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-rw-r--r--Documentation/kernel-parameters.txt116
1 files changed, 96 insertions, 20 deletions
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index e58c91ca802c..0bf8a882ee9e 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -17,6 +17,12 @@ are specified on the kernel command line with the module name plus
17 17
18 usbcore.blinkenlights=1 18 usbcore.blinkenlights=1
19 19
20Hyphens (dashes) and underscores are equivalent in parameter names, so
21 log_buf_len=1M print-fatal-signals=1
22can also be entered as
23 log-buf-len=1M print_fatal_signals=1
24
25
20This document may not be entirely up to date and comprehensive. The command 26This 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 27"modinfo -p ${modulename}" shows a current list of all parameters of a loadable
22module. Loadable modules, after being loaded into the running kernel, also 28module. Loadable modules, after being loaded into the running kernel, also
@@ -50,7 +56,6 @@ parameter is applicable:
50 ISAPNP ISA PnP code is enabled. 56 ISAPNP ISA PnP code is enabled.
51 ISDN Appropriate ISDN support is enabled. 57 ISDN Appropriate ISDN support is enabled.
52 JOY Appropriate joystick support is enabled. 58 JOY Appropriate joystick support is enabled.
53 KMEMTRACE kmemtrace is enabled.
54 LIBATA Libata driver is enabled 59 LIBATA Libata driver is enabled
55 LP Printer support is enabled. 60 LP Printer support is enabled.
56 LOOP Loopback device support is enabled. 61 LOOP Loopback device support is enabled.
@@ -231,6 +236,35 @@ and is between 256 and 4096 characters. It is defined in the file
231 power state again in power transition. 236 power state again in power transition.
232 1 : disable the power state check 237 1 : disable the power state check
233 238
239 acpi_sci= [HW,ACPI] ACPI System Control Interrupt trigger mode
240 Format: { level | edge | high | low }
241
242 acpi_serialize [HW,ACPI] force serialization of AML methods
243
244 acpi_skip_timer_override [HW,ACPI]
245 Recognize and ignore IRQ0/pin2 Interrupt Override.
246 For broken nForce2 BIOS resulting in XT-PIC timer.
247
248 acpi_sleep= [HW,ACPI] Sleep options
249 Format: { s3_bios, s3_mode, s3_beep, s4_nohwsig,
250 old_ordering, s4_nonvs }
251 See Documentation/power/video.txt for information on
252 s3_bios and s3_mode.
253 s3_beep is for debugging; it makes the PC's speaker beep
254 as soon as the kernel's real-mode entry point is called.
255 s4_nohwsig prevents ACPI hardware signature from being
256 used during resume from hibernation.
257 old_ordering causes the ACPI 1.0 ordering of the _PTS
258 control method, with respect to putting devices into
259 low power states, to be enforced (the ACPI 2.0 ordering
260 of _PTS is used by default).
261 s4_nonvs prevents the kernel from saving/restoring the
262 ACPI NVS memory during hibernation.
263
264 acpi_use_timer_override [HW,ACPI]
265 Use timer override. For some broken Nvidia NF5 boards
266 that require a timer override, but don't have HPET
267
234 acpi_enforce_resources= [ACPI] 268 acpi_enforce_resources= [ACPI]
235 { strict | lax | no } 269 { strict | lax | no }
236 Check for resource conflicts between native drivers 270 Check for resource conflicts between native drivers
@@ -250,6 +284,9 @@ and is between 256 and 4096 characters. It is defined in the file
250 ad1848= [HW,OSS] 284 ad1848= [HW,OSS]
251 Format: <io>,<irq>,<dma>,<dma2>,<type> 285 Format: <io>,<irq>,<dma>,<dma2>,<type>
252 286
287 add_efi_memmap [EFI; X86] Include EFI memory map in
288 kernel's map of available physical RAM.
289
253 advansys= [HW,SCSI] 290 advansys= [HW,SCSI]
254 See header of drivers/scsi/advansys.c. 291 See header of drivers/scsi/advansys.c.
255 292
@@ -291,11 +328,6 @@ and is between 256 and 4096 characters. It is defined in the file
291 flushed before they will be reused, which 328 flushed before they will be reused, which
292 is a lot of faster 329 is a lot of faster
293 330
294 amd_iommu_size= [HW,X86-64]
295 Define the size of the aperture for the AMD IOMMU
296 driver. Possible values are:
297 '32M', '64M' (default), '128M', '256M', '512M', '1G'
298
299 amijoy.map= [HW,JOY] Amiga joystick support 331 amijoy.map= [HW,JOY] Amiga joystick support
300 Map of devices attached to JOY0DAT and JOY1DAT 332 Map of devices attached to JOY0DAT and JOY1DAT
301 Format: <a>,<b> 333 Format: <a>,<b>
@@ -313,7 +345,7 @@ and is between 256 and 4096 characters. It is defined in the file
313 not play well with APC CPU idle - disable it if you have 345 not play well with APC CPU idle - disable it if you have
314 APC and your system crashes randomly. 346 APC and your system crashes randomly.
315 347
316 apic= [APIC,i386] Advanced Programmable Interrupt Controller 348 apic= [APIC,X86-32] Advanced Programmable Interrupt Controller
317 Change the output verbosity whilst booting 349 Change the output verbosity whilst booting
318 Format: { quiet (default) | verbose | debug } 350 Format: { quiet (default) | verbose | debug }
319 Change the amount of debugging information output 351 Change the amount of debugging information output
@@ -608,6 +640,13 @@ and is between 256 and 4096 characters. It is defined in the file
608 DMA-API debugging code disables itself because the 640 DMA-API debugging code disables itself because the
609 architectural default is too low. 641 architectural default is too low.
610 642
643 dma_debug_driver=<driver_name>
644 With this option the DMA-API debugging driver
645 filter feature can be enabled at boot time. Just
646 pass the driver to filter for as the parameter.
647 The filter can be disabled or changed to another
648 driver later using sysfs.
649
611 dscc4.setup= [NET] 650 dscc4.setup= [NET]
612 651
613 dtc3181e= [HW,SCSI] 652 dtc3181e= [HW,SCSI]
@@ -670,7 +709,7 @@ and is between 256 and 4096 characters. It is defined in the file
670 to discrete, to make X server driver able to add WB 709 to discrete, to make X server driver able to add WB
671 entry later. This parameter enables that. 710 entry later. This parameter enables that.
672 711
673 enable_timer_pin_1 [i386,x86-64] 712 enable_timer_pin_1 [X86]
674 Enable PIN 1 of APIC timer 713 Enable PIN 1 of APIC timer
675 Can be useful to work around chipset bugs 714 Can be useful to work around chipset bugs
676 (in particular on some ATI chipsets). 715 (in particular on some ATI chipsets).
@@ -714,12 +753,25 @@ and is between 256 and 4096 characters. It is defined in the file
714 ia64_pal_cache_flush instead of SAL_CACHE_FLUSH. 753 ia64_pal_cache_flush instead of SAL_CACHE_FLUSH.
715 754
716 ftrace=[tracer] 755 ftrace=[tracer]
717 [ftrace] will set and start the specified tracer 756 [FTRACE] will set and start the specified tracer
718 as early as possible in order to facilitate early 757 as early as possible in order to facilitate early
719 boot debugging. 758 boot debugging.
720 759
721 ftrace_dump_on_oops 760 ftrace_dump_on_oops
722 [ftrace] will dump the trace buffers on oops. 761 [FTRACE] will dump the trace buffers on oops.
762
763 ftrace_filter=[function-list]
764 [FTRACE] Limit the functions traced by the function
765 tracer at boot up. function-list is a comma separated
766 list of functions. This list can be changed at run
767 time by the set_ftrace_filter file in the debugfs
768 tracing directory.
769
770 ftrace_notrace=[function-list]
771 [FTRACE] Do not trace the functions specified in
772 function-list. This list can be changed at run time
773 by the set_ftrace_notrace file in the debugfs
774 tracing directory.
723 775
724 gamecon.map[2|3]= 776 gamecon.map[2|3]=
725 [HW,JOY] Multisystem joystick and NES/SNES/PSX pad 777 [HW,JOY] Multisystem joystick and NES/SNES/PSX pad
@@ -743,7 +795,7 @@ and is between 256 and 4096 characters. It is defined in the file
743 795
744 hashdist= [KNL,NUMA] Large hashes allocated during boot 796 hashdist= [KNL,NUMA] Large hashes allocated during boot
745 are distributed across NUMA nodes. Defaults on 797 are distributed across NUMA nodes. Defaults on
746 for IA-64, off otherwise. 798 for 64bit NUMA, off otherwise.
747 Format: 0 | 1 (for off | on) 799 Format: 0 | 1 (for off | on)
748 800
749 hcl= [IA-64] SGI's Hardware Graph compatibility layer 801 hcl= [IA-64] SGI's Hardware Graph compatibility layer
@@ -873,6 +925,12 @@ and is between 256 and 4096 characters. It is defined in the file
873 Formt: { "sha1" | "md5" } 925 Formt: { "sha1" | "md5" }
874 default: "sha1" 926 default: "sha1"
875 927
928 ima_tcb [IMA]
929 Load a policy which meets the needs of the Trusted
930 Computing Base. This means IMA will measure all
931 programs exec'd, files mmap'd for exec, and all files
932 opened for read by uid=0.
933
876 in2000= [HW,SCSI] 934 in2000= [HW,SCSI]
877 See header of drivers/scsi/in2000.c. 935 See header of drivers/scsi/in2000.c.
878 936
@@ -1013,15 +1071,6 @@ and is between 256 and 4096 characters. It is defined in the file
1013 use the HighMem zone if it exists, and the Normal 1071 use the HighMem zone if it exists, and the Normal
1014 zone if it does not. 1072 zone if it does not.
1015 1073
1016 kmemtrace.enable= [KNL,KMEMTRACE] Format: { yes | no }
1017 Controls whether kmemtrace is enabled
1018 at boot-time.
1019
1020 kmemtrace.subbufs=n [KNL,KMEMTRACE] Overrides the number of
1021 subbufs kmemtrace's relay channel has. Set this
1022 higher than default (KMEMTRACE_N_SUBBUFS in code) if
1023 you experience buffer overruns.
1024
1025 kgdboc= [HW] kgdb over consoles. 1074 kgdboc= [HW] kgdb over consoles.
1026 Requires a tty driver that supports console polling. 1075 Requires a tty driver that supports console polling.
1027 (only serial suported for now) 1076 (only serial suported for now)
@@ -1031,6 +1080,10 @@ and is between 256 and 4096 characters. It is defined in the file
1031 Configure the RouterBoard 532 series on-chip 1080 Configure the RouterBoard 532 series on-chip
1032 Ethernet adapter MAC address. 1081 Ethernet adapter MAC address.
1033 1082
1083 kmemleak= [KNL] Boot-time kmemleak enable/disable
1084 Valid arguments: on, off
1085 Default: on
1086
1034 kstack=N [X86] Print N words from the kernel stack 1087 kstack=N [X86] Print N words from the kernel stack
1035 in oops dumps. 1088 in oops dumps.
1036 1089
@@ -1494,6 +1547,10 @@ and is between 256 and 4096 characters. It is defined in the file
1494 register save and restore. The kernel will only save 1547 register save and restore. The kernel will only save
1495 legacy floating-point registers on task switch. 1548 legacy floating-point registers on task switch.
1496 1549
1550 noxsave [BUGS=X86] Disables x86 extended register state save
1551 and restore using xsave. The kernel will fallback to
1552 enabling legacy floating-point and sse state.
1553
1497 nohlt [BUGS=ARM,SH] Tells the kernel that the sleep(SH) or 1554 nohlt [BUGS=ARM,SH] Tells the kernel that the sleep(SH) or
1498 wfi(ARM) instruction doesn't work correctly and not to 1555 wfi(ARM) instruction doesn't work correctly and not to
1499 use it. This is also useful when using JTAG debugger. 1556 use it. This is also useful when using JTAG debugger.
@@ -1530,6 +1587,9 @@ and is between 256 and 4096 characters. It is defined in the file
1530 noinitrd [RAM] Tells the kernel not to load any configured 1587 noinitrd [RAM] Tells the kernel not to load any configured
1531 initial RAM disk. 1588 initial RAM disk.
1532 1589
1590 nointremap [X86-64, Intel-IOMMU] Do not enable interrupt
1591 remapping.
1592
1533 nointroute [IA-64] 1593 nointroute [IA-64]
1534 1594
1535 nojitter [IA64] Disables jitter checking for ITC timers. 1595 nojitter [IA64] Disables jitter checking for ITC timers.
@@ -1585,6 +1645,8 @@ and is between 256 and 4096 characters. It is defined in the file
1585 1645
1586 nowb [ARM] 1646 nowb [ARM]
1587 1647
1648 nox2apic [X86-64,APIC] Do not enable x2APIC mode.
1649
1588 nptcg= [IA64] Override max number of concurrent global TLB 1650 nptcg= [IA64] Override max number of concurrent global TLB
1589 purges which is reported from either PAL_VM_SUMMARY or 1651 purges which is reported from either PAL_VM_SUMMARY or
1590 SAL PALO. 1652 SAL PALO.
@@ -1613,6 +1675,14 @@ and is between 256 and 4096 characters. It is defined in the file
1613 oprofile.timer= [HW] 1675 oprofile.timer= [HW]
1614 Use timer interrupt instead of performance counters 1676 Use timer interrupt instead of performance counters
1615 1677
1678 oprofile.cpu_type= Force an oprofile cpu type
1679 This might be useful if you have an older oprofile
1680 userland or if you want common events.
1681 Format: { archperfmon }
1682 archperfmon: [X86] Force use of architectural
1683 perfmon on Intel CPUs instead of the
1684 CPU specific event set.
1685
1616 osst= [HW,SCSI] SCSI Tape Driver 1686 osst= [HW,SCSI] SCSI Tape Driver
1617 Format: <buffer_size>,<write_threshold> 1687 Format: <buffer_size>,<write_threshold>
1618 See also Documentation/scsi/st.txt. 1688 See also Documentation/scsi/st.txt.
@@ -1835,6 +1905,12 @@ and is between 256 and 4096 characters. It is defined in the file
1835 autoconfiguration. 1905 autoconfiguration.
1836 Ranges are in pairs (memory base and size). 1906 Ranges are in pairs (memory base and size).
1837 1907
1908 ports= [IP_VS_FTP] IPVS ftp helper module
1909 Default is 21.
1910 Up to 8 (IP_VS_APP_MAX_PORTS) ports
1911 may be specified.
1912 Format: <port>,<port>....
1913
1838 print-fatal-signals= 1914 print-fatal-signals=
1839 [KNL] debug: print fatal signals 1915 [KNL] debug: print fatal signals
1840 print-fatal-signals=1: print segfault info to 1916 print-fatal-signals=1: print segfault info to