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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 | ||
a901ebb9 SR |
20 | This document may not be entirely up to date and comprehensive. The command |
21 | "modinfo -p ${modulename}" shows a current list of all parameters of a loadable | |
22 | module. Loadable modules, after being loaded into the running kernel, also | |
23 | reveal their parameters in /sys/module/${modulename}/parameters/. Some of these | |
24 | parameters may be changed at runtime by the command | |
25 | "echo -n ${value} > /sys/module/${modulename}/parameters/${parm}". | |
26 | ||
6585fa8a SR |
27 | The parameters listed below are only valid if certain kernel build options were |
28 | enabled and if respective hardware is present. The text in square brackets at | |
29 | the beginning of each description states the restrictions within which a | |
30 | parameter is applicable: | |
1da177e4 LT |
31 | |
32 | ACPI ACPI support is enabled. | |
c99c108a | 33 | AGP AGP (Accelerated Graphics Port) is enabled. |
1da177e4 LT |
34 | ALSA ALSA sound support is enabled. |
35 | APIC APIC support is enabled. | |
36 | APM Advanced Power Management support is enabled. | |
e7ba176b | 37 | AVR32 AVR32 architecture is enabled. |
1da177e4 | 38 | AX25 Appropriate AX.25 support is enabled. |
0ae53640 | 39 | BLACKFIN Blackfin architecture is enabled. |
a9913044 | 40 | DRM Direct Rendering Management support is enabled. |
1da177e4 LT |
41 | EDD BIOS Enhanced Disk Drive Services (EDD) is enabled |
42 | EFI EFI Partitioning (GPT) is enabled | |
43 | EIDE EIDE/ATAPI support is enabled. | |
44 | FB The frame buffer device is enabled. | |
45 | HW Appropriate hardware is enabled. | |
1da177e4 LT |
46 | IA-64 IA-64 architecture is enabled. |
47 | IOSCHED More than one I/O scheduler is enabled. | |
41e2e8be | 48 | IP_PNP IP DHCP, BOOTP, or RARP is enabled. |
1da177e4 LT |
49 | ISAPNP ISA PnP code is enabled. |
50 | ISDN Appropriate ISDN support is enabled. | |
51 | JOY Appropriate joystick support is enabled. | |
11ef697b | 52 | LIBATA Libata driver is enabled |
1da177e4 LT |
53 | LP Printer support is enabled. |
54 | LOOP Loopback device support is enabled. | |
55 | M68k M68k architecture is enabled. | |
56 | These options have more detailed description inside of | |
57 | Documentation/m68k/kernel-options.txt. | |
58 | MCA MCA bus support is enabled. | |
59 | MDA MDA console support is enabled. | |
60 | MOUSE Appropriate mouse support is enabled. | |
309e57df | 61 | MSI Message Signaled Interrupts (PCI). |
c8facbb6 | 62 | MTD MTD (Memory Technology Device) support is enabled. |
1da177e4 LT |
63 | NET Appropriate network support is enabled. |
64 | NUMA NUMA support is enabled. | |
734efb46 | 65 | GENERIC_TIME The generic timeofday code is enabled. |
1da177e4 LT |
66 | NFS Appropriate NFS support is enabled. |
67 | OSS OSS sound support is enabled. | |
c8facbb6 RD |
68 | PV_OPS A paravirtualized kernel is enabled. |
69 | PARIDE The ParIDE (parallel port IDE) subsystem is enabled. | |
1da177e4 LT |
70 | PARISC The PA-RISC architecture is enabled. |
71 | PCI PCI bus support is enabled. | |
7f785763 | 72 | PCIE PCI Express support is enabled. |
1da177e4 LT |
73 | PCMCIA The PCMCIA subsystem is enabled. |
74 | PNP Plug & Play support is enabled. | |
75 | PPC PowerPC architecture is enabled. | |
76 | PPT Parallel port support is enabled. | |
77 | PS2 Appropriate PS/2 support is enabled. | |
78 | RAM RAM disk support is enabled. | |
20510f2f | 79 | ROOTPLUG The example Root Plug LSM is enabled. |
1da177e4 LT |
80 | S390 S390 architecture is enabled. |
81 | SCSI Appropriate SCSI support is enabled. | |
82 | A lot of drivers has their options described inside of | |
83 | Documentation/scsi/. | |
20510f2f | 84 | SECURITY Different security models are enabled. |
1da177e4 LT |
85 | SELINUX SELinux support is enabled. |
86 | SERIAL Serial support is enabled. | |
e523d93c | 87 | SH SuperH architecture is enabled. |
1da177e4 LT |
88 | SMP The kernel is an SMP kernel. |
89 | SPARC Sparc architecture is enabled. | |
a9913044 | 90 | SWSUSP Software suspend is enabled. |
1da177e4 LT |
91 | TS Appropriate touchscreen support is enabled. |
92 | USB USB support is enabled. | |
93 | USBHID USB Human Interface Device support is enabled. | |
94 | V4L Video For Linux support is enabled. | |
95 | VGA The VGA console has been enabled. | |
96 | VT Virtual terminal support is enabled. | |
97 | WDT Watchdog support is enabled. | |
98 | XT IBM PC/XT MFM hard disk support is enabled. | |
cd4f0ef7 | 99 | X86-32 X86-32, aka i386 architecture is enabled. |
1da177e4 LT |
100 | X86-64 X86-64 architecture is enabled. |
101 | More X86-64 boot options can be found in | |
102 | Documentation/x86_64/boot-options.txt . | |
103 | ||
104 | In addition, the following text indicates that the option: | |
105 | ||
106 | BUGS= Relates to possible processor bugs on the said processor. | |
107 | KNL Is a kernel start-up parameter. | |
108 | BOOT Is a boot loader parameter. | |
109 | ||
110 | Parameters denoted with BOOT are actually interpreted by the boot | |
111 | loader, and have no meaning to the kernel directly. | |
112 | Do not modify the syntax of boot loader parameters without extreme | |
113 | need or coordination with <Documentation/i386/boot.txt>. | |
114 | ||
5558870b KW |
115 | There are also arch-specific kernel-parameters not documented here. |
116 | See for example <Documentation/x86_64/boot-options.txt>. | |
117 | ||
1da177e4 LT |
118 | Note that ALL kernel parameters listed below are CASE SENSITIVE, and that |
119 | a trailing = on the name of any parameter states that that parameter will | |
120 | be entered as an environment variable, whereas its absence indicates that | |
121 | it will appear as a kernel argument readable via /proc/cmdline by programs | |
122 | running once the system is up. | |
123 | ||
9c4751fd | 124 | The number of kernel parameters is not limited, but the length of the |
125 | complete command line (parameters including spaces etc.) is limited to | |
126 | a fixed number of characters. This limit depends on the architecture | |
127 | and is between 256 and 4096 characters. It is defined in the file | |
128 | ./include/asm/setup.h as COMMAND_LINE_SIZE. | |
129 | ||
130 | ||
03d926f8 BW |
131 | acpi= [HW,ACPI,X86-64,i386] |
132 | Advanced Configuration and Power Interface | |
a9913044 | 133 | Format: { force | off | ht | strict | noirq } |
1da177e4 LT |
134 | force -- enable ACPI if default was off |
135 | off -- disable ACPI if default was on | |
136 | noirq -- do not use ACPI for IRQ routing | |
137 | ht -- run only enough ACPI to enable Hyper Threading | |
a9913044 | 138 | strict -- Be less tolerant of platforms that are not |
1da177e4 LT |
139 | strictly ACPI specification compliant. |
140 | ||
141 | See also Documentation/pm.txt, pci=noacpi | |
142 | ||
a1fdcc0d LB |
143 | acpi_apic_instance= [ACPI, IOAPIC] |
144 | Format: <int> | |
145 | 2: use 2nd APIC table, if available | |
146 | 1,0: use 1st APIC table | |
4e381a4f | 147 | default: 0 |
a1fdcc0d | 148 | |
1da177e4 LT |
149 | acpi_sleep= [HW,ACPI] Sleep options |
150 | Format: { s3_bios, s3_mode } | |
151 | See Documentation/power/video.txt | |
a9913044 | 152 | |
1da177e4 | 153 | acpi_sci= [HW,ACPI] ACPI System Control Interrupt trigger mode |
a9913044 | 154 | Format: { level | edge | high | low } |
1da177e4 | 155 | |
a9913044 RD |
156 | acpi_irq_balance [HW,ACPI] |
157 | ACPI will balance active IRQs | |
158 | default in APIC mode | |
1da177e4 | 159 | |
a9913044 RD |
160 | acpi_irq_nobalance [HW,ACPI] |
161 | ACPI will not move active IRQs (default) | |
162 | default in PIC mode | |
1da177e4 | 163 | |
a9913044 RD |
164 | acpi_irq_pci= [HW,ACPI] If irq_balance, clear listed IRQs for |
165 | use by PCI | |
1da177e4 LT |
166 | Format: <irq>,<irq>... |
167 | ||
a9913044 | 168 | acpi_irq_isa= [HW,ACPI] If irq_balance, mark listed IRQs used by ISA |
1da177e4 LT |
169 | Format: <irq>,<irq>... |
170 | ||
67effe8f LB |
171 | acpi_no_auto_ssdt [HW,ACPI] Disable automatic loading of SSDT |
172 | ||
a1f9e65e LB |
173 | acpi_os_name= [HW,ACPI] Tell ACPI BIOS the name of the OS |
174 | Format: To spoof as Windows 98: ="Microsoft Windows" | |
175 | ||
ae00d812 LB |
176 | acpi_osi= [HW,ACPI] Modify list of supported OS interface strings |
177 | acpi_osi="string1" # add string1 -- only one string | |
178 | acpi_osi="!string2" # remove built-in string2 | |
179 | acpi_osi= # disable all strings | |
1da177e4 LT |
180 | |
181 | acpi_serialize [HW,ACPI] force serialization of AML methods | |
182 | ||
183 | acpi_skip_timer_override [HW,ACPI] | |
184 | Recognize and ignore IRQ0/pin2 Interrupt Override. | |
185 | For broken nForce2 BIOS resulting in XT-PIC timer. | |
fa18f477 AK |
186 | acpi_use_timer_override [HW,ACPI} |
187 | Use timer override. For some broken Nvidia NF5 boards | |
188 | that require a timer override, but don't have | |
189 | HPET | |
1da177e4 | 190 | |
f989106c | 191 | acpi.debug_layer= [HW,ACPI] |
1da177e4 | 192 | Format: <int> |
a9913044 | 193 | Each bit of the <int> indicates an ACPI debug layer, |
1da177e4 LT |
194 | 1: enable, 0: disable. It is useful for boot time |
195 | debugging. After system has booted up, it can be set | |
f989106c ZR |
196 | via /sys/module/acpi/parameters/debug_layer. |
197 | CONFIG_ACPI_DEBUG must be enabled for this to produce any output. | |
198 | Available bits (add the numbers together) to enable debug output | |
199 | for specific parts of the ACPI subsystem: | |
200 | 0x01 utilities 0x02 hardware 0x04 events 0x08 tables | |
201 | 0x10 namespace 0x20 parser 0x40 dispatcher | |
202 | 0x80 executer 0x100 resources 0x200 acpica debugger | |
203 | 0x400 os services 0x800 acpica disassembler. | |
204 | The number can be in decimal or prefixed with 0x in hex. | |
205 | Warning: Many of these options can produce a lot of | |
206 | output and make your system unusable. Be very careful. | |
207 | ||
208 | acpi.debug_level= [HW,ACPI] | |
1da177e4 | 209 | Format: <int> |
a9913044 | 210 | Each bit of the <int> indicates an ACPI debug level, |
1da177e4 LT |
211 | 1: enable, 0: disable. It is useful for boot time |
212 | debugging. After system has booted up, it can be set | |
f989106c ZR |
213 | via /sys/module/acpi/parameters/debug_level. |
214 | CONFIG_ACPI_DEBUG must be enabled for this to produce any output. | |
215 | Available bits (add the numbers together) to enable different | |
216 | debug output levels of the ACPI subsystem: | |
217 | 0x01 error 0x02 warn 0x04 init 0x08 debug object | |
218 | 0x10 info 0x20 init names 0x40 parse 0x80 load | |
219 | 0x100 dispatch 0x200 execute 0x400 names 0x800 operation region | |
220 | 0x1000 bfield 0x2000 tables 0x4000 values 0x8000 objects | |
221 | 0x10000 resources 0x20000 user requests 0x40000 package. | |
222 | The number can be in decimal or prefixed with 0x in hex. | |
223 | Warning: Many of these options can produce a lot of | |
224 | output and make your system unusable. Be very careful. | |
225 | ||
cd4f0ef7 | 226 | acpi_pm_good [X86-32,X86-64] |
5d0cf410 JS |
227 | Override the pmtimer bug detection: force the kernel |
228 | to assume that this machine's pmtimer latches its value | |
229 | and always returns good values. | |
230 | ||
c99c108a CE |
231 | agp= [AGP] |
232 | { off | try_unsupported } | |
233 | off: disable AGP support | |
234 | try_unsupported: try to drive unsupported chipsets | |
235 | (may crash computer or cause data corruption) | |
236 | ||
66759a01 CE |
237 | enable_timer_pin_1 [i386,x86-64] |
238 | Enable PIN 1 of APIC timer | |
a9913044 RD |
239 | Can be useful to work around chipset bugs |
240 | (in particular on some ATI chipsets). | |
66759a01 CE |
241 | The kernel tries to set a reasonable default. |
242 | ||
243 | disable_timer_pin_1 [i386,x86-64] | |
244 | Disable PIN 1 of APIC timer | |
245 | Can be useful to work around chipset bugs. | |
246 | ||
1da177e4 LT |
247 | ad1848= [HW,OSS] |
248 | Format: <io>,<irq>,<dma>,<dma2>,<type> | |
249 | ||
1da177e4 LT |
250 | advansys= [HW,SCSI] |
251 | See header of drivers/scsi/advansys.c. | |
252 | ||
253 | advwdt= [HW,WDT] Advantech WDT | |
254 | Format: <iostart>,<iostop> | |
255 | ||
256 | aedsp16= [HW,OSS] Audio Excel DSP 16 | |
257 | Format: <io>,<irq>,<dma>,<mss_io>,<mpu_io>,<mpu_irq> | |
258 | See also header of sound/oss/aedsp16.c. | |
a9913044 | 259 | |
1da177e4 LT |
260 | aha152x= [HW,SCSI] |
261 | See Documentation/scsi/aha152x.txt. | |
262 | ||
263 | aha1542= [HW,SCSI] | |
264 | Format: <portbase>[,<buson>,<busoff>[,<dmaspeed>]] | |
265 | ||
266 | aic7xxx= [HW,SCSI] | |
267 | See Documentation/scsi/aic7xxx.txt. | |
268 | ||
269 | aic79xx= [HW,SCSI] | |
270 | See Documentation/scsi/aic79xx.txt. | |
271 | ||
1da177e4 LT |
272 | amijoy.map= [HW,JOY] Amiga joystick support |
273 | Map of devices attached to JOY0DAT and JOY1DAT | |
274 | Format: <a>,<b> | |
275 | See also Documentation/kernel/input/joystick.txt | |
276 | ||
277 | analog.map= [HW,JOY] Analog joystick and gamepad support | |
278 | Specifies type or capabilities of an analog joystick | |
279 | connected to one of 16 gameports | |
280 | Format: <type1>,<type2>,..<type16> | |
281 | ||
a9913044 RD |
282 | apc= [HW,SPARC] |
283 | Power management functions (SPARCstation-4/5 + deriv.) | |
1da177e4 LT |
284 | Format: noidle |
285 | Disable APC CPU standby support. SPARCstation-Fox does | |
286 | not play well with APC CPU idle - disable it if you have | |
287 | APC and your system crashes randomly. | |
288 | ||
c8facbb6 RD |
289 | apic= [APIC,i386] Advanced Programmable Interrupt Controller |
290 | Change the output verbosity whilst booting | |
1da177e4 LT |
291 | Format: { quiet (default) | verbose | debug } |
292 | Change the amount of debugging information output | |
293 | when initialising the APIC and IO-APIC components. | |
a9913044 | 294 | |
1da177e4 LT |
295 | apm= [APM] Advanced Power Management |
296 | See header of arch/i386/kernel/apm.c. | |
297 | ||
1da177e4 LT |
298 | arcrimi= [HW,NET] ARCnet - "RIM I" (entirely mem-mapped) cards |
299 | Format: <io>,<irq>,<nodeID> | |
300 | ||
301 | ataflop= [HW,M68k] | |
302 | ||
303 | atarimouse= [HW,MOUSE] Atari Mouse | |
304 | ||
305 | atascsi= [HW,SCSI] Atari SCSI | |
306 | ||
307 | atkbd.extra= [HW] Enable extra LEDs and keys on IBM RapidAccess, | |
308 | EzKey and similar keyboards | |
309 | ||
310 | atkbd.reset= [HW] Reset keyboard during initialization | |
311 | ||
a9913044 RD |
312 | atkbd.set= [HW] Select keyboard code set |
313 | Format: <int> (2 = AT (default), 3 = PS/2) | |
1da177e4 LT |
314 | |
315 | atkbd.scroll= [HW] Enable scroll wheel on MS Office and similar | |
316 | keyboards | |
317 | ||
318 | atkbd.softraw= [HW] Choose between synthetic and real raw mode | |
319 | Format: <bool> (0 = real, 1 = synthetic (default)) | |
a9913044 RD |
320 | |
321 | atkbd.softrepeat= [HW] | |
322 | Use software keyboard repeat | |
1da177e4 LT |
323 | |
324 | autotest [IA64] | |
325 | ||
1da177e4 LT |
326 | baycom_epp= [HW,AX25] |
327 | Format: <io>,<mode> | |
a9913044 | 328 | |
1da177e4 LT |
329 | baycom_par= [HW,AX25] BayCom Parallel Port AX.25 Modem |
330 | Format: <io>,<mode> | |
331 | See header of drivers/net/hamradio/baycom_par.c. | |
332 | ||
a9913044 RD |
333 | baycom_ser_fdx= [HW,AX25] |
334 | BayCom Serial Port AX.25 Modem (Full Duplex Mode) | |
1da177e4 LT |
335 | Format: <io>,<irq>,<mode>[,<baud>] |
336 | See header of drivers/net/hamradio/baycom_ser_fdx.c. | |
337 | ||
a9913044 RD |
338 | baycom_ser_hdx= [HW,AX25] |
339 | BayCom Serial Port AX.25 Modem (Half Duplex Mode) | |
1da177e4 LT |
340 | Format: <io>,<irq>,<mode> |
341 | See header of drivers/net/hamradio/baycom_ser_hdx.c. | |
342 | ||
bfe8df3d RD |
343 | boot_delay= Milliseconds to delay each printk during boot. |
344 | Values larger than 10 seconds (10000) are changed to | |
345 | no delay (0). | |
346 | Format: integer | |
347 | ||
1da177e4 | 348 | bttv.card= [HW,V4L] bttv (bt848 + bt878 based grabber cards) |
a9913044 RD |
349 | bttv.radio= Most important insmod options are available as |
350 | kernel args too. | |
1da177e4 LT |
351 | bttv.pll= See Documentation/video4linux/bttv/Insmod-options |
352 | bttv.tuner= and Documentation/video4linux/bttv/CARDLIST | |
353 | ||
354 | BusLogic= [HW,SCSI] | |
355 | See drivers/scsi/BusLogic.c, comment before function | |
356 | BusLogic_ParseDriverOptions(). | |
357 | ||
358 | c101= [NET] Moxa C101 synchronous serial card | |
359 | ||
cd4f0ef7 | 360 | cachesize= [BUGS=X86-32] Override level 2 CPU cache size detection. |
1da177e4 LT |
361 | Sometimes CPU hardware bugs make them report the cache |
362 | size incorrectly. The kernel will attempt work arounds | |
363 | to fix known problems, but for some CPUs it is not | |
364 | possible to determine what the correct size should be. | |
365 | This option provides an override for these situations. | |
366 | ||
20510f2f JM |
367 | capability.disable= |
368 | [SECURITY] Disable capabilities. This would normally | |
369 | be used only if an alternative security model is to be | |
370 | configured. Potentially dangerous and should only be | |
371 | used if you are entirely sure of the consequences. | |
372 | ||
14ff56bb SO |
373 | ccw_timeout_log [S390] |
374 | See Documentation/s390/CommonIO for details. | |
375 | ||
1da177e4 LT |
376 | checkreqprot [SELINUX] Set initial checkreqprot flag value. |
377 | Format: { "0" | "1" } | |
378 | See security/selinux/Kconfig help text. | |
a9913044 RD |
379 | 0 -- check protection applied by kernel (includes |
380 | any implied execute protection). | |
1da177e4 LT |
381 | 1 -- check protection requested by application. |
382 | Default value is set via a kernel config option. | |
a9913044 RD |
383 | Value can be changed at runtime via |
384 | /selinux/checkreqprot. | |
385 | ||
661ca0da SO |
386 | cio_ignore= [S390] |
387 | See Documentation/s390/CommonIO for details. | |
388 | ||
389 | cio_msg= [S390] | |
390 | See Documentation/s390/CommonIO for details. | |
391 | ||
cd4f0ef7 | 392 | clock= [BUGS=X86-32, HW] gettimeofday clocksource override. |
734efb46 | 393 | [Deprecated] |
3f6dee9b | 394 | Forces specified clocksource (if available) to be used |
734efb46 | 395 | when calculating gettimeofday(). If specified |
3f6dee9b | 396 | clocksource is not available, it defaults to PIT. |
1da177e4 LT |
397 | Format: { pit | tsc | cyclone | pmtmr } |
398 | ||
3d6ac984 RD |
399 | clocksource= [GENERIC_TIME] Override the default clocksource |
400 | Format: <string> | |
401 | Override the default clocksource and use the clocksource | |
402 | with the name specified. | |
403 | Some clocksource names to choose from, depending on | |
404 | the platform: | |
405 | [all] jiffies (this is the base, fallback clocksource) | |
406 | [ACPI] acpi_pm | |
407 | [ARM] imx_timer1,OSTS,netx_timer,mpu_timer2, | |
408 | pxa_timer,timer3,32k_counter,timer0_1 | |
409 | [AVR32] avr32 | |
cd4f0ef7 | 410 | [X86-32] pit,hpet,tsc,vmi-timer; |
3d6ac984 RD |
411 | scx200_hrt on Geode; cyclone on IBM x440 |
412 | [MIPS] MIPS | |
413 | [PARISC] cr16 | |
414 | [S390] tod | |
415 | [SH] SuperH | |
416 | [SPARC64] tick | |
417 | [X86-64] hpet,tsc | |
418 | ||
a25bd949 AV |
419 | code_bytes [IA32/X86_64] How many bytes of object code to print |
420 | in an oops report. | |
86c41837 CE |
421 | Range: 0 - 8192 |
422 | Default: 64 | |
423 | ||
f9262c12 AK |
424 | disable_8254_timer |
425 | enable_8254_timer | |
426 | [IA32/X86_64] Disable/Enable interrupt 0 timer routing | |
427 | over the 8254 in addition to over the IO-APIC. The | |
428 | kernel tries to set a sensible default. | |
429 | ||
b17530bd TG |
430 | hpet= [X86-32,HPET] option to control HPET usage |
431 | Format: { enable (default) | disable | force } | |
432 | disable: disable HPET and use PIT instead | |
d79a5f80 CC |
433 | force: allow force enabled of undocumented chips (ICH4, |
434 | VIA, nVidia) | |
1da177e4 | 435 | |
1da177e4 | 436 | com20020= [HW,NET] ARCnet - COM20020 chipset |
a9913044 RD |
437 | Format: |
438 | <io>[,<irq>[,<nodeID>[,<backplane>[,<ckp>[,<timeout>]]]]] | |
1da177e4 LT |
439 | |
440 | com90io= [HW,NET] ARCnet - COM90xx chipset (IO-mapped buffers) | |
441 | Format: <io>[,<irq>] | |
442 | ||
a9913044 RD |
443 | com90xx= [HW,NET] |
444 | ARCnet - COM90xx chipset (memory-mapped buffers) | |
1da177e4 LT |
445 | Format: <io>[,<irq>[,<memstart>]] |
446 | ||
447 | condev= [HW,S390] console device | |
448 | conmode= | |
a9913044 | 449 | |
1da177e4 LT |
450 | console= [KNL] Output console device and options. |
451 | ||
452 | tty<n> Use the virtual console device <n>. | |
453 | ||
454 | ttyS<n>[,options] | |
f1a1c2dc | 455 | ttyUSB0[,options] |
1da177e4 | 456 | Use the specified serial port. The options are of |
f1a1c2dc RD |
457 | the form "bbbbpnf", where "bbbb" is the baud rate, |
458 | "p" is parity ("n", "o", or "e"), "n" is number of | |
459 | bits, and "f" is flow control ("r" for RTS or | |
460 | omit it). Default is "9600n8". | |
461 | ||
462 | See Documentation/serial-console.txt for more | |
463 | information. See | |
464 | Documentation/networking/netconsole.txt for an | |
465 | alternative. | |
1da177e4 | 466 | |
18a8bd94 YL |
467 | uart[8250],io,<addr>[,options] |
468 | uart[8250],mmio,<addr>[,options] | |
1da177e4 LT |
469 | Start an early, polled-mode console on the 8250/16550 |
470 | UART at the specified I/O port or MMIO address, | |
471 | switching to the matching ttyS device later. The | |
472 | options are the same as for ttyS, above. | |
473 | ||
18a8bd94 YL |
474 | earlycon= [KNL] Output early console device and options. |
475 | uart[8250],io,<addr>[,options] | |
476 | uart[8250],mmio,<addr>[,options] | |
477 | Start an early, polled-mode console on the 8250/16550 | |
478 | UART at the specified I/O port or MMIO address. | |
479 | The options are the same as for ttyS, above. | |
480 | ||
8f4ce8c3 AS |
481 | no_console_suspend |
482 | [HW] Never suspend the console | |
483 | Disable suspending of consoles during suspend and | |
484 | hibernate operations. Once disabled, debugging | |
485 | messages can reach various consoles while the rest | |
486 | of the system is being put to sleep (ie, while | |
487 | debugging driver suspend/resume hooks). This may | |
488 | not work reliably with all consoles, but is known | |
489 | to work with serial and VGA consoles. | |
490 | ||
1da177e4 | 491 | cpcihp_generic= [HW,PCI] Generic port I/O CompactPCI driver |
a9913044 RD |
492 | Format: |
493 | <first_slot>,<last_slot>,<port>,<enum_bit>[,<debug>] | |
1da177e4 | 494 | |
dc009d92 EB |
495 | crashkernel=nn[KMG]@ss[KMG] |
496 | [KNL] Reserve a chunk of physical memory to | |
497 | hold a kernel to switch to with kexec on panic. | |
498 | ||
fb391599 BW |
499 | crashkernel=range1:size1[,range2:size2,...][@offset] |
500 | [KNL] Same as above, but depends on the memory | |
501 | in the running system. The syntax of range is | |
502 | start-[end] where start and end are both | |
503 | a memory unit (amount[KMG]). See also | |
504 | Documentation/kdump/kdump.txt for a example. | |
505 | ||
1da177e4 LT |
506 | cs4232= [HW,OSS] |
507 | Format: <io>,<irq>,<dma>,<dma2>,<mpuio>,<mpuirq> | |
508 | ||
509 | cs89x0_dma= [HW,NET] | |
510 | Format: <dma> | |
511 | ||
512 | cs89x0_media= [HW,NET] | |
513 | Format: { rj45 | aui | bnc } | |
a9913044 | 514 | |
a9913044 | 515 | dasd= [HW,NET] |
1da177e4 LT |
516 | See header of drivers/s390/block/dasd_devmap.c. |
517 | ||
518 | db9.dev[2|3]= [HW,JOY] Multisystem joystick support via parallel port | |
519 | (one device per port) | |
520 | Format: <port#>,<type> | |
521 | See also Documentation/input/joystick-parport.txt | |
522 | ||
523 | debug [KNL] Enable kernel debugging (events log level). | |
524 | ||
cae2ed9a IM |
525 | debug_locks_verbose= |
526 | [KNL] verbose self-tests | |
527 | Format=<0|1> | |
528 | Print debugging info while doing the locking API | |
529 | self-tests. | |
530 | We default to 0 (no extra messages), setting it to | |
531 | 1 will print _a lot_ more information - normally | |
532 | only useful to kernel developers. | |
533 | ||
1da177e4 LT |
534 | decnet= [HW,NET] |
535 | Format: <area>[,<node>] | |
536 | See also Documentation/networking/decnet.txt. | |
537 | ||
ecb77fa9 | 538 | vt.default_blu= [VT] |
55ff9780 AD |
539 | Format: <blue0>,<blue1>,<blue2>,...,<blue15> |
540 | Change the default blue palette of the console. | |
541 | This is a 16-member array composed of values | |
542 | ranging from 0-255. | |
543 | ||
ecb77fa9 | 544 | vt.default_grn= [VT] |
55ff9780 AD |
545 | Format: <green0>,<green1>,<green2>,...,<green15> |
546 | Change the default green palette of the console. | |
547 | This is a 16-member array composed of values | |
548 | ranging from 0-255. | |
549 | ||
ecb77fa9 | 550 | vt.default_red= [VT] |
55ff9780 AD |
551 | Format: <red0>,<red1>,<red2>,...,<red15> |
552 | Change the default red palette of the console. | |
553 | This is a 16-member array composed of values | |
554 | ranging from 0-255. | |
555 | ||
ecb77fa9 ST |
556 | vt.default_utf8= |
557 | [VT] | |
55ff9780 AD |
558 | Format=<0|1> |
559 | Set system-wide default UTF-8 mode for all tty's. | |
ecb77fa9 ST |
560 | Default is 1, i.e. UTF-8 mode is enabled for all |
561 | newly opened terminals. | |
55ff9780 | 562 | |
1da177e4 LT |
563 | dhash_entries= [KNL] |
564 | Set number of hash buckets for dentry cache. | |
a9913044 | 565 | |
1da177e4 LT |
566 | digi= [HW,SERIAL] |
567 | IO parameters + enable/disable command. | |
568 | ||
569 | digiepca= [HW,SERIAL] | |
570 | See drivers/char/README.epca and | |
571 | Documentation/digiepca.txt. | |
572 | ||
99fc8d42 JB |
573 | disable_mtrr_trim [X86-64, Intel only] |
574 | By default the kernel will trim any uncacheable | |
575 | memory out of your available memory pool based on | |
576 | MTRR settings. This parameter disables that behavior, | |
577 | possibly causing your machine to run very slowly. | |
578 | ||
1da177e4 LT |
579 | dmasound= [HW,OSS] Sound subsystem buffers |
580 | ||
581 | dscc4.setup= [NET] | |
582 | ||
583 | dtc3181e= [HW,SCSI] | |
584 | ||
0ae53640 | 585 | earlyprintk= [X86-32,X86-64,SH,BLACKFIN] |
1da177e4 LT |
586 | earlyprintk=vga |
587 | earlyprintk=serial[,ttySn[,baudrate]] | |
588 | ||
a9913044 | 589 | Append ",keep" to not disable it when the real console |
1da177e4 LT |
590 | takes over. |
591 | ||
592 | Only vga or serial at a time, not both. | |
593 | ||
594 | Currently only ttyS0 and ttyS1 are supported. | |
595 | ||
596 | Interaction with the standard serial driver is not | |
597 | very good. | |
598 | ||
599 | The VGA output is eventually overwritten by the real | |
600 | console. | |
601 | ||
602 | eata= [HW,SCSI] | |
603 | ||
1da177e4 LT |
604 | edd= [EDD] |
605 | Format: {"of[f]" | "sk[ipmbr]"} | |
606 | See comment in arch/i386/boot/edd.S | |
607 | ||
1da177e4 LT |
608 | eisa_irq_edge= [PARISC,HW] |
609 | See header of drivers/parisc/eisa.c. | |
610 | ||
cd4f0ef7 | 611 | elanfreq= [X86-32] |
1da177e4 LT |
612 | See comment before function elanfreq_setup() in |
613 | arch/i386/kernel/cpu/cpufreq/elanfreq.c. | |
614 | ||
615 | elevator= [IOSCHED] | |
16ab3adf | 616 | Format: {"anticipatory" | "cfq" | "deadline" | "noop"} |
a9913044 RD |
617 | See Documentation/block/as-iosched.txt and |
618 | Documentation/block/deadline-iosched.txt for details. | |
619 | ||
cd4f0ef7 | 620 | elfcorehdr= [X86-32, X86_64] |
a9913044 | 621 | Specifies physical address of start of kernel core |
aac04b32 VG |
622 | image elf header. Generally kexec loader will |
623 | pass this option to capture kernel. | |
624 | See Documentation/kdump/kdump.txt for details. | |
1da177e4 LT |
625 | |
626 | enforcing [SELINUX] Set initial enforcing status. | |
627 | Format: {"0" | "1"} | |
628 | See security/selinux/Kconfig help text. | |
629 | 0 -- permissive (log only, no denials). | |
630 | 1 -- enforcing (deny and log). | |
631 | Default value is 0. | |
632 | Value can be changed at runtime via /selinux/enforce. | |
633 | ||
1da177e4 LT |
634 | es1371= [HW,OSS] |
635 | Format: <spdif>,[<nomix>,[<amplifier>]] | |
636 | See also header of sound/oss/es1371.c. | |
a9913044 | 637 | |
1da177e4 LT |
638 | ether= [HW,NET] Ethernet cards parameters |
639 | This option is obsoleted by the "netdev=" option, which | |
640 | has equivalent usage. See its documentation for details. | |
641 | ||
642 | eurwdt= [HW,WDT] Eurotech CPU-1220/1410 onboard watchdog. | |
643 | Format: <io>[,<irq>] | |
644 | ||
de1ba09b AM |
645 | failslab= |
646 | fail_page_alloc= | |
647 | fail_make_request=[KNL] | |
648 | General fault injection mechanism. | |
649 | Format: <interval>,<probability>,<space>,<times> | |
650 | See also /Documentation/fault-injection/. | |
651 | ||
1da177e4 LT |
652 | fd_mcs= [HW,SCSI] |
653 | See header of drivers/scsi/fd_mcs.c. | |
654 | ||
655 | fdomain= [HW,SCSI] | |
656 | See header of drivers/scsi/fdomain.c. | |
657 | ||
658 | floppy= [HW] | |
659 | See Documentation/floppy.txt. | |
660 | ||
1da177e4 LT |
661 | gamecon.map[2|3]= |
662 | [HW,JOY] Multisystem joystick and NES/SNES/PSX pad | |
663 | support via parallel port (up to 5 devices per port) | |
664 | Format: <port#>,<pad1>,<pad2>,<pad3>,<pad4>,<pad5> | |
665 | See also Documentation/input/joystick-parport.txt | |
666 | ||
667 | gamma= [HW,DRM] | |
668 | ||
aaf23042 YL |
669 | gart_fix_e820= [X86_64] disable the fix e820 for K8 GART |
670 | Format: off | on | |
671 | default: on | |
672 | ||
1da177e4 LT |
673 | gdth= [HW,SCSI] |
674 | See header of drivers/scsi/gdth.c. | |
675 | ||
676 | gpt [EFI] Forces disk with valid GPT signature but | |
677 | invalid Protective MBR to be treated as GPT. | |
678 | ||
1da177e4 LT |
679 | gvp11= [HW,SCSI] |
680 | ||
681 | hashdist= [KNL,NUMA] Large hashes allocated during boot | |
682 | are distributed across NUMA nodes. Defaults on | |
683 | for IA-64, off otherwise. | |
a9913044 | 684 | Format: 0 | 1 (for off | on) |
1da177e4 LT |
685 | |
686 | hcl= [IA-64] SGI's Hardware Graph compatibility layer | |
687 | ||
688 | hd= [EIDE] (E)IDE hard drive subsystem geometry | |
689 | Format: <cyl>,<head>,<sect> | |
690 | ||
691 | hd?= [HW] (E)IDE subsystem | |
692 | hd?lun= See Documentation/ide.txt. | |
693 | ||
694 | highmem=nn[KMG] [KNL,BOOT] forces the highmem zone to have an exact | |
695 | size of <nn>. This works even on boxes that have no | |
696 | highmem otherwise. This also works to reduce highmem | |
697 | size on bigger boxes. | |
698 | ||
54cdfdb4 TG |
699 | highres= [KNL] Enable/disable high resolution timer mode. |
700 | Valid parameters: "on", "off" | |
701 | Default: "on" | |
702 | ||
1da177e4 LT |
703 | hisax= [HW,ISDN] |
704 | See Documentation/isdn/README.HiSax. | |
705 | ||
cd4f0ef7 | 706 | hugepages= [HW,X86-32,IA-64] Maximal number of HugeTLB pages. |
1da177e4 | 707 | |
1da177e4 | 708 | i8042.direct [HW] Put keyboard port into non-translated mode |
84eb8d06 ML |
709 | i8042.dumbkbd [HW] Pretend that controller can only read data from |
710 | keyboard and cannot control its state | |
1da177e4 LT |
711 | (Don't attempt to blink the leds) |
712 | i8042.noaux [HW] Don't check for auxiliary (== mouse) port | |
945ef0d4 | 713 | i8042.nokbd [HW] Don't check/create keyboard port |
1da177e4 LT |
714 | i8042.nomux [HW] Don't check presence of an active multiplexing |
715 | controller | |
716 | i8042.nopnp [HW] Don't use ACPIPnP / PnPBIOS to discover KBD/AUX | |
717 | controllers | |
718 | i8042.panicblink= | |
719 | [HW] Frequency with which keyboard LEDs should blink | |
720 | when kernel panics (default is 0.5 sec) | |
721 | i8042.reset [HW] Reset the controller during init and cleanup | |
722 | i8042.unlock [HW] Unlock (ignore) the keylock | |
723 | ||
724 | i810= [HW,DRM] | |
725 | ||
e70c9d5e DT |
726 | i8k.ignore_dmi [HW] Continue probing hardware even if DMI data |
727 | indicates that the driver is running on unsupported | |
728 | hardware. | |
1da177e4 LT |
729 | i8k.force [HW] Activate i8k driver even if SMM BIOS signature |
730 | does not match list of supported models. | |
731 | i8k.power_status | |
732 | [HW] Report power status in /proc/i8k | |
733 | (disabled by default) | |
734 | i8k.restricted [HW] Allow controlling fans only if SYS_ADMIN | |
735 | capability is set. | |
736 | ||
737 | ibmmcascsi= [HW,MCA,SCSI] IBM MicroChannel SCSI adapter | |
738 | See Documentation/mca.txt. | |
739 | ||
740 | icn= [HW,ISDN] | |
741 | Format: <io>[,<membase>[,<icn_id>[,<icn_id2>]]] | |
742 | ||
743 | ide= [HW] (E)IDE subsystem | |
744 | Format: ide=nodma or ide=doubler or ide=reverse | |
745 | See Documentation/ide.txt. | |
746 | ||
747 | ide?= [HW] (E)IDE subsystem | |
748 | Format: ide?=noprobe or chipset specific parameters. | |
749 | See Documentation/ide.txt. | |
a9913044 | 750 | |
1da177e4 LT |
751 | idebus= [HW] (E)IDE subsystem - VLB/PCI bus speed |
752 | See Documentation/ide.txt. | |
753 | ||
f039b754 AK |
754 | idle= [X86] |
755 | Format: idle=poll or idle=mwait | |
756 | Poll forces a polling idle loop that can slightly improves the performance | |
757 | of waking up a idle CPU, but will use a lot of power and make the system | |
758 | run hot. Not recommended. | |
759 | idle=mwait. On systems which support MONITOR/MWAIT but the kernel chose | |
760 | to not use it because it doesn't save as much power as a normal idle | |
761 | loop use the MONITOR/MWAIT idle loop anyways. Performance should be the same | |
762 | as idle=poll. | |
a9913044 | 763 | |
79290822 IM |
764 | ignore_loglevel [KNL] |
765 | Ignore loglevel setting - this will print /all/ | |
766 | kernel messages to the console. Useful for debugging. | |
767 | ||
1da177e4 LT |
768 | ihash_entries= [KNL] |
769 | Set number of hash buckets for inode cache. | |
770 | ||
771 | in2000= [HW,SCSI] | |
772 | See header of drivers/scsi/in2000.c. | |
773 | ||
774 | init= [KNL] | |
775 | Format: <full_path> | |
776 | Run specified binary instead of /sbin/init as init | |
777 | process. | |
778 | ||
779 | initcall_debug [KNL] Trace initcalls as they are executed. Useful | |
780 | for working out where the kernel is dying during | |
781 | startup. | |
782 | ||
783 | initrd= [BOOT] Specify the location of the initial ramdisk | |
784 | ||
785 | inport.irq= [HW] Inport (ATI XL and Microsoft) busmouse driver | |
786 | Format: <irq> | |
787 | ||
788 | inttest= [IA64] | |
789 | ||
ba395927 KA |
790 | intel_iommu= [DMAR] Intel IOMMU driver (DMAR) option |
791 | off | |
792 | Disable intel iommu driver. | |
793 | igfx_off [Default Off] | |
794 | By default, gfx is mapped as normal device. If a gfx | |
795 | device has a dedicated DMAR unit, the DMAR unit is | |
796 | bypassed by not enabling DMAR with this option. In | |
797 | this case, gfx device will use physical address for | |
798 | DMA. | |
7d3b03ce KA |
799 | forcedac [x86_64] |
800 | With this option iommu will not optimize to look | |
801 | for io virtual address below 32 bit forcing dual | |
802 | address cycle on pci bus for cards supporting greater | |
803 | than 32 bit addressing. The default is to look | |
804 | for translation below 32 bit and if not available | |
805 | then look in the higher range. | |
ba395927 | 806 | |
b02aae9c | 807 | io_delay= [X86-32,X86-64] I/O delay method |
6e7c4025 IM |
808 | 0x80 |
809 | Standard port 0x80 based delay | |
810 | 0xed | |
811 | Alternate port 0xed based delay (needed on some systems) | |
b02aae9c | 812 | udelay |
6e7c4025 IM |
813 | Simple two microseconds delay |
814 | none | |
815 | No delay | |
b02aae9c | 816 | |
1da177e4 LT |
817 | io7= [HW] IO7 for Marvel based alpha systems |
818 | See comment before marvel_specify_io7 in | |
819 | arch/alpha/kernel/core_marvel.c. | |
820 | ||
821 | ip= [IP_PNP] | |
822 | See Documentation/nfsroot.txt. | |
823 | ||
824 | ip2= [HW] Set IO/IRQ pairs for up to 4 IntelliPort boards | |
c8facbb6 RD |
825 | See comment before ip2_setup() in |
826 | drivers/char/ip2/ip2base.c. | |
1da177e4 LT |
827 | |
828 | ips= [HW,SCSI] Adaptec / IBM ServeRAID controller | |
829 | See header of drivers/scsi/ips.c. | |
830 | ||
72c4a13a SH |
831 | ports= [IP_VS_FTP] IPVS ftp helper module |
832 | Default is 21. | |
833 | Up to 8 (IP_VS_APP_MAX_PORTS) ports | |
834 | may be specified. | |
835 | Format: <port>,<port>.... | |
836 | ||
200803df AC |
837 | irqfixup [HW] |
838 | When an interrupt is not handled search all handlers | |
839 | for it. Intended to get systems with badly broken | |
840 | firmware running. | |
841 | ||
842 | irqpoll [HW] | |
843 | When an interrupt is not handled search all handlers | |
844 | for it. Also check all handlers each timer | |
845 | interrupt. Intended to get systems with badly broken | |
846 | firmware running. | |
847 | ||
1da177e4 | 848 | isapnp= [ISAPNP] |
a9913044 | 849 | Format: <RDP>,<reset>,<pci_scan>,<verbosity> |
1da177e4 LT |
850 | |
851 | isolcpus= [KNL,SMP] Isolate CPUs from the general scheduler. | |
22f2e280 DF |
852 | Format: |
853 | <cpu number>,...,<cpu number> | |
854 | or | |
855 | <cpu number>-<cpu number> (must be a positive range in ascending order) | |
856 | or a mixture | |
857 | <cpu number>,...,<cpu number>-<cpu number> | |
1da177e4 LT |
858 | This option can be used to specify one or more CPUs |
859 | to isolate from the general SMP balancing and scheduling | |
860 | algorithms. The only way to move a process onto or off | |
861 | an "isolated" CPU is via the CPU affinity syscalls. | |
862 | <cpu number> begins at 0 and the maximum value is | |
863 | "number of CPUs in system - 1". | |
864 | ||
865 | This option is the preferred way to isolate CPUs. The | |
a9913044 RD |
866 | alternative -- manually setting the CPU mask of all |
867 | tasks in the system -- can cause problems and | |
868 | suboptimal load balancer performance. | |
1da177e4 | 869 | |
a9913044 | 870 | iucv= [HW,NET] |
1da177e4 LT |
871 | |
872 | js= [HW,JOY] Analog joystick | |
873 | See Documentation/input/joystick.txt. | |
874 | ||
cd4f0ef7 | 875 | kernelcore=nn[KMG] [KNL,X86-32,IA-64,PPC,X86-64] This parameter |
ed7ed365 MG |
876 | specifies the amount of memory usable by the kernel |
877 | for non-movable allocations. The requested amount is | |
878 | spread evenly throughout all nodes in the system. The | |
879 | remaining memory in each node is used for Movable | |
880 | pages. In the event, a node is too small to have both | |
881 | kernelcore and Movable pages, kernelcore pages will | |
882 | take priority and other nodes will have a larger number | |
883 | of kernelcore pages. The Movable zone is used for the | |
884 | allocation of pages that may be reclaimed or moved | |
885 | by the page migration subsystem. This means that | |
886 | HugeTLB pages may not be allocated from this zone. | |
887 | Note that allocations like PTEs-from-HighMem still | |
888 | use the HighMem zone if it exists, and the Normal | |
889 | zone if it does not. | |
890 | ||
cd4f0ef7 | 891 | movablecore=nn[KMG] [KNL,X86-32,IA-64,PPC,X86-64] This parameter |
7e63efef MG |
892 | is similar to kernelcore except it specifies the |
893 | amount of memory used for migratable allocations. | |
894 | If both kernelcore and movablecore is specified, | |
895 | then kernelcore will be at *least* the specified | |
896 | value but may be more. If movablecore on its own | |
897 | is specified, the administrator must be careful | |
898 | that the amount of memory usable for all allocations | |
899 | is not too small. | |
900 | ||
1da177e4 LT |
901 | keepinitrd [HW,ARM] |
902 | ||
cd4f0ef7 | 903 | kstack=N [X86-32,X86-64] Print N words from the kernel stack |
1da177e4 LT |
904 | in oops dumps. |
905 | ||
906 | l2cr= [PPC] | |
907 | ||
cd4f0ef7 | 908 | lapic [X86-32,APIC] Enable the local APIC even if BIOS |
a9913044 | 909 | disabled it. |
1da177e4 | 910 | |
cd4f0ef7 | 911 | lapic_timer_c2_ok [X86-32,x86-64,APIC] trust the local apic timer in |
e585bef8 TG |
912 | C2 power state. |
913 | ||
fcb71f6f FC |
914 | libata.dma= [LIBATA] DMA control |
915 | libata.dma=0 Disable all PATA and SATA DMA | |
916 | libata.dma=1 PATA and SATA Disk DMA only | |
917 | libata.dma=2 ATAPI (CDROM) DMA only | |
918 | libata.dma=4 Compact Flash DMA only | |
919 | Combinations also work, so libata.dma=3 enables DMA | |
920 | for disks and CDROMs, but not CFs. | |
921 | ||
78e70c23 DJ |
922 | libata.noacpi [LIBATA] Disables use of ACPI in libata suspend/resume |
923 | when set. | |
924 | Format: <int> | |
925 | ||
1da177e4 LT |
926 | load_ramdisk= [RAM] List of ramdisks to load from floppy |
927 | See Documentation/ramdisk.txt. | |
928 | ||
a6b25b67 RD |
929 | lockd.nlm_grace_period=P [NFS] Assign grace period. |
930 | Format: <integer> | |
1da177e4 | 931 | |
a6b25b67 RD |
932 | lockd.nlm_tcpport=N [NFS] Assign TCP port. |
933 | Format: <integer> | |
934 | ||
935 | lockd.nlm_timeout=T [NFS] Assign timeout value. | |
936 | Format: <integer> | |
937 | ||
938 | lockd.nlm_udpport=M [NFS] Assign UDP port. | |
939 | Format: <integer> | |
1da177e4 LT |
940 | |
941 | logibm.irq= [HW,MOUSE] Logitech Bus Mouse Driver | |
942 | Format: <irq> | |
943 | ||
944 | loglevel= All Kernel Messages with a loglevel smaller than the | |
945 | console loglevel will be printed to the console. It can | |
946 | also be changed with klogd or other programs. The | |
947 | loglevels are defined as follows: | |
948 | ||
949 | 0 (KERN_EMERG) system is unusable | |
950 | 1 (KERN_ALERT) action must be taken immediately | |
951 | 2 (KERN_CRIT) critical conditions | |
952 | 3 (KERN_ERR) error conditions | |
953 | 4 (KERN_WARNING) warning conditions | |
954 | 5 (KERN_NOTICE) normal but significant condition | |
955 | 6 (KERN_INFO) informational | |
956 | 7 (KERN_DEBUG) debug-level messages | |
957 | ||
958 | log_buf_len=n Sets the size of the printk ring buffer, in bytes. | |
a9913044 RD |
959 | Format: { n | nk | nM } |
960 | n must be a power of two. The default size | |
961 | is set in the kernel config file. | |
1da177e4 | 962 | |
accaa24c RD |
963 | logo.nologo [FB] Disables display of the built-in Linux logo. |
964 | This may be used to provide more screen space for | |
965 | kernel log messages and is useful when debugging | |
966 | kernel boot problems. | |
967 | ||
1da177e4 LT |
968 | lp=0 [LP] Specify parallel ports to use, e.g, |
969 | lp=port[,port...] lp=none,parport0 (lp0 not configured, lp1 uses | |
970 | lp=reset first parallel port). 'lp=0' disables the | |
971 | lp=auto printer driver. 'lp=reset' (which can be | |
972 | specified in addition to the ports) causes | |
973 | attached printers to be reset. Using | |
974 | lp=port1,port2,... specifies the parallel ports | |
975 | to associate lp devices with, starting with | |
976 | lp0. A port specification may be 'none' to skip | |
977 | that lp device, or a parport name such as | |
978 | 'parport0'. Specifying 'lp=auto' instead of a | |
979 | port specification list means that device IDs | |
980 | from each port should be examined, to see if | |
981 | an IEEE 1284-compliant printer is attached; if | |
982 | so, the driver will manage that printer. | |
983 | See also header of drivers/char/lp.c. | |
984 | ||
985 | lpj=n [KNL] | |
986 | Sets loops_per_jiffy to given constant, thus avoiding | |
987 | time-consuming boot-time autodetection (up to 250 ms per | |
988 | CPU). 0 enables autodetection (default). To determine | |
989 | the correct value for your kernel, boot with normal | |
990 | autodetection and see what value is printed. Note that | |
991 | on SMP systems the preset will be applied to all CPUs, | |
992 | which is likely to cause problems if your CPUs need | |
993 | significantly divergent settings. An incorrect value | |
994 | will cause delays in the kernel to be wrong, leading to | |
995 | unpredictable I/O errors and other breakage. Although | |
996 | unlikely, in the extreme case this might damage your | |
997 | hardware. | |
998 | ||
999 | ltpc= [NET] | |
1000 | Format: <io>,<irq>,<dma> | |
1001 | ||
a9913044 RD |
1002 | mac5380= [HW,SCSI] Format: |
1003 | <can_queue>,<cmd_per_lun>,<sg_tablesize>,<hostid>,<use_tags> | |
1da177e4 | 1004 | |
a9913044 RD |
1005 | mac53c9x= [HW,SCSI] Format: |
1006 | <num_esps>,<disconnect>,<nosync>,<can_queue>,<cmd_per_lun>,<sg_tablesize>,<hostid>,<use_tags> | |
1da177e4 | 1007 | |
a9913044 RD |
1008 | machvec= [IA64] Force the use of a particular machine-vector |
1009 | (machvec) in a generic kernel. | |
1010 | Example: machvec=hpzx1_swiotlb | |
1da177e4 | 1011 | |
a9913044 | 1012 | max_loop= [LOOP] Maximum number of loopback devices that can |
1da177e4 LT |
1013 | be mounted |
1014 | Format: <1-256> | |
1015 | ||
1016 | maxcpus= [SMP] Maximum number of processors that an SMP kernel | |
61ec7567 LB |
1017 | should make use of. maxcpus=n : n >= 0 limits the |
1018 | kernel to using 'n' processors. n=0 is a special case, | |
1019 | it is equivalent to "nosmp", which also disables | |
1020 | the IO APIC. | |
1da177e4 | 1021 | |
2b2c3750 BP |
1022 | max_addr=[KMG] [KNL,BOOT,ia64] All physical memory greater than or |
1023 | equal to this physical address is ignored. | |
1024 | ||
a9913044 | 1025 | max_luns= [SCSI] Maximum number of LUNs to probe. |
1da177e4 LT |
1026 | Should be between 1 and 2^32-1. |
1027 | ||
1028 | max_report_luns= | |
a9913044 | 1029 | [SCSI] Maximum number of LUNs received. |
1da177e4 LT |
1030 | Should be between 1 and 16384. |
1031 | ||
cd4f0ef7 | 1032 | mca-pentium [BUGS=X86-32] |
1da177e4 LT |
1033 | |
1034 | mcatest= [IA-64] | |
1035 | ||
cd4f0ef7 | 1036 | mce [X86-32] Machine Check Exception |
1da177e4 | 1037 | |
909dd324 AK |
1038 | mce=option [X86-64] See Documentation/x86_64/boot-options.txt |
1039 | ||
1da177e4 LT |
1040 | md= [HW] RAID subsystems devices and level |
1041 | See Documentation/md.txt. | |
a9913044 | 1042 | |
1da177e4 LT |
1043 | mdacon= [MDA] |
1044 | Format: <first>,<last> | |
1045 | Specifies range of consoles to be captured by the MDA. | |
a9913044 | 1046 | |
1da177e4 LT |
1047 | mem=nn[KMG] [KNL,BOOT] Force usage of a specific amount of memory |
1048 | Amount of memory to be used when the kernel is not able | |
1049 | to see the whole system memory or for test. | |
cd4f0ef7 | 1050 | [X86-32] Use together with memmap= to avoid physical |
1da177e4 LT |
1051 | address space collisions. Without memmap= PCI devices |
1052 | could be placed at addresses belonging to unused RAM. | |
1053 | ||
cd4f0ef7 | 1054 | mem=nopentium [BUGS=X86-32] Disable usage of 4MB pages for kernel |
1da177e4 LT |
1055 | memory. |
1056 | ||
cd4f0ef7 | 1057 | memmap=exactmap [KNL,X86-32,X86_64] Enable setting of an exact |
1da177e4 LT |
1058 | E820 memory map, as specified by the user. |
1059 | Such memmap=exactmap lines can be constructed based on | |
1060 | BIOS output or other requirements. See the memmap=nn@ss | |
1061 | option description. | |
1062 | ||
1063 | memmap=nn[KMG]@ss[KMG] | |
1064 | [KNL] Force usage of a specific region of memory | |
1065 | Region of memory to be used, from ss to ss+nn. | |
1066 | ||
1067 | memmap=nn[KMG]#ss[KMG] | |
1068 | [KNL,ACPI] Mark specific memory as ACPI data. | |
1069 | Region of memory to be used, from ss to ss+nn. | |
1070 | ||
1071 | memmap=nn[KMG]$ss[KMG] | |
1072 | [KNL,ACPI] Mark specific memory as reserved. | |
1073 | Region of memory to be used, from ss to ss+nn. | |
1074 | ||
1075 | meye.*= [HW] Set MotionEye Camera parameters | |
1076 | See Documentation/video4linux/meye.txt. | |
1077 | ||
8f36881b AS |
1078 | mfgpt_irq= [IA-32] Specify the IRQ to use for the |
1079 | Multi-Function General Purpose Timers on AMD Geode | |
1080 | platforms. | |
1081 | ||
1da177e4 LT |
1082 | mga= [HW,DRM] |
1083 | ||
1084 | mousedev.tap_time= | |
1085 | [MOUSE] Maximum time between finger touching and | |
1086 | leaving touchpad surface for touch to be considered | |
1087 | a tap and be reported as a left button click (for | |
1088 | touchpads working in absolute mode only). | |
1089 | Format: <msecs> | |
1090 | mousedev.xres= [MOUSE] Horizontal screen resolution, used for devices | |
1091 | reporting absolute coordinates, such as tablets | |
1092 | mousedev.yres= [MOUSE] Vertical screen resolution, used for devices | |
1093 | reporting absolute coordinates, such as tablets | |
1094 | ||
1095 | mpu401= [HW,OSS] | |
1096 | Format: <io>,<irq> | |
1097 | ||
1098 | MTD_Partition= [MTD] | |
1099 | Format: <name>,<region-number>,<size>,<offset> | |
1100 | ||
a9913044 RD |
1101 | MTD_Region= [MTD] Format: |
1102 | <name>,<region-number>[,<base>,<size>,<buswidth>,<altbuswidth>] | |
1da177e4 LT |
1103 | |
1104 | mtdparts= [MTD] | |
c8facbb6 | 1105 | See drivers/mtd/cmdlinepart.c. |
1da177e4 LT |
1106 | |
1107 | mtouchusb.raw_coordinates= | |
a9913044 RD |
1108 | [HW] Make the MicroTouch USB driver use raw coordinates |
1109 | ('y', default) or cooked coordinates ('n') | |
1da177e4 LT |
1110 | |
1111 | n2= [NET] SDL Inc. RISCom/N2 synchronous serial card | |
1112 | ||
1113 | NCR_D700= [HW,SCSI] | |
1114 | See header of drivers/scsi/NCR_D700.c. | |
1115 | ||
1116 | ncr5380= [HW,SCSI] | |
1117 | ||
1118 | ncr53c400= [HW,SCSI] | |
1119 | ||
1120 | ncr53c400a= [HW,SCSI] | |
1121 | ||
1122 | ncr53c406a= [HW,SCSI] | |
1123 | ||
1124 | ncr53c8xx= [HW,SCSI] | |
1125 | ||
1126 | netdev= [NET] Network devices parameters | |
1127 | Format: <irq>,<io>,<mem_start>,<mem_end>,<name> | |
1128 | Note that mem_start is often overloaded to mean | |
1129 | something different and driver-specific. | |
a9913044 RD |
1130 | This usage is only documented in each driver source |
1131 | file if at all. | |
1132 | ||
1da177e4 LT |
1133 | nfsaddrs= [NFS] |
1134 | See Documentation/nfsroot.txt. | |
1135 | ||
1136 | nfsroot= [NFS] nfs root filesystem for disk-less boxes. | |
1137 | See Documentation/nfsroot.txt. | |
1138 | ||
a72b4422 TM |
1139 | nfs.callback_tcpport= |
1140 | [NFS] set the TCP port on which the NFSv4 callback | |
1141 | channel should listen. | |
1142 | ||
58df095b TM |
1143 | nfs.idmap_cache_timeout= |
1144 | [NFS] set the maximum lifetime for idmapper cache | |
1145 | entries. | |
1146 | ||
f43bf0be TM |
1147 | nfs.enable_ino64= |
1148 | [NFS] enable 64-bit inode numbers. | |
1149 | If zero, the NFS client will fake up a 32-bit inode | |
1150 | number for the readdir() and stat() syscalls instead | |
1151 | of returning the full 64-bit number. | |
1152 | The default is to return 64-bit inode numbers. | |
1153 | ||
e7ba176b HS |
1154 | nmi_debug= [KNL,AVR32] Specify one or more actions to take |
1155 | when a NMI is triggered. | |
1156 | Format: [state][,regs][,debounce][,die] | |
1157 | ||
cd4f0ef7 | 1158 | nmi_watchdog= [KNL,BUGS=X86-32] Debugging features for SMP kernels |
1da177e4 | 1159 | |
cd4f0ef7 | 1160 | no387 [BUGS=X86-32] Tells the kernel to use the 387 maths |
1da177e4 LT |
1161 | emulation library even if a 387 maths coprocessor |
1162 | is present. | |
1163 | ||
c1aee215 CL |
1164 | noaliencache [MM, NUMA, SLAB] Disables the allocation of alien |
1165 | caches in the slab allocator. Saves per-node memory, | |
1166 | but will impact performance. | |
3395ee05 | 1167 | |
a9913044 RD |
1168 | noalign [KNL,ARM] |
1169 | ||
1da177e4 LT |
1170 | noapic [SMP,APIC] Tells the kernel to not make use of any |
1171 | IOAPICs that may be present in the system. | |
1172 | ||
1da177e4 LT |
1173 | nobats [PPC] Do not use BATs for mapping kernel lowmem |
1174 | on "Classic" PPC cores. | |
1175 | ||
1176 | nocache [ARM] | |
a9913044 | 1177 | |
163ecdff SN |
1178 | nodelayacct [KNL] Disable per-task delay accounting |
1179 | ||
1da177e4 LT |
1180 | nodisconnect [HW,SCSI,M68K] Disables SCSI disconnects. |
1181 | ||
8b2cb7a8 HY |
1182 | noefi [X86-32,X86-64] Disable EFI runtime services support. |
1183 | ||
1da177e4 LT |
1184 | noexec [IA-64] |
1185 | ||
cd4f0ef7 | 1186 | noexec [X86-32,X86-64] |
1da177e4 LT |
1187 | noexec=on: enable non-executable mappings (default) |
1188 | noexec=off: disable nn-executable mappings | |
1189 | ||
cd4f0ef7 | 1190 | nofxsr [BUGS=X86-32] Disables x86 floating point extended |
4f886511 CE |
1191 | register save and restore. The kernel will only save |
1192 | legacy floating-point registers on task switch. | |
1da177e4 LT |
1193 | |
1194 | nohlt [BUGS=ARM] | |
a9913044 | 1195 | |
cd4f0ef7 | 1196 | no-hlt [BUGS=X86-32] Tells the kernel that the hlt |
1da177e4 LT |
1197 | instruction doesn't work correctly and not to |
1198 | use it. | |
1199 | ||
1200 | nohalt [IA-64] Tells the kernel not to use the power saving | |
1201 | function PAL_HALT_LIGHT when idle. This increases | |
1202 | power-consumption. On the positive side, it reduces | |
1203 | interrupt wake-up latency, which may improve performance | |
1204 | in certain environments such as networked servers or | |
1205 | real-time systems. | |
1206 | ||
79bf2bb3 TG |
1207 | nohz= [KNL] Boottime enable/disable dynamic ticks |
1208 | Valid arguments: on, off | |
1209 | Default: on | |
1210 | ||
cd4f0ef7 | 1211 | noirqbalance [X86-32,SMP,KNL] Disable kernel irq balancing |
8542b200 | 1212 | |
cd4f0ef7 | 1213 | noirqdebug [X86-32] Disables the code which attempts to detect and |
1da177e4 LT |
1214 | disable unhandled interrupt sources. |
1215 | ||
cd4f0ef7 | 1216 | no_timer_check [X86-32,X86_64,APIC] Disables the code which tests for |
8542b200 ZA |
1217 | broken timer IRQ sources. |
1218 | ||
1da177e4 LT |
1219 | noisapnp [ISAPNP] Disables ISA PnP code. |
1220 | ||
1221 | noinitrd [RAM] Tells the kernel not to load any configured | |
1222 | initial RAM disk. | |
1223 | ||
1224 | nointroute [IA-64] | |
1225 | ||
0aa366f3 TL |
1226 | nojitter [IA64] Disables jitter checking for ITC timers. |
1227 | ||
cd4f0ef7 | 1228 | nolapic [X86-32,APIC] Do not enable or use the local APIC. |
1da177e4 | 1229 | |
cd4f0ef7 | 1230 | nolapic_timer [X86-32,APIC] Do not use the local APIC timer. |
ad62ca2b | 1231 | |
1da177e4 LT |
1232 | noltlbs [PPC] Do not use large page/tlb entries for kernel |
1233 | lowmem mapping on PPC40x. | |
1234 | ||
312f1f01 H |
1235 | nomca [IA-64] Disable machine check abort handling |
1236 | ||
cd4f0ef7 | 1237 | nomce [X86-32] Machine Check Exception |
abe37e5a | 1238 | |
83d7384f AS |
1239 | nomfgpt [X86-32] Disable Multi-Function General Purpose |
1240 | Timer usage (for AMD Geode machines). | |
1241 | ||
cd4f0ef7 | 1242 | noreplace-paravirt [X86-32,PV_OPS] Don't patch paravirt_ops |
959b4fdf | 1243 | |
cd4f0ef7 | 1244 | noreplace-smp [X86-32,SMP] Don't replace SMP instructions |
b7fb4af0 JF |
1245 | with UP alternatives |
1246 | ||
1da177e4 LT |
1247 | noresidual [PPC] Don't use residual data on PReP machines. |
1248 | ||
a9913044 RD |
1249 | noresume [SWSUSP] Disables resume and restores original swap |
1250 | space. | |
1251 | ||
1da177e4 LT |
1252 | no-scroll [VGA] Disables scrollback. |
1253 | This is required for the Braillex ib80-piezo Braille | |
1254 | reader made by F.H. Papenmeier (Germany). | |
1255 | ||
1256 | nosbagart [IA-64] | |
1257 | ||
cd4f0ef7 | 1258 | nosep [BUGS=X86-32] Disables x86 SYSENTER/SYSEXIT support. |
4f886511 | 1259 | |
61ec7567 LB |
1260 | nosmp [SMP] Tells an SMP kernel to act as a UP kernel, |
1261 | and disable the IO APIC. legacy for "maxcpus=0". | |
1da177e4 | 1262 | |
97842216 DJ |
1263 | nosoftlockup [KNL] Disable the soft-lockup detector. |
1264 | ||
1da177e4 LT |
1265 | nosync [HW,M68K] Disables sync negotiation for all devices. |
1266 | ||
cd4f0ef7 | 1267 | notsc [BUGS=X86-32] Disable Time Stamp Counter |
1da177e4 LT |
1268 | |
1269 | nousb [USB] Disable the USB subsystem | |
1270 | ||
1271 | nowb [ARM] | |
a9913044 | 1272 | |
f0c0b2b8 KH |
1273 | numa_zonelist_order= [KNL, BOOT] Select zonelist order for NUMA. |
1274 | one of ['zone', 'node', 'default'] can be specified | |
1275 | This can be set from sysctl after boot. | |
1276 | See Documentation/sysctl/vm.txt for details. | |
1277 | ||
a61c2d78 DJ |
1278 | nr_uarts= [SERIAL] maximum number of UARTs to be registered. |
1279 | ||
1da177e4 LT |
1280 | opl3= [HW,OSS] |
1281 | Format: <io> | |
1282 | ||
1da177e4 LT |
1283 | oprofile.timer= [HW] |
1284 | Use timer interrupt instead of performance counters | |
1285 | ||
1da177e4 LT |
1286 | osst= [HW,SCSI] SCSI Tape Driver |
1287 | Format: <buffer_size>,<write_threshold> | |
1288 | See also Documentation/scsi/st.txt. | |
1289 | ||
1290 | panic= [KNL] Kernel behaviour on panic | |
1291 | Format: <timeout> | |
1292 | ||
1293 | parkbd.port= [HW] Parallel port number the keyboard adapter is | |
1294 | connected to, default is 0. | |
1295 | Format: <parport#> | |
1296 | parkbd.mode= [HW] Parallel port keyboard adapter mode of operation, | |
1297 | 0 for XT, 1 for AT (default is AT). | |
a9913044 RD |
1298 | Format: <mode> |
1299 | ||
1300 | parport= [HW,PPT] Specify parallel ports. 0 disables. | |
1301 | Format: { 0 | auto | 0xBBB[,IRQ[,DMA]] } | |
1302 | Use 'auto' to force the driver to use any | |
1303 | IRQ/DMA settings detected (the default is to | |
1304 | ignore detected IRQ/DMA settings because of | |
1305 | possible conflicts). You can specify the base | |
1306 | address, IRQ, and DMA settings; IRQ and DMA | |
1307 | should be numbers, or 'auto' (for using detected | |
1308 | settings on that particular port), or 'nofifo' | |
1309 | (to avoid using a FIFO even if it is detected). | |
1310 | Parallel ports are assigned in the order they | |
1311 | are specified on the command line, starting | |
1312 | with parport0. | |
1313 | ||
1314 | parport_init_mode= [HW,PPT] | |
1315 | Configure VIA parallel port to operate in | |
1316 | a specific mode. This is necessary on Pegasos | |
1317 | computer where firmware has no options for setting | |
1318 | up parallel port mode and sets it to spp. | |
1319 | Currently this function knows 686a and 8231 chips. | |
1da177e4 LT |
1320 | Format: [spp|ps2|epp|ecp|ecpepp] |
1321 | ||
a9913044 RD |
1322 | pas2= [HW,OSS] Format: |
1323 | <io>,<irq>,<dma>,<dma16>,<sb_io>,<sb_irq>,<sb_dma>,<sb_dma16> | |
1324 | ||
1da177e4 LT |
1325 | pas16= [HW,SCSI] |
1326 | See header of drivers/scsi/pas16.c. | |
1327 | ||
dd287796 AM |
1328 | pause_on_oops= |
1329 | Halt all CPUs after the first oops has been printed for | |
1330 | the specified number of seconds. This is to be used if | |
1331 | your oopses keep scrolling off the screen. | |
1332 | ||
1da177e4 LT |
1333 | pcbit= [HW,ISDN] |
1334 | ||
1335 | pcd. [PARIDE] | |
1336 | See header of drivers/block/paride/pcd.c. | |
1337 | See also Documentation/paride.txt. | |
1338 | ||
a9913044 | 1339 | pci=option[,option...] [PCI] various PCI subsystem options: |
cd4f0ef7 AC |
1340 | off [X86-32] don't probe for the PCI bus |
1341 | bios [X86-32] force use of PCI BIOS, don't access | |
a9913044 RD |
1342 | the hardware directly. Use this if your machine |
1343 | has a non-standard PCI host bridge. | |
cd4f0ef7 | 1344 | nobios [X86-32] disallow use of PCI BIOS, only direct |
a9913044 RD |
1345 | hardware access methods are allowed. Use this |
1346 | if you experience crashes upon bootup and you | |
1347 | suspect they are caused by the BIOS. | |
cd4f0ef7 | 1348 | conf1 [X86-32] Force use of PCI Configuration |
a9913044 | 1349 | Mechanism 1. |
cd4f0ef7 | 1350 | conf2 [X86-32] Force use of PCI Configuration |
a9913044 | 1351 | Mechanism 2. |
7f785763 RD |
1352 | noaer [PCIE] If the PCIEAER kernel config parameter is |
1353 | enabled, this kernel boot option can be used to | |
1354 | disable the use of PCIE advanced error reporting. | |
32a2eea7 JG |
1355 | nodomains [PCI] Disable support for multiple PCI |
1356 | root domains (aka PCI segments, in ACPI-speak). | |
cd4f0ef7 | 1357 | nommconf [X86-32,X86_64] Disable use of MMCONFIG for PCI |
61be6d66 | 1358 | Configuration |
309e57df MW |
1359 | nomsi [MSI] If the PCI_MSI kernel config parameter is |
1360 | enabled, this kernel boot option can be used to | |
1361 | disable the use of MSI interrupts system-wide. | |
cd4f0ef7 | 1362 | nosort [X86-32] Don't sort PCI devices according to |
a9913044 RD |
1363 | order given by the PCI BIOS. This sorting is |
1364 | done to get a device order compatible with | |
1365 | older kernels. | |
cd4f0ef7 | 1366 | biosirq [X86-32] Use PCI BIOS calls to get the interrupt |
a9913044 RD |
1367 | routing table. These calls are known to be buggy |
1368 | on several machines and they hang the machine | |
1369 | when used, but on other computers it's the only | |
1370 | way to get the interrupt routing table. Try | |
1371 | this option if the kernel is unable to allocate | |
1372 | IRQs or discover secondary PCI buses on your | |
1373 | motherboard. | |
cd4f0ef7 | 1374 | rom [X86-32] Assign address space to expansion ROMs. |
a9913044 RD |
1375 | Use with caution as certain devices share |
1376 | address decoders between ROMs and other | |
1377 | resources. | |
cd4f0ef7 | 1378 | irqmask=0xMMMM [X86-32] Set a bit mask of IRQs allowed to be |
a9913044 RD |
1379 | assigned automatically to PCI devices. You can |
1380 | make the kernel exclude IRQs of your ISA cards | |
1381 | this way. | |
cd4f0ef7 | 1382 | pirqaddr=0xAAAAA [X86-32] Specify the physical address |
a9913044 RD |
1383 | of the PIRQ table (normally generated |
1384 | by the BIOS) if it is outside the | |
1385 | F0000h-100000h range. | |
cd4f0ef7 | 1386 | lastbus=N [X86-32] Scan all buses thru bus #N. Can be |
a9913044 RD |
1387 | useful if the kernel is unable to find your |
1388 | secondary buses and you want to tell it | |
1389 | explicitly which ones they are. | |
cd4f0ef7 | 1390 | assign-busses [X86-32] Always assign all PCI bus |
a9913044 RD |
1391 | numbers ourselves, overriding |
1392 | whatever the firmware may have done. | |
cd4f0ef7 | 1393 | usepirqmask [X86-32] Honor the possible IRQ mask stored |
a9913044 RD |
1394 | in the BIOS $PIR table. This is needed on |
1395 | some systems with broken BIOSes, notably | |
1396 | some HP Pavilion N5400 and Omnibook XE3 | |
1397 | notebooks. This will have no effect if ACPI | |
1398 | IRQ routing is enabled. | |
cd4f0ef7 | 1399 | noacpi [X86-32] Do not use ACPI for IRQ routing |
a9913044 | 1400 | or for PCI scanning. |
62f420f8 GH |
1401 | use_crs [X86-32] Use _CRS for PCI resource |
1402 | allocation. | |
a9913044 RD |
1403 | routeirq Do IRQ routing for all PCI devices. |
1404 | This is normally done in pci_enable_device(), | |
1405 | so this option is a temporary workaround | |
1406 | for broken drivers that don't call it. | |
1407 | firmware [ARM] Do not re-enumerate the bus but instead | |
1408 | just use the configuration from the | |
1409 | bootloader. This is currently used on | |
1410 | IXP2000 systems where the bus has to be | |
1411 | configured a certain way for adjunct CPUs. | |
0637a70a AK |
1412 | noearly [X86] Don't do any early type 1 scanning. |
1413 | This might help on some broken boards which | |
1414 | machine check when some devices' config space | |
1415 | is read. But various workarounds are disabled | |
1416 | and some IOMMU drivers will not work. | |
6b4b78fe MD |
1417 | bfsort Sort PCI devices into breadth-first order. |
1418 | This sorting is done to get a device | |
1419 | order compatible with older (<= 2.4) kernels. | |
1420 | nobfsort Don't sort PCI devices into breadth-first order. | |
4516a618 AN |
1421 | cbiosize=nn[KMG] The fixed amount of bus space which is |
1422 | reserved for the CardBus bridge's IO window. | |
1423 | The default value is 256 bytes. | |
1424 | cbmemsize=nn[KMG] The fixed amount of bus space which is | |
1425 | reserved for the CardBus bridge's memory | |
1426 | window. The default value is 64 megabytes. | |
6b4b78fe | 1427 | |
1da177e4 LT |
1428 | pcmv= [HW,PCMCIA] BadgePAD 4 |
1429 | ||
1430 | pd. [PARIDE] | |
1431 | See Documentation/paride.txt. | |
1432 | ||
1433 | pdcchassis= [PARISC,HW] Disable/Enable PDC Chassis Status codes at | |
1434 | boot time. | |
1435 | Format: { 0 | 1 } | |
1436 | See arch/parisc/kernel/pdc_chassis.c | |
1437 | ||
1438 | pf. [PARIDE] | |
1439 | See Documentation/paride.txt. | |
1440 | ||
1441 | pg. [PARIDE] | |
1442 | See Documentation/paride.txt. | |
1443 | ||
1444 | pirq= [SMP,APIC] Manual mp-table setup | |
1445 | See Documentation/i386/IO-APIC.txt. | |
1446 | ||
1447 | plip= [PPT,NET] Parallel port network link | |
1448 | Format: { parport<nr> | timid | 0 } | |
1449 | See also Documentation/parport.txt. | |
1450 | ||
1451 | pnpacpi= [ACPI] | |
1452 | { off } | |
1453 | ||
1454 | pnpbios= [ISAPNP] | |
1455 | { on | off | curr | res | no-curr | no-res } | |
1456 | ||
1457 | pnp_reserve_irq= | |
1458 | [ISAPNP] Exclude IRQs for the autoconfiguration | |
1459 | ||
1460 | pnp_reserve_dma= | |
1461 | [ISAPNP] Exclude DMAs for the autoconfiguration | |
1462 | ||
1463 | pnp_reserve_io= [ISAPNP] Exclude I/O ports for the autoconfiguration | |
a9913044 | 1464 | Ranges are in pairs (I/O port base and size). |
1da177e4 LT |
1465 | |
1466 | pnp_reserve_mem= | |
a9913044 RD |
1467 | [ISAPNP] Exclude memory regions for the |
1468 | autoconfiguration. | |
1da177e4 LT |
1469 | Ranges are in pairs (memory base and size). |
1470 | ||
45807a1d IM |
1471 | print-fatal-signals= |
1472 | [KNL] debug: print fatal signals | |
1473 | print-fatal-signals=1: print segfault info to | |
1474 | the kernel console. | |
1475 | default: off. | |
1476 | ||
e84845c4 RD |
1477 | printk.time= Show timing data prefixed to each printk message line |
1478 | Format: <bool> (1/Y/y=enable, 0/N/n=disable) | |
1479 | ||
1da177e4 | 1480 | profile= [KNL] Enable kernel profiling via /proc/profile |
a9913044 RD |
1481 | Format: [schedule,]<number> |
1482 | Param: "schedule" - profile schedule points. | |
1483 | Param: <number> - step/bucket size as a power of 2 for | |
1484 | statistical time based profiling. | |
b3da2a73 MG |
1485 | Param: "sleep" - profile D-state sleeping (millisecs). |
1486 | Requires CONFIG_SCHEDSTATS | |
c0fe2e69 | 1487 | Param: "kvm" - profile VM exits. |
1da177e4 | 1488 | |
a9913044 | 1489 | processor.max_cstate= [HW,ACPI] |
1da177e4 LT |
1490 | Limit processor to maximum C-state |
1491 | max_cstate=9 overrides any DMI blacklist limit. | |
1492 | ||
41c0d868 LB |
1493 | processor.nocst [HW,ACPI] |
1494 | Ignore the _CST method to determine C-states, | |
1495 | instead using the legacy FADT method | |
1496 | ||
1da177e4 LT |
1497 | prompt_ramdisk= [RAM] List of RAM disks to prompt for floppy disk |
1498 | before loading. | |
1499 | See Documentation/ramdisk.txt. | |
1500 | ||
a9913044 RD |
1501 | psmouse.proto= [HW,MOUSE] Highest PS2 mouse protocol extension to |
1502 | probe for; one of (bare|imps|exps|lifebook|any). | |
1da177e4 LT |
1503 | psmouse.rate= [HW,MOUSE] Set desired mouse report rate, in reports |
1504 | per second. | |
a9913044 RD |
1505 | psmouse.resetafter= [HW,MOUSE] |
1506 | Try to reset the device after so many bad packets | |
1da177e4 LT |
1507 | (0 = never). |
1508 | psmouse.resolution= | |
1509 | [HW,MOUSE] Set desired mouse resolution, in dpi. | |
1510 | psmouse.smartscroll= | |
a9913044 | 1511 | [HW,MOUSE] Controls Logitech smartscroll autorepeat. |
1da177e4 LT |
1512 | 0 = disabled, 1 = enabled (default). |
1513 | ||
1514 | pss= [HW,OSS] Personal Sound System (ECHO ESC614) | |
a9913044 RD |
1515 | Format: |
1516 | <io>,<mss_io>,<mss_irq>,<mss_dma>,<mpu_io>,<mpu_irq> | |
1da177e4 LT |
1517 | |
1518 | pt. [PARIDE] | |
1519 | See Documentation/paride.txt. | |
1520 | ||
dc8c8587 KS |
1521 | pty.legacy_count= |
1522 | [KNL] Number of legacy pty's. Overwrites compiled-in | |
1523 | default number. | |
1524 | ||
7d2c502f | 1525 | quiet [KNL] Disable most log messages |
a9913044 | 1526 | |
1da177e4 LT |
1527 | r128= [HW,DRM] |
1528 | ||
1529 | raid= [HW,RAID] | |
1530 | See Documentation/md.txt. | |
1531 | ||
a9913044 | 1532 | ramdisk_blocksize= [RAM] |
1da177e4 | 1533 | See Documentation/ramdisk.txt. |
a9913044 | 1534 | |
1da177e4 | 1535 | ramdisk_size= [RAM] Sizes of RAM disks in kilobytes |
1da177e4 LT |
1536 | See Documentation/ramdisk.txt. |
1537 | ||
21a1ea9e DS |
1538 | rcu.blimit= [KNL,BOOT] Set maximum number of finished |
1539 | RCU callbacks to process in one batch. | |
1540 | ||
1541 | rcu.qhimark= [KNL,BOOT] Set threshold of queued | |
1542 | RCU callbacks over which batch limiting is disabled. | |
1543 | ||
1544 | rcu.qlowmark= [KNL,BOOT] Set threshold of queued | |
1545 | RCU callbacks below which batch limiting is re-enabled. | |
1546 | ||
ffdfc409 OJ |
1547 | rdinit= [KNL] |
1548 | Format: <full_path> | |
1549 | Run specified binary instead of /init from the ramdisk, | |
1550 | used for early userspace startup. See initrd. | |
1551 | ||
cd4f0ef7 | 1552 | reboot= [BUGS=X86-32,BUGS=ARM,BUGS=IA-64] Rebooting mode |
1da177e4 | 1553 | Format: <reboot_mode>[,<reboot_mode2>[,...]] |
e53dd083 | 1554 | See arch/*/kernel/reboot.c or arch/*/kernel/process.c |
1da177e4 LT |
1555 | |
1556 | reserve= [KNL,BUGS] Force the kernel to ignore some iomem area | |
1557 | ||
cd4f0ef7 | 1558 | reservetop= [X86-32] |
461a9aff ZA |
1559 | Format: nn[KMG] |
1560 | Reserves a hole at the top of the kernel virtual | |
1561 | address space. | |
1562 | ||
7e96287d VG |
1563 | reset_devices [KNL] Force drivers to reset the underlying device |
1564 | during initialization. | |
1565 | ||
a9913044 RD |
1566 | resume= [SWSUSP] |
1567 | Specify the partition device for software suspend | |
1da177e4 | 1568 | |
ecbd0da1 RW |
1569 | resume_offset= [SWSUSP] |
1570 | Specify the offset from the beginning of the partition | |
1571 | given by "resume=" at which the swap header is located, | |
1572 | in <PAGE_SIZE> units (needed only for swap files). | |
1573 | See Documentation/power/swsusp-and-swap-files.txt | |
1574 | ||
0a7b35cb MN |
1575 | retain_initrd [RAM] Keep initrd memory after extraction |
1576 | ||
1da177e4 LT |
1577 | rhash_entries= [KNL,NET] |
1578 | Set number of hash buckets for route cache | |
1579 | ||
1580 | riscom8= [HW,SERIAL] | |
1581 | Format: <io_board1>[,<io_board2>[,...<io_boardN>]] | |
1582 | ||
1583 | ro [KNL] Mount root device read-only on boot | |
1584 | ||
1585 | root= [KNL] Root filesystem | |
1586 | ||
1587 | rootdelay= [KNL] Delay (in seconds) to pause before attempting to | |
1588 | mount the root filesystem | |
1589 | ||
1590 | rootflags= [KNL] Set root filesystem mount option string | |
1591 | ||
1592 | rootfstype= [KNL] Set root filesystem type | |
1593 | ||
cc1ed754 PO |
1594 | rootwait [KNL] Wait (indefinitely) for root device to show up. |
1595 | Useful for devices that are detected asynchronously | |
1596 | (e.g. USB and MMC devices). | |
1597 | ||
20510f2f JM |
1598 | root_plug.vendor_id= |
1599 | [ROOTPLUG] Override the default vendor ID | |
1600 | ||
1601 | root_plug.product_id= | |
1602 | [ROOTPLUG] Override the default product ID | |
1603 | ||
1604 | root_plug.debug= | |
1605 | [ROOTPLUG] Enable debugging output | |
1606 | ||
1da177e4 LT |
1607 | rw [KNL] Mount root device read-write on boot |
1608 | ||
1609 | S [KNL] Run init in single mode | |
1610 | ||
1611 | sa1100ir [NET] | |
1612 | See drivers/net/irda/sa1100_ir.c. | |
1613 | ||
1da177e4 | 1614 | sbni= [NET] Granch SBNI12 leased line adapter |
a9913044 | 1615 | |
1da177e4 LT |
1616 | sc1200wdt= [HW,WDT] SC1200 WDT (watchdog) driver |
1617 | Format: <io>[,<timeout>[,<isapnp>]] | |
1618 | ||
1619 | scsi_debug_*= [SCSI] | |
1620 | See drivers/scsi/scsi_debug.c. | |
1621 | ||
1622 | scsi_default_dev_flags= | |
1623 | [SCSI] SCSI default device flags | |
1624 | Format: <integer> | |
1625 | ||
1626 | scsi_dev_flags= [SCSI] Black/white list entry for vendor and model | |
1627 | Format: <vendor>:<model>:<flags> | |
1628 | (flags are integer value) | |
1629 | ||
6af6632a RD |
1630 | scsi_logging_level= [SCSI] a bit mask of logging levels |
1631 | See drivers/scsi/scsi_logging.h for bits. Also | |
1632 | settable via sysctl at dev.scsi.logging_level | |
1633 | (/proc/sys/dev/scsi/logging_level). | |
1634 | There is also a nice 'scsi_logging_level' script in the | |
1635 | S390-tools package, available for download at | |
1636 | http://www-128.ibm.com/developerworks/linux/linux390/s390-tools-1.5.4.html | |
1da177e4 | 1637 | |
3e082a91 MW |
1638 | scsi_mod.scan= [SCSI] sync (default) scans SCSI busses as they are |
1639 | discovered. async scans them in kernel threads, | |
1640 | allowing boot to proceed. none ignores them, expecting | |
1641 | user space to do the scan. | |
1642 | ||
1da177e4 LT |
1643 | selinux [SELINUX] Disable or enable SELinux at boot time. |
1644 | Format: { "0" | "1" } | |
1645 | See security/selinux/Kconfig help text. | |
1646 | 0 -- disable. | |
1647 | 1 -- enable. | |
1648 | Default value is set via kernel config option. | |
1649 | If enabled at boot time, /selinux/disable can be used | |
1650 | later to disable prior to initial policy load. | |
1651 | ||
4e5ab4cb JM |
1652 | selinux_compat_net = |
1653 | [SELINUX] Set initial selinux_compat_net flag value. | |
e53dd083 MCC |
1654 | Format: { "0" | "1" } |
1655 | 0 -- use new secmark-based packet controls | |
1656 | 1 -- use legacy packet controls | |
1657 | Default value is 0 (preferred). | |
1658 | Value can be changed at runtime via | |
1659 | /selinux/compat_net. | |
4e5ab4cb | 1660 | |
cd4f0ef7 | 1661 | serialnumber [BUGS=X86-32] |
1da177e4 | 1662 | |
1da177e4 LT |
1663 | shapers= [NET] |
1664 | Maximal number of shapers. | |
a9913044 | 1665 | |
1da177e4 LT |
1666 | sim710= [SCSI,HW] |
1667 | See header of drivers/scsi/sim710.c. | |
1668 | ||
1669 | simeth= [IA-64] | |
1670 | simscsi= | |
a9913044 | 1671 | |
1da177e4 LT |
1672 | slram= [HW,MTD] |
1673 | ||
f0630fff CL |
1674 | slub_debug[=options[,slabs]] [MM, SLUB] |
1675 | Enabling slub_debug allows one to determine the | |
1676 | culprit if slab objects become corrupted. Enabling | |
1677 | slub_debug can create guard zones around objects and | |
1678 | may poison objects when not in use. Also tracks the | |
1679 | last alloc / free. For more information see | |
1680 | Documentation/vm/slub.txt. | |
c1aee215 CL |
1681 | |
1682 | slub_max_order= [MM, SLUB] | |
f0630fff CL |
1683 | Determines the maximum allowed order for slabs. |
1684 | A high setting may cause OOMs due to memory | |
1685 | fragmentation. For more information see | |
1686 | Documentation/vm/slub.txt. | |
c1aee215 CL |
1687 | |
1688 | slub_min_objects= [MM, SLUB] | |
f0630fff CL |
1689 | The minimum number of objects per slab. SLUB will |
1690 | increase the slab order up to slub_max_order to | |
1691 | generate a sufficiently large slab able to contain | |
1692 | the number of objects indicated. The higher the number | |
1693 | of objects the smaller the overhead of tracking slabs | |
1694 | and the less frequently locks need to be acquired. | |
c1aee215 CL |
1695 | For more information see Documentation/vm/slub.txt. |
1696 | ||
1697 | slub_min_order= [MM, SLUB] | |
1698 | Determines the mininum page order for slabs. Must be | |
f0630fff | 1699 | lower than slub_max_order. |
c1aee215 CL |
1700 | For more information see Documentation/vm/slub.txt. |
1701 | ||
1702 | slub_nomerge [MM, SLUB] | |
f0630fff | 1703 | Disable merging of slabs with similar size. May be |
c1aee215 | 1704 | necessary if there is some reason to distinguish |
f0630fff CL |
1705 | allocs to different slabs. Debug options disable |
1706 | merging on their own. | |
c1aee215 CL |
1707 | For more information see Documentation/vm/slub.txt. |
1708 | ||
1da177e4 LT |
1709 | smart2= [HW] |
1710 | Format: <io1>[,<io2>[,...,<io8>]] | |
1711 | ||
cd4f0ef7 | 1712 | smp-alt-once [X86-32,SMP] On a hotplug CPU system, only |
b7fb4af0 JF |
1713 | attempt to substitute SMP alternatives once at boot. |
1714 | ||
d0d4f69b BH |
1715 | smsc-ircc2.nopnp [HW] Don't use PNP to discover SMC devices |
1716 | smsc-ircc2.ircc_cfg= [HW] Device configuration I/O port | |
1717 | smsc-ircc2.ircc_sir= [HW] SIR base I/O port | |
1718 | smsc-ircc2.ircc_fir= [HW] FIR base I/O port | |
1719 | smsc-ircc2.ircc_irq= [HW] IRQ line | |
1720 | smsc-ircc2.ircc_dma= [HW] DMA channel | |
1721 | smsc-ircc2.ircc_transceiver= [HW] Transceiver type: | |
1722 | 0: Toshiba Satellite 1800 (GP data pin select) | |
1723 | 1: Fast pin select (default) | |
1724 | 2: ATC IRMode | |
1725 | ||
1da177e4 LT |
1726 | snd-ad1816a= [HW,ALSA] |
1727 | ||
1728 | snd-ad1848= [HW,ALSA] | |
1729 | ||
1730 | snd-ali5451= [HW,ALSA] | |
1731 | ||
1732 | snd-als100= [HW,ALSA] | |
1733 | ||
1734 | snd-als4000= [HW,ALSA] | |
1735 | ||
1736 | snd-azt2320= [HW,ALSA] | |
1737 | ||
1738 | snd-cmi8330= [HW,ALSA] | |
1739 | ||
1740 | snd-cmipci= [HW,ALSA] | |
1741 | ||
1742 | snd-cs4231= [HW,ALSA] | |
1743 | ||
1744 | snd-cs4232= [HW,ALSA] | |
1745 | ||
1746 | snd-cs4236= [HW,ALSA] | |
1747 | ||
1748 | snd-cs4281= [HW,ALSA] | |
1749 | ||
1750 | snd-cs46xx= [HW,ALSA] | |
1751 | ||
1752 | snd-dt019x= [HW,ALSA] | |
1753 | ||
1754 | snd-dummy= [HW,ALSA] | |
1755 | ||
1756 | snd-emu10k1= [HW,ALSA] | |
1757 | ||
1758 | snd-ens1370= [HW,ALSA] | |
1759 | ||
1760 | snd-ens1371= [HW,ALSA] | |
1761 | ||
1762 | snd-es968= [HW,ALSA] | |
1763 | ||
1764 | snd-es1688= [HW,ALSA] | |
1765 | ||
1766 | snd-es18xx= [HW,ALSA] | |
1767 | ||
1768 | snd-es1938= [HW,ALSA] | |
1769 | ||
1770 | snd-es1968= [HW,ALSA] | |
1771 | ||
1772 | snd-fm801= [HW,ALSA] | |
1773 | ||
1774 | snd-gusclassic= [HW,ALSA] | |
1775 | ||
1776 | snd-gusextreme= [HW,ALSA] | |
1777 | ||
1778 | snd-gusmax= [HW,ALSA] | |
1779 | ||
1780 | snd-hdsp= [HW,ALSA] | |
1781 | ||
1782 | snd-ice1712= [HW,ALSA] | |
1783 | ||
1784 | snd-intel8x0= [HW,ALSA] | |
1785 | ||
1786 | snd-interwave= [HW,ALSA] | |
1787 | ||
1788 | snd-interwave-stb= | |
1789 | [HW,ALSA] | |
1790 | ||
1791 | snd-korg1212= [HW,ALSA] | |
1792 | ||
1793 | snd-maestro3= [HW,ALSA] | |
1794 | ||
1795 | snd-mpu401= [HW,ALSA] | |
1796 | ||
1797 | snd-mtpav= [HW,ALSA] | |
1798 | ||
1799 | snd-nm256= [HW,ALSA] | |
1800 | ||
1801 | snd-opl3sa2= [HW,ALSA] | |
1802 | ||
1803 | snd-opti92x-ad1848= | |
1804 | [HW,ALSA] | |
1805 | ||
1806 | snd-opti92x-cs4231= | |
1807 | [HW,ALSA] | |
1808 | ||
1809 | snd-opti93x= [HW,ALSA] | |
1810 | ||
1811 | snd-pmac= [HW,ALSA] | |
1812 | ||
1813 | snd-rme32= [HW,ALSA] | |
1814 | ||
1815 | snd-rme96= [HW,ALSA] | |
1816 | ||
1817 | snd-rme9652= [HW,ALSA] | |
1818 | ||
1819 | snd-sb8= [HW,ALSA] | |
1820 | ||
1821 | snd-sb16= [HW,ALSA] | |
1822 | ||
1823 | snd-sbawe= [HW,ALSA] | |
1824 | ||
1825 | snd-serial= [HW,ALSA] | |
1826 | ||
1827 | snd-sgalaxy= [HW,ALSA] | |
1828 | ||
1829 | snd-sonicvibes= [HW,ALSA] | |
1830 | ||
1831 | snd-sun-amd7930= | |
1832 | [HW,ALSA] | |
1833 | ||
1834 | snd-sun-cs4231= [HW,ALSA] | |
1835 | ||
1836 | snd-trident= [HW,ALSA] | |
1837 | ||
1838 | snd-usb-audio= [HW,ALSA,USB] | |
1839 | ||
1840 | snd-via82xx= [HW,ALSA] | |
1841 | ||
1842 | snd-virmidi= [HW,ALSA] | |
1843 | ||
1844 | snd-wavefront= [HW,ALSA] | |
1845 | ||
1846 | snd-ymfpci= [HW,ALSA] | |
a9913044 | 1847 | |
1da177e4 LT |
1848 | sonypi.*= [HW] Sony Programmable I/O Control Device driver |
1849 | See Documentation/sonypi.txt | |
1850 | ||
1851 | specialix= [HW,SERIAL] Specialix multi-serial port adapter | |
1852 | See Documentation/specialix.txt. | |
1853 | ||
1854 | spia_io_base= [HW,MTD] | |
1855 | spia_fio_base= | |
1856 | spia_pedr= | |
1857 | spia_peddr= | |
1858 | ||
1859 | sscape= [HW,OSS] | |
1860 | Format: <io>,<irq>,<dma>,<mpu_io>,<mpu_irq> | |
a9913044 | 1861 | |
1da177e4 LT |
1862 | st= [HW,SCSI] SCSI tape parameters (buffers, etc.) |
1863 | See Documentation/scsi/st.txt. | |
1864 | ||
1865 | st0x= [HW,SCSI] | |
1866 | See header of drivers/scsi/seagate.c. | |
1867 | ||
1868 | sti= [PARISC,HW] | |
1869 | Format: <num> | |
1870 | Set the STI (builtin display/keyboard on the HP-PARISC | |
1871 | machines) console (graphic card) which should be used | |
1872 | as the initial boot-console. | |
1873 | See also comment in drivers/video/console/sticore.c. | |
1874 | ||
1875 | sti_font= [HW] | |
1876 | See comment in drivers/video/console/sticore.c. | |
1877 | ||
1878 | stifb= [HW] | |
1879 | Format: bpp:<bpp1>[:<bpp2>[:<bpp3>...]] | |
1880 | ||
42a7fc4a GB |
1881 | sunrpc.pool_mode= |
1882 | [NFS] | |
1883 | Control how the NFS server code allocates CPUs to | |
1884 | service thread pools. Depending on how many NICs | |
1885 | you have and where their interrupts are bound, this | |
1886 | option will affect which CPUs will do NFS serving. | |
1887 | Note: this parameter cannot be changed while the | |
1888 | NFS server is running. | |
1889 | ||
1890 | auto the server chooses an appropriate mode | |
1891 | automatically using heuristics | |
1892 | global a single global pool contains all CPUs | |
1893 | percpu one pool for each CPU | |
1894 | pernode one pool for each NUMA node (equivalent | |
1895 | to global on non-NUMA machines) | |
1896 | ||
1da177e4 | 1897 | swiotlb= [IA-64] Number of I/O TLB slabs |
a9913044 | 1898 | |
1da177e4 LT |
1899 | switches= [HW,M68k] |
1900 | ||
1901 | sym53c416= [HW,SCSI] | |
1902 | See header of drivers/scsi/sym53c416.c. | |
1903 | ||
5d6f647f IM |
1904 | sysrq_always_enabled |
1905 | [KNL] | |
1906 | Ignore sysrq setting - this boot parameter will | |
1907 | neutralize any effect of /proc/sys/kernel/sysrq. | |
1908 | Useful for debugging. | |
1909 | ||
1da177e4 LT |
1910 | t128= [HW,SCSI] |
1911 | See header of drivers/scsi/t128.c. | |
1912 | ||
1913 | tdfx= [HW,DRM] | |
1914 | ||
1915 | thash_entries= [KNL,NET] | |
1916 | Set number of hash buckets for TCP connection | |
1917 | ||
f8707ec9 LB |
1918 | thermal.act= [HW,ACPI] |
1919 | -1: disable all active trip points in all thermal zones | |
1920 | <degrees C>: override all lowest active trip points | |
1921 | ||
c52a7419 LB |
1922 | thermal.crt= [HW,ACPI] |
1923 | -1: disable all critical trip points in all thermal zones | |
1924 | <degrees C>: lower all critical trip points | |
1925 | ||
f5487145 LB |
1926 | thermal.nocrt= [HW,ACPI] |
1927 | Set to disable actions on ACPI thermal zone | |
1928 | critical and hot trip points. | |
1929 | ||
72b33ef8 LB |
1930 | thermal.off= [HW,ACPI] |
1931 | 1: disable ACPI thermal control | |
1932 | ||
a70cdc52 LB |
1933 | thermal.psv= [HW,ACPI] |
1934 | -1: disable all passive trip points | |
1935 | <degrees C>: override all passive trip points to this value | |
1936 | ||
730ff34d LB |
1937 | thermal.tzp= [HW,ACPI] |
1938 | Specify global default ACPI thermal zone polling rate | |
1939 | <deci-seconds>: poll all this frequency | |
1940 | 0: no polling (default) | |
1941 | ||
1da177e4 | 1942 | time Show timing data prefixed to each printk message line |
e84845c4 | 1943 | [deprecated, see 'printk.time'] |
1da177e4 LT |
1944 | |
1945 | tipar.timeout= [HW,PPT] | |
1946 | Set communications timeout in tenths of a second | |
1947 | (default 15). | |
1948 | ||
1949 | tipar.delay= [HW,PPT] | |
1950 | Set inter-bit delay in microseconds (default 10). | |
1951 | ||
1952 | tmc8xx= [HW,SCSI] | |
1953 | See header of drivers/scsi/seagate.c. | |
1954 | ||
1955 | tmscsim= [HW,SCSI] | |
1956 | See comment before function dc390_setup() in | |
1957 | drivers/scsi/tmscsim.c. | |
1958 | ||
1959 | tp720= [HW,PS2] | |
1960 | ||
1961 | trix= [HW,OSS] MediaTrix AudioTrix Pro | |
a9913044 RD |
1962 | Format: |
1963 | <io>,<irq>,<dma>,<dma2>,<sb_io>,<sb_irq>,<sb_dma>,<mpu_io>,<mpu_irq> | |
1964 | ||
a9913044 RD |
1965 | turbografx.map[2|3]= [HW,JOY] |
1966 | TurboGraFX parallel port interface | |
1967 | Format: | |
1968 | <port#>,<js1>,<js2>,<js3>,<js4>,<js5>,<js6>,<js7> | |
1da177e4 LT |
1969 | See also Documentation/input/joystick-parport.txt |
1970 | ||
1971 | u14-34f= [HW,SCSI] UltraStor 14F/34F SCSI host adapter | |
1972 | See header of drivers/scsi/u14-34f.c. | |
1973 | ||
1974 | uart401= [HW,OSS] | |
1975 | Format: <io>,<irq> | |
1976 | ||
1977 | uart6850= [HW,OSS] | |
1978 | Format: <io>,<irq> | |
1979 | ||
5f8364b7 AS |
1980 | uhci-hcd.ignore_oc= |
1981 | [USB] Ignore overcurrent events (default N). | |
1982 | Some badly-designed motherboards generate lots of | |
1983 | bogus events, for ports that aren't wired to | |
1984 | anything. Set this parameter to avoid log spamming. | |
1985 | Note that genuine overcurrent events won't be | |
1986 | reported either. | |
1987 | ||
b5e795f8 AS |
1988 | usbcore.autosuspend= |
1989 | [USB] The autosuspend time delay (in seconds) used | |
1990 | for newly-detected USB devices (default 2). This | |
1991 | is the time required before an idle device will be | |
1992 | autosuspended. Devices for which the delay is set | |
eaafbc3a | 1993 | to a negative value won't be autosuspended at all. |
b5e795f8 | 1994 | |
1da177e4 LT |
1995 | usbhid.mousepoll= |
1996 | [USBHID] The interval which mice are to be polled at. | |
a9913044 | 1997 | |
cd4f0ef7 | 1998 | vdso= [X86-32,SH,x86-64] |
1dbf527c | 1999 | vdso=2: enable compat VDSO (default with COMPAT_VDSO) |
e6e5494c IM |
2000 | vdso=1: enable VDSO (default) |
2001 | vdso=0: disable VDSO mapping | |
2002 | ||
af65d648 RM |
2003 | vdso32= [X86-32,X86-64] |
2004 | vdso32=2: enable compat VDSO (default with COMPAT_VDSO) | |
2005 | vdso32=1: enable 32-bit VDSO (default) | |
2006 | vdso32=0: disable 32-bit VDSO mapping | |
2007 | ||
d080d397 YI |
2008 | vector= [IA-64,SMP] |
2009 | vector=percpu: enable percpu vector domain | |
2010 | ||
1da177e4 LT |
2011 | video= [FB] Frame buffer configuration |
2012 | See Documentation/fb/modedb.txt. | |
2013 | ||
cd4f0ef7 | 2014 | vga= [BOOT,X86-32] Select a particular video mode |
a9913044 RD |
2015 | See Documentation/i386/boot.txt and |
2016 | Documentation/svga.txt. | |
1da177e4 LT |
2017 | Use vga=ask for menu. |
2018 | This is actually a boot loader parameter; the value is | |
2019 | passed to the kernel using a special protocol. | |
2020 | ||
a9913044 | 2021 | vmalloc=nn[KMG] [KNL,BOOT] Forces the vmalloc area to have an exact |
1da177e4 LT |
2022 | size of <nn>. This can be used to increase the |
2023 | minimum size (128MB on x86). It can also be used to | |
2024 | decrease the size and leave more room for directly | |
2025 | mapped kernel RAM. | |
2026 | ||
585c3047 PO |
2027 | vmhalt= [KNL,S390] Perform z/VM CP command after system halt. |
2028 | Format: <command> | |
1da177e4 | 2029 | |
585c3047 PO |
2030 | vmpanic= [KNL,S390] Perform z/VM CP command after kernel panic. |
2031 | Format: <command> | |
2032 | ||
2033 | vmpoff= [KNL,S390] Perform z/VM CP command after power off. | |
2034 | Format: <command> | |
a9913044 | 2035 | |
1da177e4 LT |
2036 | waveartist= [HW,OSS] |
2037 | Format: <io>,<irq>,<dma>,<dma2> | |
a9913044 | 2038 | |
1da177e4 LT |
2039 | wd33c93= [HW,SCSI] |
2040 | See header of drivers/scsi/wd33c93.c. | |
2041 | ||
2042 | wd7000= [HW,SCSI] | |
2043 | See header of drivers/scsi/wd7000.c. | |
2044 | ||
2045 | wdt= [WDT] Watchdog | |
8dfe9c21 | 2046 | See Documentation/watchdog/wdt.txt. |
1da177e4 LT |
2047 | |
2048 | xd= [HW,XT] Original XT pre-IDE (RLL encoded) disks. | |
2049 | xd_geo= See header of drivers/block/xd.c. | |
2050 | ||
2051 | xirc2ps_cs= [NET,PCMCIA] | |
a9913044 RD |
2052 | Format: |
2053 | <irq>,<irq_mask>,<io>,<full_duplex>,<do_sound>,<lockup_hack>[,<irq2>[,<irq3>[,<irq4>]]] | |
1da177e4 | 2054 | |
a62eaf15 AK |
2055 | norandmaps Don't use address space randomization |
2056 | Equivalent to echo 0 > /proc/sys/kernel/randomize_va_space | |
2057 | ||
a9913044 | 2058 | ______________________________________________________________________ |
1da177e4 LT |
2059 | |
2060 | TODO: | |
2061 | ||
2062 | Add documentation for ALSA options. | |
2063 | Add more DRM drivers. |