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 | ||
60417f59 RW |
171 | acpi_new_pts_ordering [HW,ACPI] |
172 | Enforce the ACPI 2.0 ordering of the _PTS control | |
173 | method wrt putting devices into low power states | |
174 | default: pre ACPI 2.0 ordering of _PTS | |
175 | ||
67effe8f LB |
176 | acpi_no_auto_ssdt [HW,ACPI] Disable automatic loading of SSDT |
177 | ||
a1f9e65e LB |
178 | acpi_os_name= [HW,ACPI] Tell ACPI BIOS the name of the OS |
179 | Format: To spoof as Windows 98: ="Microsoft Windows" | |
180 | ||
ae00d812 LB |
181 | acpi_osi= [HW,ACPI] Modify list of supported OS interface strings |
182 | acpi_osi="string1" # add string1 -- only one string | |
183 | acpi_osi="!string2" # remove built-in string2 | |
184 | acpi_osi= # disable all strings | |
1da177e4 LT |
185 | |
186 | acpi_serialize [HW,ACPI] force serialization of AML methods | |
187 | ||
188 | acpi_skip_timer_override [HW,ACPI] | |
189 | Recognize and ignore IRQ0/pin2 Interrupt Override. | |
190 | For broken nForce2 BIOS resulting in XT-PIC timer. | |
fa18f477 AK |
191 | acpi_use_timer_override [HW,ACPI} |
192 | Use timer override. For some broken Nvidia NF5 boards | |
193 | that require a timer override, but don't have | |
194 | HPET | |
1da177e4 | 195 | |
f989106c | 196 | acpi.debug_layer= [HW,ACPI] |
1da177e4 | 197 | Format: <int> |
a9913044 | 198 | Each bit of the <int> indicates an ACPI debug layer, |
1da177e4 LT |
199 | 1: enable, 0: disable. It is useful for boot time |
200 | debugging. After system has booted up, it can be set | |
f989106c ZR |
201 | via /sys/module/acpi/parameters/debug_layer. |
202 | CONFIG_ACPI_DEBUG must be enabled for this to produce any output. | |
203 | Available bits (add the numbers together) to enable debug output | |
204 | for specific parts of the ACPI subsystem: | |
205 | 0x01 utilities 0x02 hardware 0x04 events 0x08 tables | |
206 | 0x10 namespace 0x20 parser 0x40 dispatcher | |
207 | 0x80 executer 0x100 resources 0x200 acpica debugger | |
208 | 0x400 os services 0x800 acpica disassembler. | |
209 | The number can be in decimal or prefixed with 0x in hex. | |
210 | Warning: Many of these options can produce a lot of | |
211 | output and make your system unusable. Be very careful. | |
212 | ||
213 | acpi.debug_level= [HW,ACPI] | |
1da177e4 | 214 | Format: <int> |
a9913044 | 215 | Each bit of the <int> indicates an ACPI debug level, |
1da177e4 LT |
216 | 1: enable, 0: disable. It is useful for boot time |
217 | debugging. After system has booted up, it can be set | |
f989106c ZR |
218 | via /sys/module/acpi/parameters/debug_level. |
219 | CONFIG_ACPI_DEBUG must be enabled for this to produce any output. | |
220 | Available bits (add the numbers together) to enable different | |
221 | debug output levels of the ACPI subsystem: | |
222 | 0x01 error 0x02 warn 0x04 init 0x08 debug object | |
223 | 0x10 info 0x20 init names 0x40 parse 0x80 load | |
224 | 0x100 dispatch 0x200 execute 0x400 names 0x800 operation region | |
225 | 0x1000 bfield 0x2000 tables 0x4000 values 0x8000 objects | |
226 | 0x10000 resources 0x20000 user requests 0x40000 package. | |
227 | The number can be in decimal or prefixed with 0x in hex. | |
228 | Warning: Many of these options can produce a lot of | |
229 | output and make your system unusable. Be very careful. | |
230 | ||
cd4f0ef7 | 231 | acpi_pm_good [X86-32,X86-64] |
5d0cf410 | 232 | Override the pmtimer bug detection: force the kernel |
233 | to assume that this machine's pmtimer latches its value | |
234 | and always returns good values. | |
235 | ||
c99c108a CE |
236 | agp= [AGP] |
237 | { off | try_unsupported } | |
238 | off: disable AGP support | |
239 | try_unsupported: try to drive unsupported chipsets | |
240 | (may crash computer or cause data corruption) | |
241 | ||
66759a01 CE |
242 | enable_timer_pin_1 [i386,x86-64] |
243 | Enable PIN 1 of APIC timer | |
a9913044 RD |
244 | Can be useful to work around chipset bugs |
245 | (in particular on some ATI chipsets). | |
66759a01 CE |
246 | The kernel tries to set a reasonable default. |
247 | ||
248 | disable_timer_pin_1 [i386,x86-64] | |
249 | Disable PIN 1 of APIC timer | |
250 | Can be useful to work around chipset bugs. | |
251 | ||
1da177e4 LT |
252 | ad1848= [HW,OSS] |
253 | Format: <io>,<irq>,<dma>,<dma2>,<type> | |
254 | ||
1da177e4 LT |
255 | advansys= [HW,SCSI] |
256 | See header of drivers/scsi/advansys.c. | |
257 | ||
258 | advwdt= [HW,WDT] Advantech WDT | |
259 | Format: <iostart>,<iostop> | |
260 | ||
261 | aedsp16= [HW,OSS] Audio Excel DSP 16 | |
262 | Format: <io>,<irq>,<dma>,<mss_io>,<mpu_io>,<mpu_irq> | |
263 | See also header of sound/oss/aedsp16.c. | |
a9913044 | 264 | |
1da177e4 LT |
265 | aha152x= [HW,SCSI] |
266 | See Documentation/scsi/aha152x.txt. | |
267 | ||
268 | aha1542= [HW,SCSI] | |
269 | Format: <portbase>[,<buson>,<busoff>[,<dmaspeed>]] | |
270 | ||
271 | aic7xxx= [HW,SCSI] | |
272 | See Documentation/scsi/aic7xxx.txt. | |
273 | ||
274 | aic79xx= [HW,SCSI] | |
275 | See Documentation/scsi/aic79xx.txt. | |
276 | ||
1da177e4 LT |
277 | amijoy.map= [HW,JOY] Amiga joystick support |
278 | Map of devices attached to JOY0DAT and JOY1DAT | |
279 | Format: <a>,<b> | |
280 | See also Documentation/kernel/input/joystick.txt | |
281 | ||
282 | analog.map= [HW,JOY] Analog joystick and gamepad support | |
283 | Specifies type or capabilities of an analog joystick | |
284 | connected to one of 16 gameports | |
285 | Format: <type1>,<type2>,..<type16> | |
286 | ||
a9913044 RD |
287 | apc= [HW,SPARC] |
288 | Power management functions (SPARCstation-4/5 + deriv.) | |
1da177e4 LT |
289 | Format: noidle |
290 | Disable APC CPU standby support. SPARCstation-Fox does | |
291 | not play well with APC CPU idle - disable it if you have | |
292 | APC and your system crashes randomly. | |
293 | ||
c8facbb6 RD |
294 | apic= [APIC,i386] Advanced Programmable Interrupt Controller |
295 | Change the output verbosity whilst booting | |
1da177e4 LT |
296 | Format: { quiet (default) | verbose | debug } |
297 | Change the amount of debugging information output | |
298 | when initialising the APIC and IO-APIC components. | |
a9913044 | 299 | |
1da177e4 LT |
300 | apm= [APM] Advanced Power Management |
301 | See header of arch/i386/kernel/apm.c. | |
302 | ||
1da177e4 LT |
303 | arcrimi= [HW,NET] ARCnet - "RIM I" (entirely mem-mapped) cards |
304 | Format: <io>,<irq>,<nodeID> | |
305 | ||
306 | ataflop= [HW,M68k] | |
307 | ||
308 | atarimouse= [HW,MOUSE] Atari Mouse | |
309 | ||
310 | atascsi= [HW,SCSI] Atari SCSI | |
311 | ||
312 | atkbd.extra= [HW] Enable extra LEDs and keys on IBM RapidAccess, | |
313 | EzKey and similar keyboards | |
314 | ||
315 | atkbd.reset= [HW] Reset keyboard during initialization | |
316 | ||
a9913044 RD |
317 | atkbd.set= [HW] Select keyboard code set |
318 | Format: <int> (2 = AT (default), 3 = PS/2) | |
1da177e4 LT |
319 | |
320 | atkbd.scroll= [HW] Enable scroll wheel on MS Office and similar | |
321 | keyboards | |
322 | ||
323 | atkbd.softraw= [HW] Choose between synthetic and real raw mode | |
324 | Format: <bool> (0 = real, 1 = synthetic (default)) | |
a9913044 RD |
325 | |
326 | atkbd.softrepeat= [HW] | |
327 | Use software keyboard repeat | |
1da177e4 LT |
328 | |
329 | autotest [IA64] | |
330 | ||
1da177e4 LT |
331 | baycom_epp= [HW,AX25] |
332 | Format: <io>,<mode> | |
a9913044 | 333 | |
1da177e4 LT |
334 | baycom_par= [HW,AX25] BayCom Parallel Port AX.25 Modem |
335 | Format: <io>,<mode> | |
336 | See header of drivers/net/hamradio/baycom_par.c. | |
337 | ||
a9913044 RD |
338 | baycom_ser_fdx= [HW,AX25] |
339 | BayCom Serial Port AX.25 Modem (Full Duplex Mode) | |
1da177e4 LT |
340 | Format: <io>,<irq>,<mode>[,<baud>] |
341 | See header of drivers/net/hamradio/baycom_ser_fdx.c. | |
342 | ||
a9913044 RD |
343 | baycom_ser_hdx= [HW,AX25] |
344 | BayCom Serial Port AX.25 Modem (Half Duplex Mode) | |
1da177e4 LT |
345 | Format: <io>,<irq>,<mode> |
346 | See header of drivers/net/hamradio/baycom_ser_hdx.c. | |
347 | ||
bfe8df3d RD |
348 | boot_delay= Milliseconds to delay each printk during boot. |
349 | Values larger than 10 seconds (10000) are changed to | |
350 | no delay (0). | |
351 | Format: integer | |
352 | ||
1da177e4 | 353 | bttv.card= [HW,V4L] bttv (bt848 + bt878 based grabber cards) |
a9913044 RD |
354 | bttv.radio= Most important insmod options are available as |
355 | kernel args too. | |
1da177e4 LT |
356 | bttv.pll= See Documentation/video4linux/bttv/Insmod-options |
357 | bttv.tuner= and Documentation/video4linux/bttv/CARDLIST | |
358 | ||
359 | BusLogic= [HW,SCSI] | |
360 | See drivers/scsi/BusLogic.c, comment before function | |
361 | BusLogic_ParseDriverOptions(). | |
362 | ||
363 | c101= [NET] Moxa C101 synchronous serial card | |
364 | ||
cd4f0ef7 | 365 | cachesize= [BUGS=X86-32] Override level 2 CPU cache size detection. |
1da177e4 LT |
366 | Sometimes CPU hardware bugs make them report the cache |
367 | size incorrectly. The kernel will attempt work arounds | |
368 | to fix known problems, but for some CPUs it is not | |
369 | possible to determine what the correct size should be. | |
370 | This option provides an override for these situations. | |
371 | ||
20510f2f JM |
372 | capability.disable= |
373 | [SECURITY] Disable capabilities. This would normally | |
374 | be used only if an alternative security model is to be | |
375 | configured. Potentially dangerous and should only be | |
376 | used if you are entirely sure of the consequences. | |
377 | ||
14ff56bb SO |
378 | ccw_timeout_log [S390] |
379 | See Documentation/s390/CommonIO for details. | |
1da177e4 LT |
380 | |
381 | checkreqprot [SELINUX] Set initial checkreqprot flag value. | |
382 | Format: { "0" | "1" } | |
383 | See security/selinux/Kconfig help text. | |
a9913044 RD |
384 | 0 -- check protection applied by kernel (includes |
385 | any implied execute protection). | |
1da177e4 LT |
386 | 1 -- check protection requested by application. |
387 | Default value is set via a kernel config option. | |
a9913044 RD |
388 | Value can be changed at runtime via |
389 | /selinux/checkreqprot. | |
390 | ||
661ca0da SO |
391 | cio_ignore= [S390] |
392 | See Documentation/s390/CommonIO for details. | |
393 | ||
394 | cio_msg= [S390] | |
395 | See Documentation/s390/CommonIO for details. | |
396 | ||
cd4f0ef7 | 397 | clock= [BUGS=X86-32, HW] gettimeofday clocksource override. |
734efb46 | 398 | [Deprecated] |
3f6dee9b | 399 | Forces specified clocksource (if available) to be used |
734efb46 | 400 | when calculating gettimeofday(). If specified |
3f6dee9b | 401 | clocksource is not available, it defaults to PIT. |
1da177e4 LT |
402 | Format: { pit | tsc | cyclone | pmtmr } |
403 | ||
3d6ac984 RD |
404 | clocksource= [GENERIC_TIME] Override the default clocksource |
405 | Format: <string> | |
406 | Override the default clocksource and use the clocksource | |
407 | with the name specified. | |
408 | Some clocksource names to choose from, depending on | |
409 | the platform: | |
410 | [all] jiffies (this is the base, fallback clocksource) | |
411 | [ACPI] acpi_pm | |
412 | [ARM] imx_timer1,OSTS,netx_timer,mpu_timer2, | |
413 | pxa_timer,timer3,32k_counter,timer0_1 | |
414 | [AVR32] avr32 | |
cd4f0ef7 | 415 | [X86-32] pit,hpet,tsc,vmi-timer; |
3d6ac984 RD |
416 | scx200_hrt on Geode; cyclone on IBM x440 |
417 | [MIPS] MIPS | |
418 | [PARISC] cr16 | |
419 | [S390] tod | |
420 | [SH] SuperH | |
421 | [SPARC64] tick | |
422 | [X86-64] hpet,tsc | |
423 | ||
ac72e788 AK |
424 | clearcpuid=BITNUM [X86] |
425 | Disable CPUID feature X for the kernel. See | |
426 | include/asm-x86/cpufeature.h for the valid bit numbers. | |
427 | Note the Linux specific bits are not necessarily | |
428 | stable over kernel options, but the vendor specific | |
429 | ones should be. | |
430 | Also note that user programs calling CPUID directly | |
431 | or using the feature without checking anything | |
432 | will still see it. This just prevents it from | |
433 | being used by the kernel or shown in /proc/cpuinfo. | |
434 | Also note the kernel might malfunction if you disable | |
435 | some critical bits. | |
436 | ||
a25bd949 AV |
437 | code_bytes [IA32/X86_64] How many bytes of object code to print |
438 | in an oops report. | |
86c41837 CE |
439 | Range: 0 - 8192 |
440 | Default: 64 | |
441 | ||
f9262c12 AK |
442 | disable_8254_timer |
443 | enable_8254_timer | |
444 | [IA32/X86_64] Disable/Enable interrupt 0 timer routing | |
445 | over the 8254 in addition to over the IO-APIC. The | |
446 | kernel tries to set a sensible default. | |
447 | ||
b17530bd TG |
448 | hpet= [X86-32,HPET] option to control HPET usage |
449 | Format: { enable (default) | disable | force } | |
450 | disable: disable HPET and use PIT instead | |
d79a5f80 CC |
451 | force: allow force enabled of undocumented chips (ICH4, |
452 | VIA, nVidia) | |
1da177e4 | 453 | |
1da177e4 | 454 | com20020= [HW,NET] ARCnet - COM20020 chipset |
a9913044 RD |
455 | Format: |
456 | <io>[,<irq>[,<nodeID>[,<backplane>[,<ckp>[,<timeout>]]]]] | |
1da177e4 LT |
457 | |
458 | com90io= [HW,NET] ARCnet - COM90xx chipset (IO-mapped buffers) | |
459 | Format: <io>[,<irq>] | |
460 | ||
a9913044 RD |
461 | com90xx= [HW,NET] |
462 | ARCnet - COM90xx chipset (memory-mapped buffers) | |
1da177e4 LT |
463 | Format: <io>[,<irq>[,<memstart>]] |
464 | ||
465 | condev= [HW,S390] console device | |
466 | conmode= | |
a9913044 | 467 | |
1da177e4 LT |
468 | console= [KNL] Output console device and options. |
469 | ||
470 | tty<n> Use the virtual console device <n>. | |
471 | ||
472 | ttyS<n>[,options] | |
f1a1c2dc | 473 | ttyUSB0[,options] |
1da177e4 | 474 | Use the specified serial port. The options are of |
f1a1c2dc RD |
475 | the form "bbbbpnf", where "bbbb" is the baud rate, |
476 | "p" is parity ("n", "o", or "e"), "n" is number of | |
477 | bits, and "f" is flow control ("r" for RTS or | |
478 | omit it). Default is "9600n8". | |
479 | ||
480 | See Documentation/serial-console.txt for more | |
481 | information. See | |
482 | Documentation/networking/netconsole.txt for an | |
483 | alternative. | |
1da177e4 | 484 | |
18a8bd94 YL |
485 | uart[8250],io,<addr>[,options] |
486 | uart[8250],mmio,<addr>[,options] | |
1da177e4 LT |
487 | Start an early, polled-mode console on the 8250/16550 |
488 | UART at the specified I/O port or MMIO address, | |
489 | switching to the matching ttyS device later. The | |
490 | options are the same as for ttyS, above. | |
491 | ||
18a8bd94 YL |
492 | earlycon= [KNL] Output early console device and options. |
493 | uart[8250],io,<addr>[,options] | |
494 | uart[8250],mmio,<addr>[,options] | |
495 | Start an early, polled-mode console on the 8250/16550 | |
496 | UART at the specified I/O port or MMIO address. | |
497 | The options are the same as for ttyS, above. | |
498 | ||
8f4ce8c3 AS |
499 | no_console_suspend |
500 | [HW] Never suspend the console | |
501 | Disable suspending of consoles during suspend and | |
502 | hibernate operations. Once disabled, debugging | |
503 | messages can reach various consoles while the rest | |
504 | of the system is being put to sleep (ie, while | |
505 | debugging driver suspend/resume hooks). This may | |
506 | not work reliably with all consoles, but is known | |
507 | to work with serial and VGA consoles. | |
508 | ||
1da177e4 | 509 | cpcihp_generic= [HW,PCI] Generic port I/O CompactPCI driver |
a9913044 RD |
510 | Format: |
511 | <first_slot>,<last_slot>,<port>,<enum_bit>[,<debug>] | |
1da177e4 | 512 | |
dc009d92 EB |
513 | crashkernel=nn[KMG]@ss[KMG] |
514 | [KNL] Reserve a chunk of physical memory to | |
515 | hold a kernel to switch to with kexec on panic. | |
516 | ||
fb391599 BW |
517 | crashkernel=range1:size1[,range2:size2,...][@offset] |
518 | [KNL] Same as above, but depends on the memory | |
519 | in the running system. The syntax of range is | |
520 | start-[end] where start and end are both | |
521 | a memory unit (amount[KMG]). See also | |
522 | Documentation/kdump/kdump.txt for a example. | |
523 | ||
1da177e4 LT |
524 | cs4232= [HW,OSS] |
525 | Format: <io>,<irq>,<dma>,<dma2>,<mpuio>,<mpuirq> | |
526 | ||
527 | cs89x0_dma= [HW,NET] | |
528 | Format: <dma> | |
529 | ||
530 | cs89x0_media= [HW,NET] | |
531 | Format: { rj45 | aui | bnc } | |
a9913044 | 532 | |
a9913044 | 533 | dasd= [HW,NET] |
1da177e4 LT |
534 | See header of drivers/s390/block/dasd_devmap.c. |
535 | ||
536 | db9.dev[2|3]= [HW,JOY] Multisystem joystick support via parallel port | |
537 | (one device per port) | |
538 | Format: <port#>,<type> | |
539 | See also Documentation/input/joystick-parport.txt | |
540 | ||
541 | debug [KNL] Enable kernel debugging (events log level). | |
542 | ||
cae2ed9a IM |
543 | debug_locks_verbose= |
544 | [KNL] verbose self-tests | |
545 | Format=<0|1> | |
546 | Print debugging info while doing the locking API | |
547 | self-tests. | |
548 | We default to 0 (no extra messages), setting it to | |
549 | 1 will print _a lot_ more information - normally | |
550 | only useful to kernel developers. | |
551 | ||
2d27a966 | 552 | decnet.addr= [HW,NET] |
1da177e4 LT |
553 | Format: <area>[,<node>] |
554 | See also Documentation/networking/decnet.txt. | |
555 | ||
ecb77fa9 | 556 | vt.default_blu= [VT] |
55ff9780 AD |
557 | Format: <blue0>,<blue1>,<blue2>,...,<blue15> |
558 | Change the default blue palette of the console. | |
559 | This is a 16-member array composed of values | |
560 | ranging from 0-255. | |
561 | ||
ecb77fa9 | 562 | vt.default_grn= [VT] |
55ff9780 AD |
563 | Format: <green0>,<green1>,<green2>,...,<green15> |
564 | Change the default green palette of the console. | |
565 | This is a 16-member array composed of values | |
566 | ranging from 0-255. | |
567 | ||
ecb77fa9 | 568 | vt.default_red= [VT] |
55ff9780 AD |
569 | Format: <red0>,<red1>,<red2>,...,<red15> |
570 | Change the default red palette of the console. | |
571 | This is a 16-member array composed of values | |
572 | ranging from 0-255. | |
573 | ||
ecb77fa9 ST |
574 | vt.default_utf8= |
575 | [VT] | |
55ff9780 AD |
576 | Format=<0|1> |
577 | Set system-wide default UTF-8 mode for all tty's. | |
ecb77fa9 ST |
578 | Default is 1, i.e. UTF-8 mode is enabled for all |
579 | newly opened terminals. | |
55ff9780 | 580 | |
1da177e4 LT |
581 | dhash_entries= [KNL] |
582 | Set number of hash buckets for dentry cache. | |
a9913044 | 583 | |
1da177e4 LT |
584 | digi= [HW,SERIAL] |
585 | IO parameters + enable/disable command. | |
586 | ||
587 | digiepca= [HW,SERIAL] | |
588 | See drivers/char/README.epca and | |
589 | Documentation/digiepca.txt. | |
590 | ||
093af8d7 | 591 | disable_mtrr_trim [X86, Intel and AMD only] |
99fc8d42 JB |
592 | By default the kernel will trim any uncacheable |
593 | memory out of your available memory pool based on | |
594 | MTRR settings. This parameter disables that behavior, | |
595 | possibly causing your machine to run very slowly. | |
596 | ||
1da177e4 LT |
597 | dmasound= [HW,OSS] Sound subsystem buffers |
598 | ||
599 | dscc4.setup= [NET] | |
600 | ||
601 | dtc3181e= [HW,SCSI] | |
602 | ||
0ae53640 | 603 | earlyprintk= [X86-32,X86-64,SH,BLACKFIN] |
1da177e4 LT |
604 | earlyprintk=vga |
605 | earlyprintk=serial[,ttySn[,baudrate]] | |
606 | ||
a9913044 | 607 | Append ",keep" to not disable it when the real console |
1da177e4 LT |
608 | takes over. |
609 | ||
610 | Only vga or serial at a time, not both. | |
611 | ||
612 | Currently only ttyS0 and ttyS1 are supported. | |
613 | ||
614 | Interaction with the standard serial driver is not | |
615 | very good. | |
616 | ||
617 | The VGA output is eventually overwritten by the real | |
618 | console. | |
619 | ||
620 | eata= [HW,SCSI] | |
621 | ||
1da177e4 LT |
622 | edd= [EDD] |
623 | Format: {"of[f]" | "sk[ipmbr]"} | |
624 | See comment in arch/i386/boot/edd.S | |
625 | ||
1da177e4 LT |
626 | eisa_irq_edge= [PARISC,HW] |
627 | See header of drivers/parisc/eisa.c. | |
628 | ||
cd4f0ef7 | 629 | elanfreq= [X86-32] |
1da177e4 LT |
630 | See comment before function elanfreq_setup() in |
631 | arch/i386/kernel/cpu/cpufreq/elanfreq.c. | |
632 | ||
633 | elevator= [IOSCHED] | |
16ab3adf | 634 | Format: {"anticipatory" | "cfq" | "deadline" | "noop"} |
a9913044 RD |
635 | See Documentation/block/as-iosched.txt and |
636 | Documentation/block/deadline-iosched.txt for details. | |
637 | ||
cd4f0ef7 | 638 | elfcorehdr= [X86-32, X86_64] |
a9913044 | 639 | Specifies physical address of start of kernel core |
aac04b32 VG |
640 | image elf header. Generally kexec loader will |
641 | pass this option to capture kernel. | |
642 | See Documentation/kdump/kdump.txt for details. | |
1da177e4 LT |
643 | |
644 | enforcing [SELINUX] Set initial enforcing status. | |
645 | Format: {"0" | "1"} | |
646 | See security/selinux/Kconfig help text. | |
647 | 0 -- permissive (log only, no denials). | |
648 | 1 -- enforcing (deny and log). | |
649 | Default value is 0. | |
650 | Value can be changed at runtime via /selinux/enforce. | |
651 | ||
1da177e4 LT |
652 | es1371= [HW,OSS] |
653 | Format: <spdif>,[<nomix>,[<amplifier>]] | |
654 | See also header of sound/oss/es1371.c. | |
a9913044 | 655 | |
1da177e4 LT |
656 | ether= [HW,NET] Ethernet cards parameters |
657 | This option is obsoleted by the "netdev=" option, which | |
658 | has equivalent usage. See its documentation for details. | |
659 | ||
660 | eurwdt= [HW,WDT] Eurotech CPU-1220/1410 onboard watchdog. | |
661 | Format: <io>[,<irq>] | |
662 | ||
de1ba09b AM |
663 | failslab= |
664 | fail_page_alloc= | |
665 | fail_make_request=[KNL] | |
666 | General fault injection mechanism. | |
667 | Format: <interval>,<probability>,<space>,<times> | |
668 | See also /Documentation/fault-injection/. | |
669 | ||
1da177e4 LT |
670 | fd_mcs= [HW,SCSI] |
671 | See header of drivers/scsi/fd_mcs.c. | |
672 | ||
673 | fdomain= [HW,SCSI] | |
674 | See header of drivers/scsi/fdomain.c. | |
675 | ||
676 | floppy= [HW] | |
677 | See Documentation/floppy.txt. | |
678 | ||
1da177e4 LT |
679 | gamecon.map[2|3]= |
680 | [HW,JOY] Multisystem joystick and NES/SNES/PSX pad | |
681 | support via parallel port (up to 5 devices per port) | |
682 | Format: <port#>,<pad1>,<pad2>,<pad3>,<pad4>,<pad5> | |
683 | See also Documentation/input/joystick-parport.txt | |
684 | ||
685 | gamma= [HW,DRM] | |
686 | ||
aaf23042 YL |
687 | gart_fix_e820= [X86_64] disable the fix e820 for K8 GART |
688 | Format: off | on | |
689 | default: on | |
690 | ||
1da177e4 LT |
691 | gdth= [HW,SCSI] |
692 | See header of drivers/scsi/gdth.c. | |
693 | ||
694 | gpt [EFI] Forces disk with valid GPT signature but | |
695 | invalid Protective MBR to be treated as GPT. | |
696 | ||
1da177e4 LT |
697 | gvp11= [HW,SCSI] |
698 | ||
699 | hashdist= [KNL,NUMA] Large hashes allocated during boot | |
700 | are distributed across NUMA nodes. Defaults on | |
701 | for IA-64, off otherwise. | |
a9913044 | 702 | Format: 0 | 1 (for off | on) |
1da177e4 LT |
703 | |
704 | hcl= [IA-64] SGI's Hardware Graph compatibility layer | |
705 | ||
706 | hd= [EIDE] (E)IDE hard drive subsystem geometry | |
707 | Format: <cyl>,<head>,<sect> | |
708 | ||
709 | hd?= [HW] (E)IDE subsystem | |
710 | hd?lun= See Documentation/ide.txt. | |
711 | ||
712 | highmem=nn[KMG] [KNL,BOOT] forces the highmem zone to have an exact | |
713 | size of <nn>. This works even on boxes that have no | |
714 | highmem otherwise. This also works to reduce highmem | |
715 | size on bigger boxes. | |
716 | ||
54cdfdb4 TG |
717 | highres= [KNL] Enable/disable high resolution timer mode. |
718 | Valid parameters: "on", "off" | |
719 | Default: "on" | |
720 | ||
1da177e4 LT |
721 | hisax= [HW,ISDN] |
722 | See Documentation/isdn/README.HiSax. | |
723 | ||
cd4f0ef7 | 724 | hugepages= [HW,X86-32,IA-64] Maximal number of HugeTLB pages. |
4ec161cf | 725 | hugepagesz= [HW,IA-64,PPC] The size of the HugeTLB pages. |
1da177e4 | 726 | |
1da177e4 | 727 | i8042.direct [HW] Put keyboard port into non-translated mode |
84eb8d06 ML |
728 | i8042.dumbkbd [HW] Pretend that controller can only read data from |
729 | keyboard and cannot control its state | |
1da177e4 LT |
730 | (Don't attempt to blink the leds) |
731 | i8042.noaux [HW] Don't check for auxiliary (== mouse) port | |
945ef0d4 | 732 | i8042.nokbd [HW] Don't check/create keyboard port |
1da177e4 LT |
733 | i8042.nomux [HW] Don't check presence of an active multiplexing |
734 | controller | |
735 | i8042.nopnp [HW] Don't use ACPIPnP / PnPBIOS to discover KBD/AUX | |
736 | controllers | |
737 | i8042.panicblink= | |
738 | [HW] Frequency with which keyboard LEDs should blink | |
739 | when kernel panics (default is 0.5 sec) | |
740 | i8042.reset [HW] Reset the controller during init and cleanup | |
741 | i8042.unlock [HW] Unlock (ignore) the keylock | |
742 | ||
743 | i810= [HW,DRM] | |
744 | ||
e70c9d5e DT |
745 | i8k.ignore_dmi [HW] Continue probing hardware even if DMI data |
746 | indicates that the driver is running on unsupported | |
747 | hardware. | |
1da177e4 LT |
748 | i8k.force [HW] Activate i8k driver even if SMM BIOS signature |
749 | does not match list of supported models. | |
750 | i8k.power_status | |
751 | [HW] Report power status in /proc/i8k | |
752 | (disabled by default) | |
753 | i8k.restricted [HW] Allow controlling fans only if SYS_ADMIN | |
754 | capability is set. | |
755 | ||
756 | ibmmcascsi= [HW,MCA,SCSI] IBM MicroChannel SCSI adapter | |
757 | See Documentation/mca.txt. | |
758 | ||
759 | icn= [HW,ISDN] | |
760 | Format: <io>[,<membase>[,<icn_id>[,<icn_id2>]]] | |
761 | ||
762 | ide= [HW] (E)IDE subsystem | |
763 | Format: ide=nodma or ide=doubler or ide=reverse | |
764 | See Documentation/ide.txt. | |
765 | ||
766 | ide?= [HW] (E)IDE subsystem | |
767 | Format: ide?=noprobe or chipset specific parameters. | |
768 | See Documentation/ide.txt. | |
a9913044 | 769 | |
1da177e4 LT |
770 | idebus= [HW] (E)IDE subsystem - VLB/PCI bus speed |
771 | See Documentation/ide.txt. | |
772 | ||
f039b754 AK |
773 | idle= [X86] |
774 | Format: idle=poll or idle=mwait | |
775 | Poll forces a polling idle loop that can slightly improves the performance | |
776 | of waking up a idle CPU, but will use a lot of power and make the system | |
777 | run hot. Not recommended. | |
778 | idle=mwait. On systems which support MONITOR/MWAIT but the kernel chose | |
779 | to not use it because it doesn't save as much power as a normal idle | |
780 | loop use the MONITOR/MWAIT idle loop anyways. Performance should be the same | |
781 | as idle=poll. | |
a9913044 | 782 | |
79290822 IM |
783 | ignore_loglevel [KNL] |
784 | Ignore loglevel setting - this will print /all/ | |
785 | kernel messages to the console. Useful for debugging. | |
786 | ||
1da177e4 LT |
787 | ihash_entries= [KNL] |
788 | Set number of hash buckets for inode cache. | |
789 | ||
790 | in2000= [HW,SCSI] | |
791 | See header of drivers/scsi/in2000.c. | |
792 | ||
793 | init= [KNL] | |
794 | Format: <full_path> | |
795 | Run specified binary instead of /sbin/init as init | |
796 | process. | |
797 | ||
798 | initcall_debug [KNL] Trace initcalls as they are executed. Useful | |
799 | for working out where the kernel is dying during | |
800 | startup. | |
801 | ||
802 | initrd= [BOOT] Specify the location of the initial ramdisk | |
803 | ||
804 | inport.irq= [HW] Inport (ATI XL and Microsoft) busmouse driver | |
805 | Format: <irq> | |
806 | ||
807 | inttest= [IA64] | |
808 | ||
ba395927 KA |
809 | intel_iommu= [DMAR] Intel IOMMU driver (DMAR) option |
810 | off | |
811 | Disable intel iommu driver. | |
812 | igfx_off [Default Off] | |
813 | By default, gfx is mapped as normal device. If a gfx | |
814 | device has a dedicated DMAR unit, the DMAR unit is | |
815 | bypassed by not enabling DMAR with this option. In | |
816 | this case, gfx device will use physical address for | |
817 | DMA. | |
7d3b03ce KA |
818 | forcedac [x86_64] |
819 | With this option iommu will not optimize to look | |
820 | for io virtual address below 32 bit forcing dual | |
821 | address cycle on pci bus for cards supporting greater | |
822 | than 32 bit addressing. The default is to look | |
823 | for translation below 32 bit and if not available | |
824 | then look in the higher range. | |
ba395927 | 825 | |
b02aae9c | 826 | io_delay= [X86-32,X86-64] I/O delay method |
6e7c4025 IM |
827 | 0x80 |
828 | Standard port 0x80 based delay | |
829 | 0xed | |
830 | Alternate port 0xed based delay (needed on some systems) | |
b02aae9c | 831 | udelay |
6e7c4025 IM |
832 | Simple two microseconds delay |
833 | none | |
834 | No delay | |
b02aae9c | 835 | |
1da177e4 LT |
836 | io7= [HW] IO7 for Marvel based alpha systems |
837 | See comment before marvel_specify_io7 in | |
838 | arch/alpha/kernel/core_marvel.c. | |
839 | ||
840 | ip= [IP_PNP] | |
841 | See Documentation/nfsroot.txt. | |
842 | ||
843 | ip2= [HW] Set IO/IRQ pairs for up to 4 IntelliPort boards | |
c8facbb6 RD |
844 | See comment before ip2_setup() in |
845 | drivers/char/ip2/ip2base.c. | |
1da177e4 LT |
846 | |
847 | ips= [HW,SCSI] Adaptec / IBM ServeRAID controller | |
848 | See header of drivers/scsi/ips.c. | |
849 | ||
72c4a13a SH |
850 | ports= [IP_VS_FTP] IPVS ftp helper module |
851 | Default is 21. | |
852 | Up to 8 (IP_VS_APP_MAX_PORTS) ports | |
853 | may be specified. | |
854 | Format: <port>,<port>.... | |
855 | ||
200803df AC |
856 | irqfixup [HW] |
857 | When an interrupt is not handled search all handlers | |
858 | for it. Intended to get systems with badly broken | |
859 | firmware running. | |
860 | ||
861 | irqpoll [HW] | |
862 | When an interrupt is not handled search all handlers | |
863 | for it. Also check all handlers each timer | |
864 | interrupt. Intended to get systems with badly broken | |
865 | firmware running. | |
866 | ||
1da177e4 | 867 | isapnp= [ISAPNP] |
a9913044 | 868 | Format: <RDP>,<reset>,<pci_scan>,<verbosity> |
1da177e4 LT |
869 | |
870 | isolcpus= [KNL,SMP] Isolate CPUs from the general scheduler. | |
22f2e280 DF |
871 | Format: |
872 | <cpu number>,...,<cpu number> | |
873 | or | |
874 | <cpu number>-<cpu number> (must be a positive range in ascending order) | |
875 | or a mixture | |
876 | <cpu number>,...,<cpu number>-<cpu number> | |
1da177e4 LT |
877 | This option can be used to specify one or more CPUs |
878 | to isolate from the general SMP balancing and scheduling | |
879 | algorithms. The only way to move a process onto or off | |
880 | an "isolated" CPU is via the CPU affinity syscalls. | |
881 | <cpu number> begins at 0 and the maximum value is | |
882 | "number of CPUs in system - 1". | |
883 | ||
884 | This option is the preferred way to isolate CPUs. The | |
a9913044 RD |
885 | alternative -- manually setting the CPU mask of all |
886 | tasks in the system -- can cause problems and | |
887 | suboptimal load balancer performance. | |
1da177e4 | 888 | |
a9913044 | 889 | iucv= [HW,NET] |
1da177e4 LT |
890 | |
891 | js= [HW,JOY] Analog joystick | |
892 | See Documentation/input/joystick.txt. | |
893 | ||
cd4f0ef7 | 894 | kernelcore=nn[KMG] [KNL,X86-32,IA-64,PPC,X86-64] This parameter |
ed7ed365 MG |
895 | specifies the amount of memory usable by the kernel |
896 | for non-movable allocations. The requested amount is | |
897 | spread evenly throughout all nodes in the system. The | |
898 | remaining memory in each node is used for Movable | |
899 | pages. In the event, a node is too small to have both | |
900 | kernelcore and Movable pages, kernelcore pages will | |
901 | take priority and other nodes will have a larger number | |
902 | of kernelcore pages. The Movable zone is used for the | |
903 | allocation of pages that may be reclaimed or moved | |
904 | by the page migration subsystem. This means that | |
905 | HugeTLB pages may not be allocated from this zone. | |
906 | Note that allocations like PTEs-from-HighMem still | |
907 | use the HighMem zone if it exists, and the Normal | |
908 | zone if it does not. | |
909 | ||
cd4f0ef7 | 910 | movablecore=nn[KMG] [KNL,X86-32,IA-64,PPC,X86-64] This parameter |
7e63efef MG |
911 | is similar to kernelcore except it specifies the |
912 | amount of memory used for migratable allocations. | |
913 | If both kernelcore and movablecore is specified, | |
914 | then kernelcore will be at *least* the specified | |
915 | value but may be more. If movablecore on its own | |
916 | is specified, the administrator must be careful | |
917 | that the amount of memory usable for all allocations | |
918 | is not too small. | |
919 | ||
1da177e4 LT |
920 | keepinitrd [HW,ARM] |
921 | ||
cd4f0ef7 | 922 | kstack=N [X86-32,X86-64] Print N words from the kernel stack |
1da177e4 LT |
923 | in oops dumps. |
924 | ||
925 | l2cr= [PPC] | |
926 | ||
cd4f0ef7 | 927 | lapic [X86-32,APIC] Enable the local APIC even if BIOS |
a9913044 | 928 | disabled it. |
1da177e4 | 929 | |
cd4f0ef7 | 930 | lapic_timer_c2_ok [X86-32,x86-64,APIC] trust the local apic timer in |
e585bef8 TG |
931 | C2 power state. |
932 | ||
fcb71f6f FC |
933 | libata.dma= [LIBATA] DMA control |
934 | libata.dma=0 Disable all PATA and SATA DMA | |
935 | libata.dma=1 PATA and SATA Disk DMA only | |
936 | libata.dma=2 ATAPI (CDROM) DMA only | |
937 | libata.dma=4 Compact Flash DMA only | |
938 | Combinations also work, so libata.dma=3 enables DMA | |
939 | for disks and CDROMs, but not CFs. | |
940 | ||
78e70c23 DJ |
941 | libata.noacpi [LIBATA] Disables use of ACPI in libata suspend/resume |
942 | when set. | |
943 | Format: <int> | |
944 | ||
1da177e4 LT |
945 | load_ramdisk= [RAM] List of ramdisks to load from floppy |
946 | See Documentation/ramdisk.txt. | |
947 | ||
a6b25b67 RD |
948 | lockd.nlm_grace_period=P [NFS] Assign grace period. |
949 | Format: <integer> | |
1da177e4 | 950 | |
a6b25b67 RD |
951 | lockd.nlm_tcpport=N [NFS] Assign TCP port. |
952 | Format: <integer> | |
953 | ||
954 | lockd.nlm_timeout=T [NFS] Assign timeout value. | |
955 | Format: <integer> | |
956 | ||
957 | lockd.nlm_udpport=M [NFS] Assign UDP port. | |
958 | Format: <integer> | |
1da177e4 LT |
959 | |
960 | logibm.irq= [HW,MOUSE] Logitech Bus Mouse Driver | |
961 | Format: <irq> | |
962 | ||
963 | loglevel= All Kernel Messages with a loglevel smaller than the | |
964 | console loglevel will be printed to the console. It can | |
965 | also be changed with klogd or other programs. The | |
966 | loglevels are defined as follows: | |
967 | ||
968 | 0 (KERN_EMERG) system is unusable | |
969 | 1 (KERN_ALERT) action must be taken immediately | |
970 | 2 (KERN_CRIT) critical conditions | |
971 | 3 (KERN_ERR) error conditions | |
972 | 4 (KERN_WARNING) warning conditions | |
973 | 5 (KERN_NOTICE) normal but significant condition | |
974 | 6 (KERN_INFO) informational | |
975 | 7 (KERN_DEBUG) debug-level messages | |
976 | ||
977 | log_buf_len=n Sets the size of the printk ring buffer, in bytes. | |
a9913044 RD |
978 | Format: { n | nk | nM } |
979 | n must be a power of two. The default size | |
980 | is set in the kernel config file. | |
1da177e4 | 981 | |
accaa24c RD |
982 | logo.nologo [FB] Disables display of the built-in Linux logo. |
983 | This may be used to provide more screen space for | |
984 | kernel log messages and is useful when debugging | |
985 | kernel boot problems. | |
986 | ||
1da177e4 LT |
987 | lp=0 [LP] Specify parallel ports to use, e.g, |
988 | lp=port[,port...] lp=none,parport0 (lp0 not configured, lp1 uses | |
989 | lp=reset first parallel port). 'lp=0' disables the | |
990 | lp=auto printer driver. 'lp=reset' (which can be | |
991 | specified in addition to the ports) causes | |
992 | attached printers to be reset. Using | |
993 | lp=port1,port2,... specifies the parallel ports | |
994 | to associate lp devices with, starting with | |
995 | lp0. A port specification may be 'none' to skip | |
996 | that lp device, or a parport name such as | |
997 | 'parport0'. Specifying 'lp=auto' instead of a | |
998 | port specification list means that device IDs | |
999 | from each port should be examined, to see if | |
1000 | an IEEE 1284-compliant printer is attached; if | |
1001 | so, the driver will manage that printer. | |
1002 | See also header of drivers/char/lp.c. | |
1003 | ||
1004 | lpj=n [KNL] | |
1005 | Sets loops_per_jiffy to given constant, thus avoiding | |
1006 | time-consuming boot-time autodetection (up to 250 ms per | |
1007 | CPU). 0 enables autodetection (default). To determine | |
1008 | the correct value for your kernel, boot with normal | |
1009 | autodetection and see what value is printed. Note that | |
1010 | on SMP systems the preset will be applied to all CPUs, | |
1011 | which is likely to cause problems if your CPUs need | |
1012 | significantly divergent settings. An incorrect value | |
1013 | will cause delays in the kernel to be wrong, leading to | |
1014 | unpredictable I/O errors and other breakage. Although | |
1015 | unlikely, in the extreme case this might damage your | |
1016 | hardware. | |
1017 | ||
1018 | ltpc= [NET] | |
1019 | Format: <io>,<irq>,<dma> | |
1020 | ||
a9913044 RD |
1021 | mac5380= [HW,SCSI] Format: |
1022 | <can_queue>,<cmd_per_lun>,<sg_tablesize>,<hostid>,<use_tags> | |
1da177e4 | 1023 | |
a9913044 RD |
1024 | mac53c9x= [HW,SCSI] Format: |
1025 | <num_esps>,<disconnect>,<nosync>,<can_queue>,<cmd_per_lun>,<sg_tablesize>,<hostid>,<use_tags> | |
1da177e4 | 1026 | |
a9913044 RD |
1027 | machvec= [IA64] Force the use of a particular machine-vector |
1028 | (machvec) in a generic kernel. | |
1029 | Example: machvec=hpzx1_swiotlb | |
1da177e4 | 1030 | |
a9913044 | 1031 | max_loop= [LOOP] Maximum number of loopback devices that can |
1da177e4 LT |
1032 | be mounted |
1033 | Format: <1-256> | |
1034 | ||
1035 | maxcpus= [SMP] Maximum number of processors that an SMP kernel | |
61ec7567 LB |
1036 | should make use of. maxcpus=n : n >= 0 limits the |
1037 | kernel to using 'n' processors. n=0 is a special case, | |
1038 | it is equivalent to "nosmp", which also disables | |
1039 | the IO APIC. | |
1da177e4 | 1040 | |
2b2c3750 BP |
1041 | max_addr=[KMG] [KNL,BOOT,ia64] All physical memory greater than or |
1042 | equal to this physical address is ignored. | |
1043 | ||
a9913044 | 1044 | max_luns= [SCSI] Maximum number of LUNs to probe. |
1da177e4 LT |
1045 | Should be between 1 and 2^32-1. |
1046 | ||
1047 | max_report_luns= | |
a9913044 | 1048 | [SCSI] Maximum number of LUNs received. |
1da177e4 LT |
1049 | Should be between 1 and 16384. |
1050 | ||
cd4f0ef7 | 1051 | mca-pentium [BUGS=X86-32] |
1da177e4 LT |
1052 | |
1053 | mcatest= [IA-64] | |
1054 | ||
cd4f0ef7 | 1055 | mce [X86-32] Machine Check Exception |
1da177e4 | 1056 | |
909dd324 AK |
1057 | mce=option [X86-64] See Documentation/x86_64/boot-options.txt |
1058 | ||
1da177e4 LT |
1059 | md= [HW] RAID subsystems devices and level |
1060 | See Documentation/md.txt. | |
a9913044 | 1061 | |
1da177e4 LT |
1062 | mdacon= [MDA] |
1063 | Format: <first>,<last> | |
1064 | Specifies range of consoles to be captured by the MDA. | |
a9913044 | 1065 | |
1da177e4 LT |
1066 | mem=nn[KMG] [KNL,BOOT] Force usage of a specific amount of memory |
1067 | Amount of memory to be used when the kernel is not able | |
1068 | to see the whole system memory or for test. | |
cd4f0ef7 | 1069 | [X86-32] Use together with memmap= to avoid physical |
1da177e4 LT |
1070 | address space collisions. Without memmap= PCI devices |
1071 | could be placed at addresses belonging to unused RAM. | |
1072 | ||
cd4f0ef7 | 1073 | mem=nopentium [BUGS=X86-32] Disable usage of 4MB pages for kernel |
1da177e4 LT |
1074 | memory. |
1075 | ||
cd4f0ef7 | 1076 | memmap=exactmap [KNL,X86-32,X86_64] Enable setting of an exact |
1da177e4 LT |
1077 | E820 memory map, as specified by the user. |
1078 | Such memmap=exactmap lines can be constructed based on | |
1079 | BIOS output or other requirements. See the memmap=nn@ss | |
1080 | option description. | |
1081 | ||
1082 | memmap=nn[KMG]@ss[KMG] | |
1083 | [KNL] Force usage of a specific region of memory | |
1084 | Region of memory to be used, from ss to ss+nn. | |
1085 | ||
1086 | memmap=nn[KMG]#ss[KMG] | |
1087 | [KNL,ACPI] Mark specific memory as ACPI data. | |
1088 | Region of memory to be used, from ss to ss+nn. | |
1089 | ||
1090 | memmap=nn[KMG]$ss[KMG] | |
1091 | [KNL,ACPI] Mark specific memory as reserved. | |
1092 | Region of memory to be used, from ss to ss+nn. | |
1093 | ||
1094 | meye.*= [HW] Set MotionEye Camera parameters | |
1095 | See Documentation/video4linux/meye.txt. | |
1096 | ||
8f36881b AS |
1097 | mfgpt_irq= [IA-32] Specify the IRQ to use for the |
1098 | Multi-Function General Purpose Timers on AMD Geode | |
1099 | platforms. | |
1100 | ||
e6c4dc6c WT |
1101 | mfgptfix [X86-32] Fix MFGPT timers on AMD Geode platforms when |
1102 | the BIOS has incorrectly applied a workaround. TinyBIOS | |
1103 | version 0.98 is known to be affected, 0.99 fixes the | |
1104 | problem by letting the user disable the workaround. | |
1105 | ||
1da177e4 LT |
1106 | mga= [HW,DRM] |
1107 | ||
1108 | mousedev.tap_time= | |
1109 | [MOUSE] Maximum time between finger touching and | |
1110 | leaving touchpad surface for touch to be considered | |
1111 | a tap and be reported as a left button click (for | |
1112 | touchpads working in absolute mode only). | |
1113 | Format: <msecs> | |
1114 | mousedev.xres= [MOUSE] Horizontal screen resolution, used for devices | |
1115 | reporting absolute coordinates, such as tablets | |
1116 | mousedev.yres= [MOUSE] Vertical screen resolution, used for devices | |
1117 | reporting absolute coordinates, such as tablets | |
1118 | ||
1119 | mpu401= [HW,OSS] | |
1120 | Format: <io>,<irq> | |
1121 | ||
1122 | MTD_Partition= [MTD] | |
1123 | Format: <name>,<region-number>,<size>,<offset> | |
1124 | ||
a9913044 RD |
1125 | MTD_Region= [MTD] Format: |
1126 | <name>,<region-number>[,<base>,<size>,<buswidth>,<altbuswidth>] | |
1da177e4 LT |
1127 | |
1128 | mtdparts= [MTD] | |
c8facbb6 | 1129 | See drivers/mtd/cmdlinepart.c. |
1da177e4 LT |
1130 | |
1131 | mtouchusb.raw_coordinates= | |
a9913044 RD |
1132 | [HW] Make the MicroTouch USB driver use raw coordinates |
1133 | ('y', default) or cooked coordinates ('n') | |
1da177e4 LT |
1134 | |
1135 | n2= [NET] SDL Inc. RISCom/N2 synchronous serial card | |
1136 | ||
1137 | NCR_D700= [HW,SCSI] | |
1138 | See header of drivers/scsi/NCR_D700.c. | |
1139 | ||
1140 | ncr5380= [HW,SCSI] | |
1141 | ||
1142 | ncr53c400= [HW,SCSI] | |
1143 | ||
1144 | ncr53c400a= [HW,SCSI] | |
1145 | ||
1146 | ncr53c406a= [HW,SCSI] | |
1147 | ||
1148 | ncr53c8xx= [HW,SCSI] | |
1149 | ||
1150 | netdev= [NET] Network devices parameters | |
1151 | Format: <irq>,<io>,<mem_start>,<mem_end>,<name> | |
1152 | Note that mem_start is often overloaded to mean | |
1153 | something different and driver-specific. | |
a9913044 RD |
1154 | This usage is only documented in each driver source |
1155 | file if at all. | |
1156 | ||
1da177e4 LT |
1157 | nfsaddrs= [NFS] |
1158 | See Documentation/nfsroot.txt. | |
1159 | ||
1160 | nfsroot= [NFS] nfs root filesystem for disk-less boxes. | |
1161 | See Documentation/nfsroot.txt. | |
1162 | ||
a72b4422 TM |
1163 | nfs.callback_tcpport= |
1164 | [NFS] set the TCP port on which the NFSv4 callback | |
1165 | channel should listen. | |
1166 | ||
58df095b TM |
1167 | nfs.idmap_cache_timeout= |
1168 | [NFS] set the maximum lifetime for idmapper cache | |
1169 | entries. | |
1170 | ||
f43bf0be TM |
1171 | nfs.enable_ino64= |
1172 | [NFS] enable 64-bit inode numbers. | |
1173 | If zero, the NFS client will fake up a 32-bit inode | |
1174 | number for the readdir() and stat() syscalls instead | |
1175 | of returning the full 64-bit number. | |
1176 | The default is to return 64-bit inode numbers. | |
1177 | ||
e7ba176b HS |
1178 | nmi_debug= [KNL,AVR32] Specify one or more actions to take |
1179 | when a NMI is triggered. | |
1180 | Format: [state][,regs][,debounce][,die] | |
1181 | ||
cd4f0ef7 | 1182 | nmi_watchdog= [KNL,BUGS=X86-32] Debugging features for SMP kernels |
1da177e4 | 1183 | |
cd4f0ef7 | 1184 | no387 [BUGS=X86-32] Tells the kernel to use the 387 maths |
1da177e4 LT |
1185 | emulation library even if a 387 maths coprocessor |
1186 | is present. | |
1187 | ||
c1aee215 CL |
1188 | noaliencache [MM, NUMA, SLAB] Disables the allocation of alien |
1189 | caches in the slab allocator. Saves per-node memory, | |
1190 | but will impact performance. | |
3395ee05 | 1191 | |
a9913044 RD |
1192 | noalign [KNL,ARM] |
1193 | ||
1da177e4 LT |
1194 | noapic [SMP,APIC] Tells the kernel to not make use of any |
1195 | IOAPICs that may be present in the system. | |
1196 | ||
1da177e4 LT |
1197 | nobats [PPC] Do not use BATs for mapping kernel lowmem |
1198 | on "Classic" PPC cores. | |
1199 | ||
1200 | nocache [ARM] | |
a9913044 | 1201 | |
163ecdff SN |
1202 | nodelayacct [KNL] Disable per-task delay accounting |
1203 | ||
1da177e4 LT |
1204 | nodisconnect [HW,SCSI,M68K] Disables SCSI disconnects. |
1205 | ||
8b2cb7a8 HY |
1206 | noefi [X86-32,X86-64] Disable EFI runtime services support. |
1207 | ||
1da177e4 LT |
1208 | noexec [IA-64] |
1209 | ||
cd4f0ef7 | 1210 | noexec [X86-32,X86-64] |
1da177e4 LT |
1211 | noexec=on: enable non-executable mappings (default) |
1212 | noexec=off: disable nn-executable mappings | |
1213 | ||
cd4f0ef7 | 1214 | nofxsr [BUGS=X86-32] Disables x86 floating point extended |
4f886511 CE |
1215 | register save and restore. The kernel will only save |
1216 | legacy floating-point registers on task switch. | |
1da177e4 | 1217 | |
191679fd AK |
1218 | noclflush [BUGS=X86] Don't use the CLFLUSH instruction |
1219 | ||
1da177e4 | 1220 | nohlt [BUGS=ARM] |
a9913044 | 1221 | |
cd4f0ef7 | 1222 | no-hlt [BUGS=X86-32] Tells the kernel that the hlt |
1da177e4 LT |
1223 | instruction doesn't work correctly and not to |
1224 | use it. | |
1225 | ||
1226 | nohalt [IA-64] Tells the kernel not to use the power saving | |
1227 | function PAL_HALT_LIGHT when idle. This increases | |
1228 | power-consumption. On the positive side, it reduces | |
1229 | interrupt wake-up latency, which may improve performance | |
1230 | in certain environments such as networked servers or | |
1231 | real-time systems. | |
1232 | ||
79bf2bb3 TG |
1233 | nohz= [KNL] Boottime enable/disable dynamic ticks |
1234 | Valid arguments: on, off | |
1235 | Default: on | |
1236 | ||
cd4f0ef7 | 1237 | noirqbalance [X86-32,SMP,KNL] Disable kernel irq balancing |
8542b200 | 1238 | |
cd4f0ef7 | 1239 | noirqdebug [X86-32] Disables the code which attempts to detect and |
1da177e4 LT |
1240 | disable unhandled interrupt sources. |
1241 | ||
cd4f0ef7 | 1242 | no_timer_check [X86-32,X86_64,APIC] Disables the code which tests for |
8542b200 ZA |
1243 | broken timer IRQ sources. |
1244 | ||
1da177e4 LT |
1245 | noisapnp [ISAPNP] Disables ISA PnP code. |
1246 | ||
1247 | noinitrd [RAM] Tells the kernel not to load any configured | |
1248 | initial RAM disk. | |
1249 | ||
1250 | nointroute [IA-64] | |
1251 | ||
0aa366f3 TL |
1252 | nojitter [IA64] Disables jitter checking for ITC timers. |
1253 | ||
cd4f0ef7 | 1254 | nolapic [X86-32,APIC] Do not enable or use the local APIC. |
1da177e4 | 1255 | |
cd4f0ef7 | 1256 | nolapic_timer [X86-32,APIC] Do not use the local APIC timer. |
ad62ca2b | 1257 | |
1da177e4 LT |
1258 | noltlbs [PPC] Do not use large page/tlb entries for kernel |
1259 | lowmem mapping on PPC40x. | |
1260 | ||
312f1f01 H |
1261 | nomca [IA-64] Disable machine check abort handling |
1262 | ||
cd4f0ef7 | 1263 | nomce [X86-32] Machine Check Exception |
abe37e5a | 1264 | |
83d7384f AS |
1265 | nomfgpt [X86-32] Disable Multi-Function General Purpose |
1266 | Timer usage (for AMD Geode machines). | |
1267 | ||
cd4f0ef7 | 1268 | noreplace-paravirt [X86-32,PV_OPS] Don't patch paravirt_ops |
959b4fdf | 1269 | |
cd4f0ef7 | 1270 | noreplace-smp [X86-32,SMP] Don't replace SMP instructions |
b7fb4af0 JF |
1271 | with UP alternatives |
1272 | ||
1da177e4 LT |
1273 | noresidual [PPC] Don't use residual data on PReP machines. |
1274 | ||
a9913044 RD |
1275 | noresume [SWSUSP] Disables resume and restores original swap |
1276 | space. | |
1277 | ||
1da177e4 LT |
1278 | no-scroll [VGA] Disables scrollback. |
1279 | This is required for the Braillex ib80-piezo Braille | |
1280 | reader made by F.H. Papenmeier (Germany). | |
1281 | ||
1282 | nosbagart [IA-64] | |
1283 | ||
cd4f0ef7 | 1284 | nosep [BUGS=X86-32] Disables x86 SYSENTER/SYSEXIT support. |
4f886511 | 1285 | |
61ec7567 LB |
1286 | nosmp [SMP] Tells an SMP kernel to act as a UP kernel, |
1287 | and disable the IO APIC. legacy for "maxcpus=0". | |
1da177e4 | 1288 | |
97842216 DJ |
1289 | nosoftlockup [KNL] Disable the soft-lockup detector. |
1290 | ||
1da177e4 LT |
1291 | nosync [HW,M68K] Disables sync negotiation for all devices. |
1292 | ||
cd4f0ef7 | 1293 | notsc [BUGS=X86-32] Disable Time Stamp Counter |
1da177e4 LT |
1294 | |
1295 | nousb [USB] Disable the USB subsystem | |
1296 | ||
1297 | nowb [ARM] | |
a9913044 | 1298 | |
f0c0b2b8 KH |
1299 | numa_zonelist_order= [KNL, BOOT] Select zonelist order for NUMA. |
1300 | one of ['zone', 'node', 'default'] can be specified | |
1301 | This can be set from sysctl after boot. | |
1302 | See Documentation/sysctl/vm.txt for details. | |
1303 | ||
a61c2d78 DJ |
1304 | nr_uarts= [SERIAL] maximum number of UARTs to be registered. |
1305 | ||
1da177e4 LT |
1306 | opl3= [HW,OSS] |
1307 | Format: <io> | |
1308 | ||
1da177e4 LT |
1309 | oprofile.timer= [HW] |
1310 | Use timer interrupt instead of performance counters | |
1311 | ||
1da177e4 LT |
1312 | osst= [HW,SCSI] SCSI Tape Driver |
1313 | Format: <buffer_size>,<write_threshold> | |
1314 | See also Documentation/scsi/st.txt. | |
1315 | ||
1316 | panic= [KNL] Kernel behaviour on panic | |
1317 | Format: <timeout> | |
1318 | ||
1319 | parkbd.port= [HW] Parallel port number the keyboard adapter is | |
1320 | connected to, default is 0. | |
1321 | Format: <parport#> | |
1322 | parkbd.mode= [HW] Parallel port keyboard adapter mode of operation, | |
1323 | 0 for XT, 1 for AT (default is AT). | |
a9913044 RD |
1324 | Format: <mode> |
1325 | ||
1326 | parport= [HW,PPT] Specify parallel ports. 0 disables. | |
1327 | Format: { 0 | auto | 0xBBB[,IRQ[,DMA]] } | |
1328 | Use 'auto' to force the driver to use any | |
1329 | IRQ/DMA settings detected (the default is to | |
1330 | ignore detected IRQ/DMA settings because of | |
1331 | possible conflicts). You can specify the base | |
1332 | address, IRQ, and DMA settings; IRQ and DMA | |
1333 | should be numbers, or 'auto' (for using detected | |
1334 | settings on that particular port), or 'nofifo' | |
1335 | (to avoid using a FIFO even if it is detected). | |
1336 | Parallel ports are assigned in the order they | |
1337 | are specified on the command line, starting | |
1338 | with parport0. | |
1339 | ||
1340 | parport_init_mode= [HW,PPT] | |
1341 | Configure VIA parallel port to operate in | |
1342 | a specific mode. This is necessary on Pegasos | |
1343 | computer where firmware has no options for setting | |
1344 | up parallel port mode and sets it to spp. | |
1345 | Currently this function knows 686a and 8231 chips. | |
1da177e4 LT |
1346 | Format: [spp|ps2|epp|ecp|ecpepp] |
1347 | ||
a9913044 RD |
1348 | pas2= [HW,OSS] Format: |
1349 | <io>,<irq>,<dma>,<dma16>,<sb_io>,<sb_irq>,<sb_dma>,<sb_dma16> | |
1350 | ||
1da177e4 LT |
1351 | pas16= [HW,SCSI] |
1352 | See header of drivers/scsi/pas16.c. | |
1353 | ||
dd287796 AM |
1354 | pause_on_oops= |
1355 | Halt all CPUs after the first oops has been printed for | |
1356 | the specified number of seconds. This is to be used if | |
1357 | your oopses keep scrolling off the screen. | |
1358 | ||
1da177e4 LT |
1359 | pcbit= [HW,ISDN] |
1360 | ||
1361 | pcd. [PARIDE] | |
1362 | See header of drivers/block/paride/pcd.c. | |
1363 | See also Documentation/paride.txt. | |
1364 | ||
a9913044 | 1365 | pci=option[,option...] [PCI] various PCI subsystem options: |
cd4f0ef7 AC |
1366 | off [X86-32] don't probe for the PCI bus |
1367 | bios [X86-32] force use of PCI BIOS, don't access | |
a9913044 RD |
1368 | the hardware directly. Use this if your machine |
1369 | has a non-standard PCI host bridge. | |
cd4f0ef7 | 1370 | nobios [X86-32] disallow use of PCI BIOS, only direct |
a9913044 RD |
1371 | hardware access methods are allowed. Use this |
1372 | if you experience crashes upon bootup and you | |
1373 | suspect they are caused by the BIOS. | |
cd4f0ef7 | 1374 | conf1 [X86-32] Force use of PCI Configuration |
a9913044 | 1375 | Mechanism 1. |
cd4f0ef7 | 1376 | conf2 [X86-32] Force use of PCI Configuration |
a9913044 | 1377 | Mechanism 2. |
7f785763 RD |
1378 | noaer [PCIE] If the PCIEAER kernel config parameter is |
1379 | enabled, this kernel boot option can be used to | |
1380 | disable the use of PCIE advanced error reporting. | |
32a2eea7 JG |
1381 | nodomains [PCI] Disable support for multiple PCI |
1382 | root domains (aka PCI segments, in ACPI-speak). | |
cd4f0ef7 | 1383 | nommconf [X86-32,X86_64] Disable use of MMCONFIG for PCI |
61be6d66 | 1384 | Configuration |
309e57df MW |
1385 | nomsi [MSI] If the PCI_MSI kernel config parameter is |
1386 | enabled, this kernel boot option can be used to | |
1387 | disable the use of MSI interrupts system-wide. | |
cd4f0ef7 | 1388 | nosort [X86-32] Don't sort PCI devices according to |
a9913044 RD |
1389 | order given by the PCI BIOS. This sorting is |
1390 | done to get a device order compatible with | |
1391 | older kernels. | |
cd4f0ef7 | 1392 | biosirq [X86-32] Use PCI BIOS calls to get the interrupt |
a9913044 RD |
1393 | routing table. These calls are known to be buggy |
1394 | on several machines and they hang the machine | |
1395 | when used, but on other computers it's the only | |
1396 | way to get the interrupt routing table. Try | |
1397 | this option if the kernel is unable to allocate | |
1398 | IRQs or discover secondary PCI buses on your | |
1399 | motherboard. | |
cd4f0ef7 | 1400 | rom [X86-32] Assign address space to expansion ROMs. |
a9913044 RD |
1401 | Use with caution as certain devices share |
1402 | address decoders between ROMs and other | |
1403 | resources. | |
cd4f0ef7 | 1404 | irqmask=0xMMMM [X86-32] Set a bit mask of IRQs allowed to be |
a9913044 RD |
1405 | assigned automatically to PCI devices. You can |
1406 | make the kernel exclude IRQs of your ISA cards | |
1407 | this way. | |
cd4f0ef7 | 1408 | pirqaddr=0xAAAAA [X86-32] Specify the physical address |
a9913044 RD |
1409 | of the PIRQ table (normally generated |
1410 | by the BIOS) if it is outside the | |
1411 | F0000h-100000h range. | |
cd4f0ef7 | 1412 | lastbus=N [X86-32] Scan all buses thru bus #N. Can be |
a9913044 RD |
1413 | useful if the kernel is unable to find your |
1414 | secondary buses and you want to tell it | |
1415 | explicitly which ones they are. | |
cd4f0ef7 | 1416 | assign-busses [X86-32] Always assign all PCI bus |
a9913044 RD |
1417 | numbers ourselves, overriding |
1418 | whatever the firmware may have done. | |
cd4f0ef7 | 1419 | usepirqmask [X86-32] Honor the possible IRQ mask stored |
a9913044 RD |
1420 | in the BIOS $PIR table. This is needed on |
1421 | some systems with broken BIOSes, notably | |
1422 | some HP Pavilion N5400 and Omnibook XE3 | |
1423 | notebooks. This will have no effect if ACPI | |
1424 | IRQ routing is enabled. | |
cd4f0ef7 | 1425 | noacpi [X86-32] Do not use ACPI for IRQ routing |
a9913044 | 1426 | or for PCI scanning. |
62f420f8 GH |
1427 | use_crs [X86-32] Use _CRS for PCI resource |
1428 | allocation. | |
a9913044 RD |
1429 | routeirq Do IRQ routing for all PCI devices. |
1430 | This is normally done in pci_enable_device(), | |
1431 | so this option is a temporary workaround | |
1432 | for broken drivers that don't call it. | |
1433 | firmware [ARM] Do not re-enumerate the bus but instead | |
1434 | just use the configuration from the | |
1435 | bootloader. This is currently used on | |
1436 | IXP2000 systems where the bus has to be | |
1437 | configured a certain way for adjunct CPUs. | |
0637a70a AK |
1438 | noearly [X86] Don't do any early type 1 scanning. |
1439 | This might help on some broken boards which | |
1440 | machine check when some devices' config space | |
1441 | is read. But various workarounds are disabled | |
1442 | and some IOMMU drivers will not work. | |
6b4b78fe MD |
1443 | bfsort Sort PCI devices into breadth-first order. |
1444 | This sorting is done to get a device | |
1445 | order compatible with older (<= 2.4) kernels. | |
1446 | nobfsort Don't sort PCI devices into breadth-first order. | |
4516a618 AN |
1447 | cbiosize=nn[KMG] The fixed amount of bus space which is |
1448 | reserved for the CardBus bridge's IO window. | |
1449 | The default value is 256 bytes. | |
1450 | cbmemsize=nn[KMG] The fixed amount of bus space which is | |
1451 | reserved for the CardBus bridge's memory | |
1452 | window. The default value is 64 megabytes. | |
6b4b78fe | 1453 | |
1da177e4 LT |
1454 | pcmv= [HW,PCMCIA] BadgePAD 4 |
1455 | ||
1456 | pd. [PARIDE] | |
1457 | See Documentation/paride.txt. | |
1458 | ||
1459 | pdcchassis= [PARISC,HW] Disable/Enable PDC Chassis Status codes at | |
1460 | boot time. | |
1461 | Format: { 0 | 1 } | |
1462 | See arch/parisc/kernel/pdc_chassis.c | |
1463 | ||
1464 | pf. [PARIDE] | |
1465 | See Documentation/paride.txt. | |
1466 | ||
1467 | pg. [PARIDE] | |
1468 | See Documentation/paride.txt. | |
1469 | ||
1470 | pirq= [SMP,APIC] Manual mp-table setup | |
1471 | See Documentation/i386/IO-APIC.txt. | |
1472 | ||
1473 | plip= [PPT,NET] Parallel port network link | |
1474 | Format: { parport<nr> | timid | 0 } | |
1475 | See also Documentation/parport.txt. | |
1476 | ||
1477 | pnpacpi= [ACPI] | |
1478 | { off } | |
1479 | ||
1480 | pnpbios= [ISAPNP] | |
1481 | { on | off | curr | res | no-curr | no-res } | |
1482 | ||
1483 | pnp_reserve_irq= | |
1484 | [ISAPNP] Exclude IRQs for the autoconfiguration | |
1485 | ||
1486 | pnp_reserve_dma= | |
1487 | [ISAPNP] Exclude DMAs for the autoconfiguration | |
1488 | ||
1489 | pnp_reserve_io= [ISAPNP] Exclude I/O ports for the autoconfiguration | |
a9913044 | 1490 | Ranges are in pairs (I/O port base and size). |
1da177e4 LT |
1491 | |
1492 | pnp_reserve_mem= | |
a9913044 RD |
1493 | [ISAPNP] Exclude memory regions for the |
1494 | autoconfiguration. | |
1da177e4 LT |
1495 | Ranges are in pairs (memory base and size). |
1496 | ||
45807a1d IM |
1497 | print-fatal-signals= |
1498 | [KNL] debug: print fatal signals | |
1499 | print-fatal-signals=1: print segfault info to | |
1500 | the kernel console. | |
1501 | default: off. | |
1502 | ||
e84845c4 RD |
1503 | printk.time= Show timing data prefixed to each printk message line |
1504 | Format: <bool> (1/Y/y=enable, 0/N/n=disable) | |
1505 | ||
1da177e4 | 1506 | profile= [KNL] Enable kernel profiling via /proc/profile |
a9913044 RD |
1507 | Format: [schedule,]<number> |
1508 | Param: "schedule" - profile schedule points. | |
1509 | Param: <number> - step/bucket size as a power of 2 for | |
1510 | statistical time based profiling. | |
b3da2a73 MG |
1511 | Param: "sleep" - profile D-state sleeping (millisecs). |
1512 | Requires CONFIG_SCHEDSTATS | |
c0fe2e69 | 1513 | Param: "kvm" - profile VM exits. |
1da177e4 | 1514 | |
a9913044 | 1515 | processor.max_cstate= [HW,ACPI] |
1da177e4 LT |
1516 | Limit processor to maximum C-state |
1517 | max_cstate=9 overrides any DMI blacklist limit. | |
1518 | ||
41c0d868 LB |
1519 | processor.nocst [HW,ACPI] |
1520 | Ignore the _CST method to determine C-states, | |
1521 | instead using the legacy FADT method | |
1522 | ||
1da177e4 LT |
1523 | prompt_ramdisk= [RAM] List of RAM disks to prompt for floppy disk |
1524 | before loading. | |
1525 | See Documentation/ramdisk.txt. | |
1526 | ||
a9913044 RD |
1527 | psmouse.proto= [HW,MOUSE] Highest PS2 mouse protocol extension to |
1528 | probe for; one of (bare|imps|exps|lifebook|any). | |
1da177e4 LT |
1529 | psmouse.rate= [HW,MOUSE] Set desired mouse report rate, in reports |
1530 | per second. | |
a9913044 RD |
1531 | psmouse.resetafter= [HW,MOUSE] |
1532 | Try to reset the device after so many bad packets | |
1da177e4 LT |
1533 | (0 = never). |
1534 | psmouse.resolution= | |
1535 | [HW,MOUSE] Set desired mouse resolution, in dpi. | |
1536 | psmouse.smartscroll= | |
a9913044 | 1537 | [HW,MOUSE] Controls Logitech smartscroll autorepeat. |
1da177e4 LT |
1538 | 0 = disabled, 1 = enabled (default). |
1539 | ||
1540 | pss= [HW,OSS] Personal Sound System (ECHO ESC614) | |
a9913044 RD |
1541 | Format: |
1542 | <io>,<mss_io>,<mss_irq>,<mss_dma>,<mpu_io>,<mpu_irq> | |
1da177e4 LT |
1543 | |
1544 | pt. [PARIDE] | |
1545 | See Documentation/paride.txt. | |
1546 | ||
dc8c8587 KS |
1547 | pty.legacy_count= |
1548 | [KNL] Number of legacy pty's. Overwrites compiled-in | |
1549 | default number. | |
1550 | ||
7d2c502f | 1551 | quiet [KNL] Disable most log messages |
a9913044 | 1552 | |
1da177e4 LT |
1553 | r128= [HW,DRM] |
1554 | ||
1555 | raid= [HW,RAID] | |
1556 | See Documentation/md.txt. | |
1557 | ||
a9913044 | 1558 | ramdisk_blocksize= [RAM] |
1da177e4 | 1559 | See Documentation/ramdisk.txt. |
a9913044 | 1560 | |
1da177e4 | 1561 | ramdisk_size= [RAM] Sizes of RAM disks in kilobytes |
1da177e4 LT |
1562 | See Documentation/ramdisk.txt. |
1563 | ||
24aaef8d RD |
1564 | rcupdate.blimit= [KNL,BOOT] |
1565 | Set maximum number of finished RCU callbacks to process | |
1566 | in one batch. | |
21a1ea9e | 1567 | |
24aaef8d RD |
1568 | rcupdate.qhimark= [KNL,BOOT] |
1569 | Set threshold of queued | |
21a1ea9e DS |
1570 | RCU callbacks over which batch limiting is disabled. |
1571 | ||
24aaef8d RD |
1572 | rcupdate.qlowmark= [KNL,BOOT] |
1573 | Set threshold of queued RCU callbacks below which | |
1574 | batch limiting is re-enabled. | |
21a1ea9e | 1575 | |
ffdfc409 OJ |
1576 | rdinit= [KNL] |
1577 | Format: <full_path> | |
1578 | Run specified binary instead of /init from the ramdisk, | |
1579 | used for early userspace startup. See initrd. | |
1580 | ||
cd4f0ef7 | 1581 | reboot= [BUGS=X86-32,BUGS=ARM,BUGS=IA-64] Rebooting mode |
1da177e4 | 1582 | Format: <reboot_mode>[,<reboot_mode2>[,...]] |
e53dd083 | 1583 | See arch/*/kernel/reboot.c or arch/*/kernel/process.c |
1da177e4 LT |
1584 | |
1585 | reserve= [KNL,BUGS] Force the kernel to ignore some iomem area | |
1586 | ||
cd4f0ef7 | 1587 | reservetop= [X86-32] |
461a9aff ZA |
1588 | Format: nn[KMG] |
1589 | Reserves a hole at the top of the kernel virtual | |
1590 | address space. | |
1591 | ||
7e96287d VG |
1592 | reset_devices [KNL] Force drivers to reset the underlying device |
1593 | during initialization. | |
1594 | ||
a9913044 RD |
1595 | resume= [SWSUSP] |
1596 | Specify the partition device for software suspend | |
1da177e4 | 1597 | |
ecbd0da1 RW |
1598 | resume_offset= [SWSUSP] |
1599 | Specify the offset from the beginning of the partition | |
1600 | given by "resume=" at which the swap header is located, | |
1601 | in <PAGE_SIZE> units (needed only for swap files). | |
1602 | See Documentation/power/swsusp-and-swap-files.txt | |
1603 | ||
0a7b35cb MN |
1604 | retain_initrd [RAM] Keep initrd memory after extraction |
1605 | ||
1da177e4 LT |
1606 | rhash_entries= [KNL,NET] |
1607 | Set number of hash buckets for route cache | |
1608 | ||
1609 | riscom8= [HW,SERIAL] | |
1610 | Format: <io_board1>[,<io_board2>[,...<io_boardN>]] | |
1611 | ||
1612 | ro [KNL] Mount root device read-only on boot | |
1613 | ||
1614 | root= [KNL] Root filesystem | |
1615 | ||
1616 | rootdelay= [KNL] Delay (in seconds) to pause before attempting to | |
1617 | mount the root filesystem | |
1618 | ||
1619 | rootflags= [KNL] Set root filesystem mount option string | |
1620 | ||
1621 | rootfstype= [KNL] Set root filesystem type | |
1622 | ||
cc1ed754 PO |
1623 | rootwait [KNL] Wait (indefinitely) for root device to show up. |
1624 | Useful for devices that are detected asynchronously | |
1625 | (e.g. USB and MMC devices). | |
1626 | ||
20510f2f JM |
1627 | root_plug.vendor_id= |
1628 | [ROOTPLUG] Override the default vendor ID | |
1629 | ||
1630 | root_plug.product_id= | |
1631 | [ROOTPLUG] Override the default product ID | |
1632 | ||
1633 | root_plug.debug= | |
1634 | [ROOTPLUG] Enable debugging output | |
1635 | ||
1da177e4 LT |
1636 | rw [KNL] Mount root device read-write on boot |
1637 | ||
1638 | S [KNL] Run init in single mode | |
1639 | ||
1640 | sa1100ir [NET] | |
1641 | See drivers/net/irda/sa1100_ir.c. | |
1642 | ||
1da177e4 | 1643 | sbni= [NET] Granch SBNI12 leased line adapter |
a9913044 | 1644 | |
1da177e4 LT |
1645 | sc1200wdt= [HW,WDT] SC1200 WDT (watchdog) driver |
1646 | Format: <io>[,<timeout>[,<isapnp>]] | |
1647 | ||
1648 | scsi_debug_*= [SCSI] | |
1649 | See drivers/scsi/scsi_debug.c. | |
1650 | ||
1651 | scsi_default_dev_flags= | |
1652 | [SCSI] SCSI default device flags | |
1653 | Format: <integer> | |
1654 | ||
1655 | scsi_dev_flags= [SCSI] Black/white list entry for vendor and model | |
1656 | Format: <vendor>:<model>:<flags> | |
1657 | (flags are integer value) | |
1658 | ||
6af6632a RD |
1659 | scsi_logging_level= [SCSI] a bit mask of logging levels |
1660 | See drivers/scsi/scsi_logging.h for bits. Also | |
1661 | settable via sysctl at dev.scsi.logging_level | |
1662 | (/proc/sys/dev/scsi/logging_level). | |
1663 | There is also a nice 'scsi_logging_level' script in the | |
1664 | S390-tools package, available for download at | |
1665 | http://www-128.ibm.com/developerworks/linux/linux390/s390-tools-1.5.4.html | |
1da177e4 | 1666 | |
3e082a91 MW |
1667 | scsi_mod.scan= [SCSI] sync (default) scans SCSI busses as they are |
1668 | discovered. async scans them in kernel threads, | |
1669 | allowing boot to proceed. none ignores them, expecting | |
1670 | user space to do the scan. | |
1671 | ||
1da177e4 LT |
1672 | selinux [SELINUX] Disable or enable SELinux at boot time. |
1673 | Format: { "0" | "1" } | |
1674 | See security/selinux/Kconfig help text. | |
1675 | 0 -- disable. | |
1676 | 1 -- enable. | |
1677 | Default value is set via kernel config option. | |
1678 | If enabled at boot time, /selinux/disable can be used | |
1679 | later to disable prior to initial policy load. | |
1680 | ||
4e5ab4cb JM |
1681 | selinux_compat_net = |
1682 | [SELINUX] Set initial selinux_compat_net flag value. | |
e53dd083 MCC |
1683 | Format: { "0" | "1" } |
1684 | 0 -- use new secmark-based packet controls | |
1685 | 1 -- use legacy packet controls | |
1686 | Default value is 0 (preferred). | |
1687 | Value can be changed at runtime via | |
1688 | /selinux/compat_net. | |
4e5ab4cb | 1689 | |
cd4f0ef7 | 1690 | serialnumber [BUGS=X86-32] |
1da177e4 | 1691 | |
1da177e4 LT |
1692 | shapers= [NET] |
1693 | Maximal number of shapers. | |
a9913044 | 1694 | |
1da177e4 LT |
1695 | sim710= [SCSI,HW] |
1696 | See header of drivers/scsi/sim710.c. | |
1697 | ||
1698 | simeth= [IA-64] | |
1699 | simscsi= | |
a9913044 | 1700 | |
1da177e4 LT |
1701 | slram= [HW,MTD] |
1702 | ||
f0630fff CL |
1703 | slub_debug[=options[,slabs]] [MM, SLUB] |
1704 | Enabling slub_debug allows one to determine the | |
1705 | culprit if slab objects become corrupted. Enabling | |
1706 | slub_debug can create guard zones around objects and | |
1707 | may poison objects when not in use. Also tracks the | |
1708 | last alloc / free. For more information see | |
1709 | Documentation/vm/slub.txt. | |
c1aee215 CL |
1710 | |
1711 | slub_max_order= [MM, SLUB] | |
f0630fff CL |
1712 | Determines the maximum allowed order for slabs. |
1713 | A high setting may cause OOMs due to memory | |
1714 | fragmentation. For more information see | |
1715 | Documentation/vm/slub.txt. | |
c1aee215 CL |
1716 | |
1717 | slub_min_objects= [MM, SLUB] | |
f0630fff CL |
1718 | The minimum number of objects per slab. SLUB will |
1719 | increase the slab order up to slub_max_order to | |
1720 | generate a sufficiently large slab able to contain | |
1721 | the number of objects indicated. The higher the number | |
1722 | of objects the smaller the overhead of tracking slabs | |
1723 | and the less frequently locks need to be acquired. | |
c1aee215 CL |
1724 | For more information see Documentation/vm/slub.txt. |
1725 | ||
1726 | slub_min_order= [MM, SLUB] | |
1727 | Determines the mininum page order for slabs. Must be | |
f0630fff | 1728 | lower than slub_max_order. |
c1aee215 CL |
1729 | For more information see Documentation/vm/slub.txt. |
1730 | ||
1731 | slub_nomerge [MM, SLUB] | |
f0630fff | 1732 | Disable merging of slabs with similar size. May be |
c1aee215 | 1733 | necessary if there is some reason to distinguish |
f0630fff CL |
1734 | allocs to different slabs. Debug options disable |
1735 | merging on their own. | |
c1aee215 CL |
1736 | For more information see Documentation/vm/slub.txt. |
1737 | ||
1da177e4 LT |
1738 | smart2= [HW] |
1739 | Format: <io1>[,<io2>[,...,<io8>]] | |
1740 | ||
cd4f0ef7 | 1741 | smp-alt-once [X86-32,SMP] On a hotplug CPU system, only |
b7fb4af0 JF |
1742 | attempt to substitute SMP alternatives once at boot. |
1743 | ||
d0d4f69b BH |
1744 | smsc-ircc2.nopnp [HW] Don't use PNP to discover SMC devices |
1745 | smsc-ircc2.ircc_cfg= [HW] Device configuration I/O port | |
1746 | smsc-ircc2.ircc_sir= [HW] SIR base I/O port | |
1747 | smsc-ircc2.ircc_fir= [HW] FIR base I/O port | |
1748 | smsc-ircc2.ircc_irq= [HW] IRQ line | |
1749 | smsc-ircc2.ircc_dma= [HW] DMA channel | |
1750 | smsc-ircc2.ircc_transceiver= [HW] Transceiver type: | |
1751 | 0: Toshiba Satellite 1800 (GP data pin select) | |
1752 | 1: Fast pin select (default) | |
1753 | 2: ATC IRMode | |
1754 | ||
1da177e4 LT |
1755 | snd-ad1816a= [HW,ALSA] |
1756 | ||
1757 | snd-ad1848= [HW,ALSA] | |
1758 | ||
1759 | snd-ali5451= [HW,ALSA] | |
1760 | ||
1761 | snd-als100= [HW,ALSA] | |
1762 | ||
1763 | snd-als4000= [HW,ALSA] | |
1764 | ||
1765 | snd-azt2320= [HW,ALSA] | |
1766 | ||
1767 | snd-cmi8330= [HW,ALSA] | |
1768 | ||
1769 | snd-cmipci= [HW,ALSA] | |
1770 | ||
1771 | snd-cs4231= [HW,ALSA] | |
1772 | ||
1773 | snd-cs4232= [HW,ALSA] | |
1774 | ||
1775 | snd-cs4236= [HW,ALSA] | |
1776 | ||
1777 | snd-cs4281= [HW,ALSA] | |
1778 | ||
1779 | snd-cs46xx= [HW,ALSA] | |
1780 | ||
1781 | snd-dt019x= [HW,ALSA] | |
1782 | ||
1783 | snd-dummy= [HW,ALSA] | |
1784 | ||
1785 | snd-emu10k1= [HW,ALSA] | |
1786 | ||
1787 | snd-ens1370= [HW,ALSA] | |
1788 | ||
1789 | snd-ens1371= [HW,ALSA] | |
1790 | ||
1791 | snd-es968= [HW,ALSA] | |
1792 | ||
1793 | snd-es1688= [HW,ALSA] | |
1794 | ||
1795 | snd-es18xx= [HW,ALSA] | |
1796 | ||
1797 | snd-es1938= [HW,ALSA] | |
1798 | ||
1799 | snd-es1968= [HW,ALSA] | |
1800 | ||
1801 | snd-fm801= [HW,ALSA] | |
1802 | ||
1803 | snd-gusclassic= [HW,ALSA] | |
1804 | ||
1805 | snd-gusextreme= [HW,ALSA] | |
1806 | ||
1807 | snd-gusmax= [HW,ALSA] | |
1808 | ||
1809 | snd-hdsp= [HW,ALSA] | |
1810 | ||
1811 | snd-ice1712= [HW,ALSA] | |
1812 | ||
1813 | snd-intel8x0= [HW,ALSA] | |
1814 | ||
1815 | snd-interwave= [HW,ALSA] | |
1816 | ||
1817 | snd-interwave-stb= | |
1818 | [HW,ALSA] | |
1819 | ||
1820 | snd-korg1212= [HW,ALSA] | |
1821 | ||
1822 | snd-maestro3= [HW,ALSA] | |
1823 | ||
1824 | snd-mpu401= [HW,ALSA] | |
1825 | ||
1826 | snd-mtpav= [HW,ALSA] | |
1827 | ||
1828 | snd-nm256= [HW,ALSA] | |
1829 | ||
1830 | snd-opl3sa2= [HW,ALSA] | |
1831 | ||
1832 | snd-opti92x-ad1848= | |
1833 | [HW,ALSA] | |
1834 | ||
1835 | snd-opti92x-cs4231= | |
1836 | [HW,ALSA] | |
1837 | ||
1838 | snd-opti93x= [HW,ALSA] | |
1839 | ||
1840 | snd-pmac= [HW,ALSA] | |
1841 | ||
1842 | snd-rme32= [HW,ALSA] | |
1843 | ||
1844 | snd-rme96= [HW,ALSA] | |
1845 | ||
1846 | snd-rme9652= [HW,ALSA] | |
1847 | ||
1848 | snd-sb8= [HW,ALSA] | |
1849 | ||
1850 | snd-sb16= [HW,ALSA] | |
1851 | ||
1852 | snd-sbawe= [HW,ALSA] | |
1853 | ||
1854 | snd-serial= [HW,ALSA] | |
1855 | ||
1856 | snd-sgalaxy= [HW,ALSA] | |
1857 | ||
1858 | snd-sonicvibes= [HW,ALSA] | |
1859 | ||
1860 | snd-sun-amd7930= | |
1861 | [HW,ALSA] | |
1862 | ||
1863 | snd-sun-cs4231= [HW,ALSA] | |
1864 | ||
1865 | snd-trident= [HW,ALSA] | |
1866 | ||
1867 | snd-usb-audio= [HW,ALSA,USB] | |
1868 | ||
1869 | snd-via82xx= [HW,ALSA] | |
1870 | ||
1871 | snd-virmidi= [HW,ALSA] | |
1872 | ||
1873 | snd-wavefront= [HW,ALSA] | |
1874 | ||
1875 | snd-ymfpci= [HW,ALSA] | |
a9913044 | 1876 | |
1da177e4 LT |
1877 | sonypi.*= [HW] Sony Programmable I/O Control Device driver |
1878 | See Documentation/sonypi.txt | |
1879 | ||
1880 | specialix= [HW,SERIAL] Specialix multi-serial port adapter | |
1881 | See Documentation/specialix.txt. | |
1882 | ||
1883 | spia_io_base= [HW,MTD] | |
1884 | spia_fio_base= | |
1885 | spia_pedr= | |
1886 | spia_peddr= | |
1887 | ||
1888 | sscape= [HW,OSS] | |
1889 | Format: <io>,<irq>,<dma>,<mpu_io>,<mpu_irq> | |
a9913044 | 1890 | |
1da177e4 LT |
1891 | st= [HW,SCSI] SCSI tape parameters (buffers, etc.) |
1892 | See Documentation/scsi/st.txt. | |
1893 | ||
1da177e4 LT |
1894 | sti= [PARISC,HW] |
1895 | Format: <num> | |
1896 | Set the STI (builtin display/keyboard on the HP-PARISC | |
1897 | machines) console (graphic card) which should be used | |
1898 | as the initial boot-console. | |
1899 | See also comment in drivers/video/console/sticore.c. | |
1900 | ||
1901 | sti_font= [HW] | |
1902 | See comment in drivers/video/console/sticore.c. | |
1903 | ||
1904 | stifb= [HW] | |
1905 | Format: bpp:<bpp1>[:<bpp2>[:<bpp3>...]] | |
1906 | ||
42a7fc4a GB |
1907 | sunrpc.pool_mode= |
1908 | [NFS] | |
1909 | Control how the NFS server code allocates CPUs to | |
1910 | service thread pools. Depending on how many NICs | |
1911 | you have and where their interrupts are bound, this | |
1912 | option will affect which CPUs will do NFS serving. | |
1913 | Note: this parameter cannot be changed while the | |
1914 | NFS server is running. | |
1915 | ||
1916 | auto the server chooses an appropriate mode | |
1917 | automatically using heuristics | |
1918 | global a single global pool contains all CPUs | |
1919 | percpu one pool for each CPU | |
1920 | pernode one pool for each NUMA node (equivalent | |
1921 | to global on non-NUMA machines) | |
1922 | ||
1da177e4 | 1923 | swiotlb= [IA-64] Number of I/O TLB slabs |
a9913044 | 1924 | |
1da177e4 LT |
1925 | switches= [HW,M68k] |
1926 | ||
1927 | sym53c416= [HW,SCSI] | |
1928 | See header of drivers/scsi/sym53c416.c. | |
1929 | ||
5d6f647f IM |
1930 | sysrq_always_enabled |
1931 | [KNL] | |
1932 | Ignore sysrq setting - this boot parameter will | |
1933 | neutralize any effect of /proc/sys/kernel/sysrq. | |
1934 | Useful for debugging. | |
1935 | ||
1da177e4 LT |
1936 | t128= [HW,SCSI] |
1937 | See header of drivers/scsi/t128.c. | |
1938 | ||
1939 | tdfx= [HW,DRM] | |
1940 | ||
1941 | thash_entries= [KNL,NET] | |
1942 | Set number of hash buckets for TCP connection | |
1943 | ||
f8707ec9 LB |
1944 | thermal.act= [HW,ACPI] |
1945 | -1: disable all active trip points in all thermal zones | |
1946 | <degrees C>: override all lowest active trip points | |
1947 | ||
c52a7419 LB |
1948 | thermal.crt= [HW,ACPI] |
1949 | -1: disable all critical trip points in all thermal zones | |
1950 | <degrees C>: lower all critical trip points | |
1951 | ||
f5487145 LB |
1952 | thermal.nocrt= [HW,ACPI] |
1953 | Set to disable actions on ACPI thermal zone | |
1954 | critical and hot trip points. | |
1955 | ||
72b33ef8 LB |
1956 | thermal.off= [HW,ACPI] |
1957 | 1: disable ACPI thermal control | |
1958 | ||
a70cdc52 LB |
1959 | thermal.psv= [HW,ACPI] |
1960 | -1: disable all passive trip points | |
1961 | <degrees C>: override all passive trip points to this value | |
1962 | ||
730ff34d LB |
1963 | thermal.tzp= [HW,ACPI] |
1964 | Specify global default ACPI thermal zone polling rate | |
1965 | <deci-seconds>: poll all this frequency | |
1966 | 0: no polling (default) | |
1967 | ||
1da177e4 | 1968 | time Show timing data prefixed to each printk message line |
e84845c4 | 1969 | [deprecated, see 'printk.time'] |
1da177e4 LT |
1970 | |
1971 | tipar.timeout= [HW,PPT] | |
1972 | Set communications timeout in tenths of a second | |
1973 | (default 15). | |
1974 | ||
1975 | tipar.delay= [HW,PPT] | |
1976 | Set inter-bit delay in microseconds (default 10). | |
1977 | ||
1da177e4 LT |
1978 | tmscsim= [HW,SCSI] |
1979 | See comment before function dc390_setup() in | |
1980 | drivers/scsi/tmscsim.c. | |
1981 | ||
1982 | tp720= [HW,PS2] | |
1983 | ||
1984 | trix= [HW,OSS] MediaTrix AudioTrix Pro | |
a9913044 RD |
1985 | Format: |
1986 | <io>,<irq>,<dma>,<dma2>,<sb_io>,<sb_irq>,<sb_dma>,<mpu_io>,<mpu_irq> | |
1987 | ||
a9913044 RD |
1988 | turbografx.map[2|3]= [HW,JOY] |
1989 | TurboGraFX parallel port interface | |
1990 | Format: | |
1991 | <port#>,<js1>,<js2>,<js3>,<js4>,<js5>,<js6>,<js7> | |
1da177e4 LT |
1992 | See also Documentation/input/joystick-parport.txt |
1993 | ||
1994 | u14-34f= [HW,SCSI] UltraStor 14F/34F SCSI host adapter | |
1995 | See header of drivers/scsi/u14-34f.c. | |
1996 | ||
1997 | uart401= [HW,OSS] | |
1998 | Format: <io>,<irq> | |
1999 | ||
2000 | uart6850= [HW,OSS] | |
2001 | Format: <io>,<irq> | |
2002 | ||
5f8364b7 AS |
2003 | uhci-hcd.ignore_oc= |
2004 | [USB] Ignore overcurrent events (default N). | |
2005 | Some badly-designed motherboards generate lots of | |
2006 | bogus events, for ports that aren't wired to | |
2007 | anything. Set this parameter to avoid log spamming. | |
2008 | Note that genuine overcurrent events won't be | |
2009 | reported either. | |
2010 | ||
b5e795f8 AS |
2011 | usbcore.autosuspend= |
2012 | [USB] The autosuspend time delay (in seconds) used | |
2013 | for newly-detected USB devices (default 2). This | |
2014 | is the time required before an idle device will be | |
2015 | autosuspended. Devices for which the delay is set | |
eaafbc3a | 2016 | to a negative value won't be autosuspended at all. |
b5e795f8 | 2017 | |
1da177e4 LT |
2018 | usbhid.mousepoll= |
2019 | [USBHID] The interval which mice are to be polled at. | |
a9913044 | 2020 | |
cd4f0ef7 | 2021 | vdso= [X86-32,SH,x86-64] |
1dbf527c | 2022 | vdso=2: enable compat VDSO (default with COMPAT_VDSO) |
e6e5494c IM |
2023 | vdso=1: enable VDSO (default) |
2024 | vdso=0: disable VDSO mapping | |
2025 | ||
af65d648 RM |
2026 | vdso32= [X86-32,X86-64] |
2027 | vdso32=2: enable compat VDSO (default with COMPAT_VDSO) | |
2028 | vdso32=1: enable 32-bit VDSO (default) | |
2029 | vdso32=0: disable 32-bit VDSO mapping | |
2030 | ||
d080d397 YI |
2031 | vector= [IA-64,SMP] |
2032 | vector=percpu: enable percpu vector domain | |
2033 | ||
1da177e4 LT |
2034 | video= [FB] Frame buffer configuration |
2035 | See Documentation/fb/modedb.txt. | |
2036 | ||
cd4f0ef7 | 2037 | vga= [BOOT,X86-32] Select a particular video mode |
a9913044 RD |
2038 | See Documentation/i386/boot.txt and |
2039 | Documentation/svga.txt. | |
1da177e4 LT |
2040 | Use vga=ask for menu. |
2041 | This is actually a boot loader parameter; the value is | |
2042 | passed to the kernel using a special protocol. | |
2043 | ||
a9913044 | 2044 | vmalloc=nn[KMG] [KNL,BOOT] Forces the vmalloc area to have an exact |
1da177e4 LT |
2045 | size of <nn>. This can be used to increase the |
2046 | minimum size (128MB on x86). It can also be used to | |
2047 | decrease the size and leave more room for directly | |
2048 | mapped kernel RAM. | |
2049 | ||
585c3047 PO |
2050 | vmhalt= [KNL,S390] Perform z/VM CP command after system halt. |
2051 | Format: <command> | |
1da177e4 | 2052 | |
585c3047 PO |
2053 | vmpanic= [KNL,S390] Perform z/VM CP command after kernel panic. |
2054 | Format: <command> | |
2055 | ||
2056 | vmpoff= [KNL,S390] Perform z/VM CP command after power off. | |
2057 | Format: <command> | |
a9913044 | 2058 | |
1da177e4 LT |
2059 | waveartist= [HW,OSS] |
2060 | Format: <io>,<irq>,<dma>,<dma2> | |
a9913044 | 2061 | |
1da177e4 LT |
2062 | wd33c93= [HW,SCSI] |
2063 | See header of drivers/scsi/wd33c93.c. | |
2064 | ||
2065 | wd7000= [HW,SCSI] | |
2066 | See header of drivers/scsi/wd7000.c. | |
2067 | ||
2068 | wdt= [WDT] Watchdog | |
8dfe9c21 | 2069 | See Documentation/watchdog/wdt.txt. |
1da177e4 LT |
2070 | |
2071 | xd= [HW,XT] Original XT pre-IDE (RLL encoded) disks. | |
2072 | xd_geo= See header of drivers/block/xd.c. | |
2073 | ||
2074 | xirc2ps_cs= [NET,PCMCIA] | |
a9913044 RD |
2075 | Format: |
2076 | <irq>,<irq_mask>,<io>,<full_duplex>,<do_sound>,<lockup_hack>[,<irq2>[,<irq3>[,<irq4>]]] | |
1da177e4 | 2077 | |
a62eaf15 AK |
2078 | norandmaps Don't use address space randomization |
2079 | Equivalent to echo 0 > /proc/sys/kernel/randomize_va_space | |
2080 | ||
a9913044 | 2081 | ______________________________________________________________________ |
1da177e4 LT |
2082 | |
2083 | TODO: | |
2084 | ||
2085 | Add documentation for ALSA options. | |
2086 | Add more DRM drivers. |