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.
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.
./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 | rsdt }
force -- enable ACPI if default was off
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 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.
-
- 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>
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 }
+ 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.
+
+ 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
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
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
- 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.
-
- 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
-
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.
-
- 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.
+ consoleblank= [KNL] The console blank (screen saver) timeout in
+ seconds. Defaults to 10*60 = 10mins. A value of 0
+ disables the blank timer.
coredump_filter=
[KNL] Change the default value for
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.
Documentation/serial/digiepca.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.
ia64_pal_cache_flush instead of SAL_CACHE_FLUSH.
ftrace=[tracer]
- [ftrace] will set and start the specified 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] 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.
gamecon.map[2|3]=
[HW,JOY] Multisystem joystick and NES/SNES/PSX pad
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
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 .noprobe .nowerr .cdrom
- .chs .ignore_cable are additional options
+ .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, idle=mwait, idle=halt, idle=nomwait
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.
-
ignore_loglevel [KNL]
Ignore loglevel setting - this will print /all/
kernel messages to the console. Useful for debugging.
1 -- enable informational integrity auditing messages.
ima_hash= [IMA]
- Formt: { "sha1" | "md5" }
+ 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]
-
- 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
-
-
intel_iommu= [DMAR] Intel IOMMU driver (DMAR) option
on
Enable intel iommu driver.
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.
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
+ lapic_timer_c2_ok [X86,APIC] trust the local apic timer
in C2 power state.
libata.dma= [LIBATA] DMA control
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.
(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
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]
[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,X86-64] 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.
+ 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] Tells the kernel that the sleep(SH) or
wfi(ARM) instruction doesn't work correctly and not to
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/controllers/memory.txt)
+ controller. (See Documentation/cgroups/memory.txt)
nosync [HW,M68K] Disables sync negotiation for all devices.
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.
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.
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.
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).
+ 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
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.
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
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.
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]
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>
reported either.
unknown_nmi_panic
- [X86-32,X86-64]
+ [X86]
Set unknown_nmi_panic=1 early on boot.
usbcore.autosuspend=
medium is write-protected).
Example: quirks=0419:aaf5:rl,0421:0433:rc
- 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]
+ 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
vmpoff= [KNL,S390] Perform z/VM CP command after power off.
Format: <command>
+ 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.
+
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