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-rw-r--r--Documentation/kernel-parameters.txt111
1 files changed, 95 insertions, 16 deletions
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index e5b447a0acda..8fd5aa40585f 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -34,6 +34,7 @@ parameter is applicable:
34 ALSA ALSA sound support is enabled. 34 ALSA ALSA sound support is enabled.
35 APIC APIC support is enabled. 35 APIC APIC support is enabled.
36 APM Advanced Power Management support is enabled. 36 APM Advanced Power Management support is enabled.
37 AVR32 AVR32 architecture is enabled.
37 AX25 Appropriate AX.25 support is enabled. 38 AX25 Appropriate AX.25 support is enabled.
38 BLACKFIN Blackfin architecture is enabled. 39 BLACKFIN Blackfin architecture is enabled.
39 DRM Direct Rendering Management support is enabled. 40 DRM Direct Rendering Management support is enabled.
@@ -167,6 +168,11 @@ and is between 256 and 4096 characters. It is defined in the file
167 acpi_irq_isa= [HW,ACPI] If irq_balance, mark listed IRQs used by ISA 168 acpi_irq_isa= [HW,ACPI] If irq_balance, mark listed IRQs used by ISA
168 Format: <irq>,<irq>... 169 Format: <irq>,<irq>...
169 170
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
170 acpi_no_auto_ssdt [HW,ACPI] Disable automatic loading of SSDT 176 acpi_no_auto_ssdt [HW,ACPI] Disable automatic loading of SSDT
171 177
172 acpi_os_name= [HW,ACPI] Tell ACPI BIOS the name of the OS 178 acpi_os_name= [HW,ACPI] Tell ACPI BIOS the name of the OS
@@ -369,7 +375,8 @@ and is between 256 and 4096 characters. It is defined in the file
369 configured. Potentially dangerous and should only be 375 configured. Potentially dangerous and should only be
370 used if you are entirely sure of the consequences. 376 used if you are entirely sure of the consequences.
371 377
372 chandev= [HW,NET] Generic channel device initialisation 378 ccw_timeout_log [S390]
379 See Documentation/s390/CommonIO for details.
373 380
374 checkreqprot [SELINUX] Set initial checkreqprot flag value. 381 checkreqprot [SELINUX] Set initial checkreqprot flag value.
375 Format: { "0" | "1" } 382 Format: { "0" | "1" }
@@ -381,6 +388,12 @@ and is between 256 and 4096 characters. It is defined in the file
381 Value can be changed at runtime via 388 Value can be changed at runtime via
382 /selinux/checkreqprot. 389 /selinux/checkreqprot.
383 390
391 cio_ignore= [S390]
392 See Documentation/s390/CommonIO for details.
393
394 cio_msg= [S390]
395 See Documentation/s390/CommonIO for details.
396
384 clock= [BUGS=X86-32, HW] gettimeofday clocksource override. 397 clock= [BUGS=X86-32, HW] gettimeofday clocksource override.
385 [Deprecated] 398 [Deprecated]
386 Forces specified clocksource (if available) to be used 399 Forces specified clocksource (if available) to be used
@@ -408,8 +421,21 @@ and is between 256 and 4096 characters. It is defined in the file
408 [SPARC64] tick 421 [SPARC64] tick
409 [X86-64] hpet,tsc 422 [X86-64] hpet,tsc
410 423
411 code_bytes [IA32] How many bytes of object code to print in an 424 clearcpuid=BITNUM [X86]
412 oops report. 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
437 code_bytes [IA32/X86_64] How many bytes of object code to print
438 in an oops report.
413 Range: 0 - 8192 439 Range: 0 - 8192
414 Default: 64 440 Default: 64
415 441
@@ -523,7 +549,7 @@ and is between 256 and 4096 characters. It is defined in the file
523 1 will print _a lot_ more information - normally 549 1 will print _a lot_ more information - normally
524 only useful to kernel developers. 550 only useful to kernel developers.
525 551
526 decnet= [HW,NET] 552 decnet.addr= [HW,NET]
527 Format: <area>[,<node>] 553 Format: <area>[,<node>]
528 See also Documentation/networking/decnet.txt. 554 See also Documentation/networking/decnet.txt.
529 555
@@ -562,6 +588,12 @@ and is between 256 and 4096 characters. It is defined in the file
562 See drivers/char/README.epca and 588 See drivers/char/README.epca and
563 Documentation/digiepca.txt. 589 Documentation/digiepca.txt.
564 590
591 disable_mtrr_trim [X86, Intel and AMD only]
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
565 dmasound= [HW,OSS] Sound subsystem buffers 597 dmasound= [HW,OSS] Sound subsystem buffers
566 598
567 dscc4.setup= [NET] 599 dscc4.setup= [NET]
@@ -652,6 +684,10 @@ and is between 256 and 4096 characters. It is defined in the file
652 684
653 gamma= [HW,DRM] 685 gamma= [HW,DRM]
654 686
687 gart_fix_e820= [X86_64] disable the fix e820 for K8 GART
688 Format: off | on
689 default: on
690
655 gdth= [HW,SCSI] 691 gdth= [HW,SCSI]
656 See header of drivers/scsi/gdth.c. 692 See header of drivers/scsi/gdth.c.
657 693
@@ -686,6 +722,7 @@ and is between 256 and 4096 characters. It is defined in the file
686 See Documentation/isdn/README.HiSax. 722 See Documentation/isdn/README.HiSax.
687 723
688 hugepages= [HW,X86-32,IA-64] Maximal number of HugeTLB pages. 724 hugepages= [HW,X86-32,IA-64] Maximal number of HugeTLB pages.
725 hugepagesz= [HW,IA-64,PPC] The size of the HugeTLB pages.
689 726
690 i8042.direct [HW] Put keyboard port into non-translated mode 727 i8042.direct [HW] Put keyboard port into non-translated mode
691 i8042.dumbkbd [HW] Pretend that controller can only read data from 728 i8042.dumbkbd [HW] Pretend that controller can only read data from
@@ -743,6 +780,9 @@ and is between 256 and 4096 characters. It is defined in the file
743 loop use the MONITOR/MWAIT idle loop anyways. Performance should be the same 780 loop use the MONITOR/MWAIT idle loop anyways. Performance should be the same
744 as idle=poll. 781 as idle=poll.
745 782
783 ide-pci-generic.all-generic-ide [HW] (E)IDE subsystem
784 Claim all unknown PCI IDE storage controllers.
785
746 ignore_loglevel [KNL] 786 ignore_loglevel [KNL]
747 Ignore loglevel setting - this will print /all/ 787 Ignore loglevel setting - this will print /all/
748 kernel messages to the console. Useful for debugging. 788 kernel messages to the console. Useful for debugging.
@@ -786,6 +826,16 @@ and is between 256 and 4096 characters. It is defined in the file
786 for translation below 32 bit and if not available 826 for translation below 32 bit and if not available
787 then look in the higher range. 827 then look in the higher range.
788 828
829 io_delay= [X86-32,X86-64] I/O delay method
830 0x80
831 Standard port 0x80 based delay
832 0xed
833 Alternate port 0xed based delay (needed on some systems)
834 udelay
835 Simple two microseconds delay
836 none
837 No delay
838
789 io7= [HW] IO7 for Marvel based alpha systems 839 io7= [HW] IO7 for Marvel based alpha systems
790 See comment before marvel_specify_io7 in 840 See comment before marvel_specify_io7 in
791 arch/alpha/kernel/core_marvel.c. 841 arch/alpha/kernel/core_marvel.c.
@@ -883,6 +933,14 @@ and is between 256 and 4096 characters. It is defined in the file
883 lapic_timer_c2_ok [X86-32,x86-64,APIC] trust the local apic timer in 933 lapic_timer_c2_ok [X86-32,x86-64,APIC] trust the local apic timer in
884 C2 power state. 934 C2 power state.
885 935
936 libata.dma= [LIBATA] DMA control
937 libata.dma=0 Disable all PATA and SATA DMA
938 libata.dma=1 PATA and SATA Disk DMA only
939 libata.dma=2 ATAPI (CDROM) DMA only
940 libata.dma=4 Compact Flash DMA only
941 Combinations also work, so libata.dma=3 enables DMA
942 for disks and CDROMs, but not CFs.
943
886 libata.noacpi [LIBATA] Disables use of ACPI in libata suspend/resume 944 libata.noacpi [LIBATA] Disables use of ACPI in libata suspend/resume
887 when set. 945 when set.
888 Format: <int> 946 Format: <int>
@@ -1043,6 +1101,11 @@ and is between 256 and 4096 characters. It is defined in the file
1043 Multi-Function General Purpose Timers on AMD Geode 1101 Multi-Function General Purpose Timers on AMD Geode
1044 platforms. 1102 platforms.
1045 1103
1104 mfgptfix [X86-32] Fix MFGPT timers on AMD Geode platforms when
1105 the BIOS has incorrectly applied a workaround. TinyBIOS
1106 version 0.98 is known to be affected, 0.99 fixes the
1107 problem by letting the user disable the workaround.
1108
1046 mga= [HW,DRM] 1109 mga= [HW,DRM]
1047 1110
1048 mousedev.tap_time= 1111 mousedev.tap_time=
@@ -1115,6 +1178,10 @@ and is between 256 and 4096 characters. It is defined in the file
1115 of returning the full 64-bit number. 1178 of returning the full 64-bit number.
1116 The default is to return 64-bit inode numbers. 1179 The default is to return 64-bit inode numbers.
1117 1180
1181 nmi_debug= [KNL,AVR32] Specify one or more actions to take
1182 when a NMI is triggered.
1183 Format: [state][,regs][,debounce][,die]
1184
1118 nmi_watchdog= [KNL,BUGS=X86-32] Debugging features for SMP kernels 1185 nmi_watchdog= [KNL,BUGS=X86-32] Debugging features for SMP kernels
1119 1186
1120 no387 [BUGS=X86-32] Tells the kernel to use the 387 maths 1187 no387 [BUGS=X86-32] Tells the kernel to use the 387 maths
@@ -1139,6 +1206,8 @@ and is between 256 and 4096 characters. It is defined in the file
1139 1206
1140 nodisconnect [HW,SCSI,M68K] Disables SCSI disconnects. 1207 nodisconnect [HW,SCSI,M68K] Disables SCSI disconnects.
1141 1208
1209 noefi [X86-32,X86-64] Disable EFI runtime services support.
1210
1142 noexec [IA-64] 1211 noexec [IA-64]
1143 1212
1144 noexec [X86-32,X86-64] 1213 noexec [X86-32,X86-64]
@@ -1149,6 +1218,8 @@ and is between 256 and 4096 characters. It is defined in the file
1149 register save and restore. The kernel will only save 1218 register save and restore. The kernel will only save
1150 legacy floating-point registers on task switch. 1219 legacy floating-point registers on task switch.
1151 1220
1221 noclflush [BUGS=X86] Don't use the CLFLUSH instruction
1222
1152 nohlt [BUGS=ARM] 1223 nohlt [BUGS=ARM]
1153 1224
1154 no-hlt [BUGS=X86-32] Tells the kernel that the hlt 1225 no-hlt [BUGS=X86-32] Tells the kernel that the hlt
@@ -1493,14 +1564,17 @@ and is between 256 and 4096 characters. It is defined in the file
1493 ramdisk_size= [RAM] Sizes of RAM disks in kilobytes 1564 ramdisk_size= [RAM] Sizes of RAM disks in kilobytes
1494 See Documentation/ramdisk.txt. 1565 See Documentation/ramdisk.txt.
1495 1566
1496 rcu.blimit= [KNL,BOOT] Set maximum number of finished 1567 rcupdate.blimit= [KNL,BOOT]
1497 RCU callbacks to process in one batch. 1568 Set maximum number of finished RCU callbacks to process
1569 in one batch.
1498 1570
1499 rcu.qhimark= [KNL,BOOT] Set threshold of queued 1571 rcupdate.qhimark= [KNL,BOOT]
1572 Set threshold of queued
1500 RCU callbacks over which batch limiting is disabled. 1573 RCU callbacks over which batch limiting is disabled.
1501 1574
1502 rcu.qlowmark= [KNL,BOOT] Set threshold of queued 1575 rcupdate.qlowmark= [KNL,BOOT]
1503 RCU callbacks below which batch limiting is re-enabled. 1576 Set threshold of queued RCU callbacks below which
1577 batch limiting is re-enabled.
1504 1578
1505 rdinit= [KNL] 1579 rdinit= [KNL]
1506 Format: <full_path> 1580 Format: <full_path>
@@ -1585,7 +1659,13 @@ and is between 256 and 4096 characters. It is defined in the file
1585 Format: <vendor>:<model>:<flags> 1659 Format: <vendor>:<model>:<flags>
1586 (flags are integer value) 1660 (flags are integer value)
1587 1661
1588 scsi_logging= [SCSI] 1662 scsi_logging_level= [SCSI] a bit mask of logging levels
1663 See drivers/scsi/scsi_logging.h for bits. Also
1664 settable via sysctl at dev.scsi.logging_level
1665 (/proc/sys/dev/scsi/logging_level).
1666 There is also a nice 'scsi_logging_level' script in the
1667 S390-tools package, available for download at
1668 http://www-128.ibm.com/developerworks/linux/linux390/s390-tools-1.5.4.html
1589 1669
1590 scsi_mod.scan= [SCSI] sync (default) scans SCSI busses as they are 1670 scsi_mod.scan= [SCSI] sync (default) scans SCSI busses as they are
1591 discovered. async scans them in kernel threads, 1671 discovered. async scans them in kernel threads,
@@ -1814,9 +1894,6 @@ and is between 256 and 4096 characters. It is defined in the file
1814 st= [HW,SCSI] SCSI tape parameters (buffers, etc.) 1894 st= [HW,SCSI] SCSI tape parameters (buffers, etc.)
1815 See Documentation/scsi/st.txt. 1895 See Documentation/scsi/st.txt.
1816 1896
1817 st0x= [HW,SCSI]
1818 See header of drivers/scsi/seagate.c.
1819
1820 sti= [PARISC,HW] 1897 sti= [PARISC,HW]
1821 Format: <num> 1898 Format: <num>
1822 Set the STI (builtin display/keyboard on the HP-PARISC 1899 Set the STI (builtin display/keyboard on the HP-PARISC
@@ -1901,9 +1978,6 @@ and is between 256 and 4096 characters. It is defined in the file
1901 tipar.delay= [HW,PPT] 1978 tipar.delay= [HW,PPT]
1902 Set inter-bit delay in microseconds (default 10). 1979 Set inter-bit delay in microseconds (default 10).
1903 1980
1904 tmc8xx= [HW,SCSI]
1905 See header of drivers/scsi/seagate.c.
1906
1907 tmscsim= [HW,SCSI] 1981 tmscsim= [HW,SCSI]
1908 See comment before function dc390_setup() in 1982 See comment before function dc390_setup() in
1909 drivers/scsi/tmscsim.c. 1983 drivers/scsi/tmscsim.c.
@@ -1952,6 +2026,11 @@ and is between 256 and 4096 characters. It is defined in the file
1952 vdso=1: enable VDSO (default) 2026 vdso=1: enable VDSO (default)
1953 vdso=0: disable VDSO mapping 2027 vdso=0: disable VDSO mapping
1954 2028
2029 vdso32= [X86-32,X86-64]
2030 vdso32=2: enable compat VDSO (default with COMPAT_VDSO)
2031 vdso32=1: enable 32-bit VDSO (default)
2032 vdso32=0: disable 32-bit VDSO mapping
2033
1955 vector= [IA-64,SMP] 2034 vector= [IA-64,SMP]
1956 vector=percpu: enable percpu vector domain 2035 vector=percpu: enable percpu vector domain
1957 2036