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Diffstat (limited to 'Documentation/kernel-parameters.txt')
| -rw-r--r-- | Documentation/kernel-parameters.txt | 172 |
1 files changed, 111 insertions, 61 deletions
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 53ba7c7d82b3..d5418d528910 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -100,7 +100,7 @@ parameter is applicable: X86-32 X86-32, aka i386 architecture is enabled. X86-64 X86-64 architecture is enabled. More X86-64 boot options can be found in - Documentation/x86_64/boot-options.txt . + Documentation/x86/x86_64/boot-options.txt . X86 Either 32bit or 64bit x86 (same as X86-32+X86-64) In addition, the following text indicates that the option: @@ -112,10 +112,10 @@ In addition, the following text indicates that the option: Parameters denoted with BOOT are actually interpreted by the boot loader, and have no meaning to the kernel directly. Do not modify the syntax of boot loader parameters without extreme -need or coordination with <Documentation/i386/boot.txt>. +need or coordination with <Documentation/x86/i386/boot.txt>. There are also arch-specific kernel-parameters not documented here. -See for example <Documentation/x86_64/boot-options.txt>. +See for example <Documentation/x86/x86_64/boot-options.txt>. Note that ALL kernel parameters listed below are CASE SENSITIVE, and that a trailing = on the name of any parameter states that that parameter will @@ -198,40 +198,50 @@ and is between 256 and 4096 characters. It is defined in the file that require a timer override, but don't have HPET - acpi.debug_layer= [HW,ACPI] - Format: <int> - Each bit of the <int> indicates an ACPI debug layer, - 1: enable, 0: disable. It is useful for boot time - debugging. After system has booted up, it can be set - via /sys/module/acpi/parameters/debug_layer. - CONFIG_ACPI_DEBUG must be enabled for this to produce any output. - Available bits (add the numbers together) to enable debug output - for specific parts of the ACPI subsystem: - 0x01 utilities 0x02 hardware 0x04 events 0x08 tables - 0x10 namespace 0x20 parser 0x40 dispatcher - 0x80 executer 0x100 resources 0x200 acpica debugger - 0x400 os services 0x800 acpica disassembler. - The number can be in decimal or prefixed with 0x in hex. - Warning: Many of these options can produce a lot of - output and make your system unusable. Be very careful. - - acpi.debug_level= [HW,ACPI] + acpi_backlight= [HW,ACPI] + acpi_backlight=vendor + acpi_backlight=video + If set to vendor, prefer vendor specific driver + (e.g. thinkpad_acpi, sony_acpi, etc.) instead + of the ACPI video.ko driver. + + acpi_display_output= [HW,ACPI] + acpi_display_output=vendor + acpi_display_output=video + See above. + + acpi.debug_layer= [HW,ACPI,ACPI_DEBUG] + acpi.debug_level= [HW,ACPI,ACPI_DEBUG] Format: <int> - Each bit of the <int> indicates an ACPI debug level, - 1: enable, 0: disable. It is useful for boot time - debugging. After system has booted up, it can be set - via /sys/module/acpi/parameters/debug_level. - CONFIG_ACPI_DEBUG must be enabled for this to produce any output. - Available bits (add the numbers together) to enable different - debug output levels of the ACPI subsystem: - 0x01 error 0x02 warn 0x04 init 0x08 debug object - 0x10 info 0x20 init names 0x40 parse 0x80 load - 0x100 dispatch 0x200 execute 0x400 names 0x800 operation region - 0x1000 bfield 0x2000 tables 0x4000 values 0x8000 objects - 0x10000 resources 0x20000 user requests 0x40000 package. - The number can be in decimal or prefixed with 0x in hex. - Warning: Many of these options can produce a lot of - output and make your system unusable. Be very careful. + CONFIG_ACPI_DEBUG must be enabled to produce any ACPI + debug output. Bits in debug_layer correspond to a + _COMPONENT in an ACPI source file, e.g., + #define _COMPONENT ACPI_PCI_COMPONENT + Bits in debug_level correspond to a level in + ACPI_DEBUG_PRINT statements, e.g., + ACPI_DEBUG_PRINT((ACPI_DB_INFO, ... + See Documentation/acpi/debug.txt for more information + about debug layers and levels. + + Enable AML "Debug" output, i.e., stores to the Debug + object while interpreting AML: + acpi.debug_layer=0xffffffff acpi.debug_level=0x2 + Enable PCI/PCI interrupt routing info messages: + acpi.debug_layer=0x400000 acpi.debug_level=0x4 + Enable all messages related to ACPI hardware: + acpi.debug_layer=0x2 acpi.debug_level=0xffffffff + + Some values produce so much output that the system is + unusable. The "log_buf_len" parameter may be useful + if you need to capture more output. + + acpi.power_nocheck= [HW,ACPI] + Format: 1/0 enable/disable the check of power state. + On some bogus BIOS the _PSC object/_STA object of + power resource can't return the correct device power + state. In such case it is unneccessary to check its + power state again in power transition. + 1 : disable the power state check acpi_pm_good [X86-32,X86-64] Override the pmtimer bug detection: force the kernel @@ -284,7 +294,9 @@ and is between 256 and 4096 characters. It is defined in the file Possible values are: isolate - enable device isolation (each device, as far as possible, will get its own protection - domain) + domain) [default] + share - put every device behind one IOMMU into the + same protection domain fullflush - enable flushing of IO/TLB entries when they are unmapped. Otherwise they are flushed before they will be reused, which @@ -619,7 +631,7 @@ and is between 256 and 4096 characters. It is defined in the file digiepca= [HW,SERIAL] See drivers/char/README.epca and - Documentation/digiepca.txt. + Documentation/serial/digiepca.txt. disable_mtrr_cleanup [X86] enable_mtrr_cleanup [X86] @@ -730,7 +742,7 @@ and is between 256 and 4096 characters. It is defined in the file See header of drivers/scsi/fdomain.c. floppy= [HW] - See Documentation/floppy.txt. + See Documentation/blockdev/floppy.txt. force_pal_cache_flush [IA-64] Avoid check_sal_cache_flush which may hang on @@ -968,13 +980,15 @@ and is between 256 and 4096 characters. It is defined in the file Format: <cpu number>,...,<cpu number> or - <cpu number>-<cpu number> (must be a positive range in ascending order) + <cpu number>-<cpu number> + (must be a positive range in ascending order) or a mixture <cpu number>,...,<cpu number>-<cpu number> + This option can be used to specify one or more CPUs to isolate from the general SMP balancing and scheduling - algorithms. The only way to move a process onto or off - an "isolated" CPU is via the CPU affinity syscalls. + algorithms. You can move a process onto or off an + "isolated" CPU via the CPU affinity syscalls or cpuset. <cpu number> begins at 0 and the maximum value is "number of CPUs in system - 1". @@ -1089,7 +1103,7 @@ and is between 256 and 4096 characters. It is defined in the file the same attribute, the last one is used. load_ramdisk= [RAM] List of ramdisks to load from floppy - See Documentation/ramdisk.txt. + See Documentation/blockdev/ramdisk.txt. lockd.nlm_grace_period=P [NFS] Assign grace period. Format: <integer> @@ -1181,8 +1195,8 @@ and is between 256 and 4096 characters. It is defined in the file it is equivalent to "nosmp", which also disables the IO APIC. - max_addr=[KMG] [KNL,BOOT,ia64] All physical memory greater than or - equal to this physical address is ignored. + max_addr=nn[KMG] [KNL,BOOT,ia64] All physical memory greater than + or equal to this physical address is ignored. max_luns= [SCSI] Maximum number of LUNs to probe. Should be between 1 and 2^32-1. @@ -1195,7 +1209,7 @@ and is between 256 and 4096 characters. It is defined in the file mce [X86-32] Machine Check Exception - mce=option [X86-64] See Documentation/x86_64/boot-options.txt + mce=option [X86-64] See Documentation/x86/x86_64/boot-options.txt md= [HW] RAID subsystems devices and level See Documentation/md.txt. @@ -1282,6 +1296,9 @@ and is between 256 and 4096 characters. It is defined in the file mga= [HW,DRM] + min_addr=nn[KMG] [KNL,BOOT,ia64] All physical memory below this + physical address is ignored. + mminit_loglevel= [KNL] When CONFIG_DEBUG_MEMORY_INIT is set, this parameter allows control of the logging verbosity for @@ -1376,7 +1393,20 @@ and is between 256 and 4096 characters. It is defined in the file when a NMI is triggered. Format: [state][,regs][,debounce][,die] - nmi_watchdog= [KNL,BUGS=X86-32] Debugging features for SMP kernels + nmi_watchdog= [KNL,BUGS=X86-32,X86-64] Debugging features for SMP kernels + Format: [panic,][num] + Valid num: 0,1,2 + 0 - turn nmi_watchdog off + 1 - use the IO-APIC timer for the NMI watchdog + 2 - use the local APIC for the NMI watchdog using + a performance counter. Note: This will use one performance + counter and the local APIC's performance vector. + When panic is specified panic when an NMI watchdog timeout occurs. + This is useful when you use a panic=... timeout and need the box + quickly up again. + Instead of 1 and 2 it is possible to use the following + symbolic names: lapic and ioapic + Example: nmi_watchdog=2 or nmi_watchdog=panic,lapic no387 [BUGS=X86-32] Tells the kernel to use the 387 maths emulation library even if a 387 maths coprocessor @@ -1443,8 +1473,6 @@ and is between 256 and 4096 characters. It is defined in the file Valid arguments: on, off Default: on - noirqbalance [X86-32,SMP,KNL] Disable kernel irq balancing - noirqdebug [X86-32] Disables the code which attempts to detect and disable unhandled interrupt sources. @@ -1586,7 +1614,7 @@ and is between 256 and 4096 characters. It is defined in the file pcd. [PARIDE] See header of drivers/block/paride/pcd.c. - See also Documentation/paride.txt. + See also Documentation/blockdev/paride.txt. pci=option[,option...] [PCI] various PCI subsystem options: off [X86] don't probe for the PCI bus @@ -1611,6 +1639,17 @@ and is between 256 and 4096 characters. It is defined in the file nomsi [MSI] If the PCI_MSI kernel config parameter is enabled, this kernel boot option can be used to disable the use of MSI interrupts system-wide. + noioapicquirk [APIC] Disable all boot interrupt quirks. + Safety option to keep boot IRQs enabled. This + should never be necessary. + ioapicreroute [APIC] Enable rerouting of boot IRQs to the + primary IO-APIC for bridges that cannot disable + boot IRQs. This fixes a source of spurious IRQs + when the system masks IRQs. + noioapicreroute [APIC] Disable workaround that uses the + boot IRQ equivalent of an IRQ that connects to + a chipset where boot IRQs cannot be disabled. + The opposite of ioapicreroute. biosirq [X86-32] Use PCI BIOS calls to get the interrupt routing table. These calls are known to be buggy on several machines and they hang the machine @@ -1687,7 +1726,7 @@ and is between 256 and 4096 characters. It is defined in the file pcmv= [HW,PCMCIA] BadgePAD 4 pd. [PARIDE] - See Documentation/paride.txt. + See Documentation/blockdev/paride.txt. pdcchassis= [PARISC,HW] Disable/Enable PDC Chassis Status codes at boot time. @@ -1695,13 +1734,13 @@ and is between 256 and 4096 characters. It is defined in the file See arch/parisc/kernel/pdc_chassis.c pf. [PARIDE] - See Documentation/paride.txt. + See Documentation/blockdev/paride.txt. pg. [PARIDE] - See Documentation/paride.txt. + See Documentation/blockdev/paride.txt. pirq= [SMP,APIC] Manual mp-table setup - See Documentation/i386/IO-APIC.txt. + See Documentation/x86/i386/IO-APIC.txt. plip= [PPT,NET] Parallel port network link Format: { parport<nr> | timid | 0 } @@ -1711,6 +1750,10 @@ and is between 256 and 4096 characters. It is defined in the file Override pmtimer IOPort with a hex value. e.g. pmtmr=0x508 + pnp.debug [PNP] + Enable PNP debug messages. This depends on the + CONFIG_PNP_DEBUG_MESSAGES option. + pnpacpi= [ACPI] { off } @@ -1764,7 +1807,7 @@ and is between 256 and 4096 characters. It is defined in the file prompt_ramdisk= [RAM] List of RAM disks to prompt for floppy disk before loading. - See Documentation/ramdisk.txt. + See Documentation/blockdev/ramdisk.txt. psmouse.proto= [HW,MOUSE] Highest PS2 mouse protocol extension to probe for; one of (bare|imps|exps|lifebook|any). @@ -1784,7 +1827,7 @@ and is between 256 and 4096 characters. It is defined in the file <io>,<mss_io>,<mss_irq>,<mss_dma>,<mpu_io>,<mpu_irq> pt. [PARIDE] - See Documentation/paride.txt. + See Documentation/blockdev/paride.txt. pty.legacy_count= [KNL] Number of legacy pty's. Overwrites compiled-in @@ -1798,10 +1841,10 @@ and is between 256 and 4096 characters. It is defined in the file See Documentation/md.txt. ramdisk_blocksize= [RAM] - See Documentation/ramdisk.txt. + See Documentation/blockdev/ramdisk.txt. ramdisk_size= [RAM] Sizes of RAM disks in kilobytes - See Documentation/ramdisk.txt. + See Documentation/blockdev/ramdisk.txt. rcupdate.blimit= [KNL,BOOT] Set maximum number of finished RCU callbacks to process @@ -2133,7 +2176,7 @@ and is between 256 and 4096 characters. It is defined in the file See Documentation/sonypi.txt specialix= [HW,SERIAL] Specialix multi-serial port adapter - See Documentation/specialix.txt. + See Documentation/serial/specialix.txt. spia_io_base= [HW,MTD] spia_fio_base= @@ -2208,7 +2251,7 @@ and is between 256 and 4096 characters. It is defined in the file thermal.crt= [HW,ACPI] -1: disable all critical trip points in all thermal zones - <degrees C>: lower all critical trip points + <degrees C>: override all critical trip points thermal.nocrt= [HW,ACPI] Set to disable actions on ACPI thermal zone @@ -2236,6 +2279,13 @@ and is between 256 and 4096 characters. It is defined in the file Format: <io>,<irq>,<dma>,<dma2>,<sb_io>,<sb_irq>,<sb_dma>,<mpu_io>,<mpu_irq> + tsc= Disable clocksource-must-verify flag for TSC. + Format: <string> + [x86] reliable: mark tsc clocksource as reliable, this + disables clocksource verification at runtime. + Used to enable high-resolution timer mode on older + hardware, and in virtualized environment. + turbografx.map[2|3]= [HW,JOY] TurboGraFX parallel port interface Format: @@ -2312,7 +2362,7 @@ and is between 256 and 4096 characters. It is defined in the file See Documentation/fb/modedb.txt. vga= [BOOT,X86-32] Select a particular video mode - See Documentation/i386/boot.txt and + See Documentation/x86/i386/boot.txt and Documentation/svga.txt. Use vga=ask for menu. This is actually a boot loader parameter; the value is |