usbcore.blinkenlights=1
+Hyphens (dashes) and underscores are equivalent in parameter names, so
+ log_buf_len=1M print-fatal-signals=1
+can also be entered as
+ log-buf-len=1M print_fatal_signals=1
+
+
This document may not be entirely up to date and comprehensive. The command
"modinfo -p ${modulename}" shows a current list of all parameters of a loadable
module. Loadable modules, after being loaded into the running kernel, also
EFI EFI Partitioning (GPT) is enabled
EIDE EIDE/ATAPI support is enabled.
FB The frame buffer device is enabled.
+ GCOV GCOV profiling is enabled.
HW Appropriate hardware is enabled.
IA-64 IA-64 architecture is enabled.
+ IMA Integrity measurement architecture is enabled.
IOSCHED More than one I/O scheduler is enabled.
IP_PNP IP DHCP, BOOTP, or RARP is enabled.
+ IPV6 IPv6 support is enabled.
ISAPNP ISA PnP code is enabled.
ISDN Appropriate ISDN support is enabled.
JOY Appropriate joystick support is enabled.
+ KVM Kernel Virtual Machine support is enabled.
LIBATA Libata driver is enabled
LP Printer support is enabled.
LOOP Loopback device support is enabled.
PPT Parallel port support is enabled.
PS2 Appropriate PS/2 support is enabled.
RAM RAM disk support is enabled.
- ROOTPLUG The example Root Plug LSM is enabled.
S390 S390 architecture is enabled.
SCSI Appropriate SCSI support is enabled.
A lot of drivers has their options described inside of
SPARC Sparc architecture is enabled.
SWSUSP Software suspend (hibernation) is enabled.
SUSPEND System suspend states are enabled.
+ FTRACE Function tracing enabled.
TS Appropriate touchscreen support is enabled.
+ UMS USB Mass Storage support is enabled.
USB USB support is enabled.
USBHID USB Human Interface Device support is enabled.
V4L Video For Linux support is enabled.
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/x86/i386/boot.txt>.
+need or coordination with <Documentation/x86/boot.txt>.
There are also arch-specific kernel-parameters not documented here.
See for example <Documentation/x86/x86_64/boot-options.txt>.
./include/asm/setup.h as COMMAND_LINE_SIZE.
- acpi= [HW,ACPI,X86-64,i386]
+ acpi= [HW,ACPI,X86]
Advanced Configuration and Power Interface
- Format: { force | off | ht | strict | noirq }
+ Format: { force | off | ht | strict | noirq | rsdt }
force -- enable ACPI if default was off
off -- disable ACPI if default was on
noirq -- do not use ACPI for IRQ routing
ht -- run only enough ACPI to enable Hyper Threading
strict -- Be less tolerant of platforms that are not
strictly ACPI specification compliant.
+ rsdt -- prefer RSDT over (default) XSDT
See also Documentation/power/pm.txt, pci=noacpi
1,0: use 1st APIC table
default: 0
- acpi_sleep= [HW,ACPI] Sleep options
- Format: { s3_bios, s3_mode, s3_beep, s4_nohwsig,
- old_ordering, s4_nonvs }
- See Documentation/power/video.txt for s3_bios and s3_mode.
- s3_beep is for debugging; it makes the PC's speaker beep
- as soon as the kernel's real-mode entry point is called.
- s4_nohwsig prevents ACPI hardware signature from being
- used during resume from hibernation.
- old_ordering causes the ACPI 1.0 ordering of the _PTS
- control method, wrt putting devices into low power
- states, to be enforced (the ACPI 2.0 ordering of _PTS is
- used by default).
- s4_nonvs prevents the kernel from saving/restoring the
- ACPI NVS memory during hibernation.
-
- acpi_sci= [HW,ACPI] ACPI System Control Interrupt trigger mode
- Format: { level | edge | high | low }
-
- acpi_irq_balance [HW,ACPI]
- ACPI will balance active IRQs
- default in APIC mode
-
- acpi_irq_nobalance [HW,ACPI]
- ACPI will not move active IRQs (default)
- default in PIC mode
-
- acpi_irq_pci= [HW,ACPI] If irq_balance, clear listed IRQs for
- use by PCI
- Format: <irq>,<irq>...
-
- acpi_irq_isa= [HW,ACPI] If irq_balance, mark listed IRQs used by ISA
- Format: <irq>,<irq>...
-
- acpi_no_auto_ssdt [HW,ACPI] Disable automatic loading of SSDT
-
- acpi_os_name= [HW,ACPI] Tell ACPI BIOS the name of the OS
- Format: To spoof as Windows 98: ="Microsoft Windows"
-
- acpi_osi= [HW,ACPI] Modify list of supported OS interface strings
- acpi_osi="string1" # add string1 -- only one string
- acpi_osi="!string2" # remove built-in string2
- acpi_osi= # disable all strings
-
- acpi_serialize [HW,ACPI] force serialization of AML methods
-
- acpi_skip_timer_override [HW,ACPI]
- Recognize and ignore IRQ0/pin2 Interrupt Override.
- For broken nForce2 BIOS resulting in XT-PIC timer.
- acpi_use_timer_override [HW,ACPI}
- Use timer override. For some broken Nvidia NF5 boards
- that require a timer override, but don't have
- HPET
-
acpi_backlight= [HW,ACPI]
acpi_backlight=vendor
acpi_backlight=video
(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>
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.
+ The debug_level mask defaults to "info". See
+ Documentation/acpi/debug.txt for more information about
+ debug layers and levels.
+ Enable processor driver info messages:
+ acpi.debug_layer=0x20000000
+ Enable PCI/PCI interrupt routing info messages:
+ acpi.debug_layer=0x400000
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
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_display_output= [HW,ACPI]
+ acpi_display_output=vendor
+ acpi_display_output=video
+ See above.
- acpi_pm_good [X86-32,X86-64]
+ acpi_irq_balance [HW,ACPI]
+ ACPI will balance active IRQs
+ default in APIC mode
+
+ acpi_irq_nobalance [HW,ACPI]
+ ACPI will not move active IRQs (default)
+ default in PIC mode
+
+ acpi_irq_isa= [HW,ACPI] If irq_balance, mark listed IRQs used by ISA
+ Format: <irq>,<irq>...
+
+ acpi_irq_pci= [HW,ACPI] If irq_balance, clear listed IRQs for
+ use by PCI
+ Format: <irq>,<irq>...
+
+ acpi_no_auto_ssdt [HW,ACPI] Disable automatic loading of SSDT
+
+ acpi_os_name= [HW,ACPI] Tell ACPI BIOS the name of the OS
+ Format: To spoof as Windows 98: ="Microsoft Windows"
+
+ acpi_osi= [HW,ACPI] Modify list of supported OS interface strings
+ acpi_osi="string1" # add string1 -- only one string
+ acpi_osi="!string2" # remove built-in string2
+ acpi_osi= # disable all strings
+
+ acpi_pm_good [X86]
Override the pmtimer bug detection: force the kernel
to assume that this machine's pmtimer latches its value
and always returns good values.
- agp= [AGP]
- { off | try_unsupported }
- off: disable AGP support
- try_unsupported: try to drive unsupported chipsets
- (may crash computer or cause data corruption)
+ acpi_sci= [HW,ACPI] ACPI System Control Interrupt trigger mode
+ Format: { level | edge | high | low }
- enable_timer_pin_1 [i386,x86-64]
- Enable PIN 1 of APIC timer
- Can be useful to work around chipset bugs
- (in particular on some ATI chipsets).
- The kernel tries to set a reasonable default.
+ acpi_serialize [HW,ACPI] force serialization of AML methods
- disable_timer_pin_1 [i386,x86-64]
- Disable PIN 1 of APIC timer
- Can be useful to work around chipset bugs.
+ acpi_skip_timer_override [HW,ACPI]
+ Recognize and ignore IRQ0/pin2 Interrupt Override.
+ For broken nForce2 BIOS resulting in XT-PIC timer.
+
+ acpi_sleep= [HW,ACPI] Sleep options
+ Format: { s3_bios, s3_mode, s3_beep, s4_nohwsig,
+ old_ordering, s4_nonvs, sci_force_enable }
+ See Documentation/power/video.txt for information on
+ s3_bios and s3_mode.
+ s3_beep is for debugging; it makes the PC's speaker beep
+ as soon as the kernel's real-mode entry point is called.
+ s4_nohwsig prevents ACPI hardware signature from being
+ used during resume from hibernation.
+ old_ordering causes the ACPI 1.0 ordering of the _PTS
+ control method, with respect to putting devices into
+ low power states, to be enforced (the ACPI 2.0 ordering
+ of _PTS is used by default).
+ s4_nonvs prevents the kernel from saving/restoring the
+ ACPI NVS memory during hibernation.
+ sci_force_enable causes the kernel to set SCI_EN directly
+ on resume from S1/S3 (which is against the ACPI spec,
+ but some broken systems don't work without it).
+
+ acpi_use_timer_override [HW,ACPI]
+ Use timer override. For some broken Nvidia NF5 boards
+ that require a timer override, but don't have HPET
+
+ acpi_enforce_resources= [ACPI]
+ { strict | lax | no }
+ Check for resource conflicts between native drivers
+ and ACPI OperationRegions (SystemIO and SystemMemory
+ only). IO ports and memory declared in ACPI might be
+ used by the ACPI subsystem in arbitrary AML code and
+ can interfere with legacy drivers.
+ strict (default): access to resources claimed by ACPI
+ is denied; legacy drivers trying to access reserved
+ resources will fail to bind to device using them.
+ lax: access to resources claimed by ACPI is allowed;
+ legacy drivers trying to access reserved resources
+ will bind successfully but a warning message is logged.
+ no: ACPI OperationRegions are not marked as reserved,
+ no further checks are performed.
ad1848= [HW,OSS]
Format: <io>,<irq>,<dma>,<dma2>,<type>
+ add_efi_memmap [EFI; X86] Include EFI memory map in
+ kernel's map of available physical RAM.
+
advansys= [HW,SCSI]
See header of drivers/scsi/advansys.c.
Format: <io>,<irq>,<dma>,<mss_io>,<mpu_io>,<mpu_irq>
See also header of sound/oss/aedsp16.c.
+ agp= [AGP]
+ { off | try_unsupported }
+ off: disable AGP support
+ try_unsupported: try to drive unsupported chipsets
+ (may crash computer or cause data corruption)
+
aha152x= [HW,SCSI]
See Documentation/scsi/aha152x.txt.
flushed before they will be reused, which
is a lot of faster
- amd_iommu_size= [HW,X86-64]
- Define the size of the aperture for the AMD IOMMU
- driver. Possible values are:
- '32M', '64M' (default), '128M', '256M', '512M', '1G'
-
amijoy.map= [HW,JOY] Amiga joystick support
Map of devices attached to JOY0DAT and JOY1DAT
Format: <a>,<b>
not play well with APC CPU idle - disable it if you have
APC and your system crashes randomly.
- apic= [APIC,i386] Advanced Programmable Interrupt Controller
+ apic= [APIC,X86-32] Advanced Programmable Interrupt Controller
Change the output verbosity whilst booting
Format: { quiet (default) | verbose | debug }
Change the amount of debugging information output
when initialising the APIC and IO-APIC components.
+ autoconf= [IPV6]
+ See Documentation/networking/ipv6.txt.
+
+ show_lapic= [APIC,X86] Advanced Programmable Interrupt Controller
+ Limit apic dumping. The parameter defines the maximal
+ number of local apics being dumped. Also it is possible
+ to set it to "all" by meaning -- no limit here.
+ Format: { 1 (default) | 2 | ... | all }.
+ The parameter valid if only apic=debug or
+ apic=verbose is specified.
+ Example: apic=debug show_lapic=all
+
apm= [APM] Advanced Power Management
See header of arch/x86/kernel/apm_32.c.
possible to determine what the correct size should be.
This option provides an override for these situations.
- security= [SECURITY] Choose a security module to enable at boot.
- If this boot parameter is not specified, only the first
- security module asking for security registration will be
- loaded. An invalid security module name will be treated
- as if no module has been chosen.
-
capability.disable=
[SECURITY] Disable capabilities. This would normally
be used only if an alternative security model is to be
clearcpuid=BITNUM [X86]
Disable CPUID feature X for the kernel. See
- include/asm-x86/cpufeature.h for the valid bit numbers.
- Note the Linux specific bits are not necessarily
+ arch/x86/include/asm/cpufeature.h for the valid bit
+ numbers. Note the Linux specific bits are not necessarily
stable over kernel options, but the vendor specific
ones should be.
Also note that user programs calling CPUID directly
Also note the kernel might malfunction if you disable
some critical bits.
- code_bytes [IA32/X86_64] How many bytes of object code to print
+ cmo_free_hint= [PPC] Format: { yes | no }
+ Specify whether pages are marked as being inactive
+ when they are freed. This is used in CMO environments
+ to determine OS memory pressure for page stealing by
+ a hypervisor.
+ Default: yes
+
+ code_bytes [X86] How many bytes of object code to print
in an oops report.
Range: 0 - 8192
Default: 64
- hpet= [X86-32,HPET] option to control HPET usage
- Format: { enable (default) | disable | force }
- disable: disable HPET and use PIT instead
- force: allow force enabled of undocumented chips (ICH4,
- VIA, nVidia)
-
com20020= [HW,NET] ARCnet - COM20020 chipset
Format:
<io>[,<irq>[,<nodeID>[,<backplane>[,<ckp>[,<timeout>]]]]]
console=brl,ttyS0
For now, only VisioBraille is supported.
- earlycon= [KNL] Output early console device and options.
- uart[8250],io,<addr>[,options]
- uart[8250],mmio,<addr>[,options]
- Start an early, polled-mode console on the 8250/16550
- UART at the specified I/O port or MMIO address.
- The options are the same as for ttyS, above.
+ consoleblank= [KNL] The console blank (screen saver) timeout in
+ seconds. Defaults to 10*60 = 10mins. A value of 0
+ disables the blank timer.
- no_console_suspend
- [HW] Never suspend the console
- Disable suspending of consoles during suspend and
- hibernate operations. Once disabled, debugging
- messages can reach various consoles while the rest
- of the system is being put to sleep (ie, while
- debugging driver suspend/resume hooks). This may
- not work reliably with all consoles, but is known
- to work with serial and VGA consoles.
+ coredump_filter=
+ [KNL] Change the default value for
+ /proc/<pid>/coredump_filter.
+ See also Documentation/filesystems/proc.txt.
cpcihp_generic= [HW,PCI] Generic port I/O CompactPCI driver
Format:
a memory unit (amount[KMG]). See also
Documentation/kdump/kdump.txt for a example.
- cs4232= [HW,OSS]
- Format: <io>,<irq>,<dma>,<dma2>,<mpuio>,<mpuirq>
-
cs89x0_dma= [HW,NET]
Format: <dma>
debug_objects [KNL] Enable object debugging
+ no_debug_objects
+ [KNL] Disable object debugging
+
debugpat [X86] Enable PAT debugging
decnet.addr= [HW,NET]
Format: <area>[,<node>]
See also Documentation/networking/decnet.txt.
- vt.default_blu= [VT]
- Format: <blue0>,<blue1>,<blue2>,...,<blue15>
- Change the default blue palette of the console.
- This is a 16-member array composed of values
- ranging from 0-255.
-
- vt.default_grn= [VT]
- Format: <green0>,<green1>,<green2>,...,<green15>
- Change the default green palette of the console.
- This is a 16-member array composed of values
- ranging from 0-255.
-
- vt.default_red= [VT]
- Format: <red0>,<red1>,<red2>,...,<red15>
- Change the default red palette of the console.
- This is a 16-member array composed of values
- ranging from 0-255.
-
- vt.default_utf8=
- [VT]
- Format=<0|1>
- Set system-wide default UTF-8 mode for all tty's.
- Default is 1, i.e. UTF-8 mode is enabled for all
- newly opened terminals.
+ default_hugepagesz=
+ [same as hugepagesz=] The size of the default
+ HugeTLB page size. This is the size represented by
+ the legacy /proc/ hugepages APIs, used for SHM, and
+ default size when mounting hugetlbfs filesystems.
+ Defaults to the default architecture's huge page size
+ if not specified.
dhash_entries= [KNL]
Set number of hash buckets for dentry cache.
See drivers/char/README.epca and
Documentation/serial/digiepca.txt.
+ disable= [IPV6]
+ See Documentation/networking/ipv6.txt.
+
+ disable_ipv6= [IPV6]
+ See Documentation/networking/ipv6.txt.
+
disable_mtrr_cleanup [X86]
- enable_mtrr_cleanup [X86]
The kernel tries to adjust MTRR layout from continuous
to discrete, to make X server driver able to add WB
- entry later. This parameter enables/disables that.
-
- mtrr_chunk_size=nn[KMG] [X86]
- used for mtrr cleanup. It is largest continous chunk
- that could hold holes aka. UC entries.
-
- mtrr_gran_size=nn[KMG] [X86]
- Used for mtrr cleanup. It is granularity of mtrr block.
- Default is 1.
- Large value could prevent small alignment from
- using up MTRRs.
-
- mtrr_spare_reg_nr=n [X86]
- Format: <integer>
- Range: 0,7 : spare reg number
- Default : 1
- Used for mtrr cleanup. It is spare mtrr entries number.
- Set to 2 or more if your graphical card needs more.
+ entry later. This parameter disables that.
disable_mtrr_trim [X86, Intel and AMD only]
By default the kernel will trim any uncacheable
MTRR settings. This parameter disables that behavior,
possibly causing your machine to run very slowly.
+ disable_timer_pin_1 [X86]
+ Disable PIN 1 of APIC timer
+ Can be useful to work around chipset bugs.
+
dmasound= [HW,OSS] Sound subsystem buffers
+ dma_debug=off If the kernel is compiled with DMA_API_DEBUG support,
+ this option disables the debugging code at boot.
+
+ dma_debug_entries=<number>
+ This option allows to tune the number of preallocated
+ entries for DMA-API debugging code. One entry is
+ required per DMA-API allocation. Use this if the
+ DMA-API debugging code disables itself because the
+ architectural default is too low.
+
+ dma_debug_driver=<driver_name>
+ With this option the DMA-API debugging driver
+ filter feature can be enabled at boot time. Just
+ pass the driver to filter for as the parameter.
+ The filter can be disabled or changed to another
+ driver later using sysfs.
+
dscc4.setup= [NET]
dtc3181e= [HW,SCSI]
- earlyprintk= [X86-32,X86-64,SH,BLACKFIN]
+ dynamic_printk Enables pr_debug()/dev_dbg() calls if
+ CONFIG_DYNAMIC_PRINTK_DEBUG has been enabled.
+ These can also be switched on/off via
+ <debugfs>/dynamic_printk/modules
+
+ earlycon= [KNL] Output early console device and options.
+ uart[8250],io,<addr>[,options]
+ uart[8250],mmio,<addr>[,options]
+ Start an early, polled-mode console on the 8250/16550
+ UART at the specified I/O port or MMIO address.
+ The options are the same as for ttyS, above.
+
+ earlyprintk= [X86,SH,BLACKFIN]
earlyprintk=vga
earlyprintk=serial[,ttySn[,baudrate]]
- earlyprintk=dbgp
+ earlyprintk=ttySn[,baudrate]
+ earlyprintk=dbgp[debugController#]
Append ",keep" to not disable it when the real console
takes over.
See Documentation/block/as-iosched.txt and
Documentation/block/deadline-iosched.txt for details.
- elfcorehdr= [IA64,PPC,SH,X86-32,X86_64]
+ elfcorehdr= [IA64,PPC,SH,X86]
Specifies physical address of start of kernel core
image elf header. Generally kexec loader will
pass this option to capture kernel.
See Documentation/kdump/kdump.txt for details.
+ enable_mtrr_cleanup [X86]
+ The kernel tries to adjust MTRR layout from continuous
+ to discrete, to make X server driver able to add WB
+ entry later. This parameter enables that.
+
+ enable_timer_pin_1 [X86]
+ Enable PIN 1 of APIC timer
+ Can be useful to work around chipset bugs
+ (in particular on some ATI chipsets).
+ The kernel tries to set a reasonable default.
+
enforcing [SELINUX] Set initial enforcing status.
Format: {"0" | "1"}
See security/selinux/Kconfig help text.
Default value is 0.
Value can be changed at runtime via /selinux/enforce.
- es1371= [HW,OSS]
- Format: <spdif>,[<nomix>,[<amplifier>]]
- See also header of sound/oss/es1371.c.
-
ether= [HW,NET] Ethernet cards parameters
This option is obsoleted by the "netdev=" option, which
has equivalent usage. See its documentation for details.
parameter will force ia64_sal_cache_flush to call
ia64_pal_cache_flush instead of SAL_CACHE_FLUSH.
+ ftrace=[tracer]
+ [FTRACE] will set and start the specified tracer
+ as early as possible in order to facilitate early
+ boot debugging.
+
+ ftrace_dump_on_oops
+ [FTRACE] will dump the trace buffers on oops.
+
+ ftrace_filter=[function-list]
+ [FTRACE] Limit the functions traced by the function
+ tracer at boot up. function-list is a comma separated
+ list of functions. This list can be changed at run
+ time by the set_ftrace_filter file in the debugfs
+ tracing directory.
+
+ ftrace_notrace=[function-list]
+ [FTRACE] Do not trace the functions specified in
+ function-list. This list can be changed at run time
+ by the set_ftrace_notrace file in the debugfs
+ tracing directory.
+
+ ftrace_graph_filter=[function-list]
+ [FTRACE] Limit the top level callers functions traced
+ by the function graph tracer at boot up.
+ function-list is a comma separated list of functions
+ that can be changed at run time by the
+ set_graph_function file in the debugfs tracing directory.
+
gamecon.map[2|3]=
[HW,JOY] Multisystem joystick and NES/SNES/PSX pad
support via parallel port (up to 5 devices per port)
Format: off | on
default: on
+ gcov_persist= [GCOV] When non-zero (default), profiling data for
+ kernel modules is saved and remains accessible via
+ debugfs, even when the module is unloaded/reloaded.
+ When zero, profiling data is discarded and associated
+ debugfs files are removed at module unload time.
+
gdth= [HW,SCSI]
See header of drivers/scsi/gdth.c.
hashdist= [KNL,NUMA] Large hashes allocated during boot
are distributed across NUMA nodes. Defaults on
- for IA-64, off otherwise.
+ for 64bit NUMA, off otherwise.
Format: 0 | 1 (for off | on)
hcl= [IA-64] SGI's Hardware Graph compatibility layer
hisax= [HW,ISDN]
See Documentation/isdn/README.HiSax.
+ hlt [BUGS=ARM,SH]
+
+ hpet= [X86-32,HPET] option to control HPET usage
+ Format: { enable (default) | disable | force |
+ verbose }
+ disable: disable HPET and use PIT instead
+ force: allow force enabled of undocumented chips (ICH4,
+ VIA, nVidia)
+ verbose: show contents of HPET registers during setup
+
hugepages= [HW,X86-32,IA-64] HugeTLB pages to allocate at boot.
hugepagesz= [HW,IA-64,PPC,X86-64] The size of the HugeTLB pages.
On x86-64 and powerpc, this option can be specified
(when the CPU supports the "pdpe1gb" cpuinfo flag)
Note that 1GB pages can only be allocated at boot time
using hugepages= and not freed afterwards.
- default_hugepagesz=
- [same as hugepagesz=] The size of the default
- HugeTLB page size. This is the size represented by
- the legacy /proc/ hugepages APIs, used for SHM, and
- default size when mounting hugetlbfs filesystems.
- Defaults to the default architecture's huge page size
- if not specified.
- hlt [BUGS=ARM,SH]
+ hvc_iucv= [S390] Number of z/VM IUCV hypervisor console (HVC)
+ terminal devices. Valid values: 0..8
+ hvc_iucv_allow= [S390] Comma-separated list of z/VM user IDs.
+ If specified, z/VM IUCV HVC accepts connections
+ from listed z/VM user IDs only.
+
+ i2c_bus= [HW] Override the default board specific I2C bus speed
+ or register an additional I2C bus that is not
+ registered from board initialization code.
+ Format:
+ <bus_id>,<clkrate>
i8042.debug [HW] Toggle i8042 debug mode
i8042.direct [HW] Put keyboard port into non-translated mode
icn= [HW,ISDN]
Format: <io>[,<membase>[,<icn_id>[,<icn_id2>]]]
- ide= [HW] (E)IDE subsystem
- Format: ide=nodma or ide=doubler
+ ide-core.nodma= [HW] (E)IDE subsystem
+ Format: =0.0 to prevent dma on hda, =0.1 hdb =1.0 hdc
+ .vlb_clock .pci_clock .noflush .nohpa .noprobe .nowerr
+ .cdrom .chs .ignore_cable are additional options
See Documentation/ide/ide.txt.
- idebus= [HW] (E)IDE subsystem - VLB/PCI bus speed
- See Documentation/ide/ide.txt.
+ ide-pci-generic.all-generic-ide [HW] (E)IDE subsystem
+ Claim all unknown PCI IDE storage controllers.
idle= [X86]
- Format: idle=poll or idle=mwait, idle=halt, idle=nomwait
- Poll forces a polling idle loop that can slightly improves the performance
- of waking up a idle CPU, but will use a lot of power and make the system
- run hot. Not recommended.
- idle=mwait. On systems which support MONITOR/MWAIT but the kernel chose
- to not use it because it doesn't save as much power as a normal idle
- loop use the MONITOR/MWAIT idle loop anyways. Performance should be the same
- as idle=poll.
- idle=halt. Halt is forced to be used for CPU idle.
+ Format: idle=poll, idle=mwait, idle=halt, idle=nomwait
+ Poll forces a polling idle loop that can slightly
+ improve the performance of waking up a idle CPU, but
+ will use a lot of power and make the system run hot.
+ Not recommended.
+ idle=mwait: On systems which support MONITOR/MWAIT but
+ the kernel chose to not use it because it doesn't save
+ as much power as a normal idle loop, use the
+ MONITOR/MWAIT idle loop anyways. Performance should be
+ the same as idle=poll.
+ idle=halt: Halt is forced to be used for CPU idle.
In such case C2/C3 won't be used again.
- idle=nomwait. Disable mwait for CPU C-states
-
- ide-pci-generic.all-generic-ide [HW] (E)IDE subsystem
- Claim all unknown PCI IDE storage controllers.
+ idle=nomwait: Disable mwait for CPU C-states
ignore_loglevel [KNL]
Ignore loglevel setting - this will print /all/
ihash_entries= [KNL]
Set number of hash buckets for inode cache.
+ ima_audit= [IMA]
+ Format: { "0" | "1" }
+ 0 -- integrity auditing messages. (Default)
+ 1 -- enable informational integrity auditing messages.
+
+ ima_hash= [IMA]
+ Format: { "sha1" | "md5" }
+ default: "sha1"
+
+ ima_tcb [IMA]
+ Load a policy which meets the needs of the Trusted
+ Computing Base. This means IMA will measure all
+ programs exec'd, files mmap'd for exec, and all files
+ opened for read by uid=0.
+
in2000= [HW,SCSI]
See header of drivers/scsi/in2000.c.
inport.irq= [HW] Inport (ATI XL and Microsoft) busmouse driver
Format: <irq>
- inttest= [IA64]
-
- iommu= [x86]
- off
- force
- noforce
- biomerge
- panic
- nopanic
- merge
- nomerge
- forcesac
- soft
-
-
intel_iommu= [DMAR] Intel IOMMU driver (DMAR) option
+ on
+ Enable intel iommu driver.
off
Disable intel iommu driver.
igfx_off [Default Off]
result in a hardware IOTLB flush operation as opposed
to batching them for performance.
- io_delay= [X86-32,X86-64] I/O delay method
+ inttest= [IA64]
+
+ iomem= Disable strict checking of access to MMIO memory
+ strict regions from userspace.
+ relaxed
+
+ iommu= [x86]
+ off
+ force
+ noforce
+ biomerge
+ panic
+ nopanic
+ merge
+ nomerge
+ forcesac
+ soft
+ pt [x86, IA64]
+
+ io7= [HW] IO7 for Marvel based alpha systems
+ See comment before marvel_specify_io7 in
+ arch/alpha/kernel/core_marvel.c.
+
+ io_delay= [X86] I/O delay method
0x80
Standard port 0x80 based delay
0xed
none
No delay
- io7= [HW] IO7 for Marvel based alpha systems
- See comment before marvel_specify_io7 in
- arch/alpha/kernel/core_marvel.c.
-
ip= [IP_PNP]
- See Documentation/filesystems/nfsroot.txt.
+ See Documentation/filesystems/nfs/nfsroot.txt.
ip2= [HW] Set IO/IRQ pairs for up to 4 IntelliPort boards
See comment before ip2_setup() in
ips= [HW,SCSI] Adaptec / IBM ServeRAID controller
See header of drivers/scsi/ips.c.
- ports= [IP_VS_FTP] IPVS ftp helper module
- Default is 21.
- Up to 8 (IP_VS_APP_MAX_PORTS) ports
- may be specified.
- Format: <port>,<port>....
-
irqfixup [HW]
When an interrupt is not handled search all handlers
for it. Intended to get systems with badly broken
js= [HW,JOY] Analog joystick
See Documentation/input/joystick.txt.
- kernelcore=nn[KMG] [KNL,X86-32,IA-64,PPC,X86-64] This parameter
+ keepinitrd [HW,ARM]
+
+ kernelcore=nn[KMG] [KNL,X86,IA-64,PPC] This parameter
specifies the amount of memory usable by the kernel
for non-movable allocations. The requested amount is
spread evenly throughout all nodes in the system. The
use the HighMem zone if it exists, and the Normal
zone if it does not.
- movablecore=nn[KMG] [KNL,X86-32,IA-64,PPC,X86-64] This parameter
- is similar to kernelcore except it specifies the
- amount of memory used for migratable allocations.
- If both kernelcore and movablecore is specified,
- then kernelcore will be at *least* the specified
- value but may be more. If movablecore on its own
- is specified, the administrator must be careful
- that the amount of memory usable for all allocations
- is not too small.
-
- keepinitrd [HW,ARM]
-
- kstack=N [X86-32,X86-64] Print N words from the kernel stack
- in oops dumps.
-
kgdboc= [HW] kgdb over consoles.
Requires a tty driver that supports console polling.
- (only serial suported for now)
+ (only serial supported for now)
Format: <serial_device>[,baud]
kmac= [MIPS] korina ethernet MAC address.
Configure the RouterBoard 532 series on-chip
Ethernet adapter MAC address.
+ kmemleak= [KNL] Boot-time kmemleak enable/disable
+ Valid arguments: on, off
+ Default: on
+
+ kstack=N [X86] Print N words from the kernel stack
+ in oops dumps.
+
+ kvm.ignore_msrs=[KVM] Ignore guest accesses to unhandled MSRs.
+ Default is 0 (don't ignore, but inject #GP)
+
+ kvm.oos_shadow= [KVM] Disable out-of-sync shadow paging.
+ Default is 1 (enabled)
+
+ kvm-amd.nested= [KVM,AMD] Allow nested virtualization in KVM/SVM.
+ Default is 0 (off)
+
+ kvm-amd.npt= [KVM,AMD] Disable nested paging (virtualized MMU)
+ for all guests.
+ Default is 1 (enabled) if in 64bit or 32bit-PAE mode
+
+ kvm-intel.bypass_guest_pf=
+ [KVM,Intel] Disables bypassing of guest page faults
+ on Intel chips. Default is 1 (enabled)
+
+ kvm-intel.ept= [KVM,Intel] Disable extended page tables
+ (virtualized MMU) support on capable Intel chips.
+ Default is 1 (enabled)
+
+ kvm-intel.emulate_invalid_guest_state=
+ [KVM,Intel] Enable emulation of invalid guest states
+ Default is 0 (disabled)
+
+ kvm-intel.flexpriority=
+ [KVM,Intel] Disable FlexPriority feature (TPR shadow).
+ Default is 1 (enabled)
+
+ kvm-intel.unrestricted_guest=
+ [KVM,Intel] Disable unrestricted guest feature
+ (virtualized real and unpaged mode) on capable
+ Intel chips. Default is 1 (enabled)
+
+ kvm-intel.vpid= [KVM,Intel] Disable Virtual Processor Identification
+ feature (tagged TLBs) on capable Intel chips.
+ Default is 1 (enabled)
+
l2cr= [PPC]
l3cr= [PPC]
lapic [X86-32,APIC] Enable the local APIC even if BIOS
disabled it.
- lapic_timer_c2_ok [X86-32,x86-64,APIC] trust the local apic timer in
- C2 power state.
+ lapic_timer_c2_ok [X86,APIC] trust the local apic timer
+ in C2 power state.
libata.dma= [LIBATA] DMA control
libata.dma=0 Disable all PATA and SATA DMA
libata.dma=4 Compact Flash DMA only
Combinations also work, so libata.dma=3 enables DMA
for disks and CDROMs, but not CFs.
+
+ libata.ignore_hpa= [LIBATA] Ignore HPA limit
+ libata.ignore_hpa=0 keep BIOS limits (default)
+ libata.ignore_hpa=1 ignore limits, using full disk
libata.noacpi [LIBATA] Disables use of ACPI in libata suspend/resume
when set.
If there are multiple matching configurations changing
the same attribute, the last one is used.
+ lmb=debug [KNL] Enable lmb debug messages.
+
load_ramdisk= [RAM] List of ramdisks to load from floppy
See Documentation/blockdev/ramdisk.txt.
(machvec) in a generic kernel.
Example: machvec=hpzx1_swiotlb
- max_loop= [LOOP] Maximum number of loopback devices that can
- be mounted
- Format: <1-256>
+ machtype= [Loongson] Share the same kernel image file between different
+ yeeloong laptop.
+ Example: machtype=lemote-yeeloong-2f-7inch
+
+ max_addr=nn[KMG] [KNL,BOOT,ia64] All physical memory greater
+ than or equal to this physical address is ignored.
maxcpus= [SMP] Maximum number of processors that an SMP kernel
should make use of. maxcpus=n : n >= 0 limits the
it is equivalent to "nosmp", which also disables
the IO APIC.
- max_addr=nn[KMG] [KNL,BOOT,ia64] All physical memory greater than
- or equal to this physical address is ignored.
+ max_loop= [LOOP] Maximum number of loopback devices that can
+ be mounted
+ Format: <1-256>
max_luns= [SCSI] Maximum number of LUNs to probe.
Should be between 1 and 2^32-1.
[KNL,SH] Allow user to override the default size for
per-device physically contiguous DMA buffers.
- memmap=exactmap [KNL,X86-32,X86_64] Enable setting of an exact
+ memmap=exactmap [KNL,X86] Enable setting of an exact
E820 memory map, as specified by the user.
Such memmap=exactmap lines can be constructed based on
BIOS output or other requirements. See the memmap=nn@ss
memtest= [KNL,X86] Enable memtest
Format: <integer>
- range: 0,4 : pattern number
default : 0 <disable>
+ Specifies the number of memtest passes to be
+ performed. Each pass selects another test
+ pattern from a given set of patterns. Memtest
+ fills the memory with this pattern, validates
+ memory contents and reserves bad memory
+ regions that are detected.
meye.*= [HW] Set MotionEye Camera parameters
See Documentation/video4linux/meye.txt.
min_addr=nn[KMG] [KNL,BOOT,ia64] All physical memory below this
physical address is ignored.
+ mini2440= [ARM,HW,KNL]
+ Format:[0..2][b][c][t]
+ Default: "0tb"
+ MINI2440 configuration specification:
+ 0 - The attached screen is the 3.5" TFT
+ 1 - The attached screen is the 7" TFT
+ 2 - The VGA Shield is attached (1024x768)
+ Leaving out the screen size parameter will not load
+ the TFT driver, and the framebuffer will be left
+ unconfigured.
+ b - Enable backlight. The TFT backlight pin will be
+ linked to the kernel VESA blanking code and a GPIO
+ LED. This parameter is not necessary when using the
+ VGA shield.
+ c - Enable the s3c camera interface.
+ t - Reserved for enabling touchscreen support. The
+ touchscreen support is not enabled in the mainstream
+ kernel as of 2.6.30, a preliminary port can be found
+ in the "bleeding edge" mini2440 support kernel at
+ http://repo.or.cz/w/linux-2.6/mini2440.git
+
mminit_loglevel=
[KNL] When CONFIG_DEBUG_MEMORY_INIT is set, this
parameter allows control of the logging verbosity for
mousedev.yres= [MOUSE] Vertical screen resolution, used for devices
reporting absolute coordinates, such as tablets
+ movablecore=nn[KMG] [KNL,X86,IA-64,PPC] This parameter
+ is similar to kernelcore except it specifies the
+ amount of memory used for migratable allocations.
+ If both kernelcore and movablecore is specified,
+ then kernelcore will be at *least* the specified
+ value but may be more. If movablecore on its own
+ is specified, the administrator must be careful
+ that the amount of memory usable for all allocations
+ is not too small.
+
mpu401= [HW,OSS]
Format: <io>,<irq>
mtdparts= [MTD]
See drivers/mtd/cmdlinepart.c.
+ onenand.bdry= [HW,MTD] Flex-OneNAND Boundary Configuration
+
+ Format: [die0_boundary][,die0_lock][,die1_boundary][,die1_lock]
+
+ boundary - index of last SLC block on Flex-OneNAND.
+ The remaining blocks are configured as MLC blocks.
+ lock - Configure if Flex-OneNAND boundary should be locked.
+ Once locked, the boundary cannot be changed.
+ 1 indicates lock status, 0 indicates unlock status.
+
mtdset= [ARM]
ARM/S3C2412 JIVE boot control
[HW] Make the MicroTouch USB driver use raw coordinates
('y', default) or cooked coordinates ('n')
+ mtrr_chunk_size=nn[KMG] [X86]
+ used for mtrr cleanup. It is largest continuous chunk
+ that could hold holes aka. UC entries.
+
+ mtrr_gran_size=nn[KMG] [X86]
+ Used for mtrr cleanup. It is granularity of mtrr block.
+ Default is 1.
+ Large value could prevent small alignment from
+ using up MTRRs.
+
+ mtrr_spare_reg_nr=n [X86]
+ Format: <integer>
+ Range: 0,7 : spare reg number
+ Default : 1
+ Used for mtrr cleanup. It is spare mtrr entries number.
+ Set to 2 or more if your graphical card needs more.
+
n2= [NET] SDL Inc. RISCom/N2 synchronous serial card
NCR_D700= [HW,SCSI]
going to be removed in 2.6.29.
nfsaddrs= [NFS]
- See Documentation/filesystems/nfsroot.txt.
+ See Documentation/filesystems/nfs/nfsroot.txt.
nfsroot= [NFS] nfs root filesystem for disk-less boxes.
- See Documentation/filesystems/nfsroot.txt.
+ See Documentation/filesystems/nfs/nfsroot.txt.
nfs.callback_tcpport=
[NFS] set the TCP port on which the NFSv4 callback
channel should listen.
+ nfs.cache_getent=
+ [NFS] sets the pathname to the program which is used
+ to update the NFS client cache entries.
+
+ nfs.cache_getent_timeout=
+ [NFS] sets the timeout after which an attempt to
+ update a cache entry is deemed to have failed.
+
nfs.idmap_cache_timeout=
[NFS] set the maximum lifetime for idmapper cache
entries.
of returning the full 64-bit number.
The default is to return 64-bit inode numbers.
- nmi_debug= [KNL,AVR32] Specify one or more actions to take
+ nmi_debug= [KNL,AVR32,SH] Specify one or more actions to take
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] 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
+
+ netpoll.carrier_timeout=
+ [NET] Specifies amount of time (in seconds) that
+ netpoll should wait for a carrier. By default netpoll
+ waits 4 seconds.
no387 [BUGS=X86-32] Tells the kernel to use the 387 maths
emulation library even if a 387 maths coprocessor
is present.
+ no_console_suspend
+ [HW] Never suspend the console
+ Disable suspending of consoles during suspend and
+ hibernate operations. Once disabled, debugging
+ messages can reach various consoles while the rest
+ of the system is being put to sleep (ie, while
+ debugging driver suspend/resume hooks). This may
+ not work reliably with all consoles, but is known
+ to work with serial and VGA consoles.
+
noaliencache [MM, NUMA, SLAB] Disables the allocation of alien
caches in the slab allocator. Saves per-node memory,
but will impact performance.
nocache [ARM]
+ noclflush [BUGS=X86] Don't use the CLFLUSH instruction
+
nodelayacct [KNL] Disable per-task delay accounting
nodisconnect [HW,SCSI,M68K] Disables SCSI disconnects.
nodsp [SH] Disable hardware DSP at boot time.
- noefi [X86-32,X86-64] Disable EFI runtime services support.
+ noefi [X86] Disable EFI runtime services support.
noexec [IA-64]
- noexec [X86-32,X86-64]
+ noexec [X86]
On X86-32 available only on PAE configured kernels.
noexec=on: enable non-executable mappings (default)
noexec=off: disable non-executable mappings
register save and restore. The kernel will only save
legacy floating-point registers on task switch.
- noclflush [BUGS=X86] Don't use the CLFLUSH instruction
+ noxsave [BUGS=X86] Disables x86 extended register state save
+ and restore using xsave. The kernel will fallback to
+ enabling legacy floating-point and sse state.
- nohlt [BUGS=ARM,SH]
+ nohlt [BUGS=ARM,SH] Tells the kernel that the sleep(SH) or
+ wfi(ARM) instruction doesn't work correctly and not to
+ use it. This is also useful when using JTAG debugger.
no-hlt [BUGS=X86-32] Tells the kernel that the hlt
instruction doesn't work correctly and not to
use it.
+ no_file_caps Tells the kernel not to honor file capabilities. The
+ only way then for a file to be executed with privilege
+ is to be setuid root or executed by root.
+
nohalt [IA-64] Tells the kernel not to use the power saving
function PAL_HALT_LIGHT when idle. This increases
power-consumption. On the positive side, it reduces
Valid arguments: on, off
Default: on
+ noiotrap [SH] Disables trapped I/O port accesses.
+
noirqdebug [X86-32] Disables the code which attempts to detect and
disable unhandled interrupt sources.
- no_timer_check [X86-32,X86_64,APIC] Disables the code which tests for
+ no_timer_check [X86,APIC] Disables the code which tests for
broken timer IRQ sources.
noisapnp [ISAPNP] Disables ISA PnP code.
noinitrd [RAM] Tells the kernel not to load any configured
initial RAM disk.
+ nointremap [X86-64, Intel-IOMMU] Do not enable interrupt
+ remapping.
+
nointroute [IA-64]
nojitter [IA64] Disables jitter checking for ITC timers.
nolapic_timer [X86-32,APIC] Do not use the local APIC timer.
- nox2apic [X86-64,APIC] Do not enable x2APIC mode.
-
- x2apic_phys [X86-64,APIC] Use x2apic physical mode instead of
- default x2apic cluster mode on platforms
- supporting x2apic.
-
noltlbs [PPC] Do not use large page/tlb entries for kernel
lowmem mapping on PPC40x.
nomfgpt [X86-32] Disable Multi-Function General Purpose
Timer usage (for AMD Geode machines).
+ norandmaps Don't use address space randomization. Equivalent to
+ echo 0 > /proc/sys/kernel/randomize_va_space
+
noreplace-paravirt [X86-32,PV_OPS] Don't patch paravirt_ops
noreplace-smp [X86-32,SMP] Don't replace SMP instructions
nosoftlockup [KNL] Disable the soft-lockup detector.
+ noswapaccount [KNL] Disable accounting of swap in memory resource
+ controller. (See Documentation/cgroups/memory.txt)
+
nosync [HW,M68K] Disables sync negotiation for all devices.
notsc [BUGS=X86-32] Disable Time Stamp Counter
nowb [ARM]
+ nox2apic [X86-64,APIC] Do not enable x2APIC mode.
+
nptcg= [IA64] Override max number of concurrent global TLB
purges which is reported from either PAL_VM_SUMMARY or
SAL PALO.
+ nr_uarts= [SERIAL] maximum number of UARTs to be registered.
+
numa_zonelist_order= [KNL, BOOT] Select zonelist order for NUMA.
one of ['zone', 'node', 'default'] can be specified
This can be set from sysctl after boot.
See Documentation/sysctl/vm.txt for details.
- nr_uarts= [SERIAL] maximum number of UARTs to be registered.
+ ohci1394_dma=early [HW] enable debugging via the ohci1394 driver.
+ See Documentation/debugging-via-ohci1394.txt for more
+ info.
olpc_ec_timeout= [OLPC] ms delay when issuing EC commands
Rather than timing out after 20 ms if an EC
waiting for the ACK, so if this is set too high
interrupts *may* be lost!
+ omap_mux= [OMAP] Override bootloader pin multiplexing.
+ Format: <mux_mode0.mode_name=value>...
+ For example, to override I2C bus2:
+ omap_mux=i2c2_scl.i2c2_scl=0x100,i2c2_sda.i2c2_sda=0x100
+
opl3= [HW,OSS]
Format: <io>
oprofile.timer= [HW]
Use timer interrupt instead of performance counters
+ oprofile.cpu_type= Force an oprofile cpu type
+ This might be useful if you have an older oprofile
+ userland or if you want common events.
+ Format: { arch_perfmon }
+ arch_perfmon: [X86] Force use of architectural
+ perfmon on Intel CPUs instead of the
+ CPU specific event set.
+
osst= [HW,SCSI] SCSI Tape Driver
Format: <buffer_size>,<write_threshold>
See also Documentation/scsi/st.txt.
See also Documentation/blockdev/paride.txt.
pci=option[,option...] [PCI] various PCI subsystem options:
+ earlydump [X86] dump PCI config space before the kernel
+ changes anything
off [X86] don't probe for the PCI bus
bios [X86-32] force use of PCI BIOS, don't access
the hardware directly. Use this if your machine
disable the use of PCIE advanced error reporting.
nodomains [PCI] Disable support for multiple PCI
root domains (aka PCI segments, in ACPI-speak).
- nommconf [X86-32,X86_64] Disable use of MMCONFIG for PCI
+ nommconf [X86] Disable use of MMCONFIG for PCI
Configuration
+ check_enable_amd_mmconf [X86] check for and enable
+ properly configured MMIO access to PCI
+ config space on AMD family 10h CPU
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
cbmemsize=nn[KMG] The fixed amount of bus space which is
reserved for the CardBus bridge's memory
window. The default value is 64 megabytes.
+ resource_alignment=
+ Format:
+ [<order of align>@][<domain>:]<bus>:<slot>.<func>[; ...]
+ Specifies alignment and device to reassign
+ aligned memory resources.
+ If <order of align> is not specified,
+ PAGE_SIZE is used as alignment.
+ PCI-PCI bridge can be specified, if resource
+ windows need to be expanded.
+ ecrc= Enable/disable PCIe ECRC (transaction layer
+ end-to-end CRC checking).
+ bios: Use BIOS/firmware settings. This is the
+ the default.
+ off: Turn ECRC off
+ on: Turn ECRC on.
pcie_aspm= [PCIE] Forcibly enable or disable PCIe Active State Power
Management.
Format: { 0 | 1 }
See arch/parisc/kernel/pdc_chassis.c
+ percpu_alloc= Select which percpu first chunk allocator to use.
+ Currently supported values are "embed" and "page".
+ Archs may support subset or none of the selections.
+ See comments in mm/percpu.c for details on each
+ allocator. This parameter is primarily for debugging
+ and performance comparison.
+
pf. [PARIDE]
See Documentation/blockdev/paride.txt.
autoconfiguration.
Ranges are in pairs (memory base and size).
- dynamic_printk
- Enables pr_debug()/dev_dbg() calls if
- CONFIG_DYNAMIC_PRINTK_DEBUG has been enabled. These can also
- be switched on/off via <debugfs>/dynamic_printk/modules
+ ports= [IP_VS_FTP] IPVS ftp helper module
+ Default is 21.
+ Up to 8 (IP_VS_APP_MAX_PORTS) ports
+ may be specified.
+ Format: <port>,<port>....
print-fatal-signals=
[KNL] debug: print fatal signals
- print-fatal-signals=1: print segfault info to
- the kernel console.
+
+ If enabled, warn about various signal handling
+ related application anomalies: too many signals,
+ too many POSIX.1 timers, fatal signals causing a
+ coredump - etc.
+
+ If you hit the warning due to signal overflow,
+ you might want to try "ulimit -i unlimited".
+
default: off.
printk.time= Show timing data prefixed to each printk message line
Format: <bool> (1/Y/y=enable, 0/N/n=disable)
+ processor.max_cstate= [HW,ACPI]
+ Limit processor to maximum C-state
+ max_cstate=9 overrides any DMI blacklist limit.
+
+ processor.nocst [HW,ACPI]
+ Ignore the _CST method to determine C-states,
+ instead using the legacy FADT method
+
profile= [KNL] Enable kernel profiling via /proc/profile
Format: [schedule,]<number>
Param: "schedule" - profile schedule points.
Requires CONFIG_SCHEDSTATS
Param: "kvm" - profile VM exits.
- processor.max_cstate= [HW,ACPI]
- Limit processor to maximum C-state
- max_cstate=9 overrides any DMI blacklist limit.
-
- processor.nocst [HW,ACPI]
- Ignore the _CST method to determine C-states,
- instead using the legacy FADT method
-
prompt_ramdisk= [RAM] List of RAM disks to prompt for floppy disk
before loading.
See Documentation/blockdev/ramdisk.txt.
reboot= [BUGS=X86-32,BUGS=ARM,BUGS=IA-64] Rebooting mode
Format: <reboot_mode>[,<reboot_mode2>[,...]]
- See arch/*/kernel/reboot.c or arch/*/kernel/process.c
+ See arch/*/kernel/reboot.c or arch/*/kernel/process.c
relax_domain_level=
[KNL, SMP] Set scheduler's default relax_domain_level.
- See Documentation/cpusets.txt.
+ See Documentation/cgroups/cpusets.txt.
reserve= [KNL,BUGS] Force the kernel to ignore some iomem area
Useful for devices that are detected asynchronously
(e.g. USB and MMC devices).
- root_plug.vendor_id=
- [ROOTPLUG] Override the default vendor ID
-
- root_plug.product_id=
- [ROOTPLUG] Override the default product ID
-
- root_plug.debug=
- [ROOTPLUG] Enable debugging output
-
rw [KNL] Mount root device read-write on boot
S [KNL] Run init in single mode
sbni= [NET] Granch SBNI12 leased line adapter
+ sched_debug [KNL] Enables verbose scheduler debug messages.
+
sc1200wdt= [HW,WDT] SC1200 WDT (watchdog) driver
Format: <io>[,<timeout>[,<isapnp>]]
allowing boot to proceed. none ignores them, expecting
user space to do the scan.
- selinux [SELINUX] Disable or enable SELinux at boot time.
+ security= [SECURITY] Choose a security module to enable at boot.
+ If this boot parameter is not specified, only the first
+ security module asking for security registration will be
+ loaded. An invalid security module name will be treated
+ as if no module has been chosen.
+
+ selinux= [SELINUX] Disable or enable SELinux at boot time.
Format: { "0" | "1" }
See security/selinux/Kconfig help text.
0 -- disable.
If enabled at boot time, /selinux/disable can be used
later to disable prior to initial policy load.
- selinux_compat_net =
- [SELINUX] Set initial selinux_compat_net flag value.
- Format: { "0" | "1" }
- 0 -- use new secmark-based packet controls
- 1 -- use legacy packet controls
- Default value is 0 (preferred).
- Value can be changed at runtime via
- /selinux/compat_net.
-
serialnumber [BUGS=X86-32]
shapers= [NET]
st= [HW,SCSI] SCSI tape parameters (buffers, etc.)
See Documentation/scsi/st.txt.
+ stacktrace [FTRACE]
+ Enabled the stack tracer on boot up.
+
sti= [PARISC,HW]
Format: <num>
Set the STI (builtin display/keyboard on the HP-PARISC
stifb= [HW]
Format: bpp:<bpp1>[:<bpp2>[:<bpp3>...]]
+ sunrpc.min_resvport=
+ sunrpc.max_resvport=
+ [NFS,SUNRPC]
+ SunRPC servers often require that client requests
+ originate from a privileged port (i.e. a port in the
+ range 0 < portnr < 1024).
+ An administrator who wishes to reserve some of these
+ ports for other uses may adjust the range that the
+ kernel's sunrpc client considers to be privileged
+ using these two parameters to set the minimum and
+ maximum port values.
+
sunrpc.pool_mode=
[NFS]
Control how the NFS server code allocates CPUs to
pernode one pool for each NUMA node (equivalent
to global on non-NUMA machines)
+ sunrpc.tcp_slot_table_entries=
+ sunrpc.udp_slot_table_entries=
+ [NFS,SUNRPC]
+ Sets the upper limit on the number of simultaneous
+ RPC calls that can be sent from the client to a
+ server. Increasing these values may allow you to
+ improve throughput, but will also increase the
+ amount of memory reserved for use by the client.
+
swiotlb= [IA-64] Number of I/O TLB slabs
switches= [HW,M68k]
thermal.psv= [HW,ACPI]
-1: disable all passive trip points
- <degrees C>: override all passive trip points to this value
+ <degrees C>: override all passive trip points to this
+ value
thermal.tzp= [HW,ACPI]
Specify global default ACPI thermal zone polling rate
See comment before function dc390_setup() in
drivers/scsi/tmscsim.c.
+ topology= [S390]
+ Format: {off | on}
+ Specify if the kernel should make use of the cpu
+ topology informations if the hardware supports these.
+ The scheduler will make use of these informations and
+ e.g. base its process migration decisions on it.
+ Default is off.
+
tp720= [HW,PS2]
+ trace_buf_size=nn[KMG]
+ [FTRACE] will set tracing buffer size.
+
+ trace_event=[event-list]
+ [FTRACE] Set and start specified trace events in order
+ to facilitate early boot debugging.
+ See also Documentation/trace/events.txt
+
trix= [HW,OSS] MediaTrix AudioTrix Pro
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:
uart6850= [HW,OSS]
Format: <io>,<irq>
+ uhash_entries= [KNL,NET]
+ Set number of hash buckets for UDP/UDP-Lite connections
+
uhci-hcd.ignore_oc=
[USB] Ignore overcurrent events (default N).
Some badly-designed motherboards generate lots of
reported either.
unknown_nmi_panic
- [X86-32,X86-64]
+ [X86]
Set unknown_nmi_panic=1 early on boot.
usbcore.autosuspend=
usbhid.mousepoll=
[USBHID] The interval which mice are to be polled at.
- add_efi_memmap [EFI; x86-32,X86-64] Include EFI memory map in
- kernel's map of available physical RAM.
-
- vdso= [X86-32,SH,x86-64]
+ usb-storage.delay_use=
+ [UMS] The delay in seconds before a new device is
+ scanned for Logical Units (default 5).
+
+ usb-storage.quirks=
+ [UMS] A list of quirks entries to supplement or
+ override the built-in unusual_devs list. List
+ entries are separated by commas. Each entry has
+ the form VID:PID:Flags where VID and PID are Vendor
+ and Product ID values (4-digit hex numbers) and
+ Flags is a set of characters, each corresponding
+ to a common usb-storage quirk flag as follows:
+ a = SANE_SENSE (collect more than 18 bytes
+ of sense data);
+ b = BAD_SENSE (don't collect more than 18
+ bytes of sense data);
+ c = FIX_CAPACITY (decrease the reported
+ device capacity by one sector);
+ h = CAPACITY_HEURISTICS (decrease the
+ reported device capacity by one
+ sector if the number is odd);
+ i = IGNORE_DEVICE (don't bind to this
+ device);
+ l = NOT_LOCKABLE (don't try to lock and
+ unlock ejectable media);
+ m = MAX_SECTORS_64 (don't transfer more
+ than 64 sectors = 32 KB at a time);
+ o = CAPACITY_OK (accept the capacity
+ reported by the device);
+ r = IGNORE_RESIDUE (the device reports
+ bogus residue values);
+ s = SINGLE_LUN (the device has only one
+ Logical Unit);
+ w = NO_WP_DETECT (don't test whether the
+ medium is write-protected).
+ Example: quirks=0419:aaf5:rl,0421:0433:rc
+
+ vdso= [X86,SH]
vdso=2: enable compat VDSO (default with COMPAT_VDSO)
vdso=1: enable VDSO (default)
vdso=0: disable VDSO mapping
- vdso32= [X86-32,X86-64]
+ vdso32= [X86]
vdso32=2: enable compat VDSO (default with COMPAT_VDSO)
vdso32=1: enable 32-bit VDSO (default)
vdso32=0: disable 32-bit VDSO mapping
See Documentation/fb/modedb.txt.
vga= [BOOT,X86-32] Select a particular video mode
- See Documentation/x86/i386/boot.txt and
+ See Documentation/x86/boot.txt and
Documentation/svga.txt.
Use vga=ask for menu.
This is actually a boot loader parameter; the value is
vmpoff= [KNL,S390] Perform z/VM CP command after power off.
Format: <command>
+ vt.cur_default= [VT] Default cursor shape.
+ Format: 0xCCBBAA, where AA, BB, and CC are the same as
+ the parameters of the <Esc>[?A;B;Cc escape sequence;
+ see VGA-softcursor.txt. Default: 2 = underline.
+
+ vt.default_blu= [VT]
+ Format: <blue0>,<blue1>,<blue2>,...,<blue15>
+ Change the default blue palette of the console.
+ This is a 16-member array composed of values
+ ranging from 0-255.
+
+ vt.default_grn= [VT]
+ Format: <green0>,<green1>,<green2>,...,<green15>
+ Change the default green palette of the console.
+ This is a 16-member array composed of values
+ ranging from 0-255.
+
+ vt.default_red= [VT]
+ Format: <red0>,<red1>,<red2>,...,<red15>
+ Change the default red palette of the console.
+ This is a 16-member array composed of values
+ ranging from 0-255.
+
+ vt.default_utf8=
+ [VT]
+ Format=<0|1>
+ Set system-wide default UTF-8 mode for all tty's.
+ Default is 1, i.e. UTF-8 mode is enabled for all
+ newly opened terminals.
+
+ vt.global_cursor_default=
+ [VT]
+ Format=<-1|0|1>
+ Set system-wide default for whether a cursor
+ is shown on new VTs. Default is -1,
+ i.e. cursors will be created by default unless
+ overridden by individual drivers. 0 will hide
+ cursors, 1 will display them.
+
waveartist= [HW,OSS]
Format: <io>,<irq>,<dma>,<dma2>
wdt= [WDT] Watchdog
See Documentation/watchdog/wdt.txt.
+ x2apic_phys [X86-64,APIC] Use x2apic physical mode instead of
+ default x2apic cluster mode on platforms
+ supporting x2apic.
+
xd= [HW,XT] Original XT pre-IDE (RLL encoded) disks.
xd_geo= See header of drivers/block/xd.c.
Format:
<irq>,<irq_mask>,<io>,<full_duplex>,<do_sound>,<lockup_hack>[,<irq2>[,<irq3>[,<irq4>]]]
- norandmaps Don't use address space randomization
- Equivalent to echo 0 > /proc/sys/kernel/randomize_va_space
-
______________________________________________________________________
TODO:
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff