAC address. | |
1095 | ||
04f70336 CM |
1096 | kmemleak= [KNL] Boot-time kmemleak enable/disable |
1097 | Valid arguments: on, off | |
1098 | Default: on | |
1099 | ||
6cececfc | 1100 | kstack=N [X86] Print N words from the kernel stack |
0cb55ad2 RD |
1101 | in oops dumps. |
1102 | ||
fef07aae AP |
1103 | kvm.ignore_msrs=[KVM] Ignore guest accesses to unhandled MSRs. |
1104 | Default is 0 (don't ignore, but inject #GP) | |
1105 | ||
1106 | kvm.oos_shadow= [KVM] Disable out-of-sync shadow paging. | |
1107 | Default is 1 (enabled) | |
1108 | ||
1109 | kvm-amd.nested= [KVM,AMD] Allow nested virtualization in KVM/SVM. | |
1110 | Default is 0 (off) | |
1111 | ||
1112 | kvm-amd.npt= [KVM,AMD] Disable nested paging (virtualized MMU) | |
1113 | for all guests. | |
1114 | Default is 1 (enabled) if in 64bit or 32bit-PAE mode | |
1115 | ||
1116 | kvm-intel.bypass_guest_pf= | |
1117 | [KVM,Intel] Disables bypassing of guest page faults | |
1118 | on Intel chips. Default is 1 (enabled) | |
1119 | ||
1120 | kvm-intel.ept= [KVM,Intel] Disable extended page tables | |
1121 | (virtualized MMU) support on capable Intel chips. | |
1122 | Default is 1 (enabled) | |
1123 | ||
1124 | kvm-intel.emulate_invalid_guest_state= | |
1125 | [KVM,Intel] Enable emulation of invalid guest states | |
1126 | Default is 0 (disabled) | |
1127 | ||
1128 | kvm-intel.flexpriority= | |
1129 | [KVM,Intel] Disable FlexPriority feature (TPR shadow). | |
1130 | Default is 1 (enabled) | |
1131 | ||
1132 | kvm-intel.unrestricted_guest= | |
1133 | [KVM,Intel] Disable unrestricted guest feature | |
1134 | (virtualized real and unpaged mode) on capable | |
1135 | Intel chips. Default is 1 (enabled) | |
1136 | ||
1137 | kvm-intel.vpid= [KVM,Intel] Disable Virtual Processor Identification | |
1138 | feature (tagged TLBs) on capable Intel chips. | |
1139 | Default is 1 (enabled) | |
1140 | ||
1da177e4 LT |
1141 | l2cr= [PPC] |
1142 | ||
a78bfbfc RB |
1143 | l3cr= [PPC] |
1144 | ||
cd4f0ef7 | 1145 | lapic [X86-32,APIC] Enable the local APIC even if BIOS |
a9913044 | 1146 | disabled it. |
1da177e4 | 1147 | |
6cececfc | 1148 | lapic_timer_c2_ok [X86,APIC] trust the local apic timer |
ada9cfdd | 1149 | in C2 power state. |
e585bef8 | 1150 | |
fcb71f6f FC |
1151 | libata.dma= [LIBATA] DMA control |
1152 | libata.dma=0 Disable all PATA and SATA DMA | |
1153 | libata.dma=1 PATA and SATA Disk DMA only | |
1154 | libata.dma=2 ATAPI (CDROM) DMA only | |
1155 | libata.dma=4 Compact Flash DMA only | |
1156 | Combinations also work, so libata.dma=3 enables DMA | |
1157 | for disks and CDROMs, but not CFs. | |
20308871 MP |
1158 | |
1159 | libata.ignore_hpa= [LIBATA] Ignore HPA limit | |
1160 | libata.ignore_hpa=0 keep BIOS limits (default) | |
1161 | libata.ignore_hpa=1 ignore limits, using full disk | |
fcb71f6f | 1162 | |
78e70c23 DJ |
1163 | libata.noacpi [LIBATA] Disables use of ACPI in libata suspend/resume |
1164 | when set. | |
1165 | Format: <int> | |
1166 | ||
33267325 TH |
1167 | libata.force= [LIBATA] Force configurations. The format is comma |
1168 | separated list of "[ID:]VAL" where ID is | |
1169 | PORT[:DEVICE]. PORT and DEVICE are decimal numbers | |
1170 | matching port, link or device. Basically, it matches | |
1171 | the ATA ID string printed on console by libata. If | |
1172 | the whole ID part is omitted, the last PORT and DEVICE | |
1173 | values are used. If ID hasn't been specified yet, the | |
1174 | configuration applies to all ports, links and devices. | |
1175 | ||
1176 | If only DEVICE is omitted, the parameter applies to | |
1177 | the port and all links and devices behind it. DEVICE | |
1178 | number of 0 either selects the first device or the | |
1179 | first fan-out link behind PMP device. It does not | |
1180 | select the host link. DEVICE number of 15 selects the | |
1181 | host link and device attached to it. | |
1182 | ||
1183 | The VAL specifies the configuration to force. As long | |
1184 | as there's no ambiguity shortcut notation is allowed. | |
1185 | For example, both 1.5 and 1.5G would work for 1.5Gbps. | |
1186 | The following configurations can be forced. | |
1187 | ||
1188 | * Cable type: 40c, 80c, short40c, unk, ign or sata. | |
1189 | Any ID with matching PORT is used. | |
1190 | ||
1191 | * SATA link speed limit: 1.5Gbps or 3.0Gbps. | |
1192 | ||
1193 | * Transfer mode: pio[0-7], mwdma[0-4] and udma[0-7]. | |
1194 | udma[/][16,25,33,44,66,100,133] notation is also | |
1195 | allowed. | |
1196 | ||
1197 | * [no]ncq: Turn on or off NCQ. | |
1198 | ||
05944bdf TH |
1199 | * nohrst, nosrst, norst: suppress hard, soft |
1200 | and both resets. | |
1201 | ||
33267325 TH |
1202 | If there are multiple matching configurations changing |
1203 | the same attribute, the last one is used. | |
1204 | ||
7c4be253 RD |
1205 | lmb=debug [KNL] Enable lmb debug messages. |
1206 | ||
1da177e4 | 1207 | load_ramdisk= [RAM] List of ramdisks to load from floppy |
31c00fc1 | 1208 | See Documentation/blockdev/ramdisk.txt. |
1da177e4 | 1209 | |
a6b25b67 RD |
1210 | lockd.nlm_grace_period=P [NFS] Assign grace period. |
1211 | Format: <integer> | |
1da177e4 | 1212 | |
a6b25b67 RD |
1213 | lockd.nlm_tcpport=N [NFS] Assign TCP port. |
1214 | Format: <integer> | |
1215 | ||
1216 | lockd.nlm_timeout=T [NFS] Assign timeout value. | |
1217 | Format: <integer> | |
1218 | ||
1219 | lockd.nlm_udpport=M [NFS] Assign UDP port. | |
1220 | Format: <integer> | |
1da177e4 LT |
1221 | |
1222 | logibm.irq= [HW,MOUSE] Logitech Bus Mouse Driver | |
1223 | Format: <irq> | |
1224 | ||
1225 | loglevel= All Kernel Messages with a loglevel smaller than the | |
1226 | console loglevel will be printed to the console. It can | |
1227 | also be changed with klogd or other programs. The | |
1228 | loglevels are defined as follows: | |
1229 | ||
1230 | 0 (KERN_EMERG) system is unusable | |
1231 | 1 (KERN_ALERT) action must be taken immediately | |
1232 | 2 (KERN_CRIT) critical conditions | |
1233 | 3 (KERN_ERR) error conditions | |
1234 | 4 (KERN_WARNING) warning conditions | |
1235 | 5 (KERN_NOTICE) normal but significant condition | |
1236 | 6 (KERN_INFO) informational | |
1237 | 7 (KERN_DEBUG) debug-level messages | |
1238 | ||
1239 | log_buf_len=n Sets the size of the printk ring buffer, in bytes. | |
a9913044 RD |
1240 | Format: { n | nk | nM } |
1241 | n must be a power of two. The default size | |
1242 | is set in the kernel config file. | |
1da177e4 | 1243 | |
accaa24c RD |
1244 | logo.nologo [FB] Disables display of the built-in Linux logo. |
1245 | This may be used to provide more screen space for | |
1246 | kernel log messages and is useful when debugging | |
1247 | kernel boot problems. | |
1248 | ||
1da177e4 LT |
1249 | lp=0 [LP] Specify parallel ports to use, e.g, |
1250 | lp=port[,port...] lp=none,parport0 (lp0 not configured, lp1 uses | |
1251 | lp=reset first parallel port). 'lp=0' disables the | |
1252 | lp=auto printer driver. 'lp=reset' (which can be | |
1253 | specified in addition to the ports) causes | |
1254 | attached printers to be reset. Using | |
1255 | lp=port1,port2,... specifies the parallel ports | |
1256 | to associate lp devices with, starting with | |
1257 | lp0. A port specification may be 'none' to skip | |
1258 | that lp device, or a parport name such as | |
1259 | 'parport0'. Specifying 'lp=auto' instead of a | |
1260 | port specification list means that device IDs | |
1261 | from each port should be examined, to see if | |
1262 | an IEEE 1284-compliant printer is attached; if | |
1263 | so, the driver will manage that printer. | |
1264 | See also header of drivers/char/lp.c. | |
1265 | ||
1266 | lpj=n [KNL] | |
1267 | Sets loops_per_jiffy to given constant, thus avoiding | |
1268 | time-consuming boot-time autodetection (up to 250 ms per | |
1269 | CPU). 0 enables autodetection (default). To determine | |
1270 | the correct value for your kernel, boot with normal | |
1271 | autodetection and see what value is printed. Note that | |
1272 | on SMP systems the preset will be applied to all CPUs, | |
1273 | which is likely to cause problems if your CPUs need | |
1274 | significantly divergent settings. An incorrect value | |
1275 | will cause delays in the kernel to be wrong, leading to | |
1276 | unpredictable I/O errors and other breakage. Although | |
1277 | unlikely, in the extreme case this might damage your | |
1278 | hardware. | |
1279 | ||
1280 | ltpc= [NET] | |
1281 | Format: <io>,<irq>,<dma> | |
1282 | ||
a9913044 RD |
1283 | mac5380= [HW,SCSI] Format: |
1284 | <can_queue>,<cmd_per_lun>,<sg_tablesize>,<hostid>,<use_tags> | |
1da177e4 | 1285 | |
a9913044 RD |
1286 | machvec= [IA64] Force the use of a particular machine-vector |
1287 | (machvec) in a generic kernel. | |
1288 | Example: machvec=hpzx1_swiotlb | |
1da177e4 | 1289 | |
3209e70e WZ |
1290 | machtype= [Loongson] Share the same kernel image file between different |
1291 | yeeloong laptop. | |
1292 | Example: machtype=lemote-yeeloong-2f-7inch | |
1293 | ||
0cb55ad2 RD |
1294 | max_addr=nn[KMG] [KNL,BOOT,ia64] All physical memory greater |
1295 | than or equal to this physical address is ignored. | |
1da177e4 LT |
1296 | |
1297 | maxcpus= [SMP] Maximum number of processors that an SMP kernel | |
61ec7567 LB |
1298 | should make use of. maxcpus=n : n >= 0 limits the |
1299 | kernel to using 'n' processors. n=0 is a special case, | |
1300 | it is equivalent to "nosmp", which also disables | |
1301 | the IO APIC. | |
1da177e4 | 1302 | |
0cb55ad2 RD |
1303 | max_loop= [LOOP] Maximum number of loopback devices that can |
1304 | be mounted | |
1305 | Format: <1-256> | |
2b2c3750 | 1306 | |
a9913044 | 1307 | max_luns= [SCSI] Maximum number of LUNs to probe. |
1da177e4 LT |
1308 | Should be between 1 and 2^32-1. |
1309 | ||
1310 | max_report_luns= | |
a9913044 | 1311 | [SCSI] Maximum number of LUNs received. |
1da177e4 LT |
1312 | Should be between 1 and 16384. |
1313 | ||
1da177e4 LT |
1314 | mcatest= [IA-64] |
1315 | ||
cd4f0ef7 | 1316 | mce [X86-32] Machine Check Exception |
1da177e4 | 1317 | |
71cced6e | 1318 | mce=option [X86-64] See Documentation/x86/x86_64/boot-options.txt |
909dd324 | 1319 | |
1da177e4 LT |
1320 | md= [HW] RAID subsystems devices and level |
1321 | See Documentation/md.txt. | |
a9913044 | 1322 | |
1da177e4 LT |
1323 | mdacon= [MDA] |
1324 | Format: <first>,<last> | |
1325 | Specifies range of consoles to be captured by the MDA. | |
a9913044 | 1326 | |
1da177e4 LT |
1327 | mem=nn[KMG] [KNL,BOOT] Force usage of a specific amount of memory |
1328 | Amount of memory to be used when the kernel is not able | |
1329 | to see the whole system memory or for test. | |
cd4f0ef7 | 1330 | [X86-32] Use together with memmap= to avoid physical |
1da177e4 LT |
1331 | address space collisions. Without memmap= PCI devices |
1332 | could be placed at addresses belonging to unused RAM. | |
1333 | ||
cd4f0ef7 | 1334 | mem=nopentium [BUGS=X86-32] Disable usage of 4MB pages for kernel |
1da177e4 LT |
1335 | memory. |
1336 | ||
6902aa84 PM |
1337 | memchunk=nn[KMG] |
1338 | [KNL,SH] Allow user to override the default size for | |
1339 | per-device physically contiguous DMA buffers. | |
1340 | ||
6cececfc | 1341 | memmap=exactmap [KNL,X86] Enable setting of an exact |
1da177e4 LT |
1342 | E820 memory map, as specified by the user. |
1343 | Such memmap=exactmap lines can be constructed based on | |
1344 | BIOS output or other requirements. See the memmap=nn@ss | |
1345 | option description. | |
1346 | ||
1347 | memmap=nn[KMG]@ss[KMG] | |
1348 | [KNL] Force usage of a specific region of memory | |
1349 | Region of memory to be used, from ss to ss+nn. | |
1350 | ||
1351 | memmap=nn[KMG]#ss[KMG] | |
1352 | [KNL,ACPI] Mark specific memory as ACPI data. | |
1353 | Region of memory to be used, from ss to ss+nn. | |
1354 | ||
1355 | memmap=nn[KMG]$ss[KMG] | |
1356 | [KNL,ACPI] Mark specific memory as reserved. | |
1357 | Region of memory to be used, from ss to ss+nn. | |
1312848e PM |
1358 | Example: Exclude memory from 0x18690000-0x1869ffff |
1359 | memmap=64K$0x18690000 | |
1360 | or | |
1361 | memmap=0x10000$0x18690000 | |
1da177e4 | 1362 | |
9f077871 JF |
1363 | memory_corruption_check=0/1 [X86] |
1364 | Some BIOSes seem to corrupt the first 64k of | |
1365 | memory when doing things like suspend/resume. | |
1366 | Setting this option will scan the memory | |
1367 | looking for corruption. Enabling this will | |
1368 | both detect corruption and prevent the kernel | |
1369 | from using the memory being corrupted. | |
1370 | However, its intended as a diagnostic tool; if | |
1371 | repeatable BIOS-originated corruption always | |
1372 | affects the same memory, you can use memmap= | |
1373 | to prevent the kernel from using that memory. | |
1374 | ||
1375 | memory_corruption_check_size=size [X86] | |
1376 | By default it checks for corruption in the low | |
1377 | 64k, making this memory unavailable for normal | |
1378 | use. Use this parameter to scan for | |
1379 | corruption in more or less memory. | |
1380 | ||
1381 | memory_corruption_check_period=seconds [X86] | |
1382 | By default it checks for corruption every 60 | |
1383 | seconds. Use this parameter to check at some | |
1384 | other rate. 0 disables periodic checking. | |
1385 | ||
caadbdce | 1386 | memtest= [KNL,X86] Enable memtest |
c64df707 | 1387 | Format: <integer> |
c64df707 | 1388 | default : 0 <disable> |
9e5f6cf5 AH |
1389 | Specifies the number of memtest passes to be |
1390 | performed. Each pass selects another test | |
1391 | pattern from a given set of patterns. Memtest | |
1392 | fills the memory with this pattern, validates | |
1393 | memory contents and reserves bad memory | |
1394 | regions that are detected. | |
c64df707 | 1395 | |
1da177e4 LT |
1396 | meye.*= [HW] Set MotionEye Camera parameters |
1397 | See Documentation/video4linux/meye.txt. | |
1398 | ||
8f36881b AS |
1399 | mfgpt_irq= [IA-32] Specify the IRQ to use for the |
1400 | Multi-Function General Purpose Timers on AMD Geode | |
1401 | platforms. | |
1402 | ||
e6c4dc6c WT |
1403 | mfgptfix [X86-32] Fix MFGPT timers on AMD Geode platforms when |
1404 | the BIOS has incorrectly applied a workaround. TinyBIOS | |
1405 | version 0.98 is known to be affected, 0.99 fixes the | |
1406 | problem by letting the user disable the workaround. | |
1407 | ||
1da177e4 LT |
1408 | mga= [HW,DRM] |
1409 | ||
1c207f95 RD |
1410 | min_addr=nn[KMG] [KNL,BOOT,ia64] All physical memory below this |
1411 | physical address is ignored. | |
1412 | ||
39f45d7b MP |
1413 | mini2440= [ARM,HW,KNL] |
1414 | Format:[0..2][b][c][t] | |
1415 | Default: "0tb" | |
1416 | MINI2440 configuration specification: | |
1417 | 0 - The attached screen is the 3.5" TFT | |
1418 | 1 - The attached screen is the 7" TFT | |
1419 | 2 - The VGA Shield is attached (1024x768) | |
1420 | Leaving out the screen size parameter will not load | |
1421 | the TFT driver, and the framebuffer will be left | |
1422 | unconfigured. | |
1423 | b - Enable backlight. The TFT backlight pin will be | |
1424 | linked to the kernel VESA blanking code and a GPIO | |
1425 | LED. This parameter is not necessary when using the | |
1426 | VGA shield. | |
1427 | c - Enable the s3c camera interface. | |
1428 | t - Reserved for enabling touchscreen support. The | |
1429 | touchscreen support is not enabled in the mainstream | |
1430 | kernel as of 2.6.30, a preliminary port can be found | |
1431 | in the "bleeding edge" mini2440 support kernel at | |
1432 | http://repo.or.cz/w/linux-2.6/mini2440.git | |
1433 | ||
6b74ab97 MG |
1434 | mminit_loglevel= |
1435 | [KNL] When CONFIG_DEBUG_MEMORY_INIT is set, this | |
1436 | parameter allows control of the logging verbosity for | |
1437 | the additional memory initialisation checks. A value | |
1438 | of 0 disables mminit logging and a level of 4 will | |
1439 | log everything. Information is printed at KERN_DEBUG | |
1440 | so loglevel=8 may also need to be specified. | |
1441 | ||
1da177e4 LT |
1442 | mousedev.tap_time= |
1443 | [MOUSE] Maximum time between finger touching and | |
1444 | leaving touchpad surface for touch to be considered | |
1445 | a tap and be reported as a left button click (for | |
1446 | touchpads working in absolute mode only). | |
1447 | Format: <msecs> | |
1448 | mousedev.xres= [MOUSE] Horizontal screen resolution, used for devices | |
1449 | reporting absolute coordinates, such as tablets | |
1450 | mousedev.yres= [MOUSE] Vertical screen resolution, used for devices | |
1451 | reporting absolute coordinates, such as tablets | |
1452 | ||
6cececfc | 1453 | movablecore=nn[KMG] [KNL,X86,IA-64,PPC] This parameter |
0cb55ad2 RD |
1454 | is similar to kernelcore except it specifies the |
1455 | amount of memory used for migratable allocations. | |
1456 | If both kernelcore and movablecore is specified, | |
1457 | then kernelcore will be at *least* the specified | |
1458 | value but may be more. If movablecore on its own | |
1459 | is specified, the administrator must be careful | |
1460 | that the amount of memory usable for all allocations | |
1461 | is not too small. | |
1462 | ||
1da177e4 LT |
1463 | mpu401= [HW,OSS] |
1464 | Format: <io>,<irq> | |
1465 | ||
1466 | MTD_Partition= [MTD] | |
1467 | Format: <name>,<region-number>,<size>,<offset> | |
1468 | ||
a9913044 RD |
1469 | MTD_Region= [MTD] Format: |
1470 | <name>,<region-number>[,<base>,<size>,<buswidth>,<altbuswidth>] | |
1da177e4 LT |
1471 | |
1472 | mtdparts= [MTD] | |
c8facbb6 | 1473 | See drivers/mtd/cmdlinepart.c. |
1da177e4 | 1474 | |
5988af23 RH |
1475 | onenand.bdry= [HW,MTD] Flex-OneNAND Boundary Configuration |
1476 | ||
1477 | Format: [die0_boundary][,die0_lock][,die1_boundary][,die1_lock] | |
1478 | ||
1479 | boundary - index of last SLC block on Flex-OneNAND. | |
1480 | The remaining blocks are configured as MLC blocks. | |
1481 | lock - Configure if Flex-OneNAND boundary should be locked. | |
1482 | Once locked, the boundary cannot be changed. | |
1483 | 1 indicates lock status, 0 indicates unlock status. | |
1484 | ||
9db829f4 BD |
1485 | mtdset= [ARM] |
1486 | ARM/S3C2412 JIVE boot control | |
1487 | ||
1488 | See arch/arm/mach-s3c2412/mach-jive.c | |
1489 | ||
1da177e4 | 1490 | mtouchusb.raw_coordinates= |
a9913044 RD |
1491 | [HW] Make the MicroTouch USB driver use raw coordinates |
1492 | ('y', default) or cooked coordinates ('n') | |
1da177e4 | 1493 | |
0cb55ad2 | 1494 | mtrr_chunk_size=nn[KMG] [X86] |
19f59460 | 1495 | used for mtrr cleanup. It is largest continuous chunk |
0cb55ad2 RD |
1496 | that could hold holes aka. UC entries. |
1497 | ||
1498 | mtrr_gran_size=nn[KMG] [X86] | |
1499 | Used for mtrr cleanup. It is granularity of mtrr block. | |
1500 | Default is 1. | |
1501 | Large value could prevent small alignment from | |
1502 | using up MTRRs. | |
1503 | ||
1504 | mtrr_spare_reg_nr=n [X86] | |
1505 | Format: <integer> | |
1506 | Range: 0,7 : spare reg number | |
1507 | Default : 1 | |
1508 | Used for mtrr cleanup. It is spare mtrr entries number. | |
1509 | Set to 2 or more if your graphical card needs more. | |
1510 | ||
1da177e4 LT |
1511 | n2= [NET] SDL Inc. RISCom/N2 synchronous serial card |
1512 | ||
1513 | NCR_D700= [HW,SCSI] | |
1514 | See header of drivers/scsi/NCR_D700.c. | |
1515 | ||
1516 | ncr5380= [HW,SCSI] | |
1517 | ||
1518 | ncr53c400= [HW,SCSI] | |
1519 | ||
1520 | ncr53c400a= [HW,SCSI] | |
1521 | ||
1522 | ncr53c406a= [HW,SCSI] | |
1523 | ||
1524 | ncr53c8xx= [HW,SCSI] | |
1525 | ||
1526 | netdev= [NET] Network devices parameters | |
1527 | Format: <irq>,<io>,<mem_start>,<mem_end>,<name> | |
1528 | Note that mem_start is often overloaded to mean | |
1529 | something different and driver-specific. | |
a9913044 RD |
1530 | This usage is only documented in each driver source |
1531 | file if at all. | |
1532 | ||
58401572 KPO |
1533 | nf_conntrack.acct= |
1534 | [NETFILTER] Enable connection tracking flow accounting | |
1535 | 0 to disable accounting | |
1536 | 1 to enable accounting | |
1537 | Default value depends on CONFIG_NF_CT_ACCT that is | |
1538 | going to be removed in 2.6.29. | |
1539 | ||
1da177e4 | 1540 | nfsaddrs= [NFS] |
6ded55da | 1541 | See Documentation/filesystems/nfsroot.txt. |
1da177e4 LT |
1542 | |
1543 | nfsroot= [NFS] nfs root filesystem for disk-less boxes. | |
6ded55da | 1544 | See Documentation/filesystems/nfsroot.txt. |
1da177e4 | 1545 | |
a72b4422 TM |
1546 | nfs.callback_tcpport= |
1547 | [NFS] set the TCP port on which the NFSv4 callback | |
1548 | channel should listen. | |
1549 | ||
e571cbf1 TM |
1550 | nfs.cache_getent= |
1551 | [NFS] sets the pathname to the program which is used | |
1552 | to update the NFS client cache entries. | |
1553 | ||
1554 | nfs.cache_getent_timeout= | |
1555 | [NFS] sets the timeout after which an attempt to | |
1556 | update a cache entry is deemed to have failed. | |
1557 | ||
58df095b TM |
1558 | nfs.idmap_cache_timeout= |
1559 | [NFS] set the maximum lifetime for idmapper cache | |
1560 | entries. | |
1561 | ||
f43bf0be TM |
1562 | nfs.enable_ino64= |
1563 | [NFS] enable 64-bit inode numbers. | |
1564 | If zero, the NFS client will fake up a 32-bit inode | |
1565 | number for the readdir() and stat() syscalls instead | |
1566 | of returning the full 64-bit number. | |
1567 | The default is to return 64-bit inode numbers. | |
1568 | ||
1e1030dc | 1569 | nmi_debug= [KNL,AVR32,SH] Specify one or more actions to take |
e7ba176b HS |
1570 | when a NMI is triggered. |
1571 | Format: [state][,regs][,debounce][,die] | |
1572 | ||
6cececfc | 1573 | nmi_watchdog= [KNL,BUGS=X86] Debugging features for SMP kernels |
5b9a0e14 CG |
1574 | Format: [panic,][num] |
1575 | Valid num: 0,1,2 | |
1576 | 0 - turn nmi_watchdog off | |
1577 | 1 - use the IO-APIC timer for the NMI watchdog | |
1578 | 2 - use the local APIC for the NMI watchdog using | |
0cb55ad2 RD |
1579 | a performance counter. Note: This will use one |
1580 | performance counter and the local APIC's performance | |
1581 | vector. | |
1582 | When panic is specified, panic when an NMI watchdog | |
1583 | timeout occurs. | |
1584 | This is useful when you use a panic=... timeout and | |
1585 | need the box quickly up again. | |
5b9a0e14 CG |
1586 | Instead of 1 and 2 it is possible to use the following |
1587 | symbolic names: lapic and ioapic | |
1588 | Example: nmi_watchdog=2 or nmi_watchdog=panic,lapic | |
1da177e4 | 1589 | |
bff38771 AV |
1590 | netpoll.carrier_timeout= |
1591 | [NET] Specifies amount of time (in seconds) that | |
1592 | netpoll should wait for a carrier. By default netpoll | |
1593 | waits 4 seconds. | |
1594 | ||
cd4f0ef7 | 1595 | no387 [BUGS=X86-32] Tells the kernel to use the 387 maths |
1da177e4 LT |
1596 | emulation library even if a 387 maths coprocessor |
1597 | is present. | |
1598 | ||
0cb55ad2 RD |
1599 | no_console_suspend |
1600 | [HW] Never suspend the console | |
1601 | Disable suspending of consoles during suspend and | |
1602 | hibernate operations. Once disabled, debugging | |
1603 | messages can reach various consoles while the rest | |
1604 | of the system is being put to sleep (ie, while | |
1605 | debugging driver suspend/resume hooks). This may | |
1606 | not work reliably with all consoles, but is known | |
1607 | to work with serial and VGA consoles. | |
1608 | ||
c1aee215 CL |
1609 | noaliencache [MM, NUMA, SLAB] Disables the allocation of alien |
1610 | caches in the slab allocator. Saves per-node memory, | |
1611 | but will impact performance. | |
3395ee05 | 1612 | |
a9913044 RD |
1613 | noalign [KNL,ARM] |
1614 | ||
1da177e4 LT |
1615 | noapic [SMP,APIC] Tells the kernel to not make use of any |
1616 | IOAPICs that may be present in the system. | |
1617 | ||
1da177e4 LT |
1618 | nobats [PPC] Do not use BATs for mapping kernel lowmem |
1619 | on "Classic" PPC cores. | |
1620 | ||
1621 | nocache [ARM] | |
a9913044 | 1622 | |
0cb55ad2 RD |
1623 | noclflush [BUGS=X86] Don't use the CLFLUSH instruction |
1624 | ||
163ecdff SN |
1625 | nodelayacct [KNL] Disable per-task delay accounting |
1626 | ||
1da177e4 LT |
1627 | nodisconnect [HW,SCSI,M68K] Disables SCSI disconnects. |
1628 | ||
6902aa84 PM |
1629 | nodsp [SH] Disable hardware DSP at boot time. |
1630 | ||
6cececfc | 1631 | noefi [X86] Disable EFI runtime services support. |
8b2cb7a8 | 1632 | |
1da177e4 LT |
1633 | noexec [IA-64] |
1634 | ||
6cececfc | 1635 | noexec [X86] |
f5a1b191 | 1636 | On X86-32 available only on PAE configured kernels. |
1da177e4 | 1637 | noexec=on: enable non-executable mappings (default) |
f5a1b191 JS |
1638 | noexec=off: disable non-executable mappings |
1639 | ||
1640 | noexec32 [X86-64] | |
1641 | This affects only 32-bit executables. | |
1642 | noexec32=on: enable non-executable mappings (default) | |
1643 | read doesn't imply executable mappings | |
1644 | noexec32=off: disable non-executable mappings | |
1645 | read implies executable mappings | |
1da177e4 | 1646 | |
6902aa84 PM |
1647 | nofpu [SH] Disable hardware FPU at boot time. |
1648 | ||
cd4f0ef7 | 1649 | nofxsr [BUGS=X86-32] Disables x86 floating point extended |
4f886511 CE |
1650 | register save and restore. The kernel will only save |
1651 | legacy floating-point registers on task switch. | |
1da177e4 | 1652 | |
0c752a93 SS |
1653 | noxsave [BUGS=X86] Disables x86 extended register state save |
1654 | and restore using xsave. The kernel will fallback to | |
1655 | enabling legacy floating-point and sse state. | |
1656 | ||
01a24d2b PZ |
1657 | nohlt [BUGS=ARM,SH] Tells the kernel that the sleep(SH) or |
1658 | wfi(ARM) instruction doesn't work correctly and not to | |
1659 | use it. This is also useful when using JTAG debugger. | |
a9913044 | 1660 | |
cd4f0ef7 | 1661 | no-hlt [BUGS=X86-32] Tells the kernel that the hlt |
1da177e4 LT |
1662 | instruction doesn't work correctly and not to |
1663 | use it. | |
1664 | ||
1f29fae2 SH |
1665 | no_file_caps Tells the kernel not to honor file capabilities. The |
1666 | only way then for a file to be executed with privilege | |
1667 | is to be setuid root or executed by root. | |
1668 | ||
1da177e4 LT |
1669 | nohalt [IA-64] Tells the kernel not to use the power saving |
1670 | function PAL_HALT_LIGHT when idle. This increases | |
1671 | power-consumption. On the positive side, it reduces | |
1672 | interrupt wake-up latency, which may improve performance | |
1673 | in certain environments such as networked servers or | |
1674 | real-time systems. | |
1675 | ||
79bf2bb3 TG |
1676 | nohz= [KNL] Boottime enable/disable dynamic ticks |
1677 | Valid arguments: on, off | |
1678 | Default: on | |
1679 | ||
eeee7853 PM |
1680 | noiotrap [SH] Disables trapped I/O port accesses. |
1681 | ||
cd4f0ef7 | 1682 | noirqdebug [X86-32] Disables the code which attempts to detect and |
1da177e4 LT |
1683 | disable unhandled interrupt sources. |
1684 | ||
6cececfc | 1685 | no_timer_check [X86,APIC] Disables the code which tests for |
8542b200 ZA |
1686 | broken timer IRQ sources. |
1687 | ||
1da177e4 LT |
1688 | noisapnp [ISAPNP] Disables ISA PnP code. |
1689 | ||
1690 | noinitrd [RAM] Tells the kernel not to load any configured | |
1691 | initial RAM disk. | |
1692 | ||
03ea8155 WH |
1693 | nointremap [X86-64, Intel-IOMMU] Do not enable interrupt |
1694 | remapping. | |
1695 | ||
1da177e4 LT |
1696 | nointroute [IA-64] |
1697 | ||
0aa366f3 TL |
1698 | nojitter [IA64] Disables jitter checking for ITC timers. |
1699 | ||
cd4f0ef7 | 1700 | nolapic [X86-32,APIC] Do not enable or use the local APIC. |
1da177e4 | 1701 | |
cd4f0ef7 | 1702 | nolapic_timer [X86-32,APIC] Do not use the local APIC timer. |
ad62ca2b | 1703 | |
1da177e4 LT |
1704 | noltlbs [PPC] Do not use large page/tlb entries for kernel |
1705 | lowmem mapping on PPC40x. | |
1706 | ||
312f1f01 H |
1707 | nomca [IA-64] Disable machine check abort handling |
1708 | ||
cd4f0ef7 | 1709 | nomce [X86-32] Machine Check Exception |
abe37e5a | 1710 | |
83d7384f AS |
1711 | nomfgpt [X86-32] Disable Multi-Function General Purpose |
1712 | Timer usage (for AMD Geode machines). | |
1713 | ||
0cb55ad2 RD |
1714 | norandmaps Don't use address space randomization. Equivalent to |
1715 | echo 0 > /proc/sys/kernel/randomize_va_space | |
1716 | ||
cd4f0ef7 | 1717 | noreplace-paravirt [X86-32,PV_OPS] Don't patch paravirt_ops |
959b4fdf | 1718 | |
cd4f0ef7 | 1719 | noreplace-smp [X86-32,SMP] Don't replace SMP instructions |
b7fb4af0 JF |
1720 | with UP alternatives |
1721 | ||
1da177e4 LT |
1722 | noresidual [PPC] Don't use residual data on PReP machines. |
1723 | ||
a9913044 RD |
1724 | noresume [SWSUSP] Disables resume and restores original swap |
1725 | space. | |
1726 | ||
1da177e4 LT |
1727 | no-scroll [VGA] Disables scrollback. |
1728 | This is required for the Braillex ib80-piezo Braille | |
1729 | reader made by F.H. Papenmeier (Germany). | |
1730 | ||
1731 | nosbagart [IA-64] | |
1732 | ||
cd4f0ef7 | 1733 | nosep [BUGS=X86-32] Disables x86 SYSENTER/SYSEXIT support. |
4f886511 | 1734 | |
61ec7567 LB |
1735 | nosmp [SMP] Tells an SMP kernel to act as a UP kernel, |
1736 | and disable the IO APIC. legacy for "maxcpus=0". | |
1da177e4 | 1737 | |
97842216 DJ |
1738 | nosoftlockup [KNL] Disable the soft-lockup detector. |
1739 | ||
c077719b | 1740 | noswapaccount [KNL] Disable accounting of swap in memory resource |
21acb9ca | 1741 | controller. (See Documentation/cgroups/memory.txt) |
c077719b | 1742 | |
1da177e4 LT |
1743 | nosync [HW,M68K] Disables sync negotiation for all devices. |
1744 | ||
cd4f0ef7 | 1745 | notsc [BUGS=X86-32] Disable Time Stamp Counter |
1da177e4 LT |
1746 | |
1747 | nousb [USB] Disable the USB subsystem | |
1748 | ||
1749 | nowb [ARM] | |
a9913044 | 1750 | |
2b2fd87a WH |
1751 | nox2apic [X86-64,APIC] Do not enable x2APIC mode. |
1752 | ||
a6c75b86 FY |
1753 | nptcg= [IA64] Override max number of concurrent global TLB |
1754 | purges which is reported from either PAL_VM_SUMMARY or | |
1755 | SAL PALO. | |
1756 | ||
0cb55ad2 RD |
1757 | nr_uarts= [SERIAL] maximum number of UARTs to be registered. |
1758 | ||
f0c0b2b8 KH |
1759 | numa_zonelist_order= [KNL, BOOT] Select zonelist order for NUMA. |
1760 | one of ['zone', 'node', 'default'] can be specified | |
1761 | This can be set from sysctl after boot. | |
1762 | See Documentation/sysctl/vm.txt for details. | |
1763 | ||
7c4be253 RD |
1764 | ohci1394_dma=early [HW] enable debugging via the ohci1394 driver. |
1765 | See Documentation/debugging-via-ohci1394.txt for more | |
1766 | info. | |
1767 | ||
3ef0e1f8 AS |
1768 | olpc_ec_timeout= [OLPC] ms delay when issuing EC commands |
1769 | Rather than timing out after 20 ms if an EC | |
1770 | command is not properly ACKed, override the length | |
1771 | of the timeout. We have interrupts disabled while | |
1772 | waiting for the ACK, so if this is set too high | |
1773 | interrupts *may* be lost! | |
1774 | ||
1da177e4 LT |
1775 | opl3= [HW,OSS] |
1776 | Format: <io> | |
1777 | ||
1da177e4 LT |
1778 | oprofile.timer= [HW] |
1779 | Use timer interrupt instead of performance counters | |
1780 | ||
7e4e0bd5 RR |
1781 | oprofile.cpu_type= Force an oprofile cpu type |
1782 | This might be useful if you have an older oprofile | |
1783 | userland or if you want common events. | |
8d7ff4f2 RR |
1784 | Format: { arch_perfmon } |
1785 | arch_perfmon: [X86] Force use of architectural | |
7e4e0bd5 RR |
1786 | perfmon on Intel CPUs instead of the |
1787 | CPU specific event set. | |
1dcdb5a9 | 1788 | |
1da177e4 LT |
1789 | osst= [HW,SCSI] SCSI Tape Driver |
1790 | Format: <buffer_size>,<write_threshold> | |
1791 | See also Documentation/scsi/st.txt. | |
1792 | ||
1793 | panic= [KNL] Kernel behaviour on panic | |
1794 | Format: <timeout> | |
1795 | ||
1796 | parkbd.port= [HW] Parallel port number the keyboard adapter is | |
1797 | connected to, default is 0. | |
1798 | Format: <parport#> | |
1799 | parkbd.mode= [HW] Parallel port keyboard adapter mode of operation, | |
1800 | 0 for XT, 1 for AT (default is AT). | |
a9913044 RD |
1801 | Format: <mode> |
1802 | ||
1803 | parport= [HW,PPT] Specify parallel ports. 0 disables. | |
1804 | Format: { 0 | auto | 0xBBB[,IRQ[,DMA]] } | |
1805 | Use 'auto' to force the driver to use any | |
1806 | IRQ/DMA settings detected (the default is to | |
1807 | ignore detected IRQ/DMA settings because of | |
1808 | possible conflicts). You can specify the base | |
1809 | address, IRQ, and DMA settings; IRQ and DMA | |
1810 | should be numbers, or 'auto' (for using detected | |
1811 | settings on that particular port), or 'nofifo' | |
1812 | (to avoid using a FIFO even if it is detected). | |
1813 | Parallel ports are assigned in the order they | |
1814 | are specified on the command line, starting | |
1815 | with parport0. | |
1816 | ||
1817 | parport_init_mode= [HW,PPT] | |
1818 | Configure VIA parallel port to operate in | |
1819 | a specific mode. This is necessary on Pegasos | |
1820 | computer where firmware has no options for setting | |
1821 | up parallel port mode and sets it to spp. | |
1822 | Currently this function knows 686a and 8231 chips. | |
1da177e4 LT |
1823 | Format: [spp|ps2|epp|ecp|ecpepp] |
1824 | ||
a9913044 RD |
1825 | pas2= [HW,OSS] Format: |
1826 | <io>,<irq>,<dma>,<dma16>,<sb_io>,<sb_irq>,<sb_dma>,<sb_dma16> | |
1827 | ||
1da177e4 LT |
1828 | pas16= [HW,SCSI] |
1829 | See header of drivers/scsi/pas16.c. | |
1830 | ||
dd287796 AM |
1831 | pause_on_oops= |
1832 | Halt all CPUs after the first oops has been printed for | |
1833 | the specified number of seconds. This is to be used if | |
1834 | your oopses keep scrolling off the screen. | |
1835 | ||
1da177e4 LT |
1836 | pcbit= [HW,ISDN] |
1837 | ||
1838 | pcd. [PARIDE] | |
1839 | See header of drivers/block/paride/pcd.c. | |
31c00fc1 | 1840 | See also Documentation/blockdev/paride.txt. |
1da177e4 | 1841 | |
a9913044 | 1842 | pci=option[,option...] [PCI] various PCI subsystem options: |
1cc0ca26 BH |
1843 | earlydump [X86] dump PCI config space before the kernel |
1844 | changes anything | |
c0115606 | 1845 | off [X86] don't probe for the PCI bus |
cd4f0ef7 | 1846 | bios [X86-32] force use of PCI BIOS, don't access |
a9913044 RD |
1847 | the hardware directly. Use this if your machine |
1848 | has a non-standard PCI host bridge. | |
cd4f0ef7 | 1849 | nobios [X86-32] disallow use of PCI BIOS, only direct |
a9913044 RD |
1850 | hardware access methods are allowed. Use this |
1851 | if you experience crashes upon bootup and you | |
1852 | suspect they are caused by the BIOS. | |
c0115606 | 1853 | conf1 [X86] Force use of PCI Configuration |
a9913044 | 1854 | Mechanism 1. |
c0115606 | 1855 | conf2 [X86] Force use of PCI Configuration |
a9913044 | 1856 | Mechanism 2. |
7f785763 RD |
1857 | noaer [PCIE] If the PCIEAER kernel config parameter is |
1858 | enabled, this kernel boot option can be used to | |
1859 | disable the use of PCIE advanced error reporting. | |
32a2eea7 JG |
1860 | nodomains [PCI] Disable support for multiple PCI |
1861 | root domains (aka PCI segments, in ACPI-speak). | |
6cececfc | 1862 | nommconf [X86] Disable use of MMCONFIG for PCI |
61be6d66 | 1863 | Configuration |
12983077 AH |
1864 | check_enable_amd_mmconf [X86] check for and enable |
1865 | properly configured MMIO access to PCI | |
1866 | config space on AMD family 10h CPU | |
309e57df MW |
1867 | nomsi [MSI] If the PCI_MSI kernel config parameter is |
1868 | enabled, this kernel boot option can be used to | |
1869 | disable the use of MSI interrupts system-wide. | |
a9322f64 SA |
1870 | noioapicquirk [APIC] Disable all boot interrupt quirks. |
1871 | Safety option to keep boot IRQs enabled. This | |
1872 | should never be necessary. | |
9197979b SA |
1873 | ioapicreroute [APIC] Enable rerouting of boot IRQs to the |
1874 | primary IO-APIC for bridges that cannot disable | |
1875 | boot IRQs. This fixes a source of spurious IRQs | |
1876 | when the system masks IRQs. | |
41b9eb26 SA |
1877 | noioapicreroute [APIC] Disable workaround that uses the |
1878 | boot IRQ equivalent of an IRQ that connects to | |
1879 | a chipset where boot IRQs cannot be disabled. | |
1880 | The opposite of ioapicreroute. | |
cd4f0ef7 | 1881 | biosirq [X86-32] Use PCI BIOS calls to get the interrupt |
a9913044 RD |
1882 | routing table. These calls are known to be buggy |
1883 | on several machines and they hang the machine | |
1884 | when used, but on other computers it's the only | |
1885 | way to get the interrupt routing table. Try | |
1886 | this option if the kernel is unable to allocate | |
1887 | IRQs or discover secondary PCI buses on your | |
1888 | motherboard. | |
c0115606 | 1889 | rom [X86] Assign address space to expansion ROMs. |
a9913044 RD |
1890 | Use with caution as certain devices share |
1891 | address decoders between ROMs and other | |
1892 | resources. | |
c0115606 | 1893 | norom [X86] Do not assign address space to |
bb71ad88 GH |
1894 | expansion ROMs that do not already have |
1895 | BIOS assigned address ranges. | |
c0115606 | 1896 | irqmask=0xMMMM [X86] Set a bit mask of IRQs allowed to be |
a9913044 RD |
1897 | assigned automatically to PCI devices. You can |
1898 | make the kernel exclude IRQs of your ISA cards | |
1899 | this way. | |
c0115606 | 1900 | pirqaddr=0xAAAAA [X86] Specify the physical address |
a9913044 RD |
1901 | of the PIRQ table (normally generated |
1902 | by the BIOS) if it is outside the | |
1903 | F0000h-100000h range. | |
c0115606 | 1904 | lastbus=N [X86] Scan all buses thru bus #N. Can be |
a9913044 RD |
1905 | useful if the kernel is unable to find your |
1906 | secondary buses and you want to tell it | |
1907 | explicitly which ones they are. | |
c0115606 | 1908 | assign-busses [X86] Always assign all PCI bus |
a9913044 RD |
1909 | numbers ourselves, overriding |
1910 | whatever the firmware may have done. | |
c0115606 | 1911 | usepirqmask [X86] Honor the possible IRQ mask stored |
a9913044 RD |
1912 | in the BIOS $PIR table. This is needed on |
1913 | some systems with broken BIOSes, notably | |
1914 | some HP Pavilion N5400 and Omnibook XE3 | |
1915 | notebooks. This will have no effect if ACPI | |
1916 | IRQ routing is enabled. | |
c0115606 | 1917 | noacpi [X86] Do not use ACPI for IRQ routing |
a9913044 | 1918 | or for PCI scanning. |
236e946b | 1919 | use_crs [X86] Use _CRS for PCI resource |
62f420f8 | 1920 | allocation. |
a9913044 RD |
1921 | routeirq Do IRQ routing for all PCI devices. |
1922 | This is normally done in pci_enable_device(), | |
1923 | so this option is a temporary workaround | |
1924 | for broken drivers that don't call it. | |
13a6ddb0 YL |
1925 | skip_isa_align [X86] do not align io start addr, so can |
1926 | handle more pci cards | |
a9913044 RD |
1927 | firmware [ARM] Do not re-enumerate the bus but instead |
1928 | just use the configuration from the | |
1929 | bootloader. This is currently used on | |
1930 | IXP2000 systems where the bus has to be | |
1931 | configured a certain way for adjunct CPUs. | |
0637a70a AK |
1932 | noearly [X86] Don't do any early type 1 scanning. |
1933 | This might help on some broken boards which | |
1934 | machine check when some devices' config space | |
1935 | is read. But various workarounds are disabled | |
1936 | and some IOMMU drivers will not work. | |
6b4b78fe MD |
1937 | bfsort Sort PCI devices into breadth-first order. |
1938 | This sorting is done to get a device | |
1939 | order compatible with older (<= 2.4) kernels. | |
1940 | nobfsort Don't sort PCI devices into breadth-first order. | |
4516a618 AN |
1941 | cbiosize=nn[KMG] The fixed amount of bus space which is |
1942 | reserved for the CardBus bridge's IO window. | |
1943 | The default value is 256 bytes. | |
1944 | cbmemsize=nn[KMG] The fixed amount of bus space which is | |
1945 | reserved for the CardBus bridge's memory | |
1946 | window. The default value is 64 megabytes. | |
32a9a682 YS |
1947 | resource_alignment= |
1948 | Format: | |
1949 | [<order of align>@][<domain>:]<bus>:<slot>.<func>[; ...] | |
1950 | Specifies alignment and device to reassign | |
1951 | aligned memory resources. | |
1952 | If <order of align> is not specified, | |
1953 | PAGE_SIZE is used as alignment. | |
1954 | PCI-PCI bridge can be specified, if resource | |
1955 | windows need to be expanded. | |
43c16408 AP |
1956 | ecrc= Enable/disable PCIe ECRC (transaction layer |
1957 | end-to-end CRC checking). | |
1958 | bios: Use BIOS/firmware settings. This is the | |
1959 | the default. | |
1960 | off: Turn ECRC off | |
1961 | on: Turn ECRC on. | |
6b4b78fe | 1962 | |
e5665a45 CE |
1963 | pcie_aspm= [PCIE] Forcibly enable or disable PCIe Active State Power |
1964 | Management. | |
1965 | off Disable ASPM. | |
1966 | force Enable ASPM even on devices that claim not to support it. | |
1967 | WARNING: Forcing ASPM on may cause system lockups. | |
1968 | ||
1da177e4 LT |
1969 | pcmv= [HW,PCMCIA] BadgePAD 4 |
1970 | ||
1971 | pd. [PARIDE] | |
31c00fc1 | 1972 | See Documentation/blockdev/paride.txt. |
1da177e4 LT |
1973 | |
1974 | pdcchassis= [PARISC,HW] Disable/Enable PDC Chassis Status codes at | |
1975 | boot time. | |
1976 | Format: { 0 | 1 } | |
1977 | See arch/parisc/kernel/pdc_chassis.c | |
1978 | ||
f58dc01b | 1979 | percpu_alloc= Select which percpu first chunk allocator to use. |
e933a73f TH |
1980 | Currently supported values are "embed" and "page". |
1981 | Archs may support subset or none of the selections. | |
1982 | See comments in mm/percpu.c for details on each | |
1983 | allocator. This parameter is primarily for debugging | |
1984 | and performance comparison. | |
fa8a7094 | 1985 | |
1da177e4 | 1986 | pf. [PARIDE] |
31c00fc1 | 1987 | See Documentation/blockdev/paride.txt. |
1da177e4 LT |
1988 | |
1989 | pg. [PARIDE] | |
31c00fc1 | 1990 | See Documentation/blockdev/paride.txt. |
1da177e4 LT |
1991 | |
1992 | pirq= [SMP,APIC] Manual mp-table setup | |
71cced6e | 1993 | See Documentation/x86/i386/IO-APIC.txt. |
1da177e4 LT |
1994 | |
1995 | plip= [PPT,NET] Parallel port network link | |
1996 | Format: { parport<nr> | timid | 0 } | |
1997 | See also Documentation/parport.txt. | |
1998 | ||
de32a243 TG |
1999 | pmtmr= [X86] Manual setup of pmtmr I/O Port. |
2000 | Override pmtimer IOPort with a hex value. | |
2001 | e.g. pmtmr=0x508 | |
2002 | ||
97ef062b BH |
2003 | pnp.debug [PNP] |
2004 | Enable PNP debug messages. This depends on the | |
2005 | CONFIG_PNP_DEBUG_MESSAGES option. | |
2006 | ||
1da177e4 LT |
2007 | pnpacpi= [ACPI] |
2008 | { off } | |
2009 | ||
2010 | pnpbios= [ISAPNP] | |
2011 | { on | off | curr | res | no-curr | no-res } | |
2012 | ||
2013 | pnp_reserve_irq= | |
2014 | [ISAPNP] Exclude IRQs for the autoconfiguration | |
2015 | ||
2016 | pnp_reserve_dma= | |
2017 | [ISAPNP] Exclude DMAs for the autoconfiguration | |
2018 | ||
2019 | pnp_reserve_io= [ISAPNP] Exclude I/O ports for the autoconfiguration | |
a9913044 | 2020 | Ranges are in pairs (I/O port base and size). |
1da177e4 LT |
2021 | |
2022 | pnp_reserve_mem= | |
a9913044 RD |
2023 | [ISAPNP] Exclude memory regions for the |
2024 | autoconfiguration. | |
1da177e4 LT |
2025 | Ranges are in pairs (memory base and size). |
2026 | ||
4af94f39 RD |
2027 | ports= [IP_VS_FTP] IPVS ftp helper module |
2028 | Default is 21. | |
2029 | Up to 8 (IP_VS_APP_MAX_PORTS) ports | |
2030 | may be specified. | |
2031 | Format: <port>,<port>.... | |
2032 | ||
45807a1d IM |
2033 | print-fatal-signals= |
2034 | [KNL] debug: print fatal signals | |
2035 | print-fatal-signals=1: print segfault info to | |
2036 | the kernel console. | |
2037 | default: off. | |
2038 | ||
e84845c4 RD |
2039 | printk.time= Show timing data prefixed to each printk message line |
2040 | Format: <bool> (1/Y/y=enable, 0/N/n=disable) | |
2041 | ||
0cb55ad2 RD |
2042 | processor.max_cstate= [HW,ACPI] |
2043 | Limit processor to maximum C-state | |
2044 | max_cstate=9 overrides any DMI blacklist limit. | |
2045 | ||
2046 | processor.nocst [HW,ACPI] | |
2047 | Ignore the _CST method to determine C-states, | |
2048 | instead using the legacy FADT method | |
2049 | ||
1da177e4 | 2050 | profile= [KNL] Enable kernel profiling via /proc/profile |
a9913044 RD |
2051 | Format: [schedule,]<number> |
2052 | Param: "schedule" - profile schedule points. | |
2053 | Param: <number> - step/bucket size as a power of 2 for | |
2054 | statistical time based profiling. | |
b3da2a73 MG |
2055 | Param: "sleep" - profile D-state sleeping (millisecs). |
2056 | Requires CONFIG_SCHEDSTATS | |
c0fe2e69 | 2057 | Param: "kvm" - profile VM exits. |
1da177e4 | 2058 | |
1da177e4 LT |
2059 | prompt_ramdisk= [RAM] List of RAM disks to prompt for floppy disk |
2060 | before loading. | |
31c00fc1 | 2061 | See Documentation/blockdev/ramdisk.txt. |
1da177e4 | 2062 | |
a9913044 RD |
2063 | psmouse.proto= [HW,MOUSE] Highest PS2 mouse protocol extension to |
2064 | probe for; one of (bare|imps|exps|lifebook|any). | |
1da177e4 LT |
2065 | psmouse.rate= [HW,MOUSE] Set desired mouse report rate, in reports |
2066 | per second. | |
a9913044 RD |
2067 | psmouse.resetafter= [HW,MOUSE] |
2068 | Try to reset the device after so many bad packets | |
1da177e4 LT |
2069 | (0 = never). |
2070 | psmouse.resolution= | |
2071 | [HW,MOUSE] Set desired mouse resolution, in dpi. | |
2072 | psmouse.smartscroll= | |
a9913044 | 2073 | [HW,MOUSE] Controls Logitech smartscroll autorepeat. |
1da177e4 LT |
2074 | 0 = disabled, 1 = enabled (default). |
2075 | ||
2076 | pss= [HW,OSS] Personal Sound System (ECHO ESC614) | |
a9913044 RD |
2077 | Format: |
2078 | <io>,<mss_io>,<mss_irq>,<mss_dma>,<mpu_io>,<mpu_irq> | |
1da177e4 LT |
2079 | |
2080 | pt. [PARIDE] | |
31c00fc1 | 2081 | See Documentation/blockdev/paride.txt. |
1da177e4 | 2082 | |
dc8c8587 KS |
2083 | pty.legacy_count= |
2084 | [KNL] Number of legacy pty's. Overwrites compiled-in | |
2085 | default number. | |
2086 | ||
7d2c502f | 2087 | quiet [KNL] Disable most log messages |
a9913044 | 2088 | |
1da177e4 LT |
2089 | r128= [HW,DRM] |
2090 | ||
2091 | raid= [HW,RAID] | |
2092 | See Documentation/md.txt. | |
2093 | ||
a9913044 | 2094 | ramdisk_blocksize= [RAM] |
31c00fc1 | 2095 | See Documentation/blockdev/ramdisk.txt. |
a9913044 | 2096 | |
1da177e4 | 2097 | ramdisk_size= [RAM] Sizes of RAM disks in kilobytes |
31c00fc1 | 2098 | See Documentation/blockdev/ramdisk.txt. |
1da177e4 | 2099 | |
24aaef8d RD |
2100 | rcupdate.blimit= [KNL,BOOT] |
2101 | Set maximum number of finished RCU callbacks to process | |
2102 | in one batch. | |
21a1ea9e | 2103 | |
24aaef8d RD |
2104 | rcupdate.qhimark= [KNL,BOOT] |
2105 | Set threshold of queued | |
21a1ea9e DS |
2106 | RCU callbacks over which batch limiting is disabled. |
2107 | ||
24aaef8d RD |
2108 | rcupdate.qlowmark= [KNL,BOOT] |
2109 | Set threshold of queued RCU callbacks below which | |
2110 | batch limiting is re-enabled. | |
21a1ea9e | 2111 | |
ffdfc409 OJ |
2112 | rdinit= [KNL] |
2113 | Format: <full_path> | |
2114 | Run specified binary instead of /init from the ramdisk, | |
2115 | used for early userspace startup. See initrd. | |
2116 | ||
cd4f0ef7 | 2117 | reboot= [BUGS=X86-32,BUGS=ARM,BUGS=IA-64] Rebooting mode |
1da177e4 | 2118 | Format: <reboot_mode>[,<reboot_mode2>[,...]] |
ecb08d81 | 2119 | See arch/*/kernel/reboot.c or arch/*/kernel/process.c |
1da177e4 | 2120 | |
46b6d94e PJ |
2121 | relax_domain_level= |
2122 | [KNL, SMP] Set scheduler's default relax_domain_level. | |
21acb9ca | 2123 | See Documentation/cgroups/cpusets.txt. |
46b6d94e | 2124 | |
1da177e4 LT |
2125 | reserve= [KNL,BUGS] Force the kernel to ignore some iomem area |
2126 | ||
cd4f0ef7 | 2127 | reservetop= [X86-32] |
461a9aff ZA |
2128 | Format: nn[KMG] |
2129 | Reserves a hole at the top of the kernel virtual | |
2130 | address space. | |
2131 | ||
7e96287d VG |
2132 | reset_devices [KNL] Force drivers to reset the underlying device |
2133 | during initialization. | |
2134 | ||
a9913044 RD |
2135 | resume= [SWSUSP] |
2136 | Specify the partition device for software suspend | |
1da177e4 | 2137 | |
ecbd0da1 RW |
2138 | resume_offset= [SWSUSP] |
2139 | Specify the offset from the beginning of the partition | |
2140 | given by "resume=" at which the swap header is located, | |
2141 | in <PAGE_SIZE> units (needed only for swap files). | |
2142 | See Documentation/power/swsusp-and-swap-files.txt | |
2143 | ||
0a7b35cb MN |
2144 | retain_initrd [RAM] Keep initrd memory after extraction |
2145 | ||
1da177e4 LT |
2146 | rhash_entries= [KNL,NET] |
2147 | Set number of hash buckets for route cache | |
2148 | ||
2149 | riscom8= [HW,SERIAL] | |
2150 | Format: <io_board1>[,<io_board2>[,...<io_boardN>]] | |
2151 | ||
2152 | ro [KNL] Mount root device read-only on boot | |
2153 | ||
2154 | root= [KNL] Root filesystem | |
2155 | ||
2156 | rootdelay= [KNL] Delay (in seconds) to pause before attempting to | |
2157 | mount the root filesystem | |
2158 | ||
2159 | rootflags= [KNL] Set root filesystem mount option string | |
2160 | ||
2161 | rootfstype= [KNL] Set root filesystem type | |
2162 | ||
cc1ed754 PO |
2163 | rootwait [KNL] Wait (indefinitely) for root device to show up. |
2164 | Useful for devices that are detected asynchronously | |
2165 | (e.g. USB and MMC devices). | |
2166 | ||
20510f2f JM |
2167 | root_plug.vendor_id= |
2168 | [ROOTPLUG] Override the default vendor ID | |
2169 | ||
2170 | root_plug.product_id= | |
2171 | [ROOTPLUG] Override the default product ID | |
2172 | ||
2173 | root_plug.debug= | |
2174 | [ROOTPLUG] Enable debugging output | |
2175 | ||
1da177e4 LT |
2176 | rw [KNL] Mount root device read-write on boot |
2177 | ||
2178 | S [KNL] Run init in single mode | |
2179 | ||
2180 | sa1100ir [NET] | |
2181 | See drivers/net/irda/sa1100_ir.c. | |
2182 | ||
1da177e4 | 2183 | sbni= [NET] Granch SBNI12 leased line adapter |
a9913044 | 2184 | |
f6630114 MT |
2185 | sched_debug [KNL] Enables verbose scheduler debug messages. |
2186 | ||
1da177e4 LT |
2187 | sc1200wdt= [HW,WDT] SC1200 WDT (watchdog) driver |
2188 | Format: <io>[,<timeout>[,<isapnp>]] | |
2189 | ||
2190 | scsi_debug_*= [SCSI] | |
2191 | See drivers/scsi/scsi_debug.c. | |
2192 | ||
2193 | scsi_default_dev_flags= | |
2194 | [SCSI] SCSI default device flags | |
2195 | Format: <integer> | |
2196 | ||
2197 | scsi_dev_flags= [SCSI] Black/white list entry for vendor and model | |
2198 | Format: <vendor>:<model>:<flags> | |
2199 | (flags are integer value) | |
2200 | ||
6af6632a RD |
2201 | scsi_logging_level= [SCSI] a bit mask of logging levels |
2202 | See drivers/scsi/scsi_logging.h for bits. Also | |
2203 | settable via sysctl at dev.scsi.logging_level | |
2204 | (/proc/sys/dev/scsi/logging_level). | |
2205 | There is also a nice 'scsi_logging_level' script in the | |
2206 | S390-tools package, available for download at | |
2207 | http://www-128.ibm.com/developerworks/linux/linux390/s390-tools-1.5.4.html | |
1da177e4 | 2208 | |
3e082a91 MW |
2209 | scsi_mod.scan= [SCSI] sync (default) scans SCSI busses as they are |
2210 | discovered. async scans them in kernel threads, | |
2211 | allowing boot to proceed. none ignores them, expecting | |
2212 | user space to do the scan. | |
2213 | ||
0cb55ad2 RD |
2214 | security= [SECURITY] Choose a security module to enable at boot. |
2215 | If this boot parameter is not specified, only the first | |
2216 | security module asking for security registration will be | |
2217 | loaded. An invalid security module name will be treated | |
2218 | as if no module has been chosen. | |
2219 | ||
2220 | selinux= [SELINUX] Disable or enable SELinux at boot time. | |
1da177e4 LT |
2221 | Format: { "0" | "1" } |
2222 | See security/selinux/Kconfig help text. | |
2223 | 0 -- disable. | |
2224 | 1 -- enable. | |
2225 | Default value is set via kernel config option. | |
2226 | If enabled at boot time, /selinux/disable can be used | |
2227 | later to disable prior to initial policy load. | |
2228 | ||
cd4f0ef7 | 2229 | serialnumber [BUGS=X86-32] |
1da177e4 | 2230 | |
1da177e4 LT |
2231 | shapers= [NET] |
2232 | Maximal number of shapers. | |
a9913044 | 2233 | |
b05f78f5 YL |
2234 | show_msr= [x86] show boot-time MSR settings |
2235 | Format: { <integer> } | |
2236 | Show boot-time (BIOS-initialized) MSR settings. | |
2237 | The parameter means the number of CPUs to show, | |
2238 | for example 1 means boot CPU only. | |
2239 | ||
1da177e4 LT |
2240 | sim710= [SCSI,HW] |
2241 | See header of drivers/scsi/sim710.c. | |
2242 | ||
2243 | simeth= [IA-64] | |
2244 | simscsi= | |
a9913044 | 2245 | |
1da177e4 LT |
2246 | slram= [HW,MTD] |
2247 | ||
f0630fff CL |
2248 | slub_debug[=options[,slabs]] [MM, SLUB] |
2249 | Enabling slub_debug allows one to determine the | |
2250 | culprit if slab objects become corrupted. Enabling | |
2251 | slub_debug can create guard zones around objects and | |
2252 | may poison objects when not in use. Also tracks the | |
2253 | last alloc / free. For more information see | |
2254 | Documentation/vm/slub.txt. | |
c1aee215 CL |
2255 | |
2256 | slub_max_order= [MM, SLUB] | |
f0630fff CL |
2257 | Determines the maximum allowed order for slabs. |
2258 | A high setting may cause OOMs due to memory | |
2259 | fragmentation. For more information see | |
2260 | Documentation/vm/slub.txt. | |
c1aee215 CL |
2261 | |
2262 | slub_min_objects= [MM, SLUB] | |
f0630fff CL |
2263 | The minimum number of objects per slab. SLUB will |
2264 | increase the slab order up to slub_max_order to | |
2265 | generate a sufficiently large slab able to contain | |
2266 | the number of objects indicated. The higher the number | |
2267 | of objects the smaller the overhead of tracking slabs | |
2268 | and the less frequently locks need to be acquired. | |
c1aee215 CL |
2269 | For more information see Documentation/vm/slub.txt. |
2270 | ||
2271 | slub_min_order= [MM, SLUB] | |
2272 | Determines the mininum page order for slabs. Must be | |
f0630fff | 2273 | lower than slub_max_order. |
c1aee215 CL |
2274 | For more information see Documentation/vm/slub.txt. |
2275 | ||
2276 | slub_nomerge [MM, SLUB] | |
f0630fff | 2277 | Disable merging of slabs with similar size. May be |
c1aee215 | 2278 | necessary if there is some reason to distinguish |
f0630fff CL |
2279 | allocs to different slabs. Debug options disable |
2280 | merging on their own. | |
c1aee215 CL |
2281 | For more information see Documentation/vm/slub.txt. |
2282 | ||
1da177e4 LT |
2283 | smart2= [HW] |
2284 | Format: <io1>[,<io2>[,...,<io8>]] | |
2285 | ||
cd4f0ef7 | 2286 | smp-alt-once [X86-32,SMP] On a hotplug CPU system, only |
b7fb4af0 JF |
2287 | attempt to substitute SMP alternatives once at boot. |
2288 | ||
d0d4f69b BH |
2289 | smsc-ircc2.nopnp [HW] Don't use PNP to discover SMC devices |
2290 | smsc-ircc2.ircc_cfg= [HW] Device configuration I/O port | |
2291 | smsc-ircc2.ircc_sir= [HW] SIR base I/O port | |
2292 | smsc-ircc2.ircc_fir= [HW] FIR base I/O port | |
2293 | smsc-ircc2.ircc_irq= [HW] IRQ line | |
2294 | smsc-ircc2.ircc_dma= [HW] DMA channel | |
2295 | smsc-ircc2.ircc_transceiver= [HW] Transceiver type: | |
2296 | 0: Toshiba Satellite 1800 (GP data pin select) | |
2297 | 1: Fast pin select (default) | |
2298 | 2: ATC IRMode | |
2299 | ||
1da177e4 LT |
2300 | snd-ad1816a= [HW,ALSA] |
2301 | ||
2302 | snd-ad1848= [HW,ALSA] | |
2303 | ||
2304 | snd-ali5451= [HW,ALSA] | |
2305 | ||
2306 | snd-als100= [HW,ALSA] | |
2307 | ||
2308 | snd-als4000= [HW,ALSA] | |
2309 | ||
2310 | snd-azt2320= [HW,ALSA] | |
2311 | ||
2312 | snd-cmi8330= [HW,ALSA] | |
2313 | ||
2314 | snd-cmipci= [HW,ALSA] | |
2315 | ||
2316 | snd-cs4231= [HW,ALSA] | |
2317 | ||
2318 | snd-cs4232= [HW,ALSA] | |
2319 | ||
2320 | snd-cs4236= [HW,ALSA] | |
2321 | ||
2322 | snd-cs4281= [HW,ALSA] | |
2323 | ||
2324 | snd-cs46xx= [HW,ALSA] | |
2325 | ||
2326 | snd-dt019x= [HW,ALSA] | |
2327 | ||
2328 | snd-dummy= [HW,ALSA] | |
2329 | ||
2330 | snd-emu10k1= [HW,ALSA] | |
2331 | ||
2332 | snd-ens1370= [HW,ALSA] | |
2333 | ||
2334 | snd-ens1371= [HW,ALSA] | |
2335 | ||
2336 | snd-es968= [HW,ALSA] | |
2337 | ||
2338 | snd-es1688= [HW,ALSA] | |
2339 | ||
2340 | snd-es18xx= [HW,ALSA] | |
2341 | ||
2342 | snd-es1938= [HW,ALSA] | |
2343 | ||
2344 | snd-es1968= [HW,ALSA] | |
2345 | ||
2346 | snd-fm801= [HW,ALSA] | |
2347 | ||
2348 | snd-gusclassic= [HW,ALSA] | |
2349 | ||
2350 | snd-gusextreme= [HW,ALSA] | |
2351 | ||
2352 | snd-gusmax= [HW,ALSA] | |
2353 | ||
2354 | snd-hdsp= [HW,ALSA] | |
2355 | ||
2356 | snd-ice1712= [HW,ALSA] | |
2357 | ||
2358 | snd-intel8x0= [HW,ALSA] | |
2359 | ||
2360 | snd-interwave= [HW,ALSA] | |
2361 | ||
2362 | snd-interwave-stb= | |
2363 | [HW,ALSA] | |
2364 | ||
2365 | snd-korg1212= [HW,ALSA] | |
2366 | ||
2367 | snd-maestro3= [HW,ALSA] | |
2368 | ||
2369 | snd-mpu401= [HW,ALSA] | |
2370 | ||
2371 | snd-mtpav= [HW,ALSA] | |
2372 | ||
2373 | snd-nm256= [HW,ALSA] | |
2374 | ||
2375 | snd-opl3sa2= [HW,ALSA] | |
2376 | ||
2377 | snd-opti92x-ad1848= | |
2378 | [HW,ALSA] | |
2379 | ||
2380 | snd-opti92x-cs4231= | |
2381 | [HW,ALSA] | |
2382 | ||
2383 | snd-opti93x= [HW,ALSA] | |
2384 | ||
2385 | snd-pmac= [HW,ALSA] | |
2386 | ||
2387 | snd-rme32= [HW,ALSA] | |
2388 | ||
2389 | snd-rme96= [HW,ALSA] | |
2390 | ||
2391 | snd-rme9652= [HW,ALSA] | |
2392 | ||
2393 | snd-sb8= [HW,ALSA] | |
2394 | ||
2395 | snd-sb16= [HW,ALSA] | |
2396 | ||
2397 | snd-sbawe= [HW,ALSA] | |
2398 | ||
2399 | snd-serial= [HW,ALSA] | |
2400 | ||
2401 | snd-sgalaxy= [HW,ALSA] | |
2402 | ||
2403 | snd-sonicvibes= [HW,ALSA] | |
2404 | ||
2405 | snd-sun-amd7930= | |
2406 | [HW,ALSA] | |
2407 | ||
2408 | snd-sun-cs4231= [HW,ALSA] | |
2409 | ||
2410 | snd-trident= [HW,ALSA] | |
2411 | ||
2412 | snd-usb-audio= [HW,ALSA,USB] | |
2413 | ||
2414 | snd-via82xx= [HW,ALSA] | |
2415 | ||
2416 | snd-virmidi= [HW,ALSA] | |
2417 | ||
2418 | snd-wavefront= [HW,ALSA] | |
2419 | ||
2420 | snd-ymfpci= [HW,ALSA] | |
a9913044 | 2421 | |
9c44bc03 IM |
2422 | softlockup_panic= |
2423 | [KNL] Should the soft-lockup detector generate panics. | |
2424 | ||
1da177e4 LT |
2425 | sonypi.*= [HW] Sony Programmable I/O Control Device driver |
2426 | See Documentation/sonypi.txt | |
2427 | ||
2428 | specialix= [HW,SERIAL] Specialix multi-serial port adapter | |
31c00fc1 | 2429 | See Documentation/serial/specialix.txt. |
1da177e4 LT |
2430 | |
2431 | spia_io_base= [HW,MTD] | |
2432 | spia_fio_base= | |
2433 | spia_pedr= | |
2434 | spia_peddr= | |
2435 | ||
2436 | sscape= [HW,OSS] | |
2437 | Format: <io>,<irq>,<dma>,<mpu_io>,<mpu_irq> | |
a9913044 | 2438 | |
1da177e4 LT |
2439 | st= [HW,SCSI] SCSI tape parameters (buffers, etc.) |
2440 | See Documentation/scsi/st.txt. | |
2441 | ||
f38f1d2a SR |
2442 | stacktrace [FTRACE] |
2443 | Enabled the stack tracer on boot up. | |
2444 | ||
1da177e4 LT |
2445 | sti= [PARISC,HW] |
2446 | Format: <num> | |
2447 | Set the STI (builtin display/keyboard on the HP-PARISC | |
2448 | machines) console (graphic card) which should be used | |
2449 | as the initial boot-console. | |
2450 | See also comment in drivers/video/console/sticore.c. | |
2451 | ||
2452 | sti_font= [HW] | |
2453 | See comment in drivers/video/console/sticore.c. | |
2454 | ||
2455 | stifb= [HW] | |
2456 | Format: bpp:<bpp1>[:<bpp2>[:<bpp3>...]] | |
2457 | ||
cbf11071 TM |
2458 | sunrpc.min_resvport= |
2459 | sunrpc.max_resvport= | |
2460 | [NFS,SUNRPC] | |
2461 | SunRPC servers often require that client requests | |
2462 | originate from a privileged port (i.e. a port in the | |
2463 | range 0 < portnr < 1024). | |
2464 | An administrator who wishes to reserve some of these | |
2465 | ports for other uses may adjust the range that the | |
2466 | kernel's sunrpc client considers to be privileged | |
2467 | using these two parameters to set the minimum and | |
2468 | maximum port values. | |
2469 | ||
42a7fc4a GB |
2470 | sunrpc.pool_mode= |
2471 | [NFS] | |
2472 | Control how the NFS server code allocates CPUs to | |
2473 | service thread pools. Depending on how many NICs | |
2474 | you have and where their interrupts are bound, this | |
2475 | option will affect which CPUs will do NFS serving. | |
2476 | Note: this parameter cannot be changed while the | |
2477 | NFS server is running. | |
2478 | ||
2479 | auto the server chooses an appropriate mode | |
2480 | automatically using heuristics | |
2481 | global a single global pool contains all CPUs | |
2482 | percpu one pool for each CPU | |
2483 | pernode one pool for each NUMA node (equivalent | |
2484 | to global on non-NUMA machines) | |
2485 | ||
cbf11071 TM |
2486 | sunrpc.tcp_slot_table_entries= |
2487 | sunrpc.udp_slot_table_entries= | |
2488 | [NFS,SUNRPC] | |
2489 | Sets the upper limit on the number of simultaneous | |
2490 | RPC calls that can be sent from the client to a | |
2491 | server. Increasing these values may allow you to | |
2492 | improve throughput, but will also increase the | |
2493 | amount of memory reserved for use by the client. | |
2494 | ||
1da177e4 | 2495 | swiotlb= [IA-64] Number of I/O TLB slabs |
a9913044 | 2496 | |
1da177e4 LT |
2497 | switches= [HW,M68k] |
2498 | ||
2499 | sym53c416= [HW,SCSI] | |
2500 | See header of drivers/scsi/sym53c416.c. | |
2501 | ||
5d6f647f IM |
2502 | sysrq_always_enabled |
2503 | [KNL] | |
2504 | Ignore sysrq setting - this boot parameter will | |
2505 | neutralize any effect of /proc/sys/kernel/sysrq. | |
2506 | Useful for debugging. | |
2507 | ||
1da177e4 LT |
2508 | t128= [HW,SCSI] |
2509 | See header of drivers/scsi/t128.c. | |
2510 | ||
2511 | tdfx= [HW,DRM] | |
2512 | ||
77437fd4 DB |
2513 | test_suspend= [SUSPEND] |
2514 | Specify "mem" (for Suspend-to-RAM) or "standby" (for | |
2515 | standby suspend) as the system sleep state to briefly | |
2516 | enter during system startup. The system is woken from | |
2517 | this state using a wakeup-capable RTC alarm. | |
2518 | ||
1da177e4 LT |
2519 | thash_entries= [KNL,NET] |
2520 | Set number of hash buckets for TCP connection | |
2521 | ||
f8707ec9 LB |
2522 | thermal.act= [HW,ACPI] |
2523 | -1: disable all active trip points in all thermal zones | |
2524 | <degrees C>: override all lowest active trip points | |
2525 | ||
c52a7419 LB |
2526 | thermal.crt= [HW,ACPI] |
2527 | -1: disable all critical trip points in all thermal zones | |
22a94d79 | 2528 | <degrees C>: override all critical trip points |
c52a7419 | 2529 | |
f5487145 LB |
2530 | thermal.nocrt= [HW,ACPI] |
2531 | Set to disable actions on ACPI thermal zone | |
2532 | critical and hot trip points. | |
2533 | ||
72b33ef8 LB |
2534 | thermal.off= [HW,ACPI] |
2535 | 1: disable ACPI thermal control | |
2536 | ||
a70cdc52 LB |
2537 | thermal.psv= [HW,ACPI] |
2538 | -1: disable all passive trip points | |
ada9cfdd RD |
2539 | <degrees C>: override all passive trip points to this |
2540 | value | |
a70cdc52 | 2541 | |
730ff34d LB |
2542 | thermal.tzp= [HW,ACPI] |
2543 | Specify global default ACPI thermal zone polling rate | |
2544 | <deci-seconds>: poll all this frequency | |
2545 | 0: no polling (default) | |
2546 | ||
1da177e4 LT |
2547 | tmscsim= [HW,SCSI] |
2548 | See comment before function dc390_setup() in | |
2549 | drivers/scsi/tmscsim.c. | |
2550 | ||
2b1a61f0 HC |
2551 | topology= [S390] |
2552 | Format: {off | on} | |
2553 | Specify if the kernel should make use of the cpu | |
2554 | topology informations if the hardware supports these. | |
2555 | The scheduler will make use of these informations and | |
2556 | e.g. base its process migration decisions on it. | |
2557 | Default is off. | |
2558 | ||
1da177e4 LT |
2559 | tp720= [HW,PS2] |
2560 | ||
9d612bef LZ |
2561 | trace_buf_size=nn[KMG] |
2562 | [FTRACE] will set tracing buffer size. | |
631595fb | 2563 | |
020e5f85 LZ |
2564 | trace_event=[event-list] |
2565 | [FTRACE] Set and start specified trace events in order | |
2566 | to facilitate early boot debugging. | |
2567 | See also Documentation/trace/events.txt | |
2568 | ||
1da177e4 | 2569 | trix= [HW,OSS] MediaTrix AudioTrix Pro |
a9913044 RD |
2570 | Format: |
2571 | <io>,<irq>,<dma>,<dma2>,<sb_io>,<sb_irq>,<sb_dma>,<mpu_io>,<mpu_irq> | |
2572 | ||
395628ef AK |
2573 | tsc= Disable clocksource-must-verify flag for TSC. |
2574 | Format: <string> | |
2575 | [x86] reliable: mark tsc clocksource as reliable, this | |
2576 | disables clocksource verification at runtime. | |
2577 | Used to enable high-resolution timer mode on older | |
2578 | hardware, and in virtualized environment. | |
2579 | ||
a9913044 RD |
2580 | turbografx.map[2|3]= [HW,JOY] |
2581 | TurboGraFX parallel port interface | |
2582 | Format: | |
2583 | <port#>,<js1>,<js2>,<js3>,<js4>,<js5>,<js6>,<js7> | |
1da177e4 LT |
2584 | See also Documentation/input/joystick-parport.txt |
2585 | ||
2586 | u14-34f= [HW,SCSI] UltraStor 14F/34F SCSI host adapter | |
2587 | See header of drivers/scsi/u14-34f.c. | |
2588 | ||
2589 | uart401= [HW,OSS] | |
2590 | Format: <io>,<irq> | |
2591 | ||
2592 | uart6850= [HW,OSS] | |
2593 | Format: <io>,<irq> | |
2594 | ||
5f8364b7 AS |
2595 | uhci-hcd.ignore_oc= |
2596 | [USB] Ignore overcurrent events (default N). | |
2597 | Some badly-designed motherboards generate lots of | |
2598 | bogus events, for ports that aren't wired to | |
2599 | anything. Set this parameter to avoid log spamming. | |
2600 | Note that genuine overcurrent events won't be | |
2601 | reported either. | |
2602 | ||
e3a61b0a | 2603 | unknown_nmi_panic |
6cececfc | 2604 | [X86] |
e3a61b0a SA |
2605 | Set unknown_nmi_panic=1 early on boot. |
2606 | ||
b5e795f8 AS |
2607 | usbcore.autosuspend= |
2608 | [USB] The autosuspend time delay (in seconds) used | |
2609 | for newly-detected USB devices (default 2). This | |
2610 | is the time required before an idle device will be | |
2611 | autosuspended. Devices for which the delay is set | |
eaafbc3a | 2612 | to a negative value won't be autosuspended at all. |
b5e795f8 | 2613 | |
fd7c519d JK |
2614 | usbcore.usbfs_snoop= |
2615 | [USB] Set to log all usbfs traffic (default 0 = off). | |
2616 | ||
2617 | usbcore.blinkenlights= | |
2618 | [USB] Set to cycle leds on hubs (default 0 = off). | |
2619 | ||
2620 | usbcore.old_scheme_first= | |
2621 | [USB] Start with the old device initialization | |
2622 | scheme (default 0 = off). | |
2623 | ||
2624 | usbcore.use_both_schemes= | |
2625 | [USB] Try the other device initialization scheme | |
2626 | if the first one fails (default 1 = enabled). | |
2627 | ||
2628 | usbcore.initial_descriptor_timeout= | |
2629 | [USB] Specifies timeout for the initial 64-byte | |
2630 | USB_REQ_GET_DESCRIPTOR request in milliseconds | |
2631 | (default 5000 = 5.0 seconds). | |
2632 | ||
1da177e4 LT |
2633 | usbhid.mousepoll= |
2634 | [USBHID] The interval which mice are to be polled at. | |
a9913044 | 2635 | |
d4f373e5 AS |
2636 | usb-storage.delay_use= |
2637 | [UMS] The delay in seconds before a new device is | |
2638 | scanned for Logical Units (default 5). | |
2639 | ||
2640 | usb-storage.quirks= | |
2641 | [UMS] A list of quirks entries to supplement or | |
2642 | override the built-in unusual_devs list. List | |
2643 | entries are separated by commas. Each entry has | |
2644 | the form VID:PID:Flags where VID and PID are Vendor | |
2645 | and Product ID values (4-digit hex numbers) and | |
2646 | Flags is a set of characters, each corresponding | |
2647 | to a common usb-storage quirk flag as follows: | |
c838ea46 AS |
2648 | a = SANE_SENSE (collect more than 18 bytes |
2649 | of sense data); | |
d4f373e5 AS |
2650 | c = FIX_CAPACITY (decrease the reported |
2651 | device capacity by one sector); | |
c838ea46 AS |
2652 | h = CAPACITY_HEURISTICS (decrease the |
2653 | reported device capacity by one | |
2654 | sector if the number is odd); | |
d4f373e5 AS |
2655 | i = IGNORE_DEVICE (don't bind to this |
2656 | device); | |
2657 | l = NOT_LOCKABLE (don't try to lock and | |
2658 | unlock ejectable media); | |
2659 | m = MAX_SECTORS_64 (don't transfer more | |
2660 | than 64 sectors = 32 KB at a time); | |
c838ea46 AS |
2661 | o = CAPACITY_OK (accept the capacity |
2662 | reported by the device); | |
d4f373e5 AS |
2663 | r = IGNORE_RESIDUE (the device reports |
2664 | bogus residue values); | |
2665 | s = SINGLE_LUN (the device has only one | |
2666 | Logical Unit); | |
2667 | w = NO_WP_DETECT (don't test whether the | |
2668 | medium is write-protected). | |
2669 | Example: quirks=0419:aaf5:rl,0421:0433:rc | |
2670 | ||
6cececfc | 2671 | vdso= [X86,SH] |
1dbf527c | 2672 | vdso=2: enable compat VDSO (default with COMPAT_VDSO) |
e6e5494c IM |
2673 | vdso=1: enable VDSO (default) |
2674 | vdso=0: disable VDSO mapping | |
2675 | ||
6cececfc | 2676 | vdso32= [X86] |
af65d648 RM |
2677 | vdso32=2: enable compat VDSO (default with COMPAT_VDSO) |
2678 | vdso32=1: enable 32-bit VDSO (default) | |
2679 | vdso32=0: disable 32-bit VDSO mapping | |
2680 | ||
d080d397 YI |
2681 | vector= [IA-64,SMP] |
2682 | vector=percpu: enable percpu vector domain | |
2683 | ||
1da177e4 LT |
2684 | video= [FB] Frame buffer configuration |
2685 | See Documentation/fb/modedb.txt. | |
2686 | ||
cd4f0ef7 | 2687 | vga= [BOOT,X86-32] Select a particular video mode |
954a8b81 | 2688 | See Documentation/x86/boot.txt and |
a9913044 | 2689 | Documentation/svga.txt. |
1da177e4 LT |
2690 | Use vga=ask for menu. |
2691 | This is actually a boot loader parameter; the value is | |
2692 | passed to the kernel using a special protocol. | |
2693 | ||
a9913044 | 2694 | vmalloc=nn[KMG] [KNL,BOOT] Forces the vmalloc area to have an exact |
1da177e4 LT |
2695 | size of <nn>. This can be used to increase the |
2696 | minimum size (128MB on x86). It can also be used to | |
2697 | decrease the size and leave more room for directly | |
2698 | mapped kernel RAM. | |
2699 | ||
585c3047 PO |
2700 | vmhalt= [KNL,S390] Perform z/VM CP command after system halt. |
2701 | Format: <command> | |
1da177e4 | 2702 | |
585c3047 PO |
2703 | vmpanic= [KNL,S390] Perform z/VM CP command after kernel panic. |
2704 | Format: <command> | |
2705 | ||
2706 | vmpoff= [KNL,S390] Perform z/VM CP command after power off. | |
2707 | Format: <command> | |
a9913044 | 2708 | |
0cb55ad2 RD |
2709 | vt.default_blu= [VT] |
2710 | Format: <blue0>,<blue1>,<blue2>,...,<blue15> | |
2711 | Change the default blue palette of the console. | |
2712 | This is a 16-member array composed of values | |
2713 | ranging from 0-255. | |
2714 | ||
2715 | vt.default_grn= [VT] | |
2716 | Format: <green0>,<green1>,<green2>,...,<green15> | |
2717 | Change the default green palette of the console. | |
2718 | This is a 16-member array composed of values | |
2719 | ranging from 0-255. | |
2720 | ||
2721 | vt.default_red= [VT] | |
2722 | Format: <red0>,<red1>,<red2>,...,<red15> | |
2723 | Change the default red palette of the console. | |
2724 | This is a 16-member array composed of values | |
2725 | ranging from 0-255. | |
2726 | ||
2727 | vt.default_utf8= | |
2728 | [VT] | |
2729 | Format=<0|1> | |
2730 | Set system-wide default UTF-8 mode for all tty's. | |
2731 | Default is 1, i.e. UTF-8 mode is enabled for all | |
2732 | newly opened terminals. | |
2733 | ||
1da177e4 LT |
2734 | waveartist= [HW,OSS] |
2735 | Format: <io>,<irq>,<dma>,<dma2> | |
a9913044 | 2736 | |
1da177e4 LT |
2737 | wd33c93= [HW,SCSI] |
2738 | See header of drivers/scsi/wd33c93.c. | |
2739 | ||
2740 | wd7000= [HW,SCSI] | |
2741 | See header of drivers/scsi/wd7000.c. | |
2742 | ||
2743 | wdt= [WDT] Watchdog | |
8dfe9c21 | 2744 | See Documentation/watchdog/wdt.txt. |
1da177e4 | 2745 | |
0cb55ad2 RD |
2746 | x2apic_phys [X86-64,APIC] Use x2apic physical mode instead of |
2747 | default x2apic cluster mode on platforms | |
2748 | supporting x2apic. | |
2749 | ||
1da177e4 LT |
2750 | xd= [HW,XT] Original XT pre-IDE (RLL encoded) disks. |
2751 | xd_geo= See header of drivers/block/xd.c. | |
2752 | ||
2753 | xirc2ps_cs= [NET,PCMCIA] | |
a9913044 RD |
2754 | Format: |
2755 | <irq>,<irq_mask>,<io>,<full_duplex>,<do_sound>,<lockup_hack>[,<irq2>[,<irq3>[,<irq4>]]] | |
1da177e4 | 2756 | |
a9913044 | 2757 | ______________________________________________________________________ |
1da177e4 LT |
2758 | |
2759 | TODO: | |
2760 | ||
2761 | Add documentation for ALSA options. | |
2762 | Add more DRM drivers. |